A Covalent Organic Framework as a Long‐life and High‐Rate Anode Suitable for Both Aqueous Acidic and Alkaline Batteries

Abstract Aqueous rechargeable batteries are prospective candidates for large‐scale grid energy storage. However, traditional anode materials applied lack acid‐alkali co‐tolerance. Herein, we report a covalent organic framework containing pyrazine (C=N) and phenylimino (−NH−) groups (HPP‐COF) as a long‐cycle and high‐rate anode for both acidic and alkaline batteries. The HPP‐COF′s robust covalent linkage and the hydrogen bond network between −NH− and water molecules collectively improve the acid‐alkaline co‐tolerance. More importantly, the hydrogen bond network promotes the rapid transport of H + /OH − by the Grotthuss mechanism. As a result, the HPP‐COF delivers a superior capacity and cycle stability (66.6 mAh g −1 @ 30 A g −1 , over 40000 cycles in 1 M H 2 SO 4 electrolyte; 91.7 mAh g −1 @ 100 A g −1 , over 30000 cycles @ 30 A g −1 in 1 M NaOH electrolyte). The work opens a new direction for the structural design and application of COF materials in acidic and alkaline batteries.