Battery module and manufacturing method thereof

A battery module comprising:

• a cell assembly formed by stacking a plurality of battery cells each comprising an electrode tab;
• a connection plate comprising a rotatable fastening portion, the connection plate being disposed at a lower end of the cell assembly in a direction perpendicular to a direction in which electrode tabs protrude from the battery cells;
• and
• a bus bar assembly disposed on a side of the cell assembly where the electrode tab protrudes, the bus bar assembly electrically interconnecting the plurality of battery cells through the plurality of electrode tabs and being hinged to the connection plate through the fastening portion,
• wherein the bus bar assembly comprises a plurality of slit holes each of which is penetrated by at least one of the plurality of electrode tabs, and
• wherein the slit holes each comprise a first area and a second area which is disposed at an end in a direction adjacent to the fastening portion and which has a wider width than that of the first area.

A battery module manufacturing method comprising:

• connecting a bus bar assembly to a fastening portion disposed at an upper portion or a lower portion of a cell assembly formed by stacking a plurality of battery cells each comprising an electrode tab;
• and
• penetrating at least one of electrode tabs through each of a plurality of slit holes included in the bus bar assembly by rotating the bus bar assembly around the fastening portion,
• wherein the slit holes each comprise a first area and a second area which is disposed more adjacent to the fastening portion than the first area and which has a wider width than that of the first area.