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and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114.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 06/08/2025 has been entered.
Status of Application
Claims 1-4, 6-11 are pending. Claims 5 is cancelled. Claims 1-4, 7 are currently amended. Claims 9-11 are withdrawn.
Response to Arguments
Applicant’s arguments, see Applicant’s argument/remarks, filed 06/08/2025, with respect to Amended claim 1 has been fully considered, but is not found persuasive.
Applicant appears to argue that the anode active material of Qien is a mixture of a silicon-based active material and a carbon-based active material in a weight ratio of 1:9, and MWCNTs are included in an amount of 3 wt% based on the total weight of the anode active material. Accordingly, when recalculated based on 100 wt% of the silicon of the silicon-based active material, the MWCNT content corresponds to 33.15 wt% (i.e., 3/9.05), which does not fall within the claimed range of “3 wt% to 9 wt% with respect to a total of 100 wt% of the silicon-based active material (pg 3).
In this regard, Examiner notes that the new grounds of rejection now relies on Example 5 of Qien, wherein the negative electrode active material layer includes 94.25 wt% silicon-carbon negative electrode material mixture comprising 20% Si-based active material and 80% carbon-based active material (i.e., 18.85 wt% Si-based active material), 0.25 wt% SWCNT, 1.5 wt% MWCNT (see Example 5 of the Table in [0127] of Qien’s original copy).
When recalculated based on 100 wt% of the silicon-based active material, the MWCNT content corresponds to 8wt% (i.e., 1.5/18.85), which falls within the claimed range of “3wt% to 9wt%”.
Applicant further appears to provide additional experimental data in pg 4-5 to show the critical significance of including 3 to 9 wt% of TWCNT relative to 100 wt% of the silicon-based active material. Examiner notes that such evidence of unexpected results must be submitted as part of a declaration to be considered (see MPEP 716.01(c)).
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.
Claim(s) 1,2,4,8 is/are rejected under 35 U.S.C. 103 as being unpatentable over Qien (CN110444746A, translation attached for citation), in view of Yang (US20180277837A1, IDS cited 12/29/2022)
Regarding claims 1-2, Qien discloses a negative electrode for a secondary battery comprising:
a negative electrode current collector (porous copper foil; Example 5; [0112]); and a negative electrode active material layer formed on the negative electrode current collector [0112],
wherein the negative electrode active material layer includes a silicon-based active material (“silicon-carbon negative electrode material” comprising silicon active material and carbon active material [0045]) and a conductive material (muti-walled CNTs and single-walled CNTs [0109]),
the conductive material includes thin-walled carbon nanotubes (i.e., multi-walled CNTs [0109]) and single-walled carbon nanotubes (single-walled CNTs [0109])
Qien further discloses the lengths of the carbon nanotubes [0016], but does not disclose wherein the thin-walled carbon nanotubes have a diameter of 4 to 9 nm and 3 to 7 walls, as claimed.
In this regard, Yang teaches an electrode comprising a silicon-containing material [Yang 0029] and a conductive shell material preferably selected from the group consisting of single-walled carbon nanotube, double-walled carbon nanotube, and multi-walled carbon nanotube having 3-6 walls [Yang 0022-0023], which is wholly within the claimed range of “3 to 7 walls”. Yang further teaches that the carbon nanotube has an inner diameter of 0.5-5nm, which overlaps with the claimed “diameter of 4 to 9nm”. It would have been obvious for a person having ordinary skill in the art to have modified the MWCNT of Qien such that it has the overlapping diameter and number of walls, with a reasonable expectation to provide a conductive additive that enhances electrical conductivity [Yang 0004].
Qien further discloses in Example 5, wherein a silicon-carbon anode slurry comprises 94.25 wt% silicon-carbon negative electrode material (20% Si active material + 80% Carbon active material; i.e., 18.85wt% Si active material based on a 100wt% of the slurry), 0.25 wt% SWCNT, 1.5 wt% MWCNT, 2wt% CMC, and 2wt% SBR (see Example 5 in Table 1), which a person having ordinary skill in the art would calculate and recognize that the MWCNTs are included in an amount of 8 wt% with respect to a total of 100wt% of the silicon-based active material, which falls within the claimed range of “3 wt% to 9 wt%”.
A person having ordinary skill would further calculate and recognize that a weight ratio between the thin-walled carbon nanotubes and the single-walled carbon nanotubes is 1.5:0.25 (i.e., 1:0.17), which falls within the claimed range of “1:0.05 to 0.25”.
Regarding claim 4, modified Qien discloses the negative electrode for a secondary battery of claim 1, comprising 18.85wt% Si active material, 1.5 wt% MWCNT, 0.25 wt% SWCNT (see rejection for claim 1). When recalculated based on a total 100wt% of the silicon-based active material, the SWCNT content corresponds to 1.3 wt%, which is close but does not fall within the claimed range of “0.15 wt% or more and 1 wt% or less with respect to a total of 100 wt% of the silicon-based active material”. Qien further does not explicitly disclose a SWCNT wt% range.
However, Qien recognizes that using SWCNT alone provides high energy density (See comparative Examples 1, 3, 4 in the Table) and using both SWCNT and MWCNT improves the negative electrode sheet expansion rate and cycle performance of lithium ion batteries [0133]. Thus, it would have been obvious for a person having ordinary skill in the art to have optimized the amount of SWCNT in the negative electrode active material layer, by way of routine experimentation, to arrive at a desired balance between energy density and electrode expansion rate [0113].
Regarding claim 8, modified Qien discloses the negative electrode for a secondary battery of claim 1, wherein the negative electrode active material layer further includes a binder (i.e., SBR in Example 5 [0111]).
Claim(s) 3,6,7 is/are rejected under 35 U.S.C. 103 as being unpatentable over unpatentable over Qien (CN110444746A, translation attached for citation), in view of Yang (US20180277837A1, IDS cited 12/29/2022) and Zhao (CN105576185A, translation attached)
Regarding claim 3, modified Qien discloses the negative electrode for a secondary battery of claim 1. However, Qien does not disclose “wherein the conductive material further includes one or more selected multi-walled carbon nanotubes having 8 or more walls and carbon black” as claimed.
In this regard, Zhao also teaches a negative electrode material comprising 80-99.5% silicon-carbon composite material, 0-15% carbon nanotube conductive agent, 0-15% carbon black conductive agent [0047], wherein the carbon nanotube is at least one of single-walled carbon nanotubes, multi-walled carbon nanotubes, and modified carbon nanotubes [0050].
A person having ordinary skill in the art would reasonably add carbon black to the conductive materials (MWCNT and SWCNT) of Qien, as Zhao teaches that the point-line-surface multidimensional conductive network formed by carbon nanotubes and carbon black conductive agent establishes good conductive channels between the silicon-carbon anode particles, resulting in a silicon-carbon composite anode sheet with low surface resistivity. It further reduces the charge transfer impedance of lithium-ion batteries and improves the cycle stability of lithium-ion batteries [Zhao 0075].
Regarding claim 6, modified Qien discloses the negative electrode for a secondary battery of claim 1. However, Qien does not disclose:
wherein the conductive material further includes carbon black, and the carbon black is included in an amount of 6 wt% or more and 15 wt% or less with respect to a total of 100 wt% of the silicon-based active material
In this regard, Zhao also teaches a negative electrode material comprising 80-99.5% silicon-carbon composite material, 0-15% carbon nanotube conductive agent, 0-15% carbon black conductive agent [0047], wherein the carbon nanotube is at least one of single-walled carbon nanotubes, multi-walled carbon nanotubes, and modified carbon nanotubes [Zhao 0050].
A person having ordinary skill in the art would calculate and recognize that 0-15 wt% of carbon black relative to 80-99.5wt% of silicon-carbon composite material is equivalent to 0-18.8 wt% carbon black with respect to 100 wt% of the silicon-based active material, which encompasses the claimed range of “6 wt% or more and 15 wt% or less”. It would have been obvious for a person having ordinary skill in the art to have added the encompassed amount of carbon black, with a reasonable expectation to form a multidimensional conductive network that establishes good conductive channels between the silicon-carbon anode particles [Zhao 0075].
Regarding claim 7, modified Qien discloses the negative electrode for a secondary battery of claim 6, comprising thin-walled carbon nanotubes having a diameter of 4 to 9nm and 3 to 7 walls (see rejection for claim 1).
However, Qien does not disclose wherein a weight ratio between the thin-walled carbon nanotubes and the carbon black is 1:2 to 4, as claimed.
In this regard, Zhao also teaches a negative electrode material comprising 80-99.5% silicon-carbon composite material, 0-15% carbon nanotube conductive agent, 0-15% carbon black conductive agent [0047], wherein the carbon nanotube is at least one of single-walled carbon nanotubes, multi-walled carbon nanotubes, and modified carbon nanotubes [0050] (i.e., CNT:carbon black ratio is 0-15wt% : 0-15 wt%), which encompasses the claimed weight ratio between the thin-walled carbon nanotubes and the carbon black of 1:2-4. It would have been obvious for a person having ordinary skill in the art to have selected the encompassed ratio of thin-walled carbon nanotubes and the carbon black, with a reasonable expectation to form a multidimensional conductive network that establishes good conductive channels between the silicon-carbon anode particles [Zhao 0075].
Conclusion
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/T.S./Examiner, Art Unit 1751
/JONATHAN G LEONG/Supervisory Patent Examiner, Art Unit 1751 3/18/2026