This study investigates the synthesis and electrochemical performance of bismuth-copper oxide (Bi₂CuO₄) thin films for use in asymmetric supercapacitors. The Bi₂CuO₄ films were electrodeposited on copper substrates using a simple and cost-effective method, with varying deposition potentials to optimize their properties. XRD, XPS, FE-SEM, EDX, and TEM techniques were employed to characterize the structural and morphological features of the films. CV, CP, and EIS techniques were used to evaluate the electrochemical performance. The results showed that the Bi₂CuO₄ films exhibited excellent electrochemical properties, with a specific capacitance of 431.2 F/g at a scan rate of 2 mV/s and an energy density of 55.3 Wh/Kg at a power density of 4570 W/Kg. The films retained 81.4% of their energy after 5,000 cycles, demonstrating good stability. The asymmetric solid-state supercapacitor (ASSD) device, incorporating the Bi₂CuO₄ film as the positive electrode and activated carbon as the negative electrode, achieved a specific capacitance of 73.7 F/g and a Ragone plot indicating high energy and power density. The study highlights the potential of Bi₂CuO₄ as a promising material for advanced supercapacitor applications.This study investigates the synthesis and electrochemical performance of bismuth-copper oxide (Bi₂CuO₄) thin films for use in asymmetric supercapacitors. The Bi₂CuO₄ films were electrodeposited on copper substrates using a simple and cost-effective method, with varying deposition potentials to optimize their properties. XRD, XPS, FE-SEM, EDX, and TEM techniques were employed to characterize the structural and morphological features of the films. CV, CP, and EIS techniques were used to evaluate the electrochemical performance. The results showed that the Bi₂CuO₄ films exhibited excellent electrochemical properties, with a specific capacitance of 431.2 F/g at a scan rate of 2 mV/s and an energy density of 55.3 Wh/Kg at a power density of 4570 W/Kg. The films retained 81.4% of their energy after 5,000 cycles, demonstrating good stability. The asymmetric solid-state supercapacitor (ASSD) device, incorporating the Bi₂CuO₄ film as the positive electrode and activated carbon as the negative electrode, achieved a specific capacitance of 73.7 F/g and a Ragone plot indicating high energy and power density. The study highlights the potential of Bi₂CuO₄ as a promising material for advanced supercapacitor applications.