LiF‐Rich Solid Electrolyte Interfaces Guarantee the Cycle Stability of Metal‐Organic Frameworks for Lithium Storage

Abstract

Metal‐organic framework materials (MOFs) with hierarchical porosity, structural tunability, and rich redox‐active centers have attracted intensive attention as potential substitutes for carbonaceous anode materials. However, the practical commercialization of MOFs still remains a challenge, due to uncontrollable performance degradation. Inspired by the prolonged lifespans of traditional anode materials with LiF‐rich solid electrolyte interface (SEI), the roles of LiF are examined in enhancing the cycle stability of MOFs, with copper benzenedicarboxylate (Cu‐BDC) as an example. By adjusting the electrolyte composition, the cycle performance of Cu‐BDC material is optimized, due to the generation of LiF‐rich SEI. In the optimal 3 M LiPF6 electrolyte, the formed SEI membrane is the thinnest, and the LiF content is the highest, so the Cu‐BDC shows a specific charge/discharge capacity of 378/387.2 mAh g−1 after 100 cycles at 100 mA g−1, comparing to less than 200 mAh g−1 in the electrolyte with 1% vinyl carbonate.