High-performance, mechanically compliant energy storage: flexible MXene/silver nanowires@Co composite electrodes for wearable supercapacitors

The development of flexible and wearable electronics has created an urgent demand for lightweight energy storage devices with simultaneously high capacitance, rapid ion transport, and excellent mechanical durability. However, the severe restacking tendency of MXene nanosheets and the intrinsically low conductivity of metal-organic frameworks (MOFs) significantly limit their electrochemical performance in flexible supercapacitors. Herein, a hierarchically engineered Ti₃C₂Tₓ/AgNWs@ZIF-67 ternary composite electrode is rationally designed to address these challenges through a synergistic conductive-spacing and pseudocapacitive activation strategy. In this architecture, silver nanowires (AgNWs) serve not only as highly conductive electron transport pathways, but also as interlayer spacers that effectively suppress the restacking of Ti₃C₂Tₓ nanosheets and open ion diffusion channels into the internal MXene galleries. Meanwhile, ZIF-67 polyhedral nanoparticles are in situ grown on the surface of AgNWs, introducing abundant redox-active sites and enhancing the pseudocapacitive contribution of the composite electrode. Benefiting from the synergistic integration of MXene conductivity, AgNW-mediated porous transport networks, and ZIF-67 electrochemical activity, the optimized MX/Ag@Co-5% electrode delivers a high specific capacitance of 290 F g⁻¹ at 0.5 A g⁻¹, approximately twice that of pristine MXene electrodes. Moreover, the electrode maintains 82.5% of its initial capacitance after 5000 charge-discharge cycles at 2.5 A g⁻¹, demonstrating excellent cycling stability. Importantly, the electrode exhibits outstanding mechanical flexibility, retaining nearly unchanged galvanostatic charge-discharge characteristics under 90° bending deformation. This work provides a rational structural engineering strategy for simultaneously improving ion accessibility, charge transfer efficiency, and pseudocapacitive energy storage, offering a promising route toward next-generation high-performance flexible supercapacitors.