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电化学(中英文) ›› 2002, Vol. 8 ›› Issue (3): 269-274. 

• 研究论文 • 上一篇    下一篇

尖晶石LiMn_2O_4的表面改性研究

张仁刚,赵世玺,夏君磊,刘韩星   

  1. 武汉理工大学材料复合新技术国家重点实验室,武汉理工大学材料复合新技术国家重点实验室,武汉理工大学材料复合新技术国家重点实验室,武汉理工大学材料复合新技术国家重点实验室 湖北武汉430070 ,湖北武汉430070 ,湖北武汉430070 ,湖北武汉430070
  • 收稿日期:2002-08-28 修回日期:2002-08-28 出版日期:2002-08-28 发布日期:2002-08-28

Study on Modification of spinel LiMn_2O_4 by Overcoating

ZHANG Ren_gang *,ZHAO Shi_xi,XIA Jung_lei,LIU Han_xing   

  1. (Stata Labo. of Advanced Techn. for Materials synthesis and processing,Wuhan Univ. of Techn.,Wuhan, 430070,China
  • Received:2002-08-28 Revised:2002-08-28 Published:2002-08-28 Online:2002-08-28

摘要: 采用溶胶_凝胶法合成尖晶石LiMn2 O4 ,并以LiCoO2 对其进行包覆 ,用XRD、SEM、EPMA等方法对修饰的尖晶石结构和性能进行研究 .结果表明 ,经包覆的LiMn2 O4 在 70 0℃焙烧 10h所得的晶粒是表层富含Co的立方尖晶石 ,而且晶粒中Co3+的含量呈现出从表到里递减的梯度分布 .以该材料作锂离子电池正极 ,虽初始容量稍有降低 ,但能有效地降低Mn2 +在电解质中的溶解 ,而且对Jahn_Teller效应有一定的抑制作用 ,包覆的LiMn2 O4 尖晶石正极材料比未包覆的有更好的循环性能

关键词: 尖晶石LiMn2O4, 溶胶—凝胶, 表面包覆, 循环性能

Abstract: The surface of spinel LiMn 2O 4 was modified by the sol_gel process with LiCoO 2_coated LiMn 2O 4 and studied by XRD,SEM and EPMA.The results have shown that the surface of the coated grains heated at 700 ℃ for 10h,which is cubic spinel,were Co_rich.The amount of Co 3+ in the grains changed owing to different place of the grain and decreased from surface to inner parts. Using the coated as the cathode of Li_ion cells,the initial capacity deceased slightly,but the amount of Mn 2+ solving in electrolyte decreased,Jahn_Teller effect was suppressed to a certain extent.The LiCoO 2_coated LiMn 2O 4 showed better cycling performance than the bare spinel LiMn 2O 4.

Key words: Spinel LiMn 2O 4, Sol_gel, Surface coating, Cycling performance

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