Synthesis of hierarchically structured MnMoO4·H2O/Ni3S2 nanocomposites on Ni foam for high-performance asymmetric supercapacitors

Abstract

In this work, hierarchically structured MnMoO4·H2O/Ni3S2 (MMONS) nanocomposites are grown in situ on Ni foam (NF) using an easy two-step hydrothermal approach. Benefiting from synergistic effect of the high specific capacity of MnMoO4·H2O, the high electrical conductivity of Ni3S2 and the hierarchical structure of the nanocomposite, the prepared MnMoO4·H2O/Ni3S2 electrode exhibits excellent electrochemical performance. Additionally, the hydrothermal time of Ni3S2 affecting on the MnMoO4·H2O/Ni3S2 electrode is investigated. Unlike the pristine MnMoO4·H2O and Ni3S2 electrodes, hierarchically structured MMONS electrode exhibits a high specific capacity of 1136 C g−1 at 1 A g−1. Moreover, it exhibits excellent cycle stability performance, retaining 77.4% capacitance after 10,000 charge–discharge cycling tests at 5 A g−1. An asymmetric supercapacitor (ASC) device exhibits an energy density of 55.87 Wh kg−1 at 695.97 W kg−1 and great cycle stability performance, maintaining 85.5% capacitance after 5000 cycling tests. This finding indicates that the hierarchically structured MnMoO4·H2O/Ni3S2 nanocomposites exhibit good electrochemical properties and high potential as electrode materials for supercapacitors.