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 . If status of the application as subject to 35 U.S.C. 102 and 103 is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
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and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114.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 8/11/2026 has been entered.
Status of Claims
Claims 1-4, 6-8, & 11-15 are pending in the application. Claims 8 and 11-15 are withdrawn. Claims 1-7 were rejected in the office action mailed 5/11/2026. Applicant cancelled claim 5. Claims 1-4 & 6-7 are presently examined.
Response to Amendment / Arguments
The 8/11/2026 amendment, in response to the 5/11/2026 office action, has been entered. Applicant’s claim amendments overcame the 35 U.S.C. 103 rejections; nevertheless, the claims remain rejected under 35 U.S.C. 103 due to additional prior art.
Applicant argues that Yokoi fails to teach crude tar with a low molecular weight component. The office action never stated that Yokoi describes the low molecular weight components of crude tar. Rather, the office action asserted that this is a feature of crude tar/ coal tar, and provided online articles that teach this. Applicant failed to address this assertion in the prior office action; therefore, this assertion is presumed valid.
Claim 1 requires mixing at 50 rpm to 100 rpm for 10 minutes to 60 minutes. Yokoi fails to teach this mixing rpm and time. MPEP 2144.05(II) provides guidance for this issue:
“‘[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)”.
Mixing rpm is commonly adjusted in manufacturing processes based on cost (increased rpm requires more expensive equipment), avoiding damage to the mixture (increased rpm can result damaging components in the mixture), and time (increased rpm reduces manufacturing time). Absent a showing of unexpected results in the claimed ranges, it would have been obvious, to one of ordinary skill in the art, before the effective filing date of the invention, to adjust the mixing rpm and time for a balance of cost, avoiding damage to the mixture, and reducing mixing time.
Applicant argues that specification examples show an unexpected technical effect, with “significantly reduced BET specific surface area” from mixing in these ranges. Examiner is not convinced, for the following reasons.
First, Applicant compares BET of Comparative Example 1 to Examples 1-5. Although it is true that examples 1-5 have lower BET than Comparative Example 1, this reveals nothing about the criticality of mixing rpm and time because Comparative Example 1 has no crude tar coating, and thus skips the mixing step entirely (present specification p.25, lines 1-19 & p.33, lines 4-6). This comparison indicates the benefit of the crude tar coating, but provides no indication of unexpected results resulting from the claimed mixing rpm and time.
Second, the examples fail to show an improvement resulting from the claimed ranges. In Table 1 below, claimed ranges, Comparative Example 1 (CE1), the examples (E1-E9), wt% crude tar, mixing rpm, mixing minutes, span, and BET are presented. According to the specification (p.33, lines 4-6) and Applicant’s Remarks (p.9), smaller span and smaller BET are better.
The bold numbers in Table 1 are outside of the claimed ranges. Bad examples 5 & 8-9, which fall outside of the claimed range for rpm or time, are compared with good examples, which have rpm and time inside of the claimed ranges.
Bad Example 5 has mixing rpm outside of the claimed range, but it is tied with example 4 for the lowest span (i.e. best span) of all examples. Bad Example 5 also has a BET within the range of the good examples. Bad Examples 8-9 have mixing time outside of the claimed range, but have span and BET within the ranges of the good examples.
Table 1
Claim
2%-20%
50-100
10-60
tar%
mix rpm
mix min
span
BET m2/g
CE1
1.90
12.2
E1
20
80
30
1.41
2.69
E2
10
80
30
1.70
4.64
E3
20
80
60
1.14
2.91
E4
20
80
60
1.13
3.12
E5
20
120
60
1.13
3.48
E6
10
80
30
1.90
5.72
E7
10
80
60
1.75
5.38
E8
10
80
90
1.55
5.45
E9
10
80
120
1.52
4.95
These examples fail to prove unexpected results from mixing at 50 rpm to 100 rpm for 10 minutes to 60 minutes.
Regarding the failed priority claim, Applicant argues:
“the national stage was commenced, on June 17, 2022 before expiration of the 30-month period from the Korean priority date (i.e., on or before June 20, 2022)”
Examiner disagrees with Applicant’s analysis. The due date for claiming priority to the Korean application (KR1020190171448), filed on 12/20/2019, was 6/20/2022. USA nonprovisional patent application filing began on 6/17/2022; however, this 6/17/2022 filing was incomplete. For a complete filing, resulting in a filing date, the specification must also be filed (MPEP 601). The specification, however, was filed on 8/11/2022. The filing date of the application is thus 8/11/2022, not 6/17/2022. The 8/11/2022 filing date is after the 6/20/2022 due date; therefore, the priority claim to KR1020190171448 fails.
Priority
Acknowledgment is made of applicant's claim for priority under 35 U.S.C. 119(a)-(d) or (f), 365(a) or (b), or 386(a) based upon an application (KR1020190171448) filed in Korea on 12/20/2019. The claim for priority cannot be based on this application because the subsequent USA nonprovisional application was filed 8/11/2022, more than 30 months thereafter.
Claim Rejections - 35 USC § 112
The following is a quotation of 35 U.S.C. 112(b):
(b) CONCLUSION.—The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention.
Claims 1-4 & 6-7 are rejected under 35 U.S.C. 112(b) as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor(s) regard as the invention.
Claim 1 states:
coating a negative active material precursor containing Si with crude tar; and
annealing an obtained coating product
The present specification indicates that the “obtained coating product” is a product of the negative active material precursor with crude tar coating (page 29, lines 9-11); however, this isn’t clear from the present claim language. Examiner suggests the following amendment to clarify the meaning of the “obtained coating product”:
coating a negative active material precursor containing Si with crude tar to form an obtained coating product; and
annealing the obtained coating product
Claims 2-4 & 6-7 are rejected due to their dependence on claim 1.
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:
Determining the scope and contents of the prior art.
Ascertaining the differences between the prior art and the claims at issue.
Resolving the level of ordinary skill in the pertinent art.
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.
The claims are in bold font, the prior art is in parentheses.
Claims 1-4 are rejected under 35 U.S.C. 103 as being unpatentable over US20150372292A1 (Yokoi) in view of US20200067078A1 (Son).
With regard to claim 1, Yokoi teaches the following claim limitations:
A method of manufacturing a negative active material (paragraphs 58-59) for lithium secondary battery (abstract), comprising:
coating a negative active material precursor containing Si with crude tar (paragraphs 27 & 58-59: coal tar coating layer on Si/SiOx base particles)
Regarding the claim limitation for “crude tar”, the present specification states that “The crude tar refers to coal tar” (page 8, line 3). Yokoi teaches coal tar (paragraph 59).
Claim 1 also recites:
the crude tar contains a low molecular weight component that can be removed by a distillation process in an amount of 20 wt% or less
Yokoi fails to describe the volatile / low molecular weight components in the coal tar. Coal tar, however, has various such volatiles, which can be removed at an amount of ≤ 20 wt%, depending on the temperature and duration of distillation1,2. It would have been obvious, to one of ordinary skill in the art, for Yokoi’s coal tar to include the low molecular weight component because ordinary coal tar includes many low molecular weight components.
Yokoi also teaches the following claim 1 limitations:
annealing an obtained coating product (paragraph 66: heat-treated at 900° C)…
a content of the crude tar is 2 wt% to 20 wt% with respect to 100 wt% of the negative active material precursor (paragraph 59: coal tar is 5 mass % of the negative electrode active material)
Yokoi, however, fails to teach the following claim 1 limitation, which is taught by Son:
the negative active material precursor containing the Si is a Si-C composite comprising: silicon particles, amorphous carbon, and crystalline carbon (paragraphs 4, 9, 30; figure 1; claim 6: composite particle 221 with crystalline carbon 223, silicon particles 225, and amorphous carbon 227)
Son is directed to a negative active material for a rechargeable lithium battery for maintaining battery efficiency (abstract; paragraph 18).
It would have been obvious, to one of ordinary skill in the art, to have replaced Yokoi’s Si/SiOx base particles with Son’s composite particles, each of which includes crystalline carbon, silicon particles, and amorphous carbon, for maintaining battery efficiency.
Claim 1 also recites:
the step of coating with the crude tar is performed by: mixing the negative active material precursor and crude tar, and stirring the mixture at a speed of 50 rpm to 100 rpm for 10 minutes to 60 minutes
Yokoi teaches mixing (paragraph 59); however, Yokoi fails to teach mixing speed and time. Mixing rpm is commonly adjusted in manufacturing processes based on cost (increased rpm requires more expensive equipment), avoiding damage to the mixture (increased rpm can result damaging components in the mixture), and time (increased rpm reduces manufacturing time). It would have been obvious, to one of ordinary skill in the art, before the effective filing date of the invention, to adjust the mixing rpm and time for a balance of cost, avoiding damage to the mixture, and reducing mixing time.
With regard to claim 2, modified Yokoi teaches the limitations of claim 1 as noted above. Claim 2 recites:
the low molecular weight component has a weight average molecular weight (Mw) of 78 to 128
Yokoi fails to explicitly recite the coal tar chemical composition. Claim 2, however, is merely reciting a molecular weight range of typical crude tar / coal tar composition. Coal tar typically includes phenol1, which has a molecular weight of 96. It would have been obvious, to one of ordinary skill in the art, to have used a coal tar with a component, such as phenol, with a molecular weight of 78 to 128, because this is typical of coal tar.
With regard to claim 3, modified Yokoi teaches the limitations of claim 1 as described above. Claim 3 recites:
in the step of the coating the negative active material precursor containing Si with the crude tar, a coating solution prepared by adding the crude tar to a solvent, at a concentration of 50 wt% to 70 wt%, is used
Yokoi teaches 25 wt% coal tar in tetrahydrofuran solvent (paragraph 59). Yokoi’s 25 wt% is outside of the claimed 50-70 wt% range. Increased coal tar concentration would make mixing more difficult, but would reduce drying cost. It would have been obvious, to one of ordinary skill in the art, before the effective filing date of the invention, to adjust the coal tar concentration in the solvent to balance ease of mixing with drying cost.
With regard to claim 4, modified Yokoi teaches the limitations of claims 1 & 3 as described above. Yokoi also teaches the following claim 4 limitation:
the solvent is… tetrahydrofuran… (paragraph 59: tetrahydrofuran)
Claims 6-7 are rejected under 35 U.S.C. 103 as being unpatentable over US20150372292A1 (Yokoi) in view of US20200067078A1 (Son), with regard to claim 1, and further in view of US20190221835A1 (Imaji).
With regard to claim 6, modified Yokoi teaches the limitations of claim 1 as described above. Yokoi also teaches the following claim 6 limitation:
the step of annealing the obtained coating product is carried out at 800°C to 950°C (paragraph 66: heat-treated at 900° C)
Yokoi fails to teach the following claim 6 limitation, which is taught by Imaji:
the step of annealing the obtained coating product is carried out… for 0.5 hours to 2 hours (paragraph 131: one hour)
Imaji is directed to a method of manufacturing a negative active material (paragraphs 46-49), with high specific capacity (abstract), for a lithium secondary battery (title & paragraph 1). Imaji describes coating silicon with coal tar (paragraphs 47 & 55), then heating / firing this coated silicon (paragraphs 49 & 67-68) at 1100° C for one hour (paragraph 131). Although Imaji teaches heating at 1100° C, instead of the 900° C taught by Yokoi, Imaji provides sufficient guidance for one of ordinary skill in the art to select heating time.
It would have been obvious, to one of ordinary skill in the art, before the effective filing date of the invention, to perform the following heating operation:
heat Yokoi’s coal tar coated Si/SiOx base particles at 900° C, as taught by Yokoi; and
heat Yokoi’s coal tar coated Si/SiOx base particles for one hour, for a negative active material with high specific capacity, as taught by Imaji.
With regard to claim 7, modified Yokoi teaches the limitations of claim 1 as described above. Yokoi also teaches the following claim 7 limitation:
the step of annealing the obtained coating product is performed by raising a temperature to a final temperature of 950 °C or less (paragraph 66: heat-treated at 900° C)
Yokoi fails to teach the following claim 7 limitation, which is taught by Imaji:
the step of annealing the obtained coating product is performed by raising a temperature… at a temperature increase speed of 2 °C / min to 10 °C / min (paragraph 131: 250° C/h = 4° C/min)
Conclusion
Prior art not relied upon, but made of record and considered pertinent to applicant's disclosure:
US20180026257A1 teaches a negative active material with a composite of crystalline carbon, a silicon particle, and an amorphous carbon coating layer.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to ROBERT WEST whose telephone number is 703-756-1363 and email address is Robert.West@uspto.gov. The examiner can normally be reached Monday-Friday 10 am - 7 pm ET.
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/R.G.W./Examiner, Art Unit 1721
1 https://www.atsdr.cdc.gov/toxprofiles/tp85-c4.pdf
2 https://www.ispatguru.com/coal-tar-and-its-distillation-processes/
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