Recyclable Covalent Organic Framework Templated Polymer Entanglement for Quasi-Solid-State Lithium-Metal Batteries

Precise modulation of polymer chain entanglements, which governs the core properties of the solid polymer electrolytes (SPEs) in solid-state lithium batteries, remains challenging due to uncontrolled polymerization processes. Here, this limitation is addressed by designing a self-triggered single-Li⁺-conductive covalent organic framework (COF) with highly crystalline orientation to template the in situ polymerization of 1,3-dioxolane (DOL). The COF's ordered pores, functionalized with initiators, regulate poly(1,3-dioxolane) (PDOL) chain entanglement while creating a novel all-interconnected structure favorable for ion diffusion. The resulting COF-templated PDOL electrolyte (PDCM) exhibits exceptional ionic conductivity (1.35 mS cm⁻¹ at 20 °C), high Li⁺ transfer number (0.74), remarkable fire safety, and surprising steady lithium deposition even after operation for > 7 months (5000 h). PDCM bears a high-voltage cathode (LiNi_0.8Co_0.1Mn_0.1O₂, NCM811) and functions in LiFePO₄||Li cells over a wide operating temperature range (−20 °C to 60 °C) and maintains excellent durability even under a large current density of 0.5C in quasi-solid-state lithium-metal batteries. Notably, the COF template is readily recoverable, underscoring its scalability and industrial viability.