Hierarchical MXene/PANI porous film electrodes with improved ion transport for supercapacitors

With the growing demand for high-performance energy storage devices, the development of advanced electrode materials remains a critical challenge. Two-dimensional transition metal carbides (MXene) show great promise, yet their intrinsic tendency to restack in thin-film electrodes impedes ion transport and limits capacitance. Here, we propose a rational structural engineering strategy to overcome this limitation by constructing internally supported hierarchical porous Ti 3 C 2 T x films through hard-template-assisted pore formation. Moreover, the in-situ polymerization of polyaniline nanowires within the pores enhances conductivity and provides additional pseudocapacitance. Benefiting from the synergistic effects of hierarchical porosity and conductive polymer integration, the optimized electrode delivers a high specific capacitance of 270 F g −1 at 0.2 A g −1 and an energy density of 37.5 Wh kg −1 at 200 W kg −1 . After 8000 charge-discharge cycles, the capacitance retention remains at 80.37 %, demonstrating excellent stability. This work presents a simple and effective approach to designing robust MXene-based 3D porous electrodes, offering new insights into the development of high-performance supercapacitors.