Realizing Low‐Pressure Operation of All‐Solid‐State Lithium–Sulfur Batteries Enabled by Carbon‐Coated Current Collectors

Abstract All‐solid‐state lithium–sulfur batteries (ASSLSBs) face challenges due to the need for high stack pressures to maintain interfacial contact. This study demonstrates that surface‐engineered current collectors coated with carbon‐based primer layers enable low stack‐pressure (10 MPa) operation of ASSLSBs. Dry‐processed lithium sulfide (Li ₂ S)–composite cathodes, using carbon‐coated aluminum (Al) foil, show significantly reduced interfacial resistance, enhanced adhesion, and improved cycling stability. Interfacial resistance is reduced by 5–10 times compared to bare aluminum, and surface analyses confirmed improved mechanical interlocking between the composite cathode and current collector. Notably, carbon black‐coated Al collector leads to superior performance, with ≈800 mAh g ⁻¹ reversible capacity and 78% retention over 350 cycles at 10 MPa. Even at 1 C (1 C = 1166 mAh g ⁻¹ ), carbon‐coated cells maintained 96% of the capacity obtained at C/10. This practical strategy provides a scalable approach to enable low‐stack‐pressure operation and broaden ASSB implementation.