Patent ID: 8076023

Claim:
A battery module comprising: (a) a stack in which at least two non-aqueous electrolyte secondary batteries are stacked in at least a thickness direction thereof; (b) end plates placed at both ends of said stack, said both ends being the ends in the thickness direction of each of said batteries; and (c) at least two bridges for connecting one of said end plates with the other of said end plates to bind said batteries, wherein each of said batteries comprises an electrode assembly, a non-aqueous electrolyte, and a substantially rectangular battery case for housing said electrode assembly and said non-aqueous electrolyte, said battery case having a thickness α, a width β, and a height γ satisfying a relation α<β≦γ: wherein said electrode assembly includes a positive electrode, a negative electrode, and a porous heat-resistant layer disposed between said positive electrode and said negative electrode; said positive electrode includes a positive electrode active material layer and said negative electrode includes a negative electrode active material layer; a ratio of a pore volume in a predetermined area of said porous heat-resistant layer to a theoretical capacity of each of said batteries is 0.18 to 1.117 ml/Ah, said predetermined area having a same area as said positive electrode active material layer; a porosity of said porous heat-resistant layer is 35 to 85%, said porous heat-resistant layer includes a porous sheet comprising a heat-resistant resin; a thickness of said porous heat-resistant layer is 2 to 20 μm; and a ratio of a thickness Y of said end plate to a thickness α of the battery case, Y/α, is 0.4 to 2.