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and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114.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 September 5, 2025 has been entered.
Status of Application
Claims 1 and 3-11 are pending. Claim 1 is amended, submitted on 9/5/2025. Claims 1 and 3-11 are presented for examination.
Claim Rejections - 35 USC § 103
1. 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.
2. The factual inquiries set forth in Graham v. John Deere Co., 383 U.S. 1, 148 USPQ 459 (1966), that are applied 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.
3. 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.
4. Claims 1, 3-6 and 8-11 are rejected under 35 U.S.C. 103 as being unpatentable over Oh (KR 20190108814 A, see machine translation for citation).
* Oh (KR 20190108814 A) is a prior art reference because the foreign priority of the instant application has not been perfected with a certified priority document along with an English language translation.
Regarding claim 1, Oh discloses a negative electrode (20, FIG. 2) for a lithium secondary battery ([0088] and FIG. 2), comprising a first negative electrode active material (Tables 2 and 3) including a carbon-based material and a silicon-based material (silicon-carbon composite [0106]), wherein the carbon-based material includes artificial graphite (Table 2 and 3, Example 3, 90 wt% artificial graphite), which falls within the range 65 to 95% as claimed “wherein the first negative electrode active material comprises 65 to 95% of the low-expansion artificial graphite with respect to a total weight of the first negative electrode active material”.
Oh further discloses in Table 2, the expansion rate measurement result for Example 3 is 9.1% ([0150] and Table 2), which inherently discloses the carbon-based material includes low-expansion artificial graphite expands by less than 25% when a battery is charged and discharged (half-cell , because in Example 3, 90 weight% is artificial graphite (Table 2), because silicon is well-known for its high expansion rate of about 400%, so when the overall expansion rate is 9.1%, a skilled artisan would reasonably envisage the artificial graphite used in Example 3 are low expansion artificial graphite with expansion rate necessarily and inherently less than the overall expansion rate of 9.1%, thus falls within the range of less than 25% as claimed “low-expansion artificial graphite expands by less than 25% when a battery is charged and discharged”.
Oh uses styrene butadiene rubber as the binder and thickener in the negative active material slurry for preparing a negative electrode of Example 3 ([0122]), thus Oh does not explicitly use polyvinylidene fluoride as a binder and the only binder in the negative electrode of Example 3.
However, Oh further discloses binder may be polyvinylidene fluoride among other usable choices ([0053-0054]) without any drastic effect, a skilled artisan would reasonably expect to choose polyvinylidene fluoride from the finite list of alternatives to replace the styrene butadiene rubber binder of Example 3 without undue experimentation and with a reasonable expectation of success that the polyvinylidene fluoride binder could be used as the only binder for Example 3 without any drastic effect.
Modified Oh further discloses the expansion rate measurement of the half-cell made with Example 3 was charged and discharged 50 times at 0.5C, with continuous measurement of the thickness of the battery, and the ratio of the thickness of the battery after charging and discharging to the thickness of the battery before charging and discharging was obtained and the result shown in Table 2 is 9.1% as the expansion ratio ([0148]). While modified Oh discloses the desire of effectively suppressing expansion due to charge and discharge and exhibiting improved swelling characteristics for a negative active material for a lithium secondary battery ([0007]); and further uses measurement of the thickness change of a half-cell under charging and discharging to determine the expansion ratio, modified Oh uses a half-cell made with Example 3 which includes both silicon-based material and artificial graphite in the negative electrode active material layer (Table 2).
Thus, modified Oh does not explicitly disclose the measurement of the low-expansion artificial graphite expansion rate based on a half cell using solely low-expansion artificial graphite as the measurement negative electrode active material; 2wt% of multilayer carbon nanotubes and other detailed parameters regarding an electrolyte composition; nor the charge-discharge cycles involving charging up to 4.25 V and discharging to 2.5V, as claimed “is determined by the following method: the volume expansion rate of the low-expansion artificial graphite is determined based on …, and the charge-discharge cycles involves charging up to 4.25V and discharging to 2.5V.”
However, it would have been obvious to one having ordinary skill in the art, before the effective filing date of the invention, to reasonable expect the artificial graphite of modified Oh would successfully arrive at an expansion rate of less than 25% when a battery is charged and discharged even under the same testing measurement conditions as claimed, absent evidence to the contrary for secondary consideration, because as set forth above, in light of an overall 9.1% expansion rate achieved in Example 3 of modified Oh, containing 90 wt% of artificial graphite with highly expandable silicon as a counter effect in the negative actively material layer.
Regarding claim 3, modified Oh discloses all of the limitations as set forth above. However, modified Oh has an artificial graphite of 90 weight% in Example 3, out of the claimed range of 75 to 85% by weight.
Modified Oh further discloses in another embodiment that the artificial graphite content is 83 weight% (Comparative Example 7, Table 3), which falls within the range of 75 to 85 weight% of the low-expansion artificial graphite. It would have been obvious to a skilled artisan to arrive at the claimed “the first negative electrode active material comprises 75 to 85% of the low-expansion artificial graphite with respect to a total weight of the first negative electrode active material” as taught by another embodiment of modified Oh.
Regarding claim 4, modified Oh discloses all of the limitations as set forth above. Modified Oh further discloses the carbon-based material comprises natural graphite ([0091]) and artificial graphite (Table 2).
Regarding claim 5, modified Oh discloses all of the limitations as set forth above. Modified Oh further discloses a small amount of 8 to 16 wt% of a silicon particle content based on 100 wt% of the total negative electrode active material, thereby effectively suppressing negative electrode expansion during charge and discharge ([0037]), which overlaps the claimed range of 1 to 10 %, establishing a prima facie case of obviousness. [MPEP 2144.05 (I)].
Regarding claim 6, modified Oh discloses all of the limitations as set forth above. Modified Oh further discloses in Example 1 a negative electrode active material was prepared by mixing 10 wt% of the silicon-carbon composite prepared in manufacturing Example 1 and 90 wt% of artificial graphite ([0105]) and the manufacturing Example 1 has 50 wt% of silicon nanoparticles in the final silicon-carbon composite ([0095]), which translates to a 5 wt% of the silicon-based material with respect to a total weight of the negative electrode active material, falling within the range of 3 to 7% by weight as claimed.
It would have been obvious to a skilled artisan to arrive at the claimed “wherein the first negative electrode active material comprises 3 to 7% of the silicon-based material with respect to a total weight of the first negative electrode active material” as taught by another embodiment of modified Oh.
Regarding claim 8, modified Oh discloses all of the limitations as set forth above. Modified Oh as set forth above has a low-expansion artificial graphite with expansion ratio necessarily less than 9.1% , falls within the claimed range of “wherein a volume of the low expansion artificial graphite expands by less than 23% when a battery is charged and discharged”.
Or alternatively, as set forth in claim 1, modified Oh in view of Zhang has included a low-expansion artificial graphite with expansion rate of less than 20.3% (Zhang: [0052]), also falling within the claimed range.
Regarding claim 9, modified Oh discloses all of the limitations as set forth above. Modified Oh further discloses the negative electrode comprising: a current collector (Cu foil [0122]); and a negative electrode active material layer (slurry [0122]) disposed on at least one surface of the current collector and including the first negative electrode active material (coated and dried, [0122]).
Regarding claim 10, modified Oh discloses all of the limitations as set forth above. Modified Oh further discloses a lithium secondary battery ([0088] and FIG. 2) comprising a positive electrode (10 [0088]), the negative electrode (20, [0088]), and a separator (30, [0088]) interposed between the positive electrode and the negative electrode (FIG. 2).
Regarding claim 11, modified Oh discloses all of the limitations as set forth above. Modified Oh further discloses the lithium ion secondary battery can be a cylindrical shape ([0087]).
5. Claims 1, 3-6 and 8-11 are rejected under 35 U.S.C. 103 as being unpatentable over Oh (KR 20190108814 A, see machine translation for citation), in view of Zhang (CN 108155380 A, see machine translation for citation).
Regarding claim 1, Oh discloses a negative electrode (20, FIG. 2) for a lithium secondary battery ([0088] and FIG. 2), comprising a first negative electrode active material (Tables 2 and 3) including a carbon-based material and a silicon-based material (silicon-carbon composite [0106]), wherein the carbon-based material includes artificial graphite (Table 2 and 3, Example 3, 90 wt% artificial graphite), which falls within the range 65 to 95% as claimed “wherein the first negative electrode active material comprises 65 to 95% of the low-expansion artificial graphite with respect to a total weight of the first negative electrode active material”.
Oh further discloses in Table 2, the expansion rate measurement result for Example 3 is 9.1% ([0150] and Table 2), which inherently discloses the carbon-based material includes low-expansion artificial graphite expands by less than 25% when a battery is charged and discharged (half-cell , because in Example 3, 90 weight% is artificial graphite (Table 2), because silicon is well-known for its high expansion rate of about 400%, so when the overall expansion rate is 9.1%, a skilled artisan would reasonably envisage the artificial graphite used in Example 3 are low expansion artificial graphite with expansion rate necessarily and inherently less than the overall expansion rate of 9.1%, thus falls within the range of less than 25% as claimed “low-expansion artificial graphite expands by less than 25% when a battery is charged and discharged”.
Oh uses styrene butadiene rubber as the binder and thickener in the negative active material slurry for preparing a negative electrode of Example 3 ([0122]), thus Oh does not explicitly use polyvinylidene fluoride as a binder and the only binder in the negative electrode of Example 3.
However, Oh further discloses binder may be polyvinylidene fluoride among other usable choices ([0053-0054]) without any drastic effect, a skilled artisan would reasonably expect to choose polyvinylidene fluoride from the finite list of alternatives to replace the styrene butadiene rubber binder of Example 3 without undue experimentation and with a reasonable expectation of success that the polyvinylidene fluoride binder could be used as the only binder for Example 3 without any drastic effect.
Modified Oh further discloses the expansion rate measurement of the half-cell made with Example 3 was charged and discharged 50 times at 0.5C, with continuous measurement of the thickness of the battery, and the ratio of the thickness of the battery after charging and discharging to the thickness of the battery before charging and discharging was obtained and the result shown in Table 2 is 9.1% as the expansion ratio ([0148]). While modified Oh discloses the desire of effectively suppressing expansion due to charge and discharge and exhibiting improved swelling characteristics for a negative active material for a lithium secondary battery ([0007]); and further uses measurement of the thickness change of a half-cell under charging and discharging to determine the expansion ratio, modified Oh uses a half-cell made with Example 3 which includes both silicon-based material and artificial graphite in the negative electrode active material layer (Table 2).
Thus, modified Oh does not explicitly disclose the measurement of the low-expansion artificial graphite expansion rate based on a half cell using solely low-expansion artificial graphite as the measurement negative electrode active material; 2wt% of multilayer carbon nanotubes and other detailed parameters regarding an electrolyte composition; nor the charge-discharge cycles involving charging up to 4.25 V and discharging to 2.5V, as claimed “is determined by the following method: the volume expansion rate of the low-expansion artificial graphite is determined based on …, and the charge-discharge cycles involves charging up to 4.25V and discharging to 2.5V.”
However, it would have been obvious to one having ordinary skill in the art, before the effective filing date of the invention, to reasonable expect the artificial graphite of modified Oh would successfully arrive at an expansion rate of less than 25% when a battery is charged and discharged even under the same testing measurement conditions as claimed, absent evidence to the contrary for secondary consideration, because as set forth above, in light of an overall 9.1% expansion rate achieved in Example 3 of modified Oh, containing 90 wt% of artificial graphite with highly expandable silicon as a counter effect in the negative actively material layer.
Assuming, arguendo, that modified Oh, for some reason, is not considered to teach the artificial graphite of modified Oh would have an expansion rate of less than 25% when a battery is charged and discharged even under the same testing measurement conditions as claimed, as set forth above, the following obviousness rejections are also presented.
Zhang teaches a method for preparing a low-expansion bulk graphite material ([0012]) as a negative electrode sheet having small rebound and expansion used in the field of lithium-ion batteries, and has excellent electrical properties, can improve the reversible specific capacity, charge and discharge efficiency, cycle performance stability ([0021]). Zhang teaches the block graphite material obtained in the embodiment and the comparative example was made into a negative electrode sheet according to a conventional method, a metal lithium sheet was used as a counter electrode to prepare a half-cell and the results are shown in Table 1 ([0043]), and Table 2 for rebound and expansion performance test results of negative electrode sheet made of block graphite materials ([0049]), and it can be seen from Table 2 that the rebound and expansion of the negative electrode sheets prepared using the block graphite material obtained in Examples 1-5 are less than 20.3% ([0052]), which is within the claimed range of less than 25% of volume expansion. Since Zhang teaches the expansion characterization method with a conventional half-cell made of solely low-expansion bulk graphite material vs. lithium metal, being tested in a 1M LiPF6 in EC:EMC:DEC=1:1:1 system electrolyte ([0043] and the charging voltage is up to 4.2 V (Table 2), which is substantially equivalent to a half-cell set-up for the same purpose of the low-expansion artificial graphite expansion rate determination method as claimed, a skilled artisan would reasonably expect Zhang’s low expansion block graphite would be capable of meeting the limitation of “a volume of the low-expansion artificial graphite expands by less than 25% when a battery is charged and discharged” under the same expansion rate determination method as claimed.
It would have been obvious to one having ordinary skill in the art, before the effective filing date of the invention, to utilize the low-expansion block graphite taught by Zhang as a replacement of the artificial graphite of modified Oh, and reasonably expect to arrive at a volume of the low-expansion artificial graphite expands by less than 25% when a battery is charged and discharged under the measurement in the same method as claimed, in order to effectively suppress expansion due to charge and discharge and exhibit improved swelling characteristics as desired by modified Oh.
Regarding claim 3, modified Oh discloses all of the limitations as set forth above. However, modified Oh has an artificial graphite of 90 weight% in Example 3, out of the claimed range of 75 to 85% by weight.
Modified Oh further discloses in another embodiment that the artificial graphite content is 83 weight% (Comparative Example 7, Table 3), which falls within the range of 75 to 85 weight% of the low-expansion artificial graphite. It would have been obvious to a skilled artisan to arrive at the claimed “the first negative electrode active material comprises 75 to 85% of the low-expansion artificial graphite with respect to a total weight of the first negative electrode active material” as taught by another embodiment of modified Oh.
Regarding claim 4, modified Oh discloses all of the limitations as set forth above. Modified Oh further discloses the carbon-based material comprises natural graphite ([0091]) and artificial graphite (Table 2).
Regarding claim 5, modified Oh discloses all of the limitations as set forth above. Modified Oh further discloses a small amount of 8 to 16 wt% of a silicon particle content based on 100 wt% of the total negative electrode active material, thereby effectively suppressing negative electrode expansion during charge and discharge ([0037]), which overlaps the claimed range of 1 to 10 %, establishing a prima facie case of obviousness. [MPEP 2144.05 (I)].
Regarding claim 6, modified Oh discloses all of the limitations as set forth above. Modified Oh further discloses in Example 1 a negative electrode active material was prepared by mixing 10 wt% of the silicon-carbon composite prepared in manufacturing Example 1 and 90 wt% of artificial graphite ([0105]) and the manufacturing Example 1 has 50 wt% of silicon nanoparticles in the final silicon-carbon composite ([0095]), which translates to a 5 wt% of the silicon-based material with respect to a total weight of the negative electrode active material, falling within the range of 3 to 7% by weight as claimed.
It would have been obvious to a skilled artisan to arrive at the claimed “wherein the first negative electrode active material comprises 3 to 7% of the silicon-based material with respect to a total weight of the first negative electrode active material” as taught by another embodiment of modified Oh.
Regarding claim 8, modified Oh discloses all of the limitations as set forth above. Modified Oh as set forth above has a low-expansion artificial graphite with expansion ratio necessarily less than 9.1% , falls within the claimed range of “wherein a volume of the low expansion artificial graphite expands by less than 23% when a battery is charged and discharged”.
Or alternatively, as set forth in claim 1, modified Oh in view of Zhang has included a low-expansion artificial graphite with expansion rate of less than 20.3% (Zhang: [0052]), also falling within the claimed range.
Regarding claim 9, modified Oh discloses all of the limitations as set forth above. Modified Oh further discloses the negative electrode comprising: a current collector (Cu foil [0122]); and a negative electrode active material layer (slurry [0122]) disposed on at least one surface of the current collector and including the first negative electrode active material (coated and dried, [0122]).
Regarding claim 10, modified Oh discloses all of the limitations as set forth above. Modified Oh further discloses a lithium secondary battery ([0088] and FIG. 2) comprising a positive electrode (10 [0088]), the negative electrode (20, [0088]), and a separator (30, [0088]) interposed between the positive electrode and the negative electrode (FIG. 2).
Regarding claim 11, modified Oh discloses all of the limitations as set forth above. Modified Oh further discloses the lithium ion secondary battery can be a cylindrical shape ([0087]).
6. Claim 7 is rejected under 35 U.S.C. 103 as being unpatentable over Oh (KR 20190108814 A, see machine translation for citation) in view of Zhang (CN 108155380 A, see machine translation for citation), as applied to claim 1, further in view of Tadayoshi (JP 2015103449 A, see IDS of 1/6/2022 for original and EPO machine translation for citation).
Regarding claim 7, modified Oh discloses all of the limitations as set forth above. Modified Oh does not explicitly disclose the silicon-based material comprises silicon dioxide (SiO2).
Tadayoshi teaches the same desire to improve the cycle characteristics of a lithium ion secondary battery using a silicon-based active material as a negative electrode active material ([0007]) in light of the expansion and contraction issues of the silicon-based active material during charging and discharging ([0019]); and examples of silicon compounds include silicon oxides and silicon oxides is represented by, for example, SiOX (0<x≤2) ([0033]). A skilled artisan would have found it obvious before the effective filing date of the claimed invention, to modify the silicon-based material of modified Oh comprising silicon dioxide (SiO2) from the list of finite choices for the silicon-based material taught by Tadayoshi, with a reasonable expectation that such selection would result in a viable and easy to obtain anode active material.
7. Claims 1, 3-5 and 8-11 are rejected under 35 U.S.C. 103 as being unpatentable over Kim (US 20190355971 A1) in view of Zhang (CN 108155380 A, see machine translation for citation).
Regarding claim 1, Kim discloses a negative electrode for a lithium secondary battery (Title), comprising a first negative electrode active material (Tables 2) including a carbon-based material (crystalline carbon, [0031] and Table 2) and a silicon-based material (Si, Table 2); and polyvinylidene fluoride as the only binder ([0101]), wherein the carbon-based material includes artificial graphite (Table 2, Example 11, 90 wt% artificial graphite), which falls within the range 65 to 95% as claimed “wherein the first negative electrode active material comprises 65 to 95% of the low-expansion artificial graphite with respect to a total weight of the first negative electrode active material”.
Kim further discloses in Table 2, the expansion rate for Example 11 is 16% (Table 2), which inherently discloses the artificial graphite is low-expansion artificial graphite that expands by less than 25% when a battery is charged and discharged because Example 11 has 90 wt% artificial graphite and silicon (10 wt%) is well-known for its high expansion rate of about 400%, so when the overall expansion rate is 16%, a skilled artisan would reasonably envisage the artificial graphite used in Example 11 are low expansion artificial graphite with expansion rate necessarily and inherently less than the overall expansion rate of 16%, thus falls within the range of less than 25% as claimed “low-expansion artificial graphite expands by less than 25% when a battery is charged and discharged”.
Kim further discloses the thickness expansion rate measurement ([0105]) of an half-cell made with Example 11 was charged and discharged 50 times at 0.5C, the thickness of the battery cell was measured before and after the 50 times charging and discharging, and the ratio of the thickness of the battery after charging and discharging to the thickness of the battery before charging and discharging was calculated with the expansion rate results shown in Table 2 ([0106]); and a half-cell was manufactured using the negative electrode, a lithium metal counter electrode, and an electrolyte of 1.0 M LiPF6 in ethylene carbonate and diethyl carbonate (volume ratio 50:50) ([0102]).
Kim discloses the concern of the composite of silicon and carbon has a problem that the volume expansion occurs remarkably during charging and discharging ([0006]).
Since Example 11 containing active material of both Si and artificial graphite is used for the half-cell testing ([0102]), Kim does not explicitly disclose the measurement of the low-expansion artificial graphite expansion rate based on a half cell using solely low-expansion artificial graphite as the measurement negative electrode active material. And while Kim mentions carbon fiber as conductive material ([0050]), Kim does not explicitly discloses using 2wt% of multilayer carbon nanotubes, nor Kim discloses the charge-discharge cycles parameters involving charging up to 4.25 V and discharging to 2.5V, as claimed “is determined by the following method: the volume expansion rate of the low-expansion artificial graphite is determined based on …, and the charge-discharge cycles involves charging up to 4.25V and discharging to 2.5V.”
Zhang teaches a method for preparing a low-expansion bulk graphite material ([0012]) as a negative electrode sheet having small rebound and expansion used in the field of lithium-ion batteries, and has excellent electrical properties, can improve the reversible specific capacity, charge and discharge efficiency, cycle performance stability ([0021]). Zhang teaches the block graphite material obtained in the embodiment and the comparative example was made into a negative electrode sheet according to a conventional method, a metal lithium sheet was used as a counter electrode to prepare a half-cell and the results are shown in Table 1 ([0043]), and Table 2 for rebound and expansion performance test results of negative electrode sheet made of block graphite materials ([0049]), and it can be seen from Table 2 that the rebound and expansion of the negative electrode sheets prepared using the block graphite material obtained in Examples 1-5 are less than 20.3% ([0052]), which is within the claimed range of less than 25% of volume expansion. Since Zhang teaches the expansion characterization method with a conventional half-cell made of solely low-expansion bulk graphite material vs. lithium metal, being tested in a 1M LiPF6 in EC:EMC:DEC=1:1:1 system electrolyte ([0043] and the charging voltage is up to 4.2 V (Table 2), which is substantially equivalent to a half-cell set-up for the same purpose of the low-expansion artificial graphite expansion rate determination method as claimed, a skilled artisan would reasonably expect Zhang’s low expansion block graphite would be capable of meeting the limitation of “a volume of the low-expansion artificial graphite expands by less than 25% when a battery is charged and discharged” under the same expansion rate determination method as claimed.
It would have been obvious to one having ordinary skill in the art, before the effective filing date of the invention, to utilize the low-expansion block graphite taught by Zhang as a replacement of the artificial graphite of Kim, and reasonably expect to arrive at a volume of the low-expansion artificial graphite expands by less than 25% when a battery is charged and discharged under the measurement in the same method as claimed, in order to effectively suppress the composite of silicon and carbon expansion due to charge and discharge, as desired by Kim.
Regarding claim 3, modified Kim discloses all of the limitations as set forth above. However, modified Kim has an artificial graphite of 90 weight% in Example 11, out of the claimed range of 75 to 85% by weight.
Modified Kim further discloses Example 14 with 60 wt% the artificial graphite content (4:6 Si: artificial graphite for Example 14, Table 2) with a close value of expansion rate (17%, Table 2) comparing with that of Example 11.
It would have been obvious to a skilled artisan to increase Si content reducing the artificial graphite content for achieving a higher capacity, because Example 14 with higher Si content but only with 1% of increase of expansion rate. Therefore it would have been obvious to a skilled artisan to adjust the artificial graphite content between 60 wt% and 90 wt% as taught by Example 14 and 11 through routine experimentation, in order to have an optimized balance between capacity and expansion rate of the obtained negative electrode, with a reasonable expectation to arrive at a value that falls within the overlapping portion of the encompassing taught range and the range as claimed “the first negative electrode active material comprises 75 to 85% of the low-expansion artificial graphite with respect to a total weight of the first negative electrode active material”. [MPEP 2144.05 (II)].
Regarding claim 4, modified Kim discloses all of the limitations as set forth above. Modified Kim further discloses the carbon-based material comprises natural graphite and artificial graphite ([0031]).
Regarding claim 5, modified Kim discloses all of the limitations as set forth above. Modified Kim has included 10 wt% of silicon with respect to a total weight of the first negative electrode active material (Example 11, Table 2).
Regarding claim 8, modified Kim discloses all of the limitations as set forth above. As set forth in claim 1, modified Kim in view of Zhang has included a low-expansion artificial graphite with expansion rate of less than 20.3% (Zhang: [0052]), falling within the claimed range.
Regarding claim 9, modified Kim discloses all of the limitations as set forth above. Modified Kim further discloses the negative electrode comprising: a current collector ( [0043]); and a negative electrode active material layer (slurry [0086]) disposed on at least one surface of the current collector and including the first negative electrode active material (coated and dried, [0086]).
Regarding claim 10, modified Kim discloses all of the limitations as set forth above. Modified Kim further discloses a lithium secondary battery comprising a positive electrode, the negative electrode, and a separator interposed between the positive electrode and the negative electrode ([0076]).
Regarding claim 11, modified Kim discloses all of the limitations as set forth above. Modified Kim further discloses the lithium ion secondary battery can be a cylindrical shape ([0077]).
8. Claim 7 is rejected under 35 U.S.C. 103 as being unpatentable over Kim (US 20190355971 A1) in view of Zhang (CN 108155380 A, see machine translation for citation), as applied to claim 1, further in view of Tadayoshi (JP 2015103449 A, see IDS of 1/6/2022 for original and EPO machine translation for citation).
Regarding claim 7, modified Kim discloses all of the limitations as set forth above. Modified Kim does not explicitly disclose the silicon-based material comprises silicon dioxide (SiO2).
Tadayoshi teaches the same desire to improve the cycle characteristics of a lithium ion secondary battery using a silicon-based active material as a negative electrode active material ([0007]) in light of the expansion and contraction issues of the silicon-based active material during charging and discharging ([0019]); and examples of silicon compounds include silicon oxides and silicon oxides is represented by, for example, SiOX (0<x≤2) ([0033]). A skilled artisan would have found it obvious before the effective filing date of the claimed invention, to modify the silicon-based material of modified Kim comprising silicon dioxide (SiO2) from the list of finite choices for the silicon-based material taught by Tadayoshi, with a reasonable expectation that such selection would result in a viable and easy to obtain anode active material.
Response to Arguments
9. Applicant’s arguments regarding the amended claim 1 filed on 9/5/2025 have been fully considered but are moot in view of the new ground(s) of rejection.
Conclusion
10. Any inquiry concerning this communication or earlier communications from the examiner should be directed to KAN LUO whose telephone number is (571)270-5753. The examiner can normally be reached M-F, 8:00AM -5:00PM ET.
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/K. L./Examiner, Art Unit 1751
/JONATHAN G LEONG/Supervisory Patent Examiner, Art Unit 1751 1/12/2026