TY  - JOUR
AU  - Wang, Rui
AU  - Qian, Guoyu
AU  - Liu, Tongchao
AU  - Li, Maofan
AU  - Liu, Jiajie
AU  - Zhang, Bingkai
AU  - Zhu, Weiming
AU  - Li, Shuankui
AU  - Zhao, Wenguang
AU  - Yang, Wenyun
AU  - Ma, Xiaobai
AU  - Fu, Zhendong
AU  - Liu, Yuntao
AU  - Yang, Jinbo
AU  - Jin, Lei
AU  - Xiao, Yinguo
AU  - Pan, Feng
TI  - Tuning Li-enrichment in high-Ni layered oxide cathodes to optimize electrochemical performance for Li-ion battery
JO  - Nano energy
VL  - 62
SN  - 2211-2855
CY  - Amsterdam [u.a.]
PB  - Elsevier
M1  - FZJ-2020-01995
SP  - 709 - 717
PY  - 2019
AB  - To understand what and how structural properties affect battery performance, and to optimize the structural properties accordingly are of crucial importance to improve the performance of cathode materials for advanced Li-ion batteries. Herein, we investigated the influence of Li-enrichment in Li1+x(Ni0.8Co0.2)1-xO2 transition metal (TM) oxide cathodes, obtained by sintering Ni0.8Co0.2(OH)2 precursor with different amount of Li sources. Compared with stoichiometric Li1+x(Ni0.8Co0.2)1-xO2 (i.e. x = 0, Li:TM = 1:1), the improvements of cycling stability and rate performance were observed in material with moderate degree of Li-enrichment with respect to TMs (i.e. x = 0.019, Li:TM = 1.04:1). Further increase in Li:TM ratio up to 1.07 diminishes the electrochemical performance. Multi-scale structural characterizations including neutron diffraction and aberration-corrected transmission electron microscopy measurements show that the Li-enrichment leads to a monotonical increase in both Li/Ni exchange ratio and Li slab space. Based on the results, we argue that, in material with moderate Li-enrichment, larger Li slab space can facilitate the diffusion of Li ions and a certain amount of Li/Ni disordering can also mitigate the contraction of layered structure, therefore resulting in an optimized electrochemical performance; while in material with excessive Li:TM ratio, the diffusion path can be partially blocked due to the presence of redundant Ni ions in Li layers.
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000474636100076
DO  - DOI:10.1016/j.nanoen.2019.05.089
UR  - https://juser.fz-juelich.de/record/875384
ER  -