Cycling Performance of Different Nano Sized Silicon Particles in a Carbon Matrix

Abstract

Silicon is among the most promising material for next generation anode battery material, with over ten times higher capacity than graphite and the second most abundant element on earth crust after oxygen. However silicon faces a host of well known (but not well understood) problems that prevent it’s widespread commercialization. The pulverization of silicon particles due to volume expansion related stress is well know. 150nm is postulated as the maximum size below which particles can withstand this stress and maintain mechanical integrity (The success story of graphite as a lithium-ion anode material – fundamentals, remaining challenges, and recent developments including silicon (oxide) composites (rsc.org)). Real world materials don’t have a single particle size though, they have a particle size distribution. In this study the cycling performance of a silicon raw material with different particle size is evaluated as part of a silicon graphite composite material. Different silicon submicron to nano sized particles in a carbon matrix containing graphite and binders were produced. Through both powder characteristics and electrochemical testing, we can show that the sizes will have an impact on columbic efficiency and is crucial for the cycling life.