September 2, 2020
Journal Article

Optimized Al Doping Improves Both Interphase Stability and Bulk Structural Integrity of Ni-Rich NMC Cathode Materials

Wengao Zhao
Lianfeng Zou
Haiping Jia
Jianming Zheng
Junhua Song
Chaoyu Hong
Rui Liu
Yong Yang
Jie Xiao
Chongmin Wang
Donghao Wang

Abstract

Ni-rich layered transition metal oxide (NMC, LiNi1-x-yMxCoyO2, 1 – x – y = 0.6) is promising for high-energy-density lithium-ion batteries, but its large-scale application is still hindered by several technical challenges, including secondary particle cracking, interfacial instability, and cell degassing during cycling. Here, we report a facile wet-chemical method to modify both the surface and the bulk of the LiNi0.76Mn0.14Co0.10O2 (NMC76) cathode with Al doping to effectively improve the structural/interfacial stability of the cathode, and hence its long-term cycling capability. With only 1 mol% Al doping, the Al-NMC76 electrode delivers a good capacity retention of 79.2% after 500 cycles at a high voltage limit of 4.5 V, which is far better than those of undoped NMC76 under the similar condition. The enhanced performance can be attributed to the Al doping in the NMC76, which not only strengthens the bulk structural stability through doping into the lattice, but also suppresses acidic attack from the electrolyte through altered surface structure of NMC76.

Revised: September 2, 2020 | Published: April 27, 2020

Citation

Zhao W., L. Zou, H. Jia, J. Zheng, d. wang, J. Song, and C. Hong, et al. 2020. "Optimized Al Doping Improves Both Interphase Stability and Bulk Structural Integrity of Ni-Rich NMC Cathode Materials." ACS Applied Energy Materials 3, no. 4:3369-3377. PNNL-SA-144184. doi:10.1021/acsaem.9b02372