An electrochemical device includes a cathode current collector, a first cathode active material layer, a second cathode active material layer and an insulating layer. The first cathode active material layer covers a first portion of a first surface of the cathode current collector, and the insulating layer covers a second portion of the first surface of the cathode current collector that is different from the first portion. A first distance exists between the insulating layer and the first cathode active material layer in a longitudinal direction of the cathode current collector. By providing a gap between the active material layer in a two-layer structure and the insulating layer in the cathode, thereby ensuring the mechanical safety performance of the electrochemical device.