Supersonically Sprayed Zn₂SnO₄/SnO₂/CNT Nanocomposites for High-Performance Supercapacitor\nElectrodes

Abstract

In\nthis study, we demonstrate rapid and facile supersonic cold\nspray deposition of Zn₂SnO₄<b>/</b>SnO₂/CNT nanocomposite supercapacitor electrodes with promising\ncombinations of power and energy density. Cyclic voltammetry confirmed\nthe capacitive behavior of the optimized electrode, with specific\ncapacitance reaching 260 F·g^–1 at a current\ndensity of 10 A·g^–1. We attribute this high\nperformance to the optimal combination of CNT (carbon nanotube; double-layer\ncapacitance) and Zn₂SnO₄<b>/</b>SnO₂ (pseudocapacitance) properties. The mesoporous and accessible\nsurface of the CNT significantly contributed to the excellent retention\n(approximately 93%) of the specific capacitance after 15000 galvanostatic\ncharge/discharge cycles. In addition, the supercapacitor exhibited\na remarkable energy density, electrochemical properties, and mechanical\nstability. The materials and approach presented here can enable cost-effective,\nefficient, and scalable production of high-performance supercapacitor\nelectrodes.