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. Graphical A bioinspired strategy is proposed to construct a tree-root-like 3D skeleton of PVDF dendricolloids as hosts to achieve uniform dispersion of high-content (50 wt%) Li–Al-LDH/LDO nanosheets, breaking the filler agglomeration bottleneck in traditional composite solid-state electrolytes (CSE). This composite electrolyte design simultaneously realizes high filler content, uniform dispersion, continuous/fast Li + transport channels, and enhanced mechanical properties.