Charging batteries has become an all-too-common reality. Around the world, people plug in their mobile phones every night and laptop users spend several hours charging up every week. As everything from our watches to our cars adopt batteries that need to be topped off with electricity, the act of charging is only going to become more pervasive.
So wouldn’t it be nice if we could speed it along?
A new battery, made from aluminum foil and graphene foam, could deliver that relief. And if scientists are able to pump up the power density, the cells could power everything from electric cars to curved, wearable electronics.
Researchers have been testing aluminum batteries for years, but most prototype couldn’t withstand more than a few dozen charges before losing their potency. That’s pretty bad. Most cell phone batteries, for example, can sustain 1,000 charges before losing some capacity. The latest attempt can survive a staggering 7,000 cycles. Plus, they’re extraordinarily safe—the researchers tested the battery’s volatility by drilling a hole into it while it was in operation. Try doing that with a lithium-ion battery.
There is a drawback, though. As it’s currently formulated, the aluminum-ion batteries are fairly heavy relative to lithium ion batteries. John Timmer, writing for Ars Technica, explains why:
The electrolyte the researchers used was a solution of aluminum trichloride dissolved in an organic solvent that also contained chlorine. During charge/discharge cycles, electrons were donated to form AlCl4– and Al2Cl7– ions. This chemistry did not take advantage of the three electrons that aluminum has to donate, so it doesn’t represent much of an improvement over lithium.
The lithium atoms in lithium-ion batteries only have one electron to donate, too, but they’re less than a third as heavy as aluminum atoms. But if scientists can find a way to involve aluminum’s additional two electrons while maintaining this prototype’s durability, the playing field for batteries could change substantially.