BATTERY MODULE INCLUDING MODULE BUS BAR

A battery module includes a plurality of cylindrical battery cells respectively having electrode terminals formed at an upper portion and a lower portion thereof; a module housing including an accommodation portion having a plurality of hollow structures in which the plurality of cylindrical battery cells are inserted and accommodated; and a module bus bar including a first metal plate having a body portion located at an upper portion or a lower portion of the plurality of cylindrical battery cells to extend in a horizontal direction and a plurality of connection portions configured to extend in a horizontal direction from one side of the body portion to contact the electrode terminals of the plurality of cylindrical battery cells, and a second metal plate bonded to the body portion of the first metal plate and having a metal with a relatively higher electric conductivity than the first metal plate.