Conductive silver paste and method for preparing the same

Abstract

The application discloses a low-temperature curing conductive silver paste and a preparation method thereof. The conductive silver paste comprises silver powder, resin, solvent, curing agent, thixotropic agent and inorganic ion diffusion inhibitor in a mass ratio of (93-98):(1.0-3.0):(0.1-1.0):(0.1-1.0):(0.01-0.05):(0.01-0.2). The inorganic ion diffusion inhibitor is an inorganic salt, and the anion in the inorganic ion diffusion inhibitor is selected from one or more of carbonate, sulfate, chromate, sulfide, chloride, bromide and iodide. The conductive silver paste can inhibit silver electromigration, increase the reliability of a component and realize the best conductive performance and anti-migration performance.

Description

Technical Field

[0001] This invention belongs to the field of photovoltaic cells, specifically relating to a conductive silver paste and its preparation method. Background Technology

[0002] Photovoltaic silver paste is widely used in the screen printing process of photovoltaic cells. The grid lines prepared are crucial for electron collection in the cells, subsequent solder ribbon connection, and module reliability. However, silver is prone to electromigration (ECM) in the presence of electric fields and moisture. On the one hand, the continuously generated hydroxide increases the grid line resistance or contact resistance, leading to power loss; on the other hand, electromigration can also cause grid line damage or the formation of bypasses between unconnected conductors, resulting in decreased insulation or even short circuits, ultimately leading to module failure or even fire.

[0003] Currently, methods for addressing silver ECM include adding fluorine-containing materials, adding mixed powders, alloy powders, or compound powders of copper, tin, and manganese, and adding corrosion inhibitors commonly used for metal oxidation resistance. Fluorine-containing materials have excellent weather resistance but are water- and oil-repellent, which is detrimental to adhesion with EVA (Electrode Vapor Adhesive) solar encapsulation films. Mixed powders, alloy powders, or compound powders of copper, tin, and manganese may interact, such as forming intermetallic compounds, leading to performance instability. Corrosion inhibitors typically contain organic groups with strong coordination capabilities. These organic groups can form a dense protective film on the Ag surface, preventing the diffusion and transport of silver ions generated by Ag oxidation into the electrolyte. However, corrosion inhibitors have poor weather resistance; the organic groups are prone to decomposition and failure under sintering, curing, and light exposure, making it difficult to meet the long-term reliability requirements of photovoltaic modules.

[0004] Therefore, there is an urgent need to develop a conductive silver paste with stability, long-term reliability, excellent conductivity, and resistance to silver migration. Summary of the Invention

[0005] To address the problems existing in the prior art, this invention optimizes the formulation of photovoltaic silver paste by using inorganic additives as silver ion diffusion inhibitors. Under electric field and humid conditions, the dissolved silver ions form insoluble precipitates, which act as physical barriers to prevent the diffusion and transport of silver ions, suppress silver electromigration, and increase the long-term reliability of the module. Furthermore, by precisely controlling the amount of inorganic ion diffusion inhibitors added, optimal conductivity and anti-migration performance can be achieved.

[0006] Specifically, the present invention provides a conductive silver paste comprising silver powder, resin, solvent, curing agent, thixotropic agent, and inorganic ion diffusion inhibitor in a mass ratio of (93-98):(1.0-3.0):(0.1-1.0):(0.1-1.0):(0.01-0.05):(0.01-0.2); wherein the inorganic ion diffusion inhibitor is an inorganic salt, and the anion in the inorganic ion diffusion inhibitor is selected from one or more of carbonate, sulfate, chromate, sulfide, chloride, bromide, and iodide ions.

[0007] In one or more embodiments, the resin is selected from thermosetting resins; preferably, the thermosetting resin is selected from one or more of epoxy resins, polyamide resins, polyurethane resins, polyacrylic resins, silicone resins, polycarbonate, phenolic resins, amino resins and polyester resins.

[0008] In one or more embodiments, the epoxy resin is selected from one or more of bisphenol A type epoxy resin, polypropylene glycol glycidyl ether, n-butyl glycidyl ether, glycidyl methacrylate, acrylic modified epoxy resin, hydrogenated epoxy resin, alicyclic epoxy resin, polyurethane modified epoxy resin, and silicone modified epoxy resin.

[0009] In one or more embodiments, the solvent is selected from one or more of alcohols, ethers, esters, triethanolamine, and turpentine; preferably, the alcohol is selected from one or more of ethylene glycol, diethylene glycol, isopropanol, butyl carbitol, and terpineol; preferably, the ether is selected from one or more of ethylene glycol butyl ether, propylene glycol methyl ether, and diethylene glycol butyl ether; preferably, the ester is selected from one or more of butyl carbitol acetate, dimethyl glutarate, dibutyl phthalate, and ethylene glycol acetate.

[0010] In one or more embodiments, the curing agent is selected from one or more of blocked isocyanates, methyl ethyl ketone peroxide, boron trifluoride-monoethylamine complex, dimethyl silicone oil, polyether amine compounds, dicyandiamide, diethylenetriamine, aliphatic amine compounds, amine-blocked hexafluoroantimonate, and acid anhydride compounds; preferably, the acid anhydride compound is selected from one or more of phthalic anhydride, trimellitic anhydride, pyromellitic dianhydride, and maleic anhydride.

[0011] In one or more embodiments, the thixotropic agent is selected from one or more of fumed silica, graphene, and modified urea solutions.

[0012] In one or more embodiments, the cation in the inorganic ion diffusion inhibitor is selected from one or more of ammonium ions, potassium ions, sodium ions, lanthanum ions, cerium ions, and neodymium ions.

[0013] This invention provides a method for preparing the conductive silver paste described herein, the method comprising the following steps:

[0014] (1) The resin, the solvent, the curing agent and the thixotropic agent are mixed evenly to obtain an organic carrier;

[0015] (2) Mix the silver powder and the organic carrier evenly to obtain a mixture;

[0016] (3) Add the inorganic ion diffusion inhibitor to the mixture obtained in step (2), mix evenly, and then roll it with three rollers to obtain conductive silver paste.

[0017] This invention provides a method for preparing conductive films or grid lines using the conductive silver paste described herein.

[0018] The present invention provides a solar cell comprising the conductive film or grid lines described herein. Attached Figure Description

[0019] Figure 1 This is a schematic diagram illustrating the mechanism by which the conductive silver paste of the present invention suppresses silver ECM.

[0020] Figure 2 This is a schematic diagram of the anti-silver electromigration test of some embodiments of the present invention. Detailed Implementation

[0021] To enable those skilled in the art to understand the features and effects of the present invention, the terms and expressions used herein are explained and defined in general terms below. Unless otherwise specified, all technical and scientific terms used herein have the common meaning understood by those skilled in the art regarding the present invention, and in case of conflict, the definitions in this specification shall prevail.

[0022] The theories or mechanisms described and disclosed herein, whether right or wrong, should not in any way limit the scope of the invention, that is, the contents of the invention can be implemented without being limited by any particular theory or mechanism.

[0023] In this document, the terms “contains,” “includes,” “containing,” and similar terms encompass the meanings of “basically composed of” and “composed of.” For example, when this document discloses “A contains B and C,” “A is basically composed of B and C” and “A is composed of B and C” should be considered as having been disclosed in this document.

[0024] In this document, all features defined by numerical ranges or percentage ranges, such as numerical values, quantities, contents, and concentrations, are for the sake of brevity and convenience only. Accordingly, descriptions of numerical ranges or percentage ranges should be considered as covering and specifically disclosing all possible sub-ranges and individual numerical values ​​(including integers and fractions) within those ranges.

[0025] Unless otherwise specified, percentages refer to mass percentages and proportions refer to mass ratios in this article.

[0026] In this document, when describing embodiments or examples, it should be understood that it is not intended to limit the invention to those embodiments or examples. Rather, all alternatives, modifications, and equivalents of the methods and materials described herein are covered within the scope defined by this invention.

[0027] For the sake of brevity, not all possible combinations of the technical features in each implementation scheme or embodiment are described herein. Therefore, as long as there is no contradiction in the combination of these technical features, the technical features in each implementation scheme or embodiment can be combined arbitrarily, and all possible combinations should be considered within the scope of this specification.

[0028] During long-term use, moisture can penetrate the grid lines of photovoltaic modules, forming an electrolyte containing dissolved ion diffusion inhibitors. In the presence of this electrolyte and an electric field, adjacent silver particles act as the cathode and anode, respectively, undergoing an electrochemical reaction. For example... Figure 1 As shown, during long-term use, moisture can penetrate the grid lines of photovoltaic modules, forming an electrolyte containing dissolved ion diffusion inhibitors. In the presence of the electrolyte and an electric field, adjacent silver particles act as the cathode and anode, respectively, undergoing an electrochemical reaction. At the anode, the silver undergoes oxidation, releasing Ag into the electrolyte. + It diffuses toward the cathode and reacts with SO4 in the electrolyte. 2- CO3 2- Cr2O4 2- I - S 2- Cl - ,Br - The formation of sparingly soluble precipitates with large solubility product constants prevents Ag from precipitating. + The diffusion and migration of the silver particles further inhibit the oxidation of the anodic silver particles. The insoluble precipitate can remain stable in the electrolyte for a long time, slowing down and eventually stopping the silver ECM.

[0029] This invention provides a conductive silver paste, which comprises silver powder, resin, solvent, curing agent, thixotropic agent, and inorganic ion diffusion inhibitor in a mass ratio of (93-98):(1.0-3.0):(0.1-1.0):(0.1-1.0):(0.01-0.05):(0.01-0.2); wherein the inorganic ion diffusion inhibitor is an inorganic salt, and the anion in the inorganic ion diffusion inhibitor can be selected from one or more of carbonate, sulfate, chromate, sulfide, chloride, bromide, and iodide ions.

[0030] In this invention, the resin may be selected from thermosetting resins. Thermosetting resins may be selected from one or more of epoxy resins, polyamide resins, polyurethane resins, polyacrylic resins, silicone resins, polycarbonate, phenolic resins, amino resins, and polyester resins.

[0031] In this invention, the epoxy resin may be selected from one or more of the following: bisphenol A type epoxy resin, polypropylene glycol glycidyl ether, n-butyl glycidyl ether, glycidyl methacrylate, acrylic modified epoxy resin, hydrogenated epoxy resin, alicyclic epoxy resin, polyurethane modified epoxy resin, and organosilicon modified epoxy resin.

[0032] In this invention, the solvent may be selected from one or more of alcohols, ethers, esters, triethanolamine, and turpentine. The alcohols may be selected from one or more of ethylene glycol, diethylene glycol, isopropanol, butyl carbitol, and terpineol. The ethers may be selected from one or more of ethylene glycol butyl ether, propylene glycol methyl ether, and diethylene glycol butyl ether. The esters may be selected from one or more of butyl carbitol acetate, dimethyl glutarate, dibutyl phthalate, and ethylene glycol acetate.

[0033] In this invention, the curing agent may be selected from one or more of the following: blocked isocyanates, methyl ethyl ketone peroxide, boron trifluoride-monoethylamine complex, dimethyl silicone oil, polyether amine compounds, dicyandiamide, diethylenetriamine, aliphatic amine compounds, amine-blocked hexafluoroantimonates, and acid anhydrides. The acid anhydrides may be selected from one or more of the following: phthalic anhydride, trimellitic anhydride, pyromellitic dianhydride, and maleic anhydride.

[0034] In this invention, the thixotropic agent may be selected from one or more of fumed silica, graphene, and modified urea solution.

[0035] In this invention, the cation in the inorganic ion diffusion inhibitor can be selected from one or more of ammonium ions, potassium ions, sodium ions, lanthanum ions, cerium ions, and neodymium ions.

[0036] This invention provides a method for preparing the conductive silver paste of this invention, the method comprising the following steps:

[0037] (1) Mix the resin, solvent, curing agent and thixotropic agent evenly to obtain an organic carrier;

[0038] (2) Mix the silver powder and the organic carrier, stir until homogeneous, and obtain a mixture;

[0039] (3) Add an inorganic ion diffusion inhibitor to the mixture obtained in step (2), mix evenly, and then roll it with three rollers to obtain conductive silver paste.

[0040] The present invention also provides a conductive film and a gate line prepared by the conductive silver paste of the present invention.

[0041] The present invention also provides a solar cell containing the conductive film or grid lines of the present invention.

[0042] Compared with the prior art, the present invention has the following beneficial effects:

[0043] (1) By precisely controlling the amount of inorganic ion diffusion inhibitor added, the conductivity and anti-silver migration properties of the conductive silver paste were balanced.

[0044] (2) The insoluble precipitate formed by the inorganic ion diffusion inhibitor can exert the effect of resisting silver ion migration for a long time, thus improving the long-term reliability of photovoltaic modules.

[0045] (3) The added inorganic ion diffusion inhibitor will not affect the selection of component encapsulation materials, nor will it cause complex reactions that affect the stability of the gate line.

[0046] The present invention will be described below by way of specific embodiments. It should be understood that these embodiments are merely illustrative and are not intended to limit the scope of the invention. The methods, reagents, and materials used in the embodiments are conventional methods, reagents, and materials in the art, unless otherwise stated. The raw material compounds in the embodiments are all commercially available.

[0047] The silver powder used in the examples and comparative examples was purchased from Boqian New Materials, with the grade Ag-S2000. The average particle size of the silver powder was 1.80-2.20 μm, and the specific surface area was 0.25-0.32 m². 2 / g, tap density ≥5.0g / cm³ 3 .

[0048] The resins used in the examples and comparative examples were: bisphenol A type epoxy resin, purchased from Dow Chemical, grade DER*331; and phenolic resin, purchased from Shengquan Group, grade SQCN700-1.

[0049] The solvents used in the examples and comparative examples were: triethanolamine (AR), purchased from Xilong Scientific Chemical; and butylcarbitol (≥99.0%), purchased from Merck Chemicals.

[0050] The curing agents used in the examples and comparative examples were: dimethyl silicone oil, purchased from Dow Corning, brand name PMX200-500CS; and phthalic anhydride (≥99%), purchased from Merck Chemicals.

[0051] The thixotropic agents used in the examples and comparative examples were: modified urea solution, purchased from BYK410; and fumed silica, purchased from Huifu Nano, brand name HL-200.

[0052] Example 1

[0053] This embodiment prepares a conductive silver paste, which contains silver powder, resin, solvent, curing agent, thixotropic agent and inorganic ion diffusion inhibitor in a mass ratio of 97.0:2.0:0.4:0.3:0.03:0.01. The resin, solvent, curing agent and thixotropic agent are bisphenol A type epoxy resin, triethanolamine, dimethyl silicone oil and modified urea solution, respectively, and the inorganic ion diffusion inhibitor is a mixed salt composed of ammonium carbonate and sodium sulfate in a mass ratio of 1:1.

[0054] The preparation method of conductive silver paste is as follows:

[0055] (1) Mix the resin, solvent, curing agent and thixotropic agent evenly to obtain an organic carrier;

[0056] (2) Mix the silver powder and the organic carrier, stir until homogeneous, and obtain a mixture;

[0057] (3) Add an inorganic ion diffusion inhibitor to the mixture, stir evenly, and then roll it with three rollers to obtain conductive silver paste.

[0058] Example 2

[0059] This embodiment prepares a conductive silver paste, which contains silver powder, resin, solvent, curing agent, thixotropic agent and inorganic ion diffusion inhibitor in a mass ratio of 97.0:2.0:0.4:0.3:0.03:0.05. The resin, solvent, curing agent and thixotropic agent are bisphenol A type epoxy resin, triethanolamine, dimethyl silicone oil and modified urea solution, respectively, and the inorganic ion diffusion inhibitor is a mixed salt composed of sodium sulfate and ammonium chloride in a mass ratio of 1:1.

[0060] The preparation method of conductive silver paste is as follows:

[0061] (1) Mix the resin, solvent, curing agent and thixotropic agent evenly to obtain an organic carrier;

[0062] (2) Mix the silver powder and the organic carrier, stir until homogeneous, and obtain a mixture;

[0063] (3) Add an inorganic ion diffusion inhibitor to the mixture, stir evenly, and then roll it with three rollers to obtain conductive silver paste.

[0064] Example 3

[0065] This embodiment prepares a conductive silver paste, which contains silver powder, resin, solvent, curing agent, thixotropic agent and inorganic ion diffusion inhibitor in a mass ratio of 97.0:2.0:0.4:0.3:0.03:0.05. The resin, solvent, curing agent and thixotropic agent are bisphenol A type epoxy resin, triethanolamine, dimethyl silicone oil and modified urea solution, respectively, and the inorganic ion diffusion inhibitor is a mixed salt composed of sodium iodide and sodium bromide in a mass ratio of 1:1.

[0066] The preparation method of conductive silver paste is as follows:

[0067] (1) Mix the resin, solvent, curing agent and thixotropic agent evenly to obtain an organic carrier;

[0068] (2) Mix the silver powder and the organic carrier, stir until homogeneous, and obtain a mixture;

[0069] (3) Add an inorganic ion diffusion inhibitor to the mixture, stir evenly, and then roll it with three rollers to obtain conductive silver paste.

[0070] Example 4

[0071] This embodiment prepares a conductive silver paste, which contains silver powder, resin, solvent, curing agent, thixotropic agent and inorganic ion diffusion inhibitor in a mass ratio of 97.0:2.0:0.4:0.3:0.03:0.1. The resin, solvent, curing agent and thixotropic agent are bisphenol A type epoxy resin, triethanolamine, dimethyl silicone oil and modified urea solution, respectively, and the inorganic ion diffusion inhibitor is a mixed salt composed of ammonium carbonate, sodium sulfate and potassium chromate in a mass ratio of 1:1:1.

[0072] The preparation method of conductive silver paste is as follows:

[0073] (1) Mix the resin, solvent, curing agent and thixotropic agent evenly to obtain an organic carrier;

[0074] (2) Mix the silver powder and the organic carrier, stir until homogeneous, and obtain a mixture;

[0075] (3) Add an inorganic ion diffusion inhibitor to the mixture, stir evenly, and then roll it with three rollers to obtain conductive silver paste.

[0076] Example 5

[0077] This embodiment prepares a conductive silver paste, which contains silver powder, resin, solvent, curing agent, thixotropic agent and inorganic ion diffusion inhibitor in a mass ratio of 97.0:2.0:0.4:0.3:0.03:0.05. The resin, solvent, curing agent and thixotropic agent are bisphenol A type epoxy resin, triethanolamine, dimethyl silicone oil and modified urea solution, respectively, and the inorganic ion diffusion inhibitor is ammonium chloride.

[0078] The preparation method of conductive silver paste is as follows:

[0079] (1) Mix the resin, solvent, curing agent and thixotropic agent evenly to obtain an organic carrier;

[0080] (2) Mix the silver powder and the organic carrier, stir until homogeneous, and obtain a mixture;

[0081] (3) Add an inorganic ion diffusion inhibitor to the mixture, stir evenly, and then roll it with three rollers to obtain conductive silver paste.

[0082] Example 6

[0083] This embodiment prepares a conductive silver paste, which contains silver powder, resin, solvent, curing agent, thixotropic agent and inorganic ion diffusion inhibitor in a mass ratio of 97.0:2.0:0.4:0.3:0.03:0.1. The resin, solvent, curing agent and thixotropic agent are phenolic resin, butyl carbitol, phthalic anhydride and fumed silica, respectively, and the inorganic ion diffusion inhibitor is a mixed salt composed of lanthanum sulfide, cerium sulfide and neodymium sulfide in a mass ratio of 1:1:1.

[0084] The preparation method of conductive silver paste is as follows:

[0085] (1) Mix the resin, solvent, curing agent and thixotropic agent evenly to obtain an organic carrier;

[0086] (2) Mix the silver powder and the organic carrier, stir until homogeneous, and obtain a mixture;

[0087] (3) Add an inorganic ion diffusion inhibitor to the mixture, stir evenly, and then roll it with three rollers to obtain conductive silver paste.

[0088] Comparative Example 1

[0089] This comparative example prepares a conductive silver paste containing silver powder, resin, solvent, curing agent, and thixotropic agent in a mass ratio of 97.0:2.0:0.4:0.3:0.03. The resin, solvent, curing agent, and thixotropic agent are bisphenol A type epoxy resin, triethanolamine, dimethyl silicone oil, and modified urea solution, respectively.

[0090] The preparation method of conductive silver paste is as follows:

[0091] (1) Mix the resin, solvent, curing agent and thixotropic agent evenly to obtain an organic carrier;

[0092] (2) Mix silver powder and organic carrier, stir evenly, and then roll through three rollers to obtain conductive silver paste.

[0093] Comparative Example 2

[0094] This comparative example prepares a conductive silver paste containing silver powder, resin, solvent, curing agent, and thixotropic agent in a mass ratio of 97.0:2.0:0.4:0.3:0.03. The resin, solvent, curing agent, and thixotropic agent are phenolic resin, butyl carbitol, phthalic anhydride, and fumed silica, respectively.

[0095] The preparation method of conductive silver paste is as follows:

[0096] (1) Mix the resin, solvent, curing agent and thixotropic agent evenly to obtain an organic carrier;

[0097] (2) Mix silver powder and organic carrier, stir evenly, and then roll through three rollers to obtain conductive silver paste.

[0098] Test case

[0099] (1) Silver paste stability test

[0100] According to GB / T 17473.5, the test temperature was set to (25±0.5)℃, the rotation speed was adjusted to 10 r / min, and the initial viscosity V0 was read after 30s. Each sample was measured 3 times and the average value was taken. After the slurry was stored for 3 months, the viscosity V was measured under the same conditions. The viscosity change rate RoC was examined as (V-V0) / V0×100%. The smaller the RoC, the better the long-term stability of the slurry. The stability test results of the silver paste in Examples 1-6 and Comparative Examples 1-2 are shown in Table 1.

[0101] (2) Grid line resistance test

[0102] The paste was printed onto the solar cell, with a grid line width of 40 μm, and cured at 190℃ for 30 min. The length L of the grid line section was measured using a ruler, and the resistance R of the grid line section was measured using a multimeter with an accuracy of 0.1 mΩ. The grid line resistance R was then examined. L =R / L, where 3 grid lines are measured for each sample and the average value is taken. R L The smaller the value, the better the grid line conductivity. The grid line resistance test results for Examples 1-6 and Comparative Examples 1-2 are shown in Table 1.

[0103] (3) Anti-silver electromigration test

[0104] like Figure 2As shown, the paste was printed onto the battery cell to obtain paste sheets with dimensions of 10mm × 10mm × 10μm and a spacing of 2mm. The curing conditions were 190℃ for 30 minutes. After curing, a pair of paste sheets were cut as a whole, and 200μL of deionized water was dropped between the sheets. The VI curve under a 2V bias voltage was measured using a potentiostat. The time t until the current value reached 0.1mA was examined. Each sample was measured three times and the average value was taken. The larger the t, the better the silver electromigration resistance. The test results of silver electromigration resistance of Examples 1-6 and Comparative Examples 1-2 are shown in Table 1.

[0105] Table 1: Test results of silver paste stability, grid line resistance and anti-silver electromigration in Examples 1-6 and Comparative Examples 1-2

[0106]

Claims

1. A conductive silver paste, characterized in that, The conductive silver paste comprises silver powder, resin, solvent, curing agent, thixotropic agent, and inorganic ion diffusion inhibitor in a mass ratio of (93~98):(1.0~3.0):(0.1~1.0):(0.1~1.0):(0.01~0.05):(0.01~0.2); wherein the inorganic ion diffusion inhibitor is an inorganic salt, and the anion in the inorganic ion diffusion inhibitor is selected from one or more of carbonate, sulfate, chromate, sulfide, chloride, bromide, and iodide ions; The cation in the inorganic ion diffusion inhibitor is selected from one or more of ammonium ions, potassium ions, sodium ions, lanthanum ions, cerium ions, and neodymium ions.

2. The conductive silver paste as described in claim 1, characterized in that, The resin is selected from thermosetting resins, which are selected from one or more of epoxy resins, polyamide resins, polyurethane resins, polyacrylic resins, silicone resins, polycarbonates, phenolic resins, amino resins, and polyester resins.

3. The conductive silver paste as described in claim 2, characterized in that, The epoxy resin is selected from one or more of bisphenol A type epoxy resin, acrylic modified epoxy resin, hydrogenated epoxy resin, alicyclic epoxy resin, polyurethane modified epoxy resin and organosilicon modified epoxy resin.

4. The conductive silver paste as described in claim 1, characterized in that, The solvent is selected from one or more of alcohols, ethers, esters, triethanolamine, and turpentine; the alcohol is selected from one or more of ethylene glycol, diethylene glycol, isopropanol, butyl carbitol, and terpineol; the ether is selected from one or more of ethylene glycol butyl ether, propylene glycol methyl ether, and diethylene glycol butyl ether; and the ester is selected from one or more of butyl carbitol acetate, dimethyl glutarate, dibutyl phthalate, and ethylene glycol acetate.

5. The conductive silver paste as described in claim 1, characterized in that, The curing agent is selected from one or more of the following: blocked isocyanates, methyl ethyl ketone peroxide, boron trifluoride-monoethylamine complex, dimethyl silicone oil, polyether amine compounds, dicyandiamide, diethylenetriamine, aliphatic amine compounds, amine-blocked hexafluoroantimonate, and acid anhydride compounds; the acid anhydride compound is selected from one or more of the following: phthalic anhydride, trimellitic anhydride, pyromellitic dianhydride, and maleic anhydride.

6. The conductive silver paste as described in claim 1, characterized in that, The thixotropic agent is selected from one or more of fumed silica, graphene, and modified urea solution.

7. A method for preparing conductive silver paste according to any one of claims 1-6, characterized in that, The method includes the following steps: (1) The resin, the solvent, the curing agent and the thixotropic agent are mixed evenly to obtain an organic carrier; (2) The silver powder and the organic carrier are mixed evenly to obtain a mixture; (3) Add the inorganic ion diffusion inhibitor to the mixture obtained in step (2), mix evenly, and then roll it with three rollers to obtain conductive silver paste.

8. The conductive film or grid line prepared using the conductive silver paste according to any one of claims 1-6.

9. A solar cell, characterized in that, The solar cell contains the conductive film or grid lines as described in claim 8.

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