In a three-electrode test system, the MXene decorated 3D-printed electrode h) shows a capacitance of 30.2 mF cm −2 at a current density of 0.1 mA cm −2. The MXene layers could provide higher capacitances due to the pseudocapacitive charge storage mechanism and high metallic conductivity. Herein, a conductive carbon black-based 3D-printable filament is designed to be used as a free-standing electrode after FDM printing, solvent activation, and MXene coating. Among the different 3D-printing techniques, fused deposition modeling (FDM) is a promising technique for upscaling due to its low price and maturity in industry. Three-dimensional (3D) printing offers a unique approach to fabricating free-standing and complex structured electrodes for high-performance micro-supercapacitors (MSCs).
