Conductive Rigid-Flexible Binder for Sulfurized Polyacrylonitrile Cathodes in Rechargeable Lithium Batteries

Abstract Among various sulfur-based cathode materials, sulfurized polyacrylonitrile (SPAN) has garnered significant attention due to its ability to effectively suppress the polysulfide shuttle effect and its low self-discharge rate. This work presents a two-component binder, whereby flexible polyvinyl alcohol (PVA) forms robust bridging networks between particles within the electrode, and rigid poly(3,4-ethylenedioxythiophene): poly(styrene sulfonate) (PEDOT: PSS) binds to PVA through hydrogen bonding and electrostatic interactions, forming an effective crosslinked network, synergistically enhancing the binder’s toughness while improving the cathode’s electrochemical activity. The binder network formed by PVA synergistically interacts with conductive agents to create conductive pathways. This design enables the electrode to deliver outstanding cycling stability under conditions of a SPAN loading of 5.0 mg cm–2, with a capacity retention of 92.2% after 75 cycles at 0.2 C. Even with the binder content reduced to 2.5%, under conditions where the SPAN loading is approximately 2 mg cm–2, the electrode still maintains a retention of 93.7% after 100 cycles at 0.5 C. This study presents, for the first time, the application of a binder-based strategy to construct complete conductive pathways in SPAN cathodes while significantly reducing the binder content. This approach provides a direction for developing cathodes with higher energy density and electrochemical activity.