Manufacturing methods for battery cell support assembly with integrated thermal runaway mitigation
A method for constructing a cell support assembly with thermal runaway mitigation for a multi-cell rechargeable energy storage system (RESS) include forming a cell holder configured to support the RESS battery cells. The cell holder has a holder body defining a plurality of apertures arranged in rows, such that each aperture is configured to align and be in fluid communication with a cell vent of one of the RESS battery cells. Individual embodiments of the method also include various techniques of arranging a plurality of thermal-barrier strips and potting elements to align with apertures of the cell holder body and adhering the thermal-barrier strips to the potting elements and to the cell holder. The resultant cell support assembly operates to channel thermal runaway energy away from the affected battery cell(s) and out of the RESS enclosure without triggering thermal runaway in adjacent cells.
1 . A method of constructing a cell support assembly with thermal runaway mitigation for a multi-cell rechargeable energy storage system (RESS) having a plurality of battery cells with respective cell vents for expelling gases, the method comprising:
forming a cell holder, wherein the cell holder is configured to support the plurality of battery cells and has a holder body defining a plurality of apertures arranged in rows, and wherein each aperture is configured to align and be in fluid communication with the cell vent of one of the plurality of battery cells;
arranging the formed cell holder inside a cavity between an upper mold and a lower mold, wherein the cavity defines a first region configured to accommodate the formed cell holder and a second region configured to accommodate a plurality of potting elements, such that each potting element is arranged in one of the plurality of apertures;
introducing a potting element material into the second region of the cavity;
curing the potting element material inside the second region of the cavity to incorporate the plurality of potting elements into the formed cell holder, such that each potting element is arranged in one of the plurality of apertures and thereby forms a support sub-assembly;
separating the upper and lower molds to remove the formed support sub-assembly;
adhering a plurality of thermal-barrier strips to the formed support sub-assembly to construct the cell support assembly, wherein:
each thermal-barrier strip extends parallel to a respective row of apertures, such that each potting element is arranged between a respective battery cell and the corresponding thermal-barrier strip and configured to adhere to the battery cell and to the corresponding thermal-barrier strip to maintain position of the battery cell on the formed cell holder; and
each thermal-barrier strip is configured to thermally insulate corresponding battery cells from gases expelled by neighboring battery cells during a thermal runaway.
2 . The method of claim 1 , wherein introducing the potting element material into the second region of the cavity includes forming each of the potting elements from a non-self-leveling paste.
3 . The method of claim 2 , wherein the non-self-leveling paste includes additives configured to match a thermal expansion coefficient of the potting elements with a coefficient of thermal expansion of the cell holder.
4 . The method of claim 1 , wherein each of the potting elements includes a flame-retardant material.
5 . The method of claim 1 , wherein forming the cell holder includes constructing the cell holder from a glass-filled nylon.
6 . The method of claim 1 , wherein each of the thermal-barrier strips has folded sides extending perpendicular to a respective row of apertures.
7 . The method of claim 1 , wherein adhering the plurality of thermal-barrier strips to the formed support sub-assembly is achieved via an adhesive coating one side of each respective thermal-barrier strip.