Aluminum-Air Battery With 1000-Mile EV Range, Too Good To Be True?

Remember the scene in Back to the Future, where Doc Brown refuels his future version Delorean by opening up the lid of the Mr. Fusion, and dumping a bunch of garbage into it, including a few aluminum cans? Take out the garbage, and maybe that could be a future "home recycling/ car power" option

 

This is an interesting idea. I wish they would show/say how many kilowatt-hours are per aluminum plate instead of 20 miles per plate.

I also assume that since they have 50 of those plates in the extended range battery that they all get used in parallel to get the needed voltage and amperage. (meaning that you can't just replace a couple at a time)

In my PIP I'm getting 80% EV...so with this in place I could go 4000 miles EV and 1000 Aluminum. The big question is the cost per mile for the aluminum.

Mike

 

The Aluminum used for these non rechargeable fuel cells is not recyclable. Once "burnt" it is in the form of AlO2 or Aluminum Oxide. Only good for making sandpaper. Aluminum has to be in its elemental metallic state to be economically recycled. Nothing new here just a rehash of 70's and early 80's tech dug up to get free grant and investor money.

 

^^ Re-refine it. It will still be energy-intensive, as the original aluminum production was. But it cannot be any worse than the original bauxite ore, can it?

 

So after reading this entire very interesting thread, I've come to the following conclusion.

The Aluminum Air Battery as presented IS too good to be true.

But the further truth is there is reason to believe that someday the truth of an Aluminum Air Battery might be very, very good.

 

No thanks. I don't know if anyone told this guy, but bottled water costs more than gas, per gallon.

 

I've felt a better air-aluminum battery would work at high-temperatures using melted aluminum, a liquid metal salt, and a ceramic electrode. At 660C, the reactions would be sufficiently active that a fairly small cell should release substantial energy.

There are thermal issues including heat exchange of the reactant by-products. However, the cooled, aluminum oxide could be dumped overboard with no risk to others.

The lower temperature, chemical cells typically use hydroxides which leave the risk of being mixed with the aluminum by-products. This requires post-processing to neutralize and the aluminum oxide has to stored in the vehicle. So it gets heavier as it is discharged.

Yes, this is a primary cell. We're buying the energy originally used to make the aluminum. But that has always been the case of primary cells. Recharging a 'primary' cell means typically an industrial production of aluminum.

Bob Wilson

 

As it is presented in the OP, the aluminum air battery is hardly better than the "100 mpg carburetor" I grew up on.....or perhaps a more tangible example in sheer engine output are the 70 lb, 600 hp barrel engines that power torpedoes....and are good for one shot (because in that application, one go is all that's required). This seems like a non-starter to me, for various reasons amply supplied in this thread.

 

I think its around 3 kwh if each plate is around a pound.

Number of plates gives you a voltage for any chemistry. The surface area the amperage. You could make thinner plates to be less expensive for less capacity. If the battery is balanced they should all get replaced at the same time.

The 2002 research said recycling could cost as little as $1.10/kg, and at 25 kg this would be $28. Now I bet the 1000 miles is nedc and not epa, and energy cost more than it did 10 years ago, so maybe $100 if you are a do it yourselfer, and drop it off to a recycling center. I guesstimated $200 if you popped into something like a jiffy lube, they did it, and sent the stuff in for recycling. I don't really know costs and profit for recycling aluminum.

The point is to collect the aluminum hydroxide and recycle it. We do not want to dump the valuable aluminum on the road. There is a trade off of weight gained versus size of container. One could imagine sending the aluminum recycling gel to the recycler, before new plates are needed. Perhaps you get a credit, and when you need new plates you show them your reciepts for the discount for the new plates.

 

Its not vaporware. The military has plenty of working aluminum air batteries. What it needs are a couple of advances. First a good 100 mile BEV, and then a recycling infrastructure. PHEVs a chtoief competitor only need prices to go down. Fuel cells need 5 miracles. We are talking 10 years out for recyclable primary cells extending range of BEVs. It may never happen, it may be small, but the ideas aren't the same as vaporware.

It addresses 2 problems with BEVs that CARB seems determined to kecp in policy. 300 mile range and recharge time. Whether these are real or imagined requirements is a different story

 

I know - I know ... it's just that there are so many battery formulas that are "almost ready" - I just needed a humor break ... ergo, the smiley.

 

I'm pretty sure aluminum by-product would be fairly inert. But I was under the impression a KOH or NaOH electrolyte was used and these are nasty things to release even in trace amounts. If mixed with the aluminum by-product, it would require post processing.

Given the abundance of aluminum in the environment, I'm OK with dumping inert material overboard. After all, aluminum compounds are a significant portion of 'dirt.'

Of course my last experiments involved using a large Coke bottle, lye, and aluminum foil to fill balloons with hydrogen. . . . Yes, for Hindenburg experiments. . . .

Bob Wilson

 

Oh, we have different groups of people. We have the we are doomed group, that thinks we will run out of oil, and go to a mad max world. There are those that think oil will go on forever, and we don't need to do anything. Both of these groups seem to fight progress.

Then you have people like you and me that know things will get scarcer and more expensive, and that plug-ins are one possible solution to transition away from an oil based transportation economy. For plug-ins to really take off either batteries need to get cheaper, or gasoline more expensive. IMHO both will happen. Then the question is, what happens if the battery is not big enough for your trip. Possible solutions are carrying an ice with you - phev, another possibility is quick chargers, a third is fuel cells, and this is a fourth path a recyclable primary cell, fifth is build a battery with way more range than you normally use, and sixth is rent or keep another car. The primary cell should work well where utilization rate is high (% of electric miles), the phev where it is cold or utilization rate is low but high enough to justify the battery (gen IV 15 mile aer prius maybe, with 55 mpg in cd). The trick is to get that leaf type car good enough so that people just say, I would buy one but occasionally I need to go further. To get there we may need some of these battery advances, but they are evolutionary, not revolutionary. I would like it if they presented this though instead of running on air and water, they run on aluminum and water (potassium hydroxide solution in this chemistry needing less air), and the aluminum hydroxide is collected for recycling.

 

This particular battery uses potasium hydroxide (KOH) as the electolyte, you could use salt water instead as you do with home made aluminum air batteries. but this should be a better electrolyte. Lead acid batteries use sulfuric acid and lead, which at the concentrations used are most dangerous substances. The aluminum product will likely be Aluminum hydroxide Al(OH)3 which is a gel like substance or there might be other chemicals in the solution to react with the aluminum hydroxide and form a salt that precipitates out. Water and oxygen are consumed in the reaction, which is why you need to add the water. Definitely I would not expect the stored aluminum hydroxide to be pure, otherwise you could just sell that. Processing at a recycler will be necessary.

aluminum hydroxide is an eye and skin irritant and valuable. I would prefer not to dump it on the side of the road.

cool, for the science fair, you should build an aluminum air burrito. All you need is paper towels, salt, water, aluminum foil, and activated charcoal. Using wire helps, but as a kid I used aluminum foil as the leads out of the battery. The aluminum hydroxide will form on the foil. Wash your hands after handling it.

 

The recycling centers currently take aluminum metal, which still contains much of the enormous energy used to un-oxidize it into a metal.

The aluminum-air cells discharge oxidized, non-metallic aluminum. The valuable energy has been removed, so this material will have a different recycle value.

 

Absolutely, aluminum hydroxide has a different value than aluminum cans or aluminum oxide. I quoted a study that determined cost to recycle. You and bob seem to think we should just drop this valuable substance on the ground, because it takes energy to transform. Or something else, I'm not quite sure. If primary batteries are not recycled, then an ice would create less of a problem as a range extender than aluminum air or zinc air. To get to aluminum hydroxide from bauxite the typical process is to mine it, separate, add sodium hydroxide, separate, then deal with the pollution from the red mud. I don't know why you would not recycle the valuable aluminum hydroxide collected from the battery instead of going through these extra steps. Its like the oil companies that want to flare natural gas instead of collect it.

Aluminum hydroxide, the substance collected by these batteries is the primary intermediary between bauxite and metallic aluminum. It was created in the battery by adding water and oxygen (from the air), and heat and electricity remove water and oxygen in a two step process in the normal manufacture of aluminum. I say recycling, because we don't need all the equipment of a normal aluminum plant, which must deal with sodium hydroxide and the pollution of red mud.

 

It has to do with:

• 26.98 - Aluminum atomic mass
• 15.99 - Oxygen atomic mass
• Al{2}O{3} - 2*26.98 + 3*15.99 ~= 101.93
• Al{2} - 2*26.98 ~= 53.96
• The mass of an air-aluminum battery doubles as it discharges

Then there is the cost of collection and transportation of 'retail' quantities of aluminum oxide. The mass gain is worse if Al(OH){3} is the by-product. So the aluminum plate delivery van leaves with half load and returns with a full-load of stuff that still has to be forwarded to a reducing factory.

My interest is in aviation and it isn't nice to have the plane grow heavier in flight. Adding to the world-wide dust cloud a relatively small amount of spent aluminum oxides would not be that bad . . . except for those living under the airport flight path of air-aluminum powered aircraft.

I have great respect for aluminum as an energy source. Powdered, it is added to solid propellant rocket fuel to increase their lift and performance. It also makes those huge white clouds we used to see when the shuttle solid rocket booster fired off.

Bob Wilson

 

I have no intention of dumping it along the road. But I don't want to confuse its recycle value with that of Al metal.

 

It is most excellent for aviation, but you need to add some knowledge. The battery really is Al + H20 that you must carry. The formula is 4Al+3O2 +6H2O -> 4l(OH)3. You gain about 45% weight from the reacted oxygen from the air. You only have to add as much water as you want to consume, and you could drop off the product at an airport. Why do we use lithium now? Lower maintenance, it is charged using the the planes power, but it does not need to be inspected as often as a primary cell. The electrical load of a commercial plane is low. What about seldom used electronics, that is why the air force paid for most of the research. The batteries have long shelf life and they are light. Many space craft use these as well as hydrogen fuel cells.

Pollution is less of a problem for aircraft, but unless you are going all electric, the power to weight including keeping the aluminum hydroxide is much higher than lithium.

Yes this application is quite different than that. A fully electric prop plane might use some other aluminum battery that trailed fairly safe pollution. Its likely you would have a second tank for a reaction to create aluminum salts that were released.