JP2014222618A - Manufacturing method, evaluation method, and evaluation device for fuel cell - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a technique for improving the accuracy of an evaluation test about the drainage of a fuel cell.SOLUTION: A fuel cell evaluation device 100 supplies a reaction gas to a test laminate TS in which a plurality of single cells 10 are arranged in layers, and causes each single cell 10 to generate power. The fuel cell evaluation device 100 exerts evaluating operation control in which while the operating temperature of the test laminate TS is maintained at low temperature T, the decrease and increase of current in the test laminate TS is repeated. The fuel cell evaluating device 100 obtains the power output from each single cell 10 during the evaluating operation control. Based on change in the output power, the device 100 determines the quality of the drainage of each single cell 10.

Description

  The present invention relates to a fuel cell.

  In a polymer electrolyte fuel cell (hereinafter, also simply referred to as “fuel cell”), a large amount of water is generated in the interior by a power generation reaction. However, in a fuel cell, if the amount of water in the interior is excessive, water may accumulate in the reaction gas flow path, impeding the flow of the reaction gas and reducing the power generation performance, so-called flooding may occur. Arise. For this reason, it is required that a proper drainage is ensured in the reaction gas flow path of the fuel cell in order to suppress the occurrence of flooding.

  Conventionally, techniques for evaluating performance including drainage of fuel cells have been proposed (Patent Documents 1 and 2 below). In the fuel cell system described in Patent Document 1, the cell voltage is measured after the fuel cell stack is cooled to a temperature lower than the temperature during normal operation in order to detect cells that are flooded. Moreover, in the fuel cell evaluation system described in Patent Document 2, the generated water is retained in the fuel cell to reproduce a disadvantageous situation for power generation, and then the fuel cell is caused to generate power with a lower concentration of hydrogen than usual. Evaluate the performance of the fuel cell.

JP 2008-071637 A JP 2007-149443 A

  Incidentally, a decrease in the power generation performance of the fuel cell due to the low drainage of the fuel cell may be detected after the fuel cell has been operated for a long time (for example, about several hundred hours). Therefore, conventionally, it has been required to shorten the operation time of the fuel cell for verifying the drainage property of the fuel cell while ensuring the detection accuracy of the low drainage property of the fuel cell.

  According to the techniques of Patent Document 1 and Patent Document 2, since the drainage performance of the fuel cell is verified under operating conditions in which flooding is likely to occur, the detection accuracy of the low drainage performance of the fuel cell is improved. However, neither of Patent Documents 1 and 2 considers reducing the operating time of the fuel cell required until the low drainage of the fuel cell is detected.

  As described above, there is still room for improvement in the technology for verifying and evaluating the drainage of the fuel cell. Conventionally, in the technology for verifying and evaluating the drainage performance of a fuel cell, it has been required to reduce the size of the device, improve the usability, and facilitate the manufacture. In addition, the method for evaluating the drainage of fuel cells has been required to be simplified and simplified, cost reduction and resource saving of the devices and methods, and there is still room for improvement.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following forms.

[1] According to one aspect of the present invention, a method for manufacturing a fuel cell is provided. The manufacturing method includes: (a) supplying a reaction gas to a power generation body to generate power; and executing a current fluctuation process for repeatedly increasing and decreasing a current output to the power generation body; and (b) the current fluctuation. Measuring the output of the power generator during execution of the process; and (c) determining whether the power generator is acceptable based on a change in the output of the power generator during execution of the current variation process; And a step of constructing a fuel cell using the power generator that was judged good in the step (c). According to the manufacturing method of this embodiment, it is possible to shorten the detection time of the power generator with low drainage. Therefore, it is possible to efficiently produce a power generator that ensures drainage and a fuel cell using the power generator.

[2] In the manufacturing method of the above aspect, the step (a) performs the current variation process while controlling the temperature of the power generation body to a predetermined temperature lower than a normal operating temperature of the fuel cell. It may be. According to the manufacturing method of this embodiment, since the power generator with low drainage can be detected with high accuracy, a fuel cell with high drainage can be manufactured.

[3] In the manufacturing method of the above aspect, in the current variation process of the step (a), when the current output to the power generator is decreased, the flow rate of the reaction gas supplied to the power generator is decreased. A process of increasing the flow rate of the reaction gas supplied to the power generator when increasing the current output to the power generator may be included. According to the manufacturing method of this aspect, since the flow rate of the reaction gas during the current variation process varies in accordance with the cycle of increasing or decreasing the output current of the power generation body, it depends on the flow of the reaction gas in the power generation body during the current variation process. Moisture flow becomes discontinuous. Therefore, a drop in the drainage performance of the power generation body appears significantly during the current fluctuation process, and the evaluation accuracy of the drainage performance of the power generation body is improved.

[4] In the manufacturing method according to the above aspect, the current variation processing periodically sets a current value of the power generator, a predetermined first value, and a predetermined second value smaller than the first value; It may be a step of changing alternately. According to the manufacturing method of this embodiment, it is possible to accurately detect the tendency of the change in the output of the fuel cell during the current fluctuation process, and it is possible to improve the detection accuracy of the power generator with low drainage.

[5] In the manufacturing method of the above aspect, in the step (c), in the current variation process, the power generator when the current to be output to the power generator is increased n (n is an arbitrary natural number) times And the current output to the power generator is determined based on the difference between the output of the power generator when m is increased (m is a natural number greater than n) times. It may be a process. According to the manufacturing method of this aspect, since the change in the output of the power generation body during the current fluctuation process can be easily verified, the detectability of the power generation body with low drainage is improved.

[6] According to another aspect of the present invention, a method for evaluating a power generator constituting a fuel cell is provided. The evaluation method includes: (a) supplying a reactive gas to the power generation body to generate power, and executing a current fluctuation process for repeatedly increasing and decreasing the current output to the power generation body; (b) the current Measuring the output of the power generation body during execution of fluctuation processing; and (c) determining whether the power generation body is good or not based on a change in the output of the power generation body during execution of the current fluctuation processing. Prepare. According to this form of the evaluation method, a power generator with low drainage can be detected in a relatively short time.

[7] According to another aspect of the present invention, an evaluation apparatus for a power generator constituting a fuel cell is provided. The evaluation apparatus includes: a reaction gas supply unit that supplies a reaction gas to the power generation body; a current control unit that controls a current to be output to the power generation body; a measurement unit that measures an output of the power generation body; and the reaction gas While controlling the supply unit to supply the reactive gas to the power generation body, the current control unit is controlled to execute current fluctuation processing for repeating the increase and decrease of the current output to the power generation body, and the current fluctuation An evaluation control unit that determines the quality of the power generator based on a change in the output of the power generator measured by the measurement unit during execution of the process.

  A plurality of constituent elements of each aspect of the present invention described above are not indispensable, and some or all of the effects described in the present specification are to be solved to solve part or all of the above-described problems. In order to achieve the above, it is possible to appropriately change, delete, replace with another new component, and partially delete the limited contents of some of the plurality of components. In order to solve part or all of the above-described problems or to achieve part or all of the effects described in this specification, technical features included in one embodiment of the present invention described above. A part or all of the technical features included in the other aspects of the present invention described above may be combined to form an independent form of the present invention.

  The present invention can be implemented in various forms other than the above. For example, a manufacturing method, a manufacturing apparatus, an evaluation method, an evaluation apparatus, a computer program for realizing these methods, a computer program for controlling those apparatuses, and a temporary recording of these computer programs It can be realized in the form of a non-recording medium or the like.

Process drawing which shows the procedure of the manufacturing process of a fuel cell. Schematic which shows the structure of a single cell. Schematic which shows the structure of a fuel cell evaluation apparatus. Explanatory drawing which shows the procedure of the evaluation test of the single cell in a fuel cell evaluation apparatus. Explanatory drawing for demonstrating the operation control for evaluating the drainage property of a single cell. Explanatory drawing which shows the time change of the measured value of the output voltage of a single cell during the operation control for evaluation. Explanatory drawing which shows shortening of the detection time of the drainage fall by operation control for evaluation. Explanatory drawing for demonstrating the method of the quality determination of a single cell. Explanatory drawing for demonstrating the driving control for evaluation as a modification.

A. Embodiment:
FIG. 1 is a process diagram showing a procedure of a manufacturing process of a fuel cell as a first embodiment of the present invention. In the present embodiment, a polymer electrolyte fuel cell (hereinafter also referred to as “fuel cell stack”) having a stack structure in which a plurality of single cells that generate power upon receiving supply of oxygen and hydrogen as reaction gases are stacked and fastened. Is manufactured. In step S10, a plurality of single cells are prepared. The configuration of the single cell will be described later.

  In step S20, an evaluation test is performed on the performance of each single cell prepared in step S10. In addition, in this embodiment, the evaluation test which determines the quality about especially the drainage performance of each single cell is performed (details are mentioned later). In step S30, in the evaluation test in step S20, single cells that have been determined to be negative are excluded, and only single cells that have been determined to be good are stacked. Then, the single cell stack is sandwiched between end plates and fastened by a fastening member to form a fuel cell stack.

  FIG. 2 is a schematic cross-sectional view showing the configuration of a single cell constituting the fuel cell stack. The single cell 10 includes a membrane electrode assembly 5 that is a power generation body, two separators 6, and a seal portion 7. The membrane electrode assembly 5 includes an electrolyte membrane 1 and electrodes 2 disposed on both sides thereof. The electrolyte membrane 1 is a fluororesin-based ion exchange membrane that exhibits good proton conductivity in a wet state, and is made of, for example, Nafion (registered trademark).

  Each electrode 2 includes a catalyst layer 2c and a gas diffusion layer 2g. The catalyst layer 2 c is disposed on the surface of the electrolyte membrane 1. The catalyst layer 2c is configured as a thin film including conductive particles (for example, platinum-supported carbon) supporting a catalyst that promotes a fuel cell reaction, and an electrolyte resin similar to the electrolyte membrane 1, and has gas diffusibility and proton conductivity. Have sex.

  The gas diffusion layer 2g is laminated on each catalyst layer 2c, and diffuses the reaction gas throughout the catalyst layer 2c. The gas diffusion layer 2g is constituted by a porous base material having conductivity and gas diffusibility, such as carbon fiber and graphite fiber. A water repellent layer such as a microporous layer (MPL) may be provided on the surface of the gas diffusion layer 2g on the side in contact with the catalyst layer 2c.

  The separator 6 is composed of a dense plate-like base material having conductivity such as a metal plate, and is disposed so as to narrow the membrane electrode assembly 5 from the outside of each gas diffusion layer 2g. On the surface of the separator 6 on the gas diffusion layer 2g side, a channel groove 6p that constitutes a channel for the reactive gas is formed. The separator 6 functions as a current collecting plate for collecting electricity generated in the membrane electrode assembly 5 and also functions as a flow path member for constituting a flow path for the reaction gas. A flow path for the refrigerant may be formed on the outer surface of the separator 6.

  The seal portion 7 is disposed on the outer periphery of the membrane electrode assembly 5 and is narrowed by the separator 6 together with the membrane electrode assembly 5. The seal portion 7 prevents leakage of the reaction gas from each electrode of the membrane electrode assembly 5 and prevents a short circuit between the separators 6. The seal portion 7 is formed by, for example, injection molding of a resin member on the outer peripheral edge portion of the membrane electrode assembly 5.

  In the unit cell 10, a plurality of through-holes 8 (illustrated by broken lines) that penetrate the separator 6 and the seal portion 7 in the thickness direction are formed in the outer peripheral region of the membrane electrode assembly 5. The through holes 8 of each single cell 10 are connected in the fuel cell stack, and supply of reaction gas to the membrane electrode assembly 5 of each single cell 10 or exhaust gas discharge from the membrane electrode assembly 5 of each single cell 10 is performed. Acts as a manifold to do. Hereinafter, the through hole 8 is referred to as a “manifold hole 8”. The single cell 10 is formed with a communication path that communicates the manifold hole 8 and the flow path groove 6p of the separator 6 and functions as a flow path for reaction gas or exhaust gas (illustration and detailed description are omitted). .

  FIG. 3 is a schematic diagram showing the configuration of the fuel cell evaluation apparatus 100 for executing the single cell evaluation test in step S20. In FIG. 3, for convenience, the single cell 10 is divided into an anode side 11 to which fuel gas is supplied and a cathode side 12 to which oxidant gas is supplied. FIG. 3 schematically shows the flow of hydrogen and oxygen inside the stacked body of the unit cell 10 and the intermediate plate 20 with a one-dot chain line arrow and a two-dot chain line arrow, respectively. Further, the flow of the refrigerant in the intermediate plate 20 is schematically shown by broken line arrows.

  The fuel cell evaluation apparatus 100 causes a fuel cell stack configured in a simulated manner by stacking a plurality of single cells 10 to generate electric power, and drainage of each single cell 10 based on the output of each single cell 10 at that time. To evaluate. The fuel cell evaluation apparatus 100 includes a plurality of intermediate plates 20, first and second end plates 31, 32, a main control unit 110, a fuel gas supply unit 120, an oxidant gas supply unit 122, and a refrigerant supply. Unit 124, voltage measurement unit 130, current control unit 132, and output unit 134.

  The intermediate plate 20 is a plate-like member made of a conductive member. The intermediate plates 20 are arranged between the single cells 10 and at both ends in the stacking direction when the plurality of single cells 10 to be tested are stacked and set. Hereinafter, in the fuel cell evaluation apparatus 100, a laminate including the single cell 10 and the intermediate plate 20 is referred to as “test laminate TS”.

  The intermediate plate 20 has a terminal 21 to which the voltage measuring unit 130 is connected at its end. Further, the intermediate plate 20 has a through-hole that constitutes a manifold that is connected to the manifold hole 8 of each single cell 10 and through which the reaction gas flows (not shown). Furthermore, the intermediate plate 20 has a refrigerant flow path through which a refrigerant for controlling the temperature of each unit cell 10 flows.

  Each of the first and second end plates 31 and 32 is a plate-like member made of a conductive member, and is disposed at both ends in the stacking direction of the test stacked body TS. The first and second end plates 31 and 32 have a terminal 33 to which a current control unit 132 is connected. The first end plate 31 has a connection portion to which a pipe through which reaction gas and exhaust gas flow is connected (not shown). The first and second end plates 31 and 32 are attached with fastening members for applying a fastening force in the stacking direction to the test laminate of the unit cell 10 and the intermediate plate 20, and the illustration and details thereof are shown. Detailed explanation is omitted.

  The main control unit 110 is configured by a microcomputer including a central processing unit and a main storage device. The main control unit 110 controls each of the constituent units 120, 122, 124, 130, 132, 134 to execute an evaluation test process for evaluating the drainability of the single cell 10. The contents of the evaluation test process will be described later. In the present specification, “drainage of the single cell 10” means ease of drainage from the reaction gas flow path of the single cell 10 during power generation. Further, the “reactive gas flow path of the single cell 10” means the entire path through which the reactive gas flows between the electrolyte membrane 1 and the separator 6 in the single cell 10, and the flow path groove 6p of the separator 6 or , Including pores in the gas diffusion layer 2g and the catalyst layer 2c.

  The fuel gas supply unit 120 includes a hydrogen tank, a regulator, an injector, and the like (not shown), and supplies hydrogen (fuel gas) at a pressure and flow rate according to a command from the main control unit 110 to the test laminate TS. The oxidant gas supply unit 122 includes an air flow meter, an air compressor, an on-off valve, and the like (not shown), and a high-pressure air (oxidant gas) having a pressure and flow rate according to a command from the main control unit 110 is a test laminate. Supply to TS. The refrigerant supply unit 124 includes a radiator and a circulation pump (not shown), and circulates and supplies the refrigerant to each intermediate plate 20 of the test laminate TS while adjusting the temperature of the refrigerant according to a command from the main control unit 110. The temperature of each single cell 10 of the test laminate TS is controlled.

  The voltage measurement unit 130 is connected to the terminal 21 of each intermediate plate 20, measures the voltage of each single cell 10 inserted between the intermediate plates 20, and outputs the voltage to the main control unit 110. The current control unit 132 is connected to the first and second end plates 31 and 32 that sandwich the test laminate TS via the terminals 33. The current control unit 132 includes a DC / DC converter that controls the output voltage of the test laminate TS, and causes the test laminate TS to output a current according to a command from the main control unit 110.

  Here, the current output by the fuel cell is represented by a so-called current-voltage curve (IV curve), and is uniquely determined for the voltage output by the fuel cell according to the power generation characteristics of the fuel cell at that time. Determined. Therefore, the current control unit 132 can adjust the current to be output to the test laminate TS by controlling the output voltage of the test laminate TS using the DC / DC converter. The output unit 134 includes a display and a printer, and outputs a measurement result related to the output of each single cell 10 and a determination result in the evaluation test of the single cell 10.

  FIG. 4 is a flowchart showing the procedure of the evaluation test of the single cell 10 in the fuel cell evaluation apparatus 100. In step S110, the main control unit 110 causes each of the fuel gas supply unit 120, the oxidant gas supply unit 122, and the refrigerant supply unit 124 to start supplying the reaction gas or the refrigerant to the test laminate TS, and performs the test. Power generation is started in each single cell 10 of the stacked body TS. In step S120, the main control unit 110 starts operation control for evaluating the drainability of each single cell 10 (hereinafter referred to as “evaluation operation control”). Details of the operation control for evaluation will be described later.

  In step S <b> 130, the main control unit 110 acquires and records the measurement value of the output voltage of each single cell 10 during the execution of the evaluation operation control by the voltage measurement unit 130. In step S <b> 140, the main control unit 110 determines the quality of the drainage of the single cell 10 based on the change in the output power of each single cell 10, and causes the output unit 134 to output the result. A specific method for determining the quality of the single cell 10 in step S140 will be described later.

  FIGS. 5A to 5C are explanatory diagrams for explaining the evaluation operation control in step S120. FIG. 5A is a graph showing the change over time in the control temperature of each single cell 10 during the operation control for evaluation. FIG. 5B is a graph showing a temporal change in the current value output to the test laminate TS during the operation control for evaluation in step S120. FIG. 5C is a graph showing the start (ON) and stop (OFF) timings of the reaction gas supply to the test laminate TS during the operation control for evaluation. The time axes of the graphs in FIGS. 5A to 5C correspond to each other.

In the evaluation operation control in step S120, the main control unit 110 controls the refrigerant supply unit 124 so that the operation temperature of each unit cell 10 is lower than the normal operation temperature T _S of the fuel cell, and flooding occurs. It is held at a low temperature _TL where there is a high possibility (FIG. 5A). Here, the “normal operating temperature T _S of the fuel cell” means that a normal load (for example, a load that does not cause significant deterioration of the fuel cell) is applied to the fuel cell and the fuel cell is operated for a predetermined time (for example, several hours). Is the average operating temperature when the degree is continued. More specifically, the normal operating temperature T _S of the fuel cell stack may be a temperature of about 60 to 90 ° C., for example. Further, the low temperature T _L may be, for example, about 20 to 40 ° C.

The main control unit 110 controls the current control unit 132 to repeat increase / decrease in the output current of the test laminate TS at a predetermined cycle (FIG. 5B). Specifically, the main control unit 110 _applies currents of the first and second current values I _high and I _low (I _high > I _low ) to the test laminate TS at a constant cycle (for example, about several minutes). Output alternately. At the same time, the main control unit 110 controls the fuel gas supply unit 120 and the oxidant gas supply unit 122 to vary the flow rate of the reaction gas with respect to the test stack TS in accordance with the current fluctuation cycle of the test stack TS. . In the present embodiment, the main control unit 110 stops the supply of the reaction gas when the current of the test stack TS is decreased, and restarts the supply of the reaction gas when the current of the test stack TS is increased. The operation control for evaluation in step S120 is continued for several hours to several tens of hours, for example.

  FIG. 6 is a graph showing an example of a change over time of a measured value of the output voltage of a single cell when the above-described evaluation operation control is performed. In FIG. 6, the measurement results for the first and second experimental single cells are shown by a solid line graph G1 and a one-dot chain line graph G2, respectively. Based on the experimental results described below, the inventors of the present invention have found that, according to the operation control for evaluation, it is possible to easily detect a decrease in power generation performance due to a decrease in drainage performance of a single cell.

  In this experiment, a first experimental single cell with high drainage and a second experimental single cell with low drainage were used. Here, the cause of the flooding in the single cell (the cause of the decrease in drainage) is mainly due to clogging of the pores of the gas diffusion layer due to the generated water, or blocking of the reaction gas flow path due to the swelling of the ionomer in the catalyst layer. It is. The drainage property of the second experimental single cell is that the water repellency and air permeability of the gas diffusion layer are lowered, and the proportion of the ionomer contained in the catalyst layer is increased, so that the drainage property of the first experimental single cell is increased. Adjusted to be lower.

  For each of the first and second experimental single cells, evaluation operation control similar to that described with reference to FIGS. 5A to 5C is performed for a predetermined time, and each of the evaluation operation controls is performed. The time change of the voltage of the experimental single cell was measured. As a result, for the first experimental single cell, the voltage fluctuation range was within a substantially constant range, and the power generation performance was maintained at a constant level (graph G1). On the other hand, in the second experimental single cell, the voltage fluctuation range gradually decreased, and the power generation performance tended to decrease gradually (graph G2).

  After the above operation control for evaluation, after the inside of the second experimental single cell was once dried, normal power generation was started in the second experimental single cell. The power generation performance of the single cell was restored. This indicates that the cause of the decrease in the power generation performance of the second experimental single cell during the operation control for evaluation is temporary moisture retention due to low drainage in the reaction gas flow path. Yes.

  Thus, according to the operation control for evaluation, it is possible to easily detect a decrease in power generation performance due to the low drainage of the single cell. The reason is as follows. In the operation control for evaluation, the single cell is caused to repeatedly decrease and increase in current. However, when the current increases, the generated water significantly increases in the single cell. For this reason, during the execution of the evaluation operation control, the increase in generated water in the single cell is intermittently repeated, and the flow of water in the reaction gas flow path of the single cell becomes discontinuous. Then, the flow of water in the single cell becomes intermittent, and the change in drainage is significant compared to the state where water is continuously generated in the single cell and the flow path of water is continuously formed. It becomes easy to appear in. Therefore, according to the operation control for evaluation, it is possible to easily detect the change in drainage in the single cell.

  FIG. 7 is an explanatory diagram showing shortening of the detection time of the decrease in drainage by the operation control for evaluation. FIGS. 7A and 7B are graphs each showing a time change of output power of a single cell, and are based on the experiment result of the inventor of the present invention. The inventor of the present invention can further reduce the time until a decrease in power generation performance of a single cell due to a decrease in drainage is detected based on the following experimental results, if the operation control for evaluation is performed. Obtained knowledge.

In this experiment, with respect to the same single cell, the change in output power over time when the evaluation operation control is executed (FIG. 7A) and the output power when the constant current control for outputting a constant current is continued. The time change (FIG. 7B) was measured. Then, using the initial output power W ₀ as a reference value when good drainage is shown, until the output power of the single cell decreases by a predetermined power α (α = 0.7 kW) from the output power W ₀ The required times t ₁ and t ₂ were measured. In the constant current control, a current having a current value substantially the same as the first current value I _high in the evaluation operation control is continuously output to the single cell.

The required time t ₁ measured when the operation control for evaluation was performed was 5 hours. On the other hand, the required time t ₂ which is measured when subjected to constant current operation control was 300 hours. Thus, according to the operation control for evaluation, it is possible to detect a decrease in the power generation performance of the single cell at an extremely early stage as compared with the constant current control.

  By the way, the decrease in the power generation performance of the single cell after the operation for a long time (for example, about several hundred hours) is caused by the deterioration of the catalyst layer in which the catalyst is ionized and eluted in addition to the low drainage of the single cell. there is a possibility. On the contrary, if the operation is performed for a short time (for example, about several hours), it is unlikely that the power generation performance of the single cell is reduced due to the deterioration of the catalyst layer as described above. Therefore, if it is operation control for evaluation, it is possible to distinguish and detect the decrease in power generation performance of a single cell due to low drainage and the decrease in power generation performance due to deterioration of the catalyst layer according to the time required for detection. is there.

  FIGS. 8A and 8B are explanatory diagrams for explaining a method for determining whether or not the drainage of the single cell 10 is good based on the change in output power in step S140. FIGS. 8A and 8B each show an example of a graph showing the time change of the output power of the single cell 10. In step S140 (FIG. 4), the main control unit 110 of the fuel cell evaluation apparatus 100 determines each unit cell 10 during execution of the evaluation operation control based on the measured value of the voltage of each unit cell 10 acquired in step S130. Get the change in output power over time.

For each single cell 10, the output power P ₁ when the current of the test laminate TS is raised to the first current value I _high for the first time and the Nth time (N is an arbitrary natural number greater than 1) A difference ΔP from the output power P _N when the current of the test laminate TS is increased to the first current value I _high is calculated (ΔP = P ₁ −P _N ).

  The main control unit 110 makes a good determination that the single cell 10 having ΔP equal to or less than a predetermined threshold value has no significant decrease in power generation performance and the drainage performance in the reaction gas flow path satisfies the standard (FIG. 8). (A)). On the other hand, regarding the single cell 10 in which ΔP is larger than the predetermined threshold, the power generation performance is remarkably deteriorated, and it is determined that the drainage performance in the reaction gas flow path does not satisfy the standard (FIG. 8B). . With this method, it is possible to easily detect a decrease in the power generation performance of the single cell 10 during execution of the evaluation operation control, and it is possible to easily evaluate the drainability of the single cell 10.

  As described above, if the evaluation test of the single cell 10 is performed by the fuel cell evaluation device 100 of the present embodiment, the drainage of the single cell 10 can be detected in a relatively short time by the operation control for evaluation. The single cell 10 having low drainage can be detected easily and efficiently. If it is the manufacturing process of the fuel cell of this embodiment, since a fuel cell stack is comprised by the single cell 10 determined that the reference | standard of the evaluation test by the fuel cell evaluation apparatus 100 is satisfy | filled, the fuel cell stack which has high drainage performance Can be efficiently manufactured.

B. Variations:
B1. Modification 1:
FIGS. 9A and 9B are explanatory diagrams for explaining evaluation operation control as a modification of the embodiment. In the control for evaluation operation of the above embodiment, the current value to be output to the test laminate TS is alternately changed to the first and second current values I _hig and I _low at a constant period, and fluctuates in a square waveform. (FIG. 5B). However, in the control for evaluation operation, the current output to the test laminate TS does not have to be changed in a square wave shape. In the control for evaluation operation, the current output to the test laminate TS may be changed to a trapezoidal wave shape at an arbitrary change rate when rising or falling, as shown in the graph of FIG. 9A. . In the evaluation operation control, the current value output to the test laminate TS does not have to be alternately changed to the first and second current values I _hig and I _low at a constant period. In the evaluation operation control, the current output to the test laminate TS may be repeatedly increased and decreased with a fluctuation pattern having a predetermined cycle, as shown in the graph of FIG. 9B.

B2. Modification 2:
In the above embodiment, the output power P ₁ when the current value to be output to the test laminate TS for the first time is increased to the first current value I _high and the current value to be output to the test laminate TS for the Nth time are set. The pass / fail judgment of the single cell 10 was performed using the difference ΔP from the output power P _N when the current was increased to the first current value I _high (FIG. 8). However, the pass / fail judgment of the single cell 10 may be executed by other methods. For example, the output power P _n when the current value to be output to the test laminate TS in the nth time (n is an arbitrary natural number) is increased to the first current value I _high, and the mth time (m is a natural number greater than n). ), The quality of the single cell 10 may be determined using the difference ΔP from the output power P _m when the current value to be output to the test laminate TS is increased to the first current value I _high . Alternatively, the pass / fail judgment of the single cell 10 may be made when the output power of the single cell 10 becomes lower than a predetermined threshold. Moreover, in the pass / fail determination of the single cell 10, the determination may be made when the time average of the output power of the single cell 10 falls below a predetermined threshold. The quality determination of the single cell 10 may not be executed based on a change in the output power of the single cell 10, and may be executed based on, for example, a change in the output voltage of the single cell 10.

B3. Modification 3:
In the operation control for evaluation of the above embodiment, the operation temperature of each single cell 10 is kept lower than the normal operation temperature Ts of the fuel cell stack, and is kept at a low temperature _TL where the possibility of flooding is high (FIG. 5). (A)). However, in the operation control for evaluation, control of the operation temperature of each single cell 10 may be omitted. However, in the operation control for evaluation, if the operation temperature of each single cell 10 is controlled to a low temperature T _L , it is easy to detect a decrease in power generation performance of the single cell 10 due to flooding. The accuracy of evaluating the drainage performance of the flow path is improved.

B4. Modification 4:
In the operation control for evaluation of the above embodiment, the supply of the reaction gas to each single cell 10 is intermittently executed, and the flow rate of the reaction gas supplied to each single cell 10 is set to the current fluctuation cycle of the test laminate TS. They were also varied (FIG. 5C). However, in the operation control for evaluation, the supply of the reaction gas to each single cell 10 does not have to be executed intermittently, and the flow rate of the reaction gas supplied to each single cell 10 is the fluctuation cycle of the current of the test laminate TS. It does not have to be changed to match. In the operation control for evaluation, the reaction gas may be continuously supplied to each single cell 10 regardless of the fluctuation of the current output to the test laminate TS. However, in the evaluation operation control, the flow rate of the reaction gas supplied to each unit cell 10 is changed in accordance with the fluctuation cycle of the current of the test laminate TS, whereby the flow of water due to the reaction gas inside the unit cell 10. Can be made more discontinuous. Therefore, the influence of the drainage property in the reaction gas flow path in each single cell 10 is remarkably reflected by the change in the output of the single cell 10, and the accuracy of the evaluation of the drainage property of the single cell 10 can be improved. it can.

B5. Modification 5:
In the said embodiment, the evaluation test of the single cell 10 was performed in the state in which the several single cell 10 was laminated | stacked. However, the evaluation test of the single cell 10 may not be performed in a state where a plurality of single cells 10 are stacked, and may be performed for each single cell 10.

B6. Modification 6:
The fuel cell evaluation device 100 according to the embodiment includes the intermediate plate 20 disposed between the plurality of unit cells 10 to be stacked. However, the intermediate plate 20 may be omitted.

B7. Modification 7:
The fuel cell evaluation apparatus 100 of the above embodiment has performed an evaluation test on the single cell 10 having the configuration described in FIG. However, the single cell that is the object of the evaluation test of the fuel cell evaluation apparatus 100 may not have the configuration of the single cell 10 described in the above embodiment, and may have another configuration. For example, in a single cell that is an evaluation test target of the fuel cell evaluation device 100, the gas diffusion layer 2g and the flow channel 6p of the separator 6 may be omitted. In addition, a single cell that is an evaluation test target of the fuel cell evaluation apparatus 100 includes a gas flow path member that functions as a flow path of a reaction gas, such as an expanded metal or a punching metal, between the separator 6 and the membrane electrode assembly 5. It may be arranged.

B8. Modification 8:
In the manufacturing process of the fuel cell stack in the above embodiment, only the drainage evaluation test of the single cell 10 by the fuel cell evaluation apparatus 100 was performed (FIG. 1). However, in the manufacturing process of the fuel cell stack, other evaluation tests may be executed on each single cell 10 in addition to the drainage evaluation test of the single cell 10 by the fuel cell evaluation device 100. For example, after the conventional evaluation test described in FIG. 7 is executed, the drainage evaluation test of the single cell 10 by the fuel cell evaluation apparatus 100 may be executed.

  The present invention is not limited to the above-described embodiments, examples, and modifications, and can be realized with various configurations without departing from the spirit thereof. For example, the technical features in the embodiments, examples, and modifications corresponding to the technical features in each embodiment described in the summary section of the invention are to solve some or all of the above-described problems, or In order to achieve part or all of the above effects, replacement or combination can be performed as appropriate. Further, if the technical feature is not described as essential in the present specification, it can be deleted as appropriate.

DESCRIPTION OF SYMBOLS 1 ... Electrolyte membrane 2 ... Electrode 2c ... Catalyst layer 2g ... Gas diffusion layer 5 ... Membrane electrode assembly 6 ... Separator 6p ... Channel groove 7 ... Seal part 8 ... Manifold hole (through-hole)
DESCRIPTION OF SYMBOLS 10 ... Single cell 11 ... Anode side 12 ... Cathode side 20 ... Intermediate plate 21 ... Terminal 31 ... 1st end plate 32 ... 2nd end plate 33 ... Terminal 100 ... Fuel cell evaluation apparatus 110 ... Main control part 120 ... Fuel Gas supply unit 122 ... Oxidant gas supply unit 124 ... Refrigerant supply unit 130 ... Voltage measurement unit 132 ... Current control unit 134 ... Output unit

Claims (7)

A fuel cell manufacturing method comprising:
(A) supplying a reactive gas to the power generation body to generate electric power, and performing a current fluctuation process for repeatedly increasing and decreasing the current output to the power generation body;
(B) measuring the output of the power generator during execution of the current fluctuation process;
(C) determining the quality of the power generation body based on a change in the output of the power generation body during execution of the current fluctuation process;
(D) a step of configuring a fuel cell using the power generator that has been judged good in step (c);
A method for manufacturing a fuel cell. The manufacturing method according to claim 1,
The manufacturing method, wherein the step (a) is a step of executing the current variation process while controlling the temperature of the power generator to a predetermined temperature lower than a normal operating temperature of the fuel cell. The manufacturing method according to claim 1 or 2,
The current variation process of the step (a) decreases the flow rate of the reaction gas supplied to the power generation body and increases the current output to the power generation body when the current output to the power generation body is decreased. The manufacturing method including the process which increases the flow volume of the said reactive gas supplied to the said electric power generation body sometimes. It is a manufacturing method as described in any one of Claim 1 to 3,
The current fluctuation process is a step of periodically changing a current value to be output to the power generator to a predetermined first value and a predetermined second value smaller than the first value. There is a manufacturing method. It is a manufacturing method as described in any one of Claim 1 to 4, Comprising:
In the step (c), in the current fluctuation process, the output of the power generator when the current to be output to the power generator is increased n (n is an arbitrary natural number) times and the power generator is output. A manufacturing method, which is a step of determining pass / fail of the power generator based on a difference from an output of the power generator when the current is increased m (m is a natural number greater than n) times. A method for evaluating a power generator constituting a fuel cell,
(A) supplying a reactive gas to the power generation body to generate electric power, and performing a current variation process for repeatedly increasing and decreasing the current output to the power generation body;
(B) measuring the output of the power generator during execution of the current fluctuation process;
(C) determining the quality of the power generation body based on a change in the output of the power generation body during execution of the current fluctuation process;
An evaluation method comprising: An evaluation apparatus for a power generator constituting a fuel cell,
A reaction gas supply unit for supplying a reaction gas to the power generator;
A current control unit for controlling a current to be output to the power generator;
A measuring unit for measuring the output of the power generator;
While controlling the reaction gas supply unit to supply a reaction gas to the power generation body, the current control unit is controlled to execute a current fluctuation process for repeatedly increasing and decreasing the current output to the power generation body, An evaluation control unit that determines pass / fail of the power generation body based on a change in output of the power generation body measured by the measurement unit during execution of the current variation process;
An evaluation device.

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