Biomimetic Bamboo‐Node‐Inspired Composite Electrolyte with Hierarchical Ion Pathways for Safe and High‐Performance Solid‐State Lithium Metal Batteries

Composite solid‐state electrolytes (CSEs) are critical to enabling high‐performance solid‐state lithium metal batteries (SSLMBs). However, their development is hindered by intrinsic limitations such as high polymer crystallinity, aggregation of inorganic fillers, and heterogeneous interfacial structures, which collectively compromise ionic conductivity. Drawing inspiration from the “hollow‐channel guidance and node reinforcement” architecture of bamboo, we report a biomimetic bamboo‐node‐inspired composite solid‐state electrolyte (PHLM‐CSE), fabricated through a combination of electrospinning and in situ self‐assembly. This unique structure enables the simultaneous enhancement of mechanical robustness and ionic transport efficiency. The cooperative interaction between metal–organic framework (MOF) and LLZTO (Li 6.4 La 3 Zr 1.4 Ta 0.6 O 12 ) fillers modulates polymer chain conformation, promotes amorphous phase formation, and constructs continuous and efficient ion transport pathways. Density functional theory (DFT) calculations reveal that MOF incorporation improves the solvation environment within the polymer matrix, thereby accelerating Li + migration. At 50 °C, the electrolyte exhibits a high ionic conductivity of 5.04 × 10 −4 S·cm −1 and Li + transference number of 0.64. Symmetric Li||Li cells tested at 50 °C demonstrate ultra‐stable cycling performance exceeding 3400 h, while full cells with NCM811 cathodes retain 95.2% of initial capacity after 800 cycles at 1 C. This biomimetic composite strategy offers a promising pathway toward designing high‐performance and intrinsically safe solid‐state electrolytes for next‐generation SSLMBs.