Uniform Coating of Se on Selenophilic Surfaces of Nickel-Rich Layered Oxide Cathode Materials for High Performance Li-Ion Batteries
Uniform Coating of Se on Selenophilic Surfaces of Nickel-Rich Layered Oxide Cathode Materials for High Performance Li-Ion Batteries
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DOI：
10.1021/acssuschemeng.0c00011
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发表时间：
2020-07-06
影响因子：
8.4
通讯作者：
Sun, Fugen
中科院分区：
文献类型：
--
作者：
Ding, Guoyu;Li, Yahui;Sun, Fugen
通过简单的熔融扩散方法在富镍层状金属氧化物（LNCM）阴极材料的亲硒表面上构建了新颖且均匀的Se涂层。 LNCM 表面的高亲硒性应归因于暴露的 Ni、Co 和 Mn 原子通过形成金属-Se 键与 Se 涂层的强烈相互作用，从而导致 Se 层的共形和均匀沉积。均匀的Se涂层不仅可以保护富镍LNCM正极材料免于与电解质发生副反应，而且可以降低Li+/Ni2+阳离子无序程度。因此，由于Se涂层的多功能作用，Se涂层LNCM811正极材料表现出优异的循环稳定性和倍率性能，在0.2 C下具有205 mAh g(-1)的高初始容量，在0.2 C下第100次循环时具有173 mA h g(-1)的高可逆容量，在2 C下第200次循环时具有132 mAh g(-1)的高可逆容量， 5 C 下第 300 次循环时为 103 mAh g(-1)。目前的工作表明，通过简单的熔融扩散方法在先进的富镍层状金属氧化物正极材料上进行 Se 涂层应该有望用于高性能锂离子电池。
A novel and uniform Se coating layer on the selenophilic surface of the Ni-rich layered metal oxide (LNCM) cathode material was constructed via a facile melt-diffusion approach. The high selenophilicity of the LNCM surfaces should attribute to the strong interactions of the exposed Ni, Co, and Mn atoms with Se coating through the formation of metal-Se bonds, resulting in the conformal and homogenous deposition of Se layers. The uniform Se coating layers could not only protect the Ni-rich LNCM cathode materials from the side reaction with the electrolytes but also reduce the degree of Li+/Ni2+ cation disorder. Therefore, owing to the multifunctional effects of Se coating, the Se-coated LNCM811 cathode materials exhibit excellent cyclic stability and rate performances with a high initial capacity of 205 mA h g(-1) at 0.2 C and the high reversible capacities of 173 mA g(-1) at the 100th cycle at 0.2 C, 132 mA h g(-1) at 200th cycle at 2 C, and 103 mA h g(-1) at 300th cycle at 5 C. This present work indicates that the Se coating on the advanced Ni-rich layered metal oxide cathode material through the facile melt-diffusion approach should be promising for the high performance Li-ion battery.