正极材料LiNi1/3Co1/3Mn1/3O2的Mg掺杂及电化学性能

为提高正极材料LiNi_1/3Co_1/3Mn_1/3O₂的循环性能, 采用氢氧化物共沉淀法对前驱体进行Mg掺杂, 再经过混锂、球磨、高温煅烧后, 分别对掺杂与未掺杂的正极材料进行了XRD、SEM及电化学性能的比较.研究结果表明:掺杂与未掺杂的正极材料都为标准的α-NaFeO₂型层状结构, 粒度大小无明显变化; 对于掺杂量为0.03与未掺杂的正极材料, 首轮放电比容量分别为138.2 mAh/g和145.3 mAh/g; 而循环50轮的放电比容量则分别为131.1 mAh/g和119.5 mAh/g.由此可见, 通过Mg掺杂, 正极材料的首轮放电比容量虽有少量降低, 而循环性能却有明显增强. 

Mg-doping and electrochemical properties of Li (Ni1/3Co1/3Mn1/3) O2 cathode material

Hydroxide coprecipitation method was used to dope Mg to the precursor to improve the cycle performance of LiNi_1/3Co_1/3Mn_1/3O₂ cathode materials. The cathode materials were synthesized by mixing the precursor with lithium salt, ball milling and high temperature calcination. The doped and undoped cathode materials were compared by SEM, XRD and electrochemical Testing respectively. The results showed that both the doped and undoped cathode materials were standard α-NaFeO₂ layered structures with no obvious changes in particle sizes. The initial specific discharge capacity were 138.2 and 145.3 mAh/g for the cathode materials doped with 0.03 Mg and the undoped cathode materials. The specific discharge capacities were 131.1 and 119.5mAh/g separately after 50 cycles. The results indicated the cycle performance increased notably after doping Mg though the initial specific discharge capacity decreased slightly.