Electron Transport Kinetics for Viologen Containing Polypeptides with Varying Side Group Linker Spacing

Redox-active polymers (RAPs) such as macromolecular nitroxide radicals have been studied as electrode materials for organic batteries and electronics. However, there has been little work done to investigate the structure-electron transfer relationship for redox-active polymers swollen with battery electrolyte. In this talk, the electron transfer and performance of three viologen-based RAPs with varying linker spacing is considered using both computational and experimental methods. The polypeptide backbone is selected to introduce degradable functionalities into the polymer and enhance the recyclability. Computationally, the diffusion of the viologen group is determined from trajectory analysis for the three polymers and related to their experimentally observed charge-transport behavior. Experimentally, cyclic voltammetry and chronoamperometry were used to determine the rate of electron transfer. The capacity of the polypeptides is determined with a lithium metal half-cell battery to elucidate the linker effect on the relationship between electron transfer rates and capacity.