Fuel cell including durability enhancement layer and method of manufacturing the same

Abstract

The present disclosure relates to a fuel cell including a durability-enhancing layer and a method for manufacturing the same. The fuel cell includes: an electrolyte membrane-electrode assembly; a durability-enhancing layer formed on at least one side of the electrolyte membrane-electrode assembly; and a gas diffusion layer formed on a side of the durability-enhancing layer opposite the side on which the electrolyte membrane-electrode assembly is formed. The durability-enhancing layer includes a hydrogen peroxide decomposition catalyst and a hydrogen ion conductive polymer and is formed on at least a portion of at least one side of the electrolyte membrane-electrode assembly.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority from Korean Patent Application No. 10-2020-0065968 filed on June 1, 2020, in the Korean Intellectual Property Office, the entire contents of which are incorporated herein by reference. Technical Field

[0003] The present disclosure relates to fuel cells including durability-enhancing layers and methods of making the same. Background Art

[0004] Fuel cells are driven based on the principle of generating electrons using the redox reaction of oxygen and hydrogen, and fuel cells are key components of hydrogen fuel cell electric vehicles. In addition, fuel cells generally include a membrane electrode assembly (MEA), a gas diffusion layer (GDL), a separator, etc. Specifically, the separator includes a reaction gas inlet and a reaction gas outlet, and there is a flow path so that hydrogen and oxygen flow into the MEA. In addition, the MEA is used to generate electricity through oxidation / reduction reactions. In addition, the gas diffusion layer is used to promote the reaction of hydrogen and oxygen diffusing into the MEA, and generally includes a substrate layer and a porous layer. Here, the substrate layer is used to impart rigidity to the porous layer, and the porous layer is used to allow hydrogen and oxygen to diffuse into the MEA, so that the redox reaction proceeds smoothly.

[0005] At the same time, cerium from Ce +3 Rapidly converted into Ce +4 , and has excellent antioxidant performance, low cost, and high specific surface area to be added to electrolyte membranes or applied to GDL as an anti-deterioration agent for electrolyte membranes in fuel cells.

[0006] Specifically, Korean Patent Registration No. 1810741 (Patent Document 1) discloses a fuel cell comprising a waterproof layer on a catalyst layer of a GDL. This waterproof layer includes polytetrafluoroethylene (PTFE) as a waterproofing member and a cerium-containing oxide as a catalyst for decomposing hydrogen peroxide. However, when cerium is contained in the GDL or electrolyte membrane as in Patent Document 1, the cerium can be evenly distributed throughout each layer to increase the overall cerium content. However, locally increasing the cerium content is not feasible due to the phenomenon of severe degradation of the electrolyte membrane. In addition, cerium oxide (CeO2), a commonly used form of cerium, may have strong cohesive forces and may be unevenly distributed in the electrolyte membrane or GDL, thus potentially being insufficient in preventing electrolyte membrane degradation. Furthermore, when the cerium in the GDL is contained in the bonding surface between the GDL and the inner surface of the base layer or MEA, rather than in the bonding surface between the GDL and the MEA, there is a problem in that the degradation prevention effect is very low.

[0007] Therefore, there is a need for research and development of fuel cells and methods for manufacturing the same, in which the content of a hydrogen peroxide decomposition catalyst can be locally increased at locations where electrolyte membrane degradation is severe, thereby achieving excellent chemical durability, and a hydrogen peroxide decomposition catalyst is provided on the GDL at the bonding surface between the GDL and the MEA, thereby excelling in preventing electrolyte membrane degradation. Korean Registered Patent No. 1810741 (publication date: April 22, 2016) discloses subject matter related to the subject matter disclosed herein. Summary of the Invention

[0008] The embodiments of the present disclosure solve the problems existing in the prior art while maintaining the advantages achieved by the prior art.

[0009] The present disclosure relates to a fuel cell including a durability-enhancing layer and a method for manufacturing the same. Detailed description of the present disclosure relates to a fuel cell including a durability-enhancing layer to achieve excellent chemical durability and excellent adhesion between an electrolyte membrane-electrode assembly and a gas diffusion layer and a method for manufacturing the same.

[0010] One aspect of the present disclosure provides a fuel cell including a durability-enhancing layer on a GDL, the durability-enhancing layer containing a hydrogen peroxide decomposition catalyst at the bonding surface between the GDL and the MEA to excel in preventing degradation of the electrolyte membrane; and a method for preparing the fuel cell, which allows the content of the hydrogen peroxide decomposition catalyst to be increased in areas where degradation of the electrolyte membrane is severe, thereby effectively improving chemical durability.

[0011] Technical problems solved by embodiments of the present inventive concept are not limited to the aforementioned problems, and any other technical problems not mentioned herein will be clearly understood by those skilled in the art to which the present disclosure pertains from the following description.

[0012] According to one aspect of the present disclosure, a fuel cell includes: an electrolyte membrane-electrode assembly; a durability enhancement layer formed on at least one side of the electrolyte membrane-electrode assembly; and a gas diffusion layer formed on a side of the durability enhancement layer opposite to the side on which the electrolyte membrane-electrode assembly is formed.

[0013] The durability-enhancing layer includes a hydrogen peroxide decomposition catalyst and a hydrogen ion conductive polymer, and is formed on at least a portion of at least one side of the electrolyte membrane-electrode assembly.

[0014] According to one aspect of the present disclosure, a method for manufacturing a fuel cell includes stacking a durability-enhancing layer on one side of a gas diffusion layer, and stacking an electrolyte membrane-electrode assembly on a side of the durability-enhancing layer opposite to a side on which the gas diffusion layer is formed, the durability-enhancing layer comprising a hydrogen peroxide decomposition catalyst and a hydrogen ion conductive polymer, and the durability-enhancing layer being stacked on at least a portion of at least one side of the electrolyte membrane-electrode assembly. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The above and other objects, features and advantages of the embodiments of the present disclosure will become more apparent from the following detailed description taken in conjunction with the accompanying drawings, in which:

[0016] Figure 1 、 Figure 2 、 Figure 3 、 Figure 4 and Figure 5 is a cross-sectional view showing a fuel cell according to an embodiment of the present disclosure.

[0017] Figure 6 is an exploded view of a fuel cell according to an embodiment of the present disclosure;

[0018] Figure 7 is a schematic diagram of an embodiment of depositing a durability enhancement layer in a method of manufacturing a fuel cell according to an embodiment of the present disclosure; and

[0019] Figure 8 is a schematic diagram of spray coating used when depositing a durability enhancing layer in a method of manufacturing a fuel cell according to an embodiment. DETAILED DESCRIPTION

[0020] Throughout this specification, when a part may “include” a certain constituent element, unless otherwise stated, it may not be interpreted as excluding another constituent element but may be interpreted as further including other constituent elements.

[0021] Throughout this specification, when an element is referred to as being “on” another element, it can be “directly on” the other element or intervening elements may also be present.

[0022] fuel cells

[0023] A fuel cell according to an embodiment of the present disclosure includes: an electrolyte membrane-electrode assembly; a durability-enhancing layer formed on at least one side of the electrolyte membrane-electrode assembly; and a gas diffusion layer formed on a side of the durability-enhancing layer opposite to the side on which the electrolyte membrane-electrode assembly is formed. The electrolyte membrane-electrode assembly may include an electrolyte membrane and two electrodes formed on either side of the electrolyte membrane, and the two electrodes may be an anode and a cathode, respectively.

[0024] Reference Figure 1 and Figure 2, a fuel cell "A" according to an embodiment of the present disclosure may include: an electrolyte membrane-electrode assembly 100, including an electrolyte membrane 110, a first electrode 121 and a second electrode 122; durability enhancement layers 201 and 202, formed on opposite sides of the electrolyte membrane-electrode assembly; and gas diffusion layers 310 and 320, respectively formed on outer sides of the durability enhancement layers 201 and 202, respectively opposite to the sides on which the electrolyte membrane-electrode assembly is formed.

[0025] Electrolyte membrane-electrode assembly

[0026] The electrolyte membrane-electrode assembly (MEA) is used to generate electricity through oxidation / reduction reactions and is not particularly limited as long as the electrolyte membrane-electrode assembly may be a shape or material included in a general fuel cell.

[0027] Reference Figure 1 and Figure 2 , the electrolyte membrane-electrode assembly 100 may include an electrolyte membrane 110 and two electrodes 121 and 122 formed on opposite sides of the electrolyte membrane. Here, the two electrodes may be an anode and a cathode, respectively.

[0028] The electrolyte membrane is an ion exchange membrane with electrical conductivity and is not particularly limited as long as it can be used in a fuel cell. Furthermore, the electrolyte membrane may include a hydrogen peroxide decomposition catalyst. When the electrolyte membrane includes a hydrogen peroxide decomposition catalyst, the total amount of hydrogen peroxide decomposition catalyst in the fuel cell is increased, thereby effectively preventing degradation of the electrolyte membrane.

[0029] Durability enhancement layer

[0030] The durability enhancing layers 201, 202 are interposed on the bonding surfaces between the electrolyte membrane-electrode assembly (MEA) 100 and the gas diffusion layers (GDL) 310, 320 to increase the adhesion of the two layers and serve to improve the chemical durability of the fuel cell by preventing degradation of the electrolyte membrane.

[0031] When an adhesive is used to bond the MEA to the GDL, the adhesive may transform into ionic form as an impurity in the fuel cell, thereby adversely affecting the electrolyte membrane or electrodes or blocking the flow path through which fluid passes, thereby potentially reducing the performance and durability of the fuel cell. On the other hand, the durability-enhancing layer of an embodiment of the present disclosure includes a hydrogen peroxide decomposition catalyst to prevent degradation of the fuel cell's durability due to degradation of the electrolyte membrane, and includes a highly viscous hydrogen ion conductive polymer to improve adhesion between the MEA and the GDL. At the same time, the durability-enhancing layer allows hydrogen ions to move smoothly, thereby improving the performance of the fuel cell.

[0032] In addition, the durability-enhancing layers 201 , 202 are formed on at least a portion of at least one side of the electrolyte membrane-electrode assembly 100 .

[0033] For example, the durability enhancing layers 201, 202 may be discontinuous layers and may be in the form of a plurality of dots (see Figure 1 ). That is, Figure 1 As shown, in a fuel cell, portions of the electrolyte membrane-electrode assembly 100 where the durability-enhancing layers 201 and 202 are not formed may be bonded to the gas diffusion layers 310 and 320. When the durability-enhancing layer is in the form of dots as described above, the permeation of gas (oxygen and / or air) may be smoothed, thereby improving the performance of the fuel cell. Here, when the durability-enhancing layer is in the form of a plurality of dots, the durability-enhancing layer may not be immersed or pressed into the electrolyte membrane-electrode assembly or the gas diffusion layer, but may exist as a discontinuous layer.

[0034] As another example, the durability-enhancing layers 201, 202 may be formed on the entire side of the electrolyte membrane-electrode assembly 100 (see Figure 2 ).

[0035] Here, each point constituting the durability-enhancing layers 201 and 202 may have an average diameter of 1 μm to 10 mm, or 10 μm to 5 mm. When the average diameter of each point is greater than or equal to the diameter of the pores in the gas diffusion layers 310 and 320, the contact area between the electrolyte membrane-electrode assembly 100 and the durability-enhancing layers 201 and 202 can be increased, thereby preventing degradation of the electrolyte membrane. When the average diameter of each point is less than the diameter of the pores in the gas diffusion layers 310 and 320, some of the pores in the gas diffusion layers 310 and 320 may be filled with the durability-enhancing layer, thereby increasing the surface roughness of the gas diffusion layers 310 and 320 and ensuring that the gas diffusion layers 310 and 320 are evenly loaded when joined to the electrolyte membrane-electrode assembly 100.

[0036] In addition, the durability-enhancing layers 201 and 202 may have an average thickness of 50 nm to 50 μm, or 100 nm to 10 μm. When the average thickness of the durability-enhancing layer is within the above range, degradation of the durability of the fuel cell due to degradation of the electrolyte membrane can be prevented, and adhesion between the MEA and the GDL can be improved.

[0037] The durability enhancing layers 201 , 202 include a hydrogen peroxide decomposition catalyst and a hydrogen ion conductive polymer.

[0038] The hydrogen peroxide decomposition catalyst prevents membrane damage due to hydroxyl radicals (·OH), and has hydrophilicity so as to function as a water collector that prevents membrane drying even in a non-humidifying system.

[0039] In addition, the hydrogen peroxide decomposition catalyst may include, for example, at least one selected from the group consisting of transition metals and rare earth metals. Specifically, the hydrogen peroxide decomposition catalyst may include a metal such as Ce, Mn, Fe, Pt, Pd, Ni, Cr, Cu, Ce, Rb, Co, Ir, Ag, Au, Rh, Ti, Zr, Al, Hf, Ta, Nb, and Os, an oxide of the metal, or a composite containing the metal. In a specific embodiment, the hydrogen peroxide decomposition catalyst may include cerium (Ce).

[0040] The hydrogen peroxide decomposition catalyst may be included in the durability-enhancing layers 201 and 202 in the form of a metal, a metal oxide, a composite, or the like. Specifically, the hydrogen peroxide decomposition catalyst may be included in the durability-enhancing layers 201 and 202 in the form of cerium particles, cerium ions, cerium oxide, a cerium composite, or the like. The cerium composite may include, for example, a cerium-zirconium composite or a composite of cerium oxide and zirconium oxide. In a specific embodiment, the durability-enhancing layers 201 and 202 may include cerium oxide (CeO2). When the durability-enhancing layers include cerium oxide (CeO2), the cerium ions continuously function during the operation of the fuel cell to effectively prevent membrane damage and serve as a water collector as described above.

[0041] The hydrogen ion conductive polymer increases the three-phase boundary area by contacting the electrodes 121 and 122 in the electrolyte membrane-electrode assembly 100, thereby increasing the effective reaction area of ​​the catalyst and promoting the movement of hydrogen ions. The hydrogen ion conductive polymer can be in the form of an ionomer, and in a specific embodiment, it can be a perfluorosulfonate ionomer. Commercially available products of hydrogen ion conductive polymers include, for example, DuPont's perfluorosulfonic acid (Nafion, perfluorosulfonic acid resin), Asahi Glass's Flemion, Asahi Chemical's Asiplex, and Dow Chemical's Dow XUS, but the present disclosure is not limited thereto.

[0042] Furthermore, the hydrogen ion conductive polymer may be the same polymer as that contained in the electrodes 121 , 122 of the electrolyte membrane-electrode assembly 100 .

[0043] The durability enhancing layers 201, 202 may contain, for example, 1.0 μg / cm 2 Above hydrogen peroxide decomposition catalyst and 1μg / cm 2 In a specific embodiment, the durability enhancement layer may include 1.1 μg / cm 2 Up to 5 μg / cm 2 or 1.3 μg / cm 2 Up to 3 μg / cm 2Hydrogen peroxide decomposition catalyst, and 1μg / cm 2 Up to 5 μg / cm 2 or 1.5 μg / cm 2 Up to 4 μg / cm 2 Here, the base area of ​​the coating amount of the hydrogen peroxide decomposition catalyst and the hydrogen ion conductive polymer is based on 1 cm of the gas diffusion layer 310, 320. 2 That is, "1.0μg / cm 2 The above hydrogen peroxide decomposition catalyst refers to the 1 cm 2 The hydrogen peroxide decomposition catalyst is contained in an amount of 1.0 μg or more. Here, the hydrogen peroxide decomposition catalyst may be cerium.

[0044] When the content of the hydrogen peroxide decomposition catalyst in the durability enhancing layers 201 and 202 is less than 1.0 μg / cm 2 When the content of the hydrogen peroxide decomposition catalyst in the durability-enhancing layers 201 and 202 is excessive, the effect on improving the durability of the electrolyte membrane-electrode assembly 100 may be insufficient. In addition, when the content of the hydrogen peroxide decomposition catalyst in the durability-enhancing layers 201 and 202 is excessive, proton ion transfer is prevented, thereby reducing the performance of the electrolyte membrane-electrode assembly 100. Therefore, it is necessary to use an appropriate amount of the hydrogen peroxide decomposition catalyst to improve the durability of the electrolyte membrane-electrode assembly 100 without degrading the performance of the electrolyte membrane-electrode assembly 100.

[0045] In addition, when the content of the hydrogen ion conductive polymer in the durability enhancing layers 201 and 202 is less than 1 μg / cm 2 When the bonding strength between the gas diffusion layers 310, 320 and the electrolyte membrane-electrode assembly 100 is insufficient, a high bonding pressure and a high bonding temperature may be required. Consequently, the pores in the gas diffusion layers 310, 320 may disappear, the gas diffusion layers 310, 320 may be damaged, or the electrolyte membrane may shrink, causing the boundary between the gas diffusion layers 310, 320 and the electrolyte membrane-electrode assembly 100 to collapse. Furthermore, when the content of the hydrogen ion conductive polymer in the durability-enhancing layers 201, 202 is within the above-described range, flooding due to the hygroscopicity of the hydrogen ion conductive polymer can be prevented, and the bonding strength between the gas diffusion layers 310, 320 and the electrolyte membrane-electrode assembly 100 can be excellent, thereby improving the durability of the fuel cell.

[0046] Durability-enhancing layers 201 and 202 may include at least one additional material selected from the group consisting of TiO2, zeolite, silica, silver, carbon nanotubes, graphene oxide, and platinum. When durability-enhancing layers 201 and 202 include TiO2, zeolite, silica, or the like, the flux, fouling resistance, and salt rejection rate of the fuel cell can be improved. Furthermore, when durability-enhancing layers include silver, carbon nanotubes, graphene oxide, or the like, the electrical conductivity of the fuel cell and the rigidity of the power generation assembly (comprising the electrolyte membrane-electrode assembly 100, durability-enhancing layers 201 and 202, and gas diffusion layers 310 and 320) can be improved.

[0047] gas diffusion layer

[0048] The gas diffusion layers 310 , 320 may serve to enable hydrogen and oxygen to diffuse into the electrolyte membrane-electrode assembly 100 to promote a reaction, and may include a base layer and a porous layer.

[0049] Reference Figure 3 A fuel cell "A" according to an embodiment of the present disclosure may include: an electrolyte membrane-electrode assembly 100 including an electrolyte membrane 110, a first electrode 121, and a second electrode 122; durability-enhancing layers 201 and 202 formed on opposite sides of the electrolyte membrane-electrode assembly 100; and gas diffusion layers 310 and 320 formed on outer sides of the durability-enhancing layers 201 and 202, respectively, opposite to the side on which the electrolyte membrane-electrode assembly 100 is formed. The gas diffusion layers 310 and 320 may include base layers 311 and 321 and porous layers 312 and 322. Here, the durability-enhancing layers 201 and 202 may be formed on the porous layers 312 and 322 of the gas diffusion layers 310 and 320, respectively.

[0050] The base layers 311 and 321 are used to impart rigidity to the porous layers 312 and 322 , respectively.

[0051] As long as the base layers 311, 321 can be used as the base material of the gas diffusion layers 310, 320, each base layer 311, 321 may not be particularly limited and may include, for example, carbon paper, carbon fiber, carbon felt, or a carbon sheet. In addition, the base layers 311, 321 can be prepared according to a well-known method, a commercially available carbon fiber matrix can be used, or the carbon fiber matrix can be prepared by immersing the carbon fiber matrix in an impregnation liquid and drying the carbon fiber matrix. Here, the impregnation liquid may include a carbon precursor and a polymer. For example, the carbon precursor may include rayon, polyacrylonitrile (PAN), asphalt, etc. In addition, the polymer may include, for example, at least one selected from the group consisting of polytetrafluoroethylene (PTFE), tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA), tetrafluoroethylene-hexafluoropropylene copolymer (FEP), polytrifluorochloroethylene (PCTFE), tetrafluoroethylene-ethylene copolymer (ETFE), and polyvinyl fluoride (PVDF). In addition, the impregnation may be repeated once or multiple times, and the drying may be performed at 20°C to 40°C.

[0052] Each of the porous layers 312 , 322 serves to allow hydrogen and oxygen to diffuse into the electrolyte membrane-electrode assembly 100 , so that the redox reaction smoothly proceeds.

[0053] Furthermore, porous layers 312 and 322 are not particularly limited as long as they can be used as the porous layers of gas diffusion layers 310 and 320. For example, the porous layers can be made of a porous layer composition containing a carbon-based powder and a binder. The method for manufacturing porous layers 312 and 322 can be performed according to a known method for manufacturing a conventional porous layer.

[0054] The carbon-based powder may include at least one selected from the group consisting of, for example, carbon black, activated carbon powder, activated carbon fiber, carbon aerosol, carbon nanotubes, carbon nanofibers, carbon nanohorns, and graphite powder. Furthermore, the binder may include at least one selected from the group consisting of, for example, polytetrafluoroethylene (PTFE), tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA), tetrafluoroethylene-hexafluoropropylene copolymer (FEP), polychlorotrifluoroethylene (PCTFE), tetrafluoroethylene-ethylene copolymer (ETFE), and polyvinyl fluoride (PVDF).

[0055] Furthermore, the porous layer composition may include a hydrogen peroxide decomposition catalyst. Specifically, the porous layers 312 and 322 may be prepared from a carbon-based powder, a binder, and a hydrogen peroxide decomposition catalyst. When the porous layer composition includes a hydrogen peroxide decomposition catalyst, the total amount of hydrogen peroxide decomposition catalyst in the fuel cell can be increased, effectively preventing degradation of the electrolyte membrane.

[0056] In addition, the fuel cell according to an embodiment of the present disclosure may further include a separator plate including a reaction gas inlet and a reaction gas outlet on a side of the gas diffusion layers 310 , 320 opposite to the side in contact with the durability enhancement layers 201 , 202 .

[0057] Reference Figure 4 and Figure 5 , a fuel cell “A” according to an embodiment of the present disclosure may include: an electrolyte membrane-electrode assembly 100, including an electrolyte membrane 110, a first electrode 121, and a second electrode 122; durability-enhancing layers 201 and 202, formed on opposite sides of the electrolyte membrane-electrode assembly 100; and gas diffusion layers 310 and 320, respectively formed on the outsides of the durability-enhancing layers 201 and 202; and separators 401 and 402, respectively formed on the outsides of the gas diffusion layers 310 and 320.

[0058] Reference Figures 4 to 6 , a fuel cell "A" according to an embodiment of the present disclosure may have a structure in which a first separator 401, a first multilayer membrane "i" including a first durability enhancing layer 201 and a first gas diffusion layer 310, an electrolyte membrane-electrode assembly 100 including a first electrode 121, an electrolyte membrane 110 and a second electrode 122, a second multilayer membrane "j" including a second durability enhancing layer 202 and a second gas diffusion layer 320, and a second separator 402 are stacked in sequence.

[0059] Divider

[0060] Reference Figure 6 Each of the electrolyte membrane-electrode assembly 100 and the separators 401 and 402 may include a reaction gas inlet and a reaction gas outlet. During fuel cell operation, there is a limitation in that degradation concentrates in the electrolyte membrane at the reaction gas inlet and reaction gas outlet of the separators 401 and 402, thereby reducing the durability of the electrolyte membrane. The reaction gas may be air and / or hydrogen.

[0061] Therefore, in the fuel cell according to the embodiment of the present disclosure, the portion of the durability enhancement layer 201, 202 corresponding to the position of at least one of the reaction gas inlet and the reaction gas outlet of the separator plates 401, 402 may include an excess amount of the hydrogen peroxide decomposition catalyst, and may include, for example, 2.5 μg / cm 2 Above, 2.5 to 15 μg / cm 2 or 3 to 5 μg / cm 2 Hydrogen peroxide decomposition catalyst.

[0062] The excess hydrogen peroxide decomposition catalyst described above can increase the amount of hydrogen peroxide decomposition catalyst in the electrolyte membrane at the reaction gas inlet and / or reaction gas outlet of the separators 401 and 402 (locations where degradation of the electrolyte membrane is concentrated), thereby effectively preventing degradation of the electrolyte membrane. The content of the hydrogen peroxide decomposition catalyst can be selected according to the application of the electrolyte membrane-electrode assembly 100. When high durability of the electrolyte membrane-electrode assembly 100 is required, the upper limit of the concentration of the hydrogen peroxide decomposition catalyst can be selected. However, when an excessive amount of hydrogen peroxide decomposition catalyst is included, proton ion transfer may be reduced, resulting in reduced fuel cell performance.

[0063] Here, the base area of ​​the coating amount unit of the hydrogen peroxide decomposition catalyst is based on 1 cm 2 That is, "2.5μg / cm 2 The above hydrogen peroxide decomposition catalyst refers to the 1 cm 2 The hydrogen peroxide decomposition catalyst comprises 2.5 μg or more. In a specific embodiment, the hydrogen peroxide decomposition catalyst may be cerium.

[0064] In addition, when the electrolyte membrane-electrode assembly 100 of the fuel cell includes an auxiliary gasket, the auxiliary gasket may be partially formed on the electrode surface, and therefore the area where the GDL contacts the MEA may not be flat. Therefore, when the GDL is bonded to the MEA, although the same force is applied per unit area, a high load is applied locally to the portion of the electrode surface where the auxiliary gasket is formed, and a relatively low load is applied to other portions. Therefore, the components under relatively low load between the MEA and the GDL may lack bonding force. Therefore, when the electrolyte membrane-electrode assembly 100 includes an auxiliary gasket, an excess amount of hydrogen ion conductive polymer may be applied to portions other than the electrode surface where the auxiliary gasket is formed to improve the bonding strength between the MEA and the GDL.

[0065] Specifically, when the electrolyte membrane-electrode assembly 100 includes an auxiliary gasket, the durability enhancement layer corresponding to a portion other than the auxiliary gasket formed on the electrode surface may include 2.5 μg / cm 2 The above hydrogen peroxide decomposition catalyst.

[0066] In the fuel cell according to the embodiment of the present disclosure described above, durability-enhancing layers 201 and 202 containing a hydrogen peroxide decomposition catalyst are provided at the joint surfaces of the gas diffusion layers (GDLs) 310 and 320 and the electrolyte membrane-electrode assembly (MEA) 100, thereby effectively preventing degradation of the electrolyte membrane. Furthermore, the fuel cell includes durability-enhancing layers 201 and 202 containing a highly viscous hydrogen ion conductive polymer provided at the joint surfaces of the GDLs and the MEA, thereby exhibiting excellent adhesion.

[0067] vehicle

[0068] A vehicle according to an embodiment of the present disclosure includes a reference Figures 1 to 6 Fuel cell "A" is described.

[0069] In a particular embodiment, the vehicle may be a hydrogen fuel cell electric vehicle.

[0070] Method for manufacturing fuel cell

[0071] A method of manufacturing a fuel cell according to an embodiment of the present disclosure includes stacking a durability enhancing layer on one side of a gas diffusion layer, and stacking an electrolyte membrane-electrode assembly on the other side of the durability enhancing layer opposite to the one side of the gas diffusion layer.

[0072] Stacked durability enhancement layers

[0073] In this operation, the durability enhancing layers 201 , 202 are stacked on one side of the gas diffusion layers 310 , 320 .

[0074] The durability enhancing layers 201, 202 include a hydrogen peroxide decomposition catalyst and a hydrogen ion conducting polymer. In a specific embodiment, the hydrogen peroxide decomposition catalyst and the hydrogen ion conducting polymer are the same as those described in fuel cell "A".

[0075] Furthermore, the durability enhancing layers 201, 202 may include 1.0 μg / cm 2 Above hydrogen peroxide decomposition catalyst and 1μg / cm 2 Here, the specific coating amounts of the hydrogen peroxide decomposition catalyst and the hydrogen ion conductive polymer in the durability enhancing layers 201, 202 are the same as those described in the fuel cell "A".

[0076] Durability-enhancing layers 201, 202 are stacked on at least a portion of at least one side of electrolyte membrane-electrode assembly 100. For example, a durability-enhancing layer composition may be applied to one side of gas diffusion layers 310, 320 to prepare durability-enhancing layers 201, 202. In particular embodiments, the durability-enhancing layer composition may include a hydrogen peroxide decomposition catalyst, a hydrogen ion conductive polymer, and water.

[0077] Water improves the processability of the durability-enhancing layer composition and the dispersibility of the hydrogen ion conductive polymer. Furthermore, the water content of the durability-enhancing layer composition can be adjusted to adjust the hydrophilicity and hydrophobicity of the composition, thereby adjusting the amount of the composition introduced into the pores of the hydrophobic gas diffusion layer. Furthermore, after application, the durability-enhancing layer composition can be dried to remove the water. In other words, the resulting durability-enhancing layer can be free of water.

[0078] The durability-enhancing layer composition may include a first composition containing a hydrogen peroxide decomposition catalyst and water, and a second composition containing a hydrogen ion conductive polymer and water. As described above, the durability-enhancing layer composition may include a first composition containing a hydrogen peroxide decomposition catalyst and a second composition containing a hydrogen ion conductive polymer to prevent oxidation, precipitation, chemical side reactions, or aggregation between the components, thereby preserving the respective properties of the hydrogen peroxide decomposition catalyst and the hydrogen ion conductive polymer, and facilitating adjustment of the composition of the durability-enhancing layer prepared by adjusting the mixing ratio of the first composition and the second composition.

[0079] The durability enhancing layer composition can be applied by a method selected from the group consisting of spray coating, 3D printing technology, inkjet printing technology, slot die coating, rod coating, powder dispersion coating, screen printing technology, and doctor blade coating. Specifically, the durability enhancing layer composition can be applied by spray coating. When the durability enhancing layer composition is applied by spray coating, the application area can be close to the reaction area to achieve maximum efficiency. In addition, when the durability enhancing layer composition is applied by spray coating, the pressure during application of the composition can be adjusted to adjust the average diameter of the applied composition, thereby adjusting the roughness of the gas diffusion layer or adjusting the contact resistance and contact area of ​​the reaction area.

[0080] For example, a plurality of sprayers 10 may be used to apply the durability enhancement layer composition to the gas diffusion layer 320, such as Figure 7 When using multiple sprayers as described above, the mixing ratio of the first composition and the second composition in each sprayer can be adjusted to form a durability-enhancing layer having the target composition in the target portion of the gas diffusion layer. For example, there is a problem of degradation of the electrolyte membrane at the reactant gas inlet and reactant gas outlet of the separator plate, which may reduce the durability of the electrolyte membrane. To prevent this problem, a durability-enhancing layer composition having a high content of hydrogen peroxide decomposition catalyst can be applied to the target portion of the electrolyte membrane where degradation is concentrated.

[0081] Furthermore, the durability enhancing layers 201, 202 may be discontinuous layers and may be formed in a plurality of spots or may be formed on an entire surface of the electrolyte membrane-electrode assembly 100. The form of the durability enhancing layers 201, 202 is as described in the fuel cell "A".

[0082] The durability enhancing layer composition may include at least one additional material selected from the group consisting of TiO2, zeolite, silica, silver, carbon nanotubes, graphene oxide, and platinum.

[0083] stacked electrolyte membrane-electrode assembly

[0084] In this operation, the electrolyte membrane-electrode assembly 100 is stacked on the other side of the durability-enhancing layers 201 , 202 opposite to the side on which the gas diffusion layers 310 , 320 are formed.

[0085] The stacking of the electrolyte membrane-electrode assembly 100 may be performed by a method commonly used in manufacturing a fuel cell.

[0086] In the method of manufacturing a fuel cell according to an embodiment of the present disclosure as described above, the content of the hydrogen peroxide decomposition catalyst can be locally increased at locations where degradation of the electrolyte membrane is severe (for example, at the reaction gas inlet and the reaction gas outlet) to effectively improve the chemical durability of the fuel cell.

[0087] Hereinafter, aspects of the present disclosure will be described in more detail through examples. However, these examples are only for understanding the present disclosure, and the scope of the present disclosure is not limited to these examples in any aspect.

[0088] Example 1. Stacking durability enhancement layers

[0089] like Figure 8 As shown, a mixture of DuPont's perfluorosulfonic acid and water in a ratio of 1:1 was injected into the first cylinder 1 as a first composition using a sprayer, and a mixture of cerium oxide and water in a ratio of 1:1 was injected into the second cylinder 2 as a second composition. Figure 5 As shown, the first composition and the second composition were mixed and applied to the gas diffusion layer 320 including the base layer and the porous layer at a weight ratio of 7:3. Thereafter, drying was performed at normal pressure and a temperature of 150° C. to remove water in the durability enhancement layer composition, thereby forming a durability enhancement layer comprising a 1 cm 2 The gas diffusion layer contains 1.5 μg of cerium and 3 μg of perfluorosulfonic acid and has an average diameter of 67 μm per dot.

[0090] Examples 2 to 4 and Comparative Examples 1 and 2

[0091] A durability-enhancing layer was formed in the same manner as in Example 1, except that the durability-enhancing layer was prepared with the composition shown in Table 1 below.

[0092] Table 1

[0093] <![CDATA[Application amount of each component of gas diffusion layer per 1 cm 2 > cerium Perfluorosulfonic acid Example 1 1.5 μg 3 μg Example 2 0.5 μg 3 μg Example 3 1.5 μg 0.8 μg Example 4 1.5 μg 5.5 μg Comparative Example 1 - 3 μg Comparative Example 2 1.5 μg -

[0094] Test Example 1. Durability Test

[0095] A fuel cell stack using gas diffusion layers formed with the durability-enhancing layers of the examples and comparative examples was formed, and then chemical durability and adhesion between the MEA and the GDL were evaluated.

[0096] Specifically, the gas diffusion layers (GDL) having the durability-enhancing layers of Examples and Comparative Examples were bonded to the surfaces of the catalyst layers of the anode and cathode (as the opposite sides of the electrolyte membrane-electrode assembly (MEA)), a separator was bonded to the other side of the gas diffusion layer, and a current collector was bonded on the other side of the separator to prepare a fuel cell (see Figure 3 and Figure 4 ).

[0097] (1) Durability

[0098] The durability of the MEA was evaluated using a mixed gas containing hydrogen and air at a volume ratio of 1.5:2.0 as a reaction gas at 90°C, 20 kPa of hydrogen, atmospheric pressure, and a relative humidity of 30%.

[0099] For basic activation and soaking, the fuel cell stack was treated under the above conditions for 24 hours, the initial voltage was measured, the cell voltage was maintained, and the results of the cell voltage were calculated using regression fitting while maintaining 1.2 A / cm 2 Specifically, the time taken until 10% performance degradation occurred based on the initial voltage was measured.

[0100] (2) Adhesion

[0101] A test specimen with dimensions of 10 mm wide and 50 mm long, bonded to the durability-reinforcing layer between the MEA and the GDL, was used. Adhesion was evaluated using a UTM machine. The GDL was fixed to one fixture of the machine using a SUS plate, and the MEA was fixed to the other fixture. The adhesive tear load between the MEA and GDL was then measured by peeling at 90°C at a speed of 50 mm / minute and a gauge distance of 15 mm.

[0102] Table 2

[0103] Durability (hr) Adhesion (kgf) Example 1 780 0.36 Example 2 590 0.36 Example 3 770 0.17 Example 4 770 0.54 Comparative Example 1 280 0.38 Comparative Example 2 770 0.02

[0104] As shown in Table 2, Examples 1 to 4 were excellent in durability and adhesion.

[0105] On the other hand, Comparative Example 1 having no cerium had very low durability, and Comparative Example 2 having no hydrogen ion conductive polymer had very poor adhesion.

[0106] A fuel cell according to an embodiment of the present disclosure includes a durability-enhancing layer containing a hydrogen peroxide decomposition catalyst at the interface between the GDL and the MEA to effectively prevent degradation of the electrolyte membrane. Furthermore, the fuel cell includes a durability-enhancing layer containing a highly viscous hydrogen ion conductive polymer at the interface between the GDL and the MEA to ensure excellent adhesion between the GDL and the MEA.

[0107] Furthermore, in the method of manufacturing a fuel cell according to an embodiment of the present disclosure, the content of the hydrogen peroxide decomposition catalyst can be locally increased at locations where degradation of the electrolyte membrane is severe (e.g., the reaction gas inlet and the reaction gas outlet), thereby effectively improving chemical durability.

[0108] Although the present disclosure has been described above with reference to exemplary examples, embodiments and accompanying drawings, the present disclosure is not limited thereto, and various modifications and changes may be made by those skilled in the art without departing from the spirit and scope of the present disclosure as claimed in the appended claims.

Claims

1. A fuel cell comprising: Electrolyte membrane-electrode assembly; a durability-enhancing layer comprising a hydrogen peroxide decomposition catalyst and a hydrogen ion conductive polymer and formed on at least a portion of at least one side of the electrolyte membrane-electrode assembly; as well as a gas diffusion layer formed on a side of the durability enhancing layer opposite to a side on which the electrolyte membrane-electrode assembly is formed; further comprising: a separator plate on a side of the gas diffusion layer opposite to a side in contact with the durability enhancing layer, the separator plate including a reaction gas inlet and a reaction gas outlet; A portion of the durability-enhancing layer corresponding to at least one of the reaction gas inlet and the reaction gas outlet of the separator plate includes a higher amount of the hydrogen peroxide decomposition catalyst than other portions of the durability-enhancing layer.

2. The fuel cell according to claim 1, wherein The durability-enhancing layer is a discontinuous layer including a plurality of points formed on at least one side of the electrolyte membrane-electrode assembly.

3. The fuel cell according to claim 1, wherein The durability-enhancing layer is formed on an entire side of the electrolyte membrane-electrode assembly.

4. The fuel cell according to claim 1, wherein The durability-enhancing layer includes 1.0 μg / cm 2 The above hydrogen peroxide decomposition catalyst and 1 μg / cm 2 The hydrogen ion conductive polymer mentioned above.

5. The fuel cell according to claim 1, wherein The hydrogen ion conducting polymer is in the form of an ionomer.

6. The fuel cell according to claim 1, wherein The hydrogen peroxide decomposition catalyst includes at least one selected from the group consisting of transition metals and rare earth metals.

7. The fuel cell according to claim 1, wherein A portion of the durability-enhancing layer corresponding to at least one of the reaction gas inlet and the reaction gas outlet of the separation plate includes 2.5 μg / cm 2 The above-mentioned hydrogen peroxide decomposition catalyst.

8. The fuel cell according to claim 1, wherein The durability-enhancing layer includes at least one additional material selected from the group consisting of TiO 2 , zeolite, silica, silver, carbon nanotubes, graphene oxide, and platinum.

9. The fuel cell according to claim 1, wherein The electrolyte membrane-electrode assembly includes an auxiliary gasket; and The portion of the durability-enhancing layer corresponding to a position other than the auxiliary gasket formed on the surface of the electrolyte membrane-electrode assembly includes 2.5 μg / cm 2 The above-mentioned hydrogen peroxide decomposition catalyst.

10. The fuel cell according to claim 1, wherein The gas diffusion layer includes a base layer and a porous layer; The porous layer is prepared from carbon-based powder, a binder, and a hydrogen peroxide decomposition catalyst; and The electrolyte membrane of the electrolyte membrane-electrode assembly includes the hydrogen peroxide decomposition catalyst.

11. A method of manufacturing a fuel cell, the method comprising: stacking a durability enhancement layer on one side of the gas diffusion layer; as well as stacking an electrolyte membrane-electrode assembly on a first side of the durability-enhancing layer, the first side being opposite to a second side on which the gas diffusion layer is stacked; wherein the durability enhancing layer comprises a hydrogen peroxide decomposition catalyst and a hydrogen ion conductive polymer; and wherein the durability enhancing layer covers at least a portion of at least one side of the electrolyte membrane-electrode assembly; further comprising: a separator plate on a side of the gas diffusion layer opposite to a side in contact with the durability enhancing layer, the separator plate including a reaction gas inlet and a reaction gas outlet; A portion of the durability-enhancing layer corresponding to at least one of the reaction gas inlet and the reaction gas outlet of the separator plate includes a higher amount of the hydrogen peroxide decomposition catalyst than other portions of the durability-enhancing layer.

12. The method according to claim 11, further comprising: The durability enhancing layer is prepared from a durability enhancing layer composition including the hydrogen peroxide decomposition catalyst, the hydrogen ion conductive polymer, and water.

13. The method according to claim 12, wherein: The durability enhancing layer composition includes a first composition including the hydrogen peroxide decomposition catalyst and water, and a second composition including the hydrogen ion conductive polymer and water.

14. The method according to claim 13, further comprising: The durability enhancing layer composition is applied at a mixing ratio of the first composition and the second composition, wherein the mixing ratio is adjusted to adjust the contents of the hydrogen peroxide decomposition catalyst and the hydrogen ion conductive polymer in the durability enhancing layer.

15. The method according to claim 14, wherein The durability enhancing layer is stacked using at least one of the group consisting of a spray coating method, a 3D printing technology, an inkjet printing technology, a slot die coating method, a rod coating method, a powder dispersion coating method, a screen printing technology, and a doctor blade coating method.

16. The method according to claim 15, wherein applying the durability enhancement layer composition by the spray coating method; and The durability-enhancing layer is a discontinuous layer including a plurality of dots.

17. The method according to claim 11, wherein The durability-enhancing layer includes 1.0 μg / cm 2 The above hydrogen peroxide decomposition catalyst and 1μg / cm 2 The hydrogen ion conductive polymer mentioned above.

Images