Electrochemical properties of CNT doped nanoporous tin oxide hybrid electrode formed on cold spray tin coating for supercapacitor application

Abstract

In the present study, tin oxide film with regular nano-channels was formed on the surface of cold sprayed tin coating by the anodizing process. The microstructure of the samples was investigated by field-emission scanning electron microscope (FESEM) and transmission electron microscope (TEM). The results show that annealing the samples with the assistance of water leads to the formation of crystalline particles on the inner surface of the nanotubes by the dissolution-precipitation mechanism. The electrochemical performance of the nanoporous tin oxide film was evaluated as an electrode by cyclic voltammetry (CV), galvanostatic charge-discharge (GCD), and electrochemical impedance spectroscopy (EIS). Being employed as the supercapacitor electrode materials, the electrode revealed a specific capacitance of 0.0176 F/cm2 at a current density of 0.1mA/cm2. The appropriate capacitive properties were due to the morphology and SnO2 active materials grown on the inside wall of the nanoporous structure, resulting in the enhancement of the active surface area. The investigation of the effect of the preferred orientation on the capacitance of the produced films shows that (0 2 0) and (0 3 1) have a very positive effect on the capacitive properties of the samples. Also, (1 1 0) and (0 1 1) preferred orientation has caused a sharp decrease in capacity