Conjugated Copper–Catecholate Framework Electrodes for Efficient Energy Storage

A conjugated copper(II) catecholate based metal–organic framework (namely Cu‐DBC) was prepared using a D2‐symmetric redox‐active ligand in a copper bis(dihydroxy) coordination geometry. The π‐d conjugated framework exhibits typical semiconducting behavior with a high electrical conductivity of ca. 1.0 S m−1 at room temperature. Benefiting from the good electrical conductivity and the excellent redox reversibility of both ligand and copper centers, Cu‐DBC electrode features superior capacitor performances with gravimetric capacitance up to 479 F g−1 at a discharge rate of 0.2 A g−1. Moreover, the symmetric solid‐state supercapacitor of Cu‐DBC exhibits high areal (879 mF cm−2) and volumetric (22 F cm−3) capacitances, as well as good rate capability. These metrics are superior to most reported MOF‐based supercapacitors, demonstrating promising applications in energy‐storage devices. A semiconducting conjugated MOF (Cu‐DBC) featuring rhombus pores was easily constructed. It exhibits good crystallinity, high porosity, and excellent stability. The Cu‐DBC electrodes showcase exceptionally high gravimetric, areal, and volumetric capacitances along with good rate capability.