The only issue with the rechargeable lithium batteries is that their voltage curve is extremely sharp, so they hold the 1.5v right up until they die.

Depending on how the electronics and battery match up, your deadbolt might not be able to warn you about a low battery condition, which might mean you get locked out. I currently have two doors, both with a keypad entry, so it’s extremely unlikely they’ll both be dead at the same time. If you only have one keypad entry, then you should probably avoid using lithium rechargeable AA’s.