掺杂Mg对LiCo_(0.7)Al_(0.3)O_2性能的影响

The effects of doping Mg on the performance of LiCo_(0.7)Al_(0.3)O_2

采用溶胶-凝胶法合成了锂离子电池正极材料LiCo0.7Al0.3-xMgxO2(x=0,0.03,0.05,0.07)。用XRD和SEM研究了材料的晶体结构和表观形貌;通过恒流充放电和循环伏安研究了材料的电化学性能。结果表明:LiCo0.7Al0.3-xMgxO2样品均为-αNaFeO2型层状结构,形貌近似为球形,且颗粒分布均匀。掺杂Mg后,材料的充放电电压略有降低;LiCo0.7Al0.25Mg0.05O2样品的首次放电比容量为122.10 mAh/g,30次循环后的容量保持率为95.03%。

LiCo0.7Al0.3-xO2 （ x = 0, 0.03, 0.05, 0.07） cathode materials for Li-ion battery were synthesized by sol-gel method. The crystal structure and apparent morphology of the materials were studied by XRD and SEM. The electrochemical performance of the materials was studied by the galvanostatic charge-discharge and cyclic vohammogram（CV）. The results showed that LiCo0.7Al0.3-xO2 samples were α-NaFeO2 layered structures, the morphology was approximative spherical shape, the particle distribution was uniform. The charge-discharge voltage of the materials decreased slightly after doping Mg. The initial specific discharge capacity of LiCo0.7Al0.25Mg0.05O2 sample was 122.10 mAh/g, the capacity retention rate was 95.03 % after 30 cycles.