MXene/silk nanofibril composite films with superior capacitive ion storage performance

Journal article, 2026

Two-dimensional (2D) Ti3C2Tx MXene has shown huge potential in the energy storage fields especially worked as electrodes for supercapacitors due to the high metallic conductivity and outstanding specific capacitance. However, the restacking issue of the MXene flakes inhibits the ion diffusion kinetics and ion storage ability. Herein, we report one-dimensional (1D) silk nanofibrils (SNFs) mediated Ti3C2Tx MXene nanosheets to improve the ion diffusion kinetics and capacitive ion storage ability of supercapacitors. The 1D SNFs that are inserted into the 2D flakes can broaden the interlayer spacing, which also promotes the ion diffusion and storage between MXene flakes. In addition, the subsequent alkali treatment and high-temperature carbonization procedure change the functional groups and promote the electrical conductivity. Benefiting from the large interlayer spacing and high electrical conductivity, the freestanding MXene/SNFs-x (M/SNFs, where x = 1, 2, 5) composite film electrodes can achieve excellent electrochemical performance. The optimized M/SNFs-1 composite film electrodes show high specific capacity (544.4 F g⁻¹ at 1 A g⁻¹), outstanding rate performance, and excellent cycling stability (92.2 % after 10,000 cycles). In addition, the assembled symmetric supercapacitors based on the M/SNFs-1 composite films present high energy density of 11.89 Wh kg⁻¹ under a power density of 500 W kg⁻¹, demonstrating the potential value of the biomass assisted MXene composite films for electronic devices.