ELECTRODE ASSEMBLY, BATTERY CELL, BATTERY, AND MANUFACTURING DEVICE AND METHOD FOR ELECTRODE ASSEMBLY

An embodiment of the present application provides an electrode assembly, a battery cell, a battery, and an electrode assembly manufacturing device and method, which belong to the technical field of batteries. The electrode assembly includes a negative electrode plate and a positive electrode plate, the negative electrode plate and the positive electrode plate being wound in a winding direction to form a winding structure, the winding structure including a bending area. Both the negative electrode plate and the positive electrode plate include a plurality of bending portions located in the bending area. At least one bending portion in the negative electrode plate is a first bending portion, and an active substance capacity per unit area outside the first bending portion is greater than an active substance capacity per unit area inside the first bending portion; and/or, at least one bending portion in the positive electrode plate is a second bending portion, and an active substance capacity per unit area outside the second bending portion is greater than an active substance capacity per unit area inside the second bending portion. In the electrode assembly of this structure, the active substance arrangement in at least part area of the bending area of the electrode plate is more reasonable with better economic efficiency.