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

In this study, we demonstrate rapid and facile supersonic cold spray deposition of Zn₂SnO₄/SnO₂/CNT nanocomposite supercapacitor electrodes with promising combinations of power and energy density. Cyclic voltammetry confirmed the capacitive behavior of the optimized electrode, with specific capacitance reaching 260 F·g^-1 at a current density of 10 A·g^-1. We attribute this high performance to the optimal combination of CNT (carbon nanotube; double-layer capacitance) and Zn₂SnO₄/SnO₂ (pseudocapacitance) properties. The mesoporous and accessible surface of the CNT significantly contributed to the excellent retention (approximately 93%) of the specific capacitance after 15000 galvanostatic charge/discharge cycles. In addition, the supercapacitor exhibited a remarkable energy density, electrochemical properties, and mechanical stability. The materials and approach presented here can enable cost-effective, efficient, and scalable production of high-performance supercapacitor electrodes.