In Situ-Engineered MOF/Polymer Hybrid Electrolyte With 3D Continuous Ion Channels for High-Voltage and Thermal-Resistant Lithium Metal Batteries

Abstract

Composite quasi-solid-state electrolytes are pivotal for enabling high-energy-density lithium metal batteries (LMBs), yet their practical application is hindered by discontinuous ion transport, poor interfacial stability, and limited high-voltage endurance. Here, a universal in situ growth strategy is developed to construct a metal-organic framework (MOF)/polymer composite electrolyte (ZCPSE) with hierarchically ordered ion-conducting networks. The ultra-uniform MOF nanoparticles (e.g., ZIF-8) are anchored onto polymer nanofibers, creating abundant nanopores and Lewis acid sites that synergistically enhance Li⁺ transport and oxidative stability. The resulting ZCPSE exhibits unprecedented ionic conductivity (0.46 mS cm−1 at 25°C), a wide electrochemical window (5.15 V vs. Li/Li+), and exceptional mechanical strength (151.2 MPa, 4× higher than pristine polymer membrane). Theoretical simulations reveal that the 3D continuous MOF/polymer interface facilitates rapid Li+ dissociation and uniform flux distribution, endowing ZCPSE with a high Li+ transference number (0.74) and dendrite-free Li plating/stripping (2000 h in Li|Li symmetric cells). Practical applicability is demonstrated in Li|LiFePO4 cells (stable cycling at 25°C–100°C) and high-voltage Li|LiNi0.8Co0.1Mn0.1O2 full cells (4.5 V, 100 cycles with 99.2% capacity retention). This study provides a paradigm for designing MOF-based hybrid electrolytes with simultaneous ionic, mechanical, and interfacial optimization, paving the way for safe and high-energy LMBs.