Three-dimensional Li-ion transportation in Li2MnO3-integrated LiNi0.8Co0.1Mn0.1O2

• 作者: Xue Huang Jianqing Zhao Wenchang Zhu Machuan Hou Tong Zhou Liangmin Bu Lijun Gao Wei Zhang
• 来源期刊: 能源化学
• 年，卷（期）: 2021,（12）
• 页码范围: 376-384
• 页数: 9页
• 语种: 英文

摘要

Ni-rich layered cathodes (LiNixCoyMnzO2) have recently drawn much attention due to their high specific capacities.However,the poor rate capability of LiNixCoyMnzO2,which is mainly originated from the two-dimensional diffusion of Li ions in the Li slab and Li+/Ni2+ cation mixing that hinder the Li+ diffusion,has limited their practical application where high power density is needed.Here we integrated Li2MnO3 nan-odomains into the layered structure of a typical Ni-rich LiNi0.8Co0.1Mn0.1O2 (NCM811) material,which minimized the Li+/Ni2+ cationic disordering,and more importantly,established grain boundaries within the NCM811 matrix,thus providing a three-dimensional diffusion channel for Li ions.Accordingly,an average Li-ion diffusion coefficient (DLi+) of the Li2MnO3-integrated LiNi0.8Co0.1Mn0.1O2 (NCM811-I) dur-ing charge/discharge was calculated to be approximately 6*10-10 cm2 S-1,two times of that in the bare NCM811 (3*10-10 cm2 S-1).The capacity delivered by the NCM811-I (154.5 mAh g-1) was higher than that of NCM811 (141.3 mAh g-1) at 2 C,and the capacity retention of NCM811-I increased by 13.6％ after 100 cycles at 0.1 C and 13.4％ after 500 cycles at 1 C compared to NCM811.This work provides a valuable routine to improve the rate capability of Ni-rich cathode materials,which may be applied to other oxide cathodes with sluggish Li-ion transportation.