DETAILED ACTION
Status of Claims
Claims 1-9, 11-13, 16 and 20-21 are pending, wherein claims 1 and 20 are amended. Claims 1-9, 11-13, 16 and 20-21 are being examined on the merits in this office action.
Remarks
Applicant’s amendments and arguments have been entered. A reply to the Applicant’s remarks/arguments is presented after addressing the claims.
Any rejections and/or objections made in the previous Office Action and not repeated below, are hereby withdrawn in view of Applicant’s amendments or/and arguments.
The text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office action. References cited in the current Office action can be found in a prior Office action. Reference not previously cited can be found per the attached PTO-892 for this Office action.
Claim Rejections - 35 USC § 112
Claims 1-9, 11-13, 16 and 20-21 are 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 1 recites the limitation "the carbon-based particles” on lines 9 and 10. There is insufficient antecedent basis for this limitation in the claim. It is unclear whether or not it refers to the afore-mentioned “amorphous carbon-based particles” (line 8), rendering the claim(s) indefinite. The issue applies similarly to claim 12. See below for how this limitation is addressed.
Claim Rejections - 35 USC § 103
Claims 1-3, 8-10, 12, 16 and 20 are rejected under 35 U.S.C. 103 as being unpatentable over Lee et al. (US 20210234191 A1, hereafter Lee) in view of Kim et al. (US 20140050983 A1, hereafter Kim) and Hoshi et al. (WO 2019220576 A1, whose English machine translation is being employed for citation purposes, hereafter Hoshi).
Regarding claims 1 and 12, Lee teaches an anode for a lithium secondary battery (Abstract), comprising:
an anode current collector (“82”, Fig. 2);
a first anode active material layer formed on at least one surface of the anode current collector (“84”+”86”, Fig. 2), the first anode active material layer comprising a silicon-based active material and a graphite-based active material ([0048]-[0051]); and
a second anode active material layer formed on the first anode active material layer (“88”, Fig. 2) comprising a carbon-based material and a silicon-based material ([0077]).
Lee does not expressly disclose that the second anode active material layer comprises a porous structure. However, one of ordinary skill in the art would have readily appreciated that pores are present due to formation of secondary particles resulted from agglomeration of primary particles in the second anode active material layer.
Moreover, the prior art Kim discloses a silicon-based negative electrode active material (Abstract) (denoted as a porous structure hereafter) comprising an amorphous carbon-based material (See “10” of Fig. 1, in which “15” is an amorphous carbon coating) having pores (i.e., porous carbon), and the pores function as buffering, during charge and discharge, for volume expansion of silicon-based particles in a form of a coating (“13”), wherein said silicon-based particles are located inside the pores or on a surface of the carbon-based particles, and the resultant porous structure provides excellent electrical conductivity (Figs. 1-2, [0043]-[0044]). As such, it would have been obvious to one of ordinary skill in the art to have included, in any of anode active material layers of Lee (for example, in “88”), a porous structure comprising a silicon-based negative electrode active material taught by Kim to replace the silicon-based material (See above) in layer “88” of Lee, in order to achieve excellent electrical conductivity (Figs. 1-2, [0043]-[0044], Kim). As a result, the layer “88” of Lee modified by Kim comprises a mixture of a porous structure taught by Kim and a carbon-based material. Kim further discloses that the content of the porous structure in a negative electrode active material layer (e.g., the layer “88” of Lee modified by Kim) may be in a range of about 2 wt% to about 96.5 wt% (the calculation is based on data recited in [0072] and [0071] of Kim) based on a total weight of the second anode active material layer. The claimed range of 0.1 wt% to 35 wt% overlaps the above 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. See MPEP § 2144.05 (I).
Lee in view of Kim teaches the silicon-containing coating comprises SiOx and the SiOx, which may be amorphous ([0047]) or may be disproportionate SiOx including silicon crystal ([0047], Kim), but is silent as to a crystallite size of the silicon crystal being 7 nm or less as claimed. In the same field of endeavor, however, Hoshi discloses that a crystallite size of 8 nm or less measured by XRD of silicon included in an anode material comprising carbon and silicon composite particles would enable silicon crystallites to be likely to be localized in the silicon oxide particles and to tend to be dispersed through the particles, which makes it easier for lithium ions to diffuse within the silicon oxide particles and makes it easier to obtain a good charging capacity (at least: abstract, [0016], Kim). Moreover, when the size of the silicon crystallite is 2 nm or more, the reaction between the lithium ions and the silicon oxide is well controlled, and a good charge/discharge efficiency is likely to be obtained ([0016], Kim). Thus, it would have been obvious to one of ordinary skill in the art before the effective filing date of the instant invention to have incorporated the teachings of Hoshi into Lee in view of Kim such that the silicon included in the silicon-containing coating has a crystallite size of 2 nm or more and 8 nm or less, as taught by Hoshi, so as to achieve benefits stated above. The claimed range of 7 nm or less overlaps that of 2 to 8 nm. In the case where the claimed ranges “overlap or lie inside ranges disclosed by the prior art”, a prima facie case of obviousness exists. See MPEP § 2144.05 (I). In addition, the claimed measuring method does not patentably distinguish the invention, since one of ordinary skill in the art would appreciate that the crystallite size should not significantly depend on the measuring method or process.
Regarding claim 2, Lee as modified teaches the anode for a lithium secondary battery according to claim 1, wherein the first anode active material layer comprises a first lower anode active material layer (“84”, Fig. 2, Lee) in contact with the anode current collector (See Fig. 2) and a first upper anode active material layer (“86”, Fig. 2) formed on the first lower anode active material layer (See Fig. 2).
Regarding claim 3, Lee as modified teaches the anode for a lithium secondary battery according to claim 2, wherein a content of the silicon-based active material included in the first lower anode active material layer is in a range from about 4% to about 22% based on a total weight of the first lower anode active material layer (calculations based on “2 to 5%” in [0059] and “90 to 98 wt%” in [0069]), and
a content of the silicon-based active material included in the first upper anode active material layer is in a range from about 2% to about 14% based on a total weight of the first upper anode active material layer (calculations based on “0.5 to 5 wt.%” in [0060] and “90 to 98 wt.%” in [0069]).
The above calculated ranges read on the instantly claimed ranges, respectively.
Regarding claims 8-9, Lee as modified teaches the anode for a lithium secondary battery according to claim 1, and further teaches the third anode active material layer (“88”) may have the same material as the first (“84”) and second (“86”) anode active material layer ([0077], Lee). Thus, the third anode active material layer of Lee (corresponding to the claimed second anode active material layer) has also a weight ratio of 5:5 of artificial graphite to natural graphite ([0053], Lee), which reads on the claimed ranges in claims 8 and 9.
Regarding claim 10, Lee as modified teaches the anode for a lithium secondary battery according to claim 1, and further, since Lee teaches that the third anode active material layer (corresponding to the claimed second anode active material layer) may contain ([0077]) silicon-based active material and carbon-based active material in addition to the porous structure. In the absence of unexpected results or evidence that the claimed content of the porous structure is critical, one of ordinary skill in the art would readily arrive at the amount as instantly claimed through routine experimentation since the selection of a proportion of a component involves merely ordinary capabilities of one skilled in the art.
Regarding claim 16, Lee as modified teaches a lithium secondary battery (Abstract), comprising:
the anode of claim 1 (e.g., “80”, Fig. 2) and a cathode (“70”, Fig. 2) facing the anode.
Regarding claim 20, Lee as modified teaches the anode for a lithium secondary battery according to claim 1. The instantly claimed limitation does not patentably distinguish the invention because Lee as modified teaches the crystallite size, as addressed in the rejection of claim 1. Even though the crystallite size is limited by and defined by a measuring process, determination of patentability is based on the crystallite size itself. The patentability of the crystallite size does not depend on its method of measuring.
Claims 4-6 are rejected under 35 U.S.C. 103 as being unpatentable over Lee in view of Kim and Hoshi, as applied to claim 2 above, and further in view of Lee-II et al. (US 20220328833 A1, hereafter Lee-II).
Regarding claims 4 and 5, Lee as modified teaches the anode for a lithium secondary battery according to claim 2, wherein the graphite-based active material comprises artificial graphite and natural graphite (“mixture of natural graphite and artificial graphite”, [0052]), and
an amount of natural graphite included in the first upper anode active material layer is less than an amount of artificial graphite included in the first upper anode active material layer (See ranges of weight ratio in [0053]).
Lee in view of Kim teaches an amount of natural graphite included in the first lower anode active material layer may be equal to an amount of artificial graphite included in the first lower anode active material layer (e.g., weight ratio = 5:5, see [0053]), but is silent as to the amount of natural graphite included in the first lower anode active material layer being greater than that of artificial graphite included in the first lower anode active material layer.
In the same field of endeavor, Lee-II discloses a similar anode structure in which natural graphite and artificial graphite included in a first negative electrode mixture layer that coats on a current collector may have a weight ratio of 8:2 (Example 14) in order to achieve a desired degree of adhesion with the current collector ([0018]). Thus, it would have been obvious to one of ordinary skill in the art before the effective filing date of the instant invention to have incorporated the teachings of Lee-II into Lee in view of Kim and Hoshi such that a weight ratio of natural graphite to artificial graphite in the first lower anode active material layer being 8:2 is employed as an alternative to the equal amount of Lee, in order to achieve a desired degree of adhesion of the first lower anode active material layer with the current collector ([0018], Lee-II).
Regarding claim 6, Lee as modified teaches the anode for a lithium secondary battery according to claim 5, wherein a weight ratio of natural graphite included in the first upper anode active material layer relative to artificial graphite included in the first upper anode active material is in a range of 1:99 to 5:5 ([0053], Lee), which reads on the range as instantly claimed.
Claims 13 and 21 are rejected under 35 U.S.C. 103 as being unpatentable over Lee in view Kim and Hoshi, as applied to claim 1 above, and further in view of Mizuhata et al. (JP 2011071063 A, whose English machine translation is being employed for citation purposes, hereafter Mizuhata).
Regarding claims 13 and 21, Lee in view of Kim and Hoshi is silent as to a size of the pores being 20 nm or less, as claimed. However, in the same field of endeavor, Mizuhata discloses a carbon-containing composite material having pores, wherein a pore size of 2 nm to 10 nm will ensure a proper diffusion of lithium ions and a proper reaction area (See [0024], top of p14) so as to achieve excellent electrochemical properties when the material is used in lithium ion batteries ([0017], lines 370-373). Therefore, it would have been obvious to one of ordinary skill in the art to have modified the porous structure of Lee in view of Kim and Hoshi to have a pore size of 2 nm to 10 nm, as taught by Mizuhata, in order to ultimately achieve excellent electrochemical properties of a lithium ion battery ([0017], lines 370-373, Mizuhata).
Claim Objections
Claims 7 and 11 are 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.
Response to Arguments
Applicant's arguments filed April 7, 2026 have been fully considered but they are not persuasive.
1) Applicant’s arguments with respect to criticality of the claimed range of 0.1 wt% to 35 wt% are not persuasive. The as-alleged criticality is based on Table 10 data. It is unclear what the reasoning basis is for Applicant to draw the conclusion that 35.0 wt% is a critical point. Just because 40 wt% sample has a relatively higher volume expansion ratio (36.0%) and an insignificantly lower rapid charge capacity retention (95.52%)? Note that to establish unexpected results over a claimed range, applicants should compare a sufficient number of tests both inside and outside the claimed range to show the criticality of the claimed range. In re Hill, 284 F.2d 955, 128 USPQ 197 (CCPA 1960). See MPEP 716.02(d) II).
Whether the unexpected results are the result of unexpectedly improved results or a property not taught by the prior art, the "objective evidence of nonobviousness must be commensurate in scope with the claims which the evidence is offered to support." In other words, the showing of unexpected results must be reviewed to see if the results occur over the entire claimed range. In re Clemens, 622 F.2d 1029, 1036, 206 USPQ 289, 296 (CCPA 1980). (See MPEP 716.02(d)). For the data point 0.1 wt%, the closest data point 6.0 wt% inside the range is relatively too far from 0.1 wt%. In addition, where are the results for 0.1 wt%? Without the results, how a comparison was made?
One of ordinary skill in the art could not ascertain a trend from the Table 10 data that would allow that person to reasonably extend the probative value of the data to the full scope of the claims. For example, there is a big gap between 0.05% and 6.0% and between 30.0% and 9.0 wt%.
The burden is on the applicant to establish that the results are in fact unexpected, unobvious, and of statistical and practical significance.
2) Applicant filed a certified English translation of the priority application of the instant application on April 7, 2026. Thus, the Han reference is no longer a valid prior art under exception 102(b)(2). Applicant’s argument is persuasive.
Conclusion
THIS ACTION IS MADE FINAL. 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 ZHONGQING WEI whose telephone number is (571)272-4809. The examiner can normally be reached Mon - Fri 9:30 - 6:00.
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/ZHONGQING WEI/Primary Examiner, Art Unit 1727
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