The two terminals are only a couple of mm’s apart. The entire outer shell and the outer top is negative. The center disc on top is positive. This is why you see a plastic doughnut around the positive terminal in flashlight pictures. Only 4.2v but huge amp potential on a short. I don’t see these as stacked loose cells in anything with a crush and short potential without that additional plastic doughnut. The insulator under the positive terminal is thick enough for its job in a battery build.