Electric connector and battery string

Abstract

The utility model provides an electric connecting piece and a battery string, relates to the field of photovoltaic technology, and aims to solve the technical problem that a photovoltaic battery piece is easy to crack and fragment during preparation. The electrical connector is used for electrical connection of photovoltaic cells and comprises a solder strip and an insulating tape, the insulating tape is provided with a first surface and a second surface which are opposite to each other, and the first surface and the second surface are both provided with a photocuring layer; the solder strip is fixed on the first surface through the corresponding photocuring layer, and the orthographic projection of the solder strip on the first surface is located in the first surface; the photocuring layer on the second surface is used for fixing the insulating tape on a battery piece; the insulating tape is further provided with at least one through hole, the through hole penetrates through the first surface and the second surface and is opposite to the welding strip, and the through hole is used for forming a channel for electrical connection between the welding strip and the battery piece. When the electric connecting piece is used for electric connection of photovoltaic cells, risks of subfissure, fragments, pseudo soldering and the like are reduced in the preparation process of the photovoltaic cell assembly, the reliability is high, and the manufacturing process is simplified.

Description

Technical Field

[0001] The utility model relates to the technical field of photovoltaic, in particular to an electrical connector and a battery string. Background Technique

[0002] The statements in this part only provide the background technology related to the utility model, and do not necessarily constitute the prior art.

[0003] In the photovoltaic field, the positive and negative grid lines of the back-contact photovoltaic cell are both concentrated on the back, and the grid lines of different polarities are alternately arranged in sequence. In order to realize the electrical connection between the grid lines of the same polarity on two cell pieces, it is necessary to use a welding tape to connect the grid lines of the same polarity in series by welding. Therefore, it is necessary to electrically isolate the welding tape from the grid lines of the opposite polarity.

[0004] In the related technology, in order to realize the electrical isolation between the welding tape and the grid lines of the opposite polarity, an insulating glue is used to isolate the two by high-temperature curing. During the high-temperature curing process, it is easy to cause stress concentration on the side of the photovoltaic cell, and the cell is bent, which is very likely to cause hidden cracks and fragments in the subsequent processes. Summary of the Utility Model

[0005] The purpose of the utility model is to provide an electrical connector and a battery string to solve the technical problem of easy occurrence of hidden cracks and fragments during the preparation of photovoltaic cells.

[0006] In order to achieve the above purpose, the utility model provides the following technical solutions:

[0007] In the first aspect, the utility model provides an electrical connector for the electrical connection of photovoltaic cells. The electrical connector includes a welding tape and an insulating tape. The insulating tape has opposite first and second surfaces, and both the first surface and the second surface are provided with a light-curing layer;

[0008] The welding tape is fixed on the first surface through the corresponding light-curing layer, and the orthographic projection of the welding tape on the first surface is located within the first surface; the light-curing layer on the second surface is used to fix the insulating tape on the cell;

[0009] The insulating tape further has at least one through hole, which penetrates the first surface and the second surface and is opposite to the welding tape. The through hole is used to form a channel for the electrical connection between the welding tape and the cell.

[0010] According to at least one embodiment of the utility model, the light-curing layer is an ultraviolet light-curing glue layer.

[0011] According to at least one embodiment of the utility model, at least one first groove is formed on the first surface of the insulating tape, and the first groove extends along the length direction of the insulating tape;

[0012] At least a part of the opening of the first groove faces the solder strip; or,

[0013] The opening of the first groove is located on the periphery of the corresponding side surface of the solder strip.

[0014] According to at least one embodiment of the present invention, the number of the first grooves is two, and the two first grooves are respectively arranged on both sides of the through hole.

[0015] According to at least one embodiment of the present invention, at least one second groove is formed on the second surface of the insulating tape, and the second groove extends along the length direction of the insulating tape.

[0016] According to at least one embodiment of the present invention, the number of the second grooves is two, and the two second grooves are respectively arranged on both sides of the through hole.

[0017] According to at least one embodiment of the present invention, the electrical connector further includes at least one positioning strip, the positioning strip is fixedly arranged on the first surface and is located outside the corresponding side surface of the solder strip, and the positioning strip extends along the length direction of the insulating tape.

[0018] According to at least one embodiment of the present invention, the number of the positioning strips is two, and the two positioning strips are respectively located outside the two side surfaces of the solder strip.

[0019] According to at least one embodiment of the present invention, the positioning strip is an electrically insulating strip.

[0020] In a second aspect, the present invention provides a battery string, including an electrical connector and at least one photovoltaic cell, and the electrical connector is the electrical connector described in the first aspect;

[0021] The photovoltaic cell includes a plurality of grid lines of the same polarity, and each of the grid lines of the same polarity includes a pad provided with low-temperature solder paste, and each low-temperature solder paste passes through the corresponding through hole and is electrically connected to the solder strip.

[0022] According to at least one embodiment of the present invention, the melting point of the low-temperature solder paste is less than or equal to 200 °C

[0023] Among one or more technical solutions provided in the exemplary embodiments of the present invention, at least one of the following beneficial effects can be achieved.

[0024] The electrical connector of the exemplary embodiment of the present utility model is used for the electrical connection between the same-polarity grid lines on the photovoltaic cell and between the photovoltaic cells. The electrical connector includes a solder strip and an insulating strip. The second surface of the insulating strip is pasted on the cell through a photocuring layer, the solder strip is pasted on the insulating strip through a corresponding photocuring layer, and through holes are also provided on the insulating strip to form an electrical connection channel between the solder strip and the grid lines of the cell. Since the solder strip is electrically isolated from the corresponding grid lines of the cell through the insulating strip, and the connections between the solder strip and the insulating strip, and between the insulating strip and the cell are all formed by photocuring, the problem of stress concentration in the cell, resulting in hidden cracks and fragmentation, caused by the high temperature during the high-temperature curing of the insulating glue in the prior art is prevented. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The drawings illustrate exemplary embodiments of the present utility model and, together with the description thereof, are used to explain the principles of the present utility model. The drawings are included to provide a further understanding of the present utility model, and the drawings are included in this specification and form a part of this specification;

[0026] Figure 1 is a top view structural schematic diagram of a battery string according to an embodiment of the present utility model;

[0027] Figure 2 is a side view structural schematic diagram of a battery string according to an embodiment of the present utility model;

[0028] Figure 3 is Figure 2 an enlarged view of part A of

[0029] Figure 4 is a cross-sectional structural schematic diagram of an electrical connector according to an embodiment of the present utility model.

[0030] Reference numerals: 10, insulating strip; 20, solder strip; 30, positioning strip; 40, low-temperature solder paste; 11, first groove; 12, second groove; 13, through hole; 100, electrical connector; 200, cell. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0031] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present utility model clearer, the present utility model will be further described in detail below with reference to the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present utility model and are not used to limit the present utility model.

[0032] In the related art, the positive and negative grid lines of the back-contact photovoltaic cell are alternately concentrated on the back in sequence. By setting insulating glue, the isolation of grid lines with opposite polarities is achieved, and then the electrical connection of grid lines with the same polarity is realized by using a welding tape for welding, or the series electrical connection between adjacent cells forms a cell string; then, after laminating the back plate, the glue film, the cell string, another glue film, and the front plate in sequence, a photovoltaic cell laminate is formed. Since the curing of the insulating glue on the cell requires a high-temperature environment, and the high temperature will cause stress concentration on the cell side, the cell will bend, and due to the action of pressure during the lamination process, the cell is prone to hidden cracks and fragmentation.

[0033] In view of the above problems, the electrical connector provided by the exemplary embodiment of the present invention uses an insulating tape with a photocurable layer on both sides to fix the welding tape on the cell in the form of photocuring, which not only realizes the electrical isolation between grid lines with opposite polarities of the cell, but also avoids the curing connection of insulating glue using high temperature, thereby reducing the risk of hidden cracks and fragmentation of the cell in subsequent processes.

[0034] Figure 1 is a top view structural schematic diagram of a cell string according to an embodiment of the present invention; Figure 2 is a side view structural schematic diagram of a cell string according to an embodiment of the present invention. As Figure 1 and Figure 2 shown, the cell string of the exemplary embodiment of the present invention includes two photovoltaic cells 200. Each cell 200 is alternately arranged with positive-polarity grid lines and negative-polarity grid lines in sequence along a first direction, that is, the distribution direction from one cell 200 to another cell 200. Among them, in the same electrical connector 100, a part is electrically connected to one cell 200, and another part is electrically connected to another cell 200, so that the two cells 200 form a series electrical connection, that is, the electrical connector 100 is respectively connected to the grid lines with the same polarity of the two cells 200, and is electrically isolated from the grid lines with opposite polarities.

[0035] It can be understood that only two cells 200 are shown in the above cell string. In actual application, along a second direction (perpendicular to the first direction), a plurality of cells 200 are also serially connected through corresponding electrical connectors 100 in sequence.

[0036] Figure 4 is a cross-sectional structural schematic diagram of an electrical connector according to an embodiment of the present invention. As Figure 4As shown, the electrical connector 100 of the exemplary embodiment of the present utility model includes a solder tape 20 and an insulating tape 10. The insulating tape 10 has opposite first and second surfaces, and both the first surface and the second surface have a photocurable layer (not shown in the figure); the solder tape 20 is fixed on the first surface through the corresponding photocurable layer, and the orthographic projection of the solder tape 20 on the first surface is located within the first surface; the photocurable layer on the second surface is used to fix the insulating tape 10 on the battery cell 200; the insulating tape 10 further has at least one through hole 13, and the through hole 13 penetrates through the first surface and the second surface and is opposite to the solder tape 20, and the through hole 13 is used to form a channel for electrical connection between the solder tape 20 and the grid line of the battery cell 200.

[0037] In practical applications, the photocurable layer is an ultraviolet photocurable adhesive layer, and the photocurable layer is excited by ultraviolet light irradiation, so that a layer with adhesive force can be formed. After curing, the solder tape 20 can be fixed on the insulating tape 10, and the insulating tape 10 is fixed on the battery cell 200. The through hole 13 of the insulating tape 10 corresponds to the pad on the grid line of the same polarity on the battery cell 200. The part of the solder tape 20 corresponding to the through hole 13 is welded to the pad on the grid line in the subsequent lamination process. Since the orthographic projection of the solder tape 20 on the first surface is located within the first surface, other parts of the solder tape 20 are electrically isolated from each grid line on the battery cell 200 through the insulating tape 10.

[0038] Since the initial connection between the solder tape 20 and the insulating tape 10, and between the insulating tape 10 and the battery cell 200 is formed by ultraviolet light excitation curing, there is no need to use the method of high-temperature heating to cure the insulating glue on the battery cell 200 as in the prior art. Therefore, the problem of bending of the battery cell 200 caused by side stress concentration of the battery cell 200, and further the problem of hidden cracks and fragmentation of the battery cell 200 can be avoided.

[0039] Figure 3 is Figure 2 An enlarged view of part A. As Figure 3 and Figure 4 shown, pads are provided at the positions on the grid lines of the battery cell 200 to be connected to the solder tape 20, and low-temperature solder paste 40 is formed on the pads.

[0040] In practical applications, the low-temperature solder paste 40 on each gate line passes through the corresponding through-hole 13 of the electrical connector 100 and is fusion-welded during the lamination process, so that the gate line of the battery cell 200 and the solder strip 20 of the electrical connector 100 are electrically connected through the low-temperature solder paste 40. Exemplarily, the melting point of the above-mentioned low-temperature solder paste 40 is below 200 °C, such as 130 °C, 150 °C or 170 °C, etc. Due to the relatively low melting point of the low-temperature solder paste 40 compared with the solder paste in the prior art, during the lamination process of the battery cell (higher than the melting point temperature of the low-temperature solder paste), the welding connection between the solder strip 20 and the gate line of the battery cell 200 can be realized, avoiding the deformation problem caused by the high-temperature stress concentration of the battery cell 200 caused by high-temperature welding (200 °C - 300 °C).

[0041] Considering that the photocurable layer on the first surface of the insulating tape 10 can be in a liquid or semi-solid state after being excited by ultraviolet light, when the solder strip 20 is placed on this first surface, it may flow and then accumulate in some areas between the solder strip 20 and the insulating tape 10, resulting in uneven interface height and uneven bonding force. Therefore, it is necessary to provide a groove on the insulating tape 10.

[0042] For example, as Figure 3 and Figure 4 shown, at least one first groove 11 is formed on the first surface of the insulating tape 10, and the first groove 11 extends along the length direction of the insulating tape 10; at least part of the opening of the first groove 11 faces the solder strip 20.

[0043] For example, a first groove 11 is provided along the length direction on the first surface of the insulating tape 10. The opening of the first groove 11 can be completely opposite to the solder strip 20, that is, the first groove 11 is provided at a position opposite to the bottom of the solder strip 20; part of the opening of the first groove 11 can also be opposite to the bottom of the solder strip 20, and the other part is outside the solder strip 20, as Figure 3 and Figure 4 shown in the relative position state of the first groove 11. Optionally, the opening of the first groove 11 is located outside the corresponding side surface of the solder strip 20, that is, the opening of the first groove 11 is not completely opposite to the bottom of the solder strip 20, but close to the side surface of the solder strip 20. The first groove 11 in the above three positional relationships can receive the glue extruded at the interface between the solder strip 20 and the insulating tape 10, so that the interface between the solder strip 20 and the insulating tape 10 can be kept flat, the bonding force is uniform, and the connection stability between the two is high.

[0044] Exemplarily, two first grooves 11 are formed on the first surface of the insulating tape 10, respectively located on both sides of the through hole 13, and the two first grooves 11 may be symmetrically or asymmetrically arranged relative to the through hole 13. It can be understood that the above-mentioned first grooves 11 are arranged along the entire length of the insulating tape 10 and do not intersect with the through hole 13, so as to prevent the extruded adhesive from flowing into the through hole 13 and hindering the electrical connection between the welding tape 20 and the battery cell 200. It should be noted that the relative positions of both sides of the through hole 13 and both sides of the welding tape 20 are the same, both referring to the left and right sides as shown in Figure 4 shown.

[0045] Considering that the second surface of the insulating tape 10 also has a photocuring layer to form a fixed connection with the battery cell 200 through this photocuring layer, after being excited by ultraviolet light, on the interface between the insulating tape 10 and the battery cell 200, there will also be a problem of partial accumulation and uneven interface height between the insulating tape 10 and the battery cell 200. In order to ensure the flatness and connection stability between the two, grooves are also provided on the second surface of the insulating tape 10 to receive the extruded adhesive. It should be noted that the first surface of the insulating tape 10 refers to the surface facing the welding tape 20, and the second surface refers to the surface facing the battery cell 200.

[0046] For example, one or more second grooves 12 are formed on the second surface of the insulating tape 10, and the second grooves 12 also extend along the length direction of the insulating tape 10, are arranged along the entire length and do not intersect with the through hole 13. As shown in Figure 3 and Figure 4 shown, when two second grooves 12 are formed on the second surface of the insulating tape 10, the two second grooves 12 are also respectively arranged on both sides of the through hole 13, and the two second grooves 12 are symmetrically or asymmetrically arranged relative to the through hole 13. The opening of the second groove 12 can be formed on the second surface of the insulating tape 10, or a part of the opening can be formed on the second surface of the insulating tape 10 and another part can be formed on the side surface of the insulating tape 10.

[0047] Continuing as shown in Figure 3 shown, in order to ensure the accuracy and stability of the relative position of the welding tape 20 on the insulating tape 10, the electrical connector 100 provided by the exemplary embodiment of the present invention further includes at least one positioning tape 30, the positioning tape 30 is fixedly arranged on the first surface and is located outside the corresponding side surface of the welding tape 20, and the positioning tape 30 extends along the length direction of the insulating tape 10.

[0048] Exemplarily, the positioning strip 30 is disposed along the entire length direction of the insulating strip 10. When the electrical connector 100 includes one positioning strip 30, the positioning strip 30 can be fixed on the first surface in the form of ultraviolet light excitation and is adjacent to one side of the welding strip 20. This implementation can provide a positioning reference for the welding strip 20 when it is fixedly connected to the insulating strip 10. At the same time, during the subsequent lamination process, the positioning strip 30 can also abut against one side of the welding strip 20 to prevent it from shifting and misaligning easily.

[0049] Exemplarily, the surface of the positioning strip 30 facing the insulating strip 10 also has a photocuring layer, making the connection between the positioning strip 30 and the insulating strip 10 more stable and reliable.

[0050] In some embodiments, such as Figure 3 and Figure 4 As shown, positioning strips 30 are disposed on both sides of the welding strip 20, that is, the welding strip 20 is disposed between two positioning strips 30, thereby making the positioning of the welding strip 20 more accurate. During the subsequent lamination process, the two positioning strips 30 can prevent the welding strip 20 from shifting to the left and right sides on both sides, maintaining the stability of the welding strip 20 on the insulating strip 10.

[0051] Exemplarily, the positioning strip 30 is an electrically insulating strip to prevent leakage when the positioning strip 30 abuts against the side of the welding strip 20 and the two conduct electricity.

[0052] In some embodiments, the height of the positioning strip 30 can be higher than the height of the corresponding welding strip 20, or lower than or equal to the height of the corresponding welding strip 20.

[0053] An exemplary embodiment of the present invention further provides a battery string, including an electrical connector 100 and at least one photovoltaic cell 200. The electrical connector 100 is the electrical connector 100 in the above embodiments; the photovoltaic cell 200 includes a plurality of grid lines of the same polarity, and each of the grid lines of the same polarity includes a pad provided with low-temperature solder paste 40, and each low-temperature solder paste 40 passes through the corresponding through hole 13 and is electrically connected to the welding strip 20.

[0054] As Figure 1 shown, taking the battery string including two battery cells 200 as an example for introduction, the battery cells 200 are alternately provided with grid lines of opposite polarities along the first direction, that is, the grid lines extend along the second direction of the battery cell 200. The welding strip 20 of the same electrical connector 100 on the same battery cell 200 forms an electrical connection with a plurality of grid lines of the same polarity on the battery cell 200 through the low-temperature solder paste 40 in the through hole 13; the welding strips 20 of the same electrical connector 100 on different battery cells 200 form a series electrical connection of the grid lines of the same polarity on different battery cells 200, thereby forming a battery string. It should be noted that the welding strip 20 in the above electrical connector 100 can also be referred to as an interconnecting strip in a photovoltaic cell.

[0055] The technical advantages of the above battery string compared with the prior art are consistent with those of the electrical connectors in the above embodiments, and will not be elaborated here.

[0056] Those skilled in the art should understand that the above embodiments are merely for clearly illustrating the present invention, rather than limiting the scope of the present invention. For those skilled in the art, other changes or modifications can be made based on the above disclosure, and these changes or modifications are still within the scope of the present invention.

Claims

1. An electrical connector, characterized in that, For the electrical connection of a photovoltaic cell, the electrical connector includes a solder strip and an insulating strip. The insulating strip has opposite first and second surfaces, and both the first surface and the second surface are provided with a photocurable layer; The solder strip is fixed on the first surface through the corresponding photocurable layer, and the orthographic projection of the solder strip on the first surface is located within the first surface; the photocurable layer on the second surface is used to fix the insulating strip on the cell; The insulating strip further has at least one through hole, which penetrates the first surface and the second surface and is opposite to the solder strip. The through hole is used to form a channel for electrical connection between the solder strip and the cell.

2. The electrical connector according to claim 1, wherein The photocurable layer is an ultraviolet curable adhesive layer.

3. The electrical connector according to claim 1, characterized in that, At least one first groove is formed on the first surface of the insulating strip, and the first groove extends along the length direction of the insulating strip; At least part of the opening of the first groove is opposite to the solder strip; or, The opening of the first groove is located outside the corresponding side surface of the solder strip.

4. The electrical connector according to claim 3, characterized in that, The number of the first grooves is two, and the two first grooves are respectively arranged on both sides of the through hole.

5. The electrical connector according to claim 1, characterized in that, At least one second groove is formed on the second surface of the insulating strip, and the second groove extends along the length direction of the insulating strip.

6. The electrical connector according to claim 5, wherein The number of the second grooves is two, and the two second grooves are respectively arranged on both sides of the through hole.

7. The electrical connector according to any one of claims 1-6, characterized in that, The electrical connector further includes at least one positioning strip, which is fixedly arranged on the first surface and is located outside the corresponding side surface of the solder strip, and the positioning strip extends along the length direction of the insulating strip.

8. The electrical connector according to claim 7, characterized in that, The number of the positioning strips is two, and the two positioning strips are respectively located outside the two side surfaces of the solder strip.

9. The electrical connector according to claim 7, wherein, The positioning strip is an electrically insulating strip.

10. A battery string, characterized in that, Comprising an electrical connector and at least one photovoltaic cell, the electrical connector is the electrical connector according to any one of claims 1-9; The photovoltaic cell includes a plurality of grid lines of the same polarity, and each of the grid lines of the same polarity includes a pad provided with low-temperature solder paste. Each of the low-temperature solder pastes is electrically connected to the solder strip through the corresponding through hole.

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