UNVEILING THE ROLE OF α-MnO2 NANORODS IN BOOSTING ELECTROCHEMICAL PERFORMANCE OF AC–MnO2 SYMMETRIC SUPERCAPACITORS

Activated carbon (AC) - Manganese dioxide (MnO2) composite electrodes have attracted significant attention for supercapacitor applications due to the synergistic combination of electric double-layer capacitance from carbon materials and pseudocapacitive charge storage from MnO2. Despite their promising performance, the influence of MnO2 morphology on electrochemical behavior remains insufficiently understood when crystal phase and mass loading are controlled. In this work, α-MnO2 nanorods and α-MnO2 particles were synthesized via a hydrothermal method and incorporated into AC matrices with identical MnO2 mass loading to systematically evaluate the effect of morphology on charge-discharge performance. Structural characterization confirms that both materials possess the same α-phase, while distinct one-dimensional and particulate morphologies are observed. Electrochemical measurements show that the nanorod-based composite delivers a superior gravimetric capacitance of 40.67 F g-1 and a higher specific energy of 7.36 Wh kg-1 compared to the particle-based counterpart. These findings highlight morphology engineering of α-MnO2 as an effective strategy to further enhance the performance of AC–MnO2 composite electrodes for supercapacitors.