Alloying-promoting flux material and preparation method thereof, photovoltaic module welding process

Abstract

The present application belongs to the field of photovoltaic welding technology, and specifically provides an alloying flux material and its preparation method, as well as a photovoltaic module welding process. The preparation method of the alloying flux material comprises the following steps: 1) uniformly mixing an activator, a solvent, a film-forming agent, a surfactant, a pH regulator, an antioxidant, and a corrosion inhibitor to obtain a base liquid; 2) uniformly mixing a calcium salt, a rare earth metal salt, and ethanol, and then adding triethylamine to obtain a mixed liquid; then adding a phosphoric acid / ethanol mixed solution to the mixed liquid and stirring to obtain a precursor liquid; 3) mixing the base liquid and the precursor liquid, adding a rheological agent, and continuing to mix uniformly. The alloying flux material prepared by the present application has the advantages of good welding wetting performance and good welding effect.

Description

Technical Field

[0001] The present application belongs to the field of photovoltaic welding technology, and in particular relates to an alloying-promoting flux material and a preparation method thereof, and a photovoltaic module welding process. Background Art

[0002] As an abundant, clean, and renewable energy source, solar energy is the best alternative to traditional energy sources such as oil, natural gas, and coal. Currently, solar energy is primarily utilized through the conversion of light energy into electricity and heat energy. Photovoltaic power generation, in particular, has a wide range of applications, including power stations, oil and gas, marine applications, construction, transportation, and even daily electricity consumption.

[0003] Taking solar photovoltaic module production as an example, the production process includes cell testing, front-side single soldering, back-side string soldering, lamination and assembly, module lamination, trimming, framing, junction box welding, and testing. The production process generally involves soldering tinned copper strips to the cells to prepare for series connection. Next, the cells are soldered in series according to a specified number, and the strings are connected. The cells are then protected with glass, EVA film, and a TPT backsheet, and then bonded together under certain temperature, pressure, and vacuum conditions. Because the resulting solar photovoltaic modules must withstand a variety of harsh environments and prolonged exposure to sunlight, the various process requirements for solar photovoltaic modules are extremely high.

[0004] Photovoltaic ribbons and their welding processes are key components of photovoltaic cell modules. Their key function is to connect the cells and transmit the current generated by them. Therefore, the quality of solar cell welding directly impacts the development of photovoltaic applications. Numerous research has been conducted on this topic. For example, Wang Haidong's article, "Crystalline Silicon Solar Cell Welding Technology and Development Trends," outlines existing soldering processes for crystalline silicon solar cells and analyzes the key factors influencing the soldering process (soldering temperature, ribbon, flux, and operator specifications). He also introduces new soldering processes such as ultrasonic and conductive adhesives. Mu Erlong's article, "Research and Development of Low-Melting-Point Tin-Lead-Based Solder for Photovoltaic Ribbon," highlights the importance of optimizing the composition of the Sn-Pb solder alloy and adding flux to improve soldering performance.

[0005] Among the many factors that affect welding results, flux materials play a key role. How to develop high-performance flux materials to improve the welding effect of photovoltaic modules is an urgent problem to be solved. Summary of the Invention

[0006] In response to the above problems, in order to further improve the welding effect of photovoltaic modules, the present application provides an alloying-promoting flux material and a preparation method thereof, and a photovoltaic module welding process.

[0007] This application first provides a method for preparing an alloying flux material, comprising the following steps:

[0008] 1) The activator, solvent, film-forming agent, surfactant, pH adjuster, antioxidant and corrosion inhibitor are mixed uniformly to prepare the base liquid;

[0009] 2) Calcium salt, rare earth metal salt, and ethanol are mixed uniformly, and triethylamine is added and mixed uniformly to obtain a mixed solution. A phosphoric acid / ethanol mixed solution is then added to the mixed solution, and the precursor solution is obtained after stirring;

[0010] 3) Mix the base liquid and precursor liquid, add the rheological agent and continue mixing evenly.

[0011] Furthermore, in step 1), the activating agent is an organic acid;

[0012] And / or, in step 1), the solvent is one or more of ethylene glycol monobutyl ether, propylene glycol methyl ether, n-octanol, tetrahydrofurfural, glycerol, diethylene glycol, and ethanol;

[0013] And / or, in step 1), the film-forming agent is a rosin-type film-forming agent;

[0014] And / or, in step 1), the surfactant is a nonionic surfactant;

[0015] And / or, in step 1), the antioxidant is a phenolic antioxidant;

[0016] And / or, in step 1), the corrosion inhibitor is benzotriazole.

[0017] Furthermore, in step 2), the usage ratio of calcium salt, rare earth metal salt, ethanol and triethylamine is (0.2-0.5 g):(0.05-0.1 g):(100-120 mL):(1-5 mL).

[0018] Furthermore, in step 2), the rare earth metal salt is a scandium salt or a niobium salt.

[0019] Furthermore, in step 2), the volume ratio of phosphoric acid to ethanol in the phosphoric acid / ethanol mixed solution is 1:(40-50).

[0020] Furthermore, in step 3), the volume ratio of the base liquid to the precursor liquid is 1:(0.05-0.1);

[0021] And / or, in step 3), the rheological agent is one or more of hydrogenated castor oil, ethyl cellulose, and polyamide wax.

[0022] The present application provides an alloying-promoting flux material, which is prepared using the above-mentioned preparation method.

[0023] This application provides a photovoltaic module welding process, comprising the following steps:

[0024] S1: Install the interconnecting strip on the welding machine;

[0025] S2: Use coating equipment to evenly apply alloying flux material on the surface of the soldering pattern battery or the surface of the interconnection bar, and use hot air for preliminary curing;

[0026] and / or, using a coating device to evenly apply silver glue or solder paste or alloying flux material on the surface of the battery or the surface of the interconnect bar, and using hot air for preliminary curing; the battery is one of an HJT / topcon / BC battery, a perovskite battery, and an HJT\Topcon perovskite tandem battery;

[0027] The alloying-promoting flux material is prepared by the above-mentioned preparation method;

[0028] S3: stack the interconnection bars and the battery grid lines accordingly and then weld them into strings.

[0029] Furthermore, in step S1, the interconnection bar is a SnPb-coated interconnection bar or a SnPbBi-coated low-temperature interconnection bar.

[0030] Furthermore, in step S3, the welding is performed by infrared welding, hot air welding or electromagnetic welding.

[0031] Compared with the prior art, this application has the following beneficial effects:

[0032] 1. This application utilizes a base fluid formulated with an activator, solvent, film-forming agent, surfactant, and other raw materials. This base fluid dissolves and removes oxides from metal surfaces, then infiltrates and spreads on the metal surface to form a physical adsorption film, effectively isolating the metal from air and reducing the generation of intermetallic compounds during welding, thereby improving the strength of the weld joint. Furthermore, this base fluid can help eliminate defects during welding, reduce problems such as oxidation and corrosion, and improve weld quality.

[0033] 2. This application adds a precursor liquid to the base liquid. The precursor liquid contains nano-polymer particles formed from calcium salts and rare earth metal salts. These nano-polymer particles can form a physical adsorption film on the metal surface to protect it, inhibiting the occurrence of welding defects such as loose and porous solder joints and harmful expansion, thereby improving the strength of the weld joint. In addition, trace amounts of rare earth metal atoms can promote the growth and branching of the SnPb alloy phase, playing a good refinement role and promoting the formation of an interfacial reaction layer during welding, thereby inhibiting the formation of weld holes and cracks, further improving weld quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1Schematic diagram of the solder joint wetting performance of Examples 1-2 and Control Groups 1-2 of the present application.

[0035] Figure 2 These are SEM images of the solder joint cross sections of Examples 1-2 and Control Groups 1-2 of the present application.

[0036] Figure 3 This is a TEM image of the precursor solution of Example 2 of the present application. DETAILED DESCRIPTION

[0037] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0038] After extensive experimental research, this application provides a method for preparing a promoting alloying flux material, comprising the following steps:

[0039] 1) The activator, solvent, film-forming agent, surfactant, pH adjuster, antioxidant and corrosion inhibitor are mixed uniformly to prepare the base liquid;

[0040] 2) Calcium salt, rare earth metal salt, and ethanol are mixed uniformly, and triethylamine is added and mixed uniformly to obtain a mixed solution. A phosphoric acid / ethanol mixed solution is then added to the mixed solution, and the precursor solution is obtained after stirring;

[0041] 3) Mix the base liquid and precursor liquid, add the rheological agent and continue mixing evenly.

[0042] Furthermore, in step 1), the activating agent is an organic acid;

[0043] More preferably, in step 1), the organic acid is one or more of methylsuccinic acid, DL-malic acid, lactic acid, oxalic acid, sebacic acid, azelaic acid, citric acid, salicylic acid, palmitic acid, adipic acid, benzoic acid, and stearic acid.

[0044] In some specific embodiments, under normal circumstances, in step 1), when the organic acid consists of DL-malic acid and salicylic acid, better experimental results can be achieved. More preferably, in step 1), the organic acid consists of DL-malic acid and salicylic acid in a mass ratio of 5:3.

[0045] And / or, in step 1), the solvent is one or more of ethylene glycol monobutyl ether, propylene glycol methyl ether, n-octanol, tetrahydrofurfural, glycerol, diethylene glycol, and ethanol;

[0046] In some specific embodiments, in step 1), the solvent selected from ethylene glycol monobutyl ether, propylene glycol methyl ether, n-octanol, and tetrahydrofurfural achieves better results. More preferably, under normal circumstances, the solvent is ethylene glycol monobutyl ether, propylene glycol methyl ether, n-octanol, and tetrahydrofurfural in a mass ratio of 1:2:3:3, which achieves better experimental results.

[0047] And / or, in step 1), the film-forming agent is a rosin-type film-forming agent;

[0048] In some specific embodiments, more preferably, in step 1), the film-forming agent is ice white rosin.

[0049] And / or, in step 1), the surfactant is a nonionic surfactant;

[0050] In some specific embodiments, more preferably, in step 1), when octylphenol polyoxyethylene ether is selected as the surfactant, the effect is better.

[0051] And / or, in step 1), the antioxidant is a phenolic antioxidant;

[0052] In some specific embodiments, more preferably, in step 1), when hydroquinone is selected as the antioxidant, better experimental results can be obtained.

[0053] And / or, in step 1), the corrosion inhibitor is benzotriazole.

[0054] Furthermore, in step 2), the usage ratio of calcium salt, rare earth metal salt, ethanol and triethylamine is (0.2-0.5 g):(0.05-0.1 g):(100-120 mL):(1-5 mL).

[0055] In some specific embodiments, in step 2), the usage ratio of calcium salt, rare earth metal salt, ethanol and triethylamine can be 0.2g:0.05g:100mL:1mL, 0.3g:0.05g:100mL:1mL, 0.4g:0.05g:100mL:1mL, 0.5g:0.05g:100mL:1mL, 0.2g:0.065g:100mL:1mL, 0.3g:0.8g:100mL:1mL, 0.4g:0.9g:100mL:1mL L, 0.5g:0.1g:100mL:1mL, 0.2g:0.065g:105mL:1mL, 0.3g:0.8g:110mL:1mL, 0.4g:0.9g:115mL:1mL, 0.5g:0.1g:120mL:1mL, 0.2g:0.065g:105mL:2mL, 0.3g:0.8g:110mL:3mL, 0.4g:0.9g:115mL:4mL, 0.5g:0.1g:120mL:5mL. More preferably, under normal circumstances, in the step 2), when the usage ratio of calcium salt, rare earth metal salt, ethanol, and triethylamine is 0.3g:0.05g:100mL:5mL, better technical effects can be obtained.

[0056] Furthermore, in step 2), the rare earth metal salt is a scandium salt or a niobium salt.

[0057] In some specific embodiments, in step 2), the rare earth metal salt comprises a scandium salt and a niobium salt in a mass ratio of 1:(0.5-1). More preferably, under normal circumstances, in step 2), the rare earth metal salt comprises a scandium salt and a niobium salt in a mass ratio of 1:0.75, which can achieve better experimental results.

[0058] Furthermore, in step 2), the volume ratio of phosphoric acid to ethanol in the phosphoric acid / ethanol mixed solution is 1:(40-50).

[0059] In some specific embodiments, in step 2), the volume ratio of phosphoric acid to ethanol in the phosphoric acid / ethanol mixed solution can be 1:40, 1:41, 1:42, 1:43, 1:44, 1:45, 1:46, 1:47, 1:48, 1:49, or 1:50. Generally, in step 2), a volume ratio of phosphoric acid to ethanol in the phosphoric acid / ethanol mixed solution of 1:45 achieves optimal experimental results.

[0060] Furthermore, in step 3), the volume ratio of the base liquid to the precursor liquid is 1:(0.05-0.1);

[0061] In some specific embodiments, in step 3), the volume ratio of the base liquid to the precursor liquid is 1:0.05, 1:0.055, 1:0.06, 1:0.065, 1:0.07, 1:0.075, 1:0.08, 1:0.085, 1:0.09, 1:0.095, or 1:0.1. Generally, in step 3), a volume ratio of the base liquid to the precursor liquid of 1:0.09 achieves optimal experimental results.

[0062] More preferably, a polysaccharide quaternary ammonium derivative is added when the base liquid and the precursor liquid are mixed. More preferably, the polysaccharide quaternary ammonium salt derivative is prepared from dextran and a quaternary ammonium salt.

[0063] And / or, in step 3), the rheological agent is one or more of hydrogenated castor oil, ethyl cellulose, and polyamide wax.

[0064] In some specific embodiments, under normal circumstances, in step 3), better experimental results can be obtained when hydrogenated castor oil is used as the rheological agent.

[0065] The present application provides an alloying-promoting flux material, which is prepared using the above-mentioned preparation method.

[0066] This application provides a photovoltaic module welding process, comprising the following steps:

[0067] S1: Install the interconnecting strip on the welding machine;

[0068] S2: Use coating equipment to evenly apply alloying flux material on the surface of the soldering pattern battery or the surface of the interconnection bar, and use hot air for preliminary curing;

[0069] and / or, using a coating device to evenly apply silver glue or solder paste or alloying flux material on the surface of the battery or the surface of the interconnect bar, and using hot air for preliminary curing; the battery is one of an HJT / topcon / BC battery, a perovskite battery, and an HJT\Topcon perovskite tandem battery;

[0070] The alloying-promoting flux material is prepared by the above-mentioned preparation method;

[0071] S3: stack the interconnection bars and the battery grid lines accordingly and then weld them into strings.

[0072] Furthermore, in step S1, the interconnection bar is a SnPb-coated interconnection bar or a SnPbBi-coated low-temperature interconnection bar.

[0073] Furthermore, in step S3, the welding is performed by infrared welding, hot air welding or electromagnetic welding.

[0074] Generally, in step S1, better technical effects can be achieved when the interconnection bars are SnPbBi coated low-temperature interconnection bars.

[0075] Preferably, the photovoltaic module welding process of the present application can be applied to the welding of OBBtopcon / HJT cells and XBC / perovskite cells.

[0076] Example 1

[0077] The preparation method of the alloying-promoting flux material of this embodiment includes the following steps:

[0078] 1) Accurately weigh 8g of activator (composed of 5g DL-malic acid and 3g salicylic acid), 45g of solvent (composed of 5g ethylene glycol monobutyl ether, 10g propylene glycol methyl ether, 15g tetrahydrofurfuryl alcohol, and 15g n-octanol), 30g of film-forming agent (ice white rosin), 1g of surfactant (octylphenol polyoxyethylene ether-10), pH adjuster, 1g of antioxidant (hydroquinone), and 1g of corrosion inhibitor (benzotriazole), and mix them evenly to prepare a base solution;

[0079] 2) Add 0.3 g of calcium salt (calcium chloride dihydrate), 0.05 g of rare earth metal salt (scandium chloride and niobium chloride in a mass ratio of 1:0.75) and 100 mL of anhydrous ethanol to a beaker and mix well. Then, add 5 mL of triethylamine and mix well to obtain a mixture. Then, add a phosphoric acid / ethanol mixed solution (the volume ratio of phosphoric acid to ethanol is 1:45) to the mixture and stir to obtain a precursor solution.

[0080] 3) Take 100 mL of base liquid and 9 mL of precursor liquid, mix them, add 5 g of rheological agent (hydrogenated castor oil), and continue mixing at a stirring speed of 1200 r / min for 25 minutes to prepare the alloying flux material.

[0081] The photovoltaic module welding process of this embodiment includes the following steps:

[0082] S1: Install SnPbBi coated low temperature interconnect strips on the welding machine;

[0083] S2: Use coating equipment to evenly apply alloying flux material on the surface of the cell or interconnect bar, and use hot air for preliminary curing; the cell is one of HJT / topcon / BC cell, perovskite cell, or HJT\Topcon perovskite tandem cell;

[0084] S3: Stack the interconnection strips and battery grid lines accordingly and connect them into strings by infrared welding.

[0085] Example 2

[0086] The preparation method of the alloying-promoting flux material of this embodiment includes the following steps:

[0087] 1) Accurately weigh 8g of activator (composed of 5g DL-malic acid and 3g salicylic acid), 45g of solvent (composed of 5g ethylene glycol monobutyl ether, 10g propylene glycol methyl ether, 15g tetrahydrofurfuryl alcohol, and 15g n-octanol), 30g of film-forming agent (ice white rosin), 1g of surfactant (octylphenol polyoxyethylene ether-10), pH adjuster, 1g of antioxidant (hydroquinone), and 1g of corrosion inhibitor (benzotriazole), and mix them evenly to prepare a base solution;

[0088] 2) Add 0.3 g of calcium salt (calcium chloride dihydrate), 0.05 g of rare earth metal salt (scandium chloride and niobium chloride in a mass ratio of 1:0.75) and 100 mL of anhydrous ethanol to a beaker and mix well. Then, add 5 mL of triethylamine and mix well to obtain a mixture. Then, add a phosphoric acid / ethanol mixed solution (the volume ratio of phosphoric acid to ethanol is 1:45) to the mixture and stir to obtain a precursor solution.

[0089] 3) Take 100 mL of base liquid, 9 mL of precursor liquid, and 0.2 g of polysaccharide quaternary ammonium derivative, mix them, add 5 g of rheological agent (hydrogenated castor oil), and continue mixing at a stirring speed of 1200 r / min for 25 minutes to prepare the alloying flux material.

[0090] The polysaccharide quaternary ammonium derivative of this embodiment is prepared by the following method:

[0091] A) Add 0.1 mol of N,N-dimethylaminoethyl methacrylate and 0.1 mol of benzyl chloride to a flask, then add 100 mL of dichloromethane and mix well. Then add a small amount of hydroquinone and reflux to obtain a quaternary ammonium salt.

[0092] B) In a 500 mL three-necked flask, add 100 mL of deionized water and 1 g of konjac glucan. Purge with nitrogen. Then, add 2 mL of cerium ammonium nitrate in nitric acid solution and 3 g of quaternary ammonium salt. Heat to 70°C for 3 h. Then, precipitate with an ethanol / water mixture, filter, wash, and vacuum dry to obtain the product.

[0093] The photovoltaic module welding process of this embodiment includes the following steps:

[0094] S1: Install SnPbBi coated low temperature interconnect strips on the welding machine;

[0095] S2: Use coating equipment to evenly apply alloying flux material on the surface of the cell or interconnect bar, and use hot air for preliminary curing; the cell is one of HJT / topcon / BC cell, perovskite cell, or HJT\Topcon perovskite tandem cell;

[0096] S3: Stack the interconnection strips and battery grid lines accordingly and connect them into strings by infrared welding.

[0097] Control group 1

[0098] The preparation method of the flux material of this control group includes the following steps:

[0099] 1) Accurately weigh 8g of activator (composed of 5g DL-malic acid and 3g salicylic acid), 45g of solvent (composed of 5g ethylene glycol monobutyl ether, 10g propylene glycol methyl ether, 15g tetrahydrofurfuryl alcohol, and 15g n-octanol), 30g of film-forming agent (ice white rosin), 1g of surfactant (octylphenol polyoxyethylene ether-10), pH adjuster, 1g of antioxidant (hydroquinone), and 1g of corrosion inhibitor (benzotriazole), and mix them evenly to prepare a base solution;

[0100] 2) Take 100 mL of base liquid and 5 g of rheological agent (hydrogenated castor oil) and continue mixing at a stirring speed of 1200 r / min for 25 minutes to prepare the flux material.

[0101] The photovoltaic module welding process of this control group includes the following steps:

[0102] S1: Install SnPbBi coated low temperature interconnect strips on the welding machine;

[0103] S2: Use coating equipment to evenly apply flux material on the surface of the cell or interconnect bar, and use hot air for preliminary curing; the cell is one of HJT / topcon / BC cell, perovskite cell, or HJT\Topcon perovskite tandem cell;

[0104] S3: stack the interconnection strips and battery grid lines accordingly and connect them into strings by infrared welding.

[0105] Control group 2

[0106] The preparation method of the flux material of this control group includes the following steps:

[0107] 1) Accurately weigh 8g of activator (composed of 5g DL-malic acid and 3g salicylic acid), 45g of solvent (composed of 5g ethylene glycol monobutyl ether, 10g propylene glycol methyl ether, 15g tetrahydrofurfuryl alcohol, and 15g n-octanol), 30g of film-forming agent (ice white rosin), 1g of surfactant (octylphenol polyoxyethylene ether-10), pH adjuster, 1g of antioxidant (hydroquinone), and 1g of corrosion inhibitor (benzotriazole), and mix them evenly to prepare a base solution;

[0108] 2) Add 0.3 g of calcium salt (calcium chloride dihydrate), 0.05 g of rare earth metal salt (scandium chloride and niobium chloride in a mass ratio of 1:0.75), and 100 mL of anhydrous ethanol to a beaker and mix well to obtain a precursor solution.

[0109] 3) Take 100 mL of base liquid and 9 mL of precursor liquid, mix them, add 5 g of rheological agent (hydrogenated castor oil), and continue mixing at a stirring speed of 1200 r / min for 25 minutes to prepare the flux material.

[0110] The photovoltaic module welding process of this control group includes the following steps:

[0111] S1: Install SnPbBi coated low temperature interconnect strips on the welding machine;

[0112] S2: Use coating equipment to evenly apply flux material on the surface of the cell or interconnect bar, and use hot air for preliminary curing; the cell is one of HJT / topcon / BC cell, perovskite cell, or HJT\Topcon perovskite tandem cell;

[0113] S3: stack the interconnection strips and battery grid lines accordingly and connect them into strings by infrared welding.

[0114] Performance testing

[0115] 1. Take the soldering materials of Examples 1-2 and Control Groups 1-2 and conduct soldering performance tests according to GB / T9491-2021. The test results of the wetting angle are as follows: Figure 1 It can be seen that the flux material of the present application can effectively improve the wetting performance and expansion performance of the solder joint.

[0116] 2. Use electron scanning electron microscope to observe the cross section of the solder joint. The results are as follows: Figure 2 It can be seen that the flux material of the present application can improve the welding quality of the solder joints, with a smooth cross-sectional structure and no welding defects such as pores and microcracks, thereby improving the connection strength of the solder joints.

[0117] 3. Take the precursor solution of Example 2 and perform transmission electron microscopy to observe the morphology of the precursor solution. The results are as follows: Figure 3 As shown, it can be seen that uniform nano-polymer particles are formed in the precursor liquid, which helps to improve the welding quality.

[0118] Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments, or make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present application should be included in the scope of protection of the present invention.

Claims

1. A method for preparing a promoting alloying flux material, characterized in that: The steps include: 1) The activator, solvent, film-forming agent, surfactant, pH adjuster, antioxidant and corrosion inhibitor are mixed uniformly to prepare the base liquid; 2) Calcium salt, rare earth metal salt, and ethanol are mixed evenly, and triethylamine is added to obtain a mixed solution. A phosphoric acid / ethanol mixed solution is then added to the mixed solution, and the mixture is stirred to obtain a precursor solution. The precursor solution contains nano-polymer particles formed by calcium salt and rare earth metal salt, which inhibit the loose and porous surface of the solder joint and harmful expansion. 3) Mix the base liquid and precursor liquid, add the rheological agent and continue mixing evenly.

2. The method for preparing the alloying flux material according to claim 1, wherein: In the step 1), the activator is an organic acid; And / or, in step 1), the solvent is one or more of ethylene glycol monobutyl ether, propylene glycol methyl ether, n-octanol, tetrahydrofurfural, glycerol, diethylene glycol, and ethanol; And / or, in step 1), the film-forming agent is a rosin-type film-forming agent; And / or, in step 1), the surfactant is a nonionic surfactant; And / or, in step 1), the antioxidant is a phenolic antioxidant; And / or, in step 1), the corrosion inhibitor is benzotriazole.

3. The method for preparing the alloying flux material according to claim 1, wherein: In the step 2), the usage ratio of calcium salt, rare earth metal salt, ethanol and triethylamine is (0.2-0.5 g):(0.05-0.1 g):(100-120 mL):(1-5 mL).

4. The method for preparing the alloying-promoting flux material according to claim 3, wherein: In the step 2), the rare earth metal salt is a scandium salt or a niobium salt.

5. The method for preparing the alloying-promoting flux material according to claim 1, wherein: In step 2), the volume ratio of phosphoric acid to ethanol in the phosphoric acid / ethanol mixed solution is 1:(40-50).

6. The method for preparing the alloying-promoting flux material according to claim 1, wherein: In step 3), the volume ratio of the base liquid to the precursor liquid is 1:(0.05-0.1); And / or, in step 3), the rheological agent is one or more of hydrogenated castor oil, ethyl cellulose, and polyamide wax.

7. An alloying-promoting flux material, characterized in that: The method is as described in any one of claims 1 to 6.

8. A photovoltaic module welding process, characterized by: The steps include: S1: Install the interconnecting strip on the welding machine; S2: Using a coating device to evenly apply alloying flux material on the surface of the cell or the surface of the interconnect bar, and using hot air for preliminary curing; the cell is one of an HJT / topcon / BC cell, a perovskite cell, and an HJT / Topcon perovskite tandem cell; The alloying-promoting flux material is prepared by the preparation method according to any one of claims 1 to 6; S3: stack the interconnection bars and the battery grid lines accordingly and then weld them into strings.

9. The photovoltaic module welding process according to claim 8, characterized in that: In the step S1, the interconnection bar is a SnPb-coated interconnection bar or a SnPbBi-coated low-temperature interconnection bar.

10. The photovoltaic module welding process according to claim 8, characterized in that: In step S3, the welding is performed by infrared welding, hot air welding or electromagnetic welding.

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