I know HF is generated when primary lithium cells burn, here's someone who got HF poisoning that way: https://www.candlepowerforums.com/threads/flashlight-explosi...

On the other hand, it doesn't seem that the amount from rechargeable lion is anywhere near as much, or we'd be hearing a lot more about everyone who got lung damage from all the "stupid things people do with lithium batteries" videos on YouTube...