Aluminum Batteries for Electric Vehicles

Aluminum maker Alcoa has teamed up with battery developer Phinergy to make a battery that’s capable of powering an electric car for over 1000 miles (1600 km).

The only catch: the battery isn’t rechargeable, at least not in the traditional sense.

The Phinergy-Alcoa team is proposing a combination of batteries for electric cars: the main power source would be comprised of rechargeable Li-ion batteries, just like most electric and hybrid cars. A supplemental aluminum-air battery would provide the additional range that allows the car to go 1000 miles. Aluminum-air batteries offer a very high energy density: 2 kWh/kg, about 15 times that of their Li-ion counterparts. Its high energy density comes from the fact that air provides the oxygen needed for the chemical reaction, so one of the chemicals doesn’t need to be contained within the battery itself. That eliminates the weight of the chemical as well as its storage container.

The problem with aluminum-air batteries is that they aren’t “plug-in” rechargeable. The way to recharge aluminum-air batteries is to replace the aluminum plates. Fortunately, aluminum is inexpensive fully recyclable, and Alcoa is a world leader in aluminum production and recycling.

The team believes that electric cars would run on Li-ion batteries for their normal day-to-day driving, which, for 95% of all applications, is within 30 miles (50 km). If you’re going just a little farther, the aluminum-air batteries would give the extra range. Since that rarely happens, the companies estimate that the aluminum would need to be replaced about once per year.