3D‐Printed Sulfur‐Derived Polymers With Controlled Architectures for Lithium‐Sulfur Batteries

ABSTRACT Lithium‐sulfur batteries are emerging as a promising next‐generation energy storage system because of their high theoretical energy density, cost‐effectiveness, and sustainability. However, conventional electrode fabrication techniques face limitations in tailoring electrode structures, active material loading, and addressing the polysulfide shuttle effect, which significantly hampers the electrochemical performance and cycle life. This study presents a versatile approach exploiting direct ink writing (DIW) to fabricate multi‐scale porous sulfur‐rich copolymer cathodes. The sulfur‐dicyclopentadiene (SD) copolymer with a sulfur content of 62.1 wt. synthesized via inverse vulcanization, ensures complete copolymerization and eliminates crystalline sulfur. Aqueous ink formulations incorporating SD, graphene oxide (GO), and Pluronic F127 provide a good balance between printability and electrochemical performance. Rheological properties from large amplitude oscillatory shear experiments flag distinctive flow transitions that compromise printability when using GO as formulation additive. The DIW‐fabricated grid‐like architectures mitigate the shuttle effect through tunable macropores and micropores, and lead to effective ion and electron transport. Post‐thermal treatment further improves the copolymer matrix integration, achieving a specific capacity of 925 mAh g S −1 and a capacity retention of over 60% after 200 cycles. These design and printing strategies facilitate the fabrication of customized complex structures for high‐performance energy storage systems and can be applied to other functional materials and diverse applications.