With wind and solar power becoming more available, scientists are trying to develop a cheap battery that could store all the power made from the wind and sun. A flow battery, or a battery that could soak up enough excess wind and solar power to fuel whole cities, has the same components as the typical lithium-ion cells present in cell phones, but is scaled up to provide megawatts. Science Magazine’s Robert Service has more details on the new technology.
They have pairs of electrodes that convert energy stored in chemicals into electricity, and electrolytes that ferry charges from one electrode to another. But where conventional batteries package electrodes and electrolytes together in a cell, flow batteries keep them separate. Energy is stored in external tanks of charged liquid electrolytes that can be any size—which makes it easier to store large amounts of renewable power. During use, positive and negative electrolytes are pumped through the electrodes, which extract electricity, a process that is reversed during charging.
Today, flow batteries can store and discharge large amounts of electricity more safely, cheaply, and durably than lithium-ion batteries. But they still rely on relatively expensive electrolytes that incorporate vanadium metal particles. Chemists have been looking to organic compounds called quinones as an alternative. Organic-based flow batteries can be a third the cost of those that use vanadium, but they wear out after repeated charging cycles in an industry that expects them to last for a decade or more.
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