| CPC H01M 4/139 (2013.01) [H01M 4/623 (2013.01); H01M 4/625 (2013.01); H01M 10/0525 (2013.01); H01M 2004/021 (2013.01); H01M 2004/028 (2013.01)] | 20 Claims |

|
1. An electrochemical device, comprising a cathode, wherein the cathode comprises:
a cathode current collector;
a first cathode active material layer comprising a first cathode active material and a first conductive agent; and
a second cathode active material layer comprising a second cathode active material,
wherein the first cathode active material layer is disposed between the cathode current collector and the second cathode active material layer, and the first cathode active material layer is formed on at least one surface of the cathode current collector; wherein the first cathode active material layer is firstly formed on the cathode current collector, and the second cathode active material layer is secondly formed on the first cathode active material layer, then the second cathode active material layer and the first cathode active material layer are pressed together;
wherein the first cathode active material layer and the second cathode active material layer comprise a binder, and a content of the binder of the first cathode active material layer is greater than a content of the binder of the second cathode active material layer; and
wherein a ratio of a specific surface area of the first conductive agent to a specific surface area of the first cathode active material is greater than 1.3 and less than 11.
|