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 Arguments
Applicant's arguments filed 8/21/2025 have been fully considered and are persuasive. Applicant argues the primary reference cited in the previous action (Sriramulu et al., US20050118482A1) does not disclose the new Claim 1 limitations. Applicant’s new limitations are supported by the instant disclosure.
Although Sriramulu teaches many aspects of the claimed invention, Examiner agrees Sriramulu does not disclose, teach, or suggest the new limitation. Therefore, the rejection has been withdrawn. After an updated search and consideration of the amended claims, a new ground(s) of rejection is made in view of Blackburn et al., US 20210143447 A1, who discloses a solid oxide fuel cell comprising the claimed first and second channels perpendicular to each other.
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.
Claims 1, 5, 6, 8, 16, 18, and 19 are rejected under 35 U.S.C. 102(a)(1) and (a)(2) as being anticipated by Blackburn et al., US 20210143447 A1.
Regarding Claim 1, Blackburn discloses a solid oxide fuel cell (solid oxide fuel cell “SOFC” [0025-0028], Figs. 1-3A, 11; Annotated Figs. 1-2) comprising:
an anode (fuel electrode [0028], anode 130 in cell 100 [0028, 0084, 0093-0096], Figs. 1, 2, 11);
a cathode (oxygen electrode [0028], cathode 110 in cell 100 [0084-0085], Figs. 1, 2, 11);
an electrolyte between the anode and the cathode (solid electrolyte 120 [0084-0089] between anode 130 and cathode 110 in Figs. 1-2), the electrolyte comprising zirconia (YSZ or ScSZ [0028]); and
at least one current collector (interconnect 200 [0101-0104, 0141]) on a surface of the anode opposite the electrolyte and/or a surface of the cathode opposite the electrolyte (cell 100 is disposed in direct mechanical and electrical contact with the interconnects 200 [0141], Figs. 2 and 11), the at least one current collector including one or more first channels in a first surface (Annotated Fig. 2) and one or more second channels in a second surface opposite of the first surface (Annotated Fig. 2), the one or more second channels being substantially perpendicular to the one or more first channels (oxygen 150 and fuel 160 flow in directions perpendicular to each other [0101-0102], Fig. 2),
wherein the at least one current collector (200) comprises a material of Mn+1AXn composition, wherein M is an early transition metal, A is a Group IIIA element or a Group IVA element, X is carbon (C) or nitrogen (N), and n is an integer from 1 to 3 (interconnect 200 may comprise a coating 720, coating 720 compositions include Ti3SiC2 [0132-0133], Fig. 11).
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Blackburn – Annotated Fig 1 (left) and Annotated Fig. 2 (right)
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Blackburn – Fig. 11
Regarding Claim 5, Blackburn discloses all limitations as set forth above. Blackburn discloses the electrolyte (120) comprises yttria-stabilized zirconia (YSZ) or scandia-stabilized zirconia (ScSZ) ([0028]).
Regarding Claim 6, Blackburn discloses all limitations as set forth above. Blackburn discloses the at least one current collector (200) comprises a non-planar surface adjacent to the surface of the anode opposite the electrolyte and/or the surface of the cathode opposite the electrolyte (interconnect 200 is nonplanar, has ribs and channels to enable cross-flow, in which the oxygen source 150 and the fuel 160 flow in directions perpendicular to each other [0101-0102], Figs. 2 and 11, Annotated Fig. 2).
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Blackburn – Annotated Fig. 2
Regarding Claim 8, Blackburn discloses all limitations as set forth above. Blackburn discloses the anode comprises nickel and yttria-stabilized zirconia (YSZ) (anode 130 includes, consists essentially of, or consists of a composite of Ni and YSZ, Ni—YSZ [0028, 0092]).
Regarding Claim 16, Blackburn discloses a solid oxide fuel cell system (solid oxide fuel cell “SOFC” stack [0025-0028, 0100-0105, 0141], Figs. 1-3A, 11) comprising:
a stack of solid oxide fuel cells (one or more repeat units [0033], repeat units 310 are SOFC cells 100 [0084, 0105], Figs. 1-3A), the solid oxide fuel cells each comprising:
an anode (fuel electrode [0028], anode 130 in cell 100 [0028, 0084, 0093-0096], Figs. 1, 2, 11);
a cathode (oxygen electrode [0028], cathode 110 in cell 100 [0084-0085], Figs. 1, 2, 11);
an electrolyte between the anode and the cathode (solid electrolyte 120 [0028, 0084-0089] between anode 130 and cathode 110 in Fig. 1); and
current collectors (interconnects 200 [0100-0104]) individually interposed between the anode of a first solid oxide fuel cell (see fuel-side portion of interconnect 200 in Annotated Fig. 2) of a pair of adjacent solid oxide fuel cells and the cathode of a second solid oxide fuel cell of the pair of adjacent solid oxide fuel cells (multiple cells 100 separated by interconnects 200, cell 100 is disposed in direct mechanical and electrical contact with the interconnects 200 [0100-0104, 0141], Figs. 2, 3A, and 11, Annotated Fig. 2), each current collector including one or more first channels in a first surface and one or more second channels in a second surface opposite of the first surface, the one or more second channels being substantially perpendicular to the one or more first channels (interconnect 200 is nonplanar, has ribs and channels to enable cross-flow, in which the oxygen source 150 and the fuel 160 flow in directions perpendicular to each other [0101-0102], Annotated Fig. 2),
wherein the current collectors (200) comprise a material of Mn+1AXn composition, wherein M is an early transition metal, A is a Group IIIA element or a Group IVA element, X is carbon (C) or nitrogen (N), and n is an integer from 1 to 3 (interconnect 200 may comprise a coating 720, coating 720 compositions include Ti3SiC2 [0132-0133], Fig. 11).
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Blackburn – Annotated Fig. 2
Regarding Claim 18, Blackburn discloses all limitations as set forth above. Blackburn discloses the electrolyte comprises yttria-stabilized zirconia (YSZ) or scandia-stabilized zirconia (ScSZ) ([0028]).
Regarding Claim 19, Blackburn discloses all limitations as set forth above. Blackburn discloses the at least one current collector (200) comprises a non-planar surface adjacent to the surface of the anode opposite the electrolyte and/or the surface of the cathode opposite the electrolyte (interconnect 200 is nonplanar, has ribs and channels to enable cross-flow, in which the oxygen source 150 and the fuel 160 flow in directions perpendicular to each other [0101-0102], Figs. 2 and 11, see Annotated Fig. 2 in Claim 6).
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 2, 3, and 20 are rejected under 35 U.S.C. 103 as being unpatentable over Blackburn as applied to Claims 1 and 16 above, and further in view of Sriramulu et al., US 20050118482 A1 (previously cited).
Regarding Claim 2, Blackburn discloses all limitations as set forth above. Blackburn does not disclose “a coefficient of thermal expansion of the at least one current collector at an operating temperature is within a range of from about 90% to about 110% of a coefficient of thermal expansion of the electrolyte at the operating temperature.” However, this limitation is taught by Sriramulu.
Sriramulu teaches a SOFC with a Ti3SiC2-coated interconnect, wherein the interconnect should have a CTE that is within about 20%, preferably within about 10%, more preferably within about 2.5%, of a CTE of another component within the SOFC ([0031-0043]). Sriramulu teaches similar CTEs among SOFC components will reduce/eliminate any stress, strain, or deformation between the components during operation and/or cycling thereof ([0032]). Examiner notes Sriramulu and Blackburn both disclose Ti3SiC2 as a current collector coating material, and YSZ as an electrolyte material (Sriramulu, [0043, 0050]; Blackburn, [0132, 0028]).
Before the effective filing date of the present invention, it would have been obvious to a person of ordinary skill in the art to ensure the interconnect of Blackburn has a CTE within about 2.5% of the electrolyte CTE, and would have been motivated to do so, as Sriramulu teaches a small variation in CTE between SOFC components will reduce or eliminate any stress, strain, or deformation between the components.
Regarding Claims 3 and 20, Blackburn discloses all limitations as set forth above. Blackburn does not disclose “a coefficient of thermal expansion of the at least one current collector is within a range of from about 10 parts per million (ppm) to about 13 ppm at about 800°C.” However, this limitation is taught by Sriramulu.
Sriramulu teaches a SOFC with a coated interconnect, wherein the base material of the interconnect has a CTE in a range of 9.5 ppm to 12.5 ppm ([0040-0043], SOFC operating environment of 200ºC to 900ºC [0027]). Sriramulu teaches the coating should have a CTE that is within 5% of the base material CTE ([0043]). Sriramulu teaches similar CTEs among SOFC components will reduce/eliminate any stress, strain, or deformation between the components during operation and/or cycling thereof ([0032]), and the composition of the interconnect can be adjusted to reach a target CTE value ([0030, 0070]).
Before the effective filing date of the present invention, it would have been obvious to a person of ordinary skill in the art to have Blackburn’s interconnect CTE be within a range of 10 ppm to 13 ppm, as Sriramulu teaches a similar range will reduce or eliminate any stress, strain, or deformation between the SOFC components.
Claims 4 and 17 are rejected under 35 U.S.C. 103 as being unpatentable over Blackburn as applied to Claims 1 and 16 above, and further in view of Ljungcrantz et al., US 20110033784 A1 (previously cited).
Regarding Claims 4 and 17, Blackburn discloses all limitations as set forth above. Blackburn does not disclose the material of Mn+1AXn composition (Ti3SiC2) comprises chromium aluminum carbide (Cr2AlC). However, this limitation is taught by Ljungcrantz.
Ljungcrantz teaches a coating for a current collector (fuel cell 27 includes a coating 29 on conducting substrate 28 [0056-0057], Fig. 1C), wherein the coating is a multielement material of Mn+1AXn composition (Mn+1AXn, where M may be chromium, A may be aluminum, X is carbon or nitrogen or both, and n is 1, 2, 3 or higher [0056-0061]). Although Ljungcrantz teaches Ti3SiC2 is an acceptable coating composition ([0027]), Ljungcrantz’s coating formula also permits a coating composition of Cr2AlC, and teaches M is preferably Cr or Ni, as Cr and Ni improve corrosion resistance for the fuel cell ([0025]).
Before the effective filing date of the present invention, it would have been obvious to a person of ordinary skill in the art to replace the Ti3SiC2 interconnect coating of Blackburn with the Cr2AlC coating of Ljungcrantz, and would have been motivated to do so, as Ljungcrantz teaches a Mn+1AXn coating including chromium will increase corrosion resistance of the collector.
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Ljungcrantz – Fig. 1C
Claim 7 is rejected under 35 U.S.C. 103 as being unpatentable over Blackburn as applied to Claim 1 above, and further in view of Son et al., US 20120251917 A1 (previously cited).
Regarding Claim 7, Blackburn discloses all limitations as set forth above. Although Blackburn discloses the cathode (110) comprises lanthanum composite materials ([0028, 0085]), and discloses lanthanum strontium manganese (LSM) is one of the most common oxygen-electrode materials ([0029]), Blackburn does not disclose the cathode material comprises “a lanthanide element and yttria-stabilized zirconia (YSZ).” However, a composite LSM-YSZ cathode in a SOFC is disclosed by Son.
Son teaches a cathode for a SOFC, wherein the cathode comprises lanthanum strontium manganite (LSM) and YSZ (LSM-YSZ composite cathode with 8 mol % YSZ [0095-0099]). Son teaches a composite LSM-YSZ cathode significantly improves resistance and overall SOFC performance when compared to a LSM cathode ([0107-0110], Table 3).
Before the effective filing date of the present invention, it would have been obvious to a person of ordinary skill in the art to add LSZ to the LSM cathode of Blackburn, and would have been motivated to do so, as Son discloses superior SOFC performance can be achieved with an LSM-YSZ composite cathode when compared to an LSM-only cathode.
Pertinent Prior Art
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure: Mills, US 20130084474 A1. Mills discloses a SOFC may include an electrically conductive carbide support material and lists Cr2AlC and Ti3SiC2 as appropriate carbide materials ([0002, 0212-0220]).
Conclusion
Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a).
A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to BETHANY C GARCIA whose telephone number is (571)272-2475. The examiner can normally be reached Mon-Fri, 0800 - 1730 MT.
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If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Allison Bourke can be reached at 303-297-4684. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/BETHANY C GARCIA/Examiner, Art Unit 1721
/ALLISON BOURKE/Supervisory Patent Examiner, Art Unit 1721
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