Preparation method of electrode plate

Abstract

The invention discloses a preparation method of an electrode plate. The preparation method comprises the following steps: pre-treating a base material; preparing an agent A and an agent B; the pretreated base material is placed in a container, the container comprises a liquid storage box and a latticed mold, the agent B and the agent A are sequentially added, heating is conducted, and an electrode plate base plate is obtained; electro-deposition liquid is prepared; placing the electrode slice substrate in a container, and adding an electro-deposition liquid; the surface of the electrode plate is yellow green, and the electrode plate has uniformly distributed latticed appearance, and has the advantages of high catalytic activity, low energy consumption and the like when being applied to water electrolysis hydrogen production.

Description

Technical Field

[0001] This invention relates to the field of hydrogen production technology through water electrolysis, specifically to the field of catalyst technology for oxygen production through water electrolysis, and particularly to a method for preparing an electrode sheet. Background Technology

[0002] Currently, humanity faces severe energy problems and environmental challenges, including increased demand for energy resources due to global population growth, global warming and climate change, and severe industrial pollution. In response, people are focusing on the development and utilization of clean and renewable energy sources, such as wind power, hydropower, and solar energy. Although these energy supplies are green, environmentally friendly, and renewable, their practical use is subject to many limitations, such as seasons and climate, often making it difficult to meet people's needs for a stable energy supply.

[0003] Compared to the large amounts of greenhouse gases produced by the combustion of carbon in organic fossil fuels, hydrogen is considered the most promising energy carrier, with its only combustion product being water, and its energy density being more than three times that of gasoline. Achieving the conversion between water and hydrogen energy could significantly address both the energy crisis and environmental pollution problems. Among hydrogen production methods, electrochemical water splitting can achieve a stable and green conversion from electrical energy to chemical energy. This process can help people better utilize intermittent energy sources such as wind and hydropower, thus attracting widespread research interest. Currently, only 4% of total hydrogen production comes from green hydrogen produced by water splitting. The main reason for this is that the low hydrogen energy conversion efficiency severely restricts the industrialization of hydrogen production through water electrolysis. Furthermore, in actual electrolysis, precious metal electrocatalysts are usually required to reduce the activation energy barrier involved in water splitting. Therefore, developing low-cost, abundant, and highly reactive electrocatalysts for hydrogen production through water electrolysis is of significant research importance.

[0004] To date, the hydrogen evolution catalysts used in industrial alkaline electrolyzers are generally nickel mesh with a coating (Raney nickel), which has poor performance, with current densities typically ranging from 2000 to 4000 A / m at a chamber voltage of 2V. 2 This results in high energy consumption for water electrolysis equipment; the DC energy consumption of the electrolyzer is generally greater than 4.5 kWh / Nm³. 3 H2. Therefore, if a low-energy-consumption, high-performance hydrogen evolution catalyst suitable for large-scale water electrolysis equipment can be developed, we can strive to achieve large-scale, economical, and green oxygen production as soon as possible. Summary of the Invention

[0005] In view of the shortcomings of the prior art described above, the purpose of this invention is to provide a method for preparing an electrode sheet to solve the problems of low catalytic activity, high energy consumption and poor stability of alkaline water electrolysis oxygen production catalysts in the prior art.

[0006] To achieve the above and other related objectives, the present invention provides a method for preparing an electrode sheet.

[0007] An electrolytic oxygen production catalyst is provided, wherein the catalyst is a nickel-iron-based multi-element alloy with an ordered nanowire or nanochain microstructure, wherein the diameter of the nanowire or nanochain is 0.1–2.0 μm and the length is 0.1–200 μm; the catalyst comprises the following components by mass percentage: 85%–95% Ni, 4.98%–14.98% Fe, and the remainder being noble metals or transition metals.

[0008] Optionally, the noble metal or transition metal is selected from at least one of platinum, ruthenium, and molybdenum.

[0009] Optionally, the microstructure characteristics of the obtained catalyst include: nanowires grown vertically on a substrate with a diameter of 0.1–1.2 μm; the nanowires include a first part and a second part, the first part being a framework part, the framework part including nickel-platinum nanowires "stacked" from nanoparticles with a length of 0.1–0.6 μm; the second part including honeycomb nanowires assembled from nickel-iron nanosheets based on the framework part with a length of 0.1–100 μm.

[0010] Alternatively, the resulting catalyst is yellow-green.

[0011] A second aspect of the present invention provides an electrode sheet for producing oxygen by water electrolysis, the electrode sheet comprising a substrate on which an electrolytic hydrogen production catalyst as described in the first aspect is loaded, and nanowires or nanochains are orderly distributed on the substrate.

[0012] Optionally, the substrate can be any one of nickel foam, nickel mesh, or carbon cloth.

[0013] Optionally, the electrode sheet is square or circular.

[0014] Optionally, the area of ​​the substrate is ≥0.5m². 2 Preferably ≥1.0m 2 More preferably, it is 1.0 to 5.0 m. 2 .

[0015] Optionally, the catalyst supported on the substrate is in a mesh-like structure.

[0016] Optionally, the mesh size of the mesh catalyst supported on the substrate is 5 to 12 cm.

[0017] A second aspect of the present invention provides the application of an electrode sheet for oxygen production by water electrolysis as described in the first aspect and / or for oxygen production by water electrolysis as described in the second aspect, wherein the electrode sheet is used in alkaline water electrolysis for hydrogen production.

[0018] As described above, the electrolytic water oxygen production catalyst, electrode sheet, and their applications of the present invention have the following beneficial effects:

[0019] This invention provides a novel oxygen-generating catalyst, which is a nickel-iron-based multi-element alloy with an ordered nanowire or nanochain microstructure. The nanowires or nanochains have a diameter of 0.1–2.0 μm and a length of 0.1–200 μm. The catalyst comprises the following components by mass percentage: 85%–95% Ni, 4.98%–14.98% Fe, and the remainder being noble metals or transition metals. This invention also provides a novel oxygen-generating electrode sheet, comprising a substrate on which the catalyst is loaded. The electrode sheet has a yellow-green surface with a uniformly distributed mesh-like appearance. Compared to traditional electrode sheets with a "nickel mesh + plating" structure, the oxygen-generating catalyst and electrode sheet provided by this invention exhibit higher catalytic activity, lower energy consumption, and better stability when applied to alkaline water electrolysis for oxygen production. In summary, the catalyst and electrode sheet provided by this invention have extremely high application value in the field of water electrolysis for oxygen production, especially in alkaline water electrolysis for oxygen production, and are conducive to promoting the development of alkaline water electrolysis for oxygen production technology. Attached Figure Description

[0020] Figure 1 The diagram shown is a structural schematic of the mesh mold used in an embodiment of the present invention.

[0021] Figure 2 The image shown is an external view of the electrode substrate prepared in Embodiment 1 of the present invention.

[0022] Figure 3 The image shown is an external view of the electrode sheet prepared in Embodiment 1 of the present invention.

[0023] Figure 4 The image shown is an SEM image of the catalyst on the electrode substrate prepared in Example 1 of this invention.

[0024] Figure 5 The image shown is an SEM image of the catalyst on the electrode sheet prepared in Example 1 of this invention.

[0025] Figure 6 The diagram shows a performance comparison between the electrode sheet obtained in Example 1 of this invention and a traditional alkaline electrode sheet.

[0026] Figure 7 The image shows a comparison of the electrochemical test results of the electrode sheet obtained in Example 1 of this invention and a traditional alkaline electrode sheet. Detailed Implementation

[0027] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention.

[0028] To address the problems of low catalytic activity and high energy consumption of traditional electrode sheets ("nickel mesh + plating" structure) used in current industrial alkaline electrolyzers, this invention provides a novel water electrolysis oxygen production catalyst and electrode sheet. The catalyst is a nickel-iron based multi-element alloy with an ordered nanowire or nanochain microstructure. The diameter of the nanowires or nanochains is 0.1–2.0 μm, and the length is 0.1–200 μm. The catalyst comprises the following components by mass percentage: 85%–95% Ni, 4.98%–14.98% Fe, and the remainder being noble metals or transition metals.

[0029] In another specific embodiment of the present invention, the catalyst comprises at least one of the noble metal or transition metal, ruthenium, and molybdenum, and includes the following components in mass percentage: 85%–95% Ni, 0.02%–10.2% (Pt / Ru / Mo), and 4.98%–14.98% Fe. Wherein, “ / ” represents “and / or”.

[0030] In another specific embodiment of the present invention, the microstructure characteristics of the obtained catalyst include: nanowires grown vertically on a substrate with a diameter of 0.1 to 1.2 μm; the nanowires include a first part and a second part, the first part being a framework part, the framework part including nickel-platinum nanowires "stacked" from nanoparticles with a length of 0.1 to 0.6 μm; the second part including honeycomb nanowires assembled from nickel-iron nanosheets based on the framework part with a length of 0.1 to 100 μm.

[0031] In another specific embodiment of the present invention, the obtained catalyst is yellow-green.

[0032] In one specific embodiment of the present invention, the electrode sheet includes a substrate on which an electrolytic hydrogen production catalyst as described in the first aspect is loaded, and nanowires or nanochains are orderly distributed on the substrate.

[0033] In another specific embodiment of the present invention, the substrate is any one of nickel foam, nickel mesh, and carbon cloth.

[0034] In another specific embodiment of the present invention, the electrode sheet is square or circular.

[0035] In another specific embodiment of the present invention, the area of ​​the substrate is ≥0.5m².2 Preferably ≥1.0m 2 More preferably, it is 1.0 to 5.0 m. 2 .

[0036] In another specific embodiment of the present invention, the catalyst supported on the substrate is in the form of a mesh.

[0037] In another specific embodiment of the present invention, the mesh size of the mesh catalyst supported on the substrate is 5 to 12 cm.

[0038] In a specific embodiment of the present invention, the method for preparing the catalyst and electrode sheet described in the above embodiments includes in-situ growth and electrodeposition of the catalyst, wherein the in-situ growth of the catalyst includes the following steps:

[0039] (1) Pretreatment of the substrate;

[0040] (2) Prepare reagent A and reagent B. Reagent A includes the following four raw materials: soluble nickel salt, soluble noble metal / transition metal salt, soluble sodium salt, and soluble base. The molar concentration ratio of the four raw materials in reagent A is (1.5~3.0):(0.001~0.02):(1.2~1.9):(0.04~0.09). Reagent B includes the following two raw materials: hydrazine hydrate and soluble base. The molar concentration ratio of the two raw materials in reagent B is (1.2~1.9):0.01.

[0041] (3) Place the pretreated substrate in a container, add the B agent and A agent in sequence, heat, and grow the catalyst in situ on the substrate to obtain the electrode sheet substrate.

[0042] The electrodeposition of the catalyst includes the following steps:

[0043] (I) Prepare an electrodeposition solution, wherein the electrodeposition solution comprises the following two raw materials: soluble nickel salt and soluble ferrous salt, and the molar concentration ratio of the two raw materials in the electrodeposition solution is (0.6-1):(0.01-0.1);

[0044] (II) The electrode substrate is placed in a container, an electrodeposition solution is added, and a catalyst is grown on the electrode substrate by electrodeposition to obtain an electrode sheet.

[0045] The catalyst comprises the following components by mass percentage. In a specific embodiment of the present invention, in steps (3) and (II), the container comprises a liquid storage box and a mesh mold (e.g. Figure 1As shown), the substrate / electrode sheet is first placed flat in the storage box, then the grid-shaped mold is placed on the substrate, and then B / A reagent / electrodeposition solution is added for in-situ growth / electrodeposition to form a grid-shaped catalyst on the surface of the substrate / electrode sheet, thus obtaining a grid-shaped electrode sheet. The electrode sheet substrate obtained in step (3) is black, and the electrode sheet obtained in step (II) is yellow-green.

[0046] In this embodiment, a mold method is used to prepare a grid-shaped catalyst and electrode sheet. The large sheet is divided into several small sheets by a grid-shaped mold, which can ensure that the catalyst remains uniform.

[0047] Furthermore, the mesh mold is made of acid and alkali resistant plastic, which includes, but is not limited to, polypropylene, polyethylene, and polytetrafluoroethylene.

[0048] Furthermore, the area of ​​the substrate is ≥0.5m². 2 Preferably ≥1.0m 2 More preferably, it is 1.0 to 5.0 m. 2 The mesh size of the grid-like mold is 5-12 cm. The mold method used in this embodiment is very suitable for preparing large-size electrode sheets using large-size substrates. It is simple to operate, highly efficient, and produces electrode sheets with uniform catalyst distribution and high product quality.

[0049] Further, the difference between the depth of the liquid storage box and the height of the mesh mold is 5.5 to 11.5 cm; preferably, the depth of the liquid storage box is 6 to 12 cm and the height of the mesh mold is 0.5 to 1.5 cm.

[0050] The containers mentioned in Examples 1-4 listed below include liquid storage boxes and mesh molds (such as...). Figure 1 As shown above, those skilled in the art should know how to operate and use it, and how to adjust and design the size of the liquid storage box and the grid mold according to the size of the substrate, so no further explanation is needed.

[0051] In a specific embodiment of the present invention, step (1) of the pretreatment process for the substrate includes: leveling and cleaning the substrate. Specifically, the equipment used for leveling the substrate is selected from cold press and / or roller press; the method of cleaning the substrate includes: treatment with an air knife or soaking in a detergent containing a cleaning agent; the cleaning agent added for cleaning the substrate is selected from surfactants, anhydrous ethanol, and dilute acid solution, wherein the surfactant is selected from anionic surfactants, preferably fatty acid salt anionic surfactants, and the concentration of the dilute sulfuric acid solution is 5% to 20%; when using the above cleaning agent, the concentration of the cleaning agent in the detergent is 0.5% to 20%, and the solvent is preferably water, such as pure water, ultrapure water, etc.

[0052] In a specific embodiment of the present invention, in step (2), the soluble nickel salt is selected from at least one of nickel acetate, nickel chloride, nickel nitrate, nickel citrate, and nickel sulfate; the soluble noble metal / transition metal salt is selected from at least one of soluble platinum salt, soluble ruthenium salt, and molybdate; the soluble platinum salt is selected from at least one of ferrous nitrate, ferrous chloride, ferrous sulfate, and ferrous citrate; the soluble ruthenium salt is selected from ruthenium chloride; the soluble sodium salt is selected from at least one of sodium chloride, sodium sulfate, sodium sulfite, sodium citrate, and sodium nitrate; and the soluble alkali is selected from at least one of sodium hydroxide, potassium hydroxide, and ammonium bicarbonate.

[0053] In a specific embodiment of the present invention, in step (2), the solvent used to prepare the A agent and the B agent is water, including but not limited to pure water, ultrapure water, deionized water, tap water, etc.

[0054] In a specific embodiment of the present invention, step (2) further includes: heating and keeping warm after the preparation of the A agent and the B agent is completed, with the heating and keeping warm temperature being 50 to 100°C.

[0055] In a specific embodiment of the present invention, in step (3), the volume ratio of agent B to agent A is (1-2):(0.8-1.5).

[0056] In a specific embodiment of the present invention, in step (3), the heating temperature is 80-90°C, and after heating to the preset temperature, the holding time is 60-420 min, preferably 120-360 min.

[0057] In one specific embodiment of the present invention, the preparation method further includes: (4) drying the electrode substrate obtained in step (3), including but not limited to hanging and draining, and baking. Specifically, when the electrode substrate is dried by hanging and draining, the hanging time is 8 to 24 hours; when the electrode is dried by baking, the baking temperature is 30 to 60°C.

[0058] In one specific embodiment of the present invention, in step (I), the soluble nickel salt is selected from at least one of nickel acetate, nickel chloride, nickel nitrate, nickel citrate and nickel sulfate, and the soluble ferrous salt is selected from at least one of ferrous nitrate, ferrous chloride, ferrous sulfate and ferrous citrate.

[0059] In a specific embodiment of the present invention, in step (I), the preparation method of the electrodeposition solution includes: adding soluble nickel salt and soluble ferrous salt to a solvent in sequence and stirring thoroughly to mix evenly; preferably, the mixing time is 1 to 20 minutes, and the solvent used to prepare the electrodeposition solution is water, including but not limited to pure water, ultrapure water, deionized water, tap water, etc.

[0060] In one specific embodiment of the present invention, in step (II), the electrodeposition process conditions include: using the electrode substrate as the cathode, and a current density of 10–100 mA / cm². 2 The electrodeposition method is periodic deposition, with a total electrodeposition time of 20–400 s. The magnitude of the current is determined by the area of ​​the electrode substrate; generally, the larger the area of ​​the electrode substrate, the larger the current.

[0061] In one specific embodiment of the present invention, the periodic deposition includes: a cycle of 8 to 12 seconds, each cycle including several time periods ordered in chronological order, each time period lasting 2 to 5 seconds; preferably, the periodic deposition includes: a cycle of 8 to 12 seconds, each cycle including three time periods ordered in chronological order, namely a first time period, a second time period, and a third time period, with durations of 2 to 4 seconds, 3 to 5 seconds, and 2 to 4 seconds respectively.

[0062] In a specific embodiment of the present invention, in step (II), the electrodeposition process conditions further include: using a stainless steel plate as the anode, and the distance between the cathode and the anode is 1 to 30 cm, preferably using a corrugated stainless steel plate as the anode.

[0063] In one specific embodiment of the present invention, the electrodeposition of the catalyst further includes the following step: (III) drying the electrode sheet obtained in step (II), including but not limited to hanging and draining, and baking. Specifically, when the electrode sheet is dried by hanging and draining, the hanging time is 8 to 24 hours; when the electrode sheet is dried by baking, the baking temperature is 30 to 60°C.

[0064] The above embodiments of the present invention provide a novel oxygen-generating catalyst, which is a nickel-iron-based multi-element alloy with an ordered nanowire or nanochain microstructure. The nanowires or nanochains have a diameter of 0.1–2.0 μm and a length of 0.1–200 μm. The catalyst comprises the following components by mass percentage: 85%–95% Ni, 4.98%–14.98% Fe, and the remainder being noble metals or transition metals. The present invention also provides a novel oxygen-generating electrode sheet, comprising a substrate on which the catalyst is loaded. The electrode sheet has a yellow-green surface and a uniformly distributed mesh-like appearance. When the oxygen-generating catalyst and electrode sheet provided in the above embodiments of the present invention are applied to water electrolysis for oxygen production, compared with the traditional electrode sheet with a "nickel mesh + plating" structure, it has higher catalytic activity, lower energy consumption, and better stability.

[0065] The above embodiments of the present invention also provide a method for preparing the electrolytic water oxygen production catalyst and electrode sheet mentioned in the above embodiments. A reagent A and a reagent B are mixed to form a solution. A nickel-based binary or multi-element alloy catalyst is formed on a substrate (nickel mesh or nickel foam) through an in-situ growth process to obtain an electrode sheet substrate. Then, an oxygen production catalyst is deposited on the electrode sheet substrate through an electrode deposition process. Simultaneously, during the in-situ growth and electrode deposition of the catalyst, the above embodiments of the present invention employ a mold method. A grid-like mold is used to divide a large sheet into several smaller sheets, resulting in a grid-like catalyst on the surface of the obtained substrate / electrode sheet substrate. This ensures the uniformity of the formed catalyst. This method is very suitable for preparing large-size electrode sheets using large-size substrates, as it is simple to operate, highly efficient, and produces electrode sheets with uniform catalyst distribution and high product quality.

[0066] It should be noted that the reagents used in the embodiments of this application are all AR reagents, and the purity of soluble nickel salt, soluble platinum salt, soluble sodium salt, soluble alkali and soluble ferrous salt are all greater than or equal to 99%, and the concentration of hydrazine hydrate is greater than or equal to 85%.

[0067] The following specific examples illustrate the present invention in detail. It should also be understood that the following examples are only for specific illustrative purposes and should not be construed as limiting the scope of protection of the present invention. Any non-essential improvements and adjustments made by those skilled in the art based on the above description of the present invention are within the scope of protection of the present invention. The specific process parameters, etc., in the following examples are merely examples within a suitable range; that is, those skilled in the art can make appropriate selections within the appropriate range based on the description herein, and are not intended to be limited to the specific values ​​in the examples below.

[0068] Example 1

[0069] This embodiment prepares an electrolytic water oxygen production catalyst and electrode sheet. The preparation process includes in-situ growth and electrodeposition of the catalyst. The in-situ growth of the catalyst mainly includes the following steps:

[0070] (1) Using nickel mesh (5*5cm) as the substrate, the substrate is pretreated. The pretreatment process of the substrate includes: substrate leveling and cleaning. The equipment used for substrate leveling is a cold press or roller press. The cleaning agent added during substrate cleaning is anhydrous ethanol. The substrate cleaning method is air knife treatment.

[0071] (2) Preparation of reagents: Using pure water as solvent, prepare reagent A and reagent B according to the following formulas. Reagent A includes the following four raw materials: nickel sulfate, platinum chloride, sodium sulfate, and sodium hydroxide. The molar concentration ratio of the four raw materials in reagent A is 2.0:0.01:1.5:0.06. Reagent B includes the following two raw materials: hydrazine hydrate and sodium hydroxide. The molar concentration ratio of the two raw materials in reagent B is 1.5:0.01. After reagents A and B are prepared, they are heated and kept at a temperature between 50 and 100°C.

[0072] (3) Place the pretreated substrate in a container, add the B agent prepared in step (2) first, and ensure that the B agent is in full contact with the substrate. Then add the A agent evenly into the container. The volume ratio of the B agent to the A agent is 1.5:1.0. After the A and B agents are mixed evenly, place the container in an oven and start heating. The heating temperature is 85℃. After heating to the preset temperature, keep it warm for 420 minutes. Through heating and keeping warm, a catalyst is formed in situ on the substrate to obtain the electrode sheet substrate.

[0073] (4) Dry the electrode substrate obtained in step (3) by means of: hanging the electrode substrate and letting it stand for 24 hours.

[0074] The electrodeposition of catalysts mainly includes the following steps:

[0075] (I) Prepare the electrodeposition solution. The electrodeposition solution includes the following two raw materials: nickel sulfate and ferrous sulfate. The molar concentration ratio of the two raw materials in the electrodeposition solution is 0.8:0.05. The preparation method of the electrodeposition solution is as follows: add nickel sulfate and ferrous sulfate to pure water in sequence, stir and mix thoroughly for 20 minutes.

[0076] (II) The electrode substrate is placed in a container, and an electrodeposition solution is added. A catalyst is grown on the electrode substrate by electrodeposition to obtain the electrode sheet. The electrodeposition process conditions include: using a corrugated stainless steel plate as the anode, using the electrode substrate (5*5cm) as the cathode, maintaining a certain distance (20cm) between the cathode and anode, and a current density of 50–100 mA / cm². 2The current is 1.25–2.5 A; the electrodeposition method is periodic deposition: 10 s is one cycle, the current is 1.25 A for the first 3 s, 2.5 A for the middle 4 s, and 2.0 A for the last 3 s; the total electrodeposition time is 400 s.

[0077] (III) After electrodeposition, the obtained electrode sheet is dried. Specifically, the hanging draining method is used, that is, the electrode sheet is suspended and left to stand for 24 hours.

[0078] Figure 2 This is a view of the electrode substrate fabricated in this embodiment. Figure 2 As can be seen, the electrode sheet obtained in this embodiment has the following appearance characteristics: the electrode sheet substrate is black and its surface has a grid pattern.

[0079] Figure 3 This image shows the appearance of the electrode sheet prepared in this embodiment. From... Figure 3 As can be seen, the electrode sheet obtained in this embodiment has the following appearance characteristics: the electrode sheet is yellow-green and its surface has a grid pattern.

[0080] The electrode substrate and electrode sheet of this embodiment were observed using a scanning electron microscope to obtain... Figure 4 and Figure 5 The SEM image shown. From Figure 4 It can be seen that the microstructure of the catalyst on the electrode substrate obtained in this embodiment is as follows: nanowires are vertically grown on the substrate material (nickel mesh), and are nanowires "stacked" together by nanoparticles, with a diameter of about 0.1-0.6 μm and a length of 0.1 μm to 100 μm. From Figure 5 As can be seen, the catalyst microstructure on the electrode sheet prepared in this embodiment is as follows: platinum-nickel-iron nanowires are vertically grown on the substrate, the diameter of the platinum-nickel-iron nanowires is 0.1 to 1.2 μm, the platinum-nickel-iron nanowires include a first part and a second part, the first part is a skeleton part, the skeleton part includes nanowires of 0.1-0.6 μm "stacked" from nanoparticles, the second part is a honeycomb nanowire assembled from nanosheets based on the skeleton part, the length of the nanowires is 0.1 μm to 100 μm.

[0081] Testing revealed that the catalyst on the electrode sheet prepared in this embodiment comprises 89.50% Ni, 1.98% Pt, and 8.52% Fe.

[0082] The electrode sheet, along with the diaphragm and electrode plates, was assembled into an electrolytic cell, and operating condition tests were conducted. The performance of the electrode sheet prepared in this embodiment was compared with that of a traditional alkaline electrode sheet (“nickel mesh + Raney nickel plating” structure). The results are as follows: Figure 6 As shown.

[0083] from Figure 6It can be seen that the electrode current density in this embodiment can reach up to 11000 A / m at 2.0V. 2 It is significantly superior to traditional alkaline electrode sheets.

[0084] The performance of the electrode sheet prepared in this embodiment was compared with that of a traditional alkaline electrode sheet using electrochemical testing methods. The results are as follows: Figure 7 As shown.

[0085] from Figure 7 It can be seen that the oxygen-generating catalyst prepared in this embodiment has significantly better electrochemical activity than Raney nickel. The oxygen evolution overpotential η10 is 231 mV for the oxygen-generating catalyst prepared in this embodiment and 302 mV for Raney nickel.

[0086] Example 2

[0087] This embodiment prepares an electrolytic water oxygen production catalyst and electrode sheet, the preparation process of which mainly includes the following steps:

[0088] (1) Using nickel mesh (5*5cm) as the substrate, the substrate is pretreated. The pretreatment process of the substrate includes: substrate leveling and cleaning. The equipment used for substrate leveling is a cold press or roller press. The cleaning agent added during substrate cleaning is anhydrous ethanol. The substrate cleaning method is air knife treatment.

[0089] (2) Preparation of reagents: Using pure water as solvent, prepare reagent A and reagent B according to the following formulas. Reagent A includes the following four raw materials: nickel chloride, ruthenium chloride, sodium sulfate, and sodium hydroxide. The molar concentration ratio of the four raw materials in reagent A is 1.5:0.02:1.2:0.09. Reagent B includes the following two raw materials: hydrazine hydrate and sodium hydroxide. The molar concentration ratio of the two raw materials in reagent B is 1.2:0.01. After reagents A and B are prepared, they are heated and kept at a temperature between 50 and 100°C.

[0090] (3) Place the pretreated substrate in a container, add the B agent prepared in step (2) first, and ensure that the B agent is in full contact with the substrate. Then add the A agent evenly into the container. The volume ratio of the B agent to the A agent is 1.0:0.8. After the A and B agents are mixed evenly, place the container in an oven and start heating. The heating temperature is 80°C. After heating to the preset temperature, keep it warm for 60 minutes. Through heating and keeping warm, a catalyst is formed in situ on the substrate to obtain the electrode sheet substrate.

[0091] (4) Dry the electrode substrate obtained in step (3) by means of: hanging the electrode substrate and letting it stand for 24 hours.

[0092] The electrodeposition of catalysts mainly includes the following steps:

[0093] (I) Prepare the electrodeposition solution. The electrodeposition solution includes the following two raw materials: nickel sulfate and ferrous sulfate. The molar concentration ratio of the two raw materials in the electrodeposition solution is 0.6:0.01. The preparation method of the electrodeposition solution is as follows: add nickel sulfate and ferrous sulfate to pure water in sequence, stir and mix thoroughly for 10 minutes.

[0094] (II) The electrode substrate is placed in a container, an electrodeposition solution is added, and a catalyst is grown on the electrode substrate by electrodeposition to obtain the electrode sheet. The electrodeposition process conditions include: using a corrugated stainless steel plate as the anode, using the electrode substrate (5*5cm) as the cathode, maintaining a certain distance (1cm) between the cathode and anode, and a current density of 50-100mA / cm. 2 The current is 1.25–2.5 A; the electrodeposition method is periodic deposition: 10 s is one cycle, the current is 1.25 A for the first 3 s, 2.5 A for the middle 4 s, and 2.0 A for the last 3 s; the total electrodeposition time is 20 s.

[0095] (III) After electrodeposition, the obtained electrode sheet is dried. Specifically, the suspended drying method is used, that is, the electrode is suspended and left to stand for 24 hours.

[0096] The electrode sheet prepared in this embodiment has the same appearance and microstructure as the electrode sheet in Example 1. The catalyst prepared includes 95% Ni, 10.2% Ru, and 4.98% Fe.

[0097] Example 3

[0098] This embodiment prepares an electrolytic water oxygen production catalyst and electrode sheet, the preparation process of which mainly includes the following steps:

[0099] (1) Using nickel mesh (5*5cm) as the substrate, the substrate is pretreated. The pretreatment process of the substrate includes: substrate leveling and cleaning. The equipment used for substrate leveling is a cold press or roller press. The cleaning agent added during substrate cleaning is anhydrous ethanol. The substrate cleaning method is air knife treatment.

[0100] (2) Preparation of reagents: Using pure water as solvent, prepare reagent A and reagent B according to the following formulas. Reagent A includes the following four raw materials: nickel sulfate, platinum chloride, sodium sulfate, and sodium hydroxide. The molar concentration ratio of the four raw materials in reagent A is 3.0:0.001:1.9:0.04. Reagent B includes the following two raw materials: hydrazine hydrate and sodium hydroxide. The molar concentration ratio of the two raw materials in reagent B is 1.9:0.01. After reagents A and B are prepared, they are heated and kept at a temperature between 50 and 100°C.

[0101] (3) Place the pretreated substrate in a container, add the B agent prepared in step (2) first, and ensure that the B agent is in full contact with the substrate. Then add the A agent evenly into the container. The volume ratio of the B agent to the A agent is 2.0:1.5. After the A and B agents are mixed evenly, place the container in an oven and start heating. The heating temperature is 90℃. After heating to the preset temperature, keep it warm for 360 minutes. Through heating and keeping warm, a catalyst is formed in situ on the substrate to obtain the electrode sheet.

[0102] (4) Dry the electrode sheet obtained in step (3) by using the hanging draining method, that is, suspending the electrode and letting it stand for 24 hours.

[0103] The electrodeposition of catalysts mainly includes the following steps:

[0104] (I) Prepare the electrodeposition solution. The electrodeposition solution includes the following two raw materials: nickel sulfate and ferrous sulfate. The molar ratio of the two raw materials in the electrodeposition solution is 1:0.1. The preparation method of the electrodeposition solution is as follows: add nickel sulfate and ferrous sulfate to pure water in sequence, stir and mix thoroughly for 20 minutes.

[0105] (II) The electrode substrate is placed in a container, and an electrodeposition solution is added. A catalyst is grown on the electrode substrate (5*5cm) by electrodeposition to obtain the electrode sheet. The electrodeposition process conditions include: using a corrugated stainless steel plate as the anode, the electrode substrate as the cathode (maintaining a distance of 30cm between the cathode and anode), and a current density of 50–100 mA / cm². 2 The current is 1.25–2.5 A; the electrodeposition method is periodic deposition: 10 s is one cycle, the current is 1.25 A for the first 3 s, 2.5 A for the middle 4 s, and 2.0 A for the last 3 s; the total electrodeposition time is 200 s.

[0106] (III) After electrodeposition, the obtained electrode sheet is dried. Specifically, the suspended drying method is used, that is, the electrode is suspended and left to stand for 24 hours.

[0107] The electrode sheet prepared in this embodiment has the same appearance and microstructure as the electrode sheet in Example 1. The catalyst prepared includes 85% Ni, 0.02% Pt, and 14.98% Fe.

[0108] Example 4

[0109] This embodiment prepares an electrolytic water oxygen production catalyst and electrode sheet, the preparation process of which mainly includes the following steps:

[0110] (1) Using nickel foam (2m*2m) as the substrate, the substrate is pretreated. The pretreatment process of the substrate includes: substrate leveling and cleaning. The equipment used for substrate leveling is a cold press or roller press. The cleaning agent added during substrate cleaning is anhydrous ethanol. The substrate cleaning method is soaking in an aqueous solution containing 5% dilute sulfuric acid.

[0111] (2) Preparation of reagents: Using pure water as solvent, prepare reagent A and reagent B according to the following formulas. Reagent A includes the following four raw materials: nickel sulfate, platinum chloride, sodium sulfate, and sodium hydroxide. The molar concentration ratio of the four raw materials in reagent A is 2.5:0.005:1.8:0.08. Reagent B includes the following two raw materials: hydrazine hydrate and sodium hydroxide. The molar concentration ratio of the two raw materials in reagent B is 1.4:0.01. After reagents A and B are prepared, they are heated and kept at a temperature between 50 and 100°C.

[0112] (3) Place the pretreated substrate in a container, add the B agent prepared in step (2) first, and ensure that the B agent is in full contact with the substrate. Then add the A agent evenly into the container. The volume ratio of the B agent to the A agent is 1:1. After the A and B agents are mixed evenly, place the container in an oven and start heating. The heating temperature is 85℃. After heating to the preset temperature, keep it warm for 240 minutes. Through heating and keeping warm, a catalyst is formed in situ on the substrate to obtain the electrode sheet.

[0113] (4) Dry the electrode sheet obtained in step (3) by using the hanging draining method, that is, suspending the electrode and letting it stand for 24 hours.

[0114] The electrodeposition of catalysts mainly includes the following steps:

[0115] (I) Prepare the electrodeposition solution. The electrodeposition solution includes the following two raw materials: nickel sulfate and ferrous sulfate. The molar concentration ratio of the two raw materials in the electrodeposition solution is 0.8:0.07. The preparation method of the electrodeposition solution is as follows: add nickel sulfate and ferrous sulfate to pure water in sequence, stir and mix thoroughly for 20 minutes.

[0116] (II) The electrode substrate is placed in a container, and an electrodeposition solution is added. A catalyst is grown on the electrode substrate (5*5cm) by electrodeposition to obtain the electrode sheet. The electrodeposition process conditions include: using a corrugated stainless steel plate as the anode, the electrode substrate as the cathode (maintaining a certain distance of 10cm between the cathode and anode), and a current density of 50–100 mA / cm². 2 The current is 1.25–2.5 A; the electrodeposition method is periodic deposition: 10 s is one cycle, the current is 1.25 A for the first 3 s, 2.5 A for the middle 4 s, and 2.0 A for the last 3 s; the total electrodeposition time is 300 s.

[0117] (III) After electrodeposition, the obtained electrode sheet is dried. Specifically, the suspended drying method is used, that is, the electrode is suspended and left to stand for 24 hours.

[0118] The electrode sheet prepared in this embodiment has the same appearance and microstructure as the electrode sheet in Example 1. The catalyst prepared includes 87.50% Ni, 5.85% Pt, and 6.65% Fe.

[0119] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. A method for preparing an electrode sheet, characterized in that, include: Pretreatment of the substrate; Prepare reagent A and reagent B. Reagent A comprises a soluble nickel salt, a soluble noble metal salt, a soluble sodium salt, and a soluble alkali. The molar concentration ratio of the soluble nickel salt, soluble noble metal salt, soluble sodium salt, and soluble alkali in reagent A is (1.5–3.0):(0.001–0.02):(1.2–1.9):(0.04–0.09). Reagent B comprises hydrazine hydrate and a soluble alkali. The molar concentration ratio of the hydrazine hydrate and the soluble alkali in reagent B is (1.2–1.9):0.

01. The pretreated substrate is placed in a container, and reagents B and A are added in sequence. The mixture is heated to obtain an electrode substrate. An electrodeposition solution is prepared, wherein the electrodeposition solution comprises soluble nickel salt and soluble ferrous salt, and the molar concentration ratio of soluble nickel salt to soluble ferrous salt in the electrodeposition solution is (0.6-1):(0.01-0.1); The electrode substrate is placed in a container, and an electrodeposition solution is added to perform electrodeposition. The catalyst is a nickel-iron-based multi-element alloy with an ordered nanowire or nanochain microstructure, wherein the nanowire or nanochain has a diameter of 0.1–2.0 μm and a length of 0.1–200 μm; the catalyst comprises the following components by mass percentage: 85%–95% Ni, 4.98%–14.98% Fe, and the remainder being noble metals; The precious metal is selected from platinum and / or ruthenium; The container includes a liquid storage box and a grid-shaped mold. First, the substrate is placed flat in the liquid storage box, then the grid-shaped mold is placed on the substrate, and then B / A reagent is added to form a grid-shaped catalyst on the substrate surface. The grid-shaped mold is made of acid and alkali resistant plastic.

2. The method according to claim 1, characterized in that: The microstructure characteristics of the catalyst include: nanowires grown vertically on a substrate with a diameter of 0.1–1.2 μm; the nanowires include a first part and a second part, the first part being a framework part, which includes nickel-platinum nanowires of 0.1–0.6 μm in diameter "stacked" from nanoparticles; the second part including honeycomb nanowires of 0.1–100 μm in length assembled from nickel-iron nanosheets based on the framework part.

3. The method according to claim 1, characterized in that: The resulting catalyst is yellow-green.

4. The method according to claim 1, characterized in that: The substrate can be any one of nickel foam, nickel mesh, or carbon cloth.

5. The method according to claim 1, characterized in that: The electrode sheet is square or round; And / or, the area of ​​the substrate is ≥0.5m² 2 .

6. The method according to claim 1, characterized in that: The mesh size of the grid-like catalyst supported on the substrate is 5–12 cm.

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