| 摘要 |
PROBLEM TO BE SOLVED: To provide a battery pack capable of enhancing welding reliability between a bus bar and an external terminal in a battery pack in which a bus bar is jointed to the external terminal and a plurality of secondary batteries are connected to each other via the bus bar.SOLUTION: Between a negative electrode external terminal 151 and a bus bar 300, a connection layer 300a is interposed which is formed by accumulating metal powder made of a material different from a formation material of the bus bar 300 and excellent in weldability with the formation material of the negative electrode external terminal 151. The connection layer 300a and the bus bar 300 are jointed at the interface in metallic bond. The connection layer 300a and the negative electrode external terminal 151 are welded via a welded surface 300e of the connection layer 300a to which surface processing treatment for reducing surface roughness is applied. |
