Unveiling potential of SnS nanoflakes: A flexible solid-state symmetric supercapacitive device

The development of high-performance energy storage materials for supercapacitors is of paramount importance in the quest for efficient and sustainable energy storage solutions. In this article, we present a detailed investigation of pristine SnS nanoflakes for supercapacitor application, addressing critical gaps in existing literature. The previous research is largely focused on composite materials and surface modifications, the electrochemical performance of pristine SnS has remained unexplored. Additionally, our work uniquely emphasizes the impact of electrolyte selection and concentration variation on supercapacitive performance. Here we prepared SnS nanoflakes through the colloidal synthesis process. The nanoflake-like topography with an average thickness of 21.0 ± 5.8 nm exhibited an excellent specific capacitance of 582 F/g at 8 A/g current density, with 80 % retention over 4500 CV scans in the case of three-electrode tests. Owing to the excellent electrochemical characteristics of SnS nanoflakes, the flexible symmetric solid-state supercapacitor (FSSC) was constructed using a PVA-NaClO4 gel polymer electrolyte (GPE). The manufactured FSSC exhibits a high energy density of 13.30 Wh/kg at 1.19 kW/kg of power density. Even with a high-power density of 2.4 kW/kg, the FSSC maintained an energy density of 6.54 Wh/kg. Furthermore, the FSSC was constructed to achieve long-term durability over 5000 CV cycles at a scan rate of 100 mV/s while retaining 90 % of the initial specific capacitance. The flexibility test revealed 94 % retention of original capacitance at a bending angle of 170°. This work showcases the potential of SnS nanoflakes as better electrode materials for supercapacitors, crafting a sustainable and efficient energy storage option. Overall, this study advances the development of high-performance supercapacitors and lays a foundation for future energy storage systems.