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 .
DETAILED ACTION
This Office Action is responsive to the amendment filed on 3/27/2026. Claims 1-20 are pending. Claim 3 has been amended. Applicant’s arguments have been considered, but are not persuasive. Claims 1-20 are finally rejected for reasons below.
Claims Analysis
The instant Specification defines the limitation “composite” as follows:
[0087] The Si/C composite may be in a form in which silicon particles are uniformly dispersed in an atomic state within a carbon (C) matrix. Specifically, the term "composite" as used herein indicates a material in which two or more materials are combined to form physically and chemically different phases, exhibiting more effective functions. The "Si/C composite" does not indicate a state in which Si and carbon (C) are simply aggregated or mixed, but a state in which silicon particles are embedded within a carbon matrix. The carbon matrix is a porous carbon matrix.
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.
Claims 1-13, 15-20 are rejected under 35 U.S.C. 103 as being unpatentable over Youm (US 2015/0194698) in view of Uhm (KR 2009-0063174), Troegel (US 2020/0194778).
Regarding claim 1, Youm discloses a lithium secondary battery comprising:
an electrode assembly comprising a positive electrode, a negative electrode, and a separator positioned between the positive electrode and the negative electrode;
an electrolyte; and
a battery case accommodating the electrode assembly and the electrolyte;
wherein the negative electrode comprises a negative electrode active material layer comprising graphite-silicon composite,
wherein the electrolyte comprises a non-fluorinated saturated cyclic carbonate and a fluorine-based compound in a weight ratio of 40:1 to 40:20 [0093].
wherein the fluorine-based compound is present in an amount of 1 wt% to 5 wt% with respect to a total weight of the electrolyte [0093].
Regarding claim 1, wherein the positive electrode comprises a positive electrode active material layer comprising a lithium transition metal oxide represented by Formula 1 as a positive electrode active material;
[Formula 1]
Li1+x1 [N1y1Coz1Mnw1M1v1] O2
wherein, in Formula 1,
M1 is at least one doping element selected from the group consisting of Al, W, Cu, Fe, V, Cr, Ti, Zr, Zn, In, Ta, Y, In, La, Sr, Ga, Sc, Gd, Sm, Ca, Ce, Nb, Mg, B, and Mo, and 0<x1<0.2, 0.50<y1<1, 0<z1<0.35, 0<w1<0.4, and 0<v1<0.1, Youm discloses Lia(NibCocMndGe)O2, 0.90<a<1.8, 0.1<b<0.9, 0.1<c<0.5, 0.1<d<0.5, 0.001<e<0.1 [0067]. 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. The ranges in Formula 1 are would have been obvious, unless the ranges are critical.
Regarding claim 3, the Si/C composite contains silicon (Si) and carbon (C) in a weight ratio of 1:10 to 6:10 [0043].
Regarding claim 6, the non-fluorinated saturated cyclic carbonate is present in an amount of 10 wt% to 40 wt% with respect to a total weight of the electrolyte [0093].
Regarding claim 7, the non-fluorinated saturated cyclic carbonate comprises at least one of ethylene carbonate (EC), propylene carbonate (PC), 1,2-butylene carbonate, 2,3-butylene carbonate, 1,2-pentylene carbonate, or 2,3-pentylene carbonate [0093].
Regarding claim 8, the non-fluorinated saturated cyclic carbonate comprises ethylene carbonate [0093].
Regarding claim 9, the fluorine-based compound is fluoroethylene carbonate (FEC) [0093].
Regarding claim 10, the electrolyte comprises a lithium salt, and the lithium salt is present at a concentration of 0.5 M to 2.0 M in the electrolyte [0093].
Regarding claim 11, the lithium salt comprises LiPF6, LiClO4, LiAsF4, LiBF4, LiSbF6, LiAlO4, LiAlCl4, LiCF3SO3, LiC4F3SO3, LiN(C2F5SO3) 2, LiN(C2F5SO2)2, LiN(C2F3O2)2, LiCl, Lil, or LiB(C2O4)2 [0093].
Regarding claim 12, the lithium salt comprises LiPF6 [0093].
Regarding claim 13, the electrolyte further comprises a non-fluorinated linear carbonate-based solvent in an amount of 40 wt% to 80 wt% based on a total weight of the electrolyte [0093].
Regarding claim 15, the battery case is a pouch type battery case, it would have been obvious to one of ordinary skilled in the art at the time the invention was made to for the battery of Youm in a pouch type battery case depending on the size of the battery housing requirements for the intended application.
Regarding claim 16, an electric vehicle comprising a battery module comprising the lithium secondary battery of claim 1, it would have been obvious to one of ordinary skilled in the art at the time the invention was made to use the battery of Youm in an electric vehicle for the benefit of providing electrical power to an electric vehicle.
Regarding claim 17, Youm discloses a lithium secondary battery comprising:
an electrode assembly comprising a positive electrode, a negative electrode, and a separator placed between the positive electrode and the negative electrode;
an electrolyte; and
a battery case accommodating the electrode assembly
and the electrolyte;
wherein the negative electrode,
the negative electrode comprises a negative electrode active material layer and a solid electrolyte interphase (SEI) layer on the negative electrode active material layer [0021].
Regarding claim 18, Youm discloses wherein the electrolyte comprises a non-fluorinated saturated cyclic carbonate and a fluorine-based compound in a weight ratio of 40:1 to 40:20 [0093].
Regarding claim 19, Youm discloses wherein the fluorine-based compound is present in an amount of 1 wt% to 5 wt% with respect to a total weight of the electrolyte [0093].
Regarding claim 20, electric vehicle comprising a battery module comprising the lithium secondary battery of claim 16, it would have been obvious to one of ordinary skilled in the art at the time the invention was made to use the battery of Youm in an electric vehicle for the benefit of providing electrical power to an electric vehicle.
Regarding claims 1, 17, Youm discloses a negative electrode comprises a negative electrode active material layer comprising graphite and a Si/C composite in amounts of 95 to 85 wt% and 5 to 15 wt%, respectively [0040], but does not disclose wherein the graphite and the Si/C composite are present in a weight ratio of 93.1:6.9 to 99.9:0.1 in the negative electrode active material layer. Youm discloses when the graphite-silicon composite is included within these ranges, it may suppress (or reduce) volume expansion of the silicon (Si) particle and may facilitate good electrical conductivity, thus improving cycle-life characteristics of the battery [0041].
Regarding claim 1, Uhm teaches wherein the negative electrode comprises a negative electrode active material layer comprising graphite and a Si/C composite (page 6 of translation); wherein the graphite and the Si/C composite are present in a weight ratio of 93.1:6.9 to 99.9:0.1 in the negative electrode active material layer (page 6, and Example 5A on page 9 of translation),
Regarding claim 2, the Si/C composite is present in an amount of 1 wt% to 15 wt% with respect to a total weight of the negative electrode active material layer (page 6 of translation).
Regarding claim 5, the graphite and the Si/C composite are present in a weight ratio of 94:6 to 99:1 in the negative electrode active material layer (page 6, and Example 5A on page 9 of translation).
Regarding claim 17, wherein the negative electrode comprises a negative electrode active material layer containing graphite and a Si/C composite, the graphite and the Si/C composite are present in a weight ratio of 93.1:6.9 to 99.9:0.1 in the negative electrode active material layer (page 6, and Example 5A on page 9 of translation).
Uhm teaches a negative electrode active material comprising a Si/C composite and a second carbonaceous material. When the Si/C composite particles are mixed with a second carbonaceous material, even if the Si/C composite particles deteriorate as the battery is charged and discharged, the life of the negative electrode can be maintained at a certain rate due to the second carbonaceous material, so that the capacity of the secondary battery can be increased. If the ratio of Si-C composite particles is less than 2 part by weight, the capacity of the battery cannot be increased, and if the ratio of Si-C composite particles exceeds 10 parts by weight, the life characteristics of the battery may be deteriorated (2nd paragraph, page 6 of translation).
It would have been obvious to one of ordinary skilled in the art at the time the invention was made to further increase the amount of graphite in the mixture of graphite-silicon composite and graphite of Youm, as taught by Uhm, for the benefit of further suppress volume expansion and protecting the graphite-silicon composite.
Regarding claims 1, 17, Youm modified by Uhm discloses wherein the negative electrode comprises a negative electrode active material layer comprising graphite and a Si/C composite, but does not disclose that the Si/C composite comprises silicon particles that are embedded within a carbon matrix, and that the carbon matrix is a porous carbon matrix, as defined in the Specification. Regarding claim 4, Uhm discloses a Si/C composite, but does not disclose that the Si/C composite comprises silicon particles embedded within a carbon matrix. Troeger teaches Si/C composite particles in which silicon particles are embedded in porous carbon matrix. The Si/C composite particles produced in accordance with the invention have an advantageous, well-defined structural design, which on corresponding use of the Si/C composite particles in lithium-ion batteries, produces advantageous performance properties. The silicon particles are embedded in pores in the carbon matrix, and the size of the pores can be influenced. The pores have the capacity to buffer the expansion in volume of the silicon during the charging of a lithium-ion battery and so to reduce electrochemical milling. Furthermore, by virtue of the inventive design of the Si/C composite particles, the silicon particles can be protected against liquid media, and the formation of SEI, as a result of electrolytes, acids or alkalis, for example, in corresponding lithium-ion batteries can be reduced. Accordingly, during the operation of the lithium-ion batteries, it is possible to prevent or reduce the delamination of the SEI layer, thereby further reducing the SEI problem [0107].
It would have been obvious to one of ordinary skilled in the art at the time the invention was made to embed the silicon particles of Youm in pores of the graphite particle, as taught by Troeger, for the benefit of protecting the Si/C composite particles against electrolyte to reduce the formation of SEI.
Regarding claim 17, the SEI layer contains Li2CO3 and LiF in a weight ratio of 1:1 to 3:1, it is noted that the negative electrode of Youm as modified by Uhm and Troegel would contain the SEI layer as claimed in claim 17 because Youm as modified by Uhm and Troegel meets the structural limitations of claim 17.
Claim 14 is rejected under 35 U.S.C. 103 as being unpatentable over Youm (US 2015/0194698) in view of Uhm (KR 2009-0063174), and Troegel (US 2020/0194778), as applied to claim 1, further in view of Toma (US 2018/0190978).
Regarding claim 14, Youm modified by Uhm does not disclose the lithium transition metal oxide has an average particle size (D50) of 2 um to 10 um. Toma teaches the positive electrode active material of the present invention is adjusted so that the average particle size is within the range 1 μm to 15 μm, and preferably within the range 3 μm to 12 μm, and more preferably within the range 3 μm to 10 μm. When the average particle size of the positive electrode active material is within this kind of range, not only is it possible to increase the battery capacity per unit volume of a secondary battery that uses this positive electrode active material, it is also possible to improve the safe performance and output characteristic. However, when the average particle size is less than 1 μm, the filling property of the positive electrode active material decreases, and it is not possible to increase the battery capacity per unit volume. On the other hand, when the average particle size is greater than 15 μm, the reaction surface area of the positive electrode active material decreases, and the interface with the electrolyte decreases, so it becomes difficult to improve the output characteristics [0151].
It would have been obvious to one of ordinary skilled in the art at the time the invention was made to form the positive active material particle size of Youm modified by Uhm in the range of Toma, as taught by Toma, for the benefit of achieving good capacity.
Response to Arguments
Arguments filed 3/27/2026 are addressed herein below:
Applicant argues a person skilled in the art would have no reasonable expectation of success in modifying the negative electrode of Youm to use the carbon and Si/C composite of Uhm, as alleged by the Office. Youm teaches that the silicon content of the Si/C composite is from 15 wt% to 25 wt%. (Youm, para. [0043]). Youm goes on to teach that "when the silicon (Si) particle is included within these ranges, volume expansion of the silicon (Si) particle that occurs during the charge and discharge of the battery may be suppressed (or reduced), and cycle-life characteristics may be improved." (Id.) In contrast, Uhm teaches that the weight ratio of silicon to carbon in the Si/C composite is 40:60 to 80:20. (Uhm, p. 5). Accordingly, the silicon content in the Si/C of Uhm is about 40 wt% to 80 wt.%, which is well outside the range taught in Youm.
A person skilled in the art would not modify the negative electrode of Youm to use the Si/C composite of Uhm. It is well understood that "it is improper to combine references where the references teach away from their combination." MPEP 2145, citing In re Grasselli, 713 F.2d 731, 743, 218 USPQ 769, 779 (Fed. Cir. 1983). In the present case, Youm teaches that when the silicon content of the Si/C composite is outside the range of 15 wt% to 25 wt% volume expansion is increased. (Youm, para. [0043]). This leads to inferior cycle-life characteristics of the battery (Id.) Accordingly, a person skilled in the art would have no reasonable expectation of success in modifying the negative electrode of Youm to use the Si/C of Uhm, as one skilled in the art relying on Youm would expect the Si/C of Uhm to undergo undesirable volume expansion. Pages 6-7 of Arguments.
In response, the Examiner respectfully disagrees. The combination entails further increasing the amount of graphite in Youm’s mixture of graphite and graphite-silicon composite. The Examiner further notes that further increasing the amount of graphite in Youm’s mixture does not require changing the amount of silicon in the graphite-silicon composite, or the graphite-silicon composite itself. Hence, the rejection is proper.
Applicant argues that an ordinary artisan would not readily modify the negative electrode of Youm to have the silicon content of Uhm or to include the Si-C composite structure of Troeger.
The Si/C composite of Youm has a structure in which silicon particles are present on graphite particles and a carbon coating layer surrounds the silicon particles and the graphite particles. (Youm, para. [0010]). This structure is illustrated in FIG. 3 of Youm. As described in paragraph [0039] of Youm, the Si/C composite of Youm has a distinctive structure in which the carbon coating layer surrounding the graphite and silicon particles enables surface contact between the Si/C composite and graphite in the negative electrode active material, which reduces contact resistance. Specifically, Youm states "[t]he graphite-silicon composite and the graphite included in the negative electrode active material make surface contact, and therefore have lower contact resistance as compared to a negative active material in which a SiOₓ particle and a graphite particle are simply mixed (which simple mixture creates point contact rather than surface contact." (Youm, para. [0039]). It is understood in the art that the surface contact described in Youm is possible because the outer carbon coating layer forms a flexible interface. Accordingly, a person skilled in the art would understand from the disclosure of Youm that the structure in which the outer surface of the graphite-silicon composite particles is surrounded by the carbon coating layer plays a critical role in lowering contact resistance.
Furthermore, as described in paragraphs [0042]-[0046] of Youm, the silicon particles are included in the Si/C composite in an amount from 15 wt% to 25 wt% based on the total weight of the Si/C composite. (Youm, para. [0043]). The silicon particles are included in this amount to suppress volume expansion. (Youm, para. [0043]-[0046]). Additionally, as the silicon content increases, silicon particles are more likely to become exposed on the exterior of the Si/C composite, increasing the likelihood that adjacent graphite comes into contact with the silicon particles rather than the carbon coating layer. Accordingly, a person skilled in the art would understand that achieving the surface contact intended in Youm would be difficult.
Uhm teaches Si/C composite particles in which silicon particles are uniformly dispersed in a first carbonaceous material. Unlike Youm, the Si/C composite particles of Uhm do not have a structure in which silicon particles are covered by carbon. Instead, they have a structure in which silicon particles are exposed. Accordingly, the likelihood of forming surface contact with adjacent graphite would be reduced. Additionally, since the Si/C composite particles of Uhm have a greater silicon content than the Si/C composite particles of Youm, a person skilled in the art would expect that applying Uhm's Si/C composite to You would hinder volume expansion control, as described in more detail hereinabove.
Troegel teaches that Si/C composite particles having a structure where silicon particles are positioned within pores of a porous composite. Since the Si/C composite particles of Troegel have a porous composite structure, it can be reasonably expected that their particle strength is lower than that of Youm, in which a carbon coating layer is formed on the particles. Accordingly, when applying the structure of Troegel's Si/C composite particles to Youm modified by Uhm, it would be unclear to a person skilled in the art whether the surface contact that Youm teaches would be maintained. Accordingly, the modification proposed by the Office would not yield predictable results to one skilled in the art. Pages 7-9 of Arguments.
In response, the Examiner respectfully disagrees. The combination entails further increasing the amount of graphite in Youm’s mixture of graphite and graphite-silicon composite. The Examiner further notes that further increasing the amount of graphite in Youm’s mixture does not require changing the amount of silicon in the graphite-silicon composite, or the graphite-silicon composite itself.
Regarding Troeger, the Examiner notes that the particle strength does not have to be of concern if the all the pores are filled with silicon particles. Should the particle strength be of concern when forming pores in graphite particles, it is noted that the carbon coating would act as a support from external impact and to maintain surface contact.
Hence, the rejection is proper.
Applicant argues in the field of lithium-ion secondary batteries, silicon-based negative electrode active material vary significantly in conductivity, degree of volume expansion, and capacity, depending on several factors. Accordingly, when designing a negative electrode, factors such as volume expansion, SEI film stability, capacity, and conductivity must be comprehensively considered, and the type and content of silicon-based and graphite-based active materials, as well as conductive agents and binders are comprehensively adjusted. Thus, even if the graphite-silicon composite of Youm were modified according to Uhm or Troegel, it would not be possible for a person skilled in the art to predict the effects that would result from such modification. It is well understood that "[t]he mere fact that references can be combined or modified does not render the resultant combination obvious unless the results would have been predictable to one of ordinary skill in the art." MPEP 2143.01(III), citing KSR Int'l Co. v. Teleflex Inc., 550 U.S. 398, 417, 82 USPQ2d 1385, 1396 (2007). For the reasons described above, Applicant respectfully submits that the modification of Youm in view of Uhm and Troegel proposed by the Office would not yield predictable results to those skilled in the art. Therefore, independent claim 1 is not obvious over the cited references. Page 9 of Arguments.
In response, the Examiner respectfully disagrees. MPEP 2143.02 states:
II. AT LEAST SOME DEGREE OF PREDICTABILITY IS REQUIRED; APPLICANTS MAY PRESENT EVIDENCE SHOWING THERE WAS NO REASONABLE EXPECTATION OF SUCCESS
Obviousness does not require absolute predictability, but at least some degree of predictability is required. Evidence showing there was no reasonable expectation of success may support a conclusion of nonobviousness.
The Examiner notes that the combination of Youm modified by Uhm and Trogel yield predictable results of functioning as an active material that intercalates and deintercalates lithium ions during charging and discharging processes. Increasing the graphite in the active material mixture of Youm, as modified by Uhm, would yield predictable results of further suppressing volume expansion and protecting the graphite-silicon composite.
Further, embedding the silicon particles in the graphite particles of Youm, as taught by Troeger, yields predictable results to buffer silicon particles from expansion and further protecting silicon from exposure to electrolyte solvent. And hence, the Examiner has satisfied the Examiner’s burden to show some degree of predictability.
Applicant notes that in the presently claimed lithium secondary battery, the combination of specific compositions of the positive electrode, negative electrode, and electrolyte enables the formation of a SEI film on the negative electrode that is excellent in stability and durability due to both thickness and composition while also reducing electrolyte side reactions and swelling. These effects are demonstrated in the examples and comparative examples of the present application. In contrast, Youm focuses only on the design of the negative electrode and does not consider the relationship between the electrolyte composition and the negative electrode composition and there is no recognition of suppressing SEI film degradation. As described in more detail in the Response filed on June 9, 2025, Uhm does not teach the weight ratio of the non-fluorinated saturate cyclic carbonate to the fluorinated compound, and thus does not recognize the effects of the combination of the positive electrode, negative electrode, and electrolyte on the SEI film. Instead, as described in detail in the Response filed on June 9, 2025, Uhm teaches that it is preferable for the FEC content to exceed 5 wt% rather than being limited to 5 wt%. In other words, Youm does not recognize that the compositions of the positive electrode, the negative electrode, and the electrolyte should be mutually controlled. Moreover, since the negative electrode composition in Youm is the core design feature of the application, modifying it runs counter to the technical teaching of Youm. Additionally, the electrolyte composition of Youm is regarded as being inferior in Uhm. Accordingly, there is no motivation for one skilled in the art to selectively apply teaching regarding the negative electrode composition of Uhm to the negative electrode of Youm.
In response, Applicant is encouraged to point to specific claim language. The claims do not recite the suppression of SEI film degradation. Regarding the limitation of the “wherein the electrolyte comprises a non-fluorinated saturated cyclic carbonate and a fluorine-based compound in a weight ratio of 40:1 to 40:20 [0093], wherein the fluorine-based compound is present in an amount of 1 wt% to 5 wt% with respect to a total weight of the electrolyte [0093], refer to Youm in the rejection above.
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, Jonathan Leong can be reached at 571-270-1292. 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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