Prosecution Insights
Last updated: April 19, 2026
Application No. 17/280,574

CATHODE ACTIVE MATERIAL FOR LITHIUM SECONDARY BATTERY, PREPARATION METHOD THEREFOR, AND LITHIUM SECONDARY BATTERY COMPRISING SAME

Non-Final OA §103
Filed
Mar 26, 2021
Examiner
LUO, KAN
Art Unit
1751
Tech Center
1700 — Chemical & Materials Engineering
Assignee
Research Institute Of Industrial Science & Technology
OA Round
5 (Non-Final)
67%
Grant Probability
Favorable
5-6
OA Rounds
3y 4m
To Grant
96%
With Interview

Examiner Intelligence

Grants 67% — above average
67%
Career Allow Rate
40 granted / 60 resolved
+1.7% vs TC avg
Strong +29% interview lift
Without
With
+29.0%
Interview Lift
resolved cases with interview
Typical timeline
3y 4m
Avg Prosecution
46 currently pending
Career history
106
Total Applications
across all art units

Statute-Specific Performance

§101
1.8%
-38.2% vs TC avg
§103
62.2%
+22.2% vs TC avg
§102
19.6%
-20.4% vs TC avg
§112
14.8%
-25.2% vs TC avg
Black line = Tech Center average estimate • Based on career data from 60 resolved cases

Office Action

§103
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and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114.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 December 16, 2025 has been entered. Status of Application Claim 1 is amended, submitted on 12/16/2025. Claims 1-3, 5, and 7-13 are pending with claims 8-12 remaining withdrawn. Claims 1-3, 5, 7, and 13 are presented for examination. Claim Rejections - 35 USC § 103 1. The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action: A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made. 2. The factual inquiries set forth in Graham v. John Deere Co., 383 U.S. 1, 148 USPQ 459 (1966), that are applied for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows: 1. Determining the scope and contents of the prior art. 2. Ascertaining the differences between the prior art and the claims at issue. 3. Resolving the level of ordinary skill in the pertinent art. 4. Considering objective evidence present in the application indicating obviousness or nonobviousness. 3. This application currently names joint inventors. In considering patentability of the claims the examiner presumes that the subject matter of the various claims was commonly owned as of the effective filing date of the claimed invention(s) absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and effective filing dates of each claim that was not commonly owned as of the effective filing date of the later invention in order for the examiner to consider the applicability of 35 U.S.C. 102(b)(2)(C) for any potential 35 U.S.C. 102(a)(2) prior art against the later invention. 4. Claims 1-3, 5, 7 and 13 are rejected under 35 U.S.C. 103 as being unpatentable over Kim (US 20180026268 A1, IDS of 2/14/2024), in view of Han (US 20160365570 A1). Regarding claim 1, Kim discloses a lithium nickel cobalt manganese-based oxide represented by Chemical Formula 1 (LiNi0.6Co0.2Mn0.2O2, [0183]; LiNi0.8Co0.1Mn0.1O2, [0198]) including secondary particles obtained by agglomerating at least one primary particle ([0183] and FIGs. 1 C-D); [Chemical Formula 1] Lia[NixCoyMnz]tM1-tO2-pXp wherein, in Chemical Formula 1, M is any one element selected from Al, Mg, Sn, Ca, Ge, Ga, B, Ti, Mo, Nb, and W X is any one element selected from F, N, and P, 0.8≤a≤1.3, 0.6≤x≤0.95, 0<y≤0.2, 0<z≤0.2, x+y+z=1, 0≤t≤1, and 0≤p≤0.1. Kim further discloses a positive electrode ([0016]) nickel-based active material for a lithium secondary battery includes at least one secondary particle including an aggregate of two or more primary particles, at least a portion of the secondary particle has a radial alignment structure, and a hetero-element compound is positioned between the primary particles ([0050]), and the hetero-element compound may be for example, ZrO2, Al2O3 …, or the like ([0087]). Referring to FIG. 1C, a secondary particle of the nickel-based active material 10 includes an outer portion 14 and an inner portion 12. The hetero-element compound 15 may be present between plate particles and on surfaces of the plate particles ([0094]). The inner portion may have a pore size of …, about 150 nm to about 550 nm, and the outer portion may have a pore size of less than about 150 nm [0057], which reads on the claimed “metal oxide particles having a nano-sized average diameter (D50) and disposed inside the secondary particles” because the hetero-element compounds of ZrO2, Al2O3 are metal oxides; and since the metal oxides are positioned between the primary particles (15, FIG. 1C), metal oxide particles disposed inside the secondary particles should be smaller than the pore size of the outer portion of a secondary particle, thus metal oxide particles have a nano-sized average diameter (D50), and an average particle diameter (D50) of the metal oxide should be less than 150 nm. Even though Kim does not explicitly disclose the metal oxide has an average particle diameter (D50) of 50 nm to 80 nm, Kim discloses the desire of a nickel-based active material that could offer improved lifespan characteristics and reduced battery resistance and improved cell performance ([0005]-[0006]); and the size of the metallic hydroxide may be almost or substantially identical to that of the nickel-based active material,…, and the pore size of the outer portion may be about 50 nm to about 148 nm ([0127]). The range of pore size of the outer portion taught by Kim translates to the metal oxide would likely have an average particle diameter (D50) of 50 nm to about 148 nm, which encompasses the claimed range of an average particle diameter (D50) of the metal oxide being 50 nm to 80 nm with a shared lowed end value, 50 nm. It would have been obvious for a skilled artisan before the effective filing date of the claimed invention to adjust the average particle diameter (D50) of the metal oxide within the Kim’s taught range of 50 nm to about 148 nm according to the particle size of the nickel-based active material, with a reasonable expectation to arrive at a particle diameter value that falls within the overlapping portion of the taught range and the claimed range and obtain a successful cathode active material, in order to achieve a successful nickel-based active material that could offer improved lifespan characteristics and reduced battery resistance and improved cell performance, as desired by Kim, and thus meet the claim limitation “the metal oxide has an average particle diameter (D50) of 50 nm to 80 nm”. While Kim discloses a concern that when a positive active material is used, cracks may be formed in the positive active material as charge/discharge cycling is repeated ([0004]); and a desire of a lithium secondary battery having improved lifespan characteristics and reduced battery resistance due to suppression or reduction of crack formation during charging/discharging cycling [0005]), Kim does not disclose that the secondary particles comprise a core portion in which molar content of nickel is constant and a shell portion which surrounds the outer surface of the core portion and has a concentration gradient in which molar content of nickel gradually decreases in a direction from the an interface with the core portion to outermost surface of the shell portion, wherein the concentration gradient is such that the ratio of nickel molar content at the outermost edge to nickel molar content at the interface with the core portion is in a range from 0.6 to 0.95. Han teaches a similar problem of a cathode active material of the lithium secondary battery in that a metal component is desorbed from the cathode during storage at a high temperature under fully charged condition ([0005]); and in order to provide a lithium secondary battery which has excellent life-span property and penetration safety ([0007]), a cathode active material containing lithium-metal oxide of which at least one of metals has a continuous concentration gradient region between a core part and a surface part thereof ([0008]) is prepared. Han further teaches in Example 1 that a lithium-metal oxide with a whole composition of LiNi0.8Co0.1Mn0.1O2, a core part composition of LiNi0.84Co0.11Mn0.05O2 and a surface part composition of LiNi0.78Co0.10Mn0.12O2, having a concentration gradient between the core part and the surface part as a cathode active material ([0083]). The concentration gradient of the prepared lithium-metal oxide is listed in Table 1. For the lithium-metal oxide particle with a distance between a core of a particle to the surface thereof, that is 5 µm, the measurement sites were present at an interval of 5/7 µm from the surface ([0084]). From the data shown in Table 1, Ni has a concentration gradient gradually decreases in a direction from the core portion to the outermost surface (from site 7 to 1, Table 1). Thus, the claim limitation “wherein the secondary particles comprise a core portion in which molar content of nickel is constant and a shell portion which surrounds the outer surface of the core portion and has a concentration gradient in which molar content of nickel gradually decreases in a direction from the an interface with the core portion to outermost surface of the shell portion” is met, because the core portion has a constant nickel molar content while the shell portion which surrounds the outer surface of the core portion of the instant claim corresponds to the surface part of Han; and since a distance between a core of a particle to the surface is 5 µm, it inherently also teaches the particle is a secondary particle. Further, Han teaches in Table 1, the nickel molar content at the outermost site 1 is 0.7797 and at the core part site 7 is 0.8433 ([0084]), and the interface with the core portion should have a nickel molar content number the same as the core part site 7 because the core portion has a constant nickel molar content, therefore, the ratio of nickel molar content at the outermost edge to nickel molar content at the interface with the core portion is calculated to be 0.92, falling within the ratio range as claimed “the concentration gradient is such that the ratio of nickel molar content at the outermost edge to nickel molar content at the interface with the core portion is in a range from 0.6 to 0.95”. It would have been obvious for an ordinary skilled artisan before the effective filing date of the claimed invention, to have modified the secondary particles of the lithium nickel cobalt manganese-based oxide comprise a core portion with molar content of nickel being constant and a shell portion which surrounds the outer surface of the core portion and has a concentration gradient in which molar content of nickel gradually decreases in a direction from an interface with the core portion to outermost surface of the shell portion, wherein the concentration gradient is such that the ratio of nickel molar content at the outermost edge to nickel molar content at the interface with the core portion is in a range from 0.6 to 0.95, as taught by Han, in order to provide a lithium secondary battery having improved lifespan characteristics and reduced battery resistance due to suppression or reduction of crack formation during charging/discharging cycling. Since modified Kim has disclosed the hetero-element compound positioned between the primary particles disposed inside the secondary particles of the nickel-based active material ([0050] and FIG. 1 C-D) as set forth above; and further discloses the hetero-element compound is coated on the grain-boundaries of the primary particles constituting the secondary particles ([0112]) , modified Kim inherently discloses the metal oxide remains within the internal pores of the secondary particles because the space between the grain-boundaries of primary particles forming the secondary particles are considered as internal pores. Further, modified Kim discloses in Example 1 the metal oxide (Zirconium oxide) was dry-mixed with the secondary particle of a nickel-based active material using a high speed mixer at a rate of 2,000 rpm ([0181]) followed by a heat treatment at a temperature of about 850 °C ([0183]), based on which a skilled artisan would reasonably envisage the Zirconium oxide of Example 1 remains in a particulate state because the melting temperature of Zirconium oxide is about 2700 °C. Therefore, modified Kim anticipates the limitation as claimed “wherein the metal oxide particles remain in a particulate state within the internal pores of the secondary particles.” Regarding claim 2, modified Kim discloses all of the limitations as set forth above. Modified Kim discloses a nickel-based active material LiNi0.8Co0.1Mn0.1O2, ([0198]), which reads on the claimed “wherein in Chemical Formula 1, 0.8≤x≤0.95, 0<y≤0.1, and 0<z≤0.1”. Regarding claim 3, modified Kim discloses all of the limitations as set forth above. Modified Kim discloses the hetero-element compound may be for example, ZrO2, Al2O3 …, or the like ([0087]), which reads on the claimed “wherein the metal oxide comprises at least one selected from ZrO2, …, and a combination thereof”. Regarding claim 5, modified Kim discloses all of the limitations as set forth above. Modified Kim further discloses in Example 1 that the amount of zirconium in the zirconium oxide was controlled to be 0.0015 mol based on 1 mol of the transition metal of the secondary particles of the nickel-based active material ([0182]) with the formula of LiNi0.6Co0.2Mn0.2O2 ([0183]), which translates to a metal content of Zr is 0.14 wt% based on 100 wt% of LiNi0.6Co0.2Mn0.2O2, falling within the range of 0.1 wt% to 0.7 wt% as claimed “wherein a metal content of the metal oxide is 0.1 wt% to 0.7 wt% based on 100 wt% of the cathode active material.” Regarding claim 7, Kim discloses all of the limitations as set forth above. Kim further discloses secondary particles of the nickel-based active material (LiNi0.8Co0.1Mn0.1O2) including a zirconium oxide coating were obtained ([0198]), which reads on the claimed “The cathode active material further comprises a coating layer disposed on the surface of the secondary particles.” Regarding claim 13, modified Kim discloses all of the limitations as set forth above. Modified Kim further discloses a lithium secondary battery (Example 5, [0187]) comprising the cathode including a cathode active material of LiNi0.6Co0.2Mn0.2O2-ZrO2 ([0183]); an anode (lithium metal electrode, [0190]); and a non-aqueous electrolyte ([0190]). Response to Arguments 5. Applicant’s arguments regarding the amended claim 1 filed on 12/16/2025 have been fully considered but are not found persuasive. The Applicant argues that Kim and Han merely teach surface coating structures of metal oxide, do not disclose or suggest a structure in which metal oxides are embedded within pores of secondary particles, with contrast to the claimed material by referring to its manufacturing process and advantageous effects. The Examiner respectfully submits that modified Kim explicitly discloses a hetero-element compound is positioned between the primary particles ([0050] and FIGs. 1C-D) and coated on the grain-boundaries of the primary particles constituting the secondary particles ([0112]), see also Example 1 (LiNi0.6Co0.2Mn0.2O2,) in which ZrO2 was coated on the primary particles followed by a second heat treatment at 850 °C ([0182-0183]), which means the metal oxide ZrO2 is disposed inside the internal pores formed between grain-boundaries of the primary particles constituting the secondary particles. Even though the patentability of the product claim is depending on the claimed structure, not on the method of making, Examiner further notes that the process of forming Kim’s Example 1 ([0181-0183]) is substantially similar to the manufacturing process as argued, in that a porous oxide precursor having pores formed on its surface is first produced; after mixing with a metal oxide the metal oxide is coated along the boundaries of the primary particles which means the internal pores of the secondary particles (FIG. 1 C-D) . Further Kim discloses the effect that the resistance to lithium diffusion was significantly reduced in a low voltage range of the coil cell of Example 5 using the Example 1 cathode active material ([0252] and [0188]), which means the Applicant argued advantageous effects of reducing DC internal resistance has been achieved by Kim. Thus the Applicant argued advantageous effects are not an unexpected results, either. Thus, the arguments are not found persuasive. Conclusion 6. Any inquiry concerning this communication or earlier communications from the examiner should be directed to KAN LUO whose telephone number is (571)270-5753. The examiner can normally be reached 8:00AM -5:00PM ET. ET. Examiner interviews are available via telephone, in-person, and video conferencing using a USPTO supplied web-based collaboration tool. To schedule an interview, applicant is encouraged to use the USPTO Automated Interview Request (AIR) at http://www.uspto.gov/interviewpractice. If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Jonathan Leong can be reached on (571)270-1292. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300. Information regarding the status of published or unpublished applications may be obtained from Patent Center. Unpublished application information in Patent Center is available to registered users. To file and manage patent submissions in Patent Center, visit: https://patentcenter.uspto.gov. Visit https://www.uspto.gov/patents/apply/patent-center for more information about Patent Center and https://www.uspto.gov/patents/docx for information about filing in DOCX format. For additional questions, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000. /K. L./Examiner, Art Unit 1751 1/2/2026 /JONATHAN G LEONG/Supervisory Patent Examiner, Art Unit 1751 1/8/2026
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Prosecution Timeline

Mar 26, 2021
Application Filed
May 19, 2023
Response after Non-Final Action
May 01, 2024
Non-Final Rejection — §103
Aug 08, 2024
Response Filed
Oct 31, 2024
Final Rejection — §103
Feb 07, 2025
Request for Continued Examination
Feb 11, 2025
Response after Non-Final Action
Mar 03, 2025
Non-Final Rejection — §103
Jun 09, 2025
Response Filed
Sep 11, 2025
Final Rejection — §103
Dec 16, 2025
Request for Continued Examination
Dec 18, 2025
Response after Non-Final Action
Jan 03, 2026
Non-Final Rejection — §103 (current)

Precedent Cases

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Study what changed to get past this examiner. Based on 5 most recent grants.

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Prosecution Projections

5-6
Expected OA Rounds
67%
Grant Probability
96%
With Interview (+29.0%)
3y 4m
Median Time to Grant
High
PTA Risk
Based on 60 resolved cases by this examiner. Grant probability derived from career allow rate.

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