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

这个跨学科的双边项目旨在全面了解有机自由基电池（ORB）电极上发生的氧化还原过程。为此，我们计划开发和应用基于电子顺磁共振（EPR）以及电检测磁共振光谱的定制技术。设想设计合适的样品几何形状，使我们能够在实际操作条件下对完全加工的ORB进行自旋敏感测量。定量的操作中EPR测量将提供在ORB的充电和放电期间监测活性电极材料的不同分子片段上的自旋密度的可能性。先进的脉冲EPR实验将被设计和采用，以提供实验访问的电荷载流子离域以及氧化还原活性位点之间的距离聚合物作为活性电极材料的ORB。这些结果将有助于我们在分子水平上获得有关电荷定位和氧化机制的高度相关信息。它们将进一步有助于识别可能导致重复循环时通常观察到的电池容量降低的损失途径。

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.