Lithium = trouble
I remember my days associated with the battery industry.
You can build as many safety devices into the cell as you like, but the components are still very dangerous.
Lithium ignites on contact with water.
My guess is that this fire involved the component materials rather than finnished stock.
It is not the first Lithium cell plant to have a fire.
It is extremely difficult to stop a Lithium based fire, once it starts.
Setting up a battery plant using this technology is not a five minute job and is extremely costly.
What I saw was that whilst you could buy many brands of cell, manufacture of the more specialist types was concentrated at one or two plants.
One plant I visited had 10 major brands as customers, each selling under their own label.
The battery world will get more dangerous as designers look for more enegry from a smaller space. To get the higher energy density requires the use of more volatile chemicals.