TiO_(2)包覆高镍NCM811的电化学性能研究

Study on the electrochemical performance of TiO_(2)coating on high nickel NCM811

高镍材料具有较好的电化学性能,但其存在着表面稳定性较差的问题,通过钛酸四丁酯在NCM811材料表面水解生成TiO_(2),改善了高镍材料的表面稳定性。利用SEM和TEM对改性后的材料进行表面分析,结果表明,实验成功将TiO_(2)层均匀地包覆在高镍NCM811表面,并且发现,在表面包覆过程中,还发生了体相掺杂。利用表面包覆和体相掺杂的共同作用,在1C放电的条件下,循环200圈后,材料的容量保持率从81.40%提升至92.39%,改善了材料的电化学性能。

High nickel materials have good electrochemical performance,but there is a problem of poor surfacestability.In this study,tetrabutyl titanate was hydrolyzed on the surface of NCM811 material to generate TiO_(2).SEMand TEM analysis results indicate that the TiO_(2)layer can be uniformly coated on the surface of high nickel NCM811using the proposed method.By utilizing the combined effect of surface coating and bulk doping,the capacity retentionrate of the material increased from 81.40%to 92.39%after 200 cycles under 1C discharge condition,and theelectrochemical performance of NCM811 material was improved.