Membrane electrode and method for preparing membrane electrode

Abstract

The present invention relates to the technical field of electrolytic cells. The present invention provides a membrane electrode and a method for preparing the membrane electrode. The membrane electrode comprises a proton exchange membrane and a catalyst layer arranged in sequence; wherein at least one of the proton exchange membrane or the catalyst layer is provided with a conductive enhancement layer, the material of the conductive enhancement layer comprises one or more of platinum, gold, aluminum, zinc, nickel, chromium, iron, tin, lead, copper, silver, carbon, iridium, titanium, ruthenium, and niobium, and the conductive enhancement layer comprises one or more layers. The membrane electrode and the method for preparing the membrane electrode provided by the present invention are intended to solve the problems of low efficiency and low stability caused by the poor conductivity of the membrane electrode in the traditional technology.

Description

Technical Field

[0001] The invention relates to the technical field of electrolytic cells, and in particular to a membrane electrode and a method for preparing the membrane electrode. Background Art

[0002] Proton exchange membrane water electrolyzer (PEMEC) and fuel cells are the most promising hydrogen production and utilization equipment, with advantages such as high efficiency, high energy density and zero pollution. However, the slow kinetics in PEMEC electrodes greatly limits the energy conversion efficiency of the equipment. Taking PEMEC anode as an example, iridium-based oxide is currently the only commercial catalyst with good performance, but it is limited by its scarcity and high cost.

[0003] In addition, the oxide catalyst leads to an extremely high in-plane ohmic resistivity of the catalyst layer, which is about 1000 times that of the cathode. The high resistivity of the catalyst limits the electrochemical reaction to the edge of the contact point between the gas diffusion layer and the electrode, resulting in a large amount of catalyst waste, high overpotential, and severe electrode attenuation. This situation also occurs widely on electrodes made of other catalysts, including Pt / C and some non-precious metal catalysts, such as transition metal oxide catalysts FeCo, NiS, etc. If the electron and proton conductivity of the electrode can be increased to increase the electrode reaction sites, the efficiency and stability of hydrogen energy devices can be improved, thereby reducing the dependence on precious metal catalysts. Most of the current research focuses on enhancing the interaction between the support-electrocatalyst and the catalyst-electrolyte through nanostructured conductive supports (C, Ti, Sn and W-based materials), and very few studies are conducted on the electron and proton conductivity of the catalyst. In addition, visualizing the oxygen produced on the oxygen evolution reaction can reveal the electron distribution on the catalyst in the oxygen evolution reaction at the microscopic scale, but how the electron and proton conductivity on the electrode interact at the nano / micro scale to achieve the PEMEC reaction is still unclear. How to design the nano / microstructure of the electrode without sacrificing the nanoscale electrochemical activity to enhance its electron / proton conductivity and thus improve the efficiency and stability of PEMEC is crucial to the development of hydrogen production equipment. Summary of the invention

[0004] The present invention provides a membrane electrode and a method for preparing the membrane electrode, aiming to solve the problems of low efficiency and low stability caused by poor conductivity of the membrane electrode in the traditional technology.

[0005] In response to the problems existing in the prior art, an embodiment of the present invention provides a membrane electrode, comprising a proton exchange membrane and a catalyst layer arranged in sequence; wherein, at least one of the proton exchange membrane or the catalyst layer is provided with a conductive enhancement layer, the material of the conductive enhancement layer comprises one or more of platinum, gold, aluminum, zinc, nickel, chromium, iron, tin, lead, copper, silver, carbon, iridium, titanium, ruthenium, and niobium, and the conductive enhancement layer comprises one or more layers.

[0006] According to a membrane electrode provided by the present invention, the proton exchange membrane comprises a first side surface and a second side surface which are arranged opposite to each other, at least one of the first side surface or the second side surface is provided with a conductive enhancement layer, and the conductive enhancement layer is provided in a local area of ​​the first side surface and / or the second side surface; and / or,

[0007] The catalyst layer includes a third side and a fourth side that are arranged opposite to each other, and at least one of the third side, the fourth side, or between the third side and the fourth side is provided with a conductive reinforcement layer, and the conductive reinforcement layer is arranged in a local area between the third side and / or the fourth side and / or the third side and the fourth side.

[0008] According to a membrane electrode provided by the present invention, a protrusion is provided on the first side surface, and the end surface of the protrusion and the area on the first side surface where the protrusion is not provided are both provided with the conductive enhancement layer.

[0009] According to a membrane electrode provided by the present invention, a groove is provided on the first side surface, and the bottom wall of the groove and the area on the first side surface where the groove is not provided are both provided with the conductive enhancement layer.

[0010] According to a membrane electrode provided by the present invention, the catalyst layer includes a plurality of catalytic layers, and a side surface of one of the catalytic layers is used to set the conductive enhancement layer.

[0011] According to a membrane electrode provided by the present invention, the conductive enhancement layer further includes one or more conductive meshes with micro-nano thickness.

[0012] The present invention also provides a method for preparing a membrane electrode, wherein the membrane electrode comprises a proton exchange membrane and a catalyst layer arranged in sequence, and the method comprises:

[0013] Determine the surface to be treated in the membrane electrode;

[0014] forming a to-be-treated area and a non-treated area on the to-be-treated surface;

[0015] Providing a conductive reinforcement layer in the area to be processed;

[0016] Among them, the surface to be treated is at least located at one of the proton exchange membrane or the catalyst layer, and the material of the conductive enhancement layer includes one or more of platinum, gold, aluminum, zinc, nickel, chromium, iron, tin, lead, copper, silver, carbon, iridium, titanium, ruthenium, and niobium.

[0017] According to a method for preparing a membrane electrode provided by the present invention, the proton exchange membrane comprises a first side surface and a second side surface which are arranged opposite to each other, and the surface to be treated is at least arranged on one of the first side surface or the second side surface; and / or,

[0018] The catalyst layer includes a third side surface and a fourth side surface which are arranged opposite to each other, and the surface to be treated is at least arranged on one of the third side surface, the fourth side surface or between the third side surface and the fourth side surface.

[0019] According to a method for preparing a membrane electrode provided by the present invention, forming a to-be-treated area and a non-treated area on the to-be-treated surface comprises:

[0020] A plurality of protrusions are embossed on the surface to be processed, the end face of each protrusion and the area on the surface to be processed where the protrusion is not provided form the area to be processed, and the side wall of each protrusion forms the non-processed area; or, a plurality of grooves are pressed to form the surface to be processed, the bottom wall of each groove and the area on the surface to be processed where the groove is not provided form the area to be processed, and the side wall of each groove forms the non-processed area.

[0021] According to a method for preparing a membrane electrode provided by the present invention, setting a conductive enhancement layer in the area to be processed includes: depositing a conductive enhancement layer in the area to be processed, the deposition method including vacuum evaporation deposition, ion beam sputtering, magnetron sputtering deposition, atomic layer deposition, CVD chemical vapor deposition or electrochemical deposition, and the deposition thickness of the conductive enhancement layer is 1-10000nm.

[0022] According to a method for preparing a membrane electrode provided by the present invention, forming a to-be-treated area and a non-treated area on the to-be-treated surface includes: placing a baffle on the to-be-treated surface, the baffle being provided with a plurality of through holes and connecting holes, and each of the through holes being connected through the connecting holes; the area on the to-be-treated surface corresponding to the through holes and the connecting holes is the to-be-treated area, and the area on the to-be-treated surface not corresponding to the through holes and the connecting holes is the non-treated area.

[0023] According to a method for preparing a membrane electrode provided by the present invention, setting a conductive enhancement layer in the area to be processed includes: spraying a conductive enhancement solution or conductive enhancement particles on the baffle to form a conductive enhancement layer in the area to be processed, and the material of the conductive enhancement solution or the conductive enhancement particles includes one or more of platinum, gold, aluminum, zinc, nickel, chromium, iron, tin, lead, copper, silver, carbon, iridium, titanium, ruthenium, and niobium.

[0024] According to a method for preparing a membrane electrode provided by the present invention, providing a conductive enhancement layer in the area to be processed comprises: attaching a patch to the area to be processed, and hot pressing to transfer the conductive enhancement layer on the patch to the area to be processed.

[0025] According to a method for preparing a membrane electrode provided by the present invention, the catalyst layer is prepared from a catalyst solution, the catalyst solution includes iridium oxide, isopropyl alcohol, a perfluorosulfonic acid polymer solution and metal particles, and the metal particles include one or more of platinum, gold, aluminum, zinc, nickel, chromium, iron, tin, lead, copper, silver, carbon, iridium, titanium, ruthenium and niobium.

[0026] The membrane electrode provided by the present invention has a conductive enhancement layer arranged on the proton exchange membrane or the catalyst layer, which can achieve fast and efficient conduction of electrons and protons between the electrodes, thereby significantly improving the working efficiency of the membrane electrode. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0028] Figure 1 It is a schematic diagram of the structure of the membrane electrode provided by the present invention;

[0029] Figure 2 This is one of the structural schematic diagrams of the proton exchange membrane in the membrane electrode provided by the present invention;

[0030] Figure 3 It is a schematic diagram of the process of preparing the membrane electrode provided by the present invention;

[0031] Figure 4 yes Figure 3 A schematic diagram of the operation of forming a to-be-processed area and a non-processed area;

[0032] Figure 5 yes Figure 3 A schematic diagram of a performance test of an embodiment.

[0033] Figure numerals: 1, proton exchange membrane; 11, protrusion; 2, conductive enhancement layer; 3, catalyst layer. DETAILED DESCRIPTION

[0034] The following embodiments of the present invention are described in further detail in conjunction with the accompanying drawings and examples. The following examples are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0035] In the description of the embodiments of the present invention, it should be noted that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present invention and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as limitations on the embodiments of the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0036] In the description of the embodiments of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "connected" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the embodiments of the present invention can be understood according to specific circumstances.

[0037] In the embodiments of the present invention, unless otherwise clearly specified and limited, the first feature being "above" or "below" the second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature being "above", "above" and "above" the second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. The first feature being "below", "below" and "below" the second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0038] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the embodiment of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0039] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0040] Combine the following Figure 1-Figure 5 The invention describes the membrane electrode and the method for preparing the membrane electrode.

[0041] See also Figure 1 The present invention provides a membrane electrode, comprising a proton exchange membrane 1 and a catalyst layer 3 arranged in sequence; wherein at least one of the proton exchange membrane 1 or the catalyst layer 3 is provided with a conductive enhancement layer 2, the material of the conductive enhancement layer 2 includes one or more of platinum, gold, aluminum, zinc, nickel, chromium, iron, tin, lead, copper, silver, carbon, iridium, titanium, ruthenium, and niobium, and the conductive enhancement layer 2 can be one layer or multiple layers. The membrane electrode provided by the present invention is provided with a conductive enhancement layer 2 on the proton exchange membrane 1 or the catalyst layer 3, which can realize fast and efficient conduction of electrons and protons between electrodes, thereby significantly improving the working efficiency of the membrane electrode.

[0042] Further, the proton exchange membrane 1 includes a first side and a second side that are arranged opposite to each other, at least one of the first side or the second side is provided with a conductive enhancement layer 2, and the conductive enhancement layer 2 is arranged in a local area of ​​the first side and / or the second side; and / or, the catalyst layer 3 includes a third side and a fourth side that are arranged opposite to each other, at least one of the third side, the fourth side, or between the third side and the fourth side is provided with a conductive enhancement layer 2, and the conductive enhancement layer 2 is arranged in the third side and / or the fourth side and / or the local area between the third side and the fourth side. It should be noted that the area where the conductive enhancement layer 2 is arranged on the first side, the second side, the third side, the fourth side, or between the third side and the fourth side can provide a transmission channel for protons, and the area where the conductive enhancement layer 2 is arranged can realize fast and efficient conduction of electrons and protons between electrodes, which is conducive to improving the efficiency of the membrane electrode.

[0043] In an optional embodiment, a protrusion 11 is provided on the first side surface, and the end surface of the protrusion 11 and the area on the first side surface where the protrusion 11 is not provided are provided with a conductive reinforcement layer 2. The protrusion 11 can increase the surface area of ​​the corresponding side surface, thereby increasing the contact area with the reactants, thereby increasing the reaction sites and improving the reaction efficiency. The longitudinal side walls of the protrusion 11 are not processed, and a proton transmission channel can be formed in the through direction. The protrusion 11 can be set to a cylindrical shape, and the protrusions 11 are distributed in a regular array. The protrusions 11 can also be set to other shapes, such as a sinusoidal waveform, a serpentine shape, a circular ring shape, a triangle, a regular quadrilateral, a honeycomb shape or a random pattern, etc. The shapes of the protrusions 11 can be the same or different, and the protrusions 11 can be regularly distributed or randomly distributed, and the present invention is not limited to this. Please refer to Figure 2 One side of the proton exchange membrane 1 has a plurality of protrusions 11, which are cylindrical in shape in this embodiment. For the convenience of observation, the catalyst layer 3 and the conductive reinforcement layer 2 are not marked in the figure. The catalyst layer 3 and the conductive reinforcement layer 2 are directly coated on the protrusions 11. When viewed from the side, the surface of the prepared membrane electrode has protrusions 11.

[0044] In another optional embodiment, a groove is provided on the first side, and the bottom wall of the groove and the area on the first side where the groove is not provided are provided with a conductive enhancement layer 2. The effect of the groove is similar to that of the bump, and the contact area with the reactant is also increased, and the side wall of the groove can also form a proton transmission channel in the through direction. The groove can be set to a variety of shapes, such as a sine wave, a serpentine, a circular ring, a triangle, a regular quadrilateral, a honeycomb or a random pattern, etc. The shape of the groove can be the same or different, and the grooves can be regularly distributed or randomly distributed, and the present invention is not limited to this.

[0045] It should be noted that the above embodiment takes the first side as an example, and the second side, the third side, the fourth side, or the third side and the fourth side can all adopt the same arrangement as the first side, and the present invention is not limited to this. More specifically, when the conductive enhancement layer 2 is arranged between the third side and the fourth side, the catalyst layer 3 includes a plurality of catalytic layers, and the side of one catalytic layer is used to arrange the conductive enhancement layer 2. Please refer to Figure 1 ,exist Figure 1 The present invention provides three membrane electrode embodiments, Figure 1 In the leftmost embodiment a, a conductive enhancement layer 2 is provided on the proton exchange membrane 1, and a catalyst layer 3 is provided on the conductive enhancement layer 2; Figure 1 In the middle embodiment b, a conductive enhancement layer 2 is provided on the catalyst layer 3; Figure 1 In the embodiment c on the right, a conductive enhancement layer 2 is provided in the middle of the catalyst layer 3. It should be noted that Figure 1The three embodiments in the drawings all adopt the form of setting the conductive reinforcement layer 2 on the plane, such as spraying or hot pressing transfer. In other embodiments, bumps or grooves may be set on the plane, and the conductive reinforcement layer 2 may be set in the bumps or grooves. It should be noted that the structures of each layer in the drawings are only for illustration and do not represent the actual shape structure. In actual application, multiple conductive reinforcement layers may also be set, and the present invention is not limited to this.

[0046] It should also be noted that, in another optional embodiment, the conductive enhancement layer 2 further includes one or more micro-nano thickness conductive meshes, which may be pre-prepared nano-scale mesh structures with conductive properties. The conductive meshes may be provided separately, or the conductive meshes and the metal conductive enhancement layer may be provided simultaneously in different regions, which is not limited in the present invention.

[0047] See also Figure 3 The present invention also provides a method for preparing a membrane electrode, wherein the membrane electrode comprises a proton exchange membrane and a catalyst layer arranged in sequence, and the method comprises:

[0048] S100, determining a surface to be processed in a membrane electrode;

[0049] S200, forming a to-be-treated area and a non-treated area on the to-be-treated surface;

[0050] S300, providing a conductive reinforcement layer in the area to be processed;

[0051] Among them, the surface to be treated is at least located at one of the proton exchange membrane or the catalyst layer, and the material of the conductive enhancement layer includes one or more of platinum, gold, aluminum, zinc, nickel, chromium, iron, tin, lead, copper, silver, carbon, iridium, titanium, ruthenium, and niobium.

[0052] Specifically, the proton exchange membrane includes a first side surface and a second side surface that are arranged opposite to each other, and the surface to be treated is at least arranged on one of the first side surface or the second side surface; and / or, the catalyst layer includes a third side surface and a fourth side surface that are arranged opposite to each other, and the surface to be treated is at least arranged on the third side surface, the fourth side surface or one of the third side surface and the fourth side surface.

[0053] In the technical solution provided by the present invention, it is first necessary to determine the surface to be treated. After determining the surface to be treated, it is necessary to form a to-be-treated area and a non-treated area on the to-be-treated surface. A conductive enhancement layer needs to be provided in the to-be-treated area, and no treatment is performed in the non-treated area. The material of the conductive enhancement layer includes one or more of platinum, gold, aluminum, zinc, nickel, chromium, iron, tin, lead, copper, silver, carbon, iridium, titanium, ruthenium, and niobium. Specifically, the preparation method of the membrane electrode provided by the present invention is provided with an untreated area on the to-be-treated surface, and the untreated area can provide a transmission channel for protons; and a conductive enhancement layer is provided at the to-be-treated area, and the conductive enhancement layer can realize fast and efficient conduction of electrons and protons between electrodes, thereby significantly improving the working efficiency of the membrane electrode.

[0054] The present invention provides a variety of ways to set the to-be-treated area and the non-treated area. In an optional embodiment, forming the to-be-treated area and the non-treated area on the to-be-treated surface includes:

[0055] A plurality of protrusions are formed by embossing on the surface to be processed, the end surface of each protrusion and the area on the surface to be processed where no protrusion is provided form the area to be processed, and the side wall of each protrusion forms the non-processed area.

[0056] By forming protrusions by embossing on the surface to be treated, the protrusions can increase the surface area of ​​the surface to be treated, thereby increasing the contact area with the reactants, and further increasing the reaction sites to improve the reaction efficiency. In addition, the longitudinal side walls of the protrusions are not treated, and proton transmission channels can be formed in the through direction. It should be noted that the embossing can be performed using an embossing template, and different patterns can be set on the embossing template to form protrusions. The embossing template can be a flat, smooth, conductive stainless steel plate, aluminum plate, copper plate, nickel plate, or non-conductive glass, single crystal silicon, silicon oxide, polyimide, polyethylene terephthalate, polyethylene naphthalate, polydimethylsiloxane. Please refer to Figure 4 Taking the example of setting a conductive reinforcement layer on the first side, when using an imprinting template for imprinting, a thin film can be placed between the imprinting template and the proton exchange membrane (PEM) to prevent contamination. The thin film can be a polytetrafluoroethylene (PTFE) film or a polyvinyl fluoride (ETFE) film or other types of films. In order not to affect the imprinting effect, the thickness is between 1-1000nm. Furthermore, the imprinting template can be squeezed from both sides by two sets of clamps to form a protrusion on the surface to be treated of the proton exchange membrane. Figure 4 In the technical solution involved, a protrusion is formed only on one side of the PEM, and a clamp is fitted with the PEM on the other side. In order to prevent the clamp from contaminating the PEM, a thin film can also be set between the clamp and the PEM to prevent contamination.

[0057] In another optional embodiment, forming the to-be-treated area and the non-treated area on the to-be-treated surface includes:

[0058] A plurality of grooves are formed by pressing on the surface to be processed, the bottom wall of each groove and the area on the surface to be processed where no groove is set form the area to be processed, and the side wall of each groove forms the non-processed area.

[0059] It should be noted that the manner of setting the groove is similar to the manner of setting the bump, and can also be carried out with the assistance of the embossing template, the difference being the setting form of the embossing template, and thus the present invention will not be repeated. The setting effect of the groove is similar to that of the bump, and the contact area is also increased, and the side wall of the groove is set as a non-processing area, and a proton transmission channel can also be formed in the through direction. The groove can be set to a variety of shapes, such as a sinusoidal waveform, a serpentine, a circular ring, a triangle, a regular quadrilateral, a honeycomb or a random pattern, etc. The shape of the groove can be the same or different, and the grooves can be regularly distributed or randomly distributed, and the present invention is not limited to this.

[0060] Further, setting a conductive enhancement layer in the area to be treated includes: depositing a conductive enhancement layer in the area to be treated, and the deposition method includes vacuum evaporation deposition, ion beam sputtering, magnetron sputtering deposition, atomic layer deposition, CVD chemical vapor deposition, and electrochemical deposition, and the deposition thickness of the conductive enhancement layer is 1-10000nm. It should be noted that the above deposition method is applicable to the case where a bump or groove is provided on the surface to be treated. Taking the bump as an example, when depositing the conductive enhancement layer, the proton exchange membrane is placed horizontally, and the conductive enhancement layer is deposited on the end face of the bump, and in the area where the bump is not provided on the surface to be treated, the side wall of the bump is not attached with the conductive enhancement layer; taking the groove as an example, when depositing the conductive enhancement layer, the proton exchange membrane is placed horizontally, and the conductive enhancement layer is deposited on the bottom wall of the groove, and in the area where the groove is not provided on the surface to be treated, the side wall of the groove is not attached with the conductive enhancement layer. In an optional embodiment, the Pt conductive enhancement layer can be added by magnetron sputtering, and the sputtering time is 60s.

[0061] In other optional embodiments, the conductive enhancement layer can be set by spraying. Specifically, forming the area to be treated and the non-treated area on the surface to be treated includes: placing a baffle on the surface to be treated, and a plurality of through holes and connecting holes are provided on the baffle, and each through hole is connected through the connecting hole; the area of ​​the surface to be treated corresponding to the through hole and the connecting hole is the area to be treated, and the area of ​​the surface to be treated that does not correspond to the through hole and the connecting hole is the non-treated area. Further, setting the conductive enhancement layer in the area to be treated includes: spraying a conductive enhancement solution or conductive enhancement particles on the baffle to form a conductive enhancement layer in the area to be treated, and the material of the conductive enhancement solution or the conductive enhancement particles includes platinum, gold, aluminum, zinc, nickel, chromium, iron, tin, lead, copper, silver, carbon, iridium, titanium, ruthenium, niobium solution One or more. In the above embodiment, the baffle can act as a mold to form the area to be treated and the non-treated area on the surface to be treated. The shape of the through hole can be set with reference to the shape of the above-mentioned bump or groove, and the connecting hole can be strip-shaped, which is not limited by the present invention. The conductivity enhancing solution may be a single metal solution or a mixed metal solution, and the conductivity enhancing particles may be single metal particles or mixed metal particles. The difference between the solution and the particles lies only in the material form.

[0062] In another optional embodiment, the conductive reinforcement layer can be set by printing. Specifically, the conductive reinforcement layer is set in the area to be treated, including: attaching the patch to the area to be treated, and hot pressing to transfer the conductive reinforcement layer on the patch to the area to be treated. It should be noted that the conductive reinforcement layer can be set on the patch in advance, which can be set by deposition or spraying, and the present invention is not limited to this. Taking the conductive reinforcement layer set on the proton exchange membrane as an example, the patch can be set to an area smaller than the proton exchange membrane, so that the conductive reinforcement layer can be set separately in multiple areas of the proton exchange membrane by multiple bonding. The area of ​​the patch can also be set similar to the proton exchange membrane, and multiple spaced conductive reinforcement layers are set on the patch, and then the conductive reinforcement layers are set separately in multiple areas of the proton exchange membrane by bonding once.

[0063] It should be noted that in the embodiments of spraying and patching with a conductive enhancement layer, the plane to be treated is still a planar structure, and compared with the scheme of setting bumps and grooves, the contact area with the catalyst is not increased, but the efficiency of proton transmission can be significantly improved due to the addition of a conductive enhancement layer. The process of spraying and patching is relatively simple, while the process of embossing bumps and grooves is more complicated, but the effect is better. Those skilled in the art can choose the appropriate setting form as needed.

[0064] Furthermore, if the conductive enhancement layer is provided on the proton exchange membrane, the catalyst layer needs to be prepared after the treatment of the proton exchange membrane. It should be noted that the catalyst layer is provided on the surface of the proton exchange membrane, and will cover the area to be treated and the untreated area. Taking the preparation of the anode catalyst layer as an example, when the conductive enhancement layer is provided on one side of the proton exchange membrane close to the anode catalyst layer, it is also necessary to scrape, coat or spray the anode catalyst solution outside the conductive enhancement layer. The anode catalyst solution includes iridium oxide, isopropanol, perfluorosulfonic acid polymer solution and metal particles. The metal particles include platinum, gold, aluminum, zinc, nickel, chromium, iron, tin, lead, copper, silver, carbon, iridium, titanium, ruthenium, niobium and one or more. Specifically, it is necessary to prepare the anode catalyst first. In an optional embodiment, the anode catalyst uses iridium oxide, the solvent uses isopropanol, and the binder uses perfluorosulfonic acid polymer solution. Then it is necessary to fully stir the prepared mixture, and the magnetic stirring method can be selected, and the stirring time is 30min. The stirred catalyst slurry is further degassed to prevent the bubbles generated by the stirring from affecting the subsequent scraping process. Ultrasonic degassed method can be used. After the anode catalyst solution is prepared, wait for the surface treatment of the proton exchange membrane. After the conductive enhancement layer is formed on the proton exchange membrane, place the proton exchange membrane on a heated adsorption table and use the prepared anode catalyst solution for scraping. It should be noted that if the surface to be treated is located on the proton exchange membrane and this side of the proton exchange membrane corresponds to the cathode, the conductivity of the conductive enhancement layer should be greater than that of the cathode catalyst. By adding metal particles to the anode catalyst solution, the conductivity of the membrane electrode can also be further improved.

[0065] See also Figure 5 In an optional embodiment, a proton exchange membrane is provided with a bump, a conductive reinforcement layer is provided between the end surface of the bump and the area on the proton exchange membrane where the bump is not provided, and a conductive reinforcement layer is provided in the middle of the anode catalyst layer. Referring to the accompanying drawings, the performance of this embodiment is significantly improved compared with the control embodiment.

[0066] It should be noted that the membrane electrode provided by the present invention can be applied to proton exchange membrane water electrolyzers (PEMECs), fuel cells, and other fields, and the arrangement of the membrane electrode can help to significantly improve the reaction efficiency.

[0067] In the technical solution provided by the present invention, by changing the surface shape of the proton exchange membrane or the catalyst layer and adding a conductive enhancement layer of a certain thickness, the catalytic efficiency can be improved, thereby reducing the amount of catalyst used and achieving the goal of reducing costs. The solution is simple to operate and can be applied to large-scale production. It can not only achieve energy saving and efficiency improvement, but also is more conducive to the large-scale commercialization of membrane electrodes.

[0068] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A membrane electrode, characterized in that: It comprises a proton exchange membrane and a catalyst layer arranged in sequence; wherein at least one of the proton exchange membrane or the catalyst layer is provided with a conductive enhancement layer, the material of the conductive enhancement layer comprises one or more of platinum, gold, aluminum, zinc, nickel, chromium, iron, tin, lead, copper, silver, carbon, iridium, titanium, ruthenium, and niobium, and the conductive enhancement layer comprises one or more layers; The proton exchange membrane comprises a first side surface and a second side surface which are arranged opposite to each other, at least one of the first side surface or the second side surface is provided with a conductive enhancement layer, and the conductive enhancement layer is provided in a local area of ​​the first side surface and / or the second side surface; and / or, The catalyst layer comprises a third side surface and a fourth side surface which are arranged opposite to each other, at least one of the third side surface, the fourth side surface or the area between the third side surface and the fourth side surface is provided with a conductive enhancement layer, and the conductive enhancement layer is provided on the third side surface and / or the fourth side surface and / or a local area between the third side surface and the fourth side surface; A protrusion is provided on the side where the conductive reinforcement layer is provided, and the end face of the protrusion and the area on the side where the conductive reinforcement layer is provided but the protrusion is not provided are both provided with the conductive reinforcement layer; or a groove is provided on the side where the conductive reinforcement layer is provided, and the bottom wall of the groove and the area on the side where the conductive reinforcement layer is provided but the groove is not provided are both provided with the conductive reinforcement layer; the longitudinal side walls of the protrusion are not processed; the side walls of the groove are not processed.

2. The membrane electrode according to claim 1, characterized in that: The catalyst layer includes a plurality of catalytic layers, and a side surface of one of the catalytic layers is used for arranging the conductive enhancement layer.

3. The membrane electrode according to claim 1, characterized in that: The conductive enhancement layer also includes one or more conductive meshes with a micro-nano thickness.

4. A method for preparing a membrane electrode, characterized in that: The membrane electrode comprises a proton exchange membrane and a catalyst layer arranged in sequence, and the method comprises: Determine the surface to be treated in the membrane electrode; forming a to-be-treated area and a non-treated area on the to-be-treated surface; Providing a conductive reinforcement layer in the area to be processed; The surface to be treated is at least located at one of the proton exchange membrane or the catalyst layer, and the material of the conductive enhancement layer includes one or more of platinum, gold, aluminum, zinc, nickel, chromium, iron, tin, lead, copper, silver, carbon, iridium, titanium, ruthenium, and niobium; The proton exchange membrane comprises a first side surface and a second side surface which are arranged opposite to each other, and the surface to be treated is at least arranged on one of the first side surface or the second side surface; and / or, The catalyst layer comprises a third side surface and a fourth side surface which are arranged opposite to each other, and the surface to be treated is at least arranged on one of the third side surface, the fourth side surface or between the third side surface and the fourth side surface; Forming the to-be-treated area and the non-treated area on the to-be-treated surface includes: A plurality of protrusions are embossed on the surface to be processed, the end face of each protrusion and the area on the surface to be processed where the protrusion is not provided form the area to be processed, and the side wall of each protrusion forms the non-processed area; or, a plurality of grooves are pressed to form the surface to be processed, the bottom wall of each groove and the area on the surface to be processed where the groove is not provided form the area to be processed, and the side wall of each groove forms the non-processed area.

5. The method for preparing a membrane electrode according to claim 4, characterized in that: Setting a conductive enhancement layer in the area to be processed includes: depositing a conductive enhancement layer in the area to be processed, wherein the deposition method includes vacuum evaporation deposition, ion beam sputtering, magnetron sputtering deposition, atomic layer deposition, CVD chemical vapor deposition or electrochemical deposition, and the deposition thickness of the conductive enhancement layer is 1-10000nm.

6. The method for preparing a membrane electrode according to claim 4, characterized in that: Forming a to-be-processed area and a non-processed area on the to-be-processed surface includes: placing a baffle on the to-be-processed surface, the baffle being provided with a plurality of through holes and connecting holes, and the through holes being connected through the connecting holes; the area of ​​the to-be-processed surface corresponding to the through holes and the connecting holes is the to-be-processed area, and the area of ​​the to-be-processed surface not corresponding to the through holes and the connecting holes is the non-processed area.

7. The method for preparing a membrane electrode according to claim 6, characterized in that: Providing a conductive enhancement layer in the area to be processed includes: spraying a conductive enhancement solution or conductive enhancement particles on the baffle to form a conductive enhancement layer in the area to be processed, and the material of the conductive enhancement solution or the conductive enhancement particles includes one or more of platinum, gold, aluminum, zinc, nickel, chromium, iron, tin, lead, copper, silver, carbon, iridium, titanium, ruthenium, and niobium.

8. The method for preparing a membrane electrode according to claim 4, characterized in that: Providing a conductive reinforcement layer in the area to be processed includes: attaching a patch to the area to be processed, and hot pressing to transfer the conductive reinforcement layer on the patch to the area to be processed.

9. The method for preparing a membrane electrode according to claim 4, characterized in that: The catalyst layer is prepared from a catalyst solution, which includes iridium oxide, isopropyl alcohol, a perfluorosulfonic acid polymer solution and metal particles, and the metal particles include one or more of platinum, gold, aluminum, zinc, nickel, chromium, iron, tin, lead, copper, silver, iridium, titanium, ruthenium and niobium.

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