A Pyrene-4,5,9,10-Tetraone-Based Covalent Organic Framework Delivers High Specific Capacity as a Li-Ion Positive Electrode

Hui Gao; Alex R Neale; Qiang Zhu; Mounib Bahri; Xue Wang; Haofan Yang; Yongjie Xu; Rob Clowes; Nigel D Browning; Marc A Little; Laurence J Hardwick; Andrew I Cooper

doi:10.1021/jacs.2c02196

A Pyrene-4,5,9,10-Tetraone-Based Covalent Organic Framework Delivers High Specific Capacity as a Li-Ion Positive Electrode

J Am Chem Soc. 2022 Jun 1;144(21):9434-9442. doi: 10.1021/jacs.2c02196. Epub 2022 May 19.

Authors

Hui Gao^{1

2}, Alex R Neale², Qiang Zhu^{1

3}, Mounib Bahri⁴, Xue Wang^{1

3}, Haofan Yang^{1

3}, Yongjie Xu^{1

3}, Rob Clowes¹, Nigel D Browning⁴, Marc A Little¹, Laurence J Hardwick², Andrew I Cooper^{1

3}

Affiliations

¹ Materials Innovation Factory and Department of Chemistry, University of Liverpool, 51 Oxford Street, Liverpool L7 3NY, U.K.
² Stephenson Institute for Renewable Energy, Department of Chemistry, University of Liverpool, Peach Street, Liverpool L69 7ZF, U.K.
³ Leverhulme Research Centre for Functional Materials Design, University of Liverpool, 51 Oxford Street, Liverpool L7 3NY, U.K.
⁴ Albert Crewe Centre, University of Liverpool, Waterhouse Building, Block C, 1-3 Brownlow Street, Liverpool L69 3GL, U.K.

Abstract

Electrochemically active covalent organic frameworks (COFs) are promising electrode materials for Li-ion batteries. However, improving the specific capacities of COF-based electrodes requires materials with increased conductivity and a higher concentration of redox-active groups. Here, we designed a series of pyrene-4,5,9,10-tetraone COF (PT-COF) and carbon nanotube (CNT) composites (denoted as PT-COFX, where X = 10, 30, and 50 wt % of CNT) to address these challenges. Among the composites, PT-COF50 achieved a capacity of up to 280 mAh g^-1 as normalized to the active COF material at a current density of 200 mA g^-1, which is the highest capacity reported for a COF-based composite cathode electrode to date. Furthermore, PT-COF50 exhibited excellent rate performance, delivering a capacity of 229 mAh g^-1 at 5000 mA g^-1 (18.5C). Using operando Raman microscopy the reversible transformation of the redox-active carbonyl groups of PT-COF was determined, which rationalizes an overall 4 e^-/4 Li⁺ redox process per pyrene-4,5,9,10-tetraone unit, accounting for its superior performance as a Li-ion battery electrode.