<p>The growing demand for efficient, low-cost, and high-power energy storage devices has emphasized the limitations of conventional batteries in satisfying quick charge–discharge requirements. Supercapacitors have emerged as promising alternatives; however, their widespread application is still constrained by the lack of electrode materials that simultaneously deliver high energy density, power density, and long-term stability. In this study, hydrothermally produced CaFeO₃/ZnO composites and calcium multi-ferrite (CaFeO₃) were thoroughly studied as improved electrode materials for supercapacitor applications. Activated carbon was used as the negative electrode in the construction of an asymmetric supercapacitor device (CaFeO₃/ZnO 20%//AC), which has a specific capacity of 222.3 C g⁻¹, an energy density of 26.2 Wh kg⁻¹, and a power density of 5600 W kg⁻¹. These findings underscore the potential of CaFeO₃/ZnO composites as efficient and scalable electrode materials, offering a viable pathway toward next-generation high-performance supercapacitors for practical energy storage applications.</p>