Direct Solar-to-Electrochemical Energy Storage in a Functionalized Covalent Organic Framework

Jiangquan Lv; Yan-Xi Tan; Jiafang Xie; Rui Yang; Muxin Yu; Shanshan Sun; Ming-De Li; Daqiang Yuan; Yaobing Wang

doi:10.1002/anie.201806596

Direct Solar-to-Electrochemical Energy Storage in a Functionalized Covalent Organic Framework

Angew Chem Int Ed Engl. 2018 Sep 24;57(39):12716-12720. doi: 10.1002/anie.201806596. Epub 2018 Sep 3.

Authors

Jiangquan Lv¹, Yan-Xi Tan¹, Jiafang Xie¹, Rui Yang¹, Muxin Yu¹, Shanshan Sun², Ming-De Li², Daqiang Yuan¹, Yaobing Wang¹

Affiliations

¹ CAS Key Laboratory of Design and Assembly of Functional Nanostructures and Fujian Provincial Key Laboratory of Nanomaterials, State Key Laboratory of Structural Chemistry Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, P. R. China.
² Department of Chemistry and Key Laboratory for Preparation and Application of Ordered Structural Materials of Guangdong Province, Shantou University, Guangdong, P. R. China.

PMID: 30094899
DOI: 10.1002/anie.201806596

Abstract

A covalent organic framework integrating naphthalenediimide and triphenylamine units (NT-COF) is presented. Two-dimensional porous nanosheets are packed with a high specific surface area of 1276 m² g^-1 . Photo/electrochemical measurements reveal the ultrahigh efficient intramolecular charge transfer from the TPA to the NDI and the highly reversible electrochemical reaction in NT-COF. There is a synergetic effect in NT-COF between the reversible electrochemical reaction and intramolecular charge transfer with enhanced solar energy efficiency and an accelerated electrochemical reaction. This synergetic mechanism provides the key basis for direct solar-to-electrochemical energy conversion/storage. With the NT-COF as the cathode materials, a solar Li-ion battery is realized with decreased charge voltage (by 0.5 V), increased discharge voltage (by 0.5 V), and extra 38.7 % battery efficiency.

Keywords: bifunctional groups; covalent organic frameworks; intramolecular charge transfer; reversible electrochemical reaction; solar energy storage.