Patent ID: 8541126

Claim:
A battery pack, comprising: a multi-sided battery pack enclosure comprising first and second battery pack enclosure walls and upper and lower battery pack enclosure walls; a plurality of cells completely contained within said battery pack enclosure; and at least one thermal barrier element dividing the battery pack into a plurality of cell groups, wherein said at least one thermal barrier element extends completely between said first and second battery pack enclosure walls, wherein said at least one thermal barrier element extends completely between said upper and lower battery pack enclosure walls, wherein each cell group of said plurality of cells groups is completely segregated from other cell groups of said plurality of cell groups by said at least one thermal barrier element, wherein each of said plurality of cell groups includes at least two cells, wherein each of said at least one thermal barrier elements is comprised of a central portion sandwiched between a pair of layers, wherein said central portion exhibits a high thermal conductivity and each layer of said pair of layers is comprised of a low thermal conductivity material with a melting temperature of at least 300° C. and a thermal conductivity of less than 20 W/mK at 25° C., and wherein each of said at least one thermal barrier elements prevents a thermal runaway event in a first cell group of said plurality of cell groups from initiating a second thermal runaway event in an adjacent cell group of said plurality of cell groups.