Hydrothermal-Assisted In Situ Growth of Vertically Aligned MoS₂ Nanosheets on Reduced Graphene Oxide Fiber Fabrics toward High-Performance Flexible Supercapacitors

The intensive growth of smart portable devices has triggered a boom in the research of all-solid-state flexible supercapacitors. However, the unsatisfactory mechanical flexibility and limited energy density still hinder their practical application. Herein, a combination hydrothermal-assisted assemble strategy is proposed to design reduced graphene oxide fiber/MoS₂ nanosheet-assembled composite fabrics (rGOFF–MoS₂), where the MoS₂ nanosheets vertically grow on the surface of rGO fibers through C–O–Mo covalent bonds. The synthesized rGOFF–MoS₂ fabrics present an inter-linkage isotropy skeleton, a robust fusing node, an in situ vertical covalent bridge, an adequate pseudocapacitive reactivity, and a large electrochemical active surface (80.1 m²/g), resulting in fast interlaminar conductivity, great ionic migration and adsorption, and outstanding mechanical stability. The as-prepared flexible electrode displays a large capacitance of 330 F/g at 0.1 A/g (1330 mF/cm² at 1 mA/cm²) and a high stability (95% capacitance retention after 10,000 cycles) in the H₂SO₄ electrolyte. Additionally, the assembled solid-state flexible supercapacitor presents an energy density of 69.44 μW h/cm² (0.5 mW/cm²) and an excellent mechanical flexibility, making the rGOFF–MoS₂ fabric a highly competitive candidate for practical applications in next-generation wearable/smart electronics.