Researchers at Stanford University have developed what they claim is a high-performance aluminum battery that may be a safe alternative to current commercial batteries.
Today's alkaline batteries are not environmentally friendly, while lithium-ion batteries occasionally burst into flames. An aluminum battery, on the other hand, is an attractive alternative for three reasons: low cost, low flammability and high-charge storage capacity.
“Our new battery won't catch fire, even if you drill through it,” says researcher Hongjie Dai, professor of chemistry at Stanford.
One of Professor Hongjie Dai's colleagues demonstrating the aluminum-ion battery. Source: StanfordThe key challenge is to use materials capable of producing sufficient voltage after repeated cycles of charging and discharging. To that end, the researchers found that graphite can yield acceptable performance.
For the experimental battery, the Stanford team placed the aluminum anode and graphite cathode, in an ionic liquid electrolyte—basically a salt that is liquid at room temperature—inside a flexible polymer-coated pouch. This created a much safer battery, researchers say.
Charging capacity is also improved. While lithium-ion batteries typically lose charge after 1,000 cycles, the aluminum battery is proven to withstand more than 7,500 cycles without any loss of capacity.
Aluminum’s bendability characteristic will enable its battery to be used in flexible electronic devices, Stanford researchers say. In addition, this prototype is environmentally friendly compared to disposable alkaline batteries.
“Our rechargeable aluminum battery generates about two volts of electricity. That's higher than anyone has achieved with aluminum,” Dai says. “Improving the cathode material could eventually increase the voltage and energy density.”
The Taiwan Industrial Technology Research Institute, Hunan University and National Taiwan University of Science and Technology took part in the Stanford project, “An ultrafast rechargeable aluminum-ion battery”, which was published in the journal Nature early April.
Questions or comments on this story? Contact peter.brown@globalspec.com
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