Ultrasound irradiation mediated preparation of antimony sulfoiodide (SbSI) nanorods as a high-capacity electrode for electrochemical supercapacitors

Abstract

Nanostructured metal chalco-iodides are a new family of materials that possess numerous merits in the energy harvesting and conversion sectors. In this study, we demonstrate the use of antimony sulfoiodide (SbSI) nanorods for electrochemical energy storage device applications in both aqueous and ionic liquid-based electrolytes. The SbSI nanorods were prepared by a smart ultrasound mediated synthesis route and physico-chemical characterization suggested the formation of orthorhombic phase SbSI nanorods. The electrochemical energy storage properties of the SbSI nanorods in aqueous electrolyte (1 M NaOH) were evaluated using a half-cell test (three-electrode configuration) suggesting the presence of faradaic dominated charge-storage properties. The SbSI electrode delivered a high specific capacity of 258.68 mAh g⁻¹ estimated from the charge–discharge (CD) measurement with a better electrochemical stability over 3000 cycles and a good capacitance retention of 91.4%. Furthermore, SbSI symmetric supercapacitor (SSC) in the form of a CR-2032 coin cell with 1 M TEABF₄ electrolyte showed good electrochemical capacitive properties over a voltage window of −3.0 to +3.0 V with low equivalent series resistance. The SbSI electrode possesses a high capacitance of 161.16 F g⁻¹ (in 1 M TEABF₄ electrolyte) determined from CD analysis and this value is higher as compared to the state of the art of non-carbon-based electrode materials utilizing ionic electrolytes. The collective experimental studies suggested the promising use of SbSI nanorods as a novel electrode for supercapacitors for the first time which will be beneficial towards the development of next-generation integrated energy devices.