Electrode body for secondary batteries

An electrode assembly for a secondary battery, including:

• a positive electrode;
• a negative electrode;
• an outer separator;
• and
• an inner separator arranged inward of the outer separator,
• wherein each of the outer separator and the inner separator is formed into a three-layer structure of a separator base material containing a thermoplastic resin, and two functional layers arranged on both sides of the separator base material, the two functional layers containing an adhesive resin having a melting point higher than a melting point of the separator base material,
• wherein either one of the positive electrode or the negative electrode is an outer electrode and the other one is an inner electrode such that the outer electrode includes a circumferentially outermost portion disposed outward than a circumferentially outermost portion of the inner electrode, and the outer electrode is sandwiched by a circumferentially outermost portion of the outer separator and a circumferentially outermost portion of the inner separator, and
• the outer separator and the inner separator have two electrode facing parts which face the circumferentially outermost portion of the outer electrode and overlap via the outer electrode, and an end portion overlapping part provided at end portions of the outer separator and the inner separator, the end portion overlapping part in which the outer separator and the inner separator are not fold back and the functional layers respectively formed on one side of the outer separator and the inner separator are in contact with each other,
• a thickness of a tip part of the end portion overlapping part is larger than a sum of thicknesses of the two electrode facing parts, and a thickness of the outer separator and a thickness of the inner separator are respectively larger at the tip part of the end portion overlapping part than at the electrode facing parts,
• wherein, the positive electrode, the negative electrode, the outer separator and the inner separator have a winding structure in which they are wound in a state where they are laminated, and the outermost separator is an outermost layer of the winding structure.