Nickel-based metal ceramic material and preparation method thereof

Abstract

The invention provides a nickel-based metal ceramic material and a preparation method thereof, and relates to the technical field of thermal spraying materials. The preparation method comprises the steps that nickel powder and reducing metal powder are mixed to obtain a nickel-based composite material; mixing nickel protoxide and rare earth oxide, and sintering to obtain a sintered oxidized ceramic material; and the sintered oxidized ceramic material and the nickel-based composite material are subjected to high-energy ball milling treatment, and the nickel-based metal ceramic material is obtained. The preparation method comprises the following steps: mixing nickel powder with reducing metal powder to form a nickel-based composite material with corrosion resistance; sintering the nickel protoxide, the ceramic and the rare earth oxide to generate a stable ceramic phase; the two are uniformly combined in particle size through high-energy ball milling, and the bonding strength and the structural stability are improved. The obtained material is suitable for thermal spraying, has good corrosion resistance and catalytic activity, and is suitable for frequent starting and stopping working conditions of electrodes.

Description

Technical Field

[0001] The present invention relates to the technical field of thermal spraying materials, and in particular to a nickel-based metal ceramic material and a preparation method thereof. Background Art

[0002] Thermal spraying technology is a surface modification method that forms a coating by heating the material to a molten or semi-molten state and then spraying it onto the substrate surface at high speed. This technology is widely used in aerospace, energy, metallurgy, electronics, medical and other fields due to its applicability to a variety of material systems, flexible processes, and high efficiency. In recent years, with the increasing demand for functional materials and extreme working conditions, thermal spraying has gradually expanded to high-value-added fields such as catalysis and electrochemistry. In particular, in water electrolysis hydrogen production equipment, it can be used to construct electrode surface functional layers with excellent corrosion resistance and electrocatalytic properties, thereby improving the overall efficiency and service life of the equipment.

[0003] In alkaline water electrolysis hydrogen production systems, metal or metal oxide electrodes are often used as carriers for oxygen or hydrogen evolution reactions. To improve electrode stability and reactivity, some electrodes have been treated with thermal spraying technology to enhance their surface functionality. For example, ceramic powders such as nickel oxide, cobalt oxide, and iron oxide are sprayed to improve conductivity, corrosion resistance, and catalytic properties. These electrodes perform well under constant operating conditions and, to a certain extent, meet the hydrogen production efficiency requirements for the initial "green hydrogen" scenario.

[0004] However, with the large-scale integration of renewable energy into hydrogen production systems, electrolyzers are facing an unstable operating state with frequent starts and stops. Under this operating condition, traditional thermal spray electrode materials are unable to effectively cope with the corrosion impact caused by the reversal of the current cycle. During the frequent start-up and shutdown process, the electrode is prone to surface oxidation, and the active sites are damaged or covered by low-activity oxides, resulting in a rapid decline in catalytic performance and reduced electrolysis efficiency. Because traditional coating designs are mostly based on corrosion resistance and lack a response strategy to the reverse current-induced corrosion mechanism, the electrode service life is shortened, the maintenance frequency increases, and the system operating costs increase significantly.

[0005] In addition, existing spray coating materials still have certain limitations in terms of composition and structure. Common problems include weak bonding between the metal and ceramic phases, high interfacial stress, and uneven composition distribution. The ceramic phase is difficult to fully fuse with the metal phase during the spray coating process, affecting the density and stability of the coating, resulting in failure behaviors such as peeling and microcrack propagation under the action of cyclic start-stop stress. At the same time, the design of traditional spray powders often fails to consider the requirements of electronic structure regulation and interface engineering, limiting its potential for further improvement in improving electrode catalytic performance and reaction stability.

[0006] In summary, existing thermal spray electrode materials still have significant shortcomings in terms of counteracting reverse current corrosion during the frequent startup and shutdown of alkaline electrolyzers, maintaining catalytic performance, and structural stability. These shortcomings make it difficult to meet the practical requirements of high-frequency startup and long-life operation. These issues have severely restricted the further application of thermal spray technology in the field of green hydrogen production.

[0007] In view of this, the present invention is proposed. Summary of the Invention

[0008] The object of the present invention is to provide a nickel-based metal ceramic material and a preparation method thereof. The preparation method comprises the following steps: compounding nickel powder with reducing metal powder, combining sintering ceramic phase with high-energy ball milling treatment, and producing a nickel-based metal ceramic material with stable structure and good interface bonding. The nickel-based metal ceramic material has excellent corrosion resistance and catalytic stability and is suitable for use in thermal spray electrodes under frequent start-stop conditions.

[0009] In order to achieve the above-mentioned purpose of the present invention, the following technical solutions are adopted: In a first aspect, the present invention provides a method for preparing a nickel-based cermet material, comprising: Mixing nickel powder with reducing metal powder to obtain a nickel-based composite material; wherein the reducing property of the metal element in the reducing metal powder is higher than that of nickel; Mixing nickelous oxide and rare earth oxide, and sintering to obtain a sintered oxide ceramic material; The sintered oxide ceramic material and the nickel-based composite material are subjected to high-energy ball milling treatment. During the high-energy ball milling treatment, the sintered oxide ceramic material and the nickel-based composite material are bonded together at the particle scale through mechanical alloying effect and cold welding effect to obtain a nickel-based metal ceramic material.

[0010] In an optional embodiment, the reducing metal powder includes at least one of Mo, Co, Ti, Sn and Ta; and / or, The reducing metal powder is Ti; and / or, The nickel-based composite material comprises 0.5% to 2% reducing metal powder and the balance is nickel powder; and / or, The particle size range of nickelous oxide and the rare earth oxide is the same.

[0011] In an optional embodiment, the ratio of the sintered oxide ceramic material to the nickel-based composite material is (1-1.5):1.

[0012] In an optional embodiment, the rare earth oxide includes cerium oxide; or, the rare earth oxide includes cerium oxide and at least one of yttrium oxide, lanthanum oxide and neodymium oxide; In an optional embodiment, the percentage content of each component in the sintered oxide ceramic material is: Cerium oxide 0.2%~1%; Yttrium oxide, lanthanum oxide and neodymium oxide are 0% to 1% each; The balance is nickelous oxide.

[0013] In an optional embodiment, the processing conditions of the high-energy ball milling process include: Rotational speed 250 rpm ~ 450 rpm; and / or, Speed ​​100 rpm ~ 200 rpm; and / or, Processing time is 1 hour to 5 hours.

[0014] In a second aspect, the present invention provides a nickel-based metal ceramic material prepared by the method for preparing a nickel-based metal ceramic material as described in any one of the aforementioned embodiments.

[0015] In a third aspect, the present invention provides an electrode, the surface of which is coated with the nickel-based metal ceramic material as described in the above embodiment.

[0016] In a fourth aspect, the present invention provides a method for preparing the electrode as described in the aforementioned embodiment, comprising: pretreating the substrate to obtain a prefabricated substrate; Using nickel-based metal ceramic material as spray powder, a thermal spraying process is used to coat the surface of the prefabricated body to form a ceramic composite coating on the electrode surface; In an optional embodiment, the pretreatment includes cleaning, roughening and bonding the base layer.

[0017] In an optional embodiment, the thermal spraying process includes plasma spraying and flame spraying; In an optional embodiment, the thermal spraying process is to perform multi-layer spraying on the surface, and the thickness of each layer is controlled to be 40 μm to 50 μm; In an optional embodiment, the process conditions of the plasma spraying include: A. Power setting is 35kW~42kW; B. Keep the spraying distance at 120mm~140mm; C. The spray gun angle is 75°±1°; D. The moving speed of the spray gun is controlled at 400mm / s~500mm / s; In an optional embodiment, the process conditions of the flame spraying include: A. Temperature is controlled at 2800℃~3000℃; B. Keep the spraying distance at 120mm~150mm; C. The moving speed of the spray gun is 350mm / s~450mm / s.

[0018] In a fifth aspect, the present invention provides an electrolytic cell comprising the electrodes described in the aforementioned embodiment.

[0019] In a sixth aspect, the present invention provides an electrical equipment, comprising the electrolytic cell as described in the above embodiment.

[0020] Compared with the prior art, the present invention has the following beneficial effects: The present invention's method for preparing a nickel-based cermet material effectively enhances the material's resistance to reverse current corrosion by mixing nickel powder with reducing metal powder to form a nickel-based composite. Under frequently started and stopped alkaline electrolysis conditions, the doped reducing metal, due to its higher electrochemical activity than nickel, preferentially undergoes oxidation under external current disturbances, acting as a sacrificial anode. This inhibits the electrochemical deactivation of nickel, protects catalytically active sites from destruction, and improves the overall material's stability and durability in complex electrolytic environments.

[0021] During the preparation process, nickelous oxide and rare earth oxides are mixed and sintered to create a highly stable ceramic phase structure. The oxides form a solid solution through sintering, improving the chemical stability and mechanical integrity of the ceramic material, enhancing its corrosion resistance, and providing a good structural foundation for subsequent bonding with the metal phase. The ceramic phase design not only helps resist corrosion and oxidation in electrochemical environments but also provides structural support, preventing cracking or shedding of the coating.

[0022] During high-energy ball milling, the sintered oxide ceramic and nickel-based composite materials are uniformly bonded at the particle scale through mechanical alloying and cold welding, achieving a metallurgical bond between the metal and ceramic phases. Compared to traditional physical mixing, this method significantly enhances the interfacial bonding strength between the two phases, reduces the risk of coating failure caused by interfacial instability, and improves the structural stability of the composite powder during spraying and service.

[0023] In summary, the nickel-based metal ceramic material obtained by the preparation method provided in this application not only has excellent composition uniformity and structural integrity, but also has good corrosion resistance and physical properties suitable for thermal spraying. It can provide guarantees for the uniform deposition and long-term stability of subsequent electrode surface coatings, and adapt to the electrolytic environment requirements under complex working conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the specific 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 any creative work.

[0025] Figure 1 Schematic diagram of the process for preparing the nickel-based metal ceramic material provided in the examples of this application; Figure 2 The particle micromorphology of the nickel-based cermet material prepared in Example 1 of this application; Figure 3 This is a microscopic morphology image (50x) of the ceramic composite coating on the electrode surface prepared in Example 1 of the present application; Figure 4 This is a microscopic morphology image (200 times) of the ceramic composite coating on the electrode surface prepared in Example 1 of the present application; Figure 5 This is a comparative bar chart of hydrogen evolution overpotentials in the test experiments conducted for the embodiments and comparative examples of the present application; Figure 6 This is a comparative bar chart of the 1000-hour overpotential decay rate in the test experiments conducted for the embodiments and comparative examples of the present application; Figure 7 This is a comparative bar chart of the reverse polarization overpotential decay rates in the test experiments conducted for the embodiments and comparative examples of the present application. DETAILED DESCRIPTION

[0026] The embodiments of the present invention will be described in detail below with reference to the examples, but it will be understood by those skilled in the art that the following examples are merely illustrative of the present invention and should not be construed as limiting the scope of the invention. Where specific conditions are not specified in the examples, the methods were performed according to conventional conditions or the conditions recommended by the manufacturer. Where the manufacturers of the reagents or instruments are not specified, they are all commercially available conventional products.

[0027] refer to Figure 1 In an embodiment of the present application, a method for preparing a nickel-based metal ceramic material is provided, comprising: Step S1, mixing nickel powder with reducing metal powder to obtain a nickel-based composite material; wherein the reducing property of the metal element in the reducing metal powder is higher than that of nickel.

[0028] In this step, two different types of metal powders are mixed: one is nickel powder (Ni), and the other is a metal powder with a higher reducibility than nickel (such as Ti).

[0029] It's important to note that in alkaline electrolyzers, electrodes are frequently started and stopped, which can easily generate reverse current. This means that electrodes that should be working become targets for corrosion when there's no electrolytic load. During this process, the original catalytic metal, nickel (Ni), is easily oxidized (e.g., to form NiO). The phase change during oxidation can cause the coating structure to collapse, rapidly degrading the electrode's catalytic performance.

[0030] In this embodiment, a metal powder with a higher reducing power than nickel is mixed with nickel powder to prepare a nickel-based composite material, with the aim of constructing a "sacrificial anode effect" mechanism during the subsequent use of the electrode. The selected reducing metal (such as Ti, etc.) has a lower standard electrode potential than nickel and is more susceptible to oxidation reactions. When the electrode undergoes frequent starts and stops or current reversals in an alkaline electrolytic cell, these reducing metals doped in the system will preferentially lose electrons and be oxidized, thereby effectively inhibiting the electrochemical corrosion process of nickel. This mechanism helps to maintain the stability of nickel and prevent its catalytic active sites from being rapidly deactivated due to reverse current. Compared with traditional undoped materials, this sacrificial anode strategy significantly improves the corrosion resistance and service stability of electrode materials under complex working conditions.

[0031] The nickel powder is doped with metal powder having a higher reducing property than nickel. In some embodiments, the reducing metal powder may include at least one of Mo, Co, Ti, Sn and Ta.

[0032] In some embodiments, the reducing metal powder is Ti; Electrochemically, reducing metal powders are more likely to lose electrons, so they will be oxidized first in reverse current or corrosive environment, thereby "sacrificing themselves" to protect nickel from oxidation, forming a sacrificial anode effect.

[0033] For example, Table 1 shows the comparison of the metal elements of a typical reducing metal powder and its standard electrode potential: Table 1. Metal elements and corresponding electrode potentials

[0034] As can be seen from Table 1, the standard electrode potentials of Ti, Co, and Ta are all lower than Ni (-0.25 V), indicating that they are more easily oxidized and have higher reducibility than nickel. They can preferentially lose electrons under reverse current conditions, thereby acting as a "sacrificial anode" to protect nickel from oxidation and maintain its catalytic activity.

[0035] In contrast, Sn (-0.14V), Mo (-0.20 to -0.10V), and Cu (+0.34V) have electrode potentials higher than or close to Ni. Their insufficient reducibility makes them difficult to preferentially oxidize in a reverse current environment, making them unsuitable as doping metals for the present invention. If these metals (such as Sn, Mo, and Cu) were used without the sacrificial anode effect, Ni could still preferentially generate electrons, undergo corrosion reactions, and become deactivated, leading to catalytic failure and shortened electrode life, thus undermining the overall anti-corrosion protection mechanism.

[0036] Therefore, the "higher reducibility of the metal elements in the reducing metal powder than nickel" proposed in this embodiment is the functional mechanism for achieving "sacrificial anode protection of nickel." This technology ensures preferential oxidation of the doped metal during operation, protecting the nickel and maintaining its catalytic effect, and is a key factor in the corrosion resistance design of the entire material system.

[0037] Step S2: mixing nickelous oxide and rare earth oxide, and sintering the mixture to obtain a sintered oxide ceramic material.

[0038] The above steps are to mix the following oxide powders: nickelous oxide (NiO) and rare earth oxides, and then perform a high-temperature sintering treatment, the purpose of which is to allow these components to react, dissolve or combine at high temperature to form an integral ceramic powder.

[0039] Specifically, different oxide powders are first mixed in appropriate proportions. The mixed powders are then sintered, heating them in a high-temperature furnace, holding them for several hours, and then cooling them. This creates a high-temperature-treated ceramic material, known as "sintered oxide ceramic." This material is a composite powder composed primarily of nickelous oxide and other rare earth oxides.

[0040] The sintering used in this step helps to form a certain degree of structural bonding or solid solution relationship between different oxides, thereby producing ceramic powder with uniform structure and better thermal stability.

[0041] The mixing in this step can be performed using a planetary ball mill, dry mixer, or other equipment, and the sintering can be performed using a box-type resistance furnace or a protective atmosphere furnace. For example, typical sintering conditions include heating to 1200°C in an air atmosphere and holding the temperature for 4 hours.

[0042] In some embodiments, the rare earth oxide may be any one of the following two situations: (1) Rare earth oxides include only cerium oxide.

[0043] (2) Rare earth oxides include: A-cerium oxide, and at least one of B-yttrium oxide, C-lanthanum oxide, and D-neodymium oxide. This is “A + (at least one of B, C, and D)”. For example, it can be A + B, or A + C + D, or A + B + C + D.

[0044] It should be noted that in the ceramic phase design provided in this embodiment, cerium oxide (CeO2) is used as the core and essential component of rare earth oxides because of its unique redox buffering capacity and oxygen vacancy regulation function. CeO2 is a typical "reversible oxide" that can be used in CeO2 under alkaline conditions. 3+ / Ce 4+It can flexibly switch between two states and has good oxygen storage and release capabilities. This property enables it to play the role of "electron buffer" and "passivation regulator" in electrode surface reactions, helping to maintain the stability of the metal-ceramic system under start-stop conditions and preventing the catalytic sites from being deactivated due to overoxidation.

[0045] In contrast, rare earth oxides such as yttrium oxide (Y2O3), lanthanum oxide (La2O3), and neodymium oxide (Nd2O3) primarily provide auxiliary functions, such as enhancing lattice stability, improving sintering activity, and refining the microstructure. For example, they can act as grain boundary modifiers to increase the sintering density of the ceramic phase or improve ball milling dispersion, but they do not inherently possess the strong reduction buffering effect of CeO2.

[0046] Therefore, in this technical solution, cerium oxide is the dominant component that realizes the key functions of rare earth oxides and is irreplaceable. While other rare earth oxides can further optimize material properties, they are not necessary for achieving the main technical effects. Based on this, rare earth oxides must include cerium oxide, while other rare earth oxides (such as yttrium oxide, lanthanum oxide, and neodymium oxide) can be flexibly added without addition, or with one or more.

[0047] Step S3, subjecting the sintered oxide ceramic material and the nickel-based composite material to high-energy ball milling treatment, during which the sintered oxide ceramic material and the nickel-based composite material are bonded together at the particle scale through mechanical alloying effect and cold welding effect to obtain a nickel-based metal ceramic material.

[0048] The above steps involve "high-energy ball milling" the two powders obtained in the previous two steps: metal powder (nickel-based composite material) and oxide powder (sintered oxide ceramic material). Under the high-energy impact of the ball mill, the two powders undergo physical bonding and physical metallurgical effects.

[0049] It's important to note that high-energy ball milling (HEM) is a machining process that utilizes the intense mechanical impact, friction, and shearing between the high-speed rotating milling jar and the grinding balls to repeatedly crush, mix, and weld and fracture powder materials. Compared to conventional ball milling, HEM has a higher energy density and can achieve significant microstructural changes in a short period of time.

[0050] In the preparation process of the nickel-based metal ceramic material described in this embodiment, high-energy ball milling is used to process sintered oxide ceramic materials and nickel-based composite materials. During the ball milling process, the metal powders are repeatedly collided, compacted and cold-welded, causing the metal element atoms of different compositions to diffuse, dissolve and even form non-equilibrium structures; ceramic particles are pressed into the surface of the metal powder, and the initial adhesion and bonding between the ceramic phase and the metal matrix are achieved through the cold welding effect; and the ceramic particles can be evenly dispersed between the metal powders to improve the uniformity of the material interface bonding and the overall structural stability.

[0051] The above-mentioned mechanical alloying refers to the high-energy ball milling process in which powder particles continuously collide, deform, weld, and fracture, prompting the formation of solid solutions or mutual doping between different materials at the submicron / nanoscale.

[0052] The cold welding effect mentioned above refers to the direct bonding between powder particles due to the absence of a liquid phase but the presence of high-speed impact during ball milling. It is particularly obvious when combining metals and ceramics.

[0053] In an optional embodiment, the processing conditions of the high-energy ball milling process include: (1) The rotation speed is 250 rpm to 450 rpm; for example, it can be 250 rpm, 300 rpm, 350 rpm, 400 rpm, 450 rpm, etc.

[0054] (2) Rotating speed 100 rpm ~ 200 rpm; for example, it can be 100 rpm, 120 rpm, 140 rpm, 160 rpm, 180 rpm, 200 rpm, etc.

[0055] (3) The treatment time is 1 to 5 hours. For example, it can be 1 hour, 2 hours, 3 hours, 4 hours, 5 hours, etc.

[0056] In this embodiment, a high-energy ball mill is used to vigorously ball mill the mixed powder at set rotation and revolution speeds. The ball milling time is usually 1 to 5 hours to obtain a nickel-based metal ceramic material with uniform bonding at the particle scale, that is, a composite powder composed of metal powder and ceramic powder.

[0057] For example, powders of nickelous oxide, chromium oxide, cerium oxide, etc. are mixed with spherical nickel powder and Ti powder, placed in a high-energy planetary ball mill, and ball milled for 3 hours under the conditions of 300 rpm rotation + 150 rpm revolution to obtain nickel-based metal ceramic powder with uniform surface bonding.

[0058] The composite powder formed by the ball milling process has good composition uniformity and interface bonding, and is suitable for subsequent application processes such as thermal spraying, pressing, and sintering.

[0059] In some embodiments, the nickel-based composite material includes 0.5% to 2% reducing metal powder, with the balance being nickel powder. For example, the content of the reducing metal powder can be 0.5%, 0.8%, 1%, 1.5%, 2%, and so on.

[0060] In some embodiments, the particles of nickelous oxide and the rare earth oxide are in the same size range.

[0061] The three materials, nickelous oxide and rare earth oxide, have the same particle size range, which facilitates the simultaneous densification of the component powders during the sintering process, avoiding local porosity or structural unevenness caused by particle size differences. Furthermore, during high-energy ball milling, powder particles of similar particle sizes are evenly stressed, enabling more effective mechanical impact and cold welding, promoting uniform dispersion of the ceramic phase in the metal matrix and enhancing the interfacial bonding stability of the composite material. Furthermore, consistent particle size also facilitates powder fluidity and heating uniformity during subsequent thermal spraying, thereby improving the coating's density and service reliability.

[0062] In some embodiments, the ratio of the sintered oxide ceramic material to the nickel-based composite material is (1-1.5): 1. For example, the ratio may be 1:1, 1.1:1, 1.2:1, 1.3:1, 1.4:1, 1.5:1, and the like.

[0063] In some embodiments, the percentage of each component in the sintered oxide ceramic material is: Titanium oxide 0.5% to 2%; for example, it can be 0.5%, 0.8%, 1%, 1.5%, 2%, etc.

[0064] Chromium oxide 1% to 5%; for example, it can be 1%, 2%, 3%, 4%, 5%, etc.

[0065] Cerium oxide 0.2% to 1%; for example, it can be 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.8%, 1%, etc.

[0066] Yttrium oxide, lanthanum oxide, and neodymium oxide are each 0% to 1%; for example, they may not be added, or may be 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.8%, 1%, and the like.

[0067] The balance of the sintered oxide ceramic material other than the rare earth oxide is nickelous oxide.

[0068] A nickel-based metal ceramic material is provided in an embodiment of the present application, which is prepared by the method for preparing a nickel-based metal ceramic material as described in any one of the aforementioned embodiments.

[0069] Nickel-based metal ceramic material is a granular composite powder composed of a nickel-based composite material formed by nickel powder and metal powder with a reducibility higher than nickel, and a sintered oxide ceramic material that has been sintered; wherein the ceramic part includes nickelous oxide and rare earth oxides, preferably including chromium oxide, titanium oxide and cerium oxide, and optionally contains one or more of yttrium oxide, lanthanum oxide and neodymium oxide.

[0070] The particle sizes of the various powders are matched to enhance interface uniformity. The mass ratio of the sintered oxide ceramic to the nickel-based composite is preferably 1:1 (1-1.5). Through high-energy ball milling, mechanical alloying and cold welding create a tightly bonded composite structure at the particle scale. The resulting material exhibits structural uniformity, strong bonding, and even dispersion, while also exhibiting excellent corrosion resistance and stability, making it suitable for demanding service applications such as thermal spray electrodes.

[0071] In an embodiment of the present application, an electrode is provided, the surface of which is coated with the nickel-based metal ceramic material as described in the above embodiment.

[0072] The electrode described in the present invention is made by coating its surface with a nickel-based cermet material derived from a composite powder prepared using the aforementioned method. The electrode is suitable for electrochemical applications such as alkaline water electrolysis for hydrogen production, fuel cells, and metal electrolysis. Because the ceramic composite material possesses excellent electrical conductivity, corrosion resistance, and structural stability, the coated electrode boasts a longer service life and higher electrocatalytic efficiency, making it particularly suitable for complex operating conditions such as frequent starts and stops and reverse current surges.

[0073] The electrodes may include but are not limited to the following components: (1) Conductive substrate: For example, nickel foam, nickel mesh, nickel plate, stainless steel plate or titanium plate are used as electrode carriers to provide structural support and electron channels; (2) Ceramic composite coating: a dense nickel-based metal ceramic material layer is formed on its surface by thermal spraying, plasma spraying or cold spraying; (3) Intermediate bonding layer (optional): In some embodiments, to enhance the adhesion between the coating and the metal substrate, a metal transition layer (such as Ni, NiAl, etc.) may be pre-sprayed; (4) Pretreatment layer (optional): The substrate can be subjected to surface treatment such as mechanical roughening, pickling or ultrasonic cleaning before coating to improve the adhesion of the coating.

[0074] This electrode can be used to construct a cathode and is particularly suitable for alkaline electrolysis cell systems. It has good anti-oxidation, anti-shedding and efficient electronic conduction properties during the water electrolysis process.

[0075] In an embodiment of the present application, a method for preparing an electrode as described in the aforementioned embodiment is provided, comprising: Step S100 , pre-treating the substrate to obtain a prefabricated substrate.

[0076] In this step, a metal with electrical conductivity and heat resistance can be selected as the electrode substrate, such as nickel foam, nickel mesh, stainless steel plate or titanium plate, etc. In order to improve the coating adhesion and interface stability, the substrate is preferably subjected to multiple pretreatments.

[0077] In some embodiments, the pretreatment includes cleaning, roughening, and bonding to a base layer.

[0078] (1) Cleaning treatment can be used to remove surface oil, dust and oxide layer, and ultrasonic cleaning, organic solvent or alkaline cleaning can be used.

[0079] (2) Roughening treatment, such as sandblasting or chemical etching, to increase surface roughness and improve the coating bonding interface.

[0080] (3) Bonding base layer: a metal bonding layer (such as Ni or NiAl) can be pre-sprayed on the substrate surface to enhance the bonding strength and thermal shock resistance of the main coating.

[0081] In step S200, nickel-based metal ceramic material is used as spray powder and coated on the surface of the prefabricated body by a thermal spraying process to form a ceramic composite coating on the electrode surface.

[0082] The nickel-based metal ceramic powder prepared in the above embodiment is used as a spraying material. The material is composed of a composite of a metal phase (nickel and reducing metal) and a ceramic phase (nickel oxide, chromium oxide, titanium oxide, cerium oxide, etc.), and has a dense particle structure and good bonding properties.

[0083] The powder is evenly applied to the surface of a prefabricated substrate using a thermal spraying process. Thermal spraying techniques include, but are not limited to, plasma spraying, HVOF, and high-velocity arc spraying. Appropriate process parameters are selected based on the application requirements. After the powder is melted or semi-melted at high temperatures, it is deposited onto the substrate through high-velocity impact, forming a layer-by-layer coating.

[0084] After spraying, a dense, firmly bonded nickel-based cermet coating forms on the electrode surface, exhibiting excellent corrosion resistance, electrochemical stability, and electrical conductivity. The resulting electrode is suitable for use in alkaline water electrolysis systems, significantly improving electrode life and catalytic efficiency, particularly under complex operating conditions such as frequent start-stop cycles and reverse current surges.

[0085] In some embodiments, the thermal spraying process includes plasma spraying and flame spraying; In some embodiments, the thermal spraying process is to perform multi-layer spraying on the surface, and the thickness of each layer is controlled to be 40 μm to 50 μm; In some embodiments, the process conditions of the plasma spraying include: A. The power is set to 35kW~42kW; for example, it can be 35kW, 36kW, 37kW, 38kW, 39kW, 40kW, 41kW, 42kW, and so on.

[0086] B. The spraying distance should be kept between 120mm and 140mm; for example, it can be 120mm, 130mm, 140mm, etc.

[0087] C. The spray gun angle is 75°±1°.

[0088] D. The movement speed of the spray gun is controlled at 400mm / s~500mm / s; for example, it can be 400mm / s, 410mm / s, 420mm / s, 430mm / s, 440mm / s, 450mm / s, 460mm / s, 470mm / s, 480mm / s, 490mm / s, 500mm / s, etc.

[0089] In some embodiments, the flame spraying process conditions include: A. The temperature is controlled at 2800°C to 3000°C; for example, it can be 2800°C, 2900°C, 3000°C, etc.

[0090] B. The spraying distance should be kept between 120mm and 150mm; for example, it can be 120mm, 130mm, 140mm, 150mm, etc.

[0091] C. The spray gun movement speed is 350mm / s~450mm / s. For example, it can be 350mm / s, 360mm / s, 380mm / s, 400mm / s, 410mm / s, 420mm / s, 430mm / s, 440mm / s, 450mm / s, etc.

[0092] It should be noted that the thermal spraying process is a key step in depositing nickel-based cermets on the electrode substrate surface. Controlling its parameters significantly impacts the coating's structural uniformity, adhesion, and ultimate service performance. To achieve a ceramic composite coating that combines density with a moderately porous structure, key parameters such as spray power, spray distance, and gun travel speed must be comprehensively considered during the thermal spraying process to ensure sufficient powder melting, uniform deposition, and proper solidification.

[0093] The spraying power mainly affects the temperature level during the spraying process. The higher the power, the higher the spraying temperature, which is conducive to the full melting of the powder particles, thereby forming droplets with uniform surface and good fluidity, which helps to form a dense coating on the substrate surface. However, if the temperature is too high, it may cause abnormal growth of powder particle grains or a decrease in the cooling rate of the droplets, causing coarsening of the tissue and uneven structure; on the contrary, too low a temperature will lead to incomplete melting of the powder, and the deposited coating will appear rough, discontinuous, and have poor bonding. Therefore, by reasonably regulating the spraying power, it is possible to control the cooling behavior of the powder while ensuring full melting, and obtain a functional coating with both density and microporous structure, which is conducive to the transmission and diffusion of electrochemical reactants.

[0094] Spray distance, or the distance from the spray gun to the substrate surface, is a critical parameter affecting droplet flight and deposition quality. If the spray distance is too long, the droplets will partially cool or even solidify during flight, reducing their metallurgical bonding with the substrate and ultimately leading to a decrease in coating bond strength. If the distance is too short, the droplet kinetic energy is too great, and ceramic particles may rebound or segregate upon impact with the substrate, resulting in uneven distribution of coating components. Optimizing the spray distance helps achieve uniform deposition and good adhesion while maintaining sufficient particle plasticity, thereby improving the overall density and compositional uniformity of the coating.

[0095] The speed of the spray gun during the spraying process directly determines the material deposition rate and energy accumulation per unit area. If the speed is too slow, the coating will be deposited locally, resulting in excessively thick areas, reduced porosity, and even warping or cracking due to heat accumulation. However, if the speed is too fast, the droplets will be sparsely distributed on the substrate, causing uneven coating thickness or reduced adhesion. By properly setting the speed, not only can the thickness of a single spray layer be controlled, but multiple reciprocating passes can also be used to optimize the interlayer structure, improve porosity distribution, and enhance coating consistency and performance.

[0096] In summary, the interaction and mutual constraints between spray power, spray distance, and spray gun speed play a key role in regulating the coating's compositional uniformity, microstructure density, and adhesion properties. Systematically optimizing these process parameters can effectively enhance the structural integrity and functional stability of ceramic composite coatings, meeting the comprehensive requirements for conductivity, corrosion resistance, and service life of electrodes under complex electrochemical conditions.

[0097] An electrolytic cell is provided in an embodiment of the present application, comprising the electrodes described in the aforementioned embodiment.

[0098] The electrolytic cell may include an electrode coated with a nickel-based cermet material, as described in the aforementioned embodiments. This electrode exhibits excellent corrosion resistance, catalytic stability, and structural stability under alkaline water electrolysis conditions, making it particularly suitable for use as an electrolyzer electrode in green hydrogen production. Because the coating is a multiphase composite structure, comprising metallic nickel and a highly reducible metal synergistically with a nickel-based ceramic oxide, it effectively suppresses electrode failure caused by reverse current, significantly improving the lifespan and energy efficiency of the electrolytic cell system.

[0099] The electrolytic cell may be a working unit electrolytic cell in an alkaline water electrolysis hydrogen production system, and the structure may further include but is not limited to the following components: Anode and cathode electrodes: at least one electrode adopts the sprayed ceramic composite coating as described above; electrolyte membrane or ion exchange membrane: such as a porous polymer membrane or hydroxide ion membrane (AEM), used to achieve ion conduction between the anode and cathode and inhibit gas cross-diffusion; electrolyte: preferably a potassium hydroxide (KOH) solution or sodium hydroxide (NaOH) solution with a concentration of 20% to 30%, providing a conductive medium; gas collection chamber / channel: used to collect the produced hydrogen and oxygen; electrolytic cell shell and sealing structure: used to carry the electrolytic components and maintain the internal sealing of the electrolytic cell; (or) current collection plate or electrode support frame: improve current output efficiency and support stable operation of the electrode; (or) cooling channel or thermal management system: used to maintain temperature stability during operation of the electrolytic cell, thereby improving work efficiency and safety.

[0100] In addition, the electrolyzer can also be integrated into a water electrolysis hydrogen production module or a green hydrogen power generation device for use in industrial-scale renewable energy hydrogen production solutions, demonstrating good structural versatility and material adaptability.

[0101] An embodiment of the present application provides an electrical device, including the electrolytic cell as described in the above embodiment.

[0102] The electrical equipment provided in this application includes an electrolytic cell as in the aforementioned embodiment, which uses electrodes with nickel-based metal ceramic materials sprayed on the surface, and has excellent corrosion resistance, conductivity and electrochemical stability. It is particularly suitable for a variety of electrochemical application scenarios with high requirements on electrode durability and stability.

[0103] For example, it can be applied to the electrolyzer in the alkaline water electrolysis hydrogen production system to improve the electrode life and hydrogen yield of the system under frequent start-stop and reverse current shocks; it can also be integrated into the renewable energy coupled hydrogen production platform (such as wind-hydrogen, light-hydrogen system) to adapt to its dynamic load and intermittent operation characteristics; it can also be used in the design of fuel cell anode / cathode protection layer to improve its corrosion resistance; in addition, it is also suitable for industrial high-temperature electrolysis equipment, electrochemical reactors, hydrometallurgical anodes, electrode systems for wastewater treatment, energy storage equipment and other electrical systems, especially in working environments with strong corrosion, frequent current disturbances or high load density.

[0104] Therefore, the electrolytic cell and its applications described in this application can cover a wide range of electrical equipment fields and have important value in promoting the development of cutting-edge technologies such as green hydrogen, energy storage and sustainable electrochemical conversion.

[0105] The present invention is further described below by way of specific examples. However, it should be understood that these examples are merely provided for more detailed description and are not to be construed as limiting the present invention in any form.

[0106] Table 2. Comparison of main materials and parameters in the examples

[0107] In the above table, "ratio" represents the ratio of the sintered oxide ceramic material to the nickel-based composite material; the number line in the first row represents the example number.

[0108] Example 1 In this embodiment, the nickel-based metal ceramic material and the electrode were prepared using the following method.

[0109] Experimental methods: 1. Preparation of nickel-based cermet materials: (1) Fine-grained nickelous oxide powder with a particle size of 5 to 10 microns is mechanically mixed with cerium oxide, yttrium oxide, lanthanum oxide and neodymium oxide powders of the same particle size range (5 to 10 microns) in proportion.

[0110] (2) After mixing, the mixture was placed in a ball mill and ball milled at 400 rpm for 2 hours to increase the surface energy of the different ceramic phases. Subsequently, the ball-milled mixture was placed in a high-temperature furnace for high-temperature sintering at 1200°C for 4 hours, thereby sintering and solid-solutionizing the oxide ceramic phase into a uniform single-phase structure.

[0111] (3) The sintered material is crushed and ball-milled, and then screened to obtain oxide ceramic powder with a particle size of 15 to 45 microns, which meets the thermal spraying particle size range.

[0112] (4) The oxide ceramic powder and the metal nickel powder are placed in a planetary high-energy ball mill at a mass ratio of 1:1. During the ball milling process, the metal nickel powder is uniformly bonded to the oxide ceramic powder due to the cold welding effect, forming a nickel-based metal ceramic powder with a uniform interface and strong powder bonding force. The powder is the prepared electrode spraying material. The morphology of the nickel-based metal ceramic powder is shown in FIG. Figure 2 .

[0113] 2. Preparation of electrodes: (1) Electrode substrate pretreatment: A pure nickel wire mesh with a mesh size of 40 mesh and a wire diameter of 0.19 mm was selected as the electrode substrate. Ultrasonic cleaning was performed using organic solvents such as acetone and alcohol to ensure that there was no oil residue on the surface. The substrate surface was roughened using a sandblasting process. The sand was made of corundum, the sandblasting pressure was 0.5 MPa, and the sand particle size was 40-100 mesh. Then, atomized nickel powder with a particle size of 140-325 mesh was used as the bonding base for spraying. The spraying distance was 140 mm, the spray gun speed was 2000 mm / s, the spraying power was 38 kW, and the number of spraying passes was 2.

[0114] (2) Thermal spraying preparation of electrodes: The pre-treated electrode substrate is firmly fixed on the workbench of the thermal spraying equipment, and the distance and angle between the spray gun and the substrate are precisely adjusted. The prepared nickel-based metal ceramic powder is added to the powder feeder of the thermal spraying equipment, and the process parameters such as spraying temperature, spraying distance, and spray gun movement speed are carefully set. For plasma spraying, the power is set to 40kW, the spraying distance is maintained at 120mm, the spray gun angle is 75°, and the spray gun movement speed is controlled at 500mm / s; the thermal spraying equipment is started, and the powder is sprayed at high speed to the surface of the electrode substrate under high temperature, and the layer thickness is controlled to be 40~50μm.

[0115] The ceramic composite coating formed on the electrode surface after spraying treatment has a morphology reference Figure 3 and Figure 4 shown.

[0116] Example 2 to Example 12 In the above embodiments, nickel-based cermet materials and electrodes were prepared.

[0117] The preparation method used is basically the same as that in Example 1. For specific differences, refer to the parameters in Table 2.

[0118] Comparative Example 1 In this comparative example, nickel-based cermet materials and electrodes were prepared.

[0119] The preparation method is basically the same as that of Example 2, except that no reducing metal powder (i.e., no Ti powder) is added when preparing the nickel-based composite material. This is used to verify the sacrificial anode protection effect of the reducing metal.

[0120] Comparative Example 2 In this comparative example, nickel-based cermet materials and electrodes were prepared.

[0121] The preparation method is basically the same as that of Example 2, except that the high-energy ball milling in step S3 is replaced by ordinary low-speed mechanical mixing for 4 hours. This is used to verify the effects of mechanical alloying and cold welding effects of high-energy ball milling on material properties.

[0122] Comparative Example 3 In this comparative example, Raney nickel material and electrode were prepared.

[0123] Raney nickel-coated electrode prepared by conventional chemical leaching method.

[0124] The Ni-Al powder was sprayed onto a nickel mesh, and then the Al was leached in a KOH solution. This was used to compare the performance of the present invention with that of conventional high-performance catalysts.

[0125] Test Experiment 1. Test method: (1) Electrocatalytic hydrogen evolution activity test: Refer to the 6 overpotential test in "GB / T 45092-2024 Test and evaluation of electrode performance for hydrogen production by electrolysis of water", with 80℃, 30% KOH solution as the test conditions, -3000A / m 2 The current density is used to test the overpotential of hydrogen evolution reaction. The lower the hydrogen evolution overpotential (the smaller the absolute value), the higher the electrocatalytic hydrogen evolution activity of the electrode.

[0126] (2) Long-term stability test: Perform a chronopotentiometry test at a constant current (-3000 A / m²) in a 1M KOH electrolyte for 1000 hours. Record the change in electrode potential after 1000 hours. Smaller potential changes indicate lower constant-load overpotential decay and better long-term stability.

[0127] (3) Simulated start-stop reverse polarization test: Referring to the "Performance Test and Evaluation of Electrodes for Hydrogen Production by Water Electrolysis" (GB / T 45092-2024), section 7 on positive and negative polarization stability, we conducted a simulated start-stop stability test. The positive polarization current density was -5000 A / m² for 5 minutes, the reverse polarization current density was 10000 A / m² for 0.5 minutes, and the cycle duration was 100 times. Comparing the hydrogen evolution overpotential before and after the cycle, a smaller increase in the hydrogen evolution overpotential indicates a smaller decay rate of the reverse polarization overpotential and a higher start-stop stability.

[0128] 2. Test results: Table 3. Test results of Examples and Comparative Examples

[0129] analyze: From the results in Table 3, and Figures 5 to 7 It can be seen that all embodiments of the present invention are comprehensively and significantly superior to all comparative examples in terms of catalytic activity, long-term stability and especially simulated start-stop reverse polarization stability, solving the key pain points of the prior art.

[0130] (1) Comparison with Comparative Example 3 (conventional Raney nickel electrode): The conventional Raney nickel electrode performed poorly under industrial-grade test conditions, with a hydrogen evolution overpotential as high as 261 mV and a catalytic activity far lower than any embodiment of the present invention. More importantly, its stability was extremely poor, with a 1000-hour long-term attenuation rate and a reverse polarization attenuation rate as high as 2.10% and 38.5%, respectively, indicating that its porous structure was easily oxidized, passivated, and destroyed under dynamic conditions. This highlights the difficulty of conventional catalysts in adapting to the frequent start-stop conditions coupled with renewable energy. In contrast, the electrode of the present invention (such as Example 6) not only had an overpotential reduced by nearly 100 mV, but also had a long-term attenuation and reverse polarization attenuation rate of only about 1 / 5 and 1 / 3 of that of Comparative Example 3, with a significant performance improvement.

[0131] (2) Comparison with Comparative Example 1 (no reducing metal): Although the initial activity of this comparative example was acceptable (183 mV), its performance deteriorated sharply in the reverse polarization test simulating start-stop operation, with a decay rate as high as 35.1%. This strongly proves that the reducing metal (such as Ti) introduced in the present invention is preferentially oxidized under reverse current shock through the "sacrificial anode" protection mechanism, thereby protecting the core nickel catalytic sites from being destroyed, and is the key technical core to achieve excellent start-stop stability.

[0132] (3) Comparative Example 2 (no high-energy ball milling): All performance indicators of this comparative example are very poor, especially the catalytic activity (overpotential 226 mV) and stability, which are far inferior to those of the other groups. This proves that the high-energy ball milling process used in the present invention achieves a strong metallurgical bond between the ceramic phase and the metal phase at the particle scale through mechanical alloying and cold welding effects, which is necessary to construct a highly active interface and ensure the long-term integrity of the coating structure under harsh working conditions.

[0133] (4) Regarding the effect of the amount of reducing metal powder (compared with Examples 1, 2, and 3), as the Ti content increases, the overall performance of the electrode shows a trend of first optimizing and then slightly decreasing. Example 2 (1% Ti) exhibits the best overall performance, with its hydrogen evolution overpotential (177 mV), long-term stability (0.52% attenuation), and reverse polarization stability (13.3% attenuation) all being better than the other two groups. A Ti addition of 1% is the optimal balance point for achieving high activity and high stability. When the content is too low (0.5%), the "sacrificial anode" protection effect is insufficient; when the content is too high (2%), the performance may be slightly affected by the formation of additional oxides on the surface due to excess metal.

[0134] (5) Regarding the effect of the ratio of metal powder to ceramic powder (compared with Examples 2, 4, and 5), as the ratio of the metal phase increases, the performance shows a complex optimization trend. From 1:1 to 1.5:1, the initial activity and reverse polarization stability continue to increase (the overpotential decreases from 177mV to 173mV, and the reverse polarization decay rate decreases from 13.3% to 13.1%). However, the long-term stability reaches the best in Example 4 (1.2:1) (0.49%), and decreases at 1.5:1 (0.58%). A moderate increase in the ratio of the metal phase helps to improve the catalytic activity. Overall, Example 4 with a ratio of 1.2:1 performs best in long-term stability and is the preferred choice for long-life applications; while Example 5 with a ratio of 1.5:1 has a slight advantage in initial activity.

[0135] (6) Regarding the effect of rare earth components in ceramic powder (comparing Examples 4, 6, and 7), Example 6 (high content of multiple rare earths) showed overwhelmingly the best performance, with its hydrogen evolution overpotential (165 mV), long-term stability (0.45%), and reverse polarization stability (11.4%) being the best among all the examples. Example 7 (low content and containing only CeO2) had the worst performance. The type and content of rare earth oxides have a huge impact on performance. High content of multiple rare earth oxides (CeO2, Y2O3, La2O3, etc.) optimizes catalytic activity and structural stability through a strong synergistic effect, thereby maximizing performance.

[0136] (7) Regarding the effect of ball milling speed (compared with Examples 8, 4, and 9), the performance shows a typical optimization curve as the speed changes. Example 4 (350 rpm) has the best overall performance. When the speed is too low (250 rpm) or too high (450 rpm), the activity and stability of the electrode are inferior to those at a medium speed. There is an optimal ball milling energy input window. A speed of 350 rpm can achieve an ideal mechanical alloying effect, allowing the particles to fully recombine without excessively destroying the active structure.

[0137] (8) Regarding the effect of ball milling time (compared with Examples 10, 4, and 11), the ball milling time has a significant effect on performance. 1 hour is too short, the compounding is incomplete, and the performance is the worst. Example 4 (4 hours) shows the best balance between long-term stability and reverse polarization stability. After extending to 5 hours (Example 11), the performance did not improve compared to 4 hours, and the long-term stability decreased slightly. 4 hours is the preferred processing time for achieving optimal particle compounding and performance. If the time is too short, the compounding is insufficient, and if the time is too long, it may have a slight negative impact on stability and increase energy consumption.

[0138] (9) Regarding the effect of the type of reducing metal powder (comparing Examples 4 and 12), Example 12 (mixed metal) has a lower overpotential (168 mV) than Example 4 (175 mV), and both long-term and reverse polarization stability are better. The use of a composite of multiple reducing metals, including Ti, Sn, Co, and Ta, outperforms the use of Ti alone. This is due to the synergistic effect between the different metals: Ti provides sacrificial anode protection, while Sn, Co, and Ta are themselves excellent catalyst promoters or structural stabilizers, which together improve the overall performance of the electrode.

[0139] 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 above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for preparing a nickel-based metal ceramic material, characterized in that: include: Mixing nickel powder with reducing metal powder to obtain a nickel-based composite material; wherein the reducing property of the metal element in the reducing metal powder is higher than that of nickel; Mixing nickelous oxide and rare earth oxide, and sintering to obtain a sintered oxide ceramic material; The sintered oxide ceramic material and the nickel-based composite material are subjected to high-energy ball milling treatment. During the high-energy ball milling treatment, the sintered oxide ceramic material and the nickel-based composite material are bonded together at the particle scale through mechanical alloying effect and cold welding effect to obtain a nickel-based metal ceramic material.

2. The method for preparing the nickel-based metal ceramic material according to claim 1, wherein: The reducing metal powder includes at least one of Mo, Co, Ti, Sn and Ta; and / or, The reducing metal powder is Ti; and / or, The nickel-based composite material comprises 0.5% to 2% reducing metal powder and the balance is nickel powder; and / or, The particle size range of nickelous oxide and the rare earth oxide is the same.

3. The method for preparing the nickel-based metal ceramic material according to claim 1, wherein: The ratio of the sintered oxide ceramic material to the nickel-based composite material is (1-1.5):

1.

4. The method for preparing the nickel-based metal ceramic material according to claim 1, wherein: The rare earth oxide includes cerium oxide; or, the rare earth oxide includes cerium oxide and at least one of yttrium oxide, lanthanum oxide and neodymium oxide; Preferably, the percentage of each component in the sintered oxide ceramic material is: Cerium oxide 0.2%~1%; Yttrium oxide, lanthanum oxide and neodymium oxide are 0% to 1% each; The balance is nickelous oxide.

5. The method for preparing the nickel-based metal ceramic material according to claim 1, wherein: The processing conditions of the high-energy ball milling process include: Rotational speed 250 rpm ~ 450 rpm; and / or, Speed ​​100 rpm ~ 200 rpm; and / or, Processing time is 1 hour to 5 hours.

6. A nickel-based metal ceramic material, characterized in that: The nickel-based metal ceramic material is prepared by the preparation method according to any one of claims 1 to 5.

7. An electrode, characterized in that: The surface of the electrode is coated with the nickel-based metal ceramic material as claimed in claim 6.

8. A method for preparing the electrode according to claim 7, characterized in that: include: pretreating the substrate to obtain a prefabricated substrate; Using nickel-based metal ceramic material as spray powder, a thermal spraying process is used to coat the surface of the prefabricated body to form a ceramic composite coating on the electrode surface; Preferably, the pretreatment includes cleaning, roughening and bonding the base layer; Preferably, the thermal spraying process includes plasma spraying and flame spraying; Preferably, the thermal spraying process is to perform multi-layer spraying on the surface, and the thickness of each layer is controlled at 40 μm to 50 μm; Preferably, the process conditions of the plasma spraying include: A. Power setting is 35kW~42kW; B. Keep the spraying distance at 120mm~140mm; C. The spray gun angle is 75°±1°; D. The moving speed of the spray gun is controlled at 400mm / s~500mm / s; Preferably, the process conditions of the flame spraying include: A. Temperature is controlled at 2800℃~3000℃; B. Keep the spraying distance at 120mm~150mm; C. The moving speed of the spray gun is 350mm / s~450mm / s.

9. An electrolytic cell, characterized in that Comprising the electrode as claimed in claim 7.

10. An electrical equipment, characterized in that: Comprising the electrolytic cell of claim 9.

Images