Preparation method of modified barium sulfate, insulating ink for xbc battery, and xbc battery

Abstract

The application provides a preparation method of modified barium sulfate, comprising the following steps: carrying out surface modification on barium sulfate by a first modifier to obtain an intermediate, wherein the first modifier comprises at least one of silicate and silicate substance; and carrying out surface modification on the intermediate by a second modifier of silane to obtain modified barium sulfate. The application also provides an insulating ink for XBC battery and an XBC battery. Through surface treatment on the barium sulfate filler and then collocation with a thermosetting resin system, the prepared insulating ink can be cured under the condition of 170-190 DEG C and 5-10 min, has the characteristics of low VOC and rapid curing, and the ink edge watermark is widened and narrowed after curing, so that the influence of light is avoided.

Description

Technical Field

[0001] This application relates to the field of ink technology, and in particular to a method for preparing modified barium sulfate, an insulating ink for XBC batteries, and an XBC battery. Background Technology

[0002] Back-contact (XBC) cells are a general term for various types of crystalline silicon solar cells with back-contact structures, mainly including IBC, HBC, PBC, ABC, MBC, and HPBC cells. Due to their high efficiency, which is difficult for conventional solar cells to achieve, they have attracted much attention in the industry and have become a research hotspot for next-generation solar cell technology. In terms of cell structure, the PN junction and metal contact of an XBC cell are located on the back of the photovoltaic cell. The front surface avoids the metal grid electrodes blocking light, while the pyramidal textured structure and anti-reflection layer, forming a light-trapping structure, maximize the utilization of incident light, reduce optical losses, and achieve a higher short-circuit current. The positive and negative fine grid lines of an XBC cell are arranged in an interdigitated pattern on the back of the cell. The main grid lines and secondary fine grid lines are printed perpendicularly. The connection between the positive main grid section and the negative fine grid line is isolated by printed insulating ink, and the connection between the negative main grid section and the positive fine grid line is also isolated by printed insulating ink.

[0003] However, the insulating ink currently used in XBC batteries has problems such as long curing time, high content of volatile organic compounds (VOCs), and widening of edge watermarks after curing. Summary of the Invention

[0004] In view of this, in order to solve at least one of the above problems, this application provides a method for preparing modified barium sulfate.

[0005] In addition, embodiments of this application also provide an insulating ink for XBC batteries using the aforementioned modified barium sulfate, and an XBC battery.

[0006] This application provides a method for preparing modified barium sulfate, comprising:

[0007] Barium sulfate is surface-modified using a first modifier to obtain an intermediate, wherein the first modifier includes at least one of silicate esters and silicate substances; and

[0008] The intermediate is surface-modified using a second modifier to obtain the modified barium sulfate, wherein the second modifier has a structure as shown in formula (1) or formula (2):

[0009]

[0010] In equation (1), X is a hydrolytic functional group and n is an integer greater than or equal to 1.

[0011] In equation (2), Y is a hydrolytic functional group and n is an integer greater than or equal to 1.

[0012] In some possible embodiments, any X in formula (1) is independently selected from at least one of halogen, OR1, OOCR2 and NR3 groups, wherein R1 to R3 are at least one of hydrogen atoms and alkyl groups; any Y in formula (2) is independently selected from at least one of halogen, OR4, OOCR5 and NR6 groups, wherein R4 to R6 are at least one of hydrogen atoms and alkyl groups.

[0013] In some possible embodiments, the first modifier includes at least one of tetraethyl orthosilicate, methyl orthosilicate, and sodium silicate.

[0014] In some possible embodiments, the method for preparing the intermediate includes:

[0015] The barium sulfate was dried and then ultrasonically dispersed.

[0016] Under stirring, the first modifier is added dropwise to the ultrasonically dispersed barium sulfate at a rate of 0.5–1 g / min, followed by filtration, washing with water, and drying to coat the surface of the barium sulfate with the first modifier; and

[0017] The barium sulfate with the first modifier attached to its surface is heated to 600-700°C at a heating rate of 3-5°C / min and held for 3-5 hours to obtain the intermediate.

[0018] In some possible embodiments, the step of surface-modifying the intermediate with a second modifier includes:

[0019] The second modifier was pre-hydrolyzed and added to the intermediate. The mixture was stirred at 60–80°C for 2–4 hours, then washed and dried to obtain the modified barium sulfate.

[0020] This application also provides an insulating ink for XBC batteries, which includes component A and component B. Component A, by mass parts, includes the following components:

[0021] Epoxy resin: 90~120;

[0022] Barium sulfate: 60-90;

[0023] Component B includes the following components:

[0024] Toughening agent: 40-60;

[0025] Hardener: 1-30;

[0026] Barium sulfate disulfate: 20-30,

[0027] Both the first barium sulfate and the second barium sulfate are prepared by the modified barium sulfate preparation method described above. The second modifier in the first barium sulfate adopts the structure of formula (1), and the second modifier in the second barium sulfate adopts the structure of formula (2). For example, the weight ratio of component A to component B is 2:1.

[0028] In some possible embodiments, the curing temperature of the insulating ink is 170–190°C, and the curing time is 5–10 min.

[0029] In some possible embodiments, the epoxy resin includes at least one of bisphenol A type epoxy resin, bisphenol F type epoxy resin, phenolic epoxy resin, o-cresol epoxy resin, and alicyclic epoxy resin.

[0030] The curing agent includes at least one of hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, methylimidazole, 2-ethyl-4-methylimidazole, and dicyandiamide.

[0031] In some possible embodiments, component A further includes, by mass parts:

[0032] Reactive diluent: 10-30;

[0033] Thixotropic thickener: 0.5–5;

[0034] Adhesion promoter: 1-3;

[0035] Pigment: 0-3;

[0036] Component B further includes:

[0037] Curing accelerator: 0.1-3.

[0038] This application also provides an XBC battery, which includes a battery cell and an ink layer on the battery cell. The ink layer is formed by curing the insulating ink for XBC batteries as described above.

[0039] This application embodiment involves surface treatment of barium sulfate filler, followed by the combination of modified barium sulfate with a thermosetting resin system. By adding modified barium sulfate fillers with different structures to components A and B of the insulating ink, curing can be achieved at 170–190°C for 5–10 minutes. This effectively reduces the curing time of the insulating ink, improves curing efficiency, and lowers the VOC content. Furthermore, it effectively narrows the widening of watermarks at the edges after curing. The cured insulating ink exhibits high adhesion to the electrode sheet, especially after etching treatment, where adhesion is largely unaffected. Additionally, the insulating ink of this application embodiment helps reduce the risk of leakage current from the electrode sheet. Attached Figure Description

[0040] Figure 1 These are microscope images showing the edge watermark expansion of the insulating ink layer on the battery cell in Examples 1-3 and Comparative Examples 1-4 of this application. Detailed Implementation

[0041] The technical solution of the present invention will now be clearly and completely described in conjunction with specific embodiments. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them.

[0042] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The names of technical means used in this specification are for the purpose of describing particular embodiments only and are not intended to limit the scope of the invention.

[0043] Where there is no conflict, the following embodiments and features can be combined with each other.

[0044] This application provides a modified barium sulfate, specifically a modified nano-barium sulfate, which can be used as a filler in insulating inks to improve the thickness, abrasion resistance, water resistance, heat resistance, surface hardness, and impact resistance of the ink coating. Moreover, the modified barium sulfate has a good spatial separation ability for pigment particles, allowing the pigment particles to maintain a certain distance from each other and improving pigment efficiency.

[0045] The modified barium sulfate is obtained by sequentially surface-treating barium sulfate with a first modifier and a second modifier. The barium sulfate used here is nano-barium sulfate.

[0046] In some embodiments, the first modifier includes at least one of substances such as silicates and esters, for example, the first modifier may include at least one of tetraethyl orthosilicate, methyl orthosilicate, sodium silicate, etc.

[0047] In some embodiments, the second modifier is a silane having a structure as shown in formula (1) or formula (2):

[0048]

[0049] In formula (1), X is a hydrolytic functional group. Any X in formula (1) is independently selected from at least one of halogen, OR1, OOCR2, and NR3 groups. R1 to R3 are at least one of hydrogen atoms and alkyl groups. For example, any X can be independently selected from at least one of Cl, OCH3, OC2H5, OOCH3, and NH3 groups. n is an integer greater than or equal to 1. By adding at least one ethyl group to the structure of formula (1), the flexibility of the molecular chain can be effectively improved. Furthermore, the range of n can be 3 to 10. Within this range, it is beneficial to improve the flexibility of the molecular chain while having a suitable viscosity.

[0050] In formula (2), Y is a hydrolytic functional group. Any Y in formula (2) is independently selected from at least one of halogen, OR4, OOCR5, and NR6 groups, wherein R4 to R6 are at least one of hydrogen atoms and alkyl groups. For example, any Y can be independently selected from at least one of Cl, OCH3, OC2H5, OOCH3, and NH3 groups. n is an integer greater than or equal to 1. By adding at least one ethyl group to the structure of formula (2), the flexibility of the molecular chain can be effectively improved. Furthermore, the range of n can be 3 to 10. Within this range, it is beneficial to improve the flexibility of the molecular chain while having a suitable viscosity.

[0051] Specifically, the preparation method of this modified barium sulfate includes the following steps:

[0052] Step S1: Barium sulfate is surface modified with a first modifier to obtain an intermediate.

[0053] In some embodiments, the method for preparing the intermediate includes:

[0054] Step S11: Dry the barium sulfate and then ultrasonically disperse it.

[0055] The process involves drying the nano-barium sulfate in an oven at 100–120°C for 4–6 hours, and then sonicating a certain amount of the nano-barium sulfate in an acidic solution for 10–30 minutes.

[0056] In step S12, while stirring, the first modifier is added dropwise to the ultrasonically dispersed barium sulfate at a rate of 0.5 to 1 g / min, followed by filtration, washing with water, and drying, so that the first modifier adheres to the surface of the barium sulfate.

[0057] In this process, the first modifier is added dropwise to the ultrasonically dispersed barium sulfate at a rate of 0.5 to 1 g / min under high-speed stirring. The stirring speed can be in the range of 1500 to 2000 r / min. By combining high-speed stirring with the above-mentioned dropping speed, the surface of the barium sulfate particles can be fully coated with the first modifier, thereby improving the uniformity of the coating.

[0058] Step S13: The barium sulfate with the first modifier attached to its surface is heated to 600-700°C at a heating rate of 3-5°C / min and held for 3-5 hours to obtain the intermediate.

[0059] In this embodiment, the intermediate is prepared as follows: Nano-barium sulfate is dried in an oven at 100–120°C for 4–6 hours. Then, 20–25 g of nano-barium sulfate is ultrasonicated in an acidic solution for 10–30 minutes. While maintaining high-speed stirring, 5–10 g of a first modifier, such as tetraethyl orthosilicate, is added dropwise over 10–20 minutes. After the addition is complete, stirring continues for 2–3 hours. The mixture is then filtered, washed with water, and dried at 80°C. Finally, the temperature is increased to 600–700°C at a rate of 3–5°C / min and held for 3–5 hours. After cooling, it is ready for use.

[0060] Step S2: The intermediate is surface modified by a second modifier to obtain the modified barium sulfate.

[0061] The second modifier is first pre-hydrolyzed, then added to the intermediate, stirred at 60-80°C for 2-4 hours, then washed and dried to obtain the modified barium sulfate.

[0062] In this embodiment, the second modifier with the structure of formula (1) or (2) above can be pre-hydrolyzed and then slowly added to the above-treated nano barium sulfate. The mixture is stirred at 60-80°C for 2 hours, then washed with water, cleaned with ethanol, and dried at 60-80°C to obtain modified nano barium sulfate.

[0063] By first introducing a silicon-containing first modifier onto the surface of barium sulfate particles, silica nanoparticles are generated in situ on the surface of the barium sulfate particles. This increases the reaction sites of the subsequent silane-based second modifier on the barium sulfate surface, thereby increasing the amount of the second modifier bound to the modified barium sulfate surface. In addition, since the structure of formula (1) or (2) contains a large number of -X or -Y groups, more connection sites can be formed after pre-hydrolysis, which can then bind with the silica nanoparticles pre-formed on the barium sulfate surface, improving the adhesion of the second modifier to the barium sulfate surface.

[0064] This application also provides an insulating ink for XBC batteries, which is mainly used in the cells of XBC batteries and mainly serves as an insulating barrier. The insulating ink includes component A and component B. Component A, by mass parts, includes: 90-120 parts of epoxy resin and 60-90 parts of first barium sulfate; component B includes: 40-60 parts of toughening agent; 1-30 parts of curing agent; and 20-30 parts of second barium sulfate. Both the first and second barium sulfate are prepared by the modified barium sulfate preparation method described above. The second modifier in the first barium sulfate adopts the structure of formula (1), and the second modifier in the second barium sulfate adopts the structure of formula (2).

[0065] In this insulating ink, two different modified barium sulfates are added to components A and B respectively. The modified barium sulfates added to components A and B cannot be mixed. If barium sulfate modified with the structure of formula (2) is added to component A, the viscosity of component A will increase sharply and the shelf life of component A will be shortened. Similarly, if barium sulfate modified with the structure of formula (1) is added to component B, the viscosity of component B will increase sharply and the shelf life of component A will be shortened.

[0066] In some embodiments, the amount of first barium sulfate added can be 60 parts, 65 parts, 70 parts, 75 parts, 80 parts, 85 parts, or 90 parts, etc. If the amount of first barium sulfate added is too small, less than 60 parts, it will cause a significant decrease in the viscosity and thixotropy of the insulating ink, making it easy for the screen printing to leak adhesive, and the ink morphology after curing will be poor. If too much is added, exceeding 90 parts, it will cause the viscosity of the insulating ink to be too high, making it easy for the screen printing to stick together, resulting in low production efficiency on the production line.

[0067] In some embodiments, the amount of barium sulfate added can be 20 parts, 23 parts, 25 parts, 28 parts, or 30 parts, etc. If the amount of barium sulfate added is too small, less than 20 parts, it will cause a significant decrease in the viscosity and thixotropy of the insulating ink, making it easy for the screen printing to leak adhesive, and the ink morphology after curing will be poor. If too much is added, more than 30 parts, it will cause the viscosity of the insulating ink to be too high, making it easy for the screen printing to stick together, resulting in low production efficiency on the production line.

[0068] In some embodiments, the weight ratio of component A to component B is 2:1.

[0069] In some embodiments, the epoxy resin includes at least one of bisphenol A type epoxy resin, bisphenol F type epoxy resin, phenolic epoxy resin, o-cresol epoxy resin, and alicyclic epoxy resin.

[0070] In some embodiments, the curing agent includes at least one of hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, methylimidazole, 2-ethyl-4-methylimidazole, and dicyandiamide.

[0071] In some embodiments, the toughening agent includes one or a mixture of several of the following: liquid polysulfide rubber, liquid nitrile rubber (including carboxyl-terminated and hydroxyl-terminated nitrile rubber), polyether and polyester resin, polyurethane prepolymer, polyester polyol, polyether polyol, etc.

[0072] In some embodiments, component A further includes 10 to 30 parts of an active diluent for adjusting the flexibility of the epoxy resin, wherein the active diluent includes at least one of butyl glycidyl ether, benzyl glycidyl ether, C12 to C14 glycidyl ether, and glycidyl methacrylate.

[0073] In some embodiments, component A further includes 0.5 to 5 parts of a thixotropic thickener for adjusting the thixotropic properties of the system. The thixotropic thickener includes at least one of fumed silica, cellulose acetate butyrate, ethyl cellulose, hydroxyethyl cellulose, polyvinyl butyral, aldehyde-ketone resin, etc.

[0074] In some embodiments, component A further includes 1 to 3 parts of an adhesion promoter to provide adhesion to different substrates, wherein the adhesion promoter includes one or more of silane coupling agents, titanate coupling agents, and phosphate coupling agents.

[0075] In some embodiments, component A further includes 0 to 3 parts of color paste for positioning and identification, which may include color pastes such as carbon black, indigo, titanium dioxide, chrome green, or anthraquinone red.

[0076] In some embodiments, component B further includes 0.1 to 3 parts of a curing accelerator for adjusting the curing speed. The curing accelerator is a modified amine curing agent whose molecular structure contains at least one of hydroxyl, amine, or secondary amine groups.

[0077] This application embodiment involves surface treatment of barium sulfate filler, followed by the combination of modified barium sulfate with a thermosetting resin system. By adding modified barium sulfate fillers with different structures to components A and B of the insulating ink, curing can be achieved at 170–190°C for 5–10 minutes. This effectively reduces the curing time of the insulating ink, improves curing efficiency, and lowers the VOC content. Furthermore, it effectively narrows the widening of watermarks at the edges after curing. The cured insulating ink exhibits high adhesion to the electrode sheet, especially after etching treatment, where adhesion is largely unaffected. Additionally, the insulating ink of this application embodiment helps reduce the risk of leakage current from the electrode sheet.

[0078] The embodiments of this application will be further described below through specific examples.

[0079] Example 1

[0080] 1) Preparation of modified barium sulfate:

[0081] Preparation of barium sulfate:

[0082] Nano-barium sulfate was dried in a 100°C oven for 4 hours. Then, 23g of nano-barium sulfate was ultrasonicated in an acidic solution for 20 minutes while maintaining high-speed stirring. 8g of tetraethyl orthosilicate was added dropwise over 10 minutes. After the addition was complete, stirring was continued for 2 hours. The mixture was then filtered, washed with water, and dried at 80°C. Finally, the temperature was increased to 600°C at a rate of 3°C / min and held for 3 hours.

[0083] The second modifier with the structure of formula (1) is pre-hydrolyzed and then slowly added to the above-treated nano-barium sulfate. The mixture is stirred at 60°C for 2 hours, then washed with water and ethanol, and dried at 60°C to obtain the modified nano-barium sulfate for component A. In formula (1), X is OCH3.

[0084] Preparation of barium sulfate 2:

[0085] Nano-barium sulfate was dried in a 100°C oven for 4 hours. Then, 23g of nano-barium sulfate was ultrasonicated in an acidic solution for 20 minutes while maintaining high-speed stirring. 8g of tetraethyl orthosilicate was added dropwise over 10 minutes. After the addition was complete, stirring was continued for 2 hours. The mixture was then filtered, washed with water, and dried at 80°C. Finally, the temperature was increased to 600°C at a rate of 3°C / min and held for 3 hours.

[0086] The second modifier with the structure of formula (2) is pre-hydrolyzed and then slowly added to the above-treated nano-barium sulfate. The mixture is stirred at 60°C for 2 hours, then washed with water and ethanol, and dried at 60°C to obtain the modified nano-barium sulfate for component A. In formula (2), Y is OCH3.

[0087] 2) Preparation of insulating ink

[0088] The ingredients are prepared according to the following proportions, calculated by weight:

[0089] Component A:

[0090]

[0091]

[0092] Component B:

[0093]

[0094] In this process, the first and second barium sulfate components are modified nano-barium sulfate prepared in the first step. Each component in component A and component B is weighed according to its weight percentage, then stirred and mixed at room temperature for 15 minutes, followed by three-roll milling until a fineness of less than 6 is achieved. When used, component A and component B are mixed at a weight ratio of 2:1 to obtain the insulating ink for XBC batteries.

[0095] 3) Insulating ink usage and performance testing

[0096] The mixed insulating ink was screen-printed onto the XBC solar cell and then cured at 170°C for 5 minutes to obtain the solar cell with the insulating ink layer. The solar cell was then subjected to relevant performance tests.

[0097] Example 2

[0098] 1) Preparation of modified barium sulfate:

[0099] Preparation of barium sulfate:

[0100] Nano-barium sulfate was dried in a 100°C oven for 4 hours. Then, 20g of nano-barium sulfate was ultrasonicated in an acidic solution for 20 minutes while maintaining high-speed stirring. 10g of tetraethyl orthosilicate was added dropwise over 10 minutes. After the addition was complete, stirring was continued for 2 hours. Then, it was filtered, washed with water, and dried at 80°C. Finally, the temperature was increased to 600°C at a rate of 3°C / min and held for 3 hours.

[0101] The second modifier with the structure of formula (1) is pre-hydrolyzed and then slowly added to the above-treated nano-barium sulfate. The mixture is stirred at 60°C for 2 hours, then washed with water and ethanol, and dried at 60°C to obtain the modified nano-barium sulfate for component A. In formula (1), X is OC2H5.

[0102] Preparation of barium sulfate 2:

[0103] Nano-barium sulfate was dried in a 100°C oven for 4 hours. Then, 20g of nano-barium sulfate was ultrasonicated in an acidic solution for 20 minutes while maintaining high-speed stirring. 10g of tetraethyl orthosilicate was added dropwise over 10 minutes. After the addition was complete, stirring was continued for 2 hours. Then, it was filtered, washed with water, and dried at 80°C. Finally, the temperature was increased to 600°C at a rate of 3°C / min and held for 3 hours.

[0104] The second modifier with the structure of formula (2) is pre-hydrolyzed and then slowly added to the above-treated nano-barium sulfate. The mixture is stirred at 60°C for 2 hours, then washed with water and ethanol, and dried at 60°C to obtain the modified nano-barium sulfate for component A. In formula (2), Y is OC2H5.

[0105] 2) Preparation of insulating ink

[0106] The ingredients are prepared according to the following proportions, calculated by weight:

[0107] Component A:

[0108]

[0109] Component B:

[0110]

[0111] In this process, the first and second barium sulfate components are modified nano-barium sulfate prepared in the first step. Each component in component A and component B is weighed according to its weight percentage, then stirred and mixed at room temperature for 15 minutes, followed by three-roll milling until a fineness of less than 6 is achieved. When used, component A and component B are mixed at a weight ratio of 2:1 to obtain the insulating ink for XBC batteries.

[0112] 3) Insulating ink usage and performance testing

[0113] The mixed insulating ink was screen-printed onto the XBC solar cell and then cured at 170°C for 5 minutes to obtain the solar cell with the insulating ink layer. The solar cell was then subjected to relevant performance tests.

[0114] Example 3

[0115] 1) Preparation of modified barium sulfate:

[0116] Preparation of barium sulfate:

[0117] Nano-barium sulfate was dried in an oven at 100℃ for 4 hours. Then, 25g of nano-barium sulfate was ultrasonicated in an acidic solution for 20 minutes while maintaining high-speed stirring. 8g of tetraethyl orthosilicate was added dropwise over 10 minutes. After the addition was complete, stirring was continued for 2 hours. The mixture was then filtered, washed with water, and dried at 80℃. Finally, the temperature was increased to 600℃ at a rate of 3℃ / min and held for 3 hours.

[0118] The second modifier with the structure of formula (1) is pre-hydrolyzed and then slowly added to the above-treated nano-barium sulfate. The mixture is stirred at 60°C for 2 hours, then washed with water and ethanol, and dried at 60°C to obtain the modified nano-barium sulfate for component A. In formula (1), X is OOCR.

[0119] Preparation of barium sulfate 2:

[0120] Nano-barium sulfate was dried in an oven at 100℃ for 4 hours. Then, 25g of nano-barium sulfate was ultrasonicated in an acidic solution for 20 minutes while maintaining high-speed stirring. 8g of tetraethyl orthosilicate was added dropwise over 10 minutes. After the addition was complete, stirring was continued for 2 hours. The mixture was then filtered, washed with water, and dried at 80℃. Finally, the temperature was increased to 600℃ at a rate of 3℃ / min and held for 3 hours.

[0121] The second modifier with the structure of formula (2) is pre-hydrolyzed and then slowly added to the above-treated nano-barium sulfate. The mixture is stirred at 60°C for 2 hours, then washed with water and ethanol, and dried at 60°C to obtain the modified nano-barium sulfate for component A. In formula (2), Y represents OOCR.

[0122] 2) Preparation of insulating ink

[0123] The ingredients are prepared according to the following proportions, calculated by weight:

[0124] Component A:

[0125]

[0126] Component B:

[0127]

[0128] In this process, the first and second barium sulfate components are modified nano-barium sulfate prepared in the first step. Each component in component A and component B is weighed according to its weight percentage, then stirred and mixed at room temperature for 15 minutes, followed by three-roll milling until a fineness of less than 6 is achieved. When used, component A and component B are mixed at a weight ratio of 2:1 to obtain the insulating ink for XBC batteries.

[0129] 3) Insulating ink usage and performance testing

[0130] The mixed insulating ink was screen-printed onto the XBC solar cell and then cured at 170°C for 5 minutes to obtain the solar cell with the insulating ink layer. The solar cell was then subjected to relevant performance tests.

[0131] Comparative Example 1

[0132] The nano-barium sulfate was dried in an oven at 100°C for 4 hours and then set aside for later use. This nano-barium sulfate was used to replace the first and second barium sulfate in Example 1, and the remaining operations were the same as in Example 1, which will not be described in detail here.

[0133] Comparative Example 2

[0134] The nano-barium sulfate was dried in an oven at 100°C for 4 hours. Then, 25g of the nano-barium sulfate was ultrasonicated in an acidic solution for 20 minutes while maintaining high-speed stirring. 8g of tetraethyl orthosilicate was added dropwise over 10 minutes. After the addition was complete, stirring continued for 2 hours. The mixture was then filtered, washed with water, and dried at 80°C. Finally, the temperature was increased to 600°C at a rate of 3°C / min and held for 3 hours. After cooling, it was ready for use. This nano-barium sulfate replaced the first and second barium sulfate in Example 1. The remaining operations were the same as in Example 1, and will not be described in detail here.

[0135] Comparative Example 3

[0136] 1) Preparation of modified barium sulfate

[0137] Preparation of first nanometer barium sulfate

[0138] The nano-barium sulfate was dried in an oven at 100℃ for 4 hours and then set aside for later use.

[0139] The second modifier with the structure of formula (1) is pre-hydrolyzed and then slowly added to the above-treated nano-barium sulfate. The mixture is stirred at 60°C for 2 hours, then washed with water and ethanol, and dried at 60°C to obtain the modified nano-barium sulfate for component A. In formula (1), X is OCH3.

[0140] Preparation of second nanometer barium sulfate

[0141] The nano-barium sulfate was dried in an oven at 100℃ for 4 hours and then set aside for later use.

[0142] The second modifier with the structure of formula (2) is pre-hydrolyzed and then slowly added to the above-treated nano-barium sulfate. The mixture is stirred at 60°C for 2 hours, then washed with water and ethanol, and dried at 60°C to obtain the modified nano-barium sulfate for component A. In formula (2), Y is OCH3.

[0143] The second and third steps are the same as in Example 1, and will not be described in detail here.

[0144] Comparative Example 4

[0145] We selected commercially available KSM-386 insulating ink for testing and comparison.

[0146] The treatment methods of barium sulfate in Examples 13 and Comparative Examples 1-4, as well as the relevant performance characterization results of the solar cells, are detailed in Table 1. (The curing conditions were all 170℃@5min.)

[0147] Table 1

[0148]

[0149] Note: The test methods and conditions for the above characterization techniques are as follows:

[0150] Curing status: After the printed battery cells are cured at 170℃ for 5 minutes, remove them. After the surface temperature of the battery cells drops to room temperature, if they are sticky to the touch, they are not cured; if they are not sticky to the touch but sticky when pressed, they are surface dry; if they are not sticky when pressed, they are fully dry. If they are not cured or are only surface dry, continue curing at 170℃ until they are fully dry.

[0151] Edge watermark expansion: Observe the edge overflow of the printed pattern under a microscope after the battery cell has been cured.

[0152] Adhesion: In accordance with JIS-C-6481 "Test Method for Copper Clad Laminates for Printed Circuit Boards", photovoltaic cells containing solder resist ink film were immersed in a soldering furnace at 288℃ for 10 seconds, and the immersion was repeated three times. The appearance of the photovoltaic cells was observed for discoloration, film peeling, and solder penetration. The adhesion level was tested using the cross-cut adhesion test and recorded.

[0153] As shown in Table 1, the insulating inks of Examples 1-3, after curing at 170°C for 5 minutes, showed a faster curing speed compared to the surface drying of Comparative Examples 1 and 4. This indicates that surface treatment of nano-barium sulfate can improve the curing speed to a certain extent. Figure 1 As shown, the edge watermark expansion of the insulating inks in Examples 1-3 on the electrode sheets is significantly reduced compared to Comparative Examples 1-4. This indicates that the treatment of the nano-barium sulfate surface enables a tighter bond between the filler and the resin, preventing precipitation due to high temperatures. Furthermore, the combined effect of the two modifications is more pronounced compared to commercially available fillers. Moreover, the insulating inks in Examples 1-3 exhibit high adhesion to the battery cells after curing, especially after soldering treatment, where the surface and adhesion remain largely unaffected.

[0154] It should be noted that the above are merely specific embodiments of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Where there is no conflict, the embodiments and features described in the embodiments of this application can be combined with each other. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. An insulating ink for XBC batteries, characterized in that, It includes component A and component B, wherein, by mass parts, component A comprises the following components: Epoxy resin: 90~120; Barium sulfate: 60~90; Component B includes the following components: Toughening agent: 40~60; Hardener: 1~30; Barium sulfate 20~30, Wherein, both the first barium sulfate and the second barium sulfate are modified barium sulfate, and the preparation method of the modified barium sulfate includes: Barium sulfate is surface-modified using a first modifier, which causes silica nanoparticles to form in situ on the surface of the barium sulfate particles, yielding an intermediate. The first modifier includes at least one of silicate esters and silicate substances. The intermediate is surface-modified using a second modifier to obtain the modified barium sulfate. The second modifier has the structure shown in formula (1) or formula (2): （1）， （2）， In Equation (1), X is a hydrolytic functional group and n is an integer greater than or equal to 1; in Equation (2), Y is a hydrolytic functional group and n is an integer greater than or equal to 1; the second modifier in the first barium sulfate adopts the structure of Equation (1), and the second modifier in the second barium sulfate adopts the structure of Equation (2).

2. The insulating ink for XBC batteries according to claim 1, characterized in that, The curing temperature of the insulating ink is 170~190℃, and the curing time is 5~10min.

3. The insulating ink for XBC batteries according to claim 1, characterized in that, The epoxy resin includes at least one of bisphenol A type epoxy resin, bisphenol F type epoxy resin, phenolic epoxy resin, o-cresol epoxy resin, and alicyclic epoxy resin; The curing agent includes at least one of hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, methylimidazole, 2-ethyl-4-methylimidazole, and dicyandiamide.

4. The insulating ink for XBC batteries according to claim 1, characterized in that, Component A, by mass parts, further includes: Reactive diluent: 10~30; Thixotropic thickener: 0.5~5; Adhesion promoter: 1~3; Pigment: 0~3; Component B further includes: Curing accelerator: 0.1~3.

5. The insulating ink for XBC batteries according to claim 1, characterized in that, Any X in formula (1) is independently selected from at least one of halogen, OR1, OOCR2 and NR3 groups, wherein R1 to R3 are at least one of hydrogen atoms and alkyl groups; Any Y in formula (2) is independently selected from at least one of halogen, OR4, OOCR5 and NR6 groups, wherein R4 to R6 are at least one of hydrogen atoms and alkyl groups.

6. The insulating ink for XBC batteries according to claim 1, characterized in that, The first modifier includes at least one of tetraethyl orthosilicate, methyl orthosilicate, and sodium silicate.

7. The insulating ink for XBC batteries according to claim 1, characterized in that, The method for preparing the intermediate includes: The barium sulfate was dried and then ultrasonically dispersed. Under stirring, the first modifier is added dropwise to the ultrasonically dispersed barium sulfate at a rate of 0.5~1 g / min, followed by filtration, washing with water, and drying to coat the surface of the barium sulfate with the first modifier; and The barium sulfate with the first modifier attached to its surface is heated to 600-700°C at a heating rate of 3-5°C / min and held for 3-5 hours to obtain the intermediate.

8. The insulating ink for XBC batteries according to claim 7, characterized in that, The step of surface modification of the intermediate using a second modifier includes: The second modifier was pre-hydrolyzed and added to the intermediate. The mixture was stirred at 60-80°C for 2-4 hours, then washed and dried to obtain the modified barium sulfate.

9. An XBC battery, characterized in that, It includes a battery cell and an ink layer on the battery cell, the ink layer being formed by curing an insulating ink for XBC batteries as described in any one of claims 1 to 8.

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