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Aluminum battery from Stanford offers safe alternative to conventional batteries

news.stanford.edu

11–20 of 31 posts

Re: Aluminum battery from Stanford offers safe alternative to conventional batteries

#11
post #7

Those batteries have a lower energy density and power than the current li-ions, so you won't be seeing them in a phone, laptop or a car. At the same time they are significantly cheaper to make and durable, which might make them a good solution for home energy storage - paired with panels for example.

Where does the article discuss the energy density?

I'm skeptical myself based on the number/style of claims they make, but I can't see any details.

Re: Aluminum battery from Stanford offers safe alternative to conventional batteries

#12
post #7

Those batteries have a lower energy density and power than the current li-ions, so you won't be seeing them in a phone, laptop or a car. At the same time they are significantly cheaper to make and durable, which might make them a good solution for home energy storage - paired with panels for example.

Where does the article discuss the energy density? I'm skeptical myself based on the number/style of claims they make, but I can't see any details.

  "Our battery produces about half the voltage of a typical lithium battery," he said. "But improving the cathode material could eventually increase the voltage and energy density. Otherwise, our battery has everything else you'd dream that a battery should have. [..]

Re: Aluminum battery from Stanford offers safe alternative to conventional batteries

#13
post #7

Those batteries have a lower energy density and power than the current li-ions, so you won't be seeing them in a phone, laptop or a car. At the same time they are significantly cheaper to make and durable, which might make them a good solution for home energy storage - paired with panels for example.

Even at only half the power I'd want one in my phone. It's easy enough to charge a phone if it only take a few minutes. It's the hours that it currently takes that makes frequent charging intolerable.

Re: Aluminum battery from Stanford offers safe alternative to conventional batteries

#14
post #7

Those batteries have a lower energy density and power than the current li-ions, so you won't be seeing them in a phone, laptop or a car. At the same time they are significantly cheaper to make and durable, which might make them a good solution for home energy storage - paired with panels for example.

Even at only half the power I'd want one in my phone. It's easy enough to charge a phone if it only take a few minutes. It's the hours that it currently takes that makes frequent charging intolerable.

There are a bunch of options for that with li-ions too. For example Qualcomm claims that 3300mAh battery gets to 60% in 30 minutes with Quick Charge 2.0. Granted, that's not 'a couple of minutes', but still quite amazing.

Re: Aluminum battery from Stanford offers safe alternative to conventional batteries

#15

> "Our rechargeable aluminum battery generates about two volts of electricity." Now that's really good news. Stick it together with a 1.5V regulator inside an AA cell and never have problems with devices not accepting the 1.2V of a typical NiMH cell.

Alkaline batteries start at 1.5 V, but they do not stay there. They are 1.4 V when they have discharged by about 10%. When they have discharged by around 30%, they are at 1.3 V. When they have discharged by around 60%, they are at 1.2 V. By 90%, they are down to 1.1 V. By 95%, they are down to around 1.0 V, and they pretty much nosedive from there.

NiMH also drop as they are discharged, but the curve flattens out for much of its range. A good charger should charge an NiMH to around 1.4 V. After about 10% discharge, it will be down to 1.3 V. By 30% discharge it will be around 1.25 V, and it stays around that until around 80% discharge. From 80% to 90% it will drop to around 1.2 V, and from there it will drop to around 1.0 V at around 99% discharge, and then it falls off a cliff.

Devices designed for alkaline batteries are designed to run fine on anything from around 1.0 or 1.1 V through 1.5 V, and so should be fine with NiMH, except if they have a battery remaining indicator that is hard wired to assume alkaline it won't give accurate estimates for NiMH because of the different shapes of the discharge curves.

Re: Aluminum battery from Stanford offers safe alternative to conventional batteries

#16

Likely as a direct response to the hype of this article (a few thousand comments in the related reddit thread), Elon tweeted: Battery "breakthroughs" need to state power *and* energy density (not the same thing), plus how long they last. They usually fail on energy. https://twitter.com/elonmusk/status/585185843649716225

Exactly. Energy density is a real bugaboo. Lemons with zinc in them are really economic and safe batteries, you can cut them, mash them, and literally make lemonade out of them. They grow on trees and just simple to make zinc strips. Except they can't power an LED for longer than about a minute. Admittedly they are not rechargable.

Which is not to slam the investigation into new (or rediscovered) battery chemistries. Just that the article goes out of its way to paint this as a huge break through, which it really isn't.

Re: Aluminum battery from Stanford offers safe alternative to conventional batteries

#17
post #12

Earlier quoted context omitted.

Where does the article discuss the energy density? I'm skeptical myself based on the number/style of claims they make, but I can't see any details.

"Our battery produces about half the voltage of a typical lithium battery," he said. "But improving the cathode material could eventually increase the voltage and energy density. Otherwise, our battery has everything else you'd dream that a battery should have. [..]

Voltage is not the same as energy density. It's one component of it certainly, but not nearly enough by itself to tell you anything.

Re: Aluminum battery from Stanford offers safe alternative to conventional batteries

#18

Likely as a direct response to the hype of this article (a few thousand comments in the related reddit thread), Elon tweeted: Battery "breakthroughs" need to state power *and* energy density (not the same thing), plus how long they last. They usually fail on energy. https://twitter.com/elonmusk/status/585185843649716225

Or at least state the voltage of each cell, if it's going to be 1.2v per cell (replacing AA/AAA batteries) it's hardly something that can ever replace current LiX batteries in consumer electronics.

Re: Aluminum battery from Stanford offers safe alternative to conventional batteries

#19
post #14

Earlier quoted context omitted.

Even at only half the power I'd want one in my phone. It's easy enough to charge a phone if it only take a few minutes. It's the hours that it currently takes that makes frequent charging intolerable.

There are a bunch of options for that with li-ions too. For example Qualcomm claims that 3300mAh battery gets to 60% in 30 minutes with Quick Charge 2.0. Granted, that's not 'a couple of minutes', but still quite amazing.

I think someone did the testing and it's lower than that.

Re: Aluminum battery from Stanford offers safe alternative to conventional batteries

#20
post #7

Those batteries have a lower energy density and power than the current li-ions, so you won't be seeing them in a phone, laptop or a car. At the same time they are significantly cheaper to make and durable, which might make them a good solution for home energy storage - paired with panels for example.

Where does the article discuss the energy density? I'm skeptical myself based on the number/style of claims they make, but I can't see any details.

The linked article does not provide details. However, Engadget has an article on this that offers this tidbit:

"The aluminum-ion cell isn't perfect (yet) as it can only produce about 2 volts, far less than the 3.6V that lithium-ion an muster. Plus aluminum cells only carry 40 watts of electricity per kilogram compared to lithium's 100 to 206 W/kg power density."

http://www.engadget.com/2015/04/06/stanfords-battery-charges...

Sidenote: I suspect that passage means W-hours per Kg vs. W per Kg because typical Li-ion does have an energy density in the 100-200 W-h/kg range. See the chart in this Nature article:

http://www.nature.com/news/the-rechargeable-revolution-a-bet...

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