Accelerating ZnS Reversibility via Copper Sulfides Conductive Frameworks for Next-Generation Aqueous Zn-S Batteries.

Aqueous zinc-sulfur (Zn-S) batteries have emerged as promising candidates for next-generation energy storage owing to their intrinsic safety, low cost, and high theoretical energy density. However, their practical application is hindered by the insulating nature of sulfur and ZnS, sluggish ZnS-to-S oxidation kinetics, and poor cycling stability. Herein, we report a conductive-catalytic hybrid cathode by integrating copper sulfides (CuxS) with a porous activated carbon framework (CuxS/S@AC) to regulate sulfur conversion chemistry. The CuxS component, composed of mixed CuS/Cu1.8S phases, provides a highly conductive network and abundant catalytic interfaces that facilitate charge transport and accelerate ZnS electro-oxidation. The porous carbon host ensures homogeneous sulfur distribution, improves electrolyte accessibility, and accommodates volume variation during cycling. Benefiting from this synergistic architecture, the cathode delivers a high reversible capacity of 1121 mAh g-1, excellent rate capability, and remarkable cycling stability, retaining 1056 mAh g-1 after 100 cycles at 5 A g-1. Mechanistic investigations reveal that the interfacial coupling between CuxS and ZnS reduces charge-transfer resistance, lowers polarization, and facilitates reversible sulfur conversion reactions. This work demonstrates that constructing conductive catalytic frameworks efficiently overcomes the kinetic bottleneck of Zn-S batteries and provides new insights into the rational design of high-performance energy storage systems.