Electric storage device provided with current collecting member, and method for manufacturing current collecting member

An electric storage device comprising:

• a case;
• an electrode assembly in which a positive electrode plate and a negative electrode plate are flatly wound, while being isolated from each other, and housed in the case;
• a pair of external terminals provided for external connection;
• and
• a pair of current collecting members arranged along an inner surface of the case to electrically connect the electrode assembly with each of the pair of external terminals,
• wherein at least one of the pair of current collecting members includes an external terminal connecting portion arranged along an inner surface of the case, and an electrode assembly connecting portion extending out of an end portion of the external terminal connecting portion and connected to a laminated portion of the positive electrode plate or a laminated portion of the negative electrode plate of the electrode assembly, and is a current collecting member in which the external terminal connecting portion and the electrode assembly connecting portion are integrally formed by processing a metal plate,
• a central portion of the electrode assembly connecting portion in the width direction thereof orthogonal to the extending direction thereof is divided, thereby forming in the electrode assembly connecting portion a pair of divided portions,
• each of the pair of divided portions comprises:
• a twisted portion twisted in the width direction of the electrode assembly connecting portion;
• and
• an insertion portion provided in continuity with the twisted portion,
• the insertion portion is formed so that surfaces of the insertion portions face each other, and is inserted into a winding center of the positive electrode plate or the negative electrode plate of the electrode assembly, and
• the insertion portion is electrically connected to the laminated portion of the positive electrode plate or the laminated portion of the negative electrode plate of the electrode assembly.

A method for manufacturing a current collecting member for connecting an electrode assembly and an external terminal in an electric storage device, the method comprising the steps of:

• providing a metal plate having a length in a first direction orthogonal to a second direction longer than a length in the second direction;
• forming a score along the first direction in the metal plate, excluding at least both end portions thereof in the first direction, thereby forming a pair of divided portions lining up in the second direction;
• and
• twisting each of the divided portions in the second direction, so that the rest of each of the divided portions excluding both end portions in the first direction intersects with a surface of the metal plate in each of the divided portions.