A battery pack comprising: a first battery module and a second battery module, each comprising a plurality of battery cells having wide front surfaces arranged along one direction and aligned in parallel so that the wide front surfaces of the battery cells face each other with barriers positioned between adjacent ones of the plurality of battery cells, the plurality of battery cells of each battery module being electrically coupled to each other; and a housing accommodating the first and second battery modules (100, 200) therein, the housing having inlets at opposite edges of a first end of the housing at one end of the first and second battery modules, and an outlet at a lower portion of a second end of the housing at an opposite end of the first and second battery modules, wherein each barrier comprises a base portion facing an adjacent one of the battery cells, an upper spacer at at least one top corner of the base portion, and a lower spacer at at least one bottom corner of the base portion, wherein sides and a bottom of the first and second battery modules (100, 200) are spaced from the housing, and wherein the housing and the barriers are configured to accommodate a refrigerant flowing into the housing through the inlets of the housing, the refrigerant flowing from the side of each battery cell to the bottom of each battery cell, and being exhausted to an outside of the housing through the outlet of the housing; characterised in that one side surface of the first battery module faces a side surface of the second battery module, and a blocking plate configured to block movement of the refrigerant between the first and second battery modules (100, 200) is between the first and second battery modules (100, 200). a first battery module and a second battery module, each comprising a plurality of battery cells having wide front surfaces arranged along one direction and aligned in parallel so that the wide front surfaces of the battery cells face each other with barriers positioned between adjacent ones of the plurality of battery cells, the plurality of battery cells of each battery module being electrically coupled to each other; and a housing accommodating the first and second battery modules (100, 200) therein, the housing having inlets at opposite edges of a first end of the housing at one end of the first and second battery modules, and an outlet at a lower portion of a second end of the housing at an opposite end of the first and second battery modules, wherein each barrier comprises a base portion facing an adjacent one of the battery cells, an upper spacer at at least one top corner of the base portion, and a lower spacer at at least one bottom corner of the base portion, wherein sides and a bottom of the first and second battery modules (100, 200) are spaced from the housing, and wherein the housing and the barriers are configured to accommodate a refrigerant flowing into the housing through the inlets of the housing, the refrigerant flowing from the side of each battery cell to the bottom of each battery cell, and being exhausted to an outside of the housing through the outlet of the housing; characterised in that one side surface of the first battery module faces a side surface of the second battery module, and a blocking plate configured to block movement of the refrigerant between the first and second battery modules (100, 200) is between the first and second battery modules (100, 200).