A battery module is described. The battery module includes the battery module includes a plurality of repeating frames; a plurality of battery cells positioned between the plurality of repeating frames, the battery cells having a flexible heat conducting covering, an edge of the heat conducting covering folded over an outside edge of the repeating frame; and a heat sink contacting the edge of the heat conducting covering folded over the edge of the repeating frame. A method of cooling a battery module is also described.