DETAILED ACTION
Application 19/110342, “Positive Electrode Active Material, Preparation Method Thereof, Positive Electrode And Lithium Secondary Battery Including The Positive Electrode Active Material”, is the national stage entry of a PCT application filed on 12/21/23 and claims priority from a foreign application filed on 12/23/22.
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
This Office Action on the merits is in response to communication filed on 10/7/25.
Response to Arguments
Applicant’s arguments filed on 10/7/25 have been fully considered, but are not persuasive. Applicant presents the following arguments.
In view of applicant’s Examples versus Comparative Examples, it is apparent that the embodiments satisfying C1<C2<C3 exhibit improved performance, whereas embodiments not satisfying this relationship provide inferior performance. In response, applicant’s argument is interpreted to be an argument of unexpected results intended to overcome the prima facie case of obviousness. Applicant’s argument is unpersuasive for at least the following reasons. Firstly, to be of probative value, the evidence of unexpected results must be commensurate in scope with the claimed invention, at least to such a degree that the unexpected result will be expected over the breadth of the claimed invention (MPEP 716). Here the evidence of Table 1 is limited to a single Co/Ni ratio C1 of 0.125 and a single Co/Ni ratio C3 of for the inventive Example, and a C3 ratio spanning 0.125 to 0.98 for the Comparative Examples. Claim 1 however, is unlimited with respect to the magnitude of the parameters C1, C2 and C3 and includes no magnitudes at all. Moreover, the inventive Example uses a Co/Ni ratio C2 of 0.7 as the single favorable data point; however, this single data point is insufficient to suggest that even if an unexpected improvement were associated with this value, the improvement would also be provided if the C2 value is close to the C1 value (e.g. ~0.2) or close to the C3 value (e.g. ~0.90). Thus, any evidence of unexpected results which could be gleaned from Table 1 is much to narrow to generalize to the invention of claim 1 as presently claimed. Secondly, to be of probative value, the evidence should compare the claimed invention to the closest prior art (MPEP 716). Here, the evidence does not evaluate Kwon (US 2018/0108940) or explain why Kwon’s invention would not provide the low gas generation and internal resistance values of applicant’s Example 1. Lastly, although the specification describes the improved properties of Example 1 as excellent, it does not characterize the improvements as surprising or unexpected, or suggest that the improvement is more significant than the known advantages of the invention suggested by the prior art as is required (MPEP 716). Here, for example, applicant’s specification indicates that the inventive Examples exhibit lower gas generation and internal resistance, and improved life span and high-temperature properties than the comparative example. However, Kwon also teaches his product provides improved capacity retention and thermal stability (paragraphs [0144-0146]) than comparative examples, and exhibits low contact resistance, improved capacity and output characteristics (paragraph [0043, 0050]). Moreover, the Lim modification of Kwon is performed for the benefit of reducing unwanted dissolution of transition metal elements; therefore, improved stability [improved life span] is an expected benefit for the combined embodiment. The evidence does not characterize applicant’s improvement as a surprising or unexpected result of significance greater than the expected benefits disclosed by the prior art. For at least these reasons, the argument of unexpected results supported by the evidence of applicant’s specification, is not found to be sufficient to outweigh the prima facie case of obviousness.
Applicant questions how modifying Kwon in view of Lim leads to the claimed relationship C1<c2<C3. More specifically, the fact that a concentration of cobalt or nickel may decrease from a surface portion to a central portion tells nothing about how the ratio of cobalt to nickel varies. Applicant presumes that the nickel and cobalt would decrease in a proportionate manner such that the relative ratio would remain substantially constant. In response, the outstanding rejection has pointed to Kwon paragraph [0143] which teaches a core having a composition of Li[Ni0.82Co0.07Mn0.13]O2 and a shell of Li[Ni0.56Co0.17Mn0.27]O2. Thus, the nickel concentration of the particle decreases in the core[Wingdings font/0xE0]shell direction, while to the contrary, the cobalt concentration increases in the core[Wingdings font/0xE0]shell direction. This supports the Office’s assertion that Kwon teaches C1<C3 [e.g. transitioning 7/82 = 0.085 to 17/56 = 0.30]. Lim is relied on to teach a barrier layer/grain boundary phase which provides a concentration gradient that transitions the elemental concentration between surface of the composite particle to the interior of the composite particle, such as from core to shell (paragraphs [0032, 0130-0132]). Therefore, for the combined embodiment, the molar ratio of the transitioning barrier layer/grain possessing a cobalt/nickel ratio C2 which lies between the values C1 and C3 is suggested as present or at least obvious, considering that the grain boundary transitions the concentration of the cobalt and nickel from the interior value to the exterior value. Thus, the invention as claimed in claim 1 is found to be obvious over the combination of Kwon and Lim.
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 of this title, 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.
Claims 1-7, 10 and 16-18 is/are rejected under 35 U.S.C. 103 as being unpatentable over the combination of Kwon (US 2018/0108940) and Lim (2025/0183288).
Regarding claim 1, Kwon teaches a positive electrode active material (Fig. 1; paragraph [0013]) comprising: a lithium composite transition metal oxide (abstract, paragraph [0033]) that is in the form of a secondary particle in which a plurality of grains are aggregated (Fig. 1), and that comprises an oriented structure in which a long axis of at least one of the plurality of grains is arranged in a direction from a center of the secondary particle toward a surface thereof in at least one portion of the secondary particle (layer 2 has the arranged grains); and a coating layer that is formed on the surface of the secondary particle (layer 3) and includes a Co element (paragraph [0033]),
wherein: the lithium composite transition metal oxide contains nickel and cobalt; and C1 < C3 is satisfied, wherein C1 is a ratio of a molar number of cobalt to a molar number of nickel in at least one of the plurality of grains and C3 is a ratio of a molar number of cobalt to a molar number of nickel in the coating layer (Kwon claim 7; paragraphs [0056, 0057, 0062, 0143]).
Kwon does not appear to teach wherein C2 is a ratio of a molar number of cobalt to a molar number of nickel at a grain boundary, which is an interface between at least two of the plurality of grains, and C1< C2 < C3 is satisfied.
In the battery art, Lim teaches a transition metal oxide positive electrode active material composite particle (abstract, paragraph [0028]), wherein the particle comprises a “barrier layer” phase which coats the particle and is present at grain boundaries between primary particles of the composite particle (paragraph [0032, 0130]). Lim further teaches that the barrier layer at the grain boundary is present in as state of being diffused from the surface of the particle toward the central portion, resulting in a concentration gradient of barrier layer elements that decreases from the surface toward the central portion, resulting in reduced dissolution of transition metal from the secondary particle and/or doping of the primary particle (paragraphs [0130-0132]).
It would have been obvious to a person having ordinary skill in the art at the time of invention to configure the composite particle of Kwon to include a barrier layer having an elemental composition that decreases from a surface concentration to a central concentration for the benefit of reducing unwanted dissolution of transition metal elements as taught by Lim. In the case of the combined embodiment, the barrier layer (a grain boundary layer) would have a concentration of cobalt in the grain boundary, C2, which is between the values of C1 and C3, since elemental distribution within the barrier layer [grain boundary layer] transitions from that of the surface portion to that of the central portion, so as to teach applicant’s invention, as claimed.
Such a modification merely requires the simple substitution of one known element for another to yield predictable results therefore, a prima facie case of obviousness exists accordance with MPEP 2141.
Regarding claim 2, the cited art remains as applied to claim 1. Kwon further teaches, or at least suggests as obvious, wherein grains in which the long axis is arranged in the direction from the center of the secondary particle toward the surface thereof form an angle of from -15° to -15° between the long axis and an a-axis direction of a crystal structure.
More specifically, Kwon Figure 1 illustrates long grains having axis oriented in the radial direction and paragraph [0043] indicates that the grains grow along this direction, thereby facilitating fast lithium ion transfer and intercalation. This description appears to be substantially the same as that described in applicant’s original specification at paragraphs [0005-0006]. Therefore, the description, combined with the drawings suggests individual grains having a long axis which is parallel to, or nearly parallel to, the radial direction which is the grain growth direction, so as to suggest the claimed feature.
Regarding claim 3-6, the cited art remains as applied to claim 1. Kwon further teaches wherein the lithium composite transition metal oxide comprises: a core portion in which grains are disorderly aggregated; and a shell portion that is formed outside the core portion, and that has grains arranged in an oriented structure (Figure 1).
As described, the long axis of the particles in the shell portion are arranged in the direction from the center of the secondary particle toward the surface thereof and have an aspect ratio of from 1 to 20, which renders obvious the claimed aspect ratio of 1.5 to 15 due to the substantial overlap. See also paragraph [0138] which teaches an exemplary embodiment with an aspect ratio of 13, which lies within the claimed range.
The particles of the core portion are characterized as having a “granular” shape or a rod shape, with the “rod shaped” particles meaning that having an aspect ratio of 1 to 20 (paragraph [0034-0035]). This description, along with Figure 1, teaches or at least suggests as obvious, that the “granular” particles of the core portion have an aspect ratio of close to 1, such 0.8 to 1.2, since they are not rod-shaped particles having an aspect ratio of 1 to 20 and are roundish as schematically illustrated.
Regarding claim 7, the cited art remains as applied to claim 1. Kwon further teaches wherein the lithium composite transition metal oxide has a composition represented by the following Formula 1: Lix[NiaCobM1cM2d]O2-yAy (1), wherein: M1 is one or more elements selected from the group consisting of Mn or Al; M2 is one or more elements selected from the group consisting of W, Cu, Fe, V, Cr, Ti, Zr, Zn, Ta, Y, In, La, Sr, Ga, Sc, Gd, Sm, Ca, Ce, Nb, Mg, B, or Mo; A is one or more elements selected from the group consisting of F, Cl, Br, I, At, or S; and 0.98<x<1.20,0<a<1, 0<b<1, 0<c<1, 0<d<0.2, and 0<y<0.2 (paragraphs [0036-0039; 0045-0046]).
Regarding claim 10, the cited art remains as applied to claim 1. Kwon further teaches wherein the average particle diameter (D50) of the positive electrode active material is from 2 μm to 20 μm. (“5 μm to 30 μm”, paragraph [0075], e.g. 11.5 μm at [0138]).
Regarding claim 16-18, the cited art remains as applied to claim 1. Kwon further teaches the positive electrode active material forming the positive electrode of a lithium secondary battery, the lithium secondary battery further comprising an organic liquid electrolyte (paragraphs [0109-0111, 0118]).
Claims 8 is/are rejected under 35 U.S.C. 103 as being unpatentable over the combination of Kwon (US 2018/0108940), Lim (2025/0183288), and Lee (US 2014/0205898).
Regarding claim 8, the cited art remains as applied to claim 1. Kwon does not appear to teach wherein the positive electrode active material comprises a coating layer having a composition represented by the following Formula 2: LizCo1-wM3wO2 (2), wherein: M3 is one or more selected from the group consisting of Ni, Mn, Al, W, Cu, Fe, V, Cr, Ti, Zr, Zn, Ta, Y, In, La, Sr, Ga, Sc, Gd, Sm, Ca, Ce, Nb, Mg, B, or Mo, and 0.8≤z≤1.2, and 0≤w≤0.2.
In the battery art, Lee teaches providing a cobalt rich coating of LiCoO2 on a positive electrode active material particle (paragraph [0014, 0037]) for the benefit of improving the stability and/or charge discharge characteristics of the particle (paragraph [0028, 0030]).
It would have been obvious to a person having ordinary skill in the art at the time of invention to provide a cobalt rich coating layer having a composition readable on formula 2 for the benefit of improving the stability and/or charge discharge characteristics of the battery formed using the positive electrode active material as taught by Lee.
Claims 9 is/are rejected under 35 U.S.C. 103 as being unpatentable over the combination of Kwon (US 2018/0108940), Lim (2025/0183288), Itou (US 2009/0029253) and Park (US 2011/0079752).
Regarding claim 9, the cited art remains as applied to claim 1. Kwon does not appear to teach wherein the average particle diameter (D50) of the grains is from 0.05 μm to 4 μm.
In the battery art, Itou teaches a positive electrode active material particle which is a secondary particle comprised of a plurality of elongated grains for primary particles (Fig. 1). Itou further teaches the secondary particles having an average particle size of 0.1 to 20 microns, and the secondary particles [grains] having an average size of 0.01 to 5 microns (paragraphs [0047-0048]).
In the battery art, Park generally teaches a positive electrode active material which is a secondary particle comprised of primary particles [grains], and that the average particle diameter of the secondary particles is a result-effective variable which may affect properties such as press density, capacity, processability, stability and other aspects of overall performance (paragraphs [0008-0022]). Park further teaches the various prior art as reaching a variety of preferred primary particle size ranges which lie within or overlap the claimed 0.05 to 4 micron range (see various disclosures of paragraphs [0008-0022]). Park further teaches his own preferred primary particle size range of 3 to 10 microns for benefits such as high rate characteristics and improved reversible capacity (paragraphs [0039-0040]).
The claimed invention wherein the average particle diameter (D50) of the grains is from 0.05 μm to 4 μm, is found to be obvious over the cited art which teaches both overlapping ranges, and that the primary particle diameter is a result-effective variable which would have been obvious to optimize in order to provide a desirable combination of performance related properties as taught by Ito and/or Park.
Conclusion
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 JEREMIAH R SMITH whose telephone number is (571)270-7005. The examiner can normally be reached Mon-Fri: 9 AM-5 PM (EST).
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/JEREMIAH R SMITH/Primary Examiner, Art Unit 1723