I heard the reason for lithium ion battery explosion is lithium burns when exposed in air but Few days ago I pierced one of my batteries (10-20 holes) and it didn't explode , why ? It was broken phone battery (still works but %35 maximum capacity and 3.7v max voltage) .
Also I heard in somewhere , lithium ion batteries only explode when it's charged , is it true ?
The reason I asked because I have a lot of old & broken lithium ion batteries in my workshop and I'm collecting them in glass air tight jar so when I got enough time or batteries , I send them to recycling center for disposal.