Layered two-dimensional MXene materials exhibit tremendous potential in energy storage applications due to their high conductivity and adjustable surface chemistry. However, weak interlayer adhesion between nanosheets and self-aggregation effects induced by van der Waals interactions often lead to uncontrolled stacking phenomena of layers, significantly limiting their practical utilization in flexible energy storage devices. Addressing these challenges, herein, a free-standing nanolamellar Ti3C2Tx–OH/carboxymethyl cellulose-poly(3,4-ethylenedioxythiophene): polystyrenesulfonate (Ti3C2Tx–OH/CMC-PEDOT:PSS) hybrid film was designed as an electrode material for a flexible supercapacitor (FSC) through a convenient vacuum-assisted filtration strategy. CMC serves as an in situ polymerization template for EDOT, guiding the ordered growth of PEDOT chains to form an interconnected conductive network that suppresses PEDOT:PSS self-aggregation; simultaneously, hydrogen bonding between CMC and PEDOT strengthens interfacial interactions within the film. Serving as a multifunctional intercalator, CMC-PEDOT:PSS synergistically leveraged spatial steric hindrance and electrostatic repulsion to expand the interlayer spacing of Ti3C2Tx, while constructing efficient ion/electron transport channels. Furthermore, -F terminals on Ti3C2Tx replaced with −OH generated abundant electroactive sites for redox reactions. Benefiting from these interfacial engineering strategies and optimized structural design, the hybrid film exhibited remarkable mechanical strength (73 MPa tensile strength), outstanding electrical conductivity (75.6 S cm–1), and excellent areal specific capacitance (2968 mF cm–2 at 4 mA cm–2). Moreover, the assembled symmetric supercapacitor (SSC) device delivered a high areal energy density of 94.8 μWh cm–2 at 1600 μW cm–2 power density while maintaining 84.3% initial capacitance after 5000 cycles, demonstrating superior energy storage performance and cycling stability.
Xie et al. (Sat,) studied this question.