Nickel-iron batteries, a rechargeable technology developed by Thomas Edison more than a century ago, have been largely out of favor since the 1970s – until now.
Designed in the early 1900s to power electric vehicles, they’re today used in just a few niche applications, primarily the storage of surplus electricity from solar panels and wind turbines. “The Edison battery is very durable, but it has a number of drawbacks,” says Hongjie Dai, a professor of chemistry at Stanford. “A typical battery can take hours to charge, and the rate of discharge is also very slow.”