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Jet puts spotlight on battery risks

January 19, 2013|Ken Bensinger
  • An auxiliary power unit battery from a Boeing 787 caught fire at Logan Airport in Boston this month.
An auxiliary power unit battery from a Boeing 787 caught fire at Logan Airport… (National Transportation…)

Chances are the same kind of battery that twice caught fire in Boeing 787 Dreamliners in recent weeks is in your pocket at this very moment.

Lithium ion batteries, small and powerful, have become the electricity storage device of choice. They are everywhere -- in cellular phones, laptops, power tools, even cars. They allow us to talk, email and drill longer than ever possible in the past.

But the incidents that led to the grounding of the 787 fleet worldwide, and the decision by Boeing on Friday to temporarily halt all deliveries of the plane, have highlighted a troubling downside of these energy-dense dynamos: their tendency to occasionally burst into flames.

With investigators now working to determine the cause of the incidents, one on a Dreamliner on a Boston runway, the other forcing an emergency landing of a 787 in western Japan, the larger question of lithium ion safety has snapped into focus.

For The Record
Los Angeles Times Monday, January 21, 2013 Home Edition Main News Part A Page 4 Local Desk 2 inches; 63 words Type of Material: Correction
Dreamliner batteries: An article in the Jan. 19 Section A on lithium ion battery safety and the grounding of Boeing 787s said the battery in a Chevrolet Volt automobile burst into flames seemingly spontaneously. The battery ignited after a crash test damaged the vehicle's cooling system and the test car was left parked with the battery fully charged, eventually causing it to overheat.
For The Record
Los Angeles Times Saturday, January 26, 2013 Home Edition Main News Part A Page 4 Local Desk 1 inches; 62 words Type of Material: Correction
Dreamliner batteries: An article in the Jan. 19 Section A about lithium-ion battery safety and the grounding of Boeing 787s said that Toyota Motor Corp. had decided against using the technology. Although the automaker has abandoned plans to use lithium-ion batteries in its standard Prius hybrids, it does use them in the Prius plug-in hybrid as well as the all-electric RAV4 EV.

"Every battery can burn and every battery can be flammable," said Mike Eskra, a Milwaukee-based battery development scientist who also works as a battery fire investigator for insurers. "But lithium ion batteries are more dangerous because they store more energy. It's like a firecracker instead of a stick of dynamite."

The casualty list is long. In recent years, tens of thousands of laptop batteries have been recalled due to the risk of fire or explosion. The 400-pound lithium ion battery on General Motors' cutting-edge electric car, the Chevrolet Volt, burst into flames seemingly spontaneously while parked in 2011. And investigators blamed a cargo hold full of lithium ion batteries for a fire that caused a UPS-operated 747 to crash shortly after takeoff from Dubai in late 2010.

That crash, which killed both pilots, is one of more than 100 incidents recorded by the Federal Aviation Administration linking lithium ion batteries to onboard fires over the last two decades. This month, new rules took effect limiting the transport of lithium ion batteries in aircraft. And the FAA had long prohibited use of the technology in commercial airplanes.

That changed in 2007, when it granted Boeing permission to use the batteries in the 787 under a number of conditions to ensure safety. For Boeing the lithium ion advantage was clear.

Thanks to their chemistry, the rechargeable batteries can store as much energy as a nickel metal hydride pack that's 50% heavier, while charging and discharging faster than other battery types. That's made them attractive for military applications such as the B-2 bomber and also for use on the International Space Station and the Mars Rover.

Lithium ion batteries enabled Boeing to swap out heavy hydraulic systems in the airframe for lightweight electronics and electric motors to operate systems like wing de-icers. That's a key reason the Dreamliner burns 20% less fuel than other wide-body aircraft.

The weight and power savings are exactly what made lithium ion batteries popular in other applications. In excess of 95% of mobile phone batteries worldwide are lithium ion, and without lithium ion, laptops couldn't run anywhere near as long as they do without a recharge.

"They completely dominate the consumer market," said Vishal Sapru, energy and power systems research manager at consulting firm Frost & Sullivan in Mountain View, Calif.. He estimates that global sales of lithium ion batteries reached $14.7 billion last year, up from $9.6 billion in 2009, a 53% increase. Sapru expects the market to soar to $50.7 billion by 2018. "No other battery chemistries are growing at that rate."

But lithium ion also has downsides. The batteries tend to have shorter life spans than older, more proven battery technologies. And although the price is falling, lithium ion is still more expensive than other batteries. Although some carmakers have embraced the technology, others, such as Toyota, have decided against it. Several makers of lithium ion auto batteries for electric vehicles have filed for bankruptcy last year because of weak demand.

Safety experts also have concerns. Because lithium ion batteries can store more energy, and discharge it more quickly, than other batteries, lithium ion cells can get much hotter than other technologies in the event of an overcharge or the external application of a heat source. Larger applications, such as the 63-pound batteries on the 787, incorporate multiple cells and the heat can spread rapidly from cell to cell, a chain reaction called "thermal runaway."

And while other types of batteries use a water-based electrolyte in each cell, lithium ion relies on a highly flammable solvent. When heated up, that solvent tends to vaporize, spraying the burnable gas into the surrounding air. As a result, lithium ion battery fires burn extremely hot, as high as 2,000 degrees Fahrenheit.

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