以LiOH·H2O、Ni(OH)2和Mn3O4为原料,采用固相法合成锂离子电池正极材料Li[Li0.2Ni0.2Mn0.6]O2。通过X射线衍射(XRD)、扫描电子显微镜(SEM)对所得样品的结构和形貌进行表征,并测试了该材料的倍率性能和高低温性能。结果表明:900℃下烧结10 h后可获得晶粒细小均匀的层状Li[Li0.2Ni0.2Mn0.6]O2材料,并具有良好的电化学性能,放电容量最高可达235.9 mA.h/g;在50℃下测试时该材料的放电容量高达284.4 mA·h/g,并表现出良好的循环性能,其倍率性能和低温性能还有待进一步改善。
Li[Li0.2Ni0.2Mn0.6]O2 was synthesized by solid state method using LiOH·H2O,Ni(OH)2 and Mn3O4 as starting materials.The structure and morphologies of products were characterized by XRD and SEM.The electrochemical performances were also investigated at different rates and temperatures.It is found that the sandwich Li[Li0.2Ni0.2Mn0.6]O2 material obtained at 900 ℃ for 10 h exhibits uniform and fine particle sizes,indicating high electrochemical capacity and good cycling stability.The maximum discharge capacity is 235.9 mA-h/g.The discharge capacity can reach as high as 284.4 mA-h/g at 50℃,and an excellent cyclability is also obtained,while the performance deteriorated at low temperature and the rate capability needs to be improved.