Preparation method of tin coating structural member for energy storage system

Abstract

The invention relates to a preparation method of a tin coating structural member for an energy storage system. The method comprises the following steps: selecting a metal nickel strip Ni with the nickel content being greater than or equal to 99.96% as a raw material; annealing is conducted; performing cleaning; adjusting the surface roughness; cleaning and drying; melting the metallic tin and coating a metallic tin coating. Aiming at the requirement of high bonding strength of the metallic tin coating coated on the surface of the pure nickel strip, a metal coating technology and a surface treatment technology are combined, the surface bonding strength of the metallic nickel coating is improved, and the process has the advantages of short flow, low cost, high production efficiency, no pollution to the environment and the like, and is suitable for the requirement of the pure nickel strip coating in the energy field.

Description

Technical Field

[0001] The invention belongs to the technical field of energy storage, in particular to a method for preparing a metal nickel strip coating for an energy storage system. Background Art

[0002] The background technology of this project is the preparation technology of surface coating of pure metal nickel strip used in the field of energy storage.

[0003] Pure nickel has good heat transfer and electrical conductivity, processing ductility and corrosion resistance, and is widely used in battery energy and other industries. Compared with nickel, pure tin has better plasticity and a lower melting point of 232°C. Tin has stable chemical properties at room temperature, good thermal and electrical conductivity, is non-toxic and tasteless, corrosion-resistant, anti-oxidation, and can maintain metallic luster. Currently, tin is mainly used as solder. In recent years, the application of pure nickel strips and their composite coating strips has continued to expand, and the demand for nickel and tin has also continued to increase.

[0004] The content of metallic nickel in pure nickel exceeds 99%wt. In addition to the main element nickel, pure metallic nickel also contains trace elements. The national standard stipulates that the total content of trace impurity elements in pure nickel strip with the grade N6 is less than or equal to 0.5%wt, the total impurity content of N4 nickel strip does not exceed 0.1%wt, and the requirement for N2 nickel strip is higher, and the total impurity content does not exceed 0.02%wt. Among them, typical harmful impurity elements such as sulfur S are easy to form low-melting point eutectics with metallic nickel, affecting the high-temperature performance of the material. In addition, the elements phosphorus and sulfur have a great affinity with nickel. During solidification and crystallization, NiS2-Ni and Ni3P-Ni are formed and distributed at the grain boundaries, which makes it easy to reduce the weld strength during the material welding process; and when the carbon C content in the metal exceeds 0.1%, carbon is easy to precipitate in the nickel in the form of graphite, destroying the intercrystalline bonding force, causing cold brittleness and reducing the mechanical properties of the material.

[0005] Due to reasons such as technical level and product quality, the pure metal tin coating on the surface of the metal nickel strip currently prepared in China has low bonding strength and is easy to peel off, affecting the coating quality.

[0006] According to analysis, the preparation of nickel-plated metal strip coating materials is usually based on the principle of liquid metal wetting or penetration. There are still some process or technical problems in the preparation, such as the matrix alloy not wetting the coating material interface or the occurrence of interface reaction. For example, if there are more inorganic carbon elements on the surface of the strip, the carbon C element and the liquid metal Sn and Al do not wet each other. The reason why they are difficult to wet is that the surface tension of the metal and carbon materials is large. Moreover, C is easy to react with Sn and Al metal melts to generate unstable interface products. The generated brittle interface products cause stress concentration in the material under stress, causing the reinforcement to separate from the matrix.

[0007] In addition, before deep processing, metal strips including nickel strips have a layer of oxide film with a thickness of micrometers attached to the surface. Due to the poor wettability between the oxide layer and the metal coating during the coating process, the bonding strength of the coating will be significantly reduced. Summary of the invention

[0008] The purpose of the present invention is to address the problems that the process or technical defects existing in the preparation of metal nickel strip coating materials lead to low coating bonding strength, easy peeling and affecting the coating quality. A preparation method of tin-coated structural parts for energy storage systems is proposed. Metal tin is coated on the surface of pure metal nickel strips, the preparation cost is low, the interface bonding strength between the coating and the substrate is high, and the quality of the coating is improved.

[0009] The technical solution of the present invention is:

[0010] A method for preparing a tin-coated structural member for an energy storage system, the method comprising the following steps:

[0011] (1) Material selection: Use nickel strip with nickel content ≥ 99.96% as raw material;

[0012] (2) Annealing: The metal nickel strip is annealed in a heat treatment furnace with inert gas protection;

[0013] (3) Cleaning: Use organic solvent to clean the surface, and apply ultrasonic waves in the tank during the cleaning process;

[0014] (4) Adjust the surface roughness: polish the surface of the nickel strip to meet the surface roughness standards;

[0015] (5) Cleaning and drying: Use deionized water to clean the surface of the nickel strip and then dry it;

[0016] (6) Metal tin melting: melting metal tin under the protection of inert gas;

[0017] (7) Applying a metal tin coating: The area to be coated of the dried nickel strip is immersed in a metal tin molten pool, and then taken out to cool.

[0018] Furthermore, in the raw materials of step (1), the nickel content Ni is ≥ 99.96%, and the carbon content C is ≤ 0.03%.

[0019] Furthermore, in the step (2), the annealing temperature is 800° C. to 900° C., and the heat preservation time is 2 min to 10 min.

[0020] Furthermore, the inert gas is high-purity argon gas with a purity of ≥99.8%.

[0021] Furthermore, in step (3), the organic solvent is a hydrocarbon cleaning agent.

[0022] Furthermore, in step (3), the parameter of applying ultrasonic waves in the tank during the cleaning process is 50KHz, and the cleaning time is 10 minutes.

[0023] Furthermore, in the step (3), the surface roughness reaches the standard range of: level 6 Ra3.2 to level 8 Ra0.8.

[0024] Furthermore, in step (6), a heating tank is used to melt the metal tin, the heating temperature is 550° C. to 650° C., and argon is used as the inert gas.

[0025] Furthermore, in the step (7), the infiltration time is 2S to 5S.

[0026] Furthermore, the method also includes: (8) inspection and storage of finished products: visually inspect the surface quality of the coating, and if there are no cracks or peeling defects, qualified finished products are stored.

[0027] Beneficial effects of the present invention:

[0028] The invention improves the interface bonding strength through the processes of nickel strip annealing, surface treatment, coating and the like.

[0029] The present invention aims at the demand for high bonding strength of metal tin coating on the surface of pure nickel strip, combines metal coating technology and surface treatment technology, improves the surface bonding strength of metal nickel coating, and has the advantages of short process, low cost, high production efficiency and no pollution to the environment, and is suitable for the demand for pure nickel strip coating in the energy field.

[0030] Other features and advantages of the present invention will be described in detail in the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The above and other objects, features and advantages of the present invention will become more apparent through a more detailed description of exemplary embodiments of the present invention in conjunction with the accompanying drawings, wherein like reference numerals generally represent like components throughout the exemplary embodiments of the present invention.

[0032] Figure 1 A schematic diagram of coating of a product prepared according to a method of one embodiment of the present invention is shown.

[0033] Figure 2 A schematic diagram of coating of products prepared by traditional methods is shown. DETAILED DESCRIPTION

[0034] The scheme of the present invention will be described in more detail below with reference to examples. Although the examples show preferred embodiments of the present invention, it should be understood that the present invention can be implemented in various forms and should not be limited to the embodiments set forth herein.

[0035] In the present invention, % in the ingredients refers to the mass percentage.

[0036] Embodiment 1:

[0037] A metal nickel strip Ni with a nickel content of 99.97%wt is selected as the raw material; the carbon (C) element content is 0.02%wt;

[0038] The metal nickel strip is annealed in a heat treatment furnace with an inert gas protective atmosphere, the annealing process parameters are 800°C, and the temperature is kept for 2 minutes;

[0039] Place the metal nickel strip in a rectangular tank of suitable size, use an organic solvent to clean the surface grease and adhering pollutant particles, and apply ultrasonic waves in the tank during the cleaning process to improve the cleaning effect;

[0040] The pure metal nickel belt surface is polished with a sanding belt, and the surface roughness reaches level 6 (Ra3.2). The sanding belt model used is 1200 mesh;

[0041] The nickel strip is cleaned with deionized water and then dried;

[0042] Pure metallic tin is melted in a heating tank at a temperature of 550°C. The surface of the metallic tin molten pool is protected by high-purity argon gas to prevent the molten tin from oxidizing at high temperatures.

[0043] Immerse the nickel strip that needs to be coated into the metal tin molten pool for 2 seconds, then take out the nickel strip coated with metal tin and cool it to room temperature;

[0044] Visually inspect the surface quality of the composite coating to ensure that there are no defects such as cracks and peeling, and qualified finished products are put into storage.

[0045] Embodiment 2:

[0046] A metal nickel strip Ni with a nickel content of 99.98%wt is selected as the raw material; the carbon (C) element content is 0.01%wt;

[0047] The metal nickel strip is annealed in a heat treatment furnace with an inert gas protective atmosphere, the annealing process parameters are 900°C, and the temperature is kept for 10 minutes;

[0048] Place the metal nickel strip in a rectangular tank of suitable size, use an organic solvent to clean the surface grease and adhering pollutant particles, and apply ultrasonic waves in the tank during the cleaning process to improve the cleaning effect;

[0049] The surface of the pure metal nickel belt is polished with a sand belt, and the surface roughness reaches level 8 (Ra0.8). The sand belt model used is 1500 mesh;

[0050] The nickel strip is cleaned with deionized water and then dried;

[0051] Pure metallic tin is melted in a heating tank at a temperature of 650°C. The surface of the metallic tin molten pool is protected by high-purity argon gas to prevent the molten tin from oxidizing at high temperatures.

[0052] Immerse the nickel strip that needs to be coated into the metal tin molten pool for 5 seconds, then take out the nickel strip coated with metal tin and cool it to room temperature;

[0053] Visually inspect the surface quality of the composite coating to ensure that there are no defects such as cracks and peeling, and qualified finished products are put into storage.

[0054] like Figure 1 , 2 A schematic diagram of coating of a product prepared according to a method of an embodiment of the present invention and a schematic diagram of coating of a product prepared by a traditional method are respectively shown. The test results of the products of Embodiment 1 and Embodiment 2 compared with the traditional method are shown in Table 1.

[0055] Table 1

[0056] Process Category Bonding strength crack Surface waves fold Traditional methods Low A small amount exists Small amount A small amount exists Example 1 Method Higher none none none Example 2 Method Higher none none none

[0057] The above traditional method steps are as follows:

[0058] Material selection: nickel strip is 99.7% by weight. Nickel strip is cleaned with water solvent. Pure tin is melted in a heating tank at a temperature of 560°C. The nickel strip to be coated is immersed in the molten pool of tin for 2 seconds, and then the nickel strip coated with tin is taken out and cooled to room temperature. Visual inspection is performed to check if there are no defects such as cracks and peeling on the coating surface, and the qualified ones are put into storage.

[0059] The embodiments of the present invention have been described above, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and changes will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments.

Claims

1. A method for preparing a tin-coated structural member for an energy storage system, characterized in that: The method comprises the following steps: (1) Material selection: Use nickel strip with nickel content ≥ 99.96% as raw material; (2) Annealing: The metal nickel strip is annealed in a heat treatment furnace with inert gas protection; (3) Cleaning: Use organic solvent to clean the surface, and apply ultrasonic waves in the tank during the cleaning process; (4) Adjust the surface roughness: polish the surface of the nickel strip to meet the surface roughness standards; (5) Cleaning and drying: Use deionized water to clean the surface of the nickel strip and then dry it; (6) Metal tin melting: melting metal tin under the protection of inert gas; (7) Applying a metal tin coating: The area to be coated of the dried nickel strip is immersed in a metal tin molten pool, and then taken out to cool.

2. The method for preparing a tin-coated structural member for an energy storage system according to claim 1, characterized in that: In the raw materials of step (1), the nickel content Ni is ≥ 99.96%, and the carbon content C is ≤ 0.03%.

3. The method for preparing a tin-coated structural member for an energy storage system according to claim 1, characterized in that: In the step (2), the annealing temperature is 800° C. to 900° C., and the temperature is kept for 2 min to 10 min.

4. The method for preparing a tin-coated structural member for an energy storage system according to claim 1, characterized in that: The inert gas is high-purity argon with a purity of ≥99.8%.

5. The method for preparing a tin-coated structural member for an energy storage system according to claim 1, characterized in that: In the step (3), the organic solvent is a hydrocarbon cleaning agent.

6. The method for preparing a tin-coated structural member for an energy storage system according to claim 1, characterized in that: In the step (3), the ultrasonic wave parameters applied in the tank during the cleaning process are 50 KHz and the cleaning time is 10 minutes.

7. The method for preparing a tin-coated structural member for an energy storage system according to claim 1, characterized in that: In the step (3), the surface roughness reaches the standard range of: level 6 Ra3.2 to level 8 Ra0.

8.

8. The method for preparing a tin-coated structural member for an energy storage system according to claim 1, characterized in that: In the step (6), a heating tank is used to melt the metal tin, the heating temperature is 550° C. to 650° C., and argon is used as the inert gas.

9. The method for preparing a tin-coated structural member for an energy storage system according to claim 1, characterized in that: In the step (7), the infiltration time is 2S to 5S.

10. The method for preparing a tin-coated structural member for an energy storage system according to claim 1, characterized in that: The method also includes: (8) inspection and storage of finished products: visually inspect the surface quality of the coating, and if there are no cracks or peeling defects, qualified finished products are stored.

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