Unlocking High-Energy Density and Longevity of the NiMoO4 Nanowire Cathode via Sulfur-Doping Engineering for Aqueous Zn Batteries

Aqueous nickel–zinc (Ni–Zn) batteries face challenges in achieving high energy density and long-term stability due to the limited electronic conductivity and active sites of Ni-based cathodes. Here, we propose a sulfur-doping strategy to engineer NiMoO4 nanowires (SNMO) as a high-energy and durable cathode in Ni–Zn batteries. Experimental and theoretical analyses confirm that sulfur incorporation expands accessible active surfaces, lowers charge-transfer barriers, and improves interfacial interactions with OH– ions. The resulting SNMO cathode delivers an exceptional areal capacity of 1.07 mAh cm–2 at 1 mA cm–2, considerably superior to pristine NiMoO4 (0.20 mAh cm–2), and retains 91.7% capacity after 3000 cycles with near-100% Coulombic efficiency. Additionally, the assembled SNMO//Zn battery also exhibits a high energy density of 18.3 mWh cm–3, surpassing many aqueous counterparts. This work provides a cost-effective pathway for designing high-energy and stable cathodes, advancing the development of next-generation aqueous energy storage systems.