摘要
用柠檬酸作为螯合物的载体,采用溶胶-凝胶法合成了Al3+掺杂的锂离子电池正极材料LiAlxMn2-xO4,并用XRD、SEM等多种测试手段研究了不同掺杂铝量对粉体形貌、晶体结构的影响。结果表明,800℃烧结可获得单一尖晶石结构的物相。随着Al3+掺入量的增加,LiAlxMn2-xO4的晶格常数变小,晶格更趋于完整,有利于抑制因锂的反复脱嵌而造成结构的破坏。实验表明,当掺Al量为0.05时,首次放电容量为103.8 mAh/g,25次循环后容量还有100.6 mAh/g,容量衰减仅为3.08%。该正极材料具备高的容量和优异的循环性能。
Spinel LiMn2O4 and Al-substituted spinel LiAlxMn2- xO4 （x = 0.05,0.15） were synthesized by a solgel method using citric acid as the chelating agent. Their morphologies and microstructure were examined by powder XRD analysis and SEM. The pattems of XRD suggested that when x is not very high, LiAlxMn2- xO4 is still of spinel structure. The lattice constant decreased with increasing x. Highly crystallized LiAlxMn2-xO4 was prepared by calcination at 800℃. When x = 0.05, the capacity is 103.8 mAh/g for the first cycle, and 100.6 mAh/g after 25 cycles, only a 3.08% decline. Therefore, the Al-doped material has better capacity and cycle performances.
出处
《盐湖研究》
CSCD
2006年第3期29-33,共5页
Journal of Salt Lake Research
基金
北京市教委科技发展项目资助(项目号:km200310005004)
