Regulating Exposed Facets of Metal‐Organic Frameworks for High‐rate Alkaline Aqueous Zinc Batteries

Abstract

Metal‐organic frameworks (MOFs) have drawn growing attention as promising electrode candidates for rechargeable batteries. However, most studies focus on the direct use of MOF electrodes without any modification. Post‐synthetic modification, a judicious tool to modify targeted properties of MOFs, has been long‐neglected in the field of batteries. Herein, crystal‐facet engineering is proposed to design MOF‐based electrodes with high capacity and fast electrochemical kinetics. We found that a thermally‐modified strategy can regulate the dominant exposed facet of Ni‐based MOF (PFC‐8). With the optimally exposed facets, the battery exhibited admirable rate capability (139.4 mAh g−1 at 2.5 A g−1 and 110.0 mAh g−1 at 30 A g−1) and long‐term stability. Furthermore, density functional theory calculations demonstrate that stronger OH− adsorption behaviors and optimized electronic structures induced by the regulated exposed facets boost the electrochemical performance.