Abstract: The present application provides a rolled core and a battery, where the rolled core includes a positive electrode piece having a paste-removal portion of positive electrode piece, and a negative electrode piece including a negative current collector, a negative active material layer, and a gap filling body; the paste-removal portion of positive electrode piece is a missing part of the positive electrode piece relative to the negative electrode piece at a winding-start end of the rolled core; the negative current collector includes a first side and a second side which are opposite to each other, and at least one of the first side and the second side is provided with a negative active material layer; the gap filling body is arranged on one of the first side and the second side at a position corresponding to the winding-start end of the rolled core.

Abstract: A jelly roll includes a negative electrode plate, along a winding direction, an inner surface of a second bending region of the negative electrode plate is covered by a first tape layer, and in a thickness direction of the jelly roll, a projection of two ends of the first tape layer is connected to or partially overlapped with a projection of a winding head of the negative electrode plate. As a result, surface unevenness of the jelly roll is improved, thereby improving the flatness of a battery cell.

Abstract: Disclosed is a battery, which includes a jelly roll. The jelly roll includes a first electrode plate, a separator, and a second electrode plate; the first tab is close to a first bending portion of a first end of the jelly roll, the second tab is close to a second bending portion of a second end of the jelly roll, a winding tail end of the jelly roll covers the first bending portion, and the winding tail end extends in a direction from the first bending portion to the second bending portion; and an outer side of the jelly roll includes a first outer adhesive paper, a region between a head of the second end of the jelly roll and the second tab directly faces a first portion of the jelly roll, and the first outer adhesive paper covers at least one side surface of the first portion.

Abstract: The present application provides a positive electrode sheet, a preparation method thereof, and a lithium-ion battery including the positive electrode sheet. The positive electrode sheet includes a positive electrode current collector, and the positive electrode current collector includes a single-sided coated area and a double-sided coated area. In the single-sided coated area, a first coating layer is disposed on a first surface of the positive electrode current collector, the first coating layer includes a first and a second positive electrode active material layer, the second positive electrode active material layer is disposed on the surface of the positive electrode current collector, and the first positive electrode active material layer is disposed on a surface of the second positive electrode active material layer, and a particle size of the first positive electrode active material is larger than a particle size of the second positive electrode active material.

Abstract: The present disclosure provides a negative electrode sheet, a preparation method thereof and a lithium ion battery containing the same. The negative electrode sheet includes a negative electrode current collector, where the negative electrode current collector includes a single-sided coating area and a double-sided coating area; in the double-sided coating area, second coating layers are disposed on both side surfaces of the negative electrode current collector, respectively, wherein each of the second coating layers includes a first negative electrode active material layer and a second negative electrode active material layer, the second negative electrode active material layer is disposed on a surface of the negative electrode current collector, and the first negative electrode active material layer is disposed on a surface of the second negative electrode active material layer.

Abstract: The present application provides a positive electrode sheet, a preparation method thereof, and a lithium-ion battery including the positive electrode sheet. The positive electrode sheet includes a positive electrode current collector, and the positive electrode current collector includes a single-sided coated area and a double-sided coated area. In the single-sided coated area, a first coating layer is disposed on a first surface of the positive electrode current collector, the first coating layer includes a first positive electrode active material layer and a second positive electrode active material layer. A content of a first conductive agent for forming the first positive electrode active material layer is less than a content of a second conductive agent for forming the second positive electrode active material layer.

Abstract: The present disclosure provides a negative electrode sheet, a preparation method thereof and a lithium ion battery containing the same. The negative electrode sheet includes a negative electrode current collector, where the negative electrode current collector includes a single-sided coating area and a double-sided coating area; in the double-sided coating area, second coating layers are disposed on both side surfaces of the negative electrode current collector, respectively, wherein each of the second coating layers includes a first negative electrode active material layer and a second negative electrode active material layer, the second negative electrode active material layer is disposed on a surface of the negative electrode current collector, and the first negative electrode active material layer is disposed on a surface of the second negative electrode active material layer.