Si@Cu composite anode material prepared by magnetron sputtering for high-capacity lithium-ion batteries

Abstract In this study, Si@Cu composite anode material is prepared by magnetron sputtering method and applied for lithium-ion batteries. The Cu component with higher intrinsic conductivity can help to improve the conductivity of the Si particles effectively. The irregularly shaped micro-sized Si particles have reduced agglomeration effect compared with nano-sized particles. In order to further relieve the volume effect of the Si particles during charging and discharging processes, carbon layer is further introduced, which will further boost the conductivity and the cyclic performance. The Si@Cu@C composite electrode exhibits a remarkably improved electrochemical performance with reversible capacity of 1130 mAhg−1 after 100 cycles with coulombic efficiency of 99.3%. The methods used for the preparation of the Si@Cu and Si@Cu@C composite materials are both mass-productive, which is benefit for their practical applications. Moreover, magnetron sputtering method used for composite power preparation has broad application prospects in micro-sized composite material preparation.