室温离子液体电解液中尖晶石LiMn_2O_4的电化学性质

电化学（中英文） ›› 2005, Vol. 11 ›› Issue (3): 298-303.

室温离子液体电解液中尖晶石LiMn_2O_4的电化学性质

郑洪河,石磊,高书燕,王键吉

河南师范大学化学与环境科学学院,河南师范大学化学与环境科学学院,河南师范大学化学与环境科学学院,河南师范大学化学与环境科学学院河南新乡453007 ,河南新乡453007 ,河南新乡453007 ,河南新乡453007

收稿日期:2005-08-28 修回日期:2005-08-28 出版日期:2005-08-28 发布日期:2005-08-28

An Electrochemical Behavior of LiMn_(2)O_(4) Electrode in Electrolyte Based on Room Temperature Ionic Liquid

ZHENGHong-he~

(*), SHI Lei, GAO Shu-yan, WANG Jian-ji(College of Chemistry & Environmental Sciences, Henan Normal University, Xinxiang 453007, China

Received:2005-08-28 Revised:2005-08-28 Published:2005-08-28 Online:2005-08-28

摘要/Abstract

摘要： 应用循环伏安、恒电流充放电和电化学阻抗技术研究了尖晶石L iMn2O4于室温离子液体电解液中的电化学性质.实验表明,以室温离子液体作电解液,L iMn2O4的首次放电容量可达108.2 mAh/g、循环效率高于90%,温度和电流密度显著影响电极的电化学性能.交流阻抗测定了L i+在电极/电解液相界面迁移的活化能,为55 kJ/mol.根据界面反应的高活化能解释了L iMn2O4在该离子液体电解液中低温性能和倍率充放电性能不佳的原因.

关键词: 锂离子电池, 室温离子液体, 尖晶石LiMn2O4, 交流阻抗

Abstract: The electrochemical behavior of spinel LiMn_(2)O_(4)electrode in ionic liquid electrolyte was investigated by using cyclic voltammetry, galvanostatic charge-discharge and ACimpedance techniques. The results reveal that the spinel LiMn_(2)O_(4)can be effectively cycled in electrolyte based on the ionic liquid with discharge capacity of 108.2mAh/g and Coulombic efficiency of more than 90% in the first cycle at room temperature. Temperature and current density play an important role in the electrode performances. The activation energy for lithium ion transfer through interface between the electrode and the electrolyte was evaluated by AC impedance spectroscopy. The high activation energy accounts for the poor cell performance at low temperature and for its poor rate capability.

Key words: Lithium ion batteries, Room temperature ionic liquid, Spinel LiMn_2O_4, AC impedance

中图分类号:

O646

郑洪河,石磊,高书燕,王键吉. 室温离子液体电解液中尖晶石LiMn_2O_4的电化学性质[J]. 电化学（中英文）, 2005, 11(3): 298-303.

ZHENGHong-he~. An Electrochemical Behavior of LiMn_(2)O_(4) Electrode in Electrolyte Based on Room Temperature Ionic Liquid[J]. Journal of Electrochemistry, 2005, 11(3): 298-303.

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