Li^+、Co^(3+)和F^-共掺杂LiNi_(0.5)Mn_(1.5)O_4的结构与性能

Structure and performance of Li^+-Co^(3+)-F^-co-doped LiNi_(0.5)Mn_(1.5)O_4 as cathode material for Li-ion battery

用均匀设计法优化了Co^(3+)、Li^+、F^-共掺杂的LiNi_(0.5)Mn_(1.5)O_4的组成和性能,并用XRD、SEM和恒电流充放电技术研究掺杂对材料结构、形貌和充放电性能的影响。结果表明,共掺杂和未掺杂LiNi_(0.5)Mn_(1.5)O_4均具有Fd3m尖晶石结构,掺杂离子以固溶体形式存在,Co^(3+)、Li^+和F^-共掺杂能同时提高材料的放电比容量和循环性能,其中Li_(1.02)Co_(0.07)Ni_(0.41)Mn_(1.5)O_(3.955)F_(0.045)的放电容量为145.4 m A·h/g,50个循环后容量保持率为97.1%。

Co3＋-Li＋-F-co-doped LiNi0.5Mn1.5O4 was optimized by uniform design method.The samples were characterized by X-ray diffraction and scanning electron microscope,and their electrochemical performances were investigated by the galvanostatic charge/discharge in terms of cycling performance.Results indicated that the doped LiNi0.5Mn1.5O4 and pure LiNi0.5Mn1.5O4 had well regulated spinel structure（Fd3m）,and doping ions entered the LiNi0.5Mn1.5O4 lattice and formed the solid solution.Li1.02Co0.07Ni0.41Mn1.5O3.955F0.045 delivered a discharge capacity of 145.4 m A·h/g with a capacity retention rate of97.1% after 50 cycles,exhibiting an improved cycle performance and discharge capacity.