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 .
Continued Examination Under 37 CFR 1.114
A request for continued examination under 37 CFR 1.114, including the fee set forth in 37 CFR 1.17(e), was filed in this application after final rejection. Since this application is eligible for continued examination under 37 CFR 1.114, and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114. Applicant's submission filed on 01/13/2026 has been entered.
Claim Objections
Claims 1 and 2 are objected to because of the following informalities:
Claims 1 and 2 each introduce the idea of “reference primary particles” before defining the term. This creates confusion within the claims. The Examiner suggests rewording Claims 1 and 2 such that the definition of “reference primary particles” is introduced at the same time that the particles are claimed.
Claim 2 recites “a content proportion of reference primary particles present in a central part of the secondary particle is lower than a proportion of the reference primary particles in the surface part” (lines 6-8; emphasis added) and later “the content proportion of the reference primary particles present in the central part of the secondary particle is 20% or more and 50% or less, and the content proportion of the reference primary particles present in the surface part of the secondary particle is 30% or more and 90% or less” (lines 10-13; emphasis added). It is understood that the recitations of “the content proportion” derive antecedent basis from the preceding limitation. Therefore, the recitation of “a proportion of the reference primary particles in the surface part” should read “a content proportion of the reference primary particles in the surface part” (emphasis added) in order to provide proper antecedent basis for the limitation “the content proportion of the reference primary particles present in the surface part”.
Appropriate correction is required.
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.
Claims 1-3 and 5-15 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, “in the central part, the primary particles that have an elongated shape and the primary particles having a spherical shape are present in a mixed form” (emphasis added). There is no previous antecedent basis for “primary particles that have an elongated shape” or “primary particles having a spherical shape”. As such, it is unclear which particles are referenced. Although the Examiner notes that the claim previously recites “reference primary particles” which have an aspect ratio of 2.0 or more, it is unclear whether the recited “primary particles that have an elongated shape” refer to these “reference primary particles”, or if any primary particles which are not spherical should be interpreted as having an “elongated shape”. As such, Claim 1 and dependent claims 5-15 are rejected as being indefinite. For the sake of compact prosecution a particle with “an elongated shape” is broadly and reasonably interpreted as any particle which is not spherical as supported by the instant specification [0012].
Claim 2 recites, “a secondary particle that is an aggregate of primary particles, wherein, in a surface part of the secondary particle, the primary particles that have an elongated shape are radially arranged and aggregated outward from a center of the secondary particle” (emphasis added). There is no antecedent basis for the limitation “the primary particles that have an elongated shape”. Therefore, it is unclear which primary particles are referenced. For the sake of compact prosecution, “the primary particles that have an elongated shape” will be interpreted as any primary particles which are not spherical and which are located in a surface part, as supported by the instant specification [0012].
Additionally, Claim 2 further recites, “a content proportion of reference primary particles present in a central part of the secondary particle is lower than a proportion of the reference primary particles present in the surface part” (emphasis added). There is no previous recitation of “reference primary particles”, much less a reference to “reference primary particles present in the surface part”. As such, it is unclear whether the “reference primary particles” are intended to refer to the previously recited “primary particles” (Claim 2: line 2), or the previously recited “primary particles that have an elongated shape” (Claim 2: lines 3-4) , or whether the reference primary particles are intended to refer to different particles. For the sake of compact prosecution, it will be interpreted that “the reference primary particles” refer to new primary particles, distinct from the previously recited particles with “an elongated shape”.
Furthermore, Claim 2 recites, “in the central part, the primary particles that have an elongated shape and the primary particles having a spherical shape are present in a mixed” (emphasis added). Here, it is unclear exactly which particles are referenced. Regarding the limitation “the primary particles that have an elongated shape”, the Examiner notes that the claim previously recites “the primary particles that have an elongated shape” (Claim 2: lines 3-4). However, these particles are recited as being in the surface part. Therefore, it does not appear that there is appropriate antecedent basis for primary particles that “have an elongated shape” in the central part, and it is unclear which particles are referenced. Regarding the limitation “the primary particles having a spherical shape”, the Examiner notes that there is no antecedent basis for this limitation, and therefore it is unclear which particles are referenced. Regarding the limitation “are present in a mixed”, this limitation appears to be missing a noun and is unclear as written. Based on the amendment made to Claim 1, this limitation should read “are present in a mixed form” (emphasis added). For the sake of compact prosecution, it will be interpreted that any spherical particles read on the recited limitation of “primary particles having a spherical shape”, and that any particles which are not spherical read on the recited limitation of “primary particles that have an elongated shape”.
For the reasons laid out above, Claim 2 and dependent Claim 3 are rejected as being indefinite.
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.
Claim(s) 1-3 and 5-14 is/are rejected under 35 U.S.C. 103 as being unpatentable over Sun et al. (US-20140158932-A1) in view of Takaki et al. (WO-2016002158-A1; see English translation provided 10/18/2024 for citations).
Regarding Claims 1 and 5-6, Sun discloses a lithium secondary battery including a positive electrode active material precursor (reads on lithium composite metal oxide [0029]) comprising a secondary particle that is an aggregate of primary particles [0010, 0020, 0052].
Although Sun does not explicitly disclose that “when a cross-sectional image of the secondary particle is acquired, and the cross-sectional image is observed, a content proportion of reference primary particles present in a central part of the secondary particle is 20% or more and 50% of less, and a content proportion of reference primary particles in a surface part of the secondary particle is 30% or more and 90% or less”, the secondary particle disclosed by Sun is understood to inherently have a cross-sectional image comprising a central part and a surface part, as detailed below.
Specifically, as defined by Claim 1, a central part and a surface part constitute a cross-sectional image of a secondary particle (see Claim 1: lines 11-19). The central part of the secondary particle of Sun is a part of the secondary particle which is surrounded by an imaginary circle with a radius which is half the radius of the secondary particle (i.e. r = (S/π)0.5/2 as claimed), and the surface part is the remaining area between an edge of the imaginary circle and the edge of a cross-section of the secondary particle (see illustration of Sun Fig. 3, below).
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Illustration of Sun Fig. 3 depicting central part and surface part.
Sun discloses the secondary particle may comprise a first interior wherein the a-axis direction length to c-axis direction length (corresponds to the aspect ratio) of the primary particle is 0.5 to 2.0, and a second interior wherein the a-axis direction length to c-axis direction length (corresponds to the aspect ratio) of the primary particle is 2 to 30 [0016]. A primary particle with an aspect ratio of 2.0 or more corresponds to the reference primary particle as recited in Claim 1. Sun further discloses that aspect ratio of the primary particles increases from the center part of the secondary particle to the surface part of the secondary particle [0010, 0138]. Sun does not teach that a content of reference primary particles in the central part is 20% or more and 50% or less, or that the content of reference primary particles in the surface part is 30% or more and 90% or less.
Takaki teaches a lithium-containing transition metal oxide positive electrode active material for a non-aqueous electrolyte secondary battery (Pg. 2, Par. 1; Pg. 6, Par. 6). The positive electrode active material is composed of secondary particles formed by an aggregation of a plurality of primary particles (Pg. 3, Par. 7). Takaki teaches that stress is especially concentrated in the central part of the secondary particles during charging / discharging (Pg. 2, Pars. 6-7; Pg. 16, Par. 7). When primary particles with a high aspect ratio exist in the central portion of the secondary particles, a large distortion is added inside the secondary particles during charge / discharge, and the collapse of the active material becomes more prominent (Pg. 3, Par. 5). To mitigate this effect, Takaki teaches that primary particles having a small aspect ratio (i.e. 1 or more and 2 or less) are arranged in the central part of the secondary particles (Pg. 5, first full paragraph and second to last paragraph; see Fig. 4b) and elongated primary particles with larger aspect ratios (i.e. 2 or more and 10 or less) are located on the peripheral part of the secondary particle (Pg. 5, first full paragraph; see Fig. 4b).
Advantageously, by arranging spherical primary particles in the central part of the secondary battery and elongated primary particles in the outer peripheral portion of the secondary battery, better cycle characteristics can be obtained (Pg. 5, last three paragraphs). Specifically, Takaki teaches that arranging spherical primary particles in the central part of the secondary particle relieves stress inside the particle at the time of charging / discharging (Pg. 5, second to last paragraph) and, by arranging elongated primary particles in the outer peripheral portion of the secondary battery, peeling of the particles can be suppressed, and cycle characteristics are improved (Pg. 5, second full paragraph and second to last paragraph).
Takaki also teaches that when the appearance frequency of the aspect ratio of the elongated primary particles is greater than the aspect ratio of the spherical primary particles, it is possible to increase the contact area of the elongated primary particles with adjacent particles, thereby suppressing the occurrence of cracks at the grain boundary (Pg. 5, second full paragraph). Takaki teaches that this is advantageous for cycle characteristics at low load (Pg. 5, second full paragraph). On the other hand, when the appearance frequency of the aspect ratio of spherical primary particles is greater than the aspect ratio of the elongated primary particles, it is possible to shorten the distance for lithium diffusion, and the spherical primary particles are less affected by defects in the crystal plane (Pg. 5, third full paragraph). Takaki teaches that this is advantageous for high rate cycle characteristics (Pg. 5, third full paragraph).
It would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to have optimized the aspect ratios and contents of the primary particles in the central part and surface part of Sun as taught by Takaki, including selecting the central part of the secondary particle to comprise “20% or more and 50% or less” of reference primary particles, and selecting the surface part to comprise “30% or more and 90% or less” of reference primary particles as required by Claim 1, with a reasonable expectation that such a configuration would result in a successful balance between reducing stress in the central part of the secondary particle, thereby preventing collapse, while ensuring sufficient adhesion and increased cycle characteristics, and a further balance between low load cycle characteristics and high rate cycle characteristics (MPEP 2144.05, II).
As laid out above, modified Sun renders obvious optimizing the aspect ratios and contents of primary particles in the central portion and peripheral portion of the secondary particle as taught by Takaki. Therefore, modified Sun renders obvious that the aspect ratio of the primary particles in the central portion of the secondary particle is 1 or more and 2 or less (Takaki: Pg. 5, first full paragraph) and that the aspect ratio of the primary particles in the periphery portion of the secondary particle is 2 or more and 10 or less (Takaki: Pg. 5, first full paragraph).
Using the minimum and maximum aspect ratios disclosed in each region as the minimum and maximum possible average aspect ratios, the range of the difference in aspect ratios between the central part and the surface part can be calculated. This results in a range of 0 (i.e. a central part and surface part which both have an aspect ratio of 2) to 9 (i.e. a central part aspect ratio of 1 and a surface part aspect ratio of 10). This range encompasses the claimed range of 0.3 to 1.0 required by Claim 1, thereby rendering the claimed range obvious since one of ordinary skill in the art would have had a reasonable expectation that selecting the encompassed portion would result in a successful secondary particle capable of use in a positive electrode active material (MPEP 2144.05, I).
The aspect ratios of the primary particles rendered obvious by modified Sun in the surface part (i.e. 2 to 10; Takaki: Pg. 5, first full paragraph) represent the boundaries (i.e. minimum and maximum) for the average aspect ratios of the primary particles in the surface part. This range encompasses the range required by Claim 5 of 1.85 or more to 3.00 or less, thereby rendering the claimed range obvious since one of ordinary skill in the art would have had a reasonable expectation that selecting the encompassed portion would result in a secondary particle capable of use in a positive electrode active material (MPEP 2144.05, I).
The aspect ratios of the primary particles rendered obvious by modified Sun in the central part (i.e. 1 to 2; Takaki: Pg. 5, first full paragraph) represent the boundaries (i.e. minimum and maximum) for the average aspect ratios of the primary particles in the central part. This range encompasses the range required by Claim 6 of 1.66 or more to 2.00 or less, thereby rendering the claimed range obvious since one of ordinary skill in the art would have had a reasonable expectation that selecting the encompassed portion would result in a secondary particle capable of use in a positive electrode active material (MPEP 2144.05, I).
Modified Sun renders obvious that primary particles in the central part have an aspect ratio in the range of 1 to 2 (Takaki: Pg. 5, first full paragraph). A particle with an aspect ratio of 1 is understood to be a primary particle having “a spherical shape”. A particle with an aspect ratio greater than 1 is interpreted as a primary particle with “an elongated shape” (see 112(b) rejection, above). Since modified Sun renders obvious that the primary particles in the central part include particles having an aspect ratio from 1-2 (Takaki: Pg. 5, first full paragraph), and since Sun discloses that the aspect ratio of the primary particles increases from the center of the secondary particle to the surface of the primary particle [0010, 0138], it is understood that both primary particle having “an elongated shape” and primary particles having “a spherical shape” are present in a mixed form in the central part. Here, a “mixed form” is broadly and reasonably interpreted as indicating that both particles exist together within the central part, as supported by the instant specification [instant specification: 0019].
Regarding Claim 2, Sun discloses a lithium secondary battery including a positive electrode active material precursor (reads on lithium composite metal oxide [0029]) comprising a secondary particle that is an aggregate of primary particles [0010, 0020, 0052].
Sun discloses that the primary particles are arranged such that the longitudinal direction of the primary particles is oriented toward the center of the secondary particle [0010, 0012]. At a surface part of the secondary particle, primary particles with an elongated shape (i.e. with an aspect ratio other than 1) are provided (see Fig. 1 [0016, 0056-0057]). Therefore, Sun is interpreted (see 112(b) rejection, above) as disclosing that “in a surface part of the secondary particle, the primary particles that have an elongated shape are radially arranged and aggregated outward from a center of the secondary particle” (see Figs. 1, 3; [0014, 0016, 0056-0057]).
Although Sun does not explicitly disclose that “a content proportion of reference primary particles present in a central part of the secondary particle is lower than a proportion of the reference primary particles present in the surface part”, such a configuration would have been in view of the disclosure of Sun, as laid out below.
Specifically, as defined by Claim 2, a central part and a surface part constitute a cross-sectional image of a secondary particle (see Claim 2: lines 17-25). The central part of the secondary particle of Sun is a part of the secondary particle which is surrounded by an imaginary circle with a radius which is half the radius of the secondary particle (i.e. r = (S/π)0.5/2 as claimed), and the surface part is the remaining area between an edge of the imaginary circle and the edge of a cross-section of the secondary particle (see illustration of Sun Fig. 3, below).
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Illustration of Sun Fig. 3 depicting central part and surface part.
Sun discloses the secondary particle may comprise a first interior wherein the a-axis direction length to c-axis direction length (corresponds to the aspect ratio) of the primary particle is 0.5 to 2.0, and a second interior wherein the a-axis direction length to c-axis direction length (corresponds to the aspect ratio) of the primary particle is 2 to 30 [0016]. A primary particle with an aspect ratio of 2.0 or more corresponds to the reference primary particle of the instant application. Sun further discloses that aspect ratio of the primary particles increases from the center part of the secondary particle to the surface part of the secondary particle [0010, 0138].
Therefore, although Sun does not specifically disclose that “a content proportion of reference primary particles in the central part of the secondary particle is lower than a proportion of reference primary particles in the surface part of the secondary particle”, one of ordinary skill in the art, before the effective filing date of the claimed invention, would have found it obvious to have selected the content of reference primary particles in the central part of the secondary particle to be lower than the content of reference primary particles in the surface part of the secondary particle with a reasonable expectation that such a selection would result in a successful secondary particle for a positive electrode active material wherein the aspect ratio of the primary particles increases from the center to the surface.
Sun does not disclose that a content proportion of reference primary particles in the central part is “20% or more and 50% or less”, or that a content proportion of reference primary particles in the surface part is “30% or more and 90% or less”.
Takaki teaches a lithium-containing transition metal oxide positive electrode active material for a non-aqueous electrolyte secondary battery (Pg. 2, Par. 1; Pg. 6, Par. 6). The positive electrode active material is composed of secondary particles formed by an aggregation of a plurality of primary particles (Pg. 3, Par. 7). Takaki teaches that stress is especially concentrated in the central part of the secondary particles during charging / discharging (Pg. 2, Pars. 6-7; Pg. 16, Par. 7). When primary particles with a high aspect ratio exist in the central portion of the secondary particles, a large distortion is added inside the secondary particles during charge / discharge, and the collapse of the active material becomes more prominent (Pg. 3, Par. 5). To mitigate this effect, Takaki teaches that primary particles having a small aspect ratio (i.e. 1 or more and 2 or less) are arranged in the central part of the secondary particles (Pg. 5, first full paragraph and second to last paragraph; see Fig. 4b) and elongated primary particles with larger aspect ratios (i.e. 2 or more and 10 or less) are located on the peripheral part of the secondary particle (Pg. 5, first full paragraph; see Fig. 4b).
Advantageously, by arranging spherical primary particles in the central part of the secondary battery and elongated primary particles in the outer peripheral portion of the secondary battery, better cycle characteristics can be obtained (Pg. 5, last three paragraphs). Specifically, Takaki teaches that arranging spherical primary particles in the central part of the secondary particle relieves stress inside the particle at the time of charging / discharging (Pg. 5, second to last paragraph) and, by arranging elongated primary particles in the outer peripheral portion of the secondary battery, peeling of the particles can be suppressed, and cycle characteristics are improved (Pg. 5, second full paragraph and second to last paragraph).
Takaki also teaches that when the appearance frequency of the aspect ratio of the elongated primary particles is greater than the aspect ratio of the spherical primary particles, it is possible to increase the contact area of the elongated primary particles with adjacent particles, thereby suppressing the occurrence of cracks at the grain boundary (Pg. 5, second full paragraph). Takaki teaches that this is advantageous for cycle characteristics at low load (Pg. 5, second full paragraph). On the other hand, Takaki teaches that when the appearance frequency of the aspect ratio of spherical primary particles is greater than the aspect ratio of the elongated primary particles, it is possible to shorten the distance for lithium diffusion, and the spherical primary particles are less affected by defects in the crystal plane (Pg. 5, third full paragraph). Takaki teaches that this is advantageous for high rate cycle characteristics (Pg. 5, third full paragraph).
It would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to have optimized the aspect ratios and contents of the primary particles in the central part and surface part of Sun as taught by Takaki, including selecting the central part of the secondary particle to comprise “20% or more and 50% or less” of reference primary particles, and selecting the surface part to comprise “30% or more and 90% or less” of reference primary particles with a reasonable expectation that such a configuration would result in a successful balance between reducing stress in the central part of the secondary particle, thereby preventing collapse, while ensuring sufficient adhesion and increased cycle characteristics, and a further balance between low load cycle characteristics and high rate cycle characteristics (MPEP 2144.05, II).
As laid out above, modified Sun renders obvious optimizing the aspect ratios and contents of primary particles in the central portion and peripheral portion of the secondary particle as taught by Takaki. Therefore, modified Sun renders obvious that the aspect ratio of the primary particles in the central portion of the secondary particle is 1 or more and 2 or less (Takaki: Pg. 5, first full paragraph) and that the aspect ratio of the primary particles in the periphery portion of the secondary particle is 2 or more and 10 or less (Takaki: Pg. 5, first full paragraph).
Using the minimum and maximum aspect ratios disclosed in each region as the minimum and maximum possible average aspect ratios, the range of the difference in aspect ratios between the central part and the surface part can be calculated. This results in a range of 0 (i.e. a central part and surface part both have an aspect ratio of 2) to 9 (i.e. a central part aspect ratio of 1 and a surface part aspect ratio of 10). This range encompasses the claimed range of 0.3 to 1.0 recited in Claim 1, rendering the claimed range obvious since one of ordinary skill in the art, before the effective filing date of the claimed invention, would have had a reasonable expectation that selecting the encompassed portion would result in a successful secondary particle capable of use in a positive electrode active material (MPEP 2144.05, I).
Modified Sun renders obvious that primary particles in the central part have an aspect ratio in the range of 1 to 2 (Takaki: Pg. 5, first full paragraph). A particle with an aspect ratio of 1 is understood to be a primary particle having “a spherical shape”. A particle with an aspect ratio greater than 1 is interpreted as a primary particle with “an elongated shape” (see 112(b) rejection, above). Since modified Sun renders obvious that the primary particles in the central part include particles having an aspect ratio from 1-2 (Takaki: Pg. 5, first full paragraph), and since Sun discloses that the aspect ratio of the primary particles increases from the center of the secondary particle to the surface of the primary particle [0010, 0138], it is understood that both primary particle having “an elongated shape” and primary particles having “a spherical shape” are present in a mixed form in the central part. Here, a “mixed” form is broadly and reasonably interpreted as indicating that both particles exist together within the central part, as supported by the instant specification [instant specification: 0019].
Regarding Claim 3, modified Sun renders obvious all of the limitations as set forth above, including that providing primary particles with a small aspect ratio (i.e. with an aspect ratio of 1 or more and less than 2) in the central part of the secondary particle reduces stress inside the particle at the time of charging / discharging and that providing elongated primary particles (i.e. with an aspect ratio of 2 or more and 10 or less) in the peripheral part of the secondary particle results in increased contact between primary particles, suppressed peeling of the particles, and improved cycle characteristics (see rejection of Claim 2, above). Modified Sun further teaches that an increased content of elongated particles (reference primary particles) is advantageous for cycle characteristics at low load (Takaki: Pg. 5, second full paragraph), while an increased content of primary particles with a small aspect ratio is advantageous for high rate cycle characteristics (Takaki: Pg. 5, third full paragraph).
It would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to have optimized the aspect ratios and contents of the primary particles in the central part and surface part of Sun, including forming a secondary particle with a central part comprising 20% or more and 40% or less of reference primary particles and a surface part comprising 40% or more and 90% or less of reference primary particles, with a reasonable expectation that such a configuration would result in a successful balance between reducing stress in the central part of the secondary particle, thereby preventing collapse, while ensuring sufficient adhesion and increased cycle characteristics, and a further balance between low load cycle characteristics and high rate cycle characteristics (MPEP 2144.05, II).
Regarding Claim 7, modified Sun teaches the product of Claim 1. As described in Claim 1, above, Sun teaches that the secondary particles include a first interior and a second interior [0016]. The first interior includes the central part and the second interior includes the surface part. Sun teaches that the molar ratio of elements within the central part and the surface part can differ [0030].
Although Sun does not explicitly teach that the central part and the surface part are represented by Formula (I) as recited in instant Claim 7 (see below), Sun does teach the compositions of the first interior and second interior part of the secondary particle [0029].
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Formula (I) of instant Claim 7.
As described in detail below, the compositions disclosed by Sun fall within/overlap Formula (I), thereby rendering Formula(I) obvious.
Regarding the central part of the secondary particle, Sun teaches that the molar ratio of elements within the first interior can be expressed by the following empirical formula [0029]:
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Empirical Formula for first interior of secondary particle.
Regarding the content of Li, in the empirical formula for the first interior part of the secondary particle, the molar ratio of Li is represented by δ, wherein 1.0≤δ≤1.2 [0029]. This is within the claimed total moles of Li of 0.9 to 1.2 as recited in Claim 7 (i.e. 1+x, wherein -0.1≤x≤0.2).
Regarding the content of Co, the molar ratio of Co in the first interior part of the secondary particle is represented by a, wherein 0.00≤a≤0.40 [0029]. A molar ratio of 0 to 0.4 falls within the claimed range of 0 to 0.5 as recited in Claim 7.
Regarding the content of Mn, the molar ratio of Mn in the first interior part of the secondary particle is represented by b, wherein 0.00≤b≤0.35 [0029]. A molar ratio of 0 to 0.35 falls within the recited range of 0 to 0.5 as recited in Claim 7.
Regarding the content of “M”, the molar ratio of “M” in the first interior part of the secondary particle is represented by c, wherein 0.00≤c≤0.05 [0029]. A molar ratio of 0 to 0.05 falls within the claimed ratio of 0 to 0.1.
Furthermore, Sun discloses that “M” can include at least one element from the group consisting of Al, Mg, Fe, Cr, V, Ti, Mo, Sc, Ce, and La [0029]. Of the ten elements listed, nine elements (Al, Mg, Fe, Cr, V, Ti, Mo, Sc, La) are recited as possible identities for the metal “M” of the instant application. Therefore, one of ordinary skill in the art would have had a reasonable chance of selecting a metal “M” from the prior art which reads on the identity of “M” of the instant application. The use of a metal “M” which is significantly overlapped in scope with the prior art would have a reasonable expectation of resulting in a successful positive electrode active material.
Regarding the content of Ni, Sun also teaches that Ni is present in the composition of the first interior part of the secondary particle. Therefore this satisfies the recited limitation of Claim 7 wherein the composition of Ni is (1-y-z-w).
Regarding the surface part of the secondary particle, Sun discloses that the molar ratio of elements within the second interior part can be expressed by the following empirical formula [0029]:
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Empirical Formula for second interior part of secondary particle.
Regarding the content of Li, in the empirical formula for the second interior part of the secondary particle, the molar ratio of Li is represented by δ, wherein 1.0≤δ≤1.2 [0029]. This is within the claimed total moles of Li of 0.9 to 1.2 as recited in Claim 7 (i.e. 1+x, wherein -0.1≤x≤0.2).
Regarding the content of Co, the molar ratio of Co in the second interior part of the secondary particle is represented by x, wherein 0.07≤x≤0.3 [0029]. A molar ratio of 0.07 to 0.3 falls within the claimed range of 0 to 0.5 as recited in Claim 7.
Regarding the content of Mn, the molar ratio of Mn in the second interior part of the secondary particle is represented by y, wherein 0.2≤y≤0.5 [0029]. A molar ratio of 0.2 to 0.5 falls within the claimed range of 0 to 0.5 as recited in Claim 7.
Regarding the content of “M”, the molar ratio of “M” in the second interior part of the secondary particle is represented by z, wherein 0.00≤z≤0.1 [0029]. A molar ratio of 0 to 0.1 corresponds to the claimed range of 0 to 0.1 as recited in Claim 7.
Furthermore, Sun discloses that “M” can include at least one element from the group consisting of Al, Mg, Fe, Cr, V, Ti, Mo, Sc, Ce, and La [0029]. Of the ten elements listed, nine elements (Al, Mg, Fe, Cr, V, Ti, Mo, Sc, La) are recited as possible identities for the metal “M” of the instant application. Therefore, one of ordinary skill in the art would have had a reasonable chance of selecting a metal “M” from the prior art which reads on the identity of “M” of the instant application. The use of a metal “M” which is significantly overlapped in scope with the prior art would have a reasonable expectation of resulting in a successful positive electrode active material.
Regarding the content of Ni, Sun also teaches that Ni is present in the composition of the second interior part of the secondary particle, therefore this satisfies the recited limitation of Claim 7 wherein the composition of Ni is (1-y-z-w).
Since each of the first interior part and the second interior part individually fall within the claimed molar compositions taught in Formula (I) of the instant application, the secondary particle of the prior art necessarily reads on the claimed Formula (I).
Regarding Claim 8, modified Sun teaches the product of Claim 7. Sun discloses that the composition of Li in both the central and surface parts can range from 1.0 to 1.2 moles [0029], which corresponds to an Li value (i.e. Li1 + Lix) within the claimed range.
Regarding Claim 9, modified Sun renders obvious all of the limitations as set forth, above. Sun further discloses that the positive electrode active material precursor (reads on lithium composite metal oxide; [0029]) can be applied to a positive electrode active material for a lithium secondary battery [0009, 0020, 0029]. Therefore, one of ordinary skill in the art, before the effective filing date of the claimed invention, would have found it obvious to have provided “a positive electrode active material for a lithium secondary battery, comprising: the lithium composite metal oxide according to claim 1” with a reasonable expectation that such a configuration would result in a successful positive electrode active material.
Regarding Claims 10 and 11, modified Sun renders obvious all of the limitation as set forth above. Although Sun does not explicitly disclose that the positive electrode active material is used to form a positive electrode, Sun discloses a battery which is formed using the positive electrode active material particle powders (Table 13; [0135]). Therefore it would have been obvious to have used the positive electrode active material to form a positive electrode (i.e. by application of the positive electrode active material to a current collector) in order to form a functional battery. Sun also discloses that the positive electrode active material can be used to form a lithium secondary battery [0009, 0034, 0135]. The use of a positive electrode comprising the previously disclosed positive electrode active material to form a lithium secondary battery corresponds to the recited limitations of Claims 10 and 11.
Regarding Claims 12 and 13, modified Sun renders all of the limitations as set forth above. Sun discloses that the primary particles have a longest diameter x (corresponds to a-axis) and a maximum diameter y (corresponds to c-axis) perpendicular to the longest diameter x [0015-0016]. Sun discloses that the secondary particle has an average particle diameter in a range of 4 to 20 µm [0010]. This corresponds to a radius of 2 to 10 µm. Sun further discloses that the a-axis direction length of the primary particle may be in the range of 0.01 to 0.95 of the secondary particle radius [0012, 0013].
Therefore, although modified Sun does not explicitly disclose that an average value of the maximum diameter y perpendicular to the longest diameter x of the primary particles in the central part of the cross-sectional image of the secondary particle is between 0.20 µm and 0.60 µm as required by Claim 12 or that an average value of the maximum diameter y perpendicular to the longest diameter x of the primary particles in the surface part of the cross-sectional image of the secondary particle is between 0.20 µm and 1.00 µm as required by Claim 12, using the radius of the secondary particle and the length of the a-axis in relation to the radius of the secondary particle, the a-axis length of a primary particle is calculated as 0.02 µm to 9.5 µm. Then using the aspect ratio of the primary particles in the central part and surface part (see Takaki: Pg. 5, first full paragraph), the diameter of the c-axis length (i.e. r2 in Fig. 1; [0012]) is calculated.
In regards to Claim 12, the c-axis diameter of the central part is 0.01 µm (aspect ratio of 2 and a-axis length of 0.02 µm) to 9.5 µm (aspect ratio of 1 and a-axis length of 9.5 µm). The c-axis corresponds to the y diameter of the instant application. The range recited in the prior art overlaps the range recited in the instant application. It would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to have selected any portion of the range recited in the prior art, including selecting the average maximum diameter of the c-axis of the primary particles of the central part to be between 0.20 µm and 0.60 µm with a reasonable expectation that such an average diameter would result in a successful secondary particle for a positive electrode active material (MPEP 2144.05, I).
In regards to Claim 13, the c-axis diameter of the surface part is 0.002 µm (aspect ratio of 10 and a-axis length of 0.02 µm) to 4.75 µm (aspect ratio of 2 and a-axis length of 9.5 µm). The c-axis corresponds to the y diameter of the instant application. The range recited in the prior art overlaps the range recited in the instant application. It would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to have selected any portion of the range recited in the prior art, including selecting the average maximum diameter of the c-axis of the primary particles in the surface part to be between 0.20 µm and 1.00 µm with a reasonable expectation that such an average diameter would result in a successful secondary particle for a positive electrode active material (MPEP 2144.05, I).
Assuming, for the sake of argument, that selecting the average maximum diameter y (i.e. c-axis) of the primary particles of the central part to be between 0.20 µm and 0.60 µm and selecting the average maximum diameter y (i.e. c-axis) of the primary particles in the surface part to be between 0.20 µm and 1.00 µm is somehow persuasively shown to be unreasonable, the following rejection applies:
This is an alternative rejection of Claims 12 and 13. Modified Sun renders obvious the product of Claim 1. Modified Sun does not explicitly disclose that an average value of the maximum diameter y perpendicular to the longest diameter x of the primary particles in the central part of the cross-sectional image of the secondary particle is between 0.20 µm and 0.60 µm or that an average value of the maximum diameter y perpendicular to the longest diameter x of the primary particles in the surface part of the cross-sectional image of the secondary particle is between 0.20 µm and 1.00 µm.
Takaki teaches that the average particle size of the spherical primary particles (with a smaller aspect ratio) is 0.3 µm or more and 4 µm or less and the average particle size of the elongated primary particles (reference primary particles) is 1.5 µm or more and 13 µm or less (Pg. 7, Par.6). The average particle size corresponds to the longest diameter, x, of the instant application.
Advantageously, Takaki teaches that in the spherical primary particles, when the particle diameter is less than 2 µm, bonding strength is deteriorated (Pg. 7, Par. 7). In contrast, if the particle diameter is larger than 14 µm, cycle characteristics are deteriorated (Pg. 7, Par. 7). In the elongated primary particles (reference primary particles), when the particle diameter is less than 1 µm, interface resistance increased (Pg. 7, Par. 8 – Pg. 8, Par. 1). In contrast, if the particle diameter is larger than 26 µm, cycle characteristics are deteriorated (Pg. 7, Par. 8 – Pg. 8, Par. 1).
As discussed in the rejection of Claim 1, above, Takaki teaches that the aspect ratio of the spherical primary particles can range from 1 or more and 2 or less and the aspect ratio of the elongated primary particles (reference primary particles) can range from 2 or more and 10 or less (Takaki: Pg. 5, first full paragraph).
Therefore, in seeking to balance between bonding strength and cycle characteristics in the primary particles of the central part and in seeking to balance between interface resistance and cycle characteristics in the primary particles of the surface part, and taking into consideration the ranges of aspect ratios of primary particles of the central and surface parts, it would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to have optimized the particle diameter (longest diameter x) and aspect ratios of the primary particles in both the central and surface part (MPEP 2144.05, II). By optimizing the particle diameter and the aspect ratio, the maximum diameter y is thereby optimized. One of ordinary skill in the art would have had a reasonable expectation that providing primary particles in the central part of the cross-sectional image of the secondary particle with an average value of the maximum diameter y between 0.20 µm and 0.60 µm and providing primary particles in the surface part of the cross-sectional image of the secondary particle with an average value of the maximum diameter y between 0.20 µm and 1.00 µm would result in a successful secondary particle capable of use in a positive electrode active material. Regarding Claim 14, modified Sun renders obvious all of the limitations as set forth above, including that the content of Co in the first interior part can range from 0.00≤a≤0.40 and that the content of Co in the second interior part can range from 0.07≤x≤0.3 [0029]. Notably, while Sun desires a high Ni content in the first interior part, and a low Ni content and high Mn content in the second interior part [0059-0060], Sun does not mention limitations regarding the content of Co, and therefore does not teach away from including very low concentrations of Co, or no Co in the particle. Additionally, the Examiner notes that the scope of the claimed content of Co (i.e. “y = 0”) in light of the instant specification appears to include values slightly larger than zero. Specifically, the Examiner notes that the instant specification only includes one significant digit when denoting the molar ratios of the metals of the lithium composite metal oxide [instant specification: 0006, 0035]. In contrast, the prior art Sun uses two significant digits [Sun: 0029, 0059]. Therefore, it would appear that any value of Co rendered obvious by Sun that rounds down to zero when only considering one significant digit would read on the claimed content of Co. Since Sun discloses that the content of Co is an average of the content of Co in the interior portion (which has a lower limit of 0) and the content of Co in the second interior portion (which has a lower limit of 0.07) [0029, 0059], the average content of Co reasonably includes values which would round down to 0 (e.g. 0.035). Therefore, although modified Sun does not explicitly teach that there is no Co in the lithium composite metal oxide (i.e. wherein y = 0), the content of Co disclosed in the prior art is so close to the claimed content of Co that one of ordinary skill in the art, before the effective filing date of the claimed invention, would have expected substantially the same properties between a lithium composite metal oxide wherein the content of Co ranges from 0<Co<0.07 and a lithium composite metal oxide wherein the value of Co is 0, absent persuasive argument or evidence to the contrary (MPEP 2144.05, I).
Assuming, arguendo, that Applicant is able to show by means of evidence or persuasively argue that a lithium composite metal oxide comprising a molar ratio of Co of 0<Co<0.7 does result in distinct properties from a lithium composite metal oxide without any Co, including no cobalt in the lithium metal oxide would have been obvious over the teachings of Takaki.
Specifically, Takaki teaches a similar lithium composite metal oxide (Pg. 3 – Pg. 4, second full paragraph; Pg. 5, last three paragraphs). Takaki teaches that the lithium composite metal oxide can be represented by the formula: Li1+xNiaMnbCocO2+d, and that 0≤c/(a+b)<0.6 (see last two full paragraphs of Pg. 6; see also [0039] of original document). Takaki teaches that the proportion of cobalt is reduced to reduce the material cost of the positive electrode active material (Pg. 6, last full paragraph). The content of cobalt taught by Takaki includes no cobalt (i.e. in order for c/(a+b) to equal 0 in, 0≤c/(a+b)<0.6, c must equal 0).
Since Sun contemplates using a very small molar content of cobalt (i.e. a lower limit of 0<Co<0.07), and Takaki teaches that no cobalt can be successfully used in a lithium composite metal oxide, it would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to have selected the lithium composite metal oxide to comprise no cobalt with a reasonable expectation that such a configuration would result in a successful lithium composite metal oxide with a reduced material cost.
Claim(s) 15 is/are rejected under 35 U.S.C. 103 as being unpatentable over Sun et al. (US-20140158932-A1) in view of Takaki et al. (WO-2016002158-A1; see English translation provided 10/18/2024 for citations) as applied to 7, above, and in further view of Kwon et al. (US-20180108940-A1; cited in IDS filed 09/17/2020).
Regarding Claim 15, modified Sun renders obvious all of the limitations as set forth, above, including that “M” in the lithium composite metal oxide material can include at least one element from the group consisting of Al, Mg, Fe, Cr, V, Ti, Mo, Sc, Ce, and La, and that the molar content of “M” in the lithium composite metal oxide can range from 0 to 0.1 [0029]. The molar ratio of “M” disclosed by Sun (i.e. 0 to 0.1) corresponds to the claimed range (i.e. “0<w≤0.1).
Sun does not teach that M represents one or more elements selected from the group consisting of Ca, Sr, Ba, Zn, B, Ga, Zr, Ge, Cu, W, Y, Nb, Ta, Tc, Ru, Rh, Pd, Ag, Cd, In, and Sn.
Kwon teaches a similar lithium composite metal oxide [0013, 0017, 0033-0038]. Kwon teaches that the lithium composite metal oxide is represented by the chemical Formula Lia1M1x1M2y1M3z1M4w1O2+∂1, wherein M1, M2 and M3 each independently include at least one of Ni, Co, and Mn [0037]. Kwon further teaches that M4 includes at least one element selected from the group consisting of Fe, Na, Mg, Ca, Ti, V, Cr, Cu, Zn, Ge, Sr, Ag, Ba, Zr, Nb, Mo, Al, Ga, and B [0037]. The Examiner notes that this establishes Ca, Cu, Zn, Ge, Sr, Ag, Ba, Zr, Nb, Ga, and B as substitutable alternatives to Fe, Mg, Ti, V, Cr, Mo and Al which can be successfully used in a lithium composite metal oxide material.
It would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to have included Ca, Cu, Zn, Ge, Sr, Ag, Ba, Zr, Nb, Ga and B in the lithium composite metal oxide instead of / in addition to the elements disclosed by Sun with a reasonable expectation that the inclusion of such elements would result in a successful lithium metal oxide (MPEP 2144.06 I-II; MPEP 2144.07). The elements Ca, Cu, Zn, Ge, Sr, Ag, Ba, Zr, Nb, Ga and B are all within the claimed list of elements of Claim 15.
Response to Arguments
Applicant's arguments filed 01/13/2026 have been fully considered but they are not persuasive. Applicant has argued that amended Claim 1 is not rendered obvious by Sun in view of Takaki, and that the cited references neither teach nor suggest that “elongated primary particles and spherical primary particles are present together in a mixed form in the central part of a secondary particle” (Remarks, Pg. 6). Applicant submits that Sun implies “a gradual change of particle shapes by region”, rather than a configuration in which elongated and spherical primary particles intentionally coexist within the same central region (Remarks, Pg. 7). Applicant has further argued that Takaki also fails to teach this limitation (Remarks, Pg. 7).
The Examiner has carefully considered this argument, but respectfully does not find it persuasive. The Examiner notes that Claims 1 and 2 previously recited “the content proportion of the reference primary particles present in the central part of the secondary particle is 20% or more and 50% or less”. Since Sun and Takaki both indicate that the center part of the secondary particle comprises primary particles with a smaller aspect ratio ([Sun: 0015-0016]; Takaki: Pg. 5, last three paragraphs), including primary particles with an aspect ratio of 1 ([Sun: 0016]; Takaki: Pg. 5, first full paragraph), it is understood that the central part comprises 50% to 80% of primary particles which are not “reference primary particles”, including spherical primary particles.
Additionally, the Examiner notes that “an elongated shape” is broadly and reasonably interpreted, in light of the instant specification [instant specification: 0012], as a referring to any particle which is not spherical. Sun and Takaki reasonably suggest particles with an aspect ratio slightly larger than 1 (e.g. 1.1) in the central region. Such particles are interpreted as reading on particles with “an elongated shape” as required by Claims 1 and 2.
Conclusion
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/D.C.N./Examiner, Art Unit 1751
/JONATHAN G LEONG/Supervisory Patent Examiner, Art Unit 1751 4/14/2026
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