Composite electrode material system and preparation method thereof

Abstract

The present application relates to the field of electrode material, in particular to a kind of composite electrode material system and preparation method thereof.The composite electrode material system disclosed in the present application innovatively sets Ni-Mo plating layer and Mo plating layer as moderating layer between Ni substrate and catalyst MoS2, using the affinity between Ni substrate, Ni-Mo plating layer, Mo plating layer, MoS2 layer, can greatly improve the bonding strength between layers, thereby solve the low interface bonding strength of catalyst and substrate, gas overflow easily caused catalyst shedding, poor electrode corrosion resistance and other problems, and then can achieve the effect of prolonging electrode service life.The present application further improves the strength and stability of the composite electrode material system by designing the preparation process and process parameters of the composite electrode material system, and the service life of the prepared composite electrode material system is significantly better than that of ordinary composite electrode.

Description

Technical Field

[0001] This invention relates to the field of electrode materials, and more specifically to a composite electrode material system and its preparation method. Background Technology

[0002] With fossil fuels dwindling and environmental problems becoming increasingly severe, energy issues are a pressing problem that society urgently needs to solve. Therefore, developing clean and efficient green energy has become a current research hotspot.

[0003] Hydrogen energy stands out among numerous green and renewable energy sources due to its clean and efficient characteristics. Among these, water electrolysis plays a crucial role in hydrogen production and is one of the most promising methods for large-scale hydrogen production. However, high energy consumption and the exorbitant cost of precious metal catalysts hinder the further development of water electrolysis. Therefore, developing non-precious metal catalysts with low energy consumption and rapid reaction kinetics is an urgent task.

[0004] In recent years, hydrogen evolution electrode materials have shifted from transition metal alloys to transition metal oxides and then to transition metal compounds (transition metal phosphides (TMPs), sulfides (TMDs), carbides (TMCs), and nitrides (TMNs)). Numerous studies have shown that transition metal sulfides (TMDs) possess good hydrogen evolution catalytic activity. Among them, MoS2 exhibits unique optical, electrical, and magnetic properties, and compared to other materials, it has higher conductivity, leading to its widespread application in electrode materials, sensors, and many other fields.

[0005] Common methods for preparing MoS2 materials include electrodeposition, thermal coating decomposition, hydrothermal, and solvothermal methods. However, these methods all have problems to varying degrees, such as low bonding strength between the catalyst and the substrate, easy shedding of active materials, poor corrosion resistance, limited lifespan, and inability to produce on a large scale. Summary of the Invention

[0006] To address the problems existing in the prior art, this invention provides a composite electrode material system and its preparation method, specifically including the following:

[0007] A composite electrode material system includes a Ni substrate, a Ni-Mo coating disposed on the Ni substrate, a Mo coating disposed on the Ni-Mo coating, and a MoS2 layer disposed on the Mo coating; the thickness of the Ni-Mo coating is 100-1000 nm (e.g., 102 nm, 120 nm, 150 nm, 180 nm, 200 nm, 500 nm, 800 nm, 900 nm, etc.); the thickness of the Mo coating is 1-10 μm (e.g., 1.2 μm, 2 μm, 4 μm, 6 μm, 8 μm, 9 μm, etc.). The composite electrode material system disclosed in this invention innovatively sets a Ni-Mo coating and a Mo coating as a buffer layer between the Ni substrate and the catalyst MoS2. By utilizing the affinity between the Ni substrate, Ni-Mo coating, Mo coating and MoS2 layer, the bonding strength between the layers can be greatly improved, thereby solving the problems of low bonding strength between the catalyst and the substrate interface, easy catalyst detachment caused by gas overflow, and poor electrode corrosion resistance, and thus achieving the effect of extending the working life of the electrode.

[0008] Preferably, the Ni substrate is foamed Ni, Ni mesh, or Ni fiber felt. Choosing foamed Ni, Ni mesh, or Ni fiber felt as the Ni substrate helps to further improve the bonding strength between the Ni substrate and the Ni-Mo coating.

[0009] Preferably, the mass ratio of Ni to Mo in the Ni-Mo coating is (30%-90%):(10%-70%), for example, 3:7, 2:3, 1:1, 3:2, 7:3, 4:1, 9:1, etc. The ratio of Ni to Mo in the Ni-Mo coating has a significant impact on improving the bonding strength between the Ni substrate and the Ni-Mo coating, and the ratio disclosed in this invention is the preferred optimal ratio.

[0010] A method for preparing a composite electrode material system includes the following steps:

[0011] (1) Ni matrix pretreatment: Wash the matrix and then dry the Ni matrix after washing;

[0012] (2) Sputtering Ni-Mo coating: Using nickel-molybdenum alloy as the target material, a layer of metallic Ni-Mo coating is sputtered on the Ni substrate;

[0013] (3) Sputtered Mo coating: Using Mo as the target material, a layer of metallic Mo coating is sputtered on the outside of the Ni-Mo coating to obtain a composite substrate;

[0014] (4) Heat treatment strengthening: The composite matrix is ​​placed in a heating device and heated to 300-800℃ (e.g., 350℃, 400℃, 500℃, 600℃, 700℃, 750℃, etc.) at a certain heating rate for the first heat treatment, the heat treatment time is 10-60min (e.g., 12min, 15min, 20min, 30min, 40min, 50min, etc.); then the temperature is raised to 800-1200℃ (e.g., 820min, 850min, 900min, 950min, 1000min, 1100min, etc.) for the second heat treatment, the heat treatment time is 10-60min (e.g., 12min, 15min, 20min, 30min, 40min, 50min, etc.) to obtain the strengthened composite matrix;

[0015] (5) Coating sulfidation: Sulfur is added to the heating equipment described in step (4), and the reinforced composite substrate is heated together with sulfur to 400-800℃ (e.g., 420℃, 450℃, 500℃, 550℃, 600℃, 700℃, etc.) in N2 atmosphere, and kept at this temperature for 1-10h (e.g., 2h, 3h, 5h, 7h, 9h, 9.5h, etc.) to obtain the sulfidated composite electrode;

[0016] (6) Annealing: The sulfurized composite electrode is cooled and annealed to obtain the composite electrode material system.

[0017] Preferably, the specific operation method of step (1) is as follows: the Ni substrate is washed 3-10 times sequentially with 0.1-30% dilute hydrochloric acid, deionized water and anhydrous ethanol, and then the washed Ni substrate is dried in a vacuum oven at 50-80℃. The purpose of washing is to remove impurities on the surface of the Ni substrate, so that the subsequent coating is more tightly bonded to the substrate and the coating is less likely to fall off.

[0018] Preferably, the sputtering method in step (2) is as follows: A high vacuum magnetron sputtering device is used to sputter the coating. First, a nickel-molybdenum alloy with a Ni / Mo mass ratio of (30%-90%):(10%-70%) is mounted on the magnetron target of the high vacuum magnetron sputtering device. The Ni substrate is placed on the heating stage, and the distance between the substrate and the target is controlled to be 1-30cm (e.g., 5cm, 10cm, 15cm, 18cm, 20cm, 25cm, etc.). Then, the vacuum chamber cover is closed, and a vacuum is drawn until the vacuum degree is less than 5×10⁻⁶. -4 Pa, argon gas with a purity of 99.99% and a flow rate of 1-100 sccm is introduced, and the working gas pressure is controlled at 0.1-10 Pa (e.g. 0.5 Pa, 1 Pa, 2 Pa, 4 Pa, 6 Pa, 8 Pa, etc.) to sputter Ni-Mo coating in DC magnetron sputtering mode.

[0019] Preferably, the method for sputtering Ni-Mo coating in DC magnetron sputtering mode is as follows: first, pre-sputter for 5-30 minutes (e.g., 10 minutes, 15 minutes, 20 minutes, 25 minutes, etc.) at a bias voltage of -50V and a power of 50-100W (e.g., 60W, 70W, 80W, 90W, etc.), and then sputter for 5-60 minutes to deposit Ni-Mo layer (e.g., 10 minutes, 20 minutes, 30 minutes, 40 minutes, 50 minutes, etc.).

[0020] Preferably, the specific method for sputtering the Mo coating in step (3) is as follows: sputtering the Mo coating in DC magnetron sputtering mode, first pre-sputtering for 5-30 minutes (e.g., 10 minutes, 15 minutes, 20 minutes, 25 minutes, etc.) at a bias voltage of -50V and a power of 50-100W (e.g., 60W, 70W, 80W, 90W, etc.), and then sputtering the Mo coating for 10-100 minutes (e.g., 10 minutes, 20 minutes, 30 minutes, 40 minutes, 50 minutes, 60 minutes, 80 minutes, 90 minutes, etc.).

[0021] Preferably, the heating device in step (4) is a tubular furnace, the heating rate of the first heat treatment is 2-30℃ / min (e.g., 4℃ / min, 8℃ / min, 10℃ / min, 15℃ / min, 20℃ / min, 25℃ / min, etc.), and the heating rate of the second heat treatment is 2-15℃ / min (e.g., 4℃ / min, 6℃ / min, 8℃ / min, 10℃ / min, 12℃ / min, 14℃ / min, etc.).

[0022] Preferably, the specific operation of the coating sulfidation in step (5) is as follows: the reinforced composite substrate is placed on the downstream side of the tubular furnace, and 5-100mg (e.g., 10mg, 30mg, 50mg, 80mg, 90mg, etc.) of sulfur powder is loaded into a quartz boat and placed on the upstream side of the tubular furnace; then, in a N2 atmosphere, it is heated to 400-800℃ (e.g., 450℃, 500℃, 550℃, 600℃, 700℃, etc.) at a heating rate of 1-10℃ / min (e.g., 2℃ / min, 4℃ / min, 6℃ / min, 8℃ / min, etc.) and held for 1-10h (e.g., 2h, 4h, 6h, 8h, etc.).

[0023] The beneficial effects of this invention are:

[0024] (1) The composite electrode material system disclosed in this invention innovatively sets Ni-Mo coating and Mo coating as a buffer layer between Ni substrate and catalyst MoS2. By utilizing the affinity between Ni substrate, Ni-Mo coating, Mo coating and MoS2 layer, the bonding strength between layers can be greatly improved, thereby solving the problems of low bonding strength between catalyst and substrate interface, easy catalyst detachment caused by gas overflow, and poor electrode corrosion resistance, and thus achieving the effect of extending electrode working life.

[0025] (2) In the composite electrode material system disclosed in this invention, by designing the thickness and composition of the intermediate coating, the thickness of the Ni-Mo coating is limited to 100-1000 nm, the thickness of the Mo coating is 1-10 μm, and the mass ratio of Ni to Mo in the Ni-Mo coating is (30%-90%):(10%-70%), which maximizes the strength of each layer and the bonding strength between each layer, which is beneficial to improving the stability of the composite electrode material system.

[0026] (3) By designing the preparation process and process parameters of the composite electrode material system, this invention further improves the strength and stability of the composite electrode material system, and the service life of the prepared composite electrode material system is significantly better than that of ordinary composite electrodes. Attached Figure Description

[0027] Figure 1 A schematic diagram of the structure of a foamed Ni-based composite electrode material;

[0028] Figure 2 This is a schematic diagram of the Ni-based composite electrode material structure.

[0029] Figure 3 This is a schematic diagram of the structure of a Ni fiber felt-based composite electrode material. Detailed Implementation

[0030] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. The embodiments shown below do not limit the scope of the invention as described in the claims. Furthermore, the complete contents of the configurations illustrated in the following embodiments are not limited to those necessary for the solution of the invention as described in the claims.

[0031] Example 1

[0032] A method for preparing a foamed Ni-based composite electrode material system includes the following steps:

[0033] (1) The substrate (foamed Ni) was washed five times in sequence with 0.1-30% dilute hydrochloric acid, deionized water and anhydrous ethanol and then dried in a vacuum oven at 60°C.

[0034] (2) Install the Ni-Mo (Ni:Mo = 80%: 20%) alloy target onto the magnetron target of the ultra-high vacuum magnetron sputtering equipment;

[0035] (3) Place the cleaned substrate (foamed Ni) on the heating table and control the distance between the substrate and the target to be 15cm;

[0036] (4) Cover the vacuum chamber with the lid;

[0037] (5) Evacuate the vacuum until the vacuum level is less than 5 × 10⁻⁶. -4 Pa;

[0038] (6) Introduce argon gas with a purity of 99.99% and a flow rate of 50 sccm, and control the working pressure to 5 Pa;

[0039] (7) Ni-Mo layer deposition under DC magnetron sputtering mode: First, pre-sputter for 15 min at a bias voltage of -50V and a power of 70W, then sputter for 30 min to deposit Ni-Mo layer, controlling the thickness to 500nm;

[0040] (8) Mo layer deposition under DC magnetron sputtering mode: First, pre-sputter for 15 min at a bias voltage of -50V and a power of 70W, then sputter for 100 min to deposit the Mo layer, and control the thickness to 2μm;

[0041] (9) After the Mo layer is deposited, the cavity is allowed to cool naturally to room temperature, the argon gas supply is stopped, the vent valve is opened, and the sample is taken out.

[0042] (10) After heat treatment, 20 mg of sulfur powder was loaded into a quartz boat and placed on the tube furnace for flow measurement (the substrate was placed on the bottom for flow measurement).

[0043] (11) In a N2 atmosphere, the heating rate is 5℃ / min, and the temperature is raised to 400-800℃ and held for 1-10h;

[0044] (12) First, heat-treat in a tube furnace at 300-800℃ for 30 minutes at a heating rate of 10℃ / min to increase the interfacial bonding strength between the coating and the substrate material; then heat-treat in a tube furnace at 800-1200℃ for 30 minutes at a heating rate of 5℃ / min to obtain the coating as shown in the attached figure. Figure 1 The aforementioned composite electrode material system.

[0045] Example 2

[0046] A method for preparing a Ni mesh-based composite electrode material system includes the following steps:

[0047] (1) The substrate (Ni mesh) was washed five times in sequence with 0.1-30% dilute hydrochloric acid, deionized water and anhydrous ethanol and then dried in a vacuum oven at 60°C.

[0048] (2) Install the Ni-Mo (Ni:Mo = 80%: 20%) alloy target onto the magnetron target of the ultra-high vacuum magnetron sputtering equipment;

[0049] (3) Place the cleaned substrate (Ni mesh) on the heating table and control the distance between the substrate and the target to be 15cm;

[0050] (4) Cover the vacuum chamber with the lid;

[0051] (5) Evacuate the vacuum until the vacuum level is less than 5 × 10⁻⁶. -4 Pa;

[0052] (6) Introduce argon gas with a purity of 99.99% and a flow rate of 50 sccm, and control the working pressure to 5 Pa;

[0053] (7) Ni-Mo layer deposition under DC magnetron sputtering mode: First, pre-sputter for 15 min at a bias voltage of -50V and a power of 70W, then sputter for 30 min to deposit Ni-Mo layer, controlling the thickness to 500nm;

[0054] (8) Mo layer deposition under DC magnetron sputtering mode: First, pre-sputter for 15 min at a bias voltage of -50V and a power of 70W, then sputter for 100 min to deposit the Mo layer, and control the thickness to 2μm;

[0055] (9) After the Mo layer is deposited, the cavity is allowed to cool naturally to room temperature, the argon gas supply is stopped, the vent valve is opened, and the sample is taken out.

[0056] (10) After heat treatment, 20 mg of sulfur powder was loaded into a quartz boat and placed on the tube furnace for flow measurement (the substrate was placed on the bottom for flow measurement).

[0057] (11) In a N2 atmosphere, the heating rate is 5℃ / min, and the temperature is raised to 400-800℃ and held for 1-10h;

[0058] (12) First, heat-treat in a tube furnace at 300-800℃ for 30 minutes at a heating rate of 10℃ / min to increase the interfacial bonding strength between the coating and the substrate material; then heat-treat in a tube furnace at 800-1200℃ for 30 minutes at a heating rate of 5℃ / min to obtain the coating as shown in the attached figure. Figure 2 The aforementioned composite electrode material system.

[0059] Example 3

[0060] A method for preparing a Ni fiber felt-based composite electrode material system includes the following steps:

[0061] (1) The substrate (Ni fiber felt) was washed five times in sequence with 0.1-30% dilute hydrochloric acid, deionized water and anhydrous ethanol and then dried in a vacuum oven at 60°C.

[0062] (2) Install the Ni-Mo (Ni:Mo = 80%: 20%) alloy target onto the magnetron target of the ultra-high vacuum magnetron sputtering equipment;

[0063] (3) Place the cleaned substrate (Ni fiber felt) on the heating table and control the distance between the substrate and the target to be 15cm;

[0064] (4) Cover the vacuum chamber with the lid;

[0065] (5) Evacuate the vacuum until the vacuum level is less than 5 × 10⁻⁶. -4 Pa;

[0066] (6) Introduce argon gas with a purity of 99.99% and a flow rate of 50 sccm, and control the working pressure to 5 Pa;

[0067] (7) Ni-Mo layer deposition under DC magnetron sputtering mode: First, pre-sputter for 15 min at a bias voltage of -50V and a power of 70W, then sputter for 30 min to deposit Ni-Mo layer, controlling the thickness to 500nm;

[0068] (8) Mo layer deposition under DC magnetron sputtering mode: First, pre-sputter for 15 min at a bias voltage of -50V and a power of 70W, then sputter for 100 min to deposit the Mo layer, and control the thickness to 2μm;

[0069] (9) After the Mo layer is deposited, the cavity is allowed to cool naturally to room temperature, the argon gas supply is stopped, the vent valve is opened, and the sample is taken out.

[0070] (10) After heat treatment, 20 mg of sulfur powder was loaded into a quartz boat and placed on the tube furnace for flow measurement (the substrate was placed on the bottom for flow measurement).

[0071] (11) In a N2 atmosphere, the heating rate is 5℃ / min, and the temperature is raised to 400-800℃ and held for 1-10h;

[0072] (12) First, heat-treat in a tube furnace at 300-800℃ for 30 minutes at a heating rate of 10℃ / min to increase the interfacial bonding strength between the coating and the substrate material; then heat-treat in a tube furnace at 800-1200℃ for 30 minutes at a heating rate of 5℃ / min to obtain the coating as shown in the attached figure. Figure 3 The aforementioned composite electrode material system.

[0073] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A composite electrode material system, characterized in that, It includes a Ni substrate, a Ni-Mo coating disposed on the Ni substrate, a Mo coating disposed on the Ni-Mo coating, and a MoS2 layer disposed on the Mo coating; the thickness of the Ni-Mo coating is 100-1000 nm; and the thickness of the Mo coating is 1-10 μm.

2. The composite electrode material system according to claim 1, characterized in that, The Ni substrate is Ni foam, Ni mesh, or Ni fiber felt.

3. The composite electrode material system according to claim 1, characterized in that, The mass ratio of Ni to Mo in the Ni-Mo coating is (30%-90%):(10%-70%).

4. A method for preparing the composite electrode material system according to any one of claims 1-3, characterized in that, Includes the following steps: (1) Ni matrix pretreatment: Wash the Ni matrix and then dry it after washing. (2) Sputtering Ni-Mo coating: Using nickel-molybdenum alloy as the target material, a layer of metallic Ni-Mo coating is sputtered on the Ni substrate; (3) Sputtered Mo coating: Using Mo as the target material, a layer of metallic Mo coating is sputtered on the outside of the Ni-Mo coating to obtain a composite substrate; (4) Heat treatment strengthening: The composite matrix is ​​placed in a heating device and heated to 300-800℃ at a certain heating rate for the first heat treatment, which takes 10-60 minutes; then the temperature is raised to 800-1200℃ for the second heat treatment, which takes 10-60 minutes, to obtain the strengthened composite matrix. (5) Coating sulfidation: Sulfur is added to the heating equipment described in step (4), and the reinforced composite substrate is heated together with sulfur to 400-800℃ in N2 atmosphere and kept at the temperature for 1-10h to obtain the sulfidated composite electrode. (6) Annealing: The sulfurized composite electrode is cooled and annealed to obtain the composite electrode material system.

5. The method for preparing a composite electrode material system according to claim 4, characterized in that, The specific operation method of step (1) is as follows: wash the Ni substrate with 0.1-30% dilute hydrochloric acid, deionized water and anhydrous ethanol 3-10 times in sequence, and then dry the washed Ni substrate in a vacuum oven at 50-80℃.

6. The method for preparing a composite electrode material system according to claim 4, characterized in that, The sputtering method in step (2) is as follows: A high vacuum magnetron sputtering equipment is used to sputter the coating. First, a nickel-molybdenum alloy with a Ni / Mo mass ratio of (30%-90%):(10%-70%) is mounted on the magnetron target of the high vacuum magnetron sputtering equipment. The Ni substrate is placed on the heating stage, and the distance between the substrate and the target is controlled to be 1-30 cm. Then, the vacuum chamber cover is closed, and a vacuum is drawn until the vacuum degree is less than 5 × 10⁻⁶. -4 Pa, argon gas with a purity of 99.99% and a flow rate of 1-100 sccm is introduced, and the working gas pressure is controlled at 0.1-10 Pa. Ni-Mo coating is sputtered in DC magnetron sputtering mode.

7. The method for preparing a composite electrode material system according to claim 6, characterized in that, The method for sputtering Ni-Mo coatings in DC magnetron sputtering mode is as follows: first, pre-sputter for 5-30 minutes at a bias voltage of -50V and a power of 50-100W, and then sputter for 5-60 minutes to deposit the Ni-Mo layer.

8. The method for preparing a composite electrode material system according to claim 4, characterized in that, The specific method for sputtering the Mo coating in step (3) is as follows: sputter the Mo coating in DC magnetron sputtering mode, first pre-sputter for 5-30 minutes at a bias voltage of -50V and a power of 50-100W, and then sputter for 10-100 minutes to deposit the Mo coating.

9. The method for preparing a composite electrode material system according to claim 4, characterized in that, The heating device in step (4) is a tube furnace. The heating rate of the first heat treatment is 2-30℃ / min, and the heating rate of the second heat treatment is 2-15℃ / min.

10. The method for preparing a composite electrode material system according to claim 4, characterized in that, The specific operation of the coating sulfidation in step (5) is as follows: the reinforced composite substrate is placed on the downstream side of the tube furnace, 5-100mg of sulfur powder is loaded into a quartz boat and placed on the upstream side of the tube furnace; then, in a N2 atmosphere, it is heated to 400-800℃ at a heating rate of 1-10℃ / min and kept at that temperature for 1-10h.

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