Abstract: SnSe thin film has been successfully fabricated by using pulsed laser ablation of mixed target of Sn and Se. The structure and electrochemical properties of the as-deposited thin film at different substrate temperatures have been investigated by X-ray diffraction (XRD), the charge/discharge and cyclic voltammetry (CV) measurements. The thin film deposited at room temperature consisted of a mixture of Sn and Se. When the substrate temperature was 200 ℃, the as-deposited thin film was mainly composed of crystallized SnSe. The reversible discharge capacities fell into the range from 260 mAh•g-1 to 498 mAh•g-1. A reduction and an oxidation peaks at 0.75 V and 2.17 V from CV curves of Li/SnSe cell were firstly found, indicating the reversible formation and decomposition of Li2Se. This feature is utterly different from those of SnOx and SnSx, in which Li2O and Li2S are inactive. The lithium electrochemical reaction of SnSe thin film electrode was investigated by XRD. Both classical alloying process and the selenylation-reduction of metal tin were revealed in lithium electrochemical reaction of SnSe. SnSe as the starting material for conversion to the Li-Sn alloy can improve its electrochemical performance with high reversible capacity and good stable cycle, demonstrating to be one of promise anode materials for future rechargeable lithium batteries.

Key words: SnSe, Pulsed laser deposition, Li ion batteries, Thin films