The increasing demand for sustainable and renewable energy technologies necessitates the development of efficient, durable, and high-performance energy storage systems to support modern electronic devices and renewable power integration. Among various energy storage technologies, supercapacitors have attracted significant attention due to their high power density, rapid charge–discharge capability, and long cycle life, operating through a combination of electric double-layer capacitance (EDLC) and faradaic redox mechanisms. However, the performance of supercapacitors is strongly governed by the properties of electrode materials, including surface area, electrical conductivity, and electrochemical activity. Metal–organic frameworks (MOFs) have emerged as promising electrode materials owing to their high surface area, tunable porosity, and well-defined crystalline structures. Nevertheless, their practical application is often limited by intrinsically low electrical conductivity and insufficient redox-active sites. ZIF-67, constructed from Co²⁺ ions and 2-methylimidazole ligands, represents a representative MOF material that can be further engineered to improve its electrochemical performance. In particular, partial metal substitution with Mn²⁺ to form bimetallic Mn-ZIF-67 is expected to enhance redox activity, provide additional active sites, and facilitate charge-transfer processes. In this work, Mn-ZIF-67 was successfully synthesized via a facile room-temperature coprecipitation route using mixed Co²⁺ and Mn²⁺ precursors with 2-methylimidazole as the organic linker. The as-prepared material was dried and subsequently characterized to confirm phase formation, crystallinity, and morphological features. Structural and morphological analyses were performed using X-ray diffraction (XRD) and scanning electron microscopy (SEM), revealing the preservation of the ZIF framework and a uniform polyhedral morphology. The electrochemical performance of the Mn-ZIF-67 electrode was systematically evaluated in a three-electrode configuration by cyclic voltammetry (CV), galvanostatic charge–discharge (GCD), electrochemical impedance spectroscopy (EIS), and long-term cycling stability tests. The Mn-ZIF-67 electrode delivered a specific capacitance of 11.1 F g⁻¹ at a current density of 1 A g⁻¹, indicating a distinct contribution from faradaic charge storage processes associated with the redox activity of Co and Mn centers. Furthermore, the electrode retained approximately 83% of its initial capacitance after 5000 charge–discharge cycles, demonstrating satisfactory structural stability and electrochemical durability. The stable impedance response further suggests preserved charge-transfer characteristics during prolonged cycling. Overall, these results highlight the feasibility of Mn-modified ZIF-67 as a bimetallic MOF-based electrode material for faradaic supercapacitors and provide valuable insight into the rational design of MOF architectures for next-generation sustainable energy storage applications.