Carbon Scaffolds Enabling Asymmetric Lithium Plating-Stripping Pathways for Solid-State Batteries

Abstract Li-free all-solid-state batteries suffer from chemomechanical instability at the solid electrolyte−Li interface. To enable scalable interfacial stabilization without precious metals, we design a heterostructured carbon-only anode, termed Graphite-in-Carbon Black (GiCB). This architecture integrates complementary functions of two distinct carbon hosts: graphite promotes dense Li plating owing to its high lithiophilicity, while carbon black spatially isolates Li deposits from the electrolyte. Notably, this design induces a unique asymmetric Li pathway: Li plates laterally beneath the graphite particles to form dense deposits, yet strips vertically through the porous carbon black matrix. This mechanism ensures uniform stress distribution and maintains a planar electrode interface during cycling. Consequently, the optimized GiCB electrode sustained over 1000 h of stable cycling in half-cells and achieved 500 cycles in Li-free pouch-type full cells with an average Coulombic efficiency of 99.939% at a rate of 0.5 C. These results establish carbon-only microstructure engineering as a cost-effective, scalable strategy for durable Li-free solid-state batteries.