7 ms·

Aluminum battery from Stanford offers safe alternative to conventional batteries

73 points by msoad 12y ago

mschuster91 12y ago
> "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.
- tzs 12y ago
  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.
deeviant 12y ago
I wish they bothered to state the expected energy density of these batteries. The fact that they didn't leads me to believe it's quite low compared to something like li-ion.
- msoad 12y ago
  I believe this battery's density is not super impressive that they didn't mention in in the article and the title of the article is about it's safety rather that fast charging time or capacity
  - userbinator 12y ago
    Safe and "high-performance" as they claim are somewhat opposing; to a battery that can be discharged at high currents, with a high energy density, there's no difference between dissipating that energy in the usual load it's powering and through a short circuit of equivalent resistance. Even if the battery itself doesn't catch fire or heat up, all that energy still has to go somewhere.
    - nsrango 12y ago
      Safe here doesn't mean "can't kill you". Instead it means this chemistry doesn't exhibit thermal runaway (http://batteryuniversity.com/learn/article/lithium_ion_safety_concerns http://batteryuniversity.com/learn/article/lithium_ion_safet...)
mikeyouse 12y ago
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 https://twitter.com/elonmusk/status/585185843649716225
- marcosdumay 12y ago
  Stating the all the qualities is a good thing. But don't think all three must be good. Any two are enough to make a very successful battery.
- ChuckMcM 12y ago
  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.
  - stcredzero 12y ago
    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. Electrodes can literally be had for pennies!
- dogma1138 12y ago
  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.
  - danmaz74 12y ago
    The article states the voltage to be 2v.
c2h5oh 12y ago
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.
- allworknoplay 12y ago
  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.
  - c2h5oh 12y ago
    "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. [..]
    - mark-r 12y ago
      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.
  - onejoe 12y ago
    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-in-one-minute/ 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-better-battery-1.14815 http://www.nature.com/news/the-rechargeable-revolution-a-bet...
tankerdude 12y ago
With something like that, something like the a battery at home could become viable. Even with the lower energy density, it has a few properties that are really great if it proves to be correct: no degradation on cycles, inexpensive and reduced fire hazard. So imagine the Tesla Home Battery that would currently be double the size, at a lower price point, and could theoretically last a decade or two? So there are definitely commercial options if it ever proves truly viable and can be easily manufactured.
nikanj 12y ago
Why do we see a new "super battery" article every two weeks or so?
IkmoIkmo 12y ago
Ugh, getting tired of all these articles that may not be untrue, but ought to live in science journals, properly read as experiments with new battery tech that could deliver to consumers 5-10 years later, rather than get posted on social media as if they're consumer-grade product launches. I've read tens of breakthroughs in batteries and solar and so on, in channels that had no interest in the science behind it. HN is mostly the exception to the rule. Anyway, is there a battery guy that could explain to the rest of us what the state of battery innovation is like the next 10 years? Is it realistic to expect some big leaps? I really don't know what to expect and it'd be awesome to get some insider insights as to what kind of consumer-grade products we may see the next decade :) Thanks in advance.
- algirau 12y ago
  Battery innovation is actually bottle-necked by the fact that over 90% of all anode materials are produced in China. So global adoption is ultimately dictated if manufacturing in China follows suit. Unlike Americans, where we innovate with a short time horizon, China innovates and invest for generations (25-100 years). Thus, once a technology has been chose to be invested in overseas, the Chinese go "all-in". The current paradigm shift is that Chinese anode material manufacturers are switching from graphite based electrodes to silicon nanoparticle based electrodes due to the fact that silicon nanoparticles have a theoretical energy density of ~4,000mAh/g, a 10x increase when compared to graphite which is only ~350mAh/g. There has been substantial research on silicon based lithium-ion batteries in the US for the past 7 years; it is now hitting a true inflection point. This is one of the few "break-though" battery chemistries that is now entering full scale production - Panasonic is producing an 18650 cell made of silicon used by Tesla. *(see also Amprius, Envia,XG Sciences, etc.) Tl;dr battery adoption is limited by adoption by Chinese manufacturers which control over 90% of the global anode material manufacturing. Silicon nanoparticles are taking over.
  - IkmoIkmo 12y ago
    Sweet, thanks! So what would that (e.g. 10x the energy density) mean for consumers in practice. Can we expect 4x the range on a car, or the lifetime on a phone? Is this something we'll see around 2020, later, earlier?

73 points by msoad 12y ago

> "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.

tzs 12y ago
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.

deeviant 12y ago

I wish they bothered to state the expected energy density of these batteries. The fact that they didn't leads me to believe it's quite low compared to something like li-ion.

msoad 12y ago
I believe this battery's density is not super impressive that they didn't mention in in the article and the title of the article is about it's safety rather that fast charging time or capacity
- userbinator 12y ago
  Safe and "high-performance" as they claim are somewhat opposing; to a battery that can be discharged at high currents, with a high energy density, there's no difference between dissipating that energy in the usual load it's powering and through a short circuit of equivalent resistance. Even if the battery itself doesn't catch fire or heat up, all that energy still has to go somewhere.
  - nsrango 12y ago
    Safe here doesn't mean "can't kill you". Instead it means this chemistry doesn't exhibit thermal runaway (http://batteryuniversity.com/learn/article/lithium_ion_safety_concerns http://batteryuniversity.com/learn/article/lithium_ion_safet...)

mikeyouse 12y ago

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 https://twitter.com/elonmusk/status/585185843649716225

marcosdumay 12y ago
Stating the all the qualities is a good thing. But don't think all three must be good. Any two are enough to make a very successful battery.
ChuckMcM 12y ago
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.
- stcredzero 12y ago
  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. Electrodes can literally be had for pennies!
dogma1138 12y ago
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.
- danmaz74 12y ago
  The article states the voltage to be 2v.

c2h5oh 12y ago

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.

allworknoplay 12y ago
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.
- c2h5oh 12y ago
  "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. [..]
  - mark-r 12y ago
    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.
- onejoe 12y ago
  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-in-one-minute/ 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-better-battery-1.14815 http://www.nature.com/news/the-rechargeable-revolution-a-bet...

tankerdude 12y ago

With something like that, something like the a battery at home could become viable. Even with the lower energy density, it has a few properties that are really great if it proves to be correct: no degradation on cycles, inexpensive and reduced fire hazard. So imagine the Tesla Home Battery that would currently be double the size, at a lower price point, and could theoretically last a decade or two? So there are definitely commercial options if it ever proves truly viable and can be easily manufactured.

nikanj 12y ago

Why do we see a new "super battery" article every two weeks or so?

IkmoIkmo 12y ago

Ugh, getting tired of all these articles that may not be untrue, but ought to live in science journals, properly read as experiments with new battery tech that could deliver to consumers 5-10 years later, rather than get posted on social media as if they're consumer-grade product launches. I've read tens of breakthroughs in batteries and solar and so on, in channels that had no interest in the science behind it. HN is mostly the exception to the rule. Anyway, is there a battery guy that could explain to the rest of us what the state of battery innovation is like the next 10 years? Is it realistic to expect some big leaps? I really don't know what to expect and it'd be awesome to get some insider insights as to what kind of consumer-grade products we may see the next decade :) Thanks in advance.

algirau 12y ago
Battery innovation is actually bottle-necked by the fact that over 90% of all anode materials are produced in China. So global adoption is ultimately dictated if manufacturing in China follows suit. Unlike Americans, where we innovate with a short time horizon, China innovates and invest for generations (25-100 years). Thus, once a technology has been chose to be invested in overseas, the Chinese go "all-in". The current paradigm shift is that Chinese anode material manufacturers are switching from graphite based electrodes to silicon nanoparticle based electrodes due to the fact that silicon nanoparticles have a theoretical energy density of ~4,000mAh/g, a 10x increase when compared to graphite which is only ~350mAh/g. There has been substantial research on silicon based lithium-ion batteries in the US for the past 7 years; it is now hitting a true inflection point. This is one of the few "break-though" battery chemistries that is now entering full scale production - Panasonic is producing an 18650 cell made of silicon used by Tesla. *(see also Amprius, Envia,XG Sciences, etc.) Tl;dr battery adoption is limited by adoption by Chinese manufacturers which control over 90% of the global anode material manufacturing. Silicon nanoparticles are taking over.
- IkmoIkmo 12y ago
  Sweet, thanks! So what would that (e.g. 10x the energy density) mean for consumers in practice. Can we expect 4x the range on a car, or the lifetime on a phone? Is this something we'll see around 2020, later, earlier?