Entropy Stabilization Effect and Oxygen Vacancies Enabling Spinel Oxide Highly Reversible Lithium-Ion Storage

High-entropy materials are an emerging kind of solid-solution material, demonstrating various exotic physicochemical properties, that have led to increased research activity as electrode materials for rechargeable batteries. Here, a kind of high-entropy spinel oxide, (Co0.2Cr0.2Fe0.2Mn0.2Ni0.2)(3)O-4 (CCFMNO), was successfully fabricated via a solution combustion method. Due to the entropy stabilization effect and the intrinsic high mechanical strength of CCFMNO, an excellent cycling stability can be achieved. In addition, the fruitful oxygen vacancies in CCFMNO increase extra Li-ion accommodation sites, accelerating electronic conductivity and promoting Li-ion migration, thus enabling a high rate performance of 428 mAh g(-1) at a high current density of 10 A g(-1). More impressively, CCFMNO electrodes demonstrate excellent temperature adaptability with no capacity degeneration after 50 cycles at 0, 25, and 50 degrees C. Meanwhile, a full cell based on a CCFMNO anode and LiFePO4 cathode delivers an impressive high energy density of 372 Wh kg(-1). All these impressive lithium storage performances strongly suggest that CCFMNO could be a promising anode material for lithium-ion batteries.

Automated summary

High-entropy materials, such as the spinel oxide CCFMNO, have attracted attention as electrode materials for rechargeable batteries due to their exotic physicochemical properties. CCFMNO demonstrates excellent cycling stability and high rate performance, with abundant oxygen vacancies and high mechanical strength promoting electronic conductivity and Li-ion migration. Additionally, CCFMNO shows impressive temperature adaptability and promising energy density in full cell applications, indicating its potential as a high-performance anode material for lithium-ion batteries.