Self-adaptive Reconstructed High-Entropy Sulfide Catalysts with Optimized Surface Electronic Structure for Lithium-Oxygen Batteries

Nonaqueous lithium-oxygen batteries have attracted immense attention owing to their high theoretical energy density. High-entropy based materials, encompassing both high-entropy alloys and high-entropy oxides (sulfides), have emerged as promising candidates for cathode catalysts. However, current fabrication methods for high-entropy materials, particularly high-entropy sulfides, remain complex and expensive. And the catalytic mechanism of high-entropy sulfides under oxygen-mediated reactions remains elusive and warrants further investigation. Herein, we propose a novel synthesis method for high-entropy sulfides, involving a hydrogelxerogel conversion followed by a duplex treatment (low-temperature sulfuration and high-temperature calcination) processes. The synthesized (CoFeNiMnCu)9S8 high-entropy sulfide catalyst achieves elemental equilibrium and exhibits an optimized surface charge distribution. During oxygen-based battery reactions, the catalyst undergoes self-adaptive surface reconstruction, resulting in the formation of a nanoscale polycrystalline layer. This surface modification facilitates charge transfer between Co and Ni elements, and further modulates the localized electronic structure. Benefiting from the reconstructed (CoFeNiMnCu)9S8 cathode catalysts, lithiumoxygen batteries exhibit high reversible specific capacity (15100 mAh g- 1), good rate capability, and enhanced long-term cycling stability.