Patent ID: 7816029

Claim:
A battery module comprising: a battery cell stack including a plurality of flat secondary battery cells stacked along in a thickness direction which is a battery cell stacking direction of the flat secondary battery cells, each of the flat secondary battery cells including an electric power supplying element with a positive electrode plate and a negative electrode plate stacked on one another and sealed inside a sheet-like exterior material; and a module case enclosing the battery cell stack within an interior area of the module case, the module case including an inwardly protruding section disposed on at least one of two oppositely facing sides of the module case that faces in the battery cell stacking direction and protruding toward the interior area of the module case with the inwardly protruding section pressing an end surface of the battery cell stack that faces in the battery cell stacking direction at a point disposed inward from an edge of the battery cell stack, a first rigidity section elastically supporting a periphery of the inwardly protruding section with the first rigidity section having a lower rigidity than the inwardly protruding section, and a second rigidity section supporting a periphery of the first rigidity section with the second rigidity section having a higher rigidity than the first rigidity section.