Mesoporous ZnMoS4 as a supercapacitor electrode material with battery-like behavior

This paper reports the successful synthesis of bimetallic sulfide ZnMoS4 (ZMS) using a solvothermal method. The structural and morphological properties of ZMS were identified using several characterization methodologies. ZMS material was produced in a sheet-like morphology with a mesoporous structure and its supercapacitive performance was examined. CV and GCD measurements confirmed that ZMS is capable of storing electrical energy showing a battery-like behavior which is expected to proceed via K+ ion intercalation/de-intercalation within the layered matrix of ZMS. Upon raising the current density from 0.7 to 10 A g−1, its specific capacitance slightly decreased from 280 F g−1 to 243 F g−1, maintaining 86.79% of its initial capacitance, which indicates that the ZnMoS4 compound has a high-rate capability. In addition, the ZMS electrode displays excellent long-term stability preserving a capacitance retention of ∼110% even after 1000 cycles, which is likely attributed to the enhanced diffusion of electrolyte ions within the electrode active material as inferred from EIS measurements.