9 ms·

Electric car with massive range in demo by Phinergy, Alcoa

85 points by Element_ 12y ago

abalone 12y ago
Doesn't aluminum smelting use crazy amounts of electricity and emit significant greenhouse gases? So not only would we be doing that, we'd also have to ship these 220 lb modules back to the smelters every 1,000 miles? Is there anybody advocating for this besides aluminum smelters?
- lotsofmangos 12y ago
  Read article. The smelter they are using is hydroelectric and the 1000 miles air battery range is only used on long journeys as mostly the car runs on lithium.
  - fancyketchup 12y ago
    I think... you might want to read up on aluminum smelting, which converts alumina (Al2O3) into aluminum (Al). The process involves passing a large current between two graphite (carbon) electrodes via the alumina. Al2O3 + carbon => Al + CO2 Edit: I can only guess that the down votes are for not providing a source? Here you go: http://en.wikipedia.org/wiki/Aluminium_smelting http://en.wikipedia.org/wiki/Aluminium_smelting It doesn't matter if the smelter runs on fairy dust or hippie juice. Reducing aluminum oxide to aluminum produces CO2 no matter the energy source.
    - scotty79 12y ago
      It seems that you can significantly reduce carbon emissions of aluminum smelting if you use energy source that does not emit carbon dioxide. From http://aluminium.org.au/climate-change/smelting-greenhouse-performance http://aluminium.org.au/climate-change/smelting-greenhouse-p... The smelting of aluminium is a very energy intensive process – and over 80 per cent of smelting greenhouse gas emissions are indirect (electricity-related) emissions. The remaining emissions come from direct (on-site) emissions plus the emissions associated with the production of alumina.
      - abalone 12y ago
        That's true but the direct emissions are still very substantial. It only seems small in comparison because smelting uses so much electricity to begin with.
  - abalone 12y ago
    I read the article. Hydroelectric is not free -- to scale up to powering the automotive industry requires more dams with massive ecological impact -- and you left out the part out greenhouse gases and the transportation of heavy batteries over hundreds or thousands of miles per recharge. 1K miles could be easily used up on a couple roundtrips. That's not even 2 roundtrips between SF and LA.
- patrickg_zill 12y ago
  Aluminum does use a lot of electricity. The first time; that is why recycling aluminum which is cheap, very easy to do, and does not require much power, is such a win.
  - abalone 12y ago
    Are you suggesting "recharging" these batteries happens via recycling? That is not true. Aluminum is converted to alumina via the reaction and they need to be resmelted, just like the first time.
marvin 12y ago
I hate being a naysayer - this is cool technology - but the energy economics won't work out for metal-air batteries if they're used as the main power source. Recharging a metal-air battery is grossly inefficient, and a big part of the advantage with electric cars is that they use less energy in every step of the process except initial manufacturing. This means that the general economics of metal-air batteries will not work out either, because the system requires a physical supply chain that is much more expensive to build out than the electricity distribution network that already exists. Add to this that range anxiety is for the most part eliminated with >60kWh electric vehicles, and this is a no-starter. Where metal-air batteries could have a place, is as a trickle charging device that will be replaced only rarely, perhaps during an annual checkup, and used as a backup only on the few occasions where fast charging is unavailable or unwanted. But battery vehicle companies are onto this idea already - the Tesla Model S has space for what some suspect is in fact an upgrade slot where a metal-air trickle charging battery can be installed. The problem is, most mainstream news articles writing about progress in battery-electric vehicles are already far behind the state of the art. Tesla's innovation and execution in this space has largely removed range anxiety for all but a small (<5%) number of trips, and already have a very strong quick charging presence in multiple countries. The future is electric and is already here - most people just haven't noticed.
- greglindahl 12y ago
  Huh, the article addresses this issue pretty directly -- did you read it? 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.
  - pocketstar 12y ago
    Yes but then you are hauling around an extra 100kg of unused batteries for 95% of your trips.
    - 12y ago
akouts 12y ago
I worked at a large automotive manufacturer in near Detroit a number of years ago when they were considering whether or not to design and manufacture an electric vehicle. The had engaged in full "well to wheels" analysis of potential designs as well as that of competitors and concluded that the energy economics never made sense. That analysis considered how "carbon expensive" it is to spin up manufacturing, manufacture, service and operate a vehicle going all the way back to raw materials sourcing. They felt more optimistic about diesel hybrids but also chose not to pursue that. I find it unfortunate that we don't see a more standardized process for conducting full "well to wheels" analysis that takes into account the full life cycle of a designs, manufacturing and product lifecycle. Would be awesome if a consumer watchdog group existed that had the access and technical competence needed to audit these technologies.
venomsnake 12y ago
Chances of the magical electrolyte that removes the corundum being mercury based?
stcredzero 12y ago
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 that energy at once.
- nwmcsween 12y ago
  I highly doubt it can release that much energy at once, it's a catalytic reaction that removes the oxide from the aluminum.
  - deleted 12y ago
    [deleted]
- beloch 12y ago
  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 battery, which is actually pretty nasty but not terribly dangerous unless you deliberately try to make it so (e.g. by shorting out the terminals). Aluminum is currently under $2K/1000kg, so the yearly aluminum battery replacement would probably run a few hundred dollars. Aluminum is the most abundant metal on earth and this reaction is reversible, so costs should stay low. The real cost is likely to be the solvent.
  - venomsnake 12y ago
    There is a hint here about the solvent http://www.popsci.com/scitech/article/2004-09/amazing-rusting-aluminum http://www.popsci.com/scitech/article/2004-09/amazing-rustin...
  - nardi 12y ago
deleted 12y ago
[deleted]
- semerda 12y ago
  That is the intent => "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"
  - SyncTheory13 12y ago
    While I initially liked this idea... I think I'd much prefer this one: http://www.eptender.com/ http://www.eptender.com/ It's just a gasoline/diesel (or other fuel-powered!) generator that plugs into an electric car. I believe the company is looking to rent them out to people as needed, similar to renting a truck from uHaul. If they could land a contract with uHaul or something, it could take off... Seems the charging port isn't universal on electric cars though... Personally, I'd prefer to buy my own and have it around the house as an emergency generator as well as for the rare long trip. Much simpler and more versatile than a Hybrid, for sure.
TrainedMonkey 12y ago
"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.
alephnil 12y ago
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.
- giarc 12y ago
  But can the spent fuel cell be processed and used for something else? Perhaps not related to a car at all.
- jccooper 12y ago
  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 can see where Alcoa would like such a process. I don't know if the idea of a high-density consumable backup power supply will take off, but it's not a terrible idea until real batteries get much better.
  - maxerickson 12y ago
    It sounds like a 20 pound module would make a great rescue battery, even if putting them in the cars doesn't take off.
  - kashkhan 12y ago
    with that definition of recycling even gasoline is recyclable in plants :)
    - darkmighty 12y ago
      You can also synthesize gasoline with water + co2 + energy, not unlike this battery, but the global efficiency is very low (US navy is considering using it in nuclear powered ships for jet fuel iirc). The thermalization of the fuel (i.e. Carnot cycle) is also a significant limiter.
trhway 12y ago
metal-air batteries (fuel cells), rechargeable and not, is the future. Having comparable to gasoline energy density, yet higher efficiency - 60-90% vs. 30% of gasoline, it will transform cars and especially planes (subsonic ones). You can imagine that it is absolutely not an issue to replace a 100Kg spent aluminum fuel cell block on a small plane at airport. It would also be better than gas turbine for bigger commercial, though still propeller driven, planes (for pure jets the issue is that you need air to be hot to have high exhaust speed for the plane to reach speeds beyond 450+ knots). Interesting possibility for decreasing heat signature for military subsonic drones too :) There is also very active development for rechargeable metal-air batteries though currently it is significantly skewed toward lithium-air which is non-starter pretty much. There is very promising results with zinc, sodium and especially potassium -air batteries.
- nardi 12y ago
  But what's the efficiency of the Hall–Héroult process? [1] [1] http://en.wikipedia.org/wiki/Hall-Héroult_process http://en.wikipedia.org/wiki/Hall-Héroult_process
  - trhway 12y ago
    my bet actually is on potassium-air. The known and projected configurations of such batteries would most probably contain organic/aprotic electrolyte, so it is pretty nasty/flammable inside, yet they are rechargeable and availability and cost of components and efficiency seems to beat other commodity materials based schemas.
- frankus 12y ago
  Vanadium-boride air is also a promising chemistry (http://phys.org/news/2013-09-molten-air-battery-storage-capacity-highest.html http://phys.org/news/2013-09-molten-air-battery-storage-capa...). For aircraft, I'm not sure it would be practical, but in theory you could jettison the spent batteries (which now weigh more thanks to the air adsorption) after takeoff, at which point they would fly/glide themselves to a nearby reprocessing station.
- dredmorbius 12y ago
scythe 12y ago
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 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_and_alumina/bauxite_and_alumina_t6.html 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.
- abat 12y ago
  The idea is it's a backup battery instead of a backup gasoline engine. Being "nearly as expensive as gasoline" could still be a win because it could be used in electric vehicles without having to add a backup generator engine. Also it could have other benefits like being safer (less combustible), producing fewer emissions on the road, and weighing less than gas. That said, I'm not saying I'm believer in this tech
  - deleted 12y ago
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- 12y ago
cwt137 12y ago
Is this technology similar to the Bloom Box, but with Aluminum instead of some type of ceramic material?
scotty79 12y ago
Any chance of popping this kind of battery into laptop and running it for few days before replace is needed? Also, could it power sensor that wirelessly communicates gathered data from time to time for extended periods of time?
hardoncollider 12y ago
Anybody else notice in their demo video, that the car is pulling to the side of the road to let semi-trucks pass? Everything aside, that's quite a deceiving field test, considering they aren't simulating any type of normal driving pattern.
salem 12y ago
It sounds like this battery would be much more suitable for Tesla's automated battery swap station. Except you would install it in the frunk/trunk for longer trips, and ditch the extra weight when you're done.

85 points by Element_ 12y ago

Doesn't aluminum smelting use crazy amounts of electricity and emit significant greenhouse gases? So not only would we be doing that, we'd also have to ship these 220 lb modules back to the smelters every 1,000 miles? Is there anybody advocating for this besides aluminum smelters?

lotsofmangos 12y ago
Read article. The smelter they are using is hydroelectric and the 1000 miles air battery range is only used on long journeys as mostly the car runs on lithium.
- fancyketchup 12y ago
  I think... you might want to read up on aluminum smelting, which converts alumina (Al2O3) into aluminum (Al). The process involves passing a large current between two graphite (carbon) electrodes via the alumina. Al2O3 + carbon => Al + CO2 Edit: I can only guess that the down votes are for not providing a source? Here you go: http://en.wikipedia.org/wiki/Aluminium_smelting http://en.wikipedia.org/wiki/Aluminium_smelting It doesn't matter if the smelter runs on fairy dust or hippie juice. Reducing aluminum oxide to aluminum produces CO2 no matter the energy source.
  - scotty79 12y ago
    It seems that you can significantly reduce carbon emissions of aluminum smelting if you use energy source that does not emit carbon dioxide. From http://aluminium.org.au/climate-change/smelting-greenhouse-performance http://aluminium.org.au/climate-change/smelting-greenhouse-p... The smelting of aluminium is a very energy intensive process – and over 80 per cent of smelting greenhouse gas emissions are indirect (electricity-related) emissions. The remaining emissions come from direct (on-site) emissions plus the emissions associated with the production of alumina.
    - abalone 12y ago
      That's true but the direct emissions are still very substantial. It only seems small in comparison because smelting uses so much electricity to begin with.
- abalone 12y ago
  I read the article. Hydroelectric is not free -- to scale up to powering the automotive industry requires more dams with massive ecological impact -- and you left out the part out greenhouse gases and the transportation of heavy batteries over hundreds or thousands of miles per recharge. 1K miles could be easily used up on a couple roundtrips. That's not even 2 roundtrips between SF and LA.
patrickg_zill 12y ago
Aluminum does use a lot of electricity. The first time; that is why recycling aluminum which is cheap, very easy to do, and does not require much power, is such a win.
- abalone 12y ago
  Are you suggesting "recharging" these batteries happens via recycling? That is not true. Aluminum is converted to alumina via the reaction and they need to be resmelted, just like the first time.

marvin 12y ago

I hate being a naysayer - this is cool technology - but the energy economics won't work out for metal-air batteries if they're used as the main power source. Recharging a metal-air battery is grossly inefficient, and a big part of the advantage with electric cars is that they use less energy in every step of the process except initial manufacturing. This means that the general economics of metal-air batteries will not work out either, because the system requires a physical supply chain that is much more expensive to build out than the electricity distribution network that already exists. Add to this that range anxiety is for the most part eliminated with >60kWh electric vehicles, and this is a no-starter. Where metal-air batteries could have a place, is as a trickle charging device that will be replaced only rarely, perhaps during an annual checkup, and used as a backup only on the few occasions where fast charging is unavailable or unwanted. But battery vehicle companies are onto this idea already - the Tesla Model S has space for what some suspect is in fact an upgrade slot where a metal-air trickle charging battery can be installed. The problem is, most mainstream news articles writing about progress in battery-electric vehicles are already far behind the state of the art. Tesla's innovation and execution in this space has largely removed range anxiety for all but a small (<5%) number of trips, and already have a very strong quick charging presence in multiple countries. The future is electric and is already here - most people just haven't noticed.

greglindahl 12y ago
Huh, the article addresses this issue pretty directly -- did you read it? 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.
- pocketstar 12y ago
  Yes but then you are hauling around an extra 100kg of unused batteries for 95% of your trips.
  - 12y ago

akouts 12y ago

I worked at a large automotive manufacturer in near Detroit a number of years ago when they were considering whether or not to design and manufacture an electric vehicle. The had engaged in full "well to wheels" analysis of potential designs as well as that of competitors and concluded that the energy economics never made sense. That analysis considered how "carbon expensive" it is to spin up manufacturing, manufacture, service and operate a vehicle going all the way back to raw materials sourcing. They felt more optimistic about diesel hybrids but also chose not to pursue that. I find it unfortunate that we don't see a more standardized process for conducting full "well to wheels" analysis that takes into account the full life cycle of a designs, manufacturing and product lifecycle. Would be awesome if a consumer watchdog group existed that had the access and technical competence needed to audit these technologies.

venomsnake 12y ago

Chances of the magical electrolyte that removes the corundum being mercury based?

stcredzero 12y ago

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 that energy at once.

nwmcsween 12y ago
I highly doubt it can release that much energy at once, it's a catalytic reaction that removes the oxide from the aluminum.
- deleted 12y ago
  [deleted]
beloch 12y ago
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 battery, which is actually pretty nasty but not terribly dangerous unless you deliberately try to make it so (e.g. by shorting out the terminals). Aluminum is currently under $2K/1000kg, so the yearly aluminum battery replacement would probably run a few hundred dollars. Aluminum is the most abundant metal on earth and this reaction is reversible, so costs should stay low. The real cost is likely to be the solvent.
- venomsnake 12y ago
  There is a hint here about the solvent http://www.popsci.com/scitech/article/2004-09/amazing-rusting-aluminum http://www.popsci.com/scitech/article/2004-09/amazing-rustin...
- nardi 12y ago

deleted 12y ago

[deleted]

semerda 12y ago
That is the intent => "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"
- SyncTheory13 12y ago
  While I initially liked this idea... I think I'd much prefer this one: http://www.eptender.com/ http://www.eptender.com/ It's just a gasoline/diesel (or other fuel-powered!) generator that plugs into an electric car. I believe the company is looking to rent them out to people as needed, similar to renting a truck from uHaul. If they could land a contract with uHaul or something, it could take off... Seems the charging port isn't universal on electric cars though... Personally, I'd prefer to buy my own and have it around the house as an emergency generator as well as for the rare long trip. Much simpler and more versatile than a Hybrid, for sure.

TrainedMonkey 12y ago

"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.

alephnil 12y ago

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.

giarc 12y ago
But can the spent fuel cell be processed and used for something else? Perhaps not related to a car at all.
jccooper 12y ago
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 can see where Alcoa would like such a process. I don't know if the idea of a high-density consumable backup power supply will take off, but it's not a terrible idea until real batteries get much better.
- maxerickson 12y ago
  It sounds like a 20 pound module would make a great rescue battery, even if putting them in the cars doesn't take off.
- kashkhan 12y ago
  with that definition of recycling even gasoline is recyclable in plants :)
  - darkmighty 12y ago
    You can also synthesize gasoline with water + co2 + energy, not unlike this battery, but the global efficiency is very low (US navy is considering using it in nuclear powered ships for jet fuel iirc). The thermalization of the fuel (i.e. Carnot cycle) is also a significant limiter.

trhway 12y ago

metal-air batteries (fuel cells), rechargeable and not, is the future. Having comparable to gasoline energy density, yet higher efficiency - 60-90% vs. 30% of gasoline, it will transform cars and especially planes (subsonic ones). You can imagine that it is absolutely not an issue to replace a 100Kg spent aluminum fuel cell block on a small plane at airport. It would also be better than gas turbine for bigger commercial, though still propeller driven, planes (for pure jets the issue is that you need air to be hot to have high exhaust speed for the plane to reach speeds beyond 450+ knots). Interesting possibility for decreasing heat signature for military subsonic drones too :) There is also very active development for rechargeable metal-air batteries though currently it is significantly skewed toward lithium-air which is non-starter pretty much. There is very promising results with zinc, sodium and especially potassium -air batteries.

nardi 12y ago
But what's the efficiency of the Hall–Héroult process? [1] [1] http://en.wikipedia.org/wiki/Hall-Héroult_process http://en.wikipedia.org/wiki/Hall-Héroult_process
- trhway 12y ago
  my bet actually is on potassium-air. The known and projected configurations of such batteries would most probably contain organic/aprotic electrolyte, so it is pretty nasty/flammable inside, yet they are rechargeable and availability and cost of components and efficiency seems to beat other commodity materials based schemas.
frankus 12y ago
Vanadium-boride air is also a promising chemistry (http://phys.org/news/2013-09-molten-air-battery-storage-capacity-highest.html http://phys.org/news/2013-09-molten-air-battery-storage-capa...). For aircraft, I'm not sure it would be practical, but in theory you could jettison the spent batteries (which now weigh more thanks to the air adsorption) after takeoff, at which point they would fly/glide themselves to a nearby reprocessing station.
dredmorbius 12y ago

scythe 12y ago

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 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_and_alumina/bauxite_and_alumina_t6.html 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.

abat 12y ago
The idea is it's a backup battery instead of a backup gasoline engine. Being "nearly as expensive as gasoline" could still be a win because it could be used in electric vehicles without having to add a backup generator engine. Also it could have other benefits like being safer (less combustible), producing fewer emissions on the road, and weighing less than gas. That said, I'm not saying I'm believer in this tech
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12y ago

cwt137 12y ago

Is this technology similar to the Bloom Box, but with Aluminum instead of some type of ceramic material?

scotty79 12y ago

Any chance of popping this kind of battery into laptop and running it for few days before replace is needed? Also, could it power sensor that wirelessly communicates gathered data from time to time for extended periods of time?

hardoncollider 12y ago

Anybody else notice in their demo video, that the car is pulling to the side of the road to let semi-trucks pass? Everything aside, that's quite a deceiving field test, considering they aren't simulating any type of normal driving pattern.

salem 12y ago

It sounds like this battery would be much more suitable for Tesla's automated battery swap station. Except you would install it in the frunk/trunk for longer trips, and ditch the extra weight when you're done.