Dual modification of LiNi_(0.83)Co_(0.11)Mn_(0.06)O_(2) cathode materials by K^(+) doping and Li_(3)PO_(4) coating for lithium ions batteries  

作　　者：Wei Xiao Jia-Le Wang Zhi-Cheng Yi Cheng-Jin Liu Chang Miao Yu Xin Shu-Qing Nie 

机构地区：[1]College of Chemistry and Environmental Engineering,Yangtze University,Jingzhou 434023,China

出　　处：《Rare Metals》2024年第7期3007-3018,共12页稀有金属（英文版）

基　　金：financially supported by the National Natural Science Foundation of China (Nos.52274292 and 51874046);the Outstanding Youth Foundation of Hubei Province (No.2020CFA090)。

摘　　要：Li_(3)PO_(4)@Li_(0.99)K_(0.01)Ni_(0.83)Co_(0.11)Mn_(O.06)O_(2)(NCM-KP) cathode powders are synthesized via K^(+)doping in calcination processes and H_3PO_4 coating in sol-gel processes.K^(+) precisely enters into the lattice to widen the(003) plane to 0.4746 nm with a lower cationic disordered degree of 1.87%.Moreover,the surface residual lithium salts are treated by H_3PO_4 to generate a uniform Li_(3)PO_(4) coating layer of approximately 11.41 nm,which completely covers on the surface of secondary spherical particles to improve the interfacial stability.At 25℃,the NCM-KP electrode delivers a discharge specific capacity of 148.9 mAh·g^(-1) with a remarkable capacity retention ratio of 84.1% after 200 cycles at 1.0C and retains a high reversible specific capacity of 154.4 mAh·g^(-1) at 5.0C.Even at 1.0C and 60℃,it can maintain a reversible discharge specific capacity of 114.6 mAh·g^(-1) with 0.21% of capacity decay per cycle after 200 cycles,which is significantly lower than 0.40% for the pristine NCM powders.Importantly,the charge transfer resistance of 238.89 Ω for the NCM-KP electrode is significantly lower than 947.41 Ω for the pristine NCM one by restricting the interfacial side reactions.Therefore,combining K+doping and Li_(3)PO_(4) coating is an effective strategy to enable the significant improvement of the electrochemical property of high-nickel cathode materials,which may be mainly attributed to the widened diffusion pathway and the formed Li_(3)PO_(4) protective layer,thus promoting Li~+diffusion rate and preventing the erosion of HF.

关 键 词：High-nickel cathode material Residual lithium K^(+)doping Li_(3)PO_(4)coating Lithium ions battery 

分 类 号：TM912[电气工程—电力电子与电力传动]