Co3+-Regulated electronic structure of NiCo2Sx nanoneedle arrays as high-rate cathode materials for durable alkaline Ni–Zn batteries

Abstract

Alkaline zinc-based batteries have become a current research hotspot due to their high energy density and safety, but their low cycle stability and rate performance limit their commercial applications. Herein, vertically ordered NiCo2Sx nanoneedle arrays are prepared using different sulfidation concentrations based on the anion exchange reaction. The highly uniform nanoneedle arrays provide fast ion transport paths and abundant active sites, and the prepared NiCo2Sx@Ni foam (NiCo2Sx@NF) electrode has the excellent capacity (121.9 mAh g−1), stable cycle performance (91.1 % of capacity retention after 500 cycles), also achieves a maximum energy density of 636.3 Wh kg−1 and a maximum power density of 40.9 kW kg−1. This paper provides a more precise and accurate idea for preparing cathode materials for durable alkaline Ni–Zn batteries.