固相法合成高电压正极材料镍铬锰酸锂

摘要

5V尖晶石型LiNi0.5Mn15.O4以其高能量密度、价格低廉、无环境污染等特点被视为最具发展潜力的锂离子电池正极材料之一.分别采用蔗糖、葡萄糖、柠檬酸3种不同碳源,通过固相混合、掺铬、球磨、高温煅烧制备出镍铬锰酸锂.通过XRD、SEM、粒度测量和电池充放电性能测试,对样品的结构、形貌、粒径、粒径分布及电性能等进行了分析.结果表明,加柠檬酸可制得粒径更细、粒径分布更窄的亚微米级的尖晶石型LiCr0.2Ni0.4Mn1.4O4,且其具有更好的电化学性能,在3.4～5.2V、1C下放电比容量可达149 mA·h/g,循环100次后容量保持率为98.0％.%5 V spinel LiNi0.5Mn1.5O4 is one of the most potential cathode materials for lithium-ion batteries because of its advantages of high energy density, low cost, and no pollution to the environment etc.Different carbon sources, such as sucrose, glucose,and citric acid,were adopted respectively as first,and then LiCr0.2Ni0.4Mn1.4O4 was prepared by solid mixture,doping chromium,ball milling,and high temperature calcination.Structure, morphology, particle size,particle size distribution,and electrical performance of the samples were analyzed by XRD, EM, particle size measurement and constant current charge-discharge cycling test.Results showed that submicron spinel LiCr0.2Ni0.4Mn1.4O4 with thinner particle size, narrower size distribution , and better electrical performance was obtained when glucose was added.Specific capacity of LiCr0.2Ni0.4Mn1.4O4 cathode material was 149 mA·h/g charged at 3.4~5.2 V and 1 C and retained 98 % of the initial capacity after 100 cycles.