Ion diffusion in redox-active macrocyclic organic electrode materials

Description du projet

Diffusion des ions dans les matériaux d’électrodes organiques moléculaires

Les batteries lithium-ion conventionnelles dépendent de ressources limitées telles que le cobalt et le nickel, d’où la nécessité de trouver des solutions de remplacement durables. Les composés organiques, qui sont abondants et peuvent être obtenus de manière durable, sont prometteurs pour la technologie des batteries, en particulier pour les batteries multivalentes. Leur structure souvent très serrée pose toutefois des problèmes pour le transport des ions. Avec le soutien du programme Actions Marie Skłodowska-Curie, le projet MacroRedox va étudier la diffusion des ions dans les matériaux d’électrodes organiques moléculaires en utilisant des macrocycles à porosité intrinsèque comme systèmes modèles pour les électrodes de nouvelle génération. Ces molécules, dotées de larges nanopores et capables de subir de nombreux processus d’oxydoréduction, sont idéales pour l’étude de la diffusion des ions. La recherche entend approfondir notre compréhension de la diffusion des ions et fournir des principes de conception essentiels pour ces matériaux.

Objectif

Society has witnessed a rapid development of energy storage materials as a result of the increasing demand caused by electrification of transport and commercialization of portable electronics. Conventional, widely used lithium-ion batteries rely on transition-metal oxides (Co, Ni) used to manufacture positive electrodes; unfortunately, depletion of the Li, Co and Ni sources is inevitable and there is an urgent need for alternatives based on abundant, green and cheap materials. Organic compounds are composed of earth-abundant elements (C, N, O, S, H), and, in principle, can be accessed from renewable resources using greener methods. Organic batteries by far outperform inorganics in post-lithium battery technologies, especially in case of multivalent batteries, where they currently offer the most realistic possibility of commercialization. However, organic battery materials have many drawbacks, one of them being the fact that they are amorphous and lack ion-diffusion pathways. The goal of the research project is to investigate the fundamental processes of ion diffusion in molecular organic electrode materials with intrinsic porosity. The compounds will be investigated as model systems for next-generation organic electrode materials. The proposed molecules possess large nanopores in the structures, can stabilize charges through conjugation, and can undergo several redox processes, which makes them perfect candidates as model systems to explore ion diffusion. This project will benefit from a wealth of experience in organic synthesis and the exploration of redox properties of macrocyclic molecules accumulated by the Fellow, Dr. Wojciech Stawski, and combined with the expertise of Prof. Birgit Esser in battery research, which will lead to a deep understanding of ion-diffusion processes in those materials and provide design principles for their preparation.