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Comment by jws | Hacker News Reader

… store 10 times more power…

…after 150 charge/discharge cycles, is also five times more effective than any lithium-ion battery currently on the market

Is this the positive way of saying they lose half of their capacity after 150 cycles?

Ten times capacity is certainly a game changer for everything from wireless ear buds to electric cars, but * week-long smartphone batteries within a couple of years* sounds optimistic for something that is fabricated at the atomic level.

What exists on the market now that is designed at the atomic level and mass produced?

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Silicon chips?

FWIW, the holes are created using 'a chemical oxidation process' -- which I suspect can be done on a large scale. If someone can read the actual paper and check out how they made the holes, though, that'd be cool.

Usual Li-Ion batteries get a bit over 1000 cycles, so if this is 10 times more power, it provides more power for 150 cycles than a normal Li-Ion for its lifetime.

No they don't. Degradation of lithium-ion batteries is a function of temperature, time since manufacture and charge level rather than charge/discharge cycles. If you keep the battery cool and don't discharge it below 20% or so, it will last a very long time. If you keep it hot and constantly do full discharges, it will be dead very quickly.

Since we can't control the discharging condition and rate most of the time, and today's design often stick the battery to a heat source.

Since I am no expert in chemistry, I rather point to an article here: http://batteryuniversity.com/learn/article/how_to_prolong_li...

Basically, the capacity degrades over charge/discharge cycles. The reason is pretty simple to explain, because you can't really operate the batteries in perfect condition, it always get worse while discharging and charging it.

The other conclusion of that report points to the fact that depth of discharge is related too. So instead of using it from 100% to 0% (actually 0% doesn't mean nothing left, it just means the phone can't operate on that voltage), recharge as soon as you have a plug.

You need to discharge them really slowly to if you want to keep them cool. So, there is a link between discharging and temperature assuming a high power device.

Liquid cooling for batteries wouldn't be worth it in earbuds, but it probably would in an electric car.

Which is why battery packs in Tesla cars are liquid-cooled.

Tesla battery's still get hot, just not as hot as they would get with more limited cooling.

Small aside here:

Li-ion tech is a major pain in my ass. Storing them discharged damages them. Storing them charged damages them. Keeping them topped off damages them. Fully discharging them damages them but your battery might have a protection circuit so don't worry about it. But it might not so worry about it. You've apparently got to store them half-charged for optimal lifetime but there is a lot of wrong information out there.

I think I want to power my devices with disposables, thanks :-)

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