ZnO Nanoparticles Synthesized by the Solution Combustion Method for Supercapacitor Applications

Abstract

Pseudocapacitive materials have demonstrated their transcendence in the recent past. In this manuscript, the authors report the synthesis of ZnO nanoparticles using the solution-combustion method at varying fuel (glycine) compositions for supercapacitor applications. The material characterizations such as XRD, FTIR, SEM, EDX, TEM, XPS, and BET confirmed the successful synthesis of the material. A detailed electrochemical analysis in terms of CD and EIS was conducted. The equal molar ratio (1:1) of zinc nitrate hexahydrate and glycine fuel for ZnO resulted in the highest value of specific capacitance at 98.61 F/g (1 A g−1) under a symmetric 2E configuration in aqueous 1 m KOH electrolyte. The nanoparticles also showed the highest energy density of 13.69 Wh kg−1 and 64.10% capacitance retention after 5000 charge-discharge cycles with a minimal charge transfer resistance of 2.37 Ω. The excellent electrochemical behavior of optimized ZnO particles compared to others, was mainly due to the high electrochemically active sites. © 2025 Wiley-VCH GmbH.