锂离子电池高镍正极材料的界面改性研究  

Study on interface modification of high nickel cathode materials for lithium ion batteries

作　　者：梁凯 LIANG Kai(Hunan Yuneng New Energy Battery Material Co.,Ltd.,Xiangtan Hunan 411100,China)

机构地区：[1]湖南裕能新能源电池材料有限公司,湖南湘潭411100

出　　处：《电源技术》2021年第6期703-705,772,共4页Chinese Journal of Power Sources

摘　　要：单晶型高镍锂离子电池正极材料,具有工作电压高、比容量高、压实密度高等优势,极具应用潜力。为了改善单晶高镍材料的循环稳定性和热稳定性,选用具有良好抗氧化性的高分子聚合物PVF为表面修饰剂,通过液相法成功在高镍材料颗粒表面上均匀构筑了一层8~10 nm高分子聚合物,不仅如此还借助碱性条件下的消去反应,引入参与构成SEI重要成份LiF。研究结果表明,当修饰剂的量控制在3%(质量分数)时,材料在1 C充放电,循环100次后容量保持率为87.4%,没有经过修饰的材料容量保持率仅有75.5%。DSC测试表明提升了材料的热稳定性,从而提高了电池的安全性。The single crystal high nickel lithium ion cathode material has the advantages of high working voltage,high specific capacity and high compaction density,which is a promising cathode material.To improve the poor cycle stability and thermal stability of single crystal high nickel materials,polymer PVF with good oxidation resistance was applied as surface modification agent,the uniform layer of 8-10 nm polymer was successfully constructed on the surface of high nickel material particles by liquid phase method.Moreover,with the elimination reaction in an alkaline environment,an important composition LiF,in the formation of SEI,was introduced.The results show that when the amount of modifier is controlled at 3%,the capacity retention is 87.4%after 100 cycles at 1 C current density,and only 75.5%without the modification.More importantly,DSC tests show that the thermal stability of the material is improved,thus the safety of the battery is improved.

关 键 词：锂离子正极材料 高镍材料 单晶材料 高分子聚合物 

分 类 号：TM912[电气工程—电力电子与电力传动]