High-entropy sulfoselenide as negative electrodes with fast kinetics and high stability for sodium-ion batteries

Conversion electrodes offer higher reversible capacity and lower cost than conventional intercalation chemistry electrodes, but suffer from kinetic limitation and large volume expansion. Despite significant efforts, developing conversion electrodes with fast charging capability and extended lifespan remains challenging. Here, by leveraging the advantages of high-entropy doping and morphology tailoring, we develop a high-entropy hierarchical micro/nanostructured sulfoselenide Cu_0.88Sn_0.02Sb_0.02Bi_0.02Mn_0.02S_0.9Se_0.1 electrode with entropy-driven fast-charging capability. When used as a negative electrode material for sodium-ion batteries, it achieves a stable cycle life of 10,000 cycles at 30 A g⁻¹ and a high reversible capacity of 365.7 mAh g⁻¹ under fast charging in 13 seconds at 100 A g⁻¹. Moreover, high-entropy sulfoselenide also demonstrates stable cycling and good rate capability as a positive electrode material for lithium metal batteries, achieving a fast-charging capability of 37 seconds that is comparable with state-of-the-art layered cathodes. High-entropy sulfoselenide is characterized by its robust crystal structure, low ion diffusion barrier, and effective suppression of side reactions with electrolytes during cycling. Importantly, transmission X-ray microscopy affirms the chemical stability of HESSe, which underpins its fast-charging performance.