Component with improved surface contact resistance and reactivity and method of manufacturing thereof

Abstract

A component having improved surface contact resistance and reactivity and a method of making the same are disclosed, falling within the technical field of surface contact resistance and reactivity components. The component includes: a metal base; and a plurality of particles bonded to a surface of the metal base by a metallurgical bond; wherein the plurality of particles includes a metal, carbon, or a combination thereof, wherein the metallurgical bond is between the plurality of particles and the metal base, wherein a total projected area of the metallurgical bond is less than 90% of a total projected area of the metal base, and wherein a composition of the metallurgical bond is a combination of a composition of the metal base and a composition of the plurality of particles, a reaction product of the metal base and the plurality of particles, or a combination thereof.

Description

[0001] Citation of relevant applications

[0002] This invention claims priority to U.S. Provisional Application No. 62 / 891,879, filed February 26, 2020, and all benefits arising therefrom under 35 U.S.C., section 119, the entire contents of which are incorporated herein by reference.

[0003] This invention is a divisional application of the parent application (application number 202180007097.7, application date 2021-02-24, patent title: component with improved surface contact resistance and reactivity and method of manufacturing thereof). Technical Field

[0004] This invention discloses a component with improved surface contact resistance and reactivity, and a method for manufacturing the same. For example, the component can be a bipolar plate or electrode for use in batteries, fuel cells, or electrolyzers. Background Technology

[0005] In fuel cell, flow cell, or electrolyzer applications, bipolar plates are used to connect adjacent cells. Low surface contact resistance and strong corrosion resistance are desirable for bipolar plates to minimize internal ohmic losses and maintain operational stability throughout their service life. In electrolyzers or flow cells, highly reactive electrodes are required for efficient electrode reactions. Improvements are still needed in components, such as improved bipolar plates combining contact resistance and corrosion resistance, or highly reactive electrodes. Summary of the Invention

[0006] This invention discloses a component with improved surface contact resistance and reactivity, the component comprising: a metal substrate; and a plurality of particles bonded to the surface of the metal substrate by a metallurgical binder, wherein the plurality of particles comprise metal, carbon, or a combination thereof, wherein the metallurgical binder is located between the plurality of particles and the metal substrate, wherein the total projected area of ​​the metallurgical binder is less than 90% of the total projected area of ​​the metal substrate, and wherein the composition of the metallurgical binder is a combination of the composition of the metal substrate and the composition of the plurality of particles, a reaction product of the metal substrate and the plurality of particles, or a combination thereof.

[0007] The present invention also discloses a method for manufacturing a component with improved surface contact resistance and reactivity, the method comprising: providing a metal substrate; depositing a mixture comprising a plurality of precursor particles onto the metal substrate, wherein the plurality of precursor particles comprise metal, carbon, metal hydrides, or combinations thereof, to form a coated metal substrate, wherein the plurality of precursor particles contact less than 90% of the total projected area of ​​the metal substrate, and wherein the average particle size of the plurality of precursor particles is less than 200 μm; and heat-treating the coated metal substrate to form particles from the plurality of precursor particles, and bonding the particles to the metal substrate by a metallurgical bond formed between the particles and the metal substrate to manufacture the component, wherein the composition of the metallurgical bond is a combination of the metal substrate composition and the particle composition, a reaction product of the metal substrate and the particles, or a combination thereof. Attached Figure Description

[0008] The above and other advantages and features of this disclosure will become more apparent from a more detailed description of the embodiments thereof in conjunction with the accompanying drawings, wherein:

[0009] Figure 1 It is a schematic cross-sectional view of a metal substrate including multiple particles metallurgically bonded to the metal substrate.

[0010] Figure 2 This is a schematic cross-sectional view of a porous coating on a metal substrate;

[0011] Figure 3 It is a schematic cross-sectional view of the metallurgical bond formed between two substrates and the substrates through particles;

[0012] Figure 4 This is a photo of a stamped stainless steel bipolar plate used in fuel cells;

[0013] Figure 5 It is the cross-section of a stainless steel bipolar plate;

[0014] Figure 6 This is a SEM image of glassy carbon spherical particles metallurgically bonded to a titanium substrate;

[0015] Figure 7 It is the contact resistance (mΩ•cm) 2 The graph relative to compressive pressure (pounds per square inch, PSI) shows a comparison of the surface contact resistance of a titanium plate with or without metallurgically bonded carbon particles with that of a carbon felt.

[0016] Figure 8 This is a SEM image of graphite particles metallurgically bonded to a titanium substrate.

[0017] Figure 9This is a SEM image of a composite material consisting of titanium particles and ground carbon fiber particles that are metallurgically bonded to a stainless steel mesh.

[0018] Figure 10 This is a SEM image showing the microstructure of a composite material of titanium particles and ground carbon fiber particles.

[0019] Figure 11 These are SEM images of titanium particles metallurgically bonded to a titanium substrate; and

[0020] Figure 12 This is an SEM image of a porous titanium coating on a titanium substrate. Detailed Implementation

[0021] The invention will now be described more fully below in conjunction with the accompanying drawings, in which various embodiments are illustrated. However, the invention may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. The same reference numerals refer to the same elements throughout.

[0022] In fuel cells, flow batteries, or electrolyzer arrays, components between adjacent cells (e.g., bipolar plates) need to maintain electrical connection between the adjacent cells and separate the reactants within them. The bipolar plates maintain electrical contact with other components in the electrolyzer array (e.g., mass transport layers or electrodes). However, since solid-to-solid surface contact occurs only at high points on the surface, the number of contact points or the contact area is limited, resulting in high surface electrical or thermal contact resistance. One way to reduce surface contact resistance is to use soft materials on the contact surfaces. Soft materials can deform under pressure to match the surface morphology of the contact components, thereby increasing the actual contact area between the two components. Representative soft materials that enhance electrical or thermal contact include silver, gold, or tin. However, such soft materials are either too expensive or do not provide suitable chemical stability or corrosion resistance for electrochemical devices such as fuel cells or electrolyzers.

[0023] US Patent 10,435,782 discloses modifying surface morphology to provide microtextured structures for corrosion-resistant materials, thereby reducing electrical contact resistance. Lower contact resistance is achieved by increasing the actual contact area between components through deformation of the microtextured structure under compressive stress. However, developing a low-cost, rapid manufacturing process to provide such microtextured structures for mass production has proven difficult. For example, using pulsed lasers to provide micron- or nanometer-scale surface structures has proven too inefficient and expensive for commercial applications.

[0024] U.S. Patent Application 2018 / 0309136 teaches the mechanical bonding of particles to a substrate using electrostatic forces in a vacuum. Further evaluation revealed that the mechanical bonding interface between multiple particles and the metal substrate is prone to corrosion along the interface, which ultimately leads to bonding failure.

[0025] Adhesive bonding and brazing were also considered, but the resulting bonds have been found to provide unsuitable corrosion resistance for electrochemical applications. Diffusion bonding, in which components are pressed together under high pressure and high temperature, was also considered. However, diffusion bonding has proven to be expensive and does not provide suitable corrosion resistance.

[0026] In electrolyzers or flow batteries, electrode activity affects power and efficiency. Common methods to improve reactivity include using highly reactive materials and increasing surface area. Due to the highly corrosive operating environment in electrochemical devices, it is necessary to improve the bonding between the electrode reactive material and the electrode substrate (usually a metal) to maintain the long-term durability of the electrode.

[0027] The inventors were surprised to discover that by bonding multiple particles to a metal substrate through metallurgical binders, they could achieve improvements in overall performance such as contact resistance, reactivity, and corrosion resistance, while also obtaining components with improved performance in electrochemical applications (such as in fuel cells, flow batteries, or electrolyzers), such as bipolar plates.

[0028] This invention discloses a component with improved surface contact resistance and reactivity, the component comprising: a metal substrate; and a plurality of particles bonded to the surface of the substrate by a metallurgical binder, wherein the plurality of particles comprise metal, carbon, or a combination thereof, wherein the metallurgical binder is located between the particles and the substrate, wherein the total projected area of ​​the metallurgical binder is less than 90% of the total projected area of ​​the substrate, and wherein the composition of the metallurgical binder is a combination of a metal substrate component and a plurality of particle components, a reaction product of the metal substrate and a plurality of particles, or a combination thereof.

[0029] Figure 1 The accompanying drawing illustrates one aspect of the components disclosed in this invention, showing a metal substrate 11 and particles 12 bonded to the metal substrate by a metallurgical bond 13. In one aspect, in addition to the metallurgical bond between the particles and the substrate, a metallurgical bond can also be formed between the particles.

[0030] The metal substrate may include Ti metal, Nb metal, Ta metal, Ni metal, Cr metal, alloys of the foregoing metals, stainless steel, or combinations of the foregoing metals. The use of Ti or stainless steel (e.g., 316 or 304 stainless steel) is mentioned. The metal substrate may have any suitable form and may be completely dense or porous, and may be in the form of a thin film, foil, separator, mesh, perforated film, expanded metal foil, or microporous sheet.

[0031] In one aspect, expanded metal, screens, perforated metal, or wire mesh can be used as the metal substrate. The open area of ​​the metal substrate can be 10% to 90%, 20% to 80%, 30% to 70%, or 40% to 60% of the total projected area of ​​the metal substrate. For example, multiple layers of the above-mentioned materials can be used to form multilayer metal substrates with structural or compositional gradients. The use of titanium felt or titanium sintered material is mentioned. In one aspect, microporous sheets can be used, and the porosity can be 30% to 95%, 40% to 90%, 50% to 85%, or 55% to 80% based on the volume of the metal substrate. Any suitable combination of the upper and lower limits of the above ranges can be used.

[0032] In one aspect, the multiple particles comprise a metal or carbon. In another aspect, the multiple particles comprise a metal, wherein the metal is Ti metal, Nb metal, Ta metal, Ni metal, Cr metal, an alloy of the aforementioned metals, or a combination of the aforementioned metals. The use of Ti particles is mentioned. In one aspect, the multiple particles may comprise intermetallic compounds of Ti metal, Nb metal, Ta metal, Ni metal, and Cr metal, hydrides of Ti metal, Nb metal, Ta metal, Ni metal, and Cr metal, or combinations thereof. The fracture properties of intermetallic compounds or hydrides facilitate the formation of particles with suitable sizes. Figure 11 The image shown is an SEM image of titanium particles metallurgically bonded to a titanium substrate. The smooth edges of multiple particles with the metal substrate are signs of diffusion bonding between the titanium particles and the substrate. It also shows the formation of particle clusters through bonding between the titanium particles.

[0033] The average particle size of multiple particles can be less than 200 micrometers (μm), for example, 3 nanometers (nm) to 200 μm, 8 nm to 150 μm, 10 nm to 100 μm, 50 nm to 50 μm or 500 nm to 10 μm. Particles with average particle sizes of 3 nm to 200 μm, 0.1 nm to 5 μm, 3 nm to 8 nm, 5 nm to 10 nm, 7 nm to 100 nm, 50 nm to 500 nm, 10 nm to 20 μm, 5 nm to 0.5 μm, 20 nm to 1 μm, 100 nm to 0.9 μm, 20 nm to 5 μm, 100 nm to 2 μm, 0.5 μm to 5 μm, 1 μm to 10 μm, 5 μm to 20 μm, 10 μm to 50 μm, 20 μm to 70 μm, 50 μm to 100 μm, 70 μm to 170 μm, or 150 μm to 200 μm are mentioned. Any suitable combination of the upper and lower limits of the above ranges can be used. Multiple particles can have any suitable shape and can be spherical, elliptical, or fibrous. Furthermore, multiple particles can be primary particles or agglomerates, such as secondary particles. Metal particles with an average diameter of 50 nm to 10 μm were mentioned, such as titanium particles with an average diameter of 100 nm to 5 μm. While it is undesirable to be bound by theory, it should be understood that smaller particles (e.g., particles with an average diameter of 100 nm to 5 μm) can achieve metallurgical bonding more quickly and at lower temperatures or pressures compared to using larger particles.

[0034] In one aspect, the multiple particles include carbon particles. These carbon particles can be amorphous carbon, graphite, carbon fibers, or combinations thereof. While not wishing to be bound by theory, it should be understood that when carbon is used, the metallurgical bond includes carbides formed by the reaction between the carbon particles and the metal. Furthermore, due to the high reactivity of carbon with metals, larger particles can be used. The use of carbon particles with an average particle size of less than 200 μm is mentioned. The average particle size of these carbon particles can be 50 nm to 500 nm, 100 nm to 1 μm, 500 nm to 2 μm, 1 μm to 5 μm, 1 μm to 10 μm, 5 μm to 20 μm, 10 μm to 50 μm, 20 μm to 70 μm, 50 μm to 100 μm, 70 μm to 170 μm, or 150 μm to 200 μm. Any suitable combination of the upper and lower limits of the above ranges can be used. The carbon can be in the form of fibrous particles. The fiber diameter of the fiber particles can be from 3 nm to 20 μm, preferably from 1 to 10 μm. The diameter of the carbon fiber can be from 3 nm to 8 nm, 5 nm to 10 nm, 7 nm to 100 nm, 50 nm to 500 nm, 10 nm to 20 μm, 5 nm to 0.5 μm, 20 nm to 1 μm, 100 nm to 0.9 μm, 20 nm to 5 μm, 100 nm to 2 μm, 0.5 μm to 5 μm, 1 μm to 10 μm, or 5 μm to 20 μm. Any suitable combination of the upper and lower limits of the above ranges can be used.

[0035] In one aspect, prior to metallurgical bonding, a coating is applied to the surface of both the metal substrate and multiple particles. This coating serves to enhance the corrosion resistance and bonding activity of both the metal substrate and the particles. Metallurgical bonding can be achieved using the coating material.

[0036] The dimensions (e.g., length) measured in a cross-sectional view of the interface of the metallurgical bond formed between multiple particles and a metal substrate can correspond to the particle size. For example, the average length of the metallurgical bond can be less than 200 μm, such as 3 nm to 200 μm, 8 nm to 150 μm, 10 nm to 100 μm, 50 nm to 50 μm, or 500 nm to 10 μm. Furthermore, the area of ​​the metallurgical bond formed between the multiple particles and the metal substrate can be less than 200 μm. 2 For example, 3nm 2 Up to 200μm 2 8nm 2 Until 15:00 pm 2 10nm 2 Up to 100μm 2 50nm 2 Up to 50μm 2 Or 500nm 2 Up to 10μm 2 .

[0037] While not wishing to be bound by theory, it should be understood that employing a certain amount of multiple particles to cover a portion of the total projected area of ​​the metal substrate contributes to the formation of a metallurgical bond with desired properties. Although not wishing to be bound by theory, it is believed that by employing a certain amount of multiple particles to cover less than 90% of the total substrate area, even when there is a significant mismatch between the coefficients of thermal expansion of the multiple particles and the metal substrate, thermal stress during the formation of the metallurgical bond and the application of the component can be reduced. As used herein, the term "projected area" refers to a two-dimensional area defined in a planar view, regardless of the modularity or porosity of the substrate. In one aspect, it is mentioned that a certain amount of particles is used to cover less than 90% of the total projected area of ​​the substrate, or 1% to 90%, 10% to 80%, 20% to 70%, 30% to 70%, or 40% to 50%. The area of ​​the metallurgical bond between the multiple particles and the metal substrate can be less than 90% of the total projected area of ​​the metal substrate, or it can be 1% to 90%, 10% to 80%, 20% to 70%, 30% to 70%, or 40% to 50% of the total projected area of ​​the metal substrate. Any suitable combination of the upper and lower limits of the above ranges can be used.

[0038] In one aspect, multiple particles cover less than 90% of the total projected area of ​​the metal substrate. Adjacent particles can be spaced apart by a distance, for example, an average distance of 5 nm to 200 μm, such as 5 nm to 10 nm, 7 nm to 100 nm, 50 nm to 500 nm, 10 nm to 20 μm, 5 nm to 0.5 μm, 20 nm to 1 μm, 100 nm to 0.9 μm, 20 nm to 5 μm, 100 nm to 2 μm, 0.5 μm to 5 μm, 1 μm to 10 μm, 5 μm to 20 μm, 10 μm to 50 μm, 20 μm to 70 μm, 50 μm to 100 μm, 70 μm to 170 μm, or 150 μm to 200 μm. Any suitable combination of the upper and lower limits of the above ranges can be used.

[0039] Multiple particles may further include ceramic particles, wherein these ceramic particles include carbides, oxides, nitrides, silicides, or combinations thereof. While not wishing to be bound by theory, it should be understood that by including ceramic particles, these ceramic particles can bond to the aforementioned metal particles, thereby resulting in a reduction in thermal stress. Representative carbides include titanium carbide, niobium carbide, silicon carbide, tantalum carbide, tungsten carbide, iron carbide, chromium carbide, or zirconium carbide. Representative oxides include alumina, titanium oxide, niobium oxide, tantalum oxide, zirconium oxide, cerium oxide, silicon dioxide, tungsten oxide, or cerium oxide. Representative nitrides include titanium nitride, chromium nitride, aluminum nitride, zirconium nitride, tungsten nitride, vanadium nitride, tantalum nitride, or niobium nitride. Representative silicides include nickel silicide, niobium silicide, titanium silicide, molybdenum silicide, or tungsten silicide. Combinations comprising at least one of the above materials may be used. Alumina is mentioned.

[0040] In one aspect, multiple particles bonded to a metal substrate form a porous coating, such as Figure 2 As shown in the accompanying figure, a metal substrate 21 and a porous coating 22 comprising metallurgically bonded particles are illustrated. The average pore size of the porous coating can be from 3 nm to 100 μm, for example, 3 nm to 100 μm, 10 nm to 50 μm, or 50 nm to 500 nm. Pore sizes of 3 nm to 7 nm, 5 nm to 10 nm, 7 nm to 20 nm, 50 nm to 500 nm, 10 nm to 20 μm, 5 nm to 0.5 μm, 20 nm to 1 μm, 100 nm to 0.9 μm, 20 nm to 5 μm, 100 nm to 2 μm, 0.5 μm to 5 μm, 1 μm to 10 μm, 5 μm to 20 μm, 10 μm to 50 μm, 20 μm to 100 μm, or 50 μm to 100 μm are also mentioned. In one aspect, the thickness of the porous coating 22 ranges from 1 μm to 1 mm, for example, 1 μm to 10 μm, 5 μm to 20 μm, 10 μm to 100 μm, 50 μm to 200 μm, 100 μm to 500 μm, 200 μm to 800 μm, 500 μm to 1000 μm, or 700 μm to 1 mm. Any suitable combination of the upper and lower limits of the above ranges can be used. While not wishing to be bound by theory, it should be understood that, for example, shrinkage reduction is achieved through metallurgical bonding of the multiple particles to the metal substrate by limiting the shrinkage of the multiple particles in the vertical direction (e.g., perpendicular to the substrate surface) and reducing or eliminating shrinkage in the in-plane direction of the substrate (e.g., along the substrate surface). By eliminating shrinkage in the in-plane direction, the porous coating 22 can be formed to conform to the shape and structure of the metal substrate without deformation. Furthermore, multiple particle deposition and bonding processes can be applied to form multilayer porous structures to create porous layers with increased thickness. Figure 12 An example is shown in the attached figure, which is a SEM image of a porous titanium coating on a titanium substrate surface.

[0041] In one aspect, a second substrate can be provided and combined with particulate metallurgy. For example, the second substrate can be a mass transport layer for fuel cells or electrolyzers. Figure 3 A component having a metal substrate 31A, a second substrate 31B, and a discontinuous bonding layer 32 between the metal substrate 31A and the second substrate 31B is shown. The discontinuous bonding layer 32 includes particles 33 bonded to the first substrate 31A via a first metallurgical bond 34A and to the second substrate 32A via a second metallurgical bond 34B. The thickness of the discontinuous bonding layer 32 ranges from 1 μm to 0.5 mm, for example, 1 μm to 500 μm, 5 μm to 200 μm, or 10 μm to 100 μm. Any suitable combination of the upper and lower limits of the above ranges can be used. Figure 3 As shown, particles are disposed between a metal substrate and a second substrate, which are bonded together by the particles and a metallurgical binder to form a continuous bond with the particles in a direction perpendicular to the metal substrates, and the metal substrates are discontinuous in the in-plane direction.

[0042] The second substrate may be the same as or different from the metal substrate. The second substrate may include carbon or Ti metal, Nb metal, Ta metal, Al metal, Ni metal, Cr metal, alloys of the aforementioned metals, stainless steel, or combinations of the aforementioned metals. The second substrate may have a suitable form and be completely dense or porous, and may be in the form of a thin film, foil, separator, screen, perforated film, expanded metal foil, or microporous plate. In one aspect, the second substrate comprises carbon and may be porous nonwoven carbon paper. In another aspect, the second substrate may include a metal and may be an expanded metal substrate, such as a wire mesh or screen.

[0043] Figure 4 and Figure 5An example of a metal substrate for a fuel cell is shown, in which a fuel cell bipolar plate is illustrated. To form the bipolar plate, a stainless steel foil is stamped with flow channels 41, including plateau regions 52 and valley regions 51. The plateau regions 52 will be in electrical contact with a second substrate, such as a gas diffusion layer (GDL). Deeper channels may be required to improve water management. However, due to limitations in metal foil properties such as elongation, it is difficult to achieve deep channels simply by stamping. The channel depth can be increased by adding a thicker porous particulate coating on top of the plateau regions 52. The particles can be purely metallic or a mixture of metallic and carbon particles. The particles are deposited on the plateau regions, and the bipolar plate with particles on the plateau regions 52 is heat-treated to bond the particles to the substrate, forming a substrate with flow channels and a thicker porous coating on the plateau regions. The thickness of the porous coating is between 0.01 mm and 0.5 mm, for example, 0.01 mm to 0.05 mm, 0.02 mm to 0.1 mm, 0.05 mm to 0.2 mm, 0.1 mm to 0.3 mm, or 0.2 mm to 0.5 mm. The use of titanium particles for a thicker porous coating on platform region 52 is mentioned. The use of a mixture of titanium and carbon powder to reduce surface contact resistance is also mentioned.

[0044] If needed, additional coatings can be provided to modify the surface properties. For example, without additional coatings, the component can have a superhydrophilic water contact angle, such as less than 90°, for example, 5° to 40°, 10° to 20°, or less than 15°. In one aspect, a hydrophobic material, such as polytetrafluoroethylene, can be applied to the porous surface layer to form a superhydrophobic surface with a contact angle greater than 150° (e.g., 170°).

[0045] In one aspect, a porous metal layer is used as a mass transport layer in an electrolytic cell. The pore size ranges from 20 μm to 500 μm. The use of porous titanium particle sintered materials or titanium felt is mentioned. Generally, large pores favor gas transport, while small pores favor water transport through the mass transport layer. However, in conventional manufacturing processes, it is difficult to simultaneously achieve both small (less than 1 μm) and large pore sizes. In the components disclosed in this invention, a microporous metal coating is added to the core structure of the large-pore metal mass transport layer to form a hybrid porous layer containing both micro- and large-pore sizes. The pore size of the microporous coating ranges from 3 nm to 1 μm. It can absorb water through capillary action in the micron-sized pores to maintain a continuous water supply to the electrodes and allow gas to flow through the large pores. The capillary action of water in the micron-sized pores prevents gas from penetrating the microporous coating, thus achieving an uninterrupted water supply. In the hybrid porous structure, gas and water are transported through their respective paths. The particle size of the microporous coating can be 3nm to 2μm, preferably 10nm to 1μm, for example 3nm to 8nm, 5nm to 10nm, 7nm to 100nm, 50nm to 500nm, 10nm to 1μm, 200nm to 2μm or 0.5μm to 2μm.

[0046] As discussed further below, the component can be tested at 80°C and 0.8V in a pH 3 solution of H₂SO₄ containing 0.1 ppm HF. NHE After processing, the surface contact resistance is evaluated using carbon paper (e.g., AvCarb MGL 190) at a compression pressure of 200 PSI, as defined in the Department of Energy's (DOE) Office of Hydrogen and Fuel Cell Technologies' Multi-Year Research, Development and Demonstration Program (https: / / www.energy.gov / eere / fuelcells / downloads / hydrogen-and-fuel-cell-technologies-office-multi-year-research-development), the entire contents of which are incorporated herein by reference. When evaluated according to the DOE method, the disclosed components can have a resistance from 0.1 to 10 mΩ·cm. 2 5 to 8 mΩ·cm 2 Or 1 to 5 mΩ·cm 2 The surface contact resistance is adjusted to meet the requirements of fuel cell applications.

[0047] The present invention also discloses a method for manufacturing a component for an electrochemical device, the method comprising: providing a metal substrate; depositing a mixture comprising a plurality of precursor particles onto the metal substrate, wherein the plurality of precursor particles comprise metal, carbon, metal hydrides, or combinations thereof, to form a coated substrate, wherein the total projected area of ​​the plurality of precursor particles in contact with the metal substrate is less than 90%, and wherein the average particle size of the plurality of precursor particles is less than 200 μm; then heat-treating the coated substrate to form particles from the plurality of precursor particles, and bonding the particles to the metal substrate by a metallurgical bond formed between the particles and the metal substrate to manufacture the component, wherein the composition of the metallurgical bond is a combination of metal substrate components and particle components, reaction products of the metal substrate and particles, or a combination thereof.

[0048] The precursor particles include metals, carbon, metal hydrides, or combinations of Ti, Nb, Ta, Ni, and Cr, alloys thereof, or combinations thereof. Alloys or intermetallic compounds of Ti, Nb, Ta, Ni, or Cr are mentioned. In one aspect, the precursor particles include titanium hydride. A combination of titanium and carbon particles is mentioned to form a metallurgical composite including titanium carbide. The particle size of the precursor particles can be less than 200 micrometers (μm), for example, 3 nanometers (nm) to 200 μm, 8 nm to 150 μm, 10 nm to 100 μm, 50 nm to 50 μm, or 500 nm to 10 μm. The content of the precursor particles on the metal substrate can be set to 1% to 90%, 6% to 80%, 10% to 70%, 20% to 60%, or 40% to 50% of the total projected area covering the metal substrate. Any suitable combination of the upper and lower limits of the above ranges can be used.

[0049] Any suitable combination of the upper and lower limits of the above range can be used. In one aspect, a combination of precursor particles can be used. Although it is not desirable to be bound by theory, it should be understood that using particles with different melting temperatures can form metallurgical bonds with reduced shrinkage at lower temperatures. For example, particles with lower melting temperatures can bond particles with higher melting temperatures to a metal substrate.

[0050] The mixture of precursor particles may further comprise multiple ceramic particles, wherein these ceramic particles include carbides, oxides, nitrides, or combinations thereof, as further described above. While it is not desirable to be bound by theory, it should be understood that shrinkage can be reduced when ceramic particles are used.

[0051] Mixtures containing precursor particles can be deposited onto a metal substrate using any suitable method. Dry powder deposition, or coating or casting using a carrier or medium such as an organic solvent, is disclosed. Dry powder deposition can include electrostatic deposition of precursor particles. During electrostatic deposition, the particles can be charged, and these charged particles can be deposited onto the metal substrate under an applied electric field. While not wishing to be bound by theory, it should be understood that electrostatic deposition may be desirable for reducing particle agglomeration and forming a more uniform particle layer on the substrate. Alternatively, the precursor particles can be dispersed in a solvent including a binder to form a slurry, which is then coated onto the substrate. The binder can include binders used in ceramic processes, such as polyvinyl butyral or polyethylene carbonate. Further details of the coating process can be determined by those skilled in the art without excessive experimentation.

[0052] In one aspect, heat treatment can be performed at temperatures below the melting temperature of the particles and below the melting temperature of the metal substrate or second substrate. While not wishing to be bound by theory, it should be understood that during heat treatment, a metallurgical bond is formed at the particle-substrate interface through cross-diffusion or chemical reaction between the particles and the substrate, thus adhering the particles to the substrate. Heat treatment can include treatment at temperatures from 300°C to 1200°C (e.g., 400°C to 1000°C, 800°C or lower). Preferably, a bonding temperature of 800°C or lower can be used to avoid deformation of the metal substrate. In one aspect, it is mentioned that a temperature at least 500°C lower than the melting temperature of the metal substrate is used to avoid substrate deformation. Avoiding deformation may be advantageous when the component (e.g., a bipolar plate) includes structural features such as flow channels. Furthermore, while not wishing to be bound by theory, it is believed that the particle size disclosed herein allows for the formation of metallurgical bonds in shorter times (e.g., 0.001 hours to 20 hours, 0.01 hours to 10 hours, or 0.1 hours to 5 hours). Heat treatment may include in-furnace heat treatment, or may include laser heat treatment, electron beam heat treatment, infrared (IR) heat treatment, or plasma heat treatment. In laser heating, a high-intensity laser beam is used to scan a metal substrate on which multiple precursor particles are deposited and to heat the surface of the metal substrate to form a metallurgical bond and bind the particles to the metal substrate. In another embodiment, a high-intensity IR lamp is employed. Electron beam heating is mentioned for rapid heating.

[0053] Heat treatment can include heat treatment performed in a vacuum or in a non-oxidizing atmosphere (e.g., in argon, helium, or a combination thereof).

[0054] The method may also include pressing the coated substrate under pressures of 1 psi (PSI) to 500 psi, 20 PSI to 400 PSI, or 50 PSI to 100 PSI. If a second substrate is used, pressing may include applying pressure to both the metal substrate and the second substrate to compress the particles.

[0055] In one aspect, a textured carbon coating is obtained through a single step of melting carbon particles and simultaneously depositing the molten particles. Due to the high melting temperature of carbon (approximately 3550°C), a high temperature is used to melt the carbon particles. The high-temperature heat source can be plasma, a high-power pulsed laser, or an electric arc. At the high temperature, the carbon particles are partially evaporated, resulting in a coating that can have a textured structure comprising carbon protrusions covering a small portion of the substrate surface, with the remainder of the surface covered by a thin film of carbon coating.

[0056] As used in this article, "metallurgical bonding" is a chemical adhesion formed between two solid materials (including at least one metallic material) at high temperatures. There are two types of bonding. One is diffusion bonding, a continuous connection formed by the cross-diffusion of the two materials at high temperatures. The other is reactive bonding, where the two materials react at the contact site, and the resulting reaction products bond the two materials together. Both types of metallurgical bonding produce atomic-level mixing of the two materials and can extend the contact from point to surface / interface. Atomic-level mixing and a large contact area ensure a durable bond between the two materials.

[0057] In one aspect, the composition of the metallurgical binder is a combination of a metal substrate component and a particulate component, a reaction product of the metal substrate and the particulate component, or a combination thereof. The composition of the metallurgical binder can be a combination of a metal substrate component and a particulate component. In another aspect, the metallurgical binder includes a reaction product of the particulate component, a reaction product of the particulate component and the substrate, or a combination thereof.

[0058] The thickness of the metallurgical bond can be from 0.5 nm to 50 μm, for example, 0.5 nm to 5 nm, 1 nm to 10 nm, 5 nm to 50 nm, 10 nm to 50 nm, 10 nm to 100 μm, 50 nm to 0.2 μm, 100 nm to 1 μm, 500 nm to 5 μm, 20 nm to 5 μm, 1 μm to 10 μm, 5 μm to 20 μm, 10 μm to 50 μm, or 20 μm to 50 μm. Any suitable combination of the upper and lower limits of the above ranges can be used.

[0059] In this method, the heat-treated component can be cleaned to remove, for example, unbonded particles. Cleaning may include contacting the heat-treated component with a fluid (e.g., air or water) and may include, for example, ultrasonic water bath cleaning or acid pickling.

[0060] As used herein, “average particle size” refers to the particle size corresponding to 50% of the particles in a distribution curve, where the particles are aggregated in order of size from smallest to largest, and the total number of aggregated particles is 100%. Average particle size can be measured by methods known to those skilled in the art. For example, average particle size can be measured using a particle size analyzer (e.g., dynamic light scattering), or it can be measured using a transmission electron microscope (TEM) or a scanning electron microscope (SEM).

[0061] This invention discloses a component for an electrochemical device, the component comprising: a metal substrate; and a plurality of particles bonded to the surface of the metal substrate by a metallurgical binder, wherein the plurality of particles comprise metal, carbon, or a combination thereof, wherein the metallurgical binder is located between the plurality of particles and the metal substrate, wherein the total projected area of ​​the metallurgical binder is less than 90% of the total projected area of ​​the metal substrate, and wherein the composition of the metallurgical binder is a combination of the composition of the metal substrate and the composition of the plurality of particles, a reaction product of the metal substrate and the plurality of particles, or a combination thereof.

[0062] The present invention also discloses a method for manufacturing a component for an electrochemical device, the method comprising: providing a metal substrate; depositing a mixture comprising a plurality of precursor particles onto the metal substrate, wherein the plurality of precursor particles comprise metal, carbon, metal hydrides, or combinations thereof, to form a coated metal substrate, wherein the plurality of precursor particles contact less than 90% of the total projected area of ​​the metal substrate, and wherein the average particle size of the plurality of precursor particles is less than 200 μm; and heat-treating the coated metal substrate to form particles from the plurality of precursor particles, and bonding the particles to the metal substrate by a metallurgical bond formed between the particles and the metal substrate to manufacture the component, wherein the composition of the metallurgical bond is a combination of the metal substrate composition and the particle composition, a reaction product of the metal substrate and the particles, or a combination thereof.

[0063] In any of the above embodiments, the metal substrate may include Ti metal, Nb metal, Ta metal, Ni metal, Cr metal, alloys of the aforementioned metals, stainless steel, or combinations of the aforementioned metals; the plurality of particles may include metal, and the metal may be Ti, Nb, Ta, Ni, Cr, their alloys, or combinations thereof; the average particle size of the plurality of particles may be less than 20 μm; the plurality of particles may be metal particles with an average particle size of 50 nm to 10 μm; the plurality of particles may be Ti particles with an average particle size of 100 nm to 5 μm; the plurality of particles may include carbon, and the carbon may be amorphous carbon, graphite, carbon fiber, or combinations thereof, wherein the average particle size of the carbon is less than 200 μm; the total projected area of ​​the metallurgical bond may be 1% to 70% of the total projected area of ​​the metal substrate; optionally, it may also include a plurality of ceramic particles on the metal substrate, wherein the ceramic particles include carbides, oxides, nitrides, silicides, or combinations thereof; optionally, the component may be a bipolar plate for a fuel cell or electrolyzer; in a pH3 solution of H2SO4 and 0.1 ppm HF at 80°C and 0.8V. NHE After 100 hours of treatment, the bipolar plate exhibits a compressive strength of less than 10 mΩ·cm under a pressure of 200 PSI. 2The surface electrical contact resistance; optionally, the component can be an electrode for an electrolytic cell or a flow battery; optionally, it also includes a second substrate on the side of the plurality of particles opposite the metal substrate, wherein the second substrate comprises carbon or Ti metal, Nb metal, Ta metal, Ni metal, Cr metal, an alloy of the aforementioned metals, stainless steel, or a combination of the aforementioned metals, wherein the plurality of particles are bonded to the second substrate by a second metallurgical bond between the plurality of particles and the second substrate, wherein the projected area of ​​the second metallurgical bond is less than 90% of the total projected area of ​​the second substrate, and wherein the composition of the second metallurgical bond is a combination of the second substrate composition and the composition of the plurality of particles. The reaction products of the second substrate and multiple particles, or combinations thereof; the metal substrate and the second substrate may have the same composition; the second substrate may include multiple layers with structural or compositional gradients; based on the total projected area of ​​the second substrate, the second substrate may be a metal mesh with an open area of ​​10% to 90%; the second substrate may be a porous mass transport layer with a porosity of 30% to 95%; optionally, the electrochemical device may be a fuel cell, a battery, an electrolyzer, or a capacitor; the metal substrate may include Ti metal, Nb metal, Ta metal, Al metal, Ni metal, Cr metal, alloys of the aforementioned metals, stainless steel, or combinations thereof; multiple previous The bulk particles may include Ti metal, Nb metal, Ta metal, Al metal, Cr metal, alloys of the aforementioned metals, intermetallic compounds of the aforementioned metals, their hydrides, or combinations thereof, and have an average particle size of 50 nm to 20 μm; the plurality of precursor particles may include carbon particles with an average particle size of less than 200 μm; the plurality of precursor particles may cover 3% to 90% of the total projected area of ​​the metal substrate; the heat treatment may include heat treatment performed in a vacuum or non-oxidizing atmosphere, and wherein the heat treatment includes electron beam surface heating or laser surface heating; the composition may also include a plurality of ceramic particles, wherein these ceramic particles include carbides, Oxides, nitrides, or combinations thereof; optionally, the method further includes placing a second substrate on one side of a plurality of particles opposite a metal substrate, wherein the second substrate comprises carbon or Ti metal, Nb metal, Ta metal, Ni metal, Cr metal, alloys of the aforementioned metals, stainless steel, or combinations thereof, and wherein the plurality of particles are bonded to the second substrate by a second metallurgical bond between the plurality of particles and the second substrate, wherein the total projected area of ​​the second metallurgical bond is less than 90% of the total projected area of ​​the substrate, and wherein the composition of the second metallurgical bond is a combination of the second substrate composition and the particle composition, a reaction product of the second substrate and the particles, or a combination thereof.

[0064] Example

[0065] Comparative Example 1: Bonding sputtered carbon onto titanium

[0066] Commercial grade 2 titanium foil was used as the substrate. A 50 nm Ti and a 100 nm carbon (SP-C coating) were deposited on the entire surface of the titanium foil by sputtering.

[0067] Example 1: Bonding ground carbon fiber onto titanium foil

[0068] Commercially available grade 2 titanium foil was used as the substrate. Ground carbon fiber particles were loosely sprinkled on the surface and then heat-treated at 900°C for 1 hour in argon atmosphere. The ground carbon fiber particles had a diameter of 8 μm and a length ranging from 50 μm to 200 μm. The ground carbon fiber particles partially covered the titanium surface and could not be removed by ultrasonic cleaning, indicating a strong bond between the carbon fiber and the titanium.

[0069] Contact resistance

[0070] The contact resistance of the coated titanium foil and AvCarb MGL 190 carbon paper in Comparative Example 1 and Example 1 were measured before and after the corrosion test. The accelerated corrosion test was conducted in a pH 3 solution of H₂SO₄ containing 0.1 ppm HF at 80°C and 1.4V. NHE Accelerated corrosion tests were conducted. The electrical contact resistance before and after the corrosion test was measured using AvCarb MGL 190 carbon paper under a compression pressure of 200 PSI.

[0071] At 1.4V NHE After 0.5 hours and 2 hours of corrosion testing, the surface contact resistance of Comparative Example 1 decreased from the initial 4.0 mΩ·cm. 2 Increased to 28mΩ·cm 2 and 333mΩ.cm 2 Following the corrosion test, X-ray photoelectron spectroscopy (XPS) was used to analyze the surface composition of Comparative Example 1. XPS analysis revealed that the titanium surface was still covered with carbon, indicating that the carbon coating was not completely depleted during the corrosion test. Although it is undesirable to be bound by theory, it is believed that the higher contact resistance originates from the interface between the carbon and the titanium substrate, and more specifically, from the formation of titanium oxide beneath the carbon coating due to titanium oxidation.

[0072] In comparison, at 1.4V NHE After 1.5 hours and 6 hours of corrosion testing, the contact resistance of Example 1 decreased from the initial 0.7 mΩ·cm. 2 Increased to 1.4 mΩ·cm 2 and 1.7mΩ.cm 2 Optical microscopy revealed that most of the carbon fibers remained bonded to the titanium surface. The durability of the carbon fiber coating on titanium is believed to be due to the metallurgical bond that includes titanium carbide.

[0073] Example 2: Graphite bonded to titanium

[0074] To demonstrate the suitability of the bipolar plates for fuel cells or electrolyzers, commercially pure titanium foil was selected as the substrate for surface modification to achieve a low surface electrical contact resistance. The titanium foil thickness was 0.1 mm. Graphite powder (Alfa Aesar #46304) with an average particle size of 7 μm to 11 μm was used as the particulate material.

[0075] Graphite particles were dispersed in an ethanol solution to prepare a slurry containing 20 wt% graphite (based on the total weight of the slurry). The slurry was coated onto a titanium surface and dried, leaving graphite particles on the surface. The titanium foil containing the graphite particles was then heat-treated in a vacuum chamber by surface heating with a focused electron beam. The graphite particles reacted with the titanium, forming a metallurgical bond comprising titanium carbide between the graphite particles and the titanium foil.

[0076] Following the bonding step, the titanium foil is cleaned in an ultrasonic bath to remove unbonded graphite particles. Metallurgically bonded graphite particles remain on the surface of the titanium substrate. Figure 8 The image shown is a SEM image of graphite particles bonded to the surface of a titanium foil.

[0077] Example 3: Bonding glassy carbon onto titanium

[0078] Commercially pure titanium foil was used as the metal substrate. A 0.1 mm thick titanium foil was used as the substrate. Glassy carbon spherical powder (Alfa Aesar #3489) with a particle size of 10 μm to 20 μm was used as the particulate material. The glassy carbon powder was dispersed in an ethanol solution by ultrasonic dispersion. Polyvinyl butyral was then added to the slurry as a binder. The carbon particle concentration in the slurry was 15 wt%, and the binder concentration was 2 wt% based on the total weight of the slurry.

[0079] A titanium plate is immersed in a carbon particle slurry to coat the titanium surface with a thin layer of slurry. The coated titanium plate is then heat-treated in a vacuum at 800°C for 1 hour to metallurgically bond the carbon particles to the titanium surface. After heat treatment, the titanium plate is cleaned in an ultrasonic bath to remove unbonded carbon particles. The bonded particles remain on the surface of the titanium plate. Figure 6 The image shown is a SEM image of glassy carbon spherical particles metallurgically bonded to the surface of titanium. Figure 7 The diagram shows a comparison of the contact resistance of carbon paper (AvCarb MGL 190), titanium plates with carbon particles bonded to the surface (Ti w / C), and titanium plates without carbon particles on the surface (Ti w / o C) under different compressive pressures. Figure 7 The figure shows the electrical contact resistance of a titanium plate with carbon felt reduced from 82 mΩ / cm under a compressive pressure of 200 PSI. 2 Reduced to 1.6 mΩ·cm 2 .

[0080] Example 4: Bonding titanium-carbon composite materials to stainless steel

[0081] To demonstrate the suitability of the bipolar plate for fuel cells or the electrode for zinc-bromine flow batteries, a stainless steel mesh was used as the metal substrate. The center of the stainless steel mesh was stamped to form a channel structure. Titanium powder and ground carbon fiber particles were mixed in ethanol, with polyvinyl butyral used as a binder. The titanium powder had an average particle size of 2.2 μm, and the ground carbon fibers had an average fiber diameter of 8 μm and a length ranging from 50 μm to 200 μm. The volume ratio of titanium to carbon was 1:1, the particle concentration in the slurry was 25% by weight, and the binder concentration was 5% by weight, all based on the total weight of the slurry.

[0082] Stainless steel mesh is immersed in a slurry to coat it with a layer of slurry. After the slurry on the stainless steel mesh is dried, it is heat-treated in a vacuum at 800°C for 1 hour. Titanium particles and carbon fiber particles are metallurgically bonded to the stainless steel mesh and inter-particle bonded to form a porous metal-carbon composite plate. The resulting component retains the mesh structure with stamped stainless steel mesh and flow channels.

[0083] While it is undesirable to be bound by theory, it should be understood that stainless steel mesh can fix titanium and carbon particles during heat treatment, thereby limiting particle shrinkage in a direction perpendicular to the substrate surface and minimizing in-plane shrinkage. Figure 9 The image shown is an SEM photograph of a coated stainless steel mesh. Figure 10 The image shown is an enlarged view, illustrating the microstructure of Ti particles coated on a stainless steel mesh and ground carbon fiber particles.

[0084] Example 5: Bonding titanium to stainless steel

[0085] 316L stainless steel foil was used as the metal substrate. The thickness of the stainless steel foil was 0.1 mm. Titanium powder with a particle size of 2.2 μm was used as the particulate material.

[0086] 10 g of titanium powder was dispersed in 30 g of ethanol using ultrasonic dispersion. Then, 20 g of a 15% (w / w) polyvinyl butyral ethanol solution was added to the titanium powder slurry. The mixture was placed on a roller mixer for 12 hours to ensure complete mixing of the titanium powder and polyvinyl butyral, thus forming a slurry. The slurry was applied to stainless steel foil using an air spray gun and dried at 80°C for 1 hour. The dried titanium particle coating on the stainless steel foil was approximately 25 μm thick. The coated stainless steel foil was then heat-treated in a vacuum at 750°C for 1 hour to metallurgically bond the titanium particles to the stainless steel foil surface. The stainless steel sheet was then ultrasonically cleaned to remove any unfixed titanium powder. The titanium powder formed a rough, porous structure on the stainless steel surface.

[0087] Example 6: Graphite bonding on porous titanium

[0088] Porous titanium felt was used as the metal substrate. The titanium felt was 250 μm thick and had a porosity of 75%. Graphite powder (AlfaAesar 46304) was used as multiple particulate materials. The graphite powder was dispersed with polyvinyl butyral in an ethanol solution to prepare a stable slurry. The slurry contained 5 wt% graphite and 1 wt% polyvinyl butyral by weight. The titanium felt was then immersed in the slurry to allow the titanium felt to support the graphite particles. After the slurry dried, the graphite-supported titanium felt was heat-treated at 750 °C for 1 hour to metallurgically bond the graphite particles to the titanium felt. When this component is used as a flow battery electrode, the graphite particles will act as electrode reaction sites. Because the graphite particles are metallurgically bonded to the titanium felt, a platinum coating is not required.

[0089] It should be understood that when a component is referred to as "on another component," it can be directly on that other component, or there can be intermediate components between them. Conversely, when a component is referred to as "directly on another component," there are no intermediate components.

[0090] It should be understood that while terms such as “first,” “second,” and “third” may be used herein to describe various elements, components, regions, layers, and / or sections, these elements, components, regions, layers, and / or sections should not be limited by these terms. These terms are used only to distinguish one element, component, region, layer, or section from another. Thus, “first element,” “first component,” “first region,” “first layer,” or “first section” discussed below may be referred to as a second element, second component, second region, second layer, or second section without departing from the teachings of this document.

[0091] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting. As used herein, “a,” “the,” and “at least one” do not indicate a limitation of quantity and are intended to include both singular and plural forms unless the context clearly indicates otherwise. For example, “an element” has the same meaning as “at least one element” unless the context clearly indicates otherwise. “At least one” should not be construed as limiting “a.” “Or” means “and / or.” As used herein, the term “and / or” includes any and all combinations of one or more of the listed related items. It should also be understood that, when used in this specification, the terms “comprising” and / or “it comprises” or “includes” and / or “it includes” indicate the presence of the stated features, areas, integrals, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, areas, integrals, steps, operations, elements, components, and / or combinations thereof.

[0092] Spatial relation terms (such as “directly below,” “below,” “down,” “above,” “up,” etc.) are used herein to conveniently describe the relationship between one element or feature as shown in the accompanying drawings and another element or feature. It should be understood that, in addition to the orientations shown in the drawings, spatial relation terms are also intended to include different orientations of a device in use or operation. For example, if the device in the drawings is flipped, then the element described as “below” or “directly below” other elements or features should be facing “above” those other elements or features. Thus, the term “below” can include both above and below orientations. The device may have other orientations (rotated 90 degrees or in other orientations), and the spatial relation descriptors used herein can be understood accordingly.

[0093] Unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains. It should also be understood that terms (such as those defined in common dictionaries) should be understood to have the same meaning as they have in the relevant field and in the context of this disclosure, and should not be interpreted in an idealized or overly formal sense unless explicitly defined herein.

[0094] This document describes embodiments in conjunction with cross-sectional views that are schematic diagrams of idealized embodiments. Similarly, variations in the illustrated shapes are expected due to factors such as manufacturing techniques and / or tolerances. Therefore, the embodiments described herein should not be construed as limited to the specific shapes of the areas illustrated herein, but should include, for example, shape deviations due to manufacturing processes. For instance, areas illustrated or described as flat may generally have rough and / or non-linear characteristics. Furthermore, acute angles in the illustrations may be rounded. Therefore, the areas shown in the figures are schematic in nature, and their shapes are not intended to show precise shapes of the areas, nor are they intended to limit the scope of this claim.

[0095] The examples above are provided for illustrative purposes only and should not be construed as limiting. Although various embodiments have been referenced, the language used herein is descriptive and illustrative, not limiting. Furthermore, while references to specific devices, materials, and embodiments are shown, there is no limitation on the details disclosed herein. Rather, within the scope of the appended claims, the embodiments extend to all functionally equivalent structures, methods, and uses.

Claims

1. A component with improved surface contact resistance and reactivity, characterized in that, The component includes: a metal substrate; and a plurality of carbon particles bonded to the surface of the metal substrate by a metallurgical binder; The metallurgical bond is located between the carbon particles and the metal substrate; the total projected area of ​​the metallurgical bond is less than 90% of the total projected area of ​​the substrate. Furthermore, the metallurgical composite is a metal carbide formed by the reaction of the metal substrate and carbon particles.

2. The component according to claim 1, characterized in that, The plurality of particles include carbon particles of amorphous carbon, graphite, carbon fiber, or combinations thereof, and the average particle size of the carbon particles is less than 200 μm.

3. The component according to claim 1, characterized in that, The total projected area of ​​the metallurgical composite is 1% to 70% of the total projected area of ​​the metal substrate.

4. The component according to claim 1, characterized in that, The component is a bipolar plate for a fuel cell, flow cell, or electrolyzer, or an electrode for an electrolyzer or flow cell.

5. A method for manufacturing a component with improved surface contact resistance and reactivity, characterized in that, The method includes: Provide a metal substrate; Multiple carbon particles are deposited on the metal substrate to form a coated metal substrate; The contact area between the carbon particles and the metal substrate is less than 90% of the total projected area of ​​the substrate; and The average particle size of the carbon particles is less than 200 μm; and The metal substrate on which the carbon particles are deposited is heat-treated to form particles from the plurality of precursor particles, and the carbon particles are bonded to the metal substrate by forming metal carbides through a reaction between the carbon particles and the metal substrate to form the component.

6. The manufacturing method according to claim 5, characterized in that, The plurality of precursor particles cover 3% to 90% of the total projected area of ​​the substrate.

7. According to the manufacturing method of claim 5, the carbon particles can be applied to the surface of the metal substrate by dry powder deposition; or the carbon particles can be dispersed in a solvent containing a binder to form a slurry, and then the slurry containing carbon particles can be applied to the surface of the metal substrate.

8. The manufacturing method according to claim 5, characterized in that, The heat treatment includes heat treatment performed in a vacuum or non-oxidizing atmosphere, and the heat treatment includes electron beam surface heating or laser surface heating.

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