SECONDARY BATTERY, MANUFACTURING METHOD THEREOF, AND METHOD FOR MANUFACTURING NEGATIVE ELECTRODE SHEET USED FOR SECONDARY BATTERY

摘要

PROBLEM TO BE SOLVED: To provide a method for manufacturing a nonaqueous electrolyte secondary battery and a negative electrode sheet which enable the prevention of damage to a separator from heat generation caused by overcharge or the like, and enable the enhancement of durability.SOLUTION: A secondary battery comprises an electrode body 20 arranged by superposing a positive electrode sheet 30 and a negative electrode sheet 50 including a negative electrode current collector 52 and a negative electrode active material layer 54 on the negative electrode current collector on each other with a separator 70 interposed between the positive and negative electrode sheets, and winding them. The negative electrode active material layer is formed so that an uncoated part 53 is provided at one end of the negative electrode current collector 52 in a widthwise direction thereof, and no uncoated part is substantially provided at the other end. The separator is spread and formed to cover the negative electrode active material layer in the widthwise direction. The negative electrode active material layer formed on an outer peripheral side of the winding has a peripheral part formed at the end on the side where the uncoated part is not formed; the peripheral part is smaller in thickness than a part of the negative electrode active material layer which is located adjacently to the peripheral part along its longitudinal direction inward in a widthwise direction thereof, and does not have a corner part forming a right angle or an acute angle equal to or smaller than 90°.