Synergetic effect of lattice distortion and oxygen vacancies on high-rate lithium-ion storage in high-entropy perovskite oxides

Abstract

High-entropy oxides (HEOs) have gained great attention as an emerging kind of highperformance anode materials for lithium-ion batteries (LIBs) due to the entropy stabilization and multiprincipal synergistic effect. Herein, the porous perovskite-type RE(Co0.2Cr0.2Fe0.2Mn0.2Ni0.2)O3 (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(Co0.2Cr0.2Fe0.2Mn0.2Ni0.2)O3 electrode exhibits superior high-rate lithium-ion storage performance and excellent cycling stability. A reversible capacity of 403 mAh g -1 at a current rate of 0.2 A g -1 after 500 cycles, and a superior high-rate capacity of 394 mAh g -1 even at 1.0 A g -1 after 500 cycles are achieved. Meanwhile, Gd(Co0.2Cr0.2Fe0.2Mn0.2Ni0.2)O3 electrode also exhibits pronounced pseudocapacitive behavior, contributing to additional capacity.

High-entropy oxides: an emerging anode material for lithium-ion batteries

“…The HEO anode materials for LIBs are mainly rock-salt and spinel phase compounds rather than other HEOs with a low specific capacity and inadequate for achieving high energy density, such as pyrochlore 44 and perovskite. 87,89 To develop new high-performance HEOs, the conventional trial-and-error will lead to a lot of labor and heterogeneous compounds due to the complex composition of HEOs. Machine learning models can evaluate the possibility of pure-phase formation through computational materials science and materials informatics, significantly promoting the development of new HEOs.…”

Boosting high-rate Li-ion storage properties by La(III) ion doping in spinel (Co 0.2Cr 0.2Fe 0.2Mn 0.2Ni 0.2) 3O 4 high-entropy oxide anode

“…While the oxidation peaks keep unchanged during the subsequent cycles. As is known, the potential difference between the redox peaks represents the degree of the polarization of electrode materials [43]. In contrast with Fig.…”

“…pseudocapacitive effect [43], interfacial charge storage theory [46] or the reversible formation and decomposition of the SEI interfaces [47].…”

Recent advances and understanding of high-entropy materials for lithium-ion batteries

“…A perovskite structural [(Bi, Na) 1/5 (La, Li) 1/5 (Ce, K) 1/5 Ca 1/5 Sr 1/5 ]TiO 3 , employed as anode materials, delivers a capacity retention of about 100% at 1 A g −1 after 300 cycles, as well as a reversible capacity of 70 mAh g −1 at 3 A g −1 [54]. Given the rich O v and lattice distortion effect, the porous perovskitetype Gd(Co 0.2 Cr 0.2 Fe 0.2 Mn 0.2 Ni 0.2 )O 3 anode achieves high capacity and excellent cycling stability [55].…”