Modified barium sulfate preparation method, insulating ink for XBC battery, and XBC battery

Abstract

A modified barium sulfate preparation method, comprising: by means of a first modifier, performing surface modification of barium sulfate, to obtain an intermediate, the first modifier comprising at least one of a silicon alkoxide and a silicate substance; and, by means of a silane second modifier, performing surface modification on the intermediate, to obtain a modified barium sulfate. The present invention further relates to an insulating ink for an XBC battery, and an XBC battery. By means of performing surface treatment on a barium sulfate filler, and then matching the barium sulfate filler with a thermosetting resin system, curing is possible at 170-190°C for 5-10 min, and the prepared insulating ink has the characteristics of low VOCs and rapid curing. Furthermore, ink edge watermark expansion after curing is narrow, preventing illumination from being affected.

Description

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

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to a Chinese patent application filed with the Patent Office of China on September 25, 2023, with application number 202311266926.0 and application name “Method for preparing modified barium sulfate, insulating ink for XBC batteries and XBC battery”, the entire contents of which are incorporated by reference into this application. Technical Field

[0003] The present application relates to the field of ink technology, and in particular to a preparation method of modified barium sulfate, insulating ink for XBC batteries, and an XBC battery. Background Art

[0004] Back contact (XBC) cells are a general term for various types of crystalline silicon solar cells with back contact structures, including IBC, HBC, PBC, ABC, MBC, and HPBC cells. Due to their high efficiency, which is difficult to achieve with conventional solar cells, they have attracted much attention in the industry and have become a research hotspot for the next generation of solar cell technology. In terms of cell structure, the PN junction and metal contact of XBC cells are located on the back of the photovoltaic cell. The front surface avoids light blocking by the metal grid electrode, and the light-trapping structure composed of a pyramid velvet structure and an anti-reflection layer can maximize the use of incident light, reduce optical losses, and have a higher short-circuit current. The positive and negative fine grid lines of the XBC cell are arranged in a forked shape on the back of the cell. The main grid lines and auxiliary grid lines are printed vertically. The connection between the positive main grid segment and the negative grid line is isolated by printing insulating ink, and the connection between the negative main grid segment and the positive grid line is isolated by printing insulating ink.

[0005] However, the insulating ink currently used on XBC batteries has problems such as long curing time, high volatile organic compound (VOC) content, and widening of edge watermarks after curing.

[0006] Summary of the Invention

[0007] In view of this, in order to solve at least one of the above problems, the embodiments of the present application provide a method for preparing modified barium sulfate.

[0008] In addition, the embodiments of the present application also provide an insulating ink for XBC batteries and an XBC battery using the aforementioned modified barium sulfate.

[0009] The present invention provides a method for preparing modified barium sulfate, comprising:

[0010] Modifying the surface of barium sulfate with a first modifier to obtain an intermediate, wherein the first modifier comprises at least one of a silicate ester and a silicate; and

[0011] The intermediate is surface-modified by a second modifier to obtain the modified barium sulfate,

[0012] Wherein, the second modifier has a structure shown in the following formula (1) or formula (2):

[0013] Wherein, in the formula (1), X is a hydrolysis functional group, and n is an integer greater than or equal to 1;

[0014] In the formula (2), Y is a hydrolysis functional group, and n is an integer greater than or equal to 1.

[0015] In some possible embodiments, any one X in the 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 a hydrogen atom and an alkyl group; any one Y in the 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 a hydrogen atom and an alkyl group.

[0016] In some possible embodiments, the first modifier includes at least one of ethyl orthosilicate, methyl orthosilicate, and sodium silicate.

[0017] In some possible embodiments, the preparation method of the intermediate includes:

[0018] drying the barium sulfate and performing ultrasonic dispersion;

[0019] Under stirring, adding the first modifier to the ultrasonically dispersed barium sulfate at a rate of 0.5 to 1 g / min, then filtering, washing with water, and drying, so that the first modifier adheres to the surface of the barium sulfate; and

[0020] The barium sulfate with the first modifier attached to the surface is heated to 600-700° C. at a heating rate of 3-5° C. / min and kept at this temperature for 3-5 hours to obtain the intermediate.

[0021] In some possible embodiments, the step of surface-modifying the intermediate with a second modifier comprises:

[0022] The second modifier is pre-hydrolyzed and then added to the intermediate, stirred at a temperature of 60 to 80° C. for 2 to 4 hours, and then washed and dried to obtain the modified barium sulfate.

[0023] The present application also provides an insulating ink for an XBC battery. The insulating ink for an XBC battery includes a component A and a component B. Component A includes the following components in parts by mass:

[0024] Epoxy resin: 90-120;

[0025] First barium sulfate: 60-90;

[0026] The B component includes the following components:

[0027] Toughening agent: 40-60;

[0028] Curing agent: 1~30;

[0029] Second barium sulfate: 20-30,

[0030] The first barium sulfate and the second barium sulfate are both prepared by the modified barium sulfate preparation method described above, the second modifier in the first barium sulfate has the structure of formula (1), and the second modifier in the second barium sulfate has the structure of formula (2). Exemplarily, the weight ratio of component A to component B is 2:1.

[0031] In some possible embodiments, the insulating ink has a curing temperature of 170-190° C. and a curing time of 5-10 minutes.

[0032] In some possible embodiments, the epoxy resin includes at least one of bisphenol A epoxy resin, bisphenol F epoxy resin, novolac epoxy resin, o-cresol epoxy resin and alicyclic epoxy resin;

[0033] The curing agent includes at least one of hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, methylimidazole, 2-ethyl-4-methylimidazole and dicyandiamide.

[0034] In some possible embodiments, the component A further comprises, in parts by mass:

[0035] Active diluent: 10-30;

[0036] Thixotropic thickener: 0.5~5;

[0037] Adhesion promoter: 1-3;

[0038] Color paste: 0~3;

[0039] The B component also includes:

[0040] Curing accelerator: 0.1~3.

[0041] An embodiment of the present application further provides an XBC battery, comprising a battery cell and an ink layer on the battery cell, wherein the ink layer is formed by curing the insulating ink for the XBC battery as described above.

[0042] The embodiment of the present application performs surface treatment on the barium sulfate filler, then combines the modified barium sulfate with a thermosetting resin system, and adds modified barium sulfate fillers with different structures to components A and B in the insulating ink, respectively. Curing can be achieved under curing conditions of 170-190°C and 5-10 minutes, which can effectively reduce the curing time of the insulating ink, improve the curing efficiency, and reduce the VOC content in the insulating ink. It can also effectively narrow the widening of the edge watermark after curing; the insulating ink has high adhesion to the electrode sheet after curing, especially after corrosion treatment, the adhesion is basically unaffected; in addition, the insulating ink of the embodiment of the present application advantageously reduces the risk of leakage of the electrode sheet. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] FIG1 is a microscope photograph of the edge watermark expansion of the insulating ink layer on the battery cell in Examples 1-3 and Comparative Examples 1-4 of the present application. DETAILED DESCRIPTION

[0044] The technical solution of the present invention will be described clearly and completely below with reference to specific embodiments. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments.

[0045] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The names of the technical means used in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0046] In the absence of conflict, the following embodiments and features thereof may be combined with each other.

[0047] The embodiments of the present application provide a modified barium sulfate, which may be specifically modified nano-barium sulfate. The modified barium sulfate can be used as a filler in insulating ink to improve the thickness, wear resistance, water resistance, heat resistance, surface hardness, and impact resistance of the ink coating. Moreover, the modified barium sulfate has a good spatial spacing ability for pigment particles, so that the pigment particles can maintain a certain distance from each other, thereby improving the pigment efficiency.

[0048] The modified barium sulfate is obtained by sequentially surface-treating barium sulfate with a first modifier and a second modifier, and the barium sulfate used here is nano-barium sulfate.

[0049] In some embodiments, the first modifier includes at least one of silicates and silicates. For example, the first modifier may include at least one of ethyl orthosilicate, methyl orthosilicate, sodium silicate, and the like.

[0050] In some embodiments, the second modifier is a silane having a structure shown in the following formula (1) or formula (2):

[0051] Wherein, in the formula (1), X is a hydrolysis functional group, and any one of X in the formula (1) is independently selected from at least one of halogen, OR1, OOCR2, and NR3 groups, wherein R1 to R3 are all at least one of a hydrogen atom and an alkyl group. For example, any one of 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, n can range from 3 to 10. Within this range, it is beneficial to improve the flexibility of the molecular chain while having a suitable viscosity.

[0052] In formula (2), Y is a hydrolysis 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 each at least one of a hydrogen atom and an alkyl group. 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, n can range from 3 to 10. Within this range, it is beneficial to improve the flexibility of the molecular chain while having a suitable viscosity.

[0053] Specifically, the preparation method of the modified barium sulfate comprises the following steps:

[0054] Step S1, surface-modifying barium sulfate with a first modifier to obtain an intermediate.

[0055] In some embodiments, the preparation method of the intermediate comprises:

[0056] Step S11, drying the barium sulfate and performing ultrasonic dispersion.

[0057] The nano-barium sulfate is dried in an oven at 100-120° C. for 4-6 hours, and then a certain amount of the nano-barium sulfate is placed in an acidic solution and ultrasonicated for 10-30 minutes.

[0058] Step S12: adding the first modifier dropwise to the ultrasonically dispersed barium sulfate at a rate of 0.5-1 g / min under stirring, followed by filtering, washing with water, and drying to allow the first modifier to adhere to the surface of the barium sulfate.

[0059] In which, under high-speed stirring, the first modifier is added dropwise to the ultrasonically dispersed barium sulfate at a rate of 0.5 to 1 g / min. The stirring speed can be in the range of 1500 to 2000 r / min. By combining high-speed stirring with the above dropping speed, the surface of the barium sulfate particles can be fully coated with the first modifier, thereby improving the uniformity of the coating.

[0060] Step S13: heating the barium sulfate with the first modifier attached to its surface to 600-700° C. at a heating rate of 3-5° C. / min and keeping the temperature for 3-5 hours to obtain the intermediate.

[0061] In this embodiment, the intermediate can be prepared by drying the nanobarium sulfate in an oven at 100-120°C for 4-6 hours. Then, 20-25g of the nanobarium sulfate is ultrasonically dissolved in an acidic solution for 10-30 minutes. While maintaining high-speed stirring, 5-10g of a first modifier, such as ethyl orthosilicate, is dropwise added over 10-20 minutes. After the addition is complete, stirring is continued for 2-3 hours. The intermediate is then filtered, washed with water, and dried at 80°C. Finally, the temperature is raised to 600-700°C at a rate of 3-5°C / min and maintained at that temperature for 3-5 hours. The mixture is then cooled and set aside for later use.

[0062] Step S2, surface-modifying the intermediate with a second modifier to obtain the modified barium sulfate.

[0063] The second modifier is pre-hydrolyzed and then added to the intermediate, stirred at 60-80° C. for 2-4 hours, and then washed and dried to obtain the modified barium sulfate.

[0064] In this embodiment, the second modifier having the structure of formula (1) or (2) can be pre-hydrolyzed and then slowly added to the treated nano-barium sulfate, stirred at 60-80° C. for 2 h, then washed with water, washed with ethanol, and dried at 60-80° C. to obtain the modified nano-barium sulfate.

[0065] By first introducing a silicon-containing first modifier onto the surface of the barium sulfate particles, the in-situ generation of silica nanoparticles on the surface of the barium sulfate particles can increase the number of reactive sites for 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. Furthermore, since the structures of formula (1) or (2) contain a large number of -X or -Y groups, pre-hydrolysis can form a larger number of bonding sites, enabling them to bind to the pre-formed silica nanoparticles on the barium sulfate surface, thereby increasing the adhesion of the second modifier to the barium sulfate surface.

[0066] The present application also provides an insulating ink for XBC batteries. This insulating ink is mainly used in the battery cells of XBC batteries and mainly serves as an insulating isolation. The insulating ink includes component A and component B, wherein, by weight, component A includes the following components: 90-120 parts of epoxy resin and 60-90 parts of a first barium sulfate; and component B includes the following components: 40-60 parts of a toughening agent; 1-30 parts of a curing agent; and 20-30 parts of a second barium sulfate. The first barium sulfate and the second barium sulfate are both prepared by the preparation method of the modified barium sulfate 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).

[0067] 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 using 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 using 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.

[0068] In some embodiments, the added amount of the first barium sulfate can be 60 parts, 65 parts, 70 parts, 75 parts, 80 parts, 85 parts or 90 parts, etc. If the added amount of the first barium sulfate is too little, less than 60 parts, the viscosity and thixotropy of the insulating ink will be greatly reduced, the screen printing will easily leak glue, and the ink morphology will be poor after curing. If too much is added, more than 90 parts, the viscosity of the insulating ink will be too high, the screen printing will easily stick to the sheet, resulting in low production efficiency of the production line.

[0069] In some embodiments, the added amount of the second barium sulfate can be 20 parts, 23 parts, 25 parts, 28 parts or 30 parts, etc. If the added amount of the second barium sulfate is too little, less than 20 parts, the viscosity and thixotropy of the insulating ink will be greatly reduced, the screen printing will be prone to glue leakage, and the ink morphology will be poor after curing. If too much is added, more than 30 parts, the viscosity of the insulating ink will be too high, the screen printing will be prone to sticking, resulting in low production efficiency of the production line.

[0070] In some embodiments, the weight ratio of the A component to the B component is 2:1.

[0071] In some embodiments, the epoxy resin includes at least one of bisphenol A epoxy resin, bisphenol F epoxy resin, novolac epoxy resin, o-cresol epoxy resin, and alicyclic epoxy resin.

[0072] In some embodiments, the curing agent includes at least one of hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, methylimidazole, 2-ethyl-4-methylimidazole, and dicyandiamide.

[0073] In some embodiments, the toughening agent includes one or a mixture of liquid polysulfide rubber, liquid nitrile rubber (including carboxyl-terminated and hydroxyl-terminated nitrile rubber), polyether and polyester resins, polyurethane prepolymers, polyester polyols, polyether polyols, etc.

[0074] In some embodiments, the component A further comprises 10 to 30 parts of a reactive diluent for adjusting the flexibility of the epoxy resin, wherein the reactive diluent comprises at least one of butyl glycidyl ether, benzyl glycidyl ether, C12 to C14 glycidyl ether and methacrylate glycidyl ether.

[0075] In some embodiments, the component A further comprises 0.5 to 5 parts of a thixotropic thickener for adjusting the thixotropic properties of the system, wherein the thixotropic thickener comprises at least one of fumed silica, cellulose acetate butyrate, ethyl cellulose, hydroxyethyl cellulose, polyvinyl butyral, aldehyde-ketone resin, and the like.

[0076] In some embodiments, the component A further comprises 1 to 3 parts of an adhesion promoter for providing adhesion to different substrates. The adhesion promoter comprises a mixture of one or more of a silane coupling agent, a titanate coupling agent, and a phosphate coupling agent.

[0077] In some embodiments, the component A further comprises 0 to 3 parts of a color paste for positioning and identification, which may include carbon black, indigo, titanium dioxide, chrome green or anthraquinone red.

[0078] In some embodiments, the B component 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 containing at least one of hydroxyl, amine, and secondary amine groups in its molecular structure.

[0079] The embodiment of the present application performs surface treatment on the barium sulfate filler, then combines the modified barium sulfate with a thermosetting resin system, and adds modified barium sulfate fillers with different structures to components A and B in the insulating ink, respectively. Curing can be achieved under curing conditions of 170-190°C and 5-10 minutes, which can effectively reduce the curing time of the insulating ink, improve the curing efficiency, and reduce the VOC content in the insulating ink. It can also effectively narrow the widening of the edge watermark after curing; the insulating ink has high adhesion to the electrode sheet after curing, especially after corrosion treatment, the adhesion is basically unaffected; in addition, the insulating ink of the embodiment of the present application advantageously reduces the risk of leakage of the electrode sheet.

[0080] The embodiments of the present application are further described below through specific examples.

[0081] Example 1

[0082] 1) Preparation of modified barium sulfate:

[0083] Preparation of the first barium sulfate:

[0084] The nanobarium sulfate was dried in a 100°C oven for 4 hours. Then, 23g of the nanobarium sulfate was ultrasonically dissolved in an acidic solution for 20 minutes. Maintaining high-speed stirring, 8g of ethyl orthosilicate was added dropwise over 10 minutes. After the addition was complete, stirring was continued for 2 hours. The solution 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 maintained for 3 hours.

[0085] The second modifier of formula (1) is pre-hydrolyzed and then slowly added to the 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. Wherein, X in formula (1) is OCH3.

[0086] Preparation of the second barium sulfate:

[0087] The nanobarium sulfate was dried in a 100°C oven for 4 hours. Then, 23g of the nanobarium sulfate was ultrasonically dissolved in an acidic solution for 20 minutes. Maintaining high-speed stirring, 8g of ethyl orthosilicate was added dropwise over 10 minutes. After the addition was complete, stirring was continued for 2 hours. The solution 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 maintained for 3 hours.

[0088] The second modifier of formula (2) is pre-hydrolyzed and then slowly added to the 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. Wherein, Y in formula (2) is OCH3.

[0089] 2) Preparation of insulating ink

[0090] Calculate by mass and mix according to the following ratio:

[0091] Component A:

[0092] Component B:

[0093] The first and second barium sulfates were modified nano-barium sulfate prepared in the first step. Components A and B were weighed by weight, stirred and mixed at room temperature for 15 minutes, and then ground using three rollers to a fineness of 6 or less. During use, components A and B were mixed in a weight ratio of 2:1 to produce insulating ink for XBC batteries.

[0094] 3) Insulation ink usage and performance testing

[0095] The mixed insulating ink was screen-printed onto the XBC cell and then cured at 170°C for 5 minutes to obtain a cell with an insulating ink layer printed thereon. The cell was then subjected to relevant performance tests.

[0096] Example 2

[0097] 1) Preparation of modified barium sulfate:

[0098] Preparation of the first barium sulfate:

[0099] The nanobarium sulfate was dried in a 100°C oven for 4 hours. Then, 20g of the nanobarium sulfate was ultrasonically dissolved in an acidic solution for 20 minutes. Maintaining high-speed stirring, 10g of ethyl orthosilicate was added dropwise over 10 minutes. After the addition was complete, stirring was continued for 2 hours. The solution 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 maintained for 3 hours.

[0100] The second modifier of formula (1) is pre-hydrolyzed and then slowly added to the 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. Wherein, X in formula (1) is OC2H5.

[0101] Preparation of the second barium sulfate:

[0102] The nanobarium sulfate was dried in a 100°C oven for 4 hours. Then, 20g of the nanobarium sulfate was ultrasonically dissolved in an acidic solution for 20 minutes. Maintaining high-speed stirring, 10g of ethyl orthosilicate was added dropwise over 10 minutes. After the addition was complete, stirring was continued for 2 hours. The solution 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 maintained for 3 hours.

[0103] The second modifier of formula (2) is pre-hydrolyzed and then slowly added to the 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. Wherein, Y in formula (2) is OC2H5.

[0104] 2) Preparation of insulating ink

[0105] Calculate by mass and mix according to the following ratio:

[0106] Component A:

[0107] Component B:

[0108] The first and second barium sulfates were modified nano-barium sulfate prepared in the first step. Components A and B were weighed by weight, stirred and mixed at room temperature for 15 minutes, and then ground using three rollers to a fineness of 6 or less. During use, components A and B were mixed in a weight ratio of 2:1 to produce insulating ink for XBC batteries.

[0109] 3) Insulation ink usage and performance testing

[0110] The mixed insulating ink was screen-printed onto the XBC cell and then cured at 170°C for 5 minutes to obtain a cell with an insulating ink layer printed thereon. The cell was then subjected to relevant performance tests.

[0111] Example 3

[0112] 1) Preparation of modified barium sulfate:

[0113] Preparation of the first barium sulfate:

[0114] The nanobarium sulfate was dried in a 100°C oven for 4 hours. Then, 25g of the nanobarium sulfate was ultrasonically dissolved in an acidic solution for 20 minutes. Maintaining high-speed stirring, 8g of ethyl orthosilicate was added dropwise over 10 minutes. After the addition was complete, stirring was continued for 2 hours. The solution 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 maintained for 3 hours.

[0115] The second modifier of formula (1) is pre-hydrolyzed and then slowly added to the 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. Wherein, X in formula (1) is OOCR.

[0116] Preparation of the second barium sulfate:

[0117] The nanobarium sulfate was dried in a 100°C oven for 4 hours. Then, 25g of the nanobarium sulfate was ultrasonically dissolved in an acidic solution for 20 minutes. Maintaining high-speed stirring, 8g of ethyl orthosilicate was added dropwise over 10 minutes. After the addition was complete, stirring was continued for 2 hours. The solution 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 maintained for 3 hours.

[0118] The second modifier of formula (2) is pre-hydrolyzed and then slowly added to the 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. Wherein, Y in formula (2) is OOCR.

[0119] 2) Preparation of insulating ink

[0120] Calculate by mass and mix according to the following ratio:

[0121] Component A:

[0122] Component B:

[0123] The first and second barium sulfates were modified nano-barium sulfate prepared in the first step. Components A and B were weighed by weight, stirred and mixed at room temperature for 15 minutes, and then ground using three rollers to a fineness of 6 or less. During use, components A and B were mixed in a weight ratio of 2:1 to produce insulating ink for XBC batteries.

[0124] 3) Insulation ink usage and performance testing

[0125] The mixed insulating ink was screen-printed onto the XBC cell and then cured at 170°C for 5 minutes to obtain a cell with an insulating ink layer printed thereon. The cell was then subjected to relevant performance tests.

[0126] Comparative Example 1

[0127] The nano-barium sulfate was dried in an oven at 100° C. for 4 hours and then set aside. The nano-barium sulfate was used to replace the first barium sulfate and the second barium sulfate in Example 1. The remaining operations were the same as in Example 1 and will not be described in detail here.

[0128] Comparative Example 2

[0129] Nanobarium sulfate was dried in a 100°C oven for 4 hours. Then, 25g of nanobarium sulfate was ultrasonically added to an acidic solution for 20 minutes while maintaining high-speed stirring. Over 10 minutes, 8g of tetraethyl orthosilicate was added dropwise. 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 mixture was heated to 600°C at a rate of 3°C / min and incubated for 3 hours. The mixture was cooled and then used for standby use. This nanobarium sulfate was used to replace the first and second barium sulfates in Example 1. The remaining operations were the same as in Example 1 and will not be described in detail here.

[0130] Comparative Example 3

[0131] 1) Preparation of modified barium sulfate

[0132] Preparation of the first nanobarium sulfate

[0133] The nano-barium sulfate was dried in an oven at 100° C. for 4 h and set aside.

[0134] The second modifier of formula (1) is pre-hydrolyzed and then slowly added to the 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. Wherein, X in formula (1) is OCH3.

[0135] Preparation of the second nanobarium sulfate

[0136] The nano-barium sulfate was dried in an oven at 100° C. for 4 h and set aside.

[0137] The second modifier of formula (2) is pre-hydrolyzed and then slowly added to the 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. Wherein, Y in formula (2) is OCH3.

[0138] The second and third steps are the same as those in Example 1 and will not be described in detail here.

[0139] Comparative Example 4

[0140] KSM-386 insulating ink on the market was selected for testing and comparison.

[0141] The treatment methods of barium sulfate in Examples 1-3 and Comparative Examples 1-4 and the relevant performance characterization results of the battery cells are shown in Table 1. (The curing conditions are all 170°C @ 5 min)

[0142] Table 1

[0143] Note: The test methods and test conditions for the above characterization methods are as follows:

[0144] Curing: Curing the printed cell at 170°C for 5 minutes. After the cell surface cools to room temperature, if it is sticky to the touch, it is uncured. If it is not sticky to the touch but sticks when pressed, it is surface-dry. If it is not sticky when pressed, it is completely dry. If it is not sticky when pressed, it is completely dry. If it is not cured or is surface-dry, continue curing at 170°C until it is completely dry.

[0145] Edge watermark expansion: Observe the edge overflow of the printed pattern on the cured cell under a microscope.

[0146] Adhesion: Referring to JIS-C-6481 "Test Methods for Copper-Clad Laminates for Printed Circuit Boards", immerse the photovoltaic cells containing the solder mask ink film in a 288°C soldering furnace for 10 seconds for a total of three immersions. Observe the appearance of the photovoltaic cells for discoloration, film peeling, and solder penetration. At the same time, test the adhesion level using the 100-grid method and record it.

[0147] As can be seen from Table 1, the insulating inks of Examples 1-3 are completely dry under the curing conditions of 170°C and 5 minutes. Compared with the surface drying of Comparative Examples 1 and 4, the insulating inks of Examples 1-3 cure faster, indicating that the curing speed can be improved to a certain extent by surface treatment of nano-barium sulfate. As shown in Figure 1, the edge watermark expansion of the insulating inks of Examples 1-3 on the electrode sheets is significantly reduced compared with Comparative Examples 1-4, indicating that the surface treatment of nano-barium sulfate can make the filler and the resin bond more tightly and will not cause precipitation due to high temperature. At the same time, the combined effect of the two modifications is more obvious than that of commercially available fillers. Moreover, the insulating inks in Examples 1-3 have a high adhesion to the battery cells after curing, especially after being treated with solder solution, the surface and adhesion are basically unaffected.

[0148] It should be noted that the above are only specific embodiments of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by any person skilled in the art within the technical scope disclosed in the present application should be included in the scope of protection of the present application; the embodiments of the present application and the features of the embodiments can be combined with each other unless there is a conflict. Therefore, the scope of protection of the present application shall be based on the scope of protection of the claims.

Claims

1. A method for preparing modified barium sulfate, characterized in that: include: The barium sulfate is surface-modified by a first modifier to obtain an intermediate, wherein the first modifier comprises at least one of a silicate ester and a silicate; as well as The intermediate is surface-modified by a second modifier to obtain the modified barium sulfate, Wherein, the second modifier has a structure shown in the following formula (1) or formula (2): Wherein, in the formula (1), X is a hydrolysis functional group, and n is an integer greater than or equal to 1; In the formula (2), Y is a hydrolyzable functional group, and n is an integer greater than or equal to 1.

2. The method for preparing modified barium sulfate according to claim 1, characterized in that: Any one X in the 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 a hydrogen atom and an alkyl group; Any one Y in the 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 a hydrogen atom and an alkyl group.

3. The method for preparing modified barium sulfate according to claim 1, characterized in that: The first modifier includes at least one of ethyl orthosilicate, methyl orthosilicate and sodium silicate.

4. The method for preparing modified barium sulfate according to claim 1, characterized in that: The preparation method of the intermediate comprises: drying the barium sulfate and performing ultrasonic dispersion; Under stirring, adding the first modifier to the ultrasonically dispersed barium sulfate at a rate of 0.5-1 g / min, then filtering, washing with water and drying, so that the first modifier adheres to the surface of the barium sulfate; and The barium sulfate with the first modifier attached to the surface is heated to 600-700° C. at a heating rate of 3-5° C. / min and kept at this temperature for 3-5 hours to obtain the intermediate.

5. The method for preparing modified barium sulfate according to claim 4, characterized in that: The step of surface modifying the intermediate by a second modifying agent comprises: The second modifier is pre-hydrolyzed and then added to the intermediate, stirred at 60-80° C. for 2-4 hours, then washed and dried to obtain the modified barium sulfate.

6. An insulating ink for XBC battery, characterized in that: The invention comprises component A and component B, wherein the component A comprises the following components by weight: epoxy resin: 90-120; first barium sulfate: 60-90; The B component includes the following components: Toughening agent: 40-60; Curing agent: 1~30; Second barium sulfate: 20-30, Wherein, the first barium sulfate and the second barium sulfate are both prepared by the preparation method of modified barium sulfate as described in any one of claims 1 to 5, 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).

7. The insulating ink for XBC battery according to claim 6, characterized in that: The curing temperature of the insulating ink is 170-190° C., and the curing time is 5-10 minutes.

8. The insulating ink for XBC battery according to claim 6, characterized in that: The epoxy resin includes at least one of bisphenol A epoxy resin, bisphenol F epoxy resin, novolac epoxy resin, o-cresol epoxy resin and alicyclic epoxy resin; The curing agent includes at least one of hexahydrophthalic anhydride, methyl hexahydrophthalic anhydride, methylimidazole, 2-ethyl-4-methylimidazole and dicyandiamide.

9. The insulating ink for XBC battery according to claim 6, characterized in that: In parts by mass, the component A further comprises: active diluent: 10 to 30; thixotropic thickener: 0.5 to 5; adhesion promoter: 1 to 3; color paste: 0 to 3; The B component also includes: Curing accelerator: 0.1~3.

10. An XBC battery, characterized in that: The invention comprises a battery cell and an ink layer on the battery cell, wherein the ink layer is formed by curing the insulating ink for XBC battery according to any one of claims 6 to 9.

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