, the Chevy Volt
, and airplanes
all have something in common - fires caused by lithium batteries.
Why do lithium batteries pose such a risk compared to other battery types? Metallic lithium
is fairly reactive on its own and forms the anode of disposable ("primary") lithium batteries. Secondary, or rechargeable, batteries use a lithium compound as the cathode with an electrolyte that includes lithium salts - no metallic lithium is used, but these compounds are still very flammable. Batteries containing lithium usually fail
due to internal short-circuiting caused by external damage - manufacturing defects, overcharging, mishandling, excessive temperatures, or physical shock. The short circuit causes a thermal runaway
condition where the exothermic reaction in the battery feeds back on itself to cause more damage.
There has been quite a lot of research lately on the safety of carrying lithium batteries in cargo aircraft after several aircraft have been damaged or destroyed by cargo fires:
-FedEx Flight 0004
, Memphis, TN, 2004 (property damage, no damage to the aircraft or injuries)
-UPS Flight 1307
, Philadelphia, PA, 2006 (total hull loss, no major injuries)
-UPS Flight 0006
, Dubai, UAE, 2010 (complete hull loss and death of both crew members)
Research into aircraft flammability issues have been carried out at the Hughes Technical Center
in Atlantic City, NJ. Testing on battery ignition has been performed on primary
, and polymer-based
battery cells (all pdfs). The takeaways from this research are that:
-it doesn't take much to ignite lithium batteries
fire extinguishers, common on commercial aircraft, are ineffective at fighting metallic lithium fires (but it seems to work on lithium-ion batteries)
-because metallic lithium is highly reactive in water, water-based fire extinguishers only make things worse
-exploding batteries create enough pressure differential to potentially destroy Unit Load Devices
Because of the history of fires and the FAA research, the International Air Transport Association has come up with a set of guidelines
(pdf) that mostly restrict carrying primary lithium batteries on aircraft as cargo. The NTSB has also issued safety recommendations
regarding the use of oxygen masks in the cockpit.
Passenger-carrying flights don't carry batteries as cargo. But what happens when your neighbor's iPhone autoignites
on your flight? This FAA video
(wmv, 85 MB) shows the effectivity of various methods of extinguishing battery fires in the cabin. Long story short - skip the fire extinguisher, head for the drinks cart. This video
(wmv, 204 MB) shows more generally how to fight fires in an airplane, and is geared towards the flight crew.