JP7009828B2 - Insulation material used in fuel cell stacks and fuel cell stacks - Google Patents

Description

The present invention relates to a fuel cell stack and an insulating member used in a fuel cell stack.

Conventionally, a fuel cell stack has an electrolyte sandwiched between a pair of electrodes from both sides, and divides a flow path portion, which is a gas flow path, between a power generation cell that generates power by the supplied gas and a power generation cell. It is configured by stacking a plurality of cell units having a separator which is formed and which is conductively contacted with the electrode of the power generation cell (see, for example, Patent Document 1).

The fuel cell stack is located between the support member and the separator while electrically insulating the support member that supports the power generation cell and the support member and the separator at a position separated from the separator in the stacking direction of the cell unit. It has an insulating member that regulates the interval between the two.

Japanese Patent No. 4331790

A current collecting resistance is generated between the power generation cell and the separator due to the contact resistance. If the current collecting resistance is large, the internal resistance increases and the power generation performance of the fuel cell stack deteriorates. Therefore, it is necessary that a sufficient surface pressure acts between the power generation cell and the separator.

In the above fuel cell, since the insulating member is composed of a single member, the entire insulating member needs to be composed of a material having electrical insulating properties. Therefore, in order to improve the bonding force between the support member and the separator and the insulating member, the constituent material of the portion of the insulating member that comes into contact with the support member and the separator is considered in consideration of the zygosity of the support member and the separator with the material. It is difficult to select.

If the bonding force between the support member and the separator and the insulating member is weak and the support member and the separator are not firmly fixed to the insulating member, the bending deformation of the support member and the separator cannot be regulated, and the power generation cell and the separator Sufficient surface pressure cannot be applied during the period. Therefore, the fuel cell has a problem that it is difficult to reduce the current collecting resistance.

An object of the present invention is to provide a fuel cell stack and an insulating member used in the fuel cell stack, which can reduce the collection resistance between the power generation cell and the separator.

The fuel cell stack of the present invention for achieving the above object is formed by sandwiching an electrolyte from both sides with a pair of electrodes, and the gas is placed between a power generation cell that generates power by the supplied gas and the power generation cell. A plurality of cell units having a separator that is conductively contacted with the power generation cell and a flow path portion that is a flow passage are laminated , and the separator is formed from the flat portion and the flat portion along the stacking direction of the cell unit. It is a fuel cell stack having protrusions protruding in each of the opposite directions, in which the power generation cell and the separator are brought into conduction contact with each other. The fuel cell stack supports the power generation cell at a position separated from the separator in the stacking direction of the cell unit while electrically insulating the support member from the support member and the separator. It has an insulating member that regulates the distance between the member and the separator. The insulating member includes a first member having a first joining surface to be joined to the support member, a second member having a second joining surface to be joined to the separator, and the first member and the second member. It has an insulating layer which is arranged between the first member and insulates between the first member and the second member. The first joint surface and the second joint surface are displaced from each other in a direction orthogonal to the plan view in the plan view of the insulating member, and overlap with a region where the first joint surface and the second joint surface overlap. It has an area that does not become.

It is a perspective view which shows the fuel cell stack of 1st Embodiment. It is a perspective view which shows the state which disassembled the fuel cell stack of FIG. 1 into a cover, a cell stack assembly, and an external manifold. FIG. 3 is a perspective view showing a state in which the cell stack assembly of FIG. 2 is disassembled into an air shelter, an upper end plate, a stack, and a lower end plate. FIG. 3 is a perspective view showing a state in which the stack of FIG. 3 is disassembled into an upper module unit, a plurality of middle module units, and a lower module unit. It is a perspective view which shows the upper module unit of FIG. 4 disassembled. It is a perspective view which shows the central module unit of FIG. 4 disassembled. It is a perspective view which shows the lower module unit of FIG. 4 disassembled. 5 is a perspective view showing one cell unit of FIGS. 5 to 7 disassembled and another cell unit (configuration other than the metal support cell assembly) located below the one cell unit disassembled. FIG. 3 is a perspective view showing the metal support cell assembly of FIG. 8 in an exploded manner. It is sectional drawing of the metal support cell assembly along the line 10-10 of FIG. It is a perspective view which shows the separator of FIG. 8 from the cathode side (the side which saw the separator 102 from above like FIG. 8). It is a perspective view which shows the separator of FIG. 11 partially (region 12 in FIG. 11). It is a perspective view which shows the separator of FIG. 8 from the anode side (the side which saw the separator 102 from the bottom unlike FIG. 8). It is a perspective view which shows the separator of FIG. 13 partially (region 14 in FIG. 13). FIG. 8 is a cross-sectional view partially (region 15 in FIG. 11) showing a state in which the metal support cell assembly of FIG. 8, a separator, and a current collecting auxiliary layer are laminated. FIG. 15 is an enlarged cross-sectional view of a region surrounded by a broken line 16 in FIG. It is a perspective view of the cell unit which concerns on embodiment. It is a top view of the cell unit which concerns on embodiment. FIG. 6 is a schematic cross-sectional view taken along the line 17C-17C of FIG. 17B. It is a perspective view which shows by disassembling the insulating member which concerns on embodiment. It is a top view of the insulating member which concerns on embodiment. It is sectional drawing of the insulating member which concerns on embodiment. FIG. 18C is an enlarged view of a region surrounded by a broken line 18D in FIG. 18C. It is a perspective view which shows typically the flow of the anode gas and the cathode gas in a fuel cell stack. It is a perspective view which shows typically the flow of the cathode gas in a fuel cell stack. It is a perspective view which shows typically the flow of the anode gas in a fuel cell stack. It is a flowchart for demonstrating the manufacturing method of the fuel cell stack which concerns on embodiment. It is a flowchart for demonstrating the process of laminating cell units which concerns on embodiment. It is a flowchart for demonstrating the process of joining the insulating member which concerns on embodiment. It is a perspective view of the jig used in the process of forming the insulating member which concerns on embodiment. It is a cutting view of the jig used in the process of forming the insulating member which concerns on embodiment. It is sectional drawing of the jig used in the process of forming the insulating member which concerns on embodiment. FIG. 21C is an enlarged view of a region surrounded by a broken line 21D in FIG. 21C. It is an exploded view of the insulating member which concerns on modification 1. FIG. It is sectional drawing of the insulating member which concerns on modification 1. FIG. FIG. 22B is an enlarged view of the area surrounded by the broken line 22C in FIG. 22B. It is an exploded view of the insulating member which concerns on modification 2. It is sectional drawing of the insulating member which concerns on modification 2. FIG. FIG. 23B is an enlarged view of the area surrounded by the broken line 23C in FIG. 23B. It is a perspective view of the cell unit which concerns on modification 3. FIG. It is a top view of the cell unit which concerns on modification 3. FIG. It is a perspective view of the insulating member which concerns on modification 3. FIG. FIG. 5 is a cross-sectional view taken along the line 25B-25B of FIG. 25A. It is sectional drawing which follows the 25C-25C line of FIG. 25A. It is a figure corresponding to a part of FIG. 17C of the fuel cell which concerns on modification 4. It is a figure corresponding to a part of FIG. 17C of the fuel cell which concerns on modification 4. It is a figure corresponding to a part of FIG. 17C of the fuel cell which concerns on modification 5. It is a figure corresponding to a part of FIG. 17C of the fuel cell which concerns on modification 5. It is a schematic sectional drawing of the insulating member which concerns on modification 6. It is a schematic sectional drawing of the insulating member which concerns on modification 6. It is a schematic sectional drawing of the insulating member which concerns on modification 6. It is a schematic sectional drawing of the insulating member which concerns on modification 7. It is a schematic sectional drawing of the insulating member which concerns on modification 7. It is a schematic sectional drawing of the insulating member which concerns on modification 7. It is a schematic sectional drawing of the insulating member which concerns on modification 8. It is sectional drawing corresponding to a part of FIG. 25B of the insulating member which concerns on modification 9. It is sectional drawing corresponding to a part of FIG. 25B of the insulating member which concerns on modification 10. It is sectional drawing corresponding to a part of FIG. 25B of the insulating member which concerns on modification 10. It is sectional drawing corresponding to a part of FIG. 25B of the insulating member which concerns on modification 11. It is sectional drawing corresponding to a part of FIG. 25B of the insulating member which concerns on modification 12.

Hereinafter, embodiments of the present invention will be described with reference to the attached drawings. In the drawings, the same members are designated by the same reference numerals, and duplicate description will be omitted. In the drawings, the size and ratio of each member may be exaggerated to facilitate understanding of the embodiment and may differ from the actual size and ratio.

In each figure, the arrows represented by X, Y, and Z are used to indicate the orientations of the members constituting the fuel cell stack. The direction of the arrow represented by X indicates the lateral direction X of the fuel cell stack. The direction of the arrow represented by Y indicates the longitudinal direction Y of the fuel cell stack. The direction of the arrow represented by Z indicates the stacking direction Z of the fuel cell stack.

(Structure of fuel cell 100)
As shown in FIGS. 1 and 2, the fuel cell 100 is configured by sandwiching the cell stack assembly 100M from above and below by an external manifold 111 that supplies gas from the outside and a cover 112 that protects the cell stack assembly 100M. There is.

As shown in FIGS. 2 and 3, the cell stack assembly 100M sandwiches the fuel cell stack 100S from above and below by the lower end plate 108 and the upper end plate 109, and covers the fuel cell stack 100S with an air shelter 110 that seals the cathode gas CG. It is composed.

As shown in FIGS. 3 and 4, the fuel cell stack 100S is configured by stacking an upper module unit 100P, a plurality of middle module units 100Q, and a lower module unit 100R.

As shown in FIG. 5, the upper module unit 100P comprises a plurality of stacked cell units 100T by means of an upper current collector plate 106 that outputs power generated by the cell unit 100T to the outside and a module end 105 corresponding to an end plate. It is configured by sandwiching it from above and below.

As shown in FIG. 6, the central module unit 100Q is configured by sandwiching a plurality of stacked cell units 100T from above and below by a pair of module ends 105.

As shown in FIG. 7, the lower module unit 100R is configured by sandwiching a plurality of stacked cell units 100T from above and below by a module end 105 and a lower current collector plate 107.

As shown in FIGS. 8 and 9, the cell unit 100T is a power generation cell of a metal support cell assembly 101 provided with a power generation cell 101M that generates power by the supplied gas, and a metal support cell assembly 101 adjacent to each other along the stacking direction Z. It includes a separator 102 that separates 101M, and an insulating member 104 that electrically insulates between the cell frame 101W and the separator 102.

Here, due to the manufacturing method of the fuel cell 100, the metal support cell assembly 101 and the separator 102 form a bonded body 100U by joining the outer edges of the metal support cell assembly 101 and the separator 102 in an annular shape along the bonding line V, as shown in the center of FIG. do. Therefore, the insulating member 104 is arranged between the bonded bodies 100U (metal support cell assembly 101 and separator 102) adjacent to each other along the stacking direction Z. That is, as shown in the lower part of FIG. 8, the insulating member 104 is a separator between the metal support cell assembly 101 of one joint body 100U and another joint body 100U adjacent to one joint body 100U along the stacking direction Z. It is placed between 102 and 102. The cell unit 100T is configured by arranging an insulating member 104 between the joined body 100U and the joined body 100U which are vertically adjacent to each other.

Hereinafter, the fuel cell stack 100S will be described for each configuration.

As shown in FIGS. 9 and 10, the metal support cell assembly 101 is provided with a power generation cell 101M that generates power from the supplied gas.

In the metal support cell assembly 101, the power generation cell 101M is configured by sandwiching the electrolyte 101S between the fuel electrode side electrode (anode 101T) and the oxidant electrode side electrode (cathode 101U) as shown in FIGS. 9 and 10. ing. The metal support cell 101N is composed of a power generation cell 101M and a support metal 101V that supports the power generation cell 101M from one side. The metal support cell assembly 101 is composed of a pair of metal support cells 101N and a cell frame 101W that holds the pair of metal support cells 101N from the surroundings. In the metal support cell assembly 101, the power generation cell 101M is configured by sandwiching the electrolyte 101S between the anode 101T and the cathode 101U, as shown in FIGS. 9 and 10.

As shown in FIGS. 9 and 10, the electrolyte 101S allows oxide ions to permeate from the cathode 101U toward the anode 101T. The electrolyte 101S allows oxide ions to pass through but does not allow gas and electrons to pass through. The electrolyte 101S is formed from a rectangular parallelepiped shape. The electrolyte 101S is made of solid oxide ceramics such as stabilized zirconia in which yttria, neodymium oxide, sammalia, gadria, scandia and the like are dissolved, for example. As shown in FIGS. 9 and 10, the electrolyte 101S has a thin plate shape and has a rectangular shape slightly larger than the anode 101T. As shown in FIG. 10, the outer edge of the electrolyte 101S is refracted toward the side of the anode 101T and is in contact with the side surface of the anode 101T along the stacking direction Z. The tip of the outer edge of the electrolyte 101S is in contact with the support metal 101V.

As shown in FIGS. 9 and 10, the anode 101T is a fuel electrode and reacts an anode gas AG (for example, hydrogen) with an oxide ion to generate an oxide of the anode gas AG and extract electrons. The anode 101T has resistance to a reducing atmosphere, allows the anode gas AG to permeate, has high electrical conductivity, and has a catalytic action of reacting the anode gas AG with oxide ions. The anode 101T is formed from a rectangular parallelepiped shape larger than that of the electrolyte 101S. The anode 101T is made of, for example, a cemented carbide in which a metal such as nickel and an oxide ion conductor such as yttria-stabilized zirconia are mixed. As shown in FIGS. 9 and 10, the anode 101T has a thin plate shape and a rectangular shape.

As shown in FIGS. 9 and 10, the cathode 101U is an oxidizing agent electrode, and reacts electrons with a cathode gas CG (for example, oxygen contained in air) to convert oxygen molecules into oxide ions. The cathode 101U has resistance to an oxidizing atmosphere, permeates the cathode gas CG, has high electrical conductivity, and has a catalytic action of converting oxygen molecules into oxide ions. The cathode 101U is formed from a rectangular parallelepiped shape smaller than that of the electrolyte 101S. The cathode 101U is made of, for example, an oxide such as lanthanum, strontium, manganese, and cobalt. As shown in FIGS. 9 and 10, the cathode 101U has a thin plate shape and a rectangular shape like the anode 101T. The cathode 101U faces the anode 101T via the electrolyte 101S. Since the outer edge of the electrolyte 101S is refracted toward the anode 101T, the outer edge of the cathode 101U does not come into contact with the outer edge of the anode 101T.

As shown in FIGS. 9 and 10, the support metal 101V supports the power generation cell 101M from the side of the anode 101T. The support metal 101V has gas permeability, high electrical conductivity, and sufficient strength. The support metal 101V is formed from a rectangular parallelepiped shape sufficiently larger than the anode 101T. The support metal 101V is made of, for example, a corrosion-resistant alloy containing nickel or chromium, corrosion-resistant steel, or stainless steel.

As shown in FIGS. 9 and 10, the cell frame 101W holds the metal support cell 101N from the surroundings. The cell frame 101W is formed from a thin rectangular shape. The cell frame 101W is provided with a pair of openings 101k along the longitudinal direction Y. The pair of openings 101k of the cell frame 101W each have a rectangular through hole, which is smaller than the outer shape of the support metal 101V. The cell frame 101W is made of metal and is insulated by using an insulating material or a coating. The insulating material is formed by, for example, fixing aluminum oxide to the cell frame 101W. The metal support cell assembly 101 is joined to the cell frame 101W by joining the outer edge of the support metal 101V to the inner edge of the opening 101k of the cell frame 101W.

As shown in FIGS. 9 and 10, the cell frame 101W has a circular extending portion (first extending portion 101p, first extending portion 101p, first extending portion 101p, 1st extending portion 101p, which extends in the plane direction from the right end, the center, and the left end of one side along the longitudinal direction Y. The 2 extending portion 101q and the 3rd extending portion 101r) are provided. The cell frame 101W is provided with circular extending portions (fourth extending portion 101s and fifth extending portion 101t) extending in the plane direction from two locations separated from the center of the other side along the longitudinal direction Y. ing. In the cell frame 101W, the first extending portion 101p, the second extending portion 101q and the third extending portion 101r, and the fourth extending portion 101s and the fifth extending portion 101t are separated by a pair of openings 101k. , Alternately located along the longitudinal direction Y.

As shown in FIGS. 9 and 10, the cell frame 101W has a first anode-side inlet 101a, an anode-side second inlet 101b, and an anode-side third inlet 101c that allow the anode gas AG to pass through (inflow). It is provided in 1 extending portion 101p, 2nd extending portion 101q, and 3rd extending portion 101r. The cell frame 101W is provided with an anode-side first outlet 101d and an anode-side second outlet 101e for passing (outflowing) the anode gas AG in the fourth extending portion 101s and the fifth extending portion 101t. The anode-side first inlet 101a, anode-side second inlet 101b, anode-side third inlet 101c, anode-side first outlet 101d, and anode-side second outlet 101e of the anode gas AG are so-called manifolds. ..

As shown in FIG. 9, the cell frame 101W is provided with a cathode-side first inflow port 101f through which (inflowing) the cathode gas CG is provided in the space between the first extending portion 101p and the second extending portion 101q. There is. The cell frame 101W is provided with a cathode-side second inflow port 101g through which (inflowing) the cathode gas CG is provided in the space between the second extending portion 101q and the third extending portion 101r. The cell frame 101W is provided with a cathode-side first outlet 101h for passing (outflowing) the cathode gas CG on the right side in FIG. 9 with respect to the fourth extending portion 101s. The cell frame 101W is provided with a cathode-side second outlet 101i for passing (outflowing) the cathode gas CG in the space between the fourth extending portion 101s and the fifth extending portion 101t. The cell frame 101W is provided with a cathode-side third outlet 101j for passing (outflowing) the cathode gas CG on the left side in FIG. 9 with respect to the fifth extending portion 101t. In the cell frame 101W, the cathode side first inlet 101f, the cathode side second inlet 101g, the cathode side first outlet 101h, the cathode side second outlet 101i, and the cathode side third outlet 101j are the cell frame 101W. It corresponds to the space between the outer peripheral surface and the inner surface of the air shelter 110.

As shown in FIGS. 15 and 16, the separator 102 partitions the flow path portion 102L, which is a flow path for the anode gas AG and the cathode gas CG, with the power generation cell 101M.

The separator 102 is in conductive contact with the power generation cell 101M. The separator 102 has a current collector auxiliary layer 103. The separator 102 is in conductive contact with the power generation cell 101M via the current collecting auxiliary layer 103.

The separator 102 is arranged so as to face the metal support cell assembly 101. The separator 102 has an outer shape similar to that of the metal support cell assembly 101. The separator 102 is made of metal and is insulated by using an insulating material or a coating except for a region (flow path portion 102L) facing the power generation cell 101M. The insulating material is formed by, for example, fixing aluminum oxide to the separator 102. The separator 102 is provided with a pair of flow path portions 102L arranged side by side in the longitudinal direction Y so as to face the power generation cell 101M.

In the separator 102, as shown in FIGS. 8 and 11 to 15, the flow path portion 102L extends the flow path along the gas flow direction (short direction X) in the gas flow direction (short direction). It is formed by arranging them in a direction orthogonal to the hand direction X) (longitudinal direction Y). As shown in FIGS. 12, 14 and 15, the flow path portion 102L has a convex anode-side protrusion so as to project downward from the flat flat portion 102x in the planes of the longitudinal direction Y and the lateral direction X. 102y (corresponding to protrusions) are provided at regular intervals. The anode-side projection 102y extends along the direction of gas flow (short direction X). The anode-side projection 102y projects downward from the lower end of the separator 102. As shown in FIGS. 12, 14, and 15, the flow path portion 102L is provided with convex cathode side protrusions 102z (corresponding to protrusions) at regular intervals so as to protrude upward from the flat portion 102x. There is. The cathode side projection 102z extends along the direction of gas flow (short direction X). The cathode side projection 102z projects upward from the upper end of the separator 102. In the flow path portion 102L, the anode-side projection 102y and the convex cathode-side projection 102z are alternately provided along the longitudinal direction Y with the flat portion 102x interposed therebetween.

As shown in FIG. 15, the separator 102 constitutes a gap 175 between the flow path portion 102L and the metal support cell assembly 101 located below the flow path portion 102L (on the right side in FIG. 15) as the flow path of the anode gas AG. ing. The anode gas AG flows from the second inlet 102b on the anode side of the separator 102 shown in FIG. 13 through the plurality of grooves 102q shown in FIGS. 13 and 14 and into the flow path portion 102L on the anode side. As shown in FIGS. 13 and 14, the separator 102 has a plurality of grooves 102q formed from the anode-side first inlet 102a, the anode-side second inlet 102b, and the anode-side third inlet 102c, respectively, on the anode-side flow. It is formed radially toward the road portion 102L. As shown in FIGS. 12 and 15, the separator 102 has a gap 175 between the flow path portion 102L and the metal support cell assembly 101 located above the flow path portion 102L (left side in FIG. 15), and the flow path of the cathode gas CG. It is configured as. The cathode gas CG extends from the cathode side first inlet 102f and the cathode side second inlet 102g of the separator 102 shown in FIG. 11 to the cathode side beyond the outer edge 102p of the cathode side of the separator 102 shown in FIGS. 11 and 12. It flows into the flow path portion 102L of. As shown in FIG. 12, the separator 102 has an outer edge 102p on the cathode side formed thinner than other portions.

As shown in FIGS. 8, 11 and 13, the separator 102 is the first inlet on the anode side through which the anode gas AG is passed so that the metal support cell assembly 101 and the separator 102 are in relative positions along the stacking direction Z. 102a, an anode-side second inlet 102b, an anode-side third inlet 102c, an anode-side first outlet 102d, and an anode-side second outlet 102e are provided. The separator 102 has a cathode side first inflow port 102f, a cathode side second inflow port 102g, and a cathode side first inflow so that the cathode gas CG passes through the separator 102 so that the relative positions of the separator 102 are aligned with the metal support cell assembly 101 along the stacking direction Z. The first outlet 102h, the cathode side second outlet 102i, and the cathode side third outlet 102j are provided. In the separator 102, the cathode side first inlet 102f, the cathode side second inlet 102g, the cathode side first outlet 102h, the cathode side second outlet 102i, and the cathode side third outlet 102j are the outer peripheral surfaces of the separator 102. Corresponds to the space between the air shelter 110 and the inner surface of the air shelter 110.

As shown in FIG. 8, the current collector auxiliary layer 103 forms a space for passing gas between the power generation cell 101M and the separator 102, and equalizes the surface pressure to electrically supply the power generation cell 101M and the separator 102. It assists in contact.

The current collector auxiliary layer 103 is a so-called expanded metal. The current collector auxiliary layer 103 is arranged between the power generation cell 101M and the flow path portion 102L of the separator 102. The current collector auxiliary layer 103 has an outer shape similar to that of the power generation cell 101M. The current collector auxiliary layer 103 is formed of a wire mesh having openings such as rhombuses in a grid pattern.

As shown in FIG. 16, the power generation cell 101M and the current collector auxiliary layer 103 are in conduction contact with each other via the contact material 113. The contact material 113 increases the contact area between the power generation cell 101M and the current collection auxiliary layer 103 by filling the gap between the power generation cell 101M and the current collection auxiliary layer 103.

The contact material 113 includes a first state having at least one of viscous or elastic, and a second state of being solidified by being heated in the first state. In the first state, the contact material 113 exerts an elastic force at least along the stacking direction Z.

The material constituting the contact material 113 is not particularly limited, but a material containing a transition metal having a melting point of 600 ° C. or higher as a main component, and more specifically, a material containing silver as a main component can be used. The contact material 113 is in the form of a paste in the first state. The contact material 113 is sintered and solidified by being heated in the first state.

With reference to FIGS. 17A, 17B, and 17C, the insulating member 104 electrically insulates between the cell frame 101W (corresponding to the support member) and the separator 102, and between the cell frame 101W and the separator 102. Regulate the interval between.

The insulating member 104 has the functions of a spacer and a seal.

The insulating member 104 is arranged between the cell frame 101W and the separator 102, and partially seals the gap 175 between the cell frame 101W and the separator 102 to limit the flow of gas.

The insulating member 104 is directed from the anode-side inlet (for example, the anode-side first inlet 102a) and the anode-side outlet (for example, the anode-side first outlet 102d) of the separator 102 toward the cathode-side flow path of the separator 102. , Prevents the anode gas AG from being mixed.

As shown in FIGS. 5 to 7, the module end 105 is a plate that holds the lower end or the upper end of a plurality of stacked cell units 100T.

The module end 105 is arranged at the lower end or the upper end of the plurality of stacked cell units 100T. The module end 105 has an outer shape similar to that of the cell unit 100T. The module end 105 is made of a conductive material that is impermeable to gas and is insulated with an insulating material or coating except for some areas facing the power generation cell 101M and other module ends 105. The insulating material is configured by, for example, fixing aluminum oxide to the module end 105.

The module end 105 has an anode-side first inlet 105a, an anode-side second inlet 105b, and an anode-side third so that the cell unit 100T and the cell unit 100T are aligned relative to each other along the stacking direction Z. An inlet 105c, an anode-side first outlet 105d, and an anode-side second outlet 105e are provided. The module end 105 has a cathode side first inlet 105f, a cathode side second inlet 105g, and a cathode side first so that the cell unit 100T and the cell unit 100T are aligned relative to each other along the stacking direction Z. The outlet 105h, the cathode side second outlet 105i, and the cathode side third outlet 105j are provided. In the module end 105, the cathode side first inlet 105f, the cathode side second inlet 105g, the cathode side first outlet 105h, the cathode side second outlet 105i, and the cathode side third outlet 105j are the module ends 105. It corresponds to the space between the outer peripheral surface and the inner surface of the air shelter 110.

The upper current collector plate 106 is shown in FIG. 5, and outputs the electric power generated by the cell unit 100T to the outside.

As shown in FIG. 5, the upper current collector plate 106 is arranged at the upper end of the upper module unit 100P. The upper current collector plate 106 has an outer shape similar to that of the cell unit 100T. The upper current collector plate 106 is provided with a terminal (not shown) connected to an external current-carrying member. The upper current collector plate 106 is made of a conductive material that does not allow gas to pass through, and is insulated by using an insulating material or a coating except for a region facing the power generation cell 101M of the cell unit 100T and a terminal portion. The insulating material is formed by, for example, fixing aluminum oxide to the upper current collector plate 106.

The lower current collector plate 107 is shown in FIG. 7, and outputs the electric power generated by the cell unit 100T to the outside.

As shown in FIG. 7, the lower current collector plate 107 is arranged at the lower end of the lower module unit 100R. The lower current collector plate 107 has the same outer shape as the upper current collector plate 106. The lower current collector plate 107 is provided with a terminal (not shown) connected to an external current-carrying member. The lower current collector plate 107 is made of a conductive material that does not allow gas to pass through, and is insulated by using an insulating material or a coating except for a region facing the power generation cell 101M of the cell unit 100T and a terminal portion. The insulating material is formed by, for example, fixing aluminum oxide to the lower current collector plate 107.

The lower current collector plate 107 has an anode-side first inlet 107a, an anode-side second inlet 107b, and an anode-side through which the anode gas AG is passed so that the cell unit 100T and the cell unit 100T are in relative positions along the stacking direction Z. A third inlet 107c, an anode-side first outlet 107d, and an anode-side second outlet 107e are provided. The lower current collector plate 107 has a cathode side first inlet 107f, a cathode side second inlet 107g, and a cathode side so that the cell unit 100T and the cell unit 100T are in relative positions along the stacking direction Z. A first outlet 107h, a cathode-side second outlet 107i, and a cathode-side third outlet 107j are provided. In the lower current collector plate 107, the cathode side first inlet 107f, the cathode side second inlet 107g, the cathode side first outlet 107h, the cathode side second outlet 107i, and the cathode side third outlet 107j are lower collectors. It corresponds to the space between the outer peripheral surface of the electric plate 107 and the inner surface of the air shelter 110.

The lower end plate 108 holds the fuel cell stack 100S from below, as shown in FIGS. 2 and 3.

The lower end plate 108 is arranged at the lower end of the fuel cell stack 100S. The lower end plate 108 has an outer shape similar to that of the cell unit 100T except for a part. The lower end plate 108 is formed by extending both ends linearly along the longitudinal direction Y in order to form an inlet and an outlet for the cathode gas CG. The lower end plate 108 is formed to be sufficiently thicker than the cell unit 100T. The lower end plate 108 is made of metal, for example, and the upper surface in contact with the lower current collector plate 107 is insulated with an insulating material or a coating. The insulating material is formed by, for example, fixing aluminum oxide to the lower end plate 108.

The lower end plate 108 has an anode-side first inlet 108a, an anode-side second inlet 108b, and an anode-side first inlet so that the cell unit 100T and the cell unit 100T are aligned relative to each other along the stacking direction Z. The three inlets 108c, the anode-side first outlet 108d, and the anode-side second outlet 108e are provided. The lower end plate 108 has a cathode side first inflow port 108f, a cathode side second inflow port 108g, and a cathode side first inflow so that the cell unit 100T and the cell unit 100T are aligned relative to each other along the stacking direction Z. The first outlet 108h, the cathode side second outlet 108i, and the cathode side third outlet 108j are provided.

The upper end plate 109 holds the fuel cell stack 100S from above, as shown in FIGS. 2 and 3.

The upper end plate 109 is arranged at the upper end of the fuel cell stack 100S. The upper end plate 109 has the same outer shape as the lower end plate 108. Unlike the lower end plate 108, the upper end plate 109 is not provided with a gas inlet and outlet. The upper end plate 109 is made of, for example, metal, and the lower surface in contact with the upper current collector plate 106 is insulated with an insulating material or a coating. The insulating material is configured by, for example, fixing aluminum oxide to the upper end plate 109.

As shown in FIGS. 2 and 3, the air shelter 110 forms a flow path of the cathode gas CG with and from the fuel cell stack 100S.

As shown in FIGS. 2 and 3, the air shelter 110 covers the fuel cell stack 100S sandwiched between the lower end plate 108 and the upper end plate 109 from above. The air shelter 110 forms an inlet and an outlet for the cathode gas CG of the constituent members of the fuel cell stack 100S by the portion of the gap 175 between the inner surface of the air shelter 110 and the side surface of the fuel cell stack 100S. The air shelter 110 has a box shape and opens all of the lower part and a part of the side part. The air shelter 110 is made of, for example, metal, and its inner surface is insulated with an insulating material or coating. The insulating material is formed by, for example, fixing aluminum oxide to an air shelter 110.

As shown in FIGS. 1 and 2, the external manifold 111 supplies gas to a plurality of cell units 100T from the outside.

The external manifold 111 is arranged below the cell stack assembly 100M. The outer manifold 111 has an outer shape that simplifies the shape of the lower end plate 108. The outer manifold 111 is formed to be sufficiently thicker than the lower end plate 108. The outer manifold 111 is made of, for example, metal.

The external manifold 111 has an anode-side first inlet 111a, an anode-side second inlet 111b, and an anode-side third so that the cell unit 100T and the cell unit 100T are aligned relative to each other along the stacking direction Z. An inlet 111c, an anode-side first outlet 111d, and an anode-side second outlet 111e are provided. The external manifold 111 has a cathode side first inlet 111f, a cathode side second inlet 111g, and a cathode side first so that the cell unit 100T through which the cathode gas CG is passed is aligned with the cell unit 100T along the stacking direction Z. The outlet 111h, the cathode side second outlet 111i, and the cathode side third outlet 111j are provided.

The cover 112 covers and protects the cell stack assembly 100M, as shown in FIGS. 1 and 2.

The cover 112 sandwiches the cell stack assembly 100M together with the external manifold 111 from above and below. The cover 112 has a box shape and has an opening at the bottom. The cover 112 is made of metal, for example, and its inner surface is insulated by an insulating material.

(Insulation member 104)
Hereinafter, the insulating member 104 will be described in detail.

With reference to FIGS. 17A, 17B and 17C, the insulating member 104 has a first joining surface 121a joined to the cell frame 101W (corresponding to a supporting member) and a second joining surface 122a joined to the separator 102. , It has an insulating layer 123 that is arranged between the first joint surface 121a and the second joint surface 122a and that insulates between the first joint surface 121a and the second joint surface 122a.

The first joining surface 121a, the cell frame 101W, the second joining surface 122a, and the separator 102 are fixed by a joining method such as laser welding.

The first joining surface 121a is joined in a state where the entire surface is in contact with the cell frame 101W. The second joining surface 122a is joined in a state where the entire surface is in contact with the separator 102. The first joint surface 121a, the second joint surface 122a, and the insulating layer 123 are parallel to each other.

With reference to FIGS. 18A, 18B, 18C and 18D, the insulating member 104 has a first member 121 with a first joint surface 121a and a second member 122 with a second joint surface 122a. The insulating layer 123 is arranged between the first member 121 and the second member 122.

The first member 121 and the second member 122 are laminated via the insulating layer 123.

The first member 121 and the second member 122 are made of metal. The type of metal constituting the first member 121 and the second member 122 is not particularly limited.

The material constituting the insulating layer 123 is not particularly limited as long as it can insulate between the first joint surface 121a and the second joint surface 122a. The material constituting the insulating layer 123 is, for example, low melting point glass.

The insulating member 104 has a ring shape. The insulating member 104 is configured by laminating a first member 121 and a second member 122 having a ring shape via an insulating layer 123.

The insulating member 104 has a joint portion 130 to which the first member 121 and the second member 122 are joined via the insulating layer 123. The joint 130 has a first joint 131 to which the first member 121 and the insulating layer 123 are joined, and a second joint 132 to which the second member 122 and the insulating layer 123 are joined.

The first joint surface 121a and the second joint surface 122a are offset from each other in the plan view of the insulating member 104.

The first joint surface 121a and the second joint surface 122a are offset from each other in the radial direction of the insulating member 104 in the plan view of the insulating member 104. The first joint surface 121a is arranged inward in the radial direction of the insulating member 104 with respect to the joint portion 130. The second joint surface 122a is arranged outside the insulating member 104 in the radial direction with respect to the joint portion 130.

There is a gap SP between the first joint surface 121a and the second member 122.

The second member 122 is arranged at a position overlapping the first joint surface 121a in the plan view of the insulating member 104, and has an auxiliary portion 125 in contact with the separator 102. The gap SP is provided between the first joint surface 121a and the auxiliary portion 125 in the stacking direction Z.

The auxiliary portion 125 has a contact surface 125a that comes into contact with the separator 102 in a state where the second joint surface 122a is bonded to the separator 102.

The first joining surface 121a has a first joining region AR1 joined to the cell frame 101W and a second joining region AR2 arranged at a position different from the first joining region AR1 and joined to the cell frame 101W. .. The second joint surface 122a has a first joint region AR1 welded to the separator 102 and a second joint region AR2 arranged at a position different from the first joint region AR1 and joined to the separator 102.

The insulating member 104 includes a spring structure 150 that generates an elastic force in the stacking direction Z of the first member 121 and the second member 122.

The insulating member 104 is in contact with the first connecting portion 161 that connects the insulating layer 123 and the first bonding surface 121a, the second connecting portion 162 that connects the insulating layer 123 and the second bonding surface 122a, and the insulating layer 123. It has a third connection portion 163 that connects to the surface 125a.

In the spring structure 150, elastic forces are generated in the stacking direction Z of the insulating member 104 by bending and deforming the connecting portions 161, 162, and 163.

(Gas flow in fuel cell stack 100S)
FIG. 19A is a perspective view schematically showing the flow of the anode gas AG and the cathode gas CG in the fuel cell stack 100S. FIG. 19B is a perspective view schematically showing the flow of the cathode gas CG in the fuel cell stack 100S. FIG. 19C is a perspective view schematically showing the flow of the anode gas AG in the fuel cell stack 100S.

The anode gas AG passes through the inlets of the outer manifold 111, the lower end plate 108, the module end 105, the separator 102, and the metal support cell assembly 101, and is supplied to the anode 101T of each power generation cell 101M. That is, the anode gas AG is distributed to the flow path on the anode side provided in the gap 175 between the separator 102 and the metal support cell assembly 101, which are alternately laminated, from the external manifold 111 to the upper current collector plate 106 at the end. Is supplied. After that, the anode gas AG reacts in the power generation cell 101M, passes through each outlet of each of the above-mentioned constituent members, and is discharged in the state of exhaust gas.

As shown in FIG. 19A, the anode gas AG is supplied to the flow path portion 102L so as to cross the cathode gas CG across the separator 102. In FIG. 19C, the anode gas AG passes through the anode-side first inlet 102a, the anode-side second inlet 102b, and the anode-side third inlet 102c of the separator 102 located below FIG. 19C, and passes through the metal support cell assembly. After passing through the anode-side first inlet 101a, the anode-side second inlet 101b, and the anode-side third inlet 101c of 101, the metal flows into the flow path portion 102L of the separator 102 located above FIG. 19C. It is supplied to the anode 101T of the power generation cell 101M of the support cell assembly 101. The anode gas AG after reacting with the anode 101T flows out from the flow path portion 102L of the separator 102 located above FIG. 19C in the state of exhaust gas, and flows out from the anode side first outlet 101d of the metal support cell assembly 101. And, it passes through the second outlet 101e on the anode side, passes through the first outlet 102d on the anode side and the second outlet 102e on the anode side of the separator 102 located below in FIG. 19C, and is discharged to the outside.

The cathode gas CG passes through the inlets of the outer manifold 111, the lower end plate 108, the module end 105, the separator 102, and the metal support cell assembly 101, and is supplied to the cathode 101U of the power generation cell 101M. That is, the cathode gas CG is distributed to the cathode-side flow path provided in the gap 175 between the alternately laminated metal support cell assembly 101 and the separator 102 from the external manifold 111 to the terminal upper current collector plate 106. Is supplied. After that, the cathode gas CG reacts in the power generation cell 101M, passes through each outlet of each of the above-mentioned constituent members, and is discharged in the state of exhaust gas. The inlet and outlet of the cathode gas CG in each of the above-mentioned constituent members are formed by a gap 175 between the outer peripheral surface of each constituent member and the inner surface of the air shelter 110.

In FIG. 19B, the cathode gas CG passes through the cathode side first inflow port 102f and the cathode side second inflow port 102g of the separator 102 located below FIG. 19B, and flows into the flow path portion 102L of the separator 102. , Is supplied to the cathode 101U of the power generation cell 101M of the metal support cell assembly 101. The cathode gas CG after reacting with the cathode 101U flows out from the flow path portion 102L of the separator 102 located at the lower side in FIG. 19B in the state of exhaust gas, and the cathode side first outlet 102h of the separator 102. It passes through the cathode side second outlet 102i and the cathode side third outlet 102j and is discharged to the outside.

(Manufacturing method of fuel cell stack 100S)
With reference to FIG. 20A, the method for manufacturing the fuel cell stack 100S according to the embodiment includes a step S1 for forming the bonded body 100U, a step S2 for forming the insulating member 104, and a step S3 for laminating the cell unit 100T. Has.

In step S1 for forming the bonded body 100U, the metal support cell assembly 101 and the separator 102 are assembled. When assembling the metal support cell assembly 101 and the separator 102, the outer peripheral portion of the cell frame 101W (corresponding to the support member) and the outer peripheral portion of the separator 102 are in contact with the power generation cell 101M and the separator 102 (FIG. 15). See) to join. The outer peripheral portion of the cell frame 101W and the outer peripheral portion of the separator 102 are joined by, for example, laser welding.

In the step S2 for forming the insulating member 104, the first member 121 and the second member 122 are joined via the insulating layer 123.

With reference to FIG. 20B, the step S3 for laminating the cell unit 100T includes a step S31 for arranging the insulating member 104 on the bonded body 100U, a first joining step S32 for joining the insulating member 104 to the separator 102, and the bonded body 100U. S33, and a second joining step S34 for joining the insulating member 104 to the cell frame 101W.

In the step S31 of arranging the insulating member 104 on the bonded body 100U, the insulating member 104 is arranged on the separator 102 of the bonded body 100U.

In the first joining step S32, the insulating member 104 is joined to the separator 102 in a state where the insulating member 104 is arranged on the separator 102.

In the step S33 for laminating the bonded body 100U, the bonded body 100U is laminated so that the first joint surface 121a of the insulating member 104 bonded to the separator 102 and the cell frame 101W are in contact with each other. In the step of laminating the bonded body 100U, the contact material 113 is arranged between the power generation cell 101M and the current collecting auxiliary layer 103 (see FIG. 16). In the step of laminating the bonded body 100U, the bonded body 100U is laminated when the contact material 113 is in the first state.

In the second joining step S34, the cell frame 101W is joined to the first joining surface 121a of the insulating member 104 joined to the separator 102.

With reference to FIG. 20C, in the first joining step S32 (second joining step S34), the insulating member 104 is joined to the separator 102 (cell frame 101W) in the first joining region AR1 (see FIG. 17C), and the first joining is performed. It is determined whether or not the bonding state between the insulating member 104 and the separator 102 (cell frame 101W) in the region AR1 is good. Then, in the first joining step S32 (second joining step S34), when it is determined that the joining state between the insulating member 104 and the separator 102 (cell frame 101W) in the first joining region AR1 is not good, the second joining is performed. In the first joining step S32 and the second joining step S34 in which the insulating member 104 is joined to the separator 102 (cell frame 101W) in the region AR2 (see FIG. 17C), the first joining surface 121a, the cell frame 101W, and the first joining surface 121a are joined by laser welding. 2 The joining surface 122a and the separator 102 are joined.

As described above, the first joint surface 121a and the second joint surface 122a are offset from each other in the plan view of the insulating member 104. Therefore, the laser irradiation in the first joining step S32 and the laser irradiation in the second joining step S34 are on the same side in the stacking direction Z of the cell unit 100T, for example, the positive side of the stacking direction Z in the attached drawing (stacking direction). It can be performed from the upper side in Z) (see FIG. 17C and the like).

In the first joining step S32 (second joining step S34), the first joining surface 121a (second joining surface 122a) and the cell frame 101W (separator 102) can be welded by through welding (in FIG. 17C, M1 is , Shows through welds).

Hereinafter, the process of forming the insulating member 104 will be described in detail.

The step of forming the insulating member 104 includes a step of pressing the first member 121 and the second member 122, and a step of joining the first member 121 and the second member 122.

In the step of pressing the first member 121 and the second member 122 with reference to FIGS. 21A, 21B, 21C and 21D, the jig 200 is used with the first joint portion 131 via the insulating layer 123. The second joint portion 132 and the second joint portion 132 are pressed against each other (pressurized). At this time, in the insulating member 104, the parts other than the first joint portion 131 and the second joint portion 132 are not pressurized. As a result, when the insulating member 104 is heated when the first member 121 and the insulating layer 123 and the second member 122 and the insulating layer 123 are joined, the strength of the parts other than the first joint portion 131 and the second joint portion 132 is strengthened. It is possible to prevent harmful effects such as deterioration.

The jig 200 has a ring-shaped pressing member 210 and a base 220 for sandwiching the insulating member 104 between the pressing member 210.

In the step of pressing the first member 121 and the second member 122, the insulating layer is sandwiched between the pressing member 210 and the base 220 with the first joint portion 131 and the second joint portion 132 together with the insulating layer 123. The first joint portion 131 and the second joint portion 132 are pressed against each other via 123.

In the step of joining the first member 121 and the second member 122, the first member 121 is pressed at the first joint portion 131 while the first joint portion 131 and the second joint portion 132 are pressed against each other via the insulating layer 123. And the insulating layer 123 are joined, and the second member 122 and the insulating layer 123 are joined at the second joining portion 132.

In the joining portion 130, the method of joining the first member 121 and the insulating layer 123 and the second member 122 and the insulating layer 123 is not particularly limited, and for example, a joining method using low melting point glass can be selected. When low melting point glass is used, the low melting point glass joins the first member 121 and the second member 122 and also functions as an insulating layer.

In the method for manufacturing the fuel cell stack 100S according to the embodiment, the step S2 for forming the insulating member 104 is performed independently of the step S3 for laminating the cell unit 100T. Therefore, even if a joining method that requires high temperature treatment such as a joining method by brazing is selected as a method for joining the first member 121 and the insulating layer 123 and the second member 122 and the insulating layer 123, the power generation cell 101M , It is possible to avoid adverse effects of heat on the cell frame 101W, the separator 102, and the like.

The operation and effect of the first embodiment described above will be described.

The fuel cell stack 100S sandwiches the electrolyte 101S from both sides with the anode 101T and the cathode 101U, and generates an anode gas between the power generation cell 101M and the power generation cell 101M to generate power by the supplied anode gas AG and the cathode gas CG. It is a fuel cell stack in which a plurality of cell units 100T having a flow path portion 102L which is a flow passage of AG and a cathode gas CG are partitioned, and a separator 102 having an anode 101T of a power generation cell 101M and a separator 102 which is in conduction contact with the cathode 101U are laminated. .. At a position separated from the separator 102 in the stacking direction Z of the cell unit 100T, the cell frame 101W and the separator 102 are electrically insulated from each other while electrically insulating the cell frame 101W supporting the power generation cell 101M from the cell frame 101W and the separator 102. It has an insulating member 104 that regulates the distance between the two. The insulating member 104 includes a first member 121 having a first joining surface 121a joined to the cell frame 101W, a second member 122 having a second joining surface 122a joined to the separator 102, and a first member 121 and a first member. It has an insulating layer 123 which is arranged between the two members 122 and insulates between the first member 121 and the second member 122.

According to the fuel cell stack 100S, the insulating layer 123 ensures electrical insulation between the first member 121 and the second member 122, so that the materials constituting the first member 121 and the second member 122 can be used. , Can be selected in consideration of the bondability with the cell frame 101W and the separator 102. Thereby, the bonding force between the first bonding surface 121a and the cell frame 101W and the bonding force between the second bonding surface 122a and the separator 102 can be improved. Therefore, the first joint surface 121a can be more reliably fixed to the cell frame 101W, and the second joint surface 122a can be more reliably fixed to the separator 102. As a result, since the bending deformation of the cell frame 101W and the separator 102 can be more reliably regulated, the surface pressure can be more reliably applied between the power generation cell 101M and the separator 102. Therefore, according to the fuel cell stack 100S, the current collecting resistance between the power generation cell 101M of the power generation cell 101M and the separator 102 can be reduced.

In particular, since the fuel cell stack 100S according to the present embodiment is a solid oxide fuel cell (SOFC: Solid Oxide Fuel Cell) using solid oxide ceramics as the electrolyte 101S, the operating temperature is about 700 to 1000 ° C. Very expensive. Therefore, as compared with the polymer electrolyte membrane fuel cell, the constituent members are relatively easily deformed during operation. With the above configuration, the fuel cell stack 100S can maintain power generation performance by regulating bending deformation of the cell frame 101W and the separator 102 even in a long-term operation in a high temperature state.

Further, according to the above configuration, slipping between the first joint surface 121a and the cell frame 101W and between the second joint surface 122a and the separator 102 without applying a large stacking load to the fuel cell stack 100S. Will not occur. That is, according to the above configuration, since the stacking load can be small, the rigidity of the members constituting the fuel cell stack 100S can be reduced. As a result, the heat capacity of the members constituting the fuel cell stack 100S is reduced, so that the temperature of the fuel cell stack 100S can be raised in a shorter time during operation. This effect is remarkable in the case of a solid oxide fuel cell having a high operating temperature.

Further, in the fuel cell stack 100S, the cell frame 101W, the separator 102, the first member 121, and the second member 122 are made of metal.

According to the fuel cell stack 100S, the first member 121 and the cell frame 101W can be joined by welding, and the second member 122 and the separator 102 can be joined by welding. As a result, the first joint surface 121a can be more reliably fixed to the cell frame 101W, and the second joint surface 122a can be more reliably fixed to the separator 102. Therefore, since the bending deformation of the cell frame 101W and the separator 102 can be more reliably regulated, the surface pressure can be more reliably applied between the power generation cell 101M and the separator 102. Therefore, according to the fuel cell unit, the current collecting resistance between the power generation cell 101M of the power generation cell 101M and the separator 102 can be more reliably reduced.

Further, in the fuel cell stack 100S, the first joint surface 121a and the second joint surface 122a are offset from each other in the plan view of the insulating member 104.

According to the fuel cell stack 100S, since the first joint surface 121a and the second joint surface 122a do not overlap in the plan view of the insulating member 104, the work of joining the first joint surface 121a and the cell frame 101W and the first step. 2. The work of joining the joining surface 122a and the separator 102 can be performed from the positive side (see FIG. 17C and the like) of the insulating member 104 in the stacking direction Z. Therefore, by using such a fuel cell cell unit, the production of the fuel cell 100 becomes easy.

Further, in the fuel cell stack 100S, there is a gap SP between the first joint surface 121a and the second member 122 or between the second joint surface 122a and the first member 121.

According to the fuel cell stack 100S, the energy irradiated from the side of the cell frame 101W for joining the first joining surface 121a and the cell frame 101W is absorbed by the gap SP, so that the energy is transferred to the second member 122. It can be prevented from reaching. Thereby, it is possible to prevent the energy from reaching the second member 122 without adjusting the energy amount of the energy with high accuracy. Therefore, by using the fuel cell stack 100S, the production of the fuel cell 100 becomes easier.

Further, in the fuel cell stack 100S, the first joint surface 121a and the second joint surface 122a are arranged at positions different from the first joint region AR1 joined to the cell frame 101W or the separator 102 and the first joint region AR1. It has a second joining region AR2, which is joined to the cell frame 101W or the separator 102.

According to the fuel cell stack 100S, even if the bonding between the first bonding surface 121a and the cell frame 101W is not good in the first bonding region AR1, the second bonding region AR2 is used. , The joining between the first joining surface 121a and the cell frame 101W can be performed again. As a result, when the connection between the first joint surface 121a and the cell frame 101W is not good in the first joint region AR1, the first joint surface 121a and the cell frame 101W are not replaced without replacing the cell frame 101W. Can be joined with. Therefore, by using the fuel cell stack 100S, the yield when manufacturing the fuel cell 100 is improved.

Further, in the fuel cell stack 100S, the separator 102 is arranged between the cathode 101U and the contact material 113 which increases the contact area with the cathode 101U by filling the gap between the separator 102 and the cathode 101U. Have more. The contact material 113 includes a first state having at least one of viscous or elastic, and a second state of being solidified by being sintered.

According to the fuel cell stack 100S, when the power generation cell 101M and the separator 102 are assembled, the contact material 113 having at least one of viscosity and elasticity in the first state exerts an elastic force, whereby the power generation cell 101M and the separator 102 are separated. It is possible to prevent an excessive surface pressure from acting between the 102 and the 102. Thereby, the fuel cell stack 100S can apply a uniform surface pressure between the power generation cell 101M and the separator 102 while avoiding damage to the power generation cell 101M.

Further, in the fuel cell stack 100S, the insulating member 104 includes a spring structure 150 that generates an elastic force along the stacking direction Z of the first member 121 and the second member 122.

According to the fuel cell stack 100S, the spring structure 150 causes an excessive force between the power generation cell 101M and the separator 102 by generating an elastic force along the stacking direction Z of the first member 121 and the second member 122. It is possible to prevent various surface pressures from acting. Thereby, the fuel cell stack 100S can apply a uniform surface pressure between the power generation cell 101M and the separator 102 while avoiding damage to the power generation cell 101M.

Further, since the insulating member 104 includes the spring structure 150, the thickness of the contact material 113 arranged between the power generation cell 101M and the current collector auxiliary layer 103 can be reduced, so that the amount of the contact material 113 used can be reduced. can.

Further, the elastic deformation of the spring structure 150 can absorb dimensional errors of the components of the fuel cell stack 100S. As a result, it is possible to avoid absorbing the dimensional error due to the deformation of the flow path portion 102L between the power generation cell 101M and the separator 102. Therefore, it is possible to prevent the pressure loss of the anode gas AG and the cathode gas CG from occurring in the flow path portion 102L.

Further, in the fuel cell stack 100S, the insulating member 104 is fixed to the insulating layer 123 and has connecting portions 161, 162, and 163 for connecting the insulating layer 123 and the joint surface. Then, the spring structure 150 generates an elastic force by bending and deforming the connecting portions 161, 162, and 163.

According to the fuel cell stack 100S, the spring structure 150 can be manufactured by a simple method of bending and deforming the connection portions 161, 162, and 163. Therefore, according to the fuel cell stack 100S, the fuel cell 100 can be manufactured more easily.

Further, in the fuel cell stack 100S, the insulating member 104 seals the anode gas AG and the cathode gas CG between the cell frame 101W and the first joint surface 121a and between the separator 102 and the second joint surface 122a. It has a function.

According to the fuel cell stack 100S, the number of parts can be reduced because the insulating member 104 also serves as a sealing member. Therefore, according to the fuel cell stack 100S, the manufacturing cost of the fuel cell 100 can be reduced.

(Modification example 1)
As shown in FIGS. 22A, 22B and 22C, the second member 122 may not have the auxiliary portion 125. The insulating member 104 can also reduce the current collecting resistance between the anode 101T and the cathode 101U and the separator 102, similarly to the insulating member 104 according to the above-described embodiment.

(Modification example 2)
In the above-described embodiment, the spring structure 150 generates elastic force by bending and deforming the connecting portions 161, 162, and 163.

However, with reference to FIGS. 23A, 23B and 23C, the insulating member 104 has a first member 121 and a second member by bringing a part of the first member 121 into contact with a part of the second member 122. It may further have an interference portion 170 that causes a reaction force with the 122. Then, in the spring structure 150, the first member 121 and the second member 122 may be elastically deformed by the reaction force generated in the interference portion 170 to generate an elastic force.

Of the surface of the first member 121 (second member 122), the portion of the interference portion 170 that comes into contact with the second member 122 (first member 121) is insulated by using an insulating material or a coating. .. The insulating material is formed by, for example, fixing aluminum oxide to the first member 121 (second member 122).

Even in the insulating member 104 according to the present modification, similarly to the insulating member 104 according to the first embodiment described above, the spring structure 150 generates an elastic force between the power generation cell 101M and the separator 102. It is possible to prevent the action of excessive surface pressure. As a result, the fuel cell unit can apply a uniform surface pressure between the power generation cell 101M and the separator 102 while avoiding damage to the power generation cell 101M.

(Modification example 3)
In the above-described embodiment, the insulating member 104 is provided at the anode-side inlet (for example, the anode-side first inlet 102a) and the anode-side outlet (for example, the anode-side first outlet 102d) of the separator 102 (FIG. 19C). reference).

However, with reference to FIGS. 24A, 24B, 25A, 25B and 25C, the insulating member 104 may be provided on the outer peripheral portion of the cell frame 101W. Hereinafter, the insulating member 104 according to this modification will be described. The same members as those in the above-described embodiment are designated by the same reference numerals, and the description thereof will be omitted.

The insulating member 104 extends along the outer circumference of the cell frame 101W.

The first joint surface 121a and the second joint surface 122a are arranged on the outer peripheral side of the cell frame 101W and the separator 102 with respect to the joint portion 130 in a state where the insulating member 104 is joined to the cell frame 101W and the separator 102. The second joint surface 122a is arranged on the outer peripheral side of the separator 102 with respect to the first joint surface 121a in a state where the second joint surface 122a is bonded to the separator 102.

The insulating member 104 has an interference portion 170 that causes a reaction force between the first member 121 and the second member 122 by bringing a part of the first member 121 and a part of the second member 122 into contact with each other. ..

In the spring structure 150, the first member 121 and the second member 122 are elastically deformed by the reaction force generated in the interference portion 170 to generate an elastic force.

The interference portion 170 has a contact region 171 in which a part of the first member 121 and a part of the second member 122 come into contact with each other, and a part of the first member 121 and a part of the second member 122 in the contact region 171. It has a non-contact region 172 in which a gap 175 is formed between the first member 121 and the second member 122 in a contacted state.

The insulating member 104 has a straight line portion 104A extending linearly along the plane direction of the cell frame 101W, and a curved portion 104B curved along the contour of a corner portion of the cell frame 101W. The contact area 171 is arranged in the straight line portion 104A. The non-contact region 172 is arranged in the curved portion 104B.

The interference portion 170 is arranged in parallel with the joint portion 130. The interference portion 170 is arranged on the outer peripheral side of the cell frame 101W with respect to the joining portion 130 in a state where the insulating member 104 is joined to the cell frame 101W and the separator 102. The interference portion 170 is arranged between the first joint surface 121a and the second joint surface 122a.

The fuel cell stack 100S according to the modified example can also reduce the current collecting resistance between the power generation cell 101M and the separator 102, similarly to the fuel cell unit according to the first embodiment described above.

Further, in the fuel cell stack 100S, the interference portion 170 has a contact region 171 in which a part of the first member 121 and a part of the second member 122 come into contact with each other, and a part of the first member 121 and a first portion in the contact region 171. It has a non-contact region 172 in which a gap 175 is formed between the first member 121 and the second member 122 in a state where a part of the two members 122 is in contact with each other.

According to the fuel cell stack 100S, when the first member 121 and the second member 122 are elastically deformed by the reaction force generated in the interference portion 170, a part of the elastic deformation can be absorbed by the non-contact region 172. Therefore, it is possible to prevent an excessive reaction force from acting between the first member 121 and the second member 122 in the contact region 171. Therefore, the reliability of the insulating member 104 can be improved.

Further, in the fuel cell stack 100S, the insulating member 104 has a joint portion 130 to which the first member 121 and the second member 122 are joined via the insulating layer 123. The interference portion 170 is arranged in parallel with the joint portion 130.

Further, according to the fuel cell stack 100S, since the interference portion 170 is arranged in parallel with the joint portion 130, the first member 121 and the second member 122 are excessively elastic in the direction intersecting the interference portion 170. It can be prevented from being deformed. Therefore, it is possible to prevent an excessive surface pressure from acting between the power generation cell 101M and the separator 102.

Further, according to the fuel cell stack 100S according to the present modification, the insulating member 104 is provided on the outer peripheral portion of the cell frame 101W, so that the bending deformation of the cell frame 101W can be prevented more efficiently.

The interference portion 170 may be arranged in a direction intersecting the joint portion 130.

According to the fuel cell stack 100S, the first member 121 and the second member 122 are excessively elastically deformed in the direction along the interference portion 170 because the interference portion 170 is arranged in the direction intersecting the joint portion 130. Can be prevented from doing so. Therefore, it is possible to prevent an excessive surface pressure from acting between the power generation cell 101M of the power generation cell 101M and the separator 102.

(Modification example 4)
In the first embodiment described above, the inner diameter of the second member 122 is larger than the inner diameter of the first member 121. However, as shown in FIGS. 26A and 26B, the inner diameter of the second member 122 may be smaller than the inner diameter of the first member 121.

As shown in FIG. 26A, when the insulating layer 123 is present between the first joint surface 121a and the second member 122, the first joint surface 121a and the cell frame 101W are non-penetrating welded. As shown in FIG. 26B, when the insulating layer 123 does not exist between the first bonding surface 121a and the second member 122, the thickness of the insulating layer 123 is adjusted to the first bonding surface 121a. It can be through-welded to the cell frame 101W. In FIGS. 26A and 26B, the penetration welded portion is indicated by M1 and the non-penetrated welded portion is indicated by M2.

(Modification 5)
Further, as shown in FIGS. 27A and 27B, the inner diameter of the first member 121 and the inner diameter of the second member 122 are made the same, and the outer diameter of the second member 122 is made larger than the outer diameter of the first member 121. May be good.

As shown in FIG. 27A, when the insulating layer 123 is present between the first joint surface 121a and the second member 122, the first joint surface 121a and the cell frame 101W are non-penetrating welded. As shown in FIG. 27B, when the insulating layer 123 does not exist between the first bonding surface 121a and the second member 122, the thickness of the insulating layer 123 is adjusted to the first bonding surface 121a. It can be through-welded to the cell frame 101W. In FIGS. 27A and 27B, the penetration welded portion is indicated by M1 and the non-penetrated welded portion is indicated by M2.

(Modification 6)
As shown in FIGS. 28A, 28B and 28C, the insulating layer 123 may have a glass GS and an insulating coated CT.

The insulating coat CT can be formed, for example, by fixing aluminum oxide.

As shown in FIG. 28A, the insulating coat CT may be formed at a portion of the first member 121 to be joined to the glass GS. Further, as shown in FIG. 28B, the insulating coat CT may be formed at a portion of the second member 122 to be joined to the glass GS. Further, as shown in FIG. 28B, the insulating coat CT may be formed at a portion bonded to the glass GS in the first member 121 and a portion bonded to the glass GS in the second member 122. By applying the insulating coat CT, the wettability of the glass GS is improved, and the first member 121 and the second member 122 can be easily joined.

(Modification 7)
Further, as shown in FIG. 29A, the insulating layer 123 may be formed by applying an insulating coat CT to the first member 121 and brazing the insulating coat CT and the second member 122.

Further, as shown in FIG. 29B, the insulating layer 123 may be formed by applying an insulating coat CT to the second member 122 and brazing the insulating coat CT and the first member 121.

Further, as shown in FIG. 29C, in the insulating layer 123, the first member 121 is coated with the insulating coat CT and the second member 122 is coated with the insulating coat CT, so that the insulating coat CT of the first member 121 and the second member 122 are applied. It may be formed by brazing between the insulating coat CT and the insulating coat CT.

(Modification 8)
Further, as shown in FIG. 30, the insulating layer 123 may be formed by brazing the first member 121 and the second member 122 via the insulating spacer SC.

(Modification 9)
As shown in FIG. 31, in the interference portion 170, the first member 121 and the second member 122 may come into contact with each other via the insulating layer 123.

(Modification Example 10)
Further, as shown in FIGS. 32A and 32B, the joint portion 130 may be inclined toward the stacking direction Z. As shown in FIG. 32B, in the interference portion 170, the first member 121 and the second member 122 may come into contact with each other via the insulating layer 123.

(Modification 11)
In the modified example 4, the interference portion 170 is arranged on the outer peripheral side of the cell frame 101W with respect to the joint portion 130. However, as shown in FIG. 33, the joint portion 130 may be arranged on the outer peripheral side of the cell frame 101W with respect to the interference portion 170.

(Modification 12)
Further, as shown in FIG. 34, the interference portions 170 may be provided at two locations.

This makes it possible to prevent the insulating member 104 from being sheared and deformed when a force is applied to the insulating member 104 in the stacking direction Z. Therefore, since the rigidity of the insulating member 104 in the stacking direction Z is improved, the distance between the power generation cell 101M and the separator 102 can be reliably maintained by an appropriate distance. As a result, the pressure loss of the cathode gas CG flowing between the power generation cell 101M and the separator 102 can be more reliably reduced, so that the power generation performance of the fuel cell 100 can be further improved.

In addition, the present invention can be modified in various ways based on the configurations described in the claims, and these are also within the scope of the present invention.

For example, in the above-described embodiments and modifications, the fuel cell stack has been described as a fuel cell stack applied to a solid oxide fuel cell (SOFC, Solid Oxide Fuel Cell), but the solid polymer film fuel cell (PEMFC) has been described. , Polymer Electrolyte Membrane Fuel Cell), phosphoric acid fuel cell (PAFC, Phosphoric Acid Fuel Cell) or molten carbonate fuel cell (MCFC, Molten Carbonate Fuel Cell). That is, in addition to the solid oxide fuel cell (SOFC), the fuel cell stack can be a polymer electrolyte membrane fuel cell (PEMFC), a phosphoric acid fuel cell (PAFC) or a molten carbonate fuel cell (MCFC). Can be applied.

Further, in the above-described embodiments and modifications, a gap is formed between the first joint surface and the second member. However, a gap may be formed between the second joint surface and the first member.

100 fuel cell stack,
100M Cell Stack Assembly,
100S stack,
100T cell unit,
100U zygote,
100P upper module unit,
100Q Chubu Module Unit,
100R lower module unit,
101 Metal Support Cell Assembly,
101M power generation cell,
101N metal support cell,
101S electrolyte,
101T anode (fuel electrode),
101U cathode (oxidizing agent electrode),
101V support metal,
101W cell frame,
101k opening,
102 Separator,
102L flow path part,
102p outer edge,
102q groove,
102x flat part,
102y Anode side protrusion,
102z cathode side protrusion,
103 Current collector auxiliary layer,
104 Insulation member,
105 module end,
106 Upper current collector plate,
107 Lower current collector plate,
108 lower end plate,
109 upper end plate,
110 air shelter,
111 external manifold,
101a, 102a, 105a, 107a, 108a, 111a Anode side first inlet,
101b, 102b, 105b, 107b, 111b, 108b Anode side second inlet,
101c, 102c, 105c, 107c, 111c, 108c Anode side third inlet,
101d, 102d, 108d, 107d, 111d, 105d Anode side first outlet,
101e, 102e, 105e, 107e, 111e, 108e Anode side second outlet,
101f, 108f, 102f, 105f, 107f, 111f Cathode side first inlet,
101g, 102g, 105g, 107g, 108g, 111g Cathode side second inlet,
101h, 102h, 111h, 105h, 107h, 108h Cathode side first outlet,
101i, 102i, 105i, 107i, 108i, 111i Cathode side second outlet,
101j, 102j, 105j, 107j, 108j, 111j Cathode side third outlet,
112 cover,
113 Contact material,
121 First member,
121a 1st joint surface,
122 Second member,
122a 2nd joint surface,
123 Insulation layer,
130 joint,
150 spring structure,
161 First connection,
162 Second connection,
170 Interfering part,
171 contact area,
172 non-contact area,
175 gap,
V joining line,
AG anode gas,
CG cathode gas,
AR1 1st junction area,
AR2 second junction area,
X Short side (of fuel cell stack),
Y Longitudinal (of fuel cell stack),
Z Stacking direction (of the fuel cell stack).

Claims (13)

The electrolyte is sandwiched between a pair of electrodes from both sides, and a flow path portion, which is a flow passage for the gas, is partitioned between the power generation cell that generates power by the supplied gas and the power generation cell, and the power generation cell is formed. A plurality of cell units having a separator that is in conduction contact with the cell unit are laminated , and the separator has a flat portion and protrusions protruding from the flat portion in opposite directions along the stacking direction of the cell unit. In a fuel cell stack in which the power generation cell and the separator are brought into conduction contact with each other.
A support member that supports the power generation cell at a position separated from the separator in the stacking direction of the cell unit.
It has an insulating member that regulates the distance between the support member and the separator while electrically insulating the support member and the separator.
The insulating member includes a first member having a first joining surface to be joined to the support member, a second member having a second joining surface to be joined to the separator, and the first member and the second member. It has an insulating layer which is arranged between the first member and insulates between the first member and the second member.
The first joint surface and the second joint surface are displaced from each other in a direction orthogonal to the plan view in the plan view of the insulating member, and overlap with a region where the first joint surface and the second joint surface overlap. A fuel cell stack that has an area that does not become . The fuel cell stack according to claim 1, wherein the support member, the separator, the first member, and the second member are made of metal. The fuel cell stack according to claim 1 or 2 , wherein there is a gap between the first joint surface and the second member and at least one of the second joint surface and the first member. .. The joint surface includes one joining region joined to the support member or the separator, and another joining region arranged at a position different from the one joining region and joined to the support member or the separator. The fuel cell stack according to any one of claims 1 to 3 . Further having a contact material that increases the contact area between the power generation cell and the separator by filling the gap between the power generation cell and the separator.
13 . The described fuel cell stack. The fuel cell stack according to any one of claims 1 to 5 , wherein the insulating member includes a spring structure that generates an elastic force in the stacking direction of the cell units. The insulating member is fixed to the insulating layer and has a connecting portion for connecting the insulating layer and the joint surface.
The fuel cell stack according to claim 6 , wherein the spring structure generates the elastic force by bending and deforming the connection portion. The insulating member further has an interference portion that causes a reaction force between the first member and the second member by bringing a part of the first member and a part of the second member into contact with each other. death,
The fuel cell stack according to claim 7 , wherein the spring structure generates the elastic force by elastically deforming the first member and the second member by the reaction force generated in the interference portion. The interference portion includes a contact region where a part of the first member and a part of the second member come into contact with each other, and the part of the first member and the part of the second member in the contact region. The fuel cell stack according to claim 8 , further comprising a non-contact region in which a gap is formed between the first member and the second member in a state where the fuel cells are in contact with each other. The insulating member has a joint portion to which the first member and the second member are joined via the insulating layer.
The fuel cell stack according to claim 9 , wherein the interference portion is arranged in parallel with the joint portion. The insulating member has a joint portion to which the first member and the second member are joined via the insulating layer.
The fuel cell stack according to claim 9 , wherein the interference portion is arranged in a direction intersecting the joint portion. The fuel cell stack according to any one of claims 1 to 11 , wherein the insulating member is a sealing member that seals the gas between the support member and the separator and the joint surface. The electrolyte is sandwiched between a pair of electrodes from both sides, and a flow path portion, which is a flow passage for the gas, is partitioned between the power generation cell that generates power by the supplied gas and the power generation cell, and the power generation cell is formed. A plurality of cell units having a separator that is in conduction contact with the electrode and a support member that supports the power generation cell are laminated , and the separator is in the opposite direction from the flat portion and the flat portion along the stacking direction of the cell unit. An insulating member used for a fuel cell stack in which a power generation cell and a separator are brought into conductive contact with each other in the protrusions .
A first member having a first joining surface to be joined to the support member, a second member having a second joining surface to be joined to the separator, and arranged between the first member and the second member. It has an insulating layer that insulates between the first member and the second member.
The first joint surface and the second joint surface are displaced from each other in a direction orthogonal to the plan view in the plan view of the insulating member, and overlap with a region where the first joint surface and the second joint surface overlap. It has an area that does not become
An insulating member that regulates the distance between the support member and the separator while electrically insulating the support member and the separator.

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