Solar cell string and photovoltaic module

Abstract

The utility model relates to the photovoltaic field, and discloses a solar cell string and a photovoltaic module, and the solar cell string comprises a plurality of solar cells and conductive hot melt adhesive connectors. The solar cell comprises a base body, a grid line electrode and a transparent conductive film layer, the grid line electrode is located on the surface of the base body, and the transparent conductive film layer is located on the surface of the base body and at least covers part of the grid line electrode. And in two adjacent solar cells, the transparent conductive film layer on the grid line electrode on one solar cell is connected to the transparent conductive film layer on the opposite-polarity grid line electrode on the adjacent solar cell through a conductive hot melt adhesive connector. The transparent conductive film layers are connected with the grid line electrodes and collect and export carriers, and the transparent conductive layers of two adjacent solar cells are connected in series through the conductive hot melt adhesive connector, so that thermal stress and defects caused by welding to the cells are avoided, the risk probability of the solar cells and the packaging loss of the cells are reduced, and the reliability of the solar cells is improved. The reliability of the solar cell is improved, and the reliability of the photovoltaic module is further improved.

Description

Technical Field

[0001] The present application relates to the photovoltaic field, and in particular to a solar cell string and a photovoltaic module. Background Art

[0002] The cell string in the photovoltaic module is formed by multiple solar cells connected in series. The surface of the solar cell is distributed with grid electrodes, which include fine grids and main grids. The fine grids are used to export carriers, and the main grids are used to collect carriers. For two adjacent solar cells, the main grid on the front of one solar cell and the main grid on the back of another solar cell are connected in series through welding ribbons. When the welding ribbon is welded to the grid wire, there are thermal stresses and defects in the contact interface between the welding ribbon and the grid wire, which increases the cell packaging loss (Cell To Module, CTM), affects the reliability of the cell string, and thus buries hidden dangers for the reliability of photovoltaic modules.

[0003] Therefore, how to solve the above technical problems should be the focus of technical personnel in this field. Utility Model Content

[0004] The purpose of the present application is to provide a solar cell string and a photovoltaic module to reduce the packaging loss of solar cells and improve the reliability of the photovoltaic module.

[0005] In order to solve the above technical problems, the present application provides a solar cell string, comprising a plurality of solar cell sheets and a conductive hot melt adhesive connector;

[0006] The solar cell comprises a substrate, a grid electrode and a transparent conductive film layer, wherein the grid electrode is located on the surface of the substrate, and the transparent conductive film layer is located on the surface of the substrate and at least covers a portion of the grid electrode;

[0007] Among two adjacent solar cells, the transparent conductive film layer on the grid electrode on one solar cell is connected to the transparent conductive film layer on the grid electrode of the opposite polarity on the adjacent solar cell through the conductive hot melt adhesive.

[0008] As an implementation method, the grid line electrodes include positive grid lines and negative grid lines, and all of the grid line electrodes are located on the back side of the solar cell.

[0009] As an implementation method, the grid line electrode includes a positive grid line and a negative grid line, and the positive grid line and the negative grid line are respectively located on the front side and the back side of the solar cell.

[0010] As an implementation method, the transparent conductive film layer covers the entire surface of the substrate.

[0011] As an implementation method, the transparent conductive film layer only covers all the gate line electrodes.

[0012] As an implementation method, a plurality of gate line electrodes of the same polarity are connected together, and the transparent conductive film layer only covers the connection points of the gate line electrodes.

[0013] As an implementable embodiment, the conductive hot melt adhesive connector is connected to the side surface of the transparent conductive film layer.

[0014] As an implementable embodiment, the conductive hot melt adhesive connector is located on a surface of the transparent conductive film layer away from the substrate, and is connected to the transparent conductive film layer.

[0015] As an implementation method, the transparent conductive film layer includes an ITO film layer and / or a TCO film layer.

[0016] The present application also provides a photovoltaic assembly, which includes any one of the solar cell strings described above.

[0017] A solar cell string provided in the present application comprises a plurality of solar cell sheets and a conductive hot melt adhesive connector; the solar cell sheets comprise a substrate, a grid electrode and a transparent conductive film layer, the grid electrode being located on the surface of the substrate, and the transparent conductive film layer being located on the surface of the substrate and covering at least a portion of the grid electrode; of two adjacent solar cell sheets, the transparent conductive film layer on the grid electrode on one solar cell sheet is connected to the transparent conductive film layer on the opposite grid electrode on the adjacent solar cell sheet through the conductive hot melt adhesive connector.

[0018] It can be seen that in the battery string of the present application, the solar cell includes a substrate, a grid electrode and a transparent conductive film layer, the transparent conductive film layer is connected to the grid electrode, and the transparent conductive film layer collects and conducts the carriers on the grid electrode. Two adjacent solar cells are connected in series by a conductive hot melt adhesive connector, which melts during lamination to form an effective connection with the transparent conductive film layer, avoiding the use of welding ribbons for welding, thereby avoiding the thermal stress and defects caused by welding to the solar cell, reducing the probability of risks of solar cells and cell packaging losses, improving the reliability of solar cells, and thus improving the reliability of photovoltaic modules.

[0019] In addition, the present application also provides a photovoltaic module having the above advantages. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the embodiments of the present application or the technical solutions of the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0021] Figure 1 A schematic diagram of a partial structure of a solar cell string provided in an embodiment of the present application;

[0022] Figures 2 to 4 Schematic diagram of different distribution forms of the transparent conductive film layer on the substrate provided in the embodiments of the present application;

[0023] Figures 5 and 6 Schematic diagram of different connection positions of the conductive hot melt adhesive connector and the transparent conductive film layer provided in the embodiment of the present application;

[0024] Figures 7 and 8 A schematic diagram of different gate electrode configurations on a cell provided in an embodiment of the present application;

[0025] In the figure, 1. solar cell, 2. grid line electrode, 3. transparent conductive film layer, 4. conductive hot melt adhesive connector. DETAILED DESCRIPTION

[0026] In order to enable those skilled in the art to better understand the present application, the present application is further described in detail below in conjunction with the accompanying drawings and specific implementation methods. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without making creative work are within the scope of protection of the present application.

[0027] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0028] As described in the background technology section, in the related technology, the solar cells in the cell string are connected in series through welding ribbons. During the welding process, thermal stress and defects exist at the contact interface between the welding ribbons and the grid lines, which increases the packaging loss of the cell pieces and affects the reliability of the cell string, thereby posing a hidden danger to the reliability of photovoltaic modules.

[0029] In view of this, the present application provides a solar cell string, please refer to Figure 1, comprising a plurality of solar cells 1 and a conductive hot melt adhesive connector 4;

[0030] The solar cell 1 comprises a substrate, a gate electrode 2 and a transparent conductive film layer 3, wherein the gate electrode 2 is located on the surface of the substrate, and the transparent conductive film layer 3 is located on the surface of the substrate and at least covers a portion of the gate electrode 2;

[0031] Among two adjacent solar cells 1, the transparent conductive film layer 3 on the grid electrode 2 on one solar cell 1 is connected to the transparent conductive film layer 3 on the opposite grid electrode 2 on the adjacent solar cell 1 through the conductive hot melt adhesive connector 4.

[0032] The number of solar cells 1 is set as required and is not limited in this embodiment.

[0033] The substrate in the solar cell 1 may be a silicon substrate.

[0034] The gate line electrode 2 is a thin gate line for conducting carriers. The manufacturing method of the gate line electrode 2 includes but is not limited to an electroplating process or a screen printing process.

[0035] It should be pointed out that in this embodiment, the position of the gate electrode 2 on the solar cell 1 is not limited.

[0036] As an implementation method, the grid line electrode 2 includes a positive grid line and a negative grid line, and the grid line electrodes 2 are all located on the back of the solar cell 1. That is, the solar cell 1 is a back contact cell. At this time, the transparent conductive film layer 3 on the positive grid line on one solar cell 1 is connected to the transparent conductive film layer 3 on the negative grid line of the adjacent solar cell 1 through a conductive hot melt adhesive connector 4.

[0037] As another possible implementation, the grid line electrode 2 includes a positive grid line and a negative grid line, and the positive grid line and the negative grid line are respectively located on the front and back of the solar cell 1. The front of the solar cell 1 is entirely positive grid lines or negative grid lines, and correspondingly, the back is entirely negative grid lines or positive grid lines. At this time, the transparent conductive film layer 3 on the front of a solar cell 1 is connected to the transparent conductive film layer 3 on the back of an adjacent solar cell 1 through a conductive hot melt adhesive connector 4.

[0038] The transparent conductive film layer 3 on the front side of the substrate and the transparent conductive film layer 3 on the back side of the substrate may be the same or different, both of which are within the protection scope of the present application.

[0039] The front side is the surface that receives incident sunlight.

[0040] It should be noted that the type of solar cell 1 is not limited in this embodiment and depends on the situation. When the type of solar cell 1 is a PERC (Passivated Emitter and Rear Cell) cell or a HJT (Heterojunction Technology) cell, the corrosion resistance of the photovoltaic module can be improved because the transparent conductive film layer 3 covers the surface of the substrate.

[0041] The function of the transparent conductive film layer 3 is to collect and conduct the carriers on the gate electrode 2. The transparent conductive film layer 3 is set to be transparent in order to ensure that the light is irradiated onto the substrate.

[0042] In this embodiment, the transparent conductive film layer 3 is not limited as long as it has the functions of transparency and conductivity. The transparent conductive film layer 3 includes but is not limited to any one or any combination of an ITO (Indium tin oxide) film layer, a TCO (transparent conductive oxide) film layer, an AZO (aluminum-doped zinc oxide) film layer, and an FTO (Fluorine-doped Tin Oxide) film layer.

[0043] It should be pointed out that in this embodiment, there is no limitation on the location of the transparent conductive film layer 3 on the surface of the substrate, and the transparent conductive film layer 3 can be located at its own discretion.

[0044] The conductive hot melt adhesive connector 4 has a certain viscosity at room temperature and can be bonded to the transparent conductive film layer 3; it melts at the lamination temperature of the photovoltaic module to form a stable and effective connection with the transparent conductive film layer 3. The conductive hot melt adhesive connector 4 is made of conductive hot melt adhesive, which can be purchased directly.

[0045] It should be noted that, in this embodiment, there is no limitation on the connection position between the conductive hot melt adhesive connector 4 and the transparent conductive film layer 3 , as long as electrical connection can be achieved.

[0046] In the battery string of this embodiment, the solar cell 1 includes a substrate, a grid electrode 2 and a transparent conductive film layer 3, the transparent conductive film layer 3 is connected to the grid electrode 2, and the transparent conductive film layer 3 collects and conducts the carriers on the grid electrode 2. Two adjacent solar cells 1 are connected in series by a conductive hot melt adhesive connector 4, and the conductive hot melt adhesive connector 4 melts during lamination to form an effective connection with the transparent conductive film layer 3, avoiding the use of welding ribbons for welding, thereby avoiding the thermal stress and defects caused by welding to the solar cell 1, reducing the probability of risks of the solar cell 1 and the loss of the cell packaging, improving the reliability of the solar cell 1, and then improving the reliability of the photovoltaic module.

[0047] Based on the above embodiments, in one embodiment of the present application, when the positive pole grid lines and the negative pole grid lines are located on the front and back of the solar cell respectively, the transparent conductive film layer 3 can be located in various positions. The following describes the optional methods provided in the present application.

[0048] As an implementation method, Figure 2 As shown, the transparent conductive film layer 3 covers the entire surface of the substrate. That is, the transparent conductive film layer 3 covers the entire front side and the entire back side of the substrate, and the gate electrode 2 is covered in the transparent conductive film layer 3 .

[0049] As another possible implementation, Figure 3 As shown, the transparent conductive film layer 3 only covers all the gate line electrodes 2 .

[0050] As another possible implementation, Figure 4 As shown, multiple gate line electrodes 2 of the same polarity are connected together, and the transparent conductive film layer 3 only covers the connection points of the gate line electrodes 2. That is, the area covered by the transparent conductive film layer 3 is smaller than the area where the gate line electrodes 2 are located, and only covers the area where the gate line electrodes 2 converge, so as to collect the carriers on the gate line electrodes 2.

[0051] Based on the above embodiments, in one embodiment of the present application, when the gate line electrodes 2 are all located on the back side of the solar cell 1, the transparent conductive film layer 3 can be located in various positions. The following describes the optional methods provided in the present application.

[0052] As an implementation method, the transparent conductive film layer only covers all the gate line electrodes. Figure 3 shown.

[0053] As another possible implementation method, a plurality of gate line electrodes of the same polarity are connected together, and the transparent conductive film layer only covers the connection part of the gate line electrodes. Figure 4 shown.

[0054] The connection position between the conductive hot melt adhesive connector 4 and the transparent conductive film layer 3 is not limited in the present application, and the optional method provided in the present application is described below.

[0055] On the basis of any of the above embodiments, as an implementable embodiment, the conductive hot melt adhesive connector 4 is located on the surface of the transparent conductive film layer 3 away from the substrate, and is connected to the transparent conductive film layer 3 .

[0056] The conductive hot melt adhesive connector 4 may be located only at the end region of the surface of the transparent conductive film layer 3 facing away from the substrate, such as Figure 1Alternatively, the conductive hot melt adhesive connector 4 is located on the entire surface of the transparent conductive film layer 3 facing away from the substrate.

[0057] The conductive hot melt adhesive connector 4 is located on the entire surface of the transparent conductive film layer 3 away from the substrate. When the transparent conductive film layer 3 covers the entire surface of the substrate, the conductive hot melt adhesive connector 4 can extend from one end of the transparent conductive film layer 3 to the other end. Figure 5 When the transparent conductive film layer 3 only covers all the grid line electrodes 2, the conductive hot melt adhesive connector 4 is connected to all the surfaces of the transparent conductive film layers 3 that are away from the substrate, extending from the transparent conductive film layer 3 at one end of the solar cell 2 to the transparent conductive film layer 3 at the other end, as shown in FIG. Figure 6 shown.

[0058] On the basis of any of the above embodiments, as a feasible implementation method, the conductive hot melt adhesive connector 4 is connected to the side surface of the transparent conductive film layer 3 .

[0059] Based on any of the above embodiments, in one embodiment of the present application, the pattern of the gate line electrode 2 on the solar cell 1 is a target preset pattern, or the pattern of the gate line electrode 2 on the solar cell 1 is a local area of ​​the target preset pattern.

[0060] The target preset pattern can be set as needed, and is not limited in this embodiment. For example, the target preset pattern can be flowers, animals, landscape paintings, irregular shaped patterns, etc.

[0061] The pattern of the grid electrode 2 on a solar cell 1 can be a complete target preset pattern. For example, when the target preset pattern is an irregular shaped pattern, the grid electrode 2 on a solar cell 1 can be a complete target preset pattern. Figure 7 shown.

[0062] The pattern of the gate electrode 2 on a solar cell 1 may be a part of the target preset pattern, and the patterns of the gate electrode 2 on multiple solar cells 1 may be combined to form a complete target preset pattern, such as Figure 8 shown.

[0063] In this embodiment, by setting the pattern of the grid electrode 2 on a solar cell 1 to a target preset pattern or a part of the target preset pattern, the aesthetics of the solar cell 1 can be improved and the requirements for use on the building surface can be met.

[0064] The present application also provides a photovoltaic assembly, which includes the solar cell string described in any one of the above embodiments.

[0065] The specific structure of the photovoltaic module can be referred to in the relevant technology and will not be described in detail in this application.

[0066] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0067] The solar cell strings and photovoltaic modules provided by the present application are introduced in detail above. Specific examples are used herein to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the scheme and core ideas of the present application. It should be pointed out that for ordinary technicians in this technical field, without departing from the principles of the present application, several improvements and modifications can be made to the present application, and these improvements and modifications also fall within the scope of protection of the present application.

Claims

1. A solar cell string, characterized in that: It includes a plurality of solar cells and a conductive hot melt adhesive connector; The solar cell comprises a substrate, a grid electrode and a transparent conductive film layer, wherein the grid electrode is located on the surface of the substrate, and the transparent conductive film layer is located on the surface of the substrate and at least covers a portion of the grid electrode; Among two adjacent solar cells, the transparent conductive film layer on the grid electrode on one solar cell is connected to the transparent conductive film layer on the grid electrode of the opposite sex on the adjacent solar cell through the conductive hot melt adhesive connector.

2. The solar cell string according to claim 1, characterized in that: The grid line electrodes include positive grid lines and negative grid lines, and all of the grid line electrodes are located on the back side of the solar cell sheet.

3. The solar cell string according to claim 1, characterized in that: The grid line electrodes include positive grid lines and negative grid lines, and the positive grid lines and the negative grid lines are respectively located on the front side and the back side of the solar cell.

4. The solar cell string according to claim 3, characterized in that: The transparent conductive film layer covers the entire surface of the substrate.

5. The solar cell string according to claim 1, characterized in that: The transparent conductive film layer only covers all the gate line electrodes.

6. The solar cell string according to claim 1, characterized in that: A plurality of gate line electrodes of the same polarity are connected together, and the transparent conductive film layer only covers the connection points of the gate line electrodes.

7. The solar cell string according to claim 1, characterized in that: The conductive hot melt adhesive connector is connected to the side surface of the transparent conductive film layer.

8. The solar cell string according to claim 1, characterized in that: The conductive hot melt adhesive connector is located on the surface of the transparent conductive film layer away from the substrate and is connected to the transparent conductive film layer.

9. The solar cell string according to claim 1, characterized in that: The transparent conductive film layer includes an ITO film layer and / or a TCO film layer.

10. A photovoltaic module, characterized in that: The photovoltaic module comprises the solar cell string according to any one of claims 1 to 9.

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