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 .
Continued Examination Under 37 CFR 1.114
A request for continued examination under 37 CFR 1.114, including the fee set forth in 37 CFR 1.17(e), was filed in this application after final rejection. Since this application is eligible for continued examination under 37 CFR 1.114, and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114. Applicant's submission filed on 11/08/2024 has been entered.
Response to Amendment
This is a nonfinal office action in response to Applicant's remarks and amendments filed on 11/08/2024. Claims 1 and 5 are currently amended. Claims 13-18 remain withdrawn. Claims 2-4, 21, 23-39 are cancelled. Claims 45-50 are newly added. Claims 1, 5-8, 11, 12, 19, 20, 22, and 40-50 are pending review in this action.
The 35 U.S.C. 102 and/or 35 U.S.C. 103 rejections of the previous Office Action are withdrawn.
New grounds of rejection necessitated by Applicant's amendments are presented below.
Response to Arguments
Applicant’s arguments with respect to claim rejection under 35 U.S.C .102/103 of claims 1, 6-8, 12, and 40-41 in view of Kercher et al. "Carbon Fiber Paper Cathodes for Lithium Ion Batteries" filed 11/08/2024 have been fully considered but are moot because the amendment to claim 1 has overcome the rejection under 35 U.S.C. 102/103 in view of Kercher.
Applicants’ arguments regarding rejection under 35 U.S.C. 103 have been fully considered but are not found persuasive.
Applicant argues that one having ordinary skill in the art would not reasonably select a carbon paper of Kercher with 70% or more active material in the porous regions of the carbon paper (see Applicant remarks, pp. 10), as recited in amended claim 1.
In particular, Applicant asserts that as set forth on p. 2 of the Rule 1.132 Declaration from Jingxu Zheng (“the Zheng Declaration”) filed 01/30/2024, in No. 7, the aggregation and percolation of the particles in the slurry used in Kercher would reasonably be expected to prevent infiltration of the particles into the porous regions of the matrix and not achieve 70% or more of the materials in the porous regions of the carbon paper.
While this argument has been considered, this has not been found persuasive. Although Kercher does not disclose an exact percentage of active material in the porous regions, one having ordinary skill in the art would still reasonably visually estimate the amount of active material outside these regions is 30% or less.
Kercher teaches a carbon fiber paper as a cathode support (Experimental, p. 1323), such that the spaces, or voids, between individual carbon fibers form a plurality of porous regions throughout the paper (see fig. 1). The porous regions thus extend in the thickness direction of the cathode as far as the carbon fibers extend. Kercher specifically teaches that excess slurry is removed from the surface of the cathode (“CFP disks were manually coated with slurry, and excess slurry was carefully removed from the surface”, Experimental, p. 1323). Figs. 1(a) and 1(c) show very little active material left on the outermost surfaces of the carbon fibers, which corresponds to most of the active material being inside the porous regions, as is further borne out by the cross-sectional views provided in figs. 1(b) and 1(d).
While a small portion of slurry is present on the exterior outer surface, 30% comprises a significant fraction of active material which does not appear present. If such a significant amount of active material were present on the exterior/outer surfaces of the carbon paper, one having ordinary skill in the art would expect this amount of slurry to visibly cover the surface of the matrix, such that the pores and/or fibers of the matrix are obscured by the layer of active material. As shown in FIGs. 1a and 1c of Kercher, images of the surface of the cathode clearly show the fibers and the pores are visible underneath any surficial active material, indicating that although some active material is present on the surface, the amount does not appear to be 30% of the material or larger.
Furthermore, in the event that the embodiments of Kercher have inherently less than 70% of the active material contained in the porous regions, it would have been obvious to a person of ordinary skill in the art to have ensured at least 70% of the active material is contained in the porous regions, in order to ensure that most, and preferably all, of the active material enjoys the thermal, electrical, and structural advantages of the carbon fiber paper matrix (“The conductive carbon support and rigid carbon bonding of CFP cathodes potentially enable (1) superior thermal management due to the rigid thermally conductive structure dispersed throughout the cathode layer; (2) improved cycle life due to rigid carbon bonding of the active cathode material with the current collector; and (3) a higher electronic transport through the composite free of binders and flaws caused by compaction pressures.”, Introduction, p. 1323).
Applicant argues that Office's contentions do not support a reasonable conclusion as to how much of the active material is present in the porous regions of the carbon paper, as Kercher discloses a step of removing excess slurry material which is not incorporated in the porous regions of the carbon paper, and removal of excess slurry does not foreclose deposition of the active material on the exterior/outer surface or other non-porous portions of the carbon paper (see Remarks pp. 11).
While this argument has been considered, this has not been found persuasive. In particular, the removal of excess slurry concedes that all of the slurry is not incorporated in porous regions of the carbon paper during manufacture, not in the finished cathode or cathode material product. The instant claims are directed to a finished product, being the cathode or cathode material; the weight percentage of active material in the slurry and the amount of slurry removed from the finished cathode or cathode material is not relevant. Furthermore, while Kerscher does not disclose an exact percentage of active material in the porous regions, one having ordinary skill in the art would still reasonably visually estimate the amount of active material outside these regions is 30% or less.
Applicant further asserts that Office's reliance on Kerscher Figures 1(a) and 1(c) is improper (see Remarks pp. 11).
While this argument has been considered, the argument has not been found to be persuasive. While exact percentages of active material cannot be elucidated from the figures alone, a rough estimation of the amount and distribution is still provided in these figures, such that a prima facie case obviousness can be made.
Applicant further asserts that Kercher et al. "coated porous carbon cathodes for lithium ion batteries" (hereinafter referred to as Kercher 2), cited in an IDS filed concurrently with the response, indicates that slurry coating carbon paper results in "significant open pore volume" remaining in the cathodes produced in the first paragraph of pp. 112, and therefore, no reasonable conclusion of how much active material is incorporated in the porous regions of carbon paper of Kercher.
This is not found persuasive. The presence of some amount of pore volume remaining in the cathode as disclosed by Kercher 2 does not require that a significant amount of active material be present on the outside surface of the cathode. Furthermore, the CFP material disclosed by Kercher (see Kercher pp. A1324 Table I) comprises a fairly large porosity of 78-80% to start with; a sizeable amount of active material can be present in the large volume provided by the pores without reducing the residual porosity below a “significant open pore volume”.
Applicant again asserts that as set forth on p. 2 of the Rule 1.132 Declaration from Jingxu Zheng (“the Zheng Declaration”) filed 01/30/2024, in No. 7, the aggregation and percolation of the particles in the slurry used in Kercher would reasonably be expected to prevent infiltration of the particles into the porous regions of the matrix and not achieve 70% or more of the materials in the porous regions of the carbon paper (see Remarks pp. 12).
The Examiner respectfully disagrees and submits again that the Kercher does achieve the claimed infiltration of at least 70% active material in the porous regions as required in claim 1 (see the Experimental and Results, p. 1323-1326, and fig. 1, as discussed above). Further, the Examiner notes that Kercher does achieve infiltration of active material particles even into the centermost porous regions of the matrix (“Successful infiltration with coating slurries was observed for 0.11 and 0.37 mm thick CFP disks. Figure 1 shows scanning electron microscopy (SEM) images of top surfaces and fracture cross-sections of CFP cathodes. Both the 26 wt % slurry and the 41 wt % slurry penetrated into the center of the papers”, Results, p. 1324). The Examiner also notes that the mere fact that the claimed material was made by a novel method does not distinguish the claimed invention over the prior art. In this case, the novel step of mechanical agitation is not required to achieve the claimed invention, since the embodiments of Kercher read on the claimed invention and are made without mechanical agitation. Therefore, the method used to make the claimed invention does not distinguish the claimed invention over the prior art.
Applicant further asserts that one of ordinary skill in the art would not reasonably conclude that simply substituting the carbon paper of Kercher with a cloth/fabric would also not inherently or reasonably be expected to provide a carbon cloth/fabric with 70% or more active material in the porous regions of the carbon cloth/fabric of claim 1 (Remarks pp. 12). Applicant cites Wang et al. "Elucidating the differences between carbon paper and carbon cloth in polymer electrolyte fuel cells" that shows structural differences between carbon cloth and carbon paper.
The Examiner respectfully disagrees and submits that, in addition to further evidencing suitability and an expectation of advantage of substituting carbon cloth/fabric for the carbon fiber paper for use in Kercher’s cathode or cathode material, Applicant’s assertions and Wang’s teaching of carbon cloth/fabric and carbon fiber paper having different structures would not necessarily prevent a carbon cloth from comprising 70% or more active material in the porous regions in the carbon cloth of claim 1 when produced by Kercher’s disclosed method.
While the carbon cloth and the carbon paper appear to comprise different structures in terms of fiber distribution, Kercher does not seem to indicate that the random distribution present in carbon paper is a requirement for compatibility with the inventive disclosure. Kercher selects the carbon fiber papers due to their "mechanical integrity, electrical and thermal conductivity” (pp. A1323 col. 2 paragraph 3). Wang notes the thermal conductivity and electronic conductivity of carbon cloth is identical to that of carbon paper (pp. 3969, col. 2 paragraph 2), and both are carbon-fiber based porous materials (pp. 3965, col. 2 paragraph 2) and carbon cloth would therefore be expected to have equivalent, if not improved, mechanical properties. Furthermore, Wang indicates that carbon cloth is more porous than carbon paper (pp. 3968, paragraph 7), and therefore, would be as capable of, if not more capable, of comprising 70% or more of the active material in the porous regions. As such, one having ordinary skill in the art would reasonably conclude carbon cloth to be a suitable material for use in Kercher’s cathode or cathode material, and would have similar content of active material in porous regions.
Furthermore, while Applicant cites Wang as highlighting differences between the structure of carbon cloth/fabric and carbon paper (Remarks pp. 12-13), Applicant does not explain or reference any differences between carbon cloth/fabric matrix and carbon paper matrix that would specifically preclude a carbon cloth/fabric matrix from having 70% or more active material within the porous regions or of having this structure in light of a particular mass loading of the active material, through use of the methods disclosed or suggested by Kercher for a carbon paper matrix.
Applicant asserts that dependent claims 11, 19-20, 22, 24 are allowable, as the references cited in rejection of these claims do not cure the deficiencies of Kercher with respect to amended independent claim 1 (Remarks pp. 13-15).
This assertion has been considered but is moot because the claim amendments have necessitated a new ground of rejection under 35 U.S.C. 103 of Kerscher in view of Wang. Furthermore, an additional rejection of these claims has further been made under 35 U.S.C. 103 in view of Chen et al. WO2017152836A1 (Equivalent publication US20190088981A1 cited as an English translation) as evidenced by, or in the alternative, in view of Zhamu US20170098856A1; see pages -18-25 of this office action; see pages -18-25 of this office action.
Claim Rejections - 35 USC § 103
The text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office action.
Claims 1, 3, 5-8, 12 and 40-43 is/are rejected under 35 U.S.C. 103 as obvious over Kercher et al. "Carbon Fiber Paper Cathodes for Lithium Ion Batteries" (see copy provided in office action filed 05/08/2024), in view of Wang et al. “Elucidating differences between carbon paper and carbon cloth in polymer electrolyte fuel cells” (see copy provided in IDS filed 10/08/2024).
Regarding claim 1, Kercher teaches a cathode (Abstract) comprising:
an electrically conducting 3-dimensional (3-D) matrix comprising a plurality of porous regions (the electrically conducting carbon fiber paper support is a 3-D matrix with porous regions, as seen in fig. 1; see also Abstract and Experimental section on p. A1323).
Kerscher discloses a general desirability of the “mechanical integrity, electrical and thermal conductivity, and gas permeability” exhibited by carbon fiber paper as a matrix material in related fuel cell applications (pp. A1323 col. 2 paragraph 3), noting that poor heat conduction or points of high current density causes thermal accidents in polymerically bound powders in commercials cathodes (pp. A1323, col. 2, paragraph 2), and further discloses that lower densities of CFPs matrix material would be advantageous to improve the specific capacity of the cathode (pp. A1327 col. 1 paragraph 1); however, Kerscher does not explicitly disclose the use of carbon cloth or fabric as the electrically conducting 3-D matrix.
Secondary reference Wang teaches considerations of carbon paper and carbon cloth as materials in polymer electrolyte fuel cells (Wang, Abstract). While Wang does not discuss the use of these materials in a battery cathode, one having ordinary skill in the art would expect the material properties of carbon paper and carbon cloth to apply regardless of the application. In particular, Wang notes that carbon cloth has equivalent or superior performance with respect to current density, especially at higher current densities (Wang pp. 3970 col. 1 paragraph 2). The thermal conductivity and electronic conductivity of carbon cloth is also identical to that of carbon paper (pp. 3969, col. 2 paragraph 2), and both are carbon-fiber based porous materials (pp. 3965, col. 2 paragraph 2). Furthermore, carbon cloth is more porous than carbon paper (pp. 3968, paragraph 7), and therefore has a lower density than carbon paper.
As such, in seeking to decrease the mass density, and increase the specific capacity, and improve the performance with respect to current density of Kerscher’s cathode, it would be obvious before the effective filing date of the instant application for one having ordinary skill in the art to substitute carbon cloth for carbon paper in Kerscher’s cathode as the 3-D matrix material. Such a substitution would be made with a reasonable expectation of success, as carbon paper and carbon cloth are both porous carbon-fiber based porous materials with equivalent thermal and electrical conductivity, and as Kerscher discloses a desirability to decrease the density and improve the performance of the cathode at high current densities of the cathode.
Modified Kerscher further discloses an active material chosen from lithium iron phosphates (LFPs) (LiFePO4, see Experimental section on p. A1323).
While Modified Kerscher does not explicitly list the mass loading of the active material, Kerscher provides an example embodiment of a matrix material comprising a thickness of 0.037 cm (“0.37 mm”) and a bulk density of 0.45 g/cm3 (pp. 1324 Table I), corresponding to a total mass of 0.01665 g/cm2 or 16.65 mg/cm2. In a finished embodiment of a cathode comprising the matrix material, Kerscher measures a total weight percentage of the LFP active material to be 44 wt% (pp. 1324 Table II, 0.37mm thick CFP with 41% ORNL slurry). As there are approximately 44 parts by weight LFP to 66 parts matrix material present at 16.65 mg/cm2, a mass loading of the material is equivalent to 16.65 mg/cm2*(44/66) = 11.1 mg/cm2, which falls within the claimed range.
Furthermore, while Kerscher does not explicitly provide a mass loading of the active material in a carbon cloth matrix, as Wang indicates that carbon cloth comprises a higher porosity than carbon paper, one having ordinary skill art would reasonably expect a carbon cloth matrix with similar properties to the carbon paper matrix used by Kerscher (see pp. A1324 Table I “TGP-H-120”) “to comprise an equivalent, if not greater mass loading of active material.
Assuming arguendo that Kerscher modified in view of Wang does not comprise a mass loading of at least 10 mg/cm2, Kerscher discloses a desirability to increase the mass loading of active material in order to increase cathode capacity (Kerscher pp. A1326 col. 2 paragraph 2), and explicitly suggests optimizing an active material slurry concentration or coating method in order to do so beyond the mass loading of the provided experimental examples (pp. A1326 col. 2 paragraph 2-A1327 col. 1 paragraph 1), alongside decreasing the density of the 3-D matrix (pp. A1327 col. 1 paragraph 1).
As such, in seeking to increase the cathode capacity and active material mass loading of a carbon cloth 3-D matrix in modified Kerscher, it would be obvious to utilize at least one of the methods suggested by Kerscher such as optimizing a coating slurry composition or coating method. In doing so, one having ordinary skill in the art would reasonably be expected to produce a cathode having at least an equivalent mass loading to the experimental example provided by Kerscher being 11.1 mg/cm2.
As Kerscher provides a working embodiment of a matrix material having this mass loading, and Wang teaches that the carbon fiber cloth 3-D matrix has a higher porosity and lower density (pp. 3968, paragraph 7) alongside otherwise identical or improved properties to that of the carbon fiber paper (Wang pp. 3970 col. 1 paragraph 2, pp. 3969, col. 2 paragraph 2, pp. 3965, col. 2 paragraph 2), it would be obvious before the effective filing date of the instant application for one having ordinary skill in the art to select 11.1 mg/cm2 as a loading density of active material in the carbon cloth 3-D matrix of modified Kerscher. Such a modification would be made with a reasonable expectation of success due to the similar properties between these materials and as Kerscher discloses that decreases to the density of the matrix material allows for improved cathode capacity (Kerscher pp. A1327 col. 1 paragraph 1).
Kerscher further discloses a carbon conductivity aid (AR mesophase pitch, see Experimental section on p. A1323 and Discussion section on p. A1326),
wherein the porous regions comprise 78 or 80%, within the claimed range of 30% or more, of the total volume of the electrically conducting 3-D matrix (Table I on p. A1324),
wherein the porous regions are at least partially continuous (fig. 1 shows that the porous regions between the carbon fibers of the matrix are at least partially continuous, where porous region is understood to mean a void space between carbon fibers),
wherein the active material is disposed in or on, at least a portion of the porous regions of the electrically conducting 3-D matrix (fig. 1 shows the active material disposed in the porous regions of the matrix),
wherein the active material is not present only on an exterior surface of the electrically conducting 3-D matrix (fig. 1 shows the active material present in the interior as well as on the exterior surface of the carbon fiber paper matrix; see also Results section on p. A1324).
Kercher discloses that the coating slurry comprising LFP infiltrates the matrix such that the active material is in the porous regions (fig. 1, Experimental section on p. A1323-A1324). Kercher also teaches that the matrix provides important benefits including thermal management, structural support, and high electron transport (introductory section, p. A1323). Kercher does not explicitly teach the percentage of active material in the porous regions.
However, Kercher does teach that the matrix is infiltrated with coating slurry that comprises the active material, and that the slurry penetrated into the center of the matrix (see Results on p. 1324). Kercher also teaches that excess slurry was removed from the surface (see Experimental on p. 1323). The removal of the active material containing slurry from the surface of the matrix of Kercher maximizes the relative proportion of active material in the porous regions, thus necessarily and inherently disclosing that 70% or more of the active material is in the porous regions.
Assuming for the sake of argument that the claimed percentage of 70% or more of the active material is in the porous regions is not inherent to the cathode of Kercher, it would be obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to have selected 70% or more as the percentage of active material in the porous regions of Kercher, in order to ensure that most, if not all, of the active material enjoys the thermal, electrical, and structural advantages of the carbon fiber paper matrix. 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.).
Regarding claim 5, modified Kercher discloses all of the limitations as set forth above. Wang, relied upon to teach the structure of a carbon cloth 3-D matrix (see discussion of claim 1 above) further evidences that carbon cloth is woven (Wang pp. 3966, col. 2 paragraph 2).
Regarding claim 6, modified Kercher discloses all of the limitations as set forth above. Wang, relied upon to teach the structure of a carbon cloth 3-D matrix (see discussion of claim 1 above) further evidences that the electrically conducting 3-D matrix is a carbon framework (carbon fiber, Wang pp. 3965, col. 2 paragraph 2).
Regarding claim 7, modified Kercher discloses all of the limitations as set forth above. Kercher further discloses that the active material is disposed on a surface of the electrically conducting 3-D matrix and in the porous regions (the coating slurry infiltrated the carbon fiber paper, i.e. the active material is disposed in the porous regions; excess coating on the surface corresponds to the active material on the surface of the matrix; see Results section on Kerscher p. A1324).
Regarding claim 8, modified Kercher discloses all of the limitations as set forth above. Kercher further discloses that the active material is an ion-conducting material (see Abstract; Kercher discloses a lithium-ion battery, i.e. a battery with an active material that conducts lithium ions).
Regarding claim 12, modified Kercher discloses all of the limitations as set forth above. Kercher further discloses that at least a portion of a surface of the electrically conducting 3-D matrix is surface modified (Kercher fig. 1 shows that the surface of the matrix has portions coated with active material coating slurry, such that the matrix has a modified surface; the Results section on p. A1324 and fig. 3 show that the carbon fibers of the matrix are at least partially coated, and thus modified from the previous state of being bare fibers).
Regarding claim 40, modified Kercher discloses all of the limitations as set forth above. Kercher further discloses that the active material is infiltrated in the porous regions of the electrically conducting 3-D matrix (the coating slurry, which comprises the LFP active material, infiltrated the matrix, i.e. the active material is disposed in the porous regions; see Kercher Fig. 1 and Results section on p. A1324).
Regarding claim 41, modified Kercher discloses all of the limitations as set forth above. Kercher further discloses that the porous regions comprise 78 or 80%, within the claimed range of 50% or more, of the total volume of the electrically conducting 3-D matrix (Kercher Table I on p. A1324).
Regarding claim 42, modified Kercher discloses all of the limitations as set forth above.
Kercher teaches that the cathode or cathode material is a composite (containing at least a carbon fiber matrix, an active material, and a carbon conductivity aid, specifically AR mesophase pitch), and that the carbon conductivity aid (pitch) is present at 3.3% by weight based on the total weight of the active material (lithium iron phosphate) and the carbon conductivity aid (see Experimental section on p. A1323 and Discussion section on p. A1326; a 0.034 ratio of pitch to lithium iron phosphate is equivalent to 3.3% pitch based on a total of pitch and lithium iron phosphate). Kercher teaches that lithium iron phosphate is used as the active cathode material (col. 1, p. A1323), and that AR mesophase pitch is an additive used to improve electrical conductivity (Discussion, col. 2, p. A1326).
It would be obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to have optimized the amount of the carbon conductivity aid based on the total weight of the active material and carbon conductivity aid in order to balance the desired capacity provided by the active material (lithium iron phosphate) with the desired electrical conductivity provided by the carbon conductivity aid (AR mesophase pitch). A lower percentage of conductivity aid would result in a higher relative capacity due to the higher percentage of active material, and a higher percentage of conductivity aid would result in improved electrical conductivity. Where 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. 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.).
Regarding claim 43, modified Kercher discloses all of the limitations as set forth above.
Kercher teaches that the cathode or cathode material is a composite (containing at least a carbon fiber matrix, an active material, and a carbon conductivity aid, specifically AR mesophase pitch), and that the carbon conductivity aid (pitch) is present at 3.3% by weight based on the total weight of the active material (lithium iron phosphate) and the carbon conductivity aid (see Experimental section on p. A1323 and Discussion section on p. A1326; a 0.034 ratio of pitch to lithium iron phosphate is equivalent to 3.3% pitch based on a total of pitch and lithium iron phosphate). The lithium iron phosphate is thus present at 96.7% based on the total weight of the active material and carbon conductivity aid. Kercher teaches that lithium iron phosphate is used as the active cathode material (col. 1, p. A1323), and that AR mesophase pitch is an additive used to improve electrical conductivity (Discussion, col. 2, p. A1326).
It would be obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to have optimized the amount of the active material based on the total weight of the active material and carbon conductivity aid in order to balance the desired capacity provided by the active material (lithium iron phosphate) with the desired electrical conductivity provided by the carbon conductivity aid (AR mesophase pitch). A lower percentage of active material would result in a higher electrical conductivity due to the higher percentage of carbon conductivity aid, and a higher percentage of active material would result in a higher relative capacity. Where 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. 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.).
Regarding claim 49, modified Kercher discloses the cathode or cathode material of claim 1, wherein the cathode or cathode material does not comprise a binder (“absence of a binder”, Kercher pp. A1323 col. 2 paragraph 2)
Claim 11 is/are rejected under 35 U.S.C. 103 as being unpatentable over Kercher in view of Wang as applied to claim 1 above, and further in view of Cheng et al. (CN 103840164 A, see also machine translation enclosed with the action of 02/28/2022).
Regarding claim 11, modified Kercher discloses all of the limitations as set forth above.
Kercher teaches AR mesophase pitch as a carbon conductivity aid (see Experimental section on p. A1323 and Discussion section on p. A1326), However, Kercher is silent as to whether the carbon conductivity aid is anisotropic, isotropic, or a combination of both.
Cheng teaches a carbon conductivity aid for lithium-ion battery (Title); since conductivity is a property of the carbon conductivity aid per se, the carbon material is relevant to other types of lithium batteries such as the lithium ion battery of Kercher. Cheng teaches a specific embodiment wherein the carbon conductivity aid is a combination of an anisotropic carbon conductivity aid and an isotropic carbon conductivity aid (“2 grams of graphene, 2 grams of Super-P”, Cheng [0036], where graphene is anisotropic and Super-P is isotropic according to the instant specification [0063]).
It would have been obvious to a person having ordinary skill in the art at the time of the effective filing date of the claimed invention to substituted a combination of anisotropic graphene and isotropic Super-P as taught by Cheng for the carbon conductivity aid of Kercher. A person of ordinary skill in the art would have reasonably expected the combination of anisotropic graphene and isotropic Super-P to provide conductivity to the cathode of Kercher (see [0006] and [0026] of Cheng). 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).
Claims 19-20 is/are rejected under 35 U.S.C. 103 as being unpatentable over Kerscher in view of Wang as applied to claim 1 above, and further in view of Arrebola et al. (Arrebola, Jose C., Alvaro Caballero, Lourdes Hernan, and Julian Morales. “A high energy Li-ion battery based on nanosized LiNi0.5Mn1.5-O-4 cathode material.” Journal of Power Sources, 183, 2008, 310-315, enclosed with the action of 10/26/2022).
Regarding claim 19, modified Kercher discloses all of the limitations as set forth above.
Kercher further discloses a device comprising the cathode of claim 1 (Abstract, Experimental section on p. A1324; the lithium ion cell of Kercher is a species of device).
Kercher is silent as to the N:P ratio of the device.
Arrebola teaches a device comprising a lithium oxide active material (Title). Specifically, Arrebola teaches N/P ratios between 1:1 and 1:10, or between 0.1 and 1 (section 3.3, p. 3, col. 1; fig. 3).
It would have been obvious to a person having ordinary skill in the art at the time of the effective filing date of the claimed invention to have selected the N/P ratio of Arrebola for the device of modified Kercher in order to maximize battery performance (section 3.3, p. 3, col. 1 of Arrebola; section 4, p. 6, col. 1 of Arrebola).
Regarding claim 20, modified Kercher discloses all of the limitations as set forth above. Kercher further discloses that the device is an electrochemical device, specifically a battery (Abstract of Kercher).
Claims 22 and 44 is/are rejected under 35 U.S.C. 103 as being unpatentable over as applied to Kerscher in view of Wang as applied to claim 1 above, and further in view of Joo et al. (US 2015/0099185 A1, cited in office action filed 05/08/2024).
Regarding claims 22 and 44, modified Kercher discloses all of the limitations as set forth above.
Kercher teaches that the active material is a lithium iron phosphate material (LFP) rather than a lithium nickel manganese cobalt oxide material (Abstract of Kercher).
Joo teaches a cathode for an electrochemical device, specifically a lithium ion battery, that may comprise a porous carbon matrix and a lithium-containing active material embedded in the matrix (Abstract and [0011] of Joo). Specifically, Joo teaches that the lithium active material may be selected from lithium iron phosphate (LiFePO4), LiNi1/3Co1/3Mn1/3O2 or LiNib1Cob2Mnb3O2, wherein b1+b2+b3=1 and 0≦b1, b2, b3<1. The formula LiNib1Cob2Mnb3O2 includes the specific compound LiNi0.5Co0.2Mn0.3O2, which is a lithium nickel manganese cobalt oxide.
It would be obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to have substituted LiNi1/3Co1/3Mn1/3O2 or LiNi0.5Co0.2Mn0.3O2, as taught by Joo, for the LiFePO4 active material of modified Kercher. 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).
Claims 1, 5-8, 22, and 40-50 are rejected under 35 U.S.C. 103 as being unpatentable over Chen et al. WO2017152836A1 (U.S. equivalent of this document US20190088981A1 referenced as an English translation) as evidenced by, or in the alternative, in view of Zhamu et al. US20170098856A1.
Regarding claim 1, Chen discloses a cathode (“positive electrode piece”) and a cathode material (“electric-conductive cathode particles”, Chen, abstract) comprising an electrically conducting 3-dimensional (3-D) matrix (“cathode surface current-collecting layer”) comprising a plurality of porous regions, wherein the electrically conducting 3-D matrix is a carbon fabric (“cathode surface current-collecting layer…is a carbon fiber conductive fabric”, [0018]);
And an active material chosen from lithium nickel manganese cobalt oxides, LiCoO2 (LCO), lithium manganese oxides (“lithium-doped manganese oxide”), lithium iron phosphates (LFPs), LiMnPO4, and any combination thereof ([0012]).
Chen further discloses that the cathode or cathode material comprises a structure wherein part of or all of the cathode material may be provided inside the pores of the matrix (“partly or all provided on the surface or in the mesh pores of the cathode surface current-collecting layer”, [0020]). While Chen further discloses that the matrix preferably has a thickness of 0.05 to 1000 µm ([0018]), and a Chen discloses a cathode or cathode material with this structure can carry a larger amount of electrode active material per unit compared to cathodes of the prior art ([0003]), Chen does not explicitly indicate a mass loading of the active material is 10 mg/cm2 to 300 mg/cm2.
Secondary reference Zhamu, similarly directed to electrodes such as cathodes having active materials in an electrically conductive porous layer structure (Zhamu [0027-0028]) such as a carbon nanofiber mat ([0049]), broadly and reasonably interpreted as an analogous electrically conducting 3-D matrix, shares similar considerations of increasing the thickness and mass loading of the electrode ([0014]). Zhamu further notes that in most cases, an active material mass loading of conventional electrodes having low capacities is 15 mg/cm2 or less ([0011]). Zhamu further teaches that the cathode or cathode material having this structure may have a practical thickness of up to 1000 µm ([0178]), and suitably comprises a cathode active material loading of 60 mg/cm2 ([0179]).
While Chen and Zhamu are not identical, given the similarity in structure between Chen and Zhamu and similar aims of improving a mass loading of the active material, one having ordinary skill in the art would reasonably expect Chen to comprise a similar active material loading to Zhamu. As Chen indicates that the cathode or cathode active material comprises a larger amount of electrode active material per unit compared to cathodes of the prior art (Chen [0003]), one having ordinary skill in the art would reasonably conclude that this comprises at least 15 mg/cm2 as in line with Zhamu’s teaching of prior art typically comprising this loading amount. One having ordinary skill in the art would also reasonably conclude that a practical limit of Chen’s cathode or cathode material comprises 60 mg/cm2 for a matrix with a thickness of 1000 µm. Such a loading amount falls within the claimed range of 10 to 300 mg/cm2.
Assuming, arguendo, that Chen necessarily does not disclose an active material loading of at least 10 mg/cm2 and less than 300 mg/cm2, in seeking to improve the amount of active material electrode active material carried in the cathode layer, it would be obvious before the effective filing date of the instant application for one having ordinary skill in the art to select a value within 15 mg/cm2 to 60 mg/cm2 as an active material loading for Chen’s cathode as taught by Zhamu. Such a selection would be made with a reasonable expectation of success due to the similar dimensions and structures shared between Chen and Zhamu’s cathode and cathode materials, and due to the wide range of suitable cathode or cathode material thicknesses disclosed by Chen.
Chen further discloses the inclusion of a carbon conductivity aid (“conductive agent”, Chen [0014]).
Chen discloses that the 3-D matrix comprises a through-hole porosity, i.e., a total volume comprised by the porous regions, of 10-90% ([0018]), which overlaps with a portion of the claimed range between 30-90% and necessitates that the porous regions be at least partially continuous (“through-hole”).
Chen discloses the active material comprised by the cathode material (“electric-conductive cathode particles are compounds or mixtures of the cathode active materials and conductive agents”, [0008]) is disposed in or on at least a portion of the porous regions of the electrically conducting 3-D matrix (“provided on the surface or in the mesh pores of the cathode surface current-collecting layer”, [0020]). Chen discloses that some or all of the material may be provided in the pores of the 3-D matrix (“partly or all provided on the surface or in the mesh pores”, [0020]), and therefore, 70% or more of the active material may be present in the porous regions of the electrically conducting 3-D matrix and not on an exterior surface.
Regarding claim 5, modified Chen discloses the cathode or cathode material of claim 1. While Chen does not explicitly disclose the carbon fabric is woven, the structure of a fabric implies a weaving process; for instance, Collins dictionary defines a ‘fabric’ as “cloth or other material produced by weaving together cotton, nylon, wool, silk, or other threads”.
Regarding claim 6, modified Chen discloses the cathode or cathode material of claim 1, wherein the electrically conducting 3-D matrix is chosen from carbon frameworks (“carbon fiber conductive fabric”), metal frameworks (“metal mesh or a metal wire woven mesh”), and other frameworks formed from other conductive materials, and combinations thereof (“or conductive blanket composed of metal wires and organic fibers”, “a combination of the two or more of the above” (Chen [0018]).
Regarding claim 7, modified Chen discloses the cathode or cathode material of claim 1, wherein the active material is disposed on a surface of the electrically conducting 3-D matrix or in the porous regions or both (“partly or all provided on the surface or in the mesh pores of the cathode surface current-collecting layer”, Chen [0020]).
Regarding claim 8, modified Chen discloses the cathode or cathode material of claim 1, wherein the active material is LCO, LFP, NCM (see discussion of claim 1), and additionally sulfur (Chen [0012]); paragraph [0057] of the instant specification lists these (LCO, LFP, NCM, LMNO, sulfur, and selenium) as examples of ion-conducting materials.
Regarding claim 11, modified Chen discloses the cathode or cathode material of claim 1, wherein the carbon conductivity aid is selected from a group consisting of selected from a group consisting of at least carbon fiber, carbon nanotube, graphene, ketjen black and carbon black or a mixture thereof (Chen [0014]); paragraph [0063] lists carbon fiber, carbon nanotube, and graphene as anisotropic carbon conductivity aids and lists ketjen black and the like (“carbon black”) as isotropic carbon conductivity aids.
While Chen’s disclosure of “a mixture thereof” appears to provide sufficient specificity as to read on the claimed limitation of “a combination of an anisotropic carbon conductivity aid and an isotropic carbon conductivity aid”, assuming arguendo that Chen’s disclosure is insufficient, it would be obvious to combine an anisotropic and isotropic carbon conductivity aid as equivalents known for the same purpose of improving the conductivity of the cathode or cathode material; see MPEP 2444.06 I.
Regarding claim 40, modified Chen discloses the cathode or cathode material of claim 1, wherein the active material is disposed in or on the porous regions of the electrically conducting 3-dimensional matrix (“partly or all provided on the surface or in the mesh pores of the cathode surface current-collecting layer”, Chen [0020]), and is broadly and reasonably interpreted as infiltrated in as recited by [0084] of the instant specification, “active material is disposed in and/or on (e.g., infiltrated in)”.
Regarding claim 41, modified Chen discloses the cathode or cathode material of claim 1, wherein the porous regions comprise 10-90% of the total volume of the electrically conducting 3-D matrix (Chen [0018]), which overlaps with a portion of the claimed range between 50-90%.
Regarding claims 42 and 43, modified Chen discloses the cathode or cathode material is a composite (containing at least a carbon fiber matrix, an active material, and a carbon conductivity aid, specifically AR mesophase pitch), and a mass ratio of the cathode active material to conductive agent is 20 to 98:80 to 2 (Chen [0011]) , corresponding to (claim 42) carbon conductivity aid present at a ratio of 2% to 80% by weight based on the total weight of the active material and carbon conductivity aid which encompasses the claimed range, and (claim 43) an active material present at 20% to 98% by weight which overlaps with a portion of the claimed range between 20% to 90%.
Regarding claim 44, modified Chen discloses the cathode or cathode material of claim 1, wherein the active material is chosen from lithium nickel manganese cobalt oxides, LiCoO2 (LCO), lithium manganese oxides (“lithium-doped manganese oxide”), lithium iron phosphates (LFPs), LiMnPO4, and a combination thereof, or any combination thereof (Chen [0012]).
Regarding claim 45, modified Chen discloses the cathode or cathode active material of claim 1, comprising a mass loading of 15 mg/cm2 to 60 mg/cm2 (see rejection of claim 1), and overlaps with a portion of the claimed range to 50-60 mg/cm2.
Regarding claim 46, modified Chen discloses the cathode or cathode material of claim 1, wherein the pores of the plurality of porous regions comprise a range of pore size (“pore diameter”) of 0.01 to 2000 μm (Chen [0018]), which overlaps with a portion of the claimed range of pore size between 0.01 µm to 10 µm.
Regarding claim 47, modified Chen discloses the cathode or cathode material of claim 1, wherein the pores of the plurality of porous regions comprise a range of pore diameters of 0.01 to 2000 μm (Chen [0018]), and therefore comprise at least one linear dimension (a diameter) within a range which encompasses the claimed range of 100 nm (0.1 µm) to 200 µm.
Regarding claim 48, modified Chen discloses the cathode or cathode material of claim 1. Chen further discloses a method of making the cathode or cathode material wherein the cathode is formed without a liquid solvent (“no-liquid cell-core”) or a binder (“without adhesive bonding”) before being immerged in electrolyte (Chen [0011]). During this immerging process, the cathode particles are described as being suspended in the electrolyte ([0006]), the state of suspension inside the carbon cloth matrix being broadly and reasonably interpreted as being homogeneously dispersed in the pores of the carbon cloth matrix.
Regarding claim 49, modified Chen discloses the cathode or cathode material of claim 1, wherein the cathode or cathode material does not comprise a binder (“contains a part or all of electric-conductive cathode particles in accumulated state without adhesive bonding”, Chen [0008])
Regarding claim 50, modified Chen discloses the cathode or cathode material of claim 1, wherein the active material and the carbon conductivity aid (“electric-conductive cathode particles”) are present in, and therefore fill, the space between carbon fibers of the carbon cloth/fabric (“partly or all provided on the surface or in the mesh pores of the cathode surface current-collecting layer”, Chen [0020]). Chen further discloses a step of pressing such that the electric-conductive cathode particles are “tightly pressed by pressure, so as to improve the conductive performance between the positive electrode conductive particles” ([0008]), which would be understood to remove residue porosity through the use of compression force. Furthermore, Chen discloses a method of making the cathode or cathode material wherein the cathode is formed without a liquid solvent (“no-liquid cell-core”) or a binder (“without adhesive bonding”) before being immerged in electrolyte, forming a slurry in the cathode and causing movement of the electric-conductive cathode particles ([0011]). This step is substantially similar to the process recited in the instant specification paragraph [0089], wherein a liquid electrolyte is drawn into the interparticle region and causing a LCO/KB composite to fill a space between carbon fibers through capillary forces in combination with compression forces; as such, Chen’s cathode or cathode material would be reasonably understood to have a residue porosity configured to be substantially removed by capillary force and compression force.
Claims 19-20 are rejected under 35 U.S.C. 103 as being unpatentable over Chen as evidenced by or in view of Zhamu as applied to claim 1 above, and further in view of Arrebola et al. (Arrebola, Jose C., Alvaro Caballero, Lourdes Hernan, and Julian Morales. “A high energy Li-ion battery based on nanosized LiNi0.5Mn1.5-O-4 cathode material.” Journal of Power Sources, 183, 2008, 310-315, enclosed with the action of 10/26/2022).
Regarding claims 19 and 20, modified Chen discloses a device (“battery”, Chen [0002]) comprising one or more-cathode(s) or more cathode(s) material(s) of claim 1, wherein (claim 20) the device is a battery, and further indicates that a battery made according to the invention may comprise a lithium metal anode with a suitable thickness from 0.001 to 2 mm ([0015]), corresponding to a wide range of suitable negative electrode capacity (N) in comparison to a given positive electrode capacity ratio (P), but does not explicitly indicate that the device comprises an N:P ratio of 1:1 to 1:10.
Secondary reference Arrebola teaches a device comprising a lithium oxide active material (Title). Specifically, Arrebola teaches charge/discharge behaviors of batteries having N/P ratios of 0.47 to 0.73, equivalent corresponding to N:P ratios of about 1:1.36 to 1:2.12, and notes that increasing the N:P ratio increases the capacity of the battery while decreasing the ratio prevents a capacity loss during cycling. (pp. 312 col. 1 paragraph 2-col. 2 paragraph 1, FIGs. 3a, 3b).
As such, in seeking to balance overall capacity and capacity retention of modified Chen’s battery, it would have been obvious to a person having ordinary skill in the art at the time of the effective filing date of the claimed invention to have optimized the N:P ratio of the battery between 1:1.36 to 1:2.12 as taught by Arrebola; see MPEP 2144.05 II. Such an optimization would be made with a reasonable expectation of success as Chen discloses a wide range of suitable values of N to match a given value of P.
Claims 22 is rejected under 35 U.S.C. 103 as being unpatentable over Chen as evidenced by or in view of Zhamu as applied to claim 1 above, and further in view of Joo et al. (US 2015/0099185 A1, cited in office action filed 05/08/2024).
Regarding claim 22, modified Chen discloses the cathode or cathode material of claim 1. While Chen discloses that the cathode or cathode material may comprise a lithium nickel cobalt manganese oxide, in addition to mixtures of other lithium nickel, cobalt, and manganese oxide materials (Chen [0012]), Chen does not further specify that this lithium nickel cobalt manganese oxide is NCM111 or LiNi0.5Co0.2Mn0.3O2
Joo teaches a cathode for an electrochemical device, specifically a lithium-ion battery, that may comprise a porous carbon matrix and a lithium-containing active material embedded in the matrix (Abstract and [0011] of Joo). Specifically, Joo teaches that the lithium active material may be selected from LiNi1/3Co1/3Mn1/3O2 or LiNib1Cob2Mnb3O2, wherein b1+b2+b3=1 and 0≦b1, b2, b3<1. The formula LiNib1Cob2Mnb3O2 includes the specific compound LiNi0.5Co0.2Mn0.3O2, which is a lithium nickel manganese cobalt oxide.
It would be obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to substitute or combine the various transition metal oxides disclosed by Chen so as to produce a lithium nickel cobalt manganese oxide having the formula LiNi1/3Co1/3Mn1/3O2 or LiNi0.5Co0.2Mn0.3O2 as taught by Joo. 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).
Conclusion
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/E.C./Examiner, Art Unit 1751
/JONATHAN G LEONG/Supervisory Patent Examiner, Art Unit 1751 8/28/2025