10 ms·
Charging lithium-ion batteries at high currents first increases lifespan by 50%
- westurner 2y agoBut are there risks and thus costs?
- zweifuss 2y agoInitial Litium deactivation is 30 % compared to 9 % with slow formation loading.
- lightedman 2y agoHow much capacity is lost as a result of this?
- soulofmischief 2y agoLithium deactivation is inversely proportional to capacity. We could just add extra capacity to make up for it, though. From there, the battery would maintain capacity for a longer time than before.
- westurner 2y agoIsn't there how much fire risk from charging a _ battery at higher than spec currents?
- imp0cat 2y agoIt's just the single inital charging that has to be at high current.
- metaphor 2y ago> We could just add extra capacity to make up for it, though. At naive face value, "just" adding an extra 30% capacity to offset expected lithium deactivation implies proportional increases in material COGS and package mass/volume, all other factors being equal. Unless (a) a manufacturer is optimizing for throughput; (b) production is constrained at this initial charge stage; and (c) supply substantially lags demand; this strikes me as a non-starter in most of the consumer space.
- soulofmischief 2y agoExtra 21% capacity. Current practice still burns 9%. Lithium batteries have become very cheap, and I would pay a markup for a 50% longer battery life, assuming it didn't (a) further normalize non-replaceable batteries in consumer electronics or (b) lead to even worse conditions for the quasi-slaves currently mining lithium. Unfortunately, I doubt either of those will hold.
- metaphor 2y ago> Extra 21% capacity. Current practice still burns 9%. On a normalized basis, if current practice yields 91% finished capacity (i.e. 9% deactivation loss), and the new proposed process is expected to yield 70% finished capacity (i.e. 30% deactivation loss), then the question is how much initial material must the new proposed process start with to end with the equivalent finished capacity as the current practice? FinCap = InitCap * (1 - DeactivationRate) 0.91 0.91 = InitCap * 0.70 --> InitCap = ---- = 1.30 0.70
- soulofmischief 2y agoGood point, I didn't think that through. Thanks for the correction.
- mensetmanusman 2y agoSuch a cool finding if it pans out in production. A hidden process variable hiding in plain sight.
- userbinator 2y agoThey'll never do it because it means decreased profits. There are articles that appear here and elsewhere semi-frequently about how doing something simple extends battery lifetimes a huge amount, but those never get implemented in practice except perhaps for highly niche applications. Instead what usually happens is they'll then find a way to make them last the same amount of time, but with higher energy density. The "high voltage" lion cells (>4.2V end of charge) are an example of that process; they will last much longer than previous types if charged to 4.2V, but they'd rather advertise them as 4.3 or 4.35 or even 4.4V(!) and the extra capacity that gives.
- soulofmischief 2y agoA lot of energy research is speculative and it can take decades for research to go from the lab to the consumer. This finding, however, specifically integrates with existing infrastructure; no new, unproven technology is needed, we just simply juice the batteries more during initial charge. If it pans out after extensive testing, we can see this technique hitting the market within 2 years.
- mort96 2y agoHm this doesn't seem to be panning out in practice. Loads of devices have grown "optimize charging" style features in the recent-ish past, and those features are explicitly there to extend battery longevity (at the expense of consumer convenience even!). Clearly, the market forces are more complex than "short battery lifetime = more frequent device upgrades = profit" (although that effect is certainly *a part of& the equation).
- deleted 2y ago[deleted]
- vkou 2y ago
- fencepost 2y agoTL;DR the high current causes a layer on the negative electron to form a bit differently (and obviously faster), previously it was thought that a slower initial charge led to better formation. This is a process tweak incremental improvement, not anything truly fundamental.
- hn_throwaway_99 2y ago> This is a process tweak incremental improvement, not anything truly fundamental. Regardless of whether this is a "process tweak" or something "truly fundamental", a 50% increase in battery lifespan would be huge, regardless. The conspiracy theorist in me though thinks that a lot of consumer electronics makers wouldn't like this, because lower battery capacity has to be a big driver of upgrade cycles. I'm guessing a lot of folks are similar to me: these days, somewhere in the 2-3 year mark my cell battery capacity starts degrading noticeably. My phone otherwise works great, and I certainly don't need the features in the latest model phone, and of course I know I can pay for just a battery replacement, but sometimes I think "Well, if I need to replace the battery, I might as well get a new phone - it's got <some feature that is marginally better but that I'm now convincing myself is super cool to justify my not-really-necessary upgrade purchase>". I think with 50% more battery lifespan I would rarely, if ever, use dwindling battery capacity as an excuse for an upgrade purchase.
- dyauspitr 2y agoI doubt it. Most electric car manufacturers offer a 8-10 full battery warranty with their vehicles. I don’t think an extra 4-5 years is something they would risk consumer satisfaction for.
- readthenotes1 2y agoRight? That's why our cell phones all have replaceable batteries and use the same charging cable!
- dyauspitr 2y ago
- userbinator 2y agois 30 times faster Faster than what? It turns out this is about the very first charge after assembly of the cell, not regular use. However, I doubt that this finding will be used much, except perhaps in applications like aerospace; it is in manufacturer's economic interests that their products have short lives. Edit: looks like as usual, comments that expose the truth get buried ;-)
- thesh4d0w 2y agoJust 2 paragraphs down, it's very clearly explained: > giving batteries this first charge at unusually high currents increased their average lifespan by 50% while decreasing the initial charging time from 10 hours to just 20 minutes.
- markdown 2y ago> decreasing the initial charging time from 10 hours to just 20 minutes That's insane
- hn_throwaway_99 2y agoThe amount of time it takes to charge a battery is inversely proportional to the current - there is nothing surprising about the fact that using more current charges a battery in less time. What is surprising about this research is that one small process change (doing that initial charge with a high current instead of a low one) resulted in a 50% increase in the total lifetime of the battery. That's the part that feels like "free money" in that, if accurate, this means battery producers could produce batteries with much longer lifespans without any fundamental change to their battery architecture or chemistry.
- bluGill 2y agoIT is free money in another way for manufactures as well: since they battery doesn't have to sit in their factory/fixtures for as long getting that initial charge there is a lot less in process batteries in their factory, less charging fixtures and jigs to buy... This process savings is often invisible until an accountant looks close and then they discover it is massive.
- dzhiurgis 2y agoWhats a battery lifespan? Is it capacity degradation or random failure? If discovery slows down capacity degradation, but now your EV battery is 100x more likely spontaneously fail ($$$) - it's not really an improvement. Maybe ok for consumer device tho.
- earleybird 2y agoThere are two lifespans. The shelf life and the number of charge cycles (less of a span perhaps) where you charge to 100% and discharge to near 0. If you keep your charge/discharge to 80/20 then your battery life is limited primarily by the shelf life. eg. keep your Nissan Leaf in the 20-80% state of charge range and it will probably last 20 years, DC fast charge it every time to 100% you'll probably only get 2000 cycles (5-7 years) out of it.
- gibolt 2y agoIt isn't that black and white, plus the Leaf without active battery temperature management isn't a representative example. Modern Tesla's show fairly similar long-tail degradation that is nearly identical for cars that strictly home charge and those that only supercharge (based on customer vehicle tracking). Most will level off at 85-90% of original capacity.
- anonymous247 2y ago[flagged]
- rkagerer 2y agoTLDR: During a battery's initial "formation" charge, some of the lithium deactivates, forming a squishy, protective layer around the negative electrode, called the solid electrolyte interphase (SEI). Today, manufacturers typically do a slow formation charge, during which about 9% of the lithium is lost to the SEI. It was thought this was needed to form a robust layer. But the researchers found at the higher initial charge currents used in this study, 30% becomes SEI - so you loose some battery capacity (for a given amount of lithium), but wind up with a beefier protective layer on your electrode and better longevity across subsequent charge cycles.
- bluSCALE4 2y agoAnd how long does it take to achieve this 9% layer?
- rkagerer 2y agoFrom the article it sounds like 10 hours, which is reduced to 20 minutes using the higher current.
- user_7832 2y ago> so you loose some battery capacity (for a given amount of lithium), but wind up with a beefier protective layer on your electrode and better longevity across subsequent charge cycles If there's a capacity tradeoff, why not use a slightly modified chemistry (like how LTO is, for example)? Though I guess this article was more about the existence of the phenomenon rather than using it.
- jostmey 2y agoI’m confused… Is this just a prediction or has it been experimentally verified?
- starky 2y agoFrom having worked a bit in the industry I'm a bit skeptical about this study, I've definitely seen studies and experiments that used different initial charging conditions that would have shown better fade performance if this was true. Not to mention, how much does the increased SEI change the impedance of the cell (thus reducing the subsequent charge speed) and the capacity available.
- m463 2y agoWasn't supercharging EVs a lot frowned upon at first, but later found out not to negatively affect battery life as much? https://electrek.co/2023/08/29/tesla-battery-longevity-not-affected-frequent-supercharging-study/ https://electrek.co/2023/08/29/tesla-battery-longevity-not-a...
- starky 2y agoHow long does supercharging take? Even at 30 minutes, that is only a rate of 2C which is not that extreme for some cell chemistries as long as temperature is controlled.
- jazzyjackson 2y agoWatching the comparison of a cyber truck vs a ram 2500, supercharging at 250kw took an hour and a half https://youtu.be/HIs8zudJFzg https://youtu.be/HIs8zudJFzg
- Roark66 2y agoThis may be so in Teslas that have quite robust heat management. It definitely doesn't apply to many other brands. Anyone who knows anything about lithium batteries and sees temperatures at which fast charging is done will not believe any of the longevity claims. It is up to 55C during charging and during subsequent driving on a motorway it can take half an hour for this temperature to drop below 40C (look up BYD Seal 1000 mile challenge on YouTube for an example - all above st 9C ambient).
- 2y ago
- mleonhard 2y agoSince a good SEI layer on the electrode is important, couldn't they put the layer on the electrode before assembling the battery? Then they could make the layer's shape more even.
- Euphorbium 2y agoI remember a recent paper that found that charging at double the current, but at 2khz frequency square wave basically eliminated battery degradation.
- i80and 2y agoThere appear to be two recent papers on this phenomenon: 2021: low frequency pulsed charging: https://vbn.aau.dk/ws/portalfiles/portal/451327786/C5.pdf https://vbn.aau.dk/ws/portalfiles/portal/451327786/C5.pdf 2024: high frequency pulsed charging https://onlinelibrary.wiley.com/doi/10.1002/aenm.202400190 https://onlinelibrary.wiley.com/doi/10.1002/aenm.202400190 Not up to really reading them right now, but this is a pretty neat area of research!
- firefox2025 2y ago[dead]
- solarkraft 2y agoRule of thumb: It’s a battery innovation/“breakthrough”, so the chance it’ll reach the market any time soon is slim.
- webprofusion 2y agoAs battery innovations go, this one seems relatively trivial to implement? The bigger problem is probably shipping battery packs that are sitting fully charged for a long time before the customer gets them, depending on the chemistry.
- jillesvangurp 2y agoA more productive way to think about this is in terms of technology readiness levels: https://en.wikipedia.org/wiki/Technology_readiness_level https://en.wikipedia.org/wiki/Technology_readiness_level There's a specialized version of this called BC/RL for battery research as well. This particular article sits about half way the scale. This was an actual study, with actual batteries, that reportedly actually had improved life spans. So dismissing that with a hand wavy this is all just academic nonsense doesn't quite fly here. But of course from here to production is indeed quite a journey. I bet a lot of companies with active investment in battery R&D are paying attention and might be going to try to replicate the success. Also worth noting that if you only pay attention to the stuff that is at the highest levels, you basically miss out on new things until they are old news. For example if you have been dismissing solid state batteries, you might have missed the news that they are being used in products now.
- keepamovin 2y agoProbably burns in the microstructure making it more stable to filament formation, like the way high voltage electricity etches wood.
- sharpshadow 2y agoI was able to revive lithium batteries which have been discharged to much and didn’t charge by connecting them to a fully charged one for a couple of seconds.
- xxs 2y agoThat's all about the electronics inside the battery, rather than the chemistry. You can force feed them with any power supply, ignoring the 'standard' BMS.
- Reubachi 2y agothis is the equivilent of using a car and it's alternator (generator) to jump another car with a alt/generator you know is bad. 'risking it for the biscuit"