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. It is noted, however, that applicant has not filed a certified copy of the KR 10-2022-0092580 application as required by 37 CFR 1.55.
Claim Rejections - 35 USC § 112
The following is a quotation of 35 U.S.C. 112(b):
(b) CONCLUSION.—The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention.
The following is a quotation of 35 U.S.C. 112 (pre-AIA ), second paragraph:
The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention.
Claim 13 is rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor (or for applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention.
Claim 13 recites “an adhesive force of the first binder to the anode current collector is greater than an adhesive force of the second binder to the anode current collector.” Due to the claimed structure of the anode, the limitation “an adhesive force of the second binder to the anode current collector” is unclear.
Applicant’s claimed anode comprises a current collector 125, a first binder present in an adhesive
layer 122, and a second binder present in an anode active material layer 124 (See Examiner’s Annotations to instant Fig. 1 below). Since the adhesive layer is located on a surface of the current collector, the claimed “adhesive force of the first binder to the anode current collector” can be measured. However, it is unclear how the second binder, which is present in the anode active material layer 124 and is not in direct contact with the current collector, can have “an adhesive force of the second binder to the anode current collector.” There is no adhesive force binding the second binder (i.e., the anode active material layer 124) to the current collector 125:
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18/350,168 – Annotated Fig. 1
Based on the claimed structure of the anode and instant Fig. 1, the anode active material layer 124 is adhered to the current collector 125 via the adhesive layer 122 (i.e., the first binder), and therefore the claimed anode structure has “an adhesive force of the first binder to the anode current collector is equal to an adhesive force of the second binder to the anode current collector.” Examiner requests further clarification of Claim 13.
For the purpose of this action, Claim 13 will be examined as “an adhesive force of the first
binder to the anode current collector is equal to an adhesive force of the second binder to the anode
current collector.”
Appropriate correction is required.
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.
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.
Claims 1-3, 6-8, 13 and 20 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.
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
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 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 13, modified Kim discloses all limitations as set forth above. Modified Kim discloses an adhesive force of the first binder to the anode current collector is equal to an adhesive force of the second binder to the anode current collector (Sakitani, adhesion and peel strength testing for negative electrode [0079-0093], Tables 2-4).
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 4 and 5 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 Essaki et al., US 20130337314 A1.
Regarding Claim 4, modified Kim discloses all limitations as set forth above. 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 4. However, this limitation is taught by Essaki.
Essaki teaches a negative electrode material 100, wherein crystalline silicon 101 particles are covered by 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 5, modified Kim discloses all limitations as set forth above. Modified Kim discloses the silicon-carbon composite particles 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).
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 may have a degree of substitution of less than 1, more 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 form a silicon oxide coating layer, as taught by Essaki, on the silicon particles of modified Kim, in order to improve cycle characteristics and battery capacity.
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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.
Pertinent Prior Art
The prior art made of record and not relied upon in this action is considered pertinent to applicant's disclosure: Youm, US 20160211514 A1.
Youm discloses an anode for a lithium secondary battery (negative electrode for a rechargeable lithium battery 100 [0076-0084, 0112], Fig. 3) comprising:
an anode current collector (negative current collector [0077]);
an anode active material layer (negative active material layer [0077-0079]) comprising an anode active material including a plurality of silicon-carbon composite particles (negative active material 20 having a silicon-graphite composite [0040-0066, 0106-0108], Fig. 1B); and
a second binder (water-soluble binder [0082], 1 wt % of a styrene-butadiene rubber [0112]).
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Youm – Fig. 1B
Conclusion
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