Battery Module and Battery Pack Including the Same

A battery module according to one embodiment of the present disclosure can include a battery cell stack including a plurality of stacked battery cells a first bus bar connected to an electrode lead extending from the battery cells, a connection member connected to the first bus bar for connecting with other adjacent battery modules. The first bus bar can include a first part connected to the electrode lead and a second part connected to the connection member. A protrusion part can be formed in any one of the first part and the second part, and a through opening into which the protrusion part is inserted is formed in the other one. The protrusion part can be inserted into the through opening to connect the first part and the second part. The protrusion part can include a material that shrinks in volume or changes its shape when the temperature rises.