Improvement in capacitive performance of ZnS with MnO2 via composite (ZnS/MnO2) strategy developed by hydrothermal technique

Abstract

Nanocomposites based on manganese oxide (MnO2) exhibit a significantly wide working potential window, rendering them highly appealing for utilization in advanced energy transformation and storage technologies. The following article describes a simple method for synthesizing pure manganese oxide (MnO2), zinc sulfide (ZnS) and ZnS/MnO2 nanocomposites (NCs) for electrochemical supercapacitor applications. Various physiochemical approaches were employed to depict the structure and chemical features of the synthesized materials and electrochemical performance was determined with multiple electrochemical tests under 2.0 M KOH. The high pseudocapacitive nature and good conduction of the MnO2 in ZnS/MnO2 display a high specific capacitance (Cs) of 1002 F g−1 @ 1.0 A g−1. The ZnS/MnO2 display a higher discharge time of 467 s @ 1 A g−1 than 2 A g−1 (159 s) and 3 A g−1 (65 s). The symmetric behavior of the ZnS/MnO2 electrode materials displays the specific capacitance of 373 F g−1 and specific energy of 15.45 Wh kg−1 @ 1 A g−1. Hence, the synergistic behavior of ZnS/MnO2 nanocomposite produced via an effective and environment friendly hydrothermal method displays powerful performance toward energy storage application.