Form Energy has introduced the iron-air battery as their first step toward zero-carbon energy solutions. (Credit: Form Energy)
Lithium-ion batteries, while a modern mainstay in energy storage technology used from smartphones to electric cars, is costly and environmentally damaging, not to mention the fact that they require mining rare metals. Finding an alternative is crucial, and in the last few years, scientists have been analyzing the possibility of metal-air batteries—first designed in 1878—as a next-gen solution.
Metal-air batteries use atmospheric oxygen as a cathode along with a metal anode consisting of cheap and abundant materials like aluminum, iron, or zinc. The first example was a zinc-air battery designed by Maiche in 1878; commercial products using the technology, like hearing aids, first entered the market in 1932. Metal-air batteries are of particular interest to researchers as they have a much higher theoretical energy density than lithium-ion batteries. Yet they have been restricted from fulfilling this potential by the challenges associated with the metal anode, air cathode, and electrolyte—among them, inadequate rate capability due to the inefficiency of air catalysts, poor energy efficiency caused by substantial overpotentials at the air cathode, and unsatisfactory cycle life due to a lack of stable bifunctional electrocatalysts and cyclable metal anode.
Still, work has been done in recent years to address these issues through rational design and engineering. According to Yet-Ming Chiang, an electrochemistry professor at MIT, iron-air batteries could be commercially scaled up and used to help mitigate climate change by mid-century. When the electrical current of such a battery is reversed, it un-rusts—that is, electrons are taken away from or added to the iron as it cycles through charging and discharging. This method allows the battery to deliver 100 hours of clean electricity at a cost ten times lower than that of lithium-ion batteries.
Though this breakthrough may come too late for mass adoption in consumer electronics—a market chunk currently firmly held by lithium-ion batteries—Professor Chiang believes iron air batteries could revolutionize energy storage for large-scale renewable operations. To this end, he has founded the startup Form Energy to make this a reality with the iron-air battery as their first commercial product, intended to complement the function of lithium-ion batteries for a balance of low-cost renewable energy and reliability. Chiang and Form Energy hope to eventually enable a 100% renewable grid, run reliably and affordably, and have begun work to further develop the technology and push rapidly toward zero-carbon energy solutions.
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