Electrochemical investigation of crinum asiaticum-like BaO-CeO2 nanostructure for high-performance asymmetric supercapacitor

• The BaO-CeO 2 thin films synthesized via the SILAR method. • Polycrystalline nature with flower-like morphology. • The highest SC of 880F/g at 2 mV/s in 1 M KOH. • The 98% retention after 5500 cycles of BaO-CeO 2 //AC ASSD device. • Green LED powered using the fabricated device. In this study, barium oxide-cerium oxide (BaO-CeO 2 ) thin films with a Crinum asiaticum flower-like morphology were fabricated using the sequential ionic layer adsorption and reaction (SILAR) technique. X-ray diffraction (XRD) analysis confirmed their polycrystalline structure, while structural, elemental, and compositional studies validated their suitability as electrode materials for supercapacitors. The BaO-CeO 2 thin films exhibited excellent electrochemical stability and high performance, achieving a specific capacitance (SC) of 880 F/g in a 1 M potassium hydroxide (1 M KOH) electrolyte, with 97 % capacitance retention after 6,500 cycles. When assembled into an asymmetric solid-state supercapacitor device (ASSD), the electrodes delivered an energy density of 17.8 Wh/kg and a power density of 6.9 kW/kg, maintaining 98 % capacitance over5000 cycles. The ASSD successfully powered a green light-emitting diode, demonstrating its economic feasibility and practical potential for cost-effective energy storage applications.