Aviation experts said the energetic quality of lithium-ion can be a concern onboard aircraft. "One of the issues with lithium batteries is they get very hot," Freiwald said. "When they ignite, they can burn so hot that Halon 1301 won't extinguish a fire."
Automakers, many of whom use lithium-ion chemistries in hybrids and electric cars, typically operate their batteries with cooling systems. The Chevy Volt, for example, employs a fluid coolant that circulates through 1mm thick channels machined into 144 metal plates sitting between the battery's cells. Other automakers have employed air cooling on hybrids.
Even with cooling, however, lithium-ion automotive batteries have been known to have problems on rare occasions. In 2011, a fire started in a Chevy Volt weeks after government crash testing, causing a ripple of concern. "The chemistry is edgy," Donald Sadoway of MIT wrote in an email to Design News after the incident. "The electrolyte is an organic fluid that is flammable, highly volatile at even moderately elevated temperature and in the presence of metallic lithium, which can form on the negative electrode at high charging rates."
Although it's not known whether the Dreamliner employs battery cooling systems, its batteries are smaller than those of plug-in hybrid cars. A National Transportation Board (NTSB) examination of an auxiliary power battery unit from the JAL Boeing 787 that caught fire in Boston's Logan Airport on January 7 showed that it measures 19 inches x 13 inches x 10 inches and weighs just 63 pounds. In contrast, electric vehicle batteries can weigh more than 400 pounds.
Freiwald said he doubts the two reported fuel leaks are related to the overheating incidents. Those were more likely to have been caused by human error, he said.
Experts who spoke with Design News emphasized that the cause of the problems isn't fully understood yet, and that such incidents need to be put into perspective. "None of these were catastrophic failures," Dietz told us. "The engineering systems provided an alert to the failures and action was taken. There should be some solace in that."
Seems like the batteries are the culprit, but as of now no one knows why. They've x-rayed the batteries, put them through CT scans, disassembled them and checked the associated wiring bundles and battery management circuit boards. As of now, regulators have said that overcharging doesn't seem to be the issue, but we don't know much more than that. We'll have more coverage on this coming up.
Samsung's Galaxy line of smartphones used to fare quite well in the repairability department, but last year's flagship S5 model took a tumble, scoring a meh-inducing 5/10. Will the newly redesigned S6 lead us back into star-studded territory, or will we sink further into the depths of a repairability black hole?
In 2003, the world contained just over 500 million Internet-connected devices. By 2010, this figure had risen to 12.5 billion connected objects, almost six devices per individual with access to the Internet. Now, as we move into 2015, the number of connected 'things' is expected to reach 25 billion, ultimately edging toward 50 billion by the end of the decade.
NASA engineer Brian Trease studied abroad in Japan as a high school student and used to fold fast-food wrappers into cranes using origami techniques he learned in library books. Inspired by this, he began to imagine that origami could be applied to building spacecraft components, particularly solar panels that could one day send solar power from space to be used on earth.
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