Pressure‐Resilient Electron‐Ion Networks via Multifunctional Carbon Conductive Agents for High‐Rate Solid‐State Batteries

Abstract

ABSTRACT Silicon‐based all‐solid‐state batteries (ASSBs) promise high safety and energy density, yet their rate capability remains fundamentally constrained by the disruption of continuous electron‐ion transport networks induced by large volume variations. Herein, we introduce a pressure‐resilient electron‐ion network enabled by a molten‐salt‐mediated multifunctional carbon conductive agent featuring a graphene‐like stacked framework with uniformly distributed nanopores. This architecture enables synergistic electron‐ion transport (with electronic and ionic conductivities of 133.26 S cm −1 and 1.89 mS cm −1 ), accommodates large deformation (up to 91.3% strain) without structural failure and retains high elasticity under a compressive strain of 80.6%. Operando expansion and kinetic analysis reveal that the elastic network dynamically adapts to silicon volume changes, preserving interfacial integrity and continuous transport pathways. As a result, the composite silicon anode delivers high capacity of 1672.2 mA h g −1 at 3C with 76.5% retention over 300 cycles, and notably sustains 1030.0 mA h g −1 at 3C even under 20 MPa. In full cells, it achieves 76.8 mA h g −1 at 3C under 20 MPa, 2.7 times higher than those based on pristine silicon anodes. Beyond silicon, this strategy can extend to other alloy‐type anodes (e.g., Sn), offering a general paradigm for constructing pressure‐resilient electron‐ion networks toward high‐rate ASSBs.