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 .
Status of Claims
This is a final office action for application 17/968,866 in response to the amendment(s) filed on 10/27/2025. Claims 1-3, 6-8 and 10-12 are under examination. Claims 8-9 and 10-11 are still withdrawn from consideration.
Withdrawn Claim Rejections – 35 USC § 112
The amendment(s) to the claim(s) filed on 10/27/2025 is acknowledged and the previous rejection is withdrawn.
Response to Arguments
Applicant’s arguments filed on 10/27/2025 have been fully considered but were not found persuasive for the reasons set forth below.
Applicant argues that Lee does not disclose or suggest that the ratio B1/B2 in Relational Expression 2 is derived from paragraphs [0077]–[0078], asserting that those paragraphs only disclose a binder content ratio between a high binder content region and a low binder content region (A/B), rather than a ratio between first and second layers within the B region (see e.g. page 8 of Applicant’s arguments).
Examiner respectfully disagrees. Lee explicitly discloses forming a lower mixture layer and an upper mixture layer by sequentially coating a first mixture slurry and a second mixture slurry on a current collector (see e.g. paragraphs [0085]–[0088]). Lee further discloses that both high binder content regions and low binder content regions are present within each mixture layer (see e.g. paragraph [0080] and FIG. 1). Accordingly, the binder contents disclosed in paragraphs [0077] and [0078] apply to the first and second layers, respectively, within both the A region and the B region. Therefore, the calculation of B1/B2 = 3.5/2 = 1.75 is properly derived from Lee and lies within the claimed range of 1.0 < B1/B2 < 2.5. As previously explained, disclosure of a point within a claimed range establishes a prima facie case of obviousness. See MPEP 2144.05(I).
Applicant argues that the ratio A1/A2 of Relational Expression 2 cannot be derived from Lee II because Lee II does not disclose distinct high binder content and low binder content regions separated in a width direction (see e.g. page 9 of Applicant’s arguments).
Examiner respectfully disagrees. Lee II is relied upon to teach binder content ratios between first and second layers in a multilayer electrode active material structure, not to teach the width-direction A and B regions. Lee already discloses the electrode active material layer having A and B regions crossing in a width direction, as well as first and second layers in a thickness direction. Lee II discloses a binder ratio between first and second layers that overlaps with the claimed range of 2.0 < A1/A2 < 3.0 (see e.g. paragraph [0021]). The claimed combination merely applies the known binder ratio taught by Lee II to the layered electrode structure taught by Lee. In cases where the prior art discloses a range that overlaps with the claimed range, a prima facie case of obviousness exists. See MPEP 2144.05(I).
Applicant argues that the combination of Lee and Lee II fails to recognize or predict the improved adhesion and resistance properties allegedly achieved by satisfying Relational Expression 2, and that such effects constitute unexpected results (see e.g. pages 9-11 of Applicant’s arguments).
Examiner respectfully disagrees. Lee II expressly teaches that providing a higher binder content adjacent to the current collector improves adhesion and battery performance, including resistance characteristics. Accordingly, the improvements alleged by Applicant are consistent with, and would have been expected from, the teachings of Lee II when applied to the layered electrode structure of Lee. Applicant has not provided evidence demonstrating that the alleged results are unexpected relative to the combined teachings of Lee and Lee II, nor that such results are commensurate in scope with the full breadth of the claimed ranges.
In conclusion, the combination of Lee in view of Lee II teaches or renders obvious all of the limitations of amended claim 1. Accordingly, the claim 1 rejection has been updated to reflect this. See the rejections of claims 1–3, 6–7, and 12 below.
The text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office action.
Claim Rejections - 35 USC § 103
Claims 1-3, 6-7 and 12 are rejected under 35 U.S.C. 103 as being unpatentable over Lee et al. (KR-2021/0044503-A), co-application Lee et al. (US-20210399278-A1) was used for the rejection as a proper translation and further in view of Lee et al. (US-2019/0027740-A1), hereinafter referred to as Lee II.
Regarding Claim 1, Lee discloses an electrode for a secondary battery (see e.g. "electrode plate for a secondary battery" in paragraph [0032] and part number 100 in FIG. 1), comprising:
a current collector (see e.g. "electrode current collector" in paragraph [0032] and part number 110 in FIG. 1); and
an electrode active material layer (see e.g. "electrode mixture including an active material" in paragraph [0032]) including an electrode active material (see e.g. "active material" in paragraph [0033]) and a binder (see e.g. "a binder" in paragraph [0033]) located on at least one surface of the current collector (see e.g. "an electrode mixture layer formed on one or both sides of the current collector layer." in paragraph [0034]),
wherein the electrode active material layer includes A region and B region crossing in a direction from one side to the other side of the electrode active material layer in a width direction (see e.g. " the upper mixture layer 230 has a structure divided into regions 231 a and 231 b having a high binder content and regions 232 a and 232 b having a low binder content." in paragraph [0088] and FIG. 2 and annotated figure below),
the A region has a higher binder content than that of the B region (see e.g. "active material regions having different binder contents" in paragraph [0012] and "regions 121 a and 121 b having a high binder content and regions 122 a and 122 b having a low binder content" in paragraph [0080] and FIG. 1; part numbers 121a and 121b in FIG. 1 correspond to A region with a higher binder content, part numbers 122a and 122b in FIG. 1 correspond to B region and have a low binder content),
wherein the A region and B region of the electrode active material layer each include first layers a1 and b1 and second layers a2 and b2 in the direction from the surface of the current collector to the surface of the electrode (see e.g. part numbers 220 and 230 in FIG. 2 and annotated figure below), based on the thickness direction,
the first layers have a higher binder content than that of the second layers (see e.g. "a lower mixture layer 220 and an upper mixture layer 230 are sequentially formed on a current collector layer 210 formed of aluminum foil." in paragraph [0088] and "The first mixture slurry was coated on an aluminum foil in a loading amount of 60 mg/25 cm2 to form a lower mixture layer. An upper mixture layer was formed on the formed lower mixture layer." in paragraph [0085]; as described above and in paragraph [0077] - [0078] the first mixture slurry has the high binder content mixture which forms the first layers a1 and b1 with a higher binder content than layers a2 and b2 and are represented by part number 220 in FIG. 2), and
wherein the relation expression B1/B2 = 1.75 where B1 and B2 each are the binder contents of the first layers and the second layers in the B region (see e.g. " 3.5 parts by weight of polyvinylidene fluoride (KF9700, Kureha) as a binder polymer" in paragraph [0077] and " 2 parts by weight of KF9700 (Kureha) as a binder polymer" in paragraph [0078]; Lee discloses a first binder content (B1 layer) is 3.5 parts and a second binder content (B2 layer) is 2 parts by weight, therefore, B1/B2 = 3.5/2 = 1.75).
Lee discloses a point that lies within the range claimed by the instant application. In the case where the prior art discloses a point within the claimed range, a prima facie case of obviousness exists. See MPEP 2144.05 (I).
Lee does not disclose that the relational expression 2.0 < A1/A2 < 3.0 where A1 and A2 each are the binder contents of the first layers and the second layers in the A region, Lee II, however, in the same field of endeavor multilayer electrode active materials with varying binder content, discloses a weight ratio of first binder to second binder (first binder/second binder) may be in the range of 1.2 to 10 (see e.g. "When the second negative electrode mixture layer includes a second binder, a weight ratio of the first binder and the second binder (the first binder/the second binder) may be about 1.2 to 10, particularly 3 to 8, and more particularly 5 to 7." in paragraph [0021] of Lee II).
Lee II discloses a range that overlaps with the range claimed by the instant application. In the case where the prior art discloses a range that overlaps with the claimed range, a prima facie case of obviousness exists. See MPEP 2144.05 (I).
Lee II also teaches that having a higher binder content in contact with the current collector improves the adhesion of the interface of the current collector and the active material improving overall battery performance, cycle characteristics and safety (see e.g. paragraph [0077] of Lee II). Therefore, it would have been obvious to a person of ordinary skill in the art, before the effective filing date, to modify the binder contents of the first layer and the second layer in the A region of Lee et al. such that the binder content of the first layer and the second layer in the A region may be in the range of 1.2 to 10 as taught by Lee II et al. in order to improve the adhesion at the interface of the current collector and the active material which improves overall battery performance, cycle characteristics and safety as suggested by Lee II.
Lee in view of Lee II does not explicitly disclose that the binder content is continuous at the boundary between the first and second layers. However, paragraph [0089] of Lee teaches that in the high-binder regions of the second layer (layer 230), the variation in binder content is only about 1 wt%, indicating substantial uniformity across those regions (see e.g. “in the regions 231a and 231b with a high binder content … the actual difference was at the level of 1% by weight”). Based on this, a person of ordinary skill in the art would reasonably expect that such slurry-based coating processes would naturally result in a continuous (i.e. non-abrupt) binder content transition at the interface between the first and second layers, particularly where the slurries are deposited sequentially and without a curing step between layers. Thus, it would have been obvious to a person of ordinary skill in the art that the binder content would be continuous at the boundary between the first and second layers.
Furthermore, Lee in view of Lee II also does not explicitly disclose that the A region and B region have a continuous binder content gradient at a boundary of each region, however, it would have been obvious to a person of ordinary skill in the art at the time of the invention to include or expect a continuous binder content gradient between adjacent high and low binder content regions in the electrode active material layer of Lee. This is because, as a matter of fundamental materials science and mass transfer principles, when regions of differing binder concentrations are deposited adjacent to one another (such as during coating or slurry application) diffusion effects and process limitations inherently result in a non-zero concentration gradient at the interface. Furthermore, inclusion of such a gradient would be expected to improve interfacial adhesion, mitigate stress concentrations, and enhance electrode stability, all of which are well-known benefits in the field of battery electrode fabrication.
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(Lee, figure 2, annotated for illustration)
Regarding Claim 2, Lee in view of Lee II discloses the electrode of claim 1 (see e.g. claim 1 rejection above). Lee further discloses that relational expression 1 is satisfied:
[Relational Expression 1]
1.0 < A/B < 2.5
Where in relational expression 1, A is a binder content in the A region, and B is a binder content in the B region (see e.g. " 3.5 parts by weight of polyvinylidene fluoride (KF9700, Kureha) as a binder polymer" in paragraph [0077] and " 2 parts by weight of KF9700 (Kureha) as a binder polymer" in paragraph [0078]).
Lee discloses a first binder content (A region) is 3.5 parts by weight and a second binder content (B region) is 2 parts by weight, therefore, A/B = 3.5/2 = 1.75.
Lee discloses a point that lies within the range claimed by the instant application. In the case where the prior art discloses a point within the claimed range, a prima facie case of obviousness exists. See MPEP 2144.05 (I).
Regarding Claim 3, Lee in view of Lee II discloses the electrode of claim 1 (see e.g. claim 1 rejection above). Lee further discloses that the electrode active material layer has a ratio BL/BH of a binder content BL at a point at which a thickness of the electrode active material layer is 20% to a binder content BH at a point at which a thickness of the electrode active material is 80% which is 1.75 in a direction from a surface of the current collector to a surface of the electrode based on a thickness of the electrode active material layer direction (see e.g. (see e.g. " 3.5 parts by weight of polyvinylidene fluoride (KF9700, Kureha) as a binder polymer" in paragraph [0077] and " 2 parts by weight of KF9700 (Kureha) as a binder polymer" in paragraph [0078]; Lee discloses a first binder content (BL region) is 3.5 parts by weight and a second binder content (BH region) is 2 parts by weight, BL/BH = 3.5/2 = 1.75; see also "The first mixture slurry was coated on an aluminum foil in a loading amount of 60 mg/25 cm2 to form a lower mixture layer. An upper mixture layer was formed on the formed lower mixture layer." in paragraph [0085] and "Further, the difference in the binder contents measured at the height 20% point (DL2) and the height 80% point (DH2) is 12% by weight or less" in paragraph [0089] and FIG. 2).
Lee discloses a point that lies within the range claimed by the instant application. In the case where the prior art discloses a point within the claimed range, a prima facie case of obviousness exists. See MPEP 2144.05 (I).
Regarding Claim 6, Lee in view of Lee II discloses the electrode of claim 1 (see e.g. claim 1 rejection above). Lee further discloses that the binder includes a styrene butadiene rubber (SBR)-based binder (see e.g. "As the binder component, a binder polymer commonly used in the art may be used without limitation. For example, various kinds of binders such as... styrene-butadiene rubber (SBR)" in paragraph [0057]).
Regarding Claim 7, Lee in view of Lee II discloses the electrode of claim 1 (see e.g. claim 1 rejection above). Lee further discloses that the electrode active material layer includes 1.95 wt% of the binder based on the total weight (see e.g. "100 parts by weight of NCM (LiNi0.8Co0.1Mn0.1O2) as a positive electrode active material, 0.1 parts by weight of carbon black (FX35, Denka, average diameter (D50) 15 to 40 nm) as a conductive material, and 2 parts by weight of KF9700 (Kureha) as a binder polymer were added to NMP (N-methyl-2-pyrrolidone) as a solvent to prepare a second mixture slurry." in paragraph [0078]; 100 parts active material + 0.1 parts conductive material + 2 parts binder = 102.1 parts total, 2 parts binder / 102.1 parts total = 1.95 wt% binder).
Lee discloses a point that lies within the range claimed by the instant application. In the case where the prior art discloses a point within the claimed range, a prima facie case of obviousness exists. See MPEP 2144.05 (I).
Regarding Claim 12, Lee in view of Lee II discloses a secondary battery comprising the electrode (see e.g. "a secondary battery is processed in the form of two or more electrode strips" in paragraph [0035] of Lee) of claim 1 (see e.g. claim 1 rejection above).
Conclusion
Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a).
A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action.
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/J.J.E./ Examiner, Art Unit 1723
/TONG GUO/ Supervisory Patent Examiner, Art Unit 1723