Polymer Dendricolloids as Hosts for Uniform Fillers Dispersion Toward Robust All‐Solid‐State Electrolytes With Accelerated Li + Kinetics

To address the safety issues associated with traditional liquid lithium‐ion batteries and the performance deficiencies of single‐component solid‐state electrolytes, this work proposes a bioinspired strategy of designing composite solid‐state electrolytes (CSE). A tree‐root‐like 3D skeleton containing dendritic micro‐ and nanopoly(vinylidene fluoride) (PVDF) fibers and uniformly distributed Li–Al layered double hydroxide or oxide (Li–Al‐LDH or Li–Al‐LDO) nanosheets was constructed and combined with poly(ethylene oxide) (PEO) electrolyte; hence, LDH@PVDF/PEO or LDO@PVDF/PEO CSE films were successfully prepared. LDO@PVDF/PEO electrolyte film exhibits high tensile strength (26.4 MPa) and Young’s modulus (625.3 MPa) and is able to maintain structural integrity at 100 °C. LDO@PVDF/PEO exhibits ionic conductivity of 1.21 × 10 −4 S cm and lithium ion transference number of 0.41 at 50 °C, both higher than those of PEO, LDO/PEO, and LDH@PVDF/PEO. In addition, its electrochemical stability window extends to 4.9 V, demonstrating its potential for use with high‐voltage cathodes. Li/(LDO@PVDF/PEO)/LiFePO 4 cells were assembled and tested, showing excellent rate capability and capacity retention. In addition, Li/(LDO@PVDF/PEO)/Li symmetric cells demonstrated excellent cycling stability for over 1500 h at a current density of 0.1 mA cm −2 . This work provides an innovative biomimetic strategy for constructing high‐performance CSE applicable to next‐generation solid‐state lithium metal batteries.