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 .
Specification
The disclosure is objected to because of the following informalities: in line 1 of paragraph [0004], “(SOEC)” should be “(SOFC)”.
Appropriate correction is required.
Claim Rejections - 35 USC § 102
The following is a quotation of the appropriate paragraphs of 35 U.S.C. 102 that form the basis for the rejections under this section made in this Office action:
A person shall be entitled to a patent unless –
(a)(1) the claimed invention was patented, described in a printed publication, or in public use, on sale, or otherwise available to the public before the effective filing date of the claimed invention.
(a)(2) the claimed invention was described in a patent issued under section 151, or in an application for patent published or deemed published under section 122(b), in which the patent or application, as the case may be, names another inventor and was effectively filed before the effective filing date of the claimed invention.
Claims 1-20 are rejected under 35 U.S.C. 102(a)(2) as being anticipated by Kobayashi et al (US 2023/0075910, equivalent to EP 4145572 A1 (cited by Applicant) and JP 2023038086 A).
The applied reference has a common joint inventor and applicant with the instant application. Based upon the earlier effectively filed date of the reference, it constitutes prior art under 35 U.S.C. 102(a)(2). This rejection under 35 U.S.C. 102(a)(2) might be overcome by: (1) a showing under 37 CFR 1.130(a) that the subject matter disclosed in the reference was obtained directly or indirectly from the inventor or a joint inventor of this application and is thus not prior art in accordance with 35 U.S.C. 102(b)(2)(A); (2) a showing under 37 CFR 1.130(b) of a prior public disclosure under 35 U.S.C. 102(b)(2)(B) if the same invention is not being claimed; or (3) a statement pursuant to 35 U.S.C. 102(b)(2)(C) establishing that, not later than the effective filing date of the claimed invention, the subject matter disclosed in the reference and the claimed invention were either owned by the same person or subject to an obligation of assignment to the same person or subject to a joint research agreement.
Kobayashi et al teach (see abstract, fig. 1, paragraphs [0031]-[0051]) an interconnector for a solid oxide electrochemical cell comprising a ferritic stainless steel substrate (i.e. a metal base including an iron-based alloy containing chromium), an oxide layer (i.e. a protective film) disposed on a surface of the metal base, and a metal layer (i.e. an interlayer) disposed between the substrate and the oxide layer.
Although Kobayashi et al fail to expressly teach that the metal layer was arranged to relieve stress, it is noted that Kobayashi et al teach the metal layer being gold, silver, or copper, and that instant claim 7recites that a suitable metal for the interlayer including gold, silver, or copper. Thus, the evidence of record supports the conclusion that the metal layer of Kobayashi et al was inherently arranged to relieve stress.
Regarding claims 2-7, Kobayashi et al teach (see paragraph [0039]) that among the purposes of the metal layer was to prevent diffusion of chromium from the substrate through the oxide layer. The chromium was hardly soluble in the metal layer and thus necessarily possessed a smaller self-diffusion coefficient and smaller Young’s modulus as claimed since the structure taught by Kobayashi et al is made from identical materials as the instantly disclosed invention.
Regarding claim 8, Kobayashi et al are silent with respect to the presence of a wrinkle on the surface of the interlayer. However, a review of the instant specification, particularly paragraph [0035]) shows that the wrinkles seen in fig. 4 are formed by exposing a ferritic stainless steel coated with the metal underlayer/oxide protective layer to an oxidizing atmosphere at 700°C. No active step is taught to achieve the wrinkles. Therefore, since Kobayashi et al teach exposing an identical coated ferritic stainless steel substrate to identical conditions (see paragraph [0074] of Kobayashi et al), one of ordinary skill in the art at the time of filing would have expected the same inherent formation of wrinkles.
Regarding claims 9 and 10, Kobayashi et al teach (see paragraphs [0047]-[0049]) providing either a spinel oxide containing cobalt or a perovskite oxide containing lanthanum as the protective film.
Regarding claim 11, Kobayashi et al teach (see paragraph [0058]) that the metal layer preferably has a thickness of 0.5 to 20 mm.
Regarding claim 12, Kobayashi et al teach (see paragraph [0059]) that the oxide layer preferably has a thickness of 1 to 50 mm.
Regarding claim 13, Kobayashi et al teach (see paragraph [0033]) providing the protective coating on both surfaces of the interconnector.
Regarding claim 14, Kobayashi et al, as above, teach a solid oxide electrochemical cell stack comprising the interconnector according to claim 1. Kobayashi et al further teach (see fig. 2b, paragraph [0065]) providing a plurality of electrochemical cells, each comprising a first electrode (fuel electrode 201), a second electrode (air electrode 203), and a solid oxide electrolyte (202). The protective coatings of the interconnector were disposed on both surfaces of the interconnector (see paragraph [0033]) and thus is disposed on the second electrode side of the first electrochemical cell (as well as the first electrode side of the second electrochemical cell).
Regarding claim 15, Kobayashi et al show (see fig. 2b) a third electrochemical cell in the stack.
Regarding claims 16-20, Kobayashi et al teach (see paragraph [0039]) that among the purposes of the metal layer was to prevent diffusion of chromium from the substrate through the oxide layer. The chromium was hardly soluble in the metal layer and thus necessarily possessed a smaller self-diffusion coefficient and smaller Young’s modulus as claimed since the structure taught by Kobayashi et al is made from identical materials as the instantly disclosed invention.
Claims 1-11 and 14-20 are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Sun et al (US 2013/0216931) with evidence from Shaigan et al (“A review of recent progress in coatings, surface modifications and alloy developments for solid oxide fuel cell ferritic stainless steel interconnects”).
Sun et al teach (see abstract, fig. 1, paragraphs [0016]-[0024]) an interconnect (30) comprising a metal base coated with a metallic under-layer (42) which is further coated by a protective film (46) of an oxide.
Although Sun et al fail to expressly teach that the metallic under-layer was arranged to relieve stress, it is noted that Sun et al teach the metal layer being copper, zinc, or titanium and that instant claim 7 recites that suitable metals for the interlayer included copper, zinc, or titanium. Thus, the evidence of record supports the conclusion that the metallic sub-layer of Sun et al was inherently arranged to relieve stress.
Although Sun et al fail to distinctly disclose the composition of the metal base, it is noted that the purpose of the coatings included (see paragraph [0031]) eliminating evaporation of chromium from chromia forming alloy substrates.
As evidenced by Shaigan et al (see sections 1 and 2) the chromium evaporation problem was a problem associated with ferritic stainless steel when utilized as the interconnect in a solid oxide fuel cell.
Therefore, the evidence of record supports the conclusion that one of ordinary skill in the art at the time of filing would have immediately envisaged that the undescribed material of the interconnect of Sun et al was a ferritic stainless steel since it was the primarily utilized material for the interconnect in the prior art and had the chromium evaporation problem.
Regarding claims 2-7, Sun et al teach (see paragraph [0021]) that among the purposes of the metal layer was to prevent diffusion of chromium from the substrate through the oxide layer. In at least one embodiment the metal under-layer was chosen to have low chromium diffusivity. The metal under-layer necessarily possessed a smaller Young’s modulus as claimed since the layers taught by Sun et al are made from identical materials as the instantly disclosed invention.
Regarding claim 8, Sun et al are silent with respect to the presence of a wrinkle on the surface of the metal sublayer. However, a review of the instant specification, particularly paragraph [0035]) shows that the wrinkles seen in fig. 4 are formed by exposing a ferritic stainless steel coated with the metal underlayer/oxide protective layer to an oxidizing atmosphere at 700°C. No active step is taught to achieve the wrinkles. Therefore, since Sun et al teach exposing an identical coated ferritic stainless steel substrate to similar conditions (see paragraph [0033] of Sun et al teaching operation of a SOFC using the coated substrate), one of ordinary skill in the art at the time of filing would have expected the same inherent formation of wrinkles.
Regarding claims 9 and 10, Sun et al teach (see paragraph [0024]) providing either a spinel oxide containing cobalt or a perovskite oxide containing lanthanum as the protective film.
Regarding claim 11, Sun et al teach (see paragraph [0020]) that the metal under-layer preferably has a thickness of less than 20 mm.
Regarding claim 14, Sun et al, as above, teach a solid oxide electrochemical cell stack comprising the interconnector (30) according to claim 1. Sun et al further teach (see fig. 1, paragraphs [0016]-[0019]) providing a plurality of electrochemical cells (10, comprising multiple cells 12), each comprising a first electrode (anode electrode 26), a second electrode (cathode electrode 22), and a solid oxide electrolyte (18). The protective coatings of the interconnector were disposed on the surface of the interconnector facing the cathode (air) electrode (see paragraph [0019]) and thus is disposed on the second electrode side of the first electrochemical cell.
Regarding claim 15, Sun et al show (see fig. 1) a third electrochemical cell in the stack.
Regarding claims 16-20, Sun et al teach (see paragraph [0021]) that among the purposes of the metal layer was to prevent diffusion of chromium from the substrate through the oxide layer. In at least one embodiment the metal under-layer was chosen to have low chromium diffusivity. The metal under-layer necessarily possessed a smaller Young’s modulus as claimed since the layers taught by Sun et al are made from identical materials as the instantly disclosed invention.
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.
Claim 12 is rejected under 35 U.S.C. 103 as being unpatentable over Sun et al (US 2013/0216931) in view of Shaigan et al (“A review of recent progress in coatings, surface modifications and alloy developments for solid oxide fuel cell ferritic stainless steel interconnects”).
Sun et al fail to teach the thickness of the protective oxide layer.
Shaigan et al teach (see sections 1 and 2) known coatings for ferritic stainless steel to adapt it for use as an interconnect for solid oxide fuel cells. The coatings included either perovskite oxides (see section 4) or spinel oxides (see section 5). The thickness of these coatings was described as being 3-4 mm (perovskite) or “from a few nanometers to hundreds of microns” (spinel).
Therefore, it would have been obvious to one of ordinary skill in the art at the time of filing to have applied the protective oxide layer of Sun et al at a conventional thickness within the claimed range as taught by Shaigan et al.
Claim 13 is rejected under 35 U.S.C. 103 as being unpatentable over Sun et al (US 2013/0216931) in view of Brevet et al (WO 2013/171651).
Sun et al teach applying the protective oxide coating on the surface of the interconnect that faces the air electrode which is exposed to an oxidizing atmosphere during operation of the SOFC.
Sun et al fail to teach also applying the protective oxide coating on the surface of the interconnect that faced the fuel electrode which is exposed to a reducing atmosphere during operation of the SOFC.
Brevet et al teach (see abstract, fig. 2, paragraphs [0011]-[0018], [0032]-[0033] and [0036] of machine translation) that perovskite oxides that were known for protecting the oxygen side of an interconnector in SOFC or SOEC also improved the reliability of the interconnector when applied to the reducing atmosphere on the opposite side of the interconnector.
Therefore, it would have been obvious to one of ordinary skill in the art at the time of filing to have applied the protective layers of Sun et al to both sides of the interconnect as suggested by Brevet et al as improving the reliability of the interconnect as compared to not coating the reducing atmosphere side.
Conclusion
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/HARRY D WILKINS III/Primary Examiner, Art Unit 1794