Electrochemical performance of MWCNT nanowires-decorated ZnCo2O4 sphere nanocomposite for an asymmetric capacitor

A composite material consisting of porous ZnCo₂O₄ sphere covered with MWCNT nanowires is synthesised using a hydrothermal technique and thermal annealing. The capacitive properties of the electrode materials are examined. The ZnCo₂O₄/MWCNT composites have superior capacitive performance in comparison to pure ZnCo₂O₄ hexagonal nanoplates. The ZnCo₂O₄/MWCNT composites have a specific capacitance of 2080 F/g at 1 A g⁻¹. The cells also exhibit outstanding rate capacity, maintaining 600 F/g even at 5 A g⁻¹. The nanocomposites have exceptional retention rate, as seen by an only 4.7 % decrease in specific capacitance over 10,000 cycles. The improved capacitive efficiency of ZnCo₂O₄/MWCNT composites may be ascribed to the structural benefits of large surface area, excellent electrical characteristics, and a well-established network provided by the MWCNT support. The ASC device has a significant energy density of 52.74 Whkg⁻¹ while operating at a power density of 4205 Wkg⁻¹. Additionally, it has an operating voltage window of 0–1.6 V. The excellent capacitive performance shows the potential use of ZnCo₂O₄/MWCNT composites as electrodes for hybrid capacitors.