most phones and tablets i've worked on recently certainly do not have any plastic shell on non-removable batteries; unless you consider shrink tubing a shell.

most phones and tablets i've worked on recently certainly do not have any plastic shell on non-removable batteries; unless you consider shrink tubing a shell. They are usually constructed of layers of battery material, wrapped in kapton tape or an equivalent, with the entire package shrink-tubed and a pigtail coming out the side for the device interface. One could easily crush the unit by hand, the construction offers little to no protection from physical forces.