A breakthrough for solid-state lithium-air battery in the US?

US researchers have developed a lithium-air battery with a solid electrolyte, of which the energy density could be increased fourfold compared to today’s lithium-ion batteries. The team said it achieved 1 000 charge and discharge cycles in test cells.

Researchers drive the project at the Illinois Institute of Technology (IIT) and the US Department of Energy’s Argonne National Laboratory. The researchers involved have produced a battery design that uses a solid electrolyte made of a ceramic polymer material.

It consists of “relatively inexpensive elements in nanoparticle form”, according to a release on the project’s findings. A lithium anode and a cathode with an air-permeable structure complete the cell.

Stability problems overcome?

In a test cell with the new chemistry, the 1 000 charge and discharge cycles mentioned are said to have been achieved in the laboratory. “With further development, we expect our new design for the lithium-air battery also to reach a record energy density of 1200 Wh/kg,” declared Larry Curtiss of the Argonne team.

“The chemical reaction for lithium superoxide or peroxide only involves one or two electrons stored per oxygen molecule, whereas that for lithium oxide involves four electrons,” said Argonne chemist Rachid Amine. More electrons stored means higher energy density.

The team’s lithium-air design is the first lithium-air battery to achieve a four-electron reaction at room temperature. It also operates with oxygen supplied by air from the surrounding environment. The capability to run with air avoids the need for oxygen tanks to operate, a problem with earlier designs.

Maybe even more critical: until now, lithium-air cells have revealed significant weaknesses in terms of stability. The team from IIT and Argonne now claims to have achieved the 1 000 charge and discharge cycles mentioned at the beginning in a test cell with the new chemistry.

Highest energy density

According to these scientists, the battery could be used in electric cars, trucks, boats, and aircraft, among other applications, in the future. “For over a decade, scientists at Argonne and elsewhere have been working overtime to develop a lithium battery that uses the oxygen in the air,” Larry Curtiss sums up.

“The lithium-air battery,” he concludes, “has the highest projected energy density of any battery technology being considered for the next generation of batteries after the lithium-ion battery.” Research on the lithium-air battery was funded by the DOE Vehicle Technologies Office and the Office of Basic Energy Sciences through the Joint Center for Energy Storage Research.