A battery module including a battery cell stacked body in which a plurality of battery cells are adjacent each other in parallel and are stacked; a mono frame receiving the battery cell stacked body and including at least one opening opened in a length direction of the battery cell stacked body, and including an upper plate and a lower plate that are perpendicular to a stacked side of the battery cell stacked body and a pair of lateral plates in parallel to the stacked side of the battery cell stacked body; an external expansion controlling pad provided between the battery cell stacked body and the mono frame; and a heat radiating resin provided between the battery cell stacked body and the lower plate. The external expansion controlling pad includes two main bodies and two bridges connecting the two main bodies.