Electrochemical characteristics of Cu/Cu2O/C composite electrode for supercapacitor application

Abstract

Metal-organic frameworks (MOF) have attracted much attention from researchers in various fields due to their controllable morphology, high porosity and multifunctionalities. MOF is a new class of porous materials that are made by metal ions and organic ligands which can be applied in a wide variety of applications including energy conversion and storage devices. In this work, a simple and cost-effective method was introduced in synthesizing MOF using copper ions and 2-methylimidazole. Cu/Cu2O/C composite was then being derived from the MOF precursor, at various temperatures of 700, 800 and 900 °C as electrode materials for supercapacitor application. MOF precursor (CM-RT) contributed only 16 Cg−1 at the current density of 0.25 Ag−1 in 1 M potassium hydroxide (KOH) electrolyte. However, MOF that has been heated at temperature 900 °C (CM-900) has achieved a maximum capacity value of 249 Cg−1 at a current density of 0.25 Ag−1 in a standard three electrode system. The asymmetrical supercapacitors which were assembled using commercial activated carbon and heated MOF, AC//CM-900 cell delivered an energy density of 30 Wh kg−1 and power density of 107 W kg−1. The developed electrode materials of Cu/Cu2O/C composite showed excellent electrochemical properties and new insights of copper-based MOF as electrode materials for energy storage applications.