Architecting Triple Synergy: MXene-Enhanced Short Carbon Nanofibers Interlaced with Polyaniline for Supercapacitors

Abstract Flexible supercapacitors require electrode materials that integrate high specific capacitance, mechanical robustness, and efficient ionic transport. Herein, a novel MXene/short carbon nanofiber@polyaniline (MSCPM) hybrid membrane was synthesized via chemical oxidative polymerization and vacuum-assisted filtration. By optimizing the mass ratio of MXene to short carbon nanofiber@polyaniline (SCNF@PANI), a three-dimensional hierarchical architecture was achieved, where MXene nanosheets interlocked with PANI-coated CNFs to form covalent interface bonds. This design leverages the metallic conductivity of MXenes for rapid electron transport, CNFs' mechanical rigidity of CNFs to maintain structural integrity, and PANI's pseudo-capacitance of PANI for enhanced energy storage. The hybrid membrane exhibited exceptional electrochemical performance, achieving a specific capacitance of 601.8 F g− 1 at 5 mV s− 1, surpassing most reported MXene-based materials. Notably, the composite retained 81.5% of its capacitance after 10,000 cycles, demonstrating remarkable cycling stability. The synergistic integration of hydrophilic MXenes, porous CNFs, and polar PANI functionalities ensures efficient electrolyte infiltration and ion diffusion. Simultaneously, the covalent interface bonds enhance the charge transfer efficiency and structural integrity. This work establishes a scalable strategy for high-performance supercapacitor electrodes, advancing the integration of MXenes with carbon nanomaterials and conductive polymers. These design principles provide new insights into interfacial engineering for multifunctional energy storage applications, particularly in flexible and high-temperature devices.