Pure Ti coating corrosion-resistant bipolar plate based on atmospheric plasma spraying and preparation method of pure Ti coating corrosion-resistant bipolar plate

Abstract

The invention discloses a pure Ti coating corrosion-resistant bipolar plate based on atmospheric plasma spraying and a preparation method of the pure Ti coating corrosion-resistant bipolar plate, and belongs to the technical field of coating preparation. Pure Ti powder is sputtered on the surface of stainless steel through an atmospheric plasma spraying method to obtain the metal coating. Wherein the coating with better corrosion resistance is obtained by controlling experimental parameters, the experimental parameters mainly comprise experimental current, primary Ar gas quantity, H2 quantity and the like, and the performance of the coating is tested. According to the invention, based on coating preparation parameter control, selection of appropriate process parameters is realized, and finally, the corrosion resistance of the additive manufacturing stainless steel bipolar plate is enhanced, so that the service life and the stability of the battery are improved.

Description

Technical Field

[0001] This invention relates to the field of thermal spraying technology, specifically to a pure Ti-coated corrosion-resistant bipolar plate based on atmospheric plasma spraying and its preparation method. Background Technology

[0002] Hydrogen energy, as an excellent energy carrier, boasts zero pollution, high energy content, and wide availability, making it one of the most promising energy carriers of the 21st century. Electrolysis of water for hydrogen production has gained significant momentum globally due to its advantages such as zero carbon emissions, high product purity, and strong capacity to store intermittent renewable energy. Among these technologies, proton exchange membrane electrolysis (PEMWE) for hydrogen production, with its high operating current density, high product purity (99.99%), and ability to handle intermittent fluctuations, is a promising method for capturing solar energy and other renewable energy sources with fluctuating characteristics.

[0003] As a core multifunctional component of water electrolysis for hydrogen production, the bipolar plate accounts for as much as 53% of the total stack cost and 25% of the total cost. Its performance directly affects the electrolysis efficiency and service life. During operation, the bipolar plate may face high overpotentials, strong acids, and high temperatures. Long-term operation can lead to corrosion failure of electrolysis cell components and equipment, further hindering the industrial application of water electrolysis. Therefore, the corrosion problem in the water electrolysis hydrogen production process needs to be solved; otherwise, it will seriously impede the development of my country's hydrogen energy industry.

[0004] Although additively manufactured stainless steel has better corrosion resistance than traditional stainless steel, the corrosion resistance still does not meet the requirements. Therefore, it is necessary to modify the surface of the bipolar plate and develop a coating with good adhesion to the substrate and better corrosion resistance. This is an important task to solve the industrial application of metal bipolar plates. Summary of the Invention

[0005] The purpose of this invention is to overcome the above-mentioned problems and provide a method for preparing a corrosion-resistant coating. This method not only yields a more superior corrosion-resistant coating, but also avoids the use of precious metals, which helps to reduce manufacturing costs.

[0006] A corrosion-resistant bipolar plate with a pure Ti coating based on atmospheric plasma spraying and its preparation method, characterized by the following steps:

[0007] (1) First, grind the substrate surface to remove surface oxides or foreign matter, and clean and remove surface oil stains before drying;

[0008] (2) Sandblasting should be performed before spraying;

[0009] (3) Deposit Ti metal coating. A Ti coating is deposited on the surface of the substrate after step (2) using a thermal spray deposition process. The purity of the raw material components is 99.7%.

[0010] Further, in step (1), the substrate surface is first polished smooth with 60#, 240#, 400#, 600# and 800# sandpaper to remove surface oxides or foreign matter, and then blown dry after ultrasonic cleaning with ethanol to remove surface oil stains.

[0011] Furthermore, the sandblasting performed in step (2) facilitates better adhesion to the substrate surface;

[0012] Furthermore, the thermal spraying process in step (3) is carried out under atmospheric plasma spraying equipment. Argon is used as a protective gas during the deposition process. In the experiment, a control experiment was conducted by modifying one parameter while keeping the other parameters the same to obtain a better parameter value. The specific process parameters are: working voltage: 58V, working current: 450A / 500A / 550A, primary Ar gas flow rate: 45 / 50L / min, H2 flow rate: 8L / min, secondary Ar gas flow rate: 4L / min, powder feeding rate: 8%, powder feeding distance: 100mm / 120mm;

[0013] Compared with the prior art, the present invention has the following advantages:

[0014] 1. The corrosion-resistant coating of this invention does not require preheating or vacuum treatment, enabling rapid completion of the spraying process and improving production efficiency. Furthermore, since the spraying process is carried out under atmospheric pressure, the energy consumption of vacuum equipment is avoided.

[0015] 2. By using a spray coating method, cracks and holes caused by inherent defects in the coating process can be avoided, providing good corrosion resistance and wear resistance. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below.

[0017] Figure 1 Polarization curves with altered current parameters for additive manufacturing of 316 stainless steel;

[0018] Figure 2 Impedance curves with varying current parameters for additive manufacturing of 316 stainless steel;

[0019] Figure 3 SEM and EDS images of Ar gas flow rate of 45 L / min for additive manufacturing of 316 stainless steel.

[0020] Figure 4SEM and EDS images of Ar gas flow rate of 50 L / min for additive manufacturing of 316 stainless steel.

[0021] Figure 5 Polarization curves by changing the powder feeding distance for additive manufacturing of 316 stainless steel;

[0022] Figure 6 SEM and EDS images of 316 stainless steel powder feed distance of 100mm for additive manufacturing;

[0023] Figure 7 SEM and EDS images of 316 stainless steel powder feed distance of 120mm for additive manufacturing; Detailed Implementation

[0024] To enable those skilled in the art to fully understand the technical solutions of the present invention, the present invention will be further described below in conjunction with embodiments and accompanying drawings.

[0025] Example 1

[0026] A method for preparing a metal coating on an additively manufactured 316 stainless steel bipolar plate by changing current parameters, comprising the following steps:

[0027] (1) First, polish the substrate surface with 60#, 240#, 400#, 600# and 800# sandpaper to remove surface oxides or foreign matter, and then blow dry the surface after ultrasonic cleaning with ethanol to remove surface oil.

[0028] (2) Sandblasting should be performed before spraying;

[0029] (3) Deposition of Ti metal coating: In this example, Ti powder with a purity of 99.7% was used as the raw material. The Ti metal coating was prepared using an atmospheric plasma spraying device. The specific process parameters were: working voltage: 58V, working current: 450A / 500A / 550A, primary Ar gas flow rate: 45L / min, H2 flow rate: 8L / min, secondary Ar gas flow rate: 4L / min, powder feeding rate: 8%, powder feeding distance: 100mm;

[0030] The corrosion resistance of the coating prepared in this embodiment was tested, and the corrosion resistance performance was as follows: Figure 1 and Figure 2 As shown. Figure 1 The curve with the lowest current density is at an operating current of 500A. Figure 2 The curve at an operating current of 500A shows the largest arc on the Nyquist plot. Therefore, the coating exhibits superior corrosion resistance at an operating current of 500A.

[0031] Example 2

[0032] A method for preparing a metal coating on an additively manufactured 316 stainless steel bipolar plate by changing current parameters, comprising the following steps:

[0033] (1) First, polish the substrate surface with 60#, 240#, 400#, 600# and 800# sandpaper to remove surface oxides or foreign matter, and then blow dry the surface after ultrasonic cleaning with ethanol to remove surface oil.

[0034] (2) Sandblasting should be performed before spraying;

[0035] Depositing Ti Metal Coating: In this example, Ti powder with a purity of 99.7% was used as the raw material. An atmospheric plasma spraying system was employed to prepare the Ti metal coating. Specific process parameters were: operating voltage: 58V, operating current: 500A, primary Ar gas flow rate: 45 / 50L / min, H2 flow rate: 8L / min, secondary Ar gas flow rate: 4L / min, powder feed rate: 8%, powder feed distance: 100mm.

[0036] The surface quality of the coating prepared in this embodiment was tested, such as... Figure 3 and Figure 4 As shown in the figure. Comparison revealed that a single Ar gas flow rate of 45 L / min resulted in superior coating quality; increasing the Ar gas flow rate negatively impacted surface roughness and coating adhesion.

[0037] Example 3

[0038] A method for preparing a metal coating on an additively manufactured 316 stainless steel bipolar plate by changing current parameters, comprising the following steps:

[0039] (3) First, polish the substrate surface with 60#, 240#, 400#, 600# and 800# sandpaper to remove surface oxides or foreign matter, and then blow dry the surface after ultrasonic cleaning with ethanol to remove surface oil.

[0040] (4) Sandblasting should be performed before spraying;

[0041] Depositing Ti Metal Coating: In this example, Ti powder with a purity of 99.7% was used as the raw material. An atmospheric plasma spraying system was employed to prepare the Ti metal coating. Specific process parameters were: operating voltage: 58V, operating current: 500A, primary Ar gas flow rate: 45L / min, H2 flow rate: 8L / min, secondary Ar gas flow rate: 4L / min, powder feed rate: 8%, powder feed distance: 100 / 120mm.

[0042] The corrosion resistance of the coating prepared in this embodiment was tested, and the corrosion resistance performance was as follows: Figure 5 As shown, when the powder feeding distance is 120 mm, the polarization curve exhibits a lower corrosion current density. The surface quality of the coating prepared in this embodiment was tested, as shown... Figure 6 and Figure 7 As shown in the figure. After comparison, it was found that the powder feeding distance has little effect on the surface morphology. When the powder feeding distance is 120 mm, the surface morphology of the coating is relatively dense.

[0043] The above description of the embodiments is provided to enable those skilled in the art to understand and use the invention. It will be apparent to those skilled in the art that various modifications can be made to these embodiments, and the general principles described herein can be applied to other embodiments without inventive effort. Therefore, the present invention is not limited to the above embodiments, and any improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the invention should be within the protection scope of the present invention.

Claims

1. A corrosion-resistant bipolar plate with pure Ti coating based on atmospheric plasma spraying and its preparation method. Its features include the following steps: (1) First, grind the substrate surface to remove surface oxides or foreign matter, and clean and remove surface oil stains before drying; (2) Sandblasting should be performed before spraying; (3) Deposit Ti metal coating. A Ti coating is deposited on the substrate surface after step (2) using a thermal spray deposition process. The purity of the raw material components is 99.7%.

2. The pure Ti-coated corrosion-resistant bipolar plate based on atmospheric plasma spraying and its preparation method according to claim 1, characterized in that: In step (1), the substrate surface is first polished smooth with 60#, 240#, 400#, 600# and 800# sandpaper to remove surface oxides or foreign matter, and then ultrasonically cleaned with ethanol to remove surface oil stains and blown dry.

3. The pure Ti-coated corrosion-resistant bipolar plate based on atmospheric plasma spraying and its preparation method according to claim 1, characterized in that: The sandblasting performed in step (2) facilitates better adhesion to the substrate surface.

4. The pure Ti-coated corrosion-resistant bipolar plate based on atmospheric plasma spraying and its preparation method according to claim 1, characterized in that: The thermal spraying process in step (3) is carried out under atmospheric plasma spraying equipment. Argon is used as a protective gas during the deposition process. In the experiment, a control experiment was conducted by modifying one parameter while keeping the other parameters the same to obtain a better parameter value. The specific process parameters are: working voltage: 58V, working current: 450A / 500A / 550A, primary Ar gas flow rate: 45 / 50L / min, H2 flow rate: 8L / min, secondary Ar gas flow rate: 4L / min, powder feeding rate: 8%, powder feeding distance: 100mm / 120mm.

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