An electrochemical apparatus, including a positive electrode, a negative electrode, and an electrolyte. The positive electrode includes a positive electrode current collector and a positive electrode active layer disposed on at least one surface of the positive electrode current collector. The positive electrode active layer includes a central region and an edge region surrounding an outer periphery of the central region, the edge region includes a first positive electrode active material, and the central region includes a second positive electrode active material. A solid-phase diffusion coefficient of the first positive electrode active material is 10−15 cm2/s to 10−5 cm2/s, and a ratio of the solid-phase diffusion coefficient of the first positive electrode active material to a solid-phase diffusion coefficient of the second positive electrode active material is 1:3 to 1:1.05.