Self-assembled MnO2-MXene composite electrodes for high-performance supercapacitors

초록

In this study, we report the self-assembled electrodeposition of a binder-free MnO2-Ti3C2Tx composite electrode on nickel foam (NF), in which conductive Ti3C2Tx MXene acts as an electron-transport scaffold and MnO2 contributes abundant pseudocapacitive redox-active sites. The strong interfacial interaction between MnO2 and Ti3C2Tx enhances the composite's electrochemical performance, making it a promising electrode material for supercapacitor applications. The MnO2 offers high theoretical capacitance and low cost, however, its poor intrinsic conductivity limits practical performance. This limitation is effectively addressed by integrating MnO2 with highly conductive Ti3C2Tx MXene, resulting in improved charge transport and structural stability. The MnO2-Ti3C2Tx composite electrode exhibited a high specific capacitance of 448.72 F/g, an energy density of 15.58 Wh/kg and a power density of 500 W/kg, along with 88.85% of capacitance retention and 97.53% of coulombic efficiency after 10,000 cycles. Furthermore, an asymmetric supercapacitor device based on a MnO2-Ti3C2Tx/NF//PVA-KOH//AC/NF configuration delivered a specific capacitance of 73.56 F/g, an energy density of 20.02 Wh/kg, and a power density of 653.33 W/kg, while maintaining 79.10% capacitance retention and 97.88% coulombic efficiency over 10,000 cycles. These results highlight the potential of self-assembled MnO2-Ti3C2Tx composites for advanced energy storage applications. © 2026 Elsevier Ltd. All rights are reserved, including those for text and data mining, AI training, and similar technologies.

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