> 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.
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.
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.
"It isn't perfect so therefore it's trash" is not a helpful or intelligent take. You are not contributing to the conversation, you're wasting everyone's time by trying to appear smart.
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...
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.
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.
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.
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.
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 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.
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.
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.
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.
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.
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.
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).
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.
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)
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.
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!
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"?
> 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.
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.
Are anyone building the battery you described?
"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.
"It isn't perfect so therefore it's trash" is not a helpful or intelligent take. You are not contributing to the conversation, you're wasting everyone's time by trying to appear smart.
To be fair, the poster said “holy grail” which implies perfection.
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...
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.
"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.
Try reading more than the first sentence before replying
Exactly. Nowhere near. :)
(TNT has power, not energy.)
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.
Poorly stored gasoline can spontaneously combust, though. So more like a firebomb.
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.
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 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 EV owner disagrees, and I imagine that city dwellers without dedicated charging agree
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.
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.
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.
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
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.
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.
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.
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.
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.
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.
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.
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.
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...
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
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
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)
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.
That is false. Heat pumps are more efficient than burning gas in a home even when the electricity came from burning gas.
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!
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