Synergistic Co‐Optimization Strategy for Electron‐Ion Transport Kinetics in all‐Solid‐State Sulfurized Polyacrylonitrile Cathodes

Abstract Sulfurized polyacrylonitrile (SPAN) cathodes represent a highly promising category of sulfur‐based materials, distinguished by their superior electronic conductivity. Nevertheless, their implementation in all‐solid‐state lithium‐sulfur batteries (ASSLSBs) is hindered by inferior electrochemical performance, primarily arising from the severe exacerbation of inherent electron/ion transport kinetic limitations in conventional micron‐sized granular SPAN (GSPAN) microstructures. To circumvent these limitations, a nanofibrous SPAN cathode (FSPAN) is fabricated via electrospinning coupled with programmed pyrolysis. The fabricated 3D‐interwoven nanofiber architecture establishes a continuous conductive network, enabling unobstructed transport pathways for efficient charge‐carrier migration. This structural design significantly suppresses the interfacial resistance, thereby enhancing the electrode redox kinetics through optimized ion/electron transport dynamics. As a result, the all‐solid‐state FSPAN cathode demonstrates exceptional electrochemical performance, manifesting a high reversible specific capacity of 1467.2 mAh g −1 at 0.2 C. Notably, the FSPAN cathode delivers a stable discharge capacity of ≈500 mAh g −1 at 2 C, marking a fivefold enhancement over conventional GSPAN cathodes. These findings validate a rational materials design paradigm that significantly enhances the performance metrics of all‐solid‐state SPAN cathodes via spatially synergistic optimization of charge transport pathways.