Electrode assembly and battery cell

An electrode assembly, comprising a first electrode plate and a second electrode plate;

• wherein
• the first electrode plate comprises a first current collector and a first active material layer, the first current collector comprises a first main body and a first tab, the first tab extends from one end of the first main body in a longitudinal direction, and a size of the first tab in a lateral direction is smaller than a size of the first main body in the lateral direction, the lateral direction being parallel to the first current collector and perpendicular to the longitudinal direction;
• the first main body comprises a first coated region and a first transition region, the first transition region is disposed between the first tab and the first coated region, the first active material layer is applied on a surface of the first coated region, the first active material layer is not applied on both the first transition region and the first tab, and a size of the first transition region in the lateral direction is same as a size of the first coated region in the lateral direction and greater than the size of the first tab in the lateral direction;
• the second electrode plate comprises a second current collector and a second active material layer, the second current collector comprises a second main body and a second tab, the second tab extends from one end of the second main body in the longitudinal direction, and the second active material layer is applied on a surface of the second main body;
• in a direction of the first main body toward the first tab, an edge of the first transition region farther away from the first coated region does not extend beyond an edge of the second active material layer;
• the first tab and the second tab are located on a same side of the electrode assembly in the longitudinal direction;
• the second active material layer comprises a substrate region and a thinned region extending from the substrate region, and a thickness of the thinned region is less than a thickness of the substrate region;
• in the longitudinal direction, the thinned region is connected to a side of the substrate region close to the second tab;
• and
• in a direction of the second main body toward the second tab, a boundary between the substrate region and the thinned region is beyond an edge of the first coated region.