Large Scale Fabrication of Si-Sn Composite Materials by Electroless Deposition for Li Ion Battery

Silicon is considered an excellent negative electrode material for lithium-ion batteries due to its abundant storage on earth and high theoretical specific capacity. However, the volume effect and poor conductivity limit its large-scale promotion. In order to solve the above problems, Si-Sn composite with controllable tin contents have been prepared in large scale by a simple electroless deposition method, where temperature successfully controlled the contents of tin. The synthesized compounds were identified as silicon-tin compounds by X-ray diffraction. The particle morphology of the Si powders after ethanol washed, Sn prepared by electroless deposition without Si and Si-Sn composites were observed by SEM analysis. The cyclic voltammetry (CV) curve of Si-Sn composites electrode shows distinct peaks related to the specific lithiation or delithiation steps corresponding to Si and Sn, which indicates that the metal Sn is successfully deposited on the surface of Si powders by electroless deposition. After Sn electroless deposition, the electrochemical performance is significantly improved.