Development of High Capacity Catholyte Material for Non-Aqueous Redox Flow Batteries

Non-aqueous redox flow batteries (NRFBs) have attracted increasing attention due to their significant potential to integrate the renewable energy sources (e.g., solar and wind) into electrical grid. Unlike the traditional rechargeable batteries which store energy within solid electrodes, the active materials of NRFBs are stored in a flowable phase in two external tanks and pumped to a power-generating electroreactor. This configuration offers remarkable flexibility in terms of energy, power and even safety control. Material development of redox active molecules, especially redox active organic molecules (ROMs) is crucial to enable the extensive deployment of this energy storage technology. A family of dimethoxybenzene based molecules has drawn significant attention due to their excellent electrochemical behavior as NRFB catholytes. In this presentation, our recent efforts toward the high capacity catholyte material deriving from our previous research on 2,5-di-tert-butyl-1,4-bis(2-methoxyethoxybenzene) will be discussed. The developing story of those new ROMs as well as their electrochemical reversibility, solubility, conductivity, and galvanostatic cycling will be covered.