Method and apparatus for maintaining cell wall integrity during thermal runaway using an outer layer of intumescent material
AssigneeTesla Motors, Inc.
InventorsWeston Arthur Hermann, Vineet Haresh Mehta, Alex Prilutsky
Life of this patent
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Abstract
A method and apparatus is provided in which a layer of an intumescent material surrounds the casing of a battery, the layer helping to prevent the formation of perforations in the battery casing during a thermal runaway event and, if a perforation is formed, inhibiting the flow of hot, pressurized gas from within the battery. A sleeve, surrounding the cell, may be used to contain the intumescent material during the thermal event.
Claims19
A battery assembly, comprising:
- a battery, said battery comprising:
- a cell case having an outer surface, a first end and a second end, wherein said first end is closed by a cell case bottom, and wherein said second end is comprised of a central open portion;
- an electrode assembly contained within said cell case, wherein a first electrode of said electrode assembly is electrically connected to said cell case;
- and
- a cap assembly mounted to said cell case, said cap assembly closing said central open portion of said second end, wherein said cap assembly further comprises a battery terminal electrically isolated from said cell case and electrically connected to a second electrode of said electrode assembly;
- and
- a layer of an intumescent material surrounding said outer surface of said cell case.
A method of preventing the formation of a perforation in an outer surface of a battery case during a thermal runaway event, the method comprising the step of covering said outer surface of said battery case in a layer of an intumescent material, wherein said covering step is performed prior to said thermal runaway event, and wherein said intumescent material expands during said thermal runaway event.
Dependencies are inferred from the claim text.