The iPhone 16 lineup include a few advancements in repairability. Perhaps, the most significant hardware change is a new type of battery adhesive, that allows for simpler and safer battery replacements once the frame of the phone has been taken off.
iFixit demonstrates this in action in its teardown video. By applying a low-voltage electrical current, the adhesive holding the battery down releases, and the battery cleanly pops out of the phone chassis.