JP2005032514A - Fuel cell, manufacturing method of fuel cell, electronic device provided with fuel cell, automobile provided with fuel cell and cogeneration system provided with fuel cell - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a high power fuel cell, having a reaction layer with different amounts of catalyst depending on the location, and to provide a manufacturing method of the fuel cell. <P>SOLUTION: A first gas passage is formed at discharge devices 20a, 20b, on a first substrate conveyed by a belt conveyor BC1 driven by a driving device 58 according to a signal from a control device 56. Then a first collecting layer is formed at a discharge device 20d on the first substrate conveyed by the belt conveyor BC1. A first reaction layer having different amounts of catalyst depending on the location is formed at a discharge device 20f. An electrolyte membrane is formed at a discharge device 20g. Using the same processes, a second reaction layer is formed at a discharge device 20h, and a second collecting layer is formed at a discharge device 20j. A second substrate formed with a second gas passage at discharge devices 20l, 20m is arranged in a predetermined position on the first substrate to complete manufacturing of the fuel cell. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention provides a fuel cell that supplies different types of reaction gas to each electrode and generates power by a reaction based on the supplied reaction gas, a method for manufacturing the fuel cell, an electronic device that includes the fuel cell, and an automobile that includes the fuel cell. And a cogeneration system including a fuel cell.
[0002]
[Prior art]
Conventionally, there is a fuel cell in which an electrolyte having a property of passing ions is sandwiched between porous electrodes having a property of passing electrons. Some fuel cells generate electricity using hydrogen or alcohol as fuel. Among such fuel cells, for example, in a fuel cell using hydrogen as a fuel, a first reaction gas containing hydrogen is supplied to one electrode, and a second reaction gas containing oxygen is supplied to the other electrode. Electricity is generated by a reaction based on hydrogen contained in the first reaction gas and oxygen contained in the second reaction gas.
[0003]
In a fuel cell, a reaction layer using platinum as a catalyst for promoting a reaction is often formed. This reaction layer is formed by wiping a chloroplatinic acid solution or a solution in which platinum-supported carbon carrying platinum is dispersed on the carbon constituting the gas diffusion layer and spraying it using a spray ( Patent Document 1).
[0004]
[Patent Document 1]
JP 2002-298860 A
[0005]
[Problems to be solved by the invention]
By the way, in order to increase the output of the fuel cell and manufacture a fuel cell with good characteristics, it is necessary to form a reaction layer by accurately applying a predetermined amount of catalyst to a predetermined place. For example, the diffusion state of the reaction gas in the fuel cell differs depending on the location. Therefore, even when the reaction layer is formed by uniformly applying the catalyst, the reaction efficiency of the reaction gas in the reaction layer is not necessarily uniform. When there is a difference in the reaction efficiency of the reaction gas, electrons generated by the reaction move in the reaction layer, resulting in a decrease in the output of the fuel cell. However, it is difficult to form a reaction layer so that a uniform reaction efficiency can be obtained for the entire fuel cell by applying an appropriate amount of catalyst to the appropriate place using a spray, increasing the output of the fuel cell Is not easy.
[0006]
An object of the present invention is to provide a high-power fuel cell in which the reaction layer has a different amount of catalyst depending on the location, a method for manufacturing a fuel cell that can easily manufacture a high-power fuel cell, and an electron equipped with a high-power fuel cell It is to provide a device, an automobile equipped with a high output fuel cell, and a cogeneration system equipped with a high output fuel cell.
[0007]
[Means for Solving the Problems]
A fuel cell according to the present invention includes a first substrate on which a first gas flow path for supplying a first reaction gas is formed, and a first current collecting layer formed on the first substrate side A first gas diffusion layer formed on the first substrate side, a first reaction layer formed on the first substrate side, and a second for supplying a second reaction gas A second substrate on which a gas flow path is formed; a second current collecting layer formed on the second substrate side; a second gas diffusion layer formed on the second substrate side; A fuel cell comprising: a second reaction layer formed on a second substrate side; and an electrolyte membrane formed between the first reaction layer and the second reaction layer, In at least one of the reaction layer and the second reaction layer, the reaction layer has a different amount of catalyst depending on the location.
[0008]
According to this fuel cell, in at least one of the first reaction layer and the second reaction layer, the reaction layer has a different amount of catalyst depending on the location. Therefore, for example, by adjusting the amount of catalyst in the reaction layer based on the diffusion state of the reaction gas, the reaction efficiency in the entire fuel cell can be kept uniform and the output of the fuel cell can be increased.
[0009]
Further, in the fuel cell according to the present invention, in at least one of the first reaction layer and the second reaction layer, a portion having a lower reaction efficiency than an amount of the catalyst in a portion having a higher reaction efficiency. The amount of the catalyst is large.
[0010]
According to this fuel cell, since the amount of catalyst in the portion with low reaction efficiency is larger than the amount of catalyst in the portion with high reaction efficiency, it is possible to prevent a difference in reaction efficiency within the fuel cell and to output the fuel cell. Can be high.
[0011]
In the fuel cell according to the present invention, in at least one of the first reaction layer and the second reaction layer, the amount of the catalyst gradually increases from the upstream side to the downstream side of the gas flow path. It is characterized by increasing.
[0012]
According to this fuel cell, from the upstream side of the gas flow path where the gas pressure is high and the amount of reaction gas supplied to the reaction layer is large, the gas pressure decreases and the amount of reaction gas supplied to the reaction layer is small The amount of catalyst gradually increases toward the downstream side of the gas flow path. Therefore, the reaction efficiency in the entire fuel cell can be kept uniform, and the output of the fuel cell can be increased.
[0013]
Further, in the fuel cell according to the present invention, in at least one of the first reaction layer and the second reaction layer, the gas flow path is not formed more than the amount of the catalyst on the gas flow path. The amount of the catalyst on the part is large.
[0014]
According to this fuel cell, on the gas flow path, that is, on the portion where the gas flow path is not formed, that is, on the portion where the gas flow path is formed, rather than on the portion positioned in the vertical direction. The amount of catalyst is large on the part located between the gas flow paths. Therefore, since the amount of catalyst is larger in the portion where the reaction gas diffusion resistance is higher than the portion where the reaction gas diffusion resistance is lower, the reaction efficiency in the entire fuel cell can be kept uniform and the output of the fuel cell can be increased.
[0015]
Further, in the fuel cell according to the present invention, in at least one of the first reaction layer and the second reaction layer, the amount of the catalyst gradually increases from the central portion toward the peripheral portion. Features.
[0016]
According to this fuel cell, the amount of the catalyst gradually increases from the central portion of the reaction layer, that is, the portion where the temperature is higher due to the heat energy generated by the reaction, toward the peripheral portion where the temperature is lower than the central portion. Since it increases, the reaction efficiency in the whole fuel cell can be kept uniform, and the output of the fuel cell can be increased.
[0017]
The fuel cell manufacturing method according to the present invention includes a first gas flow path forming step of forming a first gas flow path for supplying a first reaction gas on a first substrate; A first current collecting layer forming step of forming a first current collecting layer for collecting electrons generated by reaction of the first reaction gas supplied through one gas flow path; and the first gas A first reaction layer forming step for forming a first reaction layer that performs a reaction based on the first reaction gas supplied through the flow path; an electrolyte membrane forming step for forming an electrolyte membrane; A second gas flow path forming step for forming a second gas flow path for supplying a reactive gas on the second substrate, and a second reactive gas supplied via the second gas flow path A second current collecting layer forming step of forming a second current collecting layer for supplying electrons necessary for the reaction of the second gas flow, and the second gas flow And a second reaction layer forming step of forming a second reaction layer that performs a reaction based on the second reaction gas supplied via the first reaction layer, wherein the first reaction layer forming step And at least one of the second reaction layer forming steps is characterized in that a reaction layer having a different amount of catalyst depending on a place is formed by using a discharge device.
[0018]
According to this fuel cell manufacturing method, at least one of the first reaction layer formation step and the second reaction layer formation step forms a reaction layer in which the amount of catalyst differs depending on the location using a discharge device. is doing. Therefore, by using the discharge device, a predetermined amount of catalyst can be applied to a predetermined location, and a reaction layer having a different amount of catalyst depending on the location can be easily formed.
[0019]
Further, in the fuel cell manufacturing method according to the present invention, at least one of the first reaction layer formation step and the second reaction layer formation step is more than the amount of the catalyst in the portion where the reaction efficiency is high. Is characterized in that a reaction layer having a large amount of the catalyst in a portion having low reaction efficiency is formed.
[0020]
According to this fuel cell manufacturing method, it is possible to form a reaction layer in which the amount of catalyst in the portion with low reaction efficiency is larger than the amount of catalyst in the portion with high reaction efficiency. That is, by using the discharge device, an arbitrary amount of catalyst can be applied to an arbitrary location in the reaction layer, and a high-power fuel cell can be easily manufactured.
[0021]
In the fuel cell manufacturing method according to the present invention, at least one of the first reaction layer forming step and the second reaction layer forming step is directed from the upstream side to the downstream side of the gas flow path. Thus, a reaction layer in which the amount of the catalyst gradually increases is formed.
[0022]
According to this fuel cell manufacturing method, the amount of catalyst gradually increases from the upstream side to the downstream side of the gas flow path, that is, the gas pressure increases from the upstream side of the gas flow path where the gas pressure is high and the reaction efficiency is high. A reaction layer is formed in which the amount of catalyst gradually increases toward the downstream side of the gas flow path where the pressure decreases and the reaction efficiency is low. Therefore, it is possible to easily manufacture a high output fuel cell in which the reaction efficiency in the reaction layer is kept uniform.
[0023]
Also, in the fuel cell manufacturing method of the present invention, at least one of the first reaction layer forming step and the second reaction layer forming step has a gas flow more than the amount of the catalyst on the gas flow path. A reaction layer having a large amount of the catalyst on a portion where no path is formed is formed.
[0024]
According to this fuel cell manufacturing method, the reaction layer is formed in which the amount of catalyst on the portion where the gas channel is not formed is larger than the amount of catalyst on the gas channel. Therefore, by forming a reaction layer with a large amount of catalyst in the part where the reaction gas diffusion resistance is higher than the part where the reaction gas diffusion resistance is low, it is easy to achieve a high-power fuel cell with uniform overall reaction efficiency. Can be manufactured.
[0025]
In the fuel cell manufacturing method according to the present invention, at least one of the first reaction layer formation step and the second reaction layer formation step is performed such that the amount of the catalyst from the central portion toward the peripheral portion. It is characterized in that a reaction layer in which the gradual increase is formed.
[0026]
According to this fuel cell manufacturing method, the reaction layer in which the amount of the catalyst gradually increases from the central portion toward the peripheral portion is formed. Therefore, by forming a reaction layer in which the amount of catalyst gradually increases from the central part where the temperature is high and the reaction efficiency is high toward the peripheral part where the temperature is low and the reaction efficiency is low, the high output with which the overall reaction efficiency becomes uniform This fuel cell can be easily manufactured.
[0027]
An electronic apparatus according to the present invention includes the fuel cell according to any one of claims 1 to 5 as a power supply source. An electronic apparatus according to the present invention includes a fuel cell manufactured by the manufacturing method according to any one of claims 6 to 10 as a power supply source. According to this electronic apparatus, it is possible to provide clean energy appropriately considering the global environment as a power supply source.
[0028]
An automobile according to the present invention includes the fuel cell according to any one of claims 1 to 5 as a power supply source. An automobile according to the present invention includes a fuel cell manufactured by the manufacturing method according to any one of claims 6 to 10 as a power supply source. According to this automobile, clean energy appropriately taking into account the global environment can be provided as a power supply source.
[0029]
Moreover, the cogeneration system which concerns on this invention is provided with the fuel cell as described in any one of Claims 1-5 as an energy source. Moreover, the cogeneration system which concerns on this invention is equipped with the fuel cell manufactured by the manufacturing method as described in any one of Claims 6-10 as an energy source. According to this cogeneration system, by providing a high-output fuel cell as an energy source, it is possible to realize a cogeneration system having high environmental performance and high efficiency by clean energy appropriately considering the global environment.
[0030]
DETAILED DESCRIPTION OF THE INVENTION
A method for manufacturing a fuel cell according to an embodiment of the present invention will be described below. FIG. 1 is a diagram illustrating an example of a configuration of a fuel cell production line that performs a fuel cell production process according to an embodiment. As shown in FIG. 1, the fuel cell production line includes a discharge device 20a to 20m used in each step, a belt conveyor BC1 connecting the discharge devices 20a to 20k, a belt conveyor BC2 connecting the discharge devices 20l and 20m, The driving device 58 drives the belt conveyors BC1 and BC2, the assembling device 60 that assembles the fuel cell, and the control device 56 that controls the entire fuel cell production line.
[0031]
The discharge devices 20a to 20k are arranged in a line at a predetermined interval along the belt conveyor BC1, and the discharge devices 20l and 20m are arranged in a line at a predetermined interval along the belt conveyor BC2. The control device 56 is connected to each of the discharge devices 20a to 20k, the drive device 58, and the assembly device 60. The belt conveyor BC1 is driven based on a control signal from the control device 56, and a fuel cell substrate (hereinafter simply referred to as "substrate") is conveyed to each of the discharge devices 20a to 20k, and in each of the discharge devices 20a to 20k. Process. Similarly, the belt conveyor BC2 is driven based on a control signal from the control device 56, the substrate is conveyed to the discharge devices 20l and 20m, and processing in the discharge devices 20l and 20m is performed. Further, in the assembling apparatus 60, the fuel cell is assembled by the substrates carried in via the belt conveyor BC1 and the belt conveyor BC2 based on the control signal from the control apparatus 56.
[0032]
In this fuel cell production line, a process of applying a resist solution for forming a gas flow path to the substrate is performed in the discharge device 20a, and an etching process for forming the gas flow path is performed in the discharge device 20b. In the discharge device 20c, a process of applying a supporting carbon for supporting the current collecting layer is performed. In addition, the discharge device 20d performs a process for forming a current collecting layer, the discharge device 20e performs a process for forming a gas diffusion layer, and the discharge device 20f performs a process for forming a reaction layer. In the apparatus 20g, a process for forming an electrolyte membrane is performed. Further, a process for forming a reaction layer is performed in the discharge device 20h, a process for forming a gas diffusion layer is performed in the discharge device 20i, and a process for forming a current collecting layer is performed in the discharge device 20j. In the apparatus 20k, a process of applying the supporting carbon is performed.
[0033]
Further, in the discharge device 20l, a process of applying a resist solution for forming a gas flow path to the substrate is performed, and in the discharge apparatus 20m, an etching process for forming the gas flow path is performed. When processing is performed on the first substrate in the discharge devices 20a to 20k, in the discharge devices 20l and 20m, processing for forming a gas flow path is performed on the second substrate.
[0034]
FIG. 2 is a diagram schematically showing the configuration of an ink jet type ejection device 20a used when manufacturing a fuel cell according to an embodiment of the present invention. The ejection device 20a includes an inkjet head 22 that ejects an ejected material onto a substrate. The ink jet head 22 includes a head main body 24 and a nozzle forming surface 26 on which a large number of nozzles for discharging discharged matter are formed. When a discharge channel, that is, a gas flow path for supplying a reaction gas is formed on the substrate from the nozzle of the nozzle forming surface 26, a resist solution applied to the substrate is discharged. Further, the ejection device 20a includes a table 28 on which a substrate is placed. The table 28 is installed to be movable in a predetermined direction, for example, the X-axis direction, the Y-axis direction, and the Z-axis direction. Further, the table 28 moves in the direction along the X axis as indicated by an arrow in the drawing, so that the substrate conveyed by the belt conveyor BC1 is placed on the table 28 and taken into the discharge device 20a.
[0035]
The ink jet head 22 is connected to a tank 30 containing a resist solution that is a discharge product discharged from a nozzle formed on the nozzle forming surface 26. In other words, the tank 30 and the inkjet head 22 are connected by a discharge material transport pipe 32 that transports the discharge material. In addition, the discharge material transport pipe 32 includes a discharge material flow path portion ground joint 32a and a head portion bubble elimination valve 32b for preventing charging in the flow path of the discharge material transport pipe 32. This head part bubble elimination valve 32b is used when suctioning the discharged substance in the inkjet head 22 with the suction cap 40 mentioned later. That is, when sucking the discharged material in the ink jet head 22 by the suction cap 40, the head part bubble elimination valve 32b is closed so that the discharged material does not flow from the tank 30 side. Then, when suction is performed with the suction cap 40, the flow rate of the suctioned product is increased, and the bubbles in the inkjet head 22 are quickly discharged.
[0036]
In addition, the discharge device 20a has a liquid level control sensor 36 for controlling the amount of discharged material stored in the tank 30, that is, the height of the liquid level 34a of the resist solution stored in the tank 30. It has. The liquid level control sensor 36 keeps the height difference h (hereinafter referred to as the water head value) between the tip end portion 26a of the nozzle forming surface 26 of the inkjet head 22 and the liquid level 34a in the tank 30 within a predetermined range. Take control. By controlling the height of the liquid level 34a, the discharge 34 in the tank 30 is sent to the inkjet head 22 with a pressure within a predetermined range. Then, the ejected material 34 can be stably ejected from the inkjet head 22 by sending the ejected material 34 at a pressure within a predetermined range.
[0037]
In addition, a suction cap 40 that sucks the ejected matter in the nozzles of the inkjet head 22 is disposed at a certain distance from the nozzle formation surface 26 of the inkjet head 22. The suction cap 40 is configured to be movable in the direction along the Z axis indicated by an arrow in FIG. 2, and is in close contact with the nozzle forming surface 26 so as to surround a plurality of nozzles formed on the nozzle forming surface 26. In addition, a sealed space is formed between the nozzle forming surface 26 and the nozzle can be blocked from outside air. In addition, the suction of the ejected matter in the nozzle of the inkjet head 22 by the suction cap 40 is in a state where the inkjet head 22 is not ejecting the ejected material 34, for example, the inkjet head 22 is retracted to a retracted position or the like. This is performed when the table 28 is retracted to a position indicated by a broken line.
[0038]
A flow path is provided below the suction cap 40, and a suction valve 42, a suction pressure detection sensor 44 for detecting a suction abnormality, and a suction pump 46 including a tube pump are disposed in the flow path. Has been. Further, the discharge 34 sucked by the suction pump 46 and transported through the flow path is accommodated in a waste liquid tank 48.
[0039]
The configuration of the ejection devices 20b to 20m is the same as that of the ejection device 20a, and thus the description thereof will be omitted. However, in the following description, each configuration of the ejection devices 20b to 20m is different in the description of the ejection device 20a. The description will be made using the same reference numerals as those used in the configuration. In addition, in the tank 30 provided in each of the discharge devices 20b to 20m, a discharge material necessary for a predetermined process performed in each of the discharge devices 20b to 20m is accommodated. For example, the discharge material for etching performed when forming the gas flow path is formed in the tank 30 of the discharge device 20b and the discharge device 20m, and the supporting carbon is formed in the tank 30 of the discharge device 20c and the discharge device 20k. In the discharge device 20d and the tank 30 of the discharge device 20j, discharge materials for forming a current collecting layer are respectively stored. Further, the discharge material for forming the gas diffusion layer is in the tank 30 of the discharge device 20e and the discharge device 20i, and the discharge material for forming the reaction layer is in the tank 30 of the discharge device 20f and the discharge device 20h. In the tank 30 of the discharge device 20g, discharge materials for forming the electrolyte membrane are respectively stored. Further, in the tank 30 of the discharge device 20l, the same discharge material as the discharge material for forming a gas flow path with respect to the substrate stored in the tank 30 of the discharge device 20a is stored.
[0040]
Next, a method for manufacturing a fuel cell using the discharge devices 20a to 20m according to the embodiment will be described with reference to the flowchart of FIG. 3 and the drawings.
[0041]
First, a gas flow path for supplying a reaction gas to the substrate is formed (step S10). That is, first, as shown in FIG. 4A, a rectangular flat plate shape, for example, a silicon substrate (first substrate) 2 is conveyed to the discharge device 20a by the belt conveyor BC1. The board | substrate 2 conveyed by belt conveyor BC1 is mounted on the table 28 of the discharge apparatus 20a, and is taken in in the discharge apparatus 20a. In the discharge device 20 a, the resist solution stored in the tank 30 is discharged through the nozzles of the nozzle formation surface 26 and applied to a predetermined position on the upper surface of the substrate 2 placed on the table 28. Here, as shown in FIG. 4B, the resist solution is applied linearly at a predetermined interval from the front direction to the back side in the drawing. That is, in the substrate 2, for example, a portion that forms a gas flow path (first gas flow path) for supplying a first reaction gas containing hydrogen is left, and only the other portions are resisted. The solution is applied.
[0042]
Next, the substrate 2 (see FIG. 4B) on which the resist solution is applied at a predetermined position is conveyed to the discharge device 20b by the belt conveyor BC1, and is placed on the table 28 of the discharge device 20b to be discharged. 20b. In the discharge device 20b, an etching solvent, for example, a hydrofluoric acid aqueous solution, which is used to form a gas flow path accommodated in the tank 30, is discharged through the nozzles of the nozzle forming surface 26, and is then placed on the table 28. It is applied to the entire top surface of the substrate 2 placed on the substrate.
[0043]
Here, since the resist solution is applied to the substrate 2 in a portion other than the portion that forms the gas flow path, the portion where the resist solution is not applied is etched with the hydrofluoric acid aqueous solution, and FIG. As shown, a gas flow path is formed. That is, a gas flow path having a U-shaped cross section extending from one side surface of the substrate 2 to the other side surface is formed. Further, as shown in FIG. 5A, the substrate 2 on which the gas flow path is formed is subjected to resist cleaning in a cleaning apparatus (not shown). Then, as shown in FIG. 5B, the substrate 2 on which the gas flow path is formed is transferred from the table 28 to the belt conveyor BC1, and is conveyed to the discharge device 20c by the belt conveyor BC1.
[0044]
Next, in order to prevent the gas flow path formed on the substrate 2 in step S10 from being blocked by the current collection layer, the support carbon (first support member) that supports the current collection layer is gas flow path. It is applied inside (step S11). That is, first, the substrate 2 conveyed to the discharge device 20c by the belt conveyor BC1 is placed on the table 28 and taken into the discharge device 20c. In the discharge device 20 c, the supporting carbon 4 accommodated in the tank 30 is discharged through the nozzles on the nozzle forming surface 26 and applied to the gas flow path formed on the substrate 2. Here, as the supporting carbon 4, porous carbon having a predetermined size, for example, a particle diameter of about 1 to 5 microns in diameter is used. That is, a porous carbon having a predetermined size is used as the supporting carbon 4 to prevent the gas flow path from being blocked by the current collecting layer and to ensure that the reaction gas can flow through the gas flow path. Used.
[0045]
FIG. 6 is an end view of the substrate 2 to which the supporting carbon 4 is applied. As shown in FIG. 6, by applying the supporting carbon 4 in the gas flow path, the current collecting layer formed on the substrate 2 is prevented from falling into the gas flow path. The substrate 2 coated with the supporting carbon 4 is transferred from the table 28 to the belt conveyor BC1 and is conveyed to the discharge device 20d by the belt conveyor BC1.
[0046]
Next, a current collecting layer (first current collecting layer) for collecting electrons generated by the reaction of the reaction gas is formed on the substrate 2 (step S12). That is, first, the substrate 2 conveyed to the discharge device 20d by the belt conveyor BC1 is placed on the table 28 and taken into the discharge device 20d. In the discharge device 20d, a material for forming the current collecting layer 6 accommodated in the tank 30, for example, a conductive substance such as copper, is placed on the table 28 via the nozzles of the nozzle forming surface 26. Discharge onto the substrate 2. At this time, the conductive material is discharged into a shape that does not hinder diffusion of the reaction gas supplied to the gas flow path, for example, a mesh shape, and the current collecting layer 6 is formed.
[0047]
FIG. 7 is an end view of the substrate 2 on which the current collecting layer 6 is formed. As shown in FIG. 7, the current collecting layer 6 is supported by the supporting carbon 4 in the gas flow path formed on the substrate 2, and is prevented from falling into the gas flow path. In addition, the board | substrate 2 in which the current collection layer 6 was formed is moved to the belt conveyor BC1 from the table 28, and is conveyed by the belt conveyor BC1 to the discharge apparatus 20e.
[0048]
Next, a gas diffusion layer for diffusing the reaction gas supplied through the gas flow path formed in the substrate 2 is formed on the current collecting layer 6 formed in step S12 (step S13). That is, first, the substrate 2 conveyed to the discharge device 20e by the belt conveyor BC1 is placed on the table 28 and taken into the discharge device 20e. In the discharge device 20e, a material for forming the gas diffusion layer 8 accommodated in the tank 30, for example, carbon is discharged onto the current collecting layer 6 through the nozzles of the nozzle forming surface 26, and a gas flow path. A gas diffusion layer 8 is formed for diffusing the reaction gas (first reaction gas) supplied via.
[0049]
FIG. 8 is an end view of the substrate 2 on which the gas diffusion layer 8 is formed. As shown in FIG. 8, for example, carbon having a function as an electrode is discharged onto the current collecting layer 6 to form a gas diffusion layer 8 for diffusing the reaction gas. Here, as the carbon constituting the gas diffusion layer 8, porous carbon is used that is large enough to sufficiently diffuse the reaction gas supplied through the gas flow path. . For example, porous carbon which is smaller than the supporting carbon 4 and has a particle diameter of about 0.1 to 1 micron is used. In addition, the board | substrate 2 with which the gas diffusion layer 8 was formed is moved to the belt conveyor BC1 from the table 28, and is conveyed by the belt conveyor BC1 to the discharge apparatus 20f.
[0050]
Next, a reaction layer (first reaction layer) that reacts based on the reaction gas supplied via the gas flow path formed in the substrate 2 is formed on the gas diffusion layer 8 formed in step S13. (Step S14). That is, the board | substrate 2 conveyed by the belt conveyor BC1 to the discharge apparatus 20f is mounted on the table 28, and is taken in in the discharge apparatus 20f. In the discharge device 20f, a porous carbon (platinum-supporting carbon) carrying a material for forming a reaction layer accommodated in the tank 30, for example, platinum fine particles for a catalyst having a particle diameter of several nanometers to several tens of nanometers. A reaction layer 10 is formed by ejecting a solution containing the solution onto the gas diffusion layer 8 through a nozzle.
[0051]
Here, a solution containing platinum-supporting carbon is discharged more in a portion having a lower reaction efficiency than a portion having a higher reaction efficiency on the gas diffusion layer 8 based on a discharge pattern preset in the discharge device 20f. Layer 10 is formed. For example, the substrate 2 is divided into 9 × 9 square sections, and in each section, the number of drops of the solution containing platinum-carrying carbon is discharged based on the discharge pattern for each section. Is formed.
[0052]
FIG. 9 is a diagram illustrating an example of a discharge pattern for forming the reaction layer 10. As shown in FIG. 9, when the reaction gas is supplied from the direction of the arrow through the gas flow path 4 formed in the substrate 2, the reaction gas is supplied at the inlet side (upstream side) to which the reaction gas is supplied. Since the concentration is high and the gas pressure is high, the reaction occurs even if the amount of the catalyst is small. On the other hand, on the outlet side (downstream side) of the reactive gas, the concentration of the reactive gas is low and the gas pressure is also low. Therefore, in order to react with the same efficiency as the inlet side, more catalyst than the inlet side is required. I need. Therefore, for example, as shown in FIG. 9, a solution containing platinum-supporting carbon is discharged based on a discharge pattern in which the number of droplets gradually increases from 1 to 9 for each section from the upstream side to the downstream side. The reaction layer 10 in which the amount of the catalyst gradually increases from the side toward the downstream side can be formed.
[0053]
FIG. 10 is a diagram illustrating another example of a discharge pattern for forming the reaction layer 10. As shown in FIG. 10, when the reaction gas is supplied through the gas flow path 4 formed in the substrate 2, gas diffusion is performed in the vertically upward direction of the gas flow path 4 (on the gas flow path 4). Reaction resistance of the reaction gas in the layer 8 is small, and a sufficient amount of reaction gas is supplied, so that the reaction occurs even if the amount of catalyst is small. On the other hand, on the part between the gas flow path 4 and the gas flow path 4 (on the part between the gas flow paths 4), the diffusion resistance of the reaction gas in the gas diffusion layer 8 compared to the part on the gas flow path 4. The amount of the catalyst required for the reaction is larger than the portion on the gas flow path 4. Therefore, for example, as shown in FIG. 10, based on a discharge pattern in which the number of liquid droplets discharged onto the gas flow path 4 is 1, and the number of liquid droplets discharged between the gas flow paths 4 is 5. A solution containing platinum-supported carbon can be discharged, and the reaction layer 10 having a larger amount of catalyst can be formed on the portion where the gas flow path 4 is not formed than on the gas flow path 4.
[0054]
FIG. 11 is a diagram illustrating another example of a discharge pattern for forming the reaction layer 10. When the reaction gas supplied through the gas flow path 4 formed on the substrate 2 reacts in the reaction layer 10, the temperature of the central portion of the reaction layer 10 becomes higher than the peripheral portion due to the thermal energy generated by the reaction. . Therefore, the reaction of the reaction gas at the center is promoted and the reaction rate is increased. On the other hand, since the temperature in the peripheral part is lower than that in the central part, a larger amount of catalyst is required than in the central part in order to achieve a reaction rate equivalent to that in the central part. Accordingly, as shown in FIG. 11, by discharging a solution containing platinum-supporting carbon based on a discharge pattern in which the number of droplets of the solution discharged from the central portion toward the peripheral portion is gradually increased, the peripheral portion is discharged from the central portion. The reaction layer 10 in which the amount of the catalyst increases toward the part can be formed.
[0055]
Note that a discharge pattern is set in advance in the discharge device 20f in consideration of the use and usage of the manufactured fuel cell. That is, any one of the patterns shown in FIGS. 9 to 11 described above, a pattern obtained by combining any two patterns of the patterns shown in FIGS. 9 to 11, or a pattern obtained by combining the patterns shown in FIGS. 9 to 11. Any one of the ejection patterns is set in advance.
[0056]
Here, the carbon carrying the platinum fine particles is the same carbon as the carbon constituting the gas diffusion layer 8, that is, the carbon having the same particle diameter and the porous carbon. In addition, after disperse | distributing platinum microparticles | fine-particles by adding a dispersing agent to a solvent and apply | coating on the gas diffusion layer 8, the dispersing agent is removed by heating the board | substrate 2 to 200 degreeC in nitrogen atmosphere, for example, The reaction layer 10 may be formed. In this case, the reaction layer 10 is formed by depositing platinum fine particles as a catalyst on the surface of carbon constituting the gas diffusion layer 8.
[0057]
FIG. 12 is an end view of the substrate 2 on which the reaction layer 10 is formed. As shown in FIG. 12, the reaction layer 10 is formed by applying carbon carrying platinum fine particles as a catalyst onto the gas diffusion layer 8. In FIG. 12, only platinum fine particles are shown as the reaction layer 10 so that the reaction layer 10 and the gas diffusion layer 8 can be easily identified. In the following figures, the reaction layer is shown in the same manner as in FIG. The substrate 2 on which the reaction layer 10 is formed is transferred from the table 28 to the belt conveyor BC1, and is conveyed to the discharge device 20g by the Belcoton bear BC1.
[0058]
Next, an electrolyte membrane such as an ion exchange membrane is formed on the reaction layer 10 formed in step S14 (step S15). That is, first, the substrate 2 conveyed to the discharge device 20g by the belt conveyor BC1 is placed on the table 28 and taken into the discharge device 20g. In the discharge device 20g, a material for forming an electrolyte membrane accommodated in the tank 30, for example, a material in which a ceramic solid electrolyte such as Nafion (registered trademark), tungstophosphoric acid, molybdophosphoric acid, etc. is adjusted to a predetermined viscosity, The electrolyte membrane 12 is formed by discharging onto the reaction layer 10 through the nozzle of the nozzle forming surface 26.
[0059]
FIG. 13 is an end view of the substrate 2 on which the electrolyte membrane 12 is formed. As shown in FIG. 13, an electrolyte membrane 12 having a predetermined thickness is formed on the reaction layer 10. The substrate 2 on which the electrolyte membrane 12 is formed is transferred from the table 28 to the belt conveyor BC1, and is conveyed to the discharge device 20h by the belt conveyor BC1.
[0060]
Next, a reaction layer (second reaction layer) is formed on the electrolyte membrane 12 formed in step S15 (step S16). That is, the substrate 2 transported to the discharge device 20h by the belt conveyor BC1 is placed on the table 28 and taken into the discharge device 20h. In the discharge device 20h, a solution containing carbon carrying platinum fine particles as a catalyst is discharged by a process similar to the process performed in the discharge device 20f to form the reaction layer 10 '.
[0061]
FIG. 14 is an end view of the substrate 2 on which the reaction layer 10 ′ is formed on the electrolyte membrane 12. As shown in FIG. 14, a reaction layer 10 ′ is formed by applying carbon carrying platinum fine particles as a catalyst onto the electrolyte membrane 12. Here, the reaction layer 10 ′ is a layer that reacts based on a second reaction gas, for example, a reaction gas containing oxygen.
[0062]
Next, a gas diffusion layer for diffusing the reaction gas (second reaction gas) is formed on the reaction layer 10 ′ formed in step S16 (step S17). That is, the substrate 2 on which the reaction layer 10 ′ is formed is transported to the discharge device 20 i by the belt conveyor BC 1, and the discharge device 20 i is a porous material having a predetermined particle diameter by the same process as that performed in the discharge device 20 e. The carbon is applied to form a gas diffusion layer 8 ′.
[0063]
FIG. 15 is an end view of the substrate 2 on which a gas diffusion layer is formed on the reaction layer 10 ′. As shown in FIG. 15, gas diffusion layer 8 'is formed by applying porous carbon on reaction layer 10'.
[0064]
Next, a current collecting layer (second current collecting layer) is formed on the gas diffusion layer 8 'formed in step S17 (step S18), and support for supporting the current collecting layer on the current collecting layer is performed. Carbon for application (second support member) is applied (step S19). That is, the substrate 2 transported to the discharge device 20j by the belt conveyor BC1 is placed on the table 28 and taken into the discharge device 20j, and the current collecting layer 6 is processed by the same processing as that performed in the discharge device 20d. 'Is formed on the gas diffusion layer 8'. Further, the substrate 2 transported to the discharge device 20k by the belt conveyor BC1 is placed on the table 28 and taken into the discharge device 20k, and the supporting carbon 4 is processed by the same processing as that performed in the discharge device 20c. 'Is applied. The substrate 2 coated with the supporting carbon 4 ′ is transferred from the table 28 to the belt conveyor BC 1 and conveyed to the assembling apparatus 60.
[0065]
FIG. 16 is an end view of the substrate 2 in which the current collecting layer 6 ′ and the supporting carbon 4 ′ are applied on the gas diffusion layer 8 ′. As shown in FIG. 16, the current collecting layer 6 ′ is formed by the process of step S18 described above, and the supporting carbon 4 ′ is applied by the process of step S19 described above. Here, the supporting carbon 4 ′ is applied in the same manner as the supporting carbon 4, that is, along the gas flow path formed in the substrate 2.
[0066]
Next, the fuel cell is assembled by placing the substrate (second substrate) on which the gas flow path is formed on the substrate (first substrate) coated with the supporting carbon in step S19 (step S20). That is, in the assembling apparatus 60, by placing the substrate 2 ′ (second substrate) carried in via the belt conveyor BC2 on the substrate 2 (first substrate) carried in via the belt conveyor BC1, Assemble the fuel cell. Here, a second gas flow path is formed on the substrate 2 ′ separately from the processing in the above-described Steps S10 to S19. That is, in the discharge device 20l and the discharge device 20m, the second gas flow path is formed by the same process as the process performed by the discharge device 20a and the discharge device 20b. Therefore, the U-shaped gas channel extending from one side surface to the other side surface formed on the substrate 2 is parallel to the U-shaped gas channel formed on the substrate 2 '. As described above, the substrate 2 'is arranged to assemble the fuel cell, thereby completing the manufacture of the fuel cell.
[0067]
FIG. 17 is an end view of the manufactured fuel cell. As shown in FIG. 17, the substrate 2 ′ on which the second gas flow path is formed is disposed at a predetermined position on the substrate 2, and the first gas flow path is formed on the first substrate. The manufacture of the fuel cell in which the first reaction gas is supplied and the second reaction gas is supplied through the second gas flow path formed in the second substrate is completed.
[0068]
The fuel cell manufactured by the above-described manufacturing method can be incorporated as an electric power supply source in an electronic device, particularly a portable electronic device such as a mobile phone. That is, according to the fuel cell manufacturing method described above, a small fuel cell can be easily manufactured by using the discharge device, and therefore, for example, it can be incorporated into a small electronic device such as a mobile phone as a power supply source. it can.
[0069]
In the fuel cell according to this embodiment, the amount of catalyst differs depending on the location in the reaction layer. That is, a place where the reaction efficiency is high, for example, an inlet side of the gas flow path, a portion on the gas flow path, or a place where the reaction efficiency is lower than the central part of the reaction layer, such as the outlet side of the gas flow path, between the gas flow paths More catalyst is applied to the upper part or the periphery of the reaction layer. Accordingly, it is possible to prevent a difference in reaction efficiency in the reaction layer and to maintain a uniform reaction efficiency as a whole, so that the output of the fuel cell can be increased.
[0070]
According to the method of manufacturing a fuel cell according to this embodiment, the reaction layer is formed using an ink jet type discharge device. Accordingly, a reaction layer can be formed by applying a predetermined amount of catalyst at a predetermined position, and the reaction efficiency in the fuel cell can be kept uniform, and a high output fuel cell can be easily manufactured.
[0071]
Further, according to the fuel cell manufacturing method according to this embodiment, the upstream side of the gas flow path, that is, the reaction gas inlet side has a small amount of catalyst, and the downstream side of the gas flow path, that is, the reaction gas flow rate. On the outlet side, a large amount of catalyst can be applied to form a reaction layer on the gas diffusion layer. That is, a small amount of catalyst is applied to the inlet side of the gas flow path where the amount of the catalyst required for the reaction is small and the concentration and gas pressure of the reaction gas is high, and the concentration of the reaction gas and the gas are large. A large amount of catalyst can be applied to the outlet side of the gas flow path having a low pressure. Therefore, compared with the case where the catalyst is uniformly applied to the entire reaction layer, the output of the entire fuel cell is increased by maintaining the overall reaction efficiency even when the same amount of catalyst is used. Can do.
[0072]
In addition, according to the method of manufacturing a fuel cell according to this embodiment, a reaction layer is formed in which the amount of catalyst between the gas passages where the gas passage is not formed is larger than the amount of the catalyst on the gas passage. can do. That is, it is possible to apply a small amount of catalyst to the portion where the reaction gas diffusion resistance is low and close to the gas flow channel, and to apply a large amount of catalyst to the portion where the reaction gas diffusion resistance is large. . Therefore, since the reaction efficiency in the entire reaction layer can be kept uniform, a high-power fuel cell can be easily manufactured.
[0073]
Also, according to the method of manufacturing a fuel cell according to this embodiment, the reaction layer can be formed by applying the catalyst so that the gas diffusion layer has a small central portion and a large peripheral portion. That is, the reaction is promoted in the central part where the temperature is high based on the thermal energy generated by the reaction, so the amount of catalyst is small, and in the peripheral part where the temperature is low, a reaction layer with a large amount of catalyst is formed. Can do. Therefore, it is possible to prevent a difference in reaction efficiency in the reaction layer, keep the reaction efficiency uniform, and easily manufacture a high-power fuel cell.
[0074]
In the fuel cell manufacturing method according to the above-described embodiment, an inkjet discharge device is used in all the steps. However, only in the process of forming the reaction layer, the fuel cell is manufactured using the inkjet discharge device. May be manufactured.
[0075]
In the fuel cell manufacturing method according to the above-described embodiment, a predetermined number of droplets are discharged into a predetermined section based on a predetermined discharge pattern created in advance. The amount of the catalyst discharged for each section may be changed by changing the amount of the liquid droplets. That is, by changing the drive waveform for driving the ink jet type discharge device for each section, the amount of liquid droplets containing platinum-carrying carbon discharged through the nozzle of the discharge apparatus is changed and discharged for each section. The amount of catalyst to be produced may be adjusted.
[0076]
In the fuel cell manufacturing method according to the above-described embodiment, a small fuel cell is manufactured. However, a large fuel cell may be manufactured by stacking a plurality of fuel cells. That is, as shown in FIG. 18, a gas channel is further formed on the back surface of the substrate 2 ′ of the manufactured fuel cell, and the above-described fuel cell is manufactured on the back surface of the substrate 2 ′ on which the gas channel is formed. A large fuel cell may be manufactured by forming a gas diffusion layer, a reaction layer, an electrolyte membrane and the like and laminating the fuel cells in the same manner as the manufacturing process in the method. Thus, when a large-sized fuel cell is manufactured, for example, it can be used as a power supply source of an electric vehicle, and a clean energy vehicle appropriately considering the global environment can be provided.
[0077]
Moreover, you may use the manufactured large sized fuel cell as an energy source of the cogeneration system which takes out and provides multiple types of energy, such as heat and electricity, from one energy source. In a fuel cell, since the amount of heat energy generated during power generation is large, a highly efficient cogeneration system for home use or business use can be realized. In addition, since the fuel cell does not emit toxic substances or the like during power generation, it is possible to realize a cogeneration system with high environmental characteristics in consideration of the global environment.
[0078]
According to the fuel cell of the present invention, in at least one of the first reaction layer and the second reaction layer, the reaction layer has a different amount of catalyst depending on the location. Therefore, for example, the amount of the catalyst in the reaction layer can be adjusted in consideration of the diffusion state of the reaction gas in the fuel cell, and the reaction efficiency in the entire fuel cell can be kept uniform to increase the output of the fuel cell.
[0079]
According to the method of manufacturing a fuel cell according to the present invention, at least one of the first reaction layer formation step and the second reaction layer formation step is a reaction in which the amount of catalyst varies depending on the location using the discharge device. Forming a layer. Therefore, by using the discharge device, it is possible to apply a predetermined amount of catalyst to a predetermined location, easily form a reaction layer having a different amount of catalyst depending on the location, and manufacture a high output fuel cell.
[0080]
According to the electronic device according to the present invention, the fuel cell according to the present invention or the fuel cell manufactured by the method for manufacturing the fuel cell according to the present invention is used as the power supply source. Therefore, for example, in an electronic device such as a mobile phone, there is no fear that a toxic substance or the like flows out even when discarded. In addition, according to the automobile of the present invention, the fuel cell manufactured by the fuel cell according to the present invention or the fuel cell manufacturing method according to the present invention is used as the power supply source. Therefore, for example, by using a fuel cell as a power supply source in an electric vehicle, an automobile that does not emit exhaust gas can be provided. Therefore, it is possible to realize clean energy that takes the global environment into consideration. Further, according to the cogeneration system according to the present invention, the fuel cell according to the present invention or the fuel cell manufactured by the method for manufacturing the fuel cell according to the present invention is provided as an energy source. Therefore, it is possible to realize a cogeneration system with high environmental efficiency and high efficiency.
[Brief description of the drawings]
FIG. 1 is a diagram showing an example of a production line for a fuel cell according to an embodiment.
FIG. 2 is a schematic diagram of an ink jet type ejection device according to an embodiment.
FIG. 3 is a flowchart of a method for manufacturing a fuel cell according to an embodiment.
FIG. 4 is a diagram illustrating a gas flow path forming process according to an embodiment.
FIG. 5 is another diagram for explaining a gas flow path forming process according to the embodiment;
FIG. 6 is an end view of the substrate in the manufacturing process of the fuel cell according to the embodiment.
FIG. 7 is an end view of the substrate in the manufacturing process of the fuel cell according to the embodiment.
FIG. 8 is an end view of the substrate in the process of manufacturing the fuel cell according to the embodiment.
FIG. 9 is a diagram illustrating a reaction layer forming process according to an embodiment.
FIG. 10 is a diagram illustrating a reaction layer forming process according to an embodiment.
FIG. 11 is a diagram illustrating a reaction layer forming process according to an embodiment.
FIG. 12 is an end view of the substrate in the manufacturing process of the fuel cell according to the embodiment.
FIG. 13 is an end view of the substrate in the process of manufacturing the fuel cell according to the embodiment.
FIG. 14 is an end view of the substrate in the process of manufacturing the fuel cell according to the embodiment.
FIG. 15 is an end view of the substrate in the manufacturing process of the fuel cell according to the embodiment.
FIG. 16 is an end view of the substrate in the manufacturing process of the fuel cell according to the embodiment.
FIG. 17 is an end view of the substrate of the fuel cell according to the embodiment.
18 is a diagram of a large fuel cell in which fuel cells according to an embodiment are stacked. FIG.
[Explanation of symbols]
2, 2 '... substrate, 4, 4' ... supporting carbon, 6, 6 '... current collecting layer, 8, 8' ... gas diffusion layer, 10, 10 '... reaction layer, 12 ... electrolyte membrane, 20a-20m ... Discharge device, BC1, BC2 ... Belt conveyor.

Claims (16)

A first substrate on which a first gas flow path for supplying a first reaction gas is formed;
A first current collecting layer formed on the first substrate side;
A first gas diffusion layer formed on the first substrate side;
A first reaction layer formed on the first substrate side;
A second substrate on which a second gas flow path for supplying a second reaction gas is formed;
A second current collecting layer formed on the second substrate side;
A second gas diffusion layer formed on the second substrate side;
A second reaction layer formed on the second substrate side;
A fuel cell comprising an electrolyte membrane formed between the first reaction layer and the second reaction layer,
The fuel cell, wherein at least one of the first reaction layer and the second reaction layer, the reaction layer has a different amount of catalyst depending on a location. In at least one of the first reaction layer and the second reaction layer, the amount of the catalyst in the portion with low reaction efficiency is larger than the amount of the catalyst in the portion with high reaction efficiency. The fuel cell according to claim 1. The amount of the catalyst gradually increases from the upstream side to the downstream side of the gas flow path in at least one of the first reaction layer and the second reaction layer. The fuel cell as described. In at least one of the first reaction layer and the second reaction layer, the amount of the catalyst on the portion where the gas flow path is not formed is larger than the amount of the catalyst on the gas flow path. The fuel cell according to claim 1. 2. The fuel cell according to claim 1, wherein in at least one of the first reaction layer and the second reaction layer, the amount of the catalyst gradually increases from a central portion toward a peripheral portion. . A first gas flow path forming step of forming a first gas flow path for supplying a first reaction gas on a first substrate;
A first current collecting layer forming step of forming a first current collecting layer that collects electrons generated by the reaction of the first reaction gas supplied through the first gas flow path;
A first reaction layer forming step of forming a first reaction layer for performing a reaction based on the first reaction gas supplied through the first gas flow path;
An electrolyte membrane forming step for forming an electrolyte membrane;
A second gas flow path forming step of forming a second gas flow path for supplying a second reaction gas on the second substrate;
A second current collecting layer forming step of forming a second current collecting layer for supplying electrons necessary for the reaction of the second reaction gas supplied via the second gas flow path;
A fuel cell manufacturing method including a second reaction layer forming step of forming a second reaction layer that performs a reaction based on the second reaction gas supplied through the second gas flow path.
At least one of the first reaction layer forming step and the second reaction layer forming step forms a reaction layer in which the amount of catalyst differs depending on the location using a discharge device. Manufacturing method. At least one of the first reaction layer forming step and the second reaction layer forming step has a larger amount of the catalyst in a portion with a lower reaction efficiency than a portion of the catalyst in a portion with a higher reaction efficiency. The method for producing a fuel cell according to claim 6, wherein a reaction layer is formed. At least one of the first reaction layer formation step and the second reaction layer formation step forms a reaction layer in which the amount of the catalyst gradually increases from the upstream side to the downstream side of the gas flow path. The method of manufacturing a fuel cell according to claim 6. At least one of the first reaction layer formation step and the second reaction layer formation step is performed by the catalyst on the portion where the gas flow path is not formed more than the amount of the catalyst on the gas flow path. 7. The method of manufacturing a fuel cell according to claim 6, wherein a reaction layer having a large amount is formed. At least one of the first reaction layer forming step and the second reaction layer forming step forms a reaction layer in which the amount of the catalyst gradually increases from the central portion toward the peripheral portion. A method for producing a fuel cell according to claim 6. An electronic apparatus comprising the fuel cell according to any one of claims 1 to 5 as a power supply source. An electronic apparatus comprising a fuel cell manufactured by the manufacturing method according to claim 6 as a power supply source. An automobile comprising the fuel cell according to any one of claims 1 to 5 as a power supply source. An automobile comprising the fuel cell manufactured by the manufacturing method according to any one of claims 6 to 10 as a power supply source. A cogeneration system comprising the fuel cell according to any one of claims 1 to 5 as an energy source. A cogeneration system comprising a fuel cell manufactured by the manufacturing method according to any one of claims 6 to 10 as an energy source.

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