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,” in the April 6 advance online edition
of the journal Nature.
Professor Hongjie Dai’s lab has invented an ultra-fast aluminum-ion battery
with electrodes made of inexpensive aluminum (Al) and sheets of nanocarbon.
Credit: Meng-Chang Lin & Hongjie Dai, Stanford University
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.
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.”
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.
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.
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.
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.” (Credit:
Stanford University / Journal- Nature)