Carbon Scaffolds Enabling Asymmetric Lithium Plating-Stripping Pathways for Solid-State Batteries
Seong Gyu Lee, Kyu Seok Kim, Longsheng Feng, Jeong An Kim, Su Jin Na, Dayoung Jun, Ji Eun Jung, Seihyun Shim, Seung Woo Lee, Jay Hyok Song, Seong Ho Jeon, Pil Sang Yun, Haena Yim, Hae Joo Kim, Se Hwan Park, Yun Jung LeeAbstract
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.