have repurposed a commonplace chemical used in water treatment facilities to develop an all-liquid, iron-based redox flow battery for large-scale energy storage. In the 1970s, scientists at the National Aeronautics and Space Administration (NASA) developed the first iron flow. . Researchers at the Department of Energy's Pacific Northwest National Laboratory (PNNL) have developed a new large-scale energy storage battery design featuring a commonplace chemical used in water treatment facilities.