Researchers think that swapping commercial Li-ion batteries’ carbon anodes with anodes made from silicon could boost battery capacity severalfold. That switch has not occurred, however, because the charging process—the electrochemical lithiation of silicon—causes Si anodes to swell to more than three times their initial size. That expansion, and the contraction that accompanies discharge, fatigues and cracks the anode material and leads to battery failure. Nonetheless, silicon’s large charge capacity makes it an attractive anode candidate material with potential application in electric vehicles. So researchers in industry and academia continue to study its properties. For example, 3M just announced that it is matching a $4.6 million Department of Energy grant to develop Si-anode Li-ion batteries. The PNNL team, which was led by Chongmin Wang and Fei Gao and included researchers at General Motors, Oak Ridge National Laboratory, and Applied Sciences, conducted its investigation on anodes made from a silicon-carbon nanocomposite.
by Mitch Jacoby |
March 26, 2012