Regulating Li<sup>+</sup> Transfer and Solvation Structure via Metal-Organic Framework for Stable Li Anode

Abstract

Lithium metal batteries (LMBs) possess large application potential for advanced rechargeable batteries due to the high energy density (> 500 Wh kg−1) and alternative cathode materials. Random Li dendrite growth caused by uneven Li+ distribution and local ion depletion near surface of Li anode induces battery failure with inferior long-term stability. Therefore, regulation of ion distribution near anode surface is essential to realize dendrite-free and uniform Li deposition. Herein, a metal-organic framework (MOF), i.e., ZIF-8, is applied to regulate Li+ solvation structure via unsaturated metal-ion sites to achieve uniform Li+ distribution and Li deposition. A stable cycling performance over 800 h for Li symmetrical cell at 3 mA cm−2 and 3 mAh cm−2 without short circuit is realized. The facilitated Li+ solvation via the adsorption effect of metal-ion sites on anions is demonstrated, which further enhances the uniform Li+ distribution near Li anode surface. This work demonstrates an effective strategy for regulating ion coordination and Li+ distribution to stabilize Li anode via MOF-based materials.