Fiber-Like Formations Grow As Batteries Charge, Discharge

Tiny fiber-like formations known as 'dendrites' that are created and grow as lithium-ion batteries charge and discharge are among the potential culprits in a battery failures that have caused the entire fleet of Boeing 787s to be grounded.

Dendrites are only one of several possibilities being examined by the NTSB and others as they search for the cause of the battery issue. The fibers, which often form when batteries are charged rapidly or unevenly, can lead to short circuits in batteries, according to experts.

Reuters reports that the dendrites came up in a Wall Street Journal article Monday, which indicated that the NTSB thinks that dendrites may be a "major element" in the investigation. But Kelly Nantel, director of public affairs for the NTSB, said that nothing has been ruled out, and that dendrites are only one of many potential causes that are being considered.

In her most recent briefing for the media, NTSB chair Deborah A.P. Hersman did not specifically mention dendrites as one potential cause of the problem, though she did say that one of the eight cells in the battery short-circuited, causing the fire.

Possible solutions to the issue of dendrite growth in batteries may include changing the chemical composition of the reactive components that create the electrical charge but do not promote the growth of dendrites. However, changing that formula might lead to another lengthy certification and flight-test process.

(NTSB image)

FMI: www.ntsb.gov, www.boeing.com