Porous substrate layer and electrochemical device

Abstract

The invention relates to a porous substrate layer and an electrochemical device. The porous base material layer includes: a porous base material portion provided between a membrane electrode assembly (MEA) and a separator including channels and non-channels; the channel area is limited on the porous base material part and corresponds to the channel; a non-channel region defined in the porous base material portion, corresponding to the non-channel, and provided so as to be in contact with the non-channel; and at least one through-hole provided in the non-channel region such that the target fluid passes through the through-hole, thereby obtaining advantageous effects of ensuring performance and working efficiency and improving durability and reliability.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] The present application claims priority to Korean Patent Application No. 10-2023-0076321 filed on Jun. 14, 2023, the entire contents of which application is incorporated herein for all purposes by this reference. Technical Field

[0003] The present invention relates to a porous substrate layer and an electrochemical device, and more particularly, to a porous substrate layer capable of ensuring performance and operating efficiency and improving durability and reliability. Background Art

[0004] In response to global warming and the depletion of fossil fuels, the need for research and development of alternative energy sources is increasing. Hydrogen energy has attracted attention as a practical solution to environmental and energy issues.

[0005] Hydrogen has attracted much attention as a future energy carrier due to its high energy density and suitability for grid-scale applications.

[0006] A water electrolysis stack, one of the electrochemical devices, refers to a device that generates hydrogen and oxygen by electrochemically decomposing water. The water electrolysis stack can be configured by stacking dozens or hundreds of water electrolysis cells (unit cells) in series.

[0007] The membrane electrode assembly (MEA) is located at the innermost side of the unit electrolysis cell of the water electrolysis stack. The membrane electrode assembly includes: a perfluorosulfonic acid ion-based electrolyte membrane configured for hydrogen ion (proton) movement, and an anode electrode and a cathode electrode respectively disposed on two opposite surfaces of the electrolyte membrane.

[0008] In addition, a porous transport layer (PTL), a gas diffusion layer (GDL), and a gasket may be stacked on each of the outer portion (outer surface) of the membrane electrode assembly (MEA) where the anode and the cathode are located. A diaphragm (or bipolar plate) may be disposed on the outer side (outer surface) of the porous transport layer (PTL) and the gas diffusion layer (GDL). The diaphragm includes a flow path (flow field) through which reactants, a coolant, and products produced by the reaction flow, or the diaphragm may include a structure that can replace the flow path.

[0009] The information included in the Background of the Invention is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgment or any form of suggestion that this information forms the prior art already known to a person skilled in the art. Summary of the invention

[0010] Various aspects of the present invention are directed to providing a porous substrate layer and an electrochemical device configured to ensure performance and operating efficiency and to improve durability and reliability.

[0011] The present invention also aims to effectively diffuse the target fluid and uniformly supply the target fluid to the entire area of ​​the membrane electrode assembly.

[0012] The present invention is directed to, among other things, efficient supply of a target fluid to a non-channel region of a porous substrate layer disposed in contact with a non-channel of a membrane.

[0013] The present invention is also directed to increasing the permeability of the porous substrate layer and improving the transfer efficiency of the target fluid (the permeability of the target fluid).

[0014] The present invention also aims to improve stability, reliability and durability.

[0015] Objects achieved by the exemplary embodiments are not limited to the above-mentioned objects, but also include objects or effects that can be understood from solutions or embodiments described below.

[0016] An exemplary embodiment of the present invention provides a porous substrate layer, which includes: a porous substrate portion, a channel region, a non-channel region, and at least one through hole, wherein the porous substrate portion is arranged between a membrane electrode assembly (MEA) and a diaphragm including a channel and a non-channel; the channel region is limited to the porous substrate portion corresponding to the channel; the non-channel region is limited to the porous substrate portion corresponding to the non-channel and is arranged to contact the non-channel; the at least one through hole is arranged in the non-channel region so that the target fluid passes through the through hole.

[0017] According to an exemplary embodiment of the present invention, the porosity of the non-channel region may be defined to increase in a direction from an inlet portion to an outlet portion of the channel in a length direction of the channel.

[0018] According to an exemplary embodiment of the present invention, the through hole may include: a first through hole and a second through hole; the second through hole is defined to have a size different from that of the first through hole and is spaced apart from the first through hole in a length direction of the channel.

[0019] According to an exemplary embodiment of the present invention, the through hole may include: a first through hole and a second through hole; the second through hole is disposed at a downstream side of the first through hole in a length direction of the channel and is defined to have a relatively larger cross-sectional area than the first through hole.

[0020] According to an exemplary embodiment of the present invention, the through hole may be defined to have a cross-sectional area gradually increasing in a direction from an inlet end to an outlet end of the channel in a length direction of the channel.

[0021] According to an exemplary embodiment of the present invention, the porous substrate portion may be defined to have pores of 9 μm to 16 μm.

[0022] According to an exemplary embodiment of the present invention, the through hole may be defined to have a diameter of 20 μm to 50 μm.

[0023] According to an exemplary embodiment of the present invention, the channel region may be defined to have a predetermined reference porosity, and the non-channel region including the through-holes may be defined to have a porosity of 120% to 200% of the reference porosity.

[0024] Another exemplary embodiment of the present invention provides an electrochemical device, which includes: a membrane electrode assembly (MEA), a diaphragm and a porous substrate layer; the diaphragm includes a channel and a non-channel arranged on a surface facing the membrane electrode assembly, and the diaphragm is stacked on the membrane electrode assembly; the porous substrate layer is arranged between the diaphragm and the membrane electrode assembly; wherein the porous substrate layer includes: a porous substrate portion, a channel area, a non-channel area and at least one through hole, and the porous substrate portion is arranged between the diaphragm and the membrane electrode assembly (MEA); the channel area is limited to the porous substrate portion corresponding to the channel; the non-channel area is limited to the porous substrate portion corresponding to the non-channel and is arranged to contact the non-channel; the at least one through hole is arranged in the non-channel area so that the target fluid passes through the through hole.

[0025] According to an exemplary embodiment of the present invention, the porosity of the non-channel region may be defined to increase in a direction from an inlet portion to an outlet portion of the channel in a length direction of the channel.

[0026] According to an exemplary embodiment of the present invention, the through hole may include: a first through hole and a second through hole; the second through hole is defined to have a size different from that of the first through hole and is spaced apart from the first through hole in a length direction of the channel.

[0027] According to an exemplary embodiment of the present invention, the through hole may include: a first through hole and a second through hole; the second through hole is disposed at a downstream side of the first through hole in a length direction of the channel and is defined to have a relatively larger cross-sectional area than the first through hole.

[0028] According to an exemplary embodiment of the present invention, the plurality of through holes may be respectively defined to have a cross-sectional area gradually increasing in a direction from an inlet end to an outlet end of the channel in a length direction of the channel.

[0029] According to an exemplary embodiment of the present invention, the porous substrate portion may be defined to have pores of 9 μm to 16 μm.

[0030] According to an exemplary embodiment of the present invention, the through hole may be defined to have a diameter of 20 μm to 50 μm.

[0031] According to an exemplary embodiment of the present invention, the channel region may be defined to have a predetermined reference porosity, and the non-channel region including the through-holes may be defined to have a porosity of 120% to 200% of the reference porosity.

[0032] The methods and apparatus of the present invention have other features and advantages, which will be apparent from, or will be described in more detail in, the accompanying drawings and the following detailed description incorporated herein, which together serve to explain the specific principles of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 is a schematic diagram for explaining an electrochemical device according to an exemplary embodiment of the present invention.

[0034] Figure 2 is a schematic diagram for explaining a porous substrate layer of an electrochemical device according to an exemplary embodiment of the present invention.

[0035] Figure 3 is a schematic diagram for explaining a process of manufacturing a porous substrate layer of an electrochemical device according to an exemplary embodiment of the present invention.

[0036] Figure 4 and Figure 5 is a schematic diagram of a forming roller for explaining a process for manufacturing a porous substrate layer for an electrochemical device according to an exemplary embodiment of the present invention.

[0037] Figure 6 , Figure 7 , Figure 8 and Fig. 9 : is a schematic diagram for explaining a modified example of the porous substrate layer of the electrochemical device according to the exemplary embodiment of the present invention.

[0038] It should be understood that the accompanying drawings are not necessarily drawn to scale, but are appropriately simplified drawings of various features presented to illustrate the basic principles of the present invention. The predetermined design features of the present invention included herein (for example, including specific size, direction, position and shape) will be determined in part by the specific intended application and use environment.

[0039] In the drawings, like reference numerals refer to the same or equivalent parts of the present invention throughout the several figures of the drawing. DETAILED DESCRIPTION

[0040] Reference will now be made in detail to various embodiments of the present invention, examples of which are illustrated in the accompanying drawings and described below. Although the present invention will be described in conjunction with exemplary embodiments of the present invention, it should be understood that this specification is not intended to limit the present invention to those exemplary embodiments of the present invention. On the other hand, the present invention is intended to cover not only the exemplary embodiments of the present invention, but also various alternative embodiments, modified embodiments, equivalent embodiments or other embodiments that may be included in the spirit and scope of the present invention as defined by the appended claims.

[0041] Hereinafter, various exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0042] However, the technical spirit of the present invention is not limited to the various exemplary embodiments described herein, but can be implemented in various different forms. At least one constituent element in the exemplary embodiments of the present invention can be selectively combined and replaced to be used within the scope of the technical spirit of the present invention.

[0043] In addition, unless otherwise specifically and clearly defined and explained, the terms (including technical and scientific terms) used in the exemplary embodiments of the present invention may be interpreted as the meanings commonly understood by those of ordinary skill in the art to which the present invention belongs. The meanings of commonly used terms (e.g., terms defined in dictionaries) may be interpreted based on the contextual meanings of the relevant technology.

[0044] Furthermore, terms used in the exemplary embodiments of the present invention are for explaining the embodiments but are not for limiting the present invention.

[0045] In this specification, unless otherwise specified, a singular form may also include a plural form. The expression "at least one (or one or more) of A, B, and C" may include one or more combinations of all combinations that can be formed by combining A, B, and C.

[0046] Furthermore, terms such as first, second, A, B, (a), and (b) may be used to describe constituent elements of exemplary embodiments of the present invention.

[0047] These terms are used only to distinguish one constituent element from another constituent element, and the nature, sequence or order of the constituent elements is not limited by these terms.

[0048] Furthermore, when one constituent element is referred to as being “connected,” “joined” or “attached” to another constituent element, the one constituent element may be directly connected, joined or attached to the other constituent element or connected, joined or attached to the other constituent element with another constituent element interposed therebetween.

[0049] In addition, the expression "one constituent element is disposed or arranged above (upper) or below (lower) another constituent element" includes not only the case where the two constituent elements are in direct contact with each other, but also the case where one or more other constituent elements are disposed or arranged between the two constituent elements. The expression "above (upper) or below (lower)" may refer to a downward direction and an upward direction based on one constituent element.

[0050] refer to Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 , Figure 6 , Figure 7 , Figure 8 and Fig. 9 According to an exemplary embodiment of the present invention, the porous substrate layer 200 includes a porous substrate portion 210, a channel area CA, a non-channel area (land area) LA and a through hole 220, wherein the porous substrate portion 210 is arranged between a membrane electrode assembly (MEA) 100 and a diaphragm 300, and the diaphragm 300 includes a channel 310 and a non-channel (land) 320; the channel area CA is limited to the porous substrate portion 210 corresponding to the channel 310; the non-channel area LA is limited to the porous substrate portion 210 corresponding to the non-channel 320, and is arranged to contact the non-channel 320; the through hole 220 is arranged in the non-channel area LA so that the target fluid can pass through the through hole 220.

[0051] For reference, the porous substrate layer 200 according to the exemplary embodiment of the present invention may form the electrochemical device 10 together with the membrane electrode assembly (MEA) 100 .

[0052] In this case, the electrochemical device 10 is defined to include both a water electrolysis stack configured to generate hydrogen and oxygen by electrochemically decomposing water and a fuel cell stack configured to generate electrical energy through a chemical reaction of a fuel (eg, hydrogen).

[0053] Hereinafter, an example will be described in which the electrochemical device 10 according to the exemplary embodiment of the present invention is used as a water electrolysis stack for decomposing water through an electrochemical reaction to generate hydrogen and oxygen.

[0054] The present invention aims to ensure the performance and operating efficiency of the electrochemical device 10 and to improve the stability and reliability of the electrochemical device 10 .

[0055] That is, the performance and output of the electrochemical device are determined according to the transfer flow rate of the target fluid (e.g., water) to be transferred to the membrane electrode assembly 100. Therefore, it is necessary to ensure a sufficient transfer flow rate of the target fluid to be transferred to the membrane electrode assembly 100 to improve the performance and output of the electrochemical device. In addition, it is necessary to evenly disperse (diffuse) the target fluid over the entire cross section of the membrane electrode assembly 100.

[0056] However, in the related art, since the structural characteristics of the diaphragm include a recessed channel through which the reaction gas flows and a protruding non-channel provided in contact with the porous substrate layer, the channel region of the porous substrate layer corresponding to the channel can fully ensure the transfer flow rate (transfer efficiency) of the target fluid to be transferred to the membrane electrode assembly. However, the non-channel region of the porous substrate layer in contact with the non-channel is difficult to fully ensure the transfer flow rate (transfer efficiency) of the target fluid to be transferred to the membrane electrode assembly. For this reason, there is a problem that it is difficult to achieve stable performance of the electrochemical device and improve the output.

[0057] Furthermore, in the related art, there is a problem that it is difficult to uniformly supply the target fluid to the entire area (channel area and non-channel area) of the porous substrate layer, which reduces the durability of the membrane electrode assembly and the porous substrate layer.

[0058] In contrast, in the exemplary embodiment of the present invention, the through hole 220 through which the target fluid can pass can be provided in the non-channel area LA of the porous substrate portion 210 in contact with the non-channel 320 of the diaphragm 300. Therefore, the advantageous effect of sufficiently ensuring the transfer flow rate (transfer efficiency) of the target fluid to be transferred to the membrane electrode assembly 100 can be obtained not only in the channel area CA of the porous substrate layer 200 corresponding to the channel 310 but also in the non-channel area LA of the porous substrate layer 200 in contact with the non-channel 320.

[0059] Furthermore, according to the exemplary embodiment of the present invention, the target fluid can be sufficiently supplied to the non-channel area LA of the porous substrate portion 210 through the through hole 220. Therefore, the advantageous effects of minimizing the occurrence of a dead zone where the target fluid cannot be supplied to a specific portion of the membrane electrode assembly 100 and improving the durability of the membrane electrode assembly 100 and the porous substrate layer 200 can be obtained.

[0060] Furthermore, according to the exemplary embodiment of the present invention, the through hole 220 is provided in the porous substrate layer 200 provided in contact with the membrane electrode assembly 100, so that the porosity of the porous substrate layer 200 can be increased. Therefore, the permeability of the target fluid with respect to the porous substrate layer 200 can be increased. In addition, the moving route of the target fluid passing through the porous substrate layer 200 can be shortened (compared to the actual moving route of the shortest straight line route passed by the target fluid) by reducing the tortuosity in the thickness direction of the porous substrate layer 200.

[0061] A water electrolysis stack (electrochemical device) can be configured by stacking a plurality of unit electrolysis cells in a reference stacking direction.

[0062] The unit electrolytic cell may include a reaction layer and a diaphragm 300, wherein the diaphragm 300 is stacked on one surface and the other surface of the reaction layer, respectively. The water electrolysis stack may be configured by stacking a plurality of unit electrolytic cells in a reference stacking direction and then assembling end plates to two opposite ends of the plurality of unit electrolytic cells.

[0063] The reaction layer may have various structures configured to generate an electrochemical reaction of a target fluid (eg, water). The present invention is not restricted or limited by the type and structure of the reaction layer.

[0064] For example, the reaction layer may include a membrane electrode assembly (MEA) 100 and a porous substrate layer 200 disposed in close contact with two opposite surfaces of the membrane electrode assembly 100 .

[0065] The structure and material of the membrane electrode assembly 100 may be changed differently according to required conditions and design specifications, and the present invention is not restricted or limited by the structure and material of the membrane electrode assembly 100 .

[0066] For example, the membrane electrode assembly 100 may be configured by attaching catalyst electrode layers (eg, an anode layer and a cathode layer) that generate an electrochemical reaction to two opposite surfaces of an electrolyte membrane (eg, a perfluorosulfonic acid ion-based electrolyte membrane).

[0067] For reference, water supplied to the anode layer (which is an oxidation electrode for water electrolysis) is decomposed into hydrogen ions (protons), electrons and oxygen. Accordingly, hydrogen ions move to the cathode layer as a reduction electrode through the electrolyte membrane, and electrons move to the cathode through an external circuit. In addition, oxygen can be discharged to the anode outlet, and hydrogen ions and electrons can be converted into hydrogen at the cathode and then discharged to the cathode outlet.

[0068] The diaphragm 300 and the reaction layer (membrane electrode assembly) can form a single unit electrolytic cell (water electrolytic cell). The diaphragm 300 is configured to separate and block the water (or water and oxygen) on the anode side and the hydrogen generated by the reaction layer on the cathode side. The diaphragm 300 can also be configured to ensure the flow path (flow field) of the fluid.

[0069] In addition, the diaphragm 300 may also be configured such that heat generated from the unit electrolytic cells is distributed to the entire unit electrolytic cells, and excessively generated heat may be discharged to the outside through water flowing along the diaphragm 300 .

[0070] For example, in an exemplary embodiment of the present invention, the separator 300 is defined to include both the anode separator 300 and the cathode separator 300 which independently define the flow paths (channels) of water (or water and oxygen) and the flow paths (channels) of hydrogen in the water electrolysis stack.

[0071] For example, the separator 300 (anode separator) facing one surface of the membrane electrode assembly 100 may define a flow path (channel) for water (or water and oxygen). The separator 300 (cathode separator) facing the other surface of the membrane electrode assembly 100 may define a flow path (channel) for hydrogen.

[0072] The separator 300 may be stacked on the membrane electrode assembly 100. The channel 310 through which the target fluid (hydrogen or water) flows may be provided on one surface of the separator 300 facing the membrane electrode assembly 100. The non-channel 320 in contact with the porous substrate layer 200 may be provided on one surface of the separator 300 facing the membrane electrode assembly 100. The cooling channel through which the coolant flows may be provided on the other surface of the separator 300.

[0073] According to an exemplary embodiment of the present invention, at least one of the non-channel 320 and the channel 310 may be defined as a straight line shape. Hereinafter, an example in which both the non-channel 320 and the channel 310 are defined as a straight line shape will be described.

[0074] According to another exemplary embodiment of the present invention, at least any one of the non-channel and the channel may be defined as a curved shape (e.g., an arc shape). Alternatively, at least any one of the non-channel and the channel may be configured to include a structure having a combination of a straight line shape and a curved line shape.

[0075] The diaphragm 300 may have various structures and may be made of various materials according to required conditions and design specifications. The present invention is not restricted or limited by the structure and material of the diaphragm 300 .

[0076] For example, the diaphragm 300 may include an approximately quadrilateral plate shape and be made of metal (eg, titanium, stainless steel, Inconel, or aluminum).

[0077] According to another exemplary embodiment of the present invention, the diaphragm may be provided in a circular shape or other shapes. The diaphragm may be made of other materials such as graphite or carbon composites.

[0078] refer to Figure 1 and Figure 2The porous substrate layer 200 is disposed between the membrane electrode assembly 100 and the diaphragm 300, and is configured to uniformly distribute (move or discharge) the target fluid (e.g., water or hydrogen) while being provided as a moving channel for electrons. The porous substrate layer 200 includes a porous substrate portion 210, a channel region CA, a non-channel region LA, and a through hole 220. The porous substrate portion 210 is disposed between the membrane electrode assembly (MEA) and the diaphragm 300; the channel region CA is defined in the porous substrate portion 210 corresponding to the channel 310; the non-channel region LA is defined in the porous substrate portion 210 corresponding to the non-channel 320, and is provided to be in contact with the non-channel 320; the through hole 220 is provided in the non-channel region LA so that the target fluid can pass through the through hole 220.

[0079] The porous substrate portion 210 may have various structures according to required conditions and design specifications.

[0080] For example, the porous base portion 210 may be provided in a shape of an approximately flat quadrilateral plate corresponding to the separator 300 .

[0081] The porous substrate portion 210 may be configured as a typical porous structure including pores. The present invention is not restricted or limited by the structure of the porous substrate portion 210 and the method of manufacturing the porous substrate portion 210 .

[0082] For example, the porous substrate portion 210 may be provided similarly in characteristics to a typical anode porous transport layer (PTL).

[0083] According to the exemplary embodiment of the present invention, the porous base material portion 210 may be manufactured by forming a base material layer slurry SL containing a metal element into an approximately plate shape and then performing a heat treatment process (a degreasing process and a sintering process).

[0084] The channel area CA is defined in the porous substrate portion 210 to correspond to the channel 310 .

[0085] In the exemplary embodiment of the present invention, the channel area CA may be understood as an area of ​​the porous substrate portion 210 facing the channel 310 of the separator 300. The target fluid flowing along the channel 310 may be supplied to the membrane electrode assembly 100 via the channel area CA.

[0086] For example, the channel area CA may be defined in a straight line shape corresponding to the channel 310 .

[0087] The non-channel area LA is defined in the porous substrate portion 210 to correspond to the non-channel 320 .

[0088] In the exemplary embodiment of the present invention, the non-channel area LA may be understood as an area of ​​the porous substrate portion 210 facing the non-channel 320 of the separator 300 and in direct contact with the non-channel 320 of the separator 300 .

[0089] For example, the non-channel area LA may be defined as a straight line shape corresponding to the non-channel 320 .

[0090] The through holes 220 are provided in the non-channel area LA so that the target fluid can pass through the through holes 220. The through holes 220 are provided so that even in the non-channel area LA of the porous substrate layer 200 in contact with the non-channel 320, the transfer flow rate (transfer efficiency) of the target fluid to be transferred to the membrane electrode assembly 100 can be sufficiently ensured.

[0091] This is intended to uniformly transfer the target fluid to the entire area of ​​the membrane electrode assembly 100 .

[0092] That is, the target fluid moving along the channel 310 may diffuse along the porous substrate layer 200 and then be supplied to the membrane electrode assembly 100. However, the amount of the target fluid diffused in the non-channel area LA of the porous substrate layer 200 facing the non-channel 320 of the diaphragm 300 is relatively small compared to the channel area CA of the porous substrate layer 200 facing the channel 310 of the diaphragm 300. For this reason, there is a problem in that it is difficult to uniformly supply the target fluid to the entire area of ​​the membrane electrode assembly (the entire area includes the channel area CA and the non-channel area LA).

[0093] However, according to the exemplary embodiment of the present invention, the through hole 220 is provided in the non-channel area LA of the porous substrate layer 200, so that the permeability (porosity) of the non-channel area LA can be increased. Therefore, the advantageous effect of minimizing the deterioration of the transfer flow rate of the target fluid to be supplied to the area of ​​the membrane electrode assembly 100 corresponding to the channel area CA and the area of ​​the membrane electrode assembly 100 corresponding to the non-channel area LA can be obtained. In addition, the advantageous effect of minimizing the occurrence of a dead zone where the target fluid cannot be supplied to a specific portion of the membrane electrode assembly 100 can be obtained.

[0094] The through hole 220 may have various structures and shapes according to required conditions and design specifications. The present invention is not restricted or limited by the structure and shape of the through hole 220.

[0095] According to an exemplary embodiment of the present invention, the through hole 220 may be provided as a plurality of through holes 220 that are provided in the non-channel area LA and are spaced apart from each other.

[0096] Hereinafter, an example in which the plurality of through holes 220 are provided in the non-channel area LA and are spaced apart from each other at predetermined intervals in the length direction LD and the width direction of the non-channel 320 will be described.

[0097] According to another exemplary embodiment of the present invention, a plurality of through holes may be provided in the non-channel region and spaced apart from each other at irregular intervals. Alternatively, only one through hole may be provided in the non-channel region.

[0098] In addition, the through hole 220 may have various cross-sectional shapes, such as a circular shape, a polygonal (eg, quadrilateral) shape, and an elliptical shape. The present invention is not restricted or limited by the cross-sectional shape of the through hole 220. Hereinafter, an example in which the through hole 220 has a circular cross-sectional shape will be described.

[0099] According to an exemplary embodiment of the present invention, the porosity of the porous substrate layer 200 may increase in the length direction LD of the channel 310 in a direction from the inlet portion 225 of the channel 310 to the outlet portion 235 of the channel 310 (based on Figure 7 direction from left to right).

[0100] This is based on the fact that the transfer flow rate of the target fluid to be transferred to the membrane electrode assembly 100 via the porous substrate layer 200 decreases toward the downstream side (the outlet portion of the channel) of the porous substrate layer 200. Since the porosity of the porous substrate layer 200 increases toward the downstream side (the outlet portion of the channel) of the porous substrate layer 200, an advantageous effect of more uniformly supplying the target fluid to the entire area of ​​the membrane electrode assembly 100 can be obtained.

[0101] As described above, in order to increase the porosity of the downstream side of the porous substrate layer 200, the porosity of the non-channel region LA of the porous substrate portion 210 may be increased along the length direction LD of the channel 310 from the inlet portion of the channel 310 (based on Figure 7 left end) to the exit (based on Figure 7 The direction of the right end) gradually increases.

[0102] According to an exemplary embodiment of the present invention, the through hole 220 may include a first through hole 220a and a second through hole 220b, wherein the first through hole 220a is arranged in the non-channel area LA, and the size of each second through hole 220b is different from that of the first through hole 220a and is spaced apart from the first through hole 220a along the length direction LD of the channel 310.

[0103] Specifically, the second through hole 220b is disposed at a downstream side of the first through hole 220a in the length direction LD of the passage 310. The second through hole 220b may be defined to have a relatively larger cross-sectional area (eg, a larger diameter) than the first through hole 220a.

[0104] More specifically, the plurality of through holes 220 disposed in the non-channel area LA may be respectively defined to include a cross-sectional area gradually increasing in a direction from an inlet end portion to an outlet end portion of the channel 310 in the length direction LD of the channel 310. Therefore, the porosity of the porous substrate layer 200 may gradually increase in a direction from an inlet portion to an outlet portion of the channel 310 in the length direction LD of the channel 310.

[0105] According to an exemplary embodiment of the present invention, the porous substrate portion 210 may be defined to have pores of 9 μm to 16 μm, and the through-holes 220 may be defined to have a diameter (or length) of 20 μm to 50 μm.

[0106] That is, when the diameter of the through hole 220 is less than 20 μm, it is difficult to sufficiently ensure the transmittance (porosity) of the non-channel area LA. In contrast, when the diameter of the through hole 220 is greater than 50 μm, it is difficult to sufficiently ensure the rigidity of the porous substrate layer 200.

[0107] Therefore, under the condition that the porous substrate portion 210 has pores of 9 μm to 16 μm, the through hole 220 can be defined to have a diameter (or length) of 20 μm to 50 μm. More specifically, under the condition that the porous substrate portion 210 has pores of 9 μm to 16 μm, the through hole 220 can be defined to have a diameter (or length) of 20 μm to 30 μm.

[0108] According to an exemplary embodiment of the present invention, the channel area CA may be defined to have a predetermined reference porosity, and the non-channel area LA including the through holes 220 may be defined to have a porosity of 120% to 200% of the reference porosity.

[0109] For example, the channel area CA may be defined to have a reference porosity of 30% to 40%, and the non-channel area LA including the through holes 220 may be defined to have a porosity of 120% to 200% of the reference porosity.

[0110] That is, if the porosity of the non-channel region LA (including the non-channel region of the through hole) is less than 120% of the porosity (reference porosity) of the channel region CA, it is difficult to sufficiently ensure the transmittance (porosity) of the non-channel region LA. In contrast, if the porosity of the non-channel region LA (including the non-channel region of the through hole) is greater than 200% of the porosity (reference porosity) of the channel region CA, it is difficult to sufficiently ensure the rigidity of the porous substrate layer 200.

[0111] Therefore, the channel area CA may be defined as having a reference porosity of 30% to 40%, and the non-channel area LA including the through hole 220 may be defined as having a porosity of 120% to 200% of the reference porosity. More specifically, the channel area CA may be defined as having a reference porosity of 30% to 40%, and the non-channel area LA including the through hole 220 may be defined as having a porosity of 120% to 150% of the reference porosity.

[0112] According to an exemplary embodiment of the present invention, the through hole 220 disposed on the downstream side of the non-channel area LA (the downstream side of the non-channel area LA corresponding to the outlet portion of the channel) may be defined as having a diameter (or length) of 20 μm to 50 μm. More specifically, the through hole 220 disposed on the downstream side of the non-channel area LA (the downstream side of the non-channel area corresponding to the outlet portion of the channel) may be defined as having a diameter (or length) of 20 μm to 30 μm.

[0113] According to an exemplary embodiment of the present invention, the interval (region) in which the through hole 220 is provided can be defined as a non-channel area LA corresponding to 20% to 50% of the total length of the diaphragm 300 based on the outlet end portion (the outlet end portion of the channel) of the diaphragm 300. More specifically, the interval (region) in which the through hole 220 is provided can be defined as a non-channel area LA corresponding to 20% to 30% of the total length of the diaphragm 300 based on the outlet end portion (the outlet end portion of the channel) of the diaphragm 300.

[0114] According to another exemplary embodiment of the present invention, the through hole 220 may be provided in the entire section (area) of the non-channel area LA instead of a partial section (see Fig. 9 ).

[0115] Meanwhile, the porous substrate layer 200 including the through-holes 220 may be manufactured in various ways according to required conditions and design specifications. The present invention is not restricted or limited by the method of manufacturing the porous substrate layer 200.

[0116] For example, refer to Figure 3 The porous substrate layer 200 can be manufactured in a roll-to-roll manner by the following method: a substrate layer slurry SL is applied (input) onto one surface of a release sheet 500, the substrate layer slurry SL is thinned and flattened by using a scraper or the like, and then a porous substrate portion 210 is formed (pressed) by using a molding roller 400 including a molding protrusion 410 (which is cured (solidified) by a dryer 510 (e.g., an infrared dryer)).

[0117] For reference, the release sheet 500 may be made of various materials according to the required conditions and design specifications. The present invention is not restricted or limited by the material and properties of the release sheet 500.

[0118] For reference, the release sheet 500 can be provided by utilizing at least any one of polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polycyclohexylene terephthalate (PCT), low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), thermoplastic polyurethane (TPU), unstretched polypropylene (CPP) and polyvinylidene fluoride (PVDF).

[0119] In addition, the release sheet 500 may be configured as a single layer or by stacking a plurality of different layers.

[0120] The release sheet 500 may be wound around the first winding roller. The second winding roller may be configured to wind the release sheet 500 in a direction from one side to the other side along an open loop-shaped moving track.

[0121] In this case, the configuration of winding the release sheet 500 from one side to the other side may be defined as a configuration in which the release sheet moves (winds) along an open loop type movement trajectory in a roll-to-roll manner like a typical cassette tape.

[0122] One end of the release sheet 500 may be fixed to the first winding roller, and the other end of the release sheet 500 may be fixed to the second winding roller. When the first winding roller and the second winding roller rotate (e.g., clockwise), the release sheet 500 wound around the first winding roller may be wound around the second winding roller. When the release sheet 500 is wound around the second winding roller from the first winding roller (e.g., wound at a speed of 0.3 m / min to 1 m / min), the substrate layer slurry SL may be applied to one surface of the release sheet 500.

[0123] In addition, when the release sheet 500 is wound around the second winding roller, the release sheet 500 may be wound in a state where a separate protective film is stacked on the release sheet 500 .

[0124] The base layer slurry SL can be provided by mixing various materials according to required conditions and design specifications. The present invention is not restricted or limited by the types of materials forming the base layer slurry SL and the composition ratios of the materials.

[0125] For example, the base layer slurry SL may be provided by mixing a metal element, a solvent, a dispersant, and a coupling agent.

[0126] At least one of a linear type of metal element, a powder type of metal element, and a network type of metal element may be used as the metal element included in the base material layer slurry SL.

[0127] For example, the metal element may include a titanium group element. More specifically, the titanium group element may include at least any one of titanium, zirconium, and hafnium.

[0128] According to another exemplary embodiment of the present invention, other metal elements such as nickel or stainless steel may be used as the metal element instead of the titanium group element.

[0129] In addition, the metal element (e.g., titanium group element) can have various shapes configured to manufacture the porous substrate layer 200. The present invention is not limited or restricted by the shape and structure of the metal element. For example, the metal element (e.g., titanium group element) can be arranged in a circular, oval, irregular or fibrous shape.

[0130] Specifically, the titanium group element may have an average particle size of 10 μm to 80 μm.

[0131] More specifically, the average particle size of the titanium group element may be 10 μm to 40 μm. If the average particle size of the titanium group element is less than 10 μm, there is a problem that the porosity and pore size of the porous substrate layer 200 are too small and the brittleness is high. In contrast, if the average particle size of the titanium group element is greater than 40 μm, the porosity of the porous substrate layer 200 is too high, the illumination is high, and the resistance in the water electrolysis stack increases, which may lead to performance degradation problems. Therefore, the average particle size of the titanium group element may be limited to 10 μm to 40 μm.

[0132] For example, the average particle size of the titanium group element may be defined as a particle size of 50% (D50) of cumulative distribution in a particle size distribution measured by a particle size analyzer (PSA).

[0133] According to an exemplary embodiment of the present invention, the substrate layer slurry SL may include 60 wt % to 98 wt % of a titanium group element with respect to the total weight of the substrate layer slurry SL.

[0134] If the content of the titanium group element is less than 60 wt % relative to the total weight of the substrate layer slurry SL, the distance between the titanium group elements is long during the process of heat treatment of the porous substrate layer 200 (degreasing process and sintering process), which may lead to problems such as the sintering process cannot be smoothly performed, the porosity of the porous substrate layer 200 is too high, and the rigidity is low. In contrast, if the content of the titanium group element is greater than 98 wt % relative to the total weight of the substrate layer slurry SL, the porosity of the porous substrate layer 200 is too low, and the viscosity of the substrate layer slurry SL is too high, which leads to the problem that the porous substrate layer 200 cannot be manufactured normally.

[0135] Therefore, the content of the titanium group element may be limited to 60 wt % to 98 wt % relative to the total weight of the substrate layer slurry SL. Specifically, the content of the titanium group element may be limited to 65 wt % to 85 wt % relative to the total weight of the substrate layer slurry SL. More specifically, the content of the titanium group element may be limited to 70 wt % to 80 wt % relative to the total weight of the substrate layer slurry SL.

[0136] Various solvents can be used as the solvent contained in the base material layer slurry SL according to the required conditions and design specifications. The present invention is not defined or limited by the type and nature of the solvent.

[0137] For example, ethanol, toluene, methanol, propanol, butanol, acetone, ketone, cyclohexenone, methyl acetate, ethyl acetate, etc. can be used as the solvent.

[0138] According to an exemplary embodiment of the present invention, the substrate layer slurry SL may include 10 wt % to 30 wt % of the solvent with respect to the total weight of the substrate layer slurry SL.

[0139] If the solvent content is less than 10 wt % relative to the total weight of the substrate layer slurry SL, the viscosity of the substrate layer slurry SL is high, and the coating performance of the composition (substrate layer slurry) deteriorates. For this reason, the thickness of the porous substrate layer 200 may be uneven, and excessive deviations in porosity and pore size may occur at each position of the porous substrate layer 200. In contrast, if the solvent content is greater than 30 wt % relative to the total weight of the substrate layer slurry SL, the solvent evaporates excessively during sintering of the porous substrate layer 200, which may cause contamination of materials and devices, or problems such as difficulty in meeting target thickness, target porosity, and target pore size.

[0140] Therefore, the solvent content may be limited to 10 to 30 weight % relative to the total weight of the substrate layer slurry SL. Specifically, the solvent content may be limited to 15 to 30 weight % relative to the total weight of the substrate layer slurry SL. More specifically, the solvent content may be limited to 20 to 30 weight % relative to the total weight of the substrate layer slurry SL.

[0141] Various dispersants can be used as the dispersant contained in the base material layer slurry SL according to the required conditions and design specifications. The present invention is not restricted or limited by the type and nature of the dispersant.

[0142] For example, at least any one of water, ethanol, methanol, isopropyl alcohol, xylene, cyclohexanone, acetone, and methyl ethyl ketone may be used as the dispersant.

[0143] According to an exemplary embodiment of the present invention, the substrate layer slurry SL may include 0.1 wt % to 3 wt % of the dispersant with respect to the total weight of the substrate layer slurry SL.

[0144] If the dispersant content is less than 0.1 wt % relative to the total weight of the substrate layer slurry SL, a problem of aggregation of particles of the titanium group element in the process of manufacturing the composition (substrate layer slurry) may occur. In contrast, if the dispersant content is greater than 3 wt % relative to the total weight of the substrate layer slurry SL, the viscosity of the composition (substrate layer slurry) is too low to perform the coating process, which may lead to a problem of insufficient workability.

[0145] Therefore, the content of the dispersant may be limited to 0.1 wt % to 3 wt % relative to the total weight of the substrate layer slurry SL. Specifically, the content of the dispersant may be limited to 1 wt % to 3 wt % relative to the total weight of the substrate layer slurry SL. More specifically, the content of the dispersant may be limited to 1.5 wt % to 2.3 wt % relative to the total weight of the substrate layer slurry SL.

[0146] Various coupling agents may be used as the coupling agent contained in the base material layer slurry SL according to required conditions and design specifications. The present invention is not restricted or limited by the type and nature of the dispersant.

[0147] For example, at least any one of polyvinyl butyral (PVB), polyvinyl alcohol (PVA), polyvinyl chloride (PVC), polyvinyl acetate (PVAc), and polyacrylonitrile may be used as the coupling agent.

[0148] According to an exemplary embodiment of the present invention, the substrate layer slurry SL may include 0.1 to 5 wt % of the coupling agent with respect to the total weight of the substrate layer slurry SL.

[0149] If the content of the coupling agent is less than 0.1 wt % relative to the total weight of the substrate layer slurry SL, the bonding force between the particles of the titanium group element in the porous substrate layer 200 is insufficient, which may cause the porous substrate layer 200 to hardly maintain a sheet shape. In contrast, if the content of the coupling agent is greater than 5 wt % relative to the total weight of the substrate layer slurry SL, the bonding force between the components in the composition (substrate layer slurry) is high, which may cause the coupling agent to be attached to the lower substrate (e.g., release sheet) during the coating process.

[0150] Therefore, the coupling agent content may be limited to 0.1 wt % to 4 wt % relative to the total weight of the substrate layer slurry SL. Specifically, the coupling agent content may be limited to 1 wt % to 4 wt % relative to the total weight of the substrate layer slurry SL. More specifically, the coupling agent content may be limited to 2 wt % to 3.5 wt % relative to the total weight of the substrate layer slurry SL.

[0151] For reference, the substrate layer slurry SL can be manufactured by stirring (e.g., mixing in a ball mill process) a titanium group element, a solvent, a dispersant, and a coupling agent. For example, the stirring process can be performed by appropriately mixing 5 mm to 30 mm zirconia balls with the substrate layer slurry SL. The stirring time of the substrate layer slurry SL can be 1 hour or more, 10 to 30 hours, or 18 to 24 hours. A composition (substrate layer slurry) having a viscosity of 1000 cp to 8000 cp can be manufactured by uniformly dispersing the mixture for an average of 12 hours or more.

[0152] refer to Figure 3 , Figure 4 and Figure 5 , the molding roller 400 is configured to form the through-holes 220 in the porous substrate portion 210 provided by curing the substrate layer slurry.

[0153] For example, the molding roller 400 may be disposed to be spaced apart from the support roller at a predetermined interval. Through holes 220 corresponding to the molding protrusions 410 may be disposed in the porous substrate portion 210, and the porous substrate portion 210 cured on the release sheet 500 passes between the molding roller 400 and the support roller.

[0154] The molding roller 400 may be configured to process the porous substrate portion 210 under a temperature condition of 110° C. to 140° C. and a load condition (load applied to the porous substrate portion) of 0.5 MPa to 4 MPa.

[0155] The forming roller 400 may have various structures configured to form the through-holes 220 in the porous substrate portion 210. The present invention is not restricted or limited by the structure of the forming roller 400.

[0156] For example, the molding roller 400 may include an approximately cylindrical roller body and a plurality of molding protrusions 410 protruding from the outer circumferential surface of the roller body.

[0157] For example, a plurality of molding protrusions 410 may be formed on the outer peripheral surface of the roller body to correspond to the non-channel area LA of the porous substrate part 210. All of the plurality of molding protrusions 410 may have the same size.

[0158] According to another exemplary embodiment of the present invention, the molding roller 400 may include an approximately cylindrical roller body and a plurality of molding protrusions 410 protruding from an outer circumferential surface of the roller body and having different sizes (eg, diameters).

[0159] For example, the size (diameter) of the molding protrusion 410 provided on the outer peripheral surface of the roller body may gradually increase in a direction from one end to the other end of the roller body in the length direction of the roller body.

[0160] For example, refer to Figure 6 The molding protrusion 410 may include a plurality of first molding protrusions 412 and a plurality of second molding protrusions 414, each first molding protrusion 412 having a first diameter, each second molding protrusion 414 having a second diameter greater than the first diameter and spaced apart from the first molding protrusion 412 in the length direction of the roller body.

[0161] Since the first and second molding protrusions 412 and 414 have different sizes as described above, the through holes 220 (eg, first and second through holes) formed in the porous substrate portion 210 by the molding roller 400 may have different sizes (eg, diameters).

[0162] For example, the first through hole 220a and the second through hole 220b (which has a larger cross-sectional area (diameter) than the first through hole 220a) may be formed in the porous substrate portion 210 by the molding roller 400 (see Figure 8 and Fig. 9 ).

[0163] For reference, in Figure 6 In the embodiment, the example in which the molding protrusion 410 is arranged in a partial section (a part of the outer peripheral surface of the roller body) along the length direction of the roller body has been described. However, according to another exemplary embodiment of the present invention, the molding protrusion may be arranged in the entire section along the length direction of the roller body.

[0164] Meanwhile, in the exemplary embodiment of the present invention illustrated and described above, an example is described in which the through-holes 220 are formed in the porous substrate portion 210 by pressing the porous substrate portion 210 using the molding roller 400. However, according to another exemplary embodiment of the present invention, the through-holes may be formed in the porous substrate portion by partially removing a portion of the porous substrate portion by a method such as machining or etching.

[0165] According to the exemplary embodiments of the present invention described above, advantageous effects of ensuring performance and working efficiency and improving durability and reliability can be obtained.

[0166] According to the exemplary embodiment of the present invention, it is possible to obtain advantageous effects of effectively diffusing a target fluid and uniformly supplying the target fluid to the entire area of ​​a membrane electrode assembly.

[0167] According to the exemplary embodiment of the present invention, among other things, an advantageous effect of efficiently supplying the target fluid to the non-channel region of the porous substrate layer disposed in contact with the non-channel of the separator can be obtained.

[0168] Furthermore, according to the exemplary embodiment of the present invention, advantageous effects of increasing the permeability of the porous substrate layer and improving the transfer efficiency of the target fluid (performance of transferring the target fluid) can be obtained.

[0169] Furthermore, according to the exemplary embodiments of the present invention, advantageous effects of improving stability, reliability, and durability may be obtained.

[0170] For ease of interpretation and accurate definition in the appended claims, the terms "upper", "lower", "inner", "outer", "upward", "downward", "upwardly", "downwardly", "front", "rear", "back", "inside", "outside", "inwardly", "outwardly", "inner", "external", "inwardly", "outwardly", "forward" and "rearward" are used to describe the features of the exemplary embodiments with reference to the positions of such features as shown in the accompanying drawings. It will be further understood that the term "connected" or its derivatives refer to both direct and indirect connections.

[0171] The term "and / or" may include a combination of a plurality of related listed items or any one of a plurality of related listed items. For example, "A and / or B" includes all three situations such as "A", "B" and "A and B".

[0172] In this specification, a singular expression includes a plural expression unless the context clearly indicates otherwise.

[0173] In an exemplary embodiment of the present invention, "at least one of A and B" may refer to "at least one of A or B" or "at least one of a combination of one or more of A and B". In addition, "one or more of A and B" may refer to "one or more of A or B" or "one or more of a combination of one or more of A and B".

[0174] In the exemplary embodiments of the present invention, it should be understood that terms such as "include" or "have" are intended to indicate the presence of features, values, steps, operations, elements, parts, or a combination thereof described in the specification, and do not exclude the possibility of adding or existing one or more other features, values, steps, operations, elements, parts, or a combination thereof.

[0175] The foregoing description of specific exemplary embodiments of the present invention is presented for the purpose of illustration and description. These descriptions are not intended to be exhaustive or limit the present invention to the precise form disclosed, and it is apparent that many modifications and changes may be made in accordance with the above teachings. Exemplary embodiments are selected and described in order to explain the specific principles of the present invention and their practical application, so that other persons skilled in the art can implement and utilize various exemplary embodiments of the present invention and various alternative forms and modified forms thereof. The scope of the present invention is intended to be limited by the appended claims and their equivalents.

Claims

1. A porous substrate layer, include: A porous substrate portion disposed between the membrane electrode assembly and a diaphragm including channels and non-channels; a channel region, which is defined in the porous substrate portion and corresponds to the channel; a non-channel region defined in the porous substrate portion corresponding to the non-channel and disposed in contact with the non-channel; and At least one through hole is disposed in the non-channel region so that the target fluid passes through the at least one through hole.

2. The porous substrate layer according to claim 1, in, The porosity of the non-channel region increases in the length direction of the channel from the inlet portion to the outlet portion of the channel.

3. The porous substrate layer according to claim 1, in, The at least one through hole is in plural number, and the plural through holes are defined to have a cross-sectional area different from that of adjacent through holes in the length direction of the channel.

4. The porous substrate layer according to claim 3, in, The plurality of through holes include: the first through hole; and A second through hole is defined to have a size different from that of the first through hole and is spaced apart from the first through hole in the length direction of the channel.

5. The porous substrate layer according to claim 1, in, The at least one through hole is in plural number, and the plural through holes are defined to have a cross-sectional area that increases in a direction from an inlet end to an outlet end of the channel in a length direction of the channel.

6. The porous substrate layer according to claim 5, in, The at least one through hole comprises: the first through hole; and The second through hole is disposed on a downstream side of the first through hole in the length direction of the passage and is defined to have a relatively larger cross-sectional area than the first through hole.

7. The porous substrate layer according to claim 1, in, The porous substrate portion is defined to have pores of 9 μm to 16 μm.

8. The porous substrate layer according to claim 1, in, The at least one through hole is defined to have a diameter of 20 μm to 50 μm.

9. The porous substrate layer according to claim 1, in, The channel region is defined to have a predetermined reference porosity, and the non-channel region including at least one through hole is defined to have a porosity of 120% to 200% of the reference porosity.

10. An electrochemical device, include: Membrane electrode assembly; A diaphragm including a channel and a non-channel provided on one surface facing the membrane electrode assembly, the diaphragm being stacked on the membrane electrode assembly; as well as a porous substrate layer disposed between the separator and the membrane electrode assembly, Wherein, the porous substrate layer comprises: a porous substrate portion disposed between the diaphragm and the membrane electrode assembly; a channel region, which is defined in the porous substrate portion and corresponds to the channel; a non-channel region defined in the porous substrate portion corresponding to the non-channel and disposed in contact with the non-channel; and At least one through hole is disposed in the non-channel region so that the target fluid passes through the at least one through hole.

11. The electrochemical device according to claim 10, in, The porosity of the non-channel region increases in the length direction of the channel from the inlet portion to the outlet portion of the channel.

12. The electrochemical device according to claim 10, in, The at least one through hole is in plural number, and the plural through holes are defined to have a cross-sectional area different from that of adjacent through holes in the length direction of the channel.

13. The electrochemical device according to claim 12, in, The plurality of through holes include: the first through hole; and A second through hole is defined to have a size different from that of the first through hole and is spaced apart from the first through hole in the length direction of the channel.

14. The electrochemical device according to claim 10, in, The at least one through hole is in plural number, and the plural through holes are defined to have a cross-sectional area that increases in a direction from an inlet end to an outlet end of the channel in a length direction of the channel.

15. The electrochemical device according to claim 14, in, The plurality of through holes include: the first through hole; and The second through hole is disposed on a downstream side of the first through hole in the length direction of the passage and is defined to have a relatively larger cross-sectional area than the first through hole.

16. The electrochemical device according to claim 10, in, The porous substrate portion is defined to have pores of 9 μm to 16 μm.

17. The electrochemical device according to claim 10, in, The through hole is defined to have a diameter of 20 μm to 50 μm.

18. The electrochemical device according to claim 10, in, The channel region is defined to have a predetermined reference porosity, and the non-channel region including the through-holes is defined to have a porosity of 120% to 200% of the reference porosity.

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