Abstract: A battery pack includes a cassette stack comprising a plurality of battery cell cassettes, each of the cassettes including a plurality of support structures. Each support structure comprises an electrically and thermally conductive frame for receiving at least one battery cell having a first terminal and a second terminal, and a heat pipe. The first terminal is electrically coupled to the frame when the at least one battery cell is mounted in the frame. The heat pipe provides thermal conductivity between the frame and a cooling surface. A method of cooling an electric vehicle including a battery pack comprises aligning the battery pack and a cooling structure, moving the cooling structure into contact with the electric vehicle, and circulating coolant through the cooling structure.