BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
While the specification concludes with claims particularly pointing out and distinctly claiming that which is regarded as the present invention, the advantages of this invention may be more readily ascertained from the following description of the invention when read in conjunction with the accompanying drawings in which:
FIG. 1 is a schematic diagram of a fuel cell illustrating basic principles of operation thereof;
FIG. 2 is a cross-sectional view of a single solid oxide fuel cell having a configuration that is known in the art;
FIG. 3 is a cross-sectional view of an electrolytic/fuel cell bundle that includes a plurality of fuel cells like those shown in FIG. 2;
FIG. 4 is a schematic diagram illustrating a portion of a fuel cell system illustrating basic principles of operation thereof;
FIG. 5A is a perspective view of one example of an electrolytic/fuel cell bundle that embodies teachings of the present invention and includes a plurality of individual current collectors that each include flat or planar exterior surfaces and are stacked in a hexagonal pattern;
FIG. 5B is a cross-sectional view of the electrolytic/fuel cell bundle shown in FIG. 5A;
FIG. 5C is an enlarged view of a portion the electrolytic/fuel cell bundle shown in FIG. 5B illustrating various components of a cell thereof;
FIG. 6 is a cross-sectional view of another example of an electrolytic/fuel cell bundle that embodies teachings of the present invention and includes a monolithic current collector;
FIG. 7A is a perspective view of an additional example of an electrolytic/fuel cell bundle that embodies teachings of the present invention and includes a monolithic current collector having a cross-sectional area that varies in a direction generally parallel to a direction of current flow through the current collector;
FIG. 7B is a cross-sectional view of the electrolytic/fuel cell bundle shown in FIG. 7A illustrating a current bus structure electrically coupled to the current collector;
FIG. 8 is a perspective view of another example of an electrolytic/fuel cell bundle that embodies teachings of the present invention and includes a current collector comprised of a plurality of individual current collectors that each include flat or planar exterior surfaces and are stacked in a square or rectangular pattern, the current collector having a cross-sectional area that varies in a direction generally parallel to a direction of current flow through the current collector; and
FIG. 9 is a perspective view of yet another example of an electrolytic/fuel cell bundle that embodies teachings of the present invention and includes a plurality of cells stacked in a square or rectangular pattern and a monolithic current collector having a cross-sectional area that varies in a direction generally parallel to a direction of current flow through the current collector.
DETAILED DESCRIPTION OF THE INVENTION
The illustrations presented herein are not meant to be actual views of any particular electrolytic/fuel cell bundle, but are merely idealized representations which are employed to describe the present invention. Additionally, elements common between figures may retain the same numerical designation.
As used herein, the term electrolytic/fuel cell bundle means a bundle of cells, each of which cells includes an anode and a cathode and is operable as at least one of a fuel cell and an electrolytic cell.
FIG. 5A is a perspective view of one example of an electrolytic/fuel cell bundle 70 that embodies teachings of the present invention. The electrolytic/fuel cell bundle 70 may be used, for example, in a solid oxide fuel cell system similar to the fuel cell system 30 shown in FIG. 4. FIG. 5B is a cross-sectional view of the electrolytic/fuel cell bundle 70 shown in FIG. 5A, and FIG. 5C is an enlarged view of a portion of FIG. 5B illustrating the inner electrode 74, outer electrode 76, and electrolyte layer 78 of one cell 72 of the electrolytic/fuel cell bundle 70 (the inner electrode 74, outer electrode 76, and electrolyte layer 78 of each of the cells 72 are not illustrated in FIGS. 5A-5B due to their relatively small size).
Referring to FIG. 5A, the electrolytic/fuel cell bundle 70 includes a plurality of cells 72, each of which may have a hollow, generally cylindrical tubular shape. The electrolytic/fuel cell bundle 70 further includes an electrically conductive current collector 80, which may be in direct electrical and structural communication with the outer electrode 76 of each of the cells 72 in the electrolytic/fuel cell bundle 70. In some embodiments, the current collector 80 may have a cross-sectional area that increases in a direction generally parallel to a direction of current flow through the current collector 80, as will be discussed in further detail below.
Referring to FIG. 5C, each of the cells 72 may include an inner electrode 74, an outer electrode 76, and an electrolyte layer 78 disposed between the inner electrode 74 and the outer electrode 76. In some embodiments, the inner electrode 74 of each cell 72 may include an anode and the outer electrode 76 of each cell 72 may include a cathode. In additional embodiments, the inner electrode 74 of each cell 72 may include a cathode and the outer electrode 76 of each cell 72 may include an anode. Each inner electrode 74 may have a radially inner surface 75A and a radially outer surface 75B, each outer electrode 76 may have a radially inner surface 77A and a radially outer surface 77B, and each electrolyte layer 78 may have a radially inner surface 79A and a radially outer surface 79B. Each electrolyte layer 78 may be disposed concentrically around an inner electrode 74 such that the inner surface 79A of each electrolyte layer 78 is disposed adjacent an outer surface 75B of an inner electrode 74. Similarly, each outer electrode 76 may be disposed concentrically around an electrolyte layer 78 such that the inner surface 77A of each outer electrode 76 is disposed adjacent an outer surface 79B of an electrolyte layer 78. The outer surface 77B of each outer electrode 76 may be disposed adjacent an interior surface 82 of the current collector 80. Each of the interior surfaces 82 of the current collector 80 may have a generally cylindrical shape.
By way of example and not limitation, the inner electrode 74 may be or include an anode and may include at least one of a metal-ceramic composite (cermet) material (for example, a cermet comprising nickel and yttria-stabilized zirconia (YSZ)), a precious metal (for example, silver, platinum, and gold and alloys of such metals), or a transition metal (for example, iron and nickel, as well as alloys of such metals). The inner electrode 74 may be substantially porous, and may have a pore size gradient including relatively larger pores on the side thereof proximate the inner surface 75A thereof and relatively smaller pores on the side thereof proximate the outer surface 75B thereof (the surface adjacent the electrolyte layer 78). The inner electrode 74 may have a thickness in a range extending from about ten microns up to several millimeters.
The outer electrode 76 may be or include a cathode and may include, for example, a perovskite material doped with lanthanum or strontium (e.g., manganites doped with lanthanum or strontium, lanthanum ferrite doped with strontium, etc.). The outer electrode 76 also may be substantially porous, and may have a pore size gradient. The outer electrode 76 also may have a thickness in a range extending from about ten microns up to several millimeters.
The electrolyte layer 78 may be or include a solid oxide ceramic material such as, for example, an yttria-stabilized zirconia (YSZ) (e.g., between about 3 and about 10 percent yttria), scandium-doped zirconia (SDZ), gadolinium-doped ceria, lanthanum gallate, or other perovskite material. The electrolyte layer 78 may have a thickness of between about five microns and about 100 microns.
The current collector 80 may be or include a material such as, for example, a conductive ceramic material. By way of example and not limitation, the current collector 80 may include a conductive perovskite material (e.g., lanthanum chromites and/or yttrium chromites doped with at least one of magnesium, strontium, calcium, and cobalt. In additional embodiments, the current collector 80 may be or include a material such as, for example, a conductive metal material (e.g., chrome and chrome alloys, iron and iron alloys, porous stainless steel, etc.) In some embodiments, the current collector 80 may be porous to enable an oxidant or a reductant to flow through the pores of the current collector 80 to the outer surface 77B of the outer electrode 76.
In some embodiments, the current collector 80 may be formed or otherwise provided prior to providing or forming the cells 72 therein. Each of the cells 72 may be formed or otherwise provided within the interior regions of the current collector 80 defined by the interior surfaces 82. By way of example and not limitation, each outer electrode 76 may be formed on an interior surface 82 of the current collector, the electrolyte layer 78 may be formed on the inner surface 77A of the outer electrode 76, and the inner electrode 74 then may be formed on the inner surface 79A of the electrolyte layer 78A.
In additional embodiments, the cells 72 may be formed and aligned with one another prior to forming the current collector 80 around and between the cells 72. By way of example and not limitation, the inner electrodes 74 may be formed, and the electrolyte layers 78A may be formed over the outer surfaces 75B of the inner electrodes 74. The outer electrodes 76 then may be formed over the outer surfaces 79B of the electrolyte layers 78, and the current collector 80 may be formed around and between the cells 72.
As shown in FIGS. 5A-5B, the current collector 80 may include a plurality of individual current collectors 86 that are stacked together and electrically interconnected to form the current collector 80. Each of the individual current collectors 86 may correspond to one cell 72, and each may have a plurality of generally planar exterior surfaces 88, which may extend generally along the length of the individual current collectors 86. In the embodiment shown in FIGS. 5A-5B, each of the individual current collectors 86 includes twelve generally planar exterior surfaces 88. In this configuration, the individual current collectors 86 may be stacked in a hexagonal pattern, and the generally planar exterior surfaces 88 of each individual current collector 86 may be configured to abut against a generally planar exterior surface 88 of the adjacent, nearest-neighbor individual current collectors 86. Furthermore, elongated channels 90 may be provided between the adjacent, nearest-neighbor individual current collectors 86, as shown in FIG. 5B. In this configuration, a reductant (e.g., fuel) or an oxidant (e.g., air) may be caused to flow through the elongated channels 90, as well as over the exterior surfaces of the current collector 80, during operation of the cells 72 of the electrolytic/fuel cell bundle 70.
Referring again to FIG. 5A, each of the cells 72 may have a first open end 73A and an opposite, second closed end 73B, which may be substantially similar to the open end 46 and the closed end 48 of the fuel cell 10, which is described above in relation to FIG. 4. The inner electrodes 74 (FIG. 5C) of each of the cells 72 of the electrolytic/fuel cell bundle 70 may be electrically interconnected with one another at, for example, the open ends 73A thereof (using, for example, electrical wires (not shown)). The outer electrodes 76 of each of the cells 72 of the electrolytic/fuel cell bundle 70 may be electrically interconnected with one another by the current collector 80. In this configuration, each of the inner electrodes 74 of the cells 72 may be provided at the same electrical potential, and the outer electrodes 76 of the cells 72 may be provided at the same electrical potential. In this manner, a substantially similar voltage may be provided between the inner electrode 74 and the outer electrode 76 in each of the cells 72 of the electrolytic/fuel cell bundle 70.
At least one electrolytic/fuel cell bundle 70 may be used in a fuel cell system that embodies teachings of the present invention to generate electricity, or in an electrolysis system that embodies teachings of the present invention to perform electrolysis. In some embodiments, a fuel cell system or an electrolysis system may include a plurality of substantially identical electrolytic/fuel cell bundles 70, some of which may be electrically connected in parallel (e.g., the current collector 80 of a first electrolytic/fuel cell bundle 70 electrically interconnected directly to the current collector 80 of a second electrolytic/fuel cell bundle 70, and the inner electrodes 74 of the first electrolytic/fuel cell bundle 70 electrically interconnected directly to the inner electrodes 74 of the second electrolytic/fuel cell bundle 70), and some of which may be electrically connected in series (e.g., the inner electrodes 74 of a first electrolytic/fuel cell bundle 70 electrically interconnected to a first current bus, the current collector 80 of the first electrolytic/fuel cell bundle 70 electrically interconnected directly to the inner electrodes 74 of a second electrolytic/fuel cell bundle 70, and the current collector 80 of the second electrolytic/fuel cell bundle 70 electrically interconnected to a second current bus). By selectively tailoring the number of electrolytic/fuel cell bundles 70 that are electrically interconnected in series in a fuel cell system or an electrolysis system that embodies teachings of the present invention, the operating voltage thereof may be selectively tailored. Similarly, by selectively tailoring the number of electrolytic/fuel cell bundles 70 that are electrically interconnected in parallel in a fuel cell system or an electrolysis system that embodies teachings of the present invention, the operating current thereof may be selectively tailored.
FIG. 6 is a cross-sectional view of another electrolytic/fuel cell bundle 100 that embodies teachings of the present invention and that includes a current collector 102 having a monolithic unitary structure that substantially surrounds each of a plurality of cells 72. The current collector 102 is otherwise substantially identical to the current collector 80 previously described in relation to FIGS. 5A-5B and includes a plurality of interior surfaces 82 defining regions in which the cells 72 are disposed, as well as elongated channels 90 that extend through the current collector 102.
By way of example and not limitation, the current collector 102 may be formed by extruding a precursor material through a die and pin assembly, the die of which assembly defines the exterior surfaces of the current collector 102, and the pins of which assembly define the interior surfaces 82 and the elongated channels 90 of the current collector 102. Extrusion machines for extruding such precursor materials are known in the art and commercially available. The extruded precursor material then may be consolidated to form the current collector 80. For example, the precursor material may comprise particles of a ceramic material, together with one or more additives such as, for example, binders, lubricants, sintering aids, deflocculants, plasticizers, wetting agents, and filler materials (which may be used to define pores within the current collector 80 by subsequently removing the filler materials from the extruded structure). After extrusion, the precursor material may be consolidated by, for example, heating the precursor material to a temperature sufficient to cause sintering of the particles of ceramic material and densification of the extruded structure. The cells 72 then may be formed within the interior surfaces 82 of the current collector 102.
In additional embodiments, the current collector 102 may be formed by casting or molding a precursor material in a mold using pins or other inserts to define the interior surfaces 82 and the elongated channels 90 of the current collector 102. After molding or casting the precursor material, the precursor material may be consolidated as described above to form the current collector 102.
By providing a current collector 102 comprising a substantially monolithic unitary structure, as shown in FIG. 6, there is no need to provide electrical contact between various individual current collectors, such as the individual current collectors 86 previously described in relation to FIG. 5B, which may eliminate or substantially reduce contact resistance and enhance the performance of a fuel cell system or an electrolytic cell system employing such a monolithic unitary current collector 102 relative to known fuel cell systems and electrolytic cell systems.
Another electrolytic/fuel cell bundle 110 that embodies teachings of the present invention is shown in FIG. 7A. The electrolytic/fuel cell bundle 110 is substantially similar to the electrolytic/fuel cell bundle 100 shown in FIG. 6 and includes a current collector 112 that has a monolithic unitary structure and substantially surrounds each of a plurality of cells 72. The monolithic current collector 112, however, has a cross-sectional area that increases in a direction generally parallel to a direction of current flow through the current collector 112, as described in further detail below.
During operation of the electrolytic/fuel cell bundle 110, an electrically conductive current bus structure (not shown in FIG. 7A) may be used to electrically couple the current collector 112 to an external circuit. During operation, electrons may flow from the anodes of the cells 72 through the external circuit, the electrically conductive current bus structure, and the current collector 80 to the cathodes of the cells 72. The current bus structure may be electrically coupled to any point, points, or surfaces of the current collector 112, and the direction of current flow through the current collector 80 will at least partially depend upon where the current bus structure is electrically coupled to the current collector 112. As each point on the radially outer surface 77B of the outer electrode 76 (FIG. 5C) of each of the cells 72 may not be separated from the current bus structure by an equal distance, the magnitude of the current density (i.e., the ratio of the magnitude of current flowing in the current collector 112 to the cross-sectional area of the current collector 112 perpendicular to the direction of the current flow) may not be uniform throughout the current collector 112.
It may be desirable to maintain the current density in the current collector 112 below a threshold level to optimize performance of the electrolytic/fuel cell bundle 110. Furthermore, it may be desirable to provide a generally uniform current density throughout the current collector 112. The current collector 112 may have a cross-sectional area that varies (either increases or decreases) in a direction generally parallel to a direction of current flow through the current collector 112, so as to maintain the current density in the current collector 112 below a threshold level and/or to provide a generally uniform current density throughout the current collector 112.
Referring to FIG. 7B, by way of example and not limitation, an electrically conductive current bus structure 114 may be electrically coupled to one or more exterior surfaces of the current collector 112 on a side thereof adjacent a first row 116 of the cells 72 in the electrolytic/fuel cell bundle 110. The current bus structure 114 may be in electrical contact with the current collector 112 substantially along the length thereof. In this configuration, during operation of the electrolytic/fuel cell bundle 110, electrons may flow from the current bus structure 114 through the current collector 112 to the outer electrodes 76 of the cells 72 in each of the first row 116 of cells 72, the second row 118 of cells 72, and the third row 120 of cells 72. In this configuration, the current passing through the first plane 124 shown in FIG. 7B includes the current generated by the cells 72 in each of the three rows 116, 118, 120 of cells 72, while the current passing through the second plane 126 includes the current generated only by the second and third rows 118, 120 of cells 72, and the current passing through the third plane 128 includes the current generated only by the third row 120 of cells 72. As such, the cross-sectional area of the current collector 112 may decrease in the general direction of current flow through the current collector 112 (e.g., in the direction extending from the current bus structure 114 generally towards the third row 120 of cells 72).
In additional embodiments, if the outer electrode 76 of each of the cells 72 comprises an anode, the cross-sectional area of the current collector 112 may increase in the general direction of current flow through the current collector 112 (e.g., in the direction extending from the cells 72 generally towards the current bus structure 114).
The cross-sectional area of the current collector 112 may vary in a generally continuous manner and/or in a stepwise, generally discontinuous manner across the current collector 112. In the embodiment shown in FIGS. 7A-7B, the current collector 112 is configured such that the wall thickness of the portion of the current collector 112 surrounding the cells 72 in the second row 118 is thicker than the portion of the current collector 112 surrounding the cells 72 in the third row 120, and the wall thickness of the portion of the current collector 112 surrounding the cells 72 in the first row 116 is thicker than the portion of the current collector 112 surrounding the cells 72 in the second row 118. In this manner, the cross-sectional area of the current collector 112 varies in a stepwise, generally discontinuous manner across the current collector 112. In additional embodiments, the cross-sectional area of the current collector 112 may vary in a generally continuous manner across the current collector 112.
In the embodiment shown in FIGS. 7A-7B, the diameter of the cells 72 in the first row 116 is smaller than the diameter of the cells 72 in the second and third rows 118, 120, and the diameter of the cells 72 in the second row 118 is smaller than the diameter of the cells 72 in the third row 120. The amount of current generated by each of the cells 72 may be at least partially a function of the surface area of the inner electrode 74, outer electrode 76, and electrolyte layer 78, and hence, the diameter of each of the respective cells 72. As such, in the embodiment shown in FIGS. 7A-7B, the cells 72 in the third row 120 may generate more current than the cells 72 in the second row 118, and the cells 72 in the first row 116 may generate more current than the cells 72 in the second row 118. In some embodiments of the present invention, it may be necessary or desirable to configure each of the cells 72 to generate substantially equal amounts of current, and as such, the cells 72 in each of the rows 116, 118, 120 may be the same size and have substantially identical diameters.
In additional embodiments of the present invention, the current bus structure 114 may be electrically coupled to the current collector 112 at an end thereof (e.g., the end of the current collector 112 proximate the open ends 73A (FIG. 7A) of the cells 72 or the opposite end of the current collector 112 proximate the closed ends 73B (FIG. 7A) of the cells 72). In such embodiments, the cross-sectional area of the current collector 112 may vary in a longitudinal direction along the current collector 112 parallel to the lengths of the cells 72.
By decreasing and/or maintaining generally uniform the current density within the current collector 80 during operation, the performance of a fuel cell system or an electrolytic cell system that utilizes the electrolytic/fuel cell bundle 70 shown in FIGS. 5A-5B or the electrolytic/fuel cell bundle 100 shown in FIG. 5C may be enhanced relative to known fuel cell systems and electrolytic cell systems.
While each of the embodiments of electrolytic/fuel cell bundles described above includes cells 72 that are stacked in a hexagonal pattern or arrangement, the present invention is not so limited and includes electrolytic/fuel cell bundles that include cells 72 that are stacked in other arrangements.
Another electrolytic/fuel cell bundle 130 that embodies teachings of the present invention is shown in FIG. 8. The electrolytic/fuel cell bundle 130 includes a plurality of generally tubular cells 72, as described above. In the embodiment shown in FIG. 8, however, the cells 72 are stacked in a square or rectangular pattern or arrangement, and each of the cells 72 has a substantially identical diameter, and hence, may generate a substantially similar amount of current during operation of the electrolytic/fuel cell bundle 130.
As shown in FIG. 8, the electrolytic/fuel cell bundle 130 further includes a current collector 132, which is comprised of a plurality of individual current collectors 134 that each correspond to one cell 72. Each of the individual current collectors 134 has a plurality of generally planar exterior surfaces 136, which may extend generally along the length of the individual current collectors 134. In the embodiment shown in FIG. 8, each of the individual current collectors 134 includes four generally planar exterior surfaces 136. In this configuration, the individual current collectors 134 may be stacked in the square or rectangular pattern, and the generally planar exterior surfaces 136 of each individual current collector 134 may be configured to abut against a generally planar exterior surface 136 of the adjacent, nearest-neighbor individual current collectors 136 in the electrolytic/fuel cell bundle 130. Furthermore, elongated channels 138 may be defined between the adjacent, nearest-neighbor individual current collectors 134, as shown in FIG. 8. In this configuration, a reductant (e.g., fuel) or an oxidant (e.g., air) may be caused to flow through the elongated channels 138, as well as over the exterior surfaces of the current collector 132, during operation of the cells 72 of the electrolytic/fuel cell bundle 130.
The current collector 132 may have a cross-sectional area that increases in a direction generally parallel to a direction of current flow through the current collector 132. As shown in FIG. 8, the electrolytic/fuel cell bundle 130 may include a plurality of rows of cells 72. By way of example and not limitation, the electrolytic/fuel cell bundle 130 may include a first row 140 of cells 72, a second row 142 of cells 72, and a third row 144 of cells 72. A thickness (e.g., a wall thickness) of the individual current collectors 134 corresponding to the cells 72 in the first row 140 may be greater than the thickness of the individual current collectors 134 corresponding to the cells 72 in the second row 142, and the thickness of the individual current collectors 134 corresponding to the cells 72 in the second row 142 may be greater than the thickness of the individual current collectors 134 corresponding to the cells 72 in the third row 144.
In some embodiments, the outer electrode 76 (FIG. 5C) of each of the cells 72 in the first, second, and third rows 140, 142, 143 may include a cathode. In this configuration, a current bus member 114 (FIG. 7B) may be electrically coupled to each of the individual current collectors 134 corresponding to cells 72 in the first row 140, and current may be caused to flow through the current collector 132 in a direction extending from the current bus member 114 generally towards the third row 144 of cells 72. In this configuration, the cross-sectional area of the current collector 132 may decrease across the current collector 132 in the general direction of current flow through the current collector 132.
In additional embodiments, the outer electrode 76 (FIG. 5C) of each of the cells 72 in the first, second, and third rows 140, 142, 143 may include an anode. In this configuration, a current bus member 114 (FIG. 7B) may be electrically coupled to each of the individual current collectors 134 corresponding to cells 72 in the first row 140, and current may be caused to flow through the current collector 132 in a direction parallel to a direction extending from the third row 144 of cells 72 generally towards the current bus member 114. In this configuration, the cross-sectional area of the current collector 132 may increase across the current collector 132 in the general direction of current flow through the current collector 132.
In yet another embodiment, a conductive bus member 114 (FIG. 7B) may be electrically coupled to the current collector 132 at an end thereof proximate the open ends 73A (FIG. 7A) of the cells 72 or the closed ends 73B (FIG. 7B) of the cells 72, and the cross-sectional area of each of the individual current collectors 134 (and, hence, the current collector 132) may increase in a longitudinal direction generally parallel to the longitudinal axis of the corresponding elongated tubular cell 72.
In each of the above described embodiments, a cross-sectional area of the current collector 132 varies in a direction generally parallel to a general direction of current flow through the current collector 132. In this configuration, the current density in the current collector 132 may be maintained below a threshold level, and/or the current density in the current collector 132 may be maintained substantially uniform.
Yet another electrolytic/fuel cell bundle 150 that embodies teachings of the present invention is shown in FIG. 9. The electrolytic/fuel cell bundle 150 is substantially similar to the electrolytic/fuel cell bundle 130 shown in FIG. 8 and includes a plurality of generally tubular cells 72, as described above, as well as a current collector 152. In contrast to the current collector 132 of the electrolytic/fuel cell bundle 130 shown in FIG. 8, however, the current collector 152 includes a monolithic unitary structure, substantially similar to the current collector 100 previously described with reference to FIG. 6.
By providing a current collector 152 comprising a substantially monolithic unitary structure, as shown in FIG. 9, there is no need to provide electrical contact between various individual current collectors, such as the individual current collectors 134 previously described in relation to FIG. 8, which may eliminate or substantially reduce contact resistance and enhance the performance of a fuel cell system or an electrolytic cell system employing such a monolithic unitary current collector 152 relative to known fuel cell systems and electrolytic cell systems.
Electrolytic/fuel cell bundles and systems that embody teachings of the present invention, such as those previously described herein, may have electrolytic/fuel cell packing arrangements that provide decreased overall volume of the electrolytic/fuel cells without a substantial decrease in efficiency thereof relative to known electrolytic/fuel cell bundles and systems. Additionally, by providing monolithic current collectors as described herein, contact resistance between individual current collectors may be substantially eliminated or reduced, thereby improving the efficiency of the electrolytic/fuel cell bundles and systems described herein relative to known electrolytic/fuel cell bundles and systems. Furthermore, by maintaining the current density in the current collectors below a threshold level and/or substantially uniform, as described above, the performance of the electrolytic/fuel cell bundles and systems described herein may be improved relative to known electrolytic/fuel cell bundles and systems.
While the invention may be susceptible to various modifications and alternative forms, specific embodiments have been shown by way of example in the drawings and have been described in detail herein. However, it should be understood that the invention is not intended to be limited to the particular forms disclosed. Rather, the invention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the following appended claims.
Patent Application
20080063916
