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

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 LiPF 6 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.