Synthesis and electrochemical performance of novel high-entropy spinel oxide (FeCoMgCrLi)3O4

High-entropy oxides (HEOs) are attractive options for anode materials in lithium-ion batteries (LIBs) because of their impressive specific capacity and structural stability. The multi-element composition of HEOs endows them with diverse physicochemical properties. However, the role of different elements in the energy storage mechanism remains unclear, and the limited number of successfully synthesized high-entropy oxide systems currently hinders further development. Therefore, developing HEOs with different compositions and studying their electrochemical properties is of great significance. Using the glycine-nitrate solution combustion synthesis (SCS) method, we produced two new High Entropy Oxides (HEOs), namely (FeCoMgCr)₃O₄ and (FeCoMgCrLi)₃O₄, and assessed their electrochemical performance as LIBs anode materials. The studies indicate that the inclusion of lithium significantly enhances the lithium storing capabilities of the material system. Specifically, after undergoing two hundred cycles at a current density of 200 mA/g, (FeCoMgCrLi)₃O₄ exhibited a specific capacity of 658 mAh/g, which was considerably greater than the specific capacity of (FeCoMgCr)₃O₄, which was 306.9 mAh/g. This work enriches the spinel-type high-entropy oxide systems and proposes a new design strategy for HEOs as LIBs anode materials.