Na^(+)掺杂对LiNi_(1/3)Co_(1/3)Mn_(1/3)O_(2)结构和电化学性质的影响

Effects of Sodium Ion Doping on Structure and Electrochemical Properties of LiNi_(1/3)Co_(1/3)Mn_(1/3)O_(2)

采用高温固相法成功制备了不同Na^(+)掺杂浓度的Li_(1-x)Na_(x)Ni_(1/3)Co_(1/3)Mn_(1/3)O_(2)锂离子电池正极材料,探究了Na元素掺杂对层状氧化物正极材料结构以及电化学性能的影响。通过X射线粉末衍射仪和扫描电子显微镜表征了材料的结构和形貌,结果表明,当x≤0.3时,样品不会出现其它杂相;当x>0.3时,样品中会出现NaNi_(1/3)Co1/3Mn_(1/3)O_(2)的杂相。同时随着掺杂浓度的增加,样品的阳离子混排度逐渐增加。电化学性能结果表明,少量Na+的掺入可以提高LiNi_(1/3)Co_(1/3)Mn_(1/3)O_(2)在0.2C,0.5C下的放电比容量并增强其循环稳定性,但会损坏材料的倍率性能。

Cathode material Li_(1-x)Na_(x)Ni_(1/3)Co_(1/3)Mn_(1/3)O_(2) for lithium ion battery with different doping concentrations were successfully prepared by high temperature solid-state method.Effects of sodium doping on the structure and electrochemical properties of layered oxide cathode materials were investigated.The structure and morphology of the material were characterized by powder X-ray diffraction and scanning electron microscopy.The results indicate that no impurity is observed when x≤0.3,while NaNi_(1/3)Co_(1/3)Mn_(1/3)O_(2) is found in the sample when x>0.3.Moreover,the cation mixing degree of the samples increases gradually with the increase of doping concentration.The electrochemical performance results show that the low doping concentration can improve the discharge specific capacity and cycle stability of LiNi_(1/3)Co_(1/3)Mn_(1/3)O_(2) at 0.2C and 0.5C,but decreases the rate capacity of the material.