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Alcoa and Phinergy enter joint development agreement for high energy-density aluminum-air batteries

Alcoa and Israel-based Phinergy have entered into a joint development agreement to develop further Phinergy’s aluminum-air batteries. Announced at the Advanced Automotive Battery Conference in Atlanta, the partnership will collaborate on new materials, processes and components to commercialize the aluminum-air battery, which could significantly extend electric vehicle range.

Aluminium–air cells are high-energy density primary (non-rechargeable) batteries originally developed in the 1960s. Aluminum-air batteries (a type of metal-air cell) use a catalytic air cathode in combination with an electrolyte and an aluminum anode; the systems offer a theoretical specific energy of 8.1 kWh/kg of Al—second only to the Li-air battery (13.0 kWh/kg). (Earlier post.)

However, parasitic hydrogen evolution caused by anode corrosion during the discharge process is a well-known obstacle to commercialization of such a system, because it not only causes additional consumption of the anode material but also increases the ohmic loss in the cell.

Past efforts to suppress the parasitic corrosion include doping high-purity grade aluminum with particular alloying elements and the use of corrosion inhibitors in the electrolyte.

Alcoa’s extensive technical materials expertise, along with our deep roots in bringing new products to market in the automotive industry, were of great interest to Phinergy as its revolutionary aluminum-air battery moves from research to commercialization. Automotive manufacturers are looking for technologies that enable zero-emission cars to travel the same kinds of distances as gasoline-powered cars. The aluminum-air range extender has the potential to meet that challenge.

—Dr. Raymond Kilmer, Alcoa’s Executive Vice President and Chief Technology Officer

Phinergy says that it has developed a proprietary process of anode production resulting in increased use of aluminum energy, while reducing the unwanted chemical reactions. The company says that it has also developed an advanced battery management system to increase the energetic utilization of the battery.

Battery train- Phinergy
Phinergy aluminum-air battery. Click to enlarge.

Phinergy says that its air cathodes, with a proprietary silver-based catalyst, have a unique and novel structure that allows oxygen into the electrode and the cell without letting CO2 in. As a result, the air electrodes are immune to carbonization-related problems, and have a lifespan of thousands of operating hours.

When used in an aluminum-air battery, aluminum turns into aluminum hydroxide. Aluminum hydroxide can then be recycled in the aluminum factory, enabling a closed and sustainable life cycle.

Phinergy Aluminum-Air Car
Phinergy demo aluminum-air battery car. Click to enlarge.

According to Phinergy, just one of the 50 aluminum plates in its battery can power a car for approximately 20 miles, resulting in a range of approximately 1,000 miles (1,600 km). Phinergy has successfully integrated its aluminum-air battery system into an EV for demonstration.

In addition to use in electric vehicles, Phinergy suggests that the battery technology can be used for stationary energy applications such as commercial emergency generators for hospitals and data centers, general purpose generators, and defense applications such as mobile housing and unmanned vehicles. It can also be used for first responders due to its infinite shelf life and high energy density. Phinergy and Alcoa are also working on the aluminum-air technology for these applications.

Alcoa’s team engaged on the project is based at the Alcoa Technical Center located outside of Pittsburgh, which is the largest light-metals research facility in the world.


  • Zhao Zhang, Chuncheng Zuo, Zihui Liu, Ying Yu, Yuxin Zuo, Yu Song (2014) “All-solid-state Al–air batteries with polymer alkaline gel electrolyte,” Journal of Power Sources, Volume 251, Pages 470-475 doi: 10.1016/j.jpowsour.2013.11.020

  • D.R. Egan, C. Ponce de León, R.J.K. Wood, R.L. Jones, K.R. Stokes, F.C. Walsh (2013) “Developments in electrode materials and electrolytes for aluminium–air batteries,” Journal of Power Sources, Volume 236, Pages 293-310 doi: 10.1016/j.jpowsour.2013.01.141

  • Chih-Min Wang, Kan-Lin Hsueh, and Chin-Lung Hsieh (2013) “The Kinetic Reaction of Aluminum-Air Battery in Different Aqueous Solution,” ECS Trans. 50(25): 29-35 doi: 10.1149/05025.0029ecst

  • Derek MacAodhagáin, Carlos Ponce-de-Leon-Albarran, Robert J. Wood, Keith R. Stokes and Frank C. Walsh (2012) “Comparison of Air Cathodes and Aluminium Anodes for High-Power Density Alkaline Aluminium-Air Batteries,” Honolulu PRiME 2012



Is it the 5-5-5 battery that some are waiting for ?


If they can make this work to where the Aluminum is around the cost of gasoline per mile, it could eliminate the need for a fast charging infrastructure. A BEV that gets 100mi of range, but uses this to extend the range to 300 miles or more would pretty much fill the needs for almost every driver.

So for 90%+ of your days, you'd simply use the li-ion pack in the vehicle, charged at your house/work. For the rare occasion you need to go beyond that range or just neglect to charge, you use the Aluminum-Air.


Not so sure if this could be called a battery? Seems to be closer to an FC with aluminium instead of H2 as the fuel. Collecting the aluminium hydroxide could be built in the aluminium cassettes.

If compact and cheap enough, it could make an excellent clean range extender for future BEVs or FCEVs. One could always stop at the local 7/11 (or other supply stores) to exchange the 10 to 20 Kg of used aluminium cassettes for new recycled cassettes and get a quick charge for the battery pack at the same time.


Think of it as a rechargeable battery that can only be recharged in a factory.

As people say, it would make a great range extender, and could be swapped quickly.

Plus, you could possibly rebuild them at night, using excess energy (wind, or excess day solar).


Still nothing beats charging high density batteries with solar power at home and quick charging them from secondary storage batteries on trips. I believe that will be the preferred method in the future just as it is now.

I suspect in the future people will be saying: "Stopping for a liquid refill is so retro and reminds me of the past horrors of using gasoline stations"...ha!

Gorr, I'm starting to appreciate your sly sense of humor. I hope Harvey does too.

Just think - these could be the first alcohol powered cars. As in drink the beer, flatten the can, and insert into your battery pack. Or drink soda pop if you don't drink alcohol, and call it a sugar powered car.

Actually, I am thrilled at this announcement. I just hope that Phinergy doesn't get crushed by Alcoa.


Unless you are a nightworker charging from a solar array presents difficulties, although they try to sweep them under the carpet.

Even supposing you lay out the cash to buy a battery storage system the Leaf for instance loses around 15% wall to wheel.
If you add in the charging losses for the home storage system you are talking about a substantial loss, aside from the outlay on the storage batteries.

A far better solution once solar reached a high enough penetration to cover day time peaks if you want to charge on solar would be to charge at work whilst the car is stationary.

The grid is there because it is immensely helpful to shovel power around, and reduce the individual's peaks and troughs of use.

Too much emphasis on self-sufficiency, usually fake, ignores the very real utility of the grid.

The bigger problem though is seasonal variation for solar power.
It just ain't very sunny in winter in many places, and you can't store the difference in batteries.

You can store it as hydrogen though.
The common canard about that is that is is very inefficient.

It isn't if you use the process heat from producing hydrogen in the home, which would be fed back into the grid for storage.

The process heat would provide hot water in the home.


I'm curious to know which of the staff at ev insider is posting here under that nom de plume.

Of course many here post with something other than their name, but not as the name of a company or a website.


Americans aren't going to like this....too much hassle for too little product performance.

Roger Pham

The key issues here are what is the efficiency of this alum/air battery and what is the efficiency of conversion of Al(OH)3 to metal Al and at what cost per kWh for the conversion process?

Is the weight of the Aluminum Hydroxide as waste product counted into the entire gravimetric energy density of the battery? As the Al is oxidized, the O2 will probably be removed from the air and added to the vehicle in the Al(OH)3 tank.

Otherwise, this appears to be a promising idea. The summer solar energy can be converted to Al metal to be used in the winter, so, seasonal energy storage might work if it will be cost-effective.


Aluminium making uses lots of electricity and the new battery plates-cassettes could be considered as a e-storage medium.

Plates-cassettes recycling could be done with wind-solar clean power when available or at night when grid surpluses exist, and stocked for rainy days?

Those plates-cassettes would be much easier to store for extended periods and distribute than H2.

There is plenty of aluminium around.


HarveyD, you're right about aluminum smelting using huge amounts of electricity. Giant electrodes are plunged into the molten bauxite to get what we think of as aluminum. In fact, it takes 95% less energy to melt an aluminum can than to refine an equivalent amount of bauxite into aluminum.

@Roger Pham, I think you've hit the nail on the head. What are the conversion losses of cycling aluminum? It's a bad idea if the losses are much higher than Lithium Air, or Lithium Sulfur or such. It's the same problem with generating H2 for Fuel Cells. The H2 energy has to come from somewhere, and if too much energy is lost putting energy into H2, it's bad storage medium.


A new mining company (Orbite) will start making high purity aluminium directly from clay. The pilot plant worked OK for the last year and the mass production plant will go on steam in about another year.

If this process works as it should, more lower cost high purity aluminium could be available soon.

Roger Pham

The following is some data regarding the round-trip efficiency of Al-Air battery, from Wiki:

"Aluminium as a "fuel" for vehicles has been studied by Yang and Knickle.[1] They concluded the following:

The Al/air battery system can generate enough energy and power for driving ranges and acceleration similar to gasoline powered cars...the cost of aluminium as an anode can be as low as US$ 1.1/kg as long as the reaction product is recycled. The total fuel efficiency during the cycle process in Al/air electric vehicles (EVs) can be 15% (present stage) or 20% (projected), comparable to that of internal combustion engine vehicles (ICEs) (13%). The design battery energy density is 1300 Wh/kg (present) or 2000 Wh/kg (projected). The cost of battery system chosen to evaluate is US$ 30/kW (present) or US$ 29/kW (projected). Al/air EVs life-cycle analysis was conducted and compared to lead/acid and nickel metal hydride (NiMH) EVs. Only the Al/air EVs can be projected to have a travel range comparable to ICEs. From this analysis, Al/air EVs are the most promising candidates compared to ICEs in terms of travel range, purchase price, fuel cost, and life-cycle cost."

Apparently, 15% round-trip efficiency needs a lot of work for Al-Air battery. A solid fuel may also impose additional difficulty for refueling.


The above very early efficiency estimates will probably be overpassed by 100% by 2020 or so.

Standardized combo plug-in cassette type units for the aluminium fuel and the used fuel could make the re-fueling task easier.

Cassettes could be exchanged in all existing convenience stores, gas stations, FCEVs and EVs quick charge stations etc.

Roger Pham

>>>>>"The above very early efficiency estimates will probably be overpassed by 100% by 2020 or so."

On what basis do you make this prediction, Harvey? The researchers quoted above predicted only 33% improvement in round-trip efficiency of Al-air battery, not 100% improvement.

Not so easy to change out the Aluminum anode of the Al-air battery, Harvey, since a battery is made up of many cells serially connected together. The anode of each cell must be replaced individually, meaning the entire battery pack must be opened and the anode plates must be removed and replaced with new plates. Essentially, the battery pack must be rebuilt, at additional labor cost. It may be faster to swap out the whole battery, similar to the Better Place scheme, but then this will open up a whole list of new problems, since the battery pack will weigh hundreds of pounds and will be made in many different forms and configuration to suit different car models and application.

With H2, you simply put in the filling nozzle and be done in a few minutes. H2 can flow in pipelines to move from place to place, and pipeline transportation is the cheapest and most efficient to transport fuels from place to place.


Most new technologies are improved by up to 100% between the early first generation and the improved mass produced second generation.

Aluminum-Air (batteries or FCs) will only make sense if they can be refueled quickly and easily. The plug-in combo cassettes approach could be one way of doing in. The number of cassettes would depend on their individual size and on the total energy production required. Practically, each plug-in cassette would have to be between 10 to 20 lbs and the total number should not exceed 6 or so.

I agree with you that improved H2 FCEVs and/or BEVs with 5-5-5 battery pack may be the winning technologies for vehicles. Building and installing H2 stations and quick charge stations in appropriate numbers is not a real challenge and will become just another business apportunity.

The well to wheel efficiency of these cells is not really important if they are being used as a range extender periodically.

If they were used like a spare tire - only when really needed - it would give a great deal of peace of mind to many BEV drivers at very little cost. For example, using Yang and Knickle's current figures, a 13kWh battery would weigh only 10kg, 22lbs and cost only $390. That's pretty cheap insurance for 40 miles or so of on-tap emergency range with very little weight penalty.

A comparable Li ion battery would be ~$3,900 and weigh about 150 kg, 330 lbs.

I can even imagine a 1/4 size application - 10 miles range, 5.5 lbs, $100. It would likely be a popular option. Even if manufacturers didn't build it in, I can imagine a robust 3rd party market (spare gas can, without the risk).

When used, the battery would cost $9.75 per mile, but if it wasn't used, the unit would likely retain much of its value, just like a spare wheel and tire.


Do you mean $0.0975/per mile based on current aluminium price or recycling cost?

I was just using the figures from the Yang and Knickle study. I would hope that the cost could be much lower based on recycled aluminum cost, but I don't have any data for this. My point was just that even if this was ridiculously un-economic for a typical fuel use, it could still be a useful component of any EV as a "spare" given its tremendous energy density and unlimited shelf life.


Normally, it cost about 5 times less to recycle aluminium than to for the initial new product.

If this cost ratio keeps up, the battery operation cost could go from about 10 cents/mile for the initial first charge to as low as 2 cents/mile for subsequent recharges.

Average ICEVs cost about 20 cents/miles for gas ($4.00/gallon @ 20 miles per gallon) in USA and about twice as much in EU for the same car. In Canada, the current average cost is about 27 cents/mile for gas.

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