Scientists have developed a battery that could allow a mobile phone to be charged and ready for use in one minute.
The new aluminium power cell is also much safer than existing lithium technology, can be bent and damaged, and does not catch fire.
The researchers at Stanford University in California say the battery can be recharged more often than usual batteries without losing its effectiveness.
It has the potential to be a major breakthrough as electricity storage becomes increasingly important in tandem with renewable energy.
Hongjie Dai, professor of chemistry at Stanford, 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. Lithium batteries can go off in an unpredictable manner - in the air, the car or in your pocket."
Besides safety, he said the team had transformed battery performance with "unprecedented charging times" of down to one minute being reported.
Unlike previously developed aluminium batteries, which have been reported to die after just 100 charge-discharge cycles, the Stanford prototype has been found to withstand up to 7,500 charges.
The typical lithium battery lasts for 1,000 cycles.
In an article in this month's edition of the journal Nature, the authors wrote: "This was the first time an ultra-fast aluminium-ion battery was constructed with stability over thousands of cycles."
Ming Gong, co-lead author of the Nature study, added: "Another feature of the aluminium battery is flexibility.
"You can bend it and fold it, so it has the potential for use in flexible electronic devices. Aluminium is also a cheaper metal than lithium."
I was going to post this piece I saw linked at Slashdot but you beat me to the punch. This one has more technical details.
This is probably the first major advance in battery technology in 20 years or more. Alkalines, ni-cads, nickel-metal hydride, lithium, all seem inferior to these aluminum batteries. They still need to develop them further but they can find a market immediately. This isn't a "someday" technology.
Aluminum battery from Stanford offers safe alternative to conventional batteries
Stanford University scientists have invented the first high-performance aluminum battery that's fast-charging, long-lasting and inexpensive. Researchers say the new technology offers a safe alternative to many commercial batteries in wide use today.
"We have developed a rechargeable aluminum 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," said Hongjie Dai, a professor of chemistry at Stanford. "Our new battery won't catch fire, even if you drill through it."
Dai and his colleagues describe their novel aluminum-ion battery in "An ultrafast rechargeable aluminum-ion battery," which will be published in the April 6 advance online edition of the journal Nature.
Aluminum has long been an attractive material for batteries, mainly because of its low cost, low flammability and high-charge storage capacity. For decades, researchers have tried unsuccessfully to develop a commercially viable aluminum-ion battery. A key challenge has been finding materials capable of producing sufficient voltage after repeated cycles of charging and discharging.
Graphite cathode
An aluminum-ion battery consists of two electrodes: a negatively charged anode made of aluminum and a positively charged cathode.
"People have tried different kinds of materials for the cathode," Dai said. "We accidentally discovered that a simple solution is to use graphite, which is basically carbon. In our study, we identified a few types of graphite material that give us very good performance."
For the experimental battery, the Stanford team placed the aluminum anode and graphite cathode, along with an ionic liquid electrolyte, inside a flexible polymer- coated pouch.
"The electrolyte is basically a salt that's liquid at room temperature, so it's very safe," said Stanford graduate student Ming Gong, co-lead author of the Nature study.
Aluminum batteries are safer than conventional lithium-ion batteries used in millions of laptops and cell phones today, Dai added.
"Lithium-ion batteries can be a fire hazard," he said.
As an example, he pointed to recent decisions by United and Delta airlines to ban bulk lithium-battery shipments on passenger planes.
"In our study, we have videos showing that you can drill through the aluminum battery pouch, and it will continue working for a while longer without catching fire," Dai said. "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 aluminum battery performance."
One example is ultra-fast charging. Smartphone owners know that it can take hours to charge a lithium-ion battery. But the Stanford team reported "unprecedented charging times" of down to one minute with the aluminum prototype.
Durability is another important factor. Aluminum batteries developed at other laboratories usually died after just 100 charge-discharge cycles. But the Stanford battery was able to withstand more than 7,500 cycles without any loss of capacity. "This was the first time an ultra-fast aluminum-ion battery was constructed with stability over thousands of cycles," the authors wrote.
By comparison, a typical lithium-ion battery lasts about 1,000 cycles.
"Another feature of the aluminum battery is flexibility," Gong said. "You can bend it and fold it, so it has the potential for use in flexible electronic devices. Aluminum is also a cheaper metal than lithium."
Applications
In addition to small electronic devices, aluminum batteries could be used to store renewable energy on the electrical grid, Dai said.
"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 offers an environmentally friendly alternative to disposable alkaline batteries, Dai said.
"Millions of consumers use 1.5-volt AA and AAA batteries," he said. "Our rechargeable aluminum battery generates about two volts of electricity. That's higher than anyone has achieved with aluminum."
But more improvements will be needed to match the voltage of lithium-ion batteries, Dai added.
"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."
Other co-lead authors of the study affiliated with Stanford are visiting scientists Mengchang Lin from the Taiwan Industrial Technology Research Institute, Bingan Lu from Hunan University, and postdoctoral scholar Yingpeng Wu. Other authors are Di-Yan Wang, Mingyun Guan, Michael Angell, Changxin Chen and Jiang Yang from Stanford; and Bing-Joe Hwang from National Taiwan Normal University.
They still need to develop them further but they can find a market immediately.
Battery-powered push mowers. The politicians on the left coast will pass laws making them mandatory,and even provide financial aid (tax money from the rich that are not related to them) to those who can't afford to buy one.
Battery-powered push mowers. The politicians on the left coast will pass laws making them mandatory,and even provide financial aid (tax money from the rich that are not related to them) to those who can't afford to buy one.
The immediate recharge and lower toxicity of the manufacture will be a big draw. Also the much lower cost and the much greater number of charge/discharge cycles compared to other battery tech.
A lawnmower application is ideal. Cheap battery packs, recharge in a minute while you get a drink of water. Better yet, make it a self-driving and self-recharging robot mower. Let it mow for 10 minutes, recharge, mow again, charge again...
You probably weren't being too serious but I am. Fire away!
