Enhancing Lithium Stripping Efficiency in Anode-Free Solid-State Batteries through Self-Regulated Internal Pressure

Anode-free all-solid-state lithium metal batteries (ASLMBs) promise high energy density and safety but suffer from low initial coulombic efficiency and rapid capacity decay, especially at high cathode loadings. Using operando techniques, we concluded these issues to interfacial contact loss during lithium stripping. To address this, we introduce a conductive carbon felt elastic layer that self-adjusts pressure at the anode side, ensuring consistent lithium-solid electrolyte contact. This layer simultaneously provides electronic conduction and releases plating pressure. Consequently, the first coulombic efficiency dramatically increased from 58.4% to 83.7% along with over tenfold improvement in cycling stability. Overall, this study reveals an approach to enhance anode-free ASLMB performance and longevity by mitigating lithium stripping inefficiency through self-adjusting interfacial pressure control enabled by a conductive elastic interlayer.