<p>Despite the enormous challenges posed by the global energy crisis, supercapacitors (SCs) have emerged as a promising energy storage technology due to their high power density and long cycling stability. Development of nanostructured materials with a well-defined and consistent morphological design is considered highly advantageous for enhancing electrochemical energy storage performance. In this study, a novel spinel MnCo₂O₄ decorated on multi-walled carbon nanotubes (MWCNTs) is proposed as an efficient electrode material that combines high energy density with low cost, simple synthesis, and the use of earth-abundant elements. The morphological and structural properties of MnCo₂O₄ decorated on MWCNT led to a crystallite size of 63.49&#xa0;nm, confirmed by powder X-ray diffraction. Electrochemical measurements demonstrated that the MnCo₂O₄/MWCNT electrode exhibits a high-specific capacitance of 571.42 F·g⁻¹, along with an energy density of 19.81 Wh·kg⁻¹ and a power density of 0.68&#xa0;kW·kg⁻¹ at a current density of 2 A·g⁻¹ in a 2&#xa0;M KOH electrolyte, as determined from galvanostatic charge–discharge (GCD) tests. Cyclic voltammetry (CV) analysis further yielded a specific capacitance of 457.35 F·g⁻¹ at a scan rate of 3&#xa0;mV·s⁻¹. In addition, the nanocomposite showed a high ionic conductivity of 29 S·m⁻¹, which improves interlayer electron transport, and a low charge transfer resistance (Rct) of 0.21 Ω. Measurements using electrochemical impedance spectroscopy (EIS) corroborate these conclusions. The improved electrochemical properties of MnCo₂O₄ decorated on MWCNT have much potential for real-world applications.</p>