I have enormous respect for Elon Musk, and he's right, large cells without thermal barriers between cells are dangerous. Boeing doesn't have a "decade of exper

I have enormous respect for Elon Musk, and he's right, large cells without thermal barriers between cells are dangerous. Boeing doesn't have a "decade of experience" with Lithium-Ion batteries though. The particular type of batteries have an elevated risk profile, but are light weight. The 787 has a larger APU than previous aircraft, and requires a larger battery to start the APU. These particular batteries are Lithium Cobalt Oxide. One of the sub-contractors, Securaplane, who made the battery controller/charger, had their factory destroyed by fire, after a battery malfunction in 2006. Edit: Cessna had problems with their Lithium-Ion batteries in some Citations, and had to replace them with NiCADs in a emergency airworthiness directive.