Preparation and electrochemical performance of porous si/siox/g composite anode for lithium ion batteries

Abstract

Silicon/silicon oxides/graphite (Si/SiOx/G) composite with high capacity and excellent cycling performance has been synthesized via high temperature treatment, HF etching and high-energy ball milling for mixture of silicon oxide and graphite. The chemical composition and morphology of the sample was characterized by XRD, SEM and TEM. Large numbers of nanopores were formed in the as-prepared composite, providing three-dimensional transmission pathways for lithium ions and electrons. After 100 cycles, the electrode kept an excellent reversible capacity of 804.2mAh•g-1. The excellent electrochemical properties are mainly attributed to the uniform distribution of silicon particles in amorphous silicon oxide, the buffering effect of porous structure and the improvement of conductivity of the composite by graphite.