Principal Investigator Yet-Ming Chiang
Various metal-lithium alloys have previously been studied as alternatives to carbon as negative electrodes in rechargeable lithium-ion batteries, due to their high weight- and volumetric-energy densities. However, severe volume changes during cycling usually lead to low cycleability. We are taking a new approach to synthesizing materials which can accommodate phase transformations and volume changes during electrochemical cycling. Anodes consisting of fine metal particles embedded in a conductive oxide matrix have been produced by internal reduction of solid solution oxides. Also, phase separation followed by partial reduction has been applied to spinodally-decomposed microstructures. These synthesis methods result in formation of ultrafine metal-oxide composites with inherent strains that allow the metal phase to undergo significant and cyclic lithiation.