Gas diffusion layer cutting system for fuel cells and cutting processes

Abstract

Gas diffusion layer (GDL) cutting system for a fuel cell, comprising: a laser cutting device (125) that forms a gas diffusion layer (302) by shining a laser onto a surface of a GDL fabric web (300) moving on a conveyor (130); an adsorption conveying device (135) that adsorbs and transports at least two gas diffusion layers (302) that have been cut by the laser cutting device (125); a first image sensor (140) that detects a top side of the gas diffusion layers (302) cut by the laser cutting device (125); and a second image sensor (155) that detects an underside of the gas diffusion layers (302) which are adsorbed and transported by the adsorption conveying device (135), characterized by the fact that it further includes: a fabric web unwinder (105) on which the GDL fabric web (300) is wound and which is arranged in front of the conveyor (130); a feeding device (120) which continuously feeds the GDL fabric web (300), which is wound onto the fabric web unwinder (105), to an inlet of the conveyor (130) by pulling the GDL fabric web (300); and a fabric web joining device (110) arranged between the fabric web unwinder (105) and the feed device (120) and joining a new GDL fabric web (300) to a previous GDL fabric web (300), wherein the fabric web joining device (110) further comprises: a first holder (200) designed to hold a rear end of a previous GDL fabric web (300); a second holder (205) designed to hold a leading end of a new GDL fabric sheet (300); and Holder actuators (215, 220) that actuate the first (200) and second (205) holders, so that the first (200) and second (205) holders fix the previous GDL fabric web (300) and the new GDL fabric web (300).

Description

TECHNICAL AREA

[0001] One embodiment of the present invention relates to a fuel cell. In particular, the present invention relates to a gas diffusion layer (GDL) cutting system for a fuel cell, which cuts a gas diffusion layer, which is to be attached to a membrane electrode assembly (MEA) of a fuel cell, into a predetermined shape. BACKGROUND

[0002] Fuel cells generate electrical energy using the electrochemical reaction of hydrogen and oxygen. Fuel cells are capable of continuously generating electrical energy by being supplied with chemical reactants from an external source, without requiring a specific charging process.

[0003] Fuel cells can be implemented by placing a separator (a partition plate or a bipolar plate) on both sides of a membrane electrode assembly (MEA). Individual fuel cells can be arranged sequentially in a fuel cell stack.

[0004] A metal electrode encapsulator (MEA) is an important component of a fuel cell and can include an anode and a cathode, which are electrode catalyst layers on either side of an electrolyte membrane through which hydrogen ions move. Furthermore, the MEA can have a sub-seal sleeve that protects the electrode catalyst layers and the electrolyte membrane, thus simplifying the assembly of the fuel cell.

[0005] In the production of such a MEA, an electrode membrane sheet is produced in a peeling process by unrolling a rolled electrolyte membrane and subsequently sequentially transferring electrode catalyst layers to both sides of the electrolyte membrane in order to be spaced apart from each other by a predetermined distance (approximately a distance of 150 mm).

[0006] Therefore, as a post-processing step, a rolled electrode membrane film is unwound and dispensed, the rolled sub-seal sleeve is unwound and positioned on both sides of the electrode membrane film, and the sub-seal sleeve is joined to both sides of the electrode membrane film by being guided between hot rollers, thus producing an MEA film in a roll-to-roll process.

[0007] Furthermore, a fuel cell can be manufactured by connecting a MEA and a gas diffusion layer (GDL) at high temperature and subsequently alternatingly stacking the connected arrangement and a separating plate.

[0008] For example, the GDL can be produced in the form of a film that is cut into a predetermined shape and then bonded under pressure to an electrode membrane, thus forming a MEA. The cost and production time can increase depending on the method used to produce the gas diffusion layer as a film and then cut it into a predetermined shape.

[0009] Accordingly, research was conducted on a GDL cutting system and a method for a fuel cell that efficiently cuts a coiled GDL, examines the coiled GDL, and classifies the coiled GDL in accordance with the verification result.

[0010] The description of the related technology is provided to assist in understanding the background of the present disclosure and may contain matters that are outside the prior art known to the person skilled in the art.

[0011] A generic gas diffusion layer cutting system for a fuel cell is disclosed, for example, in JP 2014 - 86 132 A. Furthermore, US 2009 / 0 004 543 A1 discloses a cutting system for a gas diffusion layer. SUMMARY

[0012] The present invention is based on the objective of providing a GDL cutting system for a fuel cell which has the advantages of obtaining a gas diffusion layer by cutting a GDL fabric web, whereby this can be examined at low cost and defective products can be avoided.

[0013] This problem is solved according to the invention by a system according to claim 1 and a method according to claim 8. Preferred embodiments of the invention are specified in the dependent claims.

[0014] According to the present invention, it is possible to continuously provide GDL tissue webs and to effectively cut gas diffusion layers using a laser.

[0015] Furthermore, it is possible to effectively detect normal and defective products by performing a visual inspection on both sides of the gas diffusion layers after cutting, in order to prevent defective products from being processed in subsequent processes by separating and loading (storing) them.

[0016] Furthermore, it is possible to automate the process of cutting gas diffusion layers from the GDL fabric sheet, thus improving productivity and effectively enhancing the quality standard of quality control. BRIEF DESCRIPTION OF THE FIGURES

[0017] The drawings are provided for reference in the description of exemplary embodiments of the present invention; however, the concept of the present invention is not intended to be explained solely by the accompanying drawings. Fig. Figure 1 is a schematic diagram of a GDL cutting system for a fuel cell according to an exemplary embodiment of the present invention. Fig. Figure 2 is a perspective view showing a fabric web joining device according to an exemplary embodiment. Fig. Figure 3 is a front view of a feeding device according to an exemplary embodiment. Fig. Figure 4 is a top view showing cutting units that have been cut (out) from a GDL fabric web by a laser, according to an exemplary embodiment. Fig. Figure 5 is a top view showing that a GDL fabric web with cutting units according to an exemplary embodiment, to which an adsorbing part of an adsorption conveying device is attached, is moved together. Fig. Figure 6 is a flowchart illustrating a method for cutting a GDL of a fuel cell according to an exemplary embodiment. DETAILED DESCRIPTION OF THE EXECUTION FORMS

[0018] The present invention is described in more detail below with reference to the accompanying drawings, which show exemplary embodiments. As those skilled in the art will recognize, the described embodiments can be modified in various ways without departing from the scope of the present invention.

[0019] Elements not related to the description of exemplary embodiments are not shown to clarify the description, and identical reference numerals denote identical elements throughout the description.

[0020] Furthermore, the sizes and thicknesses of the embodiments shown in the drawings have been selectively chosen to simplify the description, so that the present invention is not limited to those shown in the drawings and thicknesses may be exaggerated to illustrate some parts and areas more clearly.

[0021] The differentiation of the names of elements with "the first" and "the second", etc., was made in the following description to distinguish them for identical relationships of the components, and the components are not limited to the order in the following description.

[0022] Throughout this description, the word "include" and variations thereof such as "includes" or "comprehensive," unless explicitly stated otherwise, means the inclusion of the specified elements but not the exclusion of other elements.

[0023] Fig. Figure 1 is a schematic diagram of a GDL cutting system for a fuel cell according to an exemplary embodiment.

[0024] As in Fig. As shown in Figure 1, a GDL cutting system comprises a fabric web unwinder 105, a fabric web joining device 110, a letter paper winder 115, a GDL fabric web (or GDL material) 300, a feeding device 120, a laser cutting device 125, a laser beam head 129, an air spray nozzle 127, a conveyor 130, a dirt tray 147, a scrap basket 145, a particle extraction device 150, an adsorption conveying device 135, a first image sensor 140 and a second image sensor 155, a normal product magazine 165, a letter paper magazine 170, a defective product magazine 175 and a control device 100.

[0025] The GDL fabric web 300 is wound onto the fabric web unwinder 105, the feeder 120 pulls the wound-up GDL fabric web 300 to the conveyor 130 at a predetermined speed and feeds it in, and the stationery winder 115 pulls off and removes stationery adhering to one side of the GDL fabric web 300.

[0026] The conveyor 130 is actuated by a special drive unit to move the GDL fabric web 300 to the output at a predetermined speed, and the laser cutting device 125 forms cutting units 400 by shining a laser onto the GDL fabric web 300 moving along the conveyor 130, using the laser beam head 129, thereby forming gas diffusion layers 302 in a predetermined shape from the GDL fabric web 300.

[0027] The air spray nozzle 127 removes dirt adhering to the surface of the GDL fabric sheet 300 by spraying air onto the surface of the GDL fabric sheet 300, and the dirt falls away and is collected in the dirt tray 147 under the GDL fabric sheet 300.

[0028] The adsorption conveying device 135 is attached to the surface of the GDL fabric sheet 300 and is moved in the conveying direction of the GDL fabric sheet 300 behind the laser cutting device 125, thereby preventing waste and the gas diffusion layer 302 cut by the GDL fabric sheet 300 from wrinkling.

[0029] A variety of adsorption conveying devices 135 are provided to prevent waste and the gas diffusion layer 302, which are cut (separated) from the GDL fabric sheet 300, from wrinkling on the conveyor 130 and adsorb and move the gas diffusion layer 302 from the GDL fabric sheet 300.

[0030] The waste basket 145 is located at the outlet of the conveyor 130 and collects waste from the separate gas diffusion layer 302, and the particle extraction device 150 sucks and filters granular dirt.

[0031] The first image sensor 140 detects the shapes of the tops (or upper surfaces) of the gas diffusion layers 302 that remain in the GDL fabric web 300 moving along the conveyor 130, and the second image sensor 155 detects the shape of the bottoms (or lower surfaces) of the gas diffusion layers 302 that are conveyed by the adsorption conveying device 135.

[0032] Furthermore, the first image sensor 140 and the second image sensor 155 transmit acquisition data to the control unit 100, and the control unit 100 separates abnormal and normal products by controlling the adsorption conveying unit 135.

[0033] The normal product is loaded into the normal product magazine 165, the letter paper is loaded into the letter paper magazine 170, and the adsorption conveying device 135 inserts a letter paper between the gas diffusion layers 302. Furthermore, defective products are loaded into the defective product magazine 175.

[0034] In an exemplary embodiment of the present invention, the first and second image sensors 140 and 155 can detect contamination of a surface, detect particles of a predetermined size (0.4 mm) or larger, and detect the applied state of carbon slurry, the fracture of a cut surface, and the dimensions and positions of the cut layers (films).

[0035] Furthermore, the laser emitted by the laser beam head 129, which is a FIBER type, has a capacity of 50 W and can perform optimal cutting at 20 kHz, 30 W and 1064 nm.

[0036] Fig. Figure 2 is a perspective view showing a fabric web joining device according to an exemplary embodiment.

[0037] As in Fig. As shown in Figure 2, the fabric web joining device 110 comprises a press mold 210, a first holder 200, a second holder 205, a first holder actuator 215 and a second holder actuator 220.

[0038] When the feed conveyor 305 is stopped, the first holder 200 is actuated by the first holder actuator 215 to hold the front end of a new GDL fabric web 300b, which is fed from the fabric web unwinder 105 via the press mold 210, and the second holder 205 is actuated by the second holder actuator 220 to hold the rear end of the preceding GDL fabric web 300a, which is fed to the feed device 120 via the press mold 210.

[0039] A worker connects the new GDL fabric web 300b, held by the first holder 200, and the previous GDL fabric web 300a, held by the second holder 205, to join them together, and operates the feed device 120 such that the new GDL fabric web 300b is fed to the conveyor 130.

[0040] In an exemplary embodiment of the present invention, it is possible to reduce the waste of GDL fabric webs 300 and to connect the GDL fabric webs 300 more effectively through the fabric web joining device 110, thereby improving work efficiency.

[0041] Fig. Figure 3 is a front view of a feeding device according to an exemplary embodiment.

[0042] As in Fig. As shown in Figure 3, the feeding device 120 has feed belts 305 which come into contact with the lower surface and the upper surface of the GDL fabric web 300, drive rollers 315 which move the feed belts 305, guide rollers 315 and tensioning units 320 which keep the feed belts 305 taut.

[0043] In an exemplary embodiment, the feeding device 120 can stably control the feeding speed of the GDL fabric web 300 by controlling the movement speed of the feeding belts 305 by the drive rollers 310.

[0044] Fig. Figure 4 is a top view showing cutting units that have been cut by a laser in a GDL fabric web according to an exemplary embodiment.

[0045] As in Fig. As shown in Figure 4, cut parts 400 are formed in the GDL fabric web 300 by the laser emitted from the laser beam head 129. Cut parts, which are cut along the cutting units 400, are used as the gas diffusion layers 302.

[0046] As shown in the figure, four gas diffusion layers 302 with a predetermined gap (for example, 8 mm) are arranged in the width direction of the GDL fabric sheet 300. Furthermore, the gas diffusion layers 302 with a predetermined gap (for example, 10 mm) are arranged in the length direction of the GDL fabric sheet 300.

[0047] Fig. Figure 5 is a top view showing a GDL fabric web with cut parts according to an exemplary embodiment, to which an adsorbing part of an adsorption conveying device 135 is attached and moved together.

[0048] As in Fig. As shown in Figure 5, the adsorption conveying device 135 is attached to the gas diffusion layers 302, which are cut along the cutting units 400 in the GDL fabric web 300 and are moved together in the direction of movement of the GDL fabric web 300.

[0049] Accordingly, the gas diffusion layers 302 are prevented from wrinkling, and the gas diffusion layers 302 and the waste can be conveyed stably on the conveyor 130.

[0050] Fig. Figure 6 is a flowchart illustrating a method for cutting a GDL of a fuel cell according to an exemplary embodiment of the present invention.

[0051] As in Fig.As shown in Figure 6, when the control system is started, a GDL fabric web 300, which is wound onto the fabric web unwinder 105, is unwound in step S600, and the previous GDL fabric web 300a and a new GDL fabric web 300b are joined by the fabric web joining device 110 in step S610. The GDL fabric web 300 is fed to the conveyor by the feeder 120, and the conveyor 130 transports the GDL fabric web 300 to the output at a predetermined speed in step S620.

[0052] In step S630, the laser cutting device 125 forms gas diffusion layers 302 along the cutting units 400 by emitting a laser onto the GDL fabric web 300 at a predetermined speed, with a predetermined intensity, and in a predetermined shape. In step S632, the first image sensor 140 detects the upper surfaces of the gas diffusion layers 302 and transmits detection data to the control unit 100.

[0053] In step S640, the adsorption conveying device 135 adsorbs the detached gas diffusion layers 302 and moves with the GDL fabric web 300, separating and conveying the gas diffusion layers 302 from the GDL fabric web 300 by moving upwards to a predetermined position. In step S642, the second image sensor 155 detects the lower surfaces of the gas diffusion layers 302 and transmits detection data to the control unit 100.

[0054] In step S650, the control unit 100 separates the gas diffusion layers 302 into normal or abnormal products based on the data transmitted by the first image sensor 140 and the second image sensor 155. In step S652, defective products are loaded into the reject magazine 175.

[0055] In step S660, the adsorption conveying device 135 moves to the letter paper magazine 170, with the gas diffusion layers 302 adhering to it, and the letter paper is adsorbed under the gas diffusion layers 302.

[0056] This means that the adsorption conveying unit 135 adsorbs the gas diffusion layers 302 and the letter paper together. Subsequently, in step S670, the adsorption conveying unit 135 moves to the normal product magazine 165 and fills it with the letter paper and the gas diffusion layers 302 together.

Claims

[1] Gas diffusion layer (GDL) cutting system for a fuel cell, comprising: a laser cutting device (125) that forms a gas diffusion layer (302) by shining a laser onto a surface of a GDL fabric web (300) moving on a conveyor (130); an adsorption conveying device (135) that adsorbs and transports at least two gas diffusion layers (302) that have been cut by the laser cutting device (125); a first image sensor (140) that detects a top side of the gas diffusion layers (302) cut by the laser cutting device (125); and a second image sensor (155) that detects an underside of the gas diffusion layers (302) which are adsorbed and transported by the adsorption conveying device (135), characterized by , that it further includes: a fabric web unwinder (105) on which the GDL fabric web (300) is wound and which is arranged in front of the conveyor (130); a feeding device (120) which continuously feeds the GDL fabric web (300), which is wound onto the fabric web unwinder (105), to an inlet of the conveyor (130) by pulling the GDL fabric web (300); and a fabric web joining device (110) arranged between the fabric web unwinder (105) and the feed device (120) and joining a new GDL fabric web (300) to a previous GDL fabric web (300), wherein the fabric web joining device (110) further comprises: a first holder (200) designed to hold a rear end of a previous GDL fabric web (300); a second holder (205) designed to hold a leading end of a new GDL fabric sheet (300); and Holder actuators (215, 220) that actuate the first (200) and second (205) holders, so that the first (200) and second (205) holders fix the previous GDL fabric web (300) and the new GDL fabric web (300). [2] System according to claim 1, further comprising: a waste basket (145) located at an outlet of the conveyor (130) and collects waste from the gas diffusion layers (302) that has been separated from the GDL fabric web (300). [3] System according to claim 1, further comprising: a control device which determines whether the sliced ​​gas diffusion layers (302) are normal or abnormal based on image signals sent by at least one of the first image sensor (140) and the second image sensor (155). [4] System according to claim 3, further comprising: a normal product magazine (165) into which normal products of the gas diffusion layers (302) are loaded; a waste product magazine (175) into which abnormal products of the gas diffusion layers (302) are loaded; and a stationery magazine (170) into which stationery is loaded, which is to be inserted between the gas diffusion layers (302). [5] System according to claim 1, wherein the adsorption conveying device (135) moves a predetermined distance with the GDL fabric sheet (300) at the same speed on the conveyor (130), wherein an adsorption surface of the adsorption conveying device (135) is in contact with the upper surfaces of the gas diffusion layers (302), and the adsorption conveying device (135) separates the cut gas diffusion layers (302) from the GDL tissue pathway (300) by an upward movement. [6] System according to claim 1, further comprising a dirt tray (147) designed to collect dirt falling from the GDL fabric sheet (300) under the conveyor (130); and a particle extraction device (150) which is arranged at the outlet of the conveyor (130) and It filters out granular dirt. [7] System according to claim 1, wherein the laser cutting device (125) comprises: a laser head (129) with a laser that emits in a preset shape; and an air spray nozzle (127) arranged on one side of the laser head and dirt is removed by spraying air onto the surface of the GDL fabric sheet (300). [8] Method for cutting a gas diffusion layer (302) (GDL) for a fuel cell, comprising the steps: Feeding a GDL fabric web (300) to an inlet of a conveyor (130); Forming the gas diffusion layer (302) by cutting the GDL fabric sheet (300) with a laser beam directed at the GDL fabric sheet (300) moving on the conveyor (130); and Performing a visual inspection of the top and bottom surfaces of the gas diffusion layer (302), Filtering of granular dirt at one outlet of the conveyor (130). [9] The method of claim 8, further comprising a step of: Collection of waste from the gas diffusion layer (302) that has been separated from the GDL fabric sheet (300). [10] Method according to claim 8, wherein in the step of cutting the gas diffusion layer (302) with the laser, dirt adhering to the GDL fabric web (300) is removed by spraying with air. [11] Method according to claim 8, wherein normal gas diffusion layers (302) and abnormal gas diffusion layers (302) are separated and loaded according to the result of visual inspection. [12] Method according to claim 8, wherein the step of performing a visual inspection of the top and bottom of the gas diffusion layer (302) is carried out while the gas diffusion layer (302) is moved.

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