Hybrid Architecture of a Porous Polypyrrole Scaffold Loaded with Metal–Organic Frameworks for Flexible Solid-State Supercapacitors

Metal–organic frameworks (MOFs) are gaining more and more interest in the energy-storage technology. Especially, in supercapacitors, they are employed as electrode-active materials, owing to their intrinsic porous structure and high surface areas. However, the low conductivity of most MOFs severely limits their capacitance. We herein report the hybrid architecture consisting of a conductive Cu-CAT MOF loaded onto a porous polypyrrole scaffold (p-PPy) that provides sufficient loading areas and efficient conductive skeletons to promote the electrode intrinsic capacitance of 480 mF cm–2. The symmetric supercapacitor integrated by the flexible electrodes combining the p-PPy/Cu-CAT hybrid and the carbon cloth achieves a specific capacitance of 233 mF cm–2, an outstanding power density of 1.5 mW cm–2, and a maximum energy density of 12 μW h cm–2. Moreover, the supercapacitor demonstrates a stable cycling service life with capacitance retention exceeding 85% over 5000 charging/discharging cycles, excellent mechanical flexibility, as well as wide operating temperature tolerance. Our work may shed light on valuable concepts to design and fabricate a hybrid conductive architecture of MOF-based composites for electrochemical energy-storage systems.