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 .
Response to Amendment
The amendment filed 12/11/2025 has been entered. Support is found in Fig. 1 of the original disclosure for claims 1 and 16, and in specification [0016-0017] for claim 17.
Response to Arguments
Applicant’s arguments, see Remarks pages 6-7, filed 12/11/2025, with respect to the rejection(s) of claim(s) 1 and its dependent claims under 35 USC 103 over Youm and Yushin have been fully considered and are persuasive in light of the instant amendment to claim 1 (now incorporating the range of previous claim 15), since the claimed upper endpoint is now 43.5% which is not obviated by the 44.4% example of the prior art as relied upon in the 09/11/2025 rejection of record. Therefore, the rejection has been withdrawn. However, upon further consideration, a new ground(s) of rejection is made in view of the amendment to claim 1, which narrowed the scope of this independent claim and necessitated an updated search, yielding the grounds of rejection presented below.
Claim Rejections - 35 USC § 103
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.
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.
The factual inquiries 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.
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) 1-11, 13-14, and 16-17 is/are rejected under 35 U.S.C. 103 as being unpatentable over Shirane et al. (US 20090004566 A1) in view of Ogihara et al. (US 20160308258 A1. 103
Regarding claim 1, Shirane teaches a negative electrode for a secondary battery (non-aqueous electrolyte secondary battery having the negative electrode, [0006]) comprising:
a conductive material (carbon nanofiber, [0006]; CNF assures high electronic conductivity, [0036]);
a silicon-based active material-polymer binder combination (through chemical bonds provided by the first binder, [0006]) comprising a silicon-based active material (composite negative electrode active material contains a silicon-containing particle capable of charging and discharging at least lithium ions, [0006]), and a polymer binder (first binder is composed of an acryl-group-containing polymer, [0006]; examples in [0059]) bonded to a surface of the silicon-based active material (first binder has a high affinity to the silicon-containing particle, [0006]; first binder 15 on surface of silicon-containing particles 11, Fig. 3), wherein the polymer binder suppresses expansion of the silicon-based active material (even if the silicon-containing particles expand and contract during charge and discharge, the conductive structure in the mixture layer and the conductive structure between the mixture layer and the current collector are kept, such that the cycle characteristics are improved, per [0006]; expansion and contraction of silicon-containing particles during cycling per [0035]); and
a water-based binder (second binder is composed of an adhesive rubber particle, [0006]; SBR example in [0060] – meets instant [0052] disclosure of SBR being water-based),
wherein the polymer binder is included in an amount of 25 to 45 wt% based on a weight of the silicon-based active material (content of first binder is preferably 1 part by weight or more and 30 parts by weight or less with respect to 100 parts by weight of the silicon-containing particles, [0076] – overlaps instant range from 25 to 30 wt%, obviates per MPEP 2144.05 I; e.g. Sample 6: 30 parts first binder with respect to 100 parts by weight SiO per [0087] which is a sample that exhibits excellent high-load discharge characteristics and excellent cycle characteristics [0097]).
Shirane fails to explicitly teach:
the negative electrode comprising a carbon-based active material;
a ratio of a weight percentage of the polymer binder to a weight percentage of the silicon-based active material is 25.3% or greater and 43.5% or less.
Ogihara is analogous in the art of negative electrodes and teaches negative electrode active material include carbon materials, silicon-based materials, and that two or more types of negative electrode active materials may be used in combination ([0046-0047]). Ogihara specifically teaches the negative electrode active material layer preferably comprises the structure represented by the formula: α(silicon-based material)+β(carbon material)+γ(binder)+η(conductive assistant)
wherein α, β, γ, and η represent the weight % in the negative electrode active material layer and satisfy α+β+γ+η=100, 80≦α+β≦98, 3≦α≦40, 40≦β≦95, 1≦γ≦10, 1≦η≦10, and the silicon-based material is a material having silicon as the main element ([0049-0050, 0137]).
The above formula gives a ratio of a weight percentage of binder to a weight percentage of the silicon-based active material (γ/α) of 1/3 and 10/40 at the endpoints, which is 33.3% and 25%, within the overall negative electrode composition. Ogihara teaches in [0137] that by utilizing this composition of the materials that constitute the negative electrode active material layer used for the lithium ion secondary battery, it is possible to achieve a higher capacity.
Therefore, Ogihara teaches that carbon active material is known for use as a secondary constituent alongside silicon-based active material and conductive additive (e.g., carbon fiber per Ogihara [0040]), such that a person having ordinary skill in the art would have found it obvious to additionally include carbon as an active material constituent alongside the silicon-based active material within a modification to Shirane in order to achieve the higher capacity taught toward by Ogihara, and further to modify the ratio of a weight percentage of binder (i.e., polymer binder within Shirane; where Ogihara [0037] also teaches polymer binder examples) to a weight percentage of the silicon-based active material to be 25% to 33.3% as taught by Ogihara within the composition achieving the higher capacity. “[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” (see MPEP § 2144.05, II) such that optimizing the weight ratios of the Shirane polymer binder and silicon-based active material within the overall negative electrode composition to fall within the range taught toward by Ogihara would have been within the ambit of a person having ordinary skill in the art.
Thus, all limitations of claim 1 are rendered obvious.
Regarding claim 2, modified Shirane teaches the limitations of claim 1 above and wherein the silicon-based active material is included in an amount of 5 to 25 wt% (3.33 wt% to 50 wt%: see below calculation from Ogihara [0137] formula) based on a total weight of active material including the carbon-based active material and the silicon-based active material (3≦α≦40 and 80≦α+β≦98, where α is silicon-based material and β is carbon material weight percents in the negative electrode active material layer per Ogihara [0137] as applied to modify Shirane above).
The ratio of silicon-based active material total weight of active material including the carbon-based active material and the silicon-based active material is α/[α+β], which is from 3/90 to 40/80 = 3.33 wt% to 50 wt%.
In the case where the claimed ranges "overlap or lie inside ranges disclosed by the prior art", a prima facie case of obviousness exists per MPEP 2144.05 I. Here, the claimed range lies inside that taught by Ogihara.
Regarding claim 3, modified Shirane teaches the limitations of claim 1 above and wherein the polymer binder comprises a hydrophilic polymer material having a hydroxy group (-OH) (polyacrylic acid, Shirane [0059] – meets the requirement of instant [0039-0040], and known in the art to have -COOH group which has -OH group therein).
Regarding claim 4, modified Shirane teaches the limitations of claim 1 above and wherein the polymer binder comprises wherein the polymer binder comprises at least one of polyacrylic acid (PAA) (Shirane [0059, 0080, 0087]).
Regarding claim 5, modified Shirane teaches the limitations of claim 1 above and wherein the water-based binder (content of second binder is preferably 3 parts by weight or more and 80 parts by weight or less with respect to 100 parts by weight of CNFs, Shirane [0077]) is included in an amount of 30 to 40 wt% (5% to 400%: see below calculations based on Shirane [0079] data of: content of thus grown CNFs is 25 parts by weight with respect to 100 parts by weight of SiO particles) based on a weight of the polymer binder (content of first binder is preferably 1 part by weight or more and 30 parts by weight or less with respect to 100 parts by weight of the silicon-containing particles, Shirane [0076]).
Per Shirane [0079]: SiO at 100 weight proportions and CNF at 25 weight proportions, such that within the negative electrode, when 100 parts SiO is the basis, there are: 1 to 30 parts first(polymer) binder, 25 parts CNF, and thus from 3*(25/100) = 0.75 parts second(water-based) binder to 80*(25/100) = 20 parts second(water-based) binder. This gives a ratio, based on end points, of first(polymer) binder to second(water-based) from 1/20 = 5% to 30/0.75 = 400%, which encompasses the claimed range. In the case where the claimed ranges "overlap or lie inside ranges disclosed by the prior art", a prima facie case of obviousness exists per MPEP 2144.05 I.
Regarding claim 6 and claim 17, modified Shirane teaches the limitations of claim 1 and claim 4 above and wherein the water-based binder comprises a rubber-based material (second binder is composed of an adhesive rubber particle, Shirane [0006]).
Regarding claim 7, modified Shirane teaches the limitations of claim 1 above and wherein the water-based binder comprises styrene-butadiene rubber (SBR) (SBR example of second binder, Shirane [0060, 0080]).
Regarding claim 8, modified Shirane teaches the limitations of claim 1 above and a secondary battery comprising the negative electrode (a non-aqueous electrolyte secondary battery having the negative electrode and having high cycle characteristics, Shirane [0006]), but fails to explicitly teach said secondary battery having a discharge capacity retention rate of 90% or greater up to a fifth cycle under conditions of charging at 0.5 C and discharging at 0.5 C.
However, Shirane does teach evaluation of the sample cells made by their invention, teaching that 0.1 CmA can be used for a charge-discharge current to measure initial charge capacity and initial discharge, wherein 0.1 CmA indicates a current value obtained by dividing the designed capacity of batteries by 10 hours ([0093), and that 0.5 CmA can be used as a discharge current to evaluate high-load characteristics ([0094]). Thus, 0.5 CmA is a known discharge current per [0094] and that it is known for the charge current to be equivalent to the discharge current per [0093], depending on designed capacity characteristics over a certain number of hours per [0093]. Also, Shirane teaches in [0095] that the cycle number until the discharge capacity reaches 60% of the initial discharge capacity is used as an index of the cycle characteristics of each model cell, and in [0096] that the evaluation standard of the capacity retention rate is set at 60% or more while the evaluation standard of the cycle number is set at 50 cycles or more in consideration of practicality. Therefore, it can be interpolated that the cycle retention would be substantially higher than 60% at only 5 cycles, and expectedly close to 90%, since the 5th cycle is closer to the 1st cycle (i.e., 100% capacity) than to the 50th cycle (by which capacity retention has declined to 60%). Additionally, Shirane Table 1 shows at least Samples 10-11 retaining high-load capacity (i.e., 0.5 CmA discharge current per [0094]) above 90% at cycle numbers 55 and 59, respectively. Shirane [0097] characterizes Samples 10-11 as exhibiting “especially excellent characteristics”. Also, Ogihara as applied to the Shirane above – in teaching a similar composite negative active material – shows exemplary data in Table 2 of the inventive battery cells (Examples 1, 2, 4) having capacity retention rates after carrying out 100 cycles of a charge-discharge test at 1 C of above 90%. Ogihara teaches in [0137], as applied to modified Shirane above, that the inclusion of carbon as an active material and setting the proportions of each component within a given range within the negative electrode composition achieves higher capacity and suppresses deterioration of the battery.
A person having ordinary skill in the art would have found it obvious to optimize the composition of the negative electrode active material layer to achieve desirably high capacity retention over numerous cycles as taught toward by both Shirane and Ogihara.
Thereby, claim 8 is rendered obvious.
Regarding claim 9, modified Shirane teaches the limitations of claim 1 above and wherein the polymer binder is adsorbed to the surface of the silicon-based active material (first binder has a high affinity to the silicon-containing particle, Shirane [0006] and Fig. 3).
Regarding claim 10, modified Shirane teaches the limitations of claim 1 above and the polymer binder is a hydrophilic polymer binder having a plurality of hydroxy groups (polyacrylic acid, Shirane [0059, 0080, 0087]; satisfies hydrophilic and hydroxy groups per instant [0039-0040]) selectively adsorbed to the surface of the silicon-based active material (first binder has a high affinity to the silicon-containing particle, Shirane [0006] and Fig. 3).
Regarding claim 11, modified Shirane teaches the limitations of claim 1 above and the polymer binder is a hydrophilic polymer binder having a plurality of hydroxy groups (polyacrylic acid, Shirane [0059, 0080, 0087]; satisfies hydrophilic and hydroxy groups per instant [0039-0040]), and
wherein the silicon-based active material-polymer binder combination is formed by preparing a pre-dispersion slurry (silicon-containing particles having CNFs on their surfaces are mixed with first binder, second binder, and a solvent to prepare a negative electrode mixture slurry; Shirane [0058]) in which the hydrophilic polymer binder having the plurality of hydroxy groups is selectively adsorbed to a hydrophilic particle surface of the silicon-based active material (first binder has a high affinity to the silicon-containing particle, Shirane [0006] and Fig. 3).
Regarding claim 13, modified Shirane teaches the limitations of claim 1 above and wherein a ratio of a weight percentage of the conductive material to a weight percentage of the silicon-based active material is 5.3% or greater (25 parts by weight CNF to 100 parts by weight SiO, Shirane [0079] – i.e., 25/100 = 25% conductive CNF ratio to SiO active material).
Regarding claim 14, modified Shirane teaches the limitations of claim 1 above and wherein the silicon-based active material is included in an amount of 5 to 25 wt% (3.33 wt% to 50 wt%: see below calculation from Ogihara [0137] formula) based on a total weight of active material including the carbon-based active material and the silicon-based active material (3≦α≦40 and 80≦α+β≦98, where α is silicon-based material and β is carbon material weight percents in the negative electrode active material layer per Ogihara [0137] as applied to modify Shirane above), and
the water-based binder (content of second binder is preferably 3 parts by weight or more and 80 parts by weight or less with respect to 100 parts by weight of CNFs, Shirane [0077]) is included in an amount of 30 to 40 wt% (5% to 400%: see below calculations based on Shirane [0079] data of: content of thus grown CNFs is 25 parts by weight with respect to 100 parts by weight of SiO particles) based on a weight of the polymer binder (content of first binder is preferably 1 part by weight or more and 30 parts by weight or less with respect to 100 parts by weight of the silicon-containing particles, Shirane [0076]).
Ogihara calculation: Per Ogihara [0137], the ratio of silicon-based active material total weight of active material including the carbon-based active material and the silicon-based active material is α/[α+β], which is from 3/90 to 40/80 = 3.33 wt% to 50 wt%. In the case where the claimed ranges "overlap or lie inside ranges disclosed by the prior art", a prima facie case of obviousness exists per MPEP 2144.05 I. Here, the claimed range lies inside that taught by Ogihara.
Shirane calculation: Per Shirane [0079], SiO is at 100 weight proportions and CNF is at 25 weight proportions, such that within the negative electrode, when 100 parts SiO is the basis, there are: 1 to 30 parts first(polymer) binder, 25 parts CNF, and thus from 3*(25/100) = 0.75 parts second(water-based) binder to 80*(25/100) = 20 parts second(water-based) binder. This gives a ratio, based on end points, of first(polymer) binder to second(water-based) from 1/20 = 5% to 30/0.75 = 400%, which encompasses the claimed range. In the case where the claimed ranges "overlap or lie inside ranges disclosed by the prior art", a prima facie case of obviousness exists per MPEP 2144.05 I.
Regarding claim 16, modified Shirane teaches the limitations of claim 1 above and wherein the ratio of the weight percentage of the polymer binder to the weight percentage of the silicon-based active material is 25.3% or greater and 33.8% or less (25% to 33.3% per calculations from Ogihara [0137] formula, as applied to modify Shirane in rejection of claim 1 above. Sufficiently overlaps instant claim 16 range: In the case where the claimed ranges "overlap or lie inside ranges disclosed by the prior art", a prima facie case of obviousness exists per MPEP 2144.05 I).
Allowable Subject Matter
Claim 12 is objected to as being dependent upon a rejected base claim, but would be allowable if rewritten in independent form including all of the limitations of the base claim and any intervening claims. The following is a statement of reasons for the indication of allowable subject matter:
Regarding claim 12, modified Shirane teaches the limitations of claim 1 above but fails to yet teach the polymer binder is included in an amount of 33 to 45 wt% based on the weight of the silicon-based active material.
As cited above in the rejection of claim 1, Shirane teaches the content of first binder is preferably 1 part by weight or more and 30 parts by weight or less with respect to 100 parts by weight of the silicon-containing particles ([0076]), which does not overlap the range of claim 12 that is above the 30 wt% upper endpoint of Shirane.
However, Shirane does teach in Sample 7 in Table 1 that the first binder was added at 37.3 parts by weight to 100 parts of SiO active material (37.3/100 = 37.3 wt%, which falls in the claimed range), but contrarily teaches in [0102] that in Sample 7 when the content of first binder exceeds 30 part by weight with respect to 100 parts by weight of SiO, the high-load discharge characteristics are low. Shirane [0076] explains that when the content of first binder exceeds 30 parts by weight with respect to 100 parts by weight of silicon-containing particles, first binder excessively covers silicon-containing particles such that ion conductivity in the negative electrode is reduced, and the high-load discharge characteristics degrade.
Ogihara [037] teaches the binder being 1-10 wt% and silicon-based active material being 80-90 wt% of the overall negative electrode, such that the polymer binder amount based on the weight of the silicon-based active material is from 1/90 = 1.11 wt% to 10/80 = 12.5 wt%, which is also even lower compared to the range of claim 12.
No additional, closer prior art was found which would fairly suggest a modification to Shirane, while retaining the inventive goals thereof, to obviate all limitations of claim 12.
Conclusion
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/JESSIE WALLS-MURRAY/Primary Examiner, Art Unit 1728