A glass powder for a TOPCon cell main grid back silver paste, a preparation method thereof, a TOPCon cell main grid back silver paste and a TOPCon cell
By preparing lead-free glass powder composed of TeO2, Bi2O3, etc. for use in the silver paste on the back of the main grid of TOPCon batteries, the problems of environmental pollution and poor performance were solved, and low resistance and high welding pull strength were achieved, thus improving battery quality.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- CHANGSHA ADVANCED MATERIALS IND RES INST CO LTD
- Filing Date
- 2023-12-29
- Publication Date
- 2026-07-10
Smart Images
Figure SMS_1
Abstract
Description
Technical Field
[0001] This invention relates to the field of TOPCon battery technology, and in particular to a glass powder for silver paste on the back side of the main grid of a TOPCon battery and its preparation method, silver paste on the back side of the main grid of a TOPCon battery, and a TOPCon battery. Background Technology
[0002] Photovoltaic power generation boasts significant advantages such as sustainability, cleanliness, and lack of geographical limitations. In solar cells, the front electrode plays a crucial role in conducting and collecting current. With the continuous development of solar cell technology, the thickness of Topcon solar cells and passivation layers has decreased, placing higher demands on the conductivity and welding tensile strength of silver paste. Existing back-side silver pastes mainly consist of silver powder, glass powder, and an organic carrier. The performance of the glass powder directly determines whether the paste can form good contact with the silicon substrate after sintering. Solar back-side silver paste requires a low melting temperature and good fluidity, wettability, and silver dissolving and precipitation capabilities after melting; therefore, lead-based glass is still the primary material. At high temperatures, the glass powder undergoes a redox reaction with the silicon nitride film, and the lead from the reduction of lead-containing glass is produced as a byproduct, damaging the environment and harming human health. While some existing technologies use lead-free glass powders, the conductivity and welding tensile strength of the resulting back-side silver paste are unsatisfactory. Summary of the Invention
[0003] Based on the above, the purpose of this invention is to provide a glass powder for the back silver paste of the TOPCon battery main grid and its preparation method, the TOPCon battery main grid back silver paste, and the TOPCon battery. The glass powder has better environmental protection properties, and the back silver paste obtained has lower resistance and better welding tensile strength.
[0004] To achieve the above objectives, the present invention adopts the following technical solution:
[0005] A glass powder for silver paste on the back side of the main grid of a TOPCon battery, the glass powder comprising the following components in the indicated mass percentages: 10%–50% TeO2, 15%–50% Bi2O3, 10%–30% B2O3, 5%–20% SiO2, 1%–15% Sb2O3, 5%–15% Ag2O, 0.5%–3% Ga2O3, 1%–5% ZnO, 1%–5% TiO2, 1%–3% Li2O, 1%–3% Na2O, and 1%–3% K2O.
[0006] A method for preparing glass powder for silver paste on the back side of the main grid of a TOPCon battery includes the following steps:
[0007] Based on the total mass of the glass powder required as 100%, 10%–50% of TeO2, 15%–50% of Bi2O3, 10%–30% of B2O3, 5%–20% of SiO2, 1%–15% of Sb2O3, 5%–15% of Ag2O, 0.5%–3% of Ga2O3, 1%–5% of ZnO, 1%–5% of TiO2, 1%–3% of Li2O, 1%–3% of Na2O, and 1%–3% of K2O are ground, stirred, and mixed evenly to obtain a mixture.
[0008] The mixture is heated and melted to obtain a glass melt.
[0009] The molten glass is quenched with water to obtain glass fragments.
[0010] The glass fragments are crushed to obtain glass powder with a preset particle size.
[0011] As a preferred embodiment of a method for preparing glass powder for silver paste on the back side of a TOPCon battery main grid, when heating the mixture, the mixture is placed in a corundum crucible, then placed in a lifting furnace and heated at a preset temperature for a preset time to obtain the glass melt.
[0012] In a preferred embodiment of a method for preparing glass powder for silver paste on the back side of a TOPCon battery main grid, the preset temperature is 1200℃~1400℃ and the preset time is 0.5h~2h.
[0013] As a preferred embodiment of a method for preparing glass powder for silver paste on the back side of a TOPCon battery main grid, the glass molten liquid is poured into deionized water for water quenching during the water quenching process.
[0014] In a preferred embodiment of a method for preparing glass powder for silver paste on the back side of a TOPCon battery main grid, the depth of the deionized water is not less than 25 cm.
[0015] As a preferred embodiment of the method for preparing glass powder for silver paste on the back side of TOPCon battery main grid, when crushing the glass fragment particles, ball milling is used for 3h-24h or air jet milling is used for fine crushing for 1h-6h.
[0016] A TOPCon battery main grid back silver paste, based on 100% of the total weight of the back silver paste, the back silver paste comprises 0.5%-3% glass powder, 80%-90% silver powder, 8%-18% organic carrier and 0.1%-1% dispersant as described in claim 1.
[0017] As a preferred embodiment of the silver paste on the back of the main grid of a TOPCon battery, the particle size D50 of the glass powder is 1μm to 3.5μm.
[0018] A TOPCon battery comprising the silver paste on the back of the TOPCon battery main grid as described in the above technical solution.
[0019] The beneficial effects of this invention are as follows:
[0020] The glass powder used for the back silver paste of the TOPCon battery main grid in this invention does not contain lead, has better environmental protection, is less harmful to the human body, and makes the resulting back silver paste have low resistance and high welding pull with the TOPCon battery cell, thereby making the TOPCon battery of better quality.
[0021] The method for preparing glass powder for the back silver paste of TOPCon battery main grid of the present invention is simple. The glass powder prepared can be used to improve the welding pull and reduce the resistance of the TOPCon battery main grid back silver paste.
[0022] The silver paste on the back of the TOPCon battery main grid of the present invention, by using the aforementioned glass powder, has good welding pull and low resistance.
[0023] The TOPCon battery of the present invention, by using the aforementioned back silver paste, results in a higher quality and more environmentally friendly TOPCon battery. Detailed Implementation
[0024] The present invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, only the parts relevant to the present invention are shown, not all of the structures.
[0025] In the description of this invention, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.
[0026] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.
[0027] In the description of this embodiment, the terms "upper," "lower," "left," and "right," etc., are based on the indicated orientation or positional relationship and are only for ease of description and simplification of operation. They do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention. In the description of the present invention, unless otherwise stated, "a plurality of" means two or more. Furthermore, the terms "first" and "second" are only used for descriptive distinction and have no special meaning.
[0028] This embodiment provides a glass powder for the back silver paste of the TOPCon battery main grid. Based on 100% of the total mass of the glass powder, the content of each component is as follows: 10%–50% TeO2, 15%–50% Bi2O3, 10%–30% B2O3, 5%–20% SiO2, 1%–15% Sb2O3, 5%–15% Ag2O, 0.5%–3% Ga2O3, 1%–5% ZnO, 1%–5% TiO2, 1%–3% Li2O, 1%–3% Na2O, and 1%–3% K2O. The addition of Ag2O effectively improves conductivity, and the addition of Sb2O3 effectively improves welding pull strength. The above glass powder does not contain the heavy metal lead, posing less harm to the human body, and results in low resistance in the prepared back silver paste and high welding pull strength with the TOPCon battery cell, thus leading to a higher quality TOPCon battery.
[0029] This embodiment also provides a TOPCon battery main grid back side silver paste, which, based on 100% of the total weight of the back side silver paste, comprises 0.5%-3% glass powder, 80%-90% silver powder, 8%-18% organic carrier, and 0.1%-1% dispersant. By using the aforementioned glass powder, it exhibits good weld pull strength and low resistance.
[0030] The organic carrier comprises 10%-15% resin and 85%-90% organic solvent. The resin is selected from one or more of ethyl cellulose, PVB, and acrylic resin. The organic solvent is selected from one or more of dodecyl alcohol ester, diethylene glycol butyl ether, diethylene glycol butyl ether acetate, tributyl citrate, and dimethyl adipate. The dispersant is selected from one or both of BYK111 and BYK110.
[0031] Preferably, the particle size D50 of the glass powder is 1μm to 3.5μm, for example, 1μm, 2μm, 3μm, or 3.5μm. If the glass powder particle size is too small, it will cause the glass powder to form a molten glass too early during silver paste sintering, resulting in an excessively long glass liquid phase time. This makes it easier for the emitter of the solar cell to be etched through. Furthermore, a small particle size also increases processing difficulty and cost. If the glass powder particle size is too large, the glass powder reaches the molten state later, resulting in less molten glass and insufficient etching of the reflective layer, reducing the welding pull of the silver paste, and making it difficult to form a dense sintered film. Glass powder with a suitable particle size can better etch the reflective layer, improve the welding pull of the back silver paste, and prevent the emitter from being etched through.
[0032] This embodiment also provides a method for preparing glass powder for silver paste on the back side of the TOPCon battery main grid, which specifically includes the following steps:
[0033] S100: Based on the total mass of the glass powder required as 100%, grind and mix 10%–50% of TeO2, 15%–50% of Bi2O3, 10%–30% of B2O3, 5%–20% of SiO2, 1%–15% of Sb2O3, 5%–15% of Ag2O, 0.5%–3% of Ga2O3, 1%–5% of ZnO, 1%–5% of TiO2, 1%–3% of Li2O, 1%–3% of Na2O, and 1%–3% of K2O until uniformly mixed to obtain a mixture.
[0034] S200: The mixture is heated and melted to obtain molten glass;
[0035] Specifically, the mixture is returned to the corundum crucible, then placed in a lifting furnace and heated at a preset temperature for a preset time to obtain molten glass.
[0036] The preset temperature is 1200℃~1400℃, and the preset time is 0.5h~2h. For example, the temperature in the lifting furnace is 1200℃, 1300℃ or 1400℃, and the holding time is 0.5h, 1h or 2h, etc.
[0037] S300: Water quenching of molten glass to obtain glass fragments;
[0038] Specifically, when quenching molten glass, the molten glass is poured into deionized water for quenching. The depth of the deionized water is not less than 25 cm. The deeper the deionized water, the better the cooling effect, that is, the better the cold quenching effect.
[0039] S400: Crush glass fragments into glass powder of a preset particle size.
[0040] Specifically, when crushing glass fragments, ball milling is used for 3-24 hours or air jet milling for 1-6 hours. For example, ball milling can be used for 3 hours, 5 hours, 8 hours, 10 hours, 15 hours, 18 hours, or 24 hours, or air jet milling can be used for 1 hour, 3 hours, 4 hours, or 6 hours.
[0041] This embodiment also provides a TOPCon battery, which includes the aforementioned silver paste on the back of the TOPCon battery main grid. By using the aforementioned back silver paste, the TOPCon battery has better quality and is more environmentally friendly.
[0042] Example 1
[0043] The glass powder was prepared according to the above-described method for preparing glass powder for the back side silver paste of the TOPCon battery main grid. The glass powder contained the following components: 22% TeO2, 30% Bi2O3, 15% B2O3, 10% SiO2, 5.5% Sb2O3, 10% Ag2O, 0.5% Ga2O3, 2% ZnO, 2% TiO2, 1% Li2O, 1% Na2O, and 1% K2O. The powder was then ball-milled or finely pulverized using an air jet mill until the particle size D50 was 2 μm.
[0044] Then, 1.5% of the above-mentioned glass powder, 86% of silver powder, 12% of organic carrier and 1.5% of dispersant were added to the sample container and stirred. The mixture was then mixed evenly in a planetary gravity disperser and then rolled multiple times in a three-roll mill until the fineness was below 8μm to obtain the back silver paste.
[0045] The resistance and soldering pull force of the prepared back silver paste were tested. The soldering pull force test method was as follows: the back silver paste was printed onto the back of the TOPCon cell, and the TOPCon cell was sintered in a chain furnace. Then, solder ribbons were soldered onto the main grid electrode on the back of the TOPCon cell. A tensile testing machine was used to apply tension to the solder ribbon, pulling it uniformly from one end of the cell to the other. Six points were recorded, and the readings on the tensile tester were calculated. The average value was the final pull force value. Reference standards were IGBT 31985-2015 Photovoltaic Tin-Coated Solder Ribbons and GB / T17473.3-2008 Adhesion Test of Precious Metal Pastes for Microelectronics Technology. The resistance test method was as follows: the back silver paste was printed onto the back of the TOPCon cell, and the TOPCon cell was sintered in a chain furnace. The resistance of the main grid electrode on the back of the TOPCon cell was tested using a DC resistance meter, and the resistance value was recorded. Reference standard GB / T17703-2017 "Methods for Measurement of Resistance of Electronic Pastes".
[0046] The measured resistance was 0.395Ω, and the welding pull force was 3.9N.
[0047] Example 2
[0048] The glass powder was prepared according to the above-described method for preparing glass powder for the back side silver paste of the TOPCon battery main grid. The glass powder contained the following components: 22% TeO2, 24% Bi2O3, 15% B2O3, 10% SiO2, 5.5% Sb2O3, 10% Ag2O, 0.5% Ga2O3, 2% ZnO, 2% TiO2, 3% Li2O, 3% Na2O, and 3% K2O. The powder was then ball-milled or finely pulverized using an air jet mill until the particle size D50 was 2 μm.
[0049] Then, 1.5% of the above-mentioned glass powder, 86% of silver powder, 12% of organic carrier and 1.5% of dispersant were added to the sample container and stirred. The mixture was then mixed evenly in a planetary gravity disperser and then rolled multiple times in a three-roll mill until the fineness was below 8μm to obtain the back silver paste.
[0050] The resistance and welding pull were tested using the same test methods and reference standards as in Example 1. The measured resistance was 0.398Ω and the welding pull was 3.7N.
[0051] Example 3
[0052] The glass powder was prepared according to the above-described method for preparing glass powder for the back side silver paste of the TOPCon battery main grid. The glass powder contained the following components: 12% TeO2, 40% Bi2O3, 15% B2O3, 10% SiO2, 5.5% Sb2O3, 10% Ag2O, 0.5% Ga2O3, 2% ZnO, 2% TiO2, 1% Li2O, 1% Na2O, and 1% K2O. The powder was then ball-milled or finely pulverized using an air jet mill until the particle size D50 was 2 μm.
[0053] Then, 1.5% of the above-mentioned glass powder, 86% of silver powder, 12% of organic carrier and 1.5% of dispersant were added to the sample container and stirred. The mixture was then mixed evenly in a planetary gravity disperser and then rolled multiple times in a three-roll mill until the fineness was below 8μm to obtain the back silver paste.
[0054] The resistance and welding pull were tested using the same test methods and reference standards as in Example 1. The measured resistance was 0.397Ω and the welding pull was 3.6N.
[0055] Example 4
[0056] The glass powder was prepared according to the above-described method for preparing glass powder for the back side silver paste of the TOPCon battery main grid. The glass powder contained the following components: 40% TeO2, 20% Bi2O3, 10% B2O3, 8% SiO2, 4.5% Sb2O3, 10% Ag2O, 0.5% Ga2O3, 2% ZnO, 2% TiO2, 1% Li2O, 1% Na2O, and 1% K2O. The powder was then ball-milled or finely pulverized using an air jet mill until the particle size D50 was 2 μm.
[0057] Then, 1.5% of the above-mentioned glass powder, 86% of silver powder, 12% of organic carrier and 1.5% of dispersant were added to the sample container and stirred. The mixture was then mixed evenly in a planetary gravity disperser and then rolled multiple times in a three-roll mill until the fineness was below 8μm to obtain the back silver paste.
[0058] The resistance and welding pull were tested using the same test methods and reference standards as in Example 1. The measured resistance was 0.391Ω and the welding pull was 4N.
[0059] Example 5
[0060] The glass powder was prepared according to the above-described method for preparing glass powder for the back side silver paste of the TOPCon battery main grid. The glass powder contained the following components: 17% TeO2, 25% Bi2O3, 14.5% B2O3, 10% SiO2, 5.5% Sb2O3, 10% Ag2O, 5% Ga2O3, 5% ZnO, 5% TiO2, 1% Li2O, 1% Na2O, and 1% K2O. The powder was then ball-milled or finely pulverized using an air jet mill until the particle size D50 was 2 μm.
[0061] Then, 1.5% of the above-mentioned glass powder, 86% of silver powder, 12% of organic carrier and 1.5% of dispersant were added to the sample container and stirred. The mixture was then mixed evenly in a planetary gravity disperser and then rolled multiple times in a three-roll mill until the fineness was below 8μm to obtain the back silver paste.
[0062] The resistance and welding pull were tested using the same test methods and reference standards as in Example 1. The measured resistance was 0.4Ω and the welding pull was 3.5N.
[0063] Comparative Example 1
[0064] The glass powder was prepared according to the above-described method for preparing glass powder for the back side silver paste of the TOPCon battery main grid. The glass powder contained the following components: 25% TeO2, 33% Bi2O3, 17% B2O3, 12% SiO2, 5.5% Sb2O3, 0.5% Ga2O3, 2% ZnO, 2% TiO2, 1% Li2O, 1% Na2O, and 1% K2O. The powder was then ball-milled or finely pulverized using an air jet mill until the particle size D50 was 2 μm.
[0065] Then, 1.5% of the above-mentioned glass powder, 86% of silver powder, 12% of organic carrier and 1.5% of dispersant were added to the sample container and stirred. The mixture was then mixed evenly in a planetary gravity disperser and then rolled multiple times in a three-roll mill until the fineness was below 8μm to obtain the back silver paste.
[0066] The resistance and welding pull were tested using the same test methods and reference standards as in Example 1. The measured resistance was 0.456Ω and the welding pull was 3.8N.
[0067] Comparative Example 2
[0068] The glass powder was prepared according to the above-described method for preparing glass powder for the back side silver paste of the TOPCon battery main grid. The glass powder contained the following components: 24% TeO2, 32% Bi2O3, 16% B2O3, 10.5% SiO2, 10% Ag2O, 0.5% Ga2O3, 2% ZnO, 2% TiO2, 1% Li2O, 1% Na2O, and 1% K2O. The powder was then ball-milled or finely pulverized using an air jet mill until the particle size D50 was 2 μm.
[0069] Then, 1.5% of the above-mentioned glass powder, 86% of silver powder, 12% of organic carrier and 1.5% of dispersant were added to the sample container and stirred. The mixture was then mixed evenly in a planetary gravity disperser and then rolled multiple times in a three-roll mill until the fineness was below 8μm to obtain the back silver paste.
[0070] The resistance and welding pull were tested using the same test methods and reference standards as in Example 1. The measured resistance was 0.401Ω and the welding pull was 1.5N.
[0071] Comparative Example 3
[0072] The glass powder was prepared according to the above-described method for preparing glass powder for the back side silver paste of the TOPCon battery main grid. The glass powder contained the following components: 22% TeO2, 30% Bi2O3, 15% B2O3, 10% SiO2, 5.5% Sb2O3, 10% Ag2O, 0.5% Ga2O3, 2% ZnO, 2% TiO2, 1% Li2O, 1% Na2O, and 1% K2O. The powder was then ball-milled or finely pulverized using an air jet mill until the particle size D50 was 2 μm.
[0073] Then, 1.5% of the above-mentioned glass powder, 86% of silver powder, 12% of organic carrier and 1.5% of dispersant were added to the sample container and stirred. The mixture was then mixed evenly in a planetary gravity disperser and then rolled multiple times in a three-roll mill until the fineness was below 8μm to obtain the back silver paste.
[0074] The resistance and welding pull were tested using the same test methods and reference standards as in Example 1. The measured resistance was 0.421Ω and the welding pull was 2.5N.
[0075] The following are tables showing the content of each component of the glass powder in each embodiment and comparative example, as well as the test results:
[0076] Table 1 shows the content of each component of glass powder in each embodiment and comparative example.
[0077]
[0078] Table 2. Test results of the back-side silver paste prepared in each embodiment and comparative example.
[0079] Resistance (Ω) Welding tensile force (N) Example 1 0.395 3.9 Example 2 0.398 3.7 Example 3 0.397 3.6 Example 4 0.391 4 Example 5 0.400 3.5 Comparative Example 1 0.456 3.8 Comparative Example 2 0.401 1.5 Comparative Example 3 0.421 2.5
[0080] The above comparison shows that the back silver paste prepared with Ag2O-free glass powder in Comparative Example 1 has lower conductivity, i.e., higher resistance. The back silver paste prepared with Sb2O3-free glass powder in Comparative Example 2 has lower welding pull strength. The use of larger particle size glass powder in Comparative Example 3 reduces the welding pull strength and sintering density of the back silver paste. The back silver paste prepared with glass powder for the TOPCon battery main grid provided in this embodiment has better conductivity, higher welding pull strength, and better sintering density, thus improving the quality of the TOPCon battery.
[0081] Note that the above description is merely a preferred embodiment of the present invention and the technical principles employed. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and various obvious changes, readjustments, and substitutions can be made without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in detail through the above embodiments, the present invention is not limited to the above embodiments, and may include many other equivalent embodiments without departing from the concept of the present invention, the scope of which is determined by the scope of the appended claims.
Claims
1. A glass powder for silver paste on the back side of the main grid of a TOPCon battery, characterized in that, The glass powder comprises the following components in the indicated mass percentages: 10%–50% TeO2, 15%–50% Bi2O3, 10%–30% B2O3, 5%–20% SiO2, 1%–15% Sb2O3, 5%–15% Ag2O, 0.5%–3% Ga2O3, 1%–5% ZnO, 1%–5% TiO2, 1%–3% Li2O, 1%–3% Na2O, and 1%–3% K2O.
2. A method for preparing glass powder for silver paste on the back side of the main grid of a TOPCon battery, characterized in that, Includes the following steps: Based on the total mass of the glass powder required as 100%, 10%–50% of TeO2, 15%–50% of Bi2O3, 10%–30% of B2O3, 5%–20% of SiO2, 1%–15% of Sb2O3, 5%–15% of Ag2O, 0.5%–3% of Ga2O3, 1%–5% of ZnO, 1%–5% of TiO2, 1%–3% of Li2O, 1%–3% of Na2O, and 1%–3% of K2O are ground, stirred, and mixed evenly to obtain a mixture. The mixture is heated and melted to obtain a glass melt. The molten glass is quenched with water to obtain glass fragments. The glass fragments are crushed to obtain glass powder with a preset particle size.
3. The method for preparing glass powder for silver paste on the back side of the TOPCon battery main grid according to claim 2, characterized in that, When heating the mixture, the mixture is placed in a corundum crucible, then placed in a lifting furnace and heated at a preset temperature for a preset time to obtain the glass melt.
4. The method for preparing glass powder for silver paste on the back side of the TOPCon battery main grid according to claim 3, characterized in that, The preset temperature is 1200℃~1400℃, and the preset time is 0.5h~2h.
5. The method for preparing glass powder for silver paste on the back side of the TOPCon battery main grid according to claim 2, characterized in that, When quenching the molten glass, the molten glass is poured into deionized water for quenching.
6. The method for preparing glass powder for silver paste on the back side of the TOPCon battery main grid according to claim 5, characterized in that, The depth of the deionized water is not less than 25 cm.
7. The method for preparing glass powder for silver paste on the back side of the TOPCon battery main grid according to claim 2, characterized in that, When crushing the glass fragments, a ball mill is used for ball milling for 3-24 hours or an air jet mill is used for fine crushing for 1-6 hours.
8. A silver paste on the back of the main grid of a TOPCon battery, characterized in that, Based on the total weight of the back silver paste as 100%, the back silver paste comprises 0.5%-3% of the glass powder as described in claim 1, 80%-90% of silver powder, 8%-18% of organic carrier and 0.1%-1% of dispersant.
9. The silver paste on the back side of the TOPCon battery main grid according to claim 8, characterized in that, The particle size D50 of the glass powder is 1μm to 3.5μm.
10. A TOPCon battery, characterized in that, It contains the silver paste on the back side of the TOPCon battery main grid as described in claim 8 or 9.