Raney nickel hydrogen evolution cathode and preparation method thereof

Abstract

The invention discloses a Raney nickel hydrogen evolution cathode and a preparation method thereof. The Raney nickel hydrogen evolution cathode comprises a substrate and a modified Raney nickel layer arranged on the surface of the substrate, wherein the raw materials of the modified Raney nickel layer comprise Raney nickel alloy powder and hydrogen storage alloy powder, and the hydrogen storage alloy powder is at least one of LaNi5 series alloy, Ti-Ni series alloy, Zr-Ni series alloy and Mm-Ni series alloy. According to the Raney nickel hydrogen evolution cathode, the defect that in the prior art, a traditional Raney nickel electrode is short in service life due to framework corrosion under the working condition of frequent starting and stopping is overcome, and the Raney nickel hydrogen evolution cathode has the advantages of being long in service life and high in stability.

Description

Technical Field

[0001] This invention belongs to the field of water electrolysis hydrogen production technology, specifically relating to a Raney nickel hydrogen evolution cathode and its preparation method. Background Technology

[0002] In the hydrogen energy industry, alkaline water electrolysis is currently the mainstream technology for large-scale, low-cost hydrogen production. The hydrogen evolution cathode, as the core component of the electrolyzer, directly affects the system's efficiency and economy in terms of performance and lifespan. Raney nickel (typically a Ni-Al alloy with a typical ratio of Ni:Al=80:20) possesses excellent initial electrocatalytic activity due to its porous, high specific surface area structure formed after alkaline activation, and is widely used as a hydrogen evolution cathode material.

[0003] However, in actual industrial operation, especially under fluctuating conditions involving frequent start-ups and shutdowns coupled with renewable energy, traditional Raney nickel electrodes exhibit a serious short service life. The root cause lies in the fact that when the electrolysis system shuts down or experiences reverse current, the electrode is at a non-equilibrium potential, leading to preferential selective dissolution and oxidative corrosion of the active component aluminum (Al) in the Raney nickel framework. This process causes the electrode's porous framework structure to gradually collapse, its specific surface area to irreversibly decrease, and its conductivity to decline. Ultimately, this manifests as a sharp increase in the hydrogen evolution overpotential, loss of catalytic activity, and premature electrode failure. Frequent electrode replacement not only increases costs but also affects the continuous and stable operation of the system.

[0004] In existing technologies, composite structures are typically used to improve the stability of electrodes under intermittent operation. For example, patent CN105350015A discloses a "composite hydrogen evolution cathode with a microporous hydrogen storage layer," which employs a three-layer composite structure of "matrix—hydrogen storage intermediate layer—catalytic layer," aiming to protect the upper catalyst layer through an independent hydrogen storage layer. However, this method is complex (requiring multiple steps such as plasma spraying, alkali activation, and thermal decomposition), costly, and its purpose is to protect the outer noble metal catalytic components, without directly addressing the corrosion and degradation problem of the Raney nickel material's bulk framework. Furthermore, the bonding strength between the composite layers is also a significant challenge.

[0005] Therefore, the industry urgently needs an improvement solution that can fundamentally enhance the stability of Raney nickel electrodes, significantly extend their service life, and at the same time take into account the simplicity of the process and cost advantages. Summary of the Invention

[0006] The purpose of this invention is to provide a Raney nickel hydrogen evolution cathode and its preparation method. This Raney nickel hydrogen evolution cathode overcomes the shortcomings of traditional Raney nickel electrodes in the prior art, which suffer from short service life due to skeleton corrosion under frequent start-stop conditions. It has the advantages of long service life and high stability.

[0007] To achieve the above objectives, a specific embodiment of the present invention provides the following technical solution:

[0008] A Raney nickel hydrogen evolution cathode, the Raney nickel hydrogen evolution cathode comprising a substrate and a modified Raney nickel layer disposed on the surface of the substrate;

[0009] The raw materials for the modified Raney nickel layer include Raney nickel alloy powder and hydrogen storage alloy powder, wherein the hydrogen storage alloy powder is at least one of LaNi5 series alloy, Ti-Ni series alloy, Zr-Ni series alloy, and Mm-Ni series alloy.

[0010] In one or more embodiments of the present invention, the thickness of the modified Raney nickel layer is 60 μm-100 μm.

[0011] In one or more embodiments of the present invention, the atomic ratio of nickel to aluminum in the Raney nickel alloy powder is (70-90):(30-10).

[0012] In one or more embodiments of the present invention, the hydrogen storage alloy powder accounts for 1%-15% of the mass of the modified Raney nickel layer.

[0013] In one or more embodiments of the present invention, the particle size of the Raney nickel alloy powder is 15μm-150μm.

[0014] In one or more embodiments of the present invention, the particle size of the hydrogen storage alloy powder is 40μm-90μm.

[0015] In one or more embodiments of the present invention, the substrate is any one of nickel mesh, nickel felt, nickel plate, nickel alloy mesh, nickel alloy felt, and nickel alloy plate.

[0016] Another specific embodiment of the present invention provides the following technical solution:

[0017] A method for preparing a Raney nickel hydrogen evolution cathode, the method comprising the following steps:

[0018] Raney nickel alloy powder and hydrogen storage alloy powder are mixed to obtain a mixed powder;

[0019] The mixed powder was sprayed onto the substrate surface using plasma spraying to form a modified Raney nickel layer, thus obtaining a Raney nickel hydrogen evolution cathode.

[0020] In one or more embodiments of the present invention, the plasma spraying operation conditions are: current 400A-650A, voltage 50V-80V, argon flow rate 40L / min-80L / min, nitrogen flow rate 40L / min-60L / min, powder feeding rate 30g / min-80g / min, and spraying distance 100mm-150mm.

[0021] In one or more embodiments of the present invention, the substrate is pretreated as follows:

[0022] The substrate is subjected to alkaline washing, water washing, drying, and then sandblasting roughening treatment.

[0023] After sandblasting roughening treatment, the surface roughness of the substrate is 5μm-15μm.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] 1. Significantly Extended Lifespan: This invention alters the electrode failure mechanism from a materials science perspective by uniformly dispersing a hydrogen storage alloy as a lifespan enhancer within a Raney nickel matrix. The hydrogen storage alloy phase effectively buffers stress during start-up and shutdown processes and inhibits preferential dissolution of the aluminum component, thereby significantly delaying the corrosion and collapse process of the porous framework. Accelerated life testing shows that, under harsh conditions simulating frequent start-up and shutdown, the electrode of this invention has a significantly longer lifespan than that of a conventional Raney nickel electrode.

[0026] 2. Maintaining High Activity: Since the porous structure formed during service by the modified Raney nickel layer originates from Raney nickel itself, it fully inherits the advantages of the high specific surface area of ​​traditional Raney nickel. The initial hydrogen evolution overpotential is comparable to that of traditional Raney nickel electrodes, and is even slightly optimized due to the synergistic catalytic effect of the hydrogen storage alloy. More importantly, its activity decay rate is much lower than that of traditional electrodes during long-term operation.

[0027] 3. Integrated structure and strong adhesion: The modified Raney nickel layer prepared by this invention is a single, uniform composite coating. The hydrogen storage alloy particles are dispersed and reinforced within the Raney nickel matrix, without multi-layer interfaces. This integrated structure results in strong coating cohesion and a firm bond with the substrate. It is not easily peeled off under long-term electrochemical cycling and airflow erosion, and has high reliability.

[0028] 4. Simplified process and controllable cost: The core process of this method is only one-step plasma spraying, omitting the complex steps of alkali activation and additional catalyst layer deposition required in existing technologies to prepare independent hydrogen storage layers. The hydrogen storage alloy is used as an additive in small amounts (≤15%), significantly improving performance while having a limited impact on raw material costs. The process has good reproducibility and is very suitable for industrial production. Attached Figure Description

[0029] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0030] Figure 1The initial LSV curves of Embodiment 1, Embodiments 4-6, Comparative Example 1 and Comparative Example 3 of the present invention;

[0031] Figure 2 The LSV curves after accelerated testing in Examples 1, 4 and Comparative Example 1 of this invention;

[0032] Figure 3 This is a surface SEM image of the Raney nickel hydrogen evolution cathode before the accelerated test in Example 1 of the present invention;

[0033] Figure 4 This is a surface SEM image of the Raney nickel hydrogen evolution cathode after accelerated testing in Example 1 of the present invention;

[0034] Figure 5 This is a surface SEM image of the Raney nickel hydrogen evolution cathode before the accelerated test in Comparative Example 1 of this invention;

[0035] Figure 6 This is a surface SEM image of the Raney nickel hydrogen evolution cathode after accelerated testing in Comparative Example 1 of this invention. Detailed Implementation

[0036] To enable those skilled in the art to better understand the technical solutions in this disclosure, the technical solutions in the embodiments of this disclosure are described clearly and completely below. Obviously, the described embodiments are only some embodiments of this disclosure, and not all embodiments. Based on the embodiments in this disclosure, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of this disclosure.

[0037] One specific embodiment of the present invention provides a Raney nickel hydrogen evolution cathode, which includes a substrate and a modified Raney nickel layer disposed on the surface of the substrate.

[0038] Furthermore, the substrate is a conductive substrate, specifically any one of nickel mesh, nickel felt, nickel plate, nickel alloy mesh, nickel alloy felt, and nickel alloy plate.

[0039] Furthermore, the raw materials for the modified Raney nickel layer include Raney nickel alloy powder and hydrogen storage alloy powder, wherein the atomic ratio of nickel to aluminum in the Raney nickel alloy powder is (70-90):(30-10), preferably 80:20, and the particle size of the Raney nickel alloy powder is 15μm-150μm.

[0040] Furthermore, the hydrogen storage alloy powder is at least one of LaNi5 series alloy, Ti-Ni series alloy, Zr-Ni series alloy, and Mm-Ni series (mixed rare earth-nickel series) alloy, with a particle size of 40μm-90μm, accounting for 1%-15% of the mass of the modified Raney nickel layer, preferably 3%-10%.

[0041] Another specific embodiment of the present invention provides a method for preparing a Raney nickel hydrogen evolution cathode, which specifically includes the following steps:

[0042] Step 1, matrix pretreatment.

[0043] Specifically, the substrate is subjected to alkaline washing, water washing, drying, and then sandblasting roughening treatment. Specifically, the substrate is cleaned with a 5wt%-20wt% sodium hydroxide solution to remove oil, and white corundum is used for sandblasting roughening treatment. After sandblasting roughening treatment, the surface roughness Rz of the substrate is 5μm-15μm. Sandblasting roughening treatment is used to increase the surface adhesion.

[0044] Step 2: Mix Raney nickel alloy powder and hydrogen storage alloy powder to obtain a mixed powder.

[0045] Specifically, the hydrogen storage alloy powder accounts for 1%-15% of the mass of the modified Raney nickel layer. The Raney nickel alloy powder and the hydrogen storage alloy powder are weighed and then mechanically mixed evenly in a powder mixer.

[0046] Step 3: The mixed powder is sprayed onto the substrate surface using plasma spraying to form a modified Raney nickel layer, thus obtaining a Raney nickel hydrogen evolution cathode.

[0047] Specifically, the plasma spraying operation conditions are: current 400A-650A, voltage 50V-80V, main gas argon flow rate 40L / min-80L / min, nitrogen flow rate 40L / min-60L / min, powder feeding rate 30g / min-80g / min, and spraying distance 100mm-150mm.

[0048] Step 4, post-processing.

[0049] Specifically, the Raney nickel hydrogen evolution cathode obtained in step 3 can be subjected to stress relief treatment at room temperature or simply cleaned without alkaline immersion activation treatment. After being put into use in the electrolytic cell, the Raney nickel hydrogen evolution cathode will naturally form an activated porous structure in the working alkaline solution. This step can be selected as needed based on actual requirements.

[0050] The present invention will be further described in detail below with reference to specific embodiments.

[0051] Example 1

[0052] The method for preparing the Raney nickel hydrogen evolution cathode in this embodiment is as follows:

[0053] A 46-mesh nickel mesh (approximately 0.25 mm wire diameter) was selected as the substrate. It was first immersed in a 10 wt% NaOH solution at 80°C for 30 minutes to remove oil stains, then rinsed with deionized water and dried. Subsequently, 200-mesh white corundum was used for sandblasting at a pressure of 0.5 MPa and a distance of 150 mm to obtain a rough surface suitable for coating adhesion.

[0054] Raney nickel (Ni 80 Al 20 The powder and LaNi5 alloy powder were mixed at a mass ratio of 95:5 to obtain a mixed powder. The mixed powder was then sprayed onto the substrate surface using plasma spraying. The plasma spraying parameters were: current 500A, voltage 65V, main gas (argon) flow rate 60L / min, nitrogen flow rate 40L / min, powder feed rate 50g / min, spraying distance 120mm, and target coating thickness of approximately 80μm.

[0055] Example 2

[0056] The method for preparing the Raney nickel hydrogen evolution cathode in this embodiment is as follows:

[0057] A 46-mesh nickel mesh (approximately 0.25 mm wire diameter) was selected as the substrate. It was first immersed in a 10 wt% NaOH solution at 80°C for 30 minutes to remove oil stains, then rinsed with deionized water and dried. Subsequently, 200-mesh white corundum was used for sandblasting at a pressure of 0.5 MPa and a distance of 150 mm to obtain a rough surface suitable for coating adhesion.

[0058] Raney nickel (Ni 80 Al 20 Powder and Ti 30 Ni 70 Alloy powders were mixed at a mass ratio of 95:5 to obtain a mixed powder. The mixed powder was then sprayed onto the substrate surface using plasma spraying. The plasma spraying parameters were: current 500A, voltage 65V, main gas (argon) flow rate 60L / min, nitrogen flow rate 40L / min, powder feed rate 50g / min, spraying distance 120mm, and target coating thickness approximately 80μm.

[0059] Example 3

[0060] The method for preparing the Raney nickel hydrogen evolution cathode in this embodiment is as follows:

[0061] A 46-mesh nickel mesh (approximately 0.25 mm wire diameter) was selected as the substrate. It was first immersed in a 10 wt% NaOH solution at 80°C for 30 minutes to remove oil stains, then rinsed with deionized water and dried. Subsequently, 200-mesh white corundum was used for sandblasting at a pressure of 0.5 MPa and a distance of 150 mm to obtain a rough surface suitable for coating adhesion.

[0062] Raney nickel (Ni 80 Al 20 Powder and Zr 35 Ni 65 Alloy powders were mixed at a mass ratio of 95:5 to obtain a mixed powder. The mixed powder was then sprayed onto the substrate surface using plasma spraying. The plasma spraying parameters were: current 500A, voltage 65V, main gas (argon) flow rate 60L / min, nitrogen flow rate 40L / min, powder feed rate 50g / min, spraying distance 120mm, and target coating thickness approximately 80μm.

[0063] Example 4

[0064] The method for preparing the Raney nickel hydrogen evolution cathode in this embodiment is as follows:

[0065] A 46-mesh nickel mesh (approximately 0.25 mm wire diameter) was selected as the substrate. It was first immersed in a 10 wt% NaOH solution at 80°C for 30 minutes to remove oil stains, then rinsed with deionized water and dried. Subsequently, 200-mesh white corundum was used for sandblasting at a pressure of 0.5 MPa and a distance of 150 mm to obtain a rough surface suitable for coating adhesion.

[0066] Raney nickel (Ni 80 Al 20 ) powder and MmNi5 (MmNi 4.6 Sn 0.4 The alloy powder (43% Ce, 23% La, 18% Nd, 5% Pr, 3% Sm and 8% Fe) was mixed at a mass ratio of 95:5 to obtain a mixed powder. The mixed powder was then sprayed onto the substrate surface using plasma spraying. The plasma spraying parameters were: current 500A, voltage 65V, main gas (argon) flow rate 60L / min, nitrogen flow rate 40L / min, powder feed rate 50g / min, spraying distance 120mm, and target coating thickness of approximately 80μm.

[0067] Example 5

[0068] The method for preparing the Raney nickel hydrogen evolution cathode in this embodiment is as follows:

[0069] A 46-mesh nickel mesh (approximately 0.25 mm wire diameter) was selected as the substrate. It was first immersed in a 10 wt% NaOH solution at 80°C for 30 minutes to remove oil stains, then rinsed with deionized water and dried. Subsequently, 200-mesh white corundum was used for sandblasting at a pressure of 0.5 MPa and a distance of 150 mm to obtain a rough surface suitable for coating adhesion.

[0070] Raney nickel (Ni 80 Al20 The powder and LaNi5 alloy powder were mixed at a mass ratio of 99:1 to obtain a mixed powder. The mixed powder was then sprayed onto the substrate surface using plasma spraying. The plasma spraying parameters were: current 500A, voltage 65V, main gas (argon) flow rate 60L / min, nitrogen flow rate 40L / min, powder feed rate 50g / min, spraying distance 120mm, and target coating thickness of approximately 80μm.

[0071] Example 6

[0072] The method for preparing the Raney nickel hydrogen evolution cathode in this embodiment is as follows:

[0073] A 46-mesh nickel mesh (approximately 0.25 mm wire diameter) was selected as the substrate. It was first immersed in a 10 wt% NaOH solution at 80°C for 30 minutes to remove oil stains, then rinsed with deionized water and dried. Subsequently, 200-mesh white corundum was used for sandblasting at a pressure of 0.5 MPa and a distance of 150 mm to obtain a rough surface suitable for coating adhesion.

[0074] Raney nickel (Ni 80 Al 20 The powder and LaNi5 alloy powder were mixed at a mass ratio of 85:15 to obtain a mixed powder. The mixed powder was then sprayed onto the substrate surface using plasma spraying. The plasma spraying parameters were: current 500A, voltage 65V, main gas (argon) flow rate 60L / min, nitrogen flow rate 40L / min, powder feed rate 50g / min, spraying distance 120mm, and target coating thickness approximately 80μm.

[0075] Example 7

[0076] The method for preparing the Raney nickel hydrogen evolution cathode in this embodiment is as follows:

[0077] A 46-mesh nickel mesh (approximately 0.25 mm wire diameter) was selected as the substrate. It was first immersed in a 10 wt% NaOH solution at 80°C for 30 minutes to remove oil stains, then rinsed with deionized water and dried. Subsequently, 200-mesh white corundum was used for sandblasting at a pressure of 0.5 MPa and a distance of 150 mm to obtain a rough surface suitable for coating adhesion.

[0078] Raney nickel (Ni 80 Al 20 The powder and LaNi5 alloy powder were mixed at a mass ratio of 90:10 to obtain a mixed powder. The mixed powder was then sprayed onto the substrate surface using plasma spraying. The plasma spraying parameters were: current 500A, voltage 65V, main gas (argon) flow rate 60L / min, nitrogen flow rate 40L / min, powder feed rate 50g / min, spraying distance 120mm, and target coating thickness of approximately 80μm.

[0079] Comparative Example 1

[0080] The Raney nickel hydrogen evolution cathode in this comparative example is prepared as follows:

[0081] A 46-mesh nickel mesh (approximately 0.25 mm wire diameter) was selected as the substrate. It was first immersed in a 10 wt% NaOH solution at 80°C for 30 minutes to remove oil stains, then rinsed with deionized water and dried. Subsequently, 200-mesh white corundum was used for sandblasting at a pressure of 0.5 MPa and a distance of 150 mm to obtain a rough surface suitable for coating adhesion.

[0082] Raney nickel (Ni 80 Al 20 The powder was sprayed onto the substrate surface using plasma spraying. The plasma spraying parameters were: current 500A, voltage 65V, main gas (argon) flow rate 60L / min, nitrogen flow rate 40L / min, powder feeding rate 50g / min, spraying distance 120mm, and target coating thickness approximately 80μm.

[0083] Comparative Example 2

[0084] The Raney nickel hydrogen evolution cathode in this comparative example is prepared as follows:

[0085] A 46-mesh nickel mesh (approximately 0.25 mm wire diameter) was selected as the substrate. It was first immersed in a 10 wt% NaOH solution at 80°C for 30 minutes to remove oil stains, then rinsed with deionized water and dried. Subsequently, 200-mesh white corundum was used for sandblasting at a pressure of 0.5 MPa and a distance of 150 mm to obtain a rough surface suitable for coating adhesion.

[0086] Raney nickel (Ni 80 Al 20 The powder and pure nickel powder were mixed at a mass ratio of 97:3 to obtain a mixed powder. The mixed powder was then sprayed onto the substrate surface using plasma spraying. The plasma spraying parameters were: current 500A, voltage 65V, main gas (argon) flow rate 60L / min, nitrogen flow rate 40L / min, powder feeding rate 50g / min, spraying distance 120mm, and target coating thickness of approximately 80μm.

[0087] Comparative Example 3

[0088] The Raney nickel hydrogen evolution cathode in this comparative example is prepared as follows:

[0089] Substrate pretreatment: A 46-mesh nickel mesh (approximately 0.25 mm wire diameter) was selected as the substrate. It was first immersed in a 10 wt% NaOH solution at 80°C for 30 minutes to remove oil stains, rinsed with deionized water, and then dried. Subsequently, 200-mesh white corundum was used for sandblasting at a pressure of 0.5 MPa and a distance of 150 mm to obtain a rough surface suitable for coating adhesion.

[0090] Raney nickel (Ni 80 Al 20 The powder and LaNi5 alloy powder were mixed at a mass ratio of 70:30 to obtain a mixed powder. The mixed powder was then sprayed onto the substrate surface using plasma spraying. The plasma spraying parameters were: current 500A, voltage 65V, main gas (argon) flow rate 60L / min, nitrogen flow rate 40L / min, powder feed rate 50g / min, spraying distance 120mm, and target coating thickness of approximately 80μm.

[0091] The following tests were performed on the Raney nickel hydrogen evolution cathodes in each embodiment and comparative example:

[0092] 1. Electrochemical performance testing: In an electrolyte solution of 30wt% KOH at 80℃, using a three-electrode system, linear cyclic voltammetry (LSV) was used to test the electrodes at 5000 A / m. 2 The initial hydrogen evolution overpotential at current density was used to evaluate catalytic activity.

[0093] 2. Accelerated life test (simulating frequent start-stop conditions): The electrode is placed in an electrolyte of 30wt% KOH at 80℃, and subjected to 5000 A / m 2 Constant current electrolysis was performed at a high current density. For every 5 minutes of continuous electrolysis, the reverse current was 10000 A / m. 2 A high-current shock is applied for 30 seconds, constituting a "start-stop cycle". After 100 cycles, the hydrogen evolution overpotential of the test electrode (relative to the saturated calomel reference electrode) and coating changes are measured.

[0094] Table 1 Initial hydrogen evolution overpotential of Raney nickel hydrogen evolution cathode

[0095]

[0096] Table 2. Hydrogen evolution overpotential of Raney nickel hydrogen evolution cathode before and after accelerated experiment

[0097]

[0098] Combining Table 1 and Figure 1Compared to Comparative Example 1, which used only Raney nickel powder to prepare the Raney nickel hydrogen evolution cathode, the Raney nickel hydrogen evolution cathode in Example 1 exhibited a lower overpotential and superior electrochemical performance. Comparative Example 2, which used both pure nickel powder and Raney nickel powder to prepare the Raney nickel hydrogen evolution cathode, showed a higher overpotential than Example 1, indicating inferior electrochemical performance. In Example 3, the mass ratio of Raney nickel powder to LaNi5 alloy powder exceeded the range specified in this invention, specifically exceeding 1%-15% of the modified Raney nickel layer mass for the hydrogen storage alloy powder. The resulting Raney nickel hydrogen evolution cathode exhibited a higher overpotential, indicating that the amount of hydrogen storage alloy powder affects the performance of the Raney nickel hydrogen evolution cathode. Only by using a mixture of Raney nickel alloy powder and hydrogen storage alloy powder within the scope of this invention can the Raney nickel hydrogen evolution cathode be guaranteed to possess excellent electrochemical performance.

[0099] Combined with Table 2, Figures 2-6 Based on the comparison of SEM images and overpotential data before and after the accelerated test, Examples 1 and 4 showed excellent stability: the surface morphology remained intact after the test, with no obvious corrosion or structural damage, and the overpotential was significantly reduced, indicating that its electrochemical performance improved after aging, and it had good stability and activation characteristics; while Comparative Example 1 showed obvious deterioration on the surface after the test, and the overpotential increased significantly, indicating that its structural stability and electrochemical performance decreased significantly under accelerated conditions, and its stability was insufficient.

[0100] It will be apparent to those skilled in the art that this disclosure is not limited to the details of the exemplary embodiments described above, and that this disclosure can be implemented in other specific forms without departing from the spirit or essential characteristics of this disclosure. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of this disclosure is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within this disclosure.

[0101] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A Raney nickel hydrogen evolution cathode, characterized in that, The Raney nickel hydrogen evolution cathode includes a substrate and a modified Raney nickel layer disposed on the surface of the substrate; The raw materials for the modified Raney nickel layer include Raney nickel alloy powder and hydrogen storage alloy powder, wherein the hydrogen storage alloy powder is at least one of LaNi5 series alloy, Ti-Ni series alloy, Zr-Ni series alloy, and Mm-Ni series alloy.

2. The Raney nickel hydrogen evolution cathode according to claim 1, characterized in that, The thickness of the modified Raney nickel layer is 60μm-100μm.

3. The Raney nickel hydrogen evolution cathode according to claim 1, characterized in that, The atomic ratio of nickel to aluminum in the Raney nickel alloy powder is (70-90):(30-10).

4. The Raney nickel hydrogen evolution cathode according to claim 1, characterized in that, The hydrogen storage alloy powder accounts for 1%-15% of the mass of the modified Raney nickel layer.

5. The Raney nickel hydrogen evolution cathode according to claim 1, characterized in that, The Raney nickel alloy powder has a particle size of 15μm-150μm.

6. The Raney nickel hydrogen evolution cathode according to claim 1, characterized in that, The particle size of the hydrogen storage alloy powder is 40μm-90μm.

7. The Raney nickel hydrogen evolution cathode according to claim 1, characterized in that, The substrate is any one of nickel mesh, nickel felt, nickel plate, nickel alloy mesh, nickel alloy felt, and nickel alloy plate.

8. A method for preparing a Raney nickel hydrogen evolution cathode according to claim 1, characterized in that, The preparation method includes the following steps: Raney nickel alloy powder and hydrogen storage alloy powder are mixed to obtain a mixed powder; The mixed powder was sprayed onto the substrate surface using plasma spraying to form a modified Raney nickel layer, thus obtaining a Raney nickel hydrogen evolution cathode.

9. The method for preparing the Raney nickel hydrogen evolution cathode according to claim 8, characterized in that, The plasma spraying operation conditions are as follows: current 400A-650A, voltage 50V-80V, argon flow rate 40L / min-80L / min, nitrogen flow rate 40L / min-60L / min, powder feeding rate 30g / min-80g / min, and spraying distance 100mm-150mm.

10. The method for preparing the Raney nickel hydrogen evolution cathode according to claim 8, characterized in that, The substrate has undergone the following pretreatment: The substrate is subjected to alkaline washing, water washing, drying, and then sandblasting roughening treatment. After sandblasting roughening treatment, the surface roughness of the substrate is 5μm-15μm.

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