储能科学与技术 ›› 2020, Vol. 9 ›› Issue (2): 353-360.doi: 10.19799/j.cnki.2095-4239.2019.0222

• 庆祝陈立泉院士八十寿辰专刊 • 上一篇    下一篇

锂离子电池正极材料β-Li0.3V2O5 的电化学性能研究

邹剑, 汪博筠, 杨家超, 牛晓滨, 王丽平()   

  1. 电子科技大学材料与能源学院,四川 成都 610054
  • 收稿日期:2019-10-07 修回日期:2019-11-01 出版日期:2020-03-05 发布日期:2019-11-11
  • 通讯作者: 王丽平 E-mail:lipingwang@uestc.edu.cn
  • 作者简介:邹剑(1993—),男,博士研究生,从事高能量密度电池电极材料制备研究,E-mail: jian.zou.fxm@foxmail.com;
  • 基金资助:
    中央高校业务费集成攻关项目(ZYGX2019Z008)

Electrochemical performance of β-Li0.3V2O5 as a lithium-ion battery cathode material

Jian ZOU, Bojun WANG, Jiachao YANG, Xiaobin NIU, Liping WANG()   

  1. School of Materials and Energy, University of Electronic Science and Technology of China, Chengdu 610054, Sichuan, China
  • Received:2019-10-07 Revised:2019-11-01 Online:2020-03-05 Published:2019-11-11
  • Contact: Liping WANG E-mail:lipingwang@uestc.edu.cn

摘要:

随着金属锂电池和全固态锂电池的发展,具有高能量密度无锂/少锂正极材料逐渐受到大家的广泛关注。该文通过一步固相法合成了结晶良好的微米颗粒少锂正极材料β-Li0.3V2O5,电子电导率为2.20×10-4 S/cm。该材料具有良好的循环性能,在2.2~4.0 V区间,0.5C电流下可逆容量为247 mA·h/g,循环100周仍有204 mA·h/g;同时倍率性能优异,在10C下容量为160 mA·h/g。利用非原位XRD,研究了该材料在1.5~4.0 V区间锂的嵌入/脱出过程的相变化,具体过程为:β(0<x<0.27) → β'(0.57<x<0.75) → β1 (0.57<x<1.92) → β2(0.75<x<1.92) → β3(1.92<x<2.52)。整个充放电过程中,体积形变较小,晶胞参数a最大形变为3.1%(β2),晶胞参数c最大形变为4.5%(β3)。

关键词: 高能量密度, 锂离子电池, 少锂正极材料, 钒酸锂, 相转变反应

Abstract:

With the development of lithium (Li) and all-solid-state batteries, high energy-density Li-free/deficient cathode materials have received considerable attention. In this study, well-crystallized micron-size Li-deficient cathode material β-Li0.3V2O5 is synthesized via a one-step high-temperature solid-state reaction with an electronic conductivity of 2.20 × 10-4 S/cm. This material exhibits good cycling performance. It delivers a specific capacity of 247 mA·h/g when charging/discharging at 0.5 C between 2.2 V and 4.0 V, with a residual specific capacity of 204 mA·h/g after 100 cycles. In addition, β-Li0.3V2O5 shows excellent rate capabilities, i.e., 160 mA·h/g at 10C. Ex situ X-ray diffraction is applied to study phase transformations during the Li insertion/extraction process; five different phases exist in the voltage range of 1.5—4.0 V: β(0<x<0.27) → β′(0.57<x<0.75) → β1(0.57<x<1.92) → β2(0.75<x<1.92) → β3(1.92<x<2.52). The volume undergoes a small change during the cycling

process

a increases by a maximum of 3.1% (β2) and c increases by a maximum of 4.5% (β3).

Key words: high energy density, lithium ion batteries, Li deficient cathodes, vanadium oxide bronzes, phase transformations

中图分类号: