Lithium Electrochemistry of a Novel SnSe Thin-Film Anode

Abstract

SnSe thin film prepared by reactive pulsed laser deposition (PLD) method was found to be a novel and promising anode material. Cyclic voltammetry (CV) and discharge and charge behaviors of Li ∕ Sn Se cells were examined, and the reversible discharge capacities in the range from 400 to 681 mAh ∕ g were achieved during the first 40 cycles . A reduction in oxidation peaks at 1.3 and 1.9 V from CV curves of Li ∕ Sn Se cell was first observed, indicating the reversible formation and decomposition of reaction of Li 2 Se . This feature is utterly different from those of Sn O 2 or SnO and Sn S 2 , in which Li 2 O and Li 2 S are inactive. The lithium electrochemical reaction of SnSe thin-film electrode has been investigated by scanning electron microscopy (SEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). Both classical alloying process and the selenidation-reduction of nanosized metal tin were revealed in lithium electrochemical reaction of SnSe. SnSe as the starting material for conversion to Li–Sn alloy can improve its electrochemical performance with high reversible capacity and good, stable cyclability, demonstrating a promising anode material for future rechargeable lithium batteries.