Lithium-ion battery device for vehicle

A lithium-ion battery device for a vehicle, comprising:

• a housing;
• a battery cell stored inside the housing;
• and
• an adjacent member provided adjacently to and on a rearward side, in a vehicle longitudinal direction, of the battery cell,
• wherein said battery cell comprises a cell case, an electrode body stored inside the cell case, a pair of terminals provided at a face of the cell case, and a pair of collectors connecting said electrode body and said pair of terminals inside said cell case,
• said cell case includes a first main face and a second main face which respectively have a larger area than said face at which the pair of terminals are provided and face to each other in the vehicle longitudinal direction,
• said second main face is arranged on the rearward side, in the vehicle longitudinal direction, of said battery cell,
• two gap-forming portions which respectively have a smaller area than said second main face and have a specified thickness in the vehicle longitudinal direction are arranged between said second main face and said adjacent member,
• said two gap-forming portions are spaced apart from each other at a distance greater than the specified thickness in an inter-terminal direction of said battery cell without any other gap-forming portions between them, to form a space to allow bending deformation of the cell case,
• the pair of collectors are respectively joined to opposite end portions of the electrode body, in the inter-terminal direction, of the battery cell,
• each of the two gap-forming portions is offset from the pair of collectors toward a central portion, in the inter-terminal direction, of the battery cell,
• each of the two gap-forming portions overlap the electrode body when viewed from the vehicle longitudinal direction,
• a width ratio Lr/Lc between the two gap-forming portions is 0.68 or greater, where Lc is a distance between opposite ends of the of the cell case in the inter-terminal direction of the battery cell, and Lr is a distance between the respective centers of the two gap-forming portions in the inter-terminal direction of the battery cell,
• said electrode body comprises a pair of foil bodies disposed at opposite end portions of the electrode body in the inter-terminal direction of the battery cell,
• the pair of collectors are respectively joined to the pair of foil bodies, and
• each of the two gap-forming portions is offset from the pair of foil bodies and the pair of collectors toward the central portion, in the inter-terminal direction, of the battery cell such that each of the two gap-forming portions is spaced from the pair of foil bodies in the inter-terminal direction of the battery cell.