Effect of binder on the performance of zinc‐tin‐sulfide nano flakes for the high‐performance supercapattery devices

Abstract

Here in this work, we report the role of binder concentration on the electrochemical performance of Zn-Sn-S (ZTS) mesoporous material for high-performance supercapattery devices. The desired material is synthesized through the facile hydrothermal technique followed by ultra-sonication for 1 h. Material’s morphology, crystallinity, porosity, surface area, elemental analysis, and composition were analyzed through field emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), scanning transmission electron microscopy (STEM), Brunauer-Emmett-Teller (BET), Fourier transform infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopy (XPS). The effect of binder concentration on the electrochemical properties was investigated by performing cyclic voltammetry (CV), galvanostatic charge-discharge (GCD), and electrochemical impedance spectroscopy (EIS) in three-electrode assembly while maintaining the 1 M KOH electrolyte environment. In three-electrode setup, the electrodes with a binder concentration of 50%, 25%, and 10% show a specific capacity of 69.24, 154.17, and 247.91 C/g at the current density of 1.0 A/g. Correspondingly, the series resistance observed in EIS for these three electrodes are 3.27, 2.12 and 1.29 Ω, which suggests that ZTS with 10% nafion possesses better electrochemical properties. Therefore, the electrode with a 10% binder concentration was then coupled with the activated carbon to assemble a supercapattery. This assembly (ZTS//AC) was then characterized with CV, GCD, and EIS, which delivers a specific capacity of 135.27 C/g, energy density of 30.06 Wh/kg, and 3200 W/kg of power density. At last, the device's cyclic life had been investigated by initiating GCD for 2500 continuous cycles at the current density of 3.0 A/g. We found that the material’s performance significantly got affected by the binder concentration, and it showed better performance with the optimized concentration of the binder. Furthermore, the ZTS material can be utilized as an appealing electrode material for future supercapattery devices that can deliver a high energy and power density because the material had shown a stable behavior at higher current densities.