Confinement-Tailored High-Concentration Electrolytes in Metal-Organic Frameworks for Durable Lithium-Metal Batteries

High-concentration electrolytes (HCEs) face inherent challenges such as high viscosity and diminished ionic conductivity caused by the formation of three-dimensional (3D) anion networks, which limit their practical applications. In this study, it is demonstrated that encapsulating HCEs within metal-organic frameworks (MOFs) effectively disrupts these 3-D networks, resulting in significantly enhanced ionic conductivity. Raman spectroscopy, nuclear magnetic resonance (NMR), and molecular dynamics (MD) simulations reveal a significant reduction in aggregates (AGGs)-state anion within MOF-confined electrolytes, confirming the reconstruction of the solvation environment. The MOF-engineered electrolytes promote uniform lithium deposition and enable LiFePO₄||Li (LFP||Li) batteries to achieve stable cycling for over 400 cycles with minimal capacity decay. Remarkably, these batteries maintain stability at elevated temperatures and sustain the performance at 90 °C. By addressing the fundamental limitations of HCEs through nanoconfinement in MOFs, this work establishes an effective strategy for developing high-performance and robust energy storage systems.