JP2007329060A - Fuel cell module - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fuel cell module which protects a number of hollow fiber electrolyte cells and a cylindrical case incorporating the cells from thermal damage. <P>SOLUTION: This fuel cell module is fabricated by passing the inner and outer electrode layers of a number of hollow fiber electrolyte cells 2 through grating plate-like collectors each having a through hole, forming laminates each by stacking a conductive paste layer and a potting material layer respectively at both sides of each grating plate-like collector and fixing each laminate in a ring-shaped body. The ring-shaped bodies 24, 24' which fix the laminates are incorporated into a cylindrical body 28. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a fuel cell module. More specifically, the present invention relates to a fuel cell module that prevents thermal damage such as a plurality of hollow fiber electrolyte cells and a cylindrical case that accommodates them.

  A polymer electrolyte fuel cell module having a structure using a plurality of hollow fiber electrolyte cells has a structure including an electrolyte layer, an inner electrode layer, an outer electrode layer, and the like. A fluid serving as a fuel flows inside the inner electrode layer and outside the outer electrode layer. The electrolyte layer is designed not only to be an ionic conductor but also to minimize the cross leak of each fuel fluid. The inner and outer electrode layers not only function as electrodes, but are formed as porous layers so that fluids such as fuel and products such as water generated as a result of power generation can permeate and diffuse. .

  Basically, as shown in FIG. 3, potting is performed on both ends of the fuel cell module as a seal mechanism for separating the fluid flowing outside and the fluid flowing inside the hollow fiber electrolyte cell. A part is provided. In the basic configuration of the conventional example shown as a longitudinal sectional view in FIG. 3, potting layers 3, 3 ′ are provided at both ends of the hollow fiber type electrolyte cell 2 accommodated in the cylindrical case 1, The fuel A is introduced from the through-hole 4 drilled in the case wall and exhausted from the through-hole 5, and the fuel B is introduced from the inlet 6 of the hollow fiber electrolyte cell and exhausted from the outlet 7.

  The basic configuration of the hollow fiber electrolyte cell 2 is shown as a cross-sectional view in FIG. The structure consists of the hollow laminated body of the inner side porous electrode layer 11, the inner side catalyst layer 12, the electrolyte layer 13, the outer side catalyst layer 14, and the outer side porous electrode layer 15 in an order from the inside. As shown in FIG. 3, the length of each of these layers is the longest in the inner porous electrode layer 11, and the outer layers are sequentially set to the same length or shorter. However, both ends do not necessarily have the same shape, and it is preferable that the end on the side from which the generated power is taken out be longer than the other end for current collection and insulation.

  By modularizing a single fuel cell comprising hollow fiber electrolyte cells, a large amount of current can be extracted in proportion to the number of the fuel cells. In order to obtain the maximum current value, when fuel cells are modularized, the fuel cells alone, which are hollow fiber electrolyte cells, are all arranged in parallel and in the same direction. Is provided.

  The potting material layer also plays a role of separating the fuel flowing inside the hollow fiber electrolyte cell from the fuel flowing outside. At this time, the tip of the hollow fiber electrolyte cell is projected outward from the potting layer in order to collect current and introduce a fluid as a fuel into the hollow fiber electrolyte cell. In FIG. 3, only the inner porous electrode layer protrudes from one potting portion 3 and the outer porous electrode layer protrudes from the other potting portion 3 ′, and current is collected at both potting portions. Has been taken.

The electric power generated by the fuel cell is taken out from the inner electrode and outer electrode of the hollow fiber electrolyte cell. Also, by connecting a large number of hollow fiber electrolyte cells in parallel, it becomes possible to extract a large amount of current, and in a module structure in which they are connected in series, a high voltage can be extracted from both ends of the module. it can. Furthermore, the hollow fiber electrolyte cell and the external extraction electrode are electrically connected through a current collecting layer such as a conductive paste or a conductive adhesive, or a grid-shaped current collecting layer having a through hole is used. Thus, the power can be taken out with a low resistance value.
JP-T-2004-534368

  Further, as described above, in order to separate the fluid flowing outside the hollow fiber electrolyte cell from the fluid flowing inside, a potting portion is provided at both ends of the module using a cylindrical body as shown in FIG. A mechanism has been taken. However, in a fuel cell module in which a plurality of hollow fiber electrolyte cells configured as described above are simply housed in a cylindrical case, the linear expansion of the hollow fiber electrolyte cell, the cylindrical case, the potting material, etc. constituting the fuel cell module Since the coefficients are different, the hollow fiber electrolyte cell or the cylindrical case may be damaged due to the influence of thermal stress generated during potting or thermal shock during use.

  An object of the present invention is to provide a fuel cell module that prevents thermal damage such as a plurality of hollow fiber electrolyte cells and a cylindrical case that accommodates them.

  An object of the present invention is to allow the inner electrode layer portion and the outer electrode layer portion of the plurality of hollow fiber electrolyte cells to pass through the dish-shaped current collectors having through holes, respectively, A ring-shaped body that is achieved by a fuel cell module in which a laminated body in which a conductive paste layer and a potting material layer are laminated on both sides is formed, and each laminated body portion is fixed with a ring-shaped body. Is used in a cylindrical body.

  A fuel cell module according to the present invention includes a plurality of hollow fiber electrolyte cells, each of which has an inner electrode layer portion and an outer electrode layer portion that are passed through a dish-shaped current collector having a through-hole. A laminated body in which a conductive paste layer and a potting material layer are respectively laminated is formed on both sides of the body, each laminated body portion is fixed with a ring-shaped body, and the ring-shaped body in which the laminated body portion is further fixed is a cylindrical shape Since it is housed and used in the body, that is, since the laminated body portion including the potting material layer is fixed to the ring-shaped body and then housed in the tubular body, the tubular body is affected by the thermal stress generated during potting. Since there is no thermal shock at the time of operation, not only the cylindrical body but also the ring body, stress can be relieved, resulting in damage to the hollow fiber electrolyte cell and the cylindrical body containing it Enable It is possible to prevent.

  In FIG. 1, the steps for fixing the laminated body portion composed of the plate-shaped current collector 21, the conductive paste layer 22 and the potting material layer 23 with the ring-shaped bodies 24 and 24 'are shown in order. In addition, the ring-shaped bodies 24 and 24 ′ may have any shape that can surround the eye plate-like current collector 21, and may have an annular shape other than a square shape or a triangular shape.

  A plurality of hollow fiber electrolyte cells 2 arranged in the same direction are formed by penetrating the inner electrode layer portion 11 and the outer electrode layer portion 15 thereof through the plate-like current collecting layers 21 and 21 'having through holes, respectively. (A). The circumferences of the plate-shaped current collectors 21 and 21 'are installed in contact with the ring-shaped bodies 24 and 24', respectively. Further, take-out terminals 25 and 25 'for taking out the generated electricity and fixing arms 26 and 26' are attached to the plate-shaped current collectors 21 and 21 ', respectively. The extraction terminals 25 and 25 'are attached to the plate-shaped current collectors 21 and 21' during the process of removing the paraffin and pouring the conductive paste in the subsequent step (d). It may be.

  Next, a process of forming a fixing material layer in contact with the plate-shaped current collectors 21 and 21 ′ will be described. The fixing material layer only needs to have a function of fixing at least the plate-shaped current collectors 21 and 21 ′ and the hollow fiber electrolyte cell 2. And may have both functions of a fixing function and a conductive function as separate layers. In this embodiment, a manufacturing process in the case where both of these functions are provided as separate layers will be described.

  Molten paraffins 27 and 27 'are poured into the outer sides of the plate-shaped current collectors 21 and 21' using the inner peripheral surfaces of the ring-shaped bodies 24 and 24 ', and temporarily fixed (b). Thereafter, potting material layers 23 and 23 'are formed on the inner sides of the current collectors 21 and 21' using the inner peripheral surfaces of the ring-shaped bodies 24 and 24 '(c). Thereafter, the paraffin is melted and removed or dissolved and removed with a solvent, and the conductive paste is poured into it to form the conductive paste layers 22 and 22 '(d). Both the potting material layer and the conductive paste layer form a fixing material layer.

  The ring-shaped bodies 24 and 24 'for fixing the laminated body portion composed of the plate-shaped current collector, the conductive paste layer and the potting material layer are sealed with a flexible elastic sealing material such as an O-ring or a silicone-based adhesive ( (Not shown) and is fitted into the cylindrical body 28 and accommodated. In this way, by using a flexible sealing material, the sealing performance between the cylindrical body and the plate-shaped current collectors 21 and 21 'and the ring-shaped bodies 24 and 24' subjected to the thermal stress due to the fixing material is improved. improves. Covers 29 and 29 'are attached to both ends of the cylindrical body 28 as necessary. The cylindrical body may be the cylindrical body itself, or may be formed by winding a sheet-like body and fixing both ends thereof by an appropriate fixing means to form the cylindrical body. . Moreover, the cylindrical body 28 does not necessarily need to be integrated, and may be composed of two or more cylindrical bodies so as to accommodate the ring-shaped bodies 24 and 24 '. By manufacturing through these steps, the current collectors 21 and 21 'and the ring-shaped bodies 24 and 24' are used for the cylindrical body, preferably for temporary fixing after the fixing material layer is formed. Since it is stored after the removal of the paraffin layer, the cylindrical body can reduce the influence of thermal stress.

Of each part forming the hollow fiber type electrolyte cell, the inner porous electrode layer is formed from, for example, a film-forming stock solution in which silicon silicide TiSi ₂ powder is highly filled in an organic solvent solution of a polymer substance. The obtained composite film was fired at about 1300 to 1800 ° C., and at that time, at a heating temperature range of at least 400 ° C., titanium silicide TiSi obtained by firing in a vacuum or inert atmosphere environment was obtained. The outer porous electrode layer is formed of carbon or the like, and is formed of conductive porous ceramics (see Japanese Patent Application No. 2004-343678) formed as a main component. The inner and outer catalyst layers are made of, for example, carbon carrying platinum. The electrolyte layer is formed of, for example, a solid polymer electrolyte or a porous body filled with the electrolyte, or an organic-inorganic electrolyte or an inorganic electrolyte in which an electrolyte component is supported on an inorganic support. As the cylindrical case that houses a plurality of type electrolyte cells, for example, a resin made of a resin such as polysulfone resin or acrylic resin or an inorganic material such as glass or alumina is used. Further, the ring-shaped body can be made of the same material as that of the cylindrical case, and preferably a resin-made one is used due to problems such as adhesiveness.

  In addition, the current collector is made of a single metal such as copper or silver, or a conductive material such as an alloy or carbon, and is subjected to surface treatment such as plating if necessary. The current collector is formed in the shape of a plate, and the through-holes penetrate the inner and outer electrode layer portions of the hollow fiber electrolyte cell, and the through-holes are designed to have a minimum clearance. The electrical connection between the current collector and the electrode layer portion is performed using a conductive paste, a conductive adhesive, or the like. As the conductive paste formed on the current collector, for example, a commercially available silver paste or the like is used, or solder or the like may be used instead. The potting layer is formed of a potting agent such as an insulating epoxy resin, a urethane adhesive, or an inorganic adhesive.

  For a module in which 20 hollow fiber membrane electrolyte cells with a diameter of 1 mm are directly attached to a cylindrical body made of a polysulfone resin having a diameter of 30 mm and a length of 25 mm with an epoxy resin via a copper plate-shaped current collector, the temperature is 100 ° C ⇔-20 In the thermal shock test at ℃ (hold for 1 hour), the hollow fiber membrane electrolyte cell was damaged.

  In contrast, in the module of the present invention in which the ring shape made of polysulfone resin having a diameter of 25 nn and a length of 23 mm was accommodated in the cylindrical body, the hollow fiber membrane electrolyte cell was not damaged in the thermal shock test. .

The manufacturing process of one embodiment of the fuel cell module which concerns on this invention is shown as a longitudinal cross-sectional view. In the fuel cell module according to the present invention, it is a longitudinal sectional view of an embodiment further accommodated in a cylindrical body. It is a longitudinal cross-sectional view of the fuel cell module of a prior art example. It is a cross-sectional view of a hollow fiber electrolyte cell.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Cylindrical case 2 Hollow fiber type electrolyte cell 3, 3 'Potting part 4 Fuel A inlet 5 Fuel A exhaust 6 Fuel B inlet 7 Fuel B exhaust
11 Inner porous electrode layer
12 Inner catalyst layer
13 Electrolyte layer
14 Outer catalyst layer
15 Outer porous electrode layer
21, 21 'Eye plate-shaped current collector
22, 22 'Conductive paste layer
23,23 'Potting material layer
24, 24 ′ ring-shaped body
25, 25 ′ Electrical outlet terminal
26, 26 'fixing terminal
27,27 ′ Molten paraffin
28 Tube
29, 29 ′ cover

Claims (6)

  The inner electrode layer portion and the outer electrode layer portion of the plurality of hollow fiber electrolyte cells are respectively penetrated through a dish-shaped current collector having a through-hole, and a conductive paste layer is formed on both sides of each dish-shaped current collector layer. And a potting material layer. A fuel cell module is formed by forming a laminated body and fixing each laminated body portion with a ring-shaped body.   A fuel cell module in which a ring-shaped body having a laminated body portion fixed therein is accommodated in a cylindrical body.   The fuel cell module according to claim 1 or 2, wherein the hollow fiber electrolyte cell comprises a hollow laminate of an inner porous electrode layer, an inner catalyst layer, an electrolyte layer, an outer catalyst layer, and an outer porous electrode layer.   4. The fuel cell module according to claim 3, wherein the inner porous electrode layer is formed of a conductive porous ceramic layer formed mainly of siliconized titanium TiSi.   An inner electrode layer portion and an outer electrode layer portion of a plurality of hollow fiber electrolyte cells were respectively penetrated through a dish-shaped current collector having a through-hole, and the dish-shaped current collector was provided so as to surround its end. After fitting the ring-shaped body and using the inner peripheral surface of the ring-shaped body to pour the fixing material into contact with the countersink-shaped current collector to form the fixing material layer, the hollow fiber electrolyte cell, A method of manufacturing a fuel cell module, wherein a dish-shaped current collector and a ring-shaped body are accommodated in a cylindrical body. 6. The method of manufacturing a fuel cell module according to claim 5, wherein an elastic body is interposed between the ring-shaped body and the cylindrical body.

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