Surface‐amorphized nickel sulfide with boosted electrochemical performance for aqueous energy storage

Abstract

The ingenious structural design of electrode materials has a great influence on boosting the integrated conductivity and improving the electrochemical behavior of energy storage equipment. In this work, a surface‐amorphized sandwich‐type Ni3S2 nanosheet is synthesized by an easy hydrothermal and solution treatment technique. Because of the in‐built defect‐rich feature of the amorphous Ni3S2 layer, the constructed crystalline/amorphous heterointerface as well as dual nanopore structure of Ni3S2 nanosheet, the electron/ion transport and interfacial charge transfer is boosted, which contribute to high ionic conductivity and low resistance of the SA‐Ni3S2 electrode. The SA‐Ni3S2 electrode shows high specific capacitance (1767.6 F g−1 at 0.5 A g−1); the SA‐Ni3S2//AC device delivers high specific capacitance (131.2 F g−1 at 0.2 A g−1) and outstanding cycle stability (75% capacitance retention after 10000 cycles). In Ni‐Zn battery measurement, the SA‐Ni3S2//Zn exhibits satisfying specific capacity (211.2 mAh g−1 at 0.5 A g−1) and cycle durability (68% capacity decay after 2000 cycles). The results imply that the rational design of surface‐amorphized heterostructure is helpful for fabrication of electrode materials with high electrochemical performance in energy storage applications.