With nearly all types of batteries, the main thing is; don't match old and new cells of the same type in one flashlight that runs off of more than one battery.
With AA or AAA Energizer lithium batteries, same rule applies.
Now with other types of lithium primaries, it gets a bit potentially dangerous. If one of them should "vent with flame" or basically explode, the fumes they give off are extremely toxic. Best to use single-cell lights that take such batteries. In multi-cell lights there are a handful of rules:
*Don't mix and match new and old cells together.
*Don't mix and match cells made in different parts of the world.
*Don't mix and match cells from different companies.
*Don't use No-name brand, generic cells.
*Buy cells only from very reputable online dealers, and buy in bulk to save on the cost of these cells.
Realize you're greatly reducing the risk of a "vent with flame" possibility.
Lithium rechargeables.... Way too much to cover in one post. The dangers are worse compared to lithium primaries simply due to the fact that things can go very wrong during the charging process. It could be because of the charger, it could be because of the individual cells being charged up.
Honestly, it's like walking through a mine-field. If you've done the research, educated yourself to a great degree; you're crossing that mine-field with a map that shows exactly where each and every single mine is located. If you haven't done that, then you're marching across, blind.
When it comes to friends, family, co-workers (the average person) I won't gift them a light that runs off of Lithium anything. With the exception of a light that can function on alkalines or AA or AAA lithium primaries from Energizer. Since the lithium chemistry in those cells is different and safer.