Disclosed is a battery module (100) arranged with a plurality of unit cells (10) in the form of a lattice, wherein the unit cells (10) arranged in the row direction are connected in parallel by means of a first connecting body (20), and the unit cells (10) arranged in the column direction are connected in series by means of a second connecting body (30) disposed between the adjacent unit cells (10) in the column direction. When a unit cell (10) is internally short-circuited, the first connecting body (20) connected to the internally-short-circuited unit cell (10) melts down by means of the Joule heat generated by means of the short-circuit current flowing from the other unit cell (10) that did not internally short-circuit to the internally-short-circuited unit cell (10) via the first connecting body (20).