BATTERY PACK HAVING A NOVEL COOLING STRUCTURE

Disclosed herein is a battery pack having a plurality of battery cells or unit modules ('unit cells'), which can be charged and discharged, mounted in a pack case, wherein the unit cells are stacked in a direction (a Z direction) in which the unit cells are sequentially stacked in parallel to a ground in a state in which a spacing distance for coolant flow is provided between the respective unit cells to constitute a battery module, two or more battery modules are arranged in a horizontal direction (an X direction) on the plane with respect to a coolant introduction direction in which a coolant is introduced through a coolant inlet port in a state in which flow of the coolant between the battery modules is restrained to constitute a battery module group, the pack case is provided with a flow space ('a coolant introduction part') extending from the coolant inlet port to the battery module group and another flow space ('a coolant discharge past') extending from the battery modules group to a coolant outlet port, and a coolant flow channel defined between the coolant introduction part and the coolant discharge part is configured to have a structure in which the coolant, introduced through the coolant introduction part, cools the battery modules while passing through the specific battery modules in a vertical direction (a Y direction) on the plane and is discharged through the coolant discharge part.