Kyu Taek Cho, Paul Albertus, Vincent Battaglia, Aleksandar Kojic, Venkat Srinivasan and Adam Z. Weber
H2/Br2 Flow Batteries—A Grid-Scale Energy-Storage Solution: The cover image depicts a H2/Br2 flow battery of the type described in the Full Paper on page 596 by Adam Weber and colleagues at Lawrence Berkeley National Laboratory with collaborators at the Robert Bosch Research and Technology Center. Bromine and hydrogen molecules are fed during discharge and converted into hydrobromic acid with the electrons available for work on the electrical grid. During charging, the hydrobromic acid is fed and electrolyzed into hydrogen and bromine by using electricity from intermittent renewable sources such as solar photovoltaics and wind energy. In this fashion, the flow battery acts as a buffer and stabilizer against the variability of such sources of energy. The equation highlights the importance of cost modeling, which is explored in this study, on an operating parameter space that includes the key variables of area-specific resistance, current density, and various cost sources, including capital, operating, and manufacturing costs.