LiAlO_(2)包覆LiNi_(0.6)Co_(0.2)Mn_(0.2)O_(2)正极材料及其高电压性能研究

Study on LiAlO_(2)-coated LiNi_(0.6)Co_(0.2)Mn_(0.2)O_(2) Cathode Material and its High Voltage Performance

以生物质为模板制备快离子导体LiAlO_(2),并对锂离子电池正极材料LiNi_(0.6)Co_(0.2)Mn_(0.2)O_(2)(NCM622)进行包覆改性,研究其高电压性能。结果表明,在4.6 V(4.7 V)充电截止电压下,未包覆的NCM622材料1C倍率放电比容量为174.5 mAh/g(173.5 mAh/g),经过100次充放电循环后,其比容量为145.6 mAh/g(115.6mAh/g),容量保持率为83.4%(66.6%);包覆量为w(LiAlO_(2))=1%的NCM622材料,其1C倍率放电比容量为193.2 mAh/g(189.5 mAh/g),经过100次充放电循环后,其比容量为162.2 mAh/g(142.3 mAh/g),容量保持率为84.0%(75.1%)。证明LiAlO_(2)包覆能提高正极材料在高工作电压下的循环性能和倍率性能。

LiAlO_(2),a fast ion conductor,was prepared from biomass as a template.LiNi_(0.6)Co_(0.2)Mn_(0.2)O_(2)(NCM622),a lithium ion battery cathode material,was modified by coating to make a study of its high voltage performance.The results showed that the 1C rate discharge capacity of the un-coated NCM622 material was 174.5 mAh/g(173.5 mAh/g)at a charging cutoff voltage of 4.6 V(4.7 V).After 100 charge and discharge cycles,its specific capacity was 145.6 mAh/g(115.6 mAh/g),with a capacity retention rate of 83.4%(66.6%).The NCM622 material with a coating amount of w(LiAlO_(2))=1%has a 1C rate discharge capacity of 193.2 mAh/g(189.5 mAh/g).After 100 charge and discharge cycles,its specific capacity was 162.2 mAh/g(142.3 mAh/g),with a capacity retention rate of 84.0%(75.1%).it is proved that LiAlO_(2) coating can improve the cycling performance and rate capacity of cathode materials at high operating voltage.