锂离子电池正极材料LiNi_(1/3)Co_(1/3)Mn_(1/3)O_2在LiNO_3溶液中的电化学性能研究

Research on Electrochemical Performance of Lithium-Ion Battery Cathode Material LiNi_(1/3)Co_(1/3)Mn_(1/3)O_2 in Aqueous LiNO_3 Solution

由溶胶凝胶法合成的锂离子电池正极材料LiNi1/3Co1/3Mn1/3O2在水溶液体系中具有优异的高倍率充放电性能,放电时能够输出极高功率密度.XRD表征证明合成的LiNi1/3Co1/3Mn1/3O2材料具有层状α-NaFeO2结构,SEM形貌显示材料的粒径约为500nm,恒电流充放电测试表明LiNi1/3Co1/3Mn1/3O2材料在pH12的2mol·L-1LiNO3溶液中,以2C(0.36A/g)倍率充放时,比容量达到了147mAh/g.如以80C(14.4A/g)、150C(27A/g)和220C(39.6A/g)的倍率充放,材料的比容量仍可达到64mAh/g、33mAh/g和16mAh/g,而全电池的功率密度分别达到2574W/kg、3925W/kg、4967W/kg.其中80C倍率充放,经1000周循环后,容量保持率为90.9%.

The cathode material of LiNi1/3Co1/3Mn1/3O2 synthesized by sol-gel method shows excellent high rate performance,and high output power density during discharge process. A well-ordered layered α-NaFeO2 structure was confirmed by XRD and a primary particle size of about 500 nm was indicated by SEM. Galvanostatic charge-discharge test indicates that LiNi1/3Co1/3Mn1/3O2 in 2 mol·L-1 LiNO3 aqueous solution with pH 12 reached a ca-pacity of 147 mAh/g while charged and discharged at 2C. The capacities were 64、33、16 mAh/g with 80C （ 14. 4 A/g） 、150C（ 27 A/g） and 220C （ 39. 6 A/g） charge/discharge rates,while the power densities of the battery were 2574 W/kg、3925 W/kg、4967 W/kg,respectively. It retained 90. 9% of the initial capacity after 1000 cycles at 80 C.