Natural growth type titanium metal bipolar plate for electrolyzing water and preparation method of natural growth type titanium metal bipolar plate

Abstract

The invention discloses a preparation method of a natural growth type titanium metal bipolar plate for electrolysis of water. The preparation method comprises the following operation steps: pretreatment of a titanium plate: removing stains on the surface of the titanium plate; coating and calcining with butyl titanate: coating the titanium plate subjected to coating treatment with the butyl titanate solution for 12 times, putting the titanium plate into a tubular furnace, calcining at 550 DEG C, cooling to obtain a titanium oxide layer, and cutting the calcined sample into a proper size; and (4) taking out the sample in the step (3), directly putting the sample into a tubular furnace, introducing hydrogen, and setting the reaction parameter to be 930 DEG C / 10min and the temperature rising rate to be 10 DEG C / min, thereby obtaining the high-temperature-resistant carbon nanotube. The surface resistivity of the titanium substrate prepared by the process is reduced, the conductivity is improved, and the problems of low conductivity and short service life of a pure titanium substrate of a bipolar plate in hydrogen production by electrolysis of water are solved.

Description

Technical Field

[0001] The invention relates to the technical field of hydrogen production by electrolysis of water, and in particular to a naturally grown titanium metal bipolar plate for water electrolysis and a preparation method thereof. Background Art

[0002] As the global demand for environmentally friendly energy is increasing, hydrogen energy as a clean, efficient and renewable energy source is gaining more and more attention. In the process of hydrogen energy preparation, PEM water electrolysis hydrogen production technology is also gaining more and more attention. Proton exchange membrane water electrolysis hydrogen production has high energy efficiency, reaching more than 80%, fast reaction speed and strong economy. Hydrogen-powered cars have lower fuel consumption, reduced emissions and strong economy.

[0003] There are still many technical issues that need to be resolved in the production of hydrogen by proton exchange membrane water electrolysis. The bipolar plate is one of the key components of the proton exchange membrane water electrolyzer. The cost of producing hydrogen by water electrolysis is high, of which electricity costs account for nearly 70%. At present, the cost of hydrogen production by water electrolysis is higher than that of hydrogen production by fossil fuels, which limits its large-scale application. Proton exchange membrane electrolyzer bipolar plates mostly use titanium-based bipolar plates, and the precious metal catalysts used in proton exchange membrane electrolyzers are also dependent on imports. The price of the proton exchange membrane titanium plate itself is not low, and the surface needs to be coated with a precious metal coating to ensure the corrosion resistance and conductivity of the titanium plate, which makes its entire manufacturing cost account for a large proportion of the proton exchange membrane electrolyzer. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a titanium metal bipolar plate for water electrolysis with lower resistivity and a preparation method thereof.

[0005] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0006] The present invention provides a method for preparing a naturally grown titanium metal bipolar plate for water electrolysis, comprising the following steps:

[0007] (1) Tetrabutyl titanate, anhydrous ethanol and water are mixed and then magnetically stirred to obtain a coating liquid;

[0008] (2) Surface treatment of titanium metal plate: The titanium metal plate is surface treated and cleaned to remove stains. After pretreatment, the resistivity of the titanium metal plate is not less than 37 μΩ.cm;

[0009] (3) Butyl titanate coating and calcination: The titanium plate treated with butyl titanate solution was coated 12 times on both sides, placed in a tube furnace, calcined at 550°C, cooled, and a titanium oxide layer was obtained. The calcined sample was cut into a suitable size;

[0010] (4) Take out the sample from (3) and directly put it into a tubular furnace and introduce hydrogen. Set the reaction parameters to 930°C / 10min and the temperature rise rate to 10°C / min.

[0011] Preferably, in step (2), the titanium metal plate is an industrial pure titanium plate.

[0012] Preferably, in step (2), the surface treatment is to polish the sample surface using a high-pressure sandblasting machine.

[0013] Preferably, in step (2), the cleaning operation includes mixing acetone and pure water on the titanium metal plate, ultrasonic cleaning, the ultrasonic equipment frequency is 48 Hz, the cleaning time is 5 minutes, and the room temperature is; the cleaned titanium plate is wiped once with alcohol dust-free paper, and then wiped dry with dry dust-free paper and placed.

[0014] The coating in step (3) is butyl titanate, which is evenly coated on the sample and repeatedly coated with 12 layers. The coated sample is cut and placed in a tubular furnace. The titanium plate carrier is a boat-shaped corundum boat. The sample is placed flat in the corundum boat with the edge in contact with the boat and the plane not in contact with the carrier, ensuring the consistency of the reaction degree during the planar reaction. The resistivity after the reaction test shows an open circuit. Titanium dioxide is not conductive at room temperature, proving that titanium dioxide is generated on the surface of the titanium plate after butyl titanate coating, calcination and cooling.

[0015] Preferably, in step (3), there is no gas protection, and the sample is directly oxidized in contact with air, and the reaction parameters are set to 550°C / 3 hours, and the heating rate is 4°C / min. After the reaction, wait for the temperature to drop to room temperature before taking it out.

[0016] Preferably, step (4) is to take out the sample in (3) and directly put it into a tube furnace and introduce hydrogen, and set the reaction parameters to 930°C / 10min and the temperature rise rate to 10°C / min. The resistivity of the titanium plate after hydrogen reduction is 10μΩ.cm.

[0017] The titanium substrate prepared by the method of the present invention has a lower surface resistivity and an improved electrical conductivity, thereby solving the problem of low electrical conductivity and short service life of the pure titanium substrate of the bipolar plate in hydrogen production by electrolysis of water. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is the XRD diffraction pattern of the product prepared under the same reaction conditions but different reduction temperatures. DETAILED DESCRIPTION

[0019] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the accompanying drawings in the embodiments of the present invention, but this does not constitute a limitation on the protection scope of the present invention.

[0020] The present invention provides a method for preparing a naturally grown titanium metal bipolar plate for water electrolysis, comprising the following steps:

[0021] Titanium plate pretreatment: fix the industrial pure titanium plate sample to the grinding table, and use a high-pressure sandblasting machine to grind and polish until the surface is smooth and uniform. Put the polished titanium plate into an ultrasonic cleaner with an ultrasonic frequency of 48 Hz and a cleaning time of 5 minutes. Pour acetone and water into the mixture for cleaning to remove surface oil and other dirt. After cleaning, wipe the titanium plate with alcohol and dry it with dust-free paper. The resistivity of the titanium substrate is 37μΩ.cm.

[0022] The titanium plate is oxidized to generate intermediate products: the titanium plate, after pre-treating the surface and evenly coating both sides with 12 layers of titanate butyl solution (chemically pure, purity 98%), is placed flat on a corundum boat and put into a tubular furnace. The length of the tubular furnace pipe is measured, the length of the corundum boat is subtracted, and the plate is placed at half of the length, i.e., the center of the pipe. The reaction time and temperature of the tubular furnace are set, and the heating rate is 4°C / min. After the reaction, the plate is taken out after the temperature drops to room temperature. Titanium dioxide is generated in the process. The surface resistivity of the metal plate after testing this step using a four-probe tester is extremely high.

[0023] A reduction experiment was carried out on the oxidized titanium plate; the oxidized titanium plate was placed flat on a corundum boat, placed in a tubular furnace, hydrogen was introduced, the reduction temperature and time were set to 10 min, and the heating rate was 10°C / 10 min.

[0024] The reaction parameters of Examples 1-5 are shown below (prepared as described above, only the reaction condition parameters are changed):

[0025]

[0026] It can be seen from the experimental tests of Examples 1-5 that when the calcination temperature and the reduction temperature change, the surface resistivity is quite different. When the calcination temperature and the reduction temperature are slightly changed, the resistivity of the substrate after the reaction is quite different. The test analysis shows that Figure 1 As shown, when the sample was reduced at 930°C, the desired product peak was detected, the resistivity of the substrate after the reaction was significantly reduced, and the conductivity was increased. It also shows that a small temperature difference leads to a large difference in the generated substances, so there are extremely strict requirements on the reaction temperature.

[0027] The reaction parameters of Examples 6-10 are shown in the following table, wherein the calcination temperature is 550° C. and the reduction temperature is 930° C., but the number of coating layers is different.

[0028]

[0029]

[0030] The experimental data in the figure show that when the number of coating layers is less than 12, the thickness of the base after the reaction is low, the resistivity changes little, no titanium dioxide is generated, and titanium dioxide is not conductive at room temperature. When the number of coating layers is more than 12, the thickness increases significantly, the resistivity changes in a large range, and the product is uneven, indicating that the number of coatings must be strictly controlled.

[0031] In summary, the solution of the present invention has the following beneficial effects:

[0032] 1. Compared with the electroplating process for preparing metal plates, the process flow of the present invention is simple

[0033] The basic process of the present invention is: grinding and polishing → cleaning → coating, high temperature calcination → high temperature reduction

[0034] Basic electroplating process

[0035] (grinding → polishing) → coating preparation → coating → drying → processing and post-processing

[0036] 2. The electroplating process of the present invention does not produce any toxic substances

[0037] Environmental pollution: The gold electroplating process will produce waste liquid and waste gas, which contain metal ions and harmful substances. If not handled properly, it will pollute the environment.

[0038] 3. High cost: The electroplating gold process requires the use of precious metal gold for electroplating, so the cost is high, which increases the manufacturing cost of the product. The present invention uses butyl titanate raw materials that are easily available and simple to produce. After the reaction, high-purity, high-crystallinity and small-particle titanium dioxide can be produced.

[0039] In summary, the present invention directly generates titanium oxide with good conductivity on the surface of the titanium plate, which has the advantages of high adhesion and not easy to fall off, and can reduce production costs; furthermore, the present invention adopts a direct reaction generation method, and the process flow is simple.

[0040] The above is a preferred embodiment of the present invention. It should be pointed out that a person skilled in the art can make several improvements and modifications without departing from the principle of the present invention. These improvements and modifications are also considered to be within the scope of protection of the present invention.

Claims

1. A method for preparing a naturally grown titanium metal bipolar plate for water electrolysis, characterized in that: The steps include: (1) Tetrabutyl titanate, anhydrous ethanol and water are mixed and then magnetically stirred to obtain a coating liquid; (2) Surface treatment of titanium metal plate: surface treatment of the titanium metal plate, cleaning and removal of stains; (3) Butyl titanate coating and calcination: The titanium plate treated with butyl titanate solution was coated 12 times on both sides, placed in a tube furnace, calcined at 550°C, cooled, and a titanium oxide layer was obtained. The calcined sample was cut into a suitable size; (4) The sample in (3) was taken out and directly placed in a tube furnace. Hydrogen was introduced and the reaction temperature was 930°C. The temperature rise rate was 10°C / min.

2. The method for preparing a naturally grown titanium bipolar plate for water electrolysis according to claim 1, characterized in that: The titanium metal plate in step (2) is an industrial pure titanium plate.

3. The method for preparing a naturally grown titanium metal bipolar plate for water electrolysis as claimed in claim 1, characterized in that: The surface treatment described in step (2) includes grinding the sample surface using a high-pressure sandblasting machine.

4. The method for preparing a naturally grown titanium bipolar plate for water electrolysis according to claim 1, characterized in that: The cleaning operation in step (2) includes: placing the titanium metal plate in a mixture of acetone and pure water, ultrasonic cleaning, the ultrasonic equipment frequency is 48 Hz, the cleaning time is 5 minutes, and the room temperature is; the cleaned titanium plate is wiped once with alcohol dust-free paper, and then wiped dry with dry dust-free paper and placed.

5. The method for preparing a naturally grown titanium bipolar plate for water electrolysis according to claim 1, characterized in that: The calcination time in step (3) is 3 hours and the heating rate is 4°C / min.

6. The method for preparing a naturally grown titanium bipolar plate for water electrolysis according to claim 1, characterized in that: The reaction time in step (4) is 10 min.

7. A naturally grown titanium bipolar plate for water electrolysis, characterized in that: Prepared according to the method according to any one of claims 1 to 6.

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