An Olefin‐Linked Covalent Organic Framework as a Flexible Thin‐Film Electrode for a High‐Performance Micro‐Supercapacitor. Issue 35 (24th July 2019)

• Record Type: Journal Article
• Authors: Xu, Junsong; He, Yafei; Bi, Shuai; Wang, Mao; Yang, Peng; Wu, Dongqing; Wang, Jianjian; Zhang, Fan
• Is Part Of: Angewandte Chemie international edition. Volume 58:Issue 35(2019)
• Page Start: 12065
• Page End: 12069
• Publication Date: 2019-07-24
• Subjects: covalent organic frameworks -- energy storage -- free-standing films -- micro-supercapacitors; Chemistry -- Periodicals; 540
• DOI: 10.1002/anie.201905713
• Languages: English
• ISSNs: 1433-7851

Abstract

Abstract: Developing effective synthetic strategies as well as enriching functionalities for sp 2 ‐carbon‐linked covalent organic frameworks (COFs) still remains a challenge. Now, taking advantage of a variant of Knoevenagel condensation, a new fully conjugated COF (g‐C34 N6 ‐COF ) linked by unsubstituted C=C bonds was synthesized. Integrating 3, 5‐dicyano‐2, 4, 6‐trimethylpyridine and 1, 3, 5‐triazine units into the molecular framework leads to the enhanced π‐electron communication and electrochemical activity. This COF shows uniform nanofibrous morphology. By assembling it with carbon nanotubes, a flexible thin‐film electrode for a micro‐supercapacitor (MSC) can be easily obtained. The resultant COF‐based MSC shows an areal capacitance of up to 15.2 mF cm −2, a high energy density of up to 7.3 mWh cm −3, and remarkable rate capability. These values are among the highest for state‐of‐the‐art MSCs. Moreover, this device exhibits excellent flexibility and integration capability. Abstract : A fully conjugated covalent organic framework (COF) with unsubstituted C=C bond linkages was synthesized by a variant of the Knoevenagel condensation. This COF was prepared into a thin‐film electrode for a micro‐supercapacitor (MSC). The COF‐based MSC exhibited excellent areal capacitances of up to 15.2 mF cm −2, high energy densities of up to 7.3 mWh cm −3, remarkable rate capability, and outstanding flexibility.