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"?
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.)
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.
> 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.
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.
Generally a >10x is easily achievable if we use a chemical reaction that uses oxygen - which we do not have to carry around, that's why things like hydrogen fuel cells have a theoretical energy/mass that we can pretty much assume is best possible with a chemical reaction.
Unfortunately the problems with hydrogen storage and the fuel cells have prevented them from really taking off.
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.
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.
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
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.
> 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.
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.
I believe you’ve made all that up. The battery is “solid state” as in “solid state of matter”. There are no liquids, gases or plasma in the battery. It’s an elementary school physics term.
I mean the ultimate goal is still to surely have literally that. A solid state battery.
Tbf just like computronium, I actually don't care if my battery is liquid or solid but that almost every atom or molecule that makes up the battery is used for that purpose. I guess we could call it powertronium!
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]
Can someone please explain why electrons also cannot go directly through the electrolyte just like Lithium ions? Footnote 1 skips explaining this. I tried asking ChatGPT, but it is not getting to a complete answer. It says things that just pushes the question into another form.
I find the fact that the military here is setup orthogonal to the civilian sector fascinating- for the military- a unified energy carrier - that can be everything, battery, fuel, explosives is the golden grail.
Bonuspoints if you can squeeze that liquid through a fuel cell.
So, Methanol + doseable hydrogenperoxide or something similar it is. If it can drive your drone, power its onboard compute and fire a gun or convert into explosives at the end of the journey, thats pure victory.
Bonuspoints again, if you can standardize your whole setup into machine assembleable legobricks, creating changeable drones on demand, that can iterate in hours through, where normal military industrial complexes take months, years, generations. Every drone, every rocket just a stack of coke cans, foil-wrapped, going for a walk, a fly.
YouTuber "NightHawkInLight" just made a flow battery from common materials. Why would I want a solid state battery when I could have a battery whose capacity expands just by duct taping plastic water barrels to it?
It seems the solid state battery is the long awaited answer to ev development. Where we will see range of 1000km and super fast charging and reasonable battery replacement costs. Currently in the market with battery failures it is cheaper to buy another ev rather than replace the battery.
Definitely being unreasonable, but that's one of the reasons I don't have an electric vehicle yet. I'm paranoid of that thing catching fire in my garage. Which is ironic since one of my random electronic devices with li-batteries probably could catch fire regardless in my house. At least with a gasoline it seems we are better equipped to deal witg such fires.
Overall my end goal is to have a seperate storage for the e-vehicle.. Plus it be easier to slap some solar on that structure.
This article seems to confuse lithium-ion and lithium-metal batteries. Lithium-ion batteries intercalcate lithium ions into pre-existing electrodes and that doesn't form dendrites. Dendrites are a phenomenon of lithium-metal batteries, where lithium ions tend to be reduced to metal at the tips of the dendrites.
You can get lithium metal forming on lithium-ion electrodes, which could go on to form dendrites, but the failure there is the metal formation, not the dendrite formation.
China-certified solid state, CATL sodium, and ProLogium are manufacturable batteries that don't violently deflagrate under puncture, cutting, or high temperature.
When these reach markets in significant quantities, most Li ion (NMC, LiPo, and LFP) with liquid electrolyte or plastic separators should be banned for most purposes, especially vehicles and occupied areas. These are whale oil lamps that pose a silent, ubiquitous danger to life and property.
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[ 0.63 ms ] story [ 22.7 ms ] threadThe 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.)
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.
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.
what makes it so? I don't know anything about this subject, I'm really curious now about what the perfect battery would be.
I wish BYD could bring their new infra to the US - it looks pretty ::ahem:: solid!
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.
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"
Unfortunately the problems with hydrogen storage and the fuel cells have prevented them from really taking off.
is LiFePo4 immune to dendrite shorts? Or do they happen just don't burn?
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.
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.
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.
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?)
- 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
https://youtu.be/xQFVIs4leig?si=iOOt5gg_2MJAIoFR
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.
Tbf just like computronium, I actually don't care if my battery is liquid or solid but that almost every atom or molecule that makes up the battery is used for that purpose. I guess we could call it powertronium!
[0]https://www.kmbc.com/article/lithium-ion-batteries-catch-fir...
[1]https://www.kmbc.com/article/panasonic-plant-de-soto-evacuat...
So, Methanol + doseable hydrogenperoxide or something similar it is. If it can drive your drone, power its onboard compute and fire a gun or convert into explosives at the end of the journey, thats pure victory.
Bonuspoints again, if you can standardize your whole setup into machine assembleable legobricks, creating changeable drones on demand, that can iterate in hours through, where normal military industrial complexes take months, years, generations. Every drone, every rocket just a stack of coke cans, foil-wrapped, going for a walk, a fly.
Overall my end goal is to have a seperate storage for the e-vehicle.. Plus it be easier to slap some solar on that structure.
You can get lithium metal forming on lithium-ion electrodes, which could go on to form dendrites, but the failure there is the metal formation, not the dendrite formation.
When these reach markets in significant quantities, most Li ion (NMC, LiPo, and LFP) with liquid electrolyte or plastic separators should be banned for most purposes, especially vehicles and occupied areas. These are whale oil lamps that pose a silent, ubiquitous danger to life and property.