Solar cell fragmentation method, solar cell and photovoltaic module
By coating a barrier layer with photocurable adhesive before solar cell slab separation and then performing passivation treatment, the problem of plating around the cells was solved, the welding quality and stability of the solar cells were improved, and the electrical performance and photoelectric conversion efficiency of the cells were enhanced.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-30
- Publication Date
- 2026-04-07
AI Technical Summary
In the current solar cell slab process, edge passivation technology has a problem with plating around the edges, which affects the welding points, leading to poor soldering and black edges on the EL (electrode galvanometer), thus reducing the stability and performance of the cells.
Before cutting, a photocurable adhesive is applied to the area where the cell needs to be cut to form a barrier layer. After cutting, passivation treatment is performed and residual photocurable adhesive is removed. Organic solvents and non-destructive laser scratching technology are used to avoid passivation layer plating around the cell and to optimize the passivation layer and contact interface.
It reduces cold solder joints and black edges on solar cells, improves welding quality and module stability, increases open-circuit voltage and fill factor, and enhances the photoelectric conversion efficiency and stability of solar cells.
Smart Images
Figure CN121815798A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the field of photovoltaic technology, in particular to a method for slicing a solar cell, a solar cell and a photovoltaic module. BACKGROUND
[0002] With the increase of the size of the silicon wafer (such as 210mm), the current of the photovoltaic module also increases, which leads to the aggravation of power loss.
[0003] In the related art, the whole cell is cut into multiple pieces (such as two pieces, three pieces, four pieces), which can effectively reduce the output current of the photovoltaic module, reduce the heat generation of the photovoltaic module, reduce the working temperature of the photovoltaic module, effectively reduce the series resistance, and improve the overall output power of the photovoltaic module.
[0004] However, the edge passivation technology inevitably has the problem of plating around, that is, the passivation film layer is deposited in the unintended area of the edge of the cell piece, which affects the soldering point of the cell grid line, leading to poor soldering; when the plating around is serious, it will also cause the phenomenon of virtual welding, which is manifested as black edges in the EL (electroluminescence) of the module (that is, black edges will appear in the electroluminescence (EL) detection of the module), thereby affecting the stability of the cell.
[0005] However, the edge passivation technology inevitably has the problem of plating around, that is, the passivation film layer is deposited in the unintended area of the edge of the cell piece, which affects the soldering point of the cell grid line, leading to poor soldering; when the plating around is serious, it will also cause the phenomenon of virtual welding, which is manifested as black edges in the EL (electroluminescence) of the module (that is, black edges will appear in the electroluminescence (EL) detection of the module), thereby affecting the stability of the cell. SUMMARY
[0006] The purpose of the present application is to provide a method for slicing a solar cell, a solar cell and a photovoltaic module, which can improve the plating around problem of edge passivation, thereby reducing the influence on the soldering point, reducing the occurrence of virtual welding, and reducing the probability of the occurrence of EL black edges of the module, so as to improve the soldering quality of the solar cell and the stability of the module. In addition, the method for slicing a solar cell of the present application can also optimize the passivation layer, improve the contact interface, promote hydrogen passivation, reduce the passivation surface recombination rate, improve the contact electrical performance, finally improve the open circuit voltage (Voc) and the fill factor (FF) of the solar cell, and realize the efficiency gain.
[0007] The present application is implemented as follows: In a first aspect, the present application provides a method for slicing a solar cell, comprising: applying a light-curing glue at the position where the cell piece to be cut needs to be cut, and curing to form a barrier layer; cutting the cell piece at the barrier layer; The cut battery piece is subjected to passivation treatment to plate a passivation layer on the edge of the cut battery piece. The light-curing adhesive remaining on the cut battery piece is removed.
[0008] In optional embodiments, the light-curing adhesive is a silicone-based light-curing adhesive; and / or, The width of the barrier layer is 10-30 mm.
[0009] In optional embodiments, the silicone-based light-curing adhesive includes at least one of a silicone polyurethane UV light-curing adhesive, an acrylate-modified silicone UV light-curing adhesive, and an epoxy-modified silicone UV light-curing adhesive.
[0010] In optional embodiments, the wavelength of the ultraviolet light used to cure the silicone-based light-curing adhesive is 365 nm, and the intensity is 200-600 mW / cm 2 .
[0011] In optional embodiments, after the passivation layer is plated on the edge of the cut battery piece, an organic solvent is used to remove the light-curing adhesive remaining on the cut battery piece.
[0012] In optional embodiments, the organic solvent includes at least one of acetone, ethanol, isopropyl alcohol, and N-methyl pyrrolidone; and / or, Using the organic solvent to remove the light-curing adhesive on the cut battery piece specifically includes: using the organic solvent to remove the light-curing adhesive on the cut battery piece under ultrasonic conditions; and / or, Further including: after the light-curing adhesive remaining on the cut battery piece is removed, cleaning and drying at a temperature of 60-80°C.
[0013] In optional embodiments, the cutting method is non-destructive laser scribing and cutting.
[0014] In optional embodiments, the passivation treatment includes: depositing aluminum oxide on the edge of the cut battery piece by atomic layer deposition; wherein the deposition temperature is 150-190°C, and the deposition cycle is 30-240 cycles.
[0015] In a second aspect, the present application provides a solar cell prepared by the method for slicing a solar cell according to any one of the preceding embodiments.
[0016] In a third aspect, the present application provides a photovoltaic module including a solar cell prepared by the method for slicing a solar cell according to any one of the preceding embodiments, or a solar cell according to the preceding embodiments.
[0017] The present application includes the following beneficial effects: The solar cell slicing method provided by the embodiment of the present application forms a blocking layer on the position of the cell piece to be cut by using light-curing glue before cutting the cell piece, so that the cutting edge of the cut cell piece is left with the light-curing glue after curing, and when the cut cell piece is passivated, the edge of the cell piece is blocked by the cured light-curing glue, so that the passivation layer is not plated around the edge of the cell piece, thereby reducing the influence on the soldering point, reducing the phenomenon of false soldering, and reducing the probability of the appearance of EL black edge of the module, so as to improve the soldering quality of the solar cell and the stability of the module.
[0018] In addition, in the solar cell slicing method of the present application, the light-curing glue coated on the cell piece needs to be cured under light, which can play a role of light injection on the cell piece, so as to optimize the passivation layer, improve the contact interface, promote hydrogen passivation, reduce the passivation surface recombination rate, improve the contact electrical performance, and finally improve the open circuit voltage (Voc) and the fill factor (FF) of the solar cell, so as to realize efficiency gain.
[0019] The solar cell provided by the embodiment of the present application is prepared by the aforementioned slicing method, and the probability of false soldering of the solar cell is low, the probability of the appearance of EL black edge of the module is reduced, that is, the solar cell has good soldering quality and stability. Moreover, the solar cell of the embodiment of the present application also has good open circuit voltage (Voc) and fill factor (FF).
[0020] The photovoltaic module provided by the embodiment of the present application comprises the aforementioned solar cell, which has good soldering quality and stability, and also has good open circuit voltage (Voc) and fill factor (FF). BRIEF DESCRIPTION OF DRAWINGS
[0021] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiments. It should be understood that the following drawings only show some embodiments of the present application, and therefore should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can also be obtained without creative labor on the basis of these drawings.
[0022] Figure 1 The flowchart of the solar cell slicing method of the present application. DETAILED DESCRIPTION
[0023] In order to make the purpose, technical solutions and advantages of the embodiments of the present application more clear, the technical solutions in the embodiments of the present application will be described clearly and completely. The specific conditions not mentioned in the embodiments are carried out according to the conventional conditions or the conditions recommended by the manufacturer. The reagents or instruments used are not marked with the manufacturer, which are all conventional products that can be purchased on the market.
[0024] Related technologies employ methods that divide the entire solar cell into multiple segments (such as two segments, three segments, or four segments) to reduce the output current of the photovoltaic module, reduce the heat generation of the photovoltaic module, lower the operating temperature of the photovoltaic module, effectively reduce the series resistance, and improve the overall output power of the photovoltaic module.
[0025] However, during the cell slab assembly process, surface damage and dangling bonds inevitably occur at the edges of the cells. These defects increase edge leakage current, thereby reducing the cell's photoelectric conversion efficiency and stability. To improve these issues, chemical or physical passivation techniques are used to form a passivation film at the cell edges to repair these damages and dangling bonds, effectively reducing edge leakage current and improving the overall performance of the cell.
[0026] However, the inventors discovered that edge passivation technology inevitably suffers from plating issues. Specifically, the passivation film deposits in unintended areas at the cell edges, affecting the cell grid solder joints and leading to poor soldering. Severe plating can also cause cold solder joints, manifesting as black edges on the EL (electrode) plates of the module, thus affecting cell stability. Furthermore, while some methods can optimize the edge passivation process and reduce the plating area, they still cannot completely remove the plating layer. Other methods, in particular, can damage the cell during the removal of the plating passivation layer, reducing cell performance.
[0027] To address the aforementioned issues, this embodiment provides a solar cell slab segmentation method. This method improves the edge passivation plating problem, thereby reducing the impact on solder joints, decreasing the occurrence of cold solder joints, and lowering the probability of black edges appearing on the module's electroluminescence (EL) layer. This improves the soldering quality and module stability of the solar cells, extending their lifespan. Furthermore, the solar cell slab segmentation method of this invention can optimize the passivation layer, improve the contact interface, promote hydrogen passivation, reduce the recombination rate on the passivation surface, improve contact electrical performance, and ultimately increase the open-circuit voltage (Voc) and fill factor (FF) of the solar cells, achieving efficiency gains.
[0028] Please refer to Figure 1 The solar cell slicing method disclosed herein includes: applying photocurable adhesive to the location where the cell to be sliced needs to be sliced, and curing it to form a barrier layer; The solar cells are cut at the barrier layer; The cut battery cells are passivated to coat the edges of the cut battery cells with a passivation layer. Remove any residual photoresist from the cut battery cells.
[0029] Before cutting the solar cells, this slicing method first uses photocurable adhesive to form a barrier layer at the location where the cells need to be cut. This ensures that the cut edges of the cells retain the cured photocurable adhesive. When passivating the cut cells, the cured photocurable adhesive prevents the formation of a passivation layer around the edges of the cells, thus reducing the impact on the welding points, reducing the occurrence of cold solder joints, and lowering the probability of black edges appearing on the module's EL (Elastic Elastic Panel). This improves the welding quality of the solar cells and the stability of the module.
[0030] Furthermore, in the solar cell slab segmentation method of the present invention, the photocurable adhesive coated on the cell needs to be cured under light, which can play a role in light injection on the cell to optimize the passivation layer, improve the contact interface, promote hydrogen passivation, reduce the recombination rate of the passivation surface, improve the contact electrical performance, and ultimately improve the open circuit voltage (Voc) and fill factor (FF) of the solar cell, thereby achieving efficiency gain.
[0031] Optionally, the width of the barrier layer is 10~30mm, such as 10mm, 15mm, 20mm, 25mm, 30mm, etc., and is not specifically limited here. Optimizing the width of the barrier layer prepared by photocurable adhesive can ensure that the remaining barrier layer still has sufficient width after the solar cell is cut, improve the problem of edge plating caused by passivation, and save photocurable adhesive.
[0032] Optionally, cutting the solar cell at the barrier layer can mean cutting the solar cell along the centerline of the barrier layer in the width direction, so that the edges of the resulting solar cell have photocurable adhesive.
[0033] Of course, in other embodiments, the cutting position does not have to be at the center line in the width direction of the barrier layer, as long as the edges of the cut battery cells are covered with photocurable adhesive.
[0034] Optionally, the photocurable adhesive is a silicone-based photocurable adhesive. Silicone-based photocurable adhesives have a faster curing speed, which can improve production efficiency; moreover, silicone-based photocurable adhesives have good flexibility and temperature resistance, and can further optimize the fragmentation and microcrack problems of slab solar cells during the passivation and stacking process.
[0035] Optionally, the silicone-based UV curing adhesive includes at least one of silicone polyurethane UV curing adhesive, acrylate-modified silicone UV curing adhesive, and epoxy-modified silicone UV curing adhesive.
[0036] Alternatively, the methods for applying the photocurable adhesive include, but are not limited to, spin coating, spray coating, or screen printing.
[0037] Optionally, the wavelength of the ultraviolet light used to cure the silicone-based photocurable adhesive is 365 nm, and the intensity is 200-600 mW / cm. 2(For example: 200mW / cm) 2 300mW / cm 2 400mW / cm 2 500mW / cm 2 600mW / cm 2 (etc., not specifically limited here), the curing time is 5~20s (e.g.: 5s, 7s, 10s, 12s, 15s, 18s, 20s, etc., not specifically limited here).
[0038] Photocuring under ultraviolet light can further act as a light injection, optimizing the passivation layer, improving the contact interface, and promoting hydrogen passivation through multiple mechanisms. This reduces the recombination rate of the passivation surface, improves the contact electrical performance, and ultimately increases the battery open-circuit voltage (Voc) and fill factor (FF), achieving efficiency gains.
[0039] Optionally, after applying a passivation layer to the edges of the cut solar cells, residual photocurable adhesive on the cut solar cells can be removed using an organic solvent. Removing the photocurable adhesive using an organic solvent is a simple and easy process that does not damage the solar cells, thus helping to ensure their performance.
[0040] Optionally, the organic solvent includes at least one of acetone, ethanol, isopropanol, N-methylpyrrolidone, etc.
[0041] Optionally, in order to improve the removal efficiency of photocurable adhesive (i.e., improve the efficiency of photocurable adhesive dissolving in organic solvents) and to ensure that photocurable adhesive can be completely removed, the photocurable adhesive on the cut solar cells can be removed by using organic solvents under ultrasonic conditions. That is, the solar cells can be immersed in organic solvents (10~30 min) and combined with ultrasonic treatment to make the photocurable adhesive dissolve rapidly in the organic solvents.
[0042] Optionally, after removing residual photocuring adhesive from the cut solar cells (i.e., after soaking in organic solvents), the cells are cleaned and dried at a temperature of 60-80°C (e.g., 60°C, 65°C, 70°C, 75°C, 80°C, etc., without specific limitation). Drying at a lower temperature can avoid adverse effects on the performance of the solar cells.
[0043] Optionally, the cutting method is non-destructive laser scribing, which utilizes laser thermal stress control fracture technology, local rapid heating and matching cooling technology to generate a temperature gradient, cuts the battery cell, and avoids excessive temperature causing the photocurable adhesive layer to delaminate.
[0044] Specifically, the core principle of non-destructive laser scratch cutting is laser thermal stress-controlled fracture technology: A laser is used to rapidly heat the material locally, followed by a cooling process that creates a non-uniform temperature field. This temperature field generates a temperature gradient on the material surface, inducing thermal stress. The laser spot is under compressive stress, while the areas before and after the laser spot are under tensile stress. A tiny groove is machined at the edge of the solar cell. Because the compressive stiffness of brittle materials is much greater than their tensile strength, when the tensile stress reaches the material's fracture strength, the material fractures. The fracture propagates steadily along the trajectory of the laser and subsequent cooling, starting from the groove. After local heating by the laser, rapid cooling via water vapor spray utilizes the principle of thermal expansion and contraction to crack the solar cell.
[0045] Alternatively, the solar cells can be cut into half, three, or four pieces.
[0046] Optionally, passivation treatment includes: depositing aluminum oxide onto the edge of the cut solar cell by atomic layer deposition (ALD); wherein the deposition temperature is 150~190℃ (e.g., 150℃, 160℃, 170℃, 180℃, 190℃, etc., which are not specifically limited here), and the deposition cycle is 30~240 cycles (e.g., 30 cycles, 60 cycles, 90 cycles, 120 cycles, 150 cycles, 180 cycles, 210 cycles, 240 cycles, etc., which are not specifically limited here).
[0047] It should be noted that the solar cells produced by the solar cell slab method disclosed herein can be used in photovoltaic modules, and the photovoltaic modules have good welding quality and stability, as well as good open-circuit voltage (Voc) and fill factor (FF).
[0048] The present invention will be further described in detail below with reference to the embodiments.
[0049] Example 1 S1: Apply silicone polyurethane UV curing adhesive to the cut position of the solar cell.
[0050] S2: A photocurable adhesive is cured using ultraviolet light to form a barrier layer; wherein the wavelength of the ultraviolet light is 365nm and the intensity is 200mW / cm². 2 The irradiation and curing time is 20 seconds.
[0051] S3: A non-destructive laser scribing process is used to cut the solar cells along the centerline of the barrier layer to obtain a half-cell.
[0052] S4: Perform atomic layer deposition passivation treatment on the cut half cell to deposit an aluminum oxide passivation layer at the edge of the half cell; wherein the deposition temperature is 150℃ and the deposition cycle is 210 cycles.
[0053] S5: Immerse the half-cell in acetone (analytical grade, 99.99 vol%) for 10 min and sonicate it; after immersion, remove the half-cell, wash it with deionized water, and dry it at 60°C to obtain a multi-segmented passivated cell without plating.
[0054] Example 2 S1: Apply acrylate-modified silicone UV curing adhesive to the cut positions of the battery cells.
[0055] S2: A photocurable adhesive is cured using ultraviolet light to form a barrier layer; wherein the wavelength of the ultraviolet light is 365nm and the intensity is 600mW / cm². 2 The irradiation and curing time is 5 seconds.
[0056] S3: A non-destructive laser scribing process is used to cut the solar cells along the centerline of the barrier layer to obtain a half-cell.
[0057] S4: The cut half-cell is subjected to atomic layer deposition passivation treatment to form an aluminum oxide passivation layer at the edge of the half-cell; wherein the deposition temperature is 190℃ and the deposition cycle is 170 cycles.
[0058] S5: Immerse the half-cell in ethanol (analytical grade, 99.99 vol%) for 30 min and sonicate it; after immersion, remove the half-cell, wash it with deionized water, and dry it at 80°C to obtain a multi-segmented passivated cell without plating.
[0059] Example 3 S1: Apply epoxy-modified silicone UV curing adhesive to the cut position of the solar cell.
[0060] S2: A photocurable adhesive is cured using ultraviolet light to form a barrier layer; wherein the wavelength of the ultraviolet light is 365nm and the intensity is 400mW / cm². 2 The irradiation and curing time is 10 seconds.
[0061] S3: A non-destructive laser scribing process is used to cut the solar cells along the centerline of the barrier layer to obtain a half-cell.
[0062] S4: The cut half-cell is subjected to atomic layer deposition passivation treatment to form an aluminum oxide passivation layer at the edge of the half-cell; wherein the deposition temperature is 170℃ and the deposition cycle is 190 cycles.
[0063] S5: Immerse the half-cell in a mixed solution of isopropanol (analytical grade, 99.99 vol%) and N-methylpyrrolidone (NMP, analytical grade, 99.99 vol%) with a volume ratio of 1:1 for 20 min and sonicate it. After immersion, remove the half-cell, wash it with deionized water, and dry it at a temperature of 70°C to obtain a multi-segmented edge passivated cell without plating.
[0064] Comparative Example 1 The difference between Comparative Example 1 and Example 1 is that Comparative Example 1 does not include steps S1, S2 and S5; other processes are the same as in Example 1.
[0065] The open-circuit voltage and fill factor of the batteries in Examples 1-3 and Comparative Example 1 were tested (the test method refers to GB / T6495.1-2022), and whether black edges appeared in the electroluminescence (EL) test were also tested. The results are shown in Table 1.
[0066] Table 1
[0067] As shown in Table 1, the method of the present invention can improve the open-circuit voltage and fill factor, and improve the black edge problem of EL.
[0068] In summary, the solar cell slab segmentation method of the present invention can improve the edge passivation plating problem, thereby reducing the impact on the welding points, reducing the occurrence of cold solder joints, and lowering the probability of black edges appearing in the module's electroluminescence (EL) layer, thus improving the welding quality of the solar cells and the stability of the module. Furthermore, the solar cell slab segmentation method of the present invention can also optimize the passivation layer, improve the contact interface, promote hydrogen passivation, reduce the recombination rate of the passivation surface, improve contact electrical performance, and ultimately increase the open-circuit voltage (Voc) and fill factor (FF) of the solar cells, achieving efficiency gains.
[0069] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.
Claims
1. A method for segmenting solar cells, characterized in that, include: Apply photocurable adhesive to the area where the solar cell to be cut needs to be cut, and then cure it to form a barrier layer; The battery cell is cut at the barrier layer; The cut battery cells are passivated to coat the edges of the cut battery cells with a passivation layer. Remove the residual photocurable adhesive from the cut battery cells.
2. The method for segmenting solar cells according to claim 1, characterized in that, The photocurable adhesive is a silicone-based photocurable adhesive; and / or, The width of the barrier layer is 10~30mm.
3. The method for segmenting solar cells according to claim 2, characterized in that, The silicone-based UV curing adhesive includes at least one of silicone polyurethane UV curing adhesive, acrylate-modified silicone UV curing adhesive, and epoxy-modified silicone UV curing adhesive.
4. The method for segmenting solar cells according to claim 2, characterized in that, The ultraviolet light used to cure the silicone-based photocurable adhesive has a wavelength of 365 nm and an intensity of 200-600 mW / cm. 2 .
5. The method for segmenting solar cells according to claim 2, characterized in that, After the passivation layer is deposited on the edge of the cut battery cell, the residual photocuring adhesive on the cut battery cell is removed using an organic solvent.
6. The method for segmenting solar cells according to claim 5, characterized in that, The organic solvent includes at least one of acetone, ethanol, isopropanol, and N-methylpyrrolidone; and / or, Removing the photocurable adhesive from the cut battery cell using the organic solvent specifically includes: removing the photocurable adhesive from the cut battery cell using the organic solvent under ultrasonic conditions; and / or, It also includes: removing the residual photocuring adhesive from the cut battery cells, cleaning them, and drying them at a temperature of 60~80℃.
7. The method for segmenting solar cells according to claim 1, characterized in that, The cutting method is non-destructive laser scribing cutting.
8. The method for segmenting solar cells according to claim 1, characterized in that, The passivation process includes: depositing aluminum oxide onto the edge of the cut battery cell by atomic layer deposition; wherein the deposition temperature is 150~190℃ and the deposition cycle is 30~240 cycles.
9. A solar cell, characterized in that, It is prepared by the slab method of the solar cell as described in any one of claims 1-8.
10. A photovoltaic module, characterized in that, This includes solar cells manufactured by the slab-forming method of any one of claims 1-8, or solar cells as described in claim 9.