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Desperately recharging batteries
By
CIARA
LINNANE
CORPORATE NEWS EDITOR
NEW YORK (MarketWatch) — A group of scientists at Stanford University has developed an aluminum battery that can charge a smartphone in a minute and last through far more cycles than conventional ion-lithium or alkaline batteries.
The new battery, developed by a team led by Chemistry Professor Hongjie Dai, is safer than many existing commercial batteries, according to a report on the university’s website.
“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 Dai. “Our new battery won’t catch fire, even if you drill through it.”
The team accidentally discovered that graphite works as a suitable material for the positively charged cathode, which is combined with a negatively charged anode made of aluminum to power the battery.
The anode and cathode were placed 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 in the online report.
The new battery can withstand more than 7,500 cycles without any loss of capacity. That compares with a typical lithium-ion battery, which lasts about 1,000 cycles. Aluminum batteries could be used to store renewable energy on the electrical grid, said Dai.
“The grid needs a battery with a long cycle life that can rapidly store and release energy,” he said. “Our latest unpublished data suggest that an aluminum battery can be recharged tens of thousands of times.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.”
Dai said more work is now needed to match the voltage of lithium-ion batteries, as the aluminum version produces about half the voltage produced by a lithium-ion battery.
“But improving the cathode material could eventually increase the voltage and energy density,” he said. “I see this as a new battery in its early days. It’s quite exciting.”
The battery may pique the interest of Tesla Motors Inc. Chief Executive Chairman Elon Musk, who said in February, he expects to unveil a Tesla battery for homes and businesses with production slated to start in the next six months.
Tesla TSLA, +0.04% which produces lithium-ion batteries for its electric cars in conjunction with Japan’s Panasonic Corp., is building a $5 billion battery plant outside Reno, Nevada.