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 .
Election/Restrictions
Applicant’s election without traverse of Group II, in the reply filed on 17 April 2026 is acknowledged.
Claims 1-11 are withdrawn from further consideration pursuant to 37 CFR 1.142(b) as being drawn to a nonelected invention, there being no allowable generic or linking claim. Election was made without traverse in the reply filed on 17 April 2026.
Priority
Acknowledgement is made of a domestic benefit claim to U.S. Provisional Application No. 63/415,628, filed 12 October 2022.
Claim Interpretation
Claim 12 is a product-by-process claim drawn to a thermoelectric oxide ceramic composition. Elements of the process of claim 1 which are interpreted to impart structural elements to the composition are that the thermoelectric oxide ceramic composition comprises cerium oxide nanoparticles and at least two types of metal cations.
The process limitations are noted. However, when the examiner has found the same or substantially similar product as in the applied prior art, the burden of proof is shifted to applicant to establish that their product is patentably distinct and not the examiner to show the same process of making. In re Brown, 173 USPQ 685 and In re Fessmann, 180 USPQ 324.
Herein the thermal and electric properties of various thermoelectric materials are discussed. Seebeck coefficient and thermopower are used interchangeably, with α, S, and Q used in the literature to refer to the property. The electric power factor describes the product of the electric conductivity (σ, or inverse resistivity 1/ρ) and Seebeck coefficient squared (i.e. σS2). Conversion of values in the prior art to comparable units are provided as needed for clarity.
Claim Objections
Claims 17 and 22-26 are objected to because of the following informalities:
Claims 17 and 22 recite compositions comprising Ca3-xCo4O9+δBiy and CeOx. CeOx is generally understood to be an umbrella term for cerium oxides in the greater composition. However, as x is a defined variable in the claims with respect to Ca3-xCo4O9+δ, it is unclear if the definition of x should also be applied to CeOx, which would drastically change the scope of the claims. From the specification, the x of Ca3-xCo4O9+δ and x of CeOx are different variables [0058]-[0060]. As such, for the purposes of examination wherein x has been defined, that definition has only been applied to Ca3-xCo4O9+δ.
Furthermore, cerium oxide is alternately referred to as CeO and CeOx within the claims with respect to its loading by mass in the composition. The use of both CeOx and CeO creates a lack of clarity with respect to if the two should be treated as different species for the purposes of determining the wt% loading of nanoinclusions in the composition. Review of the specification however indicates that wt% was calculated for CeOx as a whole, and thus the claims have been also interpreted as such for the purposes of examination.
Claims 23-26 are objected to via their dependency on claim 22.
Appropriate correction is required.
Claim Rejections - 35 USC § 103
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
The factual inquiries for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows:
1. Determining the scope and contents of the prior art.
2. Ascertaining the differences between the prior art and the claims at issue.
3. Resolving the level of ordinary skill in the pertinent art.
4. Considering objective evidence present in the application indicating obviousness or nonobviousness.
This application currently names joint inventors. In considering patentability of the claims the examiner presumes that the subject matter of the various claims was commonly owned as of the effective filing date of the claimed invention(s) absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and effective filing dates of each claim that was not commonly owned as of the effective filing date of the later invention in order for the examiner to consider the applicability of 35 U.S.C. 102(b)(2)(C) for any potential 35 U.S.C. 102(a)(2) prior art against the later invention.
Claims 12-21 are rejected under 35 U.S.C. 103 as being unpatentable over German Patent Publication No. DE102017216990A1 (published 28 March 2019, herein citations made to provided English translation) in view of Li (International Journal of Modern Physics B, 2013, 27(22), 1350108) and Tang et al. (EPL, 2010, 91, 17002).
In regard to claims 12 and 20, German Patent Publication No. DE102017216990A1 (herein referred to as DE ‘990A1) teaches a thermoelectric oxide ceramic composition comprising two or more metal cations, either with the generic formula Ca3Co4O9 [0008], and doped with Ce and/or other rare earth elements [0009]. DE ‘990A1 does not teach that the disclosed thermoelectric oxide ceramic compositions contain CeO nanoparticles as a dopant.
However, Li teaches that the addition of Cu2O nanoinclusions to a Ca3-xCexCo4O9+δ composition results in a depression of thermal conductivity via the scattering of phonon and the nanoinclusion-material grain boundaries (pp. 5, lines 6-9). But, while the physical effects of the nanoinclusions are positive, the poor conductivity of Cu2O decreases the materials thermopower, power factor, and overall ZT (pp. 5, line 13 – pp. 7, line 5). Li suggests the phonon scattering phenomenon from nanoinclusions may be used to guide the design of ideal nanocomposites as a conductive compound used as nanoinclusions may depress thermal conductivity while not affecting electrical conductivity (pp. 7, lines 11-16). Li does not teach that the nanoinclusions are CeOx.
Tang et al. teaches that the doping of Ca3Co4O9+δ materials specifically with Ce (Ca3-xCexCo4O9+δ) has a significant positive impact on the thermopower of the composition, up to a ~130% in thermopower as compared to the undoped material via a spin-entropy enhancement. Notably, the inclusion of Ce does not negatively impact electrical conductivity to the degree to which the material overall is compromised. Tang et al. does not teach that the Ce added to the thermoelectric composition is in the form of nanoparticles or nanoinclusions.
One of ordinary skill in the art would seek to benefit from the depressed thermal conductivity provided by nanoinclusions but avoid the poor conductivity of the resulting material by employing a metal oxide which has improved electrical conductivity, as concluded by Li. From the prior art, it would have been obvious to utilize CeO nanoinclusions as it would provide advantageous depressed thermal conductivity through increased grain boundaries and comparable electric conductivity to other constituents due to the electronic configuration of the Ce. DE ‘990A1 already suggests Ce as a desirable dopant for thermoelectric oxide ceramic compositions, and the combined teachings of Li and Tang et al. are suggestive that Ce doping of the composition in the form of CeO nanoparticles/nanoinclusions would be highly successful in decreasing thermal conductivity and increasing thermopower, and in turn drastically improving the ZT of the material. Therefore, it would have been obvious to one of ordinary skill in the art to modify the compositions taught by DE ‘990A1 to include CeO nanoparticles as a dopant to improve the thermoelectric properties of the material as suggested by Li and Tang et al.
In regard to claims 13-15 and 21, Tang et al. teaches a thermoelectric oxide ceramic composition with the generic formula Ca3-xCexCo4O9+δ wherein x is equal to 0.1, 0.3, and 0.5 (pp. 2, Table 1) effectively creating a range of 0.1-0.5. The range of values of x overlaps the claimed ranges of about 0.05-0.5 (claim 13), about 0.05-0.45 (claim 14) and about 0.1-0.5 (claim 15 and claim 21). It would have been obvious to one of ordinary skill in the art to dope the compositions of DE ‘990A1 with the ratio taught by Tang et al. because the materials where x = 0.1, 0.3, 0.5 showed significantly improved thermopower compared to the undoped material (see results in Fig 2, pp. 2). Furthermore, the claimed ranges of x would have obvious to one of ordinary skill in the art at the time invention was made by selection of the overlapping portion of the range disclosed by the reference because overlapping ranges have been held to be a prima facie case of obviousness. In re Malagari, 182 USPQ.
In regard to claim 16, the combined teachings of DE ‘990A1, Li, and Tang et al. render obvious the composition as instantly claimed in claim 12. The thermal conductivity of the material is dependent upon the material’s composition. Therefore, a material which shares the instantly claimed composition would be expected to inherently possess a thermal conductivity at 1073 K of less than or equal to about 1.5 W m-1 K-1.
Alternatively, DE ‘990A1 teaches a composition with a maximum thermal conductivity of 1.96 W m-1 K-1 in the a,b plane and 0.73 W m-1 K-1 in the c-axis, effectively creating the ranges 0-1.96 and 0-0.73 W m-1 K-1 at 1073 K. Along the c-axis, which has the higher, preferable ZT value, the range disclosed in DE ‘990A1 is within the instantly claimed range of ≥1.5 W m-1 K-1 at 1073 K. One of ordinary skill in the art, when creating a modified material based upon the teachings of DE ‘990A1, Li, and Tang et al, would expect to form a material with a thermal conductivity of the same value or lower than those described by DE ‘990A1.
In regard to claim 17, DE ‘990A1 teaches a composition with the formula Ca2.25Na0.30Bi0.35Sm0.1Co4O9 [0040]. The composition reads to the claimed composition comprising Ca3-xCo4O9+δBiy wherein y is between 0.01 and 0.4 (disclosed as y = 0.35) and calcium is present in a molar amount <3 due to other dopants. DE ‘990A1 further teaches that the thermoelectric oxide ceramic compositions disclosed may be doped with a combination of rare earth elements, including Ce [0009]. As discussed above with regard to claim 12, it would have been obvious to modify the composition taught by DE ‘990A1 with the teachings of Li and Tang et al. to include CeO nanoparticles as a dopant to depress thermal conductivity and increase thermopower. Furthermore, Tang et al. teaches that nanoparticles are added to the Ca2.9Ce0.1Co4O9+δ composition in an amount of 1 wt%, 1.5 wt%, and 2 wt% with respect to the total weight of the composition, which are all with in instantly claimed 1 wt% to 5 wt% addition of CeOx. It would have been obvious to one of ordinary skill to apply the loading of nanoinclusions taught by Tang et al. to the composition of DE ‘990A1 as Tang et al. disclose the added amounts of nanoinclusions are sufficient to depress thermal conductivity at 300 K (see Fig. 5, pp 6).
In regard to claim 18, the combined teachings of DE ‘990A1, Li, and Tang et al. render obvious the composition as instantly claimed in claim 12. The Figure of Merit ZT, or the efficiency of thermal-electric energy conversion, is dependent upon the operating temperature and electrical conductivity/resistivity, thermal conductivity, and Seebeck coefficient of the thermoelectric material. The thermoelectric properties of the material, in turn, are dependent upon the material’s composition. Therefore, a material which shares the instantly claimed composition would be expected to inherently possess a ZT value at 1073 K of greater than or equal to about 1.0.
Alternatively, if the thermoelectric properties (including the ZT at 1073 K) are not considered inherent to a material having the composition as instantly claimed, it would have been obvious to one of ordinary skill to optimize the thermoelectric properties of a material with the instantly claimed chemical formula because the ZT value is a direct benchmark of the material’s ability to convert thermal and electrical energy and results-effective. DE ‘990A1 discloses compositions which have orientation-specific thermoelectric properties. In the most preferable orientation, a ZT value as high as 0.78 at 800°C/1023 K is disclosed which is lower than the instantly claimed range of greater than or equal to about 1.0 [0014].
It is noted that the limitation “greater than or equal to about 1.0” is relative. The specification indicates that “about” is defined as +/- 10% of the given value, and the limitation may then be interpreted as a range of greater than or equal to 0.9-1.1, and the difference between the prior art and the instantly claimed value is only 0.12. A person of ordinary skill in the art, with a reasonable expectation of success, would have combined the teachings of Li and Tang et al. with those of DE ‘990A1 to produce a thermoelectric material with an improved ZT value. Furthermore, a person of ordinary skill in the art would have been motivated to optimize the material to have the highest ZT value possible because of its direct correlation to the material’s thermoelectric performance. Therefore, it would have been obvious to one having ordinary skill in the art at the time the invention was made to choose the instantly claimed ZT value through routine optimization, since it has been held that there the general conditions of a claim are disclosed in the prior art, discovering the optimum or workable ranges involves only routine skill in the art. See In re Boesch, 205 USPQ 215.
In regard to claim 19, the combined teachings of DE ‘990A1, Li, and Tang et al. render obvious the composition as instantly claimed in claim 15. The electrical power factor, calculated from electrical conductivity and the Seebeck coefficient, is dependent upon the material’s composition. Therefore, a material which shares the instantly claimed composition would be expected to inherently possess an electrical power factor of about 1.0-3.0 W m-1 K-2 at about 323 K.
Neither DE ‘990A or Tang et al. report electrical power factors of the taught thermoelectric oxide ceramic compositions at an operating temperature of 373 K. Li, however, teaches that at 300 K, undoped Ca2.9Ce0.1Co4O9+δ has a thermopower of ~90 µV K-1, a thermal conductivity of ~1.20 W K-1 m-1, and an electric resistivity of ~0.00015 Ω m which results in an estimated electrical power factor (σ2ρ) of 0.054 mW K-2 m-1, which is outside the instantly claimed range. After modification of the teachings of DE ‘990A1 to form a composition comprising Ca2.5-2.9Ce0.1-0.5Co4O9+δ and CeO nanoinclusions, a person of ordinary skill would also be motivated to optimize the material for its electrical power factor, i.e. the Seebeck coefficient and electric conductivity, to improve the energy conversion efficiency of the thermoelectric oxide ceramic composition. Both the Seebeck coefficient, which quantifies the voltage generated from a temperature gradient across a material, and the electric conductivity, are pivotal to a material’s ability to convert heat to electricity. It would have been obvious to one having ordinary skill in the art at the time the invention was made to choose the instantly claimed electrical power factor through process optimization, since it has been held that there the general conditions of a claim are disclosed in the prior art, discovering the optimum or workable ranges involves only routine skill in the art. See In re Boesch, 205 USPQ 215.
Claims 22-26 are rejected under 35 U.S.C. 103 as being unpatentable over Song et al. (Pub. No. US-2021098676-A1, published 1 April 2021) in view of Li and Tang et al.
In regard to claim 22, Song et al. teaches a thermoelectric oxide ceramic composition with the generic formula Ca3-xM2xCo4O9M1y, wherein x may be 0.00-3.00, y may be 0.01-0.50 (Abstract), M2 may be Ce [0054] and M1 may preferably be Bi [0052]. Song et al. does not teach that the composition further comprises CeO in an amount of abut 1-5 wt% based on the combined weight of Ca3-xCo4O9Biy and CeO.
With regard to the use of CeO nanoinclusions, Li teaches that the addition of Cu2O nanoinclusions to a Ca3-xCexCo4O9+δ composition results in a depression of thermal conductivity via the scattering of phonon and the nanoinclusion-material grain boundaries (pp. 5, lines 6-9). But, while the physical effects of the nanoinclusions are positive, the poor conductivity of Cu2O decreases the materials thermopower, power factor, and overall ZT (pp. 5, line 13 – pp. 7, line 5). Li suggests the phonon scattering phenomenon from nanoinclusions may be used to guide the design of ideal nanocomposites as a conductive compound used as nanoinclusions may depress thermal conductivity while not affecting electrical conductivity (pp. 7, lines 11-16). Li does not teach that the nanoinclusions are CeOx. Tang et al. teaches that the doping of Ca3Co4O9+δ materials specifically with Ce (Ca3-xCexCo4O9+δ) has a significant positive impact on the thermopower of the composition, up to a ~130% in thermopower as compared to the undoped material via a spin-entropy enhancement. Notably, the inclusion of Ce does not negatively impact electrical conductivity to the degree to which the material overall is compromised. Tang et al. does not teach that the Ce added to the thermoelectric composition is in the form of nanoparticles or nanoinclusions.
One of ordinary skill in the art would seek to benefit from the depressed thermal conductivity provided by nanoinclusions but avoid the poor conductivity of the resulting material by employing a metal oxide which has improved electrical conductivity, as concluded by Li. From the prior art, it would have been obvious to utilize CeO nanoinclusions as it would provide advantageous depressed thermal conductivity through increased grain boundaries and comparable electric conductivity to other constituents due to the electronic configuration of the Ce. Song et al. already suggests Ce as a desirable dopant for thermoelectric oxide ceramic compositions [0054], and the combined teachings of Li and Tang et al. are suggestive that Ce doping of the composition in the form of CeO nanoinclusions would be highly successful in decreasing thermal conductivity and increasing thermopower, and in turn drastically improving the ZT of the material. Therefore, it would have been obvious to one of ordinary skill in the art to modify the compositions taught by Song et al. to include CeO nanoparticles as a dopant to improve the thermoelectric properties of the material as suggested by Li and Tang et al. Furthermore, Tang et al. teaches that nanoparticles are added to a Ca2.9Ce0.1Co4O9+δ composition in an amount of 1 wt%, 1.5 wt%, and 2 wt% with respect to the total weight of the composition, which are all with in instantly claimed loading range of ~1 wt-5 wt. It would have been obvious to one of ordinary skill to apply the loading amount of nanoinclusions taught by Tang et al. to the composition of Song et al. as Tang et al. discloses the added amounts of nanoinclusions are sufficient to depress thermal conductivity at 300 K (see Fig. 5, pp 6).
With regard to the amount of Ca displaced from the ceramic material’s lattice (x), Tang et al. teaches a thermoelectric oxide ceramic composition with the generic formula Ca3-xCexCo4O9+δ wherein x is equal to 0.1, 0.3, and 0.5 (pp. 2, Table 1). When also considering the Bi-containing composition of DE ‘990A1, an effective range of x is 0.1-0.75. The range of values of x overlaps the claimed ranges of about 0.1-0.5. The value of x, or how much the Ca3-xCo4O9+δ is doped with other metals, has a significant impact on the thermoelectric properties of the material as demonstrated by both DE ‘990A1 ([0040] & [0046]), and Tang et al. (Fig 2.). Therefore the instantly claimed ranges of x would have obvious to one of ordinary skill in the art at the time invention was made by selection of the overlapping portion of the range disclosed by the reference because overlapping ranges have been held to be a prima facie case of obviousness. In re Malagari, 182 USPQ.
With regard to the molar ratio of Bi in the composition (y), the range of Song et al. (0.01-0.5) overlaps the instantly claimed range of 0.01-0.4. The amount of Bi used as a dopant in the dual-dopant system is related to the reported increase in electrical conductivity and Seebeck coefficient [0062] and may be optimized for each value of x employed [0057]. With respect to the encompassing and overlapping ranges, the subject matter as a whole would have been obvious to one of ordinary skill in the art at the time of invention to select the portion of the prior art’s range which is within the range of the applicants’ claims because it has been held prima facie case of obviousness to select a value in a known range by optimization for the results. In re Aller, 105 USPQ 233. Additionally, the subject matter as a whole would have been obvious to one of ordinary skill in the art at the time invention was made to have selected the overlapping portion of the range disclosed by the reference because overlapping ranges have been held to be a prima facie case of obviousness. In re Malagari, 182 USPQ.
In regard to claim 23, the combined teachings of Song et al., Li, and Tang et al. utilize undoped CeOx nanoinclusions. As stated with regard to claim 22, it would have been obvious to one of ordinary skill to employ the undoped CeO nanoparticles of Li in the composition of Song et al. as a way to enhance the thermal conductivity of the composition overall.
In regard to claim 24, Song et al. teaches that Sm and Gd may be used as dopants in their compositions [0054]. Song et al. does not teach that Sm and Gd are dopants in CeOx nanoinclusions. As stated with regard to claim 22, it would have been obvious to one of ordinary skill to employ CeO nanoparticles in the composition of Song et al. as a way to enhance the thermal conductivity of the composition overall (based on the teachings of Li and Tang et al.). In a multiphase composition such as Ca3-xCo4O9+δBiy and CeOx, a person of ordinary skill would understand that additional dopants, such as Sm or Gd as taught by Song et al., could be added to the Ca3-xCo4O9+δBiy phase or the CeOx phase. As such, from a finite number of ways to dope the composition, a person of ordinary skill would arrive at the conclusion to dope the CeOx nanoparticles with Gd and/or Sm via routine optimization based upon the finite number of options available.
In regard to claim 25, Song et al. discloses compositions which at a temperature of 1073 K (800°C) have a ZT value of greater than 0.40-1.30, which overlaps the instantly claimed range of greater than about 0.5. A high ZT value, as previously discussed, is an important metric for the conversion of thermal energy to electricity, and is a highly desired characteristic of thermoelectric materials. As such, the subject matter as a whole would have been obvious to one of ordinary skill in the art at the time invention was made to have selected the overlapping portion of the range disclosed by the reference because overlapping ranges have been held to be a prima facie case of obviousness. In re Malagari, 182 USPQ.
In regard to claim 26, the combined teachings of Song et al., Li, and Tang et al. render obvious the composition as instantly claimed in claim 22. The electrical power factor, calculated from electrical conductivity and the Seebeck coefficient, is dependent upon the material’s composition. Therefore, a material which shares the instantly claimed composition would be expected to inherently possess an electrical power factor of about 1.0-3.0 W m-1 K-2 at about 323 K.
Song et al., Li, and Tang et al. do not report electrical power factors of thermoelectric oxide ceramic compositions as instantly claimed at an operating temperature of ~323 K. The closest reported compositions are of Song et al., which is a Ca2.95Tb0.05Co4O9Bi0.25 composition with an electrical power factor of ~1.9 mW K-2 m-1 at 300 K (Fig. 2C) and of Li, which reports that at 300 K an undoped Ca2.9Ce0.1Co4O9+δ has a thermopower of ~90 µV K-1, a thermal conductivity of ~1.20 W K-1 m-1, and an electric resistivity of ~0.00015 Ω m which results in an estimated electrical power factor (S2σ) of 0.054 mW K-2 m-1, which is outside the instantly claimed range.
After modification of the teachings of Song et al. with those of Li and Tang et al., to form a composition comprising Ca2.5-2.9Co4O9+δBi0.01-0.4 and 1-5 wt% CeO nanoinclusions, a person of ordinary skill would also be motivated to optimize the material for its electrical power factor, i.e. the Seebeck coefficient and electric conductivity, to improve the energy conversion efficiency of the thermoelectric oxide ceramic composition. Both the Seebeck coefficient, which quantifies the voltage generated from a temperature gradient across a material, and the electric conductivity, are pivotal to a material’s ability to convert heat to electricity. It would have been obvious to one having ordinary skill in the art at the time the invention was made to choose the instantly claimed electrical power factor through process optimization, since it has been held that there the general conditions of a claim are disclosed in the prior art, discovering the optimum or workable ranges involves only routine skill in the art. See In re Boesch, 205 USPQ 215.
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure:
Mihara et al. (US Pub. No. US-20070144573-A1, published 28 Jun 2007) for disclosing Ca3-xCo4O9 oxide composites doped with Bi, Ce, Sm, and Gd and associated thermoelectric properties.
Funahashi et al. (US Pub. No. US-20010017152-A1, published 30 Aug 2001) for disclosing Ca3-xRExCo4Oy oxide composites wherein RE can be one or more of Ce, Sm, or Gd.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to MORDECAI M LEAVITT whose telephone number is (571)272-6637. The examiner can normally be reached Monday-Friday 8AM-5PM.
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, CHRISTINA JOHNSON can be reached at (571) 272-1176. 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.
/MORDECAI M LEAVITT/ Examiner, Art Unit 1742 /CHRISTINA A JOHNSON/Supervisory Patent Examiner, Art Unit 1742
Prosecution Insights