An embodiment battery module for a vehicle includes first and second battery cells each having a planar shape, each battery cell being extended in one direction and including a positive electrode and a negative electrode separated from each other in a widthwise direction of the battery cells, and a main cartridge including an insertion space in which the battery cells are slidably inserted with the electrodes arranged alternately in a stacking direction and protruding outwards, wherein a stepped portion is provided in an inward end portion of the insertion space, inner surfaces of the stepped portion that are in contact with each end portion of the battery cells are spaced apart from each other in a sliding direction of the battery cells, and the end portions of the electrodes are in contact and overlap with each other when the electrodes are bent in the stacking direction to be connected to each other.