KR20130103049A - Method for manufacturing fuel cell separator using porous graphite - Google Patents

Abstract

PURPOSE: A manufacturing method of a fuel cell separator is provided to supply a separator with improved quality by a mass production and to reduce manufacturing time and manufacturing cost by introducing automatic equipment for improving a manufacturing process. CONSTITUTION: A manufacturing method of a fuel cell separator comprises a step of polishing each graphite plate; a step of impregnating the graphite plate with an impregnating solution, curing the cured graphite plate, and drying the cured graphite plate; a step of forming a fuel gas channel, an oxidation gas channel, and a coolant channel on a dried graphite plate; a step of impregnating the semi-product with the impregnating solution and washing and curing the semi-product; a step of manufacturing a final product by attaching the semi-product; and a step of carrying out the surface inspection of the fuel gas channel, oxidation gas channel, and coolant channel and a gas leakage inspection to manufacture a separator. [Reference numerals] (S11) Cutting raw material with graphite plate (cuter); (S12,S15) Grinding (grinder); (S13) Graphite plate; (S14) Transfer (transferring device); (S21) Washing (washing bath); (S22) Drying (dryer); (S23) Impregnating; (S24) Washing the surface (washing bath); (S25) Curing (curing furnace); (S26) Drying (drying furnace); (S31) Fine grinding (grinder); (S32) Shape processing (processor)

Description

Fuel cell separator manufacturing method using porous graphite {Method for Manufacturing Fuel Cell Separator using Porous Graphite}

The present invention relates to a method for manufacturing a fuel cell separator, and more particularly, to a method for manufacturing a fuel cell separator using porous graphite for standardizing the production of a separator used in a fuel cell to reduce mass production and cost.

In general, a fuel cell stack may be divided into a separator (separator), a membrane electrode assembly (MEA), and a gas diffusion layer (GDL). The fuel cell stack is constructed by stacking tens to hundreds or more and imparts a constant surface pressure by using metal plates and fastening bars at both ends. Fuel gas (hydrogen), oxidizing gas (air), and fluid (water) are supplied through the inlet and outlet of the separator to act as a transport passage for the electrical energy generated by the chemical reaction and the water generated by the chemical reaction. It plays an important role.

Types of the separator include a separator produced by processing porous graphite, a separator produced by processing a high-pressure compressed plate material of a composite powder, a separator produced by molding a composite powder, and a separator produced by pressing a metal plate material.

Conventionally, the method of manufacturing a separator manufactured by processing porous graphite in the separator, raw material input and surface processing process, surface treatment process, shape machining process, resin impregnation process, finished product bonding process, post-processing process, and performance inspection It is manufactured through a process and a shipment process.

Therefore, the steps from the input of raw materials to the shipment are complicated, many manual processes are required, and a lot of manufacturing time is required, and the ratio of manufacturing cost for mass production and commercialization is very high because there is no clear standardization of manufacturing process technology for each process. There was this.

The present invention is to solve the above problems, to stabilize the manufacturing method of the separator, which is the core component of the fuel cell stack, to maximize the utilization efficiency of the automation equipment for the production of the separator, and to establish a detailed manufacturing technology for each process to manufacture The aim is to improve production volume by stabilizing and reducing production costs due to time savings, and to implement a standardized model by systematically manufacturing manufacturing processes.

In order to achieve the above object, the present invention (a) from the graphite raw material prepared by cutting with a certain volume of graphite blocks with a cutter and polished with a grinder, and then cut a plurality of graphite plate materials with a cutter with a plurality of cutters and transfer them to a transfer device. Polishing the plane of the graphite sheet with a polishing machine; (b) After washing the dust attached to the surface of the graphite plate in the washing tank to remove the moisture of the surface in the dryer, the moisture-impregnated graphite plate is put into the impregnation tank, impregnated by adding the impregnation liquid and the impregnated graphite plate in the washing tank Surface washing followed by curing in a curing furnace and surface drying in a drying furnace to remove moisture from the surface of the hardened graphite plate; (c) precisely polishing the surface-dried graphite sheet material with a grinder according to a predetermined standard, and then processing shapes of a fuel gas passage, an oxidizing gas passage, and a cooling water passage using a processing machine; (d) After washing the dust attached to the surface of the semi-finished product processed in the washing tank, remove the moisture of the surface from the dryer, impregnate the semi-finished product is removed into the impregnation tank, impregnated by adding the impregnation liquid, and the semi-finished product finished impregnation Surface washing in the curing furnace and then surface drying in a drying furnace to remove moisture from the finished semi-finished surface; (e) dividing the surface-dried semi-finished product into a hydrogen plate and an air plate, and selecting the adhesive in consideration of the viscosity of the adhesive, the limit temperature and curing condition according to the operating conditions and operating temperature of the fuel cell, Removing impurities using a post-process to produce a finished product; And (f) manufacturing a fuel cell separator by performing a gas leakage test on an adhesive interface together with surface inspection of the fuel gas passage, the oxidizing gas passage, and the cooling water passage formed in the finished product. It is a feature that a separator manufacturing method is provided.

In addition, in the present invention, in the step (a), dried at 100 ~ 120 ℃ in the dryer, the external for 1 hour to remove the fine dust and moisture adhered to the surface of the graphite plate before the impregnation liquid is added in the impregnation tank The impregnating solution was added to the impregnation tank and pressurized for 1 hour under the pressure of 5kg / ㎠ under the condition that the external air was blocked for 1 hour under the vacuum pressure of -750mmHg. , Curing in a curing furnace for 30 minutes, can be dried for 1 hour at 110 ± 5 ℃ in a drying furnace.

In addition, in the present invention, in the step (d), dried to 100 ~ 120 ℃ in the dryer, the external for 30 minutes to remove the fine dust and moisture adhered to the graphite plate surface before the impregnation liquid is added in the impregnation tank The impregnating solution was poured into the impregnation tank and pressurized for 1 hour under the pressure of 6kg / ㎠ under the condition that the external air was blocked for 1 hour under vacuum pressure -750mmHg. , Curing in a curing furnace for 30 minutes, can be dried for 1 hour at 110 ± 5 ℃ in a drying furnace.

In addition, in the present invention, the impregnation liquid may be applied to the resin of the hydrophobic series.

The present invention also provides an apparatus for manufacturing a fuel cell separator for implementing a method for manufacturing a fuel cell separator using the porous graphite.

The present invention also provides a fuel cell separator manufactured by the fuel cell separator manufacturing method using the porous graphite.

The present invention can simplify and stabilize the manufacturing process of a fuel cell separator using porous graphite, thereby providing a separator of improved quality according to mass production, and also through the introduction and manufacture of an automated facility for improving the manufacturing process, It has the advantage of saving time and manufacturing costs.

1 is a block diagram showing a fuel cell separator according to the present invention.
2A and 2B are flowcharts illustrating a method of manufacturing a fuel cell separator using porous graphite according to the present invention.
3 is a block diagram illustrating an apparatus for automatically testing a fuel cell separator according to the present invention.

Hereinafter, embodiments of a fuel cell separator manufacturing method using porous graphite according to the present invention will be described in detail with reference to the accompanying drawings.

In FIG. 1, the separator 10, which is a core component of the fuel cell, includes a passage 11 through which fuel gas, that is, hydrogen, a passage 12 through which oxidizing gas, ie, air, and a passage through which water, which is fluid, moves ( 13) is formed. Each of the passages 11, 12, 13 formed in the separator 10 transfers electric energy generated by a chemical reaction and water generated by a chemical reaction. The separator 10 is laminated | stacked in plurality, normally tens to hundreds in the shape of a thin plate material. As the material of the separator 10, porous artificial graphite is used, but various similar materials may be used.

In order to manufacture the fuel cell separator, a cutting machine, a grinding machine, a washing tank, a dryer, an impregnation tank, a curing furnace, a drying furnace, and the like are basically provided, and additional devices, equipment, or systems such as a transfer device, a processing device, and an adhesive are used.

The manufacturing method of the fuel cell separator is roughly divided into six steps, and the steps may be divided into detailed processes. That is, the first step of cutting and autopolishing the model from the raw material made of porous artificial graphite, the second step of impregnating the porous graphite plate material, the third step of precision grinding of the graphite plate material and the precise machining of the shape by shape, and the semi-finished product The fourth step of impregnation, the fifth step of post-treatment, and the sixth step of inspecting performance.

A detailed process of manufacturing the fuel cell separator will be described with reference to FIGS. 2A and 2B.

In FIG. 2A, in the first step S10 of cutting and auto-polishing a model from raw materials, first, the prepared porous graphite raw material is cut into a predetermined volume of graphite block 1 using a cutter (S11). When the cut graphite block 1 is automatically transferred by the transfer apparatus, the plane of the graphite block 1 is polished using a polishing machine (S12). Then, the graphite block 1 is cut into a graphite plate 2 having a predetermined thickness with a cutter (S13). The graphite block 1 is repeatedly cut into a plurality of graphite plate materials 2 by a cutter, and the cut graphite plate material 2 is transferred by a transfer device (S14). At this time, the graphite plate 2 conveyed from the conveying device is conveyed with the cutting surface upward. The roughness of the plane of each graphite plate material 2 to be transferred is automatically rough-polished with a polishing machine (S15).

In the second step S20 of impregnating the porous graphite plate 2, a fine bubble layer is present inside and outside the graphite plate 2 while undergoing the detailed process of the first step S10. An impregnation process is performed to remove this bubble layer. At this time, the impregnation liquid for the impregnation of the graphite plate 2 is melted to the outside by the chemical reaction by the fuel gas passage 11, the oxidizing gas passage 12, and the cooling water passage 13 or the separator It is very important to select a hydrogen-based resin that does not deform the cured resin after the impregnation of the graphite sheet so that the contaminants are discharged from the surface and the inside of (10) so that the pollutant is not discharged from the cooling water.

Therefore, in order to remove the dust adhering to the surface of the graphite plate 2 which has been polished in the first step (S10) it is lightly washed with water flowing in the washing tank (S21). The washed graphite plate 2 is sufficiently removed from the surface of the moisture in the dryer at approximately 100 ~ 120 ℃ (S22). The graphite plate material 2 from which moisture has been removed is placed in an impregnation tank, and an impregnation solution is added to impregnate it. At this time, after the graphite plate 2, which has been dehumidified, is introduced into the impregnation tank, optimum conditions are provided for about 1 hour to be discharged to the outside to remove fine dust and moisture. After the impregnation solution was introduced into the impregnation tank, the vacuum pressure was approximately -750 mmHg or more for 1 hour, the external air was blocked, and the impregnation liquid was sufficiently infiltrated by pressurizing for 1 hour at a pressure of 5 Kg / cm 2 or more (S23). In addition, the surface of the impregnated graphite plate 2 is washed in a washing tank (S24), the washed graphite plate 2 is put into a curing furnace and cured for about 30 minutes (S25). At this time, the temperature of the hot water is maintained to be approximately 90 ℃ or more. When curing is completed, the surface is dried at a temperature of about 110 ± 5 degrees in a drying furnace to remove moisture on the surface of the graphite plate (2) (S26).

Next, the third step (S30) for precision machining and precise machining by shape. In step S26, the surface-dried graphite plate 2 is precisely polished using a grinder according to a predetermined standard (S31). At this time, the dimensional deviation of the front and rear portions of the graphite plate 2 should not be generated, and the roughness (surface roughness) of the processed surface of the abrasive stone applied to the polishing machine should be adjusted. Then, the graphite plate 2, which has been precisely polished, processes the shape of the fuel gas passage 11, the oxidizing gas passage 12, and the cooling water passage 13 using a processing machine (S32). Since the material of the graphite plate material 2, which has been precisely ground polished, contains a large amount of carbon, the wear rate progresses rapidly when processing with a general tool, and thus it is difficult to process the graphite plate. Therefore, the artificial diamond tool and the special coating tool should be used. However, since the price difference for each tool used for precision flat grinding is many, it is preferable to set the order according to the shape of the graphite sheet 2 and process the chips sequentially. When the shape is precisely processed, it is recommended to apply it after sufficient consideration because it is reflected in the production cost of the cost reduction and manufacturing cost by the tool and machine operating time.

In FIG. 2B, a fourth step S40 of impregnating the shaped semifinished product is performed. In order to remove the dust attached to the surface of the processed semi-finished product, the surface is lightly washed using a soft brush or the like in the water flowing from the washing tank (S41). Semi-finished product is washed to remove enough moisture from the surface of approximately 100 ~ 120 ℃ in the dryer (S42). The semi-finished product is removed from the moisture in the impregnation tank and impregnated with the impregnation solution. At this time, after the semi-finished product is dehumidified in the impregnation tank to provide an optimum condition for about 30 minutes to discharge to the outside to remove the fine dust and moisture. After the impregnation solution was introduced into the impregnation tank, the vacuum pressure was approximately -750 mmHg or more for 1 hour, the external air was blocked, and the impregnation solution was sufficiently infiltrated by pressurizing for 1 hour at a pressure of 6Kg / cm 2 or more (S43). For the impregnation solution, it is preferable to apply a resin of hydrogen series. In addition, after the surface of the semi-finished product is impregnated in the washing bath (S44), the washed semi-finished product is put into the curing furnace and cured for about 30 minutes (S45). At this time, the temperature of the hot water is maintained to be approximately 90 ℃ or more. When curing is completed, the surface is dried at a temperature of about 110 ± 5 degrees in a drying furnace to remove moisture on the surface of the semifinished product (S46).

Next, a fifth step S50 of post-processing is performed. In the detailed process, the graphite plate for the fuel cell stack separator in which the precise impregnation is completed is divided into hydrogen plate (Anode) and air plate (Cathode) (S51). In addition, the adhesive is selected after the adhesive is selected in consideration of the viscosity of the adhesive, the limit temperature of use, and the curing condition according to the operating conditions and operating temperatures of the fuel cell (S52). Impurities generated in the bonding process are removed using a post-treatment to produce a finished product (S53).

Finally, the sixth step (S60) to check the performance is made. The surface inspection of the fuel gas passage 11, the oxidizing gas passage 12 and the cooling water passage 13 formed in the finished product is performed (S61), and the gas leakage inspection on the adhesive interface of the separator is performed (S62). This completes the manufacture of the fuel cell separator (S63).

Since the leak test is a very important process for determining the performance of the separator 10, in FIG. 3, as a precision automated test facility, a program monitor 20, an auto controller 21, and a gas input / output system may be used. Maximize the productivity of the separator and improve the quality through the investment or production of / Out System, 22), Press Test machine 23, OK / NG Alarm 24, and Printer 25 Reduction of manufacturing cost will be realized.

While the invention has been shown and described with respect to the specific embodiments thereof, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention as defined by the appended claims. Anyone who has it will know it easily.

DESCRIPTION OF SYMBOLS 1: Graphite block 2: Graphite plate material 10: Separator 11: Combustion gas passage 12: Oxidation gas passage 13: Cooling water passage

Claims (6)

(a) cutting the prepared graphite raw material with a certain volume of graphite blocks with a cutter, grinding with a grinder, cutting a plurality of graphite plates with a cutter, transferring them to a transfer device, and polishing the plane of each graphite plate with a polishing machine. ;
(b) After washing the dust attached to the surface of the graphite plate in the washing tank to remove the moisture of the surface in the dryer, the moisture-impregnated graphite plate is put into the impregnation tank, impregnated by adding the impregnation liquid and the impregnated graphite plate in the washing tank Surface washing followed by curing in a curing furnace and surface drying in a drying furnace to remove moisture from the surface of the hardened graphite plate;
(c) precisely polishing the surface-dried graphite sheet material with a grinder according to a predetermined standard, and then processing shapes of a fuel gas passage, an oxidizing gas passage, and a cooling water passage using a processing machine;
(d) After washing the dust attached to the surface of the semi-finished product processed in the washing tank, remove the moisture of the surface from the dryer, impregnate the semi-finished product is removed into the impregnation tank, impregnated by adding the impregnation liquid, and the semi-finished product finished impregnation Surface washing in the curing furnace and then surface drying in a drying furnace to remove moisture from the finished semi-finished surface;
(e) dividing the surface-dried semi-finished product into a hydrogen plate and an air plate and then selecting the adhesive in consideration of the viscosity of the adhesive, the limit temperature of use and curing conditions according to the operating conditions and operating temperature of the fuel cell, Removing impurities using a post-process to produce a finished product; And
(f) preparing a fuel cell separator by performing a gas leakage test on an adhesive interface together with surface inspection of the fuel gas passage, the oxidizing gas passage and the cooling water passage formed in the finished product, and manufacturing a fuel cell separator. Manufacturing method.
2. The method of claim 1, wherein in step (a)
Dried in a dryer to 100-120 ℃,
In order to remove the fine dust and moisture adhering to the surface of the graphite sheet before the impregnation solution is added to the impregnation tank, it is discharged to the outside for 1 hour,
The impregnation solution was added to the impregnation tank and pressurized for 1 hour at a pressure of 5 kg / cm 2 while blocking external air for 1 hour under a vacuum pressure of -750 mmHg.
When washing the surface with a washer, the temperature of the hot water is 90 ℃,
30 minutes in the curing furnace,
A fuel cell separator manufacturing method using porous graphite which is dried for 1 hour at 110 ± 5 degrees in a drying furnace.
The method of claim 1, wherein in step (d),
Dried in a dryer to 100-120 ℃,
In order to remove the fine dust and moisture adhering to the surface of the graphite sheet before the impregnation solution is added to the impregnation tank, it is discharged to the outside for 30 minutes,
The impregnating solution was added to the impregnation tank and pressurized for 1 hour at a pressure of 6 kg / cm 2 while blocking external air for 1 hour under a vacuum pressure of -750 mmHg.
When washing the surface with a washer, the temperature of the hot water is 90 ℃,
30 minutes in the curing furnace,
A fuel cell separator manufacturing method using porous graphite which is dried for 1 hour at 110 ± 5 degrees in a drying furnace.
The method for manufacturing a fuel cell separator according to claim 2 or 3, wherein the impregnation liquid is made of porous graphite to which a hydrophobic resin is applied.
An apparatus for manufacturing a fuel cell separator for implementing the method of any one of claims 1 to 3.
A fuel cell separator manufactured by the method of any one of claims 1 to 3.

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