物理化学学报 >> 2014, Vol. 30 >> Issue (3): 460-466.doi: 10.3866/PKU.WHXB201401074

电化学和新能源 上一篇    下一篇

纳米LiMnPO4的制备与电化学性能表征

杨文超1,2, 毕玉敬2, 杨邦成2, 王德宇2, 施思齐1   

  1. 1 上海大学材料科学与工程学院, 上海200444;
    2 中国科学院宁波材料技术与工程研究所, 浙江宁波315201
  • 收稿日期:2013-12-06 修回日期:2014-01-06 发布日期:2014-02-27
  • 通讯作者: 施思齐 E-mail:sqshi@shu.edu.cn
  • 基金资助:

    浙江省钱江人才计划(2012R10078),武汉-中科院院地合作项目(20120216)及国家自然科学基金项目(51372228)资助

Preparation and Electrochemical Characterization of Nano-LiMnPO4

YANG Wen-Chao1,2, BI Yu-Jing2, YANG Bang-Cheng2, WANG De-Yu2, SHI Si-Qi1   

  1. 1 School of Materials Science and Engineering, Shanghai University, Shanghai 200444, P. R. China;
    2 Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201, Zhejiang Province, P. R. China
  • Received:2013-12-06 Revised:2014-01-06 Published:2014-02-27
  • Contact: SHI Si-Qi E-mail:sqshi@shu.edu.cn
  • Supported by:

    The project was supported by the Qianjiang Talent Project of Zhejiang Province, China (2012R10078), Cooperation ofWuhan and Chinese Academy of Sciences (20120216), and National Natural Science Foundation of China (51372228).

摘要:

采用两步加热Polyol 法制备了纳米LiMnPO4 正极材料,详细研究了第一加热平台温度T1 (T1=100,110,120,130,140,150 ℃)对样品物理性质及电化学性能的影响. 通过X 射线衍射(XRD)、扫描电镜(SEM)及比表面积测试(BET)对样品的晶体结构与微观形貌进行了表征. 结果表明,在不同温度T1下得到的样品均为片状结构;T1=100-120 ℃时合成的样品含有杂相,且比表面积小于15 m2·g-1;在T1=130 ℃时,得到纯相LiMnPO4样品,且比表面积增至46.3 m2·g-1;随着T1的进一步升高,样品比表面积稍有下降,维持在35-37 m2·g-1之间. 纳米LiMnPO4的电化学性能变化趋势与比表面积基本一致,T1=130 ℃时合成的样品呈现最优的电化学性能,在0.1C倍率下放电容量达到129 mAh·g-1,在5C倍率时达到81 mAh·g-1,这表明LiMnPO4的比表面积是决定其电化学性能的关键因素之一.

关键词: 锂离子电池, 正极材料, 纳米LiMnPO4, 比表面积, Polyol 法

Abstract:

Nano-LiMnPO4 samples were synthesized via a two-step heating polyol method. The role of the first thermal plateau temperature T1 (T1=100, 110, 120, 130, 140, 150 ℃) on the physical and electrochemical properties of the samples was investigated. Their structures and morphologies were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and N2 sorption measurements. All samples at different plateau temperatures exhibited a sheet structure. At T1=100-120 ℃, samples contained some impurities, and their specific surface areas were <15 m2·g-1. Pure nano-LiMnPO4 was obtained at T1=130 ℃, and exhibited the largest specific surface area (46.3 m2·g-1). The specific surface areas of samples remained at 35-37 m2·g-1 with further increase in T1. The electrochemical performance of the nano-LiMnPO4 samples followed the same trend as their specific surface areas. Nano-LiMnPO4 at T1=130 ℃ exhibited the best electrochemical performance, with a discharge capacity of 129 mAh·g-1 at 0.1C rate and 81 mAh·g-1 at 5C rate. This indicated that the specific surface area is one of the key factors in determining the electrochemical performance of LiMnPO4.

Key words: Lithium-ion battery, Cathode material, Nano-LiMnPO4, Specific surface area, Polyol method

MSC2000: 

  • O646