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and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114.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 12 March 2026 has been entered.
Response to Amendment
Applicant’s response (12 March 2026) has not made any amendments to the claims. Applicant’s arguments to the rejections of record are not found persuasive for the reasons detailed below; thus, the 102 rejections are maintained. A new ground of rejection (103) is provided in view of new art (Watanabe and Yang).
Response to Arguments
The claims recite a center portion having a layered structure, and a surface portion having a secondary phase having a rock salt structure with a different structure from that of the center portion only in the surface; the center portion does not include the secondary phase. Applicant argues Wu is silent regarding whether the center portion in the PM sample includes or excludes the secondary phase (i.e., Fm3m). This argument is not found persuasive.
For the PM sample, Wu determines the phase at the center portion as R3m and the phase at the surface portion as Fm3m rock-salt via XRD, HRTEM and FFT based on the evaluation of planes in each portion. For example, measurement of the center portion showed planes associated with the R3m phase (e.g., (107), (104), (003), Fig. 2c2), and the interplanar distance of the (003) planes correspond to R3m phase (Fig. 2b); measurement of the surface portion showed planes associated with a rock-salt Fm3m phase (e.g., (311), (200), (111), see Fig.2c1). The presence of a rock-salt Fm3m phase in the center portion would be supported by the presence of planes indicating a rock-salt Fm3m phase; provided the planes in the center portion match the R3m phase, and there are no planes associated with the rock-salt Fm3m, the HRTEM and FFT data in Wu supports the absence of rock-salt Fm3m in the center portion. Yang (J. Electrochem. Soc. 163 A2665, included in the IDS dated 12 March 2026) supports this conclusion. Yang shows the techniques used by Wu (e.g., HRTEM and FFT) are fully capable of detecting the rock-salt structure (Fm3m) when such a phase exists; for example, the HRTEM and FFT images of NCM811-pristine shows a rock-salt Fm3m phase in the bulk (Region 2) and in the surface (Region 1) based on the presence of the (111) plane and the interplanar distance thereof (e.g., 0.24 nm), see e.g., Fig. 8. In other words, Yang provides evidence that the HRTEM and FFT images of Wu’s center portion of the PM sample should show a plane (and corresponding interplanar distance) associated with the rock-salt phase if such a phase is present. Since the plane for the rock-salt phase is not observed in the center portion of the PM sample (rather, only an R3m phase is present), Wu suggests of the exclusion of the secondary phase (rock-salt Fm3m) from the center portion, as evidenced by Yang.
Applicant argues evidence (i.e., comparison of capacity retention data) demonstrates the center portion of Wu’s PM sample includes the secondary phase (e.g., Fm3m), thereby failing to suggest the claimed structure. Applicant’s argument is not persuasive for the same reasons set forth in the last action (item 6, pages 3-8 of the Office action dated 16 December 2025), hence not repeated here in its entirety.
In short, Applicant’s argument hinges on a comparison of electrochemical data (capacity retention) of two structurally different battery cells. However, in light of the structural differences, it is difficult to draw a conclusion on what parameter is causing the difference in the capacity retention without further evidence to resolve the differences, which applicant has not provided to support their argument, hence the argument remains unpersuasive. For example, the electrode of the instant example utilizes a mass ratio for active:carbon:binder of 95:3:2, while the mass ratio of Wu’s PM sample is 80:10:10, which utilizes much lower amounts of active material and higher amounts of inactive materials (binder and carbon). Applicant has not presented any evidence or discussion to support that the amount of active material has no effect on capacity retention. Thus, examiner remains unconvinced of Applicant’s assertion that the capacity retention data indicated a secondary phase in the center portion, and not the result of the amount of active material, or some other factor, especially considering Wu’s physical evaluation of the center portion of the PM sample using HRTEM and FFT shows no planes associated with the secondary phase (Fm3m) in the center portion. Other critical factors affecting capacity retention, e.g., electrode active material loading, are not reported in either Wu or the instant disclosure or considered for analysis. It is unclear how one can conclude with confidence the differences in capacity retention are the result of a secondary phase in the center portion when other parameters which have an effect on capacity retention have not been resolve. Since Wu’s physical measurements (via HRTEM and FFT) do not support the presence of the secondary phase in the center portion provided there were no planes to indicate the presence of a rock-salt Fm3m phase, and because applicant has not provided any additional evidence resolving the differences between the samples, Wu’s physical evidence (HRTEM, FFT) supporting the absence of the rock-salt Fm3m phase in the center portion outweighs applicant’s conclusions based on the comparison of electrochemical data of electrodes of different composition.
In response to applicant's argument that the references fail to show certain features of the invention, it is noted that the features upon which applicant relies (i.e., particular processing steps to avoid the presence of the secondary phase) are not recited in the rejected claim(s). Although the claims are interpreted in light of the specification, limitations from the specification are not read into the claims. See In re Van Geuns, 988 F.2d 1181, 26 USPQ2d 1057 (Fed. Cir. 1993). As noted already, as evidenced by Yang, the presence of an Fm3m phase would be detected by HRTEM and FFT; since Wu’s HRTEM and FFT measurements show no planes associated with the secondary phase (Fm3m) in the center portion of the PM sample, the absence thereof is confirmed by Wu’s HRTEM and FFT images.
Applicant argues the Examiner’s response to evidence is insufficient. Examiner rejected the claimed structural features based on the physical measurements of the center portion of Wu’s PM sample, e.g., Wu’s physical evidence (i.e., measurement of the PM center portion by HRTEM, and FFT) supports the absence of the rock-salt Fm3m phase in the center portion provided no planes associated with the rock-salt structure were measured; rather the planes measured in the center portion were associated with the R3m phase. Applicant presented an argument concluding the presence of a secondary phase in the center portion, relying on a comparison of capacity retention data of the PM sample and instant samples; however, the samples in the comparison have various physical difference (e.g., active material amount, binder and conductive material ratio, active material loading, see e.g., pages 3-6 of the Final action from 16 December 2025) whose effects on capacity retention have not been resolved in Applicant’s arguments or response. Thus, Examiner does not find Applicant’s argument persuasive. At present, the structural evidence presented in the rejection (e.g., Wu’s HRTEM and FFT data) outweighs the arguments/conclusions proposed by Applicant.
Claim Rejections - 35 USC § 102
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 is/are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Wu et al. (Energy Storage Materials 8 (2017) 134–140), hereinafter Wu.
Regarding Claim 1, Wu discloses a positive electrode active material (see e.g., title) comprising a lithium transition metal oxide (i.e., sample PM). The lithium transition metal oxide of Wu (i.e., LiNi0.8Co0.1Mn0.1O2) satisfies Formula 1, which requires 0≤a≤0.2 (a=0), 0.7≤x<1 (x=0.8), 0<y<0.3 (y=0.1), and 0<z<0.3 (z=0.1), and 0≤w≤0.1 (w=0).
PNG
media_image1.png
71
237
media_image1.png
Greyscale
Wu further suggests the lithium transition metal oxide comprises a center portion (core part, region 2) having a layered structure (R3m, i.e., by way of XRD, HRTEM and confirmed by FFT) and a surface portion (surface, region 1) having a secondary phase (Fm3m, by way of XRD, HRTEM and confirmed by FFT) with a different structure from that of the center portion only in the surface portion (i.e., R3m is different from Fm3m), see page 136-137, wherein the surface portion consists of a rock-salt structure (surface region 1 is identified as Fm3m), and the center portion does not include the secondary phase (i.e., core, region 2, is identified as R3m based XRD, and HRTEM (by way of the planar distance between (003) planes (Fig. 2b)), and confirmed by FFT (Fig.2c2); rock-salt Fm3m planes are not observed), wherein the surface portion has a thickness of 30 nm or less from a surface of a particle toward a center of the particle (i.e., ~5 nm, see page 137), and wherein the lithium transition metal oxide has an average particle diameter between 4 µm to 20 µm (i.e., ~ 10 microns, see e.g., page 137 left column, and Fig. 3 (a)).
Claim(s) 10-11 is/are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Wu as evidenced by Balaya (US 2016/0308212), hereinafter Balaya.
Regarding Claims 10-11, Wu discloses a lithium secondary battery (coin cell, see page 136) comprising a positive electrode comprising positive electrode collector (e.g., Al foil) and a positive electrode active material layer comprising the positive electrode active material (sample PM includes LiNi0.8Co0.1Mn0.1O2) formed on the positive electrode collector, a negative electrode (Li), and an electrolyte (e.g., EC/EMC/DMC). Wu does not explicitly disclose a separator; however, Wu contains an enabled disclosure as evidenced by Balaya. That is, coin cells are understood to include a separator (Celgard membrane) between the electrodes, see [0041].
Claim Rejections - 35 USC § 103
Claim(s) 1, and 10-11 is/are rejected under 35 U.S.C. 103 as being unpatentable over Wu (cited above) in view of Watanabe et al. (Journal of Power Sources 258 (2014) 210e217; http://dx.doi.org/10.1016/j.jpowsour.2014.02.018), and Yang (Journal of The Electrochemical Society, 163 (13) A2665-A2672 (2016); DOI: 10.1149/2.0841613jes (of record)), hereinafter Wu, Watanabe and Yang.
Regarding Claim 1, claim 1 is rejected in view of Wu as set forth above under the 102 section; in instances where Wu’s physical measurements (e.g., HRTEM and FFT) are insufficient to support/suggest the exclusion of the secondary phase (e.g., Fm3m) in the center portion, Watanabe and Yang are presented as follows.
Watanabe shows secondary active material particles (NCA) comprising a layered R3m phase in the core region, which excludes a rock-salt phase; exposure to the electrolyte forms a NiO rock-salt phase only on the surface of the secondary particle, see e.g., Fig. 11, and pages 215-216, etc. Watanabe suggests the rock-salt phase has poor conductivities of lithium ions and electrons, such that a rock-salt phase in the center portion contributes to resistance inside the secondary particles, which contributes to a rise in impedance as well as capacity fade, page 215. Watanabe suggests limiting the rock-salt phase to the surface of the particle, wherein the suppression/prevention of the rock-salt phase in the core (e.g., between primary particles) is likely to achieve excellent cycle life, see pages 215-216. Yang suggests a thin (nano-thickness) rock-salt Fm3m surface phase on an NMC particle core having an R3m phase is capable of stabilizing the structure of the NMC material with long term cycling showing superior cycling life and maintenance of capacity retention. It would be obvious to one having ordinary skill in the art the particles of Wu include an R3m center portion, which excludes the Fm3m rock-salt phase to reduce resistance, hence impedance inside the particles, as suggested by Watanabe. It would further be obvious to include an Fm3m nano-thick surface portion on the R3m center portion with the expectation of a stabilized structure, long term cycling showing superior/excellent cycling life, and a maintenance of capacity retention, as suggested by Watanabe and Yang.
Regarding Claims 10-11, Wu discloses a lithium secondary battery (coin cell, see page 136) comprising a positive electrode comprising positive electrode collector (e.g., Al foil) and a positive electrode active material layer comprising the positive electrode active material (sample PM includes LiNi0.8Co0.1Mn0.1O2) formed on the positive electrode collector, a negative electrode (Li), and an electrolyte (e.g., EC/EMC/DMC). Wu does not explicitly disclose a separator; however, Wu contains an enabled disclosure as evidenced by Yang. That is, coin cells are understood to include or necessitated a separator (Celgard 2300 film) between the electrodes, see page A2666.
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to ANNA KOROVINA whose telephone number is (571)272-9835. The examiner can normally be reached M-Th 7am - 6 pm.
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, Ula Ruddock can be reached at 5712721481. 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.
/ANNA KOROVINA/Examiner, Art Unit 1729
/ULA C RUDDOCK/Supervisory Patent Examiner, Art Unit 1729
Prosecution Insights