<p>The development of less expensive, stable, and effective nanocomposites to replace high-cost and rare noble metals (e.g., Pt, Au, and Pd) in overcoming the slow kinetic process of the oxygen reduction reaction (ORR) is vital to satisfy the demand for sustainable energy storage and conversion in the future. This work presents a comparative investigation of MnO₂<b>–</b>Fe₃O₄/C and Mn₂O₃<b>–</b>Fe₃O₄/C hybrid nanocomposites to assess their potential as dual-functional electromaterial for battery-type hybrid supercapacitors and ORR applications. Both nanocomposites were synthesized via a simple, cost-effective co-precipitation method and characterized by using XRD, Raman, FESEM/EDX, and BET, which established the successful formation of porous hybrid architectures to facilitate the rapid electron and ion transport. Electrochemical tests, assessed using GCD, EIS, CV, and LSV, show that the MnO₂<b>–</b>Fe₃O₄/C composite has a specific capacity of 294.98 C/g and a minimum charge-transfer resistance (<i>R</i>_ct) of 18.802 Ω compared to the Mn₂O₃<b>–</b>Fe₃O₄/C electrode. The MnO₂<b>–</b>Fe₃O₄/C composite has retained 99.65%, indicating its significant cyclic stability for about 3000 galvanostatic charge discharge cycles. Furthermore, the CV and LSV revealed that MnO₂–Fe₃O₄/C delivered superior ORR activity with a more positive onset potential (− 0.21&#xa0;V) via a two-electron pathway in an alkaline electrolyte and redox kinetics (Tafel slope of 197&#xa0;mV decade⁻¹), as compared to Mn₂O₃–Fe₃O₄/C owing to synergistic effects between Mn⁴⁺/Mn³⁺ redox couples and Fe₃O₄. Chronoamperometry describes the stable response over 10&#xa0;h for the ORR. The developed electromaterial is probably to open up a novel class of electromaterial in battery-type hybrid supercapacitors and fuel cell applications.</p>