They didn’t say which battery chemistry was involved.
Instead of LiFePo4 some of these devices will use less safe, but higher current lithium ion battery chemistries.
One rule not mentioned in the article:
Never charge a “pregnant” (expanding, fat) lithium battery.
An earlier report said “lithium battery”. If that really means anything these days. I did see 9V lithium batteries at the grocery. They were expensive.