This is one specific question I found interesting:

Li-ion battery fires
by Anonymous Coward

Could you speculate on the reasons behind the increasing frequency of Li-ion battery fires? Cheaper parts, smaller tolerances, higher energy density, or all of the above?

JBG: The origin of the Li-ion battery fires is the flammable organic-liquid electrolyte and the graphite anode. If the battery is charged too rapidly, metallic lithium is plated on the graphite, and lithium does not wet or is not wet by the electrolyte. As a result, on repeated charging, lithium dendrites (whiskers) form and grow across the liquid electrolyte to the cathode and create a short-circuit, which heats the battery and ignites the electrolyte. If the battery manufacturer does not incorporate a control of the rate of charge, fires follow.


for the other questions read on @ slashdot.

https://hardware.slashdot.org/story/...n-b-goodenough