Coating Porous MXene Films with Tunable Porosity for High-Performance Solid-State Supercapacitors

Two-dimensional MXenes with their outstanding physical and chemical properties have been extensively used in numerous fields such as electrochemical energy storage, catalysis, and sensing. In these applications, high active surface area and facilitated diffusion of ions/atoms/molecules are crucial. While these features can be offered by porous films and structures, their fabrication at ambient conditions, especially with scalable methods such as printing and coating has proven to be quite challenging. Here, we have developed MXene inks containing a space-holder agent, based on which porous films with tunable porosities can be easily coated. The whole fabrication process lasts only a few minutes and is carried out at room temperature and pressure, making it suitable for continuous scalable production. Films with different porosities (up to 80 %) have been coated and used for the fabrication of solid-state microsupercapacitors with enhanced rate capability and improved capacitance (241 mF/cm(2)).