A Tetrakis(terpyridine) Ligand–Based Cobalt(II) Complex Nanosheet as a Stable Dual‐Ion Battery Cathode Material

Abstract Inspired by the flexibility of the bottom‐up approach in terms of selecting molecular components and thus tailoring functionalities, a terpyridine derivative (1,2,4,5‐tetrakis(4‐(2,2′:6′,2″‐terpyridyl)phenyl)benzene) (Tetra‐tpy) is synthesized and coordinated with Co(II) ion to self‐assemble into a nanosheet Co‐sheet by a facile interface‐assisted synthesis. The bis(terpyridine)‐Co(II) complex nanosheet formed not only shows good stability, but also features the layered structure and rich electrochemical activity inherited from the embedded Co(terpyridine)₂motif. Thus, Co‐sheet can serve as a cathode material for a dual‐ion battery prototype, which exhibits a high utilization of redox‐active sites, good cycling stability, and rate capability, thus expanding the potential application of this kind of easily prepared metal‐complex nanosheets in the field of energy storage.