LiOH-LiNO_3低共熔混合锂盐体系合成LiNi_(1/3)Co_(1/3)Al_(1/3)O_2

Synthesis of LiNi_(1/3)Co_(1/3)Al_(1/3)O_2 cathode material by eutectic molten salt LiOH-LiNO_3

利用低共熔组成的0.38LiOH.H2O-0.62LiNO3混合锂盐体系与共沉淀合成的前躯体Ni1/3Co1/3Al1/3(OH)2简单混合,经三阶段温度烧结制备出锂离子电池正极材料LiNi1/3Co1/3Al1/3O2,该法工艺简单,成本低,无需研磨即可以使物料在低共熔点温度上达到均匀混合的目的。经X粉末射线衍射(XRD)分析表明,合成的LiNi1/3Co1/3Al1/3O2具有典型的α-NaFeO2六方层状结构,其特征衍射峰I(003)/I(104)的峰强比值高达1.73。电性能测试表明,在55℃,电压范围为2.8～4.3V,充放电倍率为0.2C的条件下,首次充放电比容量为156.4mAh/g,30次循环后容量保持率为94.1%,1和2C倍率放电容量仍可达到143.2和127.9mAh/g,其电性能均优于常温下的性能。

A lithium-ion battery cathode material,LiNi1/3Co1/3Al1/3O2,with excellent electrochemical properties was prepared via three-phase temperature sintering,using eutectic lithium salts（0.38LiOH·H2O-0.62LiNO3） mixed with the precursor Ni1/3Co1/3Al1/3（OH）2.This method was possessed of simple process and low cost,moreover,materials could mixed uniformly at the eutectic melting point without any grinding.The well-layered α-NaFeO2 structure was confirmed by X-ray diffraction（XRD）.The ratio of characteristic diffraction peak I（003）/I（104） was high to 1.73.The charge-discharge test indicated synthesized powder showed an initial charge-discharge capacity of 156.4mAh/g at a specific current of 0.2C at 55℃ in the rang 2.8-4.3V up to 30 cycles with no noticeable capacity-fading（94.1% of the first discharge capacity）,and the reversible capacity of 143.2 and 127.9mAh/g at a specific current of 1C and 2C charge-discharge rate.