Lattice distortion induced rock salt high-entropy oxide for high-rate lithium-ion storage
Shi‐Jie Chen, Mengfan Bao, Yanggang Jia, Xia Shao, Yuhuan Guo, Saisai Li, Aiqin Mao, Jie Tan, Xuefeng Liu
Abstract
High entropy oxides (HEOs) have garnered increasing attention as novel anode materials for high-performance lithium-ion batteries (LIBs) owing to their high structural stability and ideal element tunability. However, the defect engineering for boosting the electrochemical performance remains a major challenge. In this study, lattice distortion modulation is implemented through low-temperature post-processing strategy (post-annealed at 723 K for different times) on rock-salt-type (Co 0.2 Cu 0.2 Mg 0.2 Ni 0.2 Zn 0.2 )O to boost its Li + storage performance. It can be concluded that lattice distortion induces suitable amounts of oxygen-vacancies, thereby enhancing intrinsic conductivity and facilitating electron/ion migration kinetic. Thus, the optimal CCNMZ-10 (post-annealed at 723 K for 10 min) electrode exhibits an impressive reversible capacity of 993 mAh g −1 at 200 mA g −1 after 150 cycles, superior rate capability (66.3 % capacity retention from 100 to 3000 mA g −1 ), and outstanding high-rate capacity of 771 mAh g −1 after 400 cycles at 1000 mAh g −1 . Meanwhile, it also delivers an ultra-high pseudocapacitive contribution of 92.7 % at 1 mV s −1 . This work demonstrates a promising strategy to effectively enhance the electrochemical performance of HEOs through lattice distortion defects, and also opens new perspectives on the development of defect-rich HEO anode materials.