Facile, Efficient, and Cheap Electrode based on SnO₂/Activated Carbon Waste for Supercapacitor and Capacitive Deionization Applications

Abstract

Activated carbon granules present in our household filters used in water purification are significant waste. Activated carbon waste (ACW) was ground to a fine powder, then impregnation of SnO 2 on ACW was performed under mild conditions followed by calcination of SnO 2 -ACW at 700 °C for 2 h, producing a SnO 2 -ACW hybrid composite. This hybrid composite material was used in the preparation of electrodes for supercapacitor and capacitive deionization applications. The electrochemical performance of the electrodes was investigated by using cyclic voltammetry, galvanostatic charge–discharge, and electrochemical impedance spectroscopy. Calcination and addition of SnO 2 contributed to an obtained electrode with a high specific capacitance of 30.46 F g –1 in a solution of 1 M Na 2 SO 4 compared to the original ACW (0.122 F g –1 ) and calcined-ACW (1.42 F g –1 ) at an actual current of 1 mA. This electrode was also investigated for water desalination through the capacitive deionization technique and exhibited an electrosorption capacity of 6.44 mg/g compared to the commercial AC (8.9 mg/g) so it is a highly promising and economic electrode.

Waste-Cotton-Cloth-Derived Sustainable and Flexible High-Performance Supercapacitor

“…Several studies have reported on improving the electrochemical performance of carbon fiber electrodes by incorporating active materials such as conducting polymers, carbon nanomaterials, transition-metal compounds like metal oxides (MnO 2 , NiO, CuO, Co 3 O 4 , Fe 3 O 4 , and VO x ), metal hydroxide [Ni­(OH) 2 ], metal selenides (CoSe), etc. − Compared to carbon and conducting polymers, transition-metal compounds have a greater specific capacitance and energy density. − This is a result of the pseudocapacitancea type of charge-storage mechanism involving multielectron Faradaic charge transfer and reversible redox processesthat these metal compounds possess . Additionally, hybridizing a carbonaceous scaffold to these pseudocapacitive materials has shown promise for improving the performance because carbon improves their conductivity and capacitance. − Further to attain high flexibility, electrodes that combine pseudocapacitive materials with flexible carbon microfibers, carbon cloth (CC), cotton carbon, or cellulose substrates have advanced significantly. − …”

Enhanced Supercapacitor Performance by Harnessing Carbon Nanoparticles and Colloidal SnO2 Quantum Dots

“…The integration of metal oxide nanomaterials into supercapacitor electrodes has shown remarkable improvements in capacitance, energy density, and stability, thus contributing to the advancement of supercapacitor technology [8,9]. Furthermore, the combination of carbon and metal oxide nanomaterials into nanocomposites has received considerable attention in recent years [10]. By combining the high surface area and conductivity of carbon materials with the pseudocapacitive behaviour and ion storage capacity of metal oxides, these hybrid materials take advantage of the complementary properties of both constituents [9].…”