Notice of Pre-AIA or AIA Status
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Status of Claims
Applicant’s amendment and arguments filed 11/13/2025 have been fully considered. Claim(s) 1 is/are amended; and claim(s) 6-8 has/have been canceled. Claims 1, 3-5, 9-17 are pending review in this Office action. Examiner affirms that the original disclosure provides adequate support for the amendment.
Upon considering said amendment and arguments, the previous objection and rejections under 35 U.S.C. 102 and 35 U.S.C. 103 set forth in the Office action mailed 08/13/2025 has/have been withdrawn. Applicant’s amendment necessitated the new grounds of rejection below.
Claim Rejections - 35 USC § 103
The text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office action.
Claim(s) 1, 3-5 and 11-17 is/are rejected under 35 U.S.C. 103 as being unpatentable over Maeda et al. (JP2009004362A cited in 08/13/2025 Office action, US20080292950A1 cited as English equivalent) in view of Welke et al. DE102015007408A1 (see attached machine translation), Nakajima et al. JP2018206605A (cited with machine translation, 08/13/2025 Office action), evidenced by Bamberger Polymers (Shrink Considerations, copy in 08/13/2025 Office action).
Regarding claim(s) 1, Maeda discloses a battery module, comprising a cell stack including a plurality of battery cells (22) ([0136-0138], FIG. 21).
In an embodiment, Maeda provides composites (51, 23) between each battery cell (22) ([0136], FIG. 21), where, in the event of a battery thermal runaway, the composites open to discharge a filling agent and become thermally insulative to prevent heat spreading between cells ([0015]). While Maeda fails to disclose a battery module structure including the plurality of battery cells divided into cell groups or further indicate a plurality of single layers of a first material disposed between the cell groups and a single composite interposed between neighboring cells at a center of the cell stack, it is known in the art that Maeda’s configuration of cells and composites may be suitably rearranged to read on the claimed structure of cells, single layers, and composite without change to the composites’ functionality.
Specifically, Welke, directed to an analogous battery module using composites (3, “thermal insulation element”) which similarly function to thermally decouple (i.e., isolate) overheated cells (1) from the cell stack (Welke [0058-0060], FIGs. 11-14), teaches a suitability of using composites in both the aforementioned configuration corresponding to Maeda’s battery module (see Welke FIG. 12, Maeda FIG. 7) and in a configuration with composites (3) between cell groups (2, “cell module”) with a plurality of single layers of a first material (13, “cell holders”) disposed between the cell groups (Welke [0058], FIG. 11).
Consequently, it would be obvious before the effective filing date of the instant application for one having ordinary skill in the art to modify the structure of cells in Maeda’s battery module and cell stack to divide the battery cells into cell groups and provide a plurality of single layers of a first material, each of the plurality of single layers of the first material disposed between the cell groups as taught by Welke (MPEP 2144.04 IV. B). Such a modification would be made with a reasonable expectation of success, as Welke teaches Maeda’s disclosed configuration and the claimed configuration as being functionally equivalent in allowing operation of the composites to thermally isolate a cell(s) undergoing thermal runaway.
Welke further indicates a suitability of using as few as two cell groups (“cell modules”) in the battery module ([0017]) and both Maeda and Welke indicate as few as one composite may be suitably used in the battery module (Welke [0017], Maeda [0014]). Such a configuration would result in the structure below (see Annotated Welke FIG. 11, below) wherein a single composite (3) is interposed between neighboring battery cells (1) of the plurality of battery cells, the single composite disposed at a center of the cell stack in a stacking direction (horizontal to page):
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Annotated Welke FIG. 11
As such, it would likewise be obvious to modify the layout of the cell groups and composites in modified Maeda’s battery module to provide a configuration with a single composite interposed between neighboring battery cells of the plurality of battery cells, the single composite disposed at a center of the cell stack in a stacking direction as taught by Welke (MPEP 2144.04 IV. B). Such a modification would be made with a reasonable expectation of success, as Welke teaches that the functionality of the composite(s) is maintained in configurations using as few as two cell groups and one composite.
Maeda further discloses a module case (33, “drip pan”) configured to accommodate the cell stack (Maeda [0121]).
Maeda’s composite (51, 23) includes a spacer (51), the spacer being formed of a resin (e.g. polypropylene) (Maeda [0045-0047]) and having a structure of two plates joined on either side of the composite ([0111] showing the plate joining process, FIG. 8). A heat conductive material layer (23) adheres to the surface of the composite (51) (i.e., the resin plates) and is configured to be compressed by volume expansion of the plurality of battery cells caused by swelling (i.e., during charge-discharge operations) ([0070], FIG. 21). The sets of resin plates and heat conductive material layers on each side of the composite are collectively recognized as the first members, where the pair of a pair of first members are configured to be compressed by a volume expansion of the plurality of battery cells caused by swelling ([0070]), and comprising a same material (the resin, the heat conductive material).
Maeda discloses a second member (“filling agent”) filled into the composite, consequently being interposed between the pair of first members in a state in direct contact with the pair of first members ([0045]), and being configured to block heat transfer between the neighboring battery cells ([0015]).
Maeda teaches the forming the resin of the first members out of polypropylene due to its low cost and good processability ([0045]). Polypropylene has a melting point of approximately 150-180 °C ([0047]) and inherently undergoes shrinkage when exposed to high temperatures (Bamberger Polymers, sec. “Additional Factors”), and is consequently configured to be damaged (through melting) or shrink and configured to have a reduced thickness when a temperature reaches a reference temperature ranging from about 100-300 °C as claimed.
As a method of fire suppression, Maeda’s second member (“filling agent”) is configured to spread outside the composite to extinguish the fire, leaving a thermally insulative air-filled cavity in the composite ([0015]). While Maeda proposes use of using a rigid composite in a different embodiment to maintain an insulative gap between cells ([0165]), Maeda fails to disclose the use of a second member configured to block heat transfer between the pair of first members without being damaged at 100-300 °C for this purpose of maintaining insulation.
Nakajima, in a similar field of endeavor of methods of preventing thermal runaway of battery cells (Nakajima [0007-0008]), teaches a second member (2, “heat absorbing material layer”) comprising an intumescent material which similarly expands (i.e., intumesces) to block fire and heat ([0040]) and forms a residue with a desired amount of strength and thermal insulation, stabilizing fire prevention performance ([0052]). Nakajima teaches a finite list of suitable intumescent materials, a non-limiting example being thermally expandable graphite ([0050]) which undergoes expansion in a range of 100 to 300 °C ([0060]).
Consequently, in seeking to improve the ability of modified Maeda’s composite to maintain an insulative gap between cells and stabilize fire prevention performance, it would be obvious before the effective filing date of the instant application for one having ordinary skill in the art to provide modified Maeda’s second composite with an intumescent material as taught by Nakajima; it would also be obvious to select thermally expandable graphite as this intumescent material from the finite list of suitable materials taught by Nakajima (MPEP 2143 I. E). Such a modification would be made with a reasonable expectation of success, as Nakajima’s thermally expandable graphite similarly spreads and expands to extinguish fires like Maeda’s filling agent as the second member, and because Maeda envisions the use of a rigid structure in the composite to maintain an insulative gap between cells in an embodiment, this effect being provided by the strong, thermally insulative residue of Nakajima’s thermally expandable graphite.
In making the above modification, a skilled artisan would form modified Maeda’s second member configured to block heat transfer between the pair of first members without being damaged even when the temperature reaches the reference temperature ranging from about 100 °C to 300°C as claimed.
Regarding claim(s) 3, modified Maeda discloses the battery module according to claim 1. Modified Maeda’s second member undergoes expansion at the reference temperature (100-300 °C, see claim 1) (Nakajima [0060]) and modified Maeda’s first members are damaged or shrunk within a similar elevated temperature range (Maeda [0047], Bamberger Polymers, sec. “Additional Factors”). Consequently, Modified Maeda’s second member, which is provided in direct contact between the pair of first members (see claim 1), would fill a space created by shrinkage of the pair of first members during this expansion.
Regarding claim(s) 4, modified Maeda discloses the battery module according to claim 3. While Maeda does not explicitly specify an expansion rate of the second member, Nakajima teaches optimizing the expansion ratio within a preferable range of 3-30 times in a thickness direction to provide a sufficient balance of insulating performance and material strength (Nakajima [0052]).
Consequently, in seeking the above balance of material properties, it would be obvious before the effective filing date of the instant application for one having ordinary skill in the art to optimize the second member expansion rate within a range of 3-30 times in a thickness direction at the reference temperature or above, overlapping with a portion of the claimed range (5-50 times, claim 4) between 5-30 times such that a skilled artisan would have selected within the overlap through routine optimization under Nakajima’s teaching with a reasonable expectation of success, as modified Maeda’s secondary member necessarily comprises at least some measure of expansion rate in a thickness direction at/above the reference temperature (MPEP 2144.05 II).
Regarding claim(s) 5, modified Maeda discloses the battery module according to claim 1, wherein each of the plurality of battery cells are packaged in a soft outer casing (Maeda [0081]), recognized as a pouch-type battery cell.
Regarding claim(s) 11, modified Maeda discloses the battery module according to claim 1. Maeda’s first members comprise polypropylene ([0045]), which is noted as inherently undergoing shrinkage when exposed to high temperatures (Bamberger Polymers, sec. “Additional Factors”); conversely, Maeda’s second member (“filling agent”) is configured to expand and spread outside the composite in response to excessive heat ([0015]). A plain meaning of a coefficient of thermal expansion as defined in the art is “a material property that is indicative of the extent to which a material expands upon heating” (C-Therm, “What is Coefficient of Thermal Expansion (CTE)?”); consequently, a coefficient of thermal expansion of the second member which expands in response to excess heat is inherently less than that of the first members, which contract in response to excess heat.
Regarding claim(s) 12, modified Maeda discloses the battery module according to claim 1. Maeda discloses a finite list of filling agents as the second member including fire extinguishing agents such as ammonium dihydrogen phosphate (a solid), non-flammable liquids and gases, and non-flammable powder materials (Maeda [0043]). Nakajima’s thermal expandable graphite is recognized as a non-flammable powder material, a powder being a type of solid (Nakajima [0052]).
As a skilled artisan would necessarily select at some type of filing agent as the second member, with modified Maeda’s finite set of filling agents recognized as predictable solutions within the ambit of a skilled artisan, it would be obvious for one having ordinary skill in the art to routinely explore selection at least one or both of the suitable solid filling agents (ammonium dihydrogen phosphate, non-flammable powder material) disclosed by modified Maeda and form a solid second member with a reasonable expectation of success (MPEP 2143 I. E).
Regarding claim(s) 13, 14, modified Maeda discloses the battery module according to claim 1, wherein the pair of first members comprise polypropylene (Maeda [0045]), which undergoes shrinkage when exposed to high temperatures (Bamberger Polymers, section “Additional Factors”); as at least some amount of the first member extends in the thickness direction, modified Maeda’s pair of first members would inherently undergo a reduction of thickness at elevated temperatures (claim 13).
Furthermore, Maeda notes the melting of polypropylene at 150-180 °C (Maeda [0047]). While Bamberger Polymers fails to numerically indicate the high temperatures which result in additional shrinkage of polypropylene, given that Bamberger Polymers is primarily concerned with shrinkage and not melting of the polypropylene at these elevated temperatures, a skilled artisan would recognize this shrinkage occurs below the melting point at 150-180 °C. As such, the first members would necessarily have a reduction of thickness at any temperature beyond this inherent shrinkage temperature, with 300°C being past this temperature (claim 14)
Regarding claim(s) 15, modified Maeda discloses the battery module according to claim 1. Maeda’s pair of first members, which includes heat conductive material layers, comprises a high coefficient of heat transfer (Maeda [0075-0076]) which is necessarily higher than a coefficient of heat transfer of the second member comprising the filling agent which is noted as being insulative to heat ([0015]).
Regarding claim(s) 16, 17, modified Maeda discloses a battery pack (“power source”, [0172]) comprising the battery module according to claim 1 and an automobile (i.e., a vehicle) comprising this battery pack ([0172]).
Claim 9 is rejected under 35 U.S.C. 103 as being unpatentable over Maeda (JP2009004362A, see US20080292950A1) in view of Welke (DE102015007408A1)), Nakajima (JP2018206605A), evidenced by Bamberger Polymers as applied to claim 1, further in view of Epplix (Epplix Expanded Polypropylene, copy in 08/13/2025 Office action)
Regarding claim(s) 9, modified Maeda discloses the battery module according to claim 1. While Maeda discloses the inclusion of polypropylene in the pair of first members to improve processability (Maeda [0045]) and envisions considerations of decreasing composite weight (Maeda [0016]) and protecting the battery module against mechanical impacts ([0139]), Maeda does not further specify the polypropylene is present as expanded polypropylene (EPP) in the first member.
Epplix teaches material properties of a commercially available EPP material, noting that EPP has a particularly high strength-to-weight ratio to help reduce overall weight (Epplix pp. 1-2, see section “Strong”), and provides protection from shocks (pp. 2 sec. “Shock-absorbent”) while being easy to process (pp. 4 sec. “Epplix manufactures […]”).
As such, in seeking the above advantages taught by Epplix, it would be obvious before the effective filing date of the instant application for one having ordinary skill in the art to select expanded polypropylene as a form of polypropylene forming modified Maeda’s pair of first members. Such a modification would be made with a reasonable expectation of success as Maeda discloses a desirability of reducing the battery module weight and providing shock absorption and ease of manufacturing, and envisions a general suitability of using polypropylene in the pair of first members.
Claim 10 is rejected under 35 U.S.C. 103 as being unpatentable over Maeda (JP2009004362A, see US20080292950A1) in view of Welke (DE102015007408A1)), Nakajima (JP2018206605A), evidenced by Bamberger Polymers as applied to claim 1, further in view of Epplix, and evidenced by Arpro (SDS - ARPRO Expanded Polypropylene (EPP), copy in 08/13/2025 Office action) and Asbury Carbons (Expandable Flake Graphite, copy in 08/13/2025 Office action).
Regarding claim(s) 10, modified Maeda discloses the battery module according to claim 1. While Maeda discloses the inclusion of polypropylene in the pair of first members to improve processability ([0045]) and envisions considerations of decreasing composite weight (Maeda [0016]) and protecting the battery module against mechanical impacts ([0139]), Maeda does not further specify the polypropylene is present as expanded polypropylene (EPP) in the first member.
Epplix teaches material properties of a commercially available EPP material, noting that EPP has a particularly high strength-to-weight ratio to help reduce overall weight (Epplix pp. 1-2, see section “Strong”), and provides protection from shocks (pp. 2 sec. “Shock-absorbent”) while being easy to process (pp. 4 sec. “Epplix manufactures […]”).
As such, in seeking the above advantages taught by Epplix, it would be obvious before the effective filing date of the instant application for one having ordinary skill in the art to select expanded polypropylene as a form of polypropylene forming modified Maeda’s pair of first members. Such a modification would be made with a reasonable expectation of success as Maeda discloses a desirability of reducing the battery module weight and providing shock absorption and ease of manufacturing, and envisions a general suitability of using polypropylene in the pair of first members.
As a result of this modification, the density of the pair of first members would further decrease below that of the second member. Arpro indicates a density of EPP is typically within 0.01-0.225 g/cm3 (Arpro pp. 3 section “Physical and Chemical Properties”), significantly lower than the density of second member components, such as expanded graphite having a density of about 1 g/cm3 (Asbury Carbons pp. 8 sec. “Definition of the Expansion/Exfoliation ratio”); as such, performing the above modification would inherently result in a battery module wherein the second member has a higher density than the pair of first members.
Response to Arguments
Applicant amendments to claim 1 overcome the objections to this claim in the Office action filed 08/13/2025.
Applicant’s arguments with respect to the rejection of amended claim 1 under 35 U.S.C. 102 in view of Nakajima (Remarks pp. 5-6) or 35 U.S.C. 103 in view of Maeda, Nakajima, Epplix, Sugita (US20120028107A1), Syed (US20160336627A1) (remarks pp. 5-8) have been considered but are moot since Applicant's amendment necessitated a different interpretation of Maeda and/or Nakajima as laid out in the rejections of record, or are moot as the claim amendment has necessitated new grounds of rejection under new prior art discussed above and no longer rely on the prior art discussed in argument.
Conclusion
Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a).
A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action.
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/E.C./Examiner, Art Unit 1751
/JONATHAN G LEONG/Supervisory Patent Examiner, Art Unit 1751 2/19/2026