Hierarchically engineered hollow PEDOT:PSS/MoS₂ hybrid fiber for high‑performance flexible supercapacitor

Herein, we report the fabrication of a high-performance fiber-shaped supercapacitor (FSSC) based on a hollow poly(3,4-ethylenedioxythiophene):poly(4-styrenesulfonate)/molybdenum disulfide (PEDOT:PSS/MoS₂) hybrid fiber electrode via a hydrothermal co-assembly strategy. A three-dimensionally interconnected composite fiber electrode was constructed by the liquid-phase co-assembly of PEDOT:PSS chains and MoS₂ nanosheets, followed by acid post-treatment. This rational design alleviates several core drawbacks of conventional MoS₂-based electrodes, including inferior electrical conductivity, severe lamellar restacking, and low active site utilization efficiency. The hollow microstructure, formed by in-situ gas evolution during synthesis, improves electrolyte penetration and expands the electrode-electrolyte contact area. Electrochemical measurements on symmetric solid-state FSSCs show that the optimized hybrid fiber delivers favorable volumetric and areal capacitances of 329.9 F cm⁻³ and 390.1 mF cm⁻² at a current density of 2 A cm⁻³ , alongside a capacitance retention of 65.8% (2 −20 A cm⁻³). The improved electrochemical behavior originates from synergistic effects between conductive PEDOT and pseudocapacitive MoS₂, and the unique hierarchical hollow morphology. This facile synthesis yields advanced fiber electrodes, showing promising applications of hollow PEDOT:PSS/MoS₂ hybrids for wearable energy storage.