Abstract: A cathode includes a cathode current collector; and a cathode active material layer disposed on a surface of the cathode current collector. The cathode active material layer includes a first particle and a second particle, the first particle including a secondary particle composed of a third particle, the third particle being a primary particle, the first particle having an average particle size of 5 ?m to 20 ?m, the third particle having an average particle size of 200 nm to 700 nm, the second particle including a fourth particle and/or a secondary particle composed of the fourth particle, the fourth particle being a primary particle, the second particle having an average particle size of 3 ?m to 5 ?m, the fourth particle having an average particle size of 800 nm to 5 ?m.

Abstract: The present application relates to a cathode and an electrochemical device.

Abstract: An electrode plate includes a current collector and an active layer formed on the current collector. The current collector includes a first end portion and a second end portion facing away from the first end portion along a length direction. The active layer comprises an active material, an amount of the active material in the active layer increases from the first end portion toward the second end portion along the length direction. The disclosure also provides a battery using the electrode plate.