Power supply device, electric vehicle and power storage device using same, fastening member for power supply device, method of manufacturing power supply device, and method of manufacturing fastening member for power supply device

A fastening member for a power supply device for fastening a pair of end plates covering both end surfaces of a battery stack body including a plurality of secondary battery cells each including a prismatic exterior can are stacked, the fastening member comprising:

• fastening parts each fixed to a corresponding one of the end plates at both ends in a longer direction;
• and
• an intermediate part coupling a plurality of the fastening parts with each other, wherein
• the fastening part is higher in strength than the intermediate part, and
• the intermediate part is higher in stretchability than the fastening part.

A manufacturing method for a fastening member for a power supply device for fastening a pair of end plates covering both end surfaces of a battery stack body including a plurality of secondary battery cells each including a prismatic exterior can are stacked, the manufacturing method of steps comprising:

• preparing fastening parts each fixed to a corresponding one of the end plates at each of both ends in a longer direction and
• an intermediate part coupling a plurality of the fastening parts with each other;
• and
• welding the fastening part and an intermediate part.

A manufacturing method for a power supply device, the power supply device including

• a plurality of secondary battery cells each including a prismatic exterior can,
• a pair of end plates covering both end surfaces of a battery stack body including the plurality of secondary battery cells are stacked, and
• a plurality of fastening members made of metal, each of the plurality of fastening members including in a plate shape extending in a stack direction of the plurality of secondary battery cells, the plurality of fastening members being disposed on side surfaces of the battery stack body, the side surfaces opposing each other, each of the plurality of fastening members fastening the end plates to each other, the manufacturing method comprising:
• welding a fastening part fixed to each of the end plates at each of both ends in a longer direction and an intermediate part coupling a plurality of the fastening parts with each other;
• and
• covering both end surfaces of the battery stack body with a pair of the end plates and fastening the end plates to each other with a fastening member for a power supply device.