Silicon battery, battery passivation material and preparation method thereof

Abstract

The present application relates to a silicon battery, a battery passivation material and a preparation method thereof, wherein the silicon battery is provided with a passivation layer, and the battery passivation material used in the passivation layer is a carboxylic acid / sulfonic acid / phosphorylated polystyrene compound. It is based on polystyrene sulfonic acid, a common passivation material for silicon batteries, and introduces silicon-based, titanium-based and other highly stable groups, thereby improving the overall stability of the compound, ensuring the stability of the passivation layer, thereby improving the stability of the silicon battery and extending the service life of the silicon battery.

Description

Technical Field

[0001] The present application relates to the technical field of solar cells, and in particular to a silicon cell, a cell passivation material, and a preparation method thereof. Background Art

[0002] Silicon cells are a common and important type of solar cell. To improve their energy conversion efficiency and reduce power generation costs, they utilize passivation materials for interface passivation. Existing passivation materials for silicon cells are typically polystyrene sulfonate (PSS), as described in patent CN106601866A. However, polystyrene sulfonate (PSS) is not very stable, making it difficult for the passivation material to function properly in harsh environments. This compromises the stability of the cell, limits its application, and hinders widespread adoption.

[0003] Therefore, how to improve the stability of battery passivation materials has become an urgent problem to be solved by those skilled in the art. Summary of the Invention

[0004] In order to improve the stability of battery passivation materials, the present application provides a silicon battery, a battery passivation material and a preparation method thereof.

[0005] To achieve the purpose of this application, a method for preparing a battery passivation material is provided, comprising the following steps:

[0006] The first raw material is shown in Formula 1, and benzene and the first raw material are mixed to react to obtain a first product as shown in Formula 2;

[0007] Formula 1

[0008] Formula 2

[0009] The first product is added to an acidic solution to react to obtain a second product as shown in Formula 3;

[0010] Formula 3

[0011] A polymer initiator is added to the solution containing the second product, and a polyaddition reaction is carried out under heating or the action of a catalyst to obtain a third product which is a battery passivation material. The third product is an acidified polystyrene compound, and the third product is shown in Formula 4;

[0012] Formula 4

[0013] Wherein, X is a silyl group or a titanium group, Y is any one of a carboxylic acid group, a sulfonic acid group and a phosphoric acid group, the silyl group is as shown in Formula 5, and the titanium group is as shown in Formula 6;

[0014] Formula 5

[0015] Formula 6

[0016] According to another aspect of the present application, a battery passivation material is provided, and the battery passivation material is shown in Formula 4;

[0017] Formula 4

[0018] Wherein, X is a silyl group or a titanium group, Y is any one of a carboxylic acid group, a sulfonic acid group and a phosphoric acid group, the silyl group is as shown in Formula 5, and the titanium group is as shown in Formula 6;

[0019] Formula 5

[0020] Formula 6

[0021] According to another aspect of the present application, a silicon cell is provided. The silicon cell is provided with a passivation layer. The material of the passivation layer includes the aforementioned cell passivation material.

[0022] Traditional methods for preparing battery passivation materials use benzene and ethylene as raw materials to produce polystyrene sulfonic acid. Polystyrene sulfonic acid has low stability and often exhibits poor stability when exposed to harsh environmental conditions such as high temperature, moisture, and ultraviolet light, which reduces battery performance. This application introduces highly stable silicon-based and titanium-based groups into the passivation material to form a more stable compound, which can improve the stability of the passivation material itself, thereby ensuring the stability of battery performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 A schematic flow chart showing a method for preparing a battery passivation material according to an embodiment of the present application is shown;

[0024] Figure 2 A schematic structural diagram of a photovoltaic cell according to an embodiment of the present application is shown.

[0025] Passivation layer 100 , substrate 200 . DETAILED DESCRIPTION

[0026] It should be noted that, in order to better illustrate the present application, numerous specific details are provided in the following detailed description. Those skilled in the art will understand that the present application can be practiced without certain specific details. In some instances, methods and means well known to those skilled in the art are not described in detail in order to highlight the main purpose of the present application.

[0027] According to one aspect of the present application, a method for preparing a battery passivation material is provided, comprising the following steps:

[0028] S100, the first raw material is as shown in Formula 1, and benzene and the first raw material are mixed to react to obtain a first product as shown in Formula 2; it should be noted that the first raw material (silicon-based acetylene or titanium-based acetylene) are conventional raw materials and can be prepared by themselves or purchased commercially.

[0029] Formula 1

[0030] Formula 2

[0031] S200, the first product is added to an acidic solution to react to obtain a second product as shown in Formula 3;

[0032] Formula 3

[0033] S400, adding a polymer initiator to the solution containing the second product, and performing a polyaddition reaction under heating or the action of a catalyst to obtain a third product which is a silicon battery passivation material. The third product is shown in Formula 4;

[0034] Formula 4

[0035] Wherein, X is a silyl group or a titanium group, Y is any one of a carboxylic acid group, a sulfonic acid group and a phosphoric acid group, the silyl group is as shown in Formula 5, and the titanium group is as shown in Formula 6;

[0036] Formula 5

[0037] Formula 6

[0038] The preparation method of traditional battery passivation materials uses benzene and ethylene as raw materials to prepare polystyrene sulfonic acid. Polystyrene sulfonic acid has low stability. When faced with harsh environmental conditions such as high temperature, moisture and ultraviolet rays, it often shows poor stability and reduces the performance of the battery. The present application introduces silicon-based and titanium-based groups with higher stability into the passivation material. These three groups can effectively improve the stability of silicon batteries. Among them, the silicon-based group can effectively improve the crystal volume fraction, structure factor, optical band gap and other properties of silicon batteries. The bonding structure of the silicon-based and titanium-based groups can show good density and photosensitivity in the transition zone between the passivation layer and the substrate / absorption layer, so that the state density in the transition zone of the thin film is low, which optimizes the passivation effect of the passivation layer and provides excellent passivation effect for photovoltaic cells, especially silicon cells.

[0039] The present application introduces a silicon-based group and a titanium-based group with higher stability into the passivation material to form a compound with higher stability, which can improve the stability of the passivation material itself, thereby ensuring the stability of battery performance.

[0040] In addition, the present application also provides comparative examples and embodiments as follows:

[0041] Comparative Example: A silicon solar cell passivation layer was prepared using conventional polystyrene sulfonic acid as a passivation material. Silicon solar cells containing this passivation layer were prepared and their performance was tested. Three parallel experiments were conducted in Comparative Example 1. The passivation layer and silicon solar cell preparation processes and parameters remained consistent across the three experiments. The test results are shown in Table 1.

[0042] Example 1: A passivation layer for a silicon cell was prepared using polyphenylsiloxyethylene sulfonic acid (polyphenylsiloxyethylene sulfonic acid), as shown in the formula below, as the passivation material. The thickness of the passivation layer remained the same as in the comparative example. A silicon cell containing this passivation layer was prepared and its performance tested. Aside from the passivation material, the passivation layer and silicon cell preparation processes and parameters in Example 1 remained the same as in the comparative example. The test results are shown in Table 1.

[0043]

[0044] Example 2: A silicon solar cell passivation layer was prepared using polystyrene sulfonate-titanium as the passivation material. The passivation layer thickness remained the same as in the comparative example. A silicon solar cell containing this passivation layer was prepared and its performance tested. Aside from the passivation material, the passivation layer and silicon solar cell preparation processes and parameters in Example 2 remained the same as in the comparative example. The test results are shown in Table 1.

[0045] Table 1: Test results of silicon cells of comparative example and examples 1 to 2

[0046]

[0047] As shown in Table 1, the photoelectric conversion efficiency of the battery passivation material provided by the present application is higher than that of traditional battery passivation materials, and it has long-term stability. Therefore, the battery passivation material provided by the present application can improve the photoelectric conversion efficiency of silicon batteries and improve the stability of silicon batteries.

[0048] The passivation material provided in this application can be applied to the light-facing surface of the silicon cell substrate to form a dense passivation protective layer between the substrate and the absorption layer, isolating the cell from the external environment, reducing physical damage and oxidation reactions, and improving stability. The protective layer is also a waterproof layer, which gives the cell a certain waterproof effect and prevents water penetration from causing damage to the cell. The structure of the passivation material enables it to withstand higher operating temperatures and has good adaptability to the working environment (temperature and humidity), ensuring the stability of the cell performance, expanding the application range and scenarios of the cell, and being conducive to the promotion and application of solar cells.

[0049] In one possible implementation, X is a siloxy group as shown in Formula 5, and Y is a carboxylic acid group. The third product prepared is polyphenylsiloxyethylene carboxylic acid as shown in Formula 7.

[0050] Formula 7

[0051] The reaction formula for preparing the third product, polyphenylsiloxyethylene carboxylic acid, is shown below:

[0052]

[0053] In one possible implementation, X is a siloxy group as shown in Formula 5, and Y is a sulfonic acid group. The third product prepared is polyphenylsiloxyethylene sulfonic acid as shown in Formula 8.

[0054] Formula 8

[0055] The reaction formula for preparing the third product, polyphenylsiloxyethylene sulfonic acid, is shown below:

[0056]

[0057] In one possible implementation, X is a siloxy group as shown in Formula 5, and Y is a phosphoric acid group. The third product prepared is polyphenylsiloxyethylene phosphoric acid as shown in Formula 9.

[0058] Formula 9

[0059] The reaction formula for preparing the third product, polyphenylsiloxyethylene phosphoric acid, is shown below:

[0060]

[0061] In one possible implementation, X is a titanium group as shown in Formula 6, and Y is a carboxylic acid group. The third product prepared is polystyrene carboxylate-titanium as shown in Formula 10.

[0062] Formula 10

[0063] In one possible implementation, X is a titanium group as shown in Formula 6, and Y is a sulfonic acid group. The third product prepared is polystyrene sulfonate-titanium as shown in Formula 11.

[0064] Formula 11

[0065] The reaction formula for preparing the third product, polystyrene sulfonic acid-titanium, is shown below:

[0066]

[0067] In one possible implementation, X is a titanium group as shown in Formula 6, and Y is a phosphoric acid group. The third product prepared is polystyrene titanium phosphate as shown in Formula 12.

[0068] Formula 12

[0069] In one possible implementation, R in the siloxy group shown in Formula 5 is selected from any one of an alkyl group and a phenyl group, and the alkyl group may be a methyl group or an ethyl group.

[0070] In one possible implementation, in S100, during the step of mixing benzene and the first raw material, the molar ratio of benzene to the first raw material is 1:1. Aluminum chloride is added to the mixture of benzene and the first raw material as a reaction catalyst, and the mixing reaction is carried out for 4 to 12 hours, preferably 6 hours. The molar ratio of aluminum chloride to the initial addition of the first raw material is 1:(15-20), preferably 1:18.

[0071] In one possible implementation, in S200, adding the first product to the acidic solution specifically involves adding an excess of formic acid, concentrated sulfuric acid, chlorosulfonic acid, or concentrated phosphoric acid to the solution containing the first product. The type of acidic solution added is selected based on the intended use and Y. For example, when Y is a sulfonic acid group, the acid added is concentrated sulfuric acid or chlorosulfonic acid, and so on.

[0072] In one possible implementation, the polymerization initiator is a potassium persulfate solution, and the concentration ratio of the initial second product to ammonium persulfate is 1:(1-3), preferably 1:1 or 1:2.

[0073] In one possible implementation, in S400, the second product is heated under the action of a polymerization initiator to undergo an addition polymerization reaction; the heating temperature is 60-80°C and the heating time is 6-12 hours, that is, the product is heated to 60-80°C and maintained at this temperature for 6-12 hours. The heating temperature is preferably 60°C, 65°C, 68°C, 70°C, 75°C, or 80°C, and the heating time is preferably 6.5 hours, 7 hours, 8 hours, 9 hours, 10 hours, 11 hours, or 12 hours.

[0074] In one possible implementation, after preparing a solution containing the second product in S200, and before subjecting the second product to an addition polymerization reaction in the solution to produce a third product in S400, the solution containing the second product is purged with nitrogen or an inert gas in S300 to remove dissolved oxygen and other oxidizing gases. After the nitrogen purge, a potassium persulfate solution is added to the solution and the solution is heated to perform an addition polymerization reaction.

[0075] In one possible implementation, after the third product is prepared by the polyaddition reaction, the process further includes S500, a step of performing solvent dialysis on the solution containing the third product using a semipermeable membrane, adding the solution containing the second product to a semipermeable membrane bag, immersing the semipermeable membrane bag in pure water, and magnetically stirring the pure water during the dialysis process to accelerate the circulation of the solution outside the semipermeable membrane and promote the exchange of substances on both sides of the semipermeable membrane. The solvent passes through the semipermeable membrane bag into the external solution, and the third product is retained in the solution in the bag. The pure water outside the bag is replaced regularly (for example, every two hours), and the dialysis is performed for 3 to 5 days. The retained solution is used as a passivation material for silicon batteries.

[0076] In a possible implementation, the molecular weight cut-off of the semipermeable membrane is 2000-4000, preferably 3500.

[0077] In a possible implementation, after dialyzing to obtain the retained solution in S500 , the method further includes a step of drying the retained solution into a solid in S600 , and using the dried solid as a silicon battery passivation material.

[0078] In a possible implementation, the drying step in S600 is constant temperature vacuum drying, and the drying temperature is 50-80° C., preferably constant temperature vacuum drying at 60° C.

[0079] In one possible implementation, after drying the retained solution to a solid, a step is also included to add a UV absorber to the dried solid to enhance the passivation material's resistance to UV rays and ensure its stability. The UV absorber is titanium dioxide nanoparticles, and a solid mixture of the dried solid and titanium dioxide is used as the silicon cell passivation material. The volume ratio of the titanium dioxide nanoparticles to the retained solution dried solid in the solid mixture is 1:(10-20). The titanium dioxide nanoparticles have a particle size of 100-200 nanometers, preferably 130 nanometers, 150 nanometers, 170 nanometers, or 190 nanometers.

[0080] According to another aspect of the present application, a (silicon) battery passivation material is provided, and the battery passivation material is shown in Formula 4;

[0081] Formula 4

[0082] Wherein, X is a silyl group or a titanium group, Y is any one of a carboxylic acid group, a sulfonic acid group and a phosphoric acid group, the silyl group is as shown in Formula 5, and the titanium group is as shown in Formula 6;

[0083] Formula 5

[0084] Formula 6

[0085] In a possible implementation, the battery passivation material is prepared using the aforementioned method for preparing the battery passivation material.

[0086] According to another aspect of the present application, a battery passivation solution is provided, which contains the aforementioned battery passivation material. The battery passivation solution is coated (e.g., spin-coated) on a silicon battery substrate and allowed to stand to form a passivation layer. An absorption layer and others are prepared on the passivation layer. The passivation layer is located between the substrate and the absorption layer, which can reduce dangling bonds in the silicon battery and reduce interface defects in the silicon battery, thereby improving the photoelectric conversion efficiency of the silicon battery and improving the stability of the silicon battery.

[0087] According to another aspect of the present application, a silicon cell is provided. The silicon cell is provided with a passivation layer. The material of the passivation layer includes the aforementioned cell passivation material.

[0088] In one possible implementation, the passivation material of the passivation layer itself improves the stability of the photovoltaic cell. Furthermore, the present application also covers the outer surface of the silicon cell with a light-transmitting, waterproof protective layer. From the outside to the inside of the silicon cell, the structure is composed of an electrode, a light-transmitting, waterproof protective layer, a passivation layer, a substrate, a passivation layer, and finally an electrode. The light-transmitting, waterproof protective layer is a protective coating such as a polymer film or an aluminum oxide film, which provides a certain degree of waterproof protection and prevents the passivation layer from contacting the external environment, thereby reducing damage and oxidation reactions in the passivation layer.

[0089] In a possible implementation, the thickness of the passivation layer is 50 to 120 nm, preferably 75 nm or 90 nm; the thickness of the light-transmitting protective layer is 50 to 120 nm, preferably 75 nm or 90 nm.

[0090] In one possible implementation, the passivation layer includes not only the aforementioned battery passivation materials but also includes ultraviolet absorbers, compounds of highly stable metal elements such as tin and aluminum, and adhesives. Furthermore, the ultraviolet absorbers are titanium dioxide nanoparticles, which are added to the battery passivation solution containing the third product so that the concentration ratio of the titanium dioxide nanoparticles to the third product in the solution is 1:(10-20). The particle size of the titanium dioxide nanoparticles is 100-200 nm, preferably 130 nm, 150 nm, 170 nm, or 190 nm.

[0091] The embodiments of the present application have been described above. The above description is illustrative and not exhaustive, and is not limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is selected to best explain the principles of the embodiments, their practical applications, or improvements to the technology in the market, or to enable other persons skilled in the art to understand the embodiments disclosed herein.

Claims

1. A method for preparing a battery passivation material, characterized in that: The following steps are involved: The first raw material is shown in Formula 1, and benzene and the first raw material are mixed to react to obtain a first product as shown in Formula 2; Formula 1 ; Formula 2 ; The first product is added to an acidic solution to react to obtain a second product as shown in Formula 3; Formula 3 ; A polymer initiator is added to the solution containing the second product, and a polyaddition reaction is carried out under heating or the action of a catalyst to obtain a third product which is a battery passivation material. The third product is an acidified polystyrene compound, and the third product is shown in Formula 4; Formula 4 ; Wherein, X is a silyl group or a titanium group, Y is any one of a carboxylic acid group, a sulfonic acid group and a phosphoric acid group, the silyl group is as shown in Formula 5, and the titanium group is as shown in Formula 6; Formula 5 ; Formula 6 ; In the siloxy group shown in Formula 5, R is selected from any one of an alkyl group and a phenyl group.

2. The method for preparing a battery passivation material according to claim 1, wherein: The polymerization initiator is potassium persulfate solution.

3. The method for preparing a battery passivation material according to claim 1, wherein: The second product is heated to carry out addition polymerization under the action of a polymer initiator; The heating temperature is 60-80° C., and the heating time is 6-12 hours.

4. The method for preparing a battery passivation material according to claim 1, wherein: After the solution containing the second product is prepared, before the step of subjecting the second product in the solution to an addition polymerization reaction to prepare the third product, the solution containing the second product is purged with nitrogen or an inert gas.

5. The method for preparing a battery passivation material according to claim 1, wherein: After the third product is prepared by the addition polymerization reaction, the method further includes dialyzing the solution containing the third product using a semipermeable membrane, wherein the molecular weight cutoff of the semipermeable membrane is 2000-4000, and the retained solution is used as a battery passivation material.

6. The method for preparing a battery passivation material according to claim 5, wherein: After dialyzing to obtain the retained solution, the method further includes a step of drying the retained solution into a solid, and using the dried solid as a battery passivation material.

7. A battery passivation material, characterized in that: The battery passivation material is shown in Formula 4; Formula 4 ; Wherein, X is a silyl group or a titanium group, Y is any one of a carboxylic acid group, a sulfonic acid group and a phosphoric acid group, the silyl group is as shown in Formula 5, and the titanium group is as shown in Formula 6; Formula 5 ; Formula 6 ; In the siloxy group shown in Formula 5, R is selected from any one of an alkyl group and a phenyl group.

8. A silicon battery, characterized in that: The silicon battery comprises a passivation layer, and the material of the passivation layer comprises the battery passivation material according to claim 7.

9. The silicon cell according to claim 8, characterized in that: The outer surface of the silicon cell is covered with a light-transmitting and waterproof protective layer.

10. The silicon cell according to claim 8, characterized in that: The material of the passivation layer also includes an ultraviolet light absorber.

Images