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 .
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
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and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114.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 8/26/26 has been entered.
Claims 1-18 are pending, wherein claims 13-18 remain withdrawn.
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.
This application currently names joint inventors. In considering patentability of the claims the examiner presumes that the subject matter of the various claims was commonly owned as of the effective filing date of the claimed invention(s) absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and effective filing dates of each claim that was not commonly owned as of the effective filing date of the later invention in order for the examiner to consider the applicability of 35 U.S.C. 102(b)(2)(C) for any potential 35 U.S.C. 102(a)(2) prior art against the later invention.
Claim(s) 1-3 and 7-12 is/are rejected under 35 U.S.C. 103 as being unpatentable over KR 101820445B1 (cited in IDS filed 4/19/23) in view of Lee et al (EP 3739674 A1, previously cited).
Regarding claim 1, KR 101820445B1 teaches an anode for a lithium secondary battery (paragraph [0001]), comprising:
an anode current collector (paragraph [0012], negative electrode current collector);
a primer layer formed on a surface of the anode current collector (paragraph [0015], first coating layer having an effect similar to that of a primer coating because of its contact with the anode current collector and improving adhesive force between anode mixture layer and the current collector); and
an anode active material layer (paragraph [0021], silicon-based material is divided between the second coating layer and the third coating layer) comprising a first anode active material layer (paragraph [0021], second coating layer) and a second anode active material layer (paragraph [0021], third coating layer) sequentially disposed on the primer layer (first coating, second coating, third coating), each of the first anode active material layer and the second anode active material layer including a silicon-based active material (paragraph [0021-0022], silicon-based material as the anode active material).
KR101820445B1 teaches a content of the silicon-based active material in the third coating relative to a total amount of said third coating is in the range of between 5 wt% to 20 wt% (paragraph [0022]), and a content of the silicon-based active material in the second coating relative to a total amount of said second coating is in the range of between 0.1% to 1% (paragraph [0019]), but is quiet to a ratio of a content of the silicon-based active material in the second anode active material layer among a total weight of the anode active material layer relative to a content of the silicon-based active material in the first anode active material layer among the total weight of the anode active material layer is greater than 1.25 and less than 5.
However, KR 101820445B1 teaches that the content of the silicon-based active material present in each of the second coating and the third coating layer is an optimal value set in accordance with experiments in consideration of stress due to expansion during charging and discharging, as an advantage of an increase of energy density and desired capacity improvement is offset by the negative effects of volume expansion (paragraph [0020, 0023]). Furthermore, KR 101820445 B1 teaches the content of silicon is relatively higher in the third coating layer than in the second coating layer (paragraph [0030]).
In view of the teachings of KR 101820445B1, it would have been obvious to one of ordinary skill in the art, through routine experimentation, to optimize the ratio of the content of the silicon-based active material of the third coating to the second coating layer among a total weight of the active material layer of KR 101820445B1, to be within the claimed range of greater than 1.25 and less than 5, as KR 101820445B1 teaches that the content of silicon-based material in each of the layers is optimized through routine experimentation (paragraph [0023]), and is a result-effective variable, where an increase of the silicon-based material would increase energy density and desired capacity (paragraph [0023]), but would similarly increase volume expansion (paragraph [0023]) which has a negative effect (paragraph [0020]).
"[W]here the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation." In re Aller, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1955). MPEP 2144.05(II)(A).
KR 101820445B1 teaches a primer layer (first coating), the first anode active material, and the second anode active material layer (second and third coatings), may each include at least one binder (paragraph [0018], paragraph [0029], SBR/CMC), but is quiet to the binder comprising a copolymer of at least two selected from the group consisting of polyacrylic acid, polyvinyl alcohol, polyacrylonitrile, polyacrylamide, and polyvinyl acetate.
Lee et al teaches a secondary battery including an anode that includes an anode current collector and an anode active material layer formed on the anode current collector (abstract). The anode active material includes a silicon-based active material and a graphite-based material (abstract). The first anode active material layer formed on the anode current collector includes a binder containing styrenebutadiene-based rubber (SBR) binder, and may include a mixture of SBR and CMC (paragraph [0055]), having excellent adhesion to the current collector compared to an acryl-based binder (paragraph [0056]). A second anode active material layer formed on the first anode active material layer contains an acryl-based binder (abstract). The acryl-based binder may include poly(acrylic acid) (PAA)and/or polyacrylamide (paragraph [0066]), such as a copolymer of PVA and PAA (paragraph [0068]). The acryl-based binder may have a relatively high tensile strength and can prevent decomposition and collapse of the active material by suppressing expansion and contraction (paragraph [0065]). Lee et al teaches that an overall adhesion strength is improved through the first layer having relatively high adhesion, and that damage and defects due to expansion and contraction are suppressed by the second layer (paragraph [0074]).
It would have been obvious to one of ordinary skill in the art to substitute the SBR binder of the second and third coatings of KR 101820445B1 with an acryl-based binder such as a copolymer of PVA and PAA as taught in Lee et al, as Lee et al teaches that the acryl-based binders can provide high strength and prevent decomposition and collapse by suppressing expansion and contraction (paragraph [0065]).
KR 101820445B1 is also quiet to each of the first anode active material layer and the second anode active material layer includes carbon nanotubes.
Lee et al additionally teaches the conductive additive may include carbon-based conductive additives such as carbon black, graphene, carbon nanotube, etc (paragraph [0058]).
As KR 101820445B1 teaches the anode active material comprises a conductive additive (paragraph [0012]) but is not limited to any particular types of conductive filler (paragraph [0044]), it would have been obvious to one of ordinary skill in the art to substitute the conductive additive of KR 101820445B1 with carbon nanotubes as taught in Lee et al, as Lee et al teaches carbon nanotubes as a conductive additive (paragraph [0058]). The rationale to support a conclusion that the claim would have been obvious is that the substitution of one known element for another yields predictable results to one of ordinary skill in the art. MPEP 2143(I)(B).
Regarding claim 2, the combination is quiet to wherein the ratio of the content of the silicon-based active material in the second anode active material layer among the total weight of the anode active material layer relative to the content of the silicon-based active material in the first anode active material layer among the total weight of the anode active material layer is 2 or more, and less than 5.
However, as discussed above, KR 101820445B1 teaches that the content of the silicon-based active material present in each of the second coating and the third coating layer is an optimal value set in accordance with experiments in consideration of stress due to expansion during charging and discharging, as an advantage of an increase of energy density and desired capacity improvement is offset by the negative effects of volume expansion (paragraph [0020, 0023]).
In view of the teachings of KR 101820445B1, it would have been obvious to one of ordinary skill in the art, through routine experimentation, to optimize the ratio of the content of the silicon-based active material of the third coating to the second coating layer among a total weight of the active material layer of KR 101820445B1, to be within the claimed range of 2 or more and less than 5, as KR 101820445B1 teaches that the content of silicon-based material in each of the layers is optimized through routine experimentation (paragraph [0023]), and is a result-effective variable, where an increase of the silicon-based material would increase energy density and desired capacity (paragraph [0023]), but would similarly increase volume expansion (paragraph [0023]) which has a negative effect (paragraph [0020]).
"[W]here the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation." In re Aller, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1955). MPEP 2144.05(II)(A).
Regarding claim 3, KR 101820445B1 teaches wherein the primer layer comprises a styrene-butadiene rubber (paragraph [0018], binder of the first coating layer is not limited, examples include SBR (styrene butadiene rubber)).
Regarding claim 7, the combination teaches wherein the silicon-based active material includes at least one selected from the group consisting of silicon (Si), a silicon alloy, a silicon oxide, a silicon-carbon (Si-C) composite and a silicon alloy-based carbon composite (KR 101820445B1, paragraph [0034-0035], silicon, silicon alloy, SiC, silicon oxide, etc).
Regarding claims 8-9, the combination is quiet to wherein a content of the silicon-based active material based on a total weight of the anode active material layer is in a range from 1 wt% to 20 wt% (claim 8) or in a range from 4 wt% to 15 wt% (claim 9).
However, as discussed above, KR 101820445B1 teaches that the content of the silicon-based active material present in each of the second coating and the third coating layer is an optimal value set in accordance with experiments in consideration of stress due to expansion during charging and discharging, as an advantage of an increase of energy density and desired capacity improvement is offset by the negative effects of volume expansion (paragraph [0020, 0023]).
As the amount of silicon per each layer is optimized, it would have been obvious to one of ordinary skill in the art, through routine experimentation, to optimize the total amount of silicon-based active material based on a total weight of the anode active material layer, to be within the claimed range of 4 wt% to 15 wt%, as KR 101820445B1 teaches that the content of silicon-based material in each of the layers is optimized through routine experimentation (paragraph [0023]), and is a result-effective variable, where an increase of the silicon-based material would increase energy density and desired capacity (paragraph [0023]), but would similarly increase volume expansion (paragraph [0023]) which has a negative effect (paragraph [0020]).
"[W]here the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation." In re Aller, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1955). MPEP 2144.05(II)(A).
Regarding claim 10, the combination teaches wherein each of the first anode active material layer and the second anode active material layer further includes a carbon-based active material (KR 101820445B1, paragraph [0022],[0024],[0026], second coating has relatively high content of carbon-based material).
Regarding claim 11, the combination teaches wherein a content of the carbon-based active material in a total weight of the first anode active material layer is greater than a content of the carbon-based active material in a total weight of the second anode active material layer (KR 101820445B1, paragraph [0026], the second coating has a relatively high content ratio of carbon, whereas the third coating has a relatively low content ratio of carbon, paragraph [0024]).
Regarding claim 12, the combination teaches a lithium secondary battery (KR 101820445B1, paragraph [0001], secondary battery), comprising: the anode for a lithium secondary battery of claim 1 (see above, KR 101820445 B1, paragraph [0001], negative electrode); and a cathode facing the anode (KR 101820445 B1, further including a positive electrode).
Claim(s) 4-6 is/are rejected under 35 U.S.C. 103 as being unpatentable over KR 101820445B1 as modified by Lee et al as applied to claims 1 and 3 above, and further in view of Wang (EP 2212949 B1, previously cited).
Regarding claims 4-5, the combination of KR 101820445B1 as modified by Lee et al teaches a primer layer, but is quiet to wherein an average loading weight of the primer layer is in a range from (claim 4) 0.1% to 20% or (claim 5) 0.5% to 10% of a total electrode loading weight.
However, KR 101820445B1 teaches the average thickness of the primer layer may be relatively thin (paragraph [0028]).
Wang teaches primers for electrodes of electrochemical cells (paragraph [0001]) function as adhesion layers, and that the invention is to provide good adhesion and electrical contact (paragraph [0003]). Wang teaches that primer layers are preferably thin, to reduce overall battery weight (paragraph [0013]), and should be stable and not interfere with the structural integrity of the electrodes (paragraph [0013]).
As KR 101820445B1 teaches of a thin primer layer, and that Wang suggests that thin primer layers are for reducing overall weight, it would have been obvious to one of ordinary skill in the art, through routine experimentation, to optimize the average loading weight of the primer layer to be within the claimed range, as both KR 101820445B1 and Wang teach the desirability for a low thickness (and thus a low weight), while requiring stability and without interference with structural integrity (Wang, paragraph [0013]).
Regarding claim 6, the combination of KR 101820445B1 as modified by Lee et al fails to teach that the primer layer does not include a conductive material.
However, Wang teaches that the use of conductive filler is optional, as Wang describes that conductive filler is used in some cases to increase electrically conductive properties (paragraph [0047]). Note that Wang describes that amount of filler to be at 10-90% if present (paragraph [0047]), further suggesting that the fillers are not required. Wang teaches that determining suitable compositions and configurations of the primers can be carried out without undue experimentation (paragraph [0044]), including selecting the primer layers based on its electrically conductive properties and ability to adhere (paragraph [0044]) and that Wang teaches experiments to determine the influence of optional components, such as fillers, on the adhesion (paragraph [0045]).
In view of the teachings of Wang, it would have been obvious to one of ordinary skill in the art to modify the primer layer of the combination so as to not include a conductive filler, as Wang teaches that conductive fillers are not necessary (paragraph [0047]) and that the primers can be selected based on its conductive properties and ability to adhere (paragraph [0044]), where experiments have been performed to test the effect fillers have on adhesion (paragraph [0045]).
Response to Arguments
Applicant's arguments filed 8/26/26 have been fully considered but they are not persuasive.
Applicant argues that the cited references fail to disclose or suggest every element of the claimed invention, as the claimed invention requires that each of the first and second anode active material layers include CNT and a binder comprising a copolymer of at least two of the recited polymers.
The rejections above are based on a combination of KR 101820445 B1 in view of Lee et al (EP 3739674 A1, newly cited). KR 101820445 B1 teaches a first coating layer (construed as the primer layer), where the binder is not limited and includes examples such as CMC and SBR (paragraph [0018]). KR 101820445 B1 teaches a second and third coating (construed as the claimed first anode active material layer and second anode active material layer) where the binder may include SBR and/or CMC. Lee et al teaches a first layer coated on the current collector, and that the binder of the first layer may be SBR and CMC, to provide excellent adhesion to the current collector (paragraph [0056]), whereas a second layer coated onto the first layer, includes a binder such as a copolymer of PVA and PAA (paragraph [0068]), which provides high tensile strength to suppress decomposition and collapse as a result of expansion and contraction (paragraph [0065]). The combination thus suggests substituting the SBR/CMC binder of the second and third coating of KR 101820445 B1 with the copolymer of PVA and PAA of Lee et al to provide high strength to prevent damage and defects due to expansion and contraction, while maintaining high adhesion due to the SBR/CMC of the layer coated directly on the current collector.
Regarding carbon nanotubes, it is noted that carbon nanotubes are a known type of conductive additive, as taught in Lee, and that it would have been obvious to substitute carbon nanotubes for the conductive additives of KR 101820445 B1 as an obvious alternative for performing the same function as being a conductive additive.
Conclusion
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/JACKY YUEN/
Examiner
Art Unit 1735
/KEITH WALKER/Supervisory Patent Examiner, Art Unit 1735
