New battery charges 100 times faster

Posted by Emma Woollacott

Cellphones could charge in seconds, and laptops or even electric vehicles in minutes, thanks to a new battery technology developed by scientists at the University of Illinois.

Standard lithium-ion (Li-ion) or nickel metal hydride (NiMH) rechargeable batteries show a big drop in performance when they're rapidly charged or discharged.

But, says Paul Braun, a professor of materials science and engineering, "This system that we have gives you capacitor-like power with battery-like energy. Most capacitors store very little energy. They can release it very fast, but they can't hold much. Most batteries store a reasonably large amount of energy, but they can't provide or receive energy rapidly. This does both."

His team wrapped a thin film into a three-dimensional structure, giving it both a high capacity and large current. Braun says he's demonstrated battery electrodes that can charge or discharge in a few seconds - up to 100 times faster than equivalent bulk electrodes - but can still perform normally in existing devices.

Braun believes the new technology could provide a big boost for electric vehicles, which are handicapped by a poor battery life and longrecharging time.

"If you had the ability to charge rapidly, instead of taking hours to charge the vehicle you could potentially have vehicles that would charge in similar times as needed to refuel a car with gasoline," says Braun.

"If you had five-minute charge capability, you would think of this the same way you do an internal combustion engine. You would just pull up to a charging station and fill up."

All of the processes the group used are also used at large scales in industry so the technique could be scaled up for manufacturing.

The team's demonstrated both NiMH and Li-ion batteries, but says the structure is general, so any battery material that can be deposited on the metal frame could be used.

"We like that it's very universal, so if someone comes up with a better battery chemistry, this concept applies," says Braun. "This is not linked to one very specific kind of battery, but rather it's a new paradigm in thinking about a battery in three dimensions for enhancing properties."