Grape Cluster Inspired Biomimetic Composite Solid Electrolyte for High‐Voltage and Long‐Life Solid‐State Lithium Metal Batteries

ABSTRACT Solid‐state lithium metal batteries suffer from poor interfacial stability and dendrite growth, primarily limited by the ion transport kinetics and mechanical properties of composite solid electrolytes (CSE). Inspired by the hierarchical grape cluster, we design a biomimetic electrolyte via electrospinning PAN fiber “pedicel” integrated with mesoporous SiO 2 ‐SO 3 Li “grape berry” fillers, followed by in‐situ polymerization. This structure establishes long‐range Li + conduction channels and a robust physical barrier, delivering a high Li + transference number of 0.65, ionic conductivity of 1.44 × 10 −3 S cm −1 at 25°C, and a modulus of 520 MPa. Benefiting from these advantages, the assembled LFP|Li and NCM811|Li cells achieve 88.8% capacity retention after 1000 cycles and 94.3% after 300 cycles, respectively. Moreover, a high‐loading pouch cell realizes an energy density of 414.9 Wh kg −1 /797.8 Wh L −1 and withstands harsh abuse tests. Mechanistically, DFT and phase‐field simulations reveal the dual Li + pathways and TFSI − immobilization enabled by the ‐SO 3 Li groups. Notably, a physics‐informed neural network (PINN) framework decouples interface activation‐aging kinetics and predicts long‐term impedance evolution. This work provides a biomimetic paradigm and data‐driven methods for the design and interface analysis of high‐performance CSE.