Deciphering the synergistic mechanism for thermal stability improvement in Ni-rich single-crystal cathode materials via LiNbO3 coating and Nb5+ surface doping
Year: 2025
Type: article
Abstract: Ni-rich cathode materials are highly regarded for their potential in high-energy density lithium-ion batteries (LIBs). Nonetheless, their intrinsic thermal instability poses a significant risk of thermal runaway, which is a major obstacle to their commercial application. This study presents a novel approach to enhancing the thermal stability of Ni-rich cathode materials for LIBs through a synergistic modification strategy combining LiNbO3 coating and Nb5+ surface doping. By applying particle atomic layer deposition and high-temperature sintering, the modified cathode material Nb@SC-NCM811 shows better electrochemical performance. Thermal analysis reveals that Nb@SC-NCM811 has a higher thermal decomposition temperature, generates less heat, and releases less oxygen under thermal induction, indicating enhanced thermal stability. The microscopic mechanisms underlying the improvement of thermal stability are further revealed through aberration-corrected transmission electron microscopy and density functional theory calculations, which shows that the enhancement in thermal stability is due to the increased formation energy of oxygen vacancies and the raised energy barrier for interlayer migration of transition metal cations. This work provides insight into the Nb-modified mechanism of Ni-rich cathode materials and offers a promising avenue for designing safer, high-energy density LIBs.
Source: The Innovation Energy
Authors: Zesen Wei, Zheng Fang, Chen Liang, Shiyao Chen, Anqi Teng, Mei Sun, Yue Zhang, Yin Yu, Xiangdong Meng, Peiyu Duan, Lihua Jiang, Jinhua Sun, Qingsong Wang
Language: English
Subfield: Electrical and Electronic Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: diamond
OpenAlex ID: W4409401478