Construction of CoMo₂S₄ Nanorods/Nanosheets Electrodes with Enhanced Electrochemical Properties for Asymmetric Pseudocapacitors

Abstract

The construction of hierarchical nanostructures and the synergistic effect of bimetal compounds provide effective strategies to address the low energy density of supercapacitors. Herein, CoMo2S4 (CMS) nanosheets anchored on homogeneous nanorods vertically distributed on nickel foam (NF) were fabricated using a two‐step hydrothermal method. The hierarchical homostructure CMS materials heavily depend on the vulcanization parameter of the second step synthesis. As an electrode of supercapacitors, CoMo2S4 exhibits a large specific capacity of 1992.85 F g−1 at 2 mA cm−2, and specific capacity retention of 106 % through 8000 cycles when sulfurization condition was at 120 °C for 6 h (CMS/NF‐120). Such excellent performances benefit from hierarchical homostructure, which can provide a large reaction surface area, fast ion/electron diffusion channels and rich active sites. Furthermore, the asymmetric pseudocapacitors device constructed with CMS/NF‐120 and active carbon exhibits a maximum energy density of 39.8 Wh kg−1, and good long‐term stability (80.1 % capacitance retention after 10,000 cycles).

Enhanced-Performance Asymmetric Supercapacitor Based on a Multidimensional Hierarchically Assembled NiMoO4/ZnMoO4/NF Electrode

“…It can be seen that each curve contains a pair of redox peaks, illustrating the pseudocapacitance characteristics of NZMO/NF electrodes. And the CV curve of the NZMO/NF electrode obtained at 450 °C has the maximum enclosed area, indicating the highest specific capacitance . The GCD curves of all samples were tested at a current density of 4 mA cm –2 and a voltage window of 0–0.5 V, as shown in Figure b.…”

“…And the CV curve of the NZMO/NF electrode obtained at 450 °C has the maximum enclosed area, indicating the highest specific capacitance. 25 The GCD curves of all samples were tested at a current density of 4 mA cm −2 and a voltage window of 0−0.5 V, as shown in Figure 5b. The annealing temperature at 450 °C had the longest discharge duration, illustrating its maximum specific capacitance and further confirming the test results of the CV curve.…”