Pole piece, battery cell and battery

The utility model discloses a pole piece, a battery cell and a battery. The pole piece comprises a current collector, a first active material layer and a second active material layer, in the X direction, the current collector comprises a first surface and a second surface; the first active material layer is arranged on the first surface and comprises a first area and a second area which are arranged in the Y direction, and the second area is adjacent to the first area; the second active material layer is arranged on the second surface, and the second active material layer and the first active material layer in the first region are oppositely arranged on the current collector along the X direction; wherein the second area is provided with a concave part. According to the utility model, the problem that the energy density of a battery cell is seriously influenced due to large lithium ion embedding and separating resistance in a single-sided area of the pole piece is solved. 本实用新型公开了一种极片、电芯及电池，该极片包括集流体、第一活性物质层以及