Gamma radiation induced synthesis of Ag decorated NiMn2O4 nanoplates with enhanced electrochemical performance for asymmetric supercapacitor

Abstract

Herein, gamma radiation was used to assist the synthesis of Ag decorated nanoplates spinel-type oxide NiMn2O4 as a prospective electrode for supercapacitors. In addition to accelerating charge transfer, Ag nanoparticles provide a minor extent of pseudocapacitance. When evaluated in an aqueous KOH electrolyte, the Ag@NiMn2O4 electrode displays a capacitance of 622 Fg−1 at the current density of 1 A g−1 while retaining exceptional cycle stability (capacitance retention of nearly 88.8 % and 97.6 % coulombic efficiency at 10 Ag−1 after 5000 cycles). Whereas an asymmetric supercapacitor (Ag@NiMn2O4//rGO) has been assembled, it has a maximum specific density of 30.44 Wh kg−1 with a specific power of 10.3006 kW kg−1 within a broad potential window of 1.6 V. Moreover, the capacitance of the Ag@NiMn2O4//rGO hybrid supercapacitor device retains roughly retention of 94.8 % and exhibited approximately 100 % coulombic efficiency. As a result, with its enormous capacitance, high specific density, and extended cycle stability, the Ag-decorated the spinel-type oxide NiMn2O4 nanoplates electrode is an auspicious nominee for supercapacitors applications.