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
Claims 1, 5, and 7 are pending.
Claims 2 and 3 are cancelled.
Claim 1 is amended.
Status of Amendment
The amendment filed on April 30th, 2026 has been fully considered but does not place the application in condition for allowance.
Status of Objections and Rejections Pending Since the Office Action of February 3rd, 2026
The 103 rejections of claim 1, 5, and 7 have been withdrawn in view of the Applicant's amendment.
The 103 rejections of claims 2 and 3 are moot because those claims have been cancelled.
Claim Rejections - 35 USC § 103
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, 5, and 7 are rejected under 35 U.S.C. 103 as being unpatentable over Oki (US 8,003,015 B2) and further in view of Kim (WO 2021/066560 A1; citations will be drawn to US 2022/0216480 A1), Yoo (US 2020/0343541 A1) and Tan (US 2018/0097228 A1). The combination of all four will be referred to as modified Oki.
Regarding claim 1, Oki teaches a nonaqueous electrolyte secondary battery comprising a positive electrode, negative electrode, and nonaqueous electrolyte where the positive electrode includes a positive electrode current collector and a positive electrode active material formed on the positive electrode current collector (column 16, line 59 – column 17 line 16). Oki teaches that the positive electrode active material layer has an average thickness between 1 µm and 500 µm (column 18, lines 40-41), which overlaps with the claimed range of 100 µm or greater. Oki continues to teach that their positive active material layer is comprised of particles that have an average diameter between 0.1 µm – 10 µm (column 5, lines 65 and 66) ), which overlaps with the claimed range of 10 µm or less. Oki teaches that the positive electrode active material layer also includes “a conductive material (b)” and a “fibrous conductive material (c)” (column 4, lines 34-36). This conductive material (b) may be carbon black (column 6, lines 5-10) and the conductive material (c) may be carbon nanotubes (column 8, lines 23-40). Oki continues to teach that the carbon nanotubes have lengths between 1 µm and 10 µm (column 9, lines 12-23), which overlaps with the claimed range of 1 µm to 2 µm. Oki continues to teach that the carbon nanotubes may have a diameter of 1 nm – 300 nm (column 9, lines 24-29) which overlaps with the claimed range of 10 nm or less. 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).
The electroconductive material of Oki is thoroughly dispersed (Examples 1 – 4) and the carbon nanotubes and carbon black are dispersed in a region distinguished from a region where the positive electrode active material is present. Two different objects cannot be in the exact same space; therefore, those different objects are in regions distinguished from each other.
The present claim includes limitations drawn to an amount of electroconductive material present within the positive active material layer of an electrode, quantified by the electroconductive material’s area in a cross-sectional image of the active material layer. This cross-sectional area is closely related to its surface area, and optimizing one value is likely to optimize the other. Therefore, the following rationale that discusses surface area also describes the drawbacks and benefits of having too much or too little area in a cross-sectional image.
Oki teaches a desirable range of surface area of carbon black used as electroconductive material. The range recited is 40 m2/g – 100 m2/g. There needs to be enough surface area “from the viewpoint of suitably securing the pore volume of the positive electrode” (Oki, column 12, lines 63 – 65). On the other hand, it is preferably not too great “from the viewpoint of moderately suppressing the capacity of the positive electrode to secure the compactness (Oki, column 12, line 67 – column 13, line 2). Therefore, it would have been obvious to a person of ordinary skill in the art before the effective filing date of the present invention to optimize the surface area of the electroconductive material in the positive active material layer to 1) secure the pore volume of positive electrode and to 2) moderately suppress the capacity of the positive electrode to secure compactness. "[W]here the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation." In re Aller, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1955). See MPEP 2144.05 (II).
Oki teaches a positive active material in an electrode, but does not specifically mention lithium iron phosphate (LiFePO4). Oki, however, discloses that “any conventionally known materials can be used” as the positive active material of their disclosure (column 5, lines 45-46). Tan is analogous art to Oki because both teach positive active materials for lithium batteries (Oki, title; Tan, abstract). Tan teaches that lithium iron phosphate may be used as a cathode material [0002]. Therefore, it would have been obvious to a person of ordinary skill in the art before the effective filing date of the present invention to select LiFePO-4 as the positive active material of Oki because the selection of a known material based on its suitability for its intended use supports a prima facie obviousness determination. See MPEP 2144.07.
Oki fails to specifically teach the usage of single-walled carbon nanotubes. Kim is analogous art to Oki because both teach materials used in positive electrodes (Oki, title; Kim, abstract). Kim teaches that the usage of single-walled carbon nanotubes results in a reduction of the resistance of the positive electrode and “the input/output characteristics and life characteristics of the battery may be significantly improved” (Kim, [0052]). Therefore, it would have been obvious to a person of ordinary skill in the art before the effective filing date of the present invention to use Kim’s single-walled carbon nanotubes in Oki’s positive electrode in order to improve the input/output and life characteristics of a battery comprised of Oki’s positive electrode.
The present claim includes limitations drawn to the variation in areas of electroconductive material in a cross-sectional image of the positive electrode active material layer. Small amounts of variation between the areas indicate that the electroconductive material is well-dispersed. The claim recites that the “variation of the areas…is within 15%.” Modified Oki is silent on the quantitative degree of dispersion. Yoo is analogous art to Oki because both teach materials used in positive electrodes (Oki, abstract; Yoo, abstract). Yoo teaches that a “carbon nanotube may be uniformly dispersed to improve life-time characteristics of a battery” [0011]. “Uniformly dispersed” indicates that there is 0% variation, and 0% is less than 15%. Therefore, it would have been obvious to a person of ordinary skill in the art before the effective filing date of the present invention to apply the teachings of Yoo to achieve uniform dispersion of the electroconductive material throughout the positive active material layer to improve life-time characteristics of a battery. Furthermore, 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).
The present claim further includes limitations regarding arbitrary straight lines set in a cross-sectional image of the positive active material layer. The line would cover areas containing electroconductive material as well as positive active material. A length “d1” is the summation of the lengths of all of the line segments that cover carbon nanotubes and carbon black. A length “d2” is the summation of the lengths of all the line segments that cover the positive active material layer. The claimed ratio of “d1” to “d2” has a value between 0.1 and 0.3. This range of values describes the thorough dispersion and ratio of particle/nanotube sizes present in the Applicant’s disclosure.
Since these line segments are arbitrary in nature, let a line segment be drawn that only includes the length of a carbon nanotube (1 µm, the lower limit of a range taught by Oki in column 9, line 23) as well as the diameter of a positive active material particle (5 µm, an upper limit of one of the ranges taught by Oki in column 5, line 67). This ratio results in a value of 0.2, which lines within the range claimed by the Applicant. The length of d1 is 1 µm, which is within the range of 0.5 µm – 3 µm. Therefore, Oki, modified by Yoo, teaches a range of particle sizes and degree of dispersion that overlaps with the optimized ratio range describing the degree of dispersion that is claimed by the Applicant. "[W]here the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation." In re Aller, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1955). See MPEP § 2144.05 (II).
Regarding claim 5, modified Oki teaches that the mass ratio between the carbon nanotubes, a “conductive material (c)” may have a mass content between 0.2 to 20 parts by weight relative to 100 parts by weight of the positive electrode active material to enhance the conductivity of the active material layer (Oki, column 9, lines 30 – 44). Modified Oki teaches that carbon black, a “conductive material (b)” may also have a mass content between 0.2 and 20 parts by weight relative to 100 parts by weight of the positive electrode active material to more suitably form composite particles of the active material layer (Oki, column 7, lines 52 – 64). Based on those ranges, both the carbon nanotubes and the carbon black may be 10 parts by weight relative to 100 parts by weight of the positive electrode active material. If they have the same weight relative to positive active material layer, then they would have the same weight. If they have the same weight, the mass ratio of carbon nanotubes to carbon black is 50:50. This is not the only possible combination of weight ratios; modified Oki teaches a range for each material which would result in different ratios that would also be in the range claimed by the applicant. 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). Furthermore, it would have been obvious to a person of ordinary skill in the art before the effective filing date of the present invention to use the weight percents of the carbon nanotubes and carbon black within the claimed ratio to improve the formation and conductivity of the positive active material layer.
Regarding claim 7, modified Oki teaches that the content of the conductive materials is preferably 15 parts by weight or less relative to 100 parts by weight of the positive electrode active material (Oki, column 13, lines 48 – 62), which results in a positive electrode active material mass percent much greater than 60%. 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). Modified Oki does mention that slurries for positive electrode active material layers do include a binder (Oki, column 14, lines 17-20), but it widely known by person of ordinary skill in the art that binders typically comprise a small amount of active material slurries (<5%). An excessive proportion of binder in an electrode would lower the energy density of a battery, a generally undesirable result. See MPEP 2144.03.
Response to Arguments
Applicant’s arguments, see page 5, filed April 30th, 2026, with respect to the rejection of claim 1 under U.S.C. 103 have been fully considered and are persuasive. The Examiner agrees that the combination of Oki and Kucinskis is improper based on Kucinskis teaching away from the usage of lithium iron phosphate. Therefore, the rejection has been withdrawn. Upon further consideration, a new ground(s) of rejection is made in view of Oki and further in view of Kim, Yoo, and Tan. However, the Applicant’s other arguments, including arguments of the amended claim 1, are not persuasive.
The Applicant argues that the Examiner’s position that “the fact that the inventor has recognized another advantage which would flow naturally from following the suggestion of the prior art cannot be the basis for patentability when the differences would otherwise be obvious” is erroneous (see pages 5 and 6) . The Applicant continues to state that the fact that the present application identifies specific problems that may have not be addressed by the prior art of record supports their argument. The Examiner respectfully disagrees. The structures taught by the prior art teaches that the structures of the Applicant’s disclosure are obvious modifications. Recognizing that an obvious modification of the prior art solves a problem that is unrecognized by the prior art is not an appropriate basis for patentability.
The Applicant argues that the Examiner’s position that optimizing the area/volume of electroconductive material in a positive electrode is routine is an erroneous position (see page 7). The Applicant cites Table 1 of their specification as evidence that when an electrode is prepared using conventional materials (without the specific dispersion control), the final result is an insufficient amount of dispersion within the positive electrode. The Applicant continues to state that the “claimed ranges are not achievable through routine optimization, but require specific, non-obvious control of electroconductive material dispersion”.
Based on the Applicant’s specification (see [0020]), it seems that the cited “dispersion control” is achieved by having carbon nanotubes and carbon black (“the technology disclosed herein that the positive electrode active material layer containing, as an electroconductive material, carbon nanotubes and another electroconductive material [namely, carbon black] achieve both electroconductivity and dispersibility)”. This suggests that their presence alone contributes to dispersibility.
The specification continues to suggest that having carbon nanotubes with a length in the range of 1 µm – 2 µm improves dispersibility ([0034]; also present in claim 1). The specification also discusses the size of the carbon black; uniform dispersion is difficult when the diameter of the carbon black particles is too small [0020]. This suggests a lower limit of the particles’ size, i.e., between 1 nm – 200 nm. Oki renders this range obvious while providing a motivation identical to the Applicant’s. Oki teaches that the diameter of “the carbon black is preferably 10 to 100 nm from the viewpoint of the easiness of the forcible dispersion” (column 6, lines 50-53).
The specification also discusses the mass ratio between carbon nanotubes and “the other electroconductive carbon material”, i.e., carbon black [0027]. When the mass ratio is within the described range (the range of 90:10 to 50:50, also present in claim 7), dispersibility is achieved [0027].
The Applicant’s specification, in view of the portions cited above, suggests that the specific “dispersion control” is based on the presence of electroconductive materials with specific physical properties within specific ranges. The prior art teaches these ranges and renders them obvious. Since the prior art teaches the structure described in the Applicant’s specification, one of ordinary skill in the art would expect the prior art’s positive electrode to achieve the same degree of dispersion that the Applicant’s claimed positive electrode possesses.
The Applicant states that Examples 2 and 3 do not have the specific dispersion control. Examples 2 and 3 have a mass ratio between carbon nanotubes and carbon black that is outside of the claimed range (6:0, which is undefined and 0:8, which is zero, see Table 1 included below). Since the Applicant’s dispersion control is based on the presence and physical properties of the carbon nanotubes and carbon black, it is expected that these two Examples would have unsatisfactory performance. The prior art, however, teaches the claimed properties that would lead to the desired dispersion control and positive performance.
Additionally, the Examiner would like to point out that the Reference Example 1, a conventionally prepared electrode whose thickness is lower than the lower limit of the claimed range (43.5 µm < 100 µm) and whose Sn variation % is greater than the upper limit of the claimed range (25% > 9%) had good performance. The electroconductive material was not dispersed, but there was no presence of a voltage abnormality and the specific charge capacity, specific discharge capacity, and charge discharge efficiency values were all greater than those of the exemplary Example 1 (158.9 > 157.8, 147.1 > 143.3, and 92.5 > 90.8, respectively).
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The Applicant argues that that the Examiner’s position and rationale for rejection of the limitation drawn to the ratio of length d1 to length d2 is inappropriate. The Examiner appreciates the Applicant’s description of the intention behind these limitations. However, the Examiner maintains their position regarding the underlying rationale due to the exact language of the claim. The lines drawn across the cross-sectional image are arbitrary, and therefore can start from any position in the image as well as have any length. Therefore, a line containing only the length of a carbon nanotube and the diameter of a single positive active material particle fits this definition.
The Applicant also alleges that if the prior art is silent on quantitative dispersion, it cannot simultaneously render a specific quantitative ratio obvious. The claimed ratio is based on the structure of the dispersed positive electrode active material layer which is taught by the prior art. Deriving or optimizing a quantitative value, range, or ratio from a structure that is already present in the prior art is not a basis for patentability. "[W]here the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation." In re Aller, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1955). See MPEP 2144.05 (II).
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure:
Kawasaki (US 2012/0258363 A1) teaches the usage of lithium iron phosphate as an active material, notable deficiencies/weaknesses of the material, and suggests the usage of fibrous carbon and carbon black to cure these deficiencies. These materials have diameters and specific surface areas similar to the ranges claimed by the Applicant [0009] – [0016].
Tarumoto (US 2013/0309926 A1) discusses a myriad of benefits specific to carbon fibers in LiFePO4 – based cathodes, such as the prevention of static electricity [0002] – [0004].
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
Any inquiry concerning this communication or earlier communications from the examiner should be directed to RYAN K BLACKWELL-RUDASILL whose telephone number is (571)270-0563. The examiner can normally be reached Monday - Friday 9:00 a.m. - 5:00 p.m.
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/R.B.R./Examiner, Art Unit 1722
/NIKI BAKHTIARI/Supervisory Patent Examiner, Art Unit 1722
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