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
This is a final office action in response to Applicant’s remarks filed on 05/04/2026. No claims are currently amended. Claims 10, 12, and 17-20 remain withdrawn. Claims 1-2, 5, 13-16, and 22-23 are presented for examination.
The 35 U.S.C. 103 rejections in the previous office action are maintained.
Response to Arguments
Applicant's arguments filed 05/04/2026 have been fully considered but they are not persuasive.
Applicant argues (p. 2) claim 1 is not rendered obvious by Nagao because the b2 range of 0.01-0.25 µm is not taught or suggested by Nagao. Nagao teaches the average b2 is 0.20-1.00 µm ([0102]), which is nearly mutually exclusive with the claimed range of 0.01-0.25 µm for 90% or greater of the second primary particles because Nagao’s lower limit of 0.20 µm is already close to the claimed upper limit of 0.25 µm. Specifying b2 within the claimed range enables the second primary particles to have a sufficiently narrow cross-section to align uniformly in the radial direction of the secondary particle as disclosed in the specification ([0087] and Figs. 44-45).
Examiner respectfully disagrees. Claim 1 requires b2 in a range of 0.01 µm to 0.8 µm rather than 0.01 µm to 0.25 µm and the cited portion of the specification states that uniform orientation of the primary particles occurs over the broader range, which significantly overlaps with the range disclosed by Nagao. The narrow range argued by Applicant also overlaps with the range by Nagao and therefore would still be considered obvious over Nagao absent any showing of unexpected results or criticality [MPEP § 2144.05(I)].
Applicant argues (p. 3) Nagao does not teach the specific combination of M2 species (Ta, W, Mo, Nb, or Sb) and concentration (0.05-2 mol%) required by claim 1. The instant specification (Figures 32-33) demonstrates the specific M2 species at the claimed concentration suppress Li/Ni cation mixing as evidenced by I(003)/I(104) = 2-2.2 and Rct = 10-30 Ω.
Examiner respectfully disagrees. The combination of M2 species and concentration is obvious over Nagao, who teaches the claimed species in an overlapping amount ([0115]). Applicant’s arguments do not provide adequate evidence of nonobviousness. The cited figures merely show that the presence of any dopant appears to improve discharge capacity and capacity retention over undoped materials (FIG. 32), although not over the entire claimed range, and any amount of the claimed dopants reduces Rct (FIG. 33). It is unclear whether the alleged results are due to the specific dopant species or the mere presence of a dopant.
Applicant argues (p. 3) Nagao does not teach or suggest the specific combination of b2 ≤ 0.25 µm together with M2 = Ta/W/Mo/Nb/Sb at 0.05 – 2 mol%. The synergistic effect of this combination – suppressing microcrack formation while maintaining structural integrity – is uniquely demonstrated in the specification and is not inherent to or predictable from Nagao’s disclosure.
Examiner respectfully disagrees. As discussed above, the combination is obvious over Nagao, who teaches overlapping ranges for b2 and dopant concentration and names Ta, W, Mo, and Nb as dopant species. Applicant does not clearly and specifically point out why the claimed combination is nonobvious over Nagao. If Applicant is arguing unexpected results of the claimed dopant species and amounts, the showing of evidence must be commensurate with the independent claim. The results in the instant figures appear to require, at minimum, specific active material compositions and preparation methods.
Applicant argues (pp. 3-4) the physical properties of claims 2, 13, and 14 do not necessarily arise from Nagao’s structure because the claimed structure differs from Nagao in at least the b2 range and the specific M2 species and content. Specifically, regarding claim 2, instant figures 15 and 37 show that undoped or differently-doped materials do not achieve microcrack ≤ 13% after 100 cycles. Nagao, which neither discloses the claimed b2 range nor measures microcrack area, cannot inherently possess this property. Regarding claim 13, instant figure 32 demonstrates that dopant type and content significantly effect Rct. Without the specific M2 identity and content of claim 1, the same Rct range is not necessarily achieved. Regarding claim 14, specification figures 13 and 25 show the ratio I(003)/I(104) is sensitive to dopant species. Nagao does not disclose or measure this property. Accordingly, the Examiner has not established inherency theory for claims 2, 13, and 14 because the claimed structure differs from Nagao in at least the b2 range and the specific M2 species and content.
Examiner respectfully disagrees. As discussed above, Nagao teaches overlapping ranges for b2 and dopant concentration and names Ta, W, Mo, and Nb as dopant species. The claimed structure is therefore obvious over Nagao and the properties in claims 2, 13, and 14 are presumed to be inherent to the structure of Nagao. The figures cited by Applicant do not demonstrate why the microcrack area fraction, Rct, and XRD ratios would not be present in the material rendered obvious by Nagao if it were tested in the same manner. Specifically, figures 15 and 37 demonstrate that the presence of a dopant reduces microcrack area fraction, and Nagao teaches a dopant. Figure 32 is not related to Rct, but adjacent figure 33 demonstrates that the presence of any dopant reduces Rct to a value within the claimed range. Finally, figure 25 shows the ratio I(003)/I(104) is sensitive to calcination temperature rather than dopant species.
Applicant argues (p. 5) Jun discloses b1/a1 = 5, entirely outside the range of b1/a1 = 1-3.5 required by claim 1. As expressly disclosed in the specification at paragraphs [0088]-[0089], when b1/a1 is within the range of 1 to 3.5, the first and second primary particles have comparable aspect ratios, enabling the first primary particles to guide the second primary particles to align uniformly along the radial direction, thereby improving structural stability of the secondary particle. This cooperative alignment is not achieved at Jun's b1/a1 = 5. This is a structurally meaningful feature that achieves a distinct functional result not a trivial size optimization.
Examiner respectfully disagrees. The cited portion of the specification does not demonstrate the criticality of the claimed range, as both Jun ([P5049 C1 ll. 15-21, Figs.1(e),(f)]; [P5049 C2 ll. 3-9]) and Kwon ([0043]) teach the described uniform alignment.
Applicant argues (pp. 5-6) the prior art does not teach or suggest the specific combination of particle geometry, dopant content, and nickel content required by claim 1. Jun’s b1/a1 is outside the claimed range. Weigel’s teaching of Ta in a different NCM system does not suggest combining this specific dopant with the exact particle geometry of claim 1 with a reasonable expectation of achieving microcrack ≤ 13%. Undoped materials like the structure of Jun/Kwon do not achieve this result. Therefore, the Examiner’s combination relies on impermissible hindsight.
Examiner respectfully disagrees. The b1/a1 is obvious over Jun in view of Kwon as discussed above. In response to applicant's argument that none of the cited references teach all of the limitations of claim 1, the test for obviousness is not whether the features of a secondary reference may be bodily incorporated into the structure of the primary reference; nor is it that the claimed invention must be expressly suggested in any one or all of the references. Rather, the test is what the combined teachings of the references would have suggested to those of ordinary skill in the art. See In re Keller, 642 F.2d 413, 208 USPQ 871 (CCPA 1981). In this case, a skilled artisan would find it obvious to add a Ta as a dopant to the material of Jun and Kwon with a reasonable expectation of improving battery performance as taught by Weigel.
In response to applicant's argument that one of ordinary skill in the art would not have expected an improvement in microcrack area fraction, the fact that the inventor has recognized another advantage which would flow naturally from following the suggestion of the prior art cannot be the basis for patentability when the differences would otherwise be obvious. See Ex parte Obiaya, 227 USPQ 58, 60 (Bd. Pat. App. & Inter. 1985).
In response to applicant's argument that the examiner's conclusion of obviousness is based upon improper hindsight reasoning, it must be recognized that any judgment on obviousness is in a sense necessarily a reconstruction based upon hindsight reasoning. But so long as it takes into account only knowledge which was within the level of ordinary skill at the time the claimed invention was made, and does not include knowledge gleaned only from the applicant's disclosure, such a reconstruction is proper. See In re McLaughlin, 443 F.2d 1392, 170 USPQ 209 (CCPA 1971).
Applicant argues (pp. 6-7) the I(003)/I(104) = 2-2.2 limitation of claim 14 reflects the combined effect of specific dopant and specific particle geometry. Zhong teaches only Co-content optimization for cation mixing suppression, without any such dopant and therefore the combination of Jun, Kwon, Weigel, and Zhong does not render claim 14 obvious.
Examiner respectfully disagrees. Applicant does not provide evidence that one of ordinary skill in the art would not arrive at the claimed XRD values by optimizing the Co content of the Jun/Kwon/Weigel material as taught by Zhong and Kwon. Furthermore, the specification does not support the argument that the XRD spectrum can only be obtained with the claimed dopant content and particle geometry. FIG. 25 and [0185]-[0186], for example, show that the XRD spectrum depends on at least calcination temperature.
Applicant argues (pp. 7-8) claims 15-16 are patentably distinct from the prior art because Nagao adds the dopant differently and Xie uses Mg as a dopant rather than the claimed Ta, W, Mo, Nb, or Sb and provides no suggestion to substitute the claimed dopants for Mg. There is no reasonable expectation that doing so would yield the structural and electrochemical properties of the claimed invention.
Examiner respectfully disagrees. The rejections of claims 15 and 16 rely on Xie to teach “the positive electrode active material is prepared by mixing a composite metal oxide containing the metal, the doping element, and a lithium compound containing the lithium with each other” rather than the selection of a particular dopant. Applicant’s arguments do not clearly point out why it would not be obvious to modify the active material of either Nagao or Jun/Kwon/Weigel to be formed in this manner as taught by Xie and do not clearly demonstrate any specific structure imparted by this product-by-process limitation.
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.
Claims 1-2, 5, 13-14, and 22-23 are rejected under 35 U.S.C. 103 as being unpatentable over Nagao (US 2021/0017039 A1; priority to JP-2018-056857, filed 03/23/2018).
Regarding claim 1, Nagao discloses a positive electrode active material ([0171]) comprising secondary particles (20, FIG. 2, [0065]), wherein each secondary particle (20) is an agglomerate of a plurality of primary particles (23a and 22a, FIG. 2, [0065]), wherein the primary particles (23a and 22a) include: first primary particles (primary particles 23a in the central part, FIG. 2, [0065]) constituting a core portion (central part 23, FIG. 2, [0065]) of each secondary particle (20); and second primary particles (primary particles 22a in the surface part, FIG. 2, [0065]) constituting a shell portion (surface part 22, FIG. 2, [0065]) of each secondary particle (20), wherein the shell portion (22) surrounds the core portion (23) (FIG. 2, [0065]),
wherein an average length of a long side of a longitudinal cross-section of each first primary particle (23a) is defined as a1, and an average length of a short side thereof perpendicular to the long side is defined as a2, wherein a1 is equal to or larger than a2 (average value of the aspect ratio of the primary particles present in the central part is preferably 1.66 or more, [0092]; aspect ratio of each primary particle is calculated as the length x of the longest diameter to the length y of the maximum diameter perpendicular to the longest diameter, FIG. 3, [0067]),
wherein an average length of a long side of a longitudinal cross-section of each second primary particle (22a) is defined as b1, and an average length of a short side thereof perpendicular to the long side is defined as b2, wherein b1 is larger than b2 (average value of the aspect ratio of the primary particles present in the surface part is preferably 1.90 or more, [0088]; aspect ratio of each primary particle is calculated as the length x of the longest diameter to the length y of the maximum diameter perpendicular to the longest diameter, FIG. 3, [0067]),
wherein each of 90% or greater of the second primary particles has a b1/b2 in a range of 2 to 15 (average value of the aspect ratio of the primary particles present in the surface part is more preferably 2.10 or more and 2.50 or less, [0088]; aspect ratio of each primary particle is calculated as the length x of the longest diameter to the length y of the maximum diameter perpendicular to the longest diameter, FIG. 3, [0067]; the phrase “average value” implies 100% of the second primary particles), b1 in a range of 0.1 µm to 2.0 µm (average value of longest diameters x of the primary particles in the surface part is 0.32 µm to 1.50 µm, [0098]; the phrase “average value” implies 100% of the second primary particles), and b2 in a range of 0.01 µm to 0.8 µm (average value of maximum diameters y perpendicular to longest diameters of the primary particles in the surface part is 0.20 µm to 1.00 µm [0102], overlapping the claimed range and thereby establishing a prima facie case of obviousness [MPEP § 2144.05(I)]; the phrase “average value” implies 100% of the second primary particles),
wherein an average length of a2 of each of 90% or greater of the first primary particles is in a range of 0.01 µm to 0.8 µm (average value of maximum diameters y perpendicular to longest diameters of the primary particles in the central part is 0.20 µm to 0.60 µm, [0110]; the phrase “average value” implies 100% of the second primary particles),
wherein a ratio b1/a1 is in a range of 1 to 3.5, and a ratio b2/a2 is in a range of 0.8 to 1.5 (average value of longest diameters x of the primary particles in the surface part, or b1, is 0.32 µm to 1.50 µm [0098], average value of maximum diameters y perpendicular to longest diameters of the primary particles in the surface part, or b2, is 0.20 µm to 1.00 µm [0102], average value of longest diameters x of the primary particles in the central part, or a1, is 0.32 µm to 1.00 µm [0106], average value of maximum diameters y perpendicular to longest diameters of the primary particles in the central part, or a2, is 0.20 µm to 0.60 µm, [0110]; these values yield overlapping ranges of b1/a1 in a range of 0.32 to 4.7 and b2/a2 in a range of 0.33 to 5; in Example 1 b1/a1 is 1.22 and b2/a2 is 0.98, see Table 1 on p. 20-21).
wherein each primary particle contains nickel (Ni), M1 and M2, wherein M1 includes at least one of manganese (Mn), cobalt (Co), or a combination thereof ([0114]), wherein a content of nickel (Ni) is greater than or equal to 80 mol% (Nickel content is 1-y-z-w, [0114]-[0115]; preferred values of y, z, and w are 0.05 ≤ y ≤ 0.39 [0119], 0.01 ≤ z ≤ 0.39 [0122], and 0 < w ≤ 0.09 [0125] so the preferred Nickel content is between 13 mol% and 0.94 mol%, overlapping the claimed range; Nickel content is 84% in first example [0269]),
wherein a content of M2, as a doping element, is in a range of 0.05 mol% to 2 mol% (overlapping range of 0 ≤ w ≤ 0.1, [0115], is equivalent to 0 mol% to 0.1 mol% and establishes a prima facie case of obviousness [MPEP § 2144.05(I)]), and wherein M2 comprises tantalum (Ta), tungsten (W), molybdenum (Mo), niobium (Nb), or a combination thereof ([0115]).
Regarding claim 2, Nagao teaches the positive electrode active material of claim 1. Nagao does not teach wherein after a battery including the positive electrode active material has been subjected to multiple charging/discharging cycles, a micro crack including a space between the first primary particle or a space between the second primary particles occurs in the secondary particle, wherein when the battery including the positive electrode active material has been subjected to 100 charging/discharging cycles where each cycle includes a charging of the battery to 4.3V under 0.5C constant current and a discharging of the battery to 2.7V under 0.5C constant current, and then the battery is discharged to 0.27V, an area of the micro crack is equal to or smaller than 13% of an entire area of a longitudinal cross section of the secondary particle.
However, because this claim is directed toward a property of the material and there is no distinction between the instant claims and the prior art, this feature is considered to be inherently present in the teachings of Nagao. Where the claimed and prior art products are identical or substantially identical in structure or composition, or are produced by identical or substantially identical processes, a prima facie case of either anticipation or obviousness has been established [MPEP § 2112.01].
Regarding claim 5, Nagao teaches the positive electrode active material of claim 1, wherein at least some of the second primary particles (22a, FIG. 2) has a rod shape having an aspect ratio (elongated shape, FIG. 2, [0066]) wherein each of 50% or greater of the second primary particles (22a) having the rod shape is oriented toward a surface of the secondary particle (primary particles that have an elongated shape are radially arranged, FIG. 2, [0066]).
Regarding claim 13, Nagao teaches the positive electrode active material of claim 1. Nagao does not teach wherein after a battery including the positive electrode active material has been subjected to 100 charging/discharging cycles where each cycle includes a charging of the battery to 4.3V under 0.5C constant current and a discharging of the battery to 2.7V under 0.5C constant current, Rct of the positive electrode active material is in a range of 10Ω to 30Ω.
However, because this claim is directed toward a property of the material and there is no distinction between the instant claims and the prior art, this feature is considered to be inherently present in the teachings of Nagao. Where the claimed and prior art products are identical or substantially identical in structure or composition, or are produced by identical or substantially identical processes, a prima facie case of either anticipation or obviousness has been established [MPEP § 2112.01].
Regarding claim 14, Nagao teaches the positive electrode active material of claim 1. Nagao does not teach wherein when the positive electrode active material is subjected to X-ray diffraction analysis using a device with 45kV and 40mA output and a Cu Ka beam source at a scan rate of 1 degree per minute and at a step size spacing of 0.0131, a ratio of an intensity of a peak 003 to an intensity of a peak 104 is in a range of 2 to 2.2.
However, because this claim is directed toward a property of the material and there is no distinction between the instant claims and the prior art, this feature is considered to be inherently present in the teachings of Nagao. Where the claimed and prior art products are identical or substantially identical in structure or composition, or are produced by identical or substantially identical processes, a prima facie case of either anticipation or obviousness has been established [MPEP § 2112.01].
Regarding claim 22, Nagao teaches the positive electrode active material of claim 1, wherein M2 comprises tungsten (W), molybdenum (Mo), niobium (Nb), or a combination thereof.
Regarding claim 23, Nagao teaches the positive electrode active material of claim positive, wherein the content of M2 is in a range of 0.05 mol% to 1.2 mol% (overlapping range of preferably 0 < w ≤ 0.09, [0125], is equivalent to more than 0 mol% to 0.09 mol% and establishes a prima facie case of obviousness [MPEP § 2144.05(I)]).
Claims 15 and 16 are rejected under 35 U.S.C. 103 as being unpatentable over Nagao (US 2021/0017039 A1), as applied to claim 1 above, and further in view of Xie (A Mg-Doped High-Nickel Layered Oxide Cathode Enabling Safer, High-Energy-Density Li-ion Batteries, 2019; cited in the IDS filed 10/05/2022).
Regarding claim 15, Nagao teaches the positive electrode active material of claim 1, wherein the positive electrode active material includes a compound containing a metal (composite metal compound containing nickel, cobalt, and manganese, [0135]), lithium ([0135]), a doping element (optional metal, [0136]) and oxygen (oxide [0135]), wherein the positive electrode active material is prepared by mixing a composite metal oxide containing the metal, and a lithium compound containing the lithium with each other ([0151]) and then performing calcination of the mixture ([0154]), wherein the metal includes: nickel (Ni); and at least one of cobalt (Co) and manganese (Mn) ([0135]).
As Nagao teaches that the doping element (optional metal) is formed with the metal compound which is then mixed with a lithium compound ([0136] and [0131]), Nagao does disclose wherein “the positive electrode active material is prepared by mixing a composite metal oxide containing the metal, the doping element, and a lithium compound containing the lithium with each other.”
Xie teaches a method of formed positive electrode active material (P939 C1 ll. 1-4) wherein the positive electrode active material is prepared by mixing a composite metal oxide containing Ni and Co, a doping element (magnesium acetate), and a lithium compound containing lithium (LiOH∙H2O) with each other and then performing calcination of the mixture (Materials Synthesis, P939 C1 bridging C2). It would have been obvious to a person having ordinary skill in the art before the effective filing date of the invention to have prepared the positive electrode active material of Nagao by “mixing a composite metal oxide containing the metal, and a lithium compound containing the lithium with each other and then performing calcination of the mixture,” as the disclosure of Xie indicates that this procedure is known in the art.
Regarding claim 16, Nagao in view of Xie teaches the positive electrode active material of claim 15, wherein the positive electrode active material is prepared by performing calcination of the mixture at least one time in a temperature range of 700 °C to 800 °C (Jun: overlapping range of 700 °C – 950 °C, [0155], establishes a prima facie case of obviousness [MPEP § 2144.05(I)]).
Claims 1, 2, 5, and 13 are rejected under 35 U.S.C. 103 as being unpatentable over Jun (High-energy density core–shell structured Li[Ni0.95Co0.026Mn0.024]O2 cathode for lithium-ion batteries, 2017; cited 07/25/2024 page numbers beginning with S refer to the Supporting Information section, which begins on p. 6 of the file) in view of Kwon (WO 2016/175597 A1; English-language equivalent US 2018/0108940 A1 is referenced below) and Weigel (Structural and Electrochemical Aspects of LiNi0.8Co0.1Mn0.1O2 Cathode Materials Doped by Various Cations, 2019; cited in the IDS filed 10/05/2022).
Regarding claim 1, Jun discloses a positive electrode active material (Li[Ni0.95Co0.026Mn0.024]O2 or ‘CS’ Jun [P5048 C2 ll. 15-19]; hereinafter referred to as NCM-based material) comprising secondary particles, wherein each secondary particle is an agglomerate of a plurality of primary particles [P5048 C2 ll. 24-27; P5049 Fig. 1]. The primary particles include first primary particles constituting a core portion of each secondary particle and second primary particles constituting a shell portion of each secondary particle, wherein the shell portion surrounds the core portion [P5049 ll. 14-24, Figs. 1(e),(f)]. An average length of a long side of a longitudinal cross-section of each first primary particle (a1) is 0.1 µm [P5049 C1 ll. 15-18] and an average length of a long side of a longitudinal cross-section of each second primary particle (b1) is 0.5 µm [P5049 C1 ll. 18-21], which reads on the claimed range of “0.1 µm to 2.0 µm.”. Though Jun is silent as to the average lengths of the short sides perpendicular to the long sides of each of the first primary particles and the second primary particles (a2 and b2, respectively), Jun does disclose that the first primary particles are elongated, meaning that “a1 is equal to or larger than a2,” and the secondary particles are rod-shaped, meaning that “b1 is larger than b2.”
Jun does not disclose the value of the ratio b1/b2, but does suggest that the value should be larger than one, as the superior discharge capacity [P5049 C2 ll. 3-9] and stability [P5049 C2 ll. 28-32] of the positive electrode active material are attributed to elongated nanoscale primary particles.
Kwon teaches a nickel manganese cobalt (NCM)-based positive electrode active material 10 comprising secondary particles, wherein each secondary particle is an agglomerate of a plurality of primary particles [0033]. The primary particles include first primary particles constituting a core portion 1 (Fig. 1, [0035]) of each secondary particle and rod-shaped second primary particles that surround the core portion (the second primary particles constitute the intermediate layer 2, Fig 1, [0043]). Kwon further teaches that the aspect ratio of the second primary particles, which corresponds to the ratio b1/b2 of the claimed invention [0034], may be considered a results-effective variable. Increasing the ratio reduces contact resistance between primary particles and therefore improves the materials’ electrochemical properties [0043]. However, the mechanical properties of the particles deteriorate as the ratio b1/b2 rises, making the secondary particle more vulnerable to fractures [0044]. Therefore, in seeking to further improve the active material of Jun, a person having ordinary skill in the art before the effective filing date of the invention would have found it obvious to have optimized the ratio b1/b2 of the second primary particles, including to a range corresponding to “2 to 15,” in order to achieve the desired balance between battery performance and durability as taught by Kwon.
Since the second primary particles of modified Jun have a ratio b1/b2 in a range of 2 to 15, the average value of b2 is necessarily in a range of 0.03 µm to 0.25 µm, which lies within the claimed range of “0.01 µm to 0.25 µm.”
Though both Jun and Kwon are silent as to a size distribution of the second primary particles, the shell region depicted in Figs. 1(b),(e),(f) [Jun: P5049] and S1 [Jun: PS3] appears to comprise particles that are uniform in size and thus it is the examiner’s opinion that “each of 90% or greater of the second primary particles” of modified Jun have b1, b2, b1/b2 that lie within the claimed ranges.
Furthermore, [0087] of the instant specification states that when each of 90% or greater of the second primary particles have b1 and b2 in the claimed ranges, the secondary primary particles will be uniformly oriented within the shell of the secondary particle. Jun teaches that the second primary particles have their long axes aligned along the radial direction [P5049 C1 ll. 18-21, Figs.1(e),(f)] and that this morphology improves the stability of the active material [P5049 C2 ll. 28-32]. Kwon further teaches that arranging the rod-shaped secondary primary particles to face the outer surface of the secondary particle reduces electrical resistance and improves ion diffusion in the active material [0043]. Therefore, the dimensions of the second primary particles could be altered to meet the claimed ranges while still forming the microstructure taught by modified Jun. Accordingly, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the invention to have formed the active material such that “each of 90% or greater of the second primary particles has b1 in a range of 0.1 µm to 2.0 µm, and b2 in a range of 0.01 µm to 0.25 µm” as such a modification is considered a mere change in size [MPEP § 2144.04(IV)A].
The average value of a2 in the active material of modified Jun is less than 0.1 µm, as the long axes of the elongated first primary particles have an average length of 0.1 µm, which overlaps the claimed range of “0.01 µm to 0.8 µm.”
Though both Jun and Kwon are silent as to the desired size distributions of the first primary particles, the first primary particles depicted in Figs. 1(b),(e),(f) [Jun P5049] appear uniform in size and thus it is the examiner’s opinion that “each of 90% or greater” of the first primary particles of modified Jun have lengths a2 that lie within the claimed range of “0.01 µm to 0.8 µm.”
Furthermore, [0088]-[0089] of the instant specification state that when 90% or greater of the first primary particles have an average length of a2 within the claimed range, the first primary particles guide the second primary particles to be oriented along the first primary particles. Jun teaches that both the first and second primary particles have their long axes aligned along the radial direction [P5049 C1 ll. 15-21, Figs.1(e),(f)] and that this morphology improves the discharge capacity of the active material [P5049 C2 ll. 3-9]. Kwon teaches that arranging the rod-shaped secondary primary particles to face the outer surface the secondary particle reduces electrical resistance and improves ion diffusion in the active material [0043]. Therefore, the dimensions of the primary particles could be altered to meet the claimed ranges while still forming the microstructure taught by modified Jun. Accordingly, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the invention to have formed the active material such that “each of an average length of a2 of each of 90% or greater of the first primary particles is in a range of 0.01 µm to 0.8 µm” as such a modification is considered a mere change in size [MPEP § 2144.04(IV)A].
Jun further teaches wherein a ratio b1/a1 is 5 (b1 is 500 nm and a1 is 100 nm, see claim 1), and therefore does not disclose wherein said ratio is in a range of 1 to 3.5. Jun and Kwon are silent as to the value of the ratio b2/a2.
However, [0088]-[0089] of the instant specification state that when the ratios b1/a1 and b2/a2 are within the claimed ranges, the first primary particles guide the second primary particles to be oriented along the first primary particles. Jun teaches that both the first and second primary particles have their long axes aligned along the radial direction [P5049 C1 ll. 15-21, Figs.1(e),(f)] and that this morphology improves the discharge capacity of the active material [P5049 C2 ll. 3-9]. Kwon further teaches arranging the rod-shaped primary particles to face the outer surface of the secondary particle reduces electrical resistance and improves ion diffusion in the active material [0043]. Therefore, the dimensions of the primary particles could be altered to meet the claimed ranges while still forming the microstructure taught by modified Jun. Accordingly, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the invention to have formed the active material such that “a ratio b1/a1 is in a range of 1 to 3.5, and a ratio b2/a2 is in a range of 0.8 to 1.5” as such a modification is considered a mere change in size [MPEP § 2144.04(IV)A].
Jun further discloses that the composition of the first primary particles is LiNiO2 and the composition of the second primary particles is Li[Ni0.87Co0.065Mn0.065]O2 [P5049 C1 ll. 7-8], so “each primary particle contains nickel (Ni)” and “a content of nickel (Ni) is greater than or equal to 80 mol%.” However, Jun does not disclose wherein each of the primary particles contains Manganese (Mn) or Cobalt (Co). Jun teaches that the presence of these elements in the active material reduces capacity loss that is inherent to Ni-rich cathodes by preventing side reactions between Ni ions and the electrolyte, but also lowers the energy density of the active material and attempts to balance these effects by forming the secondary particles to have an Ni-rich core with a protective Mn and Co shell [P5048 C2 ll. 5-9].
Kwon teaches the invention as discussed in claim 1, wherein both the first and second primary particles contain Mn and Co [0039]. Kwon further teaches that the concentrations of Ni, Mn, and Co may be varied throughout the secondary particle and that each element has positive and negative effects when used in active material [0008]. Cathodes comprising high amounts of Ni have high capacity but poor thermal stability due to interactions with the electrolyte solution [0065]. Mn improves thermal stability of cathodes but reduces their capacity [0067]. Though Co improves capacity when compared to Mn [0006], it is expensive [0004]. It would have been obvious to a person having ordinary skill in the art before the effective filing date of the invention to have modified the active material of Jun, with a reasonable expectation of success, such that “each of the primary particles contains Manganese (Mn) or Cobalt (Co)” to achieve a desired balance between capacity, stability, and cost based on the teachings of Kwon.
Jun in view of Kwon does not teach wherein each primary particle further comprises a doping element.
Weigel teaches that the capacity retention of NCM-based positive electrode materials is be improved via the addition of doping elements [P508 C1 ll. 11-14]. Tantalum (Ta) is a particularly effective dopant. A cathode containing 1.5mol% Ta as a doping element had improved capacity and stability compared to both undoped cathodes [P514 C1 ll. 26-30] and cathodes doped with other elements [P514 C1 ll. 46-51]. It would have been obvious for a person having ordinary skill in the art before the effective filing date of the invention to have added 1.5 mol% tantalum, which reads on the claimed range of “0.05mol% to 2mol%,” to act as a doping element in the active material of modified Jun with a reasonable expectation of improving battery performance based on the teachings of Weigel.
Regarding claim 2, Jun in view of Kwon and Weigel teaches the invention as discussed in claim 1, but does not teach “wherein after a battery including the positive electrode active material has been subjected to multiple charging/discharging cycles, a micro crack including a space between the first primary particle or a space between the second primary particles occurs in the secondary particle, wherein when the battery including the positive electrode active material has been subjected to 100 charging/discharging cycles where each cycle includes a charging of the battery to 4.3V under 0.5C constant current and a discharging of the battery to 2.7V under 0.5C constant current, and then the battery is discharged to 0.27V, an area of the micro crack is equal to or smaller than 13% of an entire area of a longitudinal cross section of the secondary particle.” However, both Jun and Kwon seek to improve the capacity retention of Ni-based active materials by forming structurally stable secondary particles (Jun: [P5048 C2 ll. 5-11]; Kwon: [0008]). Jun further teaches that side reactions between Ni ions and the electrolyte solution cause surface degradation of the active material during battery cycling [P5048 C1 ll. 35-39]. Microcracks within the active material expose more primary particles to the electrolyte solution and thus create more surface damage. Accordingly, a person having ordinary skill in the art before the effective filing date of the invention would be motivated to minimize the area of a microcrack, including to a value “equal to or smaller than 13% of an entire area of a longitudinal cross section of the secondary particle” to reduce surface degradation within the active material.
Regarding claim 5, Jun in view of Kwon and Weigel teaches the invention as discussed in claim 1, wherein each of the second primary particles has a rod shape having an aspect ratio and wherein each of the second primary particles having the rod shape is oriented toward a surface of the secondary particle [Jun: P5049 C2 ll. 30-32, Figs. 1(e),(f)], which reads on the claimed range of “50% or greater of the second primary particles having the rod shape” being oriented toward a surface of the secondary particles.
Regarding claim 13, Jun in view of Kwon and Weigel teaches the invention as discussed in claim 1, wherein after a battery including the positive electrode active material has been subjected to 100 charging/discharging cycles where each cycle includes a charging of the battery to 4.3V under 0.5C constant current and a discharging of the battery to 2.7V under 0.5C constant current [Jun: PS2, par. 3], Rct of the positive electrode active material is 22.1 Ω [Jun: P5051 C1 ll. 5-7], which reads on the claimed range of “10 Ω to 30 Ω.”
Claim 14 is rejected under 35 U.S.C. 103 as being unpatentable over Jun in view of Kwon and Weigel as applied to claim 1 above, and further in view of Zhong (Synthesis and electrochemical properties of LiNi0.8CoxMn0.2-xO2 positive-electrode material for lithium-ion batteries, 2016).
Regarding claim 14, Jun in view of Kwon and Weigel teaches the invention as discussed in claim 1. Neither Jun nor Kwon teach “wherein when the positive electrode active material is subjected to X-ray diffraction analysis using a device with 45kV and 40mA output and a Cu Ka beam source at a scan rate of 1 degree per minute and at a step size spacing of 0.0131, a ratio of an intensity of a peak 003 to an intensity of a peak 104 is in a range of 2 to 2.2.”
Zhong teaches the use of X-ray diffraction (XRD) to analyze NCM-based positive electrode active material [P344, Results and discussion, par. 1]. Zhong explains that the ratio of the intensity of a peak 003 to the intensity of a peak 104, or I(003)/I(104), reflects the degree of cation mixing in the active material, which occurs when Ni ions occupy Li 3a sites in the crystal structure. Smaller values of I(003)/I(104) indicate high degrees of cation mixing and are undesirable because said mixing harms the cyclability and rate capability of the NCM-material. Zhong further teaches that the value of I(003)/I(104) for NCM-based materials increases with increasing Co content because Co can effectively suppress Li/Ni cation mixing [P344, Results and discussion, par. 1]. However, Kwon teaches that Co is expensive and can be unstable [0004]. One of ordinary skill in the art before the effective filing date of the invention would have optimized, by routine experimentation, the Co content in the positive electrode active material of modified Jun to obtain the desired balance between improved battery characteristics, cost, and stability based on the teachings of Zhong and Kwon, and thereby obtain an active material that, when subjected to the claimed XRD analysis, will produce a pattern in which a “ratio of an intensity of a peak 003 to an intensity of a peak 104 is in a range of 2 to 2.2.”
Claims 15 and 16 are rejected under 35 U.S.C. 103 as being unpatentable over Jun in view of Kwon and Weigel as applied to claim 1 above, and further in view of Xie (A Mg-Doped High-Nickel Layered Oxide Cathode Enabling Safer, High-Energy-Density Li-ion Batteries, 2019; cited in the IDS filed 10/05/2022).
Regarding claim 15, Jun in view of Kwon and Weigel teaches the invention as discussed in claim 1, wherein the positive electrode active material is Li[Ni0.95Co0.026Mn0.024]O2 (see claim 1), which meets the following limitations:
the positive electrode active material includes a compound containing a metal, lithium, and oxygen;
the metal includes nickel (Ni), cobalt (Co), and manganese (Mn); and
a content of Ni is 95mol%, which reads on the claimed range of “greater than or equal to 80 mol%.”
Jun further teaches that the positive electrode active material is prepared by mixing a composite metal oxide containing the metal ([Ni0.95Co0.025Mn0.025](OH)2), and a lithium compound containing the lithium (LiOH∙H2O) with each other and then performing calcination of the mixture [PS2, Synthesis of Core-Shell].
As Weigel adds doping elements to existing positive electrode material [P509 C1 ll. 40-46], Jun in view of Kwon and Weigel does not teach wherein “the positive electrode active material is prepared by mixing a composite metal oxide containing the metal, the doping element, and a lithium compound containing the lithium with each other and then performing calcination of the mixture.”
Xie teaches that the electrochemical and thermal performance of Ni-based cathode materials can be improved by doping with alien ions [P939 C1 ll. 1-4]. Xie prepares a doped active material by mixing a compound containing a composite metal oxide containing Ni and Co (Ni0.94Co0.06(OH)2), the doping element (magnesium acetate), and a lithium compound containing the lithium (LiOH∙H2O) with each other and then performing calcination of the mixture (Materials Synthesis [P939 C1 bridging C2]). Accordingly, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the invention to have prepared the positive electrode active material of modified Jun by “mixing a composite metal oxide containing the metal, and a lithium compound containing the lithium with each other and then performing calcination of the mixture,” as the disclosure of Xie indicates that this procedure is known in the art.
Regarding claim 16, Jun in view of Kwon and Weigel teaches the invention as discussed in claim 15, wherein the positive electrode active material is prepared by performing calcination of the mixture one time at 700 °C [Jun: PS2, Synthesis of Core-Shell]., which reads on the claimed ranges of “at least one time” and “in a temperature range of 700 °C to 800 °C.”
Conclusion
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/C.C.D./Examiner, Art Unit 1723 /TIFFANY LEGETTE/Supervisory Patent Examiner, Art Unit 1723
