Positive pole piece, electrochemical device and electronic device

The positive pole piece comprises a positive current collector, a bottom coating and a positive active material layer. And the bottom coating is arranged between the positive current collector and the positive active material layer. The positive electrode active material layer comprises positive electrode active material particles, and the positive electrode active material particles comprise first particles penetrating through the bottom coating layer. The number of the first particles is n1, the total number of the positive electrode active material particles connected with the bottom coating layer in the positive electrode active material layer is n2, and n1/n2 is larger than or equal to 5% and smaller than or equal to 40%. Ion polarization can be reduced, and the rate capability and the cycle performance of the electrochemical device can be improved. The invention also provides an electrochemical device applying the positive pole piece and an electronic device applying the electrochemical device. 一种正极极片，包