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> the battery retained 81.9% of its initial capacity after 100 cycles That's really terrible. It's interesting, but 20% loss after 100 cycles is just not grea
by cogman10 11mo ago
> the battery retained 81.9% of its initial capacity after 100 cycles
That's really terrible.
It's interesting, but 20% loss after 100 cycles is just not great. NMC gets that at near 1000 cycles. LFP gets that at near 5000 cycles.
- flerchin 11mo agoSeemingly adequate for certain drone applications like in Ukraine. They may only need a couple charge cycles, and 4x the capacity is huge.
- oofbaroomf 11mo ago20% loss isn't too bad if you start out at double the capacity though.
- dyauspitr 11mo agoBut does it keep dropping? Is it 60% at 200 cycles
- hinkley 11mo agoI saw a video on the CATL sodium batteries the other day and the deal is that they’ve found a way to reinforce the material in a way that brings up the slope of the back half of the discharge curve so it’s almost as good as lithium down to about 20% state of charge before falling off the cliff. Lithium is more like 10% but that’s something you can manage with charge circuitry and overprovisioning. So yeah I’d like to know the answer to your question too.
- cousinbryce 11mo agoMy first thought was put the new cells in aircraft, then cheap cars finally grid storage
- cogman10 11mo agoThat actually could make sense especially with a good recycling program. Swap the packs every flight and recycle anything that falls below standards.
- ryukoposting 11mo agoA good recycling program sounds like a tall order. I'm seeing Silver nanoparticles (heavy metal) and multiple things that react violently with water. I'm always skeptical of any idea that ends with a bespoke industrial-scale recycling process. People tend to massively underestimate the complexity of recycling, especially at scale.
- gmueckl 11mo agoIn general, bespoke recycling processes can make sense, especially if you manage to design the items to recycle with the recycling process in mind. There are several types of goods where this is put into practice (paper, compounds like TetraPak packages, various polymer plastics). Not sure about all the differrent types of batteries, though.
- ryukoposting 11mo agoWe struggle to recycle normal batteries without injuring or killing people. Lead-acid batteries contain literal plates of lead oxides, and we can't manage to keep that out of the water supply! I don't see how we'd do any better with silver nanoparticles. Nothing I'm saying is meant to condemn recycling as a concept, by the way. Only to condemn technologies where disposal is dismissed with a shrug and a "idk just recycle it."
- cogman10 11mo ago> we can't manage to keep that out of the water supply! AFAIK, the lead in the water supply doesn't come from batteries. It mostly comes from lead pipes. Lead acid battery recycling is one of the more efficient recycling programs out there.
- maximus-decimus 11mo agoGoing down 10 times faster seems like a really bad trade off for 2 times the capacity. That means your battery will only lst 1/5 or 20% as long.
- Reason077 11mo agoNot if your application requires 2X the energy. Aircraft, drones, etc. There's always trade-offs in battery design. As an old saying goes: you can have high specific energy, low degradation, or low cost... pick two!
- TrainedMonkey 11mo agoCharge cycle capacity drops are generally not linear. If we start with 2x capacity and drop to 1.6x after 100 cycles, then we might end up with 1.2x after 1000 cycles. Some smartphone manufacturers would love that as you start with extremely superior energy density and then have a built-in obsolescence.
- kazinator 11mo agoThat's only a valid concept in some embedded engineering case, where a certain capacity is required, and double that amount is provisioned to account for degradation. Few consumers think this way. Something doesn't have double the capacity that it has; the capacity is the capacity, and the decline looks bad.
- ryukoposting 11mo agoThe whole idea of the embedded part is that you make the degredation invisible to the consumer for as long as possible. From the factory, only charge up to ~4.07 Volts or thereabouts. Every N cycles, add 0.01 V to the threshold. Your phone probably already does something like this. But yeah, 20% degredation in 100 cycles is atrocious. No amount of firmware shenanigans will be able to paper over that, not in any regular consumer product at least. I can still think of use cases, though. Reserve power sources that aren't meant to be cycled daily, where smallness is valuable. Those little car jumper packs, for example. If there was a UPS close to the size of a regular power strip, I'd buy a few.
- hinkley 11mo agoEngineering is compromise though. If you can make a hybrid that loses 5% at 100 but still retains 500wh/l you’re in good shape. There was someone working on a membrane a while back that’s pretty good at diffusing the lithium transfer in a way that reduces dendrite formation substantially, for instance. That’ll drop your volumetric advantage and likely your max discharge and charge rate a bit but would fix a lot of other problems in the bargain. I’m not saying that the solution, but there is a palette of tools you can mix and match and that may be one of them.
- joecool1029 11mo ago> Your phone probably already does something like this. It most certainly does not. Most devices track battery health % (last full capacity divided by design capacity) and the gauge just presents state of charge (current capacity/lastfull) The better phone charge threshold systems measure usage and keep the phone in the 30-80% soc range as often as possible. Voltage drops faster on old cells as they age so you need a coulomb counter. Only extremely shit designs guess soc based on voltage alone.
- Reason077 11mo ago> "That's really terrible." Not really. At 1270 Wh/L, even with 20% degradation, these cells still retain far more energy than a LFP cell (which are more like 350 Wh/L). The question is, what happens at 200, 500, 1000 cycles? Does the degradation continue linearly or does it slow down? ... or accelerate?
- zoeysmithe 11mo agoNo one knows, the paper just focused on 100 cycles, but it suggests that if its good at 100 it probably is not terrible at further cycles. I guess we'll have to wait for the next paper but the conclusion seems optimistic about future research: It is important to note that additional improvements in practical cell parameters, such as further optimized electrolyte (E/C ratio), increased stack pressure, optimized separator selection, and higher areal capacity of cathodes, can potentially enhance both the energy density and cycling performance beyond laboratory-scale demonstrations. Post-mortem analyses confirmed reduced Li accumulation, minimized swelling, and suppressed cathode degradation, validating the robust interfacial stability of the system. By concurrently addressing the reversibility of Li metal and the structural stability of Ni-rich layered cathodes, this synergistic design offers a scalable and manufacturable pathway toward high-energy, long-life anode-free LMBs.
- u8080 11mo agoPerfect for kamikaze drones probably
- marcosdumay 11mo agoYou can get a lot of energy density by making the batter non-rechargeable.
- eru 11mo agoSee https://en.wikipedia.org/wiki/Metal%E2%80%93air_electrochemical_cell https://en.wikipedia.org/wiki/Metal%E2%80%93air_electrochemi... in general.
- mschuster91 11mo ago> It's interesting, but 20% loss after 100 cycles is just not great. NMC gets that at near 1000 cycles. LFP gets that at near 5000 cycles. NMC and LFP had similar issues when these chemistries were at laboratory scale. Give it time and the issues will be solved.
- cyberax 11mo agoA car with this battery can easily have a 1000-mile range (a real one, not EPA). So 100 full cycles would still mean 100k miles!
- woeirua 11mo agoYeah, exactly. After your first 100 cycles you only get 800 miles per charge, which is still way beyond what you need for EVs to replace all ICE cars.
- atomicthumbs 11mo agoAnd how much commercial development have NMC and LFP batteries had since they left the laboratory?
- gamblor956 11mo agoLFP batteries are currently being used in newer EVs, most larger power banks, and in newer high-end phones and laptops.
- joecool1029 11mo agoLFP are common in EV’s and ‘solar generator’ style battery packs, but I’ve never seen them in phones or laptops (outside OLPC), reduced capacity makes them not great in these, better to go NMC.
- atomicthumbs 11mo agoYes, I know. I'm pointing out they're comparing a laboratory prototype to a commercial product.
- tooltalk 11mo agowhich "high-end" phones and laptops use LFP? This makes no sense. Also, LFPs are mostly deployed in low-range EVs and mostly in China. Most EVs outside China still favor NCM/NCA, but I suspect that LFP is going to gain market share in budget friendly, low-range EVs.
- gamblor956 11mo agoA number of Chinese brands use LFP batteries due to the local flight ban on lithium ion batteries.
- tooltalk 10mo agoYou are conflating power banks and smartphones. In China, the current trend in "high-end" smartphones/laptop is to switch to higher-energy silicon-anode batteries. LFP is primarily for low-energy dense (gravimetric/volumetric) storage devices, such as power banks; or in vehicles, low-end/low-range EVs, or stationary energy storage (ESS) -- BYD being one notable exception. China implemented rules in mid-2025 banning uncertified (no 3C mark) and recalled power banks from Anker & Romoss models, from domestic flights due to fire risks.
- ok_dad 11mo agoI think this would be perfect for race cars. We might be getting closer to a serious EV endurance series.
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