高等学校化学学报 ›› 2020, Vol. 41 ›› Issue (8): 1859.doi: 10.7503/cjcu20200093

• 物理化学 • 上一篇    下一篇

锌离子电池正极材料V2O5的储能机理和容量衰减原因

黄永烽1,2, 黄文婷1,2, 刘文宝1,2, 刘岳峰3, 刘伟3, 徐成俊1   

  1. 1. 清华大学深圳国际研究生院, 深圳 518055;
    2. 清华大学材料科学与工程学院, 北京 100084;
    3. 中国科学院大连化学物理研究所, 大连 116023
  • 收稿日期:2020-02-24 出版日期:2020-08-10 发布日期:2020-05-09
  • 通讯作者: 徐成俊,男,博士,副研究员,主要从事多价态离子的储能性能研究.E-mail:vivaxuchengjun@163.cn E-mail:vivaxuchengjun@163.cn
  • 基金资助:
    中美国际科技合作项目(批准号:2016YFE0102200)和深圳技术计划项目(批准号:JCYJ20160301154114273)资助.

Mechanism of Storage and Capacity Attenuation of V2O5 as Cathode of Zinc-ion Battery

HUANG Yongfeng1,2, HUANG Wenting1,2, LIU Wenbao1,2, LIU Yuefeng3, LIU Wei3, XU Chengjun1   

  1. 1. International Graduate School at Shenzhen, Tsinghua University, Shenzhen 518055, China;
    2. School of Materials Science and Engineering, Tsinghua University, Beijing 100084, China;
    3. Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 116023 Dalian, China
  • Received:2020-02-24 Online:2020-08-10 Published:2020-05-09
  • Supported by:
    Supported by the International Science & Technology Cooperation Program of China(No. 2016YFE0102200) and the Shenzhen Technical Plan Project, China(No. JCYJ20160301154114273).

摘要: 采用水热法结合热处理制备了具有高结晶性的V2O5,利用X射线衍射仪、球差校正扫描透射电子显微镜和扫描电子显微镜对V2O5的物相和形貌进行了表征,发现制备的V2O5择优取向生长并且具有良好的结晶性.电化学测试结果表明,以V2O5为正极材料的电池在电流密度为0.5 A/g下首次放电比容量约为340 mA·h/g.在电流密度为5 A/g下电池的首次放电比容量为170 mA·h/g,并且循环100次后衰减为50 mA·h/g.对不同放电态的V2O5正极材料的物相进行了分析,得出了V2O5正极材料在充放电过程中发生了锌离子和质子共嵌入(脱出)的反应机理;V2O5正极材料在充放电过程中发生的非晶化和副产物碱式硫酸锌的生成是导致以V2O5作为水系锌离子电池正极材料的电池系统发生容量衰减的主要原因.

关键词: 锌离子电池, 五氧化二钒正极, 球差校正扫描透射电子显微镜, 容量衰减

Abstract: In this paper, the vanadium(V2O5) was prepared by hydrothermal and then heat treatments and characterized by X-ray diffraction(XRD), spherical aberration corrected scanning transmission electron microscopy(STEM) and scanning electron microscopy(SEM). The results show that the prepared V2O5 grew preferentially and had good crystallinity. The V2O5 cathode material had a specific capacity of 340 mA·h/g at initial discharge at constant current of 0.5 A/g. The initial capacity of the battery was 170 mA·h/g at a constant discharge-charge current density of 5 A/g, which gradually decayed to 50 mA·h/g after 100 cycles. By subsequent analysis of the phase evolution of V2O5 cathode materials at different discharge states using XRD and STEM, it was revealed that the co-insertion(extraction) of zinc-ions and protons occured during the discharge-charge processes, and the amorphization of the positive electrode material during discharge-charge and the formation of by-product basic zinc sulfate lead to capacity attenuation of the battery system.

Key words: Zinc-ion battery, V2O5 cathode, Spherical aberration corrected scanning transmission electron microscopy(STEM), Capacity attenuation

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