Some inventions last ... and last.
The nickel-iron battery, designed by Thomas Edison in 1900, was used in electric vehicles until the 1920s, and was then used as backup power for railroads and mines until the mid-1900s.
And now, Stanford University researchers have updated Edison's nickel-iron battery so that it now charges and and discharges about 1,000 times faster.
Their innovation could again make the battery fit for providing some power in electric vehicles.
A speedier charge
Edison initially built the nickel-iron battery as an alternative to lead-acid batteries, which had two downsides: They were expensive, and they were corrosive. Nickel and iron, on the other hand, are both plentiful and relatively nontoxic.
But, Edison's battery itself had downsides: It is durable, but it can also take hours to charge.
The Stanford scientists, who were led by Hailiang Wang and included chemistry professor Hongjie Dai, used graphene -- nanosized sheets of carbon only an atom thick -- to give Edison's battery a big performance boost. They also used carbon nanotubes composed of 10 graphene sheets rolled together.
The battery can now be charged in two minutes, and discharged in two-and-a-half minutes. And it's still low-cost.
As Dai told Stanford University News Service:
"Coupling the nickel and iron particles to the carbon substrate allows electrical charges to move quickly between the electrodes and the outside circuit. The result is an ultrafast version of the nickel-iron battery that's capable of charging and discharging in seconds."
The results were published in the June 26 issue of the journal Nature Communications.
Currently, most electric cars, such as the Nissan Leaf, run on lithium-ion batteries which can store a large amount of energy but also take several hours to charge. While Dai's nickel-iron battery will never be able to power an electric vehicle on its own, it could help give power to lithium-ion batteries when they need to accelerate the car more quickly or make quick emergency moves.
But before that can happen, the battery needs to get bigger: Dai has so far just built a 1-volt prototype that can power a flashlight. But the eventual goal is to get it to a size that can be useful in the electrical grid or in a car.
The other improvement needed is in its ability to hold a charge, since it loses charge relatively quickly: But Wang doesn't see a problem with that:
"It's definitely scalable. Nickel, iron and carbon are relatively inexpensive. And the electrolyte is just water with potassium hydroxide, which is also very cheap and safe. It won't blow up in a car."
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photo: Thomas Alba Edison with his nickel-iron battery in 1910 (Wikimedia)
This post was originally published on Smartplanet.com