Building porous yet robust binders towards fast-rate flexible supercapacitors based on activated carbons

Developing robust, flexible electrodes with excellent high-rate electrochemical performance is crucial for advanced wearable supercapacitors, yet it remains challenging due to the trade-off between ion-transport capability and the mechanical properties of electrodes. Here, we report a mechanically robust, flexible, 200-μm-thick activated carbon (AC)-based electrode with excellent electrochemical performance, fabricated via a thermally induced phase separation (TIPS) strategy. By generating interconnected porous structures in a multi-walled carbon nanotubes (MWCNTs)-reinforced PVDF binder during the TIPS process, we obtained an AC-based electrode with both electrochemically and mechanically enhanced performance. The resulting thick electrode demonstrates outstanding high-rate capabilities in both ionic liquids and solid gel electrolytes. An assembled flexible all-solid-state supercapacitor exhibits remarkably stable power output under bending conditions. The TIPS process is compatible with the industrial slurry-casting method for electrode fabrication, showing high potential for large-scale applications.