It was three months ago when the 2017-2019 Chevy Bolt EVs were recalled due to battery fires. It’s also been four months since the Kona EV was recalled for the same problem, and 2 months since they stopped selling it in Korea. There has been little word from either company (although one small update was provided by GM yesterday), but it appears an answer may be on the horizon.
Citing anonymous industry sources, Business Korea and NewDaily are claiming that Hyundai Motor’s Namyang Research Institute has found the problem of the battery fires. Hyundai is rumored to have concluded that the cell separator is the problem, and, if so, LG may go after their supplier for damages.
The plague of such a design is that something called dendrites can form, most commonly from overcharging, but also from any impurities whatsoever in the electrolyte. The electrolyte is a lithium salt in an organic solvent, and similar to other salts, they can facilitate growth of crystal structures. When this happens, they tend to grow dendrites like roots. If these grow in just the right way, they can pierce the separator and create a short between the cathode and anode. If the dendrite is strong enough, it will remain intact and cause the cell to heat up rapidly due to the short. Eventually, this will cause a fire.Cause of LG’s battery fires rumored to be found – Electrek