Disclosed herein is a battery module including a plurality of sequentially stacked plate-shaped battery cells, wherein the battery module is configured to have a structure in which two or more cell units are stacked in a state in which the battery cells are electrically connected to each other, each of the cell units is configured to have a structure in which two or more battery cells are connected in parallel to each other in a state in which the battery cells are in tight contact with each other, and parallel connection between electrode terminals of the battery cells of the cell units is achieved by one to one welding at a single weld point.