Researchers at MIT and Sandia National Laboratories have used transmission electron microscope (TEM) imaging to observe, at a molecular level, what goes on during a reaction called oxygen evolution as lithium-air batteries charge.

The reaction is thought to be a bottleneck limiting further improvements to these batteries. The TEM technique could help in finding ways to make such batteries practical in the near future.

Findings suggest that lithium-air battery performance would improve if electrodes had a high-surface-area structure to maximize contact between lithium peroxide and the carbon required to transport electrons away during charging.

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Also: Learn about a new class of flow batteries.