Electrochemical cells with improved fluid flow design

Abstract

An electrochemical cell stack has a plurality of electrochemical cells stacked along a longitudinal axis. The electrochemical cell includes a membrane electrode assembly, the membrane electrode assembly including a cathode catalyst layer, an anode catalyst layer, and a polymer membrane interposed between the cathode catalyst layer and the anode catalyst layer. The electrochemical cell also includes an anode plate and a cathode plate, the membrane electrode assembly is interposed between the anode plate and the cathode plate, and the anode plate defines a plurality of channels, and the plurality of channels form an anode flow field facing the anode catalyst layer. The electrochemical cell also includes a cathode flow field, the cathode flow field is located between the cathode plate and the cathode catalyst layer, wherein the cathode flow field includes a porous structure.

Description

[0001] This application claims the benefit of U.S. Provisional Application No. 62 / 618,228, filed on January 17, 2018, the entire contents of which are incorporated by reference. Technical Field

[0002] The present disclosure relates to electrochemical cells and, more particularly, to electrochemical cells having improved fluid flow designs. Background Art

[0003] Electrochemical cells, generally classified as fuel cells or electrolytic cells, are devices used to generate electric current from a chemical reaction or to initiate a chemical reaction using the flow of electric current. For example, a fuel cell converts the chemical energy of a fuel (e.g., hydrogen, natural gas, methanol, gasoline, etc.) and an oxidant (air or oxygen) into electricity and waste products of heat and water. A basic fuel cell includes a negatively charged anode, a positively charged cathode, and an ion-conducting material called an electrolyte.

[0004] Different fuel cell technologies utilize different electrolyte materials. For example, a proton exchange membrane (PEM) fuel cell utilizes a polymer ion conducting membrane as the electrolyte. In a hydrogen PEM fuel cell, hydrogen atoms are electrochemically decomposed into electrons and protons (hydrogen ions) at the anode. The electrons then flow through a circuit to the cathode and generate electricity, while the protons diffuse through the electrolyte membrane to the cathode. At the cathode, the hydrogen protons combine with the electrons and oxygen (supplied to the cathode) to produce water and heat.

[0005] An electrolysis cell represents a fuel cell operated in reverse. A basic electrolysis cell acts as a hydrogen generator by decomposing water into hydrogen and oxygen when an external potential is applied. The basic technology of a hydrogen fuel cell or electrolysis cell can be applied to electrochemical hydrogen manipulation, such as electrochemical hydrogen compression, purification or expansion. Electrochemical hydrogen manipulation has become a viable alternative to mechanical systems traditionally used for hydrogen management. The successful commercialization of hydrogen as an energy carrier and the long-term sustainable development of the "hydrogen economy" depend to a large extent on the efficiency and cost-effectiveness of fuel cells, electrolysis cells and other hydrogen manipulation / management systems.

[0006] In operation, a single fuel cell can generally generate about 1 volt. In order to obtain the desired amount of electrical power, individual fuel cells are combined to form a fuel cell stack, in which the fuel cells are stacked in sequence. Each fuel cell may include a cathode, an electrolyte membrane, and an anode. The cathode / membrane / anode assembly constitutes a "membrane electrode assembly" or "MEA", which is generally supported on both sides by a bipolar plate. The reactant gas or fuel (e.g., hydrogen) and the oxidant (e.g., air or oxygen) are supplied to the electrodes of the MEA through a flow field. In addition to providing mechanical support, the bipolar plate (also referred to as a flow field plate or separator plate) physically separates the individual cells in the stack while electrically connecting them. Typically, a fuel cell stack includes a manifold and an inlet port, which is used to guide the fuel and oxidant to the anode flow field and the cathode flow field, respectively. The fuel cell stack also includes an exhaust manifold and an outlet port, which is used to discharge excess fuel and oxidant. The fuel cell stack may also include a manifold for circulating a coolant fluid to help discharge the heat generated by the fuel cell stack.

[0007] In a fuel cell, it is desirable that the fuel and oxidant be completely evenly distributed throughout the flow field in order to maximize the active area of ​​the utilized MEA, thereby improving overall performance. However, prior art fuel cell designs have been striving to achieve completely even distribution. Additionally, it is desirable that there not be excessive pressure drops along the flow paths of the fuel and oxidant, which would otherwise consume some of the electrical energy generated by the fuel cell stack and reduce the overall efficiency of the fuel cell stack. Thus, improving the flow design of fuel cells has been a challenge.

[0008] Another way to improve the overall performance and power density of the fuel cell stack may be to reduce the pitch (i.e., spacing) between adjacent cells of the fuel cell stack and / or the thickness of the cells. The cell thickness may be reduced, for example, by reducing the thickness of the flow field of each individual fuel cell. However, since the reduction in flow path caused by compressing the fuel cell stack may increase the load on the fuel cell stack, this may be difficult to achieve without causing excessive pressure drops along the fuel and oxidant flow paths. Summary of the invention

[0009] In view of the foregoing, the present disclosure is directed to a fuel cell and fuel cell stack design having an improved flow design and improved performance and power density.

[0010] In one aspect, the present disclosure relates to an electrochemical cell stack having a plurality of electrochemical cells stacked along a longitudinal axis. The electrochemical cells may each include a membrane electrode assembly including a cathode catalyst layer, an anode catalyst layer, and a polymer membrane interposed between the cathode catalyst layer and the anode catalyst layer. The electrochemical cells may also each include an anode plate and a cathode plate, between which a membrane electrode assembly is interposed, and the anode plate defines a plurality of channels, which form an anode flow field facing the anode catalyst layer. The electrochemical cells may also each include a cathode flow field, which is located between the cathode plate and the cathode catalyst layer, wherein the cathode flow field includes a porous structure. In some embodiments, the electrochemical cells may each include a first manifold segment including an anode supply manifold and a second manifold segment including an anode exhaust manifold; a first anode distribution channel located between the first manifold segment and the anode flow field, the first anode distribution channel being configured to distribute fuel supplied from the anode supply manifold to the anode flow field; and a second anode distribution channel located between the second manifold segment and the anode flow field, the second anode distribution channel being configured to collect fuel from the anode flow field and direct the fuel to the anode exhaust manifold. In some embodiments, the first anode distribution channel and the second anode distribution channel may be formed along the longitudinal axis between the membrane electrode assembly and the anode plate and defined by it. In some embodiments, the first anode distribution channel and the second anode distribution channel may extend the width of the anode flow field. In some embodiments, the first anode distribution channel and the second anode distribution channel may have a plurality of support features located therein. In some embodiments, the support features may be evenly spaced throughout the first anode distribution channel and the second anode distribution channel. In some embodiments, the support features may be in the shape of a pit. In some embodiments, the support features may extend in opposite directions from the anode plate along the longitudinal axis. In some embodiments, the distance DC between the support features can range from about 3 to about 50 over the thickness tp of the cathode plate. In some embodiments, the distance DC between the support features is about 1.5 mm, while the thickness tp of the cathode plate is about 0.1 mm. In some embodiments, the electrochemical cells can each include a plurality of orifice openings that connect the first anode distribution channel to the anode flow field fluid. In some embodiments, the number of orifice openings can correspond to the number of channels in the anode flow field. In some embodiments, the orifice openings can be configured to apply back pressure on the fuel in the first anode distribution channel, which allows the fuel to fill the first anode distribution channel during operation of the electrochemical cell stack.

[0011] In another aspect, the present invention relates to an electrochemical cell stack having a plurality of electrochemical cells stacked along a longitudinal axis. The electrochemical cells may each include a membrane electrode assembly including a cathode catalyst layer, an anode catalyst layer, and a polymer membrane interposed between the cathode catalyst layer and the anode catalyst layer; an anode plate and a cathode plate, a membrane electrode assembly is interposed between the anode plate and the cathode plate, and the anode plate defines a plurality of channels, the plurality of channels forming an anode flow field facing the anode catalyst layer; and a cathode flow field, the cathode flow field being located between the cathode plate and the cathode catalyst layer, wherein the cathode flow field includes a porous structure. Wherein the porous structure is a porous metal foam structure, the porous metal foam structure having a first cathode distribution channel and a second cathode distribution channel in a surface of the concave porous metal foam structure facing the cathode plate. Wherein the porous metal foam structure includes support features formed throughout the first cathode distribution channel and the second cathode distribution channel. In some embodiments, the support features may be pit-shaped, hemispherical, conical, or cylindrical. In some embodiments, the first cathode distribution channel, the second cathode distribution channel, and the support features may be formed by stamping a porous metal foam structure. In some embodiments, the first cathode distribution channel and the second cathode distribution channel can be configured to facilitate uniform flow distribution of the oxidant along the width of the cathode flow field. In some embodiments, the porous structure can have a plurality of interlaced supply channels and exhaust channels, which are stamped into the surface of the porous metal foam structure facing the cathode plate, wherein the supply channel starts at the first cathode distribution channel and is fluidly connected thereto, and extends toward the second cathode distribution channel, while the exhaust channel terminates at the second cathode distribution channel and is fluidly connected thereto, and extends toward the first cathode distribution channel. In some embodiments, the width and / or depth of the supply channel and the exhaust channel can vary along the length of the porous metal foam structure. In some embodiments, the width of the supply channel can decrease as the second cathode distribution channel extends away from the first cathode distribution channel, while the width of the exhaust channel increases as the second cathode distribution channel extends away from the first cathode distribution channel. In some embodiments, the depth of the supply channel can decrease as the second cathode distribution channel extends from the first cathode distribution channel, while the depth of the exhaust channel can increase as the second cathode distribution channel extends from the first cathode distribution channel. In some embodiments, the cross-sectional area of ​​the supply channel may decrease extending away from the first cathode distribution channel toward the second cathode distribution channel, while the cross-sectional area of ​​the exhaust channel may increase extending away from the first cathode distribution channel toward the second cathode distribution channel.In some embodiments, the cross-sectional area of ​​the supply channel can decrease at a rate approximately equal to the rate at which the oxidant flows out of the supply channel and diffuses into the porous metal foam structure, while the exhaust channel can increase at a rate approximately equal to the rate at which the oxidant flows out of the porous metal foam structure into the exhaust channel, thereby maintaining the velocity of the oxidant through the supply channel and the exhaust channel approximately constant. In some embodiments, the porous metal foam structure can include a shoulder section formed between the supply channel and the exhaust channel, wherein the thickness of the shoulder section varies along the length of the porous metal foam structure.

[0012] In another aspect, the present invention relates to an electrochemical cell having a membrane electrode assembly, the membrane electrode assembly comprising a cathode catalyst layer, an anode catalyst layer, and a polymer membrane interposed between the cathode catalyst layer and the anode catalyst layer. The electrochemical cell may also have an anode plate and a cathode plate, the membrane electrode assembly being interposed between the anode plate and the cathode plate, and the anode plate defining a plurality of channels, the plurality of channels forming an anode flow field facing the anode catalyst layer. The electrochemical cell may also include a cathode flow field, the cathode flow field being located between the cathode plate and the cathode catalyst layer, wherein the cathode flow field comprises a porous structure.

[0013] In another aspect, the present disclosure relates to an electrochemical cell stack having a plurality of electrochemical cells stacked along a longitudinal axis. The electrochemical cells may each include a membrane electrode assembly, the membrane electrode assembly including a cathode catalyst layer, an anode catalyst layer, and a polymer membrane inserted between the cathode catalyst layer and the anode catalyst layer. The electrochemical cells may also each include an anode plate and a cathode plate, a membrane electrode assembly is inserted between the anode plate and the cathode plate, and the anode plate defines a plurality of channels, the plurality of channels forming an anode flow field facing the anode catalyst layer. The electrochemical cells may also each include a cathode flow field, the cathode flow field being located between the cathode plate and the cathode catalyst layer, wherein the cathode flow field includes a porous structure. The plurality of channels forming the anode flow field may be substantially square corrugated channels, the plurality of channels including an anode channel leading to the anode side, the anode channel being configured to guide the fuel flow across the anode catalyst layer, and the plurality of channels also including a coolant channel leading to the reverse side, the coolant channel being configured to guide the coolant flow. In some embodiments, the coolant channels may each have a coolant channel width A, and the anode channels may each have an anode channel width B, and a ratio of the coolant channel width A to the anode channel width B may be greater than about 1 and less than about 6. In some embodiments, a ratio of the coolant channel width A to the anode channel width B may be greater than about 2 and less than about 4. In some embodiments, the coolant channels and the anode channels are approximately equal in depth, and the channel depth is S, and a ratio of the coolant channel width A to the anode channel width B divided by the depth S is greater than about 2 and less than about 10. In some embodiments, the compressive load applied to the fuel cell during operation may be in the range of about 10 kg / cm 2 About 75kg / cm 2 . In some embodiments, the porous structure may include at least nickel and chromium. In some embodiments, the porous structure may include a nickel concentration of 60% to 80% by mass and a chromium concentration of 20% to 40% by mass, and at least one surface of the porous structure includes a chromium concentration of about 3% to about 50% by mass. In some embodiments, the porous structure may include a chromium concentration of about 3% to about 6%, a tin concentration of about 10% to about 20%, and a nickel concentration of about 74% to about 87%. In some embodiments, the chromium concentration of the first surface of the porous structure may be higher than the chromium concentration of the opposite second surface. In some embodiments, the chromium concentration of the first surface may range from about 3% to about 50% by mass, and the chromium concentration of the second surface may be less than about 3% by mass. In some embodiments, the first surface of the porous structure faces the membrane electrode assembly. In some embodiments, the cathode plate of each battery may be formed of uncoated stainless steel. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the disclosure, as claimed.

[0015] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the present disclosure and, together with the description, serve to explain the principles of the present disclosure.

[0016] Figure 1 is a schematic side view of a plurality of electrochemical cells (eg, fuel cells) stacked together according to an exemplary embodiment.

[0017] Figure 2 According to an exemplary embodiment Figure 1 A partially exploded side perspective view of various portions of an adjacent fuel cell.

[0018] Figure 3 is a diagram showing a flow path of fuel through a fuel cell according to an exemplary embodiment Figure 2 Side perspective view.

[0019] Figure 4 is a diagram showing a flow path of an oxidant through a fuel cell according to an exemplary embodiment Figure 2 Side perspective view.

[0020] Figure 5 is a diagram showing the flow path of coolant fluid through adjacent fuel cells according to an exemplary embodiment Figure 2 Side perspective view.

[0021] Figure 6 According to an exemplary embodiment Figure 2 Front view of the anode plate.

[0022] Fig. 7A yes Figure 6 Magnified views of various parts.

[0023] Figure 7B is a schematic cross-section of a portion of a fuel cell according to an exemplary embodiment.

[0024] Fig. 8A yes Figure 6 A magnified view of a portion of .

[0025] Figure 8B yes Fig. 8A Schematic cross section of a portion of.

[0026] Fig. 9 is a schematic cross-section of a fuel cell according to an exemplary embodiment.

[0027] Fig.10 According to an exemplary embodiment Figure 2 Front view of the cathode plate.

[0028] Fig.11A According to an exemplary embodiment Figure 2 Front view of the cathode flow field.

[0029] Fig. 11B is a front view of another embodiment of a cathode flow field according to an exemplary embodiment.

[0030] Fig. 11C is a front view of another embodiment of a cathode flow field according to an exemplary embodiment.

[0031] Fig.11D According to an exemplary embodiment, Fig. 11C Cross-sectional view of cross section AA.

[0032] Fig.11E According to an exemplary embodiment, Fig. 11C Cross-sectional view of BB.

[0033] Fig.11F is a front view of another embodiment of a cathode flow field according to an exemplary embodiment.

[0034] Fig.12 is a side perspective view of portions of adjacent fuel cells according to an exemplary embodiment.

[0035] Fig.13 According to an exemplary embodiment Fig.12 Front view of the anode plate.

[0036] Fig.14 According to an exemplary embodiment Fig.12 Front view of the cathode plate.

[0037] Fig.15 According to an exemplary embodiment Fig.12 Front view of the cathode flow field. DETAILED DESCRIPTION

[0038] Reference is now made in detail to the present exemplary embodiments of the present disclosure, examples of which are illustrated in the accompanying drawings. In all drawings, the same reference numerals are used to refer to the same or similar parts as much as possible. Although described with respect to electrochemical cells (particularly with respect to fuel cells using hydrogen, oxygen and water), it should be understood that the apparatus and methods of the present disclosure can be used with various types of fuel cells and electrochemical cells, including but not limited to electrolytic cells, hydrogen purifiers, hydrogen expanders, and hydrogen compressors.

[0039] Throughout the specification, the terms "substantially parallel" and "substantially perpendicular" may be used to describe the arrangement of one or more components relative to an axis, plane, or other component. When the arrangement is described as "substantially parallel" or "substantially perpendicular", the degree of parallel and perpendicular deviation that can be tolerated may vary. The allowable deviation can be, for example, a deviation of less than about 20 degrees, such as a deviation of less than about 10 degrees, a deviation of less than about 5 degrees, a deviation of less than about 3 degrees, a deviation of less than about 2 degrees, and a deviation of less than about 1 degree.

[0040] Figure 1 is a schematic side view of a plurality of electrochemical cells (e.g., a fuel cell 10 stacked together along a longitudinal axis 5 to form at least a portion of a fuel cell stack 11) according to an exemplary embodiment. The fuel cell 10 may include a cathode catalyst layer 12 (which may also be referred to herein as a cathode), an anode catalyst layer 14 (which may also be referred to herein as an anode), and a proton exchange membrane (PEM) 16 (which may be collectively referred to as a membrane electrode assembly (MEA) 18) interposed between the cathode catalyst layer 12 and the anode catalyst layer 14. The PEM 16 may include a pure polymer membrane or a composite membrane with other materials, for example, silica, heteropolyacids, layered metal phosphates, phosphates, and zirconium phosphates may be embedded in a polymer matrix. The PEM 16 may be permeable to protons without conducting electrons. The cathode catalyst layer 12 and the anode catalyst layer 14 may include porous carbon electrodes containing a catalyst. The catalyst material (e.g., platinum, platinum-cobalt alloy, non-PGM) may increase the reaction of oxygen with the fuel. In some embodiments, the average pore size of the cathode catalyst layer 12 and the anode catalyst layer 14 may be about 1 μm.

[0041] The fuel cell 10 may include two bipolar plates, for example, a cathode plate 20 and an anode plate 22. The cathode plate 20 may be positioned adjacent to the cathode catalyst layer 12, while the anode plate 22 may be positioned adjacent to the anode catalyst layer 14. The MEA 18 is interposed and enclosed between the cathode plate 20 and the anode plate 22. A cathode chamber 19 may be formed between the MEA 18 and the cathode plate 20, and an anode chamber 21 may be formed between the MEA 18 and the anode plate 22. The cathode plate 20 and the anode plate 22 may serve as current collectors, providing access flow paths for fuel and oxidant to the respective electrode surfaces (e.g., the anode catalyst layer 14 and the cathode catalyst layer 12), and providing flow paths for removing water formed during operation of the fuel cell 10. The cathode plate 20 and the anode plate 22 may also define flow paths for a coolant fluid (e.g., water, ethylene glycol, or a water-ethylene glycol mixture). For example, between the cathode plates 20 and anode plates 22 of adjacent fuel cells 10, a coolant chamber 23 may be formed, which is configured to circulate a coolant fluid between adjacent fuel cells 10. The heat generated by the fuel cells 10 may be transferred to the coolant fluid, and the heat may be taken away by the circulating coolant. The cathode plates 20 and the anode plates 22 may be made of, for example, aluminum, steel, stainless steel, titanium, copper, Ni-Cr alloy, graphite, or any other suitable conductive material.

[0042] In some embodiments, for example, Figure 1As shown, the fuel cell 10 may also include conductive gas diffusion layers (e.g., cathode gas diffusion layers 24 and anode gas diffusion layers 26) disposed within the fuel cell 10 on each side of the MEA 18. The gas diffusion layers 24, 26 may serve as diffusion media that enable the transport of gases and liquids within the cell, provide electrical conduction between the cathode plate 20, the anode plate 22, and the MEA 18, help remove heat and process water from the fuel cell 10, and in some cases, provide mechanical support to the PEM 16. The gas diffusion layers 24, 26 may include woven carbon cloth or non-woven carbon cloth, with the cathode catalyst layer 12 and the anode catalyst layer 14 coated on the side facing the PEM 16. In some embodiments, the cathode catalyst layer 12 and the anode catalyst layer 14 may be coated onto adjacent GDLs 24, 26 or the PEM 16. In some embodiments, the average pore size of the gas diffusion layers 24, 26 may be about 10 μm. The fuel cell 10 may also include a flow field located on each side of the MEA 18. For example, the fuel cell 10 may include a cathode flow field 28, which may include a porous structure located between the cathode plate 20 and the GDL 24, and an anode flow field 30, which may be formed by the anode plate 22 as further described herein. The flow fields may be configured to enable the fuel and oxidant on each side of the MEA 18 to flow through and reach the MEA 18. It is desirable that these flow fields facilitate uniform distribution of the fuel and oxidant to the cathode catalyst layer 12 and the anode catalyst layer 14 in order to achieve high performance of the fuel cell 10. The GDL 24 may provide mechanical protection for the cathode catalyst layer 12 from the cathode flow field 28.

[0043] It should be understood that although Figure 1 Only one fuel cell 10 in the stack 11 includes reference numerals for the cathode catalyst layer 12, the anode catalyst layer 14, the proton exchange membrane 16, the membrane electrode assembly (MEA) 18, the cathode chamber 19, the cathode plate 20, the anode chamber 21, the anode plate 22, the coolant chamber 23, the gas diffusion layer 24, the gas diffusion layer 26, the cathode flow field 28, and the anode flow field 30, but other fuel cells 10 in the stack 11 may include the same elements.

[0044] The fuel cell stack 11 may also include a plurality of fluid manifolds 31A, 31B extending along the longitudinal axis 5 defined by a series of stacked cathode plates 20 and anode plates 22 of the fuel cell 10. The fluid manifolds 31A, 31B may be configured to supply fuel (e.g., hydrogen) and oxidant (e.g., oxygen) to the MEA 18 of each fuel cell 10 and discharge reaction products (e.g., unreacted fuel, unreacted oxidant, and water) from the MEA 18 of each fuel cell. The fluid manifolds 31A, 31B may also be configured to supply and discharge coolant fluid through the coolant chamber 23. The flow direction through the fluid manifolds 31A, 31B, the cathode chamber 19, the anode chamber 21, and the coolant chamber 23 may change. For example, in some embodiments, the flow through the manifolds and the compartments may be in parallel, while in other embodiments, one or more flow paths may be reversed. For example, in some embodiments, the fuel flow through the anode chamber 21 may be reversed to the oxidant flow through the cathode chamber 19. The fluid manifolds 31A, 31B may be fluidly connected to the MEA 18 via passages and ports. Specific manifolds, passages, and ports may be identified herein by "supply" or "exhaust" and "inlet" or "outlet," but it should be understood that these numbers may be determined based on the direction of flow, which may be switched. Changing the flow direction may change these numbers.

[0045] Figure 2 A partially exploded side view of various portions of adjacent fuel cells 10 is shown. For example, Figure 2 The MEA 18, GDL 24 and anode plate 22 of one fuel cell 10 and the cathode plate 20, cathode flow field, MEA 18 and GDL 24 of an adjacent fuel cell 10 are shown. An anode chamber 21 may be formed between the adjacent MEA 18 and the anode plate 22. A coolant chamber 23 may be formed between the adjacent anode plate 22 and the cathode plate 20. A cathode chamber 19 may be formed between the adjacent cathode plate 20 and the MEA 18, and the cathode chamber 19 may include a cathode flow field 28. Figure 2 As shown, the fuel cell 10 can include fluid manifolds 31A, 31B, which can also be referred to as upper and lower fluid manifolds. The fluid manifolds 31A, 31B can extend along a longitudinal axis.

[0046] Figures 3 to 5 The flow paths of the fuel, oxidant, and cooling fluid through the fuel cell 10 are shown according to one illustrative embodiment. However, it should be understood that for other embodiments, the direction of one or more flow paths may be switched, such as by reversing the flow direction. Figure 3 shows the flow path of the fuel circulating through the anode side of the MEA 18 of the fuel cell 10, Figure 4shows the flow path of the oxidant circulating through the cathode side of the MEA 18 of the fuel cell 10, and Figure 5 The flow path of the coolant fluid circulating between adjacent fuel cells 10 is shown.

[0047] Now, refer to Figure 3 , the first fluid manifold 31A may include at least one anode supply manifold 32 that may connect the fuel fluid to the anode chamber 21 and direct the fuel through at least one anode inlet port 36 through at least one anode inlet passage 34 into the anode chamber 21. Fuel (e.g., unreacted fuel) from the anode chamber 21 may be directed from the anode chamber 21 through at least one anode outlet port 38 through at least one anode outlet passage 40 into at least one anode exhaust manifold 42. The anode inlet passage 34 and the anode outlet passage 40 may be located between the anode plate 22 and the cathode plate 20 of the adjacent fuel cell 10. As shown in FIG. Figure 3 As shown, the periphery of the anode inlet passage 34 and the anode outlet passage 40 and the periphery of the anode supply manifold 32 and the anode exhaust manifold 42 are sealed by a surface gasket 43. The surface gasket 43 can be made of a polymeric material or an elastic material such as silicone, fluororubber, Buna rubber, polyethylene, polypropylene or any other suitable sealing material. The cross-sectional shape of the surface gasket 43 can be rectangular, triangular, semicircular, multi-tooth (triangular), or parabolic. The shape can be determined by an acceptable leakage rate, operating pressure, tolerance compensation or other important sealing design parameters. The surface gasket 43 can be applied by any known method such as injection molding, compression molding, pick and place, robot distribution, and can be directly bonded by a molding process or by means of a pressure-sensitive adhesive or a heat-sensitive adhesive. Curing the surface gasket 43 can be completed by a known process such as thermal curing, ultraviolet curing or wet curing.

[0048] like Figure 4 As shown, the second fluid manifold 31B may include at least one cathode supply manifold 44 that may connect the oxidant fluid to the cathode chamber 19 and direct the oxidant into the cathode chamber 19 through at least one cathode inlet port 48 through at least one cathode inlet passage 46. The oxidant from the cathode chamber 19 may be directed from the cathode chamber 19 through at least one cathode outlet port 50 through at least one cathode outlet passage 52 into at least one cathode exhaust manifold 54. The cathode inlet passage 46 and the cathode outlet passage 52 may be located between the anode plate 22 and the cathode plate 20 of the adjacent fuel cell 10. Figure 4 As shown, the perimeters of the cathode inlet passage 46 and the cathode outlet passage 52 and the perimeters of the cathode supply manifold 44 and the cathode exhaust manifold 54 may be sealed by face gaskets 43 .

[0049] like Figure 5 As shown, the second fluid manifold 31B may include at least one coolant supply manifold 56, which may connect the coolant fluid to the coolant flow field 86 within the coolant chamber 23 and direct the coolant fluid through at least one coolant inlet passage 58 to the coolant flow field 86 within the coolant chamber 23. As further described herein, within the coolant chamber 23, the coolant fluid may flow between the anode plate 22 and the cathode plate 20 through the coolant flow field 86 including a plurality of coolant channels defined by the anode plate 22. Heat generated by adjacent fuel cells 10 may be transferred to the coolant fluid and removed from the fuel cells 10 by circulating the coolant fluid. The coolant fluid from the coolant chamber 23 may be directed through at least one coolant outlet passage 60 into at least one coolant exhaust manifold 62. The coolant inlet passage 58 and the coolant outlet passage 60 may be located between the anode plate 22 and the cathode plate 20 of adjacent fuel cells 10. As further described herein, Figure 5 As shown, the perimeters of the coolant inlet passage 58 and the coolant outlet passage 60 and the perimeters of the coolant supply manifold 56 and the coolant exhaust manifold 62 may be sealed by the surface gaskets 43 .

[0050] Figure 6 is a front view of anode plate 22 according to an exemplary embodiment. Figure 6 The side visible in FIG. 1 is a side configured to face the anode side of the MEA 18 (ie, the anode catalyst layer 14 and the gas diffusion layer 26) and define one side of the anode chamber 21 (eg, see Figure 1 and Figure 2 ). The anode plate 22 may include several segments. These segments may include, for example, a first manifold segment 31A and a second manifold segment 31B, a distribution channel segment (e.g., a first anode distribution channel 68 and a second anode distribution channel 70), and an anode flow field 30. Figure 6 As shown, the anode plate 22 may include an anode supply manifold 32, a cathode exhaust manifold 54, and a coolant exhaust manifold 62 in a first manifold segment 31A, while a second manifold segment 31B may include an anode exhaust manifold 42, a cathode supply manifold 44, and a coolant supply manifold 56. It should be understood that the numbering of the inlets and outlets of each manifold may be switched, for example, by switching the corresponding flow direction of the fuel, oxidant, or coolant fluids flowing through the fuel cell 10.

[0051] The cross-sectional area of ​​each manifold may vary. For example, Figure 6As shown, the cross-sectional area of ​​the cathode supply manifold 44 and the cathode exhaust manifold 54 can be larger than the cross-sectional area of ​​the coolant supply manifold 56 and the coolant exhaust manifold 62, while the cross-sectional area of ​​the coolant supply manifold 56 and the coolant exhaust manifold 62 is larger than the cross-sectional area of ​​the anode supply manifold 32 and the anode exhaust manifold 42. The cross-sectional area of ​​each passage can be determined based on a variety of variables, including, for example, the number of cells, the current density under peak power operating conditions, the design stoichiometry of the reactants, the difference between the inlet coolant temperature and the outlet coolant temperature, the flow resistance of each cell, the size of the active area, the fluid pressure, and the fluid flow rate. The size of the cross-sectional area of ​​one or more passages can be determined so as to minimize the fluid pressure variation along the length of the electrochemical cell stack, such as during high fluid flow rates.

[0052] The arrangement of the manifolds in the first manifold segment 31A and the second manifold segment 31B may also vary. Figure 6 As shown, the arrangement of the manifolds may differ between the first manifold section 31A and the second manifold section 31B. In one illustrative example, as shown in FIG. Figure 6 As shown, the coolant exhaust manifold 62 can be located between the anode supply manifold 32 and the cathode exhaust manifold 54, while the coolant supply manifold 56 can be located between the anode exhaust manifold 42 and the cathode supply manifold 44. In some embodiments, the cathode exhaust manifold 54 can be on the left side of the coolant exhaust manifold 62, the anode supply manifold 32 can be on the right side of the coolant exhaust manifold 62, and the cathode supply manifold 44 can be on the right side of the coolant supply manifold 56, and the anode exhaust manifold 42 can be on the left side of the coolant supply manifold 56. It may be advantageous to swap the positions of the anode manifold and the cathode manifold relative to the coolant manifold between the first manifold segment 31A and the second manifold segment 31B because it promotes diagonal cross-counterflow or "z flow" rather than straight-through flow. The diagonal cross-counterflow can provide an improved uniform distribution of the fuel and oxidant in the anode chamber 21 and the cathode chamber 19, which can improve the performance of the fuel cell. Because the diagonal cross-counterflow can optimize the active area utilized, the performance can be improved. For the z flow pattern, the flow path distance of one or more reactants from the inlet to the outlet can be substantially uniform, regardless of the flow path. This symmetry can cause the fluid to be evenly distributed and flow throughout the flow field. Uniform flow throughout the flow field 30 can result in a more uniform and / or linear gradient of reactant composition and coolant temperature, which can make the gradient of battery temperature uniform and / or linear. This may result in higher performance and / or lower performance variation between batteries.

[0053] It may be advantageous to locate the coolant manifolds 56, 62 in the center of the first fluid manifold 31A and the second fluid manifold 31B because the center region of the coolant chamber is most likely to receive the most coolant fluid flow, and this region corresponds to the center region of the active area of ​​the fuel cell 10, where there may be increased heat generation and / or a tendency toward higher operating temperatures. In other words, the region of the fuel cell 10 that tends to operate at higher temperatures will correspond to the region that receives the most coolant fluid flow. Additionally, the sides of the fuel cell 10 may be assisted by ambient cooling, so it is advantageous to promote coolant fluid flow through the center region of the coolant chamber 23 of each fuel cell.

[0054] like Figure 6 As shown, the first anode distribution channel 68 and the second anode distribution channel 70 are located between the first manifold segment 31A and the second manifold segment 31B and the anode flow field 30. The first anode distribution channel 68 can be configured to distribute the fuel supplied from the anode supply manifold 32 to the anode flow field 30 through the anode inlet port 36 via the anode inlet passage 34. The second anode distribution channel 70 can be configured to collect fuel (e.g., unreacted fuel) from the anode flow field 30 and guide the fuel through the anode outlet port 38 to the anode exhaust manifold 42 via the anode outlet passage 40. The first anode distribution channel 68 and the second anode distribution channel 70 can be sandwiched between the MEA 18 and the anode plate 22 and defined thereby. As shown in FIG. Figure 6 As shown, the periphery of the first anode distribution channel 68 and the second anode distribution channel 70 may be sealed by the surface gasket 43. In some embodiments, the width of the first anode distribution channel 68 and the width of the second anode distribution channel 70 may be generally equal to the width of the anode flow field 30.

[0055] The first anode distribution channel 68 can be configured such that the fuel supplied through the anode inlet port 36 can be distributed across the width of the first anode distribution channel 68 and directed to the anode flow field 30 through a plurality of openings 74. In some embodiments, each opening 74 can be configured as an orifice to create some back pressure on the fuel within the first anode distribution channel 68. This back pressure can facilitate the distribution of the fuel within the first anode distribution channel 68, thereby ensuring that the first anode distribution channel 68 is completely filled with fuel. In some embodiments, a fully filled first anode distribution channel 68 enables the fuel to be delivered to substantially all channels of the anode flow field 30 through all openings 74. A fully filled first anode distribution channel 68 can prevent or reduce the risk of short-circuiting the fuel flowing along the path of least resistance through the anode flow field 30, which may reduce the performance of the fuel cell 10 due to the reduction in active area being utilized. In some embodiments, the orifice openings 74 can be sized to ensure that the minimum amount of back pressure required to fully fill the first anode distribution channel 68 can be ensured. Figure 6As shown, the configuration of the second anode distribution channel 70 can be the same as the configuration of the first anode distribution channel 68, wherein a plurality of hole-shaped openings 74 fluidly connect the channels of the anode flow field 30 and the second anode distribution channel 70. The cross-sectional area of ​​the opening 74 is smaller than the cross-sectional area of ​​the corresponding channel in the anode flow field 30. Although the channels in the anode flow field 30 are shown as straight paths, they can also be wavy paths or zigzag paths. The cross-sectional area of ​​the channels in the anode flow field 30 is generally square, semicircular, parabolic, or any other suitable shape.

[0056] The compression of the fuel cell 10 during assembly and the compression state maintained during operation may compromise the integrity of the flow path within the distribution channel. For example, the compression of the fuel cell 10 may result in a reduction in the volume of the distribution channel, which may restrict the flow of fuel, oxidant, and coolant and increase the pressure drop through the fuel cell 10. When the fuel cell 10 is compressed, in order to prevent the first anode distribution channel 68 and the second anode distribution channel 70 from shrinking or collapsing or minimize it, the first anode distribution channel 68 and / or the second anode distribution channel 70 may include a plurality of support features 76 dispersed throughout the distribution channel. The support features 76 may be formed as an integrated feature of the anode plate 22. The support features 76 may be evenly spaced throughout the first anode distribution channel 68 and the second anode distribution channel 70.

[0057] In one illustrative embodiment, Fig. 7A An enlarged view of a portion of a plurality of crater-shaped support features 76 that may be formed in the first anode distribution channel 68 and / or the second anode distribution channel 70 is shown. These crater-shaped support features 76 may extend from the anode plate 22 in two directions along the longitudinal axis 5. For example, Figure 7B Schematic cross-sectional view of a dimple-shaped support feature 76 formed by the anode plate 22 is shown. The dimple-shaped support feature 76 can extend from the anode plate 22 in two directions to contact the cathode plate 20 on one side and contact the MEA 18 (e.g., a subgasket of the MEA 18) on the other side. Figure 7B As shown, between the anode plate 22 and the MEA 18 may be a space that forms the first anode distribution channel 68 or the second anode distribution channel 70 and enables the fuel to flow. In other embodiments, in addition to the dimples, other support features may be formed in other shapes, including, for example, cones, hemispheres, cubes, and cylinders.

[0058] like Figure 7BAs shown, on the opposite side of the anode plate 22, between the anode plate 22 and the cathode plate 20 may be a space forming a first coolant distribution channel 78 and a second coolant distribution channel 80, the first coolant distribution channel 78 and the second coolant distribution channel 80 fluidly connecting the coolant supply manifold 56, the coolant exhaust manifold 62 and the coolant flow field 86 contained in the coolant chamber 23. The configuration of the first coolant distribution channel 78 and the second coolant distribution channel 80 of the coolant chamber 23 may be similar to the configuration of the first anode distribution channel 68 and the second anode distribution channel 70. For example, the first coolant distribution channel 78 and the second coolant distribution channel 80 may include a plurality of dimple-shaped support features 76 that are uniformly spaced throughout. The first coolant distribution channel 78 and the second coolant distribution channel 80 may be configured to provide a plurality of dimple-shaped support features 76 to the coolant flow field 86 (e.g., see Figure 5 ) provides a complete and uniform distribution. Additionally, in some embodiments, a plurality of hole-shaped openings can fluidly connect the first coolant distribution channel 78 and the second coolant distribution channel 80 to the coolant flow field 86 (see Figure 5 ). These aperture-shaped openings may exert some back pressure on the coolant fluid in, for example, the first coolant distribution channel 78 and / or the second coolant distribution channel 80, for example, depending on the flow direction, to ensure even distribution and prevent or reduce the likelihood of shorting along the path of least resistance.

[0059] The number, distribution, and size of the support features 76 may be determined by taking into account a variety of design considerations. For example, too many or too large support features 76 may result in excessive pressure drop within the distribution channels 68, 70, 78, 80, while too few or too small support features 76 may result in insufficient structural support and contraction of the distribution channels 68, 70, 78, 80 under compression, which may also result in excessive pressure drop. According to an exemplary embodiment, the arrangement of the structural features may be expressed as the distance (D ) between the support features 76. C ) and the thickness of the cathode plate 20 (t p ). For example, D C / t p The ratio of may be greater than about 3 but less than about 50. According to an exemplary embodiment, D C It can be about 1.5 mm, t p It can be about 0.1 mm, so D C / t p The ratio can be about 15.

[0060] Due to the compression of the fuel cell during operation, it may be challenging to rely on gaskets to form or maintain the integrity of the flow area of ​​the inlet port and outlet port of the flow area (e.g., to prevent shrinkage). The shrinkage of the inlet port and outlet port can constrain the flow of reactants and reaction products and increase the pressure drop through the fuel cell. As described herein, one or more anode inlet ports 36 and outlet ports 38 of the fuel cell 10 can be configured to prevent or avoid shrinkage caused by compression.

[0061] The anode inlet port 36 and the anode outlet port 38 may be integrated into one or more support features 82. For example, Fig. 8A and Figure 8B As shown, the anode inlet port 36 can be formed in the side wall 84 of the support feature 82. The support feature 82 can extend from the anode plate 22 toward the MEA 18. As a result, the flow direction of the fuel can be redirected within the support feature 82, so that the flow direction through the anode inlet port 36 and the anode outlet port 38 is generally parallel to the anode plate 22. In other words, this configuration can enable the fuel through the anode inlet port 36 to be directed into the first anode distribution channel 68 in a direction generally parallel to the anode plate 22 rather than perpendicular. Similarly, this configuration can enable the fuel through the anode outlet port 38 to be directed from the second anode distribution channel 70 in a direction generally parallel to the anode plate 22 rather than perpendicular.

[0062] This configuration can prevent or avoid constriction of the flow path through the anode inlet port 36 and the anode outlet port 38 because the support member 82 can be designed to withstand compression during operation, thereby generally maintaining the cross-sectional area for flow. In contrast, conventional prior art fuel cells rely on gaskets to maintain spacing for flow, and under compression these gaskets compress, thereby reducing the available area available for fluid flow, thereby causing an increase in pressure drop by restricting flow.

[0063] The support feature 82 can be any suitable shape. Fig. 8A In one illustrative embodiment shown, the support features 82 may be generally rectangular in shape with rounded corners. In other embodiments, the support features 82 may be circular, oval, square, etc. The support features 82 may each include one or more anode ports (e.g., anode inlet port 36 and anode outlet port 38). For example, in an embodiment such as Fig. 8A In one illustrative embodiment shown, the support feature 82 may include five anode inlet ports 36 evenly spaced along the length of the support feature 82 .

[0064] The anode flow field 30 may be configured as a channel flow field that faces and is aligned with the active area of ​​the anode catalyst layer 14 on the anode side of the MEA 18. The anode flow field 30 may include a plurality of parallel channels extending between a first anode distribution channel 68 and a second anode distribution channel 70, such as Figure 6 shown. Fig. 9 is a schematic cross-sectional top view of a portion of the fuel cell 10. Fig. 9 As shown, the anode plate 22 can be shaped to form a plurality of channels 78A, 78C, which can be generally square, semi-cylindrical or parabolic corrugated channels. The anode channels 78A, which can form the anode flow field 30, can be open toward the anode chamber 21 and are configured to guide the fuel flow across the GDL 26, so that the fuel can flow through the GDL 26 and reach the anode catalyst layer 14. The coolant channels 78C, which can form the coolant flow field 86, can be open toward the coolant chamber 23 and can be a part of the coolant chamber 23, and are configured to guide the coolant fluid to flow through the coolant chamber 23, so that the heat generated by the fuel cell 10 can be transferred to the coolant fluid and taken away from the fuel cell 10 by circulating the coolant fluid.

[0065] The dimensions of the channels 78A, 78C may be determined based on many variables, including, for example, active area, power, compressive load on the fuel cell 10, desired flow resistance or design flow resistance, anode plate thickness and / or cathode plate thickness and material properties (e.g., elasticity), open flow field properties and / or thickness, gas diffusion layer properties and / or thickness, design flow resistance of the anode, cathode and / or coolant. In some embodiments, the width (A) of the coolant channel 78C may be equal to the width (B) of the anode side channel 78. In other embodiments, the width (B) of the anode channel 78A may be greater than or less than the width (A) of the coolant channel 78C. The combined width of the anode channel 78A and the coolant channel 78C may be referred to as (C). The anode channel and the coolant channel may have a depth (S). According to an exemplary embodiment, the ratio of C / S may be greater than about 1 and less than about 10. Therefore, according to an exemplary embodiment, the ratio of A / B may range from about 1 to less than about 6 or greater than about 2 or less than about 4. These ratios may be based on a range of about 10 kg / cm 2 About 75kg / cm 2 The mechanical load caused by the compression is determined.

[0066] As described herein, by integrating the anode flow field 30 and the coolant flow field 86 into alternating channels on opposite sides of the anode plate 22, the square corrugated channel design improves fluid flow while also minimizing the thickness of the fuel cell 10. This integration enables the overall thickness (e.g., pitch) of the fuel cell 10 to be reduced. In addition, the square corrugated geometry provides sufficient surface area contact between the anode plate 22 and the GDL 26 and the cathode plate 20 to prevent deformation under compression during operation. For example, if the channel is too narrow, the small surface area can act as a stress concentrator and may deform or damage adjacent components (e.g., GDL 26). Similarly, if the channel is triangularly corrugated, the triangular points may create stress concentration points that deform adjacent components.

[0067] Fig.10 is a front view of a cathode plate 20 according to an exemplary embodiment. Fig.10 The side visible in FIG. 1 is the side configured to face the adjacent anode plate 22 (see, for example, Figure 2 ). Similar to the anode plate 22, the cathode plate 20 may include a first manifold segment 31A and a second manifold segment 31B. Fig.10 As shown, the anode plate 22 may include an anode supply manifold 32, a cathode exhaust manifold 54, and a coolant exhaust manifold 62 in a first manifold. The second manifold segment 31B may include an anode exhaust manifold 42, a cathode supply manifold 44, and a coolant supply manifold 56. It should be understood that for each manifold, the designation of "inlet" or "outlet" may be switched, for example, by switching the flow direction of the fuel, oxidant, or coolant fluid through the fuel cell 10.

[0068] The cathode plate 20 may include a plurality of cathode inlet ports 48 configured to fluidically connect the cathode chamber 19 and the cathode flow field 28 to the cathode supply manifold 44 via cathode inlet passages 46. The cathode plate 20 may also include a plurality of cathode outlet ports 50 configured to fluidically connect the cathode chamber 19 and the cathode flow field 28 to the cathode exhaust manifold 54 via cathode outlet passages 52. The cathode inlet passages 46 and the cathode outlet passages 52 may be located between the anode plate 22 and the cathode plate 20 of adjacent fuel cells 10. Fig.10 As shown, the perimeters of the cathode inlet passage 46 and the cathode outlet passage 52 as well as the cathode supply manifold 44 and the cathode exhaust manifold 54 may be sealed by face gaskets 43 .

[0069] like Fig.10 As shown, the cathode inlet port 48 and the cathode outlet port 50 may be generally rectangular. Fig.10 As shown, the cathode plate 20 can be configured to have at least two cathode inlet ports 48, and the at least two cathode inlet ports 48 are arranged generally perpendicular to each other. Fig.10 As shown, the cathode plate 20 can be configured to have at least two cathode outlet ports 50, at least two cathode outlet ports 50 are arranged substantially perpendicular to each other. The cathode plate 20 can be configured to have at least one cathode inlet port 48, at least one cathode inlet port 48 is located at the opposite end of the cathode inlet passage 46. The cathode plate 20 can be configured to have at least one cathode outlet port 50, at least one cathode outlet port 50 is located at the opposite end of the cathode outlet passage 52. The cathode plate can be configured to have two cathode inlet ports 48 located at one end of the cathode inlet passage 46 and one cathode inlet port 48 located at the opposite end. The two cathode inlet ports 48 located at one end can be substantially parallel to each other and substantially perpendicular to the cathode inlet passage 46 located at the opposite end of the cathode inlet passage 46. As described herein, when the oxidant flows into the cathode chamber 19, the shape and arrangement of the cathode inlet port 48 can promote improved distribution of the oxidant.

[0070] A rectangular cathode inlet port 48 may be preferred over a rounded port because the flow through the port immediately turns 90 degrees after passing through the port. The larger the perimeter of the hole relative to its area, the more "overflow length" the fluid has, and therefore the lower its velocity (and pressure drop) when turning the corner. The net result is that for two holes (one rounded and one rectangular) with the same cross-sectional area, the pressure drop for the rectangular port is lower than the pressure drop for the rounded port. The orientation of the rectangle (where the long side generally faces the incoming fluid flow) may also result in an increased "overflow length" and a reduced pressure drop.

[0071] The total inlet area of ​​the plurality of cathode inlet ports 48 may be greater than the total outlet area of ​​the cathode outlet ports 50. Cathode outlet ports 50 having a total outlet area less than the total inlet area may generate back pressure on the oxidant flow through the cathode chamber 19 and the cathode flow field 28. Such back pressure may promote improved distribution of the oxidant in the cathode chamber.

[0072] like Fig.10 As shown, the cathode plate 20 may include surface features, such as a cathode flow field boundary 88, which protrudes from the cathode plate 20 toward the MEA 18 along one side of the cathode flow field 28 (see, for example, Figure 2 ).like Fig.10As shown, the cathode flow field boundary 88 can span between the first fluid manifold 31A and the second fluid manifold 31B along opposite sides of the cathode plate 20. The cathode flow field boundary 88 can be configured to prevent the oxidant from bypassing the cathode flow field 28 and the cathode catalyst layer 12 or reducing its flow by flowing along the outside of the cathode flow field 28 rather than flowing through the cathode flow field 28 to reach the cathode catalyst layer 12. For example, the cathode flow field boundary 88 can serve as a boundary wall on each side of the cathode flow field 28, thereby forcing the oxidant to flow through the cathode flow field 28. The cathode plate 20 can be configured so that the distance between the cathode flow field boundaries 88 is approximately equal to the width of the cathode flow field 28. The cathode flow field boundary 88 can be configured to protrude from the cathode plate 20 to a depth equal to the depth of the cathode flow field 28. The cathode flow field boundary 88 can be generally rectangular with rounded or chamfered outer corners, such as Fig.10 The cathode flow field boundary 88 can be positioned to provide a tight fit along the edge of the cathode flow field 28 so as to prevent or limit any open flow area for fluid to flow cathode "along" the peripheral length of the cathode flow field 28. In some embodiments, the cathode flow field boundary 88 can be formed by the cathode plate 20, or in some embodiments, the cathode flow field boundary 88 can be formed by applying a second material (e.g., a polymer, an elastomer, a material bonded to the surface gasket 43 of the plate in the shape of the cathode flow field boundary 88) to the cathode plate 20.

[0073] In some embodiments, rather than applying the surface gasket 43 to both the cathode plate 20 and the anode plate 22, all of the surface gaskets 43 described herein are applied to either side of the cathode plate 20 that is generally flat. This can reduce tooling costs and processing costs by affixing all of the surface gaskets 43 only to the cathode plate 20, which can be flat. For example, because the anode plate 22 has channels 78A, 78C, which causes the cathode plate 22 to be generally non-flat, applying the surface gasket to the anode plate 22 is more complicated, thereby increasing tooling costs and processing costs.

[0074] To further reduce tooling and processing costs, in some embodiments, the alignment features 112 (see, for example, Figure 6 and Fig.10 ) can be incorporated into the surface gasket to facilitate assembly of each fuel cell 10 into the fuel cell stack 11 and alignment of multiple fuel cells 10 with the fuel cell stack 11. For example, the alignment features 112 (see Figure 6 ) may be a hole aligned with the surface gasket protrusion, and the hole may be an alignment feature 112 of the cathode plate 20 (see Fig.10 ). The protrusion can be elastically deformed when inserted through the hole of the anode plate 22 and recover on the other side, thereby forming an interference fit. Assembling the battery 10 and the stack 11 using an interference fit can avoid the need for some welding operations during the assembly process.

[0075] Fig.11A is a front view of cathode flow field 28 according to an exemplary embodiment. Fig.11A The side visible in FIG. 1 is the side configured to face the adjacent cathode plate 20 (see, for example, Figure 2 ). The cathode flow field 28 may include a porous structure, in particular a porous metal foam structure having a porous three-dimensional network structure. The porous structure may be in the form of a sheet having two opposing surfaces. In some embodiments, the average pore size of the porous metal foam structure may be about 50 μm to 500 μm. The cathode flow field 28 may include a first cathode distribution channel 90 and a second cathode distribution channel 92 in the surface of the recessed porous metal foam structure facing the cathode plate 20. The thickness of the cathode flow field 28 may be, for example, about 0.2 mm to about 1.5 mm. The first cathode distribution channel 90 and / or the second cathode distribution channel 92 may be recessed in the cathode flow field to a depth between about 10% and about 75% of the thickness.

[0076] Typically, the first cathode distribution channel 90 can extend from one side of the cathode flow field 28 to the other side along the bottom edge of the cathode flow field 28. Typically, the second cathode distribution channel 92 can extend from one side of the cathode flow field 28 to the other side along the top edge of the cathode flow field 28. When the cathode flow field 28 is positioned adjacent to the cathode plate 20, the cathode inlet port 48 can be aligned with the first cathode distribution channel 90, and the cathode outlet port 50 can be aligned with the second cathode distribution channel 92.

[0077] The cathode flow field 28 may include a plurality of support features 94 formed throughout the first cathode distribution channel 90 and / or the second cathode distribution channel 92. The support features 94 may be substantially cylindrical, pit-shaped, or other suitable shapes. The height of one or more support features 94 may be approximately equal to the recessed depth of the first cathode distribution channel 90 and / or the second cathode distribution channel 92. The first cathode distribution channel 90, the second cathode distribution channel 92, and the support features 94 may be formed by stamping, rolling, or otherwise plastically deforming the porous metal foam structure that forms the cathode flow field 28.

[0078] The first cathode distribution channels 90 and the second cathode distribution channels 92 can be configured to promote uniform flow distribution of the oxidant along the width of the cathode flow field 28 by providing an open flow path along which the oxidant flows before flowing into the pores of the porous metal foam structure. The support features 94 can be configured to provide sufficient support during mechanical compression and during operation to maintain the open flow path provided by the first cathode distribution channels 90 and the second cathode distribution channels 92 when the fuel cell 10 is compressed by preventing or reducing deformation or flexing of the cathode plate 20 into the first cathode distribution channels 90 and the second cathode distribution channels 92.

[0079] Fig. 11B , Fig. 11C and Fig.11F 28. In some embodiments, cathode flow fields 28, 28, 28 may be utilized in place of cathode flow field 28 in fuel cell 10. Cathode flow fields 28', 28", 28'" may include all of the features of cathode flow field 28 as described herein, as well as additional functionality as described below. Fig. 11B , Fig. 11C and Fig.11F The side visible in FIG. 1 may be a side configured to face the adjacent cathode plate 20 or a side configured to face the adjacent MEA 18 .

[0080] The cathode flow field 28', 28" may include a plurality of supply (or first) channels 101 and a plurality of exhaust (or second) channels 102. The supply channels 101 and the exhaust channels 102 may be stamped, cut, molded or otherwise formed in the cathode flow field 28' on the surface facing the cathode plate 20. Fig. 11B and Fig. 11C As shown, the supply channel 101 can start at the first cathode distribution channel 90 and be in fluid communication therewith, and extend toward the second cathode distribution channel 92. The exhaust channel 102 can terminate at the second cathode distribution channel 92 and be in fluid communication therewith, and extend toward the first cathode distribution channel 90. Fig. 11B As shown, the supply channels 101 and the exhaust channels 102 can be staggered with each other so that the exhaust channels 102 can be located between adjacent supply channels 101. In some embodiments, the supply channels 101 and the exhaust channels 102 do not substantially impede fluid flow to enable improved oxidant distribution. In some embodiments, the supply channels 101 and the exhaust channels 102 can include pits (not shown) similar to the pits 94 found in the first cathode distribution channel 90 and the second cathode distribution channel 92.

[0081] It is contemplated that in certain embodiments, the plurality of supply channels 101 and exhaust channels 102 may have different arrangements, shapes, and / or cross-sectional areas. Fig. 11B In the embodiment, the width of the supply channel 101 and the exhaust channel 102 can vary along the length of the cathode flow field 28'. Fig. 11B In the embodiment, the supply channel 101 starts to widen at or near the first cathode distribution channel 90 and begins to narrow to a point as it extends toward the second cathode distribution channel 92, while the exhaust channel starts at a point and extends to widen toward the second cathode distribution channel 92. In some embodiments, as Fig. 11B As shown, the distal end of the supply channel 101 can be flat except for a point. Fig. 11BAs shown, the proximal end of the exhaust channel 102 can be flat except for a point. With this arrangement, there is no direct fluid communication between the supply channel 101 and the exhaust channel 102. Instead, the oxidant distributed to the supply channel 101 by the first cathode distribution channel 90 can flow through multiple supply channels 101 and be forced to diffuse through the porous structure of the cathode flow field 28' to reach the adjacent exhaust channel 102.

[0082] Fig. 11C Another arrangement of supply channels 101 and exhaust channels 102 for a cathode flow field 28″ is shown, wherein the widths of the supply channels 101 and exhaust channels 102 remain approximately the same along the length of the cathode flow field 28″. Although the widths of the supply channels 101 and exhaust channels 102 remain approximately the same, the depths of the supply channels 101 and exhaust channels 102 may vary along the length of the cathode flow field 28″. For example, Fig.11D A cross section of the cathode flow field 28" along the cross section AA through the supply channel 101 is shown. Fig.11D As shown, the supply channel 101 may be deepest (ie, have a maximum depth fd ) starting at or near the first cathode distribution channel 90. 1 ), and the depth extending toward the second cathode distribution channel 92 can be reduced. Fig.11D As shown, the depth may decrease at a constant rate (e.g., linearly), or in some embodiments, the depth may decrease at a variable rate (e.g., nonlinearly, exponentially). Fig.11D As shown, the supply channel 101 can be provided with a minimum depth (fd 2 ) terminates flat at the distal end. In other embodiments, the supply channel 101 may be at a minimum depth fd 2 If it is 0, it terminates at the far end.

[0083] Fig.11E A cross section of the cathode flow field 28" is shown along the cross section BB through the exhaust channel 102. Fig.11E As shown, the exhaust channel 102 may begin shallowest (ie, having a minimum depth dd) at or near the first cathode distribution channel 90. 1 ), and the depth extending toward the second cathode distribution channel 92 may increase. The exhaust channel 102 may be deepest (ie, has a maximum depth dd) at or near the second cathode distribution channel 92. 2 ).like Fig.11E As shown, the depth may increase at a constant rate (e.g., linearly), or in some embodiments, the depth may increase at a variable rate (e.g., nonlinearly, exponentially). Fig.11E As shown, the exhaust channel 102 can be formed with a minimum depth (dd 1 ) begins to flatten at the proximal end. In other embodiments, the discharge channel 101 may be at a minimum depth dd1 The case of zero starts at the near end.

[0084] By varying the width of the supply channel 101 and the discharge channel 102 (see, for example, Fig. 11B ) or depth (see, for example, FIG. 11C to FIG. 11E ), the cross-sectional area available for the oxidant to flow along the cathode flow fields 28′, 28″ can be varied (e.g., an increase in the exhaust channel 102 or a decrease in the supply channel 101). Along the length of the cathode flow fields 28′, 28″, the increase or decrease in the available flow area in the supply channel 101 and the exhaust channel 102 can be configured to correspond to the volume of the oxidant that has diffused from the supply channel 101 into the porous structure and from the porous structure into the exhaust channel 102, so that the flow rate of the oxidant along the supply channel 101 and the exhaust channel 102 remains approximately constant. In other words, the rate at which the cross-sectional area of ​​the supply channel 101 decreases is equal to the rate at which the oxidant flows out of the supply channel 101 and diffuses into the porous structure, so that the rate of the oxidant remains approximately constant. Similarly, the rate at which the cross-sectional area of ​​the exhaust channel 102 increases can be equal to the rate at which the oxidant flows out of the porous structure into the exhaust channel 102, so that the velocity of the oxidant remains approximately constant. In some embodiments, both the width and depth of the supply channel 101 and the exhaust channel 102 can be varied. For example, in some embodiments, in addition to Fig. 11C In addition, Fig.11D and Fig.11E It can also be expressed Fig. 11B cross section.

[0085] like Fig. 11B and Fig. 11C As shown, a separation segment may be formed between the supply channel 101 and the exhaust channel 102, which may be referred to as a shoulder segment 104. The thickness of the shoulder segment 104 between the supply channel 101 and the exhaust channel 102 may be fixed, or in some embodiments, the thickness may vary. For example, the thickness closest to the first cathode distribution channel 90 (e.g., between the proximal end of the supply channel 101 and the distal end of the exhaust channel) may be the largest, and the thickness toward the second cathode distribution channel 92 may decrease. In other embodiments, the thickness closest to the first cathode distribution channel 90 may be the smallest, and the thickness toward the second cathode distribution channel 92 may increase. In other embodiments, the thickness of the shoulder segment 104 may be the largest or smallest midway between the first cathode distribution channel 90 and the second cathode distribution channel 92.

[0086] In some embodiments, a plurality of microchannels 106 may be formed in the cathode flow fields 28, 28 in the shoulder segment 104. The microchannels 106 may be formed along the entire length of the shoulder segment 104 or along only a portion thereof. The microchannels 106 may be configured to fluidly connect the supply channel 101 with the exhaust channel 102 so as to produce a preferred flow path for the oxidant as compared to the porous network provided by the cathode flow fields 28', 28". For these embodiments, in conjunction with or in addition to diffusion, the oxidant may flow from the supply channel 101 through the microchannels to the exhaust channel 102. The size and spacing of the microchannels 106 may be designed so as to provide oxidant available to most catalyst sites that would otherwise be obscured by the shoulder segment of the cathode flow fields 28', 28".

[0087] The number of supply channels 101 and exhaust channels 102 can be adjusted based on one or more different parameters, including, for example, the width of the cathode flow field 28′, 28″, the width of the supply channel 101, the width of the exhaust channel 102, the application of the fuel cell 10, the expected operating pressure or design operating pressure of the oxidant, the expected operating flow ratio or design operating flow ratio of the oxidant, the expected power output or design power output of the fuel cell 10, or any combination of these parameters.

[0088] The cathode flow field 28′, 28″ may have several benefits. For example, the supply channel 101 and the exhaust channel 102 provide a larger cross-sectional area through which the oxidant can flow, which can reduce the pressure drop across the porous flow field compared to other porous flow field structures. In addition, the microchannels can also provide the supply channel 101 and the exhaust channel 102 with an increased cross-sectional area through which the oxidant gas can flow between the supply channel 101 and the exhaust channel 102, which can further reduce the pressure drop across the porous flow field. By reducing the pressure drop, the amount of energy required to pressurize the oxidant can be reduced (e.g., blower power), which in turn can improve the overall performance and efficiency of the fuel cell 10 (e.g., increase power density and reduce parasitic loads). In addition, the features of the cathode flow field 28′, 28″ can make the fresh oxidant more evenly distributed within the porous flow field so as to increase the oxygen concentration near the outlet of the cathode flow field (e.g., the supply channel 101, the exhaust channel 102 and the microchannels). This can keep the incoming oxidant flow, for example, oxygen-rich until the flow is distributed through the porous body, which can result in better cell voltage and potentially higher current density.

[0089] like Fig.11FAs shown, the cathode flow field can include a plurality of channels 110 formed (e.g., pressed, embossed, or cut) into the surface of the cathode flow field 28''. The plurality of channels 110 can include a first channel set 110A that begins at the first cathode distribution channel 90 and extends approximately midway to the second cathode distribution channel 92. The first channel set 110A is configured such that fresh oxidant (e.g., not yet consumed) flows directly to the back half of the cathode flow field 28'', where the oxidant typically has a lower oxygen concentration. The first channel set 110A can be sized such that they are located on top of the shoulder. Other channels 110 can be configured to reduce the overall pressure drop and facilitate mixing and / or uniform distribution. For some embodiments, the feedstock used in the cathode flow field 28 may have non-uniformity, which may result in non-uniform pressure drop and flow characteristics. The channels 110 are designed to help address this issue by making the pressure drop and flow characteristics more uniform. The first channel set 110A also helps reduce the flow velocity, thereby reducing the flow rate at the leading edge of the active area, which in turn reduces the removal of moisture in this area, thereby providing better operation and performance under dry conditions. This also helps to balance the humidity and oxygen concentration distribution along the flow path of the cathode flow field 28″′, which as a result of the electrochemical reaction, balances the current and temperature distribution throughout the active area. This improves the durability and reliability of the fuel cell and stack. In some embodiments, the first channel set 110A can be positioned relative to any flow channel on the anode side or coolant side of the fuel cell to avoid the possibility of constructive interference with high rate effects and increase the risk of potential drying out of the cell.

[0090] The porous structure that makes up the cathode flow field 28 may include one or more metals and / or alloys. For example, the porous structure may include at least nickel (Ni) and chromium (Cr) (e.g., NiCr) or a combination of nickel, tin (Sn), and chromium (e.g., NiSnCr). For the NiCr embodiment of the porous structure, the mass concentration of chromium may range from about 20% to about 40%, and the remaining balance may be nickel, which is about 60% to about 80%. For the NiSnCr embodiment of the porous structure, the concentration of chromium may range from about 3% to about 6%, the concentration of tin may range from about 10% to about 20%, and the balance may be nickel, which is about 74% to about 87%.

[0091] In some embodiments, at least one surface of the porous structure may include a chromium concentration of about 3% to about 50% by mass. For example, the chromium concentration of one or two surfaces of the porous structure forming the cathode flow field 28 may range from about 3% by mass to about 50% by mass, about 5% by mass to about 40% by mass, or about 7% by mass to about 40% by mass. Increasing the chromium concentration of the surface of the porous metal body may be advantageous because it increases the corrosion resistance of the porous structure in an acidic environment. For example, when the chromium concentration of at least one surface of the porous structure forming the cathode flow field ranges from about 3% by mass to about 50% by mass, the cathode of the bipolar plate including the porous structure may be corrosion resistant in a substantially acidic environment. As described herein, the improved corrosion resistance provided by the porous structure may advantageously enable the cathode plate to be formed of uncoated stainless steel, rather than of coated stainless steel that has been traditionally used due to its corrosion resistance.

[0092] In some embodiments, the chromium concentration of one surface of the porous structure may be higher than the chromium concentration of another surface of the porous structure. In this case, advantageously, the surface with a higher chromium concentration has better corrosion resistance. The surface with a higher chromium concentration may be arranged to face the MEA 18. In some embodiments, the chromium concentration of the surface with better corrosion resistance of the porous structure may range from about 3% by mass to about 50% by mass, while the chromium concentration of the surface with lower corrosion resistance of the metal porous structure may be less than about 3% by mass.

[0093] Various embodiments of the porous structure described herein can be formed by one or more electroplating processes. For example, in some embodiments, the resin molded body can initially be used as a substrate for a three-dimensional network structure. The resin molded body may include one or more of polyurethane, melamine, polypropylene, polyethylene, etc. The resin molded body may include holes in its three-dimensional network structure. In some embodiments, the porosity of the resin molded body may range from about 80% to about 98%, and the pore size may be from about 50 μm to about 500 μm. In some embodiments, the thickness of the resin molded body may be from about 150 μm to about 5000 μm, from about 200 μm to 2000 μm, or from about 300 μm to about 1200 μm.

[0094] In order to form a porous structure, the metal layer can be plated on the resin molded body. For the NiCr embodiment of the porous structure, for example, the nickel layer and the chromium layer can be plated on the resin molded body. For the NiSnCr embodiment of the porous structure, for example, the nickel layer, the tin layer and the chromium layer can be plated on the resin molded body. The resin molded body can be subjected to a conductive treatment, such as chemical plating (autocatalytic plating), vapor deposition, sputtering and / or applying a conductive metal (e.g., nickel particles, tin particles and / or carbon particles). Then, the nickel layer and / or the tin layer can be electroplated on the surface of the three-dimensional structure or on the skeleton of the treated resin molded body. For example, when the resin molded body is coated with a conductive layer, a nickel layer can be subsequently formed on the skeleton of the resin molded body by an electroplating process. After the nickel layer is formed, a tin layer can be subsequently formed on the skeleton of the resin molded body by another electroplating process. Alternatively, when the resin molded body is coated with a conductive layer, the tin layer can be electroplated first, and then the nickel layer can be electroplated. In some embodiments, chemical vapor deposition can be used to add chromium to a structure that is essentially nickel.

[0095] In some embodiments, after one or more metal layers are plated onto the skeleton of the resin molded body (such as a nickel layer and / or a tin layer), a chromium layer can be added by an electroplating process. In some embodiments, a chromium plating layer can be formed so that the chromium concentration of at least one surface of the porous structure ranges from about 3% by mass to about 50% by mass. After the chromium plating layer is plated or after the nickel plating layer and / or the tin plating layer is plated, the initial resin molded body can be removed by heat treatment to form a porous structure. For example, the porous structure can be heated at a temperature of about 900°C to about 1300°C in an inert atmosphere or a reducing atmosphere.

[0096] In some embodiments, the fuel cells 10 described herein may be modified to increase the active area of ​​each fuel cell 10. For example, the fuel cell 10 may be modified so that the active area is doubled by doubling the width of the active area. Fig.12 A side perspective view of various portions of an adjacent fuel cell 10' is shown, wherein the active area may be twice (2x) the active area of ​​the fuel cell 10 (see, for example, Figure 2 ). The fuel cell 10' can be positioned so that the left half of the fuel cell 10' can be positioned the same as the fuel cell 10, and the right half of the fuel cell 10' can be positioned as an inverted image of the left half along the bisector between the two halves. In some embodiments, the left and right halves can be positioned the same instead of inverted images. The fuel cell 10' can include the same elements as the fuel cell 10, except that the width is wider and the left and right halves are positioned as inverted images.

[0097] like Fig.12As shown, like the fuel cell 10, the fuel cell 10' may include a cathode catalyst layer 12', an anode catalyst layer 14', and a proton exchange membrane (PEM) 16' located between the cathode catalyst layer 12' and the anode catalyst layer 14', and the proton exchange membrane (PEM) 16' may be collectively referred to as a membrane electrode assembly (MEA) 18'. The fuel cell 10' may include two bipolar plates, a cathode plate 20' and an anode plate 22'. The cathode plate 20' may be located near the cathode catalyst layer 12', and the anode plate 22' may be located near the anode catalyst layer 14'. The MEA 18' may be inserted and enclosed between the cathode plate 20' and the anode plate 22. The fuel cell 10' may also include a conductive gas diffusion layer (e.g., a cathode gas diffusion layer 24' and an anode gas diffusion layer 26') within the fuel cell 10 on each side of the MEA 18. The fuel cell 10' may also include a flow field located on each side of the MEA 18'. For example, the fuel cell 10' may include a cathode flow field 28', which may include a porous structure between the cathode plate 20' and the GDL 24', and an anode flow field 30', which may be formed by the anode plate 22'. The fuel cell may also include a plurality of fluid manifolds 31A', 31B' extending along a longitudinal axis 5 defined by a series of stacked cathode plates 20' and anode plates 22'. It should be understood that based on at least Figure 2 and Fig.12 Similar as shown, the descriptions of the components, features, operation, and advantages described herein with respect to the fuel cell 10 are equally applicable to the fuel cell 10 ′. Fig.13 , Fig.14 and Fig.15 A front view of an anode plate 22, cathode plate 20, and cathode flow field 28 according to an exemplary embodiment of a fuel cell 10' is shown. In some embodiments, the fuel cell 10 can be modified so that the active area is increased threefold by increasing the active area and repeating the layout of the features of the fuel cell 10 (e.g., manifolds, passages, ports, etc.) three times instead of twice, just as the fuel cell 10'.

[0098] The foregoing description has been given for the purpose of illustration. It is not exhaustive and is not limited to the precise form or embodiment disclosed. By considering the description and practice of the disclosed embodiments, modifications, adaptations and other applications of the embodiments will be apparent. For example, the described embodiments of the fuel cell 10 may be suitable for use with a variety of electrochemical cells. For example, although the present disclosure is primarily focused on fuel cells with anode channel flow fields and cathode porous flow fields, it is contemplated that some of these features may be used for fuel cells utilizing anode flow fields and cathode flow fields or fuel cells utilizing anode porous flow fields and cathode porous flow fields.

[0099] In addition, although illustrative embodiments have been described herein, the scope includes any and all embodiments based on the present disclosure with equivalent elements, modifications, omissions, combinations (e.g., aspects of the various embodiments), adaptations, and / or changes. The elements in the claims should be interpreted broadly based on the language employed in the claims, and are not limited to the examples described in this specification or during the prosecution of this application, which examples should be understood to be non-exclusive. Further, the steps of the disclosed methods may be modified in any way, including reordering the steps and / or inserting or deleting steps.

[0100] The features and advantages of the present disclosure are apparent from the detailed description, and therefore, the appended claims are intended to cover all batteries and battery stacks that fall within the true spirit and scope of the present disclosure. As used herein, the indefinite articles "a" and "an" mean "one or more". Similarly, the use of plural terms does not necessarily mean plural unless clearly given in the context. Words such as "and" or "or" mean "and / or" unless otherwise expressly indicated. Further, since many modifications and variations are easily conceivable based on the study of the present disclosure, it is not desired to limit the present disclosure to the exact construction and operation shown and described, and therefore, all suitable modifications and equivalents that fall within the scope of the present disclosure may be adopted.

[0101] Other embodiments of the disclosure will be apparent to those skilled in the art from consideration of the specification and practice of the disclosure herein.It is intended that the specification and examples be considered exemplary only, with the true scope and spirit of the disclosure being indicated by the following claims.

Claims

1. An electrochemical battery stack comprising: A plurality of electrochemical cells stacked along a longitudinal axis, each electrochemical cell comprising: A membrane electrode assembly, the membrane electrode assembly comprising a cathode catalyst layer, an anode catalyst layer, and a polymer membrane interposed between the cathode catalyst layer and the anode catalyst layer; an anode plate and a cathode plate, a membrane electrode assembly is interposed between the anode plate and the cathode plate, and the anode plate defines a plurality of channels, the plurality of channels forming an anode flow field facing the anode catalyst layer; a cathode flow field, the cathode flow field being located between the cathode plate and the cathode catalyst layer, wherein the cathode flow field comprises a porous structure; a first manifold segment and a second manifold segment, the first manifold segment comprising an anode supply manifold and the second manifold segment comprising an anode exhaust manifold; a first anode distribution channel, the first anode distribution channel being located between the first manifold segment and the anode flow field, the first anode distribution channel being configured to distribute the fuel supplied from the anode supply manifold to the anode flow field; a second anode distribution channel, the second anode distribution channel being located between the second manifold segment and the anode flow field, the second anode distribution channel being configured to collect fuel from the anode flow field and direct the fuel to the anode exhaust manifold; The first anode distribution channel and the second anode distribution channel have a plurality of support features located therein; and Wherein the support features extend in opposite directions from the anode plate along the longitudinal axis to contact the cathode plate on one side and the membrane electrode assembly on the other side. 2 . The electrochemical cell stack of claim 1 , wherein the first anode distribution channel and the second anode distribution channel are formed along the longitudinal axis between and defined by the membrane electrode assembly and the anode plate. 3 . The electrochemical cell stack of claim 1 , wherein the first anode distribution channel and the second anode distribution channel extend the width of the anode flow field. 4 . The electrochemical cell stack of claim 1 , wherein the support features are evenly spaced throughout the first anode distribution channel and throughout the second anode distribution channel.

5. The electrochemical cell stack of claim 1, wherein the support feature is in the shape of a dimple.

6. The electrochemical cell stack of claim 1, wherein the distance D between the support features is C The thickness of the cathode plate is p The ratio ranges from 3 to 50.

7. The electrochemical cell stack of claim 1, wherein the distance D between the support features is C is 1.5 mm, and the thickness of the cathode plate is t p It is 0.1mm.

8. The electrochemical cell stack of claim 1, comprising a plurality of orifice openings fluidly connecting the first anode distribution channel with the anode flow field.

9. The electrochemical cell stack of claim 1, wherein: The number of orifice openings corresponds to the number of channels in the anode flow field.

10. The electrochemical cell stack of claim 1, wherein the orifice opening is configured to exert a back pressure on the fuel in the first anode distribution channel, which causes the fuel to fill the first anode distribution channel during operation of the electrochemical cell stack.

11. An electrochemical cell comprising: A membrane electrode assembly, the membrane electrode assembly comprising a cathode catalyst layer, an anode catalyst layer, and a polymer membrane interposed between the cathode catalyst layer and the anode catalyst layer; an anode plate and a cathode plate, a membrane electrode assembly is interposed between the anode plate and the cathode plate, and the anode plate defines a plurality of channels, the plurality of channels forming an anode flow field facing the anode catalyst layer; a cathode flow field, the cathode flow field being located between the cathode plate and the cathode catalyst layer, wherein the cathode flow field comprises a porous structure; a first manifold segment and a second manifold segment, the first manifold segment comprising an anode supply manifold and the second manifold segment comprising an anode exhaust manifold; a first anode distribution channel, the first anode distribution channel being located between the first manifold segment and the anode flow field, the first anode distribution channel being configured to distribute the fuel supplied from the anode supply manifold to the anode flow field; a second anode distribution channel, the second anode distribution channel being located between the second manifold segment and the anode flow field, the second anode distribution channel being configured to collect fuel from the anode flow field and direct the fuel to the anode exhaust manifold; The first anode distribution channel and the second anode distribution channel have a plurality of support features located therein; as well as Wherein the support features extend in opposite directions from the anode plate along the longitudinal axis to contact the cathode plate on one side and the membrane electrode assembly on the other side.

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