A nanosized silicon thin film as high capacity anode material for Li-ion rechargeable batteries

Silicon thin film with thickness in range 1000–5300 Å deposited on rough Cu foil by a radio frequency magnetron sputtering is used as anode materials for Li-ion rechargeable batteries. The SEM, XRD and TEM analysis reveals that the Si thin film has a floccular nano-sized multi-crystalline structure. Li ions insertion/extraction evaluation is performed mainly with constant current charge/discharge cycling and cyclic voltammetry (CV) at room temperature. The cycleability and reversible discharge capacity are found to depend on the film thickness, and thinner films give larger accommodation capacity. A 3120 Å Si film provides a reversible specific capacity over 3500 mA hg−1 with excellent cycleability under 0.5 C charge/discharge rate.