Battery module, method of manufacturing the same and battery pack

A battery module comprising:

• a battery cell stack in which a plurality of battery cells are stacked;
• and
• a module frame that accommodates the battery cell stack, the module frame including a bottom part, two side surface parts facing each other and an upper plate,
• wherein the bottom part defines two terminal edges along a longitudinal direction of the battery module, each terminal edge located between the two side surface parts, the bottom part including a first part located at at least one of the two terminal edges and a second part located inside the first part relative to the terminal edges, and wherein a thickness of the first part is thinner than that of the second part.