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.
|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 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.
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