Solid state batteries come in several flavours. Most of them don't stop dendrites.
The flavour you want is polymer, single ion conducting solid state with an ion transport activation energy below 10kJ/mol at room temperature and no phase transitions from -40C to 80C.
> The flavour you want is polymer, single ion conducting solid state with an ion transport activation energy below 10kJ/mol at room temperature and no phase transitions from -40C to 80C.
what makes it so? I don't know anything about this subject, I'm really curious now about what the perfect battery would be.
No idea why polymer single ion conducting would stop dendrites (I know people are looking for it, I don't know why).
But 10kJ/mol of activation energy is another way of saying less than 100mV of internal loses, and avoiding phase transitions means that your battery won't stop working on that temperature range.
The only thing different from this list is the ceramic separator. It’s not polymer. However, the ceramic is ultra thin to the point that it’s flexible so volume expansion isn’t a problem and it solves the dendrite problem.
Perhaps a polymer will be invented that can’t be pierced by dendrites. But existing polymers need to be heated for ion transfer efficiency and are combustable.
Technically, QuantumScape also uses an organic liquid catholyte inside the cathode. So it’s not “pure” solid state.
Well that's fine for terrestrial use but aerospace needs that range to be expanded a little in both directions, otherwise it won't be much of a holy grail if it won't cover the needs of one of the largest growing industries.
Please don't attack another user like this, no matter how wrong someone is or you feel they are. It only makes things worse.
I believe I get the positive intention behind your post, btw - to defend conversation against shallow dismissals - and of course appreciate that. But if you'd please express it in a respectful way in the future, then you'll be contributing to good conversation rather than degrading it further.
"you're wasting everyone's time by trying to appear smart."
No, I actually work in aerospace and know EXACTLY what the fuck I'm speaking of. Do you build satellites? Looking at your history - no you do not. I do. In fact, I'm responsible FOR THE POWER SYSTEMS (that's battery and solar AND any RTG should we ever go that route.)
Please don't respond to a bad comment by breaking the site guidelines yourself. That only makes things worse.
If you know more than others do, that's great! But please contribute by sharing some of what you know, so the rest of us can learn, rather than putting others down.
How does someone with such short temper get to work in the aerospace industry? You know we are just a bunch of random strangers on the internet and telling someone to "sit down" just comes across as funny more than authoritative. And I don't think telling someone "I know exactly what the fuck I'm speaking of" has ever had the desired effect on the internet, it just screams insecure - if you're really an expert make it show through your words not by trying to intimidate people.
If you know a bit about electronics, you might be a bit surprised by the term 'solid-state battery'. It's a poor analogue to the more common usage of solid-state with semiconductors, integrated circuits, etc. -- a "solid-state" cell is still a chemical cell. It's not a paradigm shift on the level of, say, replacing a relay with a MOSFET.
The article gives the technical reasons that answer the headline question (e.g. potential for better energy density)
I am surprised they didn't point out the literal "killer app" - military drones. Energy density is king for any airborne power source. And dendrite growth during charge/discharge cycling isn't as big a deal for that application (how many times would you need to charge a disposable weapon?)
For disposable applications like that, aren't there single-use chemistries that are better already? I'm thinking by analogy to things like:
- WW2 proximity fuzes that had batteries where the electrolyte was in a vial that got smashed by the G-forces of being shot out of a cannon providing power to the radio inside for the 10 seconds it needs to get to the incoming aircraft
- Hearing aid Zinc-Air batteries, that are extremely energy dense because you only have to actually manufacture the anode, the cathode is the entire atmosphere of the Earth
- Missile batteries, which are often Lithium-silicon/Iron Disulfide batteries that borrow some thermal energy from the rocket motor to get a molten salt electrolyte
Less weight (all else being equal) is the same thing as more battery for drones. I.e. better range, payload mass, and/or flight time. You probably want both cheap and poor performing as well as expensive and high performing available.
Maybe. Last I checked Ukraine preferred radio drones to fiber optic - the spool is heavy and a limitation in many ways (not all that I understand). Fiber optics are used only when you can't get something else to works. Advances in AI, radio relay systems, self-navigation, and anti electronic warfare are all things they are working on so they can use more drones without fiber. For longer ranges drones fiber is not an option and so they have no choice but use something else.
Where fiber optic is used though, that is the limit. That is a minority though.
For some uses in Ukraine that is true, but even there they are still using radio for many drones, and especially their longest range drones (100+km).
There's also payload and loiter time to consider.
If you have a drone that can watch the battlefield for hours instead of minutes that is incredibly useful. Same story if you have a drone that can 3x its payload.
Most Ukrainian drones don't use fiber optic I don't think. To deal with EW, they're favoring autonomous targeting/guidance for the final part of the strike.
Depends on the battle but yes. Even then the range is usually at least 10 km and starts to be limited by the size of the spool you're going to carry on the drone (though dealing with general cable issues over the distance is one of the reasons this type can't be used for everything).
I can - it’s called a bomb. Some of the problems with batteries are heat dissipation (one of those problems that superconductors would mostly solve), fire safety, and end of life disposal. Higher energy density makes it even worse.
A good place to start would be a BMS on individual cells that monitors them for general degradation, unexpected discharge, unexpected temperature changes, and can remove a failing cell from the array.
Gasoline has 10x the energy (MJ/Kg) than TNT, but it's not a "bomb". Being a "bomb" is about energy release rate. A battery is still controlled by its chemistry.
Liquid gasoline does not have anywhere near the energy of TNT, or even a battery for that matter. It contains basically zero releasable energy. It needs oxygen or another oxidizer to react with to actually release any energy. TNT and batteries' energy density calculations include the oxidizer and the oxidizer is in close proximity to the fuel (molecularly so in the case of TNT). If you 10x the "energy content" of gasoline it's still rate limited by access to oxygen. If you 10x the energy density of a battery (the type with the oxidizer contained within the battery, not a fuel cell or metal air battery) you've got 10x the energy ready to be released quickly if oxidizer and fuel mix in unfortunate ways
The previous point is fair though. What is the energy density of gasoline in a stoichiometric mixture with its oxidizer and not already detonated? That's where TNT beats it by a long shot. The mixture with any chance of being stored would be some relatively low pressure gas.
Edit: Or, a fair closed-system comparison to a battery would need to include a liquid oxygen tank or similar so you have the two components stored but can control the delivery...
In the context of the conversation, it doesn't actually refute the point though, which is that explosive danger is contingent on a much broader set of relations than simple energy density. Gasoline just demonstrates the disconnect. Tacking on additional conditions to make high-density batteries dangerous is exactly what the engineering goal should be.
As a stupid example, if we have a high density battery technology that never explodes unless, say, under magnetic forces only seen being produced by magnetars, that's a pretty safe battery.
That's a huge assumption that won't always be the case though. A gasoline tank with a small hole in it is a lot safer than a liquid-electrolyte battery with a hole in it.
I can remember several situations where “a little bit of gasoline” caused a lot of problems. It’s a relative term. You need a lot of air to make it really shine, but “a little bit of gas” goes a long way lol.
Gasoline, when in liquid form, is not mixed with oxygen and burns, releases energy slowly. In comparison with TNT which is both the fuel and oxidizing agent releases energy very fast, it has detonation velocity of 6,900 m/s.
There is a way how to use the energy density of gasoline for explosive purposes, Thermobaric weapons.
"A fuel–air explosive (FAE) device consists of a container of fuel and two separate explosive charges. After the munition is dropped or fired, the first explosive charge bursts open the container at a predetermined height and disperses the fuel in a cloud that mixes with atmospheric oxygen (the size of the cloud varies with the size of the munition). The cloud of fuel flows around objects and into structures. The second charge then detonates the cloud and creates a massive blast wave."
One of the problems with gasoline is its explosive nature, which the fuel storage and delivery system of a car attempts to mitigate. It has a better profile for burning off than a battery though since it will spill out and burn away from the vehicle.
Gasoline isn't that explosive. You can shoot up a gas tank and it will just burn. What you see on TV is movie magic. Gasoline vapor can explode, but you need the right air to fuel ratio and a spark.
Requires a good mix though. The parent is still correct.
Mythbusters spent a long time trying to get cars to blow up in a dramatic hollywood fashion in various episodes and determined that under most conditions it wouldn't happen.
They did get it to happen, they just had to try really hard.
"Fast X: why cars don’t really explode when they crash"
"Petrol and diesel can only explode when under pressure and mixed with air and in the case of petrol, have a small amount of energy added in the form of a spark or a flame. Engines pressurise the fuel/air mixture in the cylinder and so produce small, confined explosions which turn a crankshaft and drive the wheels."
"When cars are involved in collisions, fuel lines are often torn and petrol leaks out onto a hot engine. Liquid petrol can catch fire in the presence of air. But it can’t explode because it’s not under pressure and is in the liquid phase rather than a vapour."
My teen years would beg to differ, when some neighborhood friends and I decided to experiment with gas and bleach. The neighborhood residents, fire department and local police also had an opinion, too. (We all got into BIG trouble. Definitely one of the dumber things I did as a teen.)
No it can't. To combust it needs ~ 500F. If you left it out uncovered in the open and allowed the it to vaporize with a spark nearby, it might explode, but thats not spontaneous combustion. Gasoline sitting in a sealed container wont spontaneously combust.
Gasoline doesn't do that. Perhaps you're thinking of the following?
What it does do is slowly polymerize, becoming useless as an ICE fuel in time, typically in a year or two. This is why backup generators should run on propane, which has no degradation mechanism.
Some heavier elements have hilariously high energy densities and aren't bombs (on their own), but the catch is the energy release is a trickle. Point is it's not an automatic follow that high density = high discharge.
Tesla has been around for nearly 20 years. Model S (12 years) has gained 17% of range due to chemistry (rest is system efficiency and simply bigger battery).
BMW i3 went from 60Ah to 120Ah of battery capacity (and slightly more voltage) in the exact same chassis through the span of its life (2014-2022, RIP). It is even possible to put the later 120Ah batteries in the early 60Ah cars and reap the rewards, and is a practice that is actually supported by the cars' software natively.
Your Polestar 2 battery is based on battery technology that is 5+ years old. Right now you can buy a BYD car in China that charges at up to 1500kW - close to 10x the peak charging rate of a Polestar 2.
Yeah, when I take a road trip I genuinely enjoy the cadence of charging. 5-10 minutes every two hours, just enough to go to the bathroom or walk around. I get to my destination not materially later, and feeling far more relaxed than when I was doing death marches in a gas car.
This is such a euphemism to pretend that you’d like to wait two hours at a refueling station.
Anyone who’s ever driven between Seattle and Portland and seen the e16b charging lots of people sleeping in their cars knows there is a whole different side to your rosey picture.
EV owners are still internalizing their range anxiety into a benefit.
I get it; I like EVs for their around town purpose, but man it’s almost fantasy to sell it as “5-10 minutes every two hours”.
"This is such a euphemism to pretend that you’d like to wait two hours at a refueling station."
There is virtually no EV sold on the market today that takes two hours to charge to 80% at a HVDC charger.
"I get it; I like EVs for their around town purpose, but man it’s almost fantasy to sell it as “5-10 minutes every two hours”."
The Hyundai Ioniq 5 takes about 20 minutes to go from 10% SOC to 80% SOC in about 18 min with an 800v charger. That equates to about 3 hours of driving on the highway.
> This is such a euphemism to pretend that you’d like to wait two hours at a refueling station.
What? I said no such thing. I would hate to wait two hours at a refueling station.
> it’s almost fantasy to sell it as “5-10 minutes every two hours”.
I guess I live in fantasy land then.
Maybe the non-Tesla charging story is crap, but I made conscious choices not to participate in that circus.
I have no range anxiety. I point the car where I want to go, it tells me where to charge and for how long, and it’s earned my trust over many road trips. It hasn’t been wrong yet.
uphills + cold/hot climates, the ranges won't be able to compete with ICE. its basic physics. cold uphill still reduces charging speed, available power, and range, while sustained heat accelerates degradation. Thermal-management systems mitigate those weaknesses by consuming energy and adding cost, weight, and complexity.
meanwhile ICE has gotten ridiculously clean and efficient over the years it is more efficient at the shaft does not settle total-system efficiency, cost, weight, resource use, grid losses, battery production, or suitability for every operating env. Comparing an engine with a motor while ignoring the battery and electricity supply chain is silly
I still do not trust that sitting on a pile of lithium batteries is safe. NMC does not mean non flammable or consequence free. LFP cells can still enter thermal runaway, release toxic gases, reignite, and require difficult firefighting procedures. They also generally trade energy density and cold-weather performance for that improved safety. Also the speed charging ? That dramatically reduces the stability and lifespan of the batteries. Ton of used EVs not being sold because the battery replacement is somewhere between 40~60% of the car's value.
we had ICE for over a century now, its just like a software that gets continuous updates ICE systems are highly optimized, repairable, energy-dense, fast to refuel, and supported by enormous infrastructure. EVs are improving faster partly because they still have major weaknesses to solve. A steeper improvement curve does not prove that the present technology is superior for every use case neither is using the latest javascript framework.
Could you ELI5 these basic physics? I've heard many people make claims like this but there's never any physics that actually follows. I've had most of an undergraduate curriculum of physics, so if it's beyond basic, then don't be afraid to refer to those physical ideas.
> meanwhile ICE has gotten ridiculously clean and efficient over the years it is more efficient at the shaft does not settle total-system efficiency, cost, weight, resource use, grid losses, battery production, or suitability for every operating env
Is 30% "ridiculously clean and efficient"? 35%? I'm not sure I can agree with that at all.
Battery production? That's ridiculously efficient. For a very small amount weight, there's an insane amount of Wh that get shuttled through that material, which can then be recycled into even more kWh of storage than went into the recycling process, due to the continual improvement in battery production efficiency.
Meanwhile, every single gallon of gas results in 20 pounds of CO2 emissions. Fracking oil requires disposing of 2-10 gallons of dirty waste water for every gallon of gas. That's a massive amount of waste for only 20-50 vehicle miles.
I don't think 10x density is possible without getting into nuclear, at least not with the chemistries we know of today, everything at a certain point becomes an explosive.
Speaking of nuclear, getting tons of the material that powers mars rovers and putting them in every home would generate enough power for decades... At the cost of being able to build a nuclear bomb in a garage.
The next revolution will be small scale generation. Fuel cells, extremely efficient cheap solar, even smaller modular reactors, etc.
I live in western Pennsylvania and have both natural gas and electric service, a roof and 1/3 acre of land to utilize. I would love to get rid of at least one of my utility bills and I’m becoming more interested in decoupling from the electric grid than natural gas service. I dream of a future where competition comes to monopoly utilities by way of direct competition with each other as there is a not so far off future where I can utilize solar, batteries and a natural gas fuel cell to cut ties with my Electric Utility. If that kind of competition can exist then the game is on for those utilities to start fighting for customers.
With modern heat pumps and induction stoves getting off of natural gas is fairly easy for most people and saves money in the long run. Meanwhile the grid is switching to renewables so getting off gas is your best investment. You can get of electric too, but on your 1/3rd acre that probably means significant lifestyle compromises - I will be impressed if you are willing to live with them.
Batteries are cheap enough to build (using a commercial installer completely kills the economics, because you're paying five to ten times the actual cost in the US) a reasonable size personal battery bank (~100+ kwh), paired with some overkill solar, to totally replace the grid in a lot of cases. GP isn't limited to rooftop solar with 1/3rd an acre, so they can do it quite cheap if they want.
I seem to remember recent advances in TMSR research and construction. Those tend to e much safer and have safer byproducts than uranium or plutonium fueled water-cooled reactors.
Agreed, but I think people can imagine and companies are very motivated: powertools, phones, laptops, watches, backup UPS, cars, hospital equipment... there's high demand for durable, long-lasting batteries. I think the research is there, it's just complex chemistry. We'll get there. Impressive to see the progress in EV batteries and they've actually turned out to be more durable than first feared.
I think, apart from finding better Batteries altoghether, we should build multi-tier batteries inspired by biology.
Humans have bloodsugar, sugar in the Liver and then fat. All of them have their respective properties with availability and amount. This way, engineering tradeoffs could be allocated much more fine grained.
For example, a while ago I read about a startup building an energy storage where they heat up large amounts of sand to store the surplus of renewables. This could serve analogous to the fat in humans.
Most of the things that we copy directly from humans do not work in terms of robustness.
Its like instead of harddrive use human DNA to store the data for 3T years,but no-one is mentioning the bandwidth speed here(which is the most important thing) etc,
I know it has some usecases.Also "one spoon butter is more energy dense than a battery"
but how we are gonna use butter(I dont know enough bio) but it is way harder to convert energy .
Humans do that because we're big and extra complicated. The closest analogue is probably a hybrid car, though ideally you'd want one that can create synthetic fuel from its battery. But I suspect cellphones are properly analogous to e.g. bacteria that have much simpler energy storage.
I think I've heard of sodium, lithium hybrids. But that's only 2, what's the fat? Gasoline, LPG hybrid? Shit gets expensive fast. Probably 2x cost of just a sodium or ion EV? The human body is too amazing.
That reminds me of the gel packs in the USS Voyager. At some point they became “infected” and they needed to the raise their temperatures to let them destroy the infection!
It should be relatively straightforward to imagine — we already have that in gasoline-powered internal combustion engines.
The Watt-hours per kilogram of good Lithium Ion batteries is around 250-280 Wh/Kg; for Lithium Iron Phosphate it's about 180 Wh/kg, and for Sodium-Ion about 170 Wh/Kg.
The raw energy in gasoline is about 12,300 Wh/Kg but automobile internal combustion engines get only about 20-30% efficiency yielding about 2500-3600 Wh/Kg. For aviation piston engines it is a bit better at 25-30$ so 3000-3600 Wh/kg.
So, the batteries, instead of being 10-12X the weight of the gasoline for the same net driving/flying range, could weigh about the same as the gasoline. So, a typical car with maybe a 16 gallon tank and 30 miles per gallon fills up with 128 pounds (58 kg) of gasoline to get 480 miles of range. The Li-Ion battery for that range would weigh something like 1300 Lbs (590 kg). That is a substantial additional weight for a car that could be 2800-3800 Lbs in ICE configuration, so 35-45% added weight (a bit less because of savings on the ICE engine, etc). This requires everything else to also be heavier, from the structural frame, the suspension system, and even the wheels and tires (which is also unsprung weight, further impairing performance).
With a 130Lb/60kg battery instead, and saving the weight of the ICE engine and fuel system, the overall car design could go much more lightweight, regaining a lot of performance and range, all while gaining the huge torque of electric motors.
In aviation, a battery systems of that weight would enable all-electric aviation to go from small performance niches to the default for general aviation.
So yes, it would be a HUGE benefit to achieve 10X energy density batteries, and we do have reference points for people to imagine it.
> With a 130Lb/60kg battery instead, and saving the weight of the ICE engine and fuel system, the overall car design could go much more lightweight, regaining a lot of performance and range, all while gaining the huge torque of electric motors.
I think you're underselling it, even. A typical like-for-like modern EV is only marginally heavier than the ICE equivalent. If we were able to drop the weight of the battery by a thousand pounds, cars would be lighter than they have been in decades while retaining all the modern safety and convenience features we've come to expect. And if density improved along with weight, we could make EVs with the same form factor as today but with over a thousand miles of range. Not that we need that, but it is just as a tiny example of how mind boggling the game change would be.
As it is I've only recently internalized the notion that the most powerful electric tools are battery powered (what can I say, I grew up when rechargeable batteries were NiCad and they basically sucked). And it will just get better and better as time goes on.
Some people might need that range. If you cannot charge at home and you don't have good public charging infrastructure then you might want enough range so you only have to deal with charging once or twice a month.
Yes, underselling a bit for sure! I didn't even want to get into the optimizations available if cars were really designed for lightweight when the entire motors+battery is only 100-150kg, and the battery can be low and centered.
We could go for performance, trading off some battery for four inboard motors (fully sprung weight) with half-shafts and CV joints, steel space-frame chassis and carbon fiber body — it could put many supercars to shame.
Going for range, same light-weighting, but less powerful motors and adding more battery, the range could get silly long at something like 1000 miles for 100kg of battery.
For the kind of long range options another poster mentioned, with 100 kg for 1000 miles, a few 10-kilo swappable battery packs could make it easy to trade luggage space for range, or bring them to a charge station only occasionally, but not lug them around for most in-town trips.
An EV doesn't need to have 480 miles of range. Nobody is driving that distance daily. 98% of trips are under 50 miles. Only 0.8% of the trips are over 100 miles!
Also, EVs use regenerative braking. That should help a little bit.
EVs should be built with 100 - 150 mile range. All families with 2 cars can immediately switch one of their cars to a daily driver EV and the other vehicle is a minivan. There are lots and lots of people for whom an EV works perfectly well and if they need to go longer, US has a robust rental car industry. What would help is to let people charge anywhere they park. All workplaces should offer free charging, and companies can negotiate to get paid for charging their employees cars. The price of electricity goes negative because of lack of demand, and this is something that they can offer to the grid, demand as a service.
> EVs should be built with 100 - 150 mile range. [..] if they need to go longer, US has a robust rental car industry
As an EV owner myself, no. Absolutely not.
The reason is simple: The mere existence of low-range EVs hurts overall EV adoption, because people aren't going to rent a car just for a road trip. You're talking about adding $100+ per day on what's supposed to be a cheaper method of travel compared to flying.
ICE-holes don't think critically. They don't care that long range EVs exist. They'll just see one that only gets 100-150 miles of range and go "See? EVs have short range. They're not appropriate for road trips. That's why I'll never get one.", despite plenty of 250+ mile options.
Now, I suppose you could argue that this type of person would simply never get an EV and would just come up with a different reason, and you'd probably be right. But the general point still remains: People want a car that satisfies ALL their needs and won't settle for something that works "only" 98% of the time.
Not only that, but with a longer range, you have more flexibility in planning recharging. It may take more time to top up from 50 km left to 500 km, but you have more flexibility about when to do it. Something that needs a daily charge is going to be interfering with your schedule.
"The reason is simple: The mere existence of low-range EVs hurts overall EV adoption, because people aren't going to rent a car just for a road trip. You're talking about adding $100+ per day on what's supposed to be a cheaper method of travel compared to flying."
Just wait for people to be priced out of ICE cars. EV's should be and will be significantly cheaper to buy and manufacture.
I think people can imagine lighter cars and laptops and things. Is there something bizarre that’s unlocked like battery powered space launches or something?
High density batteries allows us to have dramatically cheaper electricity. Think of it like this, what happens when electricity is 1/10th the cost? Beyond what others have pointed out (electric airplanes, cars that drive thousands of miles), costs for everything would drop as energy is a core driver of it in every good you consume. If you can pull energy where it's very cheaply available and store/transport it anywhere the world millions of lives would be saved. For example;
If energy is cheaper than the price of water you can pull water out of thin air (dehumidifiers).
If energy is cheaper you can grow food in areas you normally couldn't.
When you can transport anything for cheap you can move food to areas that are vulnerable to food insecurity.
If you can store energy at large scale you can nearly eliminate grid failures, savings lives in the summer and winter.
Costs for transporting food would go down significantly, imagine groceries being 10-15% cheaper.
Assuming airlines have competitive pressure you could expect plane flight costs to drop 20-30% improving everyone's mobility.
Energy density doesn't matter for electricity since the storage batteries don't move and there is plenty of space for them. Cost per energy stored is what matters. Density is important for transportation especially planes.
Sodium ion batteries have worse energy density than lithium ion but they have potential to be cheaper and more reliable. Iron air batteries have poor round trip efficiency but could be even cheaper.
Batteries are not power sources, but storage. The energy still has to come from somewhere, and power generation won't magically become 10x cheaper overnight. No matter how cheap battery storage becomes.
But it IS crucial for removing bottlenecks & replace fossil fuels.
Imagine for a moment that batteries with decent shelf lives are free.
You build a power plant on a geothermal vent in Iceland. The electricity it produces is plentiful and cheap. You run it full tilt charging batteries.
You ship those batteries to wherever you need cheap power, and send them back empty. This works with hydro, wind, solar, ...
Batteries do drive down energy costs because even ignoring transmission lines, they let you move energy in both space and time, pushing all energy costs towards the cost of the cheapest means of generation on its best day.
Aviation, drones with hours+ flight range, more solar power usage as storage gets easier/cheaper, phones that last more than a day, robots with actually useful battery life, smaller IoT devices. A lot of current tech is severely limited by battery capacity.
A 1 GWh grid scale battery takes up about 4 hectares at the moment. The UKs total energy use is about 2,000GWh a day.
It would need to use 240,000 hectares to store all energy requirements (eletric, transport, heating etc) for a whole month. Even in extreme cold conditions it would last a couple of weeks.
Storing a month of energy use doesn't make any sense when it comes to renewable grids. Since you don't have to mine/extract and transport an inventory, far far less storage is required.
A month is probably excessive, but there are large regions of the world where its not uncommon for both solar and wind power to be running at <5% for multiple weeks in a row.
There's an engineering tradeoff between having excess generation capacity, for that seasonal minimum, and having more storage. The cost optimal decision on that tradeoff will be determined by the ratio of excess generation cost and storage cost for rarely-used storage.
Until that ratio falls by at least 3x to 5x in favor of batteries being cheaper than generation, extra generation is going to be the way that grids actually get built out. Batteries and generation are both falling in cost fairly quickly, but generation still has the overall edge in learning rate. Cost decreases won't bottom out for at least a decade, because there's been no slow down yet, so I wouldn't expect this ratio to change for a minimum of 20 years, which means that pretty much a full energy system interchange will have happened by the time that this price ration changes.
So there's at least a few assumptions about the current industry and it's future development that underlie my assertion that a month of storage makes no sense, but I'm confident enough that I'd place money on the bet, and there's very very few things I'd bet on.
Edit: one thing that would break my assumption is the industrial development of storage that's super cheap for once-per-year usage. Most storage now needs to be cycled about 300x per year to make economic sense. "Long duration" storage is actually better defined as "economical storage at few battery cycles per year". There's nothing like that in the research hopper, but that doesn't mean it couldn't appear tomorrow and be deployed within a decade. Something that only gets used once or twice a year has to be dirt cheap, even if you could get 10x or 20x normal electricity prices for it.
Which just emphasises the point -- density and thus land use isn't really a major concern
You could store an entire years worth of energy (not just electricity) for a fairly dense country like the UK and still have 95% of the country left for other usage.
Definitely! However I frequently encounter people on energy discussion forums that assume that we need 2-3 months of battery storage, perhaps because they see natural gas or other storage and assume that batteries need exactly the same thing, so I'm perhaps overly eager to respond to claims about month-long battery storage.
I had previously been hopeful that battery storage would allow more shared used of land, but the fire risks of batteries have been pretty severe. And since the land usage requirements are fairly low, there's no need to enhance the risk by putting batteries, say, in enclosed spaces of former natural gas generation facilities [1].
I'm hopeful that we'll see a lot more storage, say a shipping container's worth, at the end of distribution feeders, which helps suck up residential solar with minimal resources, but solving the problem of "who pays for the benefits for all" when the utility is incentivized to keep grid costs high means that nobody is knocking down doors to make that happen...
Doesn't that depend on the sources of energy though? Pretty much constant short and mid term supply like geothermal, hydro, tides, etc vs unpredictable or variable in the short term like wind and solar.
As a society relying on solar, I'd want to have more of a buffer than one that relies on hydro.
Instead of batteries, why not green hydrogen or green ammonia? Ammonia is needed for fertilizer, storage/logistics are a solved problem. Emergency plants around that can use ammonia as fuel can solve the dunkelflaute problem?
Another option is natural gas peaker plant on a ship/barge. Have a fleet of these around that can dock at any port and supply electrictity. A peaker powership is essentially a mobile, marine-class version of an onshore peaking power plant.
What would be best long term if we have a few hundred - few thousand nuclear ships/subs that can go anywhere and supply power.
It can be the sharing economy for clean power at scale.
Capital costs and round-trip efficiency are the primary reasons. Even at constant utilization, electrolyzers are expensive enough that it's hard to replace fossil-fuel generated hydrogen at the moment.
Once you 2x-10x the cost of electrolyzer capital by only using it rarely, more generation and throwing away the excess electricity often makes the most sense.
Nuclear ships are similarly super super expensive. The only reason we build them at all are for their unique and wonderful operational capabilities, as in not needing to surface or refuel. Using nuclear ships for power would so expensive that we may need to up our GDPs 10x before such wasteful use makes sense. (Though I'm hoping we do reach such future luxurious lifestyles!)
> Another option is natural gas peaker plant on a ship/barge. Have a fleet of these around that can dock at any port and supply electrictity. A peaker powership is essentially a mobile, marine-class version of an onshore peaking power plant.
Aren't sodium batteries close to production and a lot cheaper and safer?
Ambri was working on large scale batteries which seemed like a pretty good idea (looks like they ran out of money): https://en.wikipedia.org/wiki/Ambri_Inc.
Sodium ion batteries are already being mass produced in China. CATL actually just started producing their second generation sodium ion batteries. In the US, Peak energy is doing storage solutions based on sodium ion.
Anyway, you are comparing apples and oranges. While solid state sodium ion might become a thing at some point, it so far isn't. The lithium based solid state batteries currently being readied by several battery companies for mass production around 2028 or so tend to have up to 500-600 wh/kg densities. Sodium ion batteries are currently at or below 175 wh/kg typically. LFP is a bit better, and some high end NMC batteries might do 250ish wh/kg. That would be just the first generation solid state batteries. Densities might improve after that. The theoretical limit is a lot denser than that and there is a lot of money going into researching ways to do better than that.
Of course energy density is just one thing you might optimize for. Other properties you might look at are operating temperatures, amount of charge cycles the battery can handle before it degrades below 85% of its original capacity, the speed at which it can cycle, fire safety, cost, etc. Mostly sodium ion scores very well on all of this except density.
High energy density usually comes at a price. Both in dollars and in compromises with these other things. Think lower lifetime, more constrained temperature ranges, etc. Worth it if weight and volume are really constrained. Like in anything that flies.
Depends on the application - each battery technology has a trade-off between energy density, cost, lifetime, safety, scalability, etc. Sodium may have a place in grid storage, although iron-air is being deployed today and is even cheaper and safer (but poor energy density, which doesn't matter much for grid storage - https://formenergy.com/technology/battery-technology/)
The Two Bit Da Vinci YouTube channel has a good video on solid state battery fundamentals and a deep dive into a battery company (ProLogium) that has demonstrated manufacturing at scale.
The energy density scatter plot is physically correct but misleading and everyone makes this mistake.
From an engineering point of view you have to use work delivered at the end of the drive train not fuel raw energy content.
When you do that lithium ion batteries compare more favorably to liquid fuels. That’s because the conversion path is more than 90% efficient. For ICE engines you’re starting with only 20-40% Carnot efficiency (depending on how good and in good shape the engine is) and then losing in the transmission and then losing more because ICE cars have more other gears and moving parts. Power to wheel is pretty terrible. Most of the energy from gasoline heats the air around the car.
This is also why you get outrageous sounding but accurate things like: an EV charged on 100% coal fired electricity emits less carbon than a typical gasoline car. The fact that coal is literal pure carbon fuel is made up for by the high thermal efficiency of a giant supercritical steam turbine vs a small piston engine. Coal burns real hot too (steeper thermal gradient). So more of the energy from coal ends up doing actual work vs heating the air. (Well directly heating the air I mean.)
Yes, electricity should be the only abstraction layer to deliver energy to end user. We can extract a lot more energy from fossil fuels in large scale plants and also continuously switch out dirtier fuels with clean energy.
For example, no need to build natural gas infrastructure to every home. Use induction stoves (or electric coil -- already 67% of homes). Heat pump water heater instead of gas. And heat pump for HVAC.
If all energy bills are consolidated as electricity (instead of gas, natural gas and electricity), most people would install solar on their rooftops, buy EVs, and save ~$1000/month on energy bills.
> We can extract a lot more energy from fossil fuels in large scale plants
This isn't true at all for natural gas. Burning it for heat in the home is much more efficient than burning it in a plant, converting it to electricity, transferring that electricity, then turning that electricity into heat.
Depends, if you are turning that electricity into heat using a heat-pump you might win on most situations (maybe lose if the weather is really cold outside, unless you add geothermal loops, but then its a lot more expensive to make)
In addition the sibling comments (COP of heat pumps is 500%), air pollution in homes is worse than air pollution outside. If you don't have natural gas and burning fuel, it helps a lot. Not only is electricity cheaper and cleaner, but also healthier.
The theoretical efficiency maximum for burning gas in a home is 100%. Most systems won't hit that because they need to vent waste gases, which carry some heat away.
Heat pumps are significantly more efficient than 100%. They can get to 500% efficiency. So no, it's definitely not more efficient to burn gas in a home. (To say nothing of the safety of running gas lines to every house.)
But isn't it more advantageous to have the gas -> electricity conversion in a plant from an emissions point of view? You still have losses in the system when moving natural gas around from the source to individual homes too (leaks). In theory you don't, but in practice you do.
> because the liquid electrolyte currently used in batteries is flammable, replacing it with a solid could make batteries safer and less susceptible to fire.
The problem is primarily that batteries are storing a lot of energy, which can be released when things go wrong. The electrolytes (technically, the solvents) typically don't ignite under 750°F or so, which makes them less flammable than a lot of other common materials, and far less of a concern than, say, the lithium metal.
The liquid electrolyte is the thing that releases most energy when the battery burns, more than the anode and cathode. Some also have a very low self ignition temperature.
IIUC, the main problem with the current Li batteries is that the two plates can over time grow material that will 1) degrade performance; and 2) make it more likely to short circuit and catch fire. Similarly with electric car batteries after accidents where the battery is damaged, short circuits, and then catches fire.
So the main risk here would be the likelyhood of short circuiting under different failure scenarios.
The energy "stored" in the light oil electrolyte of a battery is >10x more than the electrical energy or the energy released by reacting lithium alone.
An 18650 battery weighs ~50g and stores ~10 watt-hours. 10 watt-hours is 8,604 calories, enough to heat 50g of water by 172 C or 310 F. The battery would not even burn without a liquid electrolyte to ignite.
you ever short a car battery? That much electricity running through metal will create a lot of heat which then ignites the lithium. Watch a video on thermite and you'll get the idea.
Manufacturing the batteries would probably benefit from solid state. The Panasonic battery plant in the exurbs of Kansas City, MO has had two evacuations this year from thermal issues related to lithium-ion battery production, including one yesterday morning. [0] [1]
have I misread or 3/4 of the article explained what a battery is and only final tiny part got to "short-circuiting dendrites don't happen without electrolite"?
There are a number of reasons why lithium batteries may catastrophically fail and catch fire. Dendrite shorts is one, another reason is poor alignment of the layers during assembly, allowing for eventual shifting of layers leading to internal shorting. Another is conductive or sharp debris getting into the battery during manufacturing, and after a while the anode/cathode separator getting pierced by the debris. Lots of reasons!
dendrites are not really a significant problem in popular batteries. It's associated with lithium metal, vs lithium in normal batteries is in the form of salts. Solid state lets you use metal, which is much more energy dense since you don't need the salts.
The most common lithium battery failure mode is that you have a hole in the plastic separator between the +/- sheets inside the battery, which shorts and causes a hotspot that eventually starts a fire. Dendrites cause the short by growing across the gap. In normal batteries it is caused by a manufacturing defect. The outcome is pretty similar.
Solid state batteries come in several flavours. Most of them don't stop dendrites.
The flavour you want is polymer, single ion conducting solid state with an ion transport activation energy below 10kJ/mol at room temperature and no phase transitions from -40C to 80C.
That is the holy grail of SS batteries.
> The flavour you want is polymer, single ion conducting solid state with an ion transport activation energy below 10kJ/mol at room temperature and no phase transitions from -40C to 80C.
what makes it so? I don't know anything about this subject, I'm really curious now about what the perfect battery would be.
No idea why polymer single ion conducting would stop dendrites (I know people are looking for it, I don't know why).
But 10kJ/mol of activation energy is another way of saying less than 100mV of internal loses, and avoiding phase transitions means that your battery won't stop working on that temperature range.
I’m still a novice on the material science behind it, but what is QuantumScape lacking here if anything, and why is it a dealbreaker?
The only thing different from this list is the ceramic separator. It’s not polymer. However, the ceramic is ultra thin to the point that it’s flexible so volume expansion isn’t a problem and it solves the dendrite problem.
Perhaps a polymer will be invented that can’t be pierced by dendrites. But existing polymers need to be heated for ion transfer efficiency and are combustable.
Technically, QuantumScape also uses an organic liquid catholyte inside the cathode. So it’s not “pure” solid state.
Are anyone building the battery you described?
No. The holy grail goes undiscovered for now.
Seems to be some progress on learning more about it: https://news.mit.edu/2026/discovery-helps-explain-why-solid-...
Aliens somewhere, presumably.
"no phase transitions from -40C to 80C."
Well that's fine for terrestrial use but aerospace needs that range to be expanded a little in both directions, otherwise it won't be much of a holy grail if it won't cover the needs of one of the largest growing industries.
[flagged]
Please don't attack another user like this, no matter how wrong someone is or you feel they are. It only makes things worse.
I believe I get the positive intention behind your post, btw - to defend conversation against shallow dismissals - and of course appreciate that. But if you'd please express it in a respectful way in the future, then you'll be contributing to good conversation rather than degrading it further.
https://news.ycombinator.com/newsguidelines.html
To be fair, the poster said “holy grail” which implies perfection.
Absolutely. No idea what’s going on with these downvotes.
"you're wasting everyone's time by trying to appear smart."
No, I actually work in aerospace and know EXACTLY what the fuck I'm speaking of. Do you build satellites? Looking at your history - no you do not. I do. In fact, I'm responsible FOR THE POWER SYSTEMS (that's battery and solar AND any RTG should we ever go that route.)
Sit down.
Please don't respond to a bad comment by breaking the site guidelines yourself. That only makes things worse.
If you know more than others do, that's great! But please contribute by sharing some of what you know, so the rest of us can learn, rather than putting others down.
https://news.ycombinator.com/newsguidelines.html
How does someone with such short temper get to work in the aerospace industry? You know we are just a bunch of random strangers on the internet and telling someone to "sit down" just comes across as funny more than authoritative. And I don't think telling someone "I know exactly what the fuck I'm speaking of" has ever had the desired effect on the internet, it just screams insecure - if you're really an expert make it show through your words not by trying to intimidate people.
If you know a bit about electronics, you might be a bit surprised by the term 'solid-state battery'. It's a poor analogue to the more common usage of solid-state with semiconductors, integrated circuits, etc. -- a "solid-state" cell is still a chemical cell. It's not a paradigm shift on the level of, say, replacing a relay with a MOSFET.
The article gives the technical reasons that answer the headline question (e.g. potential for better energy density)
I am surprised they didn't point out the literal "killer app" - military drones. Energy density is king for any airborne power source. And dendrite growth during charge/discharge cycling isn't as big a deal for that application (how many times would you need to charge a disposable weapon?)
For disposable applications like that, aren't there single-use chemistries that are better already? I'm thinking by analogy to things like:
- WW2 proximity fuzes that had batteries where the electrolyte was in a vial that got smashed by the G-forces of being shot out of a cannon providing power to the radio inside for the 10 seconds it needs to get to the incoming aircraft
- Hearing aid Zinc-Air batteries, that are extremely energy dense because you only have to actually manufacture the anode, the cathode is the entire atmosphere of the Earth
- Missile batteries, which are often Lithium-silicon/Iron Disulfide batteries that borrow some thermal energy from the rocket motor to get a molten salt electrolyte
If the thing is going to blow up anyway, does it need to be light? Wouldn't you rather have more cheaper drones?
Less weight (all else being equal) is the same thing as more battery for drones. I.e. better range, payload mass, and/or flight time. You probably want both cheap and poor performing as well as expensive and high performing available.
In current battle conditions isn’t the range primarily determined by the size of the fiber optic spool attached to the drone than battery capacity?
Maybe. Last I checked Ukraine preferred radio drones to fiber optic - the spool is heavy and a limitation in many ways (not all that I understand). Fiber optics are used only when you can't get something else to works. Advances in AI, radio relay systems, self-navigation, and anti electronic warfare are all things they are working on so they can use more drones without fiber. For longer ranges drones fiber is not an option and so they have no choice but use something else.
Where fiber optic is used though, that is the limit. That is a minority though.
For some uses in Ukraine that is true, but even there they are still using radio for many drones, and especially their longest range drones (100+km).
There's also payload and loiter time to consider.
If you have a drone that can watch the battlefield for hours instead of minutes that is incredibly useful. Same story if you have a drone that can 3x its payload.
Most Ukrainian drones don't use fiber optic I don't think. To deal with EW, they're favoring autonomous targeting/guidance for the final part of the strike.
Depends on the battle but yes. Even then the range is usually at least 10 km and starts to be limited by the size of the spool you're going to carry on the drone (though dealing with general cable issues over the distance is one of the reasons this type can't be used for everything).
if it’s the same range for less weight you have more room for munitions and other gadgets
Autonomous kamikaze drones don't need spools.
The lighter the further range or more explosive payload.
We need way more research on batteries. People cant ingine what is possible if we make battery 10x energy dense.
I can - it’s called a bomb. Some of the problems with batteries are heat dissipation (one of those problems that superconductors would mostly solve), fire safety, and end of life disposal. Higher energy density makes it even worse.
A good place to start would be a BMS on individual cells that monitors them for general degradation, unexpected discharge, unexpected temperature changes, and can remove a failing cell from the array.
Gasoline has 10x the energy (MJ/Kg) than TNT, but it's not a "bomb". Being a "bomb" is about energy release rate. A battery is still controlled by its chemistry.
Liquid gasoline does not have anywhere near the energy of TNT, or even a battery for that matter. It contains basically zero releasable energy. It needs oxygen or another oxidizer to react with to actually release any energy. TNT and batteries' energy density calculations include the oxidizer and the oxidizer is in close proximity to the fuel (molecularly so in the case of TNT). If you 10x the "energy content" of gasoline it's still rate limited by access to oxygen. If you 10x the energy density of a battery (the type with the oxidizer contained within the battery, not a fuel cell or metal air battery) you've got 10x the energy ready to be released quickly if oxidizer and fuel mix in unfortunate ways
It's an interesting discussion, because if you assume access to atmospheric oxygen, gasoline is MUCH more energy dense.
The previous point is fair though. What is the energy density of gasoline in a stoichiometric mixture with its oxidizer and not already detonated? That's where TNT beats it by a long shot. The mixture with any chance of being stored would be some relatively low pressure gas.
Edit: Or, a fair closed-system comparison to a battery would need to include a liquid oxygen tank or similar so you have the two components stored but can control the delivery...
In the context of the conversation, it doesn't actually refute the point though, which is that explosive danger is contingent on a much broader set of relations than simple energy density. Gasoline just demonstrates the disconnect. Tacking on additional conditions to make high-density batteries dangerous is exactly what the engineering goal should be.
As a stupid example, if we have a high density battery technology that never explodes unless, say, under magnetic forces only seen being produced by magnetars, that's a pretty safe battery.
Air is usually quite available though.
That's a huge assumption that won't always be the case though. A gasoline tank with a small hole in it is a lot safer than a liquid-electrolyte battery with a hole in it.
Yes, that's what makes it interesting.
Interesting discussions about energetics are best had from a distance.
I can remember several situations where “a little bit of gasoline” caused a lot of problems. It’s a relative term. You need a lot of air to make it really shine, but “a little bit of gas” goes a long way lol.
"Liquid gasoline does not have anywhere near the energy of TNT,"
Energy density of gasoline is approximately 44 to 45 megajoules per kilogram.
Energy density of TNT is approximately 4.184 megajoules per kilogram.
Gasoline, when in liquid form, is not mixed with oxygen and burns, releases energy slowly. In comparison with TNT which is both the fuel and oxidizing agent releases energy very fast, it has detonation velocity of 6,900 m/s.
https://en.wikipedia.org/wiki/Table_of_explosive_detonation_...
There is a way how to use the energy density of gasoline for explosive purposes, Thermobaric weapons.
"A fuel–air explosive (FAE) device consists of a container of fuel and two separate explosive charges. After the munition is dropped or fired, the first explosive charge bursts open the container at a predetermined height and disperses the fuel in a cloud that mixes with atmospheric oxygen (the size of the cloud varies with the size of the munition). The cloud of fuel flows around objects and into structures. The second charge then detonates the cloud and creates a massive blast wave."
https://en.wikipedia.org/wiki/Thermobaric_weapon
A snickers bar has nearly 5× TNT’s energy per kilogram—TNT merely has the habit of being extremely impatient about releasing it.
One of the problems with gasoline is its explosive nature, which the fuel storage and delivery system of a car attempts to mitigate. It has a better profile for burning off than a battery though since it will spill out and burn away from the vehicle.
Gasoline isn't that explosive. You can shoot up a gas tank and it will just burn. What you see on TV is movie magic. Gasoline vapor can explode, but you need the right air to fuel ratio and a spark.
Uh… gasoline has a super high vapor pressure. If you start out at the wrong ratio, it does what it can to make that ratio right.
I’ve seen a few gasoline fires that start by burning, and then much more rapidly expressing potential.
Requires a good mix though. The parent is still correct. Mythbusters spent a long time trying to get cars to blow up in a dramatic hollywood fashion in various episodes and determined that under most conditions it wouldn't happen.
They did get it to happen, they just had to try really hard.
In most accidents the gas tank will not blow up.
High velocity accidents where the gas is quickly dispersed into the air is pretty much the only way that happens.
"Fast X: why cars don’t really explode when they crash"
"Petrol and diesel can only explode when under pressure and mixed with air and in the case of petrol, have a small amount of energy added in the form of a spark or a flame. Engines pressurise the fuel/air mixture in the cylinder and so produce small, confined explosions which turn a crankshaft and drive the wheels."
"When cars are involved in collisions, fuel lines are often torn and petrol leaks out onto a hot engine. Liquid petrol can catch fire in the presence of air. But it can’t explode because it’s not under pressure and is in the liquid phase rather than a vapour."
https://theconversation.com/fast-x-why-cars-dont-really-expl...
> Gasoline ... it's not a "bomb"
My teen years would beg to differ, when some neighborhood friends and I decided to experiment with gas and bleach. The neighborhood residents, fire department and local police also had an opinion, too. (We all got into BIG trouble. Definitely one of the dumber things I did as a teen.)
Poorly stored gasoline can spontaneously combust, though. So more like a firebomb.
No it can't. To combust it needs ~ 500F. If you left it out uncovered in the open and allowed the it to vaporize with a spark nearby, it might explode, but thats not spontaneous combustion. Gasoline sitting in a sealed container wont spontaneously combust.
Didn't everyone have one of those old mechanic friends who liked to put the cigarette out in the can of gas to scare the tourists?
That is definitely one of those “it worked the first 50 times no problem” tricks.
Gasoline doesn't do that. Perhaps you're thinking of the following?
What it does do is slowly polymerize, becoming useless as an ICE fuel in time, typically in a year or two. This is why backup generators should run on propane, which has no degradation mechanism.
No, I'm thinking of improperly stored gasoline evaporating and combusting.
Some heavier elements have hilariously high energy densities and aren't bombs (on their own), but the catch is the energy release is a trickle. Point is it's not an automatic follow that high density = high discharge.
Have a look at Electric impedance spectroscopy- https://en.wikipedia.org/wiki/Dielectric_spectroscopy
Theres a handfull of Tier 1 BMS chips that support it already. though, half of them are meant for traction/EV packs instead of BESS.
Making it require air (or some other kinetic / transport process) would help with that. E.g. zinc-air battery.
The past 20 years have made lithium ion 2-3x more dense, both because of some chemistry changes and because of better pack level design.
And it's still improving at about 5% per year.
Tesla has been around for nearly 20 years. Model S (12 years) has gained 17% of range due to chemistry (rest is system efficiency and simply bigger battery).
BMW i3 went from 60Ah to 120Ah of battery capacity (and slightly more voltage) in the exact same chassis through the span of its life (2014-2022, RIP). It is even possible to put the later 120Ah batteries in the early 60Ah cars and reap the rewards, and is a practice that is actually supported by the cars' software natively.
Range is not a real issue for electric cars. Charging time is, though, and there are massive improvements happening for that right now.
Tell that to my polestar 2 pls. and then come back again in the winter when it drops another 30% due to the battery heater energizing
Your Polestar 2 battery is based on battery technology that is 5+ years old. Right now you can buy a BYD car in China that charges at up to 1500kW - close to 10x the peak charging rate of a Polestar 2.
I’m an automotive EE… I find particular interest when someone mentions BYD as what “works” in electric vehicles.
Wild fucking west right there.
I'm not an automotive EE, could you explain more about BYD? I'd love to hear more from an expert!
I'd love to learn more about this.
I would wager charging time is basically solved, adoption is only thing that's left.
Yeah, when I take a road trip I genuinely enjoy the cadence of charging. 5-10 minutes every two hours, just enough to go to the bathroom or walk around. I get to my destination not materially later, and feeling far more relaxed than when I was doing death marches in a gas car.
This is such a euphemism to pretend that you’d like to wait two hours at a refueling station.
Anyone who’s ever driven between Seattle and Portland and seen the e16b charging lots of people sleeping in their cars knows there is a whole different side to your rosey picture.
EV owners are still internalizing their range anxiety into a benefit.
I get it; I like EVs for their around town purpose, but man it’s almost fantasy to sell it as “5-10 minutes every two hours”.
"This is such a euphemism to pretend that you’d like to wait two hours at a refueling station."
There is virtually no EV sold on the market today that takes two hours to charge to 80% at a HVDC charger.
"I get it; I like EVs for their around town purpose, but man it’s almost fantasy to sell it as “5-10 minutes every two hours”."
The Hyundai Ioniq 5 takes about 20 minutes to go from 10% SOC to 80% SOC in about 18 min with an 800v charger. That equates to about 3 hours of driving on the highway.
And you mostly aren’t charging to 80%, usually it’s closer to 40-60%.
> This is such a euphemism to pretend that you’d like to wait two hours at a refueling station.
What? I said no such thing. I would hate to wait two hours at a refueling station.
> it’s almost fantasy to sell it as “5-10 minutes every two hours”.
I guess I live in fantasy land then.
Maybe the non-Tesla charging story is crap, but I made conscious choices not to participate in that circus.
I have no range anxiety. I point the car where I want to go, it tells me where to charge and for how long, and it’s earned my trust over many road trips. It hasn’t been wrong yet.
Its a huge issue in cold climates.
uphills + cold/hot climates, the ranges won't be able to compete with ICE. its basic physics. cold uphill still reduces charging speed, available power, and range, while sustained heat accelerates degradation. Thermal-management systems mitigate those weaknesses by consuming energy and adding cost, weight, and complexity.
meanwhile ICE has gotten ridiculously clean and efficient over the years it is more efficient at the shaft does not settle total-system efficiency, cost, weight, resource use, grid losses, battery production, or suitability for every operating env. Comparing an engine with a motor while ignoring the battery and electricity supply chain is silly
I still do not trust that sitting on a pile of lithium batteries is safe. NMC does not mean non flammable or consequence free. LFP cells can still enter thermal runaway, release toxic gases, reignite, and require difficult firefighting procedures. They also generally trade energy density and cold-weather performance for that improved safety. Also the speed charging ? That dramatically reduces the stability and lifespan of the batteries. Ton of used EVs not being sold because the battery replacement is somewhere between 40~60% of the car's value.
we had ICE for over a century now, its just like a software that gets continuous updates ICE systems are highly optimized, repairable, energy-dense, fast to refuel, and supported by enormous infrastructure. EVs are improving faster partly because they still have major weaknesses to solve. A steeper improvement curve does not prove that the present technology is superior for every use case neither is using the latest javascript framework.
> its basic physics
Could you ELI5 these basic physics? I've heard many people make claims like this but there's never any physics that actually follows. I've had most of an undergraduate curriculum of physics, so if it's beyond basic, then don't be afraid to refer to those physical ideas.
> meanwhile ICE has gotten ridiculously clean and efficient over the years it is more efficient at the shaft does not settle total-system efficiency, cost, weight, resource use, grid losses, battery production, or suitability for every operating env
Is 30% "ridiculously clean and efficient"? 35%? I'm not sure I can agree with that at all.
Battery production? That's ridiculously efficient. For a very small amount weight, there's an insane amount of Wh that get shuttled through that material, which can then be recycled into even more kWh of storage than went into the recycling process, due to the continual improvement in battery production efficiency.
Meanwhile, every single gallon of gas results in 20 pounds of CO2 emissions. Fracking oil requires disposing of 2-10 gallons of dirty waste water for every gallon of gas. That's a massive amount of waste for only 20-50 vehicle miles.
The latest battery chemistries perform incredibly well in cold and hot climates.
Internal combustion is not clean, and is inherently significantly less efficient than an electric motor.
Also, LFP chemistries are incredibly safe compared to NMC, which is what you're concerned about in terms of thermal runaway.
ICE is mostly stagnant tech. Meanwhile EV tech is rapidly improving!
> The latest battery chemistries perform incredibly well in cold and hot climates.
Depends on your definition of cold. California cold sure. Wisconsin cold you are looking at losing 40%-60% range.
This EV owner disagrees, and I imagine that city dwellers without dedicated charging agree
If you could charge the battery in 5 minutes at a public charger, would the range still be a problem?
Plenty of city dwellers get by without home gasoline filling spigot.
I don't think 10x density is possible without getting into nuclear, at least not with the chemistries we know of today, everything at a certain point becomes an explosive.
Speaking of nuclear, getting tons of the material that powers mars rovers and putting them in every home would generate enough power for decades... At the cost of being able to build a nuclear bomb in a garage.
The next revolution will be small scale generation. Fuel cells, extremely efficient cheap solar, even smaller modular reactors, etc.
I live in western Pennsylvania and have both natural gas and electric service, a roof and 1/3 acre of land to utilize. I would love to get rid of at least one of my utility bills and I’m becoming more interested in decoupling from the electric grid than natural gas service. I dream of a future where competition comes to monopoly utilities by way of direct competition with each other as there is a not so far off future where I can utilize solar, batteries and a natural gas fuel cell to cut ties with my Electric Utility. If that kind of competition can exist then the game is on for those utilities to start fighting for customers.
With modern heat pumps and induction stoves getting off of natural gas is fairly easy for most people and saves money in the long run. Meanwhile the grid is switching to renewables so getting off gas is your best investment. You can get of electric too, but on your 1/3rd acre that probably means significant lifestyle compromises - I will be impressed if you are willing to live with them.
Batteries are cheap enough to build (using a commercial installer completely kills the economics, because you're paying five to ten times the actual cost in the US) a reasonable size personal battery bank (~100+ kwh), paired with some overkill solar, to totally replace the grid in a lot of cases. GP isn't limited to rooftop solar with 1/3rd an acre, so they can do it quite cheap if they want.
I seem to remember recent advances in TMSR research and construction. Those tend to e much safer and have safer byproducts than uranium or plutonium fueled water-cooled reactors.
In term of dual use nuclear seems culturally radically different from everything else, wondering why.
Agreed, but I think people can imagine and companies are very motivated: powertools, phones, laptops, watches, backup UPS, cars, hospital equipment... there's high demand for durable, long-lasting batteries. I think the research is there, it's just complex chemistry. We'll get there. Impressive to see the progress in EV batteries and they've actually turned out to be more durable than first feared.
hard core lipo user here(for DIY). battery is great but it gets balloon after using some time
How is billions every year on R&D not enough, especially when you measure consistent improvement year over year in the technology?
10x energy dense does not mean 10x safer. Gasoline is still widely used because it is considered one of the safest options around!
The problem is more nuanced than just "let's do all the battery density"
maybe you are right . I was thinking a world where battery improvement is the rate as chip performance improvement ,
I think, apart from finding better Batteries altoghether, we should build multi-tier batteries inspired by biology. Humans have bloodsugar, sugar in the Liver and then fat. All of them have their respective properties with availability and amount. This way, engineering tradeoffs could be allocated much more fine grained. For example, a while ago I read about a startup building an energy storage where they heat up large amounts of sand to store the surplus of renewables. This could serve analogous to the fat in humans.
sorry in advance , but my POV is .
Most of the things that we copy directly from humans do not work in terms of robustness.
Its like instead of harddrive use human DNA to store the data for 3T years,but no-one is mentioning the bandwidth speed here(which is the most important thing) etc,
I know it has some usecases.Also "one spoon butter is more energy dense than a battery"
but how we are gonna use butter(I dont know enough bio) but it is way harder to convert energy .
Biological power is marvelous, but really inefficient. All that sugar and fat in entire human body only generates 50-150 Watts.
Humans do that because we're big and extra complicated. The closest analogue is probably a hybrid car, though ideally you'd want one that can create synthetic fuel from its battery. But I suspect cellphones are properly analogous to e.g. bacteria that have much simpler energy storage.
I think I've heard of sodium, lithium hybrids. But that's only 2, what's the fat? Gasoline, LPG hybrid? Shit gets expensive fast. Probably 2x cost of just a sodium or ion EV? The human body is too amazing.
I look to a future of regularly servicing the immune system of my battery.
That reminds me of the gel packs in the USS Voyager. At some point they became “infected” and they needed to the raise their temperatures to let them destroy the infection!
The good news is that humans already exist, so you can already use them. It will give them something to do with AI replacing them elsewhere.
You might not like the efficiency of that type of battery, though.
The article says $4B was put into solid state research/companies as of 2025 in the US alone. Seems like they are working on it
It should be relatively straightforward to imagine — we already have that in gasoline-powered internal combustion engines.
The Watt-hours per kilogram of good Lithium Ion batteries is around 250-280 Wh/Kg; for Lithium Iron Phosphate it's about 180 Wh/kg, and for Sodium-Ion about 170 Wh/Kg.
The raw energy in gasoline is about 12,300 Wh/Kg but automobile internal combustion engines get only about 20-30% efficiency yielding about 2500-3600 Wh/Kg. For aviation piston engines it is a bit better at 25-30$ so 3000-3600 Wh/kg.
So, the batteries, instead of being 10-12X the weight of the gasoline for the same net driving/flying range, could weigh about the same as the gasoline. So, a typical car with maybe a 16 gallon tank and 30 miles per gallon fills up with 128 pounds (58 kg) of gasoline to get 480 miles of range. The Li-Ion battery for that range would weigh something like 1300 Lbs (590 kg). That is a substantial additional weight for a car that could be 2800-3800 Lbs in ICE configuration, so 35-45% added weight (a bit less because of savings on the ICE engine, etc). This requires everything else to also be heavier, from the structural frame, the suspension system, and even the wheels and tires (which is also unsprung weight, further impairing performance).
With a 130Lb/60kg battery instead, and saving the weight of the ICE engine and fuel system, the overall car design could go much more lightweight, regaining a lot of performance and range, all while gaining the huge torque of electric motors.
In aviation, a battery systems of that weight would enable all-electric aviation to go from small performance niches to the default for general aviation.
So yes, it would be a HUGE benefit to achieve 10X energy density batteries, and we do have reference points for people to imagine it.
> With a 130Lb/60kg battery instead, and saving the weight of the ICE engine and fuel system, the overall car design could go much more lightweight, regaining a lot of performance and range, all while gaining the huge torque of electric motors.
I think you're underselling it, even. A typical like-for-like modern EV is only marginally heavier than the ICE equivalent. If we were able to drop the weight of the battery by a thousand pounds, cars would be lighter than they have been in decades while retaining all the modern safety and convenience features we've come to expect. And if density improved along with weight, we could make EVs with the same form factor as today but with over a thousand miles of range. Not that we need that, but it is just as a tiny example of how mind boggling the game change would be.
As it is I've only recently internalized the notion that the most powerful electric tools are battery powered (what can I say, I grew up when rechargeable batteries were NiCad and they basically sucked). And it will just get better and better as time goes on.
Some people might need that range. If you cannot charge at home and you don't have good public charging infrastructure then you might want enough range so you only have to deal with charging once or twice a month.
Yes, underselling a bit for sure! I didn't even want to get into the optimizations available if cars were really designed for lightweight when the entire motors+battery is only 100-150kg, and the battery can be low and centered.
We could go for performance, trading off some battery for four inboard motors (fully sprung weight) with half-shafts and CV joints, steel space-frame chassis and carbon fiber body — it could put many supercars to shame.
Going for range, same light-weighting, but less powerful motors and adding more battery, the range could get silly long at something like 1000 miles for 100kg of battery.
For the kind of long range options another poster mentioned, with 100 kg for 1000 miles, a few 10-kilo swappable battery packs could make it easy to trade luggage space for range, or bring them to a charge station only occasionally, but not lug them around for most in-town trips.
No question, we could go wild!
An EV doesn't need to have 480 miles of range. Nobody is driving that distance daily. 98% of trips are under 50 miles. Only 0.8% of the trips are over 100 miles!
Also, EVs use regenerative braking. That should help a little bit.
EVs should be built with 100 - 150 mile range. All families with 2 cars can immediately switch one of their cars to a daily driver EV and the other vehicle is a minivan. There are lots and lots of people for whom an EV works perfectly well and if they need to go longer, US has a robust rental car industry. What would help is to let people charge anywhere they park. All workplaces should offer free charging, and companies can negotiate to get paid for charging their employees cars. The price of electricity goes negative because of lack of demand, and this is something that they can offer to the grid, demand as a service.
> EVs should be built with 100 - 150 mile range. [..] if they need to go longer, US has a robust rental car industry
As an EV owner myself, no. Absolutely not.
The reason is simple: The mere existence of low-range EVs hurts overall EV adoption, because people aren't going to rent a car just for a road trip. You're talking about adding $100+ per day on what's supposed to be a cheaper method of travel compared to flying.
ICE-holes don't think critically. They don't care that long range EVs exist. They'll just see one that only gets 100-150 miles of range and go "See? EVs have short range. They're not appropriate for road trips. That's why I'll never get one.", despite plenty of 250+ mile options.
Now, I suppose you could argue that this type of person would simply never get an EV and would just come up with a different reason, and you'd probably be right. But the general point still remains: People want a car that satisfies ALL their needs and won't settle for something that works "only" 98% of the time.
Not only that, but with a longer range, you have more flexibility in planning recharging. It may take more time to top up from 50 km left to 500 km, but you have more flexibility about when to do it. Something that needs a daily charge is going to be interfering with your schedule.
"The reason is simple: The mere existence of low-range EVs hurts overall EV adoption, because people aren't going to rent a car just for a road trip. You're talking about adding $100+ per day on what's supposed to be a cheaper method of travel compared to flying."
Just wait for people to be priced out of ICE cars. EV's should be and will be significantly cheaper to buy and manufacture.
I think people can imagine lighter cars and laptops and things. Is there something bizarre that’s unlocked like battery powered space launches or something?
High density batteries allows us to have dramatically cheaper electricity. Think of it like this, what happens when electricity is 1/10th the cost? Beyond what others have pointed out (electric airplanes, cars that drive thousands of miles), costs for everything would drop as energy is a core driver of it in every good you consume. If you can pull energy where it's very cheaply available and store/transport it anywhere the world millions of lives would be saved. For example;
If energy is cheaper than the price of water you can pull water out of thin air (dehumidifiers).
If energy is cheaper you can grow food in areas you normally couldn't.
When you can transport anything for cheap you can move food to areas that are vulnerable to food insecurity.
If you can store energy at large scale you can nearly eliminate grid failures, savings lives in the summer and winter.
Costs for transporting food would go down significantly, imagine groceries being 10-15% cheaper.
Assuming airlines have competitive pressure you could expect plane flight costs to drop 20-30% improving everyone's mobility.
Energy density doesn't matter for electricity since the storage batteries don't move and there is plenty of space for them. Cost per energy stored is what matters. Density is important for transportation especially planes.
Sodium ion batteries have worse energy density than lithium ion but they have potential to be cheaper and more reliable. Iron air batteries have poor round trip efficiency but could be even cheaper.
Batteries are not power sources, but storage. The energy still has to come from somewhere, and power generation won't magically become 10x cheaper overnight. No matter how cheap battery storage becomes.
But it IS crucial for removing bottlenecks & replace fossil fuels.
Imagine for a moment that batteries with decent shelf lives are free.
You build a power plant on a geothermal vent in Iceland. The electricity it produces is plentiful and cheap. You run it full tilt charging batteries.
You ship those batteries to wherever you need cheap power, and send them back empty. This works with hydro, wind, solar, ...
Batteries do drive down energy costs because even ignoring transmission lines, they let you move energy in both space and time, pushing all energy costs towards the cost of the cheapest means of generation on its best day.
Aviation, drones with hours+ flight range, more solar power usage as storage gets easier/cheaper, phones that last more than a day, robots with actually useful battery life, smaller IoT devices. A lot of current tech is severely limited by battery capacity.
Electric long distance passenger planes. Possibly requiring the help of EMALs.
Electric long distance container ships.
Useful portable laser, coil- and rail- guns.
Even longer range drones.
What point is there in gasoline if we can get better energy storage in batteries?
Not all batteries need to be mobile.
A 1 GWh grid scale battery takes up about 4 hectares at the moment. The UKs total energy use is about 2,000GWh a day.
It would need to use 240,000 hectares to store all energy requirements (eletric, transport, heating etc) for a whole month. Even in extreme cold conditions it would last a couple of weeks.
That would be about 1% of land use.
Storing a month of energy use doesn't make any sense when it comes to renewable grids. Since you don't have to mine/extract and transport an inventory, far far less storage is required.
A month is probably excessive, but there are large regions of the world where its not uncommon for both solar and wind power to be running at <5% for multiple weeks in a row.
There's an engineering tradeoff between having excess generation capacity, for that seasonal minimum, and having more storage. The cost optimal decision on that tradeoff will be determined by the ratio of excess generation cost and storage cost for rarely-used storage.
Until that ratio falls by at least 3x to 5x in favor of batteries being cheaper than generation, extra generation is going to be the way that grids actually get built out. Batteries and generation are both falling in cost fairly quickly, but generation still has the overall edge in learning rate. Cost decreases won't bottom out for at least a decade, because there's been no slow down yet, so I wouldn't expect this ratio to change for a minimum of 20 years, which means that pretty much a full energy system interchange will have happened by the time that this price ration changes.
So there's at least a few assumptions about the current industry and it's future development that underlie my assertion that a month of storage makes no sense, but I'm confident enough that I'd place money on the bet, and there's very very few things I'd bet on.
Edit: one thing that would break my assumption is the industrial development of storage that's super cheap for once-per-year usage. Most storage now needs to be cycled about 300x per year to make economic sense. "Long duration" storage is actually better defined as "economical storage at few battery cycles per year". There's nothing like that in the research hopper, but that doesn't mean it couldn't appear tomorrow and be deployed within a decade. Something that only gets used once or twice a year has to be dirt cheap, even if you could get 10x or 20x normal electricity prices for it.
Which just emphasises the point -- density and thus land use isn't really a major concern
You could store an entire years worth of energy (not just electricity) for a fairly dense country like the UK and still have 95% of the country left for other usage.
Definitely! However I frequently encounter people on energy discussion forums that assume that we need 2-3 months of battery storage, perhaps because they see natural gas or other storage and assume that batteries need exactly the same thing, so I'm perhaps overly eager to respond to claims about month-long battery storage.
I had previously been hopeful that battery storage would allow more shared used of land, but the fire risks of batteries have been pretty severe. And since the land usage requirements are fairly low, there's no need to enhance the risk by putting batteries, say, in enclosed spaces of former natural gas generation facilities [1].
I'm hopeful that we'll see a lot more storage, say a shipping container's worth, at the end of distribution feeders, which helps suck up residential solar with minimal resources, but solving the problem of "who pays for the benefits for all" when the utility is incentivized to keep grid costs high means that nobody is knocking down doors to make that happen...
[1] https://www.utilitydive.com/news/moss-landing-fire-battery-s...
Doesn't that depend on the sources of energy though? Pretty much constant short and mid term supply like geothermal, hydro, tides, etc vs unpredictable or variable in the short term like wind and solar.
As a society relying on solar, I'd want to have more of a buffer than one that relies on hydro.
Instead of batteries, why not green hydrogen or green ammonia? Ammonia is needed for fertilizer, storage/logistics are a solved problem. Emergency plants around that can use ammonia as fuel can solve the dunkelflaute problem?
Another option is natural gas peaker plant on a ship/barge. Have a fleet of these around that can dock at any port and supply electrictity. A peaker powership is essentially a mobile, marine-class version of an onshore peaking power plant.
What would be best long term if we have a few hundred - few thousand nuclear ships/subs that can go anywhere and supply power.
It can be the sharing economy for clean power at scale.
Capital costs and round-trip efficiency are the primary reasons. Even at constant utilization, electrolyzers are expensive enough that it's hard to replace fossil-fuel generated hydrogen at the moment.
Once you 2x-10x the cost of electrolyzer capital by only using it rarely, more generation and throwing away the excess electricity often makes the most sense.
Nuclear ships are similarly super super expensive. The only reason we build them at all are for their unique and wonderful operational capabilities, as in not needing to surface or refuel. Using nuclear ships for power would so expensive that we may need to up our GDPs 10x before such wasteful use makes sense. (Though I'm hoping we do reach such future luxurious lifestyles!)
> Another option is natural gas peaker plant on a ship/barge. Have a fleet of these around that can dock at any port and supply electrictity. A peaker powership is essentially a mobile, marine-class version of an onshore peaking power plant.
Why would you want this?
fun fact: there is already a Sodium-battery with a solid electrolyte - but the operating temperature is above 300^C [0] [0] https://en.wikipedia.org/wiki/Sodium%E2%80%93sulfur_battery
Aren't sodium batteries close to production and a lot cheaper and safer?
Ambri was working on large scale batteries which seemed like a pretty good idea (looks like they ran out of money): https://en.wikipedia.org/wiki/Ambri_Inc.
Sodium ion batteries are already being mass produced in China. CATL actually just started producing their second generation sodium ion batteries. In the US, Peak energy is doing storage solutions based on sodium ion.
Anyway, you are comparing apples and oranges. While solid state sodium ion might become a thing at some point, it so far isn't. The lithium based solid state batteries currently being readied by several battery companies for mass production around 2028 or so tend to have up to 500-600 wh/kg densities. Sodium ion batteries are currently at or below 175 wh/kg typically. LFP is a bit better, and some high end NMC batteries might do 250ish wh/kg. That would be just the first generation solid state batteries. Densities might improve after that. The theoretical limit is a lot denser than that and there is a lot of money going into researching ways to do better than that.
Of course energy density is just one thing you might optimize for. Other properties you might look at are operating temperatures, amount of charge cycles the battery can handle before it degrades below 85% of its original capacity, the speed at which it can cycle, fire safety, cost, etc. Mostly sodium ion scores very well on all of this except density.
High energy density usually comes at a price. Both in dollars and in compromises with these other things. Think lower lifetime, more constrained temperature ranges, etc. Worth it if weight and volume are really constrained. Like in anything that flies.
Depends on the application - each battery technology has a trade-off between energy density, cost, lifetime, safety, scalability, etc. Sodium may have a place in grid storage, although iron-air is being deployed today and is even cheaper and safer (but poor energy density, which doesn't matter much for grid storage - https://formenergy.com/technology/battery-technology/)
Cheaper yes. Non-aqueous sodium ion batteries (which are most of them) are more dangerous than LiFePO4 though.
In what way, if you don't mind me asking?
In the way that they are more likely to catch fire or explode or undergo thermal runaway.
https://advanced.onlinelibrary.wiley.com/doi/10.1002/aenm.20...
https://www.sciencedirect.com/science/article/abs/pii/S20954...
When titles with rhetorical questions sound almost like dumb questions.
The Two Bit Da Vinci YouTube channel has a good video on solid state battery fundamentals and a deep dive into a battery company (ProLogium) that has demonstrated manufacturing at scale.
https://youtu.be/xQFVIs4leig?si=iOOt5gg_2MJAIoFR
BYDs battery stress testing: https://www.youtube.com/watch?v=WPTgg3joL5E
Those use liquid electrolyte cells and the video is more promo than rigorous testing.
Tangential to the main article point but…
The energy density scatter plot is physically correct but misleading and everyone makes this mistake.
From an engineering point of view you have to use work delivered at the end of the drive train not fuel raw energy content.
When you do that lithium ion batteries compare more favorably to liquid fuels. That’s because the conversion path is more than 90% efficient. For ICE engines you’re starting with only 20-40% Carnot efficiency (depending on how good and in good shape the engine is) and then losing in the transmission and then losing more because ICE cars have more other gears and moving parts. Power to wheel is pretty terrible. Most of the energy from gasoline heats the air around the car.
This is also why you get outrageous sounding but accurate things like: an EV charged on 100% coal fired electricity emits less carbon than a typical gasoline car. The fact that coal is literal pure carbon fuel is made up for by the high thermal efficiency of a giant supercritical steam turbine vs a small piston engine. Coal burns real hot too (steeper thermal gradient). So more of the energy from coal ends up doing actual work vs heating the air. (Well directly heating the air I mean.)
Yes, electricity should be the only abstraction layer to deliver energy to end user. We can extract a lot more energy from fossil fuels in large scale plants and also continuously switch out dirtier fuels with clean energy.
For example, no need to build natural gas infrastructure to every home. Use induction stoves (or electric coil -- already 67% of homes). Heat pump water heater instead of gas. And heat pump for HVAC.
If all energy bills are consolidated as electricity (instead of gas, natural gas and electricity), most people would install solar on their rooftops, buy EVs, and save ~$1000/month on energy bills.
> We can extract a lot more energy from fossil fuels in large scale plants
This isn't true at all for natural gas. Burning it for heat in the home is much more efficient than burning it in a plant, converting it to electricity, transferring that electricity, then turning that electricity into heat.
Depends, if you are turning that electricity into heat using a heat-pump you might win on most situations (maybe lose if the weather is really cold outside, unless you add geothermal loops, but then its a lot more expensive to make)
No it wouldn't depend. Electricity generation and electricity transfer has losses. Gas transfer has loss only if there is a leak.
In addition the sibling comments (COP of heat pumps is 500%), air pollution in homes is worse than air pollution outside. If you don't have natural gas and burning fuel, it helps a lot. Not only is electricity cheaper and cleaner, but also healthier.
Not what I replied to
The theoretical efficiency maximum for burning gas in a home is 100%. Most systems won't hit that because they need to vent waste gases, which carry some heat away.
Heat pumps are significantly more efficient than 100%. They can get to 500% efficiency. So no, it's definitely not more efficient to burn gas in a home. (To say nothing of the safety of running gas lines to every house.)
That is false. Heat pumps are more efficient than burning gas in a home even when the electricity came from burning gas.
But isn't it more advantageous to have the gas -> electricity conversion in a plant from an emissions point of view? You still have losses in the system when moving natural gas around from the source to individual homes too (leaks). In theory you don't, but in practice you do.
> because the liquid electrolyte currently used in batteries is flammable, replacing it with a solid could make batteries safer and less susceptible to fire.
The problem is primarily that batteries are storing a lot of energy, which can be released when things go wrong. The electrolytes (technically, the solvents) typically don't ignite under 750°F or so, which makes them less flammable than a lot of other common materials, and far less of a concern than, say, the lithium metal.
This isn't true for most lithium ion chemistries.
The liquid electrolyte is the thing that releases most energy when the battery burns, more than the anode and cathode. Some also have a very low self ignition temperature.
IIUC, the main problem with the current Li batteries is that the two plates can over time grow material that will 1) degrade performance; and 2) make it more likely to short circuit and catch fire. Similarly with electric car batteries after accidents where the battery is damaged, short circuits, and then catches fire.
So the main risk here would be the likelyhood of short circuiting under different failure scenarios.
Isn't the key difference that flammable solids have a limited reaction surface when they burn, whereas flammable liquids can be wildly unpredictable?
The energy "stored" in the light oil electrolyte of a battery is >10x more than the electrical energy or the energy released by reacting lithium alone.
An 18650 battery weighs ~50g and stores ~10 watt-hours. 10 watt-hours is 8,604 calories, enough to heat 50g of water by 172 C or 310 F. The battery would not even burn without a liquid electrolyte to ignite.
I wonder about the youtube videos of someone driving a screwdriver through a battery pack.
Is that the electrical discharge, then the lithium going off, then the electrolytes?
you ever short a car battery? That much electricity running through metal will create a lot of heat which then ignites the lithium. Watch a video on thermite and you'll get the idea.
I'm not trying to build a solid-state battery...
Manufacturing the batteries would probably benefit from solid state. The Panasonic battery plant in the exurbs of Kansas City, MO has had two evacuations this year from thermal issues related to lithium-ion battery production, including one yesterday morning. [0] [1]
[0]https://www.kmbc.com/article/lithium-ion-batteries-catch-fir...
[1]https://www.kmbc.com/article/panasonic-plant-de-soto-evacuat...
Yeah I've made peace with this too
have I misread or 3/4 of the article explained what a battery is and only final tiny part got to "short-circuiting dendrites don't happen without electrolite"?
dendrites are an inherent problem with liquid elctrolytes and I would have emphasized that as well
are dendrites why so many people are now burning down their apartment/complex charging their scooters
is LiFePo4 immune to dendrite shorts? Or do they happen just don't burn?
There are a number of reasons why lithium batteries may catastrophically fail and catch fire. Dendrite shorts is one, another reason is poor alignment of the layers during assembly, allowing for eventual shifting of layers leading to internal shorting. Another is conductive or sharp debris getting into the battery during manufacturing, and after a while the anode/cathode separator getting pierced by the debris. Lots of reasons!
dendrites are not really a significant problem in popular batteries. It's associated with lithium metal, vs lithium in normal batteries is in the form of salts. Solid state lets you use metal, which is much more energy dense since you don't need the salts.
The most common lithium battery failure mode is that you have a hole in the plastic separator between the +/- sheets inside the battery, which shorts and causes a hotspot that eventually starts a fire. Dendrites cause the short by growing across the gap. In normal batteries it is caused by a manufacturing defect. The outcome is pretty similar.