"Solid oxygen" key to high-capacity lithium-air battery

By making cells that contain their own oxygen, rather than relying on the proportion of oxygen in the air, the research team, which also includes members from Argonne National Laboratory and Peking University in Beijing, claim it have overcome many of the drawbacks that have previously plagued the development of this promising battery chemistry.

Lithium-air batteries have been a goal of energy researchers for over 40 years, because in theory they can store four times as much charge per kilogramme than lithium-ion cells. This has come at a price, however. The cells work by using oxygen to drive an electrochemical reaction with lithium in the battery’s electrodes; this oxygen is then released when the battery is discharged. But the non-oxygen components of air, especially carbon dioxide and water vapour, damage the electrodes; moreover, as the crucial reaction transforms oxygen from a gaseous phase into a solid one and then recharging changes it back; the gas-to-solid conversion consumes energy, reducing the battery efficiency; and both processes involve very large changes of volume that can dislodge connections inside the battery, reducing its life.