A major limitation of electric vehicles is that for most battery designs recharging cells can take a few hours, resulting in range anxiety for consumers. An alternative possibility is to use a flow battery, where fresh electrolyte could be pumped in and spent electrolyte pumped out at a dedicated refueling station. Unfortunately, current flow battery chemistries do not have high enough volumetric energy density to be practical for transportation applications. The proposed project will investigate a new type of flow battery that has the potential to drastically increase the volumetric energy density relative to current flow battery systems. Unlike current flow batteries where the energy is stored in dissolved metal salts, the proposed system will store energy in solid nanoparticles. The system studied in this proposal has the potential to increase the energy density of flow batteries by a factor of greater than 5, making it possible to use these flow batteries in transportation applications. Such an energy density improvement could both enable flow batteries for electric vehicles and would make the time to recharge an electric vehicle battery comparable to the time it takes to fill a gas tank. This project will also involve the creation of a remote flow battery experiment, where anyone can perform an experiment on a flow battery system in the PI's lab by accessing a publicly available website.
The goal of this project is to investigate the structure-property relationships of a flow battery where the electrolyte is comprised of a nanofluid with active electrode materials that are solid transition metal nanoparticles. The approach relies on synthesizing monodisperse, spherical electrode particles that will be used as the active materials in the nanofluid. These particles will be characterized electrochemically and rheologically in relation to application in a flow battery system. The researchers will also explore different designs of the electrode geometry that the nanofluid will come into contact with to optimize the energy and power delivered from the nanofluid. The system will result in a tradeoff between maximizing energy density and minimizing viscosity. The goal is to have high active material loading in the nanofluid while avoiding impractical operating viscosities and also maximizing collisions between the active material nanoparticles and the electrode. This project will potentially contribute to the fields of colloid stability in electrolyte solutions, battery electrode materials, and flow battery systems. This nanofluid system should be extendable to a variety of battery chemistries, which would open up a new field of research in the battery community. Implementing the nanofluid battery system would also result in new parallel fields of study, including thermal management of this unconventional energy storage system.
