Transitioning to renewable energy across society will require many changes, including more batteries. Energy storage is crucial for making sure that inconsistent renewable sources, like wind or solar, can stay humming even when the weather isn't going their way. But batteries have their own problem in the form of the commonly used lithium. Researchers at the Indian Institute of Technology (IIT) Madras have come up with what could be a possible replacement: a rechargeable iron ion battery that uses mild steel as the anode. “The major limitations of lithium-ion batteries are the unavailability of lithium in conjunction with the safety...