21–30 of 88 posts
Earlier quoted context omitted.
Maybe if the aluminum could be packaged as a liquid or a gel, it could be pumped in and out like gas.
Just use aluminum powder or prills. Bonus you get a huge surface area so the reactions happen fast.
"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 a…
Aluminium costs $1.80/kg: http://www.indexmundi.com/commodities/?commodity=aluminum
Alumina, the product of the aluminium-air reaction, costs ~$0.45/kg: http://www.indexmundi.com/en/commodities/minerals/bauxite_an...
The cost of refining aluminum from ore, in bulk, is therefore >$1.35/kg (otherwise, Alcoa would be cleaning up on the commodities market). The cost of a 3000km battery with 100kg of aluminium is therefore $135, or roughly 4.4 cents per kilometer, or 7 cents per mile.
That's nearly as expensive as gasoline, going off of commodity metal prices and assuming absolutely no overhead or profit margin. That's not to mention the environmental consequences of aluminium refining w.r.t. the massive amount of energy therefor required.
It's impressive tech, but it's not feasible. The Hall-Héroult process has been the subject of intense scientific scrutiny for over 100 years; everyone and their brother has tried to make it more efficient: we use aluminium for everything. Aluminium is not going to get any easier, barring massive breakthroughs in fusion energy and/or the Second Coming.
EDIT: Originally my calculated cents/mile was off by a factor of 10. However, the latter point, "nearly as expensive as gasoline", stands: it costs $250 for a gas car to drive 3000 km, at 30 mpg and $4/gallon. I didn't notice the error because I used this latter comparison rather than figuring out gasoline's cents/mile.
Doesn't so much feel like a battery than a new kind of chemical reactor that oxidizes aluminum plates. More like a "Shipstone" from Robert Heinlein's science fiction stories. You can't charge it at home, you just get it from the factory and use it up, except that it holds over an order of magnitude more power for the weight. 3000 mile range? I hope it doesn't have an easily reached state where it can release all of t…
I highly doubt it can release that much energy at once, it's a catalytic reaction that removes the oxide from the aluminum.
Doesn't so much feel like a battery than a new kind of chemical reactor that oxidizes aluminum plates. More like a "Shipstone" from Robert Heinlein's science fiction stories. You can't charge it at home, you just get it from the factory and use it up, except that it holds over an order of magnitude more power for the weight. 3000 mile range? I hope it doesn't have an easily reached state where it can release all of t…
First, it was 3000 kilometers, not miles. Second, the energy source is the oxidization of Aluminum. It takes specific preparation (e.g. thermite) to release that all at once. The contents of this "battery" are as safe as carrying around a bunch of crumpled up beer cans (very safe) and whatever the heck that solvent is (unknown). The solvent may be toxic, acidic, etc. but hopefully no worse than what's in your car bat…
"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 a…
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…
Aw come on! I'd rather see thinking two or more steps ahead from the HN crowd. If the CO2 emitted from the battery's materials came from the atmosphere in the first place, this will be a closed cycle and won't increase global CO2 levels. Supply the power to recycle the aluminum and charge the battery from renewable sources, and you're good.
The thing that might sink this is simply the sheer amount of energy needed. There is nothing inherently carbon intensive about it, though.
The reaction used by is not reversible, so the alumimium in the battery will be consumed, and the battery is not rechargeable. This is only said implicitly in the article. Thus this is more a fuel cell, using aluminium as fuel.
It's not reversible in the car, but it is reversible in an aluminum smelter. The power cell is turning the metal into aluminum oxide, which is (mostly) how we find Al in its ore form. So once you burn it out, it gets shipped back to Alcoa and they treat it like some nice clean ore and shortly turn it back into metallic Al. Which is not entirely energy-cheap, but at current prices of less than $1/lb isn't too bad. You…
Doesn't so much feel like a battery than a new kind of chemical reactor that oxidizes aluminum plates. More like a "Shipstone" from Robert Heinlein's science fiction stories. You can't charge it at home, you just get it from the factory and use it up, except that it holds over an order of magnitude more power for the weight. 3000 mile range? I hope it doesn't have an easily reached state where it can release all of t…
First, it was 3000 kilometers, not miles. Second, the energy source is the oxidization of Aluminum. It takes specific preparation (e.g. thermite) to release that all at once. The contents of this "battery" are as safe as carrying around a bunch of crumpled up beer cans (very safe) and whatever the heck that solvent is (unknown). The solvent may be toxic, acidic, etc. but hopefully no worse than what's in your car bat…
Not technically true, since almost all natural aluminum exists in oxide form, not metal. The process of turning Al2O3 into metallic Aluminum is incredibly energy intensive, requiring temperatures of over 1,000 degrees Celsius and some seriously heinous chemicals (HF among them).
Doesn't so much feel like a battery than a new kind of chemical reactor that oxidizes aluminum plates. More like a "Shipstone" from Robert Heinlein's science fiction stories. You can't charge it at home, you just get it from the factory and use it up, except that it holds over an order of magnitude more power for the weight. 3000 mile range? I hope it doesn't have an easily reached state where it can release all of t…
First, it was 3000 kilometers, not miles. Second, the energy source is the oxidization of Aluminum. It takes specific preparation (e.g. thermite) to release that all at once. The contents of this "battery" are as safe as carrying around a bunch of crumpled up beer cans (very safe) and whatever the heck that solvent is (unknown). The solvent may be toxic, acidic, etc. but hopefully no worse than what's in your car bat…
Whoops. Still and order of magnitude more than the Tesla Model S batteries.
So I've posted this before, but aluminum smelting is just plain old too hard for this to be as cheap as batteries. I mean, it's great if you're Alcoa, an aluminium smelter, but let's take a look at bulk prices: Aluminium costs $1.80/kg: http://www.indexmundi.com/commodities/?commodity=aluminum Alumina, the product of the aluminium-air reaction, costs ~$0.45/kg: http://www.indexmundi.com/en/commodities/minerals/bauxit…
How about vast solar thermal plants in the Sahara?