Battery module including connector having bidirectional coupling structure

A battery module comprising:

• a cell assembly including at least one battery cell;
• a module case accommodating the cell assembly;
• and
• a module connector mounted outside the module case, electrically connected to the cell assembly, and configured to connect to an external connector outside the module case,
• wherein a coupling surface of the module connector has a first fastening part opened in at least one direction, and a corresponding coupling surface outside the module case has a second fastening part opened bidirectionally so as to be received in the first fastening part by advancing the module connector relative to the coupling surface in a first direction or in a second direction opposite thereto, the first direction and the second direction extending along a central axis of the second fastening part,
• wherein the first fastening part has a locking element,
• wherein the second fastening part has a first locking protrusion and a second locking protrusion, the first locking protrusion being arranged to engage the locking element when advancing the module connector in the first direction and the second locking protrusion being arranged to engage the locking element when advancing the module connector in the second direction, and
• wherein the first locking protrusion and the second locking protrusion face each other on opposing sides of the central axis.