KOH mediated hydrothermally synthesized hexagonal-CoMn2O4 for energy storage supercapacitor applications

Abstract

In recent years, there has been much focus on how the structure and morphology of CoMn<inf>2</inf>O<inf>4</inf> materials influence their electrochemical performance. Herein we introduce a KOH-surfactant agent to form a hexagonal like-CoMn<inf>2</inf>O<inf>4</inf> via hydrothermal. The X-ray Rietveld refinement evidenced that spinel CoMn<inf>2</inf>O<inf>4</inf> with the tetragonal structured I 41/amd phase. Further, the chemical environment of this phase is identified using various techniques. Surface morphology studies revealed hexagonal-like features. Owing to its features, the material delivers an excellent capacitance of 638.8 F/g. CoMn<inf>2</inf>O<inf>4</inf> also shows attained columbic efficiency of 81% and retains a capacitance of 85% after 4000 charge-discharge cycles. The excellent cyclic stability and high performance are achieved due to the more active sites and convenient electronic transference route for the ions through an electrochemical process. The symmetrical two-electrode assembly has also been fabricated. Hence, we believed that the surfactant-KOH mediated hexagonal-like-CoMn<inf>2</inf>O<inf>4</inf> material should enhance the supercapacitor properties. © 2023 Elsevier B.V., All rights reserved.