Disclosed are a positive electrode plate, a battery cell, and a battery. The positive electrode plate includes a current collector, an active material layer, a first and a second insulation layer, where the current collector includes a first and a second surface disposed opposite each other; first surface includes a first, a second, and a third region along a short side; and second surface includes a fourth, a fifth, and a sixth region along a short side; active material layer is disposed in second and fifth region; first insulation layer is disposed in the first, third, fourth, and sixth region; and second insulation layer is disposed on active material layer and first insulation layer. The positive and negative electrode plate have a same width, to resolve a problem of poor coverage of a positive electrode and a negative electrode, thereby greatly improving safety of a battery.