Tesla Patent Suggests Mitigating Thermal Runaway With Metal-Air Batteries

The ingenious idea brings us more questions than answers.

Apart from bringing battery prices down and energy density up, electric car manufacturers have the goal of making their vehicles as safe as possible. That implies mitigating thermal runaway, the most frequent cause of EV fires. What happens is that the lithium-ion battery heats so much it expels hot gases that burn everything around. A new Tesla patent wants to prevent that with a metal-air battery pack connected to the main one.

You may wonder how that would work, but the principle is relatively simple. According to the patent, the two battery packs would be connected by tubes and valves. If a thermal runaway started, the valves would open and allow the hot gas to flow through the metal-air battery pack, cooling the gas before it escapes to the surroundings of the car.