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 I (claims 1-10) in the reply filed on 03/16/2026 is acknowledged.
Claims 11-20 are withdrawn from further consideration pursuant to 37 CFR 1.142(b) as being drawn to a nonelected group, there being no allowable generic or linking claim. Election was made without traverse in the reply filed on 03/16/2026.
Drawings
The drawings are objected to as failing to comply with 37 CFR 1.84(p)(5) because they do not include the following reference sign(s) mentioned in the description:
Seen in P46-47: 10XV1, 10PT1, 10REG, 10VEN, 10PT2, 10PSV, and 10XV2
Seen in P53: 210
Corrected drawing sheets in compliance with 37 CFR 1.121(d) are required in reply to the Office action to avoid abandonment of the application. Any amended replacement drawing sheet should include all of the figures appearing on the immediate prior version of the sheet, even if only one figure is being amended. Each drawing sheet submitted after the filing date of an application must be labeled in the top margin as either “Replacement Sheet” or “New Sheet” pursuant to 37 CFR 1.121(d). If the changes are not accepted by the examiner, the applicant will be notified and informed of any required corrective action in the next Office action. The objection to the drawings will not be held in abeyance.
The drawings are objected to as failing to comply with 37 CFR 1.84(p)(5) because they include the following reference character(s) not mentioned in the description:
As seen in Fig. 1: XV, PT, REG, VEN, PT, PSV, and REC.
Corrected drawing sheets in compliance with 37 CFR 1.121(d), or amendment to the specification to add the reference character(s) in the description in compliance with 37 CFR 1.121(b) are required in reply to the Office action to avoid abandonment of the application. Any amended replacement drawing sheet should include all of the figures appearing on the immediate prior version of the sheet, even if only one figure is being amended. Each drawing sheet submitted after the filing date of an application must be labeled in the top margin as either “Replacement Sheet” or “New Sheet” pursuant to 37 CFR 1.121(d). If the changes are not accepted by the examiner, the applicant will be notified and informed of any required corrective action in the next Office action. The objection to the drawings will not be held in abeyance.
Specification
The disclosure is objected to because of the following informalities:
It appears “grove” should be “groove” in Applicant’s P11 based upon Applicant’s Specification at P72.
Appropriate correction is required.
Claim Objections
Claim 9 is objected to because of the following informalities:
It appears “grove” should be “groove” in claim 9 based upon Applicant’s Specification at P72.
Appropriate correction is required.
Claim Interpretation
Claims 4 and 7-9 use the term “about”.
Applicant’s specification states “Approximating language, as used herein throughout the specification and claims, may be applied to modify any quantitative representation that could permissibly vary without resulting in a change in the basic function to which it is related. Accordingly, a value modified by a term or terms, such as “about,” and “substantially” is not to be limited to the precise value specified. In some instances, the approximating language may correspond to the precision of an instrument for measuring the value. Here and throughout the specification and claims, range limitations may be combined and/or interchanged. Such ranges are identified and include all the sub-ranges contained therein unless context or language indicates otherwise” (underline added by Examiner).
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 1 is rejected under 35 U.S.C. 103 as being obvious over Tighe et al (US 20070178355 A1, as given in the 06/27/2023 IDS) in view of Ko et al (US 20120070760 A1).
Regarding claim 1, Tighe discloses fuel cell system (10 in Fig. 1; see entire disclosure and especially P20) comprising a fuel cell including:
an anode and a cathode (anode side catalyst layer 26 and cathode side catalyst layer 22 I n Fig. 1; see entire disclosure and especially P20), a membrane electrode assembly (“The catalyst layers 22 and 26 and the membrane 16 define an MEA”, P20) on a first side of an anode gas diffusion layer (anode side diffusion media layer 24 in Fig. 1; see entire disclosure and especially P20), a bipolar plate on a second side of the anode gas diffusion layer comprising an anode flow field (an anode side flow field plate or bipolar plate 30 with hydrogen reactant gas flow from flow channels 28 in Fig. 1; see entire disclosure and especially P21), and
wherein the anode flow field comprises at least a first anode flow field configuration (when the actuators allow for a interdigitated reactant gas flow; see entire disclosure and especially P19, 24, 26) and a second anode flow field configuration (when the actuators allow for a straight reactant gas flow; see entire disclosure and especially P19, 24, 26), and
wherein hydrogen flows through the first anode flow field configuration and the second anode flow field configuration of the anode flow fields (reactant, which in the anode’s case is hydrogen, flows through the interdigitated configuration when the actuators close part of the channels and the straight configurations when the actuators open all of the channels),
wherein the first anode flow field configuration is an interdigitated flow configuration, and the second anode flow field configuration is a parallel flow configuration (see entire disclosure and especially P19, 24, 26).
However, Tighe does not disclose a microporous layer in between the membrane electrode assembly and the anode gas diffusion layer.
In a similar field of endeavor, Ko teaches a microporous layer can be interposed between a gas diffusion layer (GDL) and membrane electrode assembly (MEA) to further enhance water removal performance of a GDL (P59).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have utilized the teaching of Ko and provided to Tighe a microporous layer in between the membrane electrode assembly and the anode gas diffusion layer, such as that of Ko’s, given Ko teaches this can enhance water removal performance of a GDL.
Claims 1, 4, and 7 are rejected under 35 U.S.C. 103 as being obvious over Noh (US 20050287414 A1) in view of Margiott (US 6472095 B2).
Regarding claim 1, Noh discloses fuel cell system (100 in Fig. 1; see entire disclosure and especially P18) comprising a fuel cell (101 in Figs. 1-3; see entire disclosure and especially P20) including:
an anode and a cathode (anode 113 with catalyst 112 and cathode 115 with catalyst 112’ in Figs. 2-3; see entire disclosure and especially P22), a membrane electrode assembly (MEA 110 in Figs. 1-3 including the anode and cathode; see entire disclosure and especially P22) on a first side of an anode gas diffusion layer (anode gas diffusion layer 114 in Figs. 2-3; see entire disclosure and especially P28), a bipolar plate on a second side of the anode gas diffusion layer comprising an anode flow field (separator 120 in Figs. 1-3; see entire disclosure and especially P29), and
a microporous layer in between the membrane electrode assembly and the anode gas diffusion layer (see entire disclosure and especially P28).
However, Noh does not disclose wherein the anode flow field comprises at least a first anode flow field configuration and a second anode flow field configuration, wherein hydrogen flows through the first anode flow field configuration and the second anode flow field configuration of the anode flow fields, and wherein the first anode flow field configuration is an interdigitated flow configuration, and the second anode flow field configuration is a parallel flow configuration.
In a similar field of endeavor, Margiott teaches a hybrid reactant oxidant flow field configuration including ribs (17 in Fig. 2) that define parallel flow-through flow field channels (18 in Fig. 2), and a serpentine rib (20 in Fig. 2) that defines inlet channels (21 in Fig. 2) and outlet channels (22 in Fig. 2; C2 / L46-51). Margiott teaches instead of a serpentine rib as shown, other structure (such as that shown in FIG. 1) may be utilized to define the interdigitated flow field channels (C2 / L51-54).
Margiott teaches when reactant air flows through the flow field it reaches a transition point (26 in Fig. 2) wherein the oxygen in the air becomes depleted (C2 / L54-65). Margiott teaches their parallel-into-interdigitated design allows for substantial improvement in oxygen concentration, due to the forced convection of the air beneath the serpentine rib into the adjacent electro-catalyst support plate (C2 / L54-65). Margiott teaches objects of their invention include provision of fuel cells which take advantage of the reactant utilization obtainable with interdigitated reactant flow fields without requiring prohibitive parasitic power resulting from the need for increased pressure (C1 / L43-47).
While Margiott describes their invention in relation to an oxidant flow field and not an anode flow field, one of ordinary skill in the art would recognize that hydrogen, as well as oxygen, could both become depleted part of the way through a strictly-parallel flow field. Therefore, one of ordinary skill in the art would also recognize the benefits of applying Margiott’s invention to an anode flow field in order to provide improvement in hydrogen concentration due to the use of both parallel and interdigitated flow field designs. If a technique has been used to improve one device (provide a flow field wherein oxidant gas flows into parallel flow channels then into interdigitated flow channels to provide improvement in oxygen concentration), and a person of ordinary skill in the art would recognize that it would improve similar devices in the same way (provide a flow field wherein hydrogen gas flows into parallel flow channels then into interdigitated flow channels to provide improvement in hydrogen concentration), using the technique is obvious unless its actual application is beyond his or her skill. SEE MPEP § 2141 (III) Rationale C, KSR v. Teleflex (Supreme Court 2007).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have utilized the teaching of Margiott and modify Noh such that wherein the anode flow field comprises at least a first anode flow field configuration and a second anode flow field configuration, wherein hydrogen flows through the first anode flow field configuration and the second anode flow field configuration of the anode flow fields, and wherein the first anode flow field configuration is an interdigitated flow configuration, and the second anode flow field configuration is a parallel flow configuration, such as the hybrid flow field configuration of Margiott, given Margiott teaches this flow field configuration can improve the concentration of reactant within a reactant gas as it flow through a flow field plate without requiring prohibitive parasitic power resulting from the need for increased pressure.
Regarding claim 4, modified Noh meets the limitation wherein a ratio of a length of the first anode flow field configuration to a length of the second anode flow field configuration is about 1:1 (see Margiott Fig. 2).
Regarding claim 7 and the limitation “wherein a pressure drop in the first anode flow field configuration is about the same as a pressure drop in the second anode flow field configuration”:
Firstly, the structure required by claim 1, of which claim 7 depends, is substantially identical to and met by modified Noh. Therefore, it can be said that the property of the pressure drops being about the same in both the first anode flow field and the second anode flow field is met. Regarding product and apparatus claims, when the structure recited in the reference is substantially identical to that of the claims, claimed properties or functions are presumed to be inherent. The Courts have held that it is well settled that where there is a reason to believe that a functional characteristic would be inherent in the prior art, the burden of proof then shifts to the applicant to provide objective evidence to the contrary. See In re Schreiber, 128 F.3d at 1478, 44 USPQ2d at 1478, 44 USPQ2d at 1432 (Fed. Cir. 1997) (see MPEP § 2112.01, I.).
Further, Margiott teaches “A balance between the degree of reduction in reactant concentration and the reduction in required pressure drops will be achieved to suit the particular implementation of the invention” (C3 / L12-15).
Therefore, one of ordinary skill in the art would recognize that the pressure drops of each flow field are a result effect variable based upon the desired degree of reduction in reactant concentration. Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have optimized, through routine experimentation, the pressure drops of both the first anode flow field and the second anode flow field in order to reach one’s the desired degree of reduction in reactant concentration. “[W]here the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation.” See In re Aller, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1955). The discovery of an optimum value of a known result effective variable, without producing any new or unexpected results, is within the ambit of a person of ordinary skill in the art. See In re Boesch, 205 USPQ 215 (CCPA 1980) (see MPEP § 2144.05, II.).
Claim 2 is rejected under 35 U.S.C. 103 as being obvious over Noh (US 20050287414 A1) in view of Margiott (US 6472095 B2) as applied to claim 1, further in view of Limjeerajarus (Novel hybrid serpentine-interdigitated flow field with multi-inlets and outlets of gas flow channels for PEFC applications).
Regarding claim 2, modified Noh meets the limitation wherein the second anode flow field configuration is a parallel flow configuration (see Margiott Fig. 2). However, modified Noh does not meet the limitation wherein the first anode flow field configuration is a mixed flow configuration.
In a similar field of endeavor, Limjeerajarus teaches “The single channel serpentine minimizes flooding in the channel by forcing the gases out through its only channel. The liquid water cannot easily form up and block the channel. This type of flow field is often used as a reference design of PEFC GFC because of its high performance and simplicity. However, a major disadvantage of the is the large pressure drop created by friction along a single long narrow channel, especially in a large commercial cell area. The interdigitated flow field (Fig. 1d), which is dead-end channels, is mainly designed to enhance the convective flow under the rib which consequently helps the reactants to reach the reaction sites and also removes the liquid water in the porous media. Similarly, the interdigitated also provides the large pressure drop.”
Limjeerajarus teaches a hybrid serpentine-interdigitated flow field which was designed by considering that the pressure drop would be reduced by the decrease of flow channel length and the reactants would be able to reach the reaction sites under rib areas by the dead-end channels (Page 13602 Right Column).
Further, Limjeerajarus teaches their 2-IO hybrid serpentine-interdigitated flow field design provided lower pressure drop than the other flow fields tested (Page 13610 Left Column).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have utilized the teaching of Limjeerajarus and substituted the interdigitated flow field design of the first anode flow field configuration with the hybrid serpentine-interdigitated flow field of Limjeerajarus, given Limjeerajarus teaches the design can reduce pressure drop in comparison to a strict serpentine or interdigitated design.
Claim 8 is rejected under 35 U.S.C. 103 as being obvious over Noh (US 20050287414 A1) in view of Margiott (US 6472095 B2) as applied to claim 1, further in view of Hossain et al (Enhanced gas flow uniformity across parallel channel cathode flow field of Proton Exchange Membrane fuel cells).
Regarding claim 8 and the limitation “wherein a velocity of hydrogen flowing through the first anode flow field configuration is about the same as a velocity of hydrogen flowing through the second anode flow field configuration”:
Firstly, the structure required by claim 1, of which claim 8 depends, is substantially identical to and met by modified Noh. Therefore, it can be said that the property of the velocities being about the same in both the first anode flow field and the second anode flow field is met. Regarding product and apparatus claims, when the structure recited in the reference is substantially identical to that of the claims, claimed properties or functions are presumed to be inherent. The Courts have held that it is well settled that where there is a reason to believe that a functional characteristic would be inherent in the prior art, the burden of proof then shifts to the applicant to provide objective evidence to the contrary. See In re Schreiber, 128 F.3d at 1478, 44 USPQ2d at 1478, 44 USPQ2d at 1432 (Fed. Cir. 1997) (see MPEP § 2112.01, I.).
Alternatively, if Applicant disagrees:
In a similar field of endeavor, Hossain teaches Obtaining uniform flow of reactant gases across a flow field is crucial to get enhancement in electrical performance of the Polymer Electrolyte Membrane Fuel Cell (PEMFC) (Page 5272 Left Column).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have utilized the teaching of Hossain and provided uniform flow between the first anode flow field and the second anode flow field (therefore, wherein a velocity of hydrogen flowing through the first anode flow field configuration is about the same as a velocity of hydrogen flowing through the second anode flow field configuration), given Hossain teaches this is crucial to get enhancement in electrical performance of a Polymer Electrolyte Membrane Fuel Cell.
Claim 9 is rejected under 35 U.S.C. 103 as being obvious over Noh (US 20050287414 A1) in view of Margiott (US 6472095 B2) as applied to claim 1, further in view of Hatoh et al (US 20030211376 A1).
Regarding claim 9, modified Noh does not meet the limitation wherein the first anode flow field configuration includes a first grove of a width about 0.2 mm to 1 mm and the second anode flow field configuration includes a second grove of a width about 0.2 mm to 1 mm.
In a simile field of endeavor, Hatoh teaches a unit cell comprises an MEA comprising a hydrogen ion conductive polymer electrolyte membrane and a pair of electrodes respectively placed on opposite major surfaces of the electrolyte membrane, each of the electrodes comprising a gas diffusion layer and a catalyst layer; an electrically conductive separator plate contacting one of the electrodes and having a gas flow channel for supplying and exhausting a fuel gas to and from the one electrode; and a further electrically conductive separator plate contacting the other electrode and having a gas flow channel for supplying and exhausting an oxidant gas to and from the other electrode (P24).
Hatoh teaches each of the gas flow channels of each of the electrically conductive separator plates have a groove width of about 0.8 mm to 1 mm (P26, 73). Hatoh teaches when the groove width is greater than about 1 mm, particularly in the case of soft gas diffusion layers, e.g., of carbon cloth, the gas diffusion layer is likely to hang out or protrude into each groove or gas flow channel (P73). On the other hand, Hatoh teaches when the groove width is smaller than about 0.8 mm, the resultant amount of gas flow in each groove or gas flow channel may become undesirably insufficient (P73).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have utilized the teaching of Hatoh and modified the groove widths of the first anode flow field configuration and the first second flow field configuration to be between 0.8 mm and 1 mm, given Hatoh teaches this allows a balance between preventing a gas diffusion layer from protruding into the grooves/gas flow channels and providing a sufficient amount of gas flow in each groove/gas flow channel.
Claim 10 is rejected under 35 U.S.C. 103 as being obvious over Noh (US 20050287414 A1) in view of Margiott (US 6472095 B2) as applied to claim 1, further evidenced by Bhattacharya (Water flooding in the proton exchange membrane fuel cell).
Regarding claim 10 and the limitation “wherein a first local water saturation at the anode is lower than a second local water saturation at the cathode”:
Firstly, the structure required by claim 1, of which claim 10 depends, is substantially identical to and met by modified Noh. Therefore, it can be said that the property of the local water saturation at the anode being lower than the water saturation at the cathode is met. Regarding product and apparatus claims, when the structure recited in the reference is substantially identical to that of the claims, claimed properties or functions are presumed to be inherent. The Courts have held that it is well settled that where there is a reason to believe that a functional characteristic would be inherent in the prior art, the burden of proof then shifts to the applicant to provide objective evidence to the contrary. See In re Schreiber, 128 F.3d at 1478, 44 USPQ2d at 1478, 44 USPQ2d at 1432 (Fed. Cir. 1997) (see MPEP § 2112.01, I.).
Furthermore, Bhattacharya states a significant technical challenge in a proton exchange membrane fuel cell (PEMFC) is formation of excess water (Page 26 Right Column). Bhattacharya states the water formation is due to water production from the ORR at the cathode (Page 26 Right Column). Bhattacharya states electro-osmotic drag occurs when water is transported with the protons as they travel across the electrolyte from the anode to the cathode (Page 27 Left Column). Bhattacharya states the only way by which the cathode loses water is by back diffusion (Page 27 Left Column). Bhattacharya states if the rate of removal is slower than the generation and drag rates (at the cathode in particular), excess water will accumulate (Page 27 Left Column). Bhattacharya states the overall effect causes water flooding, which hinders the transport of oxygen by blocking the pores of the cathode and anode catalyst, resulting in plugging of the gas transport channels in the flow field (Page 27 Left Column).
Therefore, as can be seen by Bhattacharya, it is well known that water generation occurs at the cathode and floods the cathode before water transport makes it way to the anode.
Therefore, one of ordinary skill in the art would further believe that at, at least some point within the operation of the fuel cell system, a first local water saturation at the anode of modified Noh would be lower than a second local water saturation at the cathode of modified Noh.
Allowable Subject Matter
Claim 5, and thus claim 6, is objected to as being dependent upon a rejected base claim, but would be allowable if rewritten in independent form including all of the limitations of the base claim and any intervening claims.
Claim 5 recites “wherein the anode gas diffusion layer comprises a first anode gas diffusion layer corresponding to the first anode flow field configuration and a second anode gas diffusion layer corresponding to the second anode flow field configuration, and wherein the first anode gas diffusion layer is hydrophilic and the second anode gas diffusion layer is hydrophobic”.
Modified Tighe and modified Noh both include an anode gas diffusion layer, a first anode flow field configuration that is an interdigitated flow configuration, and a second anode flow field configuration that is a parallel flow configuration. However, neither of them teach wherein the gas diffusion layer includes a hydrophilic first anode gas diffusion layer corresponding to the interdigitated first anode flow field configuration or a hydrophobic second anode gas diffusion layer corresponding to the parallel second anode flow field configuration.
Further search and consideration revealed Kourtakis (US 20060286435 A1) which teaches gas diffusion backing for a proton exchange membrane fuel cell can optionally be treated to exhibit hydrophilic or hydrophobic behavior (P35).
Further search and consideration also revealed Lim et al (Performance improvement of polymer electrolyte membrane fuel cell by gas diffusion layer with atomic-layer-deposited HfO2 on microporous layer).
Lim states “Kitahara et al. [12,13] made hydrophilic and hydrophobic double MPL coated GDL and performed the optimization of the GDL under various humidity conditions… Shrestha et al. [18] coated a hydrophilic microporous layer to a commercial hydrophobic bi- layer GDL. PEMFC with the modified GDL decreased the ohmic resistance without anode humidification but increased mass transport resistance at high current densities… Guo et al. [20] made GDL with hydro phobic and hydrophilic synergistic surfaces using an ultrasonic atomizing hydrophilic reagent, and the GDL improved the PEMFC peak power due to its enhanced water management” (Page 1 Right Column to Page 2 Left Column). Lim stated their experiments included a reference gas diffusion layer (GDL) modified by deposition of HfO2 on the microporous layer (MPL) using atomic layer deposition (ALD) (Abstract, Page 2 Right Column).
However, none of the prior arts above specify that a hydrophilic section of a gas diffusion layer should correspond to a section of a bipolar plate having an interdigitated flow design while a hydrophobic section of a gas diffusion layer should correspond to a section of a bipolar plate having a parallel flow design.
Claim 6 is dependent upon claim 5, therefore, is objected for the same reasons.
Conclusion
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/MARY GRACE HARRIS/Examiner, Art Unit 1729
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