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 .
Response to Amendment
The amendment filed 07/28/2026 has been entered.
Claim 1 is amended while claim 6 was cancelled; support for amendment can be found at least at page 6, lines 9-12 of the specification, as well as in claim 6 as presented in claims filed 07/13/2023 (which is now canceled). Claims 1-5, and 7-14 are pending, of these, claims 7-12 have been withdrawn as being directed to non-elected subject matter, claims 1-5 and 13-14 are rejected under prior art on their merits below. Of these, claim 1 is independent, and the remainder are dependent.
Response to Arguments
Applicant's arguments, see Remarks at pages 7-10, filed 07/28/2026, with respect to amended claim 1, particularly the limitation of, “a lithium impurity of the positive electrode active material for a lithium secondary battery is present in an amount of 0.7 weight% or less”, have been fully considered but they are not persuasive.
Regarding the first argument in page 7, Applicant argues that lithium impurity of Luo is not present in an amount of 0.7 weight % or less, because Luo teaches that the lithium impurity is present on the surface of the high nickel cathode material in an amount ranging from 0.0695% to 0.1126%; and Luo is silent on the lithium impurity with respect to a total weight of the high-nickel cathode material.
The argument is not persuasive because amended claim 1 recites “a lithium impurity of the positive electrode active material … present in an amount of 0.7 weight% or less“, but does not require that a lithium impurity be present throughout the bulk of the positive electrode active material with respect to a total weight thereof, nor does the claim exclude a lithium impurity being that which is present on the surface of the positive electrode active material. Luo teaches residual lithium containing alkali on the surface of high nickel cathode material. Accordingly, the residual lithium on the surface (which can reasonably be interpreted as “a lithium impurity”) of Luo’s high nickel cathode material (which reads on “of the positive electrode active material”) reasonably reads on the claim limitation of “a lithium impurity of the positive electrode active material” within the broadest reasonable interpretation of amended claim 1. That is, since claim 1 does not specify where in the positive electrode active material (i.e., throughout the layer versus on the surface thereof, or otherwise) that a lithium impurity is measured, arguments to the contrary are not commensurate with the scope of the claim.
Applicant further argues that Luo’s disclosed amount of 0.0695% to 0.1126% cannot satisfy the claimed “weight%” limitation because Luo does not state that the percentage is in weight basis. This argument is also not persuasive. Luo determines the residual alkali content of the high-nickel positive electrode material using hydrochloric-acid titration (per Luo pg. 7, line 56) and reports the resulting impurity content as a percentage. Before the effective filing date, it was known in the art that the quantitative residual-lithium impurity values obtained by such titration of positive-electrode active material would be expressed on a mass/weight basis:
For example, Okamoto et al. (JP 2020198194 A, published December 10, 2020) expressly teaches a lithium nickel composite oxide positive-electrode active material containing excess lithium hydroxide as an “impurity,” wherein the amount of the impurity is measured by titration with hydrochloric acid and expressed as “% by mass” (Okamoto page 3, lines 23-28). Thus, Okamoto provides evidence that, before the effective filing date, the art quantified lithium impurity in a lithium-nickel positive-electrode active material using hydrochloric-acid titration and expressed the resulting impurity amount on a mass-percentage basis.
This understanding is also consistent with the standard analytical methodology of GB/T 9725-2007, Chemical Reagent—General Rule for Titration. The standard evidences that titration was a known analytical technique. Peng et al. (US 20230387463 A1) is cited only as an additional evidentiary reference rather than as prior art relied upon for the rejection. Peng explains that surface residual lithium of positive-electrode active material can be determined according to the GB/T 9725-2007 titration method, using a hydrochloric-acid standard solution, and further states that “ppm by weight” has the same meaning as “ppm by mass” [0051-0052, 0124-0125]. Peng therefore corroborates the mass-based nature of the quantitative residual-lithium determination using this titration methodology.
Therefore, the art expressly demonstrates that lithium-containing impurities in positive-electrode active materials measured using hydrochloric-acid titration are reported on a mass/weight percentage basis. These teachings are consistent with Luo's use of hydrochloric-acid titration to quantitatively determine its residual surface alkali content.
Therefore, Luo's reported 0.0695% to 0.1126% residual lithium-containing impurity content is understood to be on a weight basis in the context of the conventional quantitative titration measurement of positive-electrode material. Luo's disclosed range is below the claimed upper limit of 0.7 weight%. Applicant's argument that Luo fails to teach the claimed lithium impurity amount merely because Luo does not expressly append the word “weight” to the reported percentage is therefore not persuasive.
Regarding second argument in pages 7-8, Applicant argues that Office has failed to show that Luo recognizes the claimed weight % of the lithium impurity to be a result-effective variable and there is NO motivation from the prior art of record to arrive at the claimed weight % of the lithium impurity because the prior art was silent on this parameter. However, Luo expressly recognizes the amount of residual lithium-containing alkaline species on the surface of the high-nickel positive electrode material as a variable affecting the properties of the material. In particular, Luo teaches that a low residual alkali content is desirable for obtaining good energy density, cycle performance, and thermal stability (page 1, lines 55-60), and further teaches that an optional washing step may be employed to further reduce the residual surface alkali content (page 6, lines 45-50). Thus, Luo does not merely disclose the presence of residual lithium as a property; rather, Luo expressly recognizes that the amount of such residual material should be reduced to improve battery performance. As explained in the Office action of record, the positive electrode material composition having the low lithium impurity therefore affects the improved resultant battery performance.
Further, as discussed above, Luo quantitatively determines the residual lithium-containing impurity by hydrochloric-acid titration and reports values of approximately 0.0695% to 0.1126%. The evidentiary references further establish that, before the effective filing date, residual lithium impurities in positive-electrode active materials were conventionally quantified by hydrochloric-acid titration and expressed on a mass/weight basis.
Accordingly, the claimed amount is not an unrelated parameter that the prior art gives a person of ordinary skill no reason to investigate. Luo itself identifies residual surface alkali as undesirable, quantitatively measures that residual material, and teaches further reducing it to improve battery properties. A person of ordinary skill in the art therefore would have been motivated to control and reduce the amount of residual lithium-containing impurity, with the optimum or workable amount through routine experimentation.
Moreover, amended claim 1 merely requires “0.7 weight% or less.” Luo's disclosed residual impurity values of approximately 0.0695% to 0.1126% are already below the claimed upper limit of 0.7 weight%. Thus, it is not necessary for the Office to establish that a person of ordinary skill would have been motivated to select the precise numerical endpoint of 0.7 weight%. Rather, Luo teaches values falling within the claimed open-ended range and provides a reason to reduce the residual lithium-containing impurity. Thus, the rejection of record relies primarily on MPEP 2144.05 I rationale since this range taught toward by Luo indeed falls within and obviates the instantly claimed range.
Therefore, Applicant's argument that the prior art fails to recognize the lithium impurity amount as a result-effective variable or fails to provide motivation to arrive at the claimed amount is not persuasive.
Regarding second argument in page 8-9, Applicant argues that a person of ordinary skill in the art would not have been motivated to arrive at the claimed lithium impurity amount because Lu does not compare compositions having high and low impurity levels and also Cho is silent regarding the deteriorative effects of washing lithium impurities on the surface of the secondary particle and the advantages of reacting the lithium impurities with a cobalt source.
Applicant’s argument is not persuasive and, to the extent it requires Cho alone to teach these features, is not commensurate with the scope of the rejection, which is based on the combined teachings of the references. Luo expressly teaches that high residual alkali content is undesirable, and that reducing surface alkali improves energy density, cycle performance, and thermal stability (as cited of record and explained above). Luo therefore provides a reason for a person of ordinary skill to control and reduce residual lithium-containing impurity in Cho's positive-electrode active material.
Luo does not need to provide comparative examples specifically contrasting high and low impurity levels because Luo expressly identifies the undesirable condition and teaches reducing it, including through an optional washing step. Likewise, Cho need not independently recognize the same problem where Luo supplies the reason for the proposed modification.
Therefore, one of ordinary skill in the art would have been motivated to control and reduce the residual lithium impurity of Cho's material in view of Luo's teachings, and Applicant's argument is not persuasive.
Claim Rejections - 35 USC § 103
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
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 text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office action.
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 1-5, and 13-14 are rejected under 35 U.S.C. 103 as being unpatentable over Cho et al. (KR 101810574 B1, citation from enclosed machine translation), and further in view of Luo et al. (CN 105185962 A, citation from enclosed machine translation).
Regarding claim 1, Cho teaches a positive electrode active material for a lithium secondary battery (Technical Field paragraph, [0054]), comprising
a secondary particle ([0007]) having an average particle size (D50) of 5 to 15 μm ([0030]). This range overlaps with the claimed range of 1 to 15 μm. It has been held that in the case where claimed ranges “overlap or lie inside ranges disclosed by the prior art” a prima facie case of obviousness exists. See MPEP 2144.05 I.
Cho further teaches that the secondary particle is formed by agglomeration of a plurality of nickel-based lithium metal oxide particles ([0051]) having an average particle size (D50) of 0.2 to 15μm ([0088]), corresponding to the claimed “at least two primary macro particles”. The average particle size of the nickel-based lithium metal oxide particles (0.2 to 15μm) overlaps the claimed range of 0.1 to 3 μm. Accordingly, a prima facie case of obviousness is established for this limitation as well (see MPEP 2144.05 I).
Cho also teaches a coating layer of a lithium-metal oxide on a surface of the secondary particle ([0075-0078]).
With respect to composition, Cho teaches that the plurality of nickel-based lithium metal oxide particles may each be represented by LiaNi1-x-yCoxMyO2 ([0083-0084]) wherein 0.9<a<1.1, 0<x<0.5, 0<y<0.5, 0<x+y<0.6, and M is at least one element selected from the group consisting of Mg, Ti, Zr, Nb, Mo, Al, Mn, Mg, V, and a rare earth element ([0085-0086]). These disclosures overlap with the claimed composition LiaNi1-x-yCoxM1yM2wO2 wherein 1≤a≤1.5, 0≤x≤0.2, 0≤y≤0.2, 0≤w≤0.1, 0≤x+y≤0.2, M1 includes at least one metal of Mn or Al, and M2 includes at least one metal selected from the group consisting of Ba, Ca, Zr, Ti, Mg, Ta, Nb and Mo, as claimed. Accordingly, a prima facie case of obviousness is established for this limitation as well (see MPEP 2144.05 I).
Cho further teaches that the second coating layer is a lithium-metal oxide coating having a chemical formula of LixCoO2 , wherein 0.95≤x≤1.05 and having a spinel structure (Fd-3m) ([0019-0022]). This corresponds to the claimed lithium-metal oxide LixCoO2 (0<x≤1), having at least one of a spinel structure (Fd-3m) or a disordered rock-salt structure (Fm-3m). A prima facie case of obviousness is established for this limitation as the range of x overlaps the claimed range.
Regarding the “low-temperature phase” limitation, the instant specification indicates that such a phase is formed by sintering at temperatures of about 350-500°C for 5-40 hours. Cho teaches calcination at 400–600°C for 3-5 hours ([0104-0105]), which overlaps the claimed processing temperature range (from 400-500°C) and abuts the claimed processing time (at 5 hours) (see MPEP 2144.05 I) and would reasonably result in a similar phase. In view of the similarities in composition, structure, and processing conditions, Cho’s coating is substantially identical to the claimed lithium-metal oxide coating. Thus, Cho discloses the same type of material as claimed. Where the prior art discloses a composition that is identical or substantially identical to the claimed composition, it is reasonable to conclude that the prior art composition inherently possesses the same characteristics, including a low-temperature phase, absent evidence to the contrary (see MPEP 2112(V); MPEP 2112.01(I) and (II)). Accordingly, it would have been expected that coating of Cho necessarily exhibits a low temperature phase. Therefore, the “low-temperature phase” limitation is considered inherent or at least obvious in view of Cho.
Cho fails to teach a limitation wherein a lithium impurity of the positive electrode active material for a lithium secondary battery is present in an amount of 0.7 weight% or less.
However, Luo teaches this limitation. Specifically, Luo teaches a positive electrode material for a lithium secondary battery wherein the base material is a compound represented by formula LinNi1-x-yCoxMyO2 wherein 0.95<n<1.15, 0<x<0.3, 0.01<y<0.1, and M comprises one or more of titanium, magnesium, manganese, aluminum, zirconium, lanthanum, strontium, niobium and molybdenum (page 1, lines 55-58; page 2, lines 1-10); the base material is secondary particles formed by the primary particles spherical, the average particle diameter of primary particles is 0.1 microns to 2.5 microns, the average particle diameter of the secondary particles is 3 micron to 20 micron (page 2, lines 14-16). The composition disclosed by Luo overlaps with the range taught by Cho; accordingly, Luo’s composition is similar to that of Cho. Importantly, Luo teaches that the impurity content of lithium is 0.0695% to 0.1126% (page 7, lines 56-57), which falls well within the claimed range of 0.7 wt% or less. It has been held that in the case where claimed ranges “overlap or lie inside ranges disclosed by the prior art” a prima facie case of obviousness exists. See MPEP 2144.05. Luo also teaches this composition of positive electrode material improves battery performance, including capacity, cycle performance, and thermal stability (page 1, lines 57-59). Further, Cho and Luo are considered to be analogous to the claimed invention because both are in the same field of positive electrode material composition.
Therefore, it would have been obvious before the effective filing date of the claimed invention that one of ordinary skill in the art would modify the material of Cho to include a lithium impurity content within the range taught by Luo, motivated by Luo’s teaching that such impurity levels improve battery performance (page 1, lines 57-59). Further, lithium impurity content represents a result-effective variable, and optimizing such a variable to obtain desired performance would have been achieved through routine experimentation. See MPEP 2144.05(II), see also In re Aller, 220 F.2d (CCPA 1955). Accordingly, it would have been obvious to arrive at the claimed invention, including the limitation of a lithium impurity content of 0.7 wt% or less.
Regarding claim 2, Cho, as modified by Luo, discloses all limitations of claim 1 as stated above. Cho further teaches a limitation wherein the lithium-metal oxide has the spinel structure (Fd-3m) ([0019]).
Regarding claim 3, Cho, as modified by Luo, discloses all limitations of claim 1 as stated above. As discussed above, Cho teaches that the average particle size (D50) of the at least two primary macro particles is 0.2 to 15μm ([0088]). This range overlaps the claimed range of 1 to 3 μm. It has been held that in the case where claimed ranges “overlap or lie inside ranges disclosed by the prior art” a prima facie case of obviousness exists. See MPEP 2144.05 I.
Cho also teaches that the average particle size (D50) of the secondary particle is 5 to 15 μm ([0030]). This range overlaps with the claimed range of 3 to 10 μm. Accordingly, a prima facie case of obviousness is established for this limitation as well.
Regarding claim 4, Cho, as modified by Luo, discloses all limitations of claim 1 as stated above. Cho further teaches a limitation wherein the second coating layer is present in an amount of 0.5 to 2 parts by weight based on 100 parts by weight of the secondary particle ([0024]). This range overlaps the claimed range of 0.05 to 3 parts by weight. It has been held that in the case where claimed ranges “overlap or lie inside ranges disclosed by the prior art” a prima facie case of obviousness exists. See MPEP 2144.05 I.
Regarding claim 5, Cho, as modified by Luo, discloses all limitations of claim 1 as stated above. Cho further teaches a limitation wherein an average crystallite size of the at least two primary macro particles is 130 nm or more ([0050, 0088]). Specifically, Cho discloses that the crystallite (grain) size is equivalent to the size of primary particle ([0050]). Additionally, as noted with respect to claim 1, Cho teaches that the primary particles size ranges from 200 nm to 15 μm ([0088]). Accordingly, Cho teaches a crystallite size ranges from 200 nm to 15 μm, which overlays with the claimed lower limit of 130 nm or more. It has been held that in the case where claimed ranges “overlap or lie inside ranges disclosed by the prior art” a prima facie case of obviousness exists. See MPEP 2144.05 I.
Regarding claim 13, Cho, as modified by Luo, discloses all limitations of claim 1 as stated above. Cho further teaches a positive electrode for a lithium secondary battery ([0093]) comprising a positive electrode current collector and a positive electrode active material layer comprising the positive electrode active material according to claim 1 on the positive electrode current collector ([0118-0119]).
Regarding claim 14, Cho, as modified by Luo, discloses all limitations of claim 13 as stated above. Cho further teaches a lithium secondary battery comprising the positive electrode according to claim 13, a negative electrode opposite the positive electrode, a separator between the positive electrode and the negative electrode, and an electrolyte (Fig. 2, [0128]).
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 Lili Rassouli whose telephone number is (571)272-9760. The examiner can normally be reached Monday-Thursday 8:00 AM-4:00 PM.
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/LILI RASSOULI/ Examiner, Art Unit 1728
/JESSIE WALLS-MURRAY/Primary Examiner, Art Unit 1728
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