Preparation method of solar cell, solar cell and photovoltaic module

Abstract

The embodiment of the invention relates to the photovoltaic field, and provides a preparation method of a solar cell, the solar cell and a photovoltaic module. The preparation method of the solar cell comprises the steps that a preparation cell is provided, the preparation cell is cut, a plurality of fragmented cells with cut surfaces are obtained, and the preparation cell comprises a substrate structure, a first seed layer and a second seed layer which are stacked in sequence; the method comprises the following steps: cutting a plurality of separated batteries into a plurality of cut surfaces, sequentially carrying out cleaning treatment, air drying treatment, insulation treatment and curing treatment on the cut surfaces of the separated batteries in the same chamber, placing the separated batteries in the chamber, and carrying out insulation treatment to obtain a material comprising hyperbranched polyester, epoxy resin, nano-silica, a curing agent and a carbon-based filler. The preparation method of the solar cell provided by the embodiment of the invention at least can reduce the production cost of the solar cell.

Description

Technical Field

[0001] This application relates to the field of photovoltaics, and in particular to a method for preparing a solar cell, a solar cell, and a photovoltaic module. Background Technology

[0002] In solar cell technology, the extensive use of silver paste has significantly increased production costs. As a precious metal, silver's high price and volatility directly increase the manufacturing cost of solar cells, making it a key factor that the industry urgently needs to optimize.

[0003] Therefore, there is an urgent need for a method for fabricating solar cells that can solve the above-mentioned technical problems. Summary of the Invention

[0004] This application provides a method for preparing a solar cell, a solar cell, and a photovoltaic module, which at least helps to reduce the production cost of solar cells.

[0005] According to some embodiments of this application, one aspect of this application provides a method for preparing a solar cell, comprising: providing a pre-cell and cutting the pre-cell to obtain a plurality of segmented cells with cut surfaces, wherein the pre-cell includes a substrate structure, a first seed layer and a second seed layer stacked sequentially; and sequentially cleaning, drying, insulating and curing the cut surfaces of each segmented cell in the same chamber, wherein the chamber is used to place the segmented cells, and the insulation treatment uses a material comprising hyperbranched polyester, epoxy resin, nano-silica, curing agent and carbon-based filler.

[0006] In some embodiments, the cleaning and drying processes performed on the cut surfaces of each of the battery segments include: cleaning the cut surfaces with an alkaline solution, wherein the mass fraction of the alkaline solution is 0.5-10%; and introducing an inert gas into the chamber to remove moisture remaining on the battery segments after the cleaning process.

[0007] In some embodiments, the insulation treatment performed on the cut surfaces of each of the segmented batteries includes: a first coating step, in which an insulating layer is coated on the edge region of the cut surface of the segmented battery, wherein the cut surface includes a middle region and an edge region, the edge region being located on the outer periphery of the middle region, and the thickness of the insulating layer being 10~30μm; and a curing step, in which the cut surface of the segmented battery is irradiated with a first light source for a first predetermined duration to cure the insulating layer, wherein the wavelength range of the first light source is 365~410nm, and the power range of the first light source is 100~800mJ / cm². 2The first predetermined duration is 0.1~0.5s; the first repeating step is to repeat the first coating step and the curing step at least once until the insulation treatment of all the segmented cells is completed.

[0008] In some embodiments, the first coating step includes: a second coating step, coating a predetermined area along the edge of the edge region, wherein the width of the predetermined area perpendicular to the coating direction ranges from 50 to 300 μm, and the edge region includes a plurality of predetermined areas connected end to end in sequence; and a second repetition step, repeating the second coating step multiple times until the coating of the edge region is completed.

[0009] In some embodiments, the weight percentage of each component in the material used for the insulation treatment is as follows: 40-50 wt% of the hyperbranched polyester, 15-20 wt% of the epoxy resin, 8-15 wt% of the nano-silica, 5-10 wt% of the curing agent, and 5-15 wt% of the carbon-based filler.

[0010] In other embodiments, the curing process on the cut surfaces of each of the segmented batteries includes: irradiating the cut surfaces of each of the segmented batteries with a second light source for a second predetermined duration, wherein the light intensity of the second light source is 10~60 sun, the second predetermined duration is 1~10 min, and the temperature of the chamber is 60~150°C.

[0011] In other embodiments, providing a pre-built battery includes: providing the substrate structure; forming a first seed layer on one side of the substrate structure to obtain a first pre-built structure, and annealing the first pre-built structure; forming a second seed layer on the side of the first seed layer away from the substrate structure; and patterning the second seed layer to obtain the pre-built battery including a first region and a second region, wherein the first region and the second region are alternately arranged along a predetermined direction, the predetermined direction being perpendicular to the thickness direction of the substrate structure.

[0012] In some embodiments, after sequentially cleaning, drying, insulating and curing the cut surfaces of each of the segmented batteries in the same chamber, the method further includes: forming an electrode in the first region and removing the first seed layer and the second seed layer in the second region.

[0013] According to some embodiments of this application, another aspect of this application provides a solar cell, which is prepared by any method of preparing a solar cell.

[0014] According to some embodiments of this application, another aspect of this application provides a photovoltaic module, including: a battery string, which is formed by connecting multiple solar cells prepared by any of the methods described for preparing solar cells; an encapsulating film for covering the surface of the battery string; and a cover plate for covering the surface of the encapsulating film facing away from the battery string.

[0015] The technical solution provided in this application has at least the following advantages:

[0016] By integrating the cleaning, drying, insulation, and curing processes in the edge treatment of cellular cells into a single device, the consumption of silver paste can be effectively reduced, thereby saving on cell production costs. Simultaneously, using hyperbranched polyester, epoxy resin, nano-silica, curing agent, and carbon-based filler as insulation materials increases surface resistance, achieving electrode insulation and preventing electrolyte penetration, thus sealing the cell edges. It also reduces carrier recombination, improves the passivation effect of cellular cells, optimizes cell edge treatment, reduces cell efficiency loss, and increases module power output. Attached Figure Description

[0017] One or more embodiments are illustrated by way of example with reference to the accompanying drawings. These illustrations do not constitute a limitation on the embodiments. Unless otherwise stated, the drawings in the accompanying drawings do not constitute a limitation on scale. In order to more clearly illustrate the technical solutions in the embodiments of this application or in the conventional art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a schematic flowchart of a method for fabricating a solar cell according to an embodiment of this application;

[0019] Figure 2 This is a schematic diagram of the structure of a photovoltaic module according to an embodiment of this application.

[0020] The above figures include the following reference numerals:

[0021] 40. Solar cell; 402. Conductive strip; 41. Encapsulation layer; 42. Cover plate. Detailed Implementation

[0022] In the description of the embodiments of this application, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly defined.

[0023] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0024] In the description of the embodiments in this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent three cases: A exists, A and B exist simultaneously, and B exists. In addition, the character " / " in this document generally indicates that the related objects before and after it have an "or" relationship.

[0025] In the description of the embodiments of this application, the term "multiple" refers to two or more (including two), similarly, "multiple sets" refers to two or more (including two sets), and "multiple pieces" refers to two or more (including two pieces).

[0026] In the description of the embodiments of this application, the technical terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of this application and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this application.

[0027] In the description of the embodiments of this application, unless otherwise expressly specified and limited, the technical terms such as "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. For those skilled in the art, the specific meaning of the above terms in the embodiments of this application can be understood according to the specific circumstances.

[0028] In the accompanying drawings corresponding to the embodiments of this application, the thickness and area of ​​the layers are enlarged for better understanding and ease of description. When describing a component (such as a layer, film, region, or substrate) on or on the surface of another component, the component may be "directly" located on the surface of the other component, or there may be a third component between the two components. Conversely, when describing a component on the surface of another component, or when another component is formed or disposed on the surface of a component, it indicates that there is no third component between the two components. Furthermore, when describing a component as being "generally" formed on another component, it means that the component is not formed on the entire surface (or front surface) of the other component, nor is it formed on a portion of the edge of the entire surface.

[0029] In the description of the embodiments of this application, when a component "includes" another component, other components are not excluded unless otherwise stated, and other components may be further included. Furthermore, when a component such as a layer, film, region, or plate is referred to as being "on / located" on another component, it can be "directly on" the other component (i.e., located on the surface of the other component with no other components between them), or another component may be present therein. Moreover, when a component such as a layer, film, region, or plate is "directly located" on another component, or when a component such as a layer, film, region, or plate is located on the surface of another component, it indicates that no other components are located therein.

[0030] The terminology used in the description of the various embodiments herein is for the purpose of describing particular embodiments only and is not intended to be limiting. As used in the description of the various embodiments and the appended claims, the term "part" is also intended to include the plural form unless the context clearly indicates otherwise. Components include layers, films, regions, or plates, etc.

[0031] The embodiments of this application will now be described in detail with reference to the accompanying drawings. However, those skilled in the art will understand that many technical details have been provided in the embodiments of this application to facilitate a better understanding of the application. However, the technical solutions claimed in this application can be implemented even without these technical details and various variations and modifications based on the following embodiments.

[0032] As is known from the background art, existing methods for preparing silver paste for solar cells are characterized by high consumption and high cost. This application provides a method for preparing a solar cell, a solar cell, and a photovoltaic module to at least address the aforementioned technical problems.

[0033] Figure 1 This is a schematic flowchart illustrating a method for fabricating a solar cell according to an embodiment of this application. Figure 1 As shown, it includes:

[0034] Step S201: Provide a pre-built battery and cut the pre-built battery to obtain multiple sliced ​​batteries with cut surfaces. The pre-built battery includes a substrate structure, a first seed layer and a second seed layer stacked in sequence.

[0035] In practical applications, laser technology can be used to cut the aforementioned pre-existing cells to obtain segmented cells that meet the specifications required for subsequent photovoltaic module string welding. The materials of the first seed layer and the second seed layer can be metallic materials, and the materials of the first seed layer and the second seed layer can be the same or different. In some embodiments, the first seed layer includes at least one of aluminum-silicon alloy, aluminum-copper alloy, aluminum-titanium alloy, nickel-vanadium alloy, and copper-silicon alloy, and the second seed layer includes at least one of copper, aluminum, nickel, and silver.

[0036] In step S202, the cut surfaces of each of the above-mentioned segmented batteries are sequentially cleaned, dried, insulated, and cured in the same chamber. The chamber is used to hold the segmented batteries. The insulation treatment uses materials composed of hyperbranched polyester, epoxy resin, nano-silica, curing agent, and carbon-based filler.

[0037] The aforementioned cleaning, drying, insulation, and curing processes can be performed in a single integrated device. The cleaning process removes contaminants generated during the slab separation process, such as laser processing residues (carbides, metal particles), cutting fluid or coolant residues, silicon dust, organic oil, and metal ions (Fe, Cu, etc.). Specifically, wet cleaning can be used, for example, employing a multi-tank cleaning line that sequentially performs alkaline washing, acid washing, and deionized water rinsing. The drying process aims to completely remove moisture from the surface and edges of the cleaned cells, preventing water stains from affecting subsequent coating or printing; preventing moisture-induced oxidation or corrosion; and preventing steam generation that could lead to microcracks in subsequent high-temperature processes. Specifically, drying can be achieved using hot air drying, rotary spin drying, nitrogen blade drying, vacuum drying, and high-purity nitrogen jetting. Because the cut edges of the cells after slab separation expose numerous dangling bonds and defect states, forming highly complexed areas, this leads to increased edge leakage current, decreased open-circuit voltage and fill factor, and potential localized hot spots. Insulation treatment can alleviate these problems by passivating the cut surface. In practice, chemical passivation, plasma treatment, and laser edge isolation can be used. The aforementioned curing process is used to cross-link and cure the materials used in the insulation treatment through heating, thereby forming a dense and stable insulation layer.

[0038] Hyperbranched polyester (HBP) possesses a three-dimensional branched structure, giving it low viscosity and high solubility. It can also absorb thermal stress, inhibit post-curing coating cracking, and improve flexibility. Furthermore, its molecular chain ends are rich in hydroxyl groups, which can form hydrogen bonds or chemical bonds with epoxy resins and substrates (such as silicon and glass), enhancing adhesion. Epoxy resins are used as the main film-forming substance in inks, forming a dense, cross-linked three-dimensional network after curing. They exhibit excellent electrical insulation, chemical resistance, and thermal stability. Upon reaction with the curing agent, they form a high glass transition temperature coating, ensuring dimensional stability at high temperatures. Nano-silica, with its uniform dispersion, can fill the micropores of epoxy resin, improving coating density and blocking moisture or ion penetration. Curing agents include amines, acid anhydrides, and phenolic resins; they can undergo ring-opening polymerization with the epoxy groups of epoxy resins to form a highly cross-linked network. Different types of curing agents require different curing temperatures and times. Carbon-based fillers can be graphene and fullerene, whose edge carboxyl groups react with resin hydroxyl groups to form a "flexible-rigid" interpenetrating network that can withstand more than 10,000 bending cycles, thus alleviating the edge cracking problem caused by bending stress in solar cells.

[0039] The solar cell fabrication method of this application integrates the cleaning, drying, insulation, and curing processes in the edge treatment of segmented cells into a single device, effectively reducing silver paste consumption and thus saving on cell production costs. Simultaneously, the use of hyperbranched polyester, epoxy resin, nano-silica, curing agent, and carbon-based filler as insulation materials increases surface resistance, achieving electrode insulation and preventing electrolyte penetration, thus sealing the cell edges. It also reduces carrier recombination, improves the passivation effect of segmented cells, optimizes cell edge treatment, reduces cell efficiency loss, and increases module power output.

[0040] In the implementation process, step S202 can be achieved through the following steps: Step S2021, cleaning the cut surface with an alkaline solution, wherein the mass fraction of the alkaline solution is 0.5~10%; Step S2022, introducing an inert gas into the chamber to remove moisture remaining on the segmented battery after the cleaning process. This method can simultaneously improve the processing efficiency of both the cleaning and drying processes.

[0041] In practical applications, the above cleaning process can last from 30 to 90 seconds. The alkaline solution can be NaOH, KOH, THMA, etc. After cleaning the cutting surface with the alkaline solution and before introducing inert gas into the chamber, the cutting surface is further cleaned to remove any residual alkaline solution. In practical applications, the mass fraction of the alkaline solution can be any one of 0.5%, 1%, 2%, 3%, 5.5%, 7%, 8%, or 10%, or any value between these two.

[0042] Step S202 can also be implemented in other ways, for example: Step S2023: First coating step, coating an insulating layer on the edge region of the cut surface of the sectional battery, wherein the cut surface includes a middle region and the edge region, the edge region is located on the outer periphery of the middle region, and the thickness of the insulating layer is 10~30μm; Step S2024: Curing step, irradiating the cut surface of the sectional battery with a first light source for a first predetermined time to cure the insulating layer, wherein the wavelength range of the first light source is 365~410nm, and the power range of the first light source is 100~800mJ / cm. 2 The first predetermined duration is 0.1~0.5s; Step S2025: First repeating step, repeating the first coating step and the curing step at least once, until the insulation treatment of all the above-mentioned cell segments is completed. The above-mentioned repeated coating of the insulating layer can further improve the reliability of the insulation treatment, thereby further improving the performance of the solar cell.

[0043] In practical applications, the cut surface includes a central region and an edge region, with the edge region located on the outer periphery of the central region. The first coating step only coats the edge region. The area sizes of the central and edge regions can be set and adjusted by those skilled in the art according to actual conditions. The thickness of the insulating layer can be any value among 10μm, 20μm, and 30μm, or between any two of these values. In practical applications, the first light source can be an ultraviolet light source. In the first repeated steps, the parameters of each first coating step can be the same or different; similarly, the parameters of each curing step can be the same or different.

[0044] Step S2023 above can be achieved through the following steps: Step S20231: Second coating step, coating a predetermined area along the edge of the edge region, wherein the width of the predetermined area perpendicular to the coating direction ranges from 50 to 300 μm, and the edge region includes multiple predetermined areas connected end to end in sequence; Step S20232: Second repetition step, repeating the second coating step multiple times until the coating of the edge region is completed. This method can further improve the coating efficiency of the first coating step.

[0045] In practical applications, the aforementioned predetermined area can be the edge or corner of the cell. Taking a rectangular cut surface of the cell as an example, the coating steps can be as follows: top left corner, top edge, top right corner, right side, bottom right corner, bottom edge, bottom left corner, left side. In the above coating steps, to further improve coating efficiency, the solar cell can be rotated 45° or 90° counterclockwise or clockwise to prepare for coating at the next location.

[0046] In other embodiments, step S202 can also be implemented in other ways, for example: Step S2026: The weight percentages of each component in the material used for the above insulation treatment are as follows: the above hyperbranched polyester is 40-50 wt%, the above epoxy resin is 15-20 wt%, the above nano-silica is 8-15 wt%, the above curing agent is 5-10 wt%, and the above carbon-based filler is 5-15 wt%. The materials used in the above insulation treatment are within the above weight percentage range, which can further ensure the good effect of the insulation treatment.

[0047] In some embodiments, the molecular weight of the hyperbranched polyester-epoxy hybrid resin can be 3000~5000 Da, the particle size of the aforementioned nano-silica can be 20~50 nm, and it undergoes surface hydroxylation treatment. The carbon-based filler can be a compound of zero-dimensional fullerene (1~3 wt%) + two-dimensional graphene (3~6 wt%) to form a three-dimensional conductive shielding network with a large optical density and good shielding effect. The specific preparation process of the materials used in the above insulation treatment is as follows: Nano-SiO2 (treated with KH560 silane coupling agent) is blended with hyperbranched polyester and epoxy resin at 80°C and sheared at high speed (5000 rpm) for 30 min to form a stable sol; fullerene, graphene and dispersant (BYK-163) are added, and the mixture is ground with a sand mill until D50 < 1μm to ensure that the filler uniformly coats the resin; isocyanate curing agent is added, and NCO / OH = 1.2:1 is controlled to avoid excessive cross-linking leading to brittleness; the mixture is filtered with a 1μm filter element, encapsulated under nitrogen protection, and has a shelf life of > 6 months (stored at 25°C).

[0048] In other embodiments, step S202 can be implemented by the following steps: Step S2027: Irradiating the cut surfaces of each of the aforementioned segmented batteries with a second light source for a second predetermined duration, wherein the light intensity of the second light source is 10~60 sun, the second predetermined duration is 1~10 min, and the temperature of the chamber is 60~150°C. This method can further improve the efficiency of the curing process.

[0049] After completing all coating steps, i.e., insulation treatment, the segmented cells are cured again. The second light source can be ultraviolet light. In practical applications, the above steps can be implemented using an integrated photothermal device, providing temperature while simultaneously irradiating with the second light source.

[0050] Step S201 can be implemented through the following steps: Step S2011, providing the substrate structure; Step S2012, forming the first seed layer on one side of the substrate structure to obtain a first pre-structure, and annealing the first pre-structure; Step S2013, forming the second seed layer on the side of the first seed layer away from the substrate structure; Step S2014, patterning the second seed layer to obtain the pre-cell including a first region and a second region, wherein the first region and the second region are alternately arranged along a predetermined direction, which is perpendicular to the thickness direction of the substrate structure. This method can further improve the reliability of the pre-cell, thereby laying a good foundation for subsequent cutting, cleaning, drying, insulation, and curing processes.

[0051] The aforementioned substrate structure may include a substrate, a tunneling layer, a doped conductive layer, and a transparent conductive layer. The thickness of the first seed layer ranges from 20 to 50 nm, and the thickness of the second seed layer ranges from 70 to 1000 nm. The annealing temperature can be 500 to 730 °C, and the annealing time can be 5 to 30 minutes. The specific equipment used can be a chain annealing furnace or a tubular atmosphere annealing furnace. In practical applications, the temperature of the tubular furnace is 500 to 600 °C for 10 to 30 minutes under a nitrogen atmosphere. The temperature of the chain annealing furnace is 650 to 800 °C for 2 to 5 minutes under an atmospheric atmosphere.

[0052] Following step S202, the method further includes step S203: forming an electrode in the first region and removing the first seed layer and the second seed layer in the second region. This method allows for even faster electrode formation.

[0053] In practical applications, electrodes can be formed in the first region using methods such as screen printing.

[0054] To enable those skilled in the art to better understand the technical solution of this application, the implementation process of the solar cell fabrication method of this application will be described in detail below with reference to specific embodiments.

[0055] Example 1

[0056] This embodiment relates to a specific method for fabricating a solar cell, taking a back-contact cell as an example, and includes the following steps:

[0057] Step S1: Provide the BC battery precursor, and after completing the PECVD process, perform high-temperature annealing;

[0058] Step S2: The laser is used to open the insulating passivation layer in the N and P regions;

[0059] Step S3: Using the PVD coating and annealing integrated process, first deposit the first seed layer with AlSi material and a film thickness of about 25nm, then anneal, and then deposit the second seed layer with Cu material and a film thickness of about 500nm.

[0060] Step S4: Using screen printing technology, a film is applied to the non-metallic areas to expose the areas where electrodes need to be fabricated.

[0061] Step S5: Segment the BC battery precursor using a non-destructive laser;

[0062] Step S6: Using integrated equipment and its process solution, the diced battery side sheets are cleaned, dried, passivated and physically insulated, and then treated with UV light. The cleaning conditions are NaOH with a concentration of 0.5~10%, followed by water washing and N2 drying.

[0063] Step S7: Use nano-modified polymer ink to passivate and physically insulate the sides; then, through a photothermal integrated module, while the coating material is cured, UV light treatment is also performed. The weight percentages of each component in the nano-modified polymer ink are as follows: the above-mentioned hyperbranched polyester is 50wt%, the above-mentioned epoxy resin is 15wt%, the above-mentioned nano-silica is 10wt%, the above-mentioned curing agent is 10wt%, and the above-mentioned carbon-based filler is 15wt%.

[0064] Step S8: Electroplating to prepare copper electrodes, etching to remove the seed layer in the non-electrode area, and obtaining a solar cell.

[0065] Example 2

[0066] This embodiment relates to specific steps of a particular insulation treatment, including the following steps:

[0067] Step S71: According to the graphic design of the solar cell, the predetermined area of ​​the cell is laser-engraved, and the material coating of the predetermined area is adjusted until the coating requirements are met, and then the process parameters are fixed.

[0068] Step S72: The batteries in the basket are transferred one by one to the equipment station via an automated conveyor belt. Optical photography is used for positioning and software compensation. After confirming that the compensation is correct, the coating process is carried out. The battery cells are placed on the platform and rotated 90° along the X-axis with the platform to align with the working platform.

[0069] Step S73: Use a scraper to spread and level the coating material;

[0070] Step S74: The platform operates according to the adjusted parameters to complete the wetting of the coating material on one side or one corner of the battery;

[0071] Step S75: The platform is raised to the light curing height and subjected to UV lamp irradiation pretreatment. The above irradiation conditions are: UV lamp wavelength 400nm, UV lamp power 500mj / cm². 2 The UV lamp irradiation time is 0.3s, which completes the curing of a single side or corner.

[0072] Step S76: After completing the first edge or corner, rotate the platform 45° clockwise to prepare for coating the next position;

[0073] Step S77: Replenish the coating material using a peristaltic pump, and repeat steps S73 to S76 sequentially to complete the wetting and curing of the coating material on each side and corner of the battery. The thickness of the coating material is 30 μm and the coating width is 100 μm.

[0074] The embodiments of this application also provide a solar cell, which is manufactured by any of the above-described methods for preparing solar cells.

[0075] like Figure 2 As shown, embodiments of this application also provide a photovoltaic module, including:

[0076] The battery string is formed by connecting multiple solar cells 40 of any one of the above embodiments;

[0077] Specifically, two adjacent battery strings can be electrically connected via conductive strips 402. In some embodiments, the electrodes of the same polarity of the solar cells 40 are oriented in the same direction, and the conductive strips 402 connect the electrodes of different polarities of two adjacent solar cells 40 respectively. In other embodiments, the solar cells 40 can also be arranged according to electrodes of different polarities, that is, the electrodes of multiple adjacent cells are arranged in the order of first polarity, second polarity, and first polarity, respectively, and the conductive strips 402 connect two adjacent cells on the same side. In some embodiments, there is no gap between the cells, that is, the cells overlap each other.

[0078] Encapsulation layer 41 is used to cover the surface of the battery string;

[0079] Specifically, the encapsulation layer 41 includes a first encapsulation layer and a second encapsulation layer. The first encapsulation layer covers either the front or back side of the solar cell string, and the second encapsulation layer covers the other side of the front or back side of the string. Specifically, the material of the encapsulation layer 41 can be at least one of organic encapsulation films such as polyvinyl butyral (PVB), ethylene-vinyl acetate copolymer (EVA), polyvinyl octene elastomer (POE), or polyethylene terephthalate (PET). In practical applications, there is a gap between the first and second encapsulation layers during lamination, but after lamination, the first and second encapsulation layers together form the aforementioned encapsulation layer 41.

[0080] Cover plate 42 is used to cover the surface of the encapsulation layer 41 away from the battery string.

[0081] Specifically, the material of the cover plate 42 may include light-transmitting materials such as glass or plastic. Furthermore, the surface of the cover plate 42 facing the encapsulation layer 41 may be an uneven surface, thereby increasing the utilization rate of incident light. The cover plate 42 includes a first cover plate and a second cover plate, the first cover plate being disposed opposite to the first encapsulation layer, and the second cover plate being disposed opposite to the second encapsulation layer.

[0082] As can be seen from the above description, the embodiments of the present invention achieve the following technical effects:

[0083] By integrating the cleaning, drying, insulation, and curing processes in the edge treatment of cellular cells into a single device, the consumption of silver paste can be effectively reduced, thereby saving on cell production costs. Simultaneously, using hyperbranched polyester, epoxy resin, nano-silica, curing agent, and carbon-based filler as insulation materials increases surface resistance, achieving electrode insulation and preventing electrolyte penetration, thus sealing the cell edges. It also reduces carrier recombination, improves the passivation effect of cellular cells, optimizes cell edge treatment, reduces cell efficiency loss, and increases module power output.

[0084] Those skilled in the art will understand that the above embodiments are specific examples of implementing this application, and in practical applications, various changes in form and detail can be made without departing from the spirit and scope of this application. Any person skilled in the art can make various alterations and modifications without departing from the spirit and scope of this application; therefore, the scope of protection of this application should be determined by the scope defined in the claims.

Claims

1. A method for preparing a solar cell, characterized in that, include: A pre-built cell is provided, and the pre-built cell is cut to obtain multiple cell segments with cut surfaces. The pre-built cell includes a substrate structure, a first seed layer and a second seed layer stacked in sequence. In the same chamber, the cut surfaces of each of the segmented batteries are sequentially cleaned, dried, insulated, and cured. The chamber is used to hold the segmented batteries. The insulation treatment uses materials comprising hyperbranched polyester, epoxy resin, nano-silica, curing agent, and carbon-based filler.

2. The method for preparing a solar cell according to claim 1, characterized in that, The cleaning and drying processes performed on the cut surfaces of each of the aforementioned battery cells include: The cut surface is cleaned with an alkaline solution, wherein the mass fraction of the alkaline solution is 0.5-10%. An inert gas is introduced into the chamber to remove any moisture remaining on the battery cells after the cleaning process.

3. The method for preparing a solar cell according to claim 1, characterized in that, The insulation treatment performed on the cut surfaces of each of the aforementioned cell segments includes: In the first coating step, an insulating layer is coated on the edge region of the cut surface of the segmented battery, wherein the cut surface includes a middle region and the edge region, the edge region is located on the outer periphery of the middle region, and the thickness of the insulating layer ranges from 10 to 30 μm. In the curing step, a first light source is used to irradiate the cut surface of the segmented battery for a first predetermined duration to cure the insulating layer. The wavelength range of the first light source is 365~410nm, and the power range is 100~800mJ / cm². 2 The first predetermined duration is 0.1~0.5s; The first repeating step involves repeating the first coating step and the curing step at least once until the insulation treatment of all the segmented cells is completed.

4. The method for preparing a solar cell according to claim 3, characterized in that, The first coating step includes: The second coating step involves coating a predetermined area along the edge of the edge region, wherein the width of the predetermined area perpendicular to the coating direction ranges from 50 to 300 μm, and the edge region includes a plurality of predetermined areas connected end to end in sequence. The second repetition step involves repeating the second coating step multiple times until the coating of the edge region is complete.

5. The method for preparing a solar cell according to claim 1, characterized in that, The weight percentages of each component in the material used for the insulation treatment are as follows: 40-50 wt% for the hyperbranched polyester, 15-20 wt% for the epoxy resin, 8-15 wt% for the nano-silica, 5-10 wt% for the curing agent, and 5-15 wt% for the carbon-based filler.

6. The method for preparing a solar cell according to claim 1, characterized in that, The curing process performed on the cut surfaces of each of the aforementioned battery cells includes: The cut surfaces of each of the segmented batteries are irradiated with a second light source for a second predetermined duration, wherein the light intensity of the second light source is 10~60 sun, the second predetermined duration is 1~10 min, and the temperature of the chamber is 60~150℃.

7. The method for preparing a solar cell according to claim 1, characterized in that, Backup batteries are provided, including: Provide the substrate structure; The first seed layer is formed on one side of the substrate structure to obtain a first preparatory structure, and the first preparatory structure is annealed. A second seed layer is formed on the side of the first seed layer away from the substrate structure; The second seed layer is patterned to obtain the pre-cell structure comprising a first region and a second region, wherein the first region and the second region are alternately arranged along a predetermined direction, which is perpendicular to the thickness direction of the substrate structure.

8. The method for preparing a solar cell according to claim 7, characterized in that, After sequentially cleaning, drying, insulating, and curing the cut surfaces of each of the segmented batteries within the same chamber, the method further includes: An electrode is formed in the first region, and the first seed layer and the second seed layer in the second region are removed.

9. A solar cell, characterized in that, The solar cell is prepared by the method for preparing a solar cell according to any one of claims 1 to 8.

10. A photovoltaic module, characterized in that, include: A battery string is formed by connecting multiple solar cells prepared by the method described in any one of claims 1 to 8. An encapsulating film is used to cover the surface of the battery string; A cover plate is used to cover the surface of the encapsulating film that faces away from the battery string.

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