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 .
Response to Amendment
The amendment filed November 19, 2025 has been entered but does not place the application in condition for allowance. Claims 1, 4-20, 22-24 remain pending in the application, with claims 16-20 withdrawn as a result of an election made February 18, 2025.
Claim Rejections - 35 USC § 103
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
The factual inquiries for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows:
1. Determining the scope and contents of the prior art.
2. Ascertaining the differences between the prior art and the claims at issue.
3. Resolving the level of ordinary skill in the pertinent art.
4. Considering objective evidence present in the application indicating obviousness or nonobviousness.
This application currently names joint inventors. In considering patentability of the claims the examiner presumes that the subject matter of the various claims was commonly owned as of the effective filing date of the claimed invention(s) absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and effective filing dates of each claim that was not commonly owned as of the effective filing date of the later invention in order for the examiner to consider the applicability of 35 U.S.C. 102(b)(2)(C) for any potential 35 U.S.C. 102(a)(2) prior art against the later invention.
Claims 1, 9-14, 22-24 are rejected under 35 U.S.C. 103 as being unpatentable over Sato et al (JP2019216033A) in view of Gogotsi et al (WO 2020242982 A1). Further evidence is provided by Li et al “Flexible, High-Wettability and Fire-Resistant Separators Based on Hydroxyapatite Nanowires for Advanced Lithium-Ion Batteries” Adv. Mater. 2017, 29, 1703548, and Zeng et al “Flame-Retardant Bilayer Separator with Multifaceted van der Waals Interaction for Lithium-Ion Batteries” ACS Applied Materials & Interfaces 2019 11 (29), 26402-26411.
Regarding claim 1, Sato teaches ([0007]) a separator for a battery comprising a porous material including:
a poly (vinylidene fluoride-co-hexafluoropropylene) (PVHF)-hydroxyapatite (HAP) layer
(machine translation [0007] and [0055]: a heat-resistant porous layer provided on both surfaces of a porous substrate, wherein the layer includes a polymer binder resin that can be a copolymer containing vinylidene fluoride monomer units and hexafluoropropylene monomer units, e.g., PVDF-HFP or PVHF, and first inorganic particles made of apatite that can be hydroxyapatite [0020]; the composite material of the heat-resistant porous layer on both surfaces of a porous substrate reads on the claimed poly (vinylidene fluoride-co-hexafluoropropylene) (PVHF)-hydroxyapatite (HAP) layer)
having first and second sides
(the two exposed surfaces of the composite material facing outward correspond to the first and second sides),
wherein the PVHF-HAP layer has a hierarchical cross-linked structure of a network of HAP nanowires wrapped by bulk PVHF polymer chains such that the HAP nanowires are separated by the bulk PVHF polymer chains
(HAP is taught as having submicron sizes in [0007] and can be needle-like in shape as taught in [0064]; therefore, its form is structurally equivalent to nanowires; [0021]: the HAP is taught as making contact points with each other and the binder resin thereby reading on a network of HAP nanowires)
(According to the instant spec [00119], hydrogen bonding and van der Waals interactions can form a hierarchical cross-linked structure; Sato’s taught process of forming the heat-resistant porous layer by first dissolving HAP and PVHF in solution and stirring in [0128]-[0131], and subsequently solidifying the coating layer is presumed to facilitate contact between the components; evidentiary references Li et al, p2 right col, para 3, and Zeng et al, p26408 left col, para 2 lines 16-21, teach that HAP and PVHF can each engage in hydrogen bonding and van der Waal bonding to assemble into hierarchical structures, i.e. form a hierarchical cross-linked structure; additionally, it would be obvious to expect some degree of cross-linking interactions between HAP and PVHF polymer chains would displace original bonding between HAP nanowires and result in HAP nanowires from being separated by PVHF polymer chains; the PVHF polymer chains are constituents of the bulk PVHF resin material and read on the limitation of bulk PVHF polymer chains. As chain-like structures, the PVHF would naturally wrap around the HAP nanowires as a result of the cross-linking interactions).
Sato does not teach the Ti3C2Tx MXene nanosheets nor teaches each of the first and second sides being coated by a Ti3C2Tx MXene nanosheet of the Ti3C2Tx MXene nanosheets.
Gogotsi is relied upon to teach a composite polymer framework separator ([0051] and [0054]) that is coated on both sides with a MXene nanosheet, and discloses that the MXene can be Ti3C2Tx ([0028] lines 1-3, [0029]). Gogotsi further teaches use of the MXene nanosheet to restrain the growth of lithium dendrites which can disrupt battery separators and pose safety risks ([0003] and [0005]). Accordingly, it would have been obvious to one of ordinary skill in the art at the time the invention was filed to have modified Sato’s separator by coating the first and second sides, which are of the same PVHF-HAP layer that is a composite material, with MXene nanosheets as taught by Gogotsi for the advantages of restraining the growth of lithium dendrites and improved battery safety.
Furthermore, even if the first and second sides are respectively interpreted as the outer-facing and inner-facing sides of a single PVHF-HAP coating, the limitation of “the first and second sides of the same PVHF-HAP layer each coated by a Ti3C2Tx MXene nanosheet” (Claim 1: lines 4-5) does not require that the MXene nanosheet be directly coated on each the first and second sides. Consequently, application of a MXene nanosheet on both outer-facing sides of the PVHF-HAP layer would read on coating of the composite material and include coating of its inner-facing (i.e., second) sides.
Regarding Claim 9, the combination above teaches the separator according to claim 1, and Gogotsi further teaches that the Ti3C2Tx MXene nanosheet can have a thickness of about 50 nm to 5 microns, which lies within the claimed range ([0037] lines 6-7). In the case where the claimed ranges "overlap or lie inside ranges disclosed by the prior art" a prima facie case of obviousness exists. See In re Wertheim, 541 F.2d 257, 191 USPQ 90 (CCPA 1976); In re Woodruff, 919 F.2d 1575, 16 USPQ2d 1934 (Fed. Cir. 1990) (See MPEP § 2144.05).
Regarding Claim 10, the combination above teaches the separator of claim 1, and Sato further teaches the PVHF-HAP layer is in the form of a membrane
(Sato [0059] discloses the PVHF-HAP layer is the layer that is adhered to the electrodes and its properties enable it to withstand the heat press treatment for bonding the separator to the electrodes, thereby acting as a physical heat barrier between the porous substrate layer and the electrodes; it is also a thin layer [0074], therefore it acts as a thin barrier material and thereby reads on being in the form of a membrane).
Regarding Claim 11, the combination above teaches the separator of claim 1, and Sato also teaches ([0116]) a battery comprising of the separator.
Regarding Claim 12, the combination above teaches the separator of claim 1, and Sato further teaches the battery is a lithium ion battery having an anode and a cathode ([0108]).
Regarding Claim 13, the combination above teaches the separator of claim 12, and Sato further teaches ([0111]) the cathode material can be LiFePO4, LiCoO2, or LiMn2O4.
Regarding Claim 14, the combination above teaches the separator of claim 12, and Sato teaches the anode material can be silicon alloy, aluminum alloy, a tin alloy, lithium foil ([0113]) or graphite ([0127] lines 8-9).
Regarding Claim 22, the combination above teaches the separator of claim 1, and Sato further teaches the heat-resistant porous layer, which is a part of the claimed porous material, has a pore size of 10 nm ([0078]), which overlaps with the claimed range for a pore size of the porous material.
Regarding Claim 23, the combination above teaches the separator of claim 1, and the combination also teaches the claimed porous material as pointed out in addressing the limitations of claim 1.
Regarding Claim 24, the combination above teaches the separator of claim 1, and Sato further teaches the weight % of the polymer binder resin (e.g., PVHF) in the coating liquid can range 1% - 20% and the weight % of the inorganic particle (e.g., HAP) in the coating liquid can range 2% - 50% ([0100]), leading to a PVHF:HAP weight ratio of 0.02 to 10, which overlaps with the claimed range. The PVHF polymer chains are constituents of the bulk PVHF resin and read on the limitation of bulk PVHF polymer chains.
Claims 4 and 5 are rejected under 35 U.S.C. 103 as being unpatentable over Sato in view of Gogotsi and evidentiary references Li and Zeng as applied to claim 1 above, and in further view of Zhang et al “Synthesis of two-dimensional Ti3C2Tx MXene using HCl+LiF etchant: Enhanced exfoliation and delamination,” Journal of Alloys and Compounds 695 (2017) 818-826.
Regarding Claim 4, the combination above teaches the separator of claim 1 but is silent about the characteristics of the MXene nanosheet.
Zhang teaches a synthesis process that produces a plurality of flakes of Ti3C2Tx MXene (p 819, right column, paragraph 4 (Section 2.4), lines 4-6) within the claimed range of average diameter that can be used in lithium-ion batteries (p 819, left column, paragraph 2: lines 14-17). Zhang teaches (Figure 7c) that the flakes have a diameter of about 200 nm based on TEM measurements; Annotated Figure 7c of Zhang is included below that indicates the diameter. The value of about 200 nm or 0.2 µm is within the claimed range of about 0.1 µm to about 750 µm. In the case where the claimed ranges "overlap or lie inside ranges disclosed by the prior art" a prima facie case of obviousness exists. See In re Wertheim, 541 F.2d 257, 191 USPQ 90 (CCPA 1976); In re Woodruff, 919 F.2d 1575, 16 USPQ2d 1934 (Fed. Cir. 1990) (See MPEP § 2144.05).
Zhang further discloses that the MXene flakes offer advantages such as the uncommon combination of hydrophilicity and excellent conductivity (p 819, left column, paragraph 1: lines 12-14).
Annotated Zhang Figure 7c
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It would have been obvious at the time the invention was filed to have synthesized the MXene nanosheet of modified Sato with Zhang’s method to produce a plurality of flakes within the claimed diameter range to take advantage of its unique combination of hydrophilicity and excellent conductivity.
Regarding Claim 5, the combination above teaches the separator of claim 1 but is silent about the characteristics of the MXene nanosheet.
Zhang teaches a synthesis process that produces a plurality of flakes of Ti3C2Tx MXene (p 819, right column, paragraph 4 (Section 2.4), lines 4-6) that can be used in lithium-ion batteries (p 819, left column, paragraph 2: lines 14-17) and also teaches that the produced flakes (Figure 7e-7f including captions) have a thickness of about 1 nm. Therefore, the taught thickness is within the claimed range for the average thickness. In the case where the claimed ranges "overlap or lie inside ranges disclosed by the prior art" a prima facie case of obviousness exists. See In re Wertheim, 541 F.2d 257, 191 USPQ 90 (CCPA 1976); In re Woodruff, 919 F.2d 1575, 16 USPQ2d 1934 (Fed. Cir. 1990). (See MPEP § 2144.05).
Zhang further discloses that the MXene flakes offer advantages such as the uncommon combination of hydrophilicity, and excellent conductivity (p 819, left column, paragraph 1: lines 12-14).
It would have been obvious at the time the invention was filed to have synthesized the MXene nanosheet of modified Sato with Zhang’s method to produce a plurality of flakes within the claimed diameter range to take advantage of its unique combination of hydrophilicity and excellent conductivity.
Claim 6 is rejected under 35 U.S.C. 103 as being unpatentable over Sato in view of Gogotsi and evidentiary references Li and Zeng as applied to claim 1 above, and further in view of Rao et al “Assembly of MXene/PP Separator and Its Enhancement for Ni-Rich LiNi0.8Co0.1Mn0.1O2 Electrochemical Performance,” Polymers 2020, 12, 2192, and evidentiary references RESTCO “Types of Plastic,” 03 Dec 2021, and Bahloul et al “Study of The Porosity and Density of Synthetically Produced Hydroxyapatite,” SAJ Biotechnol 6: 104, 2020.
Regarding Claim 6, the combination above teaches the separator of claim 1, and Sato teaches a composite separator of a porous substrate such as polypropylene ([0027]) of 6 µm ([0037]) and porosity 20% ([0039]), and a heat-resistant layer coating both sides of the porous substrate of total 10 µm ([0074]) and porosity 30% ([0077]). Sato also teaches the weight % of the polymer binder resin (e.g., PVHF) in the coating liquid can be 20% and the weight % of the inorganic particle (e.g., HAP) in the coating liquid can be 13.3% ([0100]), leading to a PVHF:HAP ratio of about 60:40 in the resulting PVHF-HAP layer.
The combination is silent regarding the loading of the Ti3C2Tx MXene nanosheet and the weight of the composite separator.
Rao is relied upon to teach application of single-side loading of 0.5mg MXene coating on a 16 mm diameter polymer substrate, with the advantage of a relatively simple, cheap, and easy-to-obtain strategy to enhance the performance of lithium ion batteries (Fig. 1; p3 para 3 lines 1-4). It would have been obvious to one of ordinary skill in the art at the time the invention was filed to have modified the modified separator of Sato to use the application protocol taught by Rao to coat 0.5 mg per side on both the first and second sides for the advantages of a relatively simple, cheap, and easy-to-obtain strategy to enhance the performance of lithium ion batteries.
Within the modified separator of Sato, the mass of a polymer-ceramic layer consisting of PVHF and HAP would be area*thickness*weighted density of the PVHF-HAP layer*(100% -porosity), or (π*(16 mm)2/4)*(10 microns) (0.20*density of HAP + 0.80*density of PVHF)*(70% solid), wherein density of HAP is 3.1 g/cm3 (Bahloul, p4 para 4) and density of PVHF is 1.77 g/cm3 (RESTCO). The resulting mass of the polymer-ceramic layer would be 0.0032 g, or 3.2 mg. The mass of the polypropylene (PP) porous substrate is similarly calculated as area*thickness*density of PP*porosity, or (π*(16 mm)2/4)*(6 microns) (density of PP)*(80% porosity), wherein density of PP is 0.90 g/cm3 (RESTCO). The resulting mass of the PP layer would be 0.00087 g, or 0.87 mg. The total mass of the composite separator would be the sum of the mass of the PVHF-HAP layer and the mass of the PP layer, or 3.2 mg + 0.87 mg = 4.1 mg. Accordingly, the Ti3C2Tx MXene has the weight percentage of 1 mg/(1 + 4.1) mg, or about 20% by weight Ti3C2Tx MXene nanosheet.
Claims 7 - 8 are rejected under 35 U.S.C. 103 as being unpatentable over Sato in view of Gogotsi and evidentiary references Li and Zeng as applied to claim 1 above, and further in view of Yushin et al (US 20190198837 A1).
Regarding Claim 7, the combination above teaches the separator of claim 1, but does not specify a percentage range for the PVHF framework in the combined separator.
In the same field of endeavor, Yushin discloses that the fraction of polymer in ceramic fiber-polymer composite separators for batteries depends on the application, preparation conditions, and the desired separator membrane properties ([0130] lines 26-32; [0037] lines 1-4), wherein such properties include membrane permeability and porosity, flexibility, and/or processibility ([0130] lines 7-11, 32-36); therefore, the fraction of polymer is a result-effective variable. It would have been obvious to one of ordinary skill in the art at the time the invention was filed to have adjusted the weight percentage of the poly(vinylidene fluoride-co-hexafluoropropylene) polymer framework within the modified separator of modified Sato to the claimed range as taught by Yushin to achieve the desired separator membrane properties. Additionally, Yushin teaches that the polymer framework of the ceramic-polymer composite membrane ranges from 0.0 wt% to 80.0 wt%, or to about 80% by weight, which overlaps with the claimed range ([0130] lines 26-32). In the case where the claimed ranges "overlap or lie inside ranges disclosed by the prior art" a prima facie case of obviousness exists. In re Wertheim, 541 F.2d 257, 191 USPQ 90 (CCPA 1976); In re Woodruff, 919 F.2d 1575, 16 USPQ2d 1934 (Fed. Cir. 1990); see MPEP 2144.05, I.
Regarding Claim 8, the combination above teaches the separator of claim 1, but does not specify a percentage range for HAP nanowires in the combined separator.
In the same field of endeavor, Yushin discloses that a higher fraction of the small ceramic fiber in ceramic fiber-polymer composite separators for batteries may lead to better electrolyte wetting, higher average dielectric constant, higher mechanical strength, and/or better thermal stability ([0130] lines 11-18; [0037] lines 1-4); therefore, the fraction of ceramic fiber is a result-effective variable. It would have been obvious to one of ordinary skill in the art at the time the invention was filed to have adjusted the weight percentage of the ceramic HAP nanowires within the separator of modified Sato to the claimed range as taught by Yushin to achieve the desired separator membrane properties such as better electrolyte wetting, higher average dielectric constant, higher mechanical strength, and/or better thermal stability.
Yushin further teaches that the relative fraction of small ceramic fibers in the polymer-ceramic composite membrane may range from around 5 wt. % to around 99.9 wt. % ([0131] lines 25-28), which overlaps with the claimed range. In the case where the claimed ranges "overlap or lie inside ranges disclosed by the prior art" a prima facie case of obviousness exists. In re Wertheim, 541 F.2d 257, 191 USPQ 90 (CCPA 1976); In re Woodruff, 919 F.2d 1575, 16 USPQ2d 1934 (Fed. Cir. 1990); see MPEP 2144.05, I.
Claim 15 is rejected under 35 U.S.C. 103 as being unpatentable over Sato in view of Gogotsi and evidentiary references Li and Zeng as applied to claim 1 above, and further in view of Tech Briefs “Ethyl Methyl Carbonate as a Cosolvent for Lithium-Ion Cells,” June 2001.
Regarding Claim 15, the combination above teaches the separator of claim 12, and Sato further teaches the electrolyte can include LiPF6 dissolved in a solvent such as a cyclic carbonate or a chain carbonate ([0005]) and teaches an example electrolyte using a mixture of propylene carbonate and ethylene carbonate.
The combination does not teach ethyl methyl carbonate and dimethyl carbonate.
Tech Briefs is relied upon to teach the use of lithium-ion battery electrolyte compositions comprising of ethyl methyl carbonate (EMC), ethylene carbonate (EC), dimethyl carbonate (DMC), and lithium hexafluorophosphate (LiPF6) for lithium-ion cells (p 1, Table). Tech Briefs also teaches that the addition of EMC to the other carbonate solvents resulted in advantageous low-temperature performance such as reduced solid electrolyte interface film resistances, and enhanced intercalation kinetics and discharge characteristics of the cells (p 2, paragraph 2, lines 8-14). Therefore, it would have been obvious to one of ordinary skill in the art at the time the invention was filed to have incorporated ethyl methyl carbonate and dimethyl carbonate into modified Sato’s electrolyte in addition to lithium hexafluorophosphate and ethylene carbonate components, as taught by Tech Briefs, for the advantage of improved low temperature lithium-ion battery performance.
Response to Arguments
Applicant's arguments filed November 19, 2025 have been fully considered but they are not persuasive. Amended claim 1 recites the limitation of “the first and second sides of the same PVHF-HAP layer each coated by a Ti3C2Tx MXene nanosheet” (lines 4-5).
The claim language does not preclude PVHF-HAP layer from being a composite layer. Sato teaches a composite layer corresponding to the claimed PVHF-HAP layer that is formed of a heat-resistant porous layer provided on both surfaces of a porous substrate (machine translation [0007]), wherein the heat-resistant porous layer includes a polymer binder resin that can be a copolymer containing vinylidene fluoride monomer units and hexafluoropropylene monomer units, e.g., PVDF-HFP or PVHF [0053]-[0055], and first inorganic particles made of apatite that can be hydroxyapatite [0020]. Accordingly, the two exposed surfaces of the composite material facing outward correspond to the claimed first and second sides and would be of the same PVHF-HAP layer.
Alternatively, even if the first and second sides are respectively interpreted as the outer-facing and inner-facing sides of a single PVHF-HAP coating, wherein the inner-facing side is the side contacting a porous substrate, the claim language does not require that the MXene nanosheet be directly coated on each the first and second sides. Consequently, application of a MXene nanosheet on both outer-facing sides of the PVHF-HAP layer would read on coating of the composite material and include coating of its inner-facing (i.e., second) sides.
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.
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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/G.L.L./Examiner, Art Unit 1726
/BACH T DINH/Primary Examiner, Art Unit 1726 02/20/2026