JP2010244744A - Ultralight bipolar plate for fuel cells - Google Patents

Abstract

The present invention satisfies the strength, thermal conductivity, electrical conductivity, chemical stability and gas permeability required for fuel cells, dramatically reduces weight and volume, and is manufactured at a low unit price and a simple process. A bipolar plate having ultrafine processability is provided.
A non-conductive fuel electrode film 30 having a fuel flow channel, a non-conductive air electrode film 10 having an air flow channel, and the fuel electrode film 30 and the air electrode film 10 are provided. A non-conductive separation membrane 20 provided between the fuel electrode and the air so as not to be mixed, and the fuel electrode membrane 30, the separation membrane 20 and the air electrode membrane 10 are sequentially stacked. And a metal part 60 that provides a current transfer path so that a current moves from the separation membrane 20 to the air electrode membrane 10, and more specifically, the fuel electrode membrane 30, the air electrode membrane 10 and the separation. The films 20 are each glass, preferably photosensitive glass.
[Selection] Figure 1

Description

  The present invention relates to a fuel cell, and more particularly to a bipolar plate for a polymer electrolyte fuel cell, which is composed of photosensitive glass and metal and has excellent workability, strength, thermal conductivity and electrical conductivity. It relates to a bipolar plate that is high, has low gas permeability and is extremely light.

  The demand for energy is increasing rapidly worldwide due to industrial development and population growth, but the production of oil / natural gas as the main energy source is predicted to gradually decrease from around 2020. Has been. Along with such depletion of fossil fuels, research and development on alternative clean energy sources that do not pollute the environment is necessary.

  The Kyoto Protocol for greenhouse gas reduction was adopted in 1997, and 119 countries, including Korea, ratified it.

Technology that uses various natural resources such as solar heat, wind power, and hydrogen energy as an energy source has been researched and developed, but unlike existing thermal power generation, it is a direct power generation method that does not require a combustion process or mechanical work. , thermodynamic limitations (Carnot efficiency) without being, power generation efficiency is high, NOx is air pollutants, sulfur compounds (SOx) without having to discharge the like, CO ₂ emissions can be reduced, working noise / Vibration is extremely low, it is an environmentally friendly energy technology, a distributed power production system is possible, and a small-sized household power generation system in the range of 100kW to several tens of tens of scale for medium and large-scale power generation systems, 1kW to 10kW Fuel cell technology can be used as an alternative clean energy because it can easily adjust the power generation capacity, such as for auxiliary power sources for automobiles and mobile power supplies of several watts to several kW class. It is

A fuel cell is a device that reacts a fuel gas such as hydrogen (H ₂ ) with oxygen (O ₂ ) to directly convert chemical energy into electrical energy, and generally a fuel electrode and an air electrode are formed. ing.

  In the fuel electrode, hydrogen cations and electrons are generated by a catalytic reaction, and the generated hydrogen cations pass through the electrolyte and move to the air electrode, and the electrons move from the fuel electrode to the air electrode along an external circuit. Move to. In the air electrode, hydrogen cations that have moved through the electrolyte and electrons that have moved along the external circuit react with oxygen to generate water. At this time, a predetermined potential difference is generated between the fuel electrode and the air electrode.

  Such fuel cells vary depending on the type of electrolyte used and the operating temperature. In particular, a polymer electrolyte fuel cell (PEMFC) that operates at a relatively low temperature of 100 ° C. or less and uses hydrogen directly as fuel. Electrolyte Membrane Fuel Cell) is attracting attention as a power source for automobiles, household power generation, and mobile use.

  The polymer electrolyte fuel cell has a stack structure composed of a large number of unit cells in order to generate a required output. The unit cell has a polymer electrolyte that allows cation conduction of hydrogen cations, a catalyst layer (Electrode) that causes a redox reaction between fuel and air, and a gas diffusion layer that can uniformly supply fuel and air to the catalyst layer. Bipolar plate with a membrane electrode assembly (MEA) and a predetermined flow channel disposed on both sides of the membrane-electrode assembly for supplying fuel and air to both sides ).

  As described above, the polymer electrolyte fuel cell has a stack structure in which membrane-electrode assemblies and bipolar plates are alternately stacked and connected in series or in parallel in order to control energy output and capacity. . In such a stack, membrane-electrode assemblies and bipolar plates are alternately laminated, and metal or plastic plates are provided at both ends, and bolts and nuts are fastened to the plates, and constant from both sides. It has a structure in which it is pressed and adhered with pressure.

  The bipolar plate provided in the polymer electrolyte fuel cell is an important component that transmits electricity between unit cells by uniformly distributing fuel such as hydrogen and air (oxygen) in the reaction region in the fuel cell stack. is there. Therefore, high electrical conductivity and thermal conductivity, appropriate mechanical strength, corrosion resistance, thermal stability, etc. are required.

  However, since the weight of the bipolar plate in the fuel cell stack is generally 80% or more and the thickness is 85% or more, the bipolar plate can be used to reduce the size and weight of the fuel cell at the same output. Need to reduce the weight and capacity.

  By the way, generally, a bipolar plate uses a composite material in which a metal material, graphite, or a polymer resin is mixed.

  The most frequently used graphite (carbon-based) bipolar plate is excellent in thermal conductivity, electrical conductivity, and corrosion resistance, but has a problem of low mechanical strength. The low material density is suitable for weight reduction, but the mechanical strength and workability are poor, and the fluid permeability is high, so it is necessary to make it thicker than several millimeters. Is limited.

  In the case of metal-based bipolar plates that are often used next to graphite, they have excellent electrical conductivity, thermal conductivity, and mechanical strength, and there is no problem with respect to gas permeation problems, but there is a problem that chemical stability is low. There is a problem that the surface oxide film increases the electrical resistance. In terms of miniaturization and weight reduction, a metal having a high density inevitably increases the weight of the fuel cell.

  In the case of a composite material bipolar plate, the corrosion resistance is superior to that of metal, but there is a problem that it is difficult to simultaneously realize electrical conductivity and thermal conductivity characteristics, as well as workability and mechanical strength characteristics.

  The object of the present invention to solve the above-mentioned problems is to satisfy the strength, thermal conductivity, electrical conductivity, chemical stability and gas permeability required for fuel cells, and to revolutionize the weight and volume. It is to provide a bipolar plate which is manufactured at a low cost and a simple process, and has ultra-fine processability.

  The bipolar plate of the present invention includes a non-conductive fuel electrode film in which a fuel flow channel is formed, a non-conductive air electrode film in which an air flow channel is formed, and between the fuel electrode film and the air electrode film. A non-conductive separation membrane that separates the fuel and air so as not to be mixed, and the fuel electrode membrane, the separation membrane, and the air electrode membrane are sequentially stacked from the fuel electrode membrane through the separation membrane. And a metal part that provides a current transfer path so that a current moves to the air electrode membrane.

  Here, the fuel cell is preferably a polymer electrolyte fuel cell.

  The fuel electrode membrane, air electrode membrane, and separation membrane are non-conducting materials that satisfy the required strength, thermal conductivity, chemical stability, gas permeability, workability, bondability, and lightness of the fuel cell bipolar plate. Consists of sex substances. The metal part provides a current transfer path between the membranes (between the fuel electrode membrane, the separation membrane and the air electrode membrane) made of such a non-conductive substance.

  High strength, thermal conductivity and chemical stability, low gas permeability, very good workability, easy membrane-to-membrane (between fuel electrode membrane, separation membrane and air electrode membrane) In order to construct an extremely light bipolar plate, the fuel electrode membrane, air electrode membrane and separation membrane are each glass, preferably photosensitive glass, more preferably photosensitive crystallization. Desirably glass.

  In order to have further excellent processability including ultrafine processing, the fuel electrode membrane, the air electrode membrane and the separation membrane are each preferably photosensitive glass sensitive to ultraviolet rays.

  In the sequential stacking of the fuel electrode membrane, the separation membrane, and the air electrode membrane, the metal part that provides a current transfer path between the membranes has at least one conductivity that penetrates the fuel electrode membrane, the air electrode membrane, and the separation membrane. A metal rod is preferred.

  Here, it is preferable that the metal rod penetrates a region of an edge of the fuel electrode membrane, the air electrode membrane and the separation membrane, that is, a region where the flow path is not formed, and the number of the metal rods is It is preferably determined by the shapes of the fuel electrode membrane, the air electrode membrane, and the separation membrane. As an example, when the fuel electrode membrane, the air electrode membrane, and the separation membrane have a square shape as a whole, it is preferable that four metal rods are provided so as to penetrate each of the four edges of the quadrilateral.

  When the fuel electrode membrane, the separation membrane, and the air electrode membrane are sequentially stacked, the metal portion that provides a current transfer path between the membranes is deposited on the surfaces of the fuel electrode membrane, the air electrode membrane, and the separation membrane. A vapor deposition layer may be sufficient.

  The bipolar plate is composed of a unit body in which the fuel electrode membrane, the separation membrane and the air electrode membrane are sequentially laminated and thermally bonded, and the metal part, preferably the metal rod, on the surface of the unit body. It is preferable that the metal vapor deposition layer further provided. Preferably, the metal part includes the metal rod and a metal vapor deposition layer provided on the surface of the unit body.

  The metal vapor deposition layer provided on each of the upper and lower surfaces of the unit body effectively collects electrons generated in a membrane-electrode assembly (MEA) constituting the fuel cell, It is moved between the membranes (between the fuel electrode membrane, the separation membrane and the air electrode membrane) through the metal rod.

  The metal of the metal rod or the metal deposition layer is made of silver, gold, in terms of electrical conductivity, manufacturing cost, ease of deposition and molding, chemical stability, interfacial bonding properties with glass, and low metal density. One or more substances selected from the group consisting of platinum, nickel, chromium, titanium, and aluminum are preferable.

  The flow path of the fuel electrode film or the air electrode film is formed by removing a region selectively irradiated with light by a mask pattern on a photosensitive glass plate that is a raw material of the fuel electrode film or the air electrode film. Is done.

  Specifically, the flow path is formed by recrystallization of the light irradiation region by heat treatment and then etching the recrystallized region, or by immediately etching the light irradiation region. Is done. The etching is wet etching using an etching solution containing hydrofluoric acid (HF).

  The light irradiated to form the flow path is ultraviolet light, and the photosensitive glass plate as the raw material is a glass plate that is ultraviolet-sensitive.

  The flow path is preferably a flow path that penetrates in the thickness direction of the photosensitive glass plate that is the raw material.

  The separation membrane is preferably provided with a cooling fluid channel. Specifically, the upper separation membrane that seals one side of the fuel flow channel provided in the fuel electrode membrane, the cooling channel membrane in which the partition wall of the cooling fluid channel is formed, and the air electrode membrane are provided. And a lower separation membrane that seals one side of the air flow channel. Preferably, the upper separation membrane, the cooling channel membrane, and the lower separation membrane are sequentially stacked and thermally coupled. Preferably there is.

  The upper separation membrane physically separates the fuel flow passage and the cooling fluid passage, and the lower separation membrane physically separates the air flow passage and the cooling fluid passage. .

  The bipolar plate of the present invention satisfies the strength, thermal conductivity, electrical conductivity, chemical stability and gas permeability required for fuel cells, and can dramatically reduce weight and volume, and is simple. Through a simple process, a flow path having an ultrafine structure and a flow path having a high degree of complexity can be provided, and an ultra-compact / lightweight fuel cell unit cell can be realized.

It is an example of the disassembled perspective view of the bipolar plate by this invention. It is an example of the perspective view of the bipolar plate by this invention. 1 is an example of a fuel cell stack provided with a bipolar plate according to the present invention. It is the example of the process figure showing the manufacturing process of the fuel electrode membrane, air electrode membrane, and separation membrane with which the bipolar plate by the present invention is equipped. It is an example of a sectional view showing the structure of a fuel electrode membrane, an air electrode membrane, and a separation membrane provided in a bipolar plate according to the present invention. It is an example of sectional drawing of the unit body by this invention. It is an example of sectional drawing of the bipolar plate by this invention. It is an example of a sectional view showing the structure of a fuel electrode membrane, an air electrode membrane and a separation membrane provided with a metal vapor deposition layer of a bipolar plate according to the present invention. It is another example of sectional drawing which showed the bipolar plate by this invention. It is an example of sectional drawing of the unit body provided with the metal vapor deposition layer by this invention. It is another example of sectional drawing which showed the bipolar plate by this invention. 1 is an optical photograph of a unit body according to the present invention. It is another example of the separation membrane by this invention.

  Hereinafter, a bipolar plate of the present invention will be described in detail with reference to the accompanying drawings. The accompanying drawings are provided by way of example so that those skilled in the art may fully understand the spirit of the present invention. Therefore, the present invention is not limited to these drawings, and may be embodied in other forms. Moreover, in this specification, the same reference number shows the same component.

  Unless otherwise defined, technical and scientific terms used herein have the meanings commonly understood by persons having ordinary knowledge in the technical field to which this invention belongs, and are described below and In the accompanying drawings, descriptions of known functions and configurations that obscure the subject matter of the present invention are omitted.

  In the following description, the non-conductive materials constituting the non-conductive air electrode membrane, non-conductive separation membrane, and non-conductive fuel electrode membrane of the present invention are not considered in terms of electrical conductivity and are pure according to the characteristics of the present invention. In addition, non-conductive materials that satisfy the physical properties required for bipolar plates for fuel cells, such as chemical reactivity, strength, ease of processing, low density, gas permeability, and bondability, are used. According to the characteristic of the present invention, the metal part which is another characteristic of the present invention is provided, and it has a characteristic structure that finally satisfies the electric conductivity required for the bipolar plate.

  The non-conductive air electrode membrane, non-conductive separation membrane, and non-conductive fuel electrode membrane of the present invention are formed in terms of chemical reactivity, strength, ease of processing, low density, gas permeability, and bondability. The conductive material is glass, in particular sodium lime glass, potassium lime glass, lead glass, barium glass, silicate glass, borosilicate glass, or phosphate glass.

  Furthermore, in the present invention, the non-conductive substance constituting the non-conductive air electrode membrane, the non-conductive separation membrane, and the non-conductive fuel electrode membrane of the present invention is sensitive in terms of ultrastructural patterning and ease of processing. It has a characteristic structure that is a glass. Thereby, the workability of the bipolar plate of the present invention and the processed product can obtain performance and effects similar to those of semiconductor photolithography.

  Based on the following drawings, in order to clarify the characteristic configuration of the present invention, the case where the photosensitive glass is a substance constituting the air electrode membrane, the separation membrane and the fuel electrode membrane is described in detail.

  FIG. 1 is an example of an exploded perspective view of a bipolar plate for a fuel cell according to the present invention. As shown in FIG. 1, the bipolar plate for a fuel cell according to the present invention includes a non-conductive fuel electrode membrane 30 in which a flow path for fuel containing hydrogen is formed, and a flow path for air containing oxygen. Of the non-conductive air electrode membrane 10, the non-conductive separation membrane 20 provided between the fuel electrode membrane 30 and the air electrode membrane 10, and the air electrode membrane 10, the separation membrane 20 and the fuel electrode membrane 30. It is comprised from the metal part 60 which forms the transmembrane current transfer path.

  The example of FIG. 1 is an example in which the metal portion 60 is a metal rod 60 that penetrates the air electrode membrane 10, the separation membrane 20, and the fuel electrode membrane 30. As shown in FIG. 1, the metal rod 60 has an air electrode membrane 10, a separation membrane 20, and a fuel electrode so as not to affect the flow path formed in the air electrode membrane 10 or the fuel electrode membrane 30. It is preferable to penetrate the edge of the membrane 30.

  The metal rod 60 has high electrical conductivity, chemical stability, ease of processing, and oxide film formation suppressing property, and has a low material density almost equal to graphite, such as silver, gold, platinum, nickel, It is preferably made of a material selected from one or more selected from the group consisting of chromium, titanium and aluminum.

  FIG. 2 is a perspective view of a bipolar plate 4000 according to the present invention, in which the air electrode membrane 10, the separation membrane 20, and the fuel electrode membrane 30 are laminated in order and provided with a metal rod 60 penetrating between the membranes. It is an example.

  The bipolar plate 4000 according to the present invention forms a fuel cell stack (see FIG. 3) by alternately stacking and bonding with a membrane-electrode assembly (MEA: MEA).

  The air electrode membrane 10, the separation membrane 20 and the fuel electrode membrane 30 made of a nonconductive material are glass, preferably photosensitive glass, more preferably photosensitive crystallized glass.

The photosensitive glass, which is a preferred non-conductive material of the present invention, is a glass containing a photosensitive metal element in an ionic state, and can exhibit material characteristics or crystals by light irradiation (including heat treatment performed after light irradiation). A glass whose properties change. The photosensitive metal element is one or more elements selected from the group consisting of Cu, Ag, Au, Se, Cd, Cs, V, Cr, Mn, Fe, Ni, Co, Ti, Ce, Mo, W, and U. Yes, the photosensitive glass is sodium lime glass, potassium lime glass, lead glass, barium glass, silicate glass, borosilicate glass, or phosphate glass based on the main substance constituting the glass, as an example One selected from the group consisting of LiO ₂ , Li ₂ O ₃ , K ₂ O, Al ₂ O ₃ , Na ₂ O, ZnO, Sb ₂ O ₃ , Ag ₂ O and CeO ₂ with SiO ₂ as the main material. It is a normal photosensitive glass that further contains one or more additive substances.

  As a feature, the photosensitive glass is ultraviolet-sensitive glass, and preferably is a photosensitive glass for chemical cutting including photosensitive fogged glass and photosensitive crystallized glass.

  The photosensitive glass constituting the air electrode membrane 10, the separation membrane 20, and the fuel electrode membrane 30 has a gas permeability that is remarkably lower than that of graphite, and therefore can prevent gas mixing and leakage by itself. In addition, a very fine and complicated flow path can be formed through light irradiation and etching similar to semiconductor lithography. Further, the strength of the glass itself is remarkably superior to that of graphite, and the thickness of the flow path, the air electrode membrane 10, the separation membrane 20, and the fuel electrode membrane 30 can be arbitrarily adjusted, and the polymer electrolyte fuel cell It is characterized by a very low density, which is very chemically and chemically stable in the operating temperature range, and whose material density is approximately equal to that of graphite.

  Due to the above-described characteristics of the bipolar plate of the present invention, an ultralight and ultrasmall fuel cell can be realized, and the power density of the fuel cell stack can be improved.

  Glass, preferably photosensitive glass, is an excellent material that satisfies the physical / chemical properties required for bipolar plates for fuel cells, but it has a significantly lower electrical conductivity than graphite. It is a sex substance. In the present invention, as a characteristic configuration for solving such electric conductivity, the metal part forming the inter-membrane current transfer path is provided.

  Table 1 below is a table comparing and comparing the weight, volume, and electric conductivity of graphite used in a normal bipolar plate and the bipolar plate of the present invention.

  As shown in FIG. 4, a photosensitive glass which is a characteristic configuration of the present invention, preferably a photosensitive glass which is sensitive to ultraviolet rays, has a high-level structure including an ultrafine channel through a simple process similar to semiconductor lithography. A fine structure having a complicated shape is provided on the air electrode membrane 10, the separation membrane 20, or the fuel electrode membrane 30.

  Specifically, as shown in FIG. 4, a mask 100 having a pattern to be processed is positioned on a photosensitive glass plate 200 which is a raw material of the air electrode membrane 10, the separation membrane 20, or the fuel electrode membrane 30. Then, the photosensitive glass plate 200 is selectively irradiated with light according to the pattern. Thereafter, a heat treatment is performed so that the region irradiated with light is recrystallized 201, and a flow path is formed in the glass plate 200 through a process of selectively removing the recrystallized region by wet etching. A microstructure 301 can be formed.

  Thereby, the air electrode membrane 10, the separation membrane 20, or the fuel electrode membrane 30 is composed of the fine structure 301 including the flow path and the glass in the region not irradiated with light.

  The light is preferably ultraviolet light that allows ultra-fine processing, and the thickness of the glass plate is determined in consideration of the output of the fuel cell stack to be manufactured and its application, As a substantial example, it is preferably 0.1 mm to 2 mm. Although the said heat processing temperature is suitably adjusted with the photosensitive glass substance, it can carry out at 500 to 600 degreeC as a substantial example.

  In the example of FIG. 4, an example in which a fine structure penetrating the thickness of the glass plate is shown. However, by controlling the etching time and the like so that only one thickness of the glass plate is etched, It is also possible to form a fine structure such as surface irregularities (concave irregularities).

  In addition, in the example of FIG. 4, in the case of having selective etching characteristics (such as recrystallization) by light irradiation as in the case of photosensitive crystallized glass, wet etching is immediately performed without heat treatment, The region irradiated with can also be removed.

  FIG. 5 is an example of a cross-sectional view of the air electrode membrane 10, the separation membrane 20, and the fuel electrode membrane 30 of the present invention manufactured by light irradiation and etching as shown in FIG.

  The air electrode membrane 10 of the present invention is composed of an air flow channel 12 that penetrates in the thickness direction, a through-hole 13 provided with a metal rod, and a photosensitive glass 11, and a membrane-electrode assembly (MEA: Membrane). Electrode Assembly (MEA in FIG. 3) and a coupling hole 14 that provides a path for a coupling member (for example, a bolt and a nut) that couples the bipolar plate of the present invention.

  The coupling member provided in the coupling pore 14 couples and fixes the elements constituting the unit cell, and at the same time, couples and fixes a number of unit cells.

  The fuel electrode membrane 30 of the present invention is formed at a position corresponding to the fuel flow channel 32 penetrating in the thickness direction and the through-hole 13 of the air electrode membrane 10 and is provided with the same metal rod. 33 and a photosensitive glass 31, which are formed at positions corresponding to the coupling pores 13 of the air electrode membrane 10 and include coupling pores 33 that provide a path for the coupling member.

  The separation membrane 20 of the present invention is formed at a position corresponding to the through-hole 13 of the air electrode membrane 10 and corresponds to the through-hole 23 provided with the same metal rod and the combined pore 13 of the air electrode membrane 10. The air flow path 12 of the air electrode film 10 and the fuel flow path 32 of the fuel electrode film 30 are physically formed by the photosensitive glass 21. It has a structure separated into two.

  The air electrode membrane 10, the separation membrane 20, and the fuel electrode membrane 30 manufactured to have the structure shown in FIG. 5 by light irradiation and etching as shown in FIG. 20 and 30 are preferably thermally coupled to form a unit body 1000 as shown in FIG.

  The thermal bonding of the air electrode membrane 10, the separation membrane 20 and the fuel electrode membrane 30, which are sequentially laminated, is preferably bonding by heat treatment at a temperature equal to or higher than the glass transition temperature (the glass transition temperature of the photosensitive glass 11, 21, 31). A substantial example is thermal bonding by heat treatment at 500 ° C. or higher.

  Accordingly, the unit body 1000 includes the photosensitive glass of the air electrode membrane 10, the separation membrane 20, and the fuel electrode membrane 30, the fuel flow passage 32 and the air flow passage 12, which are physically separated by the separation membrane 20, The through-holes 40 in which the through-holes 23 of the air electrode membrane 10, the separation membrane 20 and the fuel electrode membrane 30 are combined to provide a single metal rod, and the combined pores of the air electrode membrane 10, the separation membrane 20 and the fuel electrode membrane 30. 23, and a combined pore 50 provided with a single coupling member.

  As shown in FIG. 7, the bipolar plate 2000 according to the present invention includes the unit body 1000 and a metal rod 60 provided in the through-hole 40. The metal rod 60 serves as a current transfer path between the air electrode membrane 10, the separation membrane 20 and the fuel electrode membrane 30 and between the fuel cells constituting the stack, and is used for electrical connection with an external circuit. .

The minimum area of the metal rod 60 is determined in consideration of the output of the fuel cell stack to be manufactured, the dimension of the fuel cell unit cell to be manufactured, and the application of the fuel cell. From the viewpoint of reducing and providing a stable current transfer path, the metal rod 60 preferably has a cross-sectional area of 100 μm ^{2 to} 5000 mm ² .

  5 to 7 show the case where the metal part of the present invention is a metal rod 60, and FIGS. 8 and 9 show the case where the metal part is a metal deposition layer 71, 72, 73, 70. FIG. Is shown.

  The structure of the air electrode membrane 10, the separation membrane 20 and the fuel electrode membrane 30 in FIG. 8 is similar to the structure described in detail with reference to FIG. 5, but the through-holes 13, 23, 33 is not provided, and metal vapor-deposited layers 71, 72, and 73 are provided on the surfaces of the photosensitive glasses 11, 21, and 31 that constitute the films 10, 20, and 30, respectively.

  Preferably, the metal vapor deposition layer is provided on the entire surface of the air electrode membrane 10, the entire surface of the separation membrane 20, and the entire surface of the fuel electrode membrane 30.

  The metal deposition layers 71, 72, 73 are preferably one or more materials selected from the group consisting of silver, gold, platinum, nickel, chromium, titanium, and aluminum. A normal electron beam (E-beam) is used. Deposition can be performed using a vapor deposition device, a sputter, a thermal / physical vaporizer, or the like.

  The metal vapor-deposited layers 71, 72, 73, like the metal rods described above, serve as current transfer paths between the membranes and between the fuel cells and between the fuel cells and the external circuit, and generate electrons generated in the membrane-electrode assembly. It can be collected effectively.

  From the standpoint of sheet resistance, durability, and maintenance of the ultrafine structure provided in the bipolar plate as a feature of the present invention, the thickness of the metal vapor-deposited layers 71, 72, 73 is preferably 10 nm to 100 μm.

  As shown in FIG. 8, even when the metal part is a metal vapor deposition layer, it is preferable to have a unit structure as shown in FIG. 9 due to thermal coupling between the films 10, 20, and 30.

  FIG. 10 shows a case where a metal vapor deposition layer 80 is provided on the surface of the unit body 1000 described in detail with reference to FIG. 6, and the metal vapor deposition layer 80 is made of silver, gold, platinum, nickel, chromium. Preferably, the unit is one or more selected from the group consisting of titanium and aluminum, in terms of surface resistance, durability, and maintenance of the ultrastructure provided in the bipolar plate according to the features of the present invention. The thickness of the metal vapor deposition layer provided on the body 1000 is preferably 10 nm to 100 μm. At this time, the metal vapor deposition layer 80 is preferably provided on the entire surface of the unit body 1000.

  FIG. 11 is an example of a cross-sectional view of a preferred bipolar plate 4000 of the present invention, in which a metal vapor deposition layer 80 and a metal rod 60 provided on the surface of the unit body 1000 constitute a metal part. With such a structure, the bipolar plate 4000 effectively collects the electrons generated in the membrane-electrode assembly, and at the same time, stably forms the interelectrode and stack of the air electrode membrane 10, the separation membrane 20, and the fuel electrode membrane 30. It becomes a current transfer path between the fuel cells to be used, and is used for electrical connection with an external circuit.

  FIG. 12 is an optical photograph of the above-described unit body 1000 among the components of the bipolar plate according to the present invention. The metal rod according to the present invention is inserted into the through-holes provided on both left / right sides of the unit body of FIG. Will be provided.

  FIG. 13 shows another example of the separation membrane 20 among the components of the bipolar plate according to the present invention. Specifically, the fuel flow channel 32 provided in the fuel electrode membrane 30 and the air electrode membrane are shown. 10 is an example of a separation membrane 20 provided with a cooling fluid passage 25 at the same time as separating the air flow passage 12 provided in FIG.

  As shown in FIG. 13A, the separation membrane 20 includes an upper separation membrane 20 (i) that seals one side of the fuel flow channel 32 provided in the fuel electrode membrane 30, and a cooling fluid flow. A cooling channel membrane 20 (ii) in which a partition wall 21 '(ii) of the passage is formed, and a lower separation membrane 20 (iii) for sealing one side of the air flow channel 12 provided in the air electrode membrane 10. Preferably, the upper separation membrane 20 (i), the cooling channel membrane 20 (ii), and the lower separation membrane 20 (iii) are laminated in order as shown in FIG. It is a combined structure.

  The upper separation membrane 20 (i) physically separates the fuel flow passage 32 and the cooling fluid passage 25, and the lower separation membrane 20 (iii) The cooling fluid channel 25 is physically separated.

  The upper separation membrane 20 (i), the cooling channel membrane 20 (ii), and the lower separation membrane 20 (iii) are respectively exposed to ultraviolet rays using the mask described in detail with reference to FIG. In addition, the flow path of the cooling fluid provided in the separation membrane 20 can also have a very fine partition wall structure, and thus the very fine flow path can be manufactured. Even if the shape of the flow path is provided, a highly complicated shape is possible.

  As described above, the present invention has been described with reference to specific embodiments and limited embodiments and drawings, which are provided to assist in a more general understanding of the present invention. The present invention is not limited to these, and various modifications and variations can be made by those skilled in the art to which the present invention pertains.

  Accordingly, the spirit of the invention should not be limited to the embodiments described, but is to be construed in conjunction with the appended claims, as well as all that are equivalent or equivalent to the scope of the claims. Belongs to the category of the idea of the present invention.

DESCRIPTION OF SYMBOLS 10 Air electrode membrane 11, 21, 31 Photosensitive glass 12 Air flow path 20 Separation film 25 Cooling fluid flow path 30 Fuel electrode film 32 Fuel flow path 60 Metal rod 70, 80 Metal vapor deposition layer

Claims (14)

A non-conductive fuel electrode membrane in which a fuel flow channel is formed;
A non-conductive air electrode membrane formed with an air flow channel;
A non-conductive separation membrane provided between the fuel electrode membrane and the air electrode membrane to separate the fuel and air so as not to be mixed;
A metal part that provides a current transfer path so that current flows from the fuel electrode film to the air electrode film through the separation film when the fuel electrode film, the separation film, and the air electrode film are sequentially stacked;
A bipolar plate for a fuel cell, comprising:   The bipolar plate according to claim 1, wherein each of the fuel electrode membrane, the air electrode membrane, and the separation membrane is made of glass.   The bipolar plate according to claim 2, wherein each of the fuel electrode membrane, the air electrode membrane, and the separation membrane is photosensitive glass.   The bipolar plate according to claim 2, wherein each of the fuel electrode membrane, the air electrode membrane, and the separation membrane is photosensitive crystallized glass.   The bipolar plate according to claim 3, wherein the fuel electrode membrane, the air electrode membrane, and the separation membrane are photosensitive glass that is sensitive to ultraviolet rays.   The bipolar plate according to claim 2, wherein the metal part is one or more conductive metal rods penetrating the fuel electrode membrane, the air electrode membrane, and the separation membrane.   The bipolar plate according to claim 2, wherein the metal part is a metal vapor deposition layer deposited on each surface of the fuel electrode membrane, the air electrode membrane, and the separation membrane.   3. The bipolar plate according to claim 2, wherein the bipolar plate is composed of a unit body in which the fuel electrode membrane, the separation membrane, and the air electrode membrane are sequentially laminated and thermally bonded, and the metal portion. Bipolar plate.   The bipolar plate according to claim 8, wherein the bipolar plate further comprises a metal vapor deposition layer provided on a surface of the unit body.   The bipolar plate according to claim 6, 7 or 9, wherein the metal is at least one selected from the group consisting of silver, gold, platinum, nickel, chromium, titanium and aluminum.   A region of the photosensitive glass plate, which is a raw material of the fuel electrode film or the air electrode film, that is selectively irradiated with light by a mask pattern is removed to form a flow path for the fuel electrode film or the air electrode film. The bipolar plate according to claim 5, wherein the bipolar plate is provided.   The bipolar plate according to claim 11, wherein the flow path is a flow path penetrating in a thickness direction of the photosensitive glass plate.   The bipolar plate according to claim 11, wherein the flow path is formed by recrystallizing the light irradiation region by heat treatment and then etching the recrystallized region. The bipolar plate according to claim 13, wherein the separation membrane is provided with a flow path of a cooling fluid.