Symmetric supercapacitors composed of ternary metal oxides (NiO/V2O5/MnO2) nanoribbon electrodes with high energy storage performance

Abstract

Supercapacitors with improved specific capacitance, long cycling life, high power density and energy density are fabricated to close the gap between traditional and emerging energy storage. We develop interactive ternary metal oxides nano-ribbon electrodes used to assemble symmetric supercapacitor. The well-aligned vanadium oxide ribbon arrays act as the matrix, growing from nickel oxide/nickel substrate and then being grafted by manganese oxide nanoparticles. These tri-metallic oxides are formed in a cost-effective and green hydrothermal chemistry. The electrodes composed of ribbon arrays retain their crystallographic structure during charging and discharging processes, enabling steadiness at 83.6 % after 10,000 cycles. These as-prepared electrodes demonstrate a specific capacitance of 788 F g−1 at 5 mV s−1. The symmetrical supercapacitors are assembled using triple component electrodes, achieving a high energy density of 138 W h kg−1 at a power density of 450 W kg−1. These binderless single-cell devices are reported with a simplified design showing 10–20 times higher energy density in comparison with reported results of the V2O5-MnO2 system. The nanografting results in reactive interfaces with interpenetrating channels for efficient ion transport and electron conduction. The advances to design nanostructured supercapacitor materials are based on these heterojunction arrays to enhance their supercapacitive performances.