CYLINDRICAL SECONDARY BATTERY MODULE

A cylindrical secondary battery module including a plurality of cylindrical secondary battery cells respectively having a battery case in which an electrode assembly and an electrolyte are accommodated; a cell frame at which the plurality of cylindrical secondary battery cells are disposed; and a bus bar electrically connected to the plurality of cylindrical secondary battery cells and having a fusing portion, wherein the bus bar has a plurality of layers made of different materials from each other.