LAUSR

Redox-active covalent organic frameworks (COFs) are promising materials for energy storage devices because of their high density of redox sites, permanent and con-trolled porosity, high surface areas, and tunable structures. However, the low electrochemical accessibility of their redox-active sites has limited COF-based devices either to thin films (<250 nm) grown on conductive substrates, or to thicker films (1 µm) when a conductive polymer is introduced into the COF pores. Electrical energy storage devices constructed from bulk microcrystalline COF powders, eliminating the need for both thin-film formation and conductive polymer guests, would offer both improved capacity and potentially scalable fabrication processes. Here we report on the synthesis and electrochemical evaluation of a new phenazine-based 2D COF (DAPH-TFP COF), as well as its composite with poly(3,4-ethylenedioxythiophene) (PEDOT). Both the COF, and its PEDOT composite, were evaluated as powders that were solution-cast onto bulk electrodes serving as current collectors. The unmodified DAPH-TFP COF exhibited excellent electrical access to its redox sites, even without PEDOT functionalization, and outperformed the PEDOT composite of our previously reported anthraquinone-based system. Devices containing DAPH-TFP COF were able to deliver both high energy (250 Wh/kg) and power densities (2950 W/kg), validating the promise of unmodified redox-active COFs that are easily incorporated into electrical energy storage devices.