铝掺杂富锂锰基正极材料Li_(1.2)Ni_(0.2)Mn_(0.6)O_2的研究  

Study on aluminum-doped lithium-rich manganese-based cathode materials of Li_(1.2)Ni_(0.2)Mn_(0.6)O_2

作　　者：周伟[1] 陈彦逍[1] 郭孝东[1] 向伟 Zhou Wei;Chen Yanxiao;Guo Xiaodong;Xiang Wei(Sichuan University,Che ngdu 610065,China;Chengdu University of Technology)

机构地区：[1]四川大学,四川成都610065 [2]成都理工大学

出　　处：《无机盐工业》2021年第6期128-133,共6页Inorganic Chemicals Industry

基　　金：国家自然科学基金项目(项目编号为21805198;项目名称为球形核壳P2层状-隧道复合钠锰氧正极材料制备及协同效应的原位研究)。

摘　　要：针对无钴锰基富锂材料Li_(1.2)Ni_(0.2)Mn_(0.6)O_2固有的循环稳定性差、循环电压衰减严重等问题,研究了铝掺杂结合固相煅烧法对该材料在微观形貌及结构、电化学性能等方面的影响。研究结果显示,铝掺杂不仅能促使该材料的表层形貌更加致密,而且可以为该材料带来更稳定的晶体结构,这有利于该材料在长充放电循环中抵抗因结构降级带来的一系列不利因素,最终致使其电化学性能更加优异。此外,当铝掺杂量为1%(物质的量分数)时该材料在高倍率下的放电比容量、循环稳定性、电压保持率等均达到最优效果,在2.0~4.8 V电压区间内0.1C倍率下首圈放电比容量高达248.8 mA·h/g,200圈循环充放电后其放电比容量保持率由未掺杂时的57.9%提升至77.6%,循环电压保持率也由84.2%提升至85.6%。以上结果充分显示了1%铝掺杂对锰基富锂材料Li_(1.2)Ni_(0.2)Mn_(0.6)O_2具有优异的改良效果。In order to solve the inherent problems of poor cycling stability and serious cycling voltage attenuation of cobaltfree Mn-based lithium-rich materials of Li1.2Ni0.2Mn0.6O2,the effect of aluminum doping combined with solid phase calcination method on the micromorphology,structure and electrochemical properties of the material were studied in this paper.The results showed that the aluminum doping not only made the surface morphology of the material denser,but also brought a more stable crystal structure to the material,which was conducive to the resistance of the material to a series of adverse factors caused by the structural reversion in the long charge-discharge cycle,and finally led to its more excellent electrochemical performance.In addition,when the doping amount of aluminum was 1%,the discharge specific capacity,cycle stability and voltage retention of the material at high rate all achieved the best optimization performance.The discharge specific capacity of the first cycle at 0.1 C ratio was as high as 248.8 mA·h/g in the voltage range of 2.0~4.8 V.After 200 cycles of charging and discharging,the discharge specific capacity retention rate increased from 57.9%to 77.6%,and the cycle voltage retention rate also increased from 84.2%to 85.6%.The above results fully showed that 1%aluminum doping had excellent improvement effect on Mn-based lithium-rich materials of Li1.2Ni0.2Mn0.6O2.

关 键 词：锂离子电池 正极材料 铝掺杂 Li1.2Ni0.2Mn0.6O2 

分 类 号：TQ131.11[化学工程—无机化工]