A positive electrode plate includes a positive electrode current collector and two positive electrode active material layers on both surfaces of the positive electrode current collector. The positive electrode active material layer includes a positive electrode active material and graphene. And 7.74≤Dv501/2+0.05 THK≤10.2, Dv50 is a particle size of the positive electrode active material and THK is a thickness of the positive electrode plate. And 0.078≤w*CW+0.01n≤1.9, n is a quantity of layers of the graphene, w is a mass percentage of the graphene in the positive electrode active layer, and CW is a one-side coating weight of the positive electrode active material layer.