Lithium-air battery four times as much energy per pound as today’s best lithium-ion batteries

Imaging reveals what happens during charging; could lead to improved batteries for electric cars.

One of the most promising new kinds of battery to power electric cars is called a lithium-air battery, which could store up to four times as much energy per pound as today’s best lithium-ion batteries.

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; this 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.

The work is described in a Nano Letters paper by Robert Mitchell, who recently received a PhD in materials science and engineering from MIT; mechanical engineering PhD student Betar Gallant; Carl Thompson, the Stavros Salapatas Professor of Materials Science and Engineering; Yang Shao-Horn, the Gail E. Kendall Associate Professor of Mechanical Engineering and Materials Science and Engineering; and four other authors.

Faster charging

In fact, the rate of lithium peroxide oxidation in these experiments was approximately 100 times faster than the charging time for laboratory-scale lithium-air batteries, and approaches what is needed for applications. This demonstrates that if these batteries’ electron-transfer characteristics can be improved, it could allow for much faster charging while minimizing energy losses.

Source: http://web.mit.edu/newsoffice/2013/real-time-charging-of-lithium-air-battery-0513.html