Hydrogen-Bond-Networked Robust Binder Enabling Long-Cycling Sulfide-Based All-Solid-State Lithium Batteries

Wet processing is promising for scalable manufacture of sulfide-based all-solid-state lithium batteries (ASSBs), but it demands binders compatible with low-polarity solvents and sulfides while enabling thin sulfide solid electrolyte (SSE) films (≤ 30 µm) and high-loading composite cathodes (≥ 30 mg cm^-2). To address these, we present a dynamic hydrogen bonding-empowered robust polymer (denoted as PNO) binder via soft-hard segment synergism design. In the PNO binder, the polybutadiene-based soft segments retain easy processability of SSE films and composite cathodes, while carbamate motif-containing hard segments improve the mechanical strength of them mainly via forming dynamic hydrogen bonding interactions not only among adjacent PNO chains but also between PNO chains and the surface of sulfide or cathode particles. The breaking and reforming of hydrogen bonds enable effective stress dissipation, thereby maintaining the structural stability of both SSE films and composite cathodes during processing and battery cycling. Benefiting from these, ASSBs assembled with PNO binder-based LiNi_0.8Co_0.1Mn_0.1O₂ cathodes and Li₆PS₅Cl films exhibit outstanding cycling stability, which compares favorably with recently reported sulfide-based ASSBs. This work highlights a soft-hard segment synergism binder design strategy that overcomes the bottleneck in wet processing of practical ASSBs, conducive to accelerating the scale-up production of advanced sulfide-based ASSBs.