A 3D Cross-Linked Metal-Organic Framework (MOF)-Derived Polymer Electrolyte for Dendrite-Free Solid-State Lithium-Ion Batteries

Lithium metal batteries (LMBs) with high energy density have received widespread attention; however, there are usually issues with lithium dendrite growth and safety. Therefore, there is a demand for solid electrolytes with high mechanical strength, room-temperature ionic conductivity, and good interface performance. Herein, a 3D cross-linked metal-organic framework (MOF)-derived polymer solid electrolyte exhibits good mechanical and ionic conductive properties simultaneously, in which the MOF with optimized pore size and strong imidazole cation sites can restrict the migration of anions, resulting in a uniform Li+ flux and a high lithium-ion transference number (0.54). Moreover, the MOF-derived polymer solid electrolytes with the 3D cross-linked network can promote the rapid movement of Li+ and inhibit the growth of lithium dendrites. Lithium symmetric batteries assembled with the 3D MOF-derived polymer solid electrolytes are subjected to lithium plating/stripping and cycled over 2000 h at a current density of 0.1 mA cm-2 and over 800 h at a current density of 0.2 mA cm-2. The Li/P-PETEA-MOF/LiFePO4 batteries exhibit excellent long-cycle stability and cycle reversibility. A novel 3D cross-linked metal-organic framework (MOF)-derived polymer solid electrolyte with good mechanical, ionic conductive properties, and interfacial compatibility is achieved by cross-linking vinyl-functionalized MOFs (Vinyl-ZIF-8) to polyethylene glycol diacrylate (PEGDA) through pentaerythritol tetraacrylate (PETEA). The unique structure of the MOFs-derived hybrids electrolytes adsorb anions and only allow Li+ to pass through, resulting in uniform Li+ flux distribution, high t+, and dendrite-free.image