Middle or Large-sized Battery Pack Case Providing Improved Distribution Uniformity in Coolant Flux

The present invention in a direction perpendicular to a middle- or large-sized battery pack case in which a mounted battery module to which a plurality dog ​​laminate capable battery cells or unit modules ( 'unit cells'), the charge and discharge, the refrigerant is a unit cell stacking direction for the cooling of the unit cells to flow toward the opposite from the one side of the battery module, the refrigerant inlet and the refrigerant outlet is situated on the top and bottom of the pack case in mutually opposite directions, the flow space leading from the coolant inlet port to the battery module ( 'coolant introduction part') and the battery module from the opposite end direction of the flow space ( 'coolant discharge part') which are each formed in the pack case and the upper inner surface of the coolant introduction part facing the top end of the battery module is the distance to the battery module upper coolant inlet port leading to the refrigerant outlet consisting of a reduced structure, wherein the refrigerant downward projection for guiding the progression of the coolant into the battery module A distance from the opposite end of the inlet as to provide a middle- or large-sized battery pack case, which is formed on the top inner surface of said refrigerant.