Hybrid Acid/alkali All Covalent Organic Frameworks Battery.

Covalent organic frameworks (COFs), thanks to their adjustable porous structure and abundant build‐in functional motifs, have been recently regarded as promising electrode materials for a variety of batteries. There still remain grand opportunities to further utilizing their merits for developing advanced COFs‐based batteries. In this paper, we propose a hybrid acid/alkali all‐COFs battery by coupling pyrene‐4,5,9,10‐tetraone based COF cathode with anthraquinone based COF anode. In such a hybrid acid/alkali all‐COFs battery, the cathodic COF favorably works in acid with a relatively positive potential, while the anodic COF preferably runs in alkali with a relatively negative potential. It thus can deliver a decently high discharge capacity of 92.97 mAh g−1 with a wide voltage window of 2.0 V, and exhibit high energy density of 74.2 Wh kg−1 along with a considerable cyclic stability over 300 cycles. The development of the proof‐of‐concept all‐COFs battery may drive forward the improvement of newly cost‐effective and performance‐reliable energy storage devices. [ABSTRACT FROM AUTHOR]