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and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114.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 12/29/2025 has been entered.
Response to Amendment
This Office Action is responsive to the amendment filed on 12/29/2025. Claims 1, 6, 10 are amended. Claims 1-7, 10-13, 15-22 are pending. Claim 17 is withdrawn from further consideration as being drawn to a non-elected invention, in accordance with 37 CFR 1.142(b). Applicant’s arguments have been considered. Claims 1-7, 10-13, 15, 16, 18-22 are non-finally rejected for reasons below.
Claim Rejections - 35 USC § 103
The following is a quotation of 35 U.S.C. 103(a) which forms the basis for all obviousness rejections set forth in this Office action:
(a) A patent may not be obtained though the invention is not identically disclosed or described as set forth in section 102 of this title, if the differences between the subject matter sought to be patented and the prior art are such that the subject matter as a whole would have been obvious at the time the invention was made to a person having ordinary skill in the art to which said subject matter pertains. Patentability shall not be negatived by the manner in which the invention was made.
Claims 1-3, 5-7, 10-13, 15, 16, 18-22 are rejected under 35 U.S.C. 103(a) as being unpatentable over Youm (EP 3046167) in view of Iyama (JP 2018-110076).
Regarding claim 1, Youm discloses a negative active material composite, comprising: a core and a coating layer around the core,
the core comprising crystalline carbon, amorphous carbon, and silicon nanoparticles, and pores [0005, 0052],
the coating layer comprising amorphous carbon [0011], and
Regarding claim 1, in total the amorphous carbon is comprised in an amount of about 20 wt% to about 80 wt% based on a total weight of the negative active material composite, Youm discloses 5-40% amorphous carbon [0010]. Youm further discloses 10% amorphous carbon coating [0093].
Regarding claim 1, the crystalline carbon is in a form of particles and selected from a natural graphite, an artificial graphite, and a combination thereof [0041].
Regarding claim 1, a total volume of all the pores in the negative active material composite is less than or equal to about 3.0 x 10-2 cm3/g, Youm discloses that a compression-forming method may decrease a size of a pore inside the silicon-graphite composite [0052]. Referring to FIG. 10, the rechargeable lithium battery cells manufactured in a compression-forming method according to Examples 1 to 3 exhibited a small expansion ratio of each electrode plate, compared with the rechargeable lithium battery cell manufactured without compression-forming (according to Comparative Example 1) and the rechargeable lithium battery cell manufactured without adding amorphous carbon before compression-forming (according to Comparative Example 2) [0147]. Accordingly, the negative active material according to an embodiment may show that a volume expansion due to Si particles is minimized and thus, may contribute to realization of a rechargeable lithium battery cell having excellent cycle-life characteristics and storage characteristics at a high temperature [0148].
It would have been obvious to one of ordinary skill in the art at the time the invention was made to reduce the pore size as much as possible for the benefit of obtaining efficient packing of the active material in the composite.
Regarding claim 1, the silicon nanoparticles and the amorphous carbon are comprised in a weight ratio of about 50:50 to about 80:20, and regarding claim 16, the silicon nanoparticles and the amorphous carbon are comprised in a weight ratio of about 60:80 to about 80:20 [0095], Youm discloses in Example 1 [0093], for a given 100 g of the silicon-graphite particle, there is 90 g of 54 wt% graphite, 15 wt% Si and 8 wt% amorphous carbon, after drying the ethanol solvent. In this mixture, there is 70.1 wt% graphite, 19.5 wt% Si, and 10.4 wt% amorphous carbon coal-based pitch, after drying the ethanol solvent. This is equivalent to 63.09 g graphite, 17.55 g Si, and 9.36 amorphous carbon coal-based pitch. Further, the coating possesses 10 grams of amorphous carbon coal-based pitch. There is 17.55 g Si and 9.36 g amorphous carbon, and further 10 g amorphous carbon in the coating. Hence, the ratio of Si and amorphous carbon is 17.55:19.36, or 48:52.
Youm discloses the amorphous carbon may be present inside the graphite particle and this, may help suppress volume expansion of the silicon particle and may help improve-cycle life characteristics of a rechargeable lithium battery [0045]. It would have been obvious to one of ordinary skill in the art at the time the invention was made to adjust the amount of amorphous carbon of Youm depending on the amount of need to suppress volume expansion of the silicon particle.
Youm clearly teaches that silicon is a result effective variable. It has been held by the courts that discovering an optimum value or workable ranges of a result-effective variable involves only routine skill in the art, and thus not novel. In re Boesch, 617 F.2d 272, 205 USPQ 215 (CCPA 1980). See MPEP 2144.05.
Regarding claim 2, the crystalline carbon particles are larger in size than each of the silicon nanoparticles [0040, 0043].
Regarding claim 3, the silicon nanoparticles have an average particle diameter (D50) of about 50 nm to about 150 nm [0093].
Regarding claim 6, the silicon nanoparticles are comprised in an amount of about 20 wt% to about 80 wt% based on the total weight of the negative active material composite [0039].
Regarding claim 7, the amorphous carbon is selected from a soft carbon, a hard carbon, a mesophase pitch, carbonized product, a fired coke, and a combination thereof [0059, 0061].
Regarding claim 10, the crystalline carbon is comprised in an amount of about 20 wt% to about 80 wt% based on the total weight of the negative active material composite [0044].
Regarding claim 11, the negative active material composite has an average particle diameter (D50) of about 2 um to about 15 um [0093].
Regarding claim 12, the coating layer has a thickness of about 1 nm to about 900 nm [0093].
Regarding claim 13, an average pore size of the negative active material composite is less than or equal to about 200 nm, Youm discloses that a compression-forming method may decrease a size of a pore inside the silicon-graphite composite [0052]. The compression-forming method compresses the composite precursor at a pressure between 2MPa to 10 MPa [0060]. It would have been obvious to one of ordinary skill in the art at the time the invention was made to reduce the pore size as much as possible for the benefit of obtaining efficient packing of the active material in the composite.
Regarding claim 15, the negative active material composite has a BET specific surface area of less than or equal to about 10 m2/g [0052].
Regarding claim 18, Youm teaches a negative electrode comprising: a current collector; and a negative active material layer on the current collector and comprising a negative active material, wherein the negative active material comprises the negative active material composite of claim 1.
Regarding claim 19, the silicon nanoparticles in the negative active material composite are comprised in an amount of about 1 wt% to about 30 wt% based on a total weight of the negative active material layer [0093].
Regarding claim 20, Youm teaches a rechargeable lithium battery, comprising: a positive electrode comprising a positive active material; the negative electrode of claim 18; and an electrolyte.
Regarding claim 21, the negative active material composite is a compressed negative active material manufactured by compression, under a pressure of about 50 MPa to about 150 MPa, a mixture comprising the crystalline carbon, the silicon nanoparticles, and the amorphous carbon, to achieve the adjacent distance between the silicon nanoparticles of less than or equal to about 100 nm, Youm discloses a mixture comprising the crystalline carbon, the silicon nanoparticles, and the amorphous carbon. Youm discloses that a compression-forming method may decrease a size of a pore inside the silicon-graphite composite [0052]. The compression-forming method compresses the composite precursor at a pressure between 2MPa to 10 MPa [0060]. It would have been obvious to one of ordinary skill in the art at the time the invention was made to increase the pressure of the compression for the benefit to reduce the pore size as much as possible for the benefit of obtaining efficient packing of the active material in the composite.
Regarding claim 22, the negative active material composite is comprised in an amount of about 1 wt% to about 70 wt% based on a total weight of the negative active material layer, Youm discloses 98 wt% negative active material composite in the active material layer with 2 wt% binder and [0099]. It would have been obvious to one of ordinary skill in the art at the time the invention was made to adjust the amount of the active material composite and the binder of Youm depending on the amount of the binder needed in the active material layer, unless the claimed range is critical.
Regarding claim 1, Youm does not disclose an adjacent distance between the silicon nanoparticles being less than or equal to about 100 nm, and wherein the adjacent distance between the silicon nanoparticles is a distance between centers of the adjacent silicon nanoparticles. Regarding claim 5, Youm does not disclose the silicon nanoparticles have an aspect ratio of about 2 to about 8. Youm discloses a silicon particle having an average particle diameter of between about 50 nm to about 300 nm for the benefit of suppressing from a volume expansion due to smooth in-and-out of lithium ions and low ion resistance and cycle-life characteristics [0040]. lyama teaches negative active material in which flat silicon particles having an aspect ratio of 1 to 20 and a thickness of 0.5 um or less, in particular, an aspect ratio of 5 to 10. See Abstract and [0016]. The silicon particles have a carbon layer on the surface of the silicon particles [0008]. When the aspect ratio is 1 or more, the contact area between particles increases, tending to further improve conductivity, and when the aspect ratio is 20 or less, collapse of silicon during charge/discharge cycles is suppressed, tending to result in a longer life for the lithium ion secondary battery [0016]. Further, the thickness of the silicon particles is 0.5 um or less, preferably 0.01 um to 0.4 um, and more preferably 0.05 um to 0.3 um. When the thickness of the silicon particles is 0.5 um or less, then breakdown of silicon during charge/discharge cycles is suppressed, and the lithium ion secondary battery tends to have a long life [0018].
It would have been obvious to one of ordinary skilled in the art at the time invention was made to form the silicon particles of Youm in the form of flat particles disposed as close as possible, with an aspect ratio between 5 to 10, as taught by Iyama, for the benefit of having good conductivity and having long life.
Hence, the prior art combination would entail modifying Youm’s silicon particle with size between 50 nm to about 300 nm by forming them with an aspect ratio of between 5 and 10.
For the purposes of calculating the adjacent distance between silicon nanoparticles, the mass ratio of the carbon layer to the silicon particles is 0.001 to 0.3 [0008], and is minimal compared to the mass of silicon. It is noted that when two flat particles with a thickness of, for example, 10 nm, the adjacent distance between the centers of the adjacent silicon nanoparticles is approximately 10 nm, and hence meets Applicant’s limitation in claim 1.
Regarding claim 1, wherein the silicon nanoparticles have a short axis length of about 20 nm to about 50 nm, and a long axis length of about 50 nm to about 300 nm, forming Youm’s silicon particle size between 50 nm to about 300 nm with an aspect ratio of between 5 and 10 would form a short axis length in a range of 300 nm/5 = 60 nm and 50 nm/10=5 nm, greater than 5 nm and less than 60 nm. The long axis length would be less than 300 nm and greater than 50 um. In the case where the claimed ranges “overlap or lie inside ranges disclosed by the prior art” a prima facie case of obviousness exists. In re Wertheim, 541 F.2d 257, 191 USPQ 90 (CCPA 1976); In re Woodruff, 919 F.2d 1575, 16 USPQ2d 1934 (Fed. Cir. 1990). See MPEP 2144.05.
Claim 4 is rejected under 35 U.S.C. 103(a) as being unpatentable over Youm (EP 3046167) in view of Iyama (JP 2018-110076) as applied to claim 1, further in view of Otsuka (US 2017/0040610).
Regarding claim 4, an X-ray diffraction (XRD) peak of a (111) plane of the silicon nanoparticles has a full width at half maximum (FWHM) of about 0.3° to about 7°, Otsuka teaches a negative electrode material containing silicon-containing particles, graphitic carbon particles, and carbon material (Abstract). the composite material according to the present invention has a full width at half maximum of 111 diffraction peak derived from silicon, as observed in the X-ray diffraction with CuK . radiation, of preferably 0.3o to 0.5 o in terms of a scatter angle (2). If the full width at half maximum on the (111) plane is within the range, a balance between cycle retention rate and initial charge and discharge efficiency is improved. Moreover, from a viewpoint of improving the cycle retention rate in the lithium ion battery, the full width at half maximum of the 111 diffraction peak is preferably 0.3 o or more, further preferably 0.5 o or more, and still further preferably 0.7 o or more in terms of the scatter angle (2) [0077]. It would have been obvious to one of ordinary skill in the art at the time the invention was made to adjust the full width at half maximum of 111 diffraction peak derived from silicon, as taught by Otsuka, for the benefit of having good cycle retention rate.
Response to Arguments
Arguments filed 12/29/2025 are addressed below:
The Applicant asserts that the Office's reliance on lyama's aspect ratio and hypothetical calculation of adjacent distance (based on an assumed particle thickness of 10 nm) appears to be legally and technically flawed. Iyama does not disclose such thickness; rather, lyama teaches a thickness range of up to 0.5 µm (500 nm), and even its preferred range of 0.01-0.4 µm (10-400 nm) does not disclose or suggest the claimed combination of short axis (20-50 nm) and long axis (50-300 nm) together with the required adjacent distance and composite structure. The Office's reliance on thickness to approximate adjacent distance conflates distinct dimensions. This impermissible hindsight reconstruction should not supply the missing limitations.
In response, it is noted that the rejection is based on the combination of Youm modified by Iyama, and not Iyama alone. Youm discloses a silicon particle having an average particle diameter of between about 50 nm to about 300 nm for the benefit of suppressing from a volume expansion due to smooth in-and-out of lithium ions and low ion resistance and cycle-life characteristics [0040]. lyama teaches negative active material in which flat silicon particles having an aspect ratio of 1 to 20 and a thickness of 0.5 um or less, in particular, an aspect ratio of 5 to 10. See Abstract and [0016]. The silicon particles have a carbon layer on the surface of the silicon particles [0008]. When the aspect ratio is 1 or more, the contact area between particles increases, tending to further improve conductivity, and when the aspect ratio is 20 or less, collapse of silicon during charge/discharge cycles is suppressed, tending to result in a longer life for the lithium ion secondary battery [0016]. Further, the thickness of the silicon particles is 0.5 um or less, preferably 0.01 um to 0.4 um, and more preferably 0.05 um to 0.3 um. When the thickness of the silicon particles is 0.5 um or less, then breakdown of silicon during charge/discharge cycles is suppressed, and the lithium ion secondary battery tends to have a long life [0018].
It would have been obvious to one of ordinary skilled in the art at the time invention was made to form the silicon particles of Youm in the form of flat particles disposed as close as possible, with an aspect ratio between 5 to 10, as taught by Iyama, for the benefit of having good conductivity and having long life.
Regarding claim 1, wherein the silicon nanoparticles have a short axis length of about 20 nm to about 50 nm, and a long axis length of about 50 nm to about 300 nm, forming Youm’s silicon particle size between 50 nm to about 300 nm with an aspect ratio of between 5 and 10 would form a short axis length in a range of 300 nm/5 = 60 nm and 50 nm/10=5 nm, greater than 5 nm and less than 60 nm. The long axis length would be less than 300 nm and greater than 50 um. In the case where the claimed ranges “overlap or lie inside ranges disclosed by the prior art” a prima facie case of obviousness exists. In re Wertheim, 541 F.2d 257, 191 USPQ 90 (CCPA 1976); In re Woodruff, 919 F.2d 1575, 16 USPQ2d 1934 (Fed. Cir. 1990). See MPEP 2144.05.
Although Applicant argues that Iyama teaches that the length of the silicon particle is 0.5 um or more, Iyama does not teach that the aspect ratio applies when the length of the silicon particle is 0.5 um or more. An ordinary artisan would note Youm’s disclosure that a silicon particle having an average particle diameter of between about 50 nm to about 300 nm suppresses from a volume expansion due to smooth in-and-out of lithium ions and low ion resistance and cycle-life characteristics [0040]. Hence, the prior art combination would entail modifying Youm’s silicon particle with size between 50 nm to about 300 nm by forming them with an aspect ratio of between 5 and 10. Hence, the combination is proper.
In response to applicant's arguments against the references individually, one cannot show nonobviousness by attacking references individually where the rejections are based on combinations of references. See In re Keller, 642 F.2d 413, 208 USPQ 871 (CCPA 1981); In re Merck & Co., 800 F.2d 1091, 231 USPQ 375 (Fed. Cir. 1986).
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to CYNTHIA KYUNG SOO WALLS whose telephone number is (571)272-8699. The examiner can normally be reached on M-F until 5pm.
If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Miriam Stagg can be reached at 571-270-5256. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/CYNTHIA K WALLS/Primary Examiner, Art Unit 1751
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