Researchers develop aluminium battery that charges smartphones in a minute
08 Apr 2015
A new battery made from aluminium, that is both greener and safer, can charge mobiles in under one minute, making the frustration of the long wait to charge a smartphone or tablet a thing of the past.
Conventional alkaline batteries are not environmentally friendly and lithium-ion batteries used in millions of laptops and smartphones are known to unexpectedly burst into flames and take a long time to charge.
Stanford University researchers have invented the first high-performance aluminium battery that not only charges in a jiffy it is also long-lasting and inexpensive. Last the not the least, it is also flexible and can therefore be used in new folding devices in development.
However, the only hitch was that it had only half the voltage of present lithium-ion batteries, according to the study published in the journal Nature.
Professor of chemistry Hongjie Dai said, "We have developed a rechargeable aluminium battery that may replace existing storage devices, such as alkaline batteries, which are bad for the environment, and lithium-ion batteries, which occasionally burst into flames
"Our new battery won't catch fire, even if you drill through it."
The aluminum-ion battery has two electrodes - a negatively charged anode made of aluminum and a positively-charged graphite cathode. Additionally, it has an ionic liquid electrolyte, contained in a flexible polymer-coated pouch.
Stanford graduate student Ming Gong adds, "The electrolyte is basically a salt that's liquid at room temperature, so it's very safe. Lithium-ion batteries can be a fire hazard.
"In our study, we have videos showing that you can drill through the aluminium battery pouch, and it will continue working for a while longer without catching fire.
"But lithium batteries can go off in an unpredictable manner in the air, the car or in your pocket. Besides safety, we have achieved major breakthroughs in aluminium battery performance."
According to Dai, in addition to small electronic devices, aluminum batteries could be used to store renewable energy on the electrical grid.
"The grid needs a battery with a long cycle life that can rapidly store and release energy," he explained. "Our latest unpublished data suggest that an aluminum battery can be recharged tens of thousands of times. It's hard to imagine building a huge lithium-ion battery for grid storage."
Aluminum-ion technology also offered an environmentally friendly alternative to disposable alkaline batteries, Dai added.
"Millions of consumers use 1.5-volt AA and AAA batteries," he says. "Our rechargeable aluminum battery generates about two volts of electricity. That's higher than anyone has achieved with aluminum."
However, more improvements would be needed to match the voltage of lithium-ion batteries, he said.
"Our battery produces about half the voltage of a typical lithium battery," he said. "But improving the cathode material could eventually increase the voltage and energy density. Otherwise, our battery has everything else you'd dream that a battery should have: inexpensive electrodes, good safety, high-speed charging, flexibility and long cycle life. I see this as a new battery in its early days. It's quite exciting."
(Read more: Aluminum battery from Stanford offers safe alternative to conventional batteries)