Interface-Engineered Strategy on Metal-Organic Framework to Chemical Stabilize PVDF-HFP as Self-Healing High-Voltage...

The integration of metal organic framework (MOF) fillers into the polymer matrices is recognized as an effective strategy to improve the performance of lithium metal batteries. However, the poor interfacial interactions between the polymer matrices and MOF fillers limit their further optimization and commercial application. Here, an interface engineering strategy is proposed to prepare a self-healing high-voltage PVDF-HFP/graphene oxide/UiO-66/Borate bond (PGUB) quasi-solid-state electrolyte (QSSE), which enables a significant enhancement in the electrochemical properties of lithium metal battery. The interaction between PVDF-HFP and UiO-66 is significantly enhanced through synergistic effect of boric acid bonds and graphene oxide, which effectively expanded the electrochemical window and formed the fast Li+ transport channels, but also improved the mechanical flexibility and the ability to eliminate lithium dendrite. The PGUB QSSE exhibits extended electrochemical voltage windows (5.06 V), high elongation at break (205%), outstanding thermal stability (200 °C), and high-capacity retention (95.46% after 500 cycles), which is better than previously reported solid polymer electrolytes. Density functional theory calculations further reveal the mechanism of charge transfer and lithium transport performance enhancement of QSSE based on interface engineering and dynamic cross-linking. This work proposes a novel interface engineering strategy at the molecular level for next-generation high-energy batteries.