Back contact type battery string based on multi-coating welding strip

Abstract

The utility model relates to a back contact type battery string based on a multi-coating solder strip, which comprises at least two battery pieces arranged at intervals, the solder strip is fixedly connected between the battery pieces, and positive grid lines and negative grid lines are alternately arranged on the back surfaces of the battery pieces at equal intervals; the bottom surface of the welding strip is provided with a sectional mixed coating, the mixed coating comprises a conductive coating, an insulating coating and a black coating, the positive electrode welding strip is electrically connected with the positive electrode grid line through the conductive coating, the positive electrode welding strip is isolated from the negative electrode grid line through the insulating coating, the negative electrode welding strip is isolated from the positive electrode grid line through the insulating coating, and the black coating is arranged between the positive electrode welding strip and the negative electrode grid line. The negative electrode welding strip is electrically connected with the negative electrode grid line through the conductive coating; and the black coating covers a gap between two adjacent battery pieces. According to the utility model, the periphery of the welding strip body is coated with the coating, and the black coating is used for replacing conventional black shielding components such as black adhesive tapes, so that the overall appearance effect of the photovoltaic module can be improved, and the battery series welding process is simplified.

Description

Technical Field

[0001] This utility model relates to the field of photovoltaic cell technology, and in particular to a back-contact battery string based on multi-coated solder strips. Background Technology

[0002] Back-contact solar cells have significant advantages in the photovoltaic field due to their high conversion efficiency, low degradation, low temperature coefficient, and high bifaciality. Back-contact solar cells have both positive and negative electrodes fabricated on the back side of the cell, eliminating the obstruction of electrode grids and solder ribbons on the front. This results in aesthetically pleasing photovoltaic modules, making all-black back-contact solar modules popular in distributed generation applications.

[0003] When back-contact cells are connected in series, the solder ribbons are all located on the back of the cells, but they are still faintly visible when viewed from the gaps between the cells on the front, affecting the overall appearance of the photovoltaic module. Currently, the common method is to place black spacers within the gaps between the cells or to attach black tape to the solder ribbons. This increases the complexity of the process, creates a more complex structural layout, and can also negatively impact product reliability to some extent. Utility Model Content

[0004] The technical problem to be solved by this utility model is: in order to overcome the shortcomings of the prior art, this utility model provides a back-contact battery string based on multi-coated solder strips to simplify the manufacturing and stringing process of battery cells.

[0005] The technical solution adopted by this utility model to solve its technical problem is as follows: a back-contact battery string based on multi-coated solder strips, comprising at least two spaced battery cells, with solder strips fixed between the battery cells. Positive and negative grid lines are alternately arranged at equal intervals on the back of the battery cell body. The solder strip body is surrounded by a coating, which includes a tin alloy coating on the upper surface and both sides of the solder strip. The bottom surface of the solder strip has a segmented mixed coating, which includes a conductive coating, an insulating coating, and a black coating. The black coating is located in the middle of the solder strip, and the conductive and insulating coatings are located on both sides of the black coating, alternating between them. The solder strip is divided into a positive solder strip and a negative solder strip. The positive solder strip is electrically connected to the positive grid line through the conductive coating, and the positive solder strip is isolated from the negative grid line through the insulating coating. The negative solder strip is also isolated from the positive grid line through the insulating coating, and the negative solder strip is electrically connected to the negative grid line through the conductive coating. The black coating covers the gap between adjacent battery cells.

[0006] To improve the connection strength between the battery cell and the solder ribbon, an adhesive is provided between the battery cell and the solder ribbon to reinforce the solder ribbon, and the adhesive covers the solder ribbon.

[0007] Preferably, the solder strip body material is a copper substrate, the solder strip width is 0.5-0.8 mm, and the solder strip thickness is 0.1-0.2 mm.

[0008] Preferably, the coating thickness is 5–15 μm.

[0009] Preferably, the conductive coating is a tin alloy layer, wherein the tin alloy layer is made of tin-lead, tin-lead-bismuth, or tin-lead-silver alloy.

[0010] Preferably, the insulating coating is a mixture of one or more of acrylic resin, silicone resin, epoxy resin, and polyurethane in a certain proportion.

[0011] Preferably, the black coating is made by adding black pigment to a composite resin composed of one or more of acrylic resin, silicone resin, epoxy resin, and polyurethane.

[0012] The beneficial effects of this utility model are as follows: By covering the body of the solder ribbon with a coating, and using a black coating to replace conventional black tape and other black-covering components, this utility model can improve the overall appearance of photovoltaic modules and simplify the cell stringing process. Furthermore, the use of conductive and insulating coatings can eliminate the steps of applying insulating glue, solder paste and drying in the stringing process. The positive and negative grid lines can be made continuous, avoiding the interdigitated design and simplifying the cell and module process. Attached Figure Description

[0013] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0014] Figure 1 This is a schematic diagram of the structure of this utility model.

[0015] Figure 2 This is a schematic diagram of the structure of the battery cell described in this utility model.

[0016] Figure 3 This is a schematic diagram of the cross-section of the welding strip described in this utility model.

[0017] Figure 4 This is a schematic diagram of the longitudinal section of the welding strip described in this utility model.

[0018] Figure 5 This is a schematic diagram of the installation structure of the positive electrode welding strip described in this utility model.

[0019] Figure 6 This is a schematic diagram of the installation structure of the negative electrode welding strip described in this utility model.

[0020] In the diagram: 1. Battery cell, 2. Solder ribbon, 2-1. Positive electrode solder ribbon, 2-2. Negative electrode solder ribbon, 3. Positive electrode grid line, 4. Negative electrode grid line, 5. Tin alloy coating, 6. Conductive coating, 7. Insulating coating, 8. Black coating, 9. Glue. Detailed Implementation

[0021] The present invention will now be described in further detail with reference to the accompanying drawings. These drawings are simplified schematic diagrams, illustrating only the basic structure of the present invention, and therefore only show the components relevant to the present invention.

[0022] like Figure 1 , Figure 2 The diagram shows a back-contact battery string based on multi-coated solder strips, comprising three spaced battery cells 1, with positive grid lines 3 and negative grid lines 4 arranged alternately at equal intervals on the back of each battery cell 1; solder strips 2 are fixed between adjacent battery cells 1 by infrared welding, the solder strip 2 is made of copper substrate, the solder strip 2 is 0.60mm wide and 0.16mm thick.

[0023] The battery cell 1 and the solder ribbon 2 are spaced apart by an adhesive 9. The adhesive 9 covers the solder ribbon 2 to reinforce the solder ribbon 2, improve the connection effect between the solder ribbon 2 and the positive grid line 3 and the negative grid line 4, and prevent the solder ribbon 2 from detaching from the battery grid line when the battery string is moved in the subsequent process. The adhesive 9 can be a UV-curable or thermosetting type, acrylic resin, silicone resin, epoxy resin or amino resin system, etc.

[0024] like Figures 3-6 As shown, the solder strip 2 is perpendicular to the positive grid line 3 and the negative grid line 4. The solder strip 2 is divided into positive solder strip 2-1 and negative solder strip 2-2. A coating is wrapped around the body of the solder strip 2, and the thickness of the coating is 10μm.

[0025] The coating includes a tin alloy coating 5 on the upper surface and both sides of the solder strip 2. The bottom surface of the solder strip 2 is provided with a segmented mixed coating. The mixed coating includes a conductive coating 6, an insulating coating 7 and a black coating 8. The black coating 8 is located in the middle of the solder strip 2. The conductive coating 6 and the insulating coating 7 are located on both sides of the black coating 8 and are alternately arranged.

[0026] The conductive coating 6 of the positive electrode solder strip 2-1 corresponds to the position of the positive electrode grid line 3, and the insulating coating 7 of the positive electrode solder strip 2-1 corresponds to the position of the negative electrode grid line 4. That is, the positive electrode solder strip 2-1 and the positive electrode grid line 3 are electrically connected through the conductive coating 6, and the positive electrode solder strip 2-1 and the negative electrode grid line 4 are isolated through the insulating coating 7. The conductive coating 6 of the negative electrode solder strip 2-2 corresponds to the position of the negative electrode grid line 4, and the insulating coating 7 of the negative electrode solder strip 2-2 corresponds to the position of the positive electrode grid line 3. That is, the negative electrode solder strip 2-2 and the positive electrode grid line 3 are isolated through the insulating coating 7, and the negative electrode solder strip 2-2 and the negative electrode grid line 4 are electrically connected through the conductive coating 6. The black coating 8 covers the gap between two adjacent battery cells 1 and the edge areas at both ends of the battery cell 1.

[0027] The conductive coating 6 is a tin alloy layer, which is made of tin-lead, tin-lead-bismuth, or tin-lead-silver alloy; the insulating coating 7 is a mixture of one or more of acrylic resin, silicone resin, epoxy resin, and polyurethane in a certain proportion; the black coating 8 is a composite resin made of one or more of acrylic resin, silicone resin, epoxy resin, and polyurethane with added black pigment.

[0028] This invention simplifies the battery stringing process by covering the body of the solder strip 2 with a coating. The use of a black coating 8 to replace conventional black tape and other blackening components can improve the overall appearance of the photovoltaic module. The use of conductive coating 6 and insulating coating 7 can eliminate the steps of applying insulating glue, solder paste and drying in the stringing process. The positive grid line 3 and negative grid line 4 can be made into a continuous type to avoid the interdigitated design and simplify the battery and module process.

[0029] Based on the above-described preferred embodiments of this utility model, and through the foregoing description, those skilled in the art can make various changes and modifications without departing from the technical concept of this utility model. The technical scope of this utility model is not limited to the contents of the specification, but must be determined according to the scope of the claims.

Claims

1. A back-contact battery string based on multi-coated solder strips, comprising at least two spaced battery cells (1), wherein solder strips (2) are fixedly connected between the battery cells (1), characterized in that: The back of the battery cell (1) is alternately and evenly spaced with positive grid lines (3) and negative grid lines (4); the body of the solder strip (2) is covered with a coating, which includes a tin alloy coating (5) on the upper surface and both sides of the solder strip (2); the bottom surface of the solder strip (2) is provided with a segmented mixed coating, which includes a conductive coating (6), an insulating coating (7) and a black coating (8); the black coating (8) is located in the middle of the solder strip (2); the conductive coating (6) and the insulating coating (7) are located on both sides of the black coating (8); and the conductive coating (6) is located in the middle of the solder strip (2). The solder strips (2) are alternately arranged with the insulating coating (7); the solder strips (2) are divided into positive solder strips (2-1) and negative solder strips (2-2), wherein the positive solder strip (2-1) and the positive grid line (3) are electrically connected through the conductive coating (6), the positive solder strip (2-1) and the negative grid line (4) are isolated by the insulating coating (7), the negative solder strip (2-2) and the positive grid line (3) are isolated by the insulating coating (7), the negative solder strip (2-2) and the negative grid line (4) are electrically connected through the conductive coating (6), and the black coating (8) covers the gap between two adjacent battery cells (1).

2. The back-contact battery string based on multi-coated solder strips as described in claim 1, characterized in that: An adhesive (9) is provided between the battery cell (1) and the solder strip (2) to reinforce the solder strip (2), and the adhesive (9) covers the solder strip (2).

3. The back-contact battery string based on multi-coated solder strips as described in claim 1, characterized in that: The main body material of the welding strip (2) is copper substrate, the width of the welding strip (2) is 0.5-0.8mm, and the thickness of the welding strip (2) is 0.1-0.2mm.

4. The back-contact battery string based on multi-coated solder strips as described in claim 3, characterized in that: The coating thickness is 5–15 μm.

5. The back-contact battery string based on multi-coated solder strips as described in claim 4, characterized in that: The conductive coating (6) is a tin alloy layer, which is made of tin-lead, tin-lead-bismuth, or tin-lead-silver alloy.

6. The back-contact battery string based on multi-coated solder strips as described in claim 4, characterized in that: The insulating coating (7) is a mixture of one or more of acrylic resin, silicone resin, epoxy resin and polyurethane in a certain proportion.

7. The back-contact battery string based on multi-coated solder strips as described in claim 4, characterized in that: The black coating (8) is made by adding black pigment to a composite resin composed of one or more of acrylic resin, silicone resin, epoxy resin, and polyurethane.

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