Electron Spins as Probes for Understanding Energy Storage Materials based on Nitroxyl-containing Polymers

• Applicant: Professor Dr. Jan Behrends
• Subject Area: Physical Chemistry of Solids and Surfaces, Material Characterisation
• Term: since 2021
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 464998689

This interdisciplinary bilateral project aims at developing a comprehensive understanding of the redox processes occurring at the electrodes in Organic Radical Batteries (ORBs). For this purpose we are planning to develop and apply tailor-made techniques based on Electron Paramagnetic Resonance (EPR) as well as Electrically Detected Magnetic Resonance spectroscopy. It is envisaged to design suitable sample geometries that allow us to perform spin-sensitive measurements on fully-processed ORBs under realistic operating conditions. Quantitative in‐operando EPR measurements will provide the possibility of monitoring the spin density on different molecular fragments of the active electrode materials during charging and discharging of ORBs. Advanced pulse EPR experiments will be designed and employed to provide experimental access to charge-carrier delocalisation as well as distances between redox-active sites in polymers as active electrode materials for ORBs. The results will help us to obtain highly relevant information on charge localisation and oxidation mechanisms on a molecular level. They will further contribute to the identification of loss pathways that may be responsible for the decrease of the battery capacity commonly observed upon repeated cycling.

• DFG Programme: Research Grants
• International Connection: Russia
• Partner Organisation: Russian Science Foundation, until 3/2022
• Cooperation Partner: Professor Dr. Oleg V. Levin, until 3/2022