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 .
Priority
Receipt is acknowledged of certified copies of papers required by 37 CFR 1.55.
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.
Claim(s) 1-6, 8, and 10-12 is/are rejected under 35 U.S.C. 103 as being unpatentable over Moon et al. (US 20200127281 A1) in view of Mesuda (US 20150180018 A1).
Regarding claim 1, Moon teaches an electrode for a secondary battery (a lithium secondary battery including the positive electrode, [0007]), comprising:
a current collector (positive electrode current collector, [0058]); and
a mixture layer provided on the current collector (a positive electrode active material layer formed by applying the positive electrode slurry to at least one surface of a positive electrode current collector, [0057]), wherein the mixture layer contains
an electrode active material containing a metal element (a lithium-containing transition metal oxide as positive electrode active material, [0026]), a water-insoluble additive (binder polymer polyvinylidene fluoride (PVdF), [0035-0036, 0091]), and a water-soluble additive (dispersing agent, [0037-0038]),
the water-soluble additive contains a polysaccharide (cellulose compounds e.g. CMC in [0091], chitosan, and/or starch as examples of dispersing agent per [0038]), and
… a particle diameter of the electrode active material (the positive electrode active material may have an average particle diameter (D50) of 0.5-15 μm, considering a significant effect of improving the rate characteristics and initial capacity characteristics derived from the controlled particle size of the positive electrode active material; [0027]).
However, Moon fails to teach: a particle diameter of the polysaccharide is larger than [the] particle diameter of the electrode active material. As cited above to [0027], Moon does teach controlling the positive electrode active material diameter to be preferably small such that it is possible to prevent degradation of the dispersibility in the positive electrode slurry caused by aggregation of the positive electrode active material particles, and to ensure mechanical strength and specific surface area of the positive electrode active material. In their inventive Example 1, Moon teaches the positive electrode active material having an average particle diameter (D50) 11 μm ([0091]).
Mesuda is analogous in the art of electrodes and teaches a polysaccharide of carboxymethylcellulose (CMC) as an additive in an electrode active mixture ([0013]). Mesuda teaches that if CMC has an extremely small particle size, it is difficult to handle CMC, therefore for this reason, the particle size of CMC is preferably adjusted to a level (e.g., 25 μm) at which CMC can be handled without difficulty ([0061]). Mesuda also teaches CMC for use in the electrode active mixture alongside a PVDF binder ([0049-0050]). Mesuda teaches such thickener with adjusted particle size is useful in a positive electrode ([0072]).
It would have been obvious, at the time of filing, for a person having ordinary skill in the art to modify the mixture layer of Moon with the CMC sufficiently sized as taught by Masuda such that the particle diameter of the polysaccharide (25 μm per Masuda) is larger than the particle diameter of the electrode active material (11 μm per Moon) to achieve easy handling of the polysaccharide within the mixture as motivated by Mesuda.
Thus, the instant claim 1 is rendered obvious.
Regarding claim 2 and claim 3, modified Moon teaches the limitations of claim 1 above and wherein the water-insoluble additive includes a fluorine-based resin, and wherein the fluorine- based resin includes polyvinylidene fluoride (PVdF) (PVDF in Moon [0036, 0091] as cited above).
Regarding claim 4, modified Moon teaches the limitations of claim 1 above and wherein a content of the polysaccharide is greater than or equal to 0.1 mass % and less than or equal to 2 mass % with respect to a mass of the mixture layer (0.3 parts by weight of carboxymethyl cellulose, Moon [0091]) excluding the polysaccharide (from Moon [0091] data: 0.3/(95+3+1.7) = 0.301 mass % CMC versus other mixture ingredients).
Regarding claim 5, modified Moon teaches the limitations of claim 4 above and wherein the content of the polysaccharide is greater than or equal to 0.1 mass % and less than or equal to 1 mass % with respect to the mass of the mixture layer excluding the polysaccharide (0.301 mass %, per Moon [0091] calculation above).
Regarding claim 6, modified Moon teaches the limitations of claim 1 above and wherein the polysaccharide includes at least one of a polysaccharide having a carboxyl group … (carboxymethylcellulose of Moon [0091] has carboxyl group).
Regarding claim 8, modified Moon teaches the limitations of claim 1 above and wherein the electrode active material is a positive electrode active material (Moon [0026, 0091] as cited above).
Regarding claim 10, Moon teaches a method for producing an electrode for a secondary battery (a lithium secondary battery including the positive electrode, [0007]; a method for preparing positive electrode slurry for a lithium secondary battery, [0022]; there is provided a positive electrode using the positive electrode slurry obtained by the above-described method, [0056]; coating/drying/pressing steps in [0061-0063] to produce the electrode), comprising:
… an electrode active material containing a metal element (a lithium-containing transition metal oxide as positive electrode active material, [0026]), a water-insoluble additive (binder polymer polyvinylidene fluoride (PVdF), [0035-0036, 0091]), and a water-soluble additive (dispersing agent, [0037-0038]) containing a polysaccharide (cellulose compounds e.g. CMC in [0091], chitosan, and/or starch as examples of dispersing agent per [0038]) … in a non-aqueous solvent to prepare a paste (adding a positive electrode active material, a conductive material, a binder polymer and a dispersing agent to a solvent and mixing them to obtain slurry per [0008]; non-aqueous solvent examples listed in [0039]); and
applying the paste to a current collector to form a mixture layer (positive electrode active material layer formed by applying the positive electrode slurry to at least one surface of a positive electrode current collector, [0057]).
However, Moon fails to teach: explicitly “kneading” the above-cited components, nor that [the] polysaccharide having a particle diameter larger than that of the electrode active material. As cited above to [0027], Moon does teach controlling the positive electrode active material diameter to be preferably small such that it is possible to prevent degradation of the dispersibility in the positive electrode slurry caused by aggregation of the positive electrode active material particles, and to ensure mechanical strength and specific surface area of the positive electrode active material. In their inventive Example 1, Moon teaches the positive electrode active material having an average particle diameter (D50) 11 μm ([0091]).
Mesuda is analogous in the art of electrodes and teaches a polysaccharide of carboxymethylcellulose (CMC) as an additive in an electrode active mixture ([0013]). Mesuda teaches that if CMC has an extremely small particle size, it is difficult to handle CMC, therefore for this reason, the particle size of CMC is preferably adjusted to a level (e.g., 25 μm) at which CMC can be handled without difficulty ([0061]). Mesuda also teaches CMC for use in the electrode active mixture alongside a PVDF binder ([0049-0050]). Mesuda teaches such thickener with adjusted particle size is useful in a positive electrode ([0072]). Mesuda also teaches that in a positive electrode forming step, the positive electrode active material is dispersed together with the conductive auxiliary agent, the binder and the like in a solvent with the use of a kneader such as a twin-screw kneader to prepare the paste-like positive electrode mixture ([0035]), and then such positive electrode mixture is applied in the form of a layer onto the surface of the positive electrode current collector and is then dried ([0036]). Mesuda also teaches in forming a negative electrode specifically containing thickener (of CMC as cited above), the components are fed into a kneader to knead them (0041-0042]) and that beneficially the solvent may be fed into the kneader in several batches to adjust the solid content of the electrode mixture to a desired value ([0046]).
It would have been obvious, at the time of filing, for a person having ordinary skill in the art to modify the mixture layer of Moon with the CMC sufficiently sized as taught by Masuda such that the particle diameter of the polysaccharide (25 μm per Masuda) is larger than the particle diameter of the electrode active material (11 μm per Moon) to achieve easy handling of the polysaccharide within the mixture as motivated by Mesuda. It would have been further obvious, at the time of filing, for a person having ordinary skill in the art to modify the method of Moon to specifically employ “kneading” as the mixing technique by feeding the active material and above-cited additives along with a solvent into a kneader in order to knead them into a paste to be coated onto the current collector, as is taught by Mesuda to be a known technique to achieve the shared inventive goal of obtaining the active material mixture layer slurry/paste, and further to be able to use said kneader to feed solvent batch-wise to beneficially adjust solid content of the resultant electrode mixture as also taught toward by Mesuda.
Thus, all limitations of instant claim 10 are rendered obvious.
Regarding claim 11, modified Moon teaches the limitations of claim 1 above and a secondary battery comprising: a positive electrode (there is provided a lithium secondary battery including the positive electrode, Moon [0066]); and a negative electrode (the lithium secondary battery includes the positive electrode, a negative electrode, … [0067-0068]),
wherein at least one of the positive electrode and the negative electrode is the electrode for a secondary battery according to claim 1 (the positive electrode according to the present disclosure, Moon [0057, 0066]; see also citations to Moon above in regards to claim 1, regarding positive electrode layer components; negative electrode slurry can also include the CMC polysaccharide per Moon [0075], and the negative electrode active material can include metals listed in Moon [0071]).
Regarding claim 12, modified Moon teaches the limitations of claim 8 above and a secondary battery comprising: a positive electrode(there is provided a lithium secondary battery including the positive electrode, Moon [0066]); and a negative electrode (the lithium secondary battery includes the positive electrode, a negative electrode, … [0067-0068]),
wherein the positive electrode is the electrode for a secondary battery according to claim 8 (positive electrode active material per Moon [0026, 0091] as cited in regards to claim 8 above; the positive electrode according to the present disclosure, Moon [0057, 0066]).
Claim(s) 7 is/are rejected under 35 U.S.C. 103 as being unpatentable over Moon et al. (US 20200127281 A1) in view of Mesuda (US 20150180018 A1) as applied to claim 6 above, and further in view of Morishima et al. (US 20110239446 A1).
Regarding claim 7, modified Moon teaches the limitations of claim 6 above but fails to teach the polysaccharide includes at least one of gum arabic and carrageenan.
Morishima is analogous in the art of battery electrodes and teaches an active material layer for a lithium-ion battery ([0034]) and teaches the electrode active material layer may also contain as necessary one or two or more materials, listing CMC and gum arabic as equivalent examples of known binders which are dispersible in water, and that in addition to being used as binders these polymer materials can be used as thickeners ([0036]).
Simple substitution of one known material for another to achieve predictable results, and the selection of a known material suitable for a given use, are obvious per MPEP 2143 I B and 2144.07, respectively. Therefore, in view of Morishima teaching that CMC and gum arabic are both suitable for use as binders and/or thickeners within an electrode active material layer, a person having ordinary skill in the art would have found it obvious to substitute gum arabic for CMC as the polysaccharide within the active material mixture of Moon and expect desired functionality thereof. Further, though Morishima [0036] focuses on a negative electrode mixture and above citations to Moon focus on a positive electrode mixture, Moon teaches that CMC as a thickener can be used in either the negative electrode mixture (Moon [0075]) or within the positive electrode mixture (Moon [0091]). Therefore, when modifying Moon in view of Morishima, substituting/selecting gum arabic as an additive to serve as the polysaccharide within the positive electrode mixture layer would have indeed been obvious.
Thereby, claim 7 is rendered obvious.
Claim(s) 9 is/are rejected under 35 U.S.C. 103 as being unpatentable over Moon et al. (US 20200127281 A1) in view of Mesuda (US 20150180018 A1) as applied to claim 8 above, and further in view of Hosoya et al. (US 20040076882 A1).
Regarding claim 9, modified Moon teaches the limitations of claim 8 above and wherein
the positive electrode active material is a Li-containing transition metal oxide (lithium-containing transition metal oxide preferred as the positive electrode active material, Moon [0026]; exemplary Li(Ni0.6Mn0.2Co0.2)O2 in Moon [0091]),
a ratio (B/A) of the number of moles (B) of Li to the total number of moles (A) of the metal element other than Li is … equal to 1 (ratio from Li(Ni0.6Mn0.2Co0.2)O2 formula in Moon [0091] = 1 / (0.6+0.2+0.2) = 1/1 = 1), and
a ratio (C/A) of the number of moles (C) of Ni to the total number of moles (A) of the metal element other than Li is greater than … 0.5 (ratio from Li(Ni0.6Mn0.2Co0.2)O2 formula in Moon [0091] = 0.6/1 = 0.6).
Moon fails to explicitly teach the Li-containing transition metal oxide of the positive electrode active material “having a layered structure”.
Hosoya is analogous in the art of positive electrode active material and teaches a cathode active material composed of a mixture of a first lithium-transition metal composite oxide containing Ni and Co and comprising a layer structure and a second lithium-transition metal composite oxide containing Ni and Mn and comprising a layer structure (abstract and [0042-0046]). Hosoya teaches exemplary formulas of such layered-structure lithium-transition metal composite oxides in [0043-0048] which are similar to and overlap compositional formulas of the lithium-containing transition metal oxides exemplified in Moon [0026]. Formulas (1) and (2) of Hosoya also have appropriate subscript ratios meeting the instant claim 9 ratios of B/A and C/A since lithium is the major component and the nickel content can be sufficiently high and still within the ranges taught by Moon, Hosoya, and required by the instant claim.
Therefore, although Moon is not explicit regarding the layered structure of the positive electrode active material, a person having ordinary skill in the art would have expected the lithium-transition metal composite oxide of Moon to exhibit a layered structure since the compositional formula of such overlapped those taught by Hosoya to indeed have a layered structure, while still satisfying the ratios of the instant claim. Additionally, simple substitution of the layered structure lithium-transition metal composite oxide(s) taught by Hosoya for the lithium-transition metal composite oxide of Moon to expect predictable functionality as positive electrode active material would have also been obvious (MPEP 2143 I B).
Thereby, all limitations of claim 9 are rendered obvious.
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to Jessie Walls-Murray whose telephone number is (571)272-1664. The examiner can normally be reached M-F, typically 10-4.
Examiner interviews are available via telephone, in-person, and video conferencing using a USPTO supplied web-based collaboration tool. To schedule an interview, applicant is encouraged to use the USPTO Automated Interview Request (AIR) at http://www.uspto.gov/interviewpractice.
If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Matthew Martin can be reached at (571) 270-7871. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
Information regarding the status of published or unpublished applications may be obtained from Patent Center. Unpublished application information in Patent Center is available to registered users. To file and manage patent submissions in Patent Center, visit: https://patentcenter.uspto.gov. Visit https://www.uspto.gov/patents/apply/patent-center for more information about Patent Center and https://www.uspto.gov/patents/docx for information about filing in DOCX format. For additional questions, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000.
/JESSIE WALLS-MURRAY/Primary Examiner, Art Unit 1728
Prosecution Insights