EventDr. Ertan Agar

Design and Diagnostics of Redox Flow Batteries for Grid-Scale Energy Storage

Redox flow batteries (RFBs) are a promising grid-scale energy storage technology for integration of intermittent renewable sources, such as wind and solar, into the electrical grid. Among several types of RFBs under development, nonaqueous redox flow batteries (NRFBs) have recently gained significant interest due to their wide electrochemical potential windows, offering high energy and power densities. However, the poor stability of electrolytes and related performance and lifetime issues hinder their widespread implementation as an emerging technology. In the first part of this talk, our bio-inspired approach to address the problem of redox-active material instability that impedes commercialization of NRFBs will be demonstrated by introducing a family of molecules that is naturally occurring and produced biologically. This approach leverages millions of generations of biological evolution as a toolkit to elucidate molecules that provide a stable scaffold for further development. The performance characteristics of the proposed NRFB system using charge/discharge cycling, electrochemical impedance spectroscopy and efficiency analyses will be presented. Additionally, an in-situ spectroscopic analysis to demonstrate the chemical stability during cycling and tight coupling between current and electrochemical formation of the oxidized and reduced form of the active material will be introduced. The second part of the talk will focus on strategies for improving the long-term performance and lifetime of most-commonly studied vanadium redox flow batteries (VRFBs). Our recent studies to investigate electrochemical degradation of carbon-based electrodes for VRFBs will be discussed.