Synergetic effect of lattice distortion and oxygen vacancies on high-rate lithium-ion storage in high-entropy perovskite oxides
Yanggang Jia, Shi‐Jie Chen, Xia Shao, Jie Chen, Dao-Lai Fang, Saisai Li, Aiqin Mao, Canhua Li
Abstract
High-entropy oxides (HEOs) have gained great attention as an emerging kind of high-performance anode materials for lithium-ion batteries (LIBs) due to the entropy stabilization and multi-principal synergistic effect. Herein, the porous perovskite-type RE(Co<sub>0.2</sub>Cr<sub>0.2</sub>Fe<sub>0.2</sub>Mn<sub>0.2</sub>Ni<sub>0.2</sub>)O<sub>3</sub> (RE=La, Sm and Gd) HEOs were successfully synthesized by a solution combustion synthesis method. Owing to the synergistic effect of lattice distortion and oxygen vacancies, the Gd(Co<sub>0.2</sub>Cr<sub>0.2</sub>Fe<sub>0.2</sub>Mn<sub>0.2</sub>Ni<sub>0.2</sub>)O<sub>3</sub> electrode exhibits superior high-rate lithium-ion storage performance and excellent cycling stability. A reversible capacity of 403 mAh g<sup>-1</sup> at a current rate of 0.2 A g<sup> -1</sup> after 500 cycles, and a superior high-rate capacity of 394 mAh g<sup>-1</sup> even at 1.0 A g<sup> -1</sup> after 500 cycles are achieved. Meanwhile, Gd(Co<sub>0.2</sub>Cr<sub>0.2</sub>Fe<sub>0.2</sub>Mn<sub>0.2</sub>Ni<sub>0.2</sub>)O<sub>3</sub> electrode also exhibits pronounced pseudo-capacitive behavior, contributing to additional capacity. By adjusting and balancing the lattice distortion and oxygen vacancies of the electrode materials, the lithium-ion storage performance can be further regulated.