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.