New charging algorithm could double life of li-ion batteries

[Alfonso Maruccia]

Forward-looking: Despite being one of the most practical and effective technologies for storing and delivering electric energy, lithium-ion batteries have started to show their limits. Scientists are looking for alternative materials and energy storage solutions, but researchers now say they can make li-ion batteries work better and for extended periods.

A team of European researchers from Helmholtz-Zentrum Berlin (HZB) and Humboldt University in Berlin developed an alternative charging solution to make li-ion batteries last much longer than they do now. The study shows that batteries become more resilient and retain a higher energy capacity after hundreds of discharge-recharge cycles by changing how the charger delivers current to electrolyte materials.

Lithium-ion batteries are compact, robust energy containers that have become ubiquitous. Electric vehicles and electronic devices rely on them, but their capacity gradually degrades as electrolytes pass through the membrane that separates the anode and cathode. The best commercial-grade lithium-ion batteries available use electrodes made of a compound known as NMC532 and graphite, and they provide a service life of up to 8 years.

Conventional charging uses a constant current (CC) of external electric energy. The study analyzed what happened to battery samples when using the CC charging and discovered that the anode's solid electrolyte interface (SEI) was "significantly thicker." Furthermore, they found more cracks in the NMC532 and graphite electrode structures.

A thicker SEI and more cracks in the electrodes mean a significant loss of capacity for the li-ion batteries. So, the researchers developed a charging protocol based on pulsed current (PC). After charging the batteries with the new PC protocol, the team discovered that the SEI interface was much thinner, and the electrode materials underwent fewer structural changes.

The team used two of Europe's leading synchrotron facilities for particle acceleration, "BESSY II" and "PETRA III," to conduct the pulsed-current recharging experiments. They discovered that PC charging promotes the "homogeneous distribution" of lithium ions in the graphite, which reduces mechanical stress and cracking in the graphite particles. The protocol can also suppress structural degradation in the NMC532 cathode.

The study shows that high-frequency pulsing with square-wave current produced the best results. The tests show that PC charging can double the service life of commercial li-ion batteries with an 80 percent capacity retention.

"Pulsed charging could bring many advantages in terms of the stability of the electrode materials and the interfaces and significantly extend the service life of batteries," said TU Berlin professor Dr. Julia Kowal, co-author of the study.

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New charging algorithm could double life of li-ion batteries

 

[Theinsanegamer]

Sounds promising, especially if it can extend current tech. Getting 8-9 years out of a phone battery instead of 4-5 sounds great.

 

[WhiteLeaff]

Well, it would increase by 20x using LTO batteries, for off grid it would be the ideal technology

 

[Dreadcthulhu]

That is pretty nifty, though I wonder how it would interact with electric cars using other battery chemistries - lithium iron phosphate batteries are becoming a lot more common, for example, and some Chinese EVs are now rolling out with sodium-ion batteries. Though I suppose "charging style" could be added as something the charger and car communicate to each other for different kinds of batteries.

 

[kiwigraeme]

When I was on the road 25 years ago, I used to re-charge AA alkaline batteries for my sony walkman . with some cheap chinese charger. Actually worked ok, was super careful , had it in a safe space, never left it unattended. So imagine though not necessary, with right tech you probably could charge an Alkaline pretty well.
Also when I used rechargeables , the smarter stations , could refresh to some degree , recover dead batteries to some degree. So not surprising still learning stuff. Also with greater knowledge it works both ways , ie can physically tweak the battery build to optimise this.

Plus though people here hate telemetry, the likes of Tesla, Apple must have a huge amount of knowledge. I'm sure Apple knows how to tank your battery

 

[ScottSoapbox]

The author (or his AI helper) means ubiquitous, not obsequious.

 

[ScottSoapbox]

Double the charges with a new (non-exotic) charger type is quite a breakthrough. Sign me up.

 

[whateversa]

I'd love to extend the lifespan of my LFP solar batteries... How do we get this up and running on an Deye inverter? I'd also like longer life from my phone - until security updates end.

 

[envirovore]

When I was on the road 25 years ago, I used to re-charge AA alkaline batteries for my sony walkman . with some cheap chinese charger. Actually worked ok, was super careful , had it in a safe space, never left it unattended. So imagine though not necessary, with right tech you probably could charge an Alkaline pretty well.
Also when I used rechargeables , the smarter stations , could refresh to some degree , recover dead batteries to some degree. So not surprising still learning stuff. Also with greater knowledge it works both ways , ie can physically tweak the battery build to optimise this.

Plus though people here hate telemetry, the likes of Tesla, Apple must have a huge amount of knowledge. I'm sure Apple knows how to tank your battery

Ah, I remember the old alkaline chargers. Had one of those for my walkman/diskman growing up.

Looking back on it I suppose it was sorta sketchy tech, but worked better than Ni-Cad rechargables at the time.

 

[Endymio]

That is pretty nifty, though I wonder how it would interact with electric cars using other battery chemistries - lithium iron phosphate batteries are becoming a lot more common, for example

According to the research, pulse charging would benefit any battery chemisty based on graphite anodes, so LiFePo batteries would qualify as well.

One interesting fact I noted from the source paper itself (not mentioned in any of the popular articles about it) is that a pulse frequency of 2khz+ is required for maximum benefit. In practice, this would mean slightly less efficient charging due to inductive losses ... not a big deal for a phone or laptop, but moreso for EVs.

 

[Theinsanegamer]

According to the research, pulse charging would benefit any battery chemisty based on graphite anodes, so LiFePo batteries would qualify as well.

One interesting fact I noted from the source paper itself (not mentioned in any of the popular articles about it) is that a pulse frequency of 2khz+ is required for maximum benefit. In practice, this would mean slightly less efficient charging due to inductive losses ... not a big deal for a phone or laptop, but moreso for EVs.

I think a lot of EV owners would trade slightly less effective charging if it meant doubling the life expectancy of the car's battery, considering what a major failure point that part is.

 

[mountains]

I have long wondered why EV cars like Tesla, to promote long battery life, have that built-in protection where you don't over charge (mostly you only charge to around 80 percent or so, if I recall) or under charge your battery, yet cell phones happily let you charge to 100 percent, or down to 0%.

I appreciate the idea behind this research (new ways to look at recharging). I wonder how willing device makers will be to implement tech that makes their devices last longer.

 

[Dreadcthulhu]

I have long wondered why EV cars like Tesla, to promote long battery life, have that built-in protection where you don't over charge (mostly you only charge to around 80 percent or so, if I recall) or under charge your battery, yet cell phones happily let you charge to 100 percent, or down to 0%.

I appreciate the idea behind this research (new ways to look at recharging). I wonder how willing device makers will be to implement tech that makes their devices last longer.

Part of it is that people expect cars to last a long time, and would not buy a car that does not have long lasting batteries, especially with how expensive auto batteries are; also US law requires EV batteries to come with 8 year 100k mile warranties, and auto makers really don't want to deal with warranty claims, again because EV batteries are so expensive. People do not expect phones to last nearly as long, and there are not nearly as many pesky warranty rules to deal with, so phone makers end up selling more phones by having them die early than they think they would get by marketing more durable phones.

 

[DanteSmith]

What you forget to mention is that doubling the life comes in exchange for charging speed.

 

[Endymio]

What you forget to mention is that doubling the life comes in exchange for charging speed.

Nope. The algorithm uses a 50% duty cycle, with the high pulses at 200% of normal charging current. Average power delivery to the battery is unchanged.

 

[AdamNovagen]

What you forget to mention is that doubling the life comes in exchange for charging speed.

Nope. The algorithm uses a 50% duty cycle, with the high pulses at 200% of normal charging current. Average power delivery to the battery is unchanged.

This, and frankly, even if it DID reduce the charging speed I'd be fine with it since the majority of super-giga-ultra-fast-zip-zap-zoop charging methods tend to hammer battery life anyway, which makes me avoid them. I'd gladly trade having to wait 1hr instead of 30min to recharge my phone if it meant I could continue getting useful battery life for an extra 3-5 years, some of us don't want to spend hundreds of dollars to prematurely replace a device because we're impatient.

 

[mattferg]

Well, it would increase by 20x using LTO batteries, for off grid it would be the ideal technology

LFP would be the better choice - more of a middle ground between LTO and NMC.

 

[DanteSmith]

Nope. The algorithm uses a 50% duty cycle, with the high pulses at 200% of normal charging current. Average power delivery to the battery is unchanged.

So has this been tested with the ultrafast chargers used commercially in EVs or just individual cells? Is it feasible to double the voltage? I don't think so.

Maybe it makes sense for those who charge slowly at home.

 

[MorbidEel]

I have long wondered why EV cars like Tesla, to promote long battery life, have that built-in protection where you don't over charge (mostly you only charge to around 80 percent or so, if I recall) or under charge your battery, yet cell phones happily let you charge to 100 percent, or down to 0%.

I appreciate the idea behind this research (new ways to look at recharging). I wonder how willing device makers will be to implement tech that makes their devices last longer.

Some phones have that as well for example the Samsung A25. I assume the higher end models have it as well

 

[Vanderlinde]

yet cell phones happily let you charge to 100 percent, or down to 0%.

its never charged up to 100% - we see 100% but software wise it might just have bin 85%.

Full depletion does not work either. You can turn your phone on and off for 50 times even.

 

[mountains]

its never charged up to 100% - we see 100% but software wise it might just have bin 85%.

Full depletion does not work either. You can turn your phone on and off for 50 times even.

So are you saying that the effect I am referring to is already happening, but it is just not transparent to the user?

 

[Robby-san]

What you forget to mention is that doubling the life comes in exchange for charging speed.

Any idea how much the charge rate declines? I had thought the same thing.

 

[Endymio]

So has this been tested with the ultrafast chargers used commercially in EVs or just individual cells? Is it feasible to double the voltage? I don't think so.

An excellent point. It hasn't been tested anywhere except within this one study. And doubling the charging voltage may not be feasible: it might require instead that such batteries be redesigned with a lower internal resistance to allow higher charging currents without voltage increases.

 

[RaXelliX]

Normally is dismiss these battery related articles because nothing ever comes of it but this is different.
As opposed to developing a new complex and expensive battery it tries to solve the degradation problem from the charger side. And if it works out then getting a new charger is all that's needed.

 

[Capt Obvious]

AI written content for clicks... Brilliant... What IS the algorithm? Don't just say there is one and then talk about the characteristics of lithium batteries. Tell us what the algorithm is so we can determine if it is something we'd want to try...