Yb 2 O 3 ‐Polyoxometalate Sub‐1 nm Heterogeneous Cluster Chains with Local Electron Rearrangement for Accelerated Li + Transport in Composite Solid Electrolytes

Abstract Composite solid‐state electrolytes have received widespread attention due to their excellent comprehensive performance. Herein, sub‐1 nm Yb 2 O 3 ‐based polyoxometalates heterogeneous cluster chains (YOP) are designed to construct enrich and continuous Li + interface pathways. The terminal oxygen in phosphomolybdic acid attracts local electrons from Yb in the heterogeneous structure, inducing electron rearrangement and strengthening the local positive charge of Yb 3 ⁺, which enhances interfacial interactions and promotes lithium salt dissociation. Then, the YOP cluster chains are grafted with polyether amine and uniformly dispersed in the PVDF‐HFP matrix via hydrogen bonds, significantly increasing the organic–inorganic interface area. Under the effect of strong local charge, the β‐phase transformation of PVDF‐HFP is induced for aligning dipoles of ─CF 2 ─ groups to optimize Li + distribution and form continuous, oriented Li + interface pathways. Consequently, the YOPSE exhibits high ionic conductivity (0.68 mS cm −1 ), a lithium‐ion transference number of 0.62, and excellent cycling stability (98.5% capacity retention of LFP/Li batteries after 800 cycles at 2C). This study demonstrates the synergetic effects of hetero‐structure nanomaterials and polymer matrix, providing insights into solid‐state battery designs.