Hierarchical Assembly of MnO2 Nanosheet on CuCo2O4 Nanoflake over Fabric Scaffold for Symmetric Supercapacitor

The soaring fidelity of spinel cobaltite system in electrochemistry presents its candidature as an electrode material for high-performance energy storage system and next generation portable devices. In this work, geometrically intricate heterostructure comprising CuCo2O4 and MnO2 is realized on flexible carbon fabric to utilize as an electrode material. Facile hydrothermal technique was adopted to synthesize mesoporous spinel copper cobaltite on fabric substrate which further acts as scaffold for the growth of MnO2 hierarchy. Distinctive hierarchical designing of the hybrid capitalizes the combined effects from large specific capacitance of the shape-controlled nanoforms and good electrical conductivity of the carbon fabric platform. Optimized hybrid sample with maximum porosity in it and high surface area offered specific capacitance of 1458 F/g at 0.5 A/g with stable rate capability. Cycle stability analysis of the electrode suggests 93% retention of its initial capacitance value even after 5000 long cycles. Electrochemical performance delivered by the synthesized hybrid is far better compared to pristine samples. Observed differences in electrochemical behavior among the synthesized nanoforms were elucidated on the basis of geometry–porosity–property relationship. Flexible symmetric solid-state supercapacitor was devised with the optimized hybrid which attains a high gravimetric capacitance of 181.3 F/g. Additionally, the device offers a high energy density of 64.1 Wh/kg at a power density of 1.5 kW/kg corresponding to a current density of 2.8 A/g and displayed high cycle stability. Such electrochemical results reveal the impact of amalgamation of low dimensional nanoform in a geometrically intricate hybrid and nanostructure morphology controlling device performance maximization and thereby providing a pathway for rational development of noble electrode materials.