Understanding a cerium quirk could help advance grid-scale energy storage

It turns out cerium flow batteries lose voltage when electrolyte molecules siphon off energy to form different complexes around the metal. Study: Unveiling the cerium(III)/(IV) structures and charge transfer mechanism in sulfuric acid (DOI: 10.1021/jacsau.2c00484) An explanation for why flow batteries using the metal cerium in a sulfuric acid electrolyte fall short on voltage, discovered through a study led by the University of Michigan, could pave the way for better battery chemistry. Flow batteries are one of the methods under consideration for storing intermittent sources of renewable electricity, such as solar and wind power. They can bank large quantities of energy by keeping the chemical potential in liquid form, with two electrolytes that flow through porous electrodes to charge and discharge. The metal cerium could store energy at a relatively high voltage, meaning more energy per metal ion, and at low cost. One of the challenges with cerium is figuring out how to make electric charges transfer to and from the electrode efficiently. On its way through the positive electrode, cerium either picks up or drops off an electron, depending on whether the battery is charging or discharging.