Organic radicals are crucial intermediates generated during the redox processes of organic electrode materials. However, the poor stability of organic radicals often results in the capacity fade of organic electrodes, and their stabilization mechanism is rarely explored.
Additionally, the structure-property relationship between the organic radicals and the resultant organic electrodes is rarely reported. Therefore, finely regulating the stability of organic radicals to optimize the electrochemical performance of organic electrodes remains a significant challenge.
Recently, an article titled "Regulating the radical intermediates by conjugated units in covalent organic frameworks for optimized lithium ion storage" co-authored by Prof. Zhouguang Lu from SUSTech and Prof. Kaili Zhang from CityU was published in Journal of Energy Chemistry.
It reported a facile and efficient strategy to modulate the molecular orbital energies, charge transport capacities, and spin electron densities of the active units in covalent organic frameworks (COFs) by regulating the conjugated unit size to optimize the redox activity and stability of the organic radicals. COFs based on different imide conjugated units exhibit tunable discharge voltages, rate performance, and cycling stabilities. Detailed characterizations and theoretical calculation reveal that imide radicals are important active intermediates during the redox processes of these COFs. Specifically, increasing the size of the imide conjugated units could effectively delocalize the radical electrons and improve the stability of the COFs electrodes. This study offers an effective strategy to modulate the redox chemistry of organic materials for electrochemical energy storage.
Zhouguang Lu acknowledges the supports from the Basic Research Project of the Science and Technology Innovation Commission of Shenzhen (No. JCYJ20200109141640095), the Shenzhen Key Laboratory of Interfacial Science and Engineering of Materials (No. ZDSYS20200421111401738), the Leading Talents of Guangdong Province Program (No. 2016LJ06C536), the Guangdong-Hong Kong-Macao Joint Laboratory (No. 2019B121205001), and the National Natural Science Foundation of China (No. 21875097). Kaili Zhang acknowledges the support from the Hong Kong Research Grants Council (Project number CityU 11218420). EPR spectra and TEM images were obtained on the instruments from the Southern University of Science and Technology Core Research Facilities. DFT calculations were supported by the Center for Computational Science and Engineering at the Southern University of Science and Technology.
About the journal
The Journal of Energy Chemistry is a publication that mainly reports on creative researches and innovativeapplications of chemical conversions of fossil energy, carbon dioxide, electrochemical energy and hydrogen energy,as well as the conversions of biomass and solar energy related with chemical issues to promote academicexchanges in the field of energy chemistry and to accelerate the exploration, research and development of energyscience and technologies.
At Elsevier
https://www.sciencedirect.com/journal/journal-of-energy-chemistry
Manuscript submission
https://www.editorialmanager.com/jechem/default.aspx