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 .
Priority
Acknowledgment is made of applicant's claim for foreign priority based on an application filed in KR on 7/26/2022 (see Applicant’s Application Data Sheet filed on 8/8/2023). It is noted, however, that applicant has not filed a certified copy of the foreign application as required by 37 CFR 1.55.
Applicant’s reply filed 7/7/2026 confirms a “re-submitted [the] request to obtain the priority document through the priority document exchange.” Examiner notes at least one attempt by the Office to electronically retrieve the priority document through the document exchange has failed. See correspondence sent 12/26/2023:
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Examiner is unsure whether Applicant’s re-submission occurred before or after the Office’s failed attempt. Since a certified copy has not yet been retrieved, acknowledgement of the foreign priority remains acknowledged but not verified.
Response to Arguments
Applicant's reply filed 7/7/2026 includes claim amendments and corresponding arguments. The 35 USC 112(b) Rejection for Claim 13 set forth in the previous action has been withdrawn due to Applicant’s amendments. Applicant presents four arguments regarding why the art of record does not disclose the following limitation of amended Claim 1 (previously Claim 4): “the silicon-carbon composite particles further comprise a silicon oxide coating layer formed on a surface of the silicon coating layer.”
Applicant’s first and fourth arguments state there is no proper motivation to modify the primary reference with Essaki, and “the references themselves contradict the Office's proffered motivation to combine.” Applicant states “Essaki only includes silicon oxide because it is structurally necessary,” and “Essaki discloses that it is desirable to decrease oxide content to preserve efficiency, a PHOSITA would not be motivated to import the oxide from Essaki into Kim.” Applicant also states that the problem of volume expansion is already solved by Kim, so further modification by Essaki would not be necessary.
Examiner maintains the position that modifying Kim (primary reference) with Essaki is proper. Kim discloses the active material comprises silicon nanoparticles (Kim, metal nano-particles 225 are silicon [0008, 0044-0056]). Essaki cautions that repeatedly inserting and extracting lithium will expand/increase the grain size of silicon, leading to cracks in the material (Essaki, [0040]). Essaki teaches adding silicon oxide to grains of silicon is advantageous (Essaki, “in order to prevent the combination of the growth of the grains of silicon 101 is prevented, and there is an advantage that the cycle characteristics of silicon are improved" [0022]). Essaki does not discourage coating the silicon particle with silicon oxide, but does caution the oxygen content in the silicon oxide (value of “x” in SiOx) should be closely controlled within a range of 0.1≦x≦0.8, in order to prevent decreases in charge-discharge efficiency that occur when x=1 ([0006, 0019-0023]). In response to applicant's argument that the problem is already solved by Kim, Examiner agrees Kim and Essaki are within the same field of endeavor. Examiner is unable to provide an opinion on whether the silicon nanoparticle expansion-discouraging method of Kim or Essaki would be more beneficial. However, Essaki teaches modifying the surface of the silicon particle with silicon oxide will not only prevent particle expansion, but will also allow the particle surface area to be changed/controlled. Essaki teaches a relationship between the BET specific surface area of the silicon oxide and improvements in charge-discharge performance (Essaki, [0019, 0025-0027, 0145], Table 1). These additional benefits of controlling particle surface area are neither taught nor suggested by Kim.
Applicant’s second and third arguments are regarding a perceived incompatibility between Kim and Essaki’s method of making the silicon oxide particle. Applicant states “it would be impractical to form a silicon oxide coating on Kim because Kim does not have an exposed silicon surface,” and “A PHOSITA would have no reasonable expectation of success in growing silicon oxide on the surface of silicon nanoparticles encapsulated by carbon.” Applicant also states there is no reasonable expectation of success in the combination of Kim and Essaki, since Essaki’s high-temperature application of silicon oxide could not be performed on silicon particles “already seated within the pores of a graphite core and encapsulated in carbon.”
Examiner disagrees. Kim discloses the silicon nanoparticles of Kim are separately prepared in a solution and then dispersed into the graphite active material (Kim, “Next, [a] solution of the silicon nano-particles was prepared by mixing the silicon nano-particles with alcohol. The graphite core was dipped into the solution of the silicon nano-particles.” [0053-0054]). Essaki does not teach or suggest a silicon oxide doping process that grows silicon oxide “on the surface of silicon nanoparticles encapsulated by carbon” as argued by Applicant. Instead, Essaki teaches preparing the silicon oxide-coated particles as a separate step prior to carbon encapsulation (i.e., prior to placing the particles in a solution to be combined with the graphite, see Essaki [0120-0123]).
The claimed invention remains obvious over the previously-cited references.
Claim Rejections - 35 USC § 103
The text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office action.
Claims 1-3, 5-8, and 20 are rejected under 35 U.S.C. 103 as being unpatentable over Kim et al., US 20090269669 A1, and further in view of Sakitani et al., US 20100273052 A1 and Essaki et al., US 20130337314 A1 (previously cited).
Regarding Claim 1, Kim discloses an anode for a lithium secondary battery (negative electrode plate 200 for a lithium rechargeable battery 1000 [0022-0028], Figs. 1-2) comprising:
an anode current collector (negative electrode collector 210 [0026], Fig. 2);
an anode active material layer (negative electrode coating portion 220 [0026-0028], Example 1
[0053-0056]) comprising an anode active material including a plurality of silicon-carbon composite particles (negative electrode active material 221 [0008, 0033-0052], Figs. 3-5; Example 1: Si-carbon composite [0053-0056]) and a second binder (SBR binder [0028], Example 1: 3 wt% SBR [0056]),
wherein the silicon-carbon composite particles comprise carbon-based particles comprising a plurality of pores (negative electrode active material 221 includes a graphite core 223 having pores 229 [0007-0010, 0033], Fig. 4), and a silicon coating layer formed inside the pores (metal nano-particles 225 provided in pores 229 [0033]; nano-particles 225 are silicon [0008, 0044, 0053-0056]).
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Kim – Fig. 4
Kim does not disclose “an adhesive layer formed on the anode current collector and comprising a first binder,” and also does not disclose the anode active material layer is “formed on the anode adhesive layer” as required by Claim 1. However, these limitations are taught by Sakitani.
Sakitani teaches an adhesive precoat layer 6 comprising a first binder is formed on a negative electrode current collector 1, and a negative electrode active material layer 2 is formed on the adhesive precoat layer 6 ([0012-0023], Fig. 1; styrene-butadiene binder of precoat layer 6 is the “first adhesive”). Sakitani teaches by having the precoat layer, adhesion between the active material layer and current collector is increased, resulting in improved battery performance and reliability ([0013-0015]).
Before the effective filing date of the present invention, it would have been obvious to a person of ordinary skill in the art to add the adhesive precoat layer 6 of Sakitani, between the current collector and anode active material layer of Kim, in order to increase adhesion between the active material layer and current collector, resulting in improved battery performance and reliability.
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Sakitani – Fig. 1
Modified Kim does not disclose “the silicon-carbon composite particles further comprise a silicon oxide coating layer formed on a surface of the silicon coating layer” as required by Claim 1. However, this limitation is taught by Essaki.
Essaki teaches a negative electrode material 100, wherein crystalline silicon 101 particles are covered in silicon oxide 102 ([0021-0031], Fig. 1). Essaki teaches by coating the crystalline silicon in silicon oxide, growth of the grains of silicon 101 is prevented, which improves cycle characteristics and battery capacity ([0005, 0022-0023]). Essaki also teaches the negative electrode material 100 may be embedded in pores of a carbonaceous material 201 such as graphite ([0032-0035], Fig. 4), a configuration similar to Kim.
Before the effective filing date of the present invention, it would have been obvious to a person of ordinary skill in the art to form a silicon oxide coating layer, as taught by Essaki, on the silicon particles of modified Kim (Kim, metal nano-particles 225), in order to improve cycle characteristics and battery capacity.
Regarding Claim 2, modified Kim discloses all limitations as set forth above. Modified Kim discloses a silicon coating layer is also formed on an outer surface of the silicon-carbon composite particles (Kim, the outer surface of the graphite core comprises amorphous carbon and metal nano-particles, metal nano-particles 225 existing on the outer surface of the graphite core 223 [0008, 0049], Fig. 4).
Regarding Claim 3, modified Kim discloses all limitations as set forth above. Modified Kim discloses the pores comprise a larger amount of silicon atoms than the outer surface of the silicon-carbon composite particles (see Kim Fig. 4, more silicon particles 225 present in pores 229 compared to
the number of silicon particles 225 on the outer circumference/surface of active material particle 221).
Regarding Claim 5, modified Kim discloses all limitations as set forth above. Modified Kim discloses the silicon-carbon composite particles (silicon nano-particles 225 of Kim covered in the silicon oxide of Essaki) further comprise a carbon coating layer formed on a surface of the silicon oxide coating layer (Kim, amorphous carbon 227 is coated on the metal nano-particles 225 existing on the outer surface of the graphite core 223 [0047-0050], Fig. 4).
Regarding Claim 6, modified Kim discloses all limitations as set forth above. Modified Kim discloses the silicon-carbon composite particles comprise about 30% to about 50% by weight of silicon atoms (Kim, metal nano-particles 225 generally comprise 5 wt% to 50 wt % of the entire negative electrode active material [0046]).
Regarding Claim 7, modified Kim discloses all limitations as set forth above. Modified Kim discloses the adhesive layer (Sakitani, 6) comprises about 80% by weight or more of first binder (Sakitani, the weight ratio between the binder and carboxymethyl cellulose is preferably in the range of 0.5:1 to 10:1 [0022], Example 3, CMC:SBR in precoat layer is 1:5 [0063], Tables 3 and 4).
Regarding Claim 8, modified Kim discloses all limitations as set forth above. Modified Kim discloses the anode active material layer comprises about 80 wt.% or more of the silicon-carbon composite particles (Kim, Negative slurry comprises 80 wt % of Si-carbon composite materials [0056]).
Regarding Claim 20, modified Kim discloses all limitations as set forth above. Modified Kim
discloses a lithium secondary battery comprising the anode according to claim 1 (Kim, negative
electrode plate 200 for a lithium rechargeable battery 1000 [0022-0028], Figs. 1-2); and
a cathode disposed to face the anode (Kim, the lithium rechargeable battery 1000 includes positive electrode and negative electrode plates 100 and 200 [0024], Fig. 1).
Claims 9-12, 14, and 19 are rejected under 35 U.S.C. 103 as being unpatentable over modified Kim as applied to Claim 1 above, and further in view of Ahn et al., KR 102111480 B1.
Regarding Claim 9, modified Kim discloses all limitations as set forth above. Modified Kim discloses the anode active material layer comprises a first cellulosic thickener (Kim, Example 1: Negative slurry comprises 2 wt % CMC [0056]). Modified Kim does not disclose the first cellulosic thickener (CMC) has “a weight average molecular weight of about 4×105 g/mol to about 3×106 g/mol” as required by Claim 9. However, this limitation is taught by Ahn.
Ahn teaches a multilayer negative electrode, comprising a first negative active material layer positioned between a current collector and a second negative active material layer, and the second negative active material layer comprises a cellulose-based compound such as CMC (second cellulose-based compound [0020, 0080-0086]). Ahn teaches if the weight-average molecular weight (“Mw”) of the cellulose-based compound is less than 500,000 g/mol, the thickening effect of the active material layer may not be achieved, but if the Mw exceeds 1,500,000 g/mol, the dispersibility of the conductive material will be reduced ([0082]).
Before the effective filing date of the present invention, it would have been obvious to a person of ordinary skill in the art to use the first cellulosic thickener of Ahn (Ahn, second cellulose-based compound) in the anode active material layer of modified Kim, and arrive at a Mw within the claimed range, as Ahn teaches an overlapping Mw range will thicken the electrode mixture but not affect dispersibility.
Regarding Claims 10 and 11, modified Kim discloses all limitations as set forth above. Modified Kim discloses the adhesive layer further comprises a second cellulosic thickener (Sakitani, precoat layer 6 includes a carboxymethyl cellulose aqueous dispersant [0017-0022]). Modified Kim does not disclose the second cellulosic thickener has “a greater weight average molecular weight than that of the first cellulosic thickener” as required by Claim 10, and also does not disclose “the second cellulosic thickener has a weight average molecular weight of about 3×106 g/mol to about 6×106 g/mol” as required by Claim 11. However, these limitations are also taught by Ahn.
Ahn teaches the first negative active material layer is positioned between the current collector
and the second negative active material layer, wherein the first negative active material layer comprises a cellulose-based compound such as CMC (first cellulose-based compound [0020, 0070-0078]). Ahn teaches the first cellulose-based compound most preferably has a Mw of 2,000,000 g/mol to 4,000,000 g/mol, and improves the binding strength and durability of the electrode ([0072, 0074]). Ahn teaches if the Mw of the first cellulose-based compound is less than 1,500,000 g/mol, there is a risk of aggregation, and if it exceeds 4,000,000 g/mol, there is a risk of electrode failure due to undissolved material ([0078]). Examiner notes Ahn’s second cellulosic thickener has a greater Mw than the first cellulosic thickener (see Claim 9).
Before the effective filing date of the present invention, it would have been obvious to a person of ordinary skill in the art to use the second cellulosic thickener of Ahn (Ahn, first cellulose-based compound) in the adhesive layer of modified Kim, and arrive at a Mw within the claimed range, as Ahn teaches an overlapping Mw range will bind to the electrode while avoiding issues such as aggregation and undissolved material.
It has been held that where the general conditions of a claim are disclosed in the prior art, discovering the optimum or working ranges involves only routine skill in the art [MPEP 2144.05].
Regarding Claim 12, modified Kim discloses all limitations as set forth above. Modified Kim discloses the first cellulosic thickener has a degree of substitution of about 0.8 to about 1.5 (Ahn, the second cellulose-based compound may have a degree of substitution of 1 to 1.2 [0080]), and
the second cellulosic thickener has a degree of substitution of about 0.5 to about 1 (Ahn, the first cellulose-based compound has a degree of substitution of less than 1, specifically 0.7 to 0.95 [0072]).
Regarding Claim 14, modified Kim discloses all limitations as set forth above. Modified Kim does
not disclose the second binder (Kim, SBR binder in the active material layer) has a smaller specific resistance than a specific resistance of the first binder (Sakitani, styrene-butadiene binder in the adhesive precoat layer 6). However, this limitation is taught by Ahn.
Ahn teaches when a SBR binder of an active material layer is modified to include structural units derived from (meth)acrylic acid ester, the resistance of the binder is “reduced due to the excellent conductivity of the (meth)acrylic acid ester itself, thereby lowering the resistance” ([0057]).
Before the effective filing date of the present invention, it would have been obvious to a person of ordinary skill in the art to have the second binder of modified Kim include structural units derived from (meth)acrylic acid ester, in the anode active material layer of modified Kim, as Ahn teaches a SBR binder in an active material layer can include (meth)acrylic acid ester structural units, in order to increase conductivity and exhibit have lower resistance.
Regarding Claim 19, modified Kim discloses all limitations as set forth above. Modified Kim discloses the first cellulosic thickener is CMC (Ahn, the second cellulose-based compound may be CMC [0076]), and also discloses the second cellulosic thickener is CMC (Ahn, the first cellulose-based compound may be CMC [0076]).
Claims 15 and 16 are rejected under 35 U.S.C. 103 as being unpatentable over modified Kim as applied to Claim 1 above, and further in view of Guo et al., CN 114094041 A.
Regarding Claims 15 and 16, modified Kim discloses all limitations as set forth above. Modified Kim discloses the first binder includes a first styrene-butadiene rubber (Sakitani, binder is styrene-butadiene [0018], examples with SBR binder [0053-0066]) and the second binder includes a second styrene-butadiene rubber (Kim, SBR binder [0028], Example 1: 3 wt% SBR [0056]).
Modified Kim does not disclose “the first styrene-butadiene rubber comprises a greater molar ratio of butadiene-derived units than the second styrene-butadiene rubber” as required by Claim 15. Modified Kim also does not disclose “the first styrene-butadiene rubber comprises about 55 mol% to about 95 mol% of butadiene-derived units, and the second styrene-butadiene rubber comprises about 5 mol% to about 50 mol% of butadiene-derived units” as required by Claim 16. However, these limitations are taught by Guo.
Guo teaches a negative electrode comprising first layer A and a first adhesive; a second layer B and a second adhesive; and a current collector C ([0033], Fig. 1). Guo teaches the first and second adhesives may be styrene-butadiene copolymers comprising styrene and butadiene monomers, and in order for layer B to adhere to the current collector C and reduce expansion of the electrode, the second adhesive needs to have a lower glass transition temperature (Tg) than the first adhesive in layer A ([0010-0020, 0050, 0060]). Guo teaches the lower Tg can be achieved by increasing the amount of butadiene monomer in the second adhesive in layer B ([0060-0062]). Guo demonstrates when the Tg of the binder used in the first active material layer A is -5℃, and the Tg of the binder used in the second active material layer B gradually increases from -20℃ to -40℃, the battery cells can obtain excellent energy density, cycle capacity, and low thickness expansion ([0060]).
Before the effective filing date of the present invention, it would have been obvious to a person of ordinary skill in the art to have the first styrene-butadiene rubber comprise a greater molar ratio of butadiene-derived units than the second styrene-butadiene rubber, in the anode modified Kim, as Guo teaches an adhesive in contact with a current collector should have a higher amount of butadiene monomer compared to an adhesive in other layers.
Additionally, before the effective filing date of the present invention, it would have been obvious
to a person of ordinary skill in the art to optimize the molar ratio of butadiene-derived units in the first and second styrene-butadiene rubbers, in the anode modified Kim, as Guo teaches excellent energy density, cycle capacity, and low thickness expansion is achieved with a higher amount of butadiene-derived units in the layer in contact with a current collector.
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Guo – Fig. 1
Claims 17 and 18 are rejected under 35 U.S.C. 103 as being unpatentable over modified Kim as applied to Claim 1 above, and further in view of Yamazaki et al., US 20130004855 A1.
Regarding Claim 17, modified Kim discloses all limitations as set forth above. Modified Kim discloses a “thickness of the precoat layer is smaller than that of the mixture layer,” (See Sakitani Claim 8) and “a thickness of the precoat layer is more preferably in the range of 0.1 to 1 μm” (Sakitani, [0023]), but modified Kim does not disclose a “ratio of a thickness of the anode active material layer to a thickness of the adhesive layer is about 15 to about 80” as required by Claim 17. However, this limitation is taught by Yamazaki.
Yamazaki teaches depositing a binder solution layer 56 and a mixed material electrode paste layer 46 on a current collector 10 ([0032], Fig. 4). Yamazaki teaches in order to obtain a smooth mixed material layer, the thickness of the binder solution layer is set to about 2.5 μm or less, and even more preferably to about 1.5 μm or less ([0043, 0062-0063]), and teaches a ratio of a thickness of the anode active material layer to a thickness of the adhesive layer is within the claimed range (binder solution layer 56 thickness: 2.0 μm, mixed material paste layer 46 thickness: 46 μm [0059]).
Before the effective filing date of the present invention, it would have been obvious to a person of ordinary skill in the art to have a ratio of a thickness of the anode active material layer to a thickness of the adhesive layer be within the claimed range, in the anode of modified Kim, as Yamazaki teaches a similar and overlapping range will obtain a smooth mixed material layer.
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Yamazaki – Fig. 4
Regarding Claim 18, modified Kim discloses all limitations as set forth above. Modified Kim discloses the adhesive layer has a thickness of about 0.5 μm to about 5 μm (Sakitani, [0023] and/or Yamazaki, 2.5 μm or less [0043]), and the anode active material layer has a thickness of about 30 μm to about 40 μm (Yamazaki, 46 μm [0059]).
Examiner notes Yamazaki’s anode active material layer thickness of 46 μm is within 15% of the claimed range of “about 30 μm to about 40 μm.” Since Applicant’s disclosure states “about” means within 20% or less of a given value or range (see [0038] of the instant specification), Yamazaki’s thickness meets the claim.
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.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to BETHANY C GARCIA whose telephone number is (571)272-2475. The examiner can normally be reached Mon-Fri, 0800 - 1730 MT.
Examiner interviews are available via telephone, in-person, and video conferencing using a USPTO supplied web-based collaboration tool. To schedule an interview, applicant is encouraged to use the USPTO Automated Interview Request (AIR) at http://www.uspto.gov/interviewpractice.
If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Allison Bourke can be reached at 303-297-4684. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/BETHANY C GARCIA/Examiner, Art Unit 1721
/ALLISON BOURKE/Supervisory Patent Examiner, Art Unit 1721
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