A MOF-Reinforced Hybrid Crosslinked Quasi-Solid Electrolytes via In Situ Polymerization for Stable Lithium Metal Batteries

Although polymer electrolytes constructed by in-situ curing of cyclic ethers show great application potential, they also face challenges such as poor oxidation stability and low lithium-ion transference number. Herein, a strategy is proposed to fabricate a network structural composite polymer electrolyte (CPE) via in situ hybrid crosslinking polymerization, using nano-UIO66 as the centers and DOL as the polymeric matrix (PDOL@UIO66). This design not only enhances the ionic conductivity of the CPE, but also addresses the issues of filler sedimentation and agglomeration associated with conventional composite electrolytes. Moreover, the incorporation of MOF fillers contributes to further improvements in both the stability and electrochemical performance of the CPE. As a result, the PDOL@UIO66 electrolyte achieves a high ionic conductivity of 1.31 × 10^–3 S cm^-1 and a satisfactory oxidation potential of 4.8 V. These properties enable the PDOL@UIO66-based lithium symmetric battery exhibit exceptional cycling stability over 1100 h at 0.2 mA cm^-2. And the capacity retention of the prepared LiCoO₂ and NCM523/Li quasi-solid state batteries reached 86.1% after 500 cycles and 87.4% after 200 cycles at room temperature. This strategy of constructing hybrid crosslinking CPE utilizing MOF as the center through in situ polymerization provides new insights for the commercialization of high energy density lithium metal batteries.