Chemical synthesis and super capacitance performance of novel CuO@Cu₄O₃/rGO/PANI nanocomposite electrode

Copper oxide-based nanocomposites are promising electrode materials for high-performance supercapacitors due to their unique properties that aid electrolyte access and ion diffusion to the electrode surface. Herein, a facile and low-cost synthesis in situ strategy based on co-precipitation and incorporation processes of reduced graphene oxide (rGO), followed by in situ oxidative polymerization of aniline monomer has been reported. CuO@Cu₄O₃/rGO/PANI nanocomposite revealed the good distribution of CuO@Cu₄O₃ and rGO within the polymer matrix which allows improved electron transport and ion diffusion process. Galvanostatic charge-discharge (GCD) results displayed a higher specific capacitance value of 508 F g^-1 for CuO@Cu₄O₃/rGO/PANI at 1.0 A g^-1 in comparison to the pure CuO@Cu₄O₃ 278 F g^-1. CuO@Cu₄O₃/rGO/PANI displays an energy density of 23.95 W h kg^-1 and power density of 374 W kg^-1 at the current density of 1 A g^-1 which is 1.8 times higher than that of CuO@Cu₄O₃ (13.125 W h kg^-1) at the same current density. The retention of the electrode was 93% of its initial capacitance up to 5000 cycles at a scan rate of 100 mV s^-1. The higher capacitance of the CuO@Cu₄O₃/rGO/PANI electrode was credited to the formation of a fibrous network structure and rapid ion diffusion paths through the nanocomposite matrix that resulted in enhanced surface-dependent electrochemical properties.