Lithium-Ion Batteries A Threat to Airline Safety?
Lithium batteries ubiquitous and a necessity in modern life, they are thought to present a fire hazard for airlines. This topic of discussion raised headlines when American Airlines flight attendants confiscated 58 cellphones, lithium-ion batteries, and charging devices from a passenger on a June 23 flight.
Not only are standard rechargeable Lithium-ion batteries becoming a growing concern for airlines, but now also non-rechargeable lithium metal batteries like those used in digital cameras and everyday flashlights.
Some of us may remember the recent recalls of laptop batteries to replace faulty battery packs – lithium-ion batteries were thought to potentially short-circuit or overheat, sometimes even to catch on fire or explode. A bigger problem is that lithium fires (an alkali metal) may not be as easy to extinguish as a normal combustion fire, requiring dry powder fire extinguishers, specifically Class D type (used for fires involving combustible metals).
FAA data show that from March 20, 1991, through Aug. 3, 2010, batteries and battery-powered devices were involved in 113 incidents with “smoke, fire, extreme heat or explosion” on passenger and cargo planes. The data are for lithium and non-lithium batteries and are not a complete list of such incidents, the agency says.
It is reassuring (for now) that there’s no limit to how many lithium-ion batteries a passenger can carry aboard a flight. Furthermore the Transportation Security Administration (TSA) confirms that the agency has studied the matter and determined that these devices “… cannot be used as an explosive and are not a security threat in personal carry-on quantities.”
American Airlines has not taken a public position on the quantity of batteries passengers can bring on board. Then what will the future hold for all of us? As of January 1, 2008, the Department of Transportation (DOT) through the Pipeline and Hazardous Materials Safety Administration (PHMSA) no longer allows loose lithium batteries in checked baggage.
Though the FAA sees lithium-ion and lithium-metal batteries as fire risks, passengers are allowed to bring them with their checked luggage as long as they are attached to an electronic device.
We agree there is a public safety need to mitigate fire hazards associated with advanced Li-ion batteries, particularly when carried onboard aircraft in passengers’ luggage, or when large numbers of such batteries are shipped in densely packed arrays placed inside various types of containers stored in aircraft cargo holds during flight.
Interestingly, our company has applied specialized theoretical knowledge on a practical level to try to understand the underlying causes of certain anomalous fires and explosions that occasionally occur in smaller lithium-ion batteries as well as in large multi-battery packs. In doing so, we have uncovered what may be a new class of potentially serious, previously unrecognized safety risks arising from Lithium metal dendrite structures that can ‘grow’ over time inside Li-ion batteries. A new paper by academic researchers published in May 2010 supports our deep concerns about the involvement of dendrites in catastrophic Li-ion battery failures (please see R. Bhattacharyya et al., “In situ NMR observation of the formation of metallic Lithium microstructures in Lithium batteries,” Nature Materials 9 pp. 504 – 510). Details of our thoughts on this new source of concern have been publicly released in a 68-slide technical presentation on SlideShare.net titled, “Low Energy Neutron Reactions (LENRs) in Advanced Batteries and Other Condensed Matter Environments — Could LENRs be involved in some Li-ion battery fires?” See URL