DETAILED ACTION
Introductory Notes
Any paragraph citation of the instant is in reference to the U.S. published patent application.
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 .
Joint Inventors
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.
Drawings
The drawings are objected to because Figs 2 and 3 lack any reference numbers. In Fig. 3, which according to the specification is “a schematic top view of a positive electrode sheet” it is specifically unclear as to what the small rectangles visually on top of the large rectangle presumed to be the electrode sheet (placing these small rectangles on a side surface according the stated orientation).
Corrected drawing sheets in compliance with 37 CFR 1.121(d) are required in reply to the Office action to avoid abandonment of the application. Any amended replacement drawing sheet should include all of the figures appearing on the immediate prior version of the sheet, even if only one figure is being amended. The figure or figure number of an amended drawing should not be labeled as “amended.” If a drawing figure is to be canceled, the appropriate figure must be removed from the replacement sheet, and where necessary, the remaining figures must be renumbered and appropriate changes made to the brief description of the several views of the drawings for consistency. Additional replacement sheets may be necessary to show the renumbering of the remaining figures. Each drawing sheet submitted after the filing date of an application must be labeled in the top margin as either “Replacement Sheet” or “New Sheet” pursuant to 37 CFR 1.121(d). If the changes are not accepted by the examiner, the applicant will be notified and informed of any required corrective action in the next Office action. The objection to the drawings will not be held in abeyance.
Claim Rejections - 35 USC § 102
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 the appropriate paragraphs of 35 U.S.C. 102 that form the basis for the rejections under this section made in this Office action:
A person shall be entitled to a patent unless –
(a)(1) the claimed invention was patented, described in a printed publication, or in public use, on sale, or otherwise available to the public before the effective filing date of the claimed invention.
(a)(2) the claimed invention was described in a patent issued under section 151, or in an application for patent published or deemed published under section 122(b), in which the patent or application, as the case may be, names another inventor and was effectively filed before the effective filing date of the claimed invention.
Claims 1, 3-4, 8, 10, 15, and 17-20 are rejected under 35 U.S.C. 102(a)(1) as being anticipated by SONG (KR 20170021487 A, English translation used for citations).
Regarding claim 1, SONG discloses a positive electrode sheet for a secondary battery (“positive electrode for a secondary battery” [0001]), comprising: a current collector (110) comprising a coating region (Fig. 3, region with conductive adhesive layer 120) and a non-coating region other than the coating region (Fig. 3, region without conductive adhesive layer 120 where positive electrode mixture 130 is in contact with current collector 110);
a resistance layer (conductive adhesive layer 120) disposed on the current collector and comprising a conductive agent (“containing a conductive material” [0018]) and a first binder (“a polymer material” [0018]), but not comprising a positive electrode active material (active material is absent from this layer);
a positive electrode active material layer (positive electrode mixture 130) comprising the positive electrode active material (“positive electrode active material” [0017]), a conductive agent (“conductive material” [0017]), and a second binder (“binder” [0017]);
wherein: a resistance of the resistance layer is greater than a resistance of the positive electrode active material layer (“since they contain an adhesive material, they have a higher electrical resistance than the conductive material, and thus have a problem in that they can act as a resistance between the current collector and the positive electrode active material, thereby increasing the internal resistance of the battery” [0012] where the invention utilizes pattern-coating is done for the reason of “minimizing a decrease in electrical conductivity due to the addition of the conductive adhesive layer” [0015] as such SONG recognizes the binder layer has greater resistance than the active material due to the necessary presence of adhesive material);
and in a cross section of the positive electrode sheet: a projection of a part of the positive electrode active material layer on the current collector overlaps with a projection of the resistance layer on the current collector, and a projection of another part of the positive electrode active material layer on the current collector does not overlap with the projection of the resistance layer on the current collector (as shown in Fig. 3).
Regarding claim 3, SONG discloses an area ratio of the resistance layer to the coating region of the current collector is in a range of 0.20 to 0.80 (“The coating layer of the conductive adhesive layer (120) is applied with a coating area of 30% to 70% based on the total area of the current collector (110).” [0057]).
Regarding claim 4, SONG discloses a projection of the positive electrode active material layer on the current collector fully covers the projection of the resistance layer on the current collector (as shown in Fig. 3).
Regarding claim 8, SONG discloses a conductive agent layer is provided on the current collector; a projection of the conductive agent layer on the current collector does not overlap with the projection of the resistance layer on the current collector (Fig. 1 shows electrode tabs 21 and 22 which are on the current collector and do overlap with the resistance layer);
and a resistance of the conductive agent layer is less than the resistance of the positive electrode active material layer (the tabs being metal have higher conductivity and therefore less resistance that the active material layer).
Regarding claim 10, SONG discloses a ratio of a film resistance value R1 of a part of the positive electrode sheet where the resistance layer is provided to a film resistance value R2 of a part of the positive electrode sheet in the coating region where the resistance layer is not provided is in a range of 1.15 to 26.00.
Regarding claim 15, SONG discloses a thickness of the resistance layer is 1 to 30 μm (“the coating thickness of the conductive adhesive layer may … more specifically 2 μm to 5 μm” [0027]).
Regarding claims 17-20, SONG discloses in claims 19, 20, 21 a secondary battery as well as a pack (where a pack includes at least a single module) and a device. The remaining limitations are as discussed in the rejection of claim 1.
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.
Claims 2 and 11-13 are rejected under 35 U.S.C. 103 as being unpatentable over SONG.
Regarding claim 2, SONG discloses a polarization parameter (notably this is a phrase defined by the subsequent equation and not common to the art) P = ((1-S)/S)(R1/R2) of the positive electrode sheet is in a range of 0.5 to 70.0, where S is an area ratio of the resistance layer to the coating region of the current collector, R1 is a film resistance value of a part of the positive electrode sheet where the resistance layer is provided, and R2 is a film resistance value of a part of the positive electrode sheet in the coating region where the resistance layer is not provided (“coating layer of the conductive adhesive layer (120) is applied with a coating area of 30% to 70% based on the total area of the current collector (110)” [0057] as well as “the conductive adhesive layer can have a sheet resistance of 1 mOhm /sq to 100 Ohm/sq, specifically 100 mOhm/sq to 50 Ohm/sq, and more specifically 1 Ohm/sq to 10 Ohm/sq” [0029]; putting these values in for S and R1 arrives at situation where R2, which includes the active material, may be anywhere from 1% to 99% of R1, a condition readily achievable by one of ordinary skill in the art; example math where the coverage is 60% and the adhesive layer has a resistance of 1 ohm even when the area with the active material has very low comparative resistance of 0.01 Ohm: “polarization parameter” = ((1-0.6)/0.6*(1/0.01) = 67; example math where the coverage is 60% and the adhesive layer has a resistance of 1 ohm even when the area with the active material has very high comparative resistance of 0.99 Ohm: “polarization parameter” = ((1-0.6)/0.6*(1/0.99) = 0.67; notably both of these extreme values are within the claimed range for the “polarization parameter”; the equation combines multiple values each with a wide range is therefore very broad).
Regarding claim 11, SONG discloses R1 is in a range of 0.3 to 9.0 Ω (“the conductive adhesive layer may have a sheet resistance of … 1 Ohm/sq to 10 Ohm/sq” [0029] which significantly overlaps the claimed range).
Regarding claims 12 and 13, SONG discloses the positive electrode active material comprises one or more selected from lithium cobalt oxide, lithium manganate, lithium nickel cobalt manganese oxide, lithium nickel cobalt aluminium oxide, lithium iron phosphate, and lithium manganese nickel oxide (“lithium metal oxide” [0033] including the formula and elements in paragraphs [0034-0036] reading on the limitation; furthermore Li-NMC, encompassed by the formula in SONG and well known to the art, has a layered crystal structure reading on claim 13);
the conductive agent comprises one or more selected from graphite, carbon black, acetylene black, graphene, and carbon nanotubes (“carbon black-based material” [0023]);
and each of the first binder and the second binder comprises one or more selected from polyvinylidene fluoride, polyacrylic acid, polytetrafluoroethylene, and polyimide (“polyvinylidene fluoride” [0024]).
Claims 5-7, 14, and 16 are rejected under 35 U.S.C. 103 as being unpatentable over SONG in view of KONG (US 20220173377 A1).
Regarding claim 5, SONG discloses “the content ratio of the carbon black material and the polymer material is in the range of 1:1 to 100:1 by weight” [0052] where the content of conductive materials such as carbon black in active material layers is understood to be routinely less than that in the cathode by one of ordinary skill in the art. However, SONG does not expressly teach the combined limitations.
KONG is directed to conductive adhesive layers disposed between the current collector and the electroactive material layers (Abstract) like SONG.
Regarding the resistance layer, KONG discloses “the electronically conductive adhesive layers 336, 338 may have a mass ratio (SP:PAA) of about 1:3” [0092] where SP:PAA is super-P (carbon black) and PAA is binder polyacrylate. The inverse value 3:1 gives the binder to conductive ratio. Regarding the active material layer, KONG discloses “electroactive layers 424, 426 may each include … about 2 wt. % of the one or more electrically conductive materials, and about 3 wt. % of the one or more binders” as such the ratio for binder to conductive is 3:2. The active material layer ratio of binder is therefore less than the adhesive layer ratio of binder (math: 3/(3+2) or 60% relative is less than 3/(3+1) or 75% relative). KONG teaches the electrode including such ratios exhibit high capacity and capacity retention as demonstrated by Figs. 9A-9D.
Before the effective filing date of the claimed invention, it would have been obvious to one of ordinary skill in the art to utilize the ratios of conductive agent of KONG in the electrode of SONG because doing so had shown to contribute to a battery with high capacity and capacity retention.
Therefore, modified SONG discloses a mass ratio of the first binder to the conductive agent in the resistance layer is greater than a mass ratio of the second binder to the conductive agent in the positive electrode active material layer (as taught by KONG).
Regarding claim 6, modified SONG discloses all the claim limitations as set forth above and KONG further discloses the mass ratio of the first binder to the conductive agent is in a range of 2.2 to 50.0 (“the electronically conductive adhesive layers 336, 338 may have a mass ratio (SP:PAA) of about 1:3” [0092] where SP:PAA is super-P (carbon black) and PAA is binder polyacrylate; the inverse value 3:1 gives the binder to conductive ratio).
Regarding claim 7, SONG does not expressly teach the combination of limitations.
KONG discloses “the electronically conductive adhesive layers 336, 338 may have a mass ratio (SP:PAA) of about 1:3” [0092] where SP:PAA is super-P (carbon black) and PAA is binder polyacrylate. Thus KONG discloses the mass content of the conductive is 25% (1/(1+3)) and the mass content of the binder is 75% (3/(1+3)). KONG teaches the electrode including such ratios exhibit high capacity and capacity retention as demonstrated by Figs. 9A-9D.
Before the effective filing date of the claimed invention, it would have been obvious to one of ordinary skill in the art to utilize the ratios of conductive agent of KONG in the electrode of SONG because doing so had shown to contribute to a battery with high capacity and capacity retention.
Therefore, modified SONG discloses in the resistance layer, a mass content of the conductive agent is 2.0 to 30.0 wt% of a total weight of the resistance layer, and a mass content of the first binder is 70.0 to 98.0 wt% of the total weight of the resistance layer (as taught by KONG).
Regarding claim 14, SONG does not expressly teach the compact density of the positive electrode sheet. However, the compact density is a variable well within the control of one of ordinary skill in the art and furthermore KONG discloses “the electrode may have a press density of greater than or equal to about 1.0 g/cc to less than or equal to about 3.0 g/cc” [0022]. KONG teaches the electrode including such ratios exhibit high capacity and capacity retention as demonstrated by Figs. 9A-9D.
Before the effective filing date of the claimed invention, it would have been obvious to one of ordinary skill in the art to utilize the press density of KONG in the electrode of SONG because doing so had shown to contribute to a battery with high capacity and capacity retention.
Therefore, modified SONG discloses a compacted density of the positive electrode sheet is 1.5 to 4.0 g/cm3 (as taught by KONG).
Regarding claim 16, SONG does not expressly teach the D50 of the positive electrode active material. However, the D50 is a variable well within the control of one of ordinary skill in the art and furthermore KONG discloses “positive electrode 24 may comprise a positive electroactive material that has … small secondary particles sizes (e.g., D50 less than or equal to about 3 μm)” [0076]. KONG teaches the electrode including such ratios exhibit high capacity and capacity retention as demonstrated by Figs. 9A-9D.
Before the effective filing date of the claimed invention, it would have been obvious to one of ordinary skill in the art to utilize the D50 of the positive electrode active material of KONG in the electrode of SONG because doing so had shown to contribute to a battery with high capacity and capacity retention.
Therefore, modified SONG discloses Dv50 of the positive electrode active material is 1 to 20 μm (as taught by KONG).
Allowable Subject Matter
Claim 9 is objected to as being dependent upon a rejected base claim but would be allowable if rewritten in independent form including all the limitations of the base claim (claim 1) and any intervening claims (claim 8).
Searching failed to identify any additional prior art that would render the limitations of Claim 9 either anticipated or obvious.
Therefore, the allowable feature of Claim 9 is “the projection of the conductive agent layer and the projection of the resistance layer on the current collector fully cover the projection of the positive electrode active material layer on the current collector; and a ratio of a film resistance value of a part of the positive electrode sheet where the conductive agent layer is provided to a film resistance value of a part of the positive electrode sheet where the resistance layer is provided is in a range of 0.10 to 0.95”, in combination with the other limitations of the claim.
The closest prior art is represented by SONG and KONG cited previously along with ZHANG (US 20230122728 A1).
SONG discloses resistance and conductive layers as discussed in the rejections of claims 1 and 8, however SONG does not disclose or teach the combination of these two layers projected onto the current collectors fully covers the projection of the active material layer. KONG discloses an adhesive layer, reading on resistance layer, fully covering the projection of the active material but does not disclose or teach the claimed ratio film resistance values between conductive agent and resistance layers.
ZHANG discloses in figure 1 a bottom coating layer 2, reading on resistance layer, as well as a central tab 4, reading on conductive agent layer. However, the projection of these two layers does not full cover the projection of the active material layer 3 and the claimed ratio is not taught.
For this reason, the claims as written read free of the closest available prior art, placing the application in condition for allowance.
Conclusion
The prior art made of record and not relied upon considered pertinent to applicant's disclosure:
Komura (US 20170279114 A1) directed to manufacturing an electrode including pattern-coating a binder liquid.
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/T.L.M./Examiner, Art Unit 1721
/ALLISON BOURKE/Supervisory Patent Examiner, Art Unit 1721