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 .
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, 3-6, 8, 10, and 13-14 are rejected under 35 U.S.C. 103 as being unpatentable over Dumont et al. (US 20150349334 A1, published 3 Dec 2015) in view of Sikha et al. (US 20160013480 A1, published 14 Jan 2016).
Regarding claim 1, Dumont et al. discloses a positive electrode comprising a positive electrode active material layer (1, 2, 3) formed on a positive electrode collector (4, [0011-0012]), wherein the positive electrode active material layer has a two-layer structure (at least 2 layers, 1, 2, 3, [0012]) including: a first positive electrode active material layer (1) which is formed on the positive electrode collector (4, [0013]) and includes a first positive electrode active material (compound iii) represented by the formula LixMn2-y-zM′yM″zO4 (herein referred to as Formula LMO, [0016]) and a second positive electrode active material (compound i) represented by the formula LixMn1-y-zM′yM″zPO4 (herein referred to as Formula LMP, [0014]). Dumont further discloses that in both Formula LMO and Formula LMP, M’ and M’’ are selected from a group comprising B, Mg, Al, Si, V, Cr, Fe, Co, Ni, Cu, Zn, and Y, and M’ and M’’ are different from each other ([0014, 0016]). Furthermore, in Formula LMO, Dumont teaches that 1≤x≤1.4, 0≤y≤0.6, 0≤z≤0.2 ([0016]), and in Formula LMP, Dumont teaches that 0.8≤x≤1.2, 0≤y≤0.6, 0≤z≤0.2 ([0014]).
Regarding Formula LMO and the claimed Formula 1, the examiner interprets M’ as equivalent to M1, x as equivalent to 1+a, y as equivalent to b, and the values of z and c as zero. Following this interpretation, Formula LMO meets the limitations of Formula 1, as claimed, when M’’ is any of the elements listed in the group above, 1≤x≤1.05, and 0≤y≤0.5. Regarding Formula LMP and the claimed Formula 2, the examiner interprets x as equivalent to 1+a1, 1-z (in Formula LMP) as equivalent to z (in Formula 2), z (in Formula LMP) as equivalent to 1-z (in Formula 1), and the value of y in both formulae as zero. Following this interpretation, Formula LMP meets the limitations of Formula 2, as claimed, when M’’ is Fe, 1≤x≤1.03, and 0≤z≤0.2.
Dumont et al. also discloses a second positive electrode active material layer (2) which is formed on the first positive electrode active material layer (1) and includes a third positive electrode active material ([0017]). Dumont further discloses that the thicknesses of the layers (1 and 2) may be identical or different ([0082]). In the case that the thicknesses of the layers are identical, a thickness ratio of the first positive electrode active material layer to the second positive electrode active material layer is 5:5. However, Dumont does not disclose that the third positive electrode active material is represented by Formula LMO. Instead, Dumont teaches that the third positive electrode active material is a lithium iron phosphate. Dumont is also silent to the average particle diameter of the active materials.
Sikha et al. discloses a similarly layered positive electrode, comprising a positive electrode active material layer (202) formed on a positive electrode collector (113), wherein the positive electrode active material layer has a two-layer structure (210, 220, [0037-0038, 0053]; Fig. 2c). Sikha further discloses LiMn2O4, LiMg0.5Mn1.5O4, and LiNi0.5Mn1.5O4 as exemplary cathode active materials ([0030, 0041]), which may be included in either the first positive electrode active material layer (210) or the second positive electrode active material layer (220, [0053, 0063]). Each of these oxides meets the limitations of Formula 1. For LiMn2O4, a, b, and c are all zero. For LiMg0.5Mn1.5O4 and LiNi0.5Mn1.5O4, a and c are zero, and b is 0.5. Furthermore, Sikha teaches that the average particle size of the cathodically active material of the first layer (210) and the average particle size of the cathodically active material of the second layer (220) may be similar or different. In certain implementations, Sikha teaches that the cathodically active material of the first cathode material layer (210) and the cathodically active material of the second cathode material layer (220) comprise the same material with different particle size, and that the difference in average particle size leads to different surface areas and/or different porosities for each layer ([0064]).
It would have been obvious to one of ordinary skill in the art to substitute LiMn2O4, LiMg0.5Mn1.5O4, or LiNi0.5Mn1.5O4, as taught by Sikha, for the lithium iron phosphate used as the third positive electrode material taught by Dumont. The examiner notes that each of LiMn2O4, LiMg0.5Mn1.5O4, and LiNi0.5Mn1.5O4 meets the limitations of both Formula LMO as taught by Dumont, and Formula 1 as claimed. The simple substitution of one known element for another is likely to be obvious when predictable results are achieved (see MPEP § 2143, B.). Additionally, the selection of a known material, which is based upon its suitability for the intended use, is within the ambit of one of ordinary skill in the art (see MPEP § 2144.07). It further would have been obvious for the average particle diameter D50 of the third positive electrode active material to the same or different from an average particle diameter D50 of the first positive electrode active material, as taught by Sikha, to optimize the surface areas or porosities for each layer. The discovery of an optimum value of a known result effective variable, without producing any new or unexpected results, is within the ambit of a person of ordinary skill in the art (see MPEP § 2144.05, II.). Therefore, modified Dumont meets the limitations of claim 1.
Regarding claim 3, modified Dumont et al. meets the limitations of claim 1 as discussed above. Dumont further discloses that the thicknesses of the layers (1 and 2) may be identical or different ([0082]). In the case that the thicknesses of the layers are identical, a thickness ratio of the first positive electrode active material layer to the second positive electrode active material layer is 5:5. Therefore, modified Dumont meets the limitations of claim 3.
Regarding claim 4, modified Dumont et al. meets the limitations of claim 1 as discussed above. Dumont further discloses that when layer 1 comprises a mixture of two active materials, this mixture comprises, based on the total weight of active materials, preferably between 10 and 90% of one of the two active materials and 90 to 10% of the other active material ([0082]).
It would have been obvious to one of ordinary skill in the art to include the first positive electrode active material and the second electrode active material in a weight ratio of 5:5 to 6:4 as claimed. 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 MPEP § 2144.05). Therefore, modified Dumont meets the limitations of claim 4.
Regarding claim 5, modified Dumont et al. meets the limitations of claim 1 as discussed above. Dumont is silent to the average particle diameters of the positive electrode active materials. However, Sikha et al. discloses an exemplary implementation in which the first cathode material layer comprises a cathodically active material having an average particle size of about 3 μm ([0067]).
It would have been obvious to one of ordinary skill in the art for the first positive electrode active material of modified Dumont to have an average particle diameter D50 of 3 µm as taught by Sikha. A specific example in the prior art which is within a claimed range anticipates the claimed range. Furthermore, Sikha, like Dumont, discloses active materials that meet the claimed Formula 1, as discussed above regarding claim 1, thus one of ordinary skill in the art would expect predictable results when selecting an average particle diameter of 3 µm. Therefore, modified Dumont meets the limitations of claim 5.
Regarding claim 6, modified Dumont et al. meets the limitations of claim 1 as discussed above. Dumont is silent to the average particle diameters of the positive electrode active materials. However, Sikha et al. discloses an exemplary implementation in which the second cathode material layer comprises a cathodically active material having an average particle size of about 10 μm ([0067]).
It would have been obvious to one of ordinary skill in the art for the third positive electrode active material of modified Dumont to have an average particle diameter D50 of 10 µm as taught by Sikha. A specific example in the prior art which is within a claimed range anticipates the claimed range. Furthermore, as discussed above regarding claim 1, the cathodically active material in the second cathode material layer of Sikha is substituted for the third positive electrode active material of modified Dumont, thus one of ordinary skill in the art would expect predictable results when selecting an average particle diameter of 10 µm. Therefore, modified Dumont meets the limitations of claim 6.
Regarding claim 8, modified Dumont et al. meets the limitations of claim 1 as discussed above. Dumont further discloses that the deposition of each layer may be performed by preparing a paste which comprises the active material(s), a binder, an electron-conductive compound (conductive agent) and an organic solvent ([0092]). Therefore, modified Dumont meets the limitations of claim 8.
Regarding claim 10, modified Dumont et al. meets the limitations of claim 8 as discussed above. Dumont further discloses that the electron-conductive additive is generally selected from graphite, carbon black, acetylene black, soot or a mixture thereof ([0099]). Graphite, carbon black, and acetylene black are known point-type conductive agents. Therefore, Dumont meets the limitations of claim 10.
Regarding claim 13, modified Dumont et al. meets the limitations of claim 10 as discussed above. Dumont further discloses that the electron-conductive additive may comprise carbon black, acetylene black, or a mixture thereof ([0099]). Therefore, Dumont meets the limitations of claim 13.
Regarding claim 14, modified Dumont et al. meets the limitations of claim 1 as discussed above. Dumont further discloses a lithium secondary battery comprising the positive electrode discussed above regarding claim 1 ([0030-0032]). Therefore, modified Dumont meets the limitations of claim 14.
Claims 7 and 15 are rejected under 35 U.S.C. 103 as being unpatentable over Dumont et al. (US 20150349334 A1) in view of Sikha et al. (US 20160013480 A1) as applied to claims 1, 3-6, 8, 10, and 13-14 above, and further in view of Hoshina et al. (US 20170271668 A1, published 21 Sep 2017).
Regarding claim 7, modified Dumont et al. meets the limitations of claim 1 as discussed above. Dumont does not disclose the crystalline size of the first positive electrode active material. Hoshina et al. discloses a lithium manganese composite oxide represented by the general formula LixMn2O4, wherein x is 0<x≤1 ([0109]). Provided that x equals 1, the lithium manganese composite oxide disclosed by Hoshina meets the limitations of Formula 1 as claimed, and thus could be used as a first positive electrode material. Hoshina further discloses that the active material preferably has a crystalline size of 110 nm to 500 nm, because if the average crystalline size is less than 100 nm, the crystallinity is low, the crystal structure is unstable, and cycle characteristics are poor ([0174]). Table 3 of Hoshina provides example crystal sizes in this range ([0339]).
It would have been obvious to one of ordinary skill in the art for the first positive electrode active material of modified Dumont to have a crystalline size of 110 nm to 500 nm, to prevent an unstable crystal structure and poor cycle characteristics, as taught by Hoshina. 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 MPEP § 2144.05). Therefore, modified Dumont meets the limitations of claim 7.
Regarding claim 15, modified Dumont et al. meets the limitations of claim 1 as discussed above. Dumont does not disclose the crystalline size of the first positive electrode active material. Hoshina et al. discloses a lithium manganese composite oxide represented by the general formula LixMn2O4, wherein x is 0<x≤1 ([0109]). Provided that x equals 1, the lithium manganese composite oxide disclosed by Hoshina meets the limitations of Formula 1 as claimed, and thus could be used as a first positive electrode material. Hoshina further discloses that the active material preferably has a crystalline size of 110 nm to 500 nm, because if the average crystalline size is less than 100 nm, the crystallinity is low, the crystal structure is unstable, and cycle characteristics are poor ([0174]).
It would have been obvious to one of ordinary skill in the art for the first positive electrode active material of modified Dumont to have a crystalline size of 110 nm to 500 nm, to prevent an unstable crystal structure and poor cycle characteristics, as taught by Hoshina. 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 MPEP § 2144.05). Therefore, modified Dumont meets the limitations of claim 15.
Claims 9 and 11 are rejected under 35 U.S.C. 103 as being unpatentable over Dumont et al. (US 20150349334 A1) in view of Sikha et al. (US 20160013480 A1) as applied to claims 1, 3-6, 8, 10, and 13-14 above, and further in view of Sugihara (JP 2018081787 A, published 24 May 2018, paragraphs cited from provided English translation).
Regarding claim 9, modified Dumont et al. meets the limitations of claim 8 as discussed above. Dumont does not disclose a line-type conductive agent. Sugihara discloses a positive electrode active material with an added conductive material ([0009]). Sugihara further discloses carbon nanotubes as a suitable conductive material ([0024]). Carbon nanotubes are a line-type conductive agent.
It would be obvious to one of ordinary skill in the art to substitute the conductive material of modified Dumont with carbon nanotubes as taught by Sugihara. The simple substitution of one known element for another is likely to be obvious when predictable results are achieved (see MPEP § 2143, B.). Furthermore, the selection of a known material, which is based upon its suitability for the intended use, is within the ambit of one of ordinary skill in the art (see MPEP § 2144.07). Therefore, modified Dumont meets the limitations of claim 9.
Regarding claim 11, modified Dumont et al. meets the limitations of claim 9 as discussed above. Dumont does not disclose carbon nanotubes. Sugihara discloses a positive electrode active material with an added conductive material ([0009]). Sugihara further discloses carbon nanotubes as a suitable conductive material ([0024]).
It would be obvious to one of ordinary skill in the art to substitute the conductive material of modified Dumont with carbon nanotubes as taught by Sugihara. The simple substitution of one known element for another is likely to be obvious when predictable results are achieved (see MPEP § 2143, B.). Furthermore, the selection of a known material, which is based upon its suitability for the intended use, is within the ambit of one of ordinary skill in the art (see MPEP § 2144.07). Therefore, modified Dumont meets the limitations of claim 11.
Claim 12 is rejected under 35 U.S.C. 103 as being unpatentable over Dumont et al. (US 20150349334 A1) in view of Sikha et al. (US 20160013480 A1) as applied to claims 1, 3-6, 8, 10, and 13-14 above, and further in view of Takano et al. (US 20130130113 A1, published 23 May 2013).
Regarding claim 12, modified Dumont et al. meets the limitations of claim 10 as discussed above. Dumont does not disclose the average particle diameter of the point-type conductive agent. Takano teaches a positive electrode material with a carbon black additive having an average particle size between 10 and 35 nm ([0038]), and further teaches that such a carbon black material has favorable properties ([0034]).
It would be obvious to one of ordinary skill in the art to substitute the conductive material of modified Dumont with the carbon black particles (point-type) of Takano, because Takano identifies such particles as providing beneficial properties for a positive electrode material in a battery. The simple substitution of one known element for another is likely to be obvious when predictable results are achieved (see MPEP § 2143, B.). Furthermore, the particle diameter range taught by Takano lies totally within the claimed range of 5 nm to 50 nm. A specific range in the prior art which is within a claimed range anticipates the claimed range. Therefore, modified Dumont meets the limitations of claim 12.
Response to Arguments
Applicant's arguments filed 24 December 2025 have been fully considered but they are not persuasive.
In response to applicant’s argument that a person skilled in the art would have no reasonable expectation of success in modifying the positive electrode of Dumont to replace LFP with LMO, it is noted that the features upon which applicant relies (i.e., ignition temperature when subjected to external penetration) are not recited in the rejected claim(s). Although the claims are interpreted in light of the specification, limitations from the specification are not read into the claims. See In re Van Geuns, 988 F.2d 1181, 26 USPQ2d 1057 (Fed. Cir. 1993). Furthermore, as applicant identifies that material properties such as crystal structure, lithium diffusion pathways, particle size, weight ratio, and thickness all have an effect on the results of the experimental examples, one of ordinary skill in the art cannot definitively determine whether or not the safety concerns noted in Additional Comparative Example 6 would subsequently apply to other examples in which the LFP in the second active material layer was substituted with another active material such as LCO (as used in Comparative Example 6) or LMO (as claimed). Therefore, applicant’s argument is unpersuasive.
In response to applicant’s argument that Dumont does not teach a thickness ratio of the first positive electrode active material layer to the second positive electrode active material layer is in a range of 3:7 to 7:3, applicant disagrees. Dumont discloses that the thicknesses of the layers (1 and 2) may be identical or different ([0082]). In the case that the thicknesses of the layers are identical, a thickness ratio of the first positive electrode active material layer to the second positive electrode active material layer is 5:5, which is within the claimed range of 3:7 to 7:3.
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to ALEXANDRA J SIMMONS whose telephone number is (571)272-3036. The examiner can normally be reached M-F: 9:30a - 6p.
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/A.J.S./Examiner, Art Unit 1728
/MATTHEW T MARTIN/Supervisory Patent Examiner, Art Unit 1728