Eco‐Friendly High‐Performance Symmetric All‐COF/Graphene Aqueous Zinc‐Ion Batteries
Pengshu Yi, Xuanyang Li, Longli Ma, Bingjian Feng, Zhu Liu, Yongshuai Liu, Wenyi Lu, Shaochong Cao, Huayi Fang, Mingxin Ye, Jianfeng Shen
Abstract
Abstract Developing high‐performance aqueous symmetric all‐organic batteries (SAOBs) by replacing metal‐based batteries or batteries with organic electrolytes is highly attractive to achieve a greener rechargeable world. However, such a new energy storage system still exhibits unsatisfactory rate capability and cycling stability due to the limitations in electrode materials screening. Here, a novel covalent organic framework (COF) containing abundant CN and CO for the electrode material is designed, which is combined with graphene and assembled into all‐COF/graphene batteries for the first time. Moreover, the co‐storage of Zn 2+ and H + in COF can be achieved in a mild aqueous electrolyte. Impressively, benefiting from the extended porous structure of COF, plentiful active reaction sites, more extensive electron delocalization from CO modification at molecular level, as well as enhanced fast H + storage capacity of graphene and CO in COF, this kind of SAOBs show excellent cycle life and high rate performance (over 15000 cycles with a capacity of 80 mAh g −1 at a high current density of 5 A g −1 in pouch cell). This work will open a new window for the design of high‐performance aqueous organic batteries, further moving toward a more eco‐friendly electrochemical world.