By Devin Powell
A rechargeable battery patented by Thomas Edison more than a century ago is staging a comeback. The nickel-iron battery may yet prove to be a viable power source for electric cars, as the inventor had intended.
Thanks to a redesign, Edison’s battery can now store almost as much energy, gram for gram, as the lithium-ion battery in Nissan’s all-electric car, the Leaf. But the redesigned battery charges faster and promises to be cheaper and safer, researchers report online June 26 in Nature Communications.
“People abandoned this type of battery in the 1970s because there were better batteries at the time,” says Hongjie Dai, a chemist at Stanford University. “We have made the Edison battery interesting again by drastically increasing the ability to charge and discharge it.”
Edison’s original design, patented in 1901, calls for two metal electrodes. A mixture of iron compounds and carbon gives off electricity that flows to a sheet of nickel, discharging the battery. Though hardy, it didn’t usher in the revolution in electric cars that Edison had hoped for. Ultimately it was eclipsed by other technologies, including the lithium-ion battery, that stored and delivered more energy.