物理化学学报 >> 2005, Vol. 21 >> Issue (07): 707-710.doi: 10.3866/PKU.WHXB20050702

研究论文 上一篇    下一篇

脉冲激光沉积LiFePO4阴极薄膜材料及其电化学性能

薛明喆; 傅正文   

  1. 复旦大学化学系激光化学研究所, 上海市分子催化和功能材料重点实验室, 上海 200433
  • 收稿日期:2004-11-09 修回日期:2004-12-20 发布日期:2005-07-15
  • 通讯作者: 傅正文 E-mail:zhengwen@sh163.net

Electrochemical Properties of LiFePO4 Cathode Thin Film Fabricated by Pulsed Laser Deposition

XUE Ming-zhe; FU Zheng-wen   

  1. Department of Chemistry & Laser Chemistry Institute, Shanghai Key Laboratory of Molecular Catalysts and Innovative Materials, Fudan University, Shanghai 200433
  • Received:2004-11-09 Revised:2004-12-20 Published:2005-07-15
  • Contact: FU Zheng-wen E-mail:zhengwen@sh163.net

摘要: 采用脉冲激光沉积结合高温退火的方法在不锈钢基片上制备了LiFePO4薄膜电极. XRD谱图显示, 经650 ℃退火制得的是具有橄榄石结构的LiFePO4薄膜. 充放电测试表明, LiFePO4薄膜具有3.45/3.40 V的充放电平台, 与LiFePO4粉体材料相当. 首次放电容量约为27 mAh•g-1, 充放电循环100次后容量衰减51%.

关键词: 脉冲激光沉积, 锂离子电池, LiFePO4, 薄膜

Abstract: LiFePO4 thin films have been successfully fabricated by using pulsed laser deposition (PLD) coupled with high temperature annealing. The morphology, structure and electrochemical behaviors of the obtained thin films were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), the charge/discharge and cyclic voltammetry (CV) measurements. These results indicated that LiFePO4 thin films had a well-crystallized olivinetype structure before and after annealed at 650 ℃. The annealed LiFePO4 thin film exhibited a 3.45/3.40 V plateau vs Li+/Li in the discharge/charge curves. The first discharge capacity was found to be 27 mAh•g-1 and the discharge capacity kept 49% of the first discharge capacity after cycling 100 times. The low reversible capacity and poor cycling performance of LiFePO4 thin films fabricated by pulsed laser deposition may be due to the lower electrochemical activity of the large particle on the surface of thin film electrode, the existence of part of Fe2O3 produced by the high temperature annealing and the poor conductivity of LiFePO4 material.

Key words: Pulsed laser deposition, Li ion batteries, LiFePO4, Thin films