Structural and electrochemical investigation of rGO/SrO nanocomposites for asymmetric supercapacitor applications

Reduced graphene oxide/strontium oxide (rGO/SrO) nanocomposites were effectively produced for supercapacitor applications using a hydrothermal-assisted approach followed by calcination. XRD, XPS, FESEM, and TEM investigations all showed the presence of cubic SrO nanorods evenly dispersed over wrinkled rGO sheets. The addition of rGO greatly improved electrochemical performance by increasing conductivity and ion diffusion behavior. The rGO/SrO electrode has a greater specific capacitance (354 F g ⁻1 at 5 mV s ⁻1 and 192 F g ⁻1 at 0.1 A g ⁻1 ) than bare SrO. The built rGO/SrO//AC asymmetric supercapacitor device had specific capacitance values ranging from 89 to 48 F g ⁻1 at current densities of 0.1–0.6 A g ⁻1 . It also attained a maximum energy density of 12.9 Wh kg ⁻1 at a power density of 3600 W kg ⁻1 . The improved electrochemical performance is ascribed to the synergistic interaction of conductive rGO sheets and electroactive SrO nanostructures, highlighting the promise of rGO/SrO composites for advanced energy storage applications.