Batteries that use aluminum and oxygen normally live fast and die young. But a new design could help these high-energy devices endure.
Aluminum-air batteries are promising candidates for a new generation of non-rechargeable batteries, because they’re super lightweight and compact. The batteries, however, aren’t widely used because their internal components quickly degrade each other. In the new aluminum-air setup, described in the Nov. 9 Science, oil acts as a buffer between the battery’s corrosive components to greatly extend the device’s shelf life. Such improved single-use batteries could provide backup power to electric cars or supply energy in remote, off-the-grid regions.
“This is a very smart design,” says Yiying Wu, a chemist at Ohio State University not involved in the work. The oil-buffer scheme might also improve other types of metal-air batteries susceptible to self-corrosion, like zinc-air devices, he says (SN: 1/21/17, p. 22).
Each aluminum-air battery cell contains two electrodes, an aluminum anode and a cathode, separated by a liquid called an electrolyte. Oxygen molecules sucked from the air enter the cathode, where they react with electrons and aluminum particles that flow through the electrolyte from the anode, releasing energy to power electronics. Unfortunately, when the battery is on standby, the watery electrolyte eats away at the aluminum anode.