A battery module includes a cell assembly having a plurality of secondary batteries and a plurality of heat dissipation plates interposed between the plurality of secondary batteries. At least a portion of a front end and a rear end of the heat dissipation plates is recessed to form an inlet portion and an outlet portion so that a coolant is introduced from the outside or discharged to the outside, and the heat dissipation plates have a coolant moving portion so that the coolant moves to a front end, an upper end, a lower end and a rear end of the secondary batteries. A bus bar assembly has a plurality of bus bars and a bus bar frame having insert holes into which the electrode leads of the secondary batteries are inserted; an end cover having a vent hole communicating with the coolant moving portion and a plurality of side plates.