Microfluidic Spinning to Construct 3D MXene Fiber Fabric Electrodes for Flexible Supercapacitors

Flexible supercapacitors are promising energy storage devices for smart wearable fields. Achieving simultaneously their high energy density and actual applications is still challenging for portable supercapacitors assembled by MXene electrode materials. In this study, the microfluidic combined wet-spinning strategy and vacuum-assisted film forming technology are proposed to fabricate three-dimensional MXene fiber fabrics (3DMFF) with an ordered, porous, and interconnected network structure. The 3DMFF electrodes exhibit an excellent specific areal capacitance of 6925 mF cm–2 at a current density of 5.0 mA cm–2 in a three-electrode system. The sandwich structure symmetric supercapacitors constructed by the 3DMFF electrodes can still achieve a high specific areal capacitance of 4531.3 mF cm–2, a large energy density of 402.8 μWh cm–2 at a power density of 2000 μW cm–2, and a reversible charge/discharge stability. The flexible supercapacitors show good bending deformation ability and can power several miniaturized electronic devices to realize the practical application.