Silicon anode prepared by rotary evaporation for lithium ion batteries

Abstract

A rotary evaporation process was applied to improve electrical contact between acetylene black (AB) and Si electrode. Morphologies and electrochemical properties of the Si electrode were compared with those of conventionally prepared Si electrode. In the evaporated Si electrode, AB particles consisted of network-like structure surrounding the surface of Si particle, while in the conventional one, AB particles partially stuck on the Si surface. Increasing the current density from 0.1 to 0.5 C, stable cycle behavior with a slight decrease in discharge capacity was found in the evaporated electrode, while unstable cycle behavior with a significantly decreased capacity was observed in the conventional electrode. At high-current density (0.5 C rate), the discharge capacity of the evaporated Si electrode was maintained over 480 mAh g−1 after 100 cycles. The good cycle performance was attributed to the low resistance induced by the improved interfacial contact between AB and Si particles.