In Situ Constructing Robust and Highly Conductive Solid Electrolyte with Tailored Interfacial Chemistry for Durable...

Employing nanofiber framework for in situ polymerized solid-state lithium metal batteries (SSLMBs) is impeded by the insufficient Li⁺ transport properties and severe dendritic Li growth. Both critical issues originate from the shortage of Li⁺ conduction highways and nonuniform Li⁺ flux, as randomly-scattered nanofiber backbone is highly prone to slippage during battery assembly. Herein, a robust fabric of Li_0.33La_0.56Ce_0.06Ti_0.94O_3-δ/polyacrylonitrile framework (p-LLCTO/PAN) with inbuilt Li⁺ transport channels and high interfacial Li⁺ flux is reported to manipulate the critical current density of SSLMBs. Upon the merits of defective LLCTO fillers, TFSI^- confinement and linear alignment of Li⁺ conduction pathways are realized inside 1D p-LLCTO/PAN tunnels, enabling remarkable ionic conductivity of 1.21 mS cm^-1 (26 °C) and t_Li+ of 0.93 for in situ polymerized polyvinylene carbonate (PVC) electrolyte. Specifically, molecular reinforcement protocol on PAN framework further rearranges the Li⁺ highway distribution on Li metal and alters Li dendrite nucleation pattern, boosting a homogeneous Li deposition behavior with favorable SEI interface chemistry. Accordingly, excellent capacity retention of 76.7% over 1000 cycles at 2 C for Li||LiFePO₄ battery and 76.2% over 500 cycles at 1 C for Li||LiNi_0.5Co_0.2Mn_0.3O₂ battery are delivered by p-LLCTO/PAN/PVC electrolyte, presenting feasible route in overcoming the bottleneck of dendrite penetration in in situ polymerized SSLMBs.