# US 2014/0154549 A1 · Battery Pack Assembly > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0154549 A1 - Document ID: US20140154549A1 - Status: Published application - Kind: A1 - Application number: 14/235,532 - Filed: 2012-08-13 - Published: 2014-06-05 - Earliest claimed: 2011-08-14 - Assignees: GrafTech International Holdings Inc. - Inventors: Ryan J. Wayne; Jonathan Andrew Taylor; Martin David Smalc - Web page: https://patentgrep.com/patent/US20140154549A1 ## CPC - H01M 10/613: Cooling or keeping cold - H01M 10/625: Vehicles - H01M 10/647: Prismatic or flat cells, e.g. pouch cells - H01M 10/6551: Surfaces specially adapted for heat dissipation or radiation, e.g. fins or coatings - H01M 10/6555: arranged between the cells - H01M 50/209: adapted for prismatic or rectangular cells (H01M50/216 takes precedence) - H01M 50/271: Lids or covers for the racks or secondary casings - H01M 50/293: characterised by the material - H01M 2250/20: Fuel cells in motive systems, e.g. vehicle, ship, plane - Y02E 60/10: Energy storage using batteries - Y02E 60/50: Fuel cells - Y02T 90/40: Application of hydrogen technology to transportation, e.g. using fuel cells - Y10T 29/4935: Heat exchanger or boiler making - H01M: PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY - Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION - Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION - Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION ## Abstract A battery pack thermal management assembly draws heat from prismatic batteries having opposed major surfaces and arranged in a stacked configuration inside a housing. The thermal management assembly includes a plurality of thermal transfer sheets made from sheets of a compressed mass of exfoliated graphite particles. Each thermal transfer sheet is positioned to contact the major surface of at least one of the prismatic batteries. A cover plate has a top face and a bottom face and includes a plurality of apertures through which the plurality of thermal transfer sheets extend. The apertures include at least one curved sidewall and the thermal transfer sheets are bent over the curved sidewall. At least a portion of each of the thermal transfer sheets is secured between a heat sink and the top face. ## Claims ### Claim 1 A battery pack thermal management assembly for drawing heat from a plurality of generally rectangular prismatic batteries having opposed major surfaces and arranged in a stacked configuration inside a housing, the thermal management assembly comprising: a plurality of thermal transfer sheets made from sheets of a compressed mass of exfoliated graphite particles, each said thermal transfer sheet being positioned to contact the major surface of at least one of the prismatic batteries; a cover plate having a top face and a bottom face and including a plurality of apertures through which the plurality of thermal transfer sheets extend, said apertures including at least one curved sidewall, said thermal transfer sheets being bent over said curved sidewall; and a heat sink, at least a portion of each of said thermal transfer sheets being secured between said heat sink and said top face. ### Claim 2 (depends on 1) The battery pack thermal management assembly of claim 1 wherein said thermal transfer sheets extend into said apertures substantially perpendicular from said bottom face and substantially parallel to said top face. ### Claim 3 (depends on 1) The battery pack thermal management assembly of claim 1 wherein said curved sidewall includes a radius between about 1 mm and about 10 mm. ### Claim 4 (depends on 1) The battery pack thermal management assembly of claim 1 wherein said curved sidewall includes a radius of between about 2 mm and about 5 mm. ### Claim 5 (depends on 1) The battery pack thermal management assembly of claim 1 wherein said sheet of a compressed mass of exfoliated graphite particles includes an in-plane thermal conductivity of at least about 250 W/mK. ### Claim 6 (depends on 1) The battery pack thermal management assembly of claim 1 wherein said sheet of a compressed mass of exfoliated graphite particles includes an in-plane thermal conductivity of at least about 400 W/mK. ### Claim 7 (depends on 1) The battery pack thermal management assembly of claim 1 wherein one of said plurality of thermal transfer sheets is positioned between each pair of adjacent prismatic batteries in the stack. ### Claim 8 (depends on 1) The battery pack thermal management assembly of claim 1 wherein said heat sink is made of a thermally conductive metal and includes fins. ### Claim 9 (depends on 1) The battery pack thermal management assembly of claim 1 wherein said heat sink comprises a manifold through which a thermal transfer medium flows. ### Claim 10 (depends on 1) The battery pack thermal management assembly of claim 1 wherein each said apertures is sized and positioned to receive therethrough one of said plurality of thermal transfer sheets. ### Claim 11 (depends on 1) The battery pack thermal management assembly of claim 1 wherein the radius of said curved sidewall is greater than the minimum bend radius of said thermal transfer sheet that would cause cracking. ### Claim 12 A method of forming a thermal management system for a battery pack including a plurality of generally rectangular prismatic batteries having opposed major surfaces and arranged in a stacked configuration inside a housing; the method comprising: positioning a thermal transfer sheets in contact with the major surface of at least one of the prismatic batteries, said thermal transfer sheet being made from a sheet of a compressed mass of exfoliated graphite particles; placing a cover plate over said housing, said cover plate including at least one aperture said thermal transfer sheet extending through said aperture, said aperture including a curved sidewall; bending said thermal transfer sheets over said curved sidewall; and securing a heat sink to said cover plate to hold at least a portion of said thermal transfer sheet between said heat sink and said cover plate. ### Claim 13 (depends on 12) The method of claim 12 wherein said step of bending further comprises contacting at least a portion of said thermal transfer sheet with said heat sink and moving said heat sink laterally along the surface of said cover plate. ### Claim 14 (depends on 12) The method of claim 12 wherein said step of bending further comprises bending said thermal transfer sheet so that a portion of said thermal transfer sheet is substantially flush with a top face of said cover plate. ### Claim 15 (depends on 12) The method of claim 12 wherein said thermal transfer sheets extend into said apertures substantially perpendicular from a bottom face of said cover plate. ### Claim 16 (depends on 12) The method of claim 12 wherein said curved sidewall includes a radius between about 1 mm and about 10 mm. ### Claim 17 (depends on 12) The method of claim 12 wherein said curved sidewall includes a radius of between about 2 mm and about 5 mm. ### Claim 18 (depends on 12) The method of claim 12 wherein said sheet of a compressed mass of exfoliated graphite particles includes an in-plane thermal conductivity of at least about 250 W/mK. ### Claim 19 (depends on 12) The method of claim 12 wherein said sheet of a compressed mass of exfoliated graphite particles includes an in-plane thermal conductivity of at least about 400 W/mK. ### Claim 20 (depends on 12) The method of claim 12 wherein the heat sink is made of a thermally conductive metal and includes fins. ### Claim 21 (depends on 12) The method of claim 12 wherein the heat sink comprises a manifold through which a thermal transfer medium flows.