Exploring Space with Non-Aqueous Redox Flow Batteries: Synthesis and Characterization of New Electrolytes

To explore the watery worlds of the moons of Europa and Enceladus, NASA's Ocean World Exploration Program is interested in the development of electrochemical energy storage systems that function at low temperatures (at or below -40 ºC). In these conditions, the popular lithium-ion battery will be used to send initial probes, is sluggish because of slow discharge rates. Non-aqueous redox flow batteries, however, offer promise for efficient low-temperature operation because many aprotic, organic solvents remain liquids at low temperatures, thus potentially allowing for high charge and discharge rates to be maintained. This proposal involves the development of new electro-active materials for non-aqueous redox flow batteries, specifically with an emphasis of materials that have high solubility in organic solvents that remain liquid at low temperatures (acetonitrile, m.p. -45 º; dimethylether, m.p. - 177 ºC, etc.), as high concentrations are important to develop high-capacity batteries. Once synthesized, we will determine the potentials for reduction and oxidation events and the reversibility of these events in different solvents. Soluble materials with reversible oxidation events will be scaled up and shipped to collaborators at the Jet Propulsion Laboratory.