Structure and Electrochemical Properties of Hierarchically Porous Silicon Film Prepared with the Combination of Magnetron Sputtering Deposition and Metal-Assisted Chemical Etching

A novel hierarchically porous silicon film on Cu foil was fabricated by employing the combination of magnetron sputtering deposition and metal-assisted chemical etching technology. The as-prepared porous Si film were directly used as working electrodes without adding of binder or electron conductive agent, which exhibited high specific capacities and stable cyclability. Specifically, a high initial discharge capacity of 1976 mAh g(-1) is attained at a current density of 300 mA g(-1) and a stable discharge capacity of 1629 mAh g(-1) obtained after 100 cycles. This superior electrochemical properties could be ascribed to the unique hierarchically porous structure, effectively buffering volume changes during the charge/discharge process.