摘要
以燃烧法按不同Li/Mn比制备了一系列尖晶石LiMn2O4正极材料,并对其晶体结构及电化学性能进行了研究。根据样品的化学成分、晶胞参数、理论密度及真密度计算了它们的晶体化学式;发现随着Li/Mn比增加,锰酸锂材料晶体结构中的金属离子缺陷及氧缺陷增加。充放电循环测试结果表明:晶体结构中离子缺陷少的材料在低倍率放电时表现出相对高的比容量和差的循环性能;适量Li掺杂导致晶体结构中含一定离子缺陷的材料在高倍率放电时表现出较高的比容量和优异的循环性能。
The crystal structure and electrochemical performance of spinel LiMn2O4 samples synthesized by combustion method with different ratios of Li/Mn were investigated.The crystal formulas were studied with their chemical compositions,lattice parameters,theoretical densities and real densities.It is concluded that both the metal cation defect and oxygen defect increased with the ratio rise of Li/Mn in the crystal structure of spinel LiMn2O4.The rusult shows that the sample with less ion defect in its crystal structure inclines to be with better capacity and worse cyclic performance at the current density of 0.2 C and the sample with certain ion defect prepared by doping excess of Li exhibites greatly improved capacity and cyclic performance at the current density of 1.0 C.
出处
《电源技术》
CAS
CSCD
北大核心
2010年第3期249-252,共4页
Chinese Journal of Power Sources
