Photochemically synthesized tin oxide nanoparticles: Electrode to device grade solid-state supercapacitor

Present article emphasis the use of unique and cost-effective post annealing photochemical method to synthesize SnO2 nanoparticles towards supercapacitive application through electrode to the solid-state device grade development. Coating of tin oxide has been performed on stainless steel substrate via doctor blade followed by in-depth analysis through structural, surface morphological, chemical, and oxidation state using XRD, FTIR, FE-SEM, HR-TEM and XPS. Fabricated SnO2 electrode delivered a specific capacitance of 46.4 F g−1 at 5 mV s−1 with excellent cyclic stability of 117.30 % over 10,000 cycles when tested in LiClO4 electrolyte. Furthermore, SnO2 solid-state supercapacitor in symmetric configuration with Li+ ions embedded in non-conducting PVA gel matrix delivered the specific capacitance of 13.04 F g−1 at 5 mV s−1 with impressive potential window of 1.5 V and exhibited a good specific energy density of 2.2 Wh kg−1 and power density of 416.3 W kg−1 along with cyclic capacitive retentivity of 97.8 % over 10,000 voltammetry cycles. To demonstrate the practical applicability, designed symmetric device employed to lighten 21 red LEDs VNIT panel and power a small 1 V DC fan. [Display omitted] •Exploring unique and effective room temperature, post annealing-free photochemical route to synthesize SnO2 nanoparticles.•SnO2 nanoparticles have been utilized for designing electrode for supercapacitor application.•Solid-state symmetric supercapacitor device exhibited good specific capacitance of 13.04 F g-1 at 5 mV s-1.•Illumination of ‘VNIT’ acronym with 21 red LEDs and running a small DC fan rendering practical applications.