Disclosed herein are a battery module constructed in a structure in which a plurality of plate-shaped secondary battery cells ('battery cells'), which can be charged and discharged, are sequentially stacked on a lower plate, and an upper plate is coupled to the uppermost battery cell, wherein the plates are provided at the top and bottom and/or the right and left sides thereof with a sliding coupling structure, and the battery module is provided at the front thereof with grips, and a middle- or large-sized battery pack including a plurality of battery modules.