Application of Hydrogen‐Bonded Organic Frameworks with Redox‐Active Imide Units as Cathode‐Active Materials in Lithium‐ and Sodium‐Ion Batteries

Abstract

AbstractHydrogen‐bonded organic frameworks (HOFs) have been widely researched and used in industrial fields owing to their relatively low weight and high pore volume. Furthermore, HOFs with redox‐active units have recently gained attention as electrode‐active materials for energy storage devices as well as other porous organic polymers. This study focuses on N,N‐bis(2‐isophthalicacid)naphthalenediimide (ECUT‐HOF‐30), which exhibits good redox and mechanical properties owing to the redox‐active imide units in heterocyclic compounds, and 1,3,6,8‐tetrakis(4‐carboxyphenyl)pyrene (PFC‐1) and 3,3’,5,5’‐tetrakis‐(4‐carboxyphenyl)‐1,1’‐biphenyl (TCBP) without imide units as relatively lightweight HOFs. We evaluated the battery performance using three HOFs with and without redox‐active imide units as cathode active materials for rechargeable lithium‐ion and sodium‐ion batteries (LIBs and SIBs). The HOFs maintained their cycle stability and battery capacities even by HOF formation and ECUT‐HOF‐30 with redox‐active imide units particularly exhibited good battery performance. These results imply the potential of rigid HOFs with redox‐active imide units for realizing high‐performance energy storage devices.