A battery module comprising: a cartridge stack comprising a plurality of secondary batteries which each comprise an electrode lead, and a plurality of cartridges which each accommodate at least one of the plurality of secondary batteries such that at least a portion of the electrode lead protrudes outwardly, and which are stacked in a plurality of stages; and an interconnect board housing comprising a stepped connection end, a power terminal installed fixedly to the connection end, and a bus bar electrically connecting the electrode lead with the power terminal, and mounted on a surface of the cartridge stack, the bus bar comprises a first connection part which is provided in opposition to the power terminal, having the connection end therebetween, and is connected with the electrode lead, a second connection part which is provided in opposition to the first connection part, having the connection end therebetween, and is connected with the power terminal, and a connection part which connects the first connection part with the second connection part and is embedded in the connection end, wherein said battery module further comprises an ICB cover mounted on an outer surface of the ICB housing to cover the first connection part and the electrode lead, a cooling plate mounted on another surface of the cartridge stack and receiving heat generated from the plurality of secondary batteries through the plurality of cartridges and radiating the heat to outside, and the ICB cover is integrally coupled with the cooling plate such that the ICB cover is mounted on the outer surface of the ICB housing when the cooling plate is mounted on another surface of the cartridge stack, thus forming a cooling plate assembly. a cartridge stack comprising a plurality of secondary batteries which each comprise an electrode lead, and a plurality of cartridges which each accommodate at least one of the plurality of secondary batteries such that at least a portion of the electrode lead protrudes outwardly, and which are stacked in a plurality of stages; and an interconnect board housing comprising a stepped connection end, a power terminal installed fixedly to the connection end, and a bus bar electrically connecting the electrode lead with the power terminal, and mounted on a surface of the cartridge stack, the bus bar comprises a first connection part which is provided in opposition to the power terminal, having the connection end therebetween, and is connected with the electrode lead, a second connection part which is provided in opposition to the first connection part, having the connection end therebetween, and is connected with the power terminal, and a connection part which connects the first connection part with the second connection part and is embedded in the connection end, wherein said battery module further comprises an ICB cover mounted on an outer surface of the ICB housing to cover the first connection part and the electrode lead, a cooling plate mounted on another surface of the cartridge stack and receiving heat generated from the plurality of secondary batteries through the plurality of cartridges and radiating the heat to outside, and the ICB cover is integrally coupled with the cooling plate such that the ICB cover is mounted on the outer surface of the ICB housing when the cooling plate is mounted on another surface of the cartridge stack, thus forming a cooling plate assembly.