Alkaline zinc-based batteries are becoming promising candidates for green and economical energy-storage systems, thanks to their low cost and high energy density. The exploitation of the stable cathode materials with high rate capability and cycling stability is crucial for their further development. Herein, a series of NiSx coated with nitrogen-doped carbon (denoted as NiSx@NC) compounds (x = 0.5-1.0) are synthesized using the facile single-source precursor method. Benefiting from the unique phase-transitional NiSx@NC with high activity and enhanced conductivity from the well-balanced conductive metal nickel and carbon layer, the alkaline zinc-nickel batteries with a phase-transitional NiSx@NC cathode deliver a high capacity of 148 mA h g-1 at a high current density of 100 mA cm-2 and demonstrate a long lifespan of over 500 cycles with a high capacity retention of 98.8%. This work provides a significant guideline for the structural design and optimization of nickel-based materials in alkaline energy-storage devices.
Keywords: NiSx; cathode material; transitional phase; zinc-based batteries.