Preparation method of photovoltaic module and photovoltaic module
Through hydrogen negative ion treatment and the use of film-forming substances, or deoxidation and welding in a high-temperature and oxygen-free environment, the problem of flux residue during the welding of photovoltaic modules is solved, and the reliability and stability of the module are improved.
Patent Information
- Application Number
- CN202411679596.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-22
- Publication Date
- 2025-03-21
AI Technical Summary
The use of flux during the welding of existing photovoltaic modules results in active agent residues and metal salt residues, which poses a potential risk of reliability.
The surface oxide of the coated copper tape is removed by hydrogen negative ion treatment, plasma cleaning or laser cleaning, and film-forming substances without carboxyl groups are applied to the surface, or deoxidation and welding are carried out in a high-temperature and oxygen-free environment to avoid the use of flux.
The hidden dangers of active agent residues and metal salt residues are completely eliminated, the reliability of photovoltaic modules is improved, and corrosion and oxidation problems are avoided.
Smart Images
Figure CN119677213A_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the field of photovoltaic new energy technology, and in particular to a method for preparing a photovoltaic module and a photovoltaic module. Background Art
[0002] As we all know, to collect the current generated by crystalline silicon solar cells, it is necessary to make a metal upper electrode on the light-receiving surface (the incident surface of sunlight) of the crystalline silicon solar cell. The metal upper electrode generally includes a secondary grid line and a main grid line. The secondary grid line is used to collect the current generated by the crystalline silicon solar cell and transmit it to the main grid line. The main grid line then connects multiple crystalline silicon solar cells in series through interconnection strips (also called welding strips, tinned copper strips) welded thereon, and then outputs the current through the mutually electrically connected bus bars and external wires.
[0003] During the production of interconnecting strips, the role of flux is to remove surface oxides to ensure the smooth progress of the tinning process. At the same time, during the welding process of photovoltaic modules, flux still needs to be applied to the surface tin layer to ensure smooth welding of the interconnecting strips and the silver-plated layer of the battery. During the welding process, the active ingredients in the flux will react with the oxides on the metal surface to generate metal salts. The metal salt residues are hygroscopic, expand in volume in a humid environment, and cause corrosion. At the same time, if the activator in the flux is not completely decomposed, it will remain on the surface of the battery and corrode the interconnecting strips and the battery, posing a reliability risk. Summary of the invention
[0004] Based on this, a method for preparing a photovoltaic module and a photovoltaic module are provided, which effectively integrate the processing of interconnection strips with the module preparation method, realize welding without flux, completely eliminate the hidden dangers caused by residual activators and metal salt residues, and obtain a high-reliability photovoltaic module.
[0005] In a first aspect, the present application provides a method for preparing a photovoltaic module, comprising the following steps:
[0006] S1: providing a coated copper strip; the coated copper strip comprises a substrate, a flux layer covering the substrate, a tin-plated layer covering the flux layer, and an oxide covering at least a portion of the surface of the tin-plated layer;
[0007] S2: treating the plated copper strip with nitrogen-hydrogen mixed gas of negative hydrogen ions, plasma cleaning or laser cleaning to remove surface oxides;
[0008] S3: immersing the plated copper strip after removing the surface oxide into a film-forming substance, and drying to obtain a photovoltaic interconnection strip with a film; the film-forming substance does not contain a carboxyl group;
[0009] S4: applying adhesive to the front and back of the battery cell respectively;
[0010] S5: pre-fixing the photovoltaic interconnection strips to the adhesives on the front and back sides of the battery cells, respectively, and repeating this step to complete the stacking of the battery strings;
[0011] S6: curing the adhesive on the front and back of the cell, fixing the photovoltaic interconnection strip on the cell, and completing the production of the cell string;
[0012] S7: Arrange, stack, and laminate a plurality of battery strings according to a layout, so that the photovoltaic interconnection strips form alloy contact with the fine grids of the battery cells during the lamination process, and finally obtain a photovoltaic module.
[0013] In a second aspect, the present application provides a method for preparing a photovoltaic module, comprising the following steps:
[0014] S1: providing a coated copper strip; the coated copper strip comprises a substrate, a flux layer covering the substrate, a tin-plated layer covering the flux layer, and an oxide covering at least a portion of the surface of the tin-plated layer;
[0015] S2: treating the plated copper strip with nitrogen-hydrogen mixed gas of negative hydrogen ions, plasma cleaning or laser cleaning to remove surface oxides;
[0016] S3: immersing the plated copper strip after removing the surface oxide into a film-forming substance, and drying to obtain a photovoltaic interconnection strip with a film; the film-forming substance does not contain a carboxyl group;
[0017] S4: pre-fix the film material and the photovoltaic interconnection strip on the front and back of the battery sheet, and repeat this step to complete the stacking of the battery string;
[0018] S5: The stacked battery string is subjected to heating treatment, and the film material above the photovoltaic interconnection strip shrinks due to the heat. After cooling, the photovoltaic interconnection strip is fixed on the battery sheet to complete the production of the battery string;
[0019] S6: Arrange, stack, and laminate a number of battery strings according to a layout, wherein the photovoltaic interconnection strips form alloy contact with the fine grids of the battery cells during the lamination process, and finally a photovoltaic module is obtained.
[0020] A preferred solution is that the film-forming substance consists of a film-forming agent and a solvent, the volume proportion of the film-forming agent is ≤8%, and the rest is the solvent; wherein the melting point of the film-forming agent is greater than 220°C.
[0021] A preferred solution is that the film-forming agent is one or more of hydrocarbons, alcohols, and lipids.
[0022] A preferred solution is that the solvent is one or more of water, ethanol, and isopropanol.
[0023] In a third aspect, the present application provides a method for preparing a photovoltaic module, comprising the following steps:
[0024] S1: pre-fixing a plated copper strip on the front and back of the battery cell, and repeating this step to complete the stacking of the battery string; at least a portion of the surface of the plated copper strip has an oxide;
[0025] S2: sending the pre-fixed battery string into a high-temperature oxygen-free environment of nitrogen-hydrogen mixed gas or plasma containing negative hydrogen ions to simultaneously complete deoxidation and welding of the surface of the coated copper strip;
[0026] S3: Apply adhesive to the front and back of the welded battery string at the position where the plated copper strip is fixed;
[0027] S4: curing the adhesive on the front and back of the battery string, fixing the plated copper tape on the battery sheet, and completing the production of the battery string;
[0028] S5: Arrange several battery strings according to the layout, stack and laminate them, and the plated copper tape forms alloy contact with the fine grid of the battery cell during the lamination process to finally obtain a photovoltaic module.
[0029] In a fourth aspect, the present application provides a method for preparing a photovoltaic module, comprising the following steps:
[0030] S1: applying adhesive to the front and back of the battery cell respectively, and pre-fixing the plated copper tape on the adhesive on the front and back of the battery cell respectively; or, pre-fixing the plated copper tape on the front and back of the battery cell respectively, and applying adhesive to the front and back of the battery cell at the position of the plated copper tape respectively; at least a part of the surface of the plated copper tape has an oxide;
[0031] S2: curing the adhesive on the front and back of the battery cell, fixing the plated copper tape on the battery cell, and repeating this step to complete the stacking of the battery string;
[0032] S3: Sending the battery string into a high-temperature oxygen-free environment of nitrogen-hydrogen mixed gas or plasma containing negative hydrogen ions to simultaneously complete deoxidation and welding of the surface of the coated copper strip, thereby completing the production of the battery string;
[0033] S4: Arrange several battery strings according to the layout, stack and laminate them. The plated copper tape forms alloy contact with the fine grid of the battery cell during the lamination process to finally obtain a photovoltaic module.
[0034] In a fifth aspect, the present application provides a photovoltaic module, which is prepared using the photovoltaic module preparation method.
[0035] A preferred solution is that the photovoltaic module includes a front plate material, a front adhesive film, a battery string, a back adhesive film and a back plate material which are stacked in sequence.
[0036] Beneficial effects:
[0037] On the first aspect, the preparation method of the photovoltaic module of the present application uses hydrogen anion treatment, plasma cleaning, laser cleaning and other technologies to remove the surface oxide of the coated copper strip, that is, the conventional interconnection strip. This method can avoid the traditional method of using flux to remove oxides, avoid the generation of metal salt residues and activator residues, and apply a film-forming substance to the surface of the treated coated copper strip. During the welding process, the film-forming substance does not participate in the reaction, and the melting point of the film-forming agent in the film-forming substance is relatively high, greater than 220°C, and will not volatilize during the welding process, thereby effectively isolating oxygen and preventing oxidation of the coated copper strip during the welding process, and then no oxide is generated during the welding process; and because the film-forming substance does not contain a carboxyl group, it will not react with the oxide during the welding process, and then no carboxylic acid will be generated. Salt substances will not cause harm; in addition, the film-forming substance can reduce surface tension, which is helpful for the plated copper strip to form an alloy with the silver paste on the battery cell, thereby forming a good welding effect. Therefore, the film-forming substance of the present application not only has the effect of reducing surface tension of traditional flux, but also can prevent the production of carboxylates; compared with the traditional method of welding photovoltaic modules, in which the interconnecting strips need to be coated with flux again, and the oxides are removed by relying on the active substances in the flux to ensure smooth welding of the interconnecting strips and the silver-plated layer of the battery, the preparation method of the present application no longer needs to rely on the active substances in the flux to remove oxides, and completely eliminates the hidden dangers caused by the residual active agent and the residual metal salts. The photovoltaic modules prepared in this way have higher reliability than the photovoltaic modules prepared by traditional interconnecting strips.
[0038] Secondly, in the preparation method of the photovoltaic module of the present application, the coated copper strip, that is, the conventional interconnection strip, can be first deoxidized and welded with the battery cell in a high-temperature oxygen-free environment containing a nitrogen-hydrogen mixed gas or plasma containing hydrogen anions. When this method is adopted, there is no need to apply a film-forming material to the surface of the coated copper strip. The surface oxide of the coated copper strip is removed by a nitrogen-hydrogen mixed gas or plasma containing hydrogen anions in a high-temperature oxygen-free environment. At the same time, the temperature of the oxygen-free environment is controlled so that the tin coating of the coated copper strip reacts with the battery cell in an oxygen-free environment and completes the welding. Since it is in an oxygen-free environment, no oxide is generated during the welding process. This method also does not need to rely on the active substances in the flux to remove the oxides generated by heating during the welding process like traditional interconnection strips, and completely eliminates the hidden dangers caused by residual active agents and metal salt residues. The photovoltaic modules prepared in this way have higher reliability than photovoltaic modules prepared from traditional interconnection strips. BRIEF DESCRIPTION OF THE DRAWINGS
[0039] Figure 1 This is a schematic diagram of the equipment composition in the method for preparing a photovoltaic module in Example 1 of the present application;
[0040] Figure 2 is a cross-sectional schematic diagram of a conventional interconnection strip in the prior art;
[0041] Figure 3 This is an internal schematic diagram of the deoxidation device in Example 1 of the present application;
[0042] Figure 4 This is a schematic diagram of a photovoltaic interconnection strip fixed to a cell sheet by adhesive in Example 1 of the present application;
[0043] Figure 5 This is a schematic diagram of a photovoltaic module in Example 1 of the present application;
[0044] Figure 6 This is a schematic diagram of the photovoltaic interconnection strip being fixed on the solar cell through the film material in the second embodiment of the present application;
[0045] Figure 7 This is a schematic diagram of a battery string being introduced into a flux-free welding device via a conveyor belt in Example 3 of the present application;
[0046] Figure 8 This is a schematic diagram of the structure of the protective pressing device in Example 3 of the present application.
[0047] Figure numerals: 1. Coated copper strip; 1-1. Base material; 1-2. Flux layer; 1-3. Tinning layer; 2. Traction mechanism; 3. Deoxidation equipment; 31. Furnace; 32. Electron emission device; 33. Conveying device; 4. Film forming equipment; 5. Photovoltaic interconnection strip; 6. Cutting mechanism; 7. Battery string; 71. Battery cell; 8. Adhesive; 9. Photovoltaic module; 10. Film material; 11. Protective press; 12. Conveyor belt; 13. Flux-free welding device. DETAILED DESCRIPTION
[0048] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.
[0049] It should be noted that the illustrations provided in this embodiment only illustrate the basic concept of the present application in a schematic manner, and therefore the drawings only show components related to the present application rather than being drawn according to the number, shape and size of components in actual implementation. In actual implementation, the type, quantity and proportion of each component may be changed arbitrarily, and the component layout may also be more complicated.
[0050] The structures, proportions, sizes, etc. illustrated in the drawings of this specification are only used to match the contents disclosed in the specification so as to facilitate understanding and reading by persons familiar with this technology. They are not used to limit the conditions under which this application can be implemented, and therefore have no substantive technical significance. Any structural modification, change in proportion or adjustment of size, without affecting the effects and purposes that can be achieved by this application, should still fall within the scope of the technical contents disclosed in this application.
[0051] The directions or positional relationships indicated by the terms "upper", "lower", "left", "right", "middle", "longitudinal", "lateral", "horizontal", "inner", "outer", "radial", "circumferential" and the like in this specification are based on the directions or positional relationships shown in the drawings and are only for the convenience of simplifying the description. They do not indicate or imply that the devices or elements referred to must have a specific direction, be constructed and operate in a specific direction, and therefore cannot be understood as limiting the present application. In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.
[0052] The embodiments of the present application provide a method for preparing a photovoltaic module and a photovoltaic module, which effectively integrate the processing of interconnection strips with the module preparation method, realize welding without flux, completely eliminate the hidden dangers caused by residual activators and metal salt residues, and obtain a high-reliability photovoltaic module.
[0053] Example 1
[0054] The present invention provides a method for preparing a photovoltaic module, which is described in detail below. Figure 1 , Figure 2 As shown, the following steps are included:
[0055] Step S1: providing a coated copper strip; the coated copper strip comprises a substrate, a flux layer covering the substrate, a tin-plated layer covering the flux layer, and an oxide covering at least a portion of the surface of the tin-plated layer;
[0056] In this embodiment, it should be noted that a coated copper strip 1 is provided, which includes, from the inside to the outside, a substrate 1-1, a flux layer 1-2 covering the substrate 1-1, a tin-plated layer 1-3 covering the flux layer 1-2, and an oxide covering at least a portion of the surface of the tin-plated layer 1-3. The coated copper strip of this structure is a conventional interconnection strip on the market.
[0057] Step S2: treating the above-mentioned plated copper strip with nitrogen-hydrogen mixed gas of negative hydrogen ions or plasma cleaning or laser cleaning to remove surface oxides;
[0058] In this embodiment, it should be noted that the wire drum containing the coated copper strip 1 is installed, and the released coated copper strip 1 is sequentially pulled to each process by the pulling mechanism 2. In this process, the coated copper strip 1 is first pulled through a nitrogen-hydrogen mixed gas containing hydrogen anions or plasma cleaning or laser cleaning to remove the surface oxide of the tin-plated layer 1-3, and a low-temperature alloy is used as the tin-plated layer 1-3. The melting point of the low-temperature alloy is 130-148°C. Preferably, the alloy is Sn 32 Pb 42 Bi 26 Specifically, the coated copper strip 1 can be introduced into the deoxidation device 3, and a nitrogen-hydrogen mixed gas containing hydrogen anions (the volume of hydrogen in the nitrogen-hydrogen mixed gas is less than 4%) is diffused in the deoxidation device 3. The coated copper strip 1 can remove the surface oxides of the tin-plated layers 1-3 in the deoxidation device 3, and the temperature of the deoxidation device 3 is set at 120°C. Hydrogen anions can achieve a reduction reaction with the surface oxides of the coated copper strip 1, and then the oxides are removed by reducing the oxides. Nitrogen can be used as a protective gas to achieve an explosion-proof effect.
[0059] It should be noted that the deoxidation equipment 3 uses the electron attachment (EA) principle to activate the hydrogen in the non-flammable nitrogen-hydrogen (<4% hydrogen) mixture, so as to achieve the purpose of removing oxides: when low-energy electrons collide with hydrogen molecules, the hydrogen molecules produce excited molecular hydrogen ions, which then dissociate to obtain atomic hydrogen ions. The atomic hydrogen ions will automatically move to the welding surface for reduction reaction under the drive of the applied electric field.
[0060] H2+e-→H2-*→H-+H (1)
[0061] H+e-→H-* (2)
[0062] 2H-+SnO→Sn+H2O+2e- (3)
[0063] Reaction (1) describes the dissociative attachment of hydrogen molecules, where a hydrogen molecule (H 2 ) combines with electrons (e-) to produce excited molecular hydrogen ions (H 2-* ), and then dissociated to obtain atomic hydrogen ions (H -) and neutral hydrogen atoms (H). The neutral hydrogen atom can capture an electron again by direct attachment (3) to form an excited atomic hydrogen anion (H-*). The excited atomic anion can be stabilized by releasing photons or colliding with nitrogen molecules. Nitrogen is inert to EA as a diluent gas because its electron affinity is close to zero. Driven by the applied electric field, the atomic hydrogen anions formed under EA will automatically move to the welding surface for reduction reaction. Reaction (3) gives an example of the reduction of tin monoxide. The water vapor generated in the reaction can be discharged out of the furnace along the airflow, and the free electrons can be removed in an appropriate manner.
[0064] Please refer to Figure 1 , Figure 3 As shown, specifically, the deoxidation equipment 3 is provided with a furnace 31, an electron emission device 32 containing a large number of needles is installed on the top of the furnace 31, and a non-flammable nitrogen-hydrogen mixed gas (<4% hydrogen) is introduced into the furnace 31. The electronic components to be welded, such as the coated copper strip 1, are loaded on the conveying device 33 of the furnace 31 and are continuously transported from the inlet end to the outlet end of the furnace 31. When the coated copper strip 1 passes under the electron emission device 32, it will be completely in the EA-activated atmosphere. After completing the surface cleaning under the EA, the coated copper strip 1 is sent out for welding, cooling and other operations.
[0065] Please refer to Figure 1 As shown, step S3: immersing the plated copper strip after removing the surface oxide into a film-forming substance, and drying to obtain a photovoltaic interconnection strip with a film; the film-forming substance does not contain a carboxyl group;
[0066] In this embodiment, it should be noted that the coated copper strip 1 after removing the surface oxide is immersed in the film-forming substance, and after drying, a photovoltaic interconnection strip with a film is obtained. The film-forming substance does not contain a carboxyl group, and is specifically composed of a film-forming agent and a solvent, the volume proportion of the film-forming agent is ≤8%, preferably 5%, and the melting point of the film-forming agent is set to be greater than 220°C, specifically one or more of hydrocarbons, alcohols, and lipids, preferably polyethylene glycol; the rest is a solvent, and the solvent is one or more of water, ethanol, and isopropanol, preferably water. Specifically, the coated copper strip 1 continues to be pulled into the film-forming device 4 containing the film-forming substance through the traction mechanism 2, and the surface of the coated copper strip 1 through the film-forming device 4 will be evenly coated with a layer of film-forming substance, which is dried so that the film-forming substance is effectively wrapped on the surface of the coated copper strip 1, and then a photovoltaic interconnection strip 5 with a film is obtained, and the photovoltaic interconnection strip 5 is cut and used by the cutting mechanism 6. Of course, the coated copper strip 1 after removing the surface oxide can also be immersed in the film-forming substance before serial connection, and then the photovoltaic module is directly produced. Of course, the film-forming device 4 in this embodiment can be an open groove containing a film-forming substance, and the plated copper strip 1 can be evenly coated by the film-forming substance when introduced into the open groove. As for how to set it, this embodiment does not make specific restrictions.
[0067] Please refer to Figure 1 , Figure 4 As shown, step S4: applying adhesive to the front and back of the battery cell respectively;
[0068] In this embodiment, it should be noted that the battery cell 71 uses a busbar-free heterojunction battery, and adhesive glue 8 is applied to the front and back of the battery cell 71. The adhesive glue 8 can be a light-curing glue or a thermosetting glue. In an achievable manner, glue is applied to the battery cell 71 so that a plurality of glue points arranged in sequence and at intervals are formed at each photovoltaic interconnection bar 5 installation position of the battery cell 71.
[0069] Please refer to Figure 1 , Figure 4 As shown, step S5: pre-fix the photovoltaic interconnection strips to the adhesives on the front and back of the battery sheet respectively, and repeat this step to complete the stacking of the battery string;
[0070] In this embodiment, it should be noted that the photovoltaic interconnection strip 5 is placed on the battery cell 71 in a direction perpendicular to the fine grid on the battery cell 71 for preliminary positioning, one end of the photovoltaic interconnection strip 5 falls above the battery cell 71, and the other end falls below the adjacent battery cell 71, connecting the positive and negative poles of the two adjacent cells to achieve circuit connection. After preliminary positioning, a press is used to pre-fix the photovoltaic interconnection strip 5 to the adhesive 8, i.e., the glue points, on the front and back sides of the battery cell 71, respectively, and this step is repeated to complete the stacking of the battery string 7.
[0071] Please continue to refer to Figure 1 , Figure 4 As shown, step S6: curing the adhesive on the front and back of the cell, fixing the photovoltaic interconnection strip on the cell, and completing the production of the cell string;
[0072] In this embodiment, it should be noted that the adhesive 8, such as a photocurable adhesive, is rapidly solidified by irradiation with a UV lamp. The photocurable adhesive contains a UV adhesive component, which can be rapidly cured within a few seconds to more than ten seconds by irradiation with a UV lamp, thereby fixing the photovoltaic interconnection bar 5 on the battery cell 71; or, the adhesive 8, such as a thermosetting adhesive, is cured by heating, thereby fixing the photovoltaic interconnection bar 5 on the battery cell 71, thereby completing the production of the battery string 7. The use of the adhesive 8 can improve the bonding tightness between the photovoltaic interconnection bar 5 and the battery cell 71 on the one hand, and prevent the photovoltaic interconnection bar 5 from falling off due to vibration, which affects the use of the battery cell 71; on the other hand, it can protect the photovoltaic interconnection bar 5 when an external impact occurs.
[0073] Please refer to Figure 4 , Figure 5 As shown, step S7: arranging, stacking, and laminating a plurality of battery strings according to the layout, so that the photovoltaic interconnection strips form good alloy contact with the fine grids of the battery cells during the lamination process, and finally obtaining a photovoltaic module.
[0074] In this embodiment, it should be noted that the above-mentioned battery string 7 is arranged, stacked and laminated according to the stacking drawing, so that the photovoltaic interconnection strip 5 forms a good alloy contact with the fine grid of the battery cell 71 during the lamination process, and finally a photovoltaic module 9 is obtained.
[0075] Example 2
[0076] The difference between Example 2 and Example 1 is only the difference between step S4 and step S5;
[0077] Please refer to Figure 6 As shown, S4: pre-fix the film material and the photovoltaic interconnection strip on the front and back of the battery sheet, and repeat this step to complete the stacking of the battery string;
[0078] In this embodiment, it should be noted that if the film material 10 is made of pure PO material (propylene oxide) or EVA material (ethylene-vinyl acetate copolymer and rubber-plastic foam material made thereof), the battery cell 71 uses a busbar-free heterojunction battery. The film material 10 is laid on the photovoltaic interconnection bar 5 and the battery cell 71. After heating, the film material 10 will produce a cross-linking reaction and have a certain adhesive property to fix the photovoltaic interconnection bar 5 on the battery cell 71.
[0079] First, the photovoltaic interconnection strip 5 is placed on the battery cell 71 in a direction perpendicular to the fine grid on the battery cell 71 for preliminary positioning, with one end of the photovoltaic interconnection strip 5 falling above the battery cell 71 and the other end falling below the adjacent battery cell 71. Then, the film material 10 is laid on the photovoltaic interconnection strip 5 in the direction of the fine grid. The film material 10 covers the arranged photovoltaic interconnection strips 5, and the film material 10 and the photovoltaic interconnection strips 5 are pressed on the front and back of the battery cell 71 by a press. Repeat this step to complete the stacking of the battery string 7.
[0080] Step S5: The stacked battery string is subjected to heating treatment, and the film material above the photovoltaic interconnection strip shrinks due to the heat. After cooling, the photovoltaic interconnection strip is fixed on the battery sheet to complete the production of the battery string;
[0081] In this embodiment, it should be noted that the stacked battery string 7 is subjected to a heating treatment such as using an infrared light box to heat the film material 10, and the film material 10 above the photovoltaic interconnection strip 5 shrinks due to the heat. After cooling, the photovoltaic interconnection strip 5 is fixed on the battery cell 71, thereby completing the production of the battery string 7.
[0082] Example 3
[0083] An embodiment of the present application provides a method for preparing a photovoltaic module, in which the coated copper strip can be first welded to the battery in a flux-free welding device. When this method is adopted, there is no need to apply a film-forming material to the surface of the coated copper strip. The flux-free welding device is a relatively mature equipment in the prior art, and its interior is divided into preheating, heating, EA treatment, reflow, cooling and other areas. The samples such as battery strings are transported by conveyor rollers for sequential processing. Among them, a heating device and an inert gas introduction device are arranged inside the flux-free welding device. The heating method of the heating device can be resistance wire heating, such as the heating method of an oven or a tunnel furnace; the inert gas introduction device is used to continuously introduce a nitrogen-hydrogen mixed gas, and the inlet and outlet areas of the flux-free welding device are small enough to ensure that the oxygen content in the cavity is maintained below 10ppm.
[0084] The following is a detailed description of it, including the following steps:
[0085] Step S1: pre-fixing the plated copper strip on the front and back of the battery cell, and repeating this step to complete the stacking of the battery string; at least a portion of the surface of the plated copper strip has an oxide;
[0086] In this embodiment, it should be noted that the plated copper strip is placed on the cell in a direction perpendicular to the fine grid on the cell for preliminary positioning, with one end of the plated copper strip falling above the cell and the other end falling below the adjacent cell, and then a protective press 11 (such as Figure 7As shown in FIG. 1 ), a copper strip is fixed on the front and back sides of the battery cell, and this step is repeated to complete the stacking of the battery string, wherein at least a portion of the surface of the copper strip has an oxide. Figure 7 , Figure 8 As shown, part of the surface of the protection press 11 is hollowed out to form equally spaced hollow areas 111 on the protection press 11. The hollow areas 111 correspond to the positions of the plated copper tape and the adhesive on the battery cell, and the remaining area of the battery cell surface is blocked by the protection press 11 to protect the area from the influence of reducing hydrogen.
[0087] Step S2: sending the pre-fixed battery string into a high-temperature oxygen-free environment of nitrogen-hydrogen mixed gas or plasma containing negative hydrogen ions to simultaneously complete deoxidation and welding of the surface of the plated copper strip;
[0088] In this embodiment, it should be noted that the battery string pre-fixed by the protective press 11 is sent into a high-temperature oxygen-free environment containing a nitrogen-hydrogen mixed gas or plasma containing negative hydrogen ions to simultaneously complete the deoxidation and welding of the surface of the coated copper strip. For example, the battery string is sent into a flux-free welding device 13 with a conveyor belt 12. The nitrogen-hydrogen mixed gas or argon plasma containing negative hydrogen ions is diffused in the flux-free welding device 13. When the battery string passes through the flux-free welding device 13, the surface oxide of the coated copper strip is removed by the reducing effect of the negative hydrogen ions. At the same time, the high temperature is used to make the tin coating on the surface of the coated copper strip react with the battery cell to complete the welding. The welding temperature is 5°C-10°C higher than the melting point of the solder of the coated copper strip, preferably 5°C. Since the interior of the flux-free welding device 13 is an oxygen-free environment, no oxides are generated during the welding process, and then there is no need to rely on the active substances in the flux to remove the oxides during the welding process, which completely eliminates the hidden dangers caused by the residual active agent and the residual metal salts.
[0089] Step S3: applying adhesive to the front and back of the battery string after welding at the position where the plated copper strip is fixed;
[0090] In this embodiment, it should be noted that after the battery string is welded in step S2, it is stepped forward, and adhesive is applied to the positions of fixing the plated copper strip on the front and back of the battery string, respectively. The adhesive may be a light-curing adhesive or a thermosetting adhesive. In an achievable manner, the adhesive is applied to the plated copper strip so that a plurality of adhesive dots arranged in sequence are formed at each installation position of the plated copper strip.
[0091] Step S4: curing the adhesive on the front and back of the battery string, fixing the plated copper strip on the battery sheet, and completing the production of the battery string;
[0092] In this embodiment, it should be noted that the adhesive such as photocuring adhesive is rapidly solidified by using UV lamp irradiation. The photocuring adhesive contains UV glue, which can be rapidly cured within a few seconds to more than ten seconds by UV lamp irradiation, and then the plated copper strip is fixed on the battery cell; or, the adhesive such as thermosetting adhesive is cured by heating, and then the plated copper strip is fixed on the battery cell, thereby completing the production of the battery string. The use of adhesive can improve the bonding tightness between the plated copper strip and the battery cell on the one hand, and prevent the plated copper strip from falling off due to vibration, affecting the use of the battery cell; on the other hand, it can protect the plated copper strip when external impact occurs, and at the same time reduce silver consumption and assist in fixation.
[0093] Step S5: Arrange, stack, and laminate several battery strings according to the layout, so that the plated copper strip forms good alloy contact with the fine grid of the battery cell during the lamination process, and finally obtain a photovoltaic module.
[0094] In this embodiment, it should be noted that the above-mentioned battery string is arranged, stacked and laminated according to the stacking drawing, so that the plated copper strip forms a good alloy contact with the fine grid of the battery cell during the lamination process, and finally a photovoltaic module is obtained.
[0095] Example 4
[0096] The embodiment of the present application provides a method for preparing a photovoltaic module, in which the coated copper strip can first be connected in series with the battery by means of adhesive, and then welded in a flux-free welding device. When this method is adopted, no film-forming material needs to be applied to the surface of the coated copper strip, which is described in detail below, including the following steps:
[0097] Step S1: applying adhesive to the front and back of the battery cell respectively, and pre-fixing the plated copper tape on the adhesive on the front and back of the battery cell respectively; or, pre-fixing the plated copper tape on the front and back of the battery cell respectively, and applying adhesive to the front and back of the battery cell at the position of the plated copper tape respectively; at least a part of the surface of the plated copper tape has an oxide;
[0098] In this embodiment, it should be noted that the battery cell uses a non-busbar heterojunction battery, and adhesive glue is applied to the front and back of the battery cell, respectively. The adhesive glue can be a light-curing glue or a thermosetting glue. In a feasible manner, glue is applied on the battery cell so that a plurality of glue points arranged in sequence are formed on each copper strip installation position of the battery cell. Then the copper strip is placed on the battery cell in a direction perpendicular to the fine grid on the battery cell for preliminary positioning. One end of the copper strip falls on the top of the battery cell, and the other end falls on the bottom of the adjacent battery cell. The positive and negative electrodes of the two adjacent cells are connected to achieve the circuit connection effect, specifically, the copper strip is fixed to the adhesive glue on the front and back of the battery cell, that is, the glue point. Of course, the copper strip can also be pre-fixed on the front and back of the battery cell respectively, and then the adhesive glue is applied to the front and back of the battery cell at the position of the copper strip. The specific setting is not specifically limited in this embodiment. Among them, at least a part of the surface of the copper strip has an oxide.
[0099] Step S2: curing the adhesive on the front and back of the battery cell, fixing the plated copper tape on the battery cell, and repeating this step to complete the stacking of the battery string;
[0100] In this embodiment, it should be noted that the adhesive such as photocuring adhesive is rapidly solidified by using UV lamp irradiation. The photocuring adhesive contains UV glue, which can be rapidly cured within a few seconds to more than ten seconds by UV lamp irradiation, and then the plated copper strip is fixed on the battery cell; or, the adhesive such as thermosetting adhesive is cured by heating, and then the plated copper strip is fixed on the battery cell, and this step is repeated to complete the stacking of the battery string. The use of adhesive can improve the bonding tightness between the plated copper strip and the battery cell, prevent the plated copper strip from falling off due to vibration, and affect the use of the battery cell; on the other hand, it can protect the plated copper strip when external impact occurs.
[0101] Step S3: sending the battery string into a high-temperature oxygen-free environment of nitrogen-hydrogen mixed gas or plasma containing negative hydrogen ions to simultaneously complete deoxidation and welding of the surface of the coated copper strip, thereby completing the production of the battery string;
[0102] In this embodiment, it should be noted that a protective press is placed above the stacked battery string in step S2, and the battery string pre-fixed by the protective press is sent into a high-temperature oxygen-free environment containing a nitrogen-hydrogen mixed gas or plasma containing negative hydrogen ions to simultaneously complete the deoxidation and welding of the surface of the coated copper strip. For example, the battery string is sent into a flux-free welding device with a conveyor belt, and the nitrogen-hydrogen mixed gas or argon plasma containing negative hydrogen ions is diffused in the flux-free welding device. When the battery string passes through the flux-free welding device, the surface oxide of the coated copper strip is removed by the reducing effect of the negative hydrogen ions, and the tin coating on the surface of the coated copper strip reacts with the battery cell by the effect of high temperature to complete the welding. The welding temperature is 5°C-10°C higher than the melting point of the solder of the coated copper strip, preferably 5°C. Since the interior of the flux-free welding device is an oxygen-free environment, no oxides are generated during the welding process, and then there is no need to rely on the active substances in the flux to remove the oxides during the welding process, which completely eliminates the hidden dangers caused by the residual active agent and the residual metal salts.
[0103] Step S4: Arrange several battery strings according to the layout, stack and laminate them. The plated copper strip forms good alloy contact with the fine grid of the battery cell during the lamination process, and finally a photovoltaic module is obtained.
[0104] In this embodiment, it should be noted that the above-mentioned battery string is arranged, stacked and laminated according to the stacking drawing, so that the plated copper strip forms a good alloy contact with the fine grid of the battery cell during the lamination process, and finally a photovoltaic module is obtained.
[0105] Example 5
[0106] The embodiment of the present application provides a photovoltaic module, which is prepared using the above-mentioned method for preparing a photovoltaic module.
[0107] In some embodiments, a photovoltaic module includes a front panel material, a front adhesive film, a battery string, a back adhesive film and a back panel material stacked in sequence, wherein the battery string includes battery cells, adhesive or film materials and photovoltaic interconnection strips.
[0108] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.
[0109] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be construed as limiting the scope of the patent application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent application shall be subject to the attached claims.
Claims
1. A method for preparing a photovoltaic module, characterized in that: The steps include: S1: providing a coated copper strip; the coated copper strip comprises a substrate, a flux layer covering the substrate, a tin-plated layer covering the flux layer, and an oxide covering at least a portion of the surface of the tin-plated layer; S2: treating the plated copper strip with nitrogen-hydrogen mixed gas of negative hydrogen ions, plasma cleaning or laser cleaning to remove surface oxides; S3: immersing the plated copper strip after removing the surface oxide into a film-forming substance, and drying to obtain a photovoltaic interconnection strip with a film; the film-forming substance does not contain a carboxyl group; S4: applying adhesive to the front and back of the battery cell respectively; S5: pre-fixing the photovoltaic interconnection strips to the adhesives on the front and back sides of the battery cells, respectively, and repeating this step to complete the stacking of the battery strings; S6: curing the adhesive on the front and back of the cell, fixing the photovoltaic interconnection strip on the cell, and completing the production of the cell string; S7: Arrange, stack, and laminate a plurality of battery strings according to a layout, so that the photovoltaic interconnection strips form alloy contact with the fine grids of the battery cells during the lamination process, and finally obtain a photovoltaic module.
2. A method for preparing a photovoltaic module, characterized in that: The steps include: S1: providing a coated copper strip; the coated copper strip comprises a substrate, a flux layer covering the substrate, a tin-plated layer covering the flux layer, and an oxide covering at least a portion of the surface of the tin-plated layer; S2: treating the plated copper strip with nitrogen-hydrogen mixed gas of negative hydrogen ions, plasma cleaning or laser cleaning to remove surface oxides; S3: immersing the plated copper strip after removing the surface oxide into a film-forming substance, and drying to obtain a photovoltaic interconnection strip with a film; the film-forming substance does not contain a carboxyl group; S4: pre-fix the film material and the photovoltaic interconnection strip on the front and back of the battery sheet, and repeat this step to complete the stacking of the battery string; S5: The stacked battery string is subjected to heating treatment, and the film material above the photovoltaic interconnection strip shrinks due to the heat. After cooling, the photovoltaic interconnection strip is fixed on the battery sheet to complete the production of the battery string; S6: Arrange, stack, and laminate a number of battery strings according to a layout, wherein the photovoltaic interconnection strips form alloy contact with the fine grids of the battery cells during the lamination process, and finally a photovoltaic module is obtained.
3. The method for preparing a photovoltaic module according to claim 1 or 2, characterized in that: The film-forming substance consists of a film-forming agent and a solvent, wherein the volume proportion of the film-forming agent is ≤8% and the rest is the solvent; wherein the melting point of the film-forming agent is greater than 220°C.
4. The method for preparing a photovoltaic module according to claim 3, characterized in that: The film-forming agent is one or more of hydrocarbons, alcohols and lipids.
5. The method for preparing a photovoltaic module according to claim 3, characterized in that: The solvent is one or more of water, ethanol and isopropanol.
6. A method for preparing a photovoltaic module, characterized in that: The steps include: S1: pre-fixing a plated copper strip on the front and back of the battery cell, and repeating this step to complete the stacking of the battery string; at least a portion of the surface of the plated copper strip has an oxide; S2: sending the pre-fixed battery string into a high-temperature oxygen-free environment of nitrogen-hydrogen mixed gas or plasma containing negative hydrogen ions to simultaneously complete deoxidation and welding of the surface of the coated copper strip; S3: Apply adhesive to the front and back of the welded battery string at the position where the plated copper strip is fixed; S4: curing the adhesive on the front and back of the battery string, fixing the plated copper tape on the battery sheet, and completing the production of the battery string; S5: Arrange several battery strings according to the layout, stack and laminate them, and the plated copper tape forms alloy contact with the fine grid of the battery cell during the lamination process to finally obtain a photovoltaic module.
7. A method for preparing a photovoltaic module, characterized in that: The steps include: S1: applying adhesive to the front and back of the battery cell respectively, and pre-fixing the plated copper tape on the adhesive on the front and back of the battery cell respectively; or, pre-fixing the plated copper tape on the front and back of the battery cell respectively, and applying adhesive to the front and back of the battery cell at the position of the plated copper tape respectively; at least a part of the surface of the plated copper tape has an oxide; S2: curing the adhesive on the front and back of the battery cell, fixing the plated copper tape on the battery cell, and repeating this step to complete the stacking of the battery string; S3: Sending the battery string into a high-temperature oxygen-free environment of nitrogen-hydrogen mixed gas or plasma containing negative hydrogen ions to simultaneously complete deoxidation and welding of the surface of the coated copper strip, thereby completing the production of the battery string; S4: Arrange several battery strings according to the layout, stack and laminate them. The plated copper tape forms alloy contact with the fine grid of the battery cell during the lamination process to finally obtain a photovoltaic module.
8. A photovoltaic module, prepared by the method for preparing a photovoltaic module according to any one of claims 1 to 7.
9. The photovoltaic module according to claim 8, characterized in that: The photovoltaic module comprises a front plate material, a front adhesive film, a battery string, a back adhesive film and a back plate material which are stacked in sequence.