Lithium ion batteries become exothermic when exposed to air. The playing card probably sliced the casing of the battery. Similar to a paper cut.
Hope no one got hurt. That example is why I don't mind when someone counters a suggestion I make, so long as they give some kind of link showing why they question me. It can turn out I may be wrong. And I have been. Most times there is a misunderstanding and it gets cleared up.This!
About four years ago, I was using an older 2008 black MacBook and the battery was swelling up inside. I took out the battery and continued to use the laptop. One day I was reading up on what I could do to save the battery and someone on a forum had suggested to someone else that could take a pin and poke the plastic casing wrapping the battery cells that were swollen. I took a small pin and poked one of the two swollen cells and immediately flames started to come out until all the gas leaked out. The battery was immediately ruined at that point and I threw it in the trash since I didn't know what else to do with it.
Anyways, I learned you don't mess with these batteries, ever.
Hope no one got hurt. That example is why I don't mind when someone counters a suggestion I make, so long as they give some king of link showing why they question me. It can turn out I may be wrong. And I have been. Most times there is a misunderstanding and it gets cleared up.
Why what? Why did it catch on fire or why did I have the phone apart?
I was replacing a cracked screen. Samsung made it accessible.
I took an iPhone 6 apart to replace the battery. It was glued down with a cement like substance. I used a folded playing card for that one and "rolled" the battery up as I loosened it...not fires or explosions.