Mg <sup>2+</sup> Doped LiNi <sub>1/3</sub> Co <sub>1/3</sub> Mn <sub>1/3</sub> O <sub>2</sub> Hollow Flake–Like Structures with Enhanced Performances Cathodes for Lithium–Ion Batteries
Qiangchao Sun, Hongwei Cheng, Kangning Zhao, Huijie Zhou, Hongbin Zhao, Wenli Yao, Qian Xu, Xionggang Lu
Abstract
Abstract LiNi 1/3 Co 1/3 Mn 1/3 O 2 ternary cathode is a dominant cathode material for lithium ion batteries due to its relatively stable structure. However, LiNi 1/3 Co 1/3 Mn 1/3 O 2 still suffers from the poor rate capability and high cation disorder problems. Herein, the Mg–doped Li(Ni 1/3 Co 1/3 Mn 1/3 ) 0.99 Mg 0.01 O 2 cathode materials with hollow flake–like hierarchical fiber structures are successfully synthesized by a facile wet spinning method and the pressing pretreatment of precursor powders on the electrochemical performance is also systematically investigated. The diameter of the pre−synthesized hollow laminar nano−fibers are about 20 μm and approximately 50 nm in thickness with homogeneous primary nanoparticles (∼50 nm). Benefitting from the pillaring effects of inert Mg in the crystal structure and hollow laminar structure, the Li(Ni 1/3 Co 1/3 Mn 1/3 ) 0.99 Mg 0.01 O 2 cathodes deliver significantly improved electrochemical performance, achieving high stability discharge specific capacity 178.8 mA h g −1 with capacity retention of 88 % at 0.5 C (137.5 mA g −1 ) rate after 200 cycles. Moreover, it maintains a high rate capacity of 110 mA h g −1 even at a current density of 5 C. Based on this work, the conception of combining microstructure design and doping modification can facilitate the development of higher−performance Li−ion battery cathode materials.