Thermal Management Structures for Battery Packs
A battery pack includes a plurality of cylindrical battery cells. Damage caused by thermal energy generated in the battery pack is minimized by a one or more graphite sheets in contact with a portion of each cylindrical battery cell.
1 . A battery pack comprising:
a plurality of cylindrical battery cells having a longitudinal length and a radial outer surface, said cylindrical battery cells being arranged in at least one linear row; and
at least one heat spreader comprised of a graphite sheet and extending at least substantially the entire longitudinal length of said cylindrical battery cells and the entire length of said linear row; and
wherein a single heat spreader contacts at least a portion of said radial outer surface of each said cylindrical battery in said row.
2 . The battery pack of claim 1 wherein said graphite sheet comprises compressed expanded natural graphite.
3 . The battery pack of claim 1 wherein said graphite sheet comprises resin impregnated compressed natural graphite sheet.
4 . The battery pack of claim 1 wherein said graphite sheet comprises graphitized polyimide sheet.
5 . The battery pack of claim 1 wherein said heat spreader includes a top surface and a bottom surface, said heat spreader contacting said battery cells in said row alternately on said top surface and said bottom surface.
6 . The battery pack of claim 1 wherein said heat spreader includes a plurality of semi-circular portions in cross-section, each said semi-circular portion receiving a portion of the radial outer surface of each battery cell in said row.
7 . The battery pack of claim 1 wherein a leg extends perpendicular to said row at opposed ends of said heat spreader.
8 . The battery pack of claim 7 wherein said heat spreader further comprises a top sheet that extends between said legs and forms an interior channel.
9 . A battery pack comprising:
a plurality of cylindrical battery cells having a longitudinal length and a radial outer surface; and
a plurality of heat spreaders comprised of a graphite sheet, each said cylindrical battery being positioned in a heat spreader, said heat spreader extending at least substantially the entire longitudinal length of said battery cell and contacting at least a portion of said radial outer surface.
10 . The battery pack of claim 9 wherein said heat spreaders are piscine shaped in cross-section.
11 . The battery pack of claim 9 wherein said heat spreaders are cruciform shaped in cross-section.
12 . The battery pack of claim 9 wherein said heat spreaders each include a square outer wall and a plurality of legs extending inwardly, at least one of said legs contacting said radial outer surface of said battery cell.
13 . The battery pack of claim 9 wherein said heat spreaders having a corrugated cross-section.
14 . The battery pack of claim 9 wherein said heat spreaders are eyelid shaped in cross-section.
15 . The battery pack of claim 9 wherein said heat spreaders are teardrop shaped in cross-section.
16 . The battery pack of claim 9 wherein said heat spreaders are U-shaped in cross-section.
17 . The battery pack of claim 9 wherein a longitudinally extending channel is formed between each said heat spreader and an associated battery cell.
18 . The battery pack of claim 9 wherein said graphite sheet comprises compressed expanded natural graphite.
19 . The battery pack of claim 9 wherein said graphite sheet comprises resin impregnated compressed natural graphite sheet.
20 . The battery pack of claim 9 wherein said graphite sheet comprises graphitized polyimide sheet.