Effect of sintering on structural, morphological and electrochemical properties of CuCo2O4/CuO nanocomposites and fabrication of symmetric supercapacitor with high energy density

CuCo 2 O 4 /CuO nanostructures are highly promising for energy storage applications due to their unique structural characteristics and mixed-phase composition, which can be tuned for enhanced electrochemical performance. In the present study, CuCo 2 O 4 /CuO nanostructures are synthesized by hydrothermal method , followed by sintering at temperatures of 400, 500, 600, and 700 °C to investigate the impact of sintering on their structural, morphological, and electrochemical characteristics. X-ray diffraction (XRD) analysis confirms the formation of mixed CuO and CuCo 2 O 4 phases while scanning electron microscopy (SEM) reveals the cubic morphology and grain growth with increasing sintering temperature . Electrochemical performance is assessed using both half-cell and full-cell configurations, with the symmetric pouch cell, fabricated from the 600 °C sintered sample and a PVA-based gel electrolyte, demonstrating superior performance. The pouch cell exhibits a specific capacitance of 600 F g −1 at 1 A g −1 , with a capacitance retention of 92.6 % over 5000 cycles and a coulombic efficiency of 96.5 %. Additionally, it delivers a high-power density of 14,062.8 W kg −1 and an energy density of 93 W h kg −1 . The practical applicability of the device is successfully validated by powering an LED. • The effect of sintering temperatures on the electrochemical properties of CuCo 2 O 4 /CuO were studied. • The phase and morphological variation with sintering temperature influenced its properties. • Optimum sintering temperature was identified for CuCo 2 O 4 /CuO electrode material. • PVA and KOH based gel electrolyte was developed and fabricated 1.5 V all solid-state supercapacitor. • The device exhibited high power density of 14,062.8 W kg −1 and energy density of 93 Wh kg −1 .