DETAILED ACTION
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
This is a final office action for application 17/915,645 in response to the amendment(s) filed on 08/13/2025. Claims 1 and 3-21 are under examination.
Response to Arguments
Applicant’s arguments filed on 08/13/2025 have been fully considered but were not found persuasive.
Applicant argues that the Office’s reliance on inherency to meet the claimed Formula 1 (1.0 ≤ Mw2nd / Mw1st ≤ 2.0) is erroneous because polymer molecular weights can vary depending on the degree of polymerization, and the cited references are silent as to such values. It is acknowledged that Su and Ohashi do not expressly disclose numerical molecular weight values for the first and second binders. However, the rejection no longer relies on inherency. Rather, the molecular weight of polymeric binders is a well-known result effective variable in polymer science that directly impacts adhesion, viscosity, film-forming ability, and cycle-life stability. See MPEP 2144.05(II).
Both Su and Ohashi teach that the purpose of the binder is to improve adhesion between electrode layers and the current collector and to enhance cycle-life performance (see e.g. “the binder allows a better adhesion between the active material layer to the cathode current collector” in paragraph [0051] of Su and “The present invention provides electrodes for batteries and cells whose adhesion between the electrode activator and the collector is improved so as the cycle property of the cells.” in Column 1 lines 61-64 of Ohashi). Applicant’s own specification states that Formula 1 is directed to the same goals, namely to “prevent deterioration of the interface performance of the first mixture layer and the second mixture layer and to prevent the decrease of the lifespan due to the deviation of the weight average molecular weight of the first binder and the second binder” (see e.g. Page 13 lines 9-19 of the Instant Specification). Thus, Applicant admits that the effect of Formula 1 is to optimize the properties already recognized in the prior art as critical.
It would have been obvious to one of ordinary skill in the art to adjust the molecular weights of the first and second binders such that their ratio falls within the claimed range in order to predictably optimize adhesion and cycle performance. The precise values of polymer molecular weight are routinely varied and selected through ordinary experimentation to balance viscosity, dispersion, and mechanical integrity.
In conclusion, Applicant’s arguments regarding inherency are not persuasive. The USC 103 rejection is maintained on the basis of obvious optimization of a known, result effective variable. The claim 1 rejection has been updated to rely on obvious optimization rather than inherency. Furthermore, dependent claims 3-12 do not overcome the prior art rejection of record and remain rejected. Newly added claims 13-21 have also been rejected. See claims 1 and 3-21 rejection below.
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 Rejections - 35 USC § 103
Claims 1, 3-14, 17 and 20-21 are rejected under 35 U.S.C. 103 as being unpatentable over Su et al. (US-20200144605-A1) and further in view of Ohashi et al. (US-6228533-B1).
Regarding Claim 1, Su discloses a positive electrode for a lithium secondary battery (see e.g. “cathode” in paragraph [0005] and FIG. 1), the positive electrode comprising a structure including a laminate (see e.g. FIG. 1) including sequential lamination of a current collector (see e.g. “cathode current collector” in paragraph [0006] and part number 11 in FIG. 1), a first mixture layer (see e.g. “a first cathode active material layer” in paragraph [0006] and part number 12 in FIG. 1), and a second mixture layer (see e.g. “a second cathode active material layer” in paragraph [0006] and part number 13 in FIG. 1), in order (see e.g. FIG. 1), wherein the first mixture layer includes a first binder containing a fluorine-based homopolymer (see e.g. “the first cathode active material layer… include a binder and a conductive agent, wherein the binder is selected from the group consisting of polyvinylidene fluoride” in paragraph [0013] and “The lithium iron phosphate slurry, composed of 95.8 wt % of lithium iron phosphate (LiFePO4), 2.8 wt % of polyvinylidene fluoride (PVDF) and 1.4 wt % of conductive carbon black” in Embodiment 1 paragraph [0084]), and wherein the second mixture layer includes a second binder containing a fluorine-based copolymer (see e.g. “the second cathode active material layer… include a binder… wherein the binder is… a vinylidene fluoride-hexafluoropropylene copolymer” in paragraph [0013]).
Su does not explicitly disclose that the second mixture layer includes a second binder containing a fluorine-based copolymer having a miscible functional group derived from one or more monomers selected from the group consisting of (meth)acrylic acid, C1 to C10 alkyl(meth)acrylate, C1 to C10 alkyl(meth)acrylonitrile, and C1 to C10 alkyl(meth)acrylamide.
Ohashi, however, in the same field of endeavor, electrode binders for lithium secondary batteries, discloses a mixture layer which includes a fluoroplastic binder having a miscible functional group of at least one acrylic polymer, wherein the monomer of the acrylic polymer is an ester of acrylic acid and/or methacrylic acid (see e.g. Column 1, lines 66–67 and Column 2, lines 1–60). This explicitly overlaps with a subset of the claimed monomers (i.e. (meth)acrylic acid and C1 to C10 alkyl(meth)acrylate). Ohashi further teaches that the fluoroplastic may be polyvinylidene fluoride (PVDF) or a copolymer thereof, such as PVDF-HFP (see e.g. “For the present invention, PVDF means homopolymers of vinylidenefluoride (VF2) and copolymers of VF2 and at least another fluorinated comonomer preferably chosen among tetrafluoroethylene, hexafluoropropylene, trifluoroethylene and/or chlorotrifluoroethylene that can be used alone or in combination” in Column 2, lines 51–56).
Ohashi also teaches that this type of mixture provides electrodes with improved adhesion between the mixture and the current collector, and that when this mixture is used in batteries, the discharge capacity does not deteriorate after repeated charge-discharge cycles, making this useful in lithium-ion batteries (see e.g. Column 3 lines 61-67). Therefore, it would have been obvious to a person of ordinary skill in the art, before the effective filing date of the claimed invention, to use the teachings of Ohashi and utilize a mixture of PVDF-HFP and an acrylic polymer as the second mixture layer disclosed by Su in order to enhance adhesion between the layer and the current collector, while maintaining stable discharge performance during cycling, as taught by Ohashi.
With respect to the limitation requiring that the first and second binders satisfy Formula 1 (1.0 ≤ Mw2nd / Mw1st ≤ 2.0), neither Su nor Ohashi disclose specific molecular weight values of the binders. However, molecular weight of polymeric binders is a well-known parameter that directly affects adhesion, viscosity, and film integrity. Both Su and Ohashi emphasize adhesion and cycle performance as critical binder properties (see e.g. “the binder allows a better adhesion between the active material layer to the cathode current collector” in paragraph [0051] of Su and “The present invention provides electrodes for batteries and cells whose adhesion between the electrode activator and the collector is improved so as the cycle property of the cells.” in Column 1 lines 61-64 of Ohashi). Applicant’s own specification confirms that Formula 1 is directed to the same goals, namely preventing deterioration at the interface between layers and preventing lifespan reduction due to mismatched binder molecular weights (see e.g. Page 13 lines 9-19 of the Instant Specification). Thus, the claimed ratio merely reflects routine optimization of a known, result effective variable (polymer molecular weight) to achieve the same properties. Selection of binder molecular weights to achieve a ratio within the range of 1.0–2.0 would have been an obvious matter of routine experimentation for a person of ordinary skill in the art. See MPEP 2144.05(II).
Regarding Claim 3, Su in view of Ohashi discloses the positive electrode of claim 1 (see claim 1 rejection above). Su in view of Ohashi is silent as to the molecular weight of the first and second binder, respectively, and thus does not explicitly disclose that a weight average molecular weight (MW1st) of the first binder is in a range of 10,000 g/mol to 1,000,000 g/mol.
Su in view of Ohashi, however, discloses a first binder that has no compositional distinction from the first binder claimed in the instant application. Because of this, it would be obvious to a person of ordinary skill in the art that the binder composition in both the prior art and the instant application are the same, and thus the molecular weights of the weight average molecular weight of the first binder would be inherent and a prima facie case of obviousness exists. See MPEP 2112 (III) and MPEP 2112.01 (I).
Regarding Claim 4, Su in view of Ohashi discloses the positive electrode of claim 1 (see claim 1 rejection above). Su does not disclose that a content of the miscible functional group is in a range of 0.1 mol% to 10 mol% of the fluorine-based copolymer. Ohashi, however, discloses that the content of the acrylic polymer is preferably 0.3 to 5% by weight of the fluoroplastic (see e.g. "the content of the acrylic polymer is 0.1 to 20% by weight, preferably 0.2 to 20% by weight, more preferably 0.3 to 5% by weight of the grafted fluoroplastic." in Column 2 lines 7-10) and further teaches that the acrylic polymer includes monomers such as (meth)acrylic acid esters and/or methacrylic acid which fall within the scope of the claimed miscible functional group. While mol% and wt% are distinct units, a person of ordinary skill in the art would understand that depending on the molecular weight of the grafted or blended acrylic polymer, 0.3 to 5 wt% would more than likely correspond to a mol% within the claimed range of 0.1 to 10 mol%. Given the nature of copolymer composition and the relatively small molecular size of acrylic monomers compared to the fluoroplastic backbone, the wt% disclosed in Ohashi would reasonably be expected to result in a mol% within the claimed range.
Ohashi also teaches that this type of mixture provides electrodes with improved adhesion between the mixture and the current collector, and that when this mixture is used in batteries, the discharge capacity does not deteriorate after repeated charge-discharge cycles, making this useful in lithium-ion batteries (see e.g. Column 3 lines 61-67). Therefore, it would have been obvious to a person of ordinary skill in the art, before the effective filing date of the claimed invention, to use the teachings of Ohashi and utilize a mixture of PVDF-HFP and an acrylic polymer as the second mixture layer disclosed by Su in order to enhance adhesion between the layer and the current collector, while maintaining stable discharge performance during cycling, as taught by Ohashi.
Regarding Claim 5, Su in view of Ohashi discloses the positive electrode of claim 1 (see claim 1 rejection above). Su further discloses that the first mixture includes 95.8 wt% of a first active material, 2.8 wt% of a first binder, and 1.5 wt % of a first conductive material (see e.g. "The lithium iron phosphate slurry, composed of 95.8 wt % of lithium iron phosphate (LiFePO4), 2.8 wt % of polyvinylidene fluoride (PVDF) and 1.4 wt % of conductive carbon black" in paragraph [0084]).
Su discloses points that lie within the range claimed by the instant application. In the case where the prior art discloses a point within the claimed range, a prima facie case of obviousness exists. See MPEP 2144.05 (I).
Regarding Claim 6, Su in view of Ohashi discloses the positive electrode of claim 5 (see claim 5 rejection above). Su further discloses that the first active material includes lithium iron phosphate and is represented by LiFePO4 (see e.g. "The lithium iron phosphate slurry, composed of 95.8 wt % of lithium iron phosphate (LiFePO4)" in paragraph [0084]). This corresponds directly with the claimed species, Li1-xFe1-yM1y(PO4-z)Xz, where M1 denotes at least one species selected from the group consisting of Al, Mg and Ti, and X denotes at least one species selected from the group consisting of F, S and N, and -0.5 ≤ x ≤ 0.5, 0 ≤ y ≤ 0.5 and 0 ≤ z ≤ 0.1. In the case where x = 0, y = 0, and z = 0 the claimed species becomes LiFePO4 which is the same species disclosed by Su.
Su discloses points that lie within the range claimed by the instant application. In the case where the prior art discloses a point within the claimed range, a prima facie case of obviousness exists. See MPEP 2144.05 (I).
Regarding Claim 7, Su in view of Ohashi discloses the positive electrode of claim 1 (see claim 1 rejection above). Su further discloses that the content of the first binder is 2.8 wt% and the content of first conductive material is 1.4 wt% (see e.g. "2.8 wt % of polyvinylidene fluoride (PVDF) and 1.4 wt % of conductive carbon black" in Embodiment 1 paragraph [0084]) Thus a/c = 2.8/1.4 = 2, where a denotes a content of a first active material and c denotes a content of a first conductive material.
Su discloses a point that lies within the range claimed by the instant application. In the case where the prior art discloses a point within the claimed range, a prima facie case of obviousness exists. See MPEP 2144.05 (I).
Regarding Claim 8, Su in view of Ohashi discloses the positive electrode of claim 1 (see claim 1 rejection above). Su further discloses that the second mixture has a second binder content between 0.5 and 4 wt% (see e.g. "the content of the binder of the second cathode active material layer is from about 0.5 wt % to about 4 wt % based on the total weight of the second cathode active material layer" in paragraph [0051]) and a second conductive active material content between 0.5 wt% and 5 wt% (see e.g. " the content of the conductive agent of the second cathode active material layer is from about 0.5 wt % to about 5 wt % based on the total weight of the second cathode active material layer." in paragraph [0052]). Based on this it would be obvious to a person of ordinary skill in the art that the remaining portion of the second mixture must be the second active material in a content between 91 wt % and 99 wt%.
Su discloses ranges which lie within or overlap with the ranges claimed by the instant application. In the case where the prior art discloses a range that lies within or overlaps with the claimed range, a prima facie case of obviousness exists. See MPEP 2144.05 (I).
Regarding Claim 9, Su in view of Ohashi discloses the positive electrode of claim 1 (see claim 1 rejection above). Su further discloses that a content of first binder is 2.8 wt% (see e.g. "2.8 wt % of polyvinylidene fluoride (PVDF)" in paragraph [0084]) and a content of second binder is 0.8 wt% (see e.g. "0.8 wt % of polyvinylidene fluoride (PVDF)" in paragraph [0084]). Thus, Su discloses that b > b' where b denotes a content of the first binder and b' denotes a content of the second binder.
Su discloses a point that lies within the range claimed by the instant application. In the case where the prior art discloses a point within the claimed range, a prima facie case of obviousness exists. See MPEP 2144.05 (I).
Regarding Claim 10, Su in view of Ohashi discloses the positive electrode of claim 1 (see claim 1 rejection above). Su further discloses that the thickness of the first mixture layer is 8 μm (see e.g. "the thickness of the first cathode active material layer was 8 μm" in paragraph [0084]).
Su discloses a point that lies within the range claimed by the instant application. In the case where the prior art discloses a point within the claimed range, a prima facie case of obviousness exists. See MPEP 2144.05 (I).
Regarding Claim 11, Su in view of Ohashi discloses the positive electrode of claim 1 (see claim 1 rejection above). Su further discloses that the thickness of the first mixture layer is 8 μm (see e.g. " the thickness of the first cathode active material layer was 8 μm" in paragraph [0084]).
Su discloses a point that lies within the range claimed by the instant application. In the case where the prior art discloses a point within the claimed range, a prima facie case of obviousness exists. See MPEP 2144.05 (I).
Regarding Claim 12, Su in view of Ohashi disclose a lithium secondary battery comprising the positive electrode according to claim 1 (see claim 1 rejection above). Su further discloses a lithium secondary battery (see e.g. "electrochemical device" in paragraph [0016] and FIGs. 4a and 4b), a negative electrode (see e.g. "anode" in paragraph [0016]), and a separator (see e.g. "separator" in paragraph [0016]) positioned between the positive electrode and the negative electrode (see e.g. "the separator is disposed between the anode and the cathode, and the anode" in paragraph [0016]).
Regarding Claim 13, Su in view of Ohashi discloses the positive electrode of claim 1 (see claim 1 rejection above). Su does not disclose that the miscible functional group is derived from one or more monomers selected from the group consisting of (meth)acrylic acid and C1 to C10 alkyl(meth)acrylate.
Ohashi, however, discloses that the miscible functional group is derived from one or more monomers selected from the group consisting of (meth)acrylic acid (see e.g. "methacrylic acid" in Column 2 line 6 of Ohashi).
Ohashi also teaches that this type of mixture provides electrodes with improved adhesion between the mixture and the current collector, and that when this mixture is used in batteries, the discharge capacity does not deteriorate after repeated charge-discharge cycles, making this useful in lithium-ion batteries (see e.g. Column 3 lines 61-67). Therefore, it would have been obvious to a person of ordinary skill in the art, before the effective filing date of the claimed invention, to use the teachings of Ohashi and utilize a mixture of PVDF-HFP and an acrylic polymer as the second mixture layer disclosed by Su in order to enhance adhesion between the layer and the current collector, while maintaining stable discharge performance during cycling, as taught by Ohashi.
Regarding Claim 14, Su in view of Ohashi disclose the positive electrode of claim 1 (see claim 1 rejection above). Su does not disclose that the miscible functional group is derived from C1 alkyl(meth)acrylate.
Ohashi, however, discloses that the miscible functional group is derived from C1 alkyl(meth)acrylate (see e.g. "methylacrylate" in Column 2 line 64 of Ohashi; methylmethacrylate is a specific embodiment of a C1 alkyl(meth)acrylate, because “C1 alkyl” refers to a one-carbon substituent (methyl), and methacrylate is the same functional methacrylate moiety).
Ohashi also teaches that this type of mixture provides electrodes with improved adhesion between the mixture and the current collector, and that when this mixture is used in batteries, the discharge capacity does not deteriorate after repeated charge-discharge cycles, making this useful in lithium-ion batteries (see e.g. Column 3 lines 61-67). Therefore, it would have been obvious to a person of ordinary skill in the art, before the effective filing date of the claimed invention, to use the teachings of Ohashi and utilize a mixture of PVDF-HFP and an acrylic polymer as the second mixture layer disclosed by Su in order to enhance adhesion between the layer and the current collector, while maintaining stable discharge performance during cycling, as taught by Ohashi.
Regarding Claim 17, Su in view of Ohashi discloses the positive electrode of claim 1 (see claim 1 rejection above). Su in view of Ohashi does not explicitly disclose that the first binder and the second binder satisfy Formula 1 wherein 1.05 ≤ Mw2nd / Mw1st ≤ 1.95.
However, as discussed in the response to arguments and claim 1 rejection above, the molecular weight of polymeric binders is a result effective variable that directly impacts adhesion, viscosity, film-forming ability, and cycle-life stability. See MPEP 2144.05(II). Applicant’s own specification admits that Formula 1 is directed to achieving these same properties (see e.g. page 13, lines 9–19 of the Instant Specification). It would have been obvious to a person of ordinary skill in the art to adjust the molecular weights of the first and second binders such that their ratio falls within the narrower range of 1.05–1.95 in order to predictably optimize adhesion and cycle performance.
Regarding Claim 20, Su in view of Ohashi discloses the positive electrode of claim 7 (see claim 7 rejection above). Su further discloses that the first mixture layer satisfies Formula 3 (see e.g. "2.8 wt % of polyvinylidene fluoride (PVDF) and 1.4 wt % of conductive carbon black" in paragraph [0084]) The content of the first binder is 2.8 wt% and the content of first conductive material is 1.4 wt%, thus a/c = 2.8/1.4 = 2 where a denotes a content of a first active material and c denotes a content of a first conductive material.
Su discloses a point that lies within the range claimed by the instant application. In the case where the prior art discloses a point within the claimed range, a prima facie case of obviousness exists. See MPEP 2144.05 (I).
Su does not disclose that the first mixture layer satisfies Formula 2 which states 4 ≤ a/b ≤ 20, where a denotes a content of a first active material, b denotes a content of the first binder, and c denotes a content of a first conductive material.
Ohashi, however, discloses a first mixture layer which satisfies Formula 2 (see e.g. "In order to prepare a cathode, 92 parts by weight of LiCoO2 as cathode activator and 6 parts of graphite as electro-conductive additive were dispersed in a solution of N-methylpyrolidone in which 8 parts by weight of the same binder that was used for the preparation of the anode was dissolved to obtain a slurry (paste)." in Column 4 lines 43-48 of Ohashi). Ohashi discloses that a = 92 and b = 8, thus a/b = 11.5.
Ohashi discloses a point that lies within the range claimed by the instant application. In the case where the prior art discloses a point within the claimed range, a prima facie case of obviousness exists. See MPEP 2144.05 (I).
Ohashi also teaches that this type of mixture provides electrodes with improved adhesion between the mixture and the current collector, and that when this mixture is used in batteries, the discharge capacity does not deteriorate after repeated charge-discharge cycles, making this useful in lithium-ion batteries (see e.g. Column 3 lines 61-67). Therefore, it would have been obvious to a person of ordinary skill in the art, before the effective filing date of the claimed invention, to use the teachings of Ohashi and utilize a mixture of PVDF-HFP and an acrylic polymer as the second mixture layer disclosed by Su in order to enhance adhesion between the layer and the current collector, while maintaining stable discharge performance during cycling, as taught by Ohashi.
Regarding Claim 21, Su in view of Ohashi discloses the positive electrode of claim 9 (see claim 9 rejection above). Su further discloses that the first mixture layer and the second mixture layer satisfy Formulas 4-5.
Specifically,
Formula 4 (a < a′): Su discloses that the first active material comprises 95.8 wt% LiFePO4 (see e.g. paragraph [0084]) and the second active material comprises 97.8 wt% LiCoO2 (see e.g., paragraph [0084]). Thus, Su teaches that the content of the first active material (a) is less than the content of the second active material (a′), satisfying Formula 4.
Formula 5 (b > b′): Su discloses that the content of the first binder is 2.8 wt% PVDF and the content of the second binder is 0.8 wt% PVDF (see e.g. paragraph [0084]). Thus, Su teaches that the first binder content (b) is greater than the second binder content (b′), satisfying Formula 5.
Su does not explicitly disclose Formula 6 (c < c′). Su discloses that the content of the first conductive material is 1.4 wt% carbon black and the content of the second conductive material is 1.4 wt% carbon black (see e.g. paragraph [0084]). While Su teaches equal amounts (c = c′), Ohashi discloses that the amount of conductive additive is increased relative to the active material loading (see e.g., “6 parts of graphite as electro-conductive additive” relative to 92 parts LiCoO₂ and 8 parts binder in Column 4, lines 53–59 of Ohashi). It would have been obvious to a person of ordinary skill in the art that the relative content of conductive additive in the second mixture layer could be adjusted upward to improve conductivity of high-loading LiCoO₂ cathodes, which are known to have poorer conductivity than LiFePO₄. Therefore, it would have been obvious to adjust the amount of the second conductive material relative to the first conductive material to satisfy c < c′ in order to balance conductivity across the stacked cathode layers. Furthermore, Ohashi discloses that the conductive additive is 5.66% by weight (6/106 = 5.66) and thus, if substituted with the second conductive additive of Su, would disclose Formula 6.
Ohashi also teaches that this type of mixture provides electrodes with improved adhesion between the mixture and the current collector, and that when this mixture is used in batteries, the discharge capacity does not deteriorate after repeated charge-discharge cycles, making this useful in lithium-ion batteries (see e.g. Column 3 lines 61-67). Therefore, it would have been obvious to a person of ordinary skill in the art, before the effective filing date of the claimed invention, to use the teachings of Ohashi and utilize a mixture of PVDF-HFP and an acrylic polymer as the second mixture layer disclosed by Su in order to enhance adhesion between the layer and the current collector, while maintaining stable discharge performance during cycling, as taught by Ohashi.
Claims 15-16 are rejected under 35 U.S.C. 103 as being unpatentable over Su et al. (US-20200144605-A1) in view of Ohashi et al. (US-6228533-B1) as applied to claim 1 above, and further in view of Hatanaka et al. (US-20200083516-A1).
Regarding Claim 15, Su in view of Ohashi disclose the positive electrode of claim 1 (see claim 1 rejection above). Su in view of Ohashi does not disclose that the miscible functional group is derived from C1 to C10 alkyl(meth)acrylonitrile.
Hatanaka, however, in the same field of endeavor, polymer binders for electrochemical applications, discloses the miscible functional group that is (meth)acrylonitrile (see e.g. "illustrative examples of hydrophilic functional group-containing (meth)acrylic monomers include... (meth)acrylonitrile" in paragraph [0067] of Hatanaka; (meth)acrylonitrile is the C1 alkyl(meth)acrylonitrile variant).
Hatanaka further teaches that the use of this functional group in the binder allows for better adhesion and enables energy storage devices to be made even smaller and thinner which is desirable in the art (see e.g. paragraphs [0003] and [0013] of Hatanaka). Therefore, it would have been obvious to a person of ordinary skill in the art, before the effective filing date of the claimed invention, to use the teachings of Hatanaka in order to have better adhesion between active material layers and current collectors which enables batteries to be made smaller and thinner as taught by Hatanaka.
Regarding Claim 16, Su in view of Ohashi disclose the positive electrode of claim 1 (see claim 1 rejection above). Su in view of Ohashi does to disclose that the miscible functional group is derived from C1 to C10 alkyl(meth)acrylamide.
Hatanaka, however, discloses the miscible functional group that is (meth)acrylamide (see e.g. "illustrative examples of hydrophilic functional group-containing (meth)acrylic monomers include... (meth)acrylamide" in paragraph [0067] of Hatanaka; (meth)acrylamide is the C1 alkyl(meth)acrylamide variant).
Hatanaka further teaches that the use of this functional group in the binder allows for better adhesion and enables energy storage devices to be made even smaller and thinner which is desirable in the art (see e.g. paragraphs [0003] and [0013] of Hatanaka). Therefore, it would have been obvious to a person of ordinary skill in the art, before the effective filing date of the claimed invention, to use the teachings of Hatanaka in order to have better adhesion between active material layers and current collectors which enables batteries to be made smaller and thinner as taught by Hatanaka.
Claim 18 is rejected under 35 U.S.C. 103 as being unpatentable over Su et al. (US-20200144605-A1) in view of Ohashi et al. (US-6228533-B1) as applied to claim 1 above, and further in view of Bizet et al. (US-20180355206-A1).
Regarding Claim 18, Su in view of Ohashi discloses the positive electrode of claim 1 (see claim 1 rejection above). Su in view of Ohashi does not disclose that a content of the miscible functional group is in a range of 3 mol% to 8 mol% of the fluorine-based copolymer.
Bizet, however, in the same field of endeavor, fluorinated binders with miscible functional groups for use in lithium-ion battery electrodes, discloses PVDF acrylic copolymer with miscible functional groups that are 10 mol% of the copolymer (see e.g. "the acrylic copolymer contains 10 mol % of monomers bearing functional groups" in paragraph [0038] of Bizet). Although Bizet does not expressly disclose a content of 3–8 mol%, it would have been obvious to a person of ordinary skill in the art to adjust the content of the miscible functional group to a value within the claimed range in order to balance adhesion to the current collector and electrochemical performance of the electrode. Selection of an optimum value of a result effective variable is considered routine and within the level of ordinary skill. See MPEP 2144.05(I) and MPEP 2144.05(II).
Bizet further teaches that functional groups in this range can significantly boost adhesion of the PVDF binder to metal substrates (i.e. current collectors) (see e.g. paragraph [0038] of Bizet). Therefore, it would have been obvious to a person of ordinary skill in the art, before the effective filing date of the claimed invention, to use the teachings of Bizet in order to significantly boost the adhesion of the fluorine-based copolymer binder as taught by Bizet.
Claim 19 is rejected under 35 U.S.C. 103 as being unpatentable over Su et al. (US-20200144605-A1) in view of Ohashi et al. (US-6228533-B1) as applied to claim 1 above, and further in view of Kwon et al. (US-20140246085-A1).
Regarding Claim 19, Su in view of Ohashi disclose the positive electrode of claim 1 (see claim 1 rejection above). Su in view of Ohashi is silent as to the properties of the binders use and thus do not disclose that the weight average molecular weight (Mw1st) of the first binder is in a range of 200,000 to 500,000 g/mol.
Kwon, however, in the same field of endeavor coatings for electrochemical application discloses fluorine-based polymers having a weight average molecular weight of 50,000 to 1,000,000 (see e.g. "The fluorine-based polymer may have a weight average molecular weight of 50,000 to 1,000,000" in paragraph [0035] of Kwon). Both the binders disclosed in Su and Ohashi are fluorine-based polymers (see claim 1 rejection above).
Kwon discloses a range that encompasses the range claimed by the instant application. In the case where the prior art discloses a range that encompasses the claimed range, a prima facie case of obviousness exists. See MPEP 2144.05 (I).
Kwon further teaches that the polymer may have an excellent adhesive property to the base film (see e.g. paragraph [0029] of Kwon). Therefore, it would have been obvious to a person of ordinary skill in the art, before the effective filing date of the claimed invention, to use the teachings of Kwon in order to have a polymer with excellent adhesion properties to base films as taught by Kwon.
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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/J.J.E./Examiner, Art Unit 1723
/MILTON I CANO/Supervisory Patent Examiner
Art Unit 1723
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