Preparation of LiFePO_4 Thin Films by Pulsed Laser Deposition and Their Electrochemical Properties

摘要

Olivine structured LiFePO_4 thin films were prepared by pulsed laser deposition and their electrochemical properties were investigated by cyclic voltammetry (CV) and charge-discharge tests. The resultant films exhibited only a couple of anodic and cathodic peaks at approx 3.4 V, which is characteristic of olivine LiFePO_4, on CV between 2.0 and 5.0 V (vs. Li/Li~+). The discharge capacity estimated from the CV obtained at 100mVs~(-1) maintained 69 percent of that obtained at 1 mVs~(-1). This high rate capability is probably due to the film being so thin that the intrinsically poor electronic conductivity of LiFePO_4 was not of importance.