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"Because the car would still rely on its regular rechargable lithium-ion battery most of the time and would switch to the aluminum-air battery as a backup only

"Because the car would still rely on its regular rechargable lithium-ion battery most of the time and would switch to the aluminum-air battery as a backup only if the lithium-ion battery ran out, and because most car trips are 50 kilometres or less, Alcoa estimates the aluminum-air batteries would only need to be changed about once a year." This is a chemical battery with very limited lifespan. Additionally without any details on recycling of used batteries "green" qualities of this battery are suspect.

ianbicking 12y ago
> The batteries are "charged" not from the electrical grid, but from hydroelectric power generated at Alcoa's smelter in Baie-Comeau, Que., Tzidon said. When they are full-charged, they are thick, heavy panels made mostly of aluminum. In a sense it's green if they are produced from green energy, like hydroelectric power in remote Canada. In that case it's not just green because it's hydroelectric, but also because it's inconveniently located hydroelectric it's not displacing more productive uses of the electricity. Maybe geothermal energy in Iceland would be another option.
xur17 12y ago
This is actually a pretty ingenious way of solving the distance issue for electric cars. As long as replacing the backup isn't egregiously expensive, I don't see why it wouldn't work. This solves the last issue I have with electric cars (other than cost).
dojomouse 12y ago
It's highly recyclable. Aluminium oxide (the result of the reaction in the battery) is one of the feedstocks for industrial aluminium smelting. Recyclable isn't necessarily the same as 'efficient' or 'a good idea' though. It's energy intensive (haven't checked the efficiency of 'recharging'), and additionally has, as a byproduct, massive amounts of CO2 even before considering CO2 emitted in generating the electricity required for the smelting process. I can't see how that a single use battery like this (which also needs swap infrastructure) has any net advantage over the rechargable swappable packs + fast chargers as Tesla use. Maybe it could have applications in aerospace where existing lithium ion cells don't have sufficient energy density to even come close to a viable solution. But you'd want to compare it to other 'single use' options like synfuel.
- JoeAltmaier 12y ago
  Maybe if the aluminum could be packaged as a liquid or a gel, it could be pumped in and out like gas.
  - rpedela 12y ago
    Something that requires 1,221 F (660.3 C) doesn't seem like something you would want to sit on or pump without serious protection.
    - pjc50 12y ago
      Slurry, not molten. This (aluminium powder suspended in a liquid) was considered as a rocket fuel at one point.
      - trhway 12y ago
        Russian super-sonic solid fuel anti-ship missiles burn aluminum based fuel in their ramjet engines :)
      - lotsofmangos 12y ago
        The Space Shuttle solid rocket boosters were basically just oxidiser and aluminium powder.
  - bane 12y ago
    Just use aluminum powder or prills. Bonus you get a huge surface area so the reactions happen fast.
    - JoeAltmaier 12y ago
      and just dump the alumina result out the tailpipe - its just ceramic dust. And refill with new powder. So it becomes very much like the process of gasoline fueling.
      - 12y ago
deleted 12y ago
[deleted]

ianbicking 12y ago

> The batteries are "charged" not from the electrical grid, but from hydroelectric power generated at Alcoa's smelter in Baie-Comeau, Que., Tzidon said. When they are full-charged, they are thick, heavy panels made mostly of aluminum. In a sense it's green if they are produced from green energy, like hydroelectric power in remote Canada. In that case it's not just green because it's hydroelectric, but also because it's inconveniently located hydroelectric it's not displacing more productive uses of the electricity. Maybe geothermal energy in Iceland would be another option.

xur17 12y ago

This is actually a pretty ingenious way of solving the distance issue for electric cars. As long as replacing the backup isn't egregiously expensive, I don't see why it wouldn't work. This solves the last issue I have with electric cars (other than cost).

dojomouse 12y ago

It's highly recyclable. Aluminium oxide (the result of the reaction in the battery) is one of the feedstocks for industrial aluminium smelting. Recyclable isn't necessarily the same as 'efficient' or 'a good idea' though. It's energy intensive (haven't checked the efficiency of 'recharging'), and additionally has, as a byproduct, massive amounts of CO2 even before considering CO2 emitted in generating the electricity required for the smelting process. I can't see how that a single use battery like this (which also needs swap infrastructure) has any net advantage over the rechargable swappable packs + fast chargers as Tesla use. Maybe it could have applications in aerospace where existing lithium ion cells don't have sufficient energy density to even come close to a viable solution. But you'd want to compare it to other 'single use' options like synfuel.

JoeAltmaier 12y ago
Maybe if the aluminum could be packaged as a liquid or a gel, it could be pumped in and out like gas.
- rpedela 12y ago
  Something that requires 1,221 F (660.3 C) doesn't seem like something you would want to sit on or pump without serious protection.
  - pjc50 12y ago
    Slurry, not molten. This (aluminium powder suspended in a liquid) was considered as a rocket fuel at one point.
    - trhway 12y ago
      Russian super-sonic solid fuel anti-ship missiles burn aluminum based fuel in their ramjet engines :)
    - lotsofmangos 12y ago
      The Space Shuttle solid rocket boosters were basically just oxidiser and aluminium powder.
- bane 12y ago
  Just use aluminum powder or prills. Bonus you get a huge surface area so the reactions happen fast.
  - JoeAltmaier 12y ago
    and just dump the alumina result out the tailpipe - its just ceramic dust. And refill with new powder. So it becomes very much like the process of gasoline fueling.
    - 12y ago

deleted 12y ago

[deleted]