LITHIUM ION SECONDARY BATTERY AND MANUFACTURING METHOD OF THE SAME

摘要

PROBLEM TO BE SOLVED: To provide a lithium ion secondary battery capable of realizing high capacitance of an electrode film by suppressing an uneven distribution of a binder in the electrode film, and to provide a manufacturing method of the same.SOLUTION: The lithium ion secondary battery comprises: an electrode film formed on a surface of a current collector foil; and a binder which bonds the current collector foil and the electrode film. A binder concentration on a side of the current collector foil side of the electrode film is higher than a binder concentration on an opposite side of the current collector foil.