A Highly Adhesive Binder Enables Sulfide‐Based All‐Solid‐State Batteries with High Cycling Stability at Low Stack Pressure

Sulfide-based all-solid-state lithium-ion batteries are promising next-generation energy storage systems owing to their high energy density and enhanced safety. However, the contact loss and unwanted reactions at the electrode|electrolyte interface lead to capacity degradation, which impedes their commercialization. Herein, we introduced hydroxyl polar groups into commercial polystyrene-b-polybutadiene-b-polystyrene (SBS) binder via click chemistry. The modified SBS-Click binder could form hydrogen bonds with the LiNi0.9Co0.06Mn0.04O₂@Li₃BO₃ cathode active material and the sulfide electrolyte, thereby enhancing adhesion strength even in non-polar solvents compared to SBS. Consequently, SBS-Click cells exhibited superior rate performance and cycling stability over both SBS- and HNBR-based cells, particularly under comparatively lower stack pressure conditions. The cells using SBS-Click delivered areal capacities of up to 5.4 mAh cm⁻² at 0.1 C and at room temperature and 175 MPa. Notably, they achieved about 83% capacity retention after 6000 cycles at 3 C. Furthermore, stable operation exceeding 10 000 cycles was also achieved with 5 C. Overall, this work paves the way for alleviating electro-chemo-mechanical failures in all-solid-state lithium-ion batteries, accelerating their commercialization.