Microfluidic-assembled hierarchical macro-microporous graphene fabrics towards high-performance robust supercapacitors

Advanced fabric with ordered structures, unimpeded ionic channels, and high mechanical flexibility are profoundly significant for wearable supercapacitors. However, the restacking structure and weakened porosity, both of which block ionic kinetic migration and surface accessibility, result in low energy density. Here, we develop a hierarchical porous graphene fibers-assembled fabric (HP-GFF) for high-performance supercapacitors. By precisely manipulating the microfluidic assembly and chemical etching processes, the HP-GFF maintains open inter-linkage porous backbone, ordered pathways, large accessible surface (221 m²/g), high mechanical flexibility (elongation: 197%) and large production size (30 × 20 cm), which also help in facilitating electrolyte ions migration and intercalation. The resulting HP-GFF displays a large capacitance of 312.9F/g (1248.5 mF/cm²) and ultrahigh stability (60000 cycles) in H₂SO₄ electrolyte. Furthermore, the HP-GFF-constructed solid-state flexible supercapacitor also delivers high energy density (120.2 μWh/cm²), excellent capacitance, and washable/deformable capabilities, which are remarkably demonstrated in actually wearable and self-powered applications such as a toy boat, electrical fan and smart watch.