NEGATIVE ELECTRODE ACTIVE MATERIAL, AND NEGATIVE ELECTRODE AND SECONDARY BATTERY WHICH INCLUDE THE SAME
DETAILED ACTION
Status of Claims
Claim 1 is amended and claim 16 is newly added. Claims 1, 3-4 and 7-16 are pending and being examined on the merits in this office action.
Remarks
Applicant’s amendments and arguments have been entered. A reply to the Applicant’s remarks/arguments is presented after addressing the claims.
Any rejections and/or objections made in the previous Office Action and not repeated below, are hereby withdrawn in view of Applicant’s amendments or/and arguments.
The text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office action. References cited in the current Office action can be found in a prior Office action.
Claim Rejections - 35 USC § 103
Claims 1, 3-4, 9-16 are rejected under 35 U.S.C. 103 as being unpatentable over Lee et al. (US 20200259162 A1, hereafter Lee) in view of Lee-II et al. (US 20210075015 A1, hereafter Lee-II).
Regarding claims 1 and 15:
Claim 1. A negative electrode active material for use in a negative electrode slurry comprising water as a solvent comprising artificial graphite particles,
wherein the negative electrode active material satisfies the following condition:
wherein a solid content value of a sample consisting of the negative electrode active material and water is 69.5 wt% or more based on a total weight of the sample, and
wherein the solid content value is a content value of the sample at a maximum torque value of the sample during torque measurement of the sample measured by a method including steps (a) to (c):
(a) adding the negative electrode active material into a sample container of a torque rheometer;
(b) measuring a torque value according to a solid content value of the sample by operating the torque rheometer while injecting water into the sample container of the torque rheometer at a constant rate; and
(c) deriving a solid content value when the sample has a maximum torque value in the step (b),
wherein the negative electrode active material has a sphericity ranging from 0.75 to 1,
wherein the negative electrode active material has an average particle diameter D50 of 14 µm to 20 µm, and
wherein the negative electrode active material has a Brunauer-Emmett-Teller (BET) specific surface area of 0.1 m2/g to 2.0 m2/g.
The above underlined claim languages are related to intended use. Specifically:
As to “for use in a negative electrode slurry comprising water as a solvent”, note that a preamble is generally not accorded any patentable weight where it merely recites the purpose of a process or the intended use of a structure, and where the body of the claim does not depend on the preamble for completeness but, instead, the process steps or structural limitations are able to stand alone. See In re Hirao, 535 F.2d 67, 190 USPQ 15 (CCPA 1976) and Kropa v. Robie, 187 F.2d 150, 152, 88 USPQ 478, 481 (CCPA 1951). In the instant case, the invention is about a negative electrode active material whose composition or/and structure do not depend on whether or not it is used to mix water to form “a sample”.
Likewise, other underlined claim languages relate to intended use, and do not change the composition or structure of the negative electrode active material comprising artificial graphite particles. The determination of patentability is based on the product (i.e., the negative electrode active material comprising artificial graphite particles) itself. It does not matter whether or how a/the sample (resulted from intend use of the claimed negative electrode active material comprising artificial graphite particles) is prepared or measured. Also, it does not matter how a maximum torque technique is employed to determine a solid content value of the sample. The claimed subject matter is essentially a negative electrode active material comprising graphite particles, rather than a sample containing water.
In short, while intended use recitations and other types of functional language cannot be entirely disregarded. However, in apparatus, article, and composition claims, intended use must result in a structural difference between the claimed invention and the prior art in order to patentably distinguish the claimed invention from the prior art. If the prior art structure is capable of performing the intended use, then it meets the claim.
The prior art Lee teaches a negative electrode active material comprising artificial graphite ([0040]-[041]) particles (one of ordinary skill in the art would know that a material is composed of material particles). The artificial graphite is capable of performing the intended use as claimed.
Lee is silent as to the sphericity as claimed. However, in the same field of endeavor, Lee-II discloses that a negative electrode active material (e.g., artificial graphite, [0029]) having a sphericity of 0.83 to 0.91 would significantly improve adherence between the current collector and the anode active material layer of the negative electrode ([0079]). Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the instant invention to have incorporated the teachings of Lee-II into Lee to use artificial graphite particles having a sphericity of 0.83 to 0.91 as the artificial graphite of Lee in order to significantly improve adherence as mentioned above. The sphericity range of 0.75 to 1 as claimed in claim 1 overlaps that of 0.83 to 0.91. 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 (I). Also, the range of 0.75 to 0.81 as claimed in claim 15 is close to 0.83 to 0.91. A prima facie case of obviousness exists where the claimed ranges or amounts do not overlap with the prior art but are merely close. See MPEP § 2144.05.
Lee as modified teaches the negative electrode active material has an average particle diameter D50 of 10 µm to 30 µm ([0042]). The claimed range of 14 µm to 20 µm overlaps or lies inside the range disclosed by Lee. 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 (I).
Lee as modified further discloses that the specific surface area of the negative electrode active material affects initial efficiency, output properties and storage stability ([0043], Lee) and therefore is a result-effective variable. It would have been obvious to one of ordinary skill in the art before the effective filing date of the instant invention to have optimized the specific surface area of the negative electrode active material of Lee to arrive at the claimed range of specific surface area, in order to achieve desired initial efficiency, output properties and storage stability.
Regarding claim 3, Lee as modified teaches the negative electrode active material of claim 1, and the limitation “wherein compression density measured by powder flow test of the negative electrode active material is in a range of 850 kg/m3 to 1200 kg/m3” represents a characteristic or property of the negative electrode active material. Since Lee teaches the same negative electrode active material comprising artificial graphite as claimed, the claimed characteristic or property is necessarily present. Products of identical chemical composition cannot have mutually exclusive properties.” A chemical composition and its properties are inseparable. Therefore, if the prior art teaches the identical chemical structure, the properties applicant discloses and/or claims are necessarily present. In re Spada, 911 F.2d 705, 709, 15 USPQ2d 1655, 1658 (Fed. Cir. 1990).
Regarding claim 4, Lee as modified teaches the negative electrode active material of claim 1, and it is a general knowledge for one of ordinary skill in the battery field that two or more primary particles of a negative electrode active material, including the instantly claimed artificial graphite, will form a secondary particle structure in the negative electrode.
Regarding claim 9, Lee as modified teaches a negative electrode slurry ([0025], Lee), comprising:
the negative electrode active material of claim 1 ([0025], [0040], Lee);
a negative electrode binder ([0012], [0068], Lee);
a negative electrode conductive agent ([0047], Lee); and
a solvent ([0025], Lee).
Regarding claim 10, Lee as modified teaches the negative electrode slurry of claim 9, wherein a solid content of the negative electrode slurry is 77.5 wt% to 99 wt% based on a total weight of the negative electrode slurry ([0046]), overlapping the instantly claimed “46 wt% or more”. 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 (I).
Regarding claim 11, Lee as modified teaches the negative electrode slurry of claim 9, wherein a solid content of the negative electrode slurry is 77.5 wt% to 99 wt% based on a total weight of the negative electrode slurry ([0046], Lee), overlapping the instantly claimed “46 wt% or more”. 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 (I).
Regarding claim 12, Lee as modified teaches a negative electrode ([0095]) comprises a negative electrode current collector and a negative electrode active material layer on at least one surface of the negative electrode current collector (this is general knowledge in the battery field, as indicated in [0095], Lee), and the negative electrode active material layer comprises the negative electrode active material of claim 1 ([0095], Lee).
Regarding claim 13, Lee as modified teaches a secondary battery, comprising the negative electrode of claim 12 ([0093]-[0095], Lee), a positive electrode facing the negative electrode, a separator disposed between the negative electrode and the positive electrode ([0093]-[0095], Lee), and an electrolyte ([0108], [0107], Lee).
Regarding claim 14, Lee teaches the negative electrode active material of claim 1, and the use of spheronized artificial graphite particles represents a specific shape of the graphite. However, providing the artificial graphite particles with a specific shape is a matter of choice which a person of ordinary skill in the art would have found obvious absent persuasive evidence that the particular shape is significant. See MPEP § 2144.04 IV.
Regarding claim 16, Lee teaches a negative electrode slurry (See, at least, Abstract) comprising a negative electrode active material (“(3)”) and a solvent (“(4)”),
wherein the negative electrode active material comprises artificial graphite particles (See, e.g., [0040], [0041]), and
wherein the solvent comprises water (e.g., [0027]).
Lee is silent as to the sphericity as claimed. However, in the same field of endeavor, Lee-II discloses that a negative electrode active material (e.g., artificial graphite, [0029]) having a sphericity of 0.83 to 0.91 would significantly improve adherence between the current collector and the anode active material layer of the negative electrode ([0079]). Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the instant invention to have incorporated the teachings of Lee-II into Lee to use artificial graphite particles having a sphericity of 0.83 to 0.91 as the artificial graphite of Lee in order to significantly improve adherence as mentioned above. The sphericity range of 0.75 to 1 as claimed in claim 1 overlaps that of 0.83 to 0.91. 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 (I). Also, the range of 0.75 to 0.81 as claimed in claim 15 is close to 0.83 to 0.91. A prima facie case of obviousness exists where the claimed ranges or amounts do not overlap with the prior art but are merely close. See MPEP § 2144.05.
Lee as modified teaches the negative electrode active material has an average particle diameter D50 of 10 µm to 30 µm ([0042]). The claimed range of 14 µm to 20 µm overlaps or lies inside the range disclosed by Lee. 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 (I).
Lee as modified further discloses that the specific surface area of the negative electrode active material affects initial efficiency, output properties and storage stability ([0043], Lee) and therefore is a result-effective variable. It would have been obvious to one of ordinary skill in the art before the effective filing date of the instant invention to have optimized the specific surface area of the negative electrode active material of Lee to arrive at the claimed range of specific surface area, in order to achieve desired initial efficiency, output properties and storage stability.
The following underlined recitations in claim 16 relates to intended use of the negative electrode active material comprising artificial graphite particles. That is, the electrode active material comprising artificial graphite particles is used to mix with water to form “a sample”, which is then characterized/measured. Note that according to an interpretation based on the instant specification, the “a sample” is different from a “slurry” as claimed since a slurry contains also other components (See, e.g., Examples in the instant specification).
wherein a solid content value of a sample consisting of the negative electrode active material and water is 69.5 wt% or more based on a total weight of the sample, and
wherein the solid content value is a content value of the sample at a maximum torque value of the sample during torque measurement of the sample measured by a method including steps (a) to (c):
(a) adding the negative electrode active material into a sample container of a torque rheometer;
(b) measuring a torque value according to a solid content value of the sample by operating the torque rheometer while injecting water into the sample container of the torque rheometer at a constant rate; and
(c) deriving a solid content value when the sample has a maximum torque value in the step (b),
The intended use recitations do not change the composition or structure of the claimed negative electrode active material slurry comprising a negative electrode active material and a solvent. While intended use recitations and other types of functional language cannot be entirely disregarded. However, in apparatus, article, and composition claims, intended use must result in a structural difference between the claimed invention and the prior art in order to patentably distinguish the claimed invention from the prior art. If the prior art structure is capable of performing the intended use, then it meets the claim. In the instant case, the negative electrode active material comprising artificial graphite particles and water are capable of performing the intended use as underlined above. See also the rejection of claim 1.
Claims 7-8 are rejected under 35 U.S.C. 103 as being unpatentable over Lee in view of Lee-II, as applied to claim 1 above, and further in view of Iida et al. (US 20220393169 A1, hereafter Iida).
Regarding claims 7-8, Lee as modified teaches the negative electrode active material of claim 1, but is silent as to an amorphous carbon coating layer on a surface of the artificial graphite particle. However, in the same field of endeavor, Iida discloses that an artificial graphite coated with an amorphous carbon coating in an amount of about 5 wt% in the negative electrode active material is used as a negative electrode active material (e.g., Example 1). It would have been obvious to one of ordinary skill in the art before the effective filing date of the instant invention to have used artificial graphite particles coated with an amorphous carbon coating as an alternative to the artificial graphite particles, since simple substitution of one known element for another to obtain predictable results is prima facie obvious. See MPEP § 2143. As a result, about 5 wt% reads on the range as claimed in claim 8.
Response to Arguments
Applicant's arguments filed on August 22, 2025 have been fully considered but they are not persuasive.
In response Applicant’s argument associated with “… The parameter measurement method of the present invention is for deriving the parameters, and has nothing to do with the preparation method of the negative electrode”, it is respectfully noted that the instant invention is about a product, not about a method (whether a method for deriving parameters or a method for preparation).
The argument related to “solid content value” is not persuasive, because the solid content value is a characteristic of “a sample”, which results from intended use of the negative electrode active material. The prior art has already taught the compositional or/and structural limitation of the negative electrode active material. The intended use does not make a difference in the composition or/and structure of the negative electrode active material.
Conclusion
THIS ACTION IS MADE FINAL. 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 ZHONGQING WEI whose telephone number is (571)272-4809. The examiner can normally be reached Mon - Fri 9:30 - 6:00.
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/ZHONGQING WEI/
ZHONGQING WEI, Ph.D.Primary Examiner, Art Unit 1727