Preparation method of metal electrode, solar cell and preparation method thereof, and photovoltaic module
By setting the mask layer and covering the solvent layer on the base of solar cells, the high -width ratio preparation of the metal electrode is achieved, the optical loss problem caused by the electrode shielding area, and improved the optoelectronic efficiency of solar cells.
Patent Information
- Application Number
- CN202411528850.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-30
- Publication Date
- 2025-01-28
AI Technical Summary
The optical loss caused by the large light-blocking area of the electrode in solar cells limits the improvement of the photoelectric efficiency of solar cells.
By setting the mask layer on the base, the groove of the predetermined pattern is to cover the solvent layer, and the injecting of at least two consecutive metal slurry in the groove is prepared to prepare a high -width -wide metal electrode.
This method can reduce the width of the grid line and increase the light area of solar cells, thereby improving the efficiency of photoelectric conversion. At the same time, the preparation method is simple, the cost is low, and the high width ratio of the electrode can be controlled.
Smart Images
Figure CN119384072A_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the technical field of solar cells, and in particular to a method for preparing a metal electrode, a solar cell and a method for preparing the same, and a photovoltaic module. Background Art
[0002] Solar cells are semiconductor elements that convert solar energy into electrical energy and have a pn junction form. When light is incident on a solar cell, it is absorbed by the solar cell and interacts with the semiconductor material that constitutes the solar cell. Furthermore, the electrons and holes that are formed as minority carriers move to the connected electrodes on both sides before recombination, thereby obtaining an electromotive force.
[0003] The grid electrode is an important component of the solar cell, responsible for collecting current and transporting it to the outside of the cell. The grid electrode is an important component of the cell, responsible for collecting current and transporting it to the outside of the cell, and the optical loss caused by the electrode shading area is one of the main factors restricting the efficiency of solar cells. The thinner the grid electrode on the surface of the solar cell, the smaller the optical loss caused by the electrode shading. Therefore, it is necessary to make an electrode with a large aspect ratio to overcome the problem of low photoelectric efficiency of solar cells caused by large shading area.
[0004] It should be noted that the above content is not necessarily prior art, nor is it intended to limit the scope of patent protection of this application. Summary of the invention
[0005] The embodiments of the present application provide a method for preparing a metal electrode, a solar cell and a method for preparing the same, and a photovoltaic module to solve or alleviate the above-mentioned problems such as optical loss caused by a large shading area of the electrode.
[0006] Accordingly, the first aspect of the embodiment of the present application provides a method for preparing a metal electrode. The method includes: providing a mask layer on a substrate to form a groove of a predetermined pattern; covering the inner wall of the groove with a solvent to form a solvent layer; and injecting a metal slurry into the groove having the solvent layer to obtain a metal electrode.
[0007] The method of the embodiment of the present application can obtain a metal electrode with a large aspect ratio, thereby increasing the illuminated area of the solar cell containing the metal electrode and improving the photoelectric conversion efficiency of the solar cell. Specifically, the present application forms a groove of a predetermined pattern by setting a mask layer on the substrate; then covering the inner wall of the groove with a solvent layer to reduce the adhesion of the subsequent metal slurry on the mask layer; then injecting the metal slurry into the groove to obtain a metal electrode with a large aspect ratio, reduce the width of the grid line, increase the illuminated area of the cell, and thus improve the photoelectric conversion efficiency. In addition, the preparation method is simple and low-cost, and the aspect ratio of the electrode can be controlled by designing the depth and width of the groove.
[0008] According to an embodiment of the present application, the injection of the metal slurry includes: injecting the metal slurry at least twice in succession into the groove having the solvent layer. In this way, injecting the metal slurry at least twice in succession can reduce the situation of overprinting failure, because each injection is performed in a pre-prepared groove, which can reduce the problem of misalignment, thereby improving the overprinting effect and efficiency.
[0009] According to an embodiment of the present application, the mask layer includes a binder, a plasticizer, a thermal inhibitor and a flame retardant.
[0010] According to an embodiment of the present application, the mask layer further includes an adhesion promoter.
[0011] According to the embodiments of the present application, based on 100 parts by weight of the binder, the plasticizer is 15-25 parts by weight, the tackifier is 5-20 parts by weight, the thermal inhibitor is 2-10 parts by weight, and the flame retardant is 2-10 parts by weight. The mask layer containing the aforementioned materials hardly reacts with the substrate and is easier to remove later.
[0012] According to an embodiment of the present application, the binder includes at least one of polymethacrylate, styrene, and maleic acid.
[0013] According to an embodiment of the present application, the plasticizer includes triethylene glycol diacetate.
[0014] According to an embodiment of the present application, the adhesion promoter includes a nitrogen-containing heterocyclic compound.
[0015] According to an embodiment of the present application, the thermal inhibitor includes at least one of hydroquinone and p-methoxyphenol.
[0016] According to an embodiment of the present application, the flame retardant includes an aromatic halide.
[0017] According to an embodiment of the present application, the depth of the groove is 15-30 μm.
[0018] According to an embodiment of the present application, in the extension direction of the battery cell, the width of the groove is 25-45 μm.
[0019] According to an embodiment of the present application, the solvent includes at least one of diethylene glycol butyl ether, terpineol, methanol, ethanol, propanol, and ethylene glycol ethyl ether acetate.
[0020] According to an embodiment of the present application, the thickness of the solvent layer is 1-5 μm.
[0021] According to an embodiment of the present application, the height of the metal electrode is 8-30 μm.
[0022] According to an embodiment of the present application, the method further includes: removing the mask layer.
[0023] According to an embodiment of the present application, the mask layer is removed by using a 3-10wt% alkaline solution.
[0024] According to an embodiment of the present application, the temperature for removing the mask layer is 40-70°C.
[0025] According to an embodiment of the present application, the time for removing the mask layer is 3-10 minutes.
[0026] The second aspect of the embodiment of the present application provides a method for preparing a solar cell. The method includes providing a substrate, the substrate being a cell sheet; and preparing a metal electrode on the cell sheet using the method described in the first aspect. In this way, a solar cell with high photoelectric efficiency can be obtained.
[0027] In a third aspect of the embodiments of the present application, a solar cell is provided, wherein the metal electrode of the solar cell is prepared by the method of the first aspect or the solar cell is prepared by the method of the second aspect. The solar cell has good photoelectric efficiency, which is because a high aspect ratio cell is prepared by the aforementioned method, which can increase the illumination area of the solar cell.
[0028] In a fourth aspect of the embodiment of the present application, a photovoltaic module may be provided, the photovoltaic module comprising a plurality of solar cells connected in series and / or in parallel; wherein at least one solar cell is the solar cell of the third aspect as described above. The plurality of solar cells in series form a cell string, and adjacent solar cells may be connected together by string welding. BRIEF DESCRIPTION OF THE DRAWINGS
[0029] In the accompanying drawings, unless otherwise specified, the same reference numerals throughout the multiple drawings represent the same or similar parts or elements. These drawings are not necessarily drawn to scale. It should be understood that these drawings only depict some embodiments disclosed in the present application and should not be regarded as limiting the scope of the present application.
[0030] Figure 1 It is a schematic diagram of the process of overprinting metal electrodes provided in an embodiment of the present application; Figure 2 It is a schematic diagram of the process of overprinting metal electrodes provided in an embodiment of the present application.
[0031] Description of reference numerals: 1: first scraper; 2: screen; 3: solvent layer; 4: mask layer; 5: battery cell; 6: second scraper. DETAILED DESCRIPTION
[0032] Embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings. In the accompanying drawings, for clarity, the sizes of layers, regions, elements and their relative sizes may be exaggerated. Wherein the same or similar reference numerals throughout represent the same or similar elements or elements with the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application, and cannot be understood as limitations on the present application. It should be noted that, in the absence of conflict, the embodiments in the present application and the features in the embodiments can be combined with each other.
[0033] It should be understood that when an element or layer is referred to as "on ...", "adjacent to ...", "connected to" or "coupled to" other elements or layers, it can be directly on, adjacent to, connected to or coupled to other elements or layers, or there can be intervening elements or layers. On the contrary, when an element is referred to as "directly on ...", "directly adjacent to ...", "directly connected to" or "directly coupled to" other elements or layers, there is no intervening element or layer. It should be understood that although the terms first, second, third, etc. can be used to describe various elements, components, regions, layers and / or parts, these elements, components, regions, layers and / or parts should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer or part from another element, component, region, layer or part. Therefore, without departing from the teachings of the present application, the first element, component, region, layer or part discussed below can be represented as the second element, component, region, layer or part. When the second element, component, region, layer or part is discussed, it does not indicate that the present application necessarily has the first element, component, region, layer or part.
[0034] In this application, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.
[0035] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the terms used in this way can be interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein, for example. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.
[0036] In the present application, when it comes to a numerical interval (i.e., a numerical range), unless otherwise specified, the distribution of the optional numerical values in the numerical interval is considered to be continuous, and includes the two numerical endpoints (i.e., the minimum and maximum values) of the numerical interval, and each numerical value between the two numerical endpoints. Unless otherwise specified, when the numerical interval only refers to an integer in the numerical interval, it includes the two endpoint integers of the numerical range, and each integer between the two endpoints, which is equivalent to directly listing each integer. When multiple numerical ranges are provided to describe features or characteristics, these numerical ranges can be merged. In other words, unless otherwise specified, the numerical range disclosed in the present application should be understood to include any and all sub-ranges included therein. The "numerical value" in the numerical interval can be any quantitative value, such as a number, a percentage, a ratio, etc. "Numerical interval" allows for broadly including quantitative intervals such as percentage intervals, ratio intervals, and ratio intervals.
[0037] At present, the production of high aspect ratio electrodes generally uses overprinting technology, that is, after the first printing and drying, a second printing is performed on the surface of the electrode obtained in the first printing. In the process of printing electrodes, there are the following problems: on the one hand, the printing efficiency is low; on the other hand, overprinting failure occurs, that is, it is difficult to accurately overprint and overprinting occurs, which will cause optical loss of solar cells, current drop and other problems.
[0038] Accordingly, the first aspect of the embodiment of the present application provides a method for preparing a metal electrode. The method includes: providing a mask layer on a substrate to form a groove of a predetermined pattern; covering the inner wall of the groove with a solvent to form a solvent layer; and injecting a metal slurry into the groove having the solvent layer to obtain a metal electrode.
[0039] The method of the embodiment of the present application can obtain a metal electrode with a large aspect ratio, thereby increasing the illuminated area of the solar cell containing the metal electrode and improving the photoelectric conversion efficiency of the solar cell. Specifically, the present application forms a groove of a predetermined pattern by setting a mask layer on the substrate; then covering the inner wall of the groove with a solvent layer to reduce the adhesion of the subsequent metal slurry on the mask layer; then injecting the metal slurry into the groove to obtain a metal electrode with a large aspect ratio, reduce the width of the grid line, increase the illuminated area of the cell, and thus improve the photoelectric conversion efficiency. In addition, the preparation method is simple and low-cost, and the aspect ratio of the electrode can be controlled by designing the depth and width of the groove.
[0040] According to this application, reference Figure 1 , step (1) provides a mask layer on the substrate. In this step, a mask layer is provided on the substrate to form a groove of a predetermined pattern. The groove is used for subsequent overprinting of metal electrodes.
[0041] In some embodiments, the substrate includes a cell having a heterojunction solar cell, a back contact solar cell, a tunnel passivation contact solar cell, or the like of a solar cell.
[0042] In some embodiments, the mask layer includes a binder, a plasticizer, a thermal inhibitor, and a flame retardant, so that the mask layer can protect the non-electrode area.
[0043] In some embodiments, the mask layer further includes a tackifier, so that the tackifier has a certain degree of adhesion and can increase the bonding force between the mask layer and the battery cell.
[0044] Optionally, based on 100 parts by weight of the adhesive, the plasticizer is 15-25 parts by weight, the tackifier is 5-20 parts by weight, the thermal inhibitor is 2-10 parts by weight, and the flame retardant is 2-10 parts by weight.
[0045] Optionally, the binder includes at least one of polymethacrylate, styrene, maleic acid, and acrylate. The binder can act as a skeleton, which can improve the stability of the groove during the metal slurry injection process.
[0046] Optionally, the plasticizer includes triethylene glycol diacetate.
[0047] Optionally, the adhesion promoter includes a nitrogen-containing heterocyclic compound.
[0048] Furthermore, the nitrogen-containing heterocyclic compound includes at least one of benzotriazole, benzimidazole, indazole and derivatives thereof.
[0049] Optionally, the thermal inhibitor includes at least one of hydroquinone and p-methoxyphenol; Optionally, the flame retardant comprises an aromatic halide.
[0050] Further, the aromatic halide includes chlorobenzene.
[0051] In some embodiments, the mask layer is prepared by dissolving a binder, a plasticizer, a tackifier, a thermal inhibitor and a flame retardant in an organic solvent to obtain a mask layer solution, and then applying the mask layer solution on a substrate according to a predetermined pattern to form a mask layer.
[0052] Optionally, the organic solvent includes at least one of toluene, acetone, and butanone.
[0053] In some embodiments, a mask layer is disposed on a substrate to form grooves of a predetermined pattern, comprising: placing a mask layer on the substrate, and forming grooves between adjacent mask layers.
[0054] In other embodiments, the mask layer is molded according to a predetermined pattern to form a groove. When the mold is opened, a MARK point can be set on the mask layer in advance, and the MARK point can be used for positioning, and the coordinate position of the MARK point is the same as the position of the MARK point on the printing screen.
[0055] Optionally, the MARK spot size is 200-600 μm.
[0056] Optionally, in the thickness direction of the battery, the height of the mask layer is 15-30 μm.
[0057] In some embodiments, the depth of the grooves is 15-30 μm.
[0058] In some embodiments, in the extension direction of the battery cell, the width of the groove is 25-45 μm.
[0059] According to the embodiments of the present application, reference Figure 1 , step (2) covers the inner wall of the groove with a solvent. In this step, the inner wall of the groove is covered with a solvent to form a solvent layer. The solvent layer is conducive to reducing the adhesion of subsequent metal slurry on the mask layer, thereby facilitating the reuse of the mask layer.
[0060] In some embodiments, the solvent includes at least one of diethylene glycol butyl ether, terpineol, methanol, ethanol, propanol, and ethylene glycol ethyl ether acetate.
[0061] In some embodiments, the thickness of the solvent layer is 1-5 um, which can reduce the adhesion of the metal slurry to the inner wall of the groove and reduce the cost.
[0062] In some embodiments, covering the solvent layer comprises coating.
[0063] According to the embodiments of the present application, reference Figure 1 , step (3) injecting metal slurry. In this step, metal slurry is injected into the groove having the solvent layer to obtain a metal electrode.
[0064] In some embodiments, the injection of the metal slurry includes: injecting the metal slurry at least twice in succession into the groove having the solvent layer. Thus, the metal slurry is injected at least twice in succession, that is, the metal electrode is prepared by overprinting. Due to the presence of the groove, the overprinting effect is better and the overprinting efficiency is better, and a metal electrode with a larger aspect ratio can be obtained, thereby increasing the illumination area of the solar cell containing the metal electrode, and improving the photoelectric conversion efficiency of the solar cell. Specifically, the present application forms a groove of a predetermined pattern by providing a mask layer on the substrate; then covering the inner wall of the groove with a solvent layer to reduce the adhesion of the subsequent metal slurry on the mask layer; and then injecting the metal slurry into the groove at least twice in succession. The at least two injection processes are performed continuously, which can not only improve the overprinting efficiency and obtain a metal electrode with a larger aspect ratio, but also the at least two injection processes do not require the debugging of the injection equipment, thereby greatly reducing the problems of overprinting failure or poor overprinting alignment.
[0065] In some embodiments, the injecting method includes doctor blade printing.
[0066] In some embodiments, reference Figure 2 A mask layer 4 with a groove is arranged on the battery cell 5, and a solvent layer 3 is coated on the inner wall of the groove. Then, when metal slurry is injected into the groove, a first scraper 1 is used and a screen 2 is used to inject the groove for the first time, and then a second scraper 6 is used to continuously inject the metal slurry for the second time, and the metal slurry is not dried between the two injections.
[0067] In some embodiments, the metal slurry is injected into the groove having the solvent layer twice in succession. After the first injection, the second injection operation is directly performed without drying to complete the operation of overprinting the metal electrode.
[0068] In some embodiments, the height of the metal electrode is 8-30 μm. Alternatively, the height of the metal electrode is 8-12 μm.
[0069] It can be understood that the amount of metal injected each time can be set according to the height of the metal electrode finally formed.
[0070] In some embodiments, reference Figure 1 , further comprising step (4): drying the injected metal slurry at a temperature of 160-180°C.
[0071] In some embodiments, reference Figure 1 , further comprising step (5): removing the mask layer.
[0072] Optionally, the process of removing the mask layer is performed in an alkaline solution with a concentration of 3-10wt%.
[0073] Furthermore, the alkaline solution is an aqueous alkaline solution, and the aqueous alkaline solution includes an aqueous sodium hydroxide solution. Using an alkaline solution to remove the mask layer can reduce corrosion of the metal electrode and the battery cell.
[0074] Optionally, the temperature for removing the mask is 40-70° C. In this way, the alkali and the mask layer can react and the mask layer can be removed to a greater extent, thereby reducing the residue.
[0075] Optionally, the time for removing the mask is 3-10 minutes. In this way, the alkali is used to react with the mask layer to remove the mask layer to a greater extent, reduce residue, and reduce damage to the battery cell.
[0076] Furthermore, the mask layer may be removed by tank cleaning or spraying.
[0077] In some embodiments, after removing the mask, the mask may be cleaned again with clean water.
[0078] The second aspect of the embodiment of the present application provides a method for preparing a solar cell. The method includes providing a substrate, the substrate being a cell sheet; and preparing a metal electrode on the cell sheet using the method described in the first aspect. In this way, a solar cell with high photoelectric efficiency can be obtained.
[0079] In some embodiments, the cell has a heterojunction solar cell, a back contact solar cell, a tunnel passivation contact solar cell, etc.
[0080] As an example, after cleaning, the N-type silicon wafer is double-sided textured, and the resulting morphology includes positive and inverted pyramids or other light-trapping geometric figures; the intrinsic layer amorphous silicon and the doped microcrystalline / amorphous silicon layer are deposited on the front and back sides in sequence, and the doped atoms are the fifth main group elements represented by phosphorus or the third main group elements represented by boron; TCO films are deposited on the front and back sides in sequence to obtain heterojunction solar cells; the method of the first aspect is used to prepare metal grid line electrode printing on the front and back sides of the heterojunction solar cells in sequence, and when printing the metal paste, after the first printing of the electrode, the cell is not turned out on the printing table, and the second printing is directly carried out to complete the overprinting; the metal paste is then dried and solidified to obtain a heterojunction solar cell.
[0081] In some embodiments, the metal in the metal paste includes silver, aluminum, copper, and silver-clad copper metal grid lines.
[0082] In a third aspect of the embodiments of the present application, a solar cell is provided, wherein the metal electrode of the solar cell is prepared by the method of the first aspect or the solar cell is prepared by the method of the second aspect. The solar cell has good photoelectric efficiency, which is because a high aspect ratio cell is prepared by the aforementioned method, which can increase the illumination area of the solar cell.
[0083] In a fourth aspect of the embodiment of the present application, a photovoltaic module may be provided, the photovoltaic module comprising a plurality of solar cells connected in series and / or in parallel; wherein at least one solar cell is the solar cell of the third aspect as described above. The plurality of solar cells in series form a cell string, and adjacent solar cells may be connected together by string welding.
[0084] Hereinafter, exemplary embodiments according to the present application will be described in more detail with reference to the accompanying drawings. It should be noted that these exemplary embodiments can be implemented in many different forms and should not be construed as being limited to the embodiments described herein.
[0085] The embodiment and the comparative example both use a 110 μm N-type silicon wafer, which is processed and textured to form a textured surface on both surfaces.
[0086] Example 1 S1: Texturing and cleaning The N-type single crystal silicon wafer is textured and cleaned to form a uniform "positive pyramid" texture surface on the two opposite surfaces of the silicon wafer, with a texture height of 5μm.
[0087] S2: Forming a first intrinsic amorphous silicon layer and a second intrinsic amorphous silicon layer A PECVD plasma deposition device is used to deposit a first intrinsic amorphous silicon layer with a thickness of 5 nm on the front side of the silicon wafer after texturing and cleaning, and a second intrinsic amorphous silicon layer with a thickness of 6 nm is deposited on the back side of the silicon wafer.
[0088] S3: Forming N-type doping layer and P-type doping layer A PECVD plasma deposition device is used to deposit an 8 nm thick phosphorus-doped amorphous silicon layer (N-type doped layer) on the surface of the first intrinsic amorphous silicon layer, and a 10 nm thick boron-doped amorphous silicon layer (P-type doped layer) is deposited on the surface of the second intrinsic amorphous silicon layer.
[0089] S4: Forming a first conductive layer and a second conductive layer A first conductive layer with a thickness of about 100 nm is deposited on the surface of the N-type amorphous silicon layer by using a PVD magnetron sputtering device, and a second conductive layer with a thickness of about 100 nm is deposited on the surface of the P-type amorphous silicon layer to obtain a battery cell.
[0090] S5: Overprinting Metal Electrodes According to the predetermined pattern, the mask layer is molded to form a groove. When the mold is opened, a MARK point can be set on the mask layer, and the size of the MARK point is 300um; a mask layer is set on the light-receiving surface of the battery cell, and a solvent is applied to form a solvent layer; metal slurry is injected into the groove twice in succession and then cured and dried at 170°C. In this process, the depth of the groove is controlled to be 25μm, and the width of the groove is 35μm in the extension direction of the battery cell. In the mask layer, 100 parts by weight of the binder (polymethacrylate) is used as the basis, the plasticizer (triethylene glycol diacetate) is 22 parts by weight, the viscosity enhancer (benzotriazole) is 10 parts by weight, the thermal inhibitor (hydroquinone) is 5 parts by weight, and the flame retardant (chlorobenzene) is 5 parts by weight; when injecting metal slurry into the groove, the first scraper is used and the screen is used to inject the groove for the first time, and then the second scraper is used continuously to inject the second injection of metal slurry, and the metal slurry is not dried during the two injection processes.
[0091] The operation of S5 is repeated, and printing is performed twice on the back side of the battery cell to obtain a metal electrode with a height of 12 μm.
[0092] S6: Remove the mask layer Use 3w% sodium hydroxide aqueous solution to soak in a tank for 5 minutes at 60°C to remove the mask, then take it out and wash it with water.
[0093] S7: Light Injection The cell obtained in S6 is subjected to light injection treatment to form a solar cell, wherein the light injection temperature is 220° C. and the time is 120 s to obtain a solar cell.
[0094] Comparative Example 1 The solar cell was prepared in the same manner as in Example 1, except that the solvent layer was not prepared.
[0095] Comparative Example 2 The solar cell was prepared in the same manner as in Example 1, except that the metal electrode was overprinted without masking, but in a conventional manner: after the metal electrode was printed for the first time, it was dried first, then printed for the second time, and then cured and light injected.
[0096] The above-mentioned embodiments and comparative examples were tested as follows, and the test results are shown in Table 1.
[0097] Photoelectric performance test: After light injection, the cell was tested using FCT650 at AM1.5, 1000W / m², and a temperature of 25°C for IV testing.
[0098] Table 1
[0099] It can be seen from Table 1 that compared with Example 1, since no solvent is applied in the groove in Example 1, adhesion occurs on the inner wall of the mask when the metal paste is injected by screen printing, and the contact between the metal paste and the TCO on the battery surface is poor, resulting in disadvantages in series resistance and filling, and reduced efficiency.
[0100] Compared with Example 1 and Comparative Example 2, in the second printing process, the alignment of Comparative Example 2 is deviated, resulting in wider gate lines in local areas. At the same time, there is no mask blocking effect, and the gate line shape is poor, resulting in a decrease in current and a decrease in filling. The wet weight of the metal paste printed in Comparative Example 2 decreases. Under the combined influence, the battery efficiency decreases.
[0101] It should be noted that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. The orientation words "inside" and "outside" refer to the inside and outside relative to the outline of each component itself. For example, if the device in the accompanying drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Therefore, the exemplary term "above..." can include both "above..." and "below..." orientations. The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used here are interpreted accordingly.
[0102] It should also be noted that the "some embodiments", "other embodiments", "embodiments", etc. mentioned in this application refer to the specific features, structures or characteristics described in conjunction with the embodiment included in at least one embodiment generally described in this application. The same expression appearing in multiple places in the specification does not necessarily refer to the same embodiment. Furthermore, when a specific feature, structure or characteristic is described in conjunction with any embodiment, it is claimed that the realization of such feature, structure or characteristic in conjunction with other embodiments also falls within the scope of this application.
[0103] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.
[0104] It should also be noted that the above are only preferred embodiments of the present application, and the patent protection scope of the present application is not limited thereto. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly used in other related technical fields, are also included in the patent protection scope of the present application.
Claims
1. A method for preparing a metal electrode, characterized in that: include: Disposing a mask layer on the substrate to form grooves of a predetermined pattern; Covering the inner wall of the groove with a solvent to form a solvent layer; The metal slurry is injected into the groove having the solvent layer to obtain a metal electrode.
2. The preparation method according to claim 1, characterized in that: The injection of the metal slurry includes: The metal slurry is injected into the groove having the solvent layer at least twice in succession.
3. The preparation method according to claim 1, characterized in that: The mask layer comprises a binder, a plasticizer, a thermal inhibitor and a flame retardant.
4. The preparation method according to claim 3, characterized in that: Also includes: Tackifiers; And / or, based on 100 parts by weight of the binder, the plasticizer is 15-25 parts by weight, the tackifier is 5-20 parts by weight, the thermal inhibitor is 2-10 parts by weight, and the flame retardant is 2-10 parts by weight.
5. The method according to claim 4, characterized in that The binder includes at least one of polymethacrylate, styrene, and maleic acid; And / or, the plasticizer includes triethylene glycol diacetate; and / or, the tackifier comprises a nitrogen-containing heterocyclic compound; And / or, the thermal inhibitor includes at least one of hydroquinone and p-methoxyphenol; And / or, the flame retardant includes an aromatic halide.
6. The method according to claim 1 or 2, characterized in that: The depth of the groove is 15-30 μm; And / or, in the extension direction of the battery cell, the width of the groove is 25-45 μm.
7. The method according to claim 1 or 2, characterized in that: The solvent includes at least one of diethylene glycol butyl ether, terpineol, methanol, ethanol, propanol, and ethylene glycol ethyl ether acetate.
8. The method according to claim 7, characterized in that The thickness of the solvent layer is 1-5 μm.
9. The method according to claim 1 or 2, characterized in that: The height of the metal electrode is 8-30 μm.
10. The method according to claim 1 or 2, characterized in that: The method further includes: removing the mask layer.
11. The method according to claim 10, characterized in that The process of removing the mask layer satisfies at least one of the following conditions: 3-10wt% alkali solution; Temperature is 40-70℃; Time: 3-10 minutes.
12. A method for preparing a solar cell, characterized in that: include: Providing a substrate, wherein the substrate is a battery cell; A metal electrode is prepared on the battery cell by using the method described in any one of claims 1 to 11.
13. A solar cell, characterized in that: The solar cell is prepared by the method according to claim 12 or the metal electrode of the solar cell is prepared by the method according to any one of claims 1 to 11.
14. A photovoltaic module, characterized in that: The photovoltaic module comprises the solar cell according to claim 13.