物理化学学报 >> 2016, Vol. 32 >> Issue (8): 2007-2017.doi: 10.3866/PKU.WHXB201604261

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电解液对水系可充电池MnO2正极电化学性能的影响

白守礼1,李欣1,文越华2,*(),程杰2,曹高萍2,杨裕生1,2,李殿卿1,*()   

  1. 1 北京化工大学理学院,北京110159
    2 北京防化研究院,北京100191
  • 收稿日期:2016-02-15 发布日期:2016-07-29
  • 通讯作者: 文越华,李殿卿 E-mail:wen_yuehua@126.com;lidq@mail.buct.edu.cn

Effect of Electrolyte on the Electrochemical Performance of the MnO2 Cathode for Aqueous Rechargeable Batteries

Shou-Li BAI1,Xin LI1,Yue-Hua WEN2,*(),Jie CHENG2,Gao-Ping CAO2,Yu-Sheng YANG1,2,Dian-Qing LI1,*()   

  1. 1 Faculty of Science, Beijing University of Chemical Technology, Beijing 110159, P. R. China
    2 Research Institute of Chemical Defence, Beijing 100191, P. R. China
  • Received:2016-02-15 Published:2016-07-29
  • Contact: Yue-Hua WEN,Dian-Qing LI E-mail:wen_yuehua@126.com;lidq@mail.buct.edu.cn

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摘要：

研究了水系电解液中Li+、Zn2+和Mn2+阳离子对具有不同晶型结构和形貌的MnO2正极电化学性能的影响，探讨其储能机理。结果表明，在不含Mn(II)离子的水溶液中，MnO2电极所表现的电化学性能趋同，容量低，衰减快。含有Zn2+离子的水溶液中，MnO2电极因二价锌离子的嵌入-脱出，容量明显提升，但衰减严重。当溶液中同时含有Zn2+、Mn2+离子时，基于Mn2+和Zn2+离子之间的协同作用和Mn2+离子氧化/还原反应过程的作用，有效抑制MnO2颗粒的聚集和结构塌陷，削弱碱式硫酸锌杂质不利的影响，保持了锌离子在MnO2电极中嵌入-脱出的高容量特性(200 mAh·g-1，电流密度：100 mA·g-1)，及良好的循环稳定性。

关键词: 水系可充电池, MnO2, 电解液, 锌锰离子存储

Abstract:

The effect of Li+, Zn2+, and Mn2+ ions in aqueous solution on the electrochemical performance of the MnO2 cathode characterized by different crystal structures and morphologies was investigated. The energy storage mechanism of MnO2 in the mixed solution was probed. The results show that in aqueous solution without Mn2+ ions, various MnO2 electrodes exhibit similar electrochemical performance with low capacity and severe attenuation. In an aqueous solution with Zn2+ ions, the capacity of MnO2 electrodes is enhanced, which can be attributed to insertion/extraction of zinc ions. However, the decay of the capacity is drastic. When aqueous solutions containing Mn2+ and Zn2+ ions are used, particle aggregation and crystal structure collapse of MnO2 are effectively prevented owing to the synergistic effect of zinc and manganese ions and the redox reaction process of Mn2+ ions. The negative influence of the ZnSO4·3Zn(OH)2 impurity is also weakened. As a result, the high capacity of MnO2 electrodes resulting from insertion/extraction of zinc ions is maintained (~200 mAh·g-1 at 100 mA·g-1) with excellent cycling stability.

Key words: Aqueous rechargeable battery, Manganese dioxide, Electrolyte, Zinc and manganese ion storage