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 .
Response to Amendment
This Office Action is responsive to the amendment filed on 2/10/2026. Claims 1, 3, 5, 6, 8, 9 are pending. Applicant’s arguments have been considered. Claims 1, 3, 5, 6, 8, 9 are 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, 6, 8, 9 are rejected under 35 U.S.C. 103(a) as being unpatentable over Tuduki (US 2015/0380735) in view of Hirose (US 2016/0104884), Akira (US 2017/0117541), and Cho (US 2017/0033357).
Regarding claim 1, Tuduki discloses a negative active material for a rechargeable lithium battery, comprising:
a silicon primary particle core consisting of silicon [0032],
the particle layer has a thickness in a range of about 60 nm to about 500 nm [0040].
Regarding claim 1, a particle layer 1 formed by agglomerating silicon oxide primary particles having a particle size of 10 nm or less on a surface of the core, Tuduki discloses the phases B are composed of silicon oxide. Tuduki discloses the average thickness thereof is preferably not more than 100 nm, and more preferably 0.1 nm to 10 nm. The average thickness of the phases B may be measured by SEM-EDS or TEM. In the negative electrode active material particles, the phases B in the particle are bonded together as a result of treatment such as sintering to form a network structure. That is, the phases B may be described as being finely dispersed with a size of 100 nm or less in the particle. This may be confirmed also based on the results of energy dispersive X-ray spectroscopy (EDS) showing microscopic and uniform distribution of oxygen. Because the silicon oxide in the negative electrode active material particles is dispersed uniformly with a microscopic size, it may serve as a buffer that reduces the swelling and the shrinkage of the active material in spite of the fact that the amount of the silicon oxide is small, thus achieving both enhanced cycle characteristics and higher capacity [0040]. Further, the primary particles are exposed to the air and the surface is naturally oxidized to form silicon oxide (the phase B) [0045]. Sintering the particles forms microcrystalline silicon phases and uniformly and finely dispersed silicon oxide phases [0046]. It appears that the finely dispersed and uniformly formed silicon oxide phases reads on Applicant’s limitation “agglomerating” silicon oxide primary particles. It is further supported by Tuduki’s silicon oxide is formed by silicon particles being oxidized by its environment air [0045]. The instant Specification states that the Applicant’s silicon oxide is formed by silicon particles being oxidized by its environment water [0052].
Should it not be anticipatory, it would have been obvious to one of ordinary skilled in the art at the time the invention was made to adjust the amount of silicon oxide of the phase B of Tuduki for the benefit of protecting the silicon particle from excessive swelling and shrinking.
Regarding claim 5, considering the broadness of the term “continuously positioned”, the particle layer of Tuduki is continuously positioned on the surface of the core in a form of a layer because it forms a uniform and finely dispersed silicon oxide phases [0071]. Should it not be anticipatory, it would have been obvious to one of ordinary skilled in the art at the time the invention was made to continuously position the particle layer on the surface of the core in a form of a layer for the benefit of uniformly forming a buffer to reduce the swelling and the shrinkage of the silicon active material particle.
Regarding claim 1, having a particle size of micrometers, the silicon primary particle core has a particle size in a range of about 1 um to about 20 um, Tuduki discloses the silicon primary particle core has a particle size in a range of about 0.5 um to about 0.5 um [0044]. Hirose teaches a silicon active material particle comprising a silicon core and a silicon oxide shell. The core portion 201 preferably has a median diameter of 0.3 μm to 20 μm because the core portion 201 easily occludes and releases lithium ions during charge and discharge and because the core portion 201 is not easily broken. More particularly, a median diameter of less than 0.3 μm can facilitate expansion and contraction during charge and discharge because of an excessively large total surface area of the core portion 201. A median diameter exceeding 20 μm is liable to lead to a break of the core portion 201 during charge and discharge [0055]. It would have been obvious to one of ordinary skilled in the art at the time the invention was made to adjust the size of Tuduki’s silicon core, as taught by Hirose, for the benefit of having good facilitation between expansion and contraction during charge and discharge.
Regarding claim 1, Tuduki does not disclose the particle layer comprising pores, a carbon-based material filled in the pores of the particle layer. Akira teaches a mixed phase coating containing SiO2 and carbon [0017]. When carbon is dispersed in a phase formed of SiO2 in the mixed phase coating, the direct reaction between an electrolytic solution and the base particle is suppressed and also the negative electrode active material is allowed to have conductivity [0019]. It would have been obvious to one of ordinary skill in the art at the time the invention was made to mix carbon particles in the silicon oxide layer of Son for the benefit of making the active material conductive.
Akira discloses a mixed phase coating containing SiO2 and carbon that covers the surface of the base particle [0019]. Since the SiO2 and carbon are mixed, Son modified by Akira reads on Applicant’s “pores” because the Applicant’s pores are filled by carbon.
Regarding claim 1, Tuduki modified by Akira does not disclose the carbon-based material consists of amorphous carbon. Cho teaches a silicon active material particle having a conductive layer. The conductive layer may include an amorphous carbon layer or conductive metal oxide particles [0010]. It would have been obvious to one of ordinary skill in the art at the time the invention was made to use amorphous carbon as carbon particles of Tuduki modified by Akira, as taught by Cho, for the benefit of making the silicon oxide layer conductive. It has been held by the court that the selection of a known material based on its suitability for its intended use is prima facie obvious. Sinclair & Carroll Co. v. Interchemical Corp., 325 U.S. 327, 65 USPQ 297 (1945). See MPEP 2144.07.
Regarding claim 1, wherein an amount of oxygen in the negative active material is about 5 wt% to about 20 wt% based on the total 100 wt%, of the negative active material, Tuduki discloses the silicon oxide in the negative electrode active material particles dispersed uniformly with a microscopic size serve as a buffer that reduces the swelling and the shrinkage of the active material in spite of the fact that the amount of the silicon oxide is small, thus achieving both enhanced cycle characteristics and higher capacity [0040]. In the negative electrode active material particles (the two-phase regions), the molar ratio of oxygen to silicon is preferably O/Si≦0.3, and more preferably 0.01≦O/Si≦0.2. The oxygen to silicon molar ratio may be obtained by EDS measurement. For reasons such as that the phases B composed of silicon oxide have high reactivity with lithium to produce inert reaction products with lithium and also that the reversible capacity depends on the amount of silicon, an increase in the amount of silicon leads to an increase in capacity. On the other hand, silicon oxide is inevitable from the viewpoint of the enhancement of cycle characteristics. In light of these facts, the aforementioned range of the oxygen to silicon molar ratio is advantageous [0043].
It is noted that the negative active material of Tuduki modified by Hirose, Akira and Cho contains silicon, oxygen, and carbon. Hence, the amount of oxygen is less than 30 wt%, preferably less than 20 wt%, based on the total of the negative active material.
It would have been obvious to one of ordinary skilled in the art at the time the invention was made to adjust the amount of oxygen of Tuduki in a minor amount for the benefit of obtaining good cycle characteristics.
Tuduki clearly teaches that oxygen 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 6, an amount of the carbon-based material is in a range of about 1 wt% to about 5 wt% based on the total of 100 wt% of the negative active material, Akira disclose the ratio of SiO.sub.2 to carbon in the mixed phase coating is preferably 9:1 to 1:9. If the proportion of SiO.sub.2 is excessively small, the direct reaction between the electrolytic solution and the base particle is not easily suppressed. If the proportion of carbon is excessively small, the conductivity of the negative electrode active material tends to degrade [0021]. 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 carbon in the particle layer depending on the desired amount of conductivity.
Regarding claim 8, Tuduki modified by Hirose, Akira, and Cho teaches a rechargeable lithium battery comprising: a negative electrode comprising the negative active material of claim 1; a positive electrode; and an electrolyte.
Regarding claim 9, Tuduki does not teach the negative electrode further comprises a carbon-based negative active material. Akira teaches the silicon negative electrode active material 13a is suitably used in combination with another negative electrode active material 13b having a smaller volume change due to charge and discharge than the negative electrode active material 13a from the viewpoints of achieving high capacity and improving cycle characteristics. The negative electrode active material 13b is not particularly limited, but is preferably a carbon-based active material such as graphite or hard carbon. [0028]. It would have been obvious to one of ordinary skill in the art at the time the invention was made to add a carbon-based negative active material to the negative active material of Tuduki modified by Hirose, Akira, and Cho, as taught by Akira, for the benefit of having a smaller volume change due to charge and discharge than the negative electrode active material 13a from the viewpoints of achieving high capacity and improving cycle characteristics.
Response to Arguments
Arguments filed 2/10/2026 are moot in view of the new grounds of rejection.
Conclusion
Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). 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 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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