Bimetallic NiSe2-CoSe2 heterogeneous with enhanced capacity for aqueous alkaline zinc-based batteries

Rechargeable aqueous alkaline zinc-based batteries (AZBs) have sparked widespread attention considering their cost-effectiveness, favorable safety profiles, and robust output voltage. Nonetheless, the advancement of AZBs is being constrained by the lack of suitable cathode materials that exhibit high energy storage capacity and great cycle stability. In this work, nickel-cobalt bimetallic selenides (NCS) were synthesized as cathodes for AZBs using a simple one-pot hydrothermal approach, which avoided traditional high-temperature heating procedures, effectively lowering preparation costs, and improving production safety. The optimized sample, NCS-3, presents an impressive capacity of 225.8 mAh g–1 at 1 A g–1 and a satisfactory rate capacity of 194.8 mAh g–1 at an elevated current density of 10 A g–1. In addition, the NCS-3 electrode also achieves long-cycle stability (only 1 % capacity fade after 2000 cycles) and almost 100 % Coulomb efficiency, indicating outstanding structural stability and reversibility. Notably, the NCS-3//Zn battery constructed shows a maximum energy density of 339.3 Wh kg–1, and a power density of 12.5 kW kg–1, highlighting its potential for energy storage applications. [Display omitted] •A one-pot hydrothermal approach is reported to nickel-cobalt bimetallic selenides (NCS).•The optimized NCS electrode presents a high capacity of 225.8 mAh g–1 at 1 A g–1.•The fabricated battery can deliver a maximum energy density of 339.3 Wh kg–1.•This work reports a nickel-cobalt bimetallic selenide as a cathode for AZBs with enhanced capacity and cycling stability.