摘要
采用高温固相法合成掺杂Gd3+的锰酸锂LiGdxMn2-xO4(x=0、0.01、0.05、0.1)锂离子电池正极材料并研究了其结构与电化学特性。XRD分析表明,随着Gd3+含量的增加,材料的晶格参数、晶胞体积、Mn—Mn、Mn—O键距、Mn3+/Mn4+比值均下降,材料结构稳定性得到改善。当x≥0.05时第二相Gd2O3析出。循环伏安(CV)和电化学阻抗(EIS)分析表明掺杂Gd3+能降低LiMn2O4在电化学过程中的阴/阳极极化和电荷转移电阻,提高材料的电化学可逆性和动力学性能。恒流充放电实验发现Gd3+的掺入明显改善了材料的循环性能、高温性能以及倍率性能。
Gd3＋-doping lithium manganese oxide LiGdxMn2-xO4（x=0,0.01,0.05,0.1） materials were synthesized by solid-state sintering method and their structure and electrochemical performance were investigated in this paper.The part substitution of rare-earth element Gd3＋ for Mn in LiMn2O4 was found to decrease the lattice parameter,unit cell volume,Mn—Mn and Mn—O bond spacings,Mn3＋/Mn4＋ ratio,which result in the improvement of structure stability of LiMn2O4.When x≥0.05,Gd2O3 second phase appears.Cyclic voltammongram（CV） and electrochemical impedance spectroscopy（EIS） analyses indicated that Gd3＋-doping could reduce the cathode anode polarization and the charge transfer resistance during the electrochemical process,and thus improve the electrochemical reversibility and kinetics of LiMn2O4 electrode material.Electrochemical measurements showed that the cyclability,high-temperature and high-rate performances of LiMn2O4 electrode materials were significantly improved with increasing Gd3＋ addition.
出处
《功能材料》
EI
CAS
CSCD
北大核心
2011年第5期955-958,共4页
Journal of Functional Materials
关键词
锂离子电池
锰酸锂
掺杂
钆
电化学性能
lithium-ion battery
LiMn2O4
Gd3＋-doping
electrochemical performance
