Multilayered flexible battery interconnects and methods of fabricating thereof

Provided are multilayered flexible battery interconnects for interconnecting batteries in battery packs and methods of fabricating thereof. A multilayered flexible battery interconnect comprises insulating layers and two conductive layers, stacked together and positioned between the insulating layers. One conductive layer is thicker than the other. The thinner conductive layer comprises flexible tabs for connecting to batteries and, in some examples, comprises voltage sense traces. The smaller thickness of these flexible tabs ensures welding quality and allows using less energy during welding. The battery cell contacts, to which these flexible tabs are welded, can be significantly thicker. Furthermore, the smaller thickness enables fusible link integration into flexible tabs. At the same time, the two conductive layers collectively conduct current within the interconnect, with the thicker layer enhancing the overall current-carrying capacity. The two conductive layers can be welded together to ensure electric connections and mechanical support.