Multi-carbonyl-COFs as high-capacity organic cathodes for lithium batteries

Lithium-ion batteries are the most promising materials for sustainable energy storage due to their high energy density, low self-discharge rate, and longer life cycles.

Organic electrodes based on redox-active covalent organic frameworks (COFs) are promising alternatives to the often-used inorganic electrode materials.

However, improving specific capacity, voltage, cycling stability and rate performance is required for practical applications.

In this project, we aim to develop six polyimide-linked Multi-carbonyl-COFs (McCOFs) as cathodes with high energy density.

We will achieve it by [3 + 2] reticular condensation of tritopic knots such as hexaazatripheas tris anhydride (HATTA) and mellitic trianhydride (MTA) with various diatopic linkers such as 2,7-diaminopyrene-4,5,9,10-tetraone (DAPT), 2,7-diaminobenzophenanthroline-tetraone (DANT) and pyromellitic-N,N′-bisaminoimide (BDH).

The designed McCOFs incorporate the highest numbers (24) of carbonyl groups per pore along with six pyrazine of HATTA groups, which are evenly distributed along the pore walls, assisting rapid Li+ ions diffusion.

Additionally, some of the targeted McCOFs have the highest theoretical capacity values such as HATTA-DAPT (Qtheo = 484 mAh g−1), HATA-BDH (Qtheo = 423 mAh g−1), HATA-DNT and (Qtheo = 385 mAh g−1).

Thus, McCOFs aim to develop high-performance organic cathodes with superior energy density than previously reported for other McCOFs by the rational combination of carbonyl-rich framework, pyrazine-based building block with multiple redox centres and stable polyimide-linkages. I will receive advanced training in the synthesis, characterization, and exfoliation of McCOFs (Prof.

Manuel Souto, Host PI, CIQUS-USC) and in the fabrication of COF-based bucky paper electrodes (Dr. Rebeca Marcilla, IMDEA Energy, Secondment).

This work addresses ambitious objectives and nurtures my scientific development and independence in organic chemistry, polymer chemistry, and materials science.