A battery module according to an exemplary embodiment of the present invention includes: a battery cell stack made by stacking a plurality of battery cells adjacent to one another in parallel; and a heating/cooling composite fin interposed between adjacent battery cells of the battery cell stack. The heating/cooling composite fin includes: a compressive pad positioned between the adjacent battery cells; cooling fins each positioned between the compressive pad and a respective one of the adjacent battery cells; and heating films each positioned between the compressive pad and a respective one of the cooling fins.