Energy storage device

An energy storage device comprising:

• an electrode assembly;
• a container which accommodates the electrode assembly and includes a lid body extending in a longitudinal direction;
• a shaft which penetrates the lid body;
• a current collecting member which has a leg portion to be connected to the electrode assembly;
• an insulating member which is disposed between the current collecting member and the lid body;
• and
• a first locking portion for locking a rotation of the current collecting member about the shaft with respect to the insulating member,
• wherein the first locking portion includes:
• a recessed portion or a projecting portion formed on the insulating member, and a projecting portion or a recessed portion formed on the current collecting member,
• the recessed portion or the projecting portion formed on the insulating member is indented away from the shaft or projects toward the shaft in a direction which intersects with the shaft,
• the projecting portion or the recessed portion formed on the current collecting member projects away from the shaft or is indented toward the shaft in the direction which intersects with the shaft,
• the recessed portion or the projecting portion formed on the insulating member and the projecting portion or the recessed portion formed on the current collecting member are configured to engage with each other, and
• the leg portion is positioned closer to an end portion of the lid body in the longitudinal direction than the first locking portion is.