As more wind and solar energy sources are harnessed to generate electricity, the intermittent nature of these supplies requires the deployment of electrical energy storage capacity to stabilize the grid. Existing technologies for storing vast amounts of electricity are either too expensive or ultimately limited by other factors, such as geographic location, or the lack of critical materials needed for large-scale manufacture of energy storage systems. Redox flow batteries are a promising new technology for storing large amounts of electricity as electrochemical energy, but suffer from many technical challenges, including use of expensive or rare materials, flammability of organic solvents used as electrolytes, and low electrochemical energy storage capacity. The goal of this project is to develop a new electrolyte for redox flow batteries based on organic compounds called quinones that are dissolved in water as the solvent. This electrolyte is potentially inexpensive, noncorrosive, nontoxic, and nonflammable. The proposed research will design quinone molecules to improve electrochemical energy storage capacity, and develop fundamental understanding of their underlying electrochemical processes. As part of the educational activities of this project, interactive presentations and demonstrations on energy conservation and renewable energy topics will be developed for the public programs offered through the Boston Museum of Science.
This project will explore new electrolytes for redox flow batteries based on aqueous quinones. Some quinones and comparable molecules are nontoxic and have the potential to improve electrochemical energy storage capacity, avoid acid corrosion, and reduce the potential for flammability based elimination of organic solvents. In neutral and basic solution, certain quinones undergo reversible two-electron processes, but these processes are poorly understood. Since two-electron reduction stores twice the energy of single-electron reduction, it is hypothesized that the use of aqueous quinones as electrolytes could improve electrochemical storage capacity for redox flow battery applications. The goal of the research is to develop a fundamental understanding of two-electron reduction process by quinones and comparable molecules in alkaline medium through substituent modification of quinones guided by molecular design of their proton transfer processes. The roles of intermolecular and intramolecular hydrogen bonding, as well as interactions with electrolyte cations and anions, in enabling two-electron reduction processes will be elucidated. Further studies will clarify the role of molecular geometry, substituent groups, and electronic structure on the electrochemical behavior of this process. The research outcomes could suggest new electrolyte systems for redox flow batteries which are more efficient, cost less, and are safer than existing systems for electrochemical-based mass storage applications. Furthermore, an interactive demonstration based on a redox flow battery from the PI's laboratory will be developed for the Boston Museum of Science.
