High entropy spinel-structure oxides as an anode material for lithium-ion batteries

High-entropy oxides (HEOs) are single-phase crystal structures composed of multiple metal elements that provide great potential for energy storage applications due to the synergistic effect of various metal species. They are considered effective anode materials for high-performance lithium-ion batteries (LIBs) because of their structural stability, high electronic conductivity, and ability to create anode materials with novel structures using several elemental compounds. Because the effects of different types of electrochemically active elements on the properties of anode materials are unknown, it is necessary to develop HEOs and investigate their properties. Herein, to investigate the electrochemical properties of high entropy oxides by changing the content of metallic elements with different lithium mechanisms storage, we synthesized three samples of high entropy oxides with spinel structure using the solid-state method, one of which is equimolar ((MgNiTiFeZn)۰.۶O۴) and two numbers are near-equimolar ((Mg۰.۶Ni۰.۶Ti۰.۳Fe۰.۹Zn۰.۶)O۴ and (Mg۰.۶Ni۰.۶Ti۰.۳Zn۰.۹Fe۰.۶)O۴)). For structural properties determination, X-ray diffraction analysis was used. The results confirmed the formation of three single-phase high-entropy oxides.Electrochemical tests indicated the structural stability of three compounds of entropy oxides, and the composition of (MgNiTiFeZn)۰.۶O۴, relative to the others, has better rate capability (۱۶۳ mAhg−۱ at ۱۰۰۰ mAg–۱) and higher discharge capacity (۲۲۰ mAhg−۱ at ۲۰۰ mAg–۱) after ۲۰۰ cycles.