Solar cell string and photovoltaic module

Abstract

The utility model relates to a solar cell string and a photovoltaic module. The solar cell string comprises a cell piece, a conductive piece and a welding wire, the cell piece comprises a base body and a plurality of auxiliary grid lines arranged on the base body in parallel, the conductive piece is connected with at least two auxiliary grid lines, and colloid is arranged on the conductive piece. The welding wire is welded with the conductive piece, and the welding wire is bonded with the conductive piece through the colloid. According to the solar cell string and the photovoltaic module, the electric connection reliability of the welding wires and the cell pieces is ensured, and the virtual connection problem caused by the fact that the welding wires cannot be in good lap joint with the auxiliary grid lines below the colloid or adjacent to the colloid due to the existence of the height of the colloid is avoided.

Description

Technical Field

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

[0002] In the photovoltaic industry, a single solar cell cannot be directly used as a power source due to its disadvantages such as being fragile and not resistant to aging. Multiple solar cells need to be connected in series and parallel by welding wires to form a cell string, and then through layout, stack welding, and encapsulation to form a photovoltaic module before it can be used for a long time.

[0003] Currently, the mainstream connection method between solar cells and welding wires is as follows: main grid lines and PAD points are designed on the front and back of the solar cells respectively. Both the main grid lines and the PAD points are welded to the welding wires to form an electrical connection. At the same time, the PAD points provide a certain adhesion force for the welding wires to improve the reliability of the cell string. However, the design of the PAD points will increase the consumption of silver paste, resulting in high manufacturing costs. At the same time, due to the characteristics of low-temperature paste, the PAD points cannot provide high tensile strength, resulting in loose contact between the welding wires and the solar cells. With the continuous innovation of solar cell technology, the cell technology has shifted from SMBB (super multi-busbar) to 0BB (zero busbar) technology. 0BB cells can reduce the amount of silver paste used due to the design without main grid lines, thereby reducing costs and improving production efficiency. In 0BB cells, the welding wires are usually fixed to the solar cells by dispensing glue between the welding wires and the solar cells. However, the glue used for dispensing has a certain height, which easily causes loose contact between the sub-grid lines under the glue or the sub-grid lines adjacent to the glue and the welding wires, thereby affecting the current collection in this area. Summary of the Utility Model

[0004] Based on this, in view of the problem of how to ensure the connection reliability between solar cells and welding wires, it is necessary to provide a solar cell string and a photovoltaic module.

[0005] On the one hand, the present application provides a solar cell string, including:

[0006] Solar cells, the solar cells including a substrate and a plurality of sub-grid lines arranged in parallel on the substrate;

[0007] A conductive member, the conductive member connecting at least two of the sub-grid lines, and a glue is provided on the conductive member; and

[0008] Welding wires, the welding wires are welded to the conductive member, and the welding wires are adhered to the conductive member through the glue.

[0009] The technical solution is further described below:

[0010] In one embodiment, the conductive member connects some of the sub-grid lines among all the sub-grid lines, and the welding wires are also welded to the sub-grid lines that are not connected to the conductive member.

[0011] In one embodiment, the number of the conductive members is plural, and the plural conductive members are arranged at intervals in a direction perpendicular to the sub-grid lines to form a connection group. In one connection group, each conductive member is connected to a plurality of adjacent sub-grid lines, and there is at least one sub-grid line between two adjacent conductive members. The welding wire is connected to all the conductive members in the connection group.

[0012] In one embodiment, the number of the connection groups is plural, and all the connection groups are arranged at intervals along the length direction of the sub-grid lines. The number of the welding wires is plural, and each welding wire is arranged corresponding to each connection group one by one.

[0013] In one embodiment, each conductive member is connected to three sub-grid lines, and in each connection group, there are three sub-grid lines between two adjacent conductive members.

[0014] In one embodiment, in each connection group, the intervals between two adjacent colloids are equal.

[0015] In one embodiment, a first alloy point is formed at the welding position of the welding wire and the conductive member, and the first alloy point is arranged at an interval from the colloid.

[0016] In one embodiment, the number of the first alloy points is plural, and the first alloy points and the colloids are arranged alternately on the conductive member.

[0017] In one embodiment, the number of the battery chips is plural, and all the battery chips are connected through the welding wires.

[0018] On the other hand, the present application further provides a photovoltaic module, including the above-mentioned solar cell string.

[0019] In the above-mentioned solar cell string and photovoltaic module, the welding wire is bonded to the battery chip through the colloid, which improves the adhesion of the welding wire to the battery chip, thereby improving the stability of the welding wire. And by arranging the colloid on the conductive member, the conductive member is connected to at least two sub-grid lines, so that the sub-grid lines below the colloid or adjacent to the colloid can be electrically connected to each other through the conductive member. Then, through the welding of the welding wire and the conductive member, the welding wire can form a good electrical connection with the sub-grid lines below the colloid or adjacent to the colloid through the conductive member, ensuring the electrical connection reliability between the welding wire and the battery chip, and avoiding the virtual connection problem caused by the inability of the welding wire to be well lapped with the sub-grid lines below the colloid or adjacent to the colloid due to the existence of the height of the colloid. Description of the Drawings

[0020] The accompanying drawings, which form a part of this application, are used to provide a further understanding of this application. The schematic embodiments of this application and their descriptions are used to explain this application and do not constitute an improper limitation of this application.

[0021] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings required for the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings in the following description are only some embodiments of this application. For those of ordinary skill in the art, without creative efforts, other accompanying drawings can also be obtained based on these drawings.

[0022] In addition, the accompanying drawings are not drawn to a 1:1 scale, and the relative sizes of the respective elements are only schematically drawn in the accompanying drawings and not necessarily drawn to the actual scale. In the accompanying drawings:

[0023] Figure 1 It is a schematic structural diagram of a battery cell in an embodiment.

[0024] Figure 2 It is a schematic structural diagram of a solar cell string in an embodiment.

[0025] Figure 3 It is Figure 2 A cross-sectional view of the solar cell string shown in along the A-A section.

[0026] Description of the reference numerals:

[0027] 10. Battery cell; 11. Substrate; 12. Minor grid line; 2. Connection group; 20. Conductive member; 21. Colloid; 22. First alloy point; 30. Welding wire. Detailed implementation manners

[0028] To make the above objects, features, and advantages of this application more apparent and understandable, the following will describe the detailed implementation manners of this application in conjunction with the accompanying drawings. Many specific details are set forth in the following description to fully understand this application. However, this application can be implemented in many other ways different from those described herein. Those skilled in the art can make similar improvements without departing from the connotation of this application. Therefore, this application is not limited by the specific embodiments disclosed below.

[0029] In the description of the present application, it should be understood that if there are terms such as "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., the orientation or positional relationship indicated by these terms is based on the orientation or positional relationship shown in the drawings. These are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the present application.

[0030] In addition, if there are terms such as "first" and "second", these terms are only used for descriptive purposes and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include at least one such feature. In the description of the present application, if there is a term "plurality", the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise specifically and clearly defined.

[0031] In the present application, unless otherwise clearly specified and limited, if there are terms such as "mounted", "connected", "connected to", "fixed", etc., these terms should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or integrated; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the communication inside two elements or the interaction relationship between two elements, unless otherwise clearly limited. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific circumstances.

[0032] In the present application, unless otherwise clearly specified and limited, if there is a description such as a first feature being "on" or "under" a second feature, the meaning may be that the first and second features are in direct contact, or the first and second features are indirectly in contact through an intermediate medium. Moreover, the first feature being "above", "over" and "on" the second feature may mean that the first feature is directly above or obliquely above the second feature, or simply indicates that the first feature has a higher horizontal height than the second feature. The first feature being "under", "beneath" and "under" the second feature may be that the first feature is directly below or obliquely below the second feature, or simply indicates that the first feature has a lower horizontal height than the second feature.

[0033] It should be noted that if an element is referred to as "fixed to" or "disposed on" another element, it can be directly on the other element or there may also be an intermediate element. If an element is considered to be "connected" to another element, it can be directly connected to the other element or there may be an intermediate element at the same time. If any, the terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used in this application are only for illustrative purposes and do not represent the only implementation.

[0034] An embodiment of the present application provides a solar cell string. Specifically, refer to Figures 1 to 3 , a solar cell string of an embodiment includes a cell 10, a conductive member 20, and a solder wire 30. Among them, the cell 10 includes a substrate 11 and a plurality of sub-grid lines 12 disposed in parallel on the substrate 11. Exemplarily, the substrate 11 can be a silicon wafer, and the plurality of sub-grid lines 12 are parallel and spaced apart on the surface of the substrate 11. The conductive member 20 is connected to at least two sub-grid lines 12, and a colloid 21 is provided on the conductive member 20; Exemplarily, the conductive member 20 can be a conductive wire, and the conductive member 20 is connected to at least two sub-grid lines 12 by welding to achieve electrical conduction. The colloid 21 can be disposed on the conductive member 20 by glue dispensing. The solder wire 30 is welded to the conductive member 20, and the solder wire 30 is adhered to the conductive member 20 through the colloid 21. The solder wire 30 is used to collect the current on the sub-grid lines 12.

[0035] Specifically, in the above solar cell string, the solder wire 30 is adhered to the cell 10 through the colloid 21, which improves the adhesion of the solder wire 30 to the cell 10, thereby improving the stability of the solder wire 30. And by disposing the colloid 21 on the conductive member 20, and the conductive member 20 is connected to at least two sub-grid lines 12, the sub-grid lines 12 below the colloid 21 or adjacent to the colloid 21 can be electrically connected to each other through the conductive member 20. Then, through the welding of the solder wire 30 and the conductive member 20, the solder wire 30 can form a good electrical connection with the sub-grid lines 12 below the colloid 21 or adjacent to the colloid 21 through the conductive member 20, ensuring the electrical connection reliability between the solder wire 30 and the cell 10, and avoiding the virtual connection problem caused by the inability of the solder wire 30 to be well lapped with the sub-grid lines 12 below the colloid 21 or adjacent to the colloid 21 due to the height of the colloid 21.

[0036] Refer to Figure 1 and Figure 3, in one embodiment, the conductive member 20 is connected to some of the sub-grid lines 12 among all the sub-grid lines 12, and the welding wire 30 is also welded to the sub-grid lines 12 that are not connected to the conductive member 20. In this way, the welding wire 30 forms electrical connections with all the sub-grid lines 12, ensuring that the welding wire 30 can collect the current on all the sub-grid lines 12. Understandably, in other embodiments, the conductive member 20 can also be connected to all the sub-grid lines 12. In this case, the welding wire 30 only needs to be welded to the conductive member 20 to be electrically connected to all the sub-grid lines 12.

[0037] Continue to refer to Figure 1 , a plurality of conductive members 20 are arranged at intervals in a direction perpendicular to the sub-grid lines 12 to form a connection group 2. In a connection group 2, each conductive member 20 is connected to a plurality of adjacent sub-grid lines 12, and there is at least one sub-grid line 12 between two adjacent conductive members 20, and the welding wire 30 is connected to all the conductive members 20 in the connection group 2. In this way, the welding wire 30 is bonded to all the conductive members 20 in the connection group 2 through the colloid 21, forming a plurality of bonding points between the welding wire 30 and the battery cell 10, further improving the firmness of the welding wire 30 attached to the battery cell 10; at the same time, since the plurality of conductive members 20 are arranged at intervals, the welding wire 30 is welded to all the conductive members 20 in the connection group 2 and to the sub-grid lines 12 between two adjacent conductive members 20, which can save the material cost of the conductive member 20 while ensuring the electrical connection between the welding wire 30 and all the sub-grid lines 12.

[0038] Optionally, in one embodiment, each conductive member 20 is connected to three sub-grid lines 12. In this way, while ensuring that the welding wire 30 can form a good electrical connection with the sub-grid lines 12 below or adjacent to the colloid 21 through the conductive member 20, the length of a single conductive member 20 is reduced, thereby reducing the material cost. Understandably, in other embodiments, each conductive member 20 can be connected to two, four, five or more sub-grid lines 12.

[0039] Furthermore, in each connection group 2, there are three sub-grid lines 12 between two adjacent conductive members 20. In this way, it is ensured that the distance between two adjacent colloids 21 is not too close, thereby saving the material cost, and it is also ensured that the distance between two adjacent colloids 21 is not too far, thereby ensuring the strength of the adhesion of the welding wire 30. Understandably, in other embodiments, in each connection group 2, two adjacent conductive members 20 can also be separated by one, two, four, five or more sub-grid lines 12.

[0040] Furthermore, in each connection group 2, the intervals between two adjacent colloids 21 are equal. In this way, it is ensured that the bonding points of each welding wire 30 and the conductive member 2 are evenly distributed, thereby ensuring the stable connection between the welding wire 30 and the battery cell 10.

[0041] In one embodiment, refer to Figure 1 and Figure 2, there are multiple connection groups 2, and the multiple connection groups 2 are arranged at intervals along the length direction of the auxiliary grid line 12. The number of welding wires 30 is multiple, and each welding wire 30 is correspondingly arranged with each connection group 2. In this way, the current of the auxiliary grid line 12 can be collected by multiple welding wires 30 at the same time, reducing the transmission distance of the current on the auxiliary grid line 12, thereby reducing the current loss.

[0042] See Figure 3 , in an embodiment, a first alloy point 22 is formed at the welding joint of the welding wire 30 and the conductive member 20, and the first alloy point 22 is arranged at an interval from the colloid 21. Specifically, through welding, the tin on the surface of the conductive member 20 and the welding wire 30 can form a first alloy point 22 with an alloy phase structure, thereby ensuring good electrical connection between the conductive member 20 and the welding wire 30. At the same time, by arranging the first alloy point 22 at an interval from the colloid 21, it is ensured that there is a certain distance between the welding joint of the welding wire 30 and the conductive member 20 and the colloid 21, thereby avoiding the influence of the height of the colloid 21 on the welding stability of the welding wire 30 and the conductive member 20, and also avoiding the problem that the colloid 21 covers the first alloy point 22 and affects the electrical conduction between the welding wire 30 and the conductive member 20.

[0043] Optionally, in an embodiment, the number of the first alloy points 22 is multiple, and the first alloy points 22 and the colloid 21 are alternately arranged on the conductive member 20. Exemplarily, one colloid 21 and two first alloy points 22 are arranged on each conductive member 20, and the two first alloy points 22 are respectively arranged on both sides of the colloid 21. In this way, good electrical contact is achieved while ensuring the firm connection between the welding wire 30 and the conductive member 20. It can be understood that in other embodiments, the number of colloids 21 on each conductive member 20 can also be multiple, and the multiple colloids 21 and the multiple first alloys are alternately arranged one by one.

[0044] In an embodiment, the number of battery chips 10 is multiple, and all the battery chips 10 are connected by welding wires 30. Specifically, all the battery chips 10 are connected in parallel or in series by welding wires 30, thereby improving the current output efficiency.

[0045] Another embodiment of the present application also provides a photovoltaic module. Specifically, the photovoltaic module in an embodiment includes the above-mentioned solar cell string.

[0046] In the above photovoltaic module, the welding wire 30 is bonded to the battery cell 10 by the colloid 21, which improves the adhesion of the welding wire 30 to the battery cell 10, thereby enhancing the stability of the welding wire 30. And by arranging the colloid 21 on the conductive member 20, the conductive member 20 is connected to at least two sub-grid lines 12, enabling the sub-grid lines 12 below the colloid 21 or adjacent to the colloid 21 to be electrically connected to each other through the conductive member 20. Then, by welding the welding wire 30 to the conductive member 20, the welding wire 30 can form a good electrical connection with the sub-grid lines 12 below the colloid 21 or adjacent to the colloid 21 through the conductive member 20, ensuring the electrical connection reliability between the welding wire 30 and the battery cell 10 and avoiding the virtual connection problem caused by the inability of the welding wire 30 to be well lapped with the sub-grid lines 12 below the colloid 21 or adjacent to the colloid 21 due to the height of the colloid 21.

[0047] The technical features of the above-described embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope described in this specification.

[0048] The above-described embodiments only represent several implementation manners of the present application. The description is relatively specific and detailed, but it should not be construed as a limitation on the scope of the patent application. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present application, several modifications and improvements can be made, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application should be subject to the appended claims.

Claims

1. A solar cell string, characterized in that: include: A battery cell (10), the battery cell (10) comprising a substrate (11) and a plurality of secondary grid lines (12) arranged in parallel on the substrate (11); A conductive member (20), the conductive member (20) connecting at least two of the secondary grid lines (12), the conductive member (20) being provided with a colloid (21); and A welding wire (30), the welding wire (30) being welded to the conductive member (20), and the welding wire (30) being bonded to the conductive member (20) via the colloid (21).

2. The solar cell string according to claim 1, characterized in that: The conductive member (20) connects part of the secondary grid lines (12) among all the secondary grid lines (12), and the welding wire (30) is also welded to the secondary grid lines (12) that are not connected to the conductive member (20).

3. The solar cell string according to claim 2, characterized in that: There are a plurality of conductive members, and the plurality of conductive members (20) are arranged at intervals in a direction perpendicular to the secondary grid lines (12) to form a connection group (2). In one connection group (2), each conductive member (20) is connected to a plurality of adjacent secondary grid lines (12), and at least one secondary grid line (12) is spaced between two adjacent conductive members (20). The welding wire (30) is connected to all the conductive members (20) in the connection group (2).

4. The solar cell string according to claim 3, characterized in that: There are a plurality of connection groups (2), all of which are arranged at intervals along the length direction of the secondary grid line (12); there are a plurality of welding wires (30), and each welding wire (30) is arranged in one-to-one correspondence with each connection group (2).

5. The solar cell string according to claim 3, characterized in that: Each of the conductive members (20) is connected to three of the secondary grid lines (12); in each of the connection groups (2), three of the secondary grid lines (12) are spaced between two adjacent conductive members (20).

6. The solar cell string according to claim 3, characterized in that: In each of the connection groups (2), the intervals between two adjacent colloids (21) are equal.

7. The solar cell string according to claim 1, characterized in that: A first alloy point (22) is formed at the welding point between the welding wire (30) and the conductive member (20), and the first alloy point (22) is spaced apart from the colloid (21).

8. The solar cell string according to claim 7, characterized in that: The number of the first alloy points (22) is plural, and the first alloy points (22) and the colloid (21) are arranged alternately on the conductive member (20).

9. The solar cell string according to claim 6, characterized in that: There are a plurality of battery cells (10), and all of the battery cells (10) are connected via the welding wire (30).

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

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