Solar cell and solar module

Abstract

The utility model discloses a solar cell and a solar assembly, relates to the technical field of solar cells, and aims to solve the problem that an end pad is affected by contraction tension of a welding strip to the greatest extent in the welding process of the welding strip. Therefore, the problem of bending and even subfissure of the battery piece main body caused by large difference of welding strip contraction tension applied to the first surface and the second surface of the battery piece main body during welding is solved. The solar cell comprises a cell piece body, a first electrode structure and a second electrode structure. The first electrode structure comprises a first edge welding structure close to the first edge and a second edge welding structure close to the second edge. The second electrode structure comprises a third edge welding structure close to the first edge and a fourth edge welding structure close to the second edge. The distance between the first edge welding structure and the first edge is smaller than the distance between the third edge welding structure and the first edge, and the distance between the second edge welding structure and the second edge is smaller than the distance between the fourth edge welding structure and the second edge.

Description

Technical Field

[0001] The utility model relates to the technical field of solar cells, in particular to a solar cell and a solar energy component. Background Art

[0002] A solar panel generally consists of a plurality of cell strings, each of which consists of a plurality of solar cells. In the process of preparing the cell string, a plurality of solar cells are usually welded in series using a welding ribbon.

[0003] During the string soldering process, the first part of the soldering ribbon is soldered to the front side of the previous solar cell, and the second part of the soldering ribbon is soldered to the back side of the next solar cell. The soldering ribbon is bent during the transition from the previous solar cell to the next solar cell.

[0004] The solar cell mentioned above generally includes a cell body, a plurality of pads and a plurality of busbar electrodes. The cell body includes a first surface and a second surface relative to each other. In order to solve the stress concentration problem of pad welding, the orthographic projection of the end pad located on the first surface on the cell body and the orthographic projection of the end pad located on the second surface on the cell body are often arranged so as not to completely overlap. At the same time, during the welding process of the welding strip, the end pad is most affected by the shrinkage tension of the welding strip. Therefore, during welding, the shrinkage tension of the welding strip on the first surface and the second surface of the cell body is greatly different, which often causes the cell body to bend or even crack. Utility Model Content

[0005] The utility model aims to provide a solar cell and a solar module, which are used to reduce the probability of bending or even cracking of a solar cell body, so as to ensure the quality of the solar module finally obtained.

[0006] In order to achieve the above-mentioned purpose, in a first aspect, the utility model provides a solar cell. The solar cell includes a cell body, the cell body includes a first surface and a second surface relative to each other, and a first electrode structure and a second electrode structure formed on the first surface and the second surface, respectively. Along a first direction, the cell body includes a first edge and a second edge relative to each other. The first electrode structure includes at least two first welding structures spaced apart along the first direction, and the second electrode structure includes at least two second welding structures spaced apart along the first direction. The first welding structure includes: a first edge welding structure close to the first edge, and a second edge welding structure close to the second edge. The second welding structure includes: a third edge welding structure close to the first edge, and a fourth edge welding structure close to the second edge. The distance between the first edge welding structure and the first edge is smaller than the distance between the third edge welding structure and the first edge, and the distance between the second edge welding structure and the second edge is smaller than the distance between the fourth edge welding structure and the second edge.

[0007] Compared with the prior art, in the solar cell provided by the utility model, the distance between the first edge welding structure and the first edge is smaller than the distance between the third edge welding structure and the first edge, and the distance between the second edge welding structure and the second edge is smaller than the distance between the fourth edge welding structure and the second edge. It can be seen that after actual welding, on the first surface of the battery cell body, the first edge welding structure and the second edge welding structure are both subjected to a pulling force in the direction of the inside of the battery cell body (for the convenience of subsequent description, referred to as the first pulling force). On the second surface of the battery cell body, the third edge welding structure and the fourth edge welding structure are both subjected to a pulling force in the direction of the inside of the battery cell body (for the convenience of subsequent description, referred to as the second pulling force). When the above technical solution is adopted, it can be ensured that the perpendicular midline of the line connecting the first edge welding structure and the second edge welding structure and the perpendicular midline of the line connecting the third edge welding structure and the fourth edge welding structure are close and located in the middle area of ​​the battery cell. At this time, the first tension and the second tension can basically offset each other or offset each other, so as to basically balance or balance the effect of the solder strip tension on the first surface and the second surface, so that the effect of the solder strip shrinkage on the first surface and the effect of the solder strip shrinkage on the second surface on the solar cell body are balanced as much as possible, thereby reducing or eliminating the probability of bending or even cracking of the solar cell body, so as to ensure the quality of the final solar cell module.

[0008] In one implementation, the difference between the distance between the first edge welding structure and the first edge and the distance between the third edge welding structure and the first edge is equal to the difference between the distance between the second edge welding structure and the second edge and the distance between the fourth edge welding structure and the second edge.

[0009] When the above technical solution is adopted, the perpendicular midline of the line connecting the first edge welding structure and the second edge welding structure and the perpendicular midline of the line connecting the third edge welding structure and the fourth edge welding structure are infinitely close to or coincide with each other. At this time, the first tension and the second tension can be almost completely offset, which can better prevent the battery cell body from bending or even cracking.

[0010] In one implementation, the distance between the first edge welding structure and the first edge is greater than or equal to 4.5 mm and less than or equal to 8.5 mm; the distance between the second edge welding structure and the second edge is greater than or equal to 5.5 mm and less than or equal to 9.5 mm; the distance between the third edge welding structure and the first edge is greater than or equal to 5 mm and less than or equal to 9 mm; the distance between the fourth edge welding structure and the second edge is greater than or equal to 6.5 mm and less than or equal to 10.5 mm.

[0011] When the above technical solution is adopted, stress concentration is reduced while ensuring that the conductive connecting member (such as a welding strip) is stably welded to the first edge welding structure, the second edge welding structure, the third edge welding structure and the fourth edge welding structure after actual welding.

[0012] In one implementation, along the first direction, an overlap rate of an orthographic projection of the first edge welding structure on the battery cell body and an orthographic projection of a corresponding third edge welding structure on the battery cell body is greater than or equal to 0 and less than 70%.

[0013] Along the first direction, an overlap rate of an orthographic projection of the second edge welding structure on the battery cell body and an orthographic projection of a corresponding fourth edge welding structure on the battery cell body is greater than or equal to 0 and less than 70%.

[0014] In the case of adopting the above technical solution, when both overlap rates are equal to 0, the first edge welding structure and the third edge welding structure are completely staggered, and the second edge welding structure and the fourth edge welding structure are completely staggered. At this time, in the actual welding process, the probability of welding stress concentration in the first welding structure and the second welding structure on the first surface and the second surface of the solar cell can be further reduced to ensure the welding reliability of the solar module finally obtained. Furthermore, the overlap rate is less than 70%, which can ensure stress concentration caused by excessive overlap rate on the one hand, and provide greater flexibility in the design of the welding pad on the other hand.

[0015] In one implementation, along the first direction, the overlap rate of the orthographic projection of the first edge welding structure on the battery cell body and the orthographic projection of the corresponding third edge welding structure on the battery cell body, and the overlap rate of the orthographic projection of the second edge welding structure on the battery cell body and the orthographic projection of the corresponding fourth edge welding structure on the battery cell body are equal or unequal.

[0016] In one implementation, along the first direction, when the overlap rate of the orthographic projection of the first edge welding structure on the battery cell body and the orthographic projection of the corresponding third edge welding structure on the battery cell body is zero, the overlap rate of the orthographic projection of the second edge welding structure on the battery cell body and the orthographic projection of the corresponding fourth edge welding structure on the battery cell body is greater than 50% and less than 100%. Or,

[0017] Along the first direction, when the overlap rate of the orthographic projection of the second edge welding structure on the battery cell body and the orthographic projection of the corresponding fourth edge welding structure on the battery cell body is equal to zero, the overlap rate of the orthographic projection of the first edge welding structure on the battery cell body and the orthographic projection of the corresponding third edge welding structure on the battery cell body is greater than 50% and less than 100%.

[0018] When the above-mentioned technical solution is adopted, the probability of welding stress concentration occurring in the first welding structure and the second welding structure on the first surface and the second surface of the solar cell can be reduced, and the first edge welding structure and the second edge welding structure can be avoided from being distributed in a relatively concentrated manner, or the third edge welding structure and the fourth edge welding structure can be avoided from being distributed in a relatively concentrated manner, so as to ensure the uniformity of current collection.

[0019] In one implementation, the first welding structure further includes a first intermediate welding structure between the first edge welding structure and the second edge welding structure. The height of the first intermediate welding structure is equal to the height of the first edge welding structure, and the height of the first edge welding structure is equal to the height of the second edge welding structure.

[0020] At this time, it can be ensured that the conductive connector is firmly connected to the first edge welding structure, the second edge welding structure and the first middle welding structure, so as to ensure the quality of the solar cell. Furthermore, it can also be avoided that the conductive connector is raised due to the height of the first middle welding structure being higher than the first edge welding structure and the second edge welding structure, thereby avoiding the occurrence of hidden cracks or fragments of the solar cell.

[0021] The cross-sectional area of ​​the first middle welding structure is smaller than the cross-sectional area of ​​the first edge welding structure, the cross-sectional area of ​​the first edge welding structure is equal to the cross-sectional area of ​​the second edge welding structure, and the cross-sectional areas of the first middle welding structure, the first edge welding structure and the second edge welding structure are all parallel to the battery cell body.

[0022] At this time, the shielding area of ​​the first middle welding structure on the battery cell body can be reduced to improve the utilization of light by the solar cell, thereby improving the cell efficiency of the solar cell.

[0023] In one implementation, the second welding structure further includes a second intermediate welding structure located between the third edge welding structure and the fourth edge welding structure. The height of the second intermediate welding structure is equal to the height of the third edge welding structure, and the height of the third edge welding structure is equal to the height of the fourth edge welding structure.

[0024] At this time, it can be ensured that the conductive connector is firmly connected to the third edge welding structure, the fourth edge welding structure and the second middle welding structure to ensure the quality of the solar cell. Furthermore, it can also avoid the situation where the conductive connector is raised due to the height of the second middle welding structure being higher than the third edge welding structure and the fourth edge welding structure, thereby avoiding the situation where the solar cell is cracked or broken.

[0025] The cross-sectional area of ​​the second middle welding structure is smaller than that of the third edge welding structure, the cross-sectional area of ​​the third edge welding structure is equal to the cross-sectional area of ​​the fourth edge welding structure, and the cross-sectional areas of the second middle welding structure, the third edge welding structure and the fourth edge welding structure are all parallel to the battery cell body.

[0026] At this time, the shielding area of ​​the second middle welding structure on the battery cell body can be reduced to improve the utilization of light by the solar cell, thereby improving the cell efficiency of the solar cell.

[0027] In one implementation, the first welding structure includes at least two first intermediate welding structures, and the orthographic projections of half of the first intermediate welding structures on the battery cell body do not overlap with the orthographic projections of the second intermediate welding structures on the battery cell body.

[0028] When the above technical solution is adopted, during the actual welding process, the probability of welding stress concentration occurring in the first welding structure and the second welding structure on the first surface and the second surface of the solar cell can be further reduced, so as to ensure the welding reliability of the final solar module.

[0029] In one implementation, the orthographic projections of all first intermediate welding structures on the battery cell body are misaligned with the orthographic projections of the corresponding second intermediate welding structures on the battery cell body.

[0030] In one implementation, the difference in distance between the midline of the line connecting the first edge welding structure and the second edge welding structure and the midline of the line connecting the third edge welding structure and the fourth edge welding structure is less than 0.5 mm; or, the midline of the line connecting the first edge welding structure and the second edge welding structure passes through one of the first intermediate welding structures; or, the midline of the line connecting the third edge welding structure and the fourth edge welding structure passes through one of the second intermediate welding structures.

[0031] When the above technical solution is adopted, the probability of bending or even cracking of the battery cell body can be reduced while maintaining the reasonable position of the first middle welding structure or the second middle welding structure to ensure the strength and effect of the connection of the conductive connector.

[0032] In a second aspect, the utility model further provides a solar module, which includes a battery string, the battery string includes a plurality of conductive connectors and a plurality of solar cells arranged at intervals as described in the above technical solution, and the conductive connectors connect the plurality of solar cells in series.

[0033] Compared with the prior art, the beneficial effects of the solar cell assembly provided by the utility model are the same as the beneficial effects of the solar cell described in the above technical solution, which will not be described in detail here.

[0034] In one implementation, a plurality of spaced-apart solar cells include a first solar cell and a second solar cell adjacent to each other, and the conductive connector includes a first connection segment located on a first surface of the first solar cell, a second connection segment located on a second surface of the second solar cell, and a third connection segment. The first connection segment includes a first end segment and a second end segment, the first end segment is welded to a first edge welding structure of the first solar cell, and the second end segment is welded to a second edge welding structure of the first solar cell. The second connection segment includes a third end segment and a fourth end segment, the third end segment is welded to a third edge welding structure of the second solar cell, the fourth end segment is welded to a fourth edge welding structure of the second solar cell, and the second end segment and the third end segment are connected via the third connection segment.

[0035] Combined with the previous description, it can be known that since the distance between the first edge welding structure and the first edge is smaller than the distance between the third edge welding structure and the first edge, the distance between the second edge welding structure and the second edge is smaller than the distance between the fourth edge welding structure and the second edge. It can be seen that after actual welding, on the first surface of the battery cell body, the first edge welding structure and the second edge welding structure are both subjected to a pulling force toward the inside of the battery cell body (for the convenience of subsequent description, referred to as the first pulling force). On the second surface of the battery cell body, the third edge welding structure and the fourth edge welding structure are both subjected to a pulling force toward the inside of the battery cell body (for the convenience of subsequent description, referred to as the second pulling force). When the above technical solution is adopted, it can be ensured that the perpendicular midline of the line connecting the first edge welding structure and the second edge welding structure and the perpendicular midline of the line connecting the third edge welding structure and the fourth edge welding structure are close and located in the middle area of ​​the battery cell. At this time, the first tension and the second tension can basically offset each other or offset each other, so as to basically balance or balance the effect of the solder strip tension on the first surface and the second surface, so that the effect of the solder strip shrinkage on the first surface and the effect of the solder strip shrinkage on the second surface on the solar cell body are balanced as much as possible, thereby reducing or eliminating the probability of bending or even cracking of the solar cell body, so as to ensure the quality of the final solar cell module. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation on the present invention. In the drawings:

[0037] Figure 1 This is a schematic structural diagram of the first surface of a solar cell in an embodiment of the utility model;

[0038] Figure 2 This is a schematic diagram of the structure of the second surface of the solar cell in an embodiment of the utility model;

[0039] Figure 3 This is a schematic diagram of the structure of a solar panel in an embodiment of the present utility model;

[0040] Figure 4 In the embodiment of the utility model Figure 3 A partial enlarged schematic diagram of the structure.

[0041] Reference numerals:

[0042] 1-battery cell body, 10-first surface, 11-second surface, 12-first edge, 13-second edge; 2-first electrode structure, 20-first welding structure, 21-first edge welding structure, 22-second edge welding structure, 23-first middle welding structure; 3-second electrode structure, 30-second welding structure, 31-third edge welding structure, 32-fourth edge welding structure, 33-second middle welding structure; 4-conductive connector, 40-first connecting section, 41-second connecting section, 42-third connecting section, 43-first end section, 44-second end section, 45-third end section, 46-fourth end section; 5-first solar cell, 6-second solar cell. DETAILED DESCRIPTION

[0043] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0044] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it can be directly on the other element or indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element.

[0045] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present utility model, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined. The meaning of "several" is one or more, unless otherwise clearly and specifically defined.

[0046] In the description of the present invention, it should be understood that the terms "upper", "lower", "front", "back", "left", "right", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as a limitation on the present invention.

[0047] In the description of the present utility model, it should be noted that, unless otherwise clearly specified and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.

[0048] In order to solve the above technical problems, in the first aspect, the utility model provides a solar cell. Figure 1 and Figure 2 The solar cell comprises a cell body 1, the cell body 1 comprises a first surface 10 and a second surface 11 opposite to each other, and a first electrode structure 2 and a second electrode structure 3 respectively formed on the first surface 10 and the second surface 11. Along a first direction A, the cell body 1 comprises a first edge 12 and a second edge 13 opposite to each other. The structure and specification of the cell body can be set according to actual conditions and are not specifically limited here. The first direction is parallel to the surface of the cell body.

[0049] See also Figure 1 and Figure 2 The first electrode structure 2 includes at least two first welding structures 20 distributed along the first direction A at intervals, and the second electrode structure 3 includes at least two second welding structures 30 distributed along the first direction A at intervals.

[0050] See also Figure 1 The first welding structure 20 includes: a first edge welding structure 21 close to the first edge 12 , and a second edge welding structure 22 close to the second edge 13 .

[0051] In an optional manner, the first electrode structure may include a main grid extending along a first direction, and at least two first welding structures spaced apart along the first direction and arranged on the main grid. The first electrode structure may include multiple main grids, and multiple first welding structures. Therefore, the above-mentioned "at least two first welding structures spaced apart along the first direction" can be understood as referring to the first welding structure on the same main grid. Furthermore, in order to facilitate the subsequent description, the first welding structure is divided into a first edge welding structure close to the first edge, and a second edge welding structure close to the second edge.

[0052] See also Figure 2 The second welding structure 30 includes: a third edge welding structure 31 close to the first edge 12 , and a fourth edge welding structure 32 close to the second edge 13 .

[0053] In an optional manner, the second electrode structure may include a main grid extending along the first direction, and at least two second welding structures spaced apart along the first direction and arranged on the main grid. The second electrode structure may include multiple main grids, and multiple second welding structures. Therefore, the above-mentioned "at least two second welding structures spaced apart along the first direction" can be understood as referring to the second welding structure on the same main grid. Furthermore, in order to facilitate the subsequent description, the second welding structure is divided into a third edge welding structure close to the first edge, and a fourth edge welding structure close to the second edge.

[0054] See also Figures 1 to 4 , the distance L1 between the first edge welding structure 21 and the first edge 12 is less than the distance L2 between the third edge welding structure 31 and the first edge 12. The distance L3 between the second edge welding structure 22 and the second edge 13 is less than the distance L4 between the fourth edge welding structure 32 and the second edge 13. It can be seen from this that the orthographic projection of the first edge welding structure 21 on the battery cell body 1 does not completely overlap with the orthographic projection of the third edge welding structure 31 on the battery cell body 1, and the orthographic projection of the second edge welding structure 22 on the battery cell body 1 does not completely overlap with the orthographic projection of the fourth edge welding structure 32 on the battery cell body 1. In other words, the first edge welding structure 21 and the third edge welding structure 31 are partially offset, and the second edge welding structure 22 and the fourth edge welding structure 32 are partially offset. At this time, in the actual welding process, the probability of welding stress concentration in the first welding structure 20 and the second welding structure 30 on the first surface 10 and the second surface 11 of the solar cell can be reduced to ensure the welding reliability of the solar module finally obtained.

[0055] Furthermore, the distance between the first edge welding structure and the first edge is smaller than the distance between the third edge welding structure and the first edge, and the distance between the second edge welding structure and the second edge is smaller than the distance between the fourth edge welding structure and the second edge. It can be seen that after actual welding, on the first surface of the battery cell body, both the first edge welding structure and the second edge welding structure are subjected to a pulling force toward the inside of the battery cell body (referred to as the first pulling force for the convenience of subsequent description). On the second surface of the battery cell body, both the third edge welding structure and the fourth edge welding structure are subjected to a pulling force toward the inside of the battery cell body (referred to as the second pulling force for the convenience of subsequent description). When the above technical solution is adopted, it can be ensured that the perpendicular midline of the line connecting the first edge welding structure and the second edge welding structure and the perpendicular midline of the line connecting the third edge welding structure and the fourth edge welding structure are close and located in the middle area of ​​the battery cell. At this time, the first tension and the second tension can basically offset each other or offset each other, so as to basically balance or balance the effect of the solder strip tension on the first surface and the second surface, so that the effect of the solder strip shrinkage on the first surface and the effect of the solder strip shrinkage on the second surface on the solar cell body are balanced as much as possible, thereby reducing or eliminating the probability of bending or even cracking of the solar cell body, so as to ensure the quality of the final solar cell module.

[0056] As a possible implementation, see Figures 1 to 4 The difference between the distance L1 between the first edge welding structure 21 and the first edge 12 and the distance L2 between the third edge welding structure 31 and the first edge 12 is equal to the difference between the distance L3 between the second edge welding structure 22 and the second edge 13 and the distance L4 between the fourth edge welding structure 32 and the second edge 13.

[0057] See also Figures 1 to 4 In the case of adopting the above technical solution, the perpendicular midline M of the line connecting the first edge welding structure 21 and the second edge welding structure 22 and the perpendicular midline N of the line connecting the third edge welding structure 31 and the fourth edge welding structure 32 are infinitely close to or coincide with each other. At this time, the first tension and the second tension can be almost completely offset, which can better prevent the battery cell body from bending or even cracking.

[0058] As a possible implementation, see Figure 4 , the distance L1 between the first edge welding structure 21 and the first edge 12 is greater than or equal to 4.5 mm and less than or equal to 8.5 mm; for example, the distance between the first edge welding structure 21 and the first edge 12 can be 4.5 mm, 5 mm, 5.5 mm, 6 mm, 6.5 mm, 7 mm, 7.5 mm, 8 mm or 8.5 mm, etc.

[0059] The distance L3 between the second edge welding structure 22 and the second edge 13 is greater than or equal to 5.5 mm and less than or equal to 9.5 mm; for example, the distance between the second edge welding structure 22 and the second edge 13 can be 5.5 mm, 6 mm, 6.5 mm, 7 mm, 7.5 mm, 8 mm, 8.5 mm, 9 mm or 9.5 mm, etc.

[0060] The distance L2 between the third edge welding structure 31 and the first edge 12 is greater than or equal to 5 mm and less than or equal to 9 mm; for example, the distance between the third edge welding structure 31 and the first edge 12 can be 5 mm, 5.5 mm, 6 mm, 6.5 mm, 7 mm, 7.5 mm, 8 mm, 8.5 mm or 9 mm, etc.

[0061] The distance L4 between the fourth edge welding structure 32 and the second edge 13 is greater than or equal to 6.5 mm and less than or equal to 10.5 mm. For example, the distance between the fourth edge welding structure 32 and the second edge 13 can be 6.5 mm, 7 mm, 7.5 mm, 8 mm, 8.5 mm, 9 mm, 9.5 mm, 10 mm or 10.5 mm, etc.

[0062] When the above technical solution is adopted, stress concentration is reduced while ensuring that the conductive connecting member 4 (such as a welding strip) is stably welded to the first edge welding structure 21, the second edge welding structure 22, the third edge welding structure 31 and the fourth edge welding structure 32 after actual welding.

[0063] As a possible implementation, along the first direction, the overlap rate of the orthographic projection of the first edge welding structure on the battery cell body and the orthographic projection of the corresponding third edge welding structure on the battery cell body is greater than or equal to 0 and less than 70%. For example, the overlap rate can be 0, 1%, 5%, 13%, 20%, 50%, 60% or 69%, etc.

[0064] Along the first direction, the overlap rate of the orthographic projection of the second edge welding structure on the battery cell body and the orthographic projection of the corresponding fourth edge welding structure on the battery cell body is greater than or equal to 0 and less than 70%. For example, the overlap rate can be 0, 1%, 5%, 13%, 20%, 35%, 50%, 60% or 69%, etc.

[0065] In the case of adopting the above technical solution, when both overlap rates are equal to 0, the first edge welding structure and the third edge welding structure are completely staggered, and the second edge welding structure and the fourth edge welding structure are completely staggered. At this time, in the actual welding process, the probability of welding stress concentration in the first welding structure and the second welding structure on the first surface and the second surface of the solar cell can be further reduced to ensure the welding reliability of the solar module finally obtained. Furthermore, the overlap rate is less than 70%, which can ensure stress concentration caused by excessive overlap rate on the one hand, and provide greater flexibility in the design of the welding pad on the other hand.

[0066] As a possible implementation method, along the first direction, the overlap rate of the orthographic projection of the first edge welding structure on the battery cell body and the corresponding orthographic projection of the third edge welding structure on the battery cell body, and the overlap rate of the orthographic projection of the second edge welding structure on the battery cell body and the corresponding orthographic projection of the fourth edge welding structure on the battery cell body are equal or unequal.

[0067] As a possible implementation, along the first direction, when the overlap rate of the orthographic projection of the first edge welding structure on the battery cell body and the orthographic projection of the corresponding third edge welding structure on the battery cell body is equal to zero, the overlap rate of the orthographic projection of the second edge welding structure on the battery cell body and the orthographic projection of the corresponding fourth edge welding structure on the battery cell body is greater than 50% and less than 100%. For example, the overlap rate can be 51%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90% or 99%, etc. Or, along the first direction, when the overlap rate of the orthographic projection of the second edge welding structure on the battery cell body and the orthographic projection of the corresponding fourth edge welding structure on the battery cell body is equal to zero, the overlap rate of the orthographic projection of the first edge welding structure on the battery cell body and the orthographic projection of the corresponding third edge welding structure on the battery cell body is greater than 50% and less than 100%. For example, the overlap rate can be 51%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90% or 99%, etc.

[0068] At this time, while reducing the probability of welding stress concentration in the first welding structure and the second welding structure on the first surface and the second surface of the solar cell, it is possible to avoid the first edge welding structure and the second edge welding structure being distributed more concentratedly, or to avoid the third edge welding structure and the fourth edge welding structure being distributed more concentratedly, so as to ensure the uniformity of current collection.

[0069] As a possible implementation, see Figure 1, the first welding structure 20 further includes a first intermediate welding structure 23 located between the first edge welding structure 21 and the second edge welding structure 22. Exemplarily, the number of the first intermediate welding structures 23 is greater than or equal to 5 and less than or equal to 9. For example, it can be 5, 6, 7, 8 or 9. Further, when the first welding structure 20 includes a plurality of first intermediate welding structures 23, the plurality of first intermediate welding structures 23 can be arranged at equal intervals or at unequal intervals.

[0070] The height of the first intermediate welding structure is equal to the height of the first edge welding structure, and the height of the first edge welding structure is equal to the height of the second edge welding structure.

[0071] At this time, it can be ensured that the conductive connector is firmly connected to the first edge welding structure, the second edge welding structure and the first middle welding structure, so as to ensure the quality of the solar cell. Furthermore, it can also be avoided that the conductive connector is raised due to the height of the first middle welding structure being higher than the first edge welding structure and the second edge welding structure, thereby avoiding the occurrence of hidden cracks or fragments of the solar cell.

[0072] Furthermore, the cross-sectional area of ​​the first middle welding structure is smaller than the cross-sectional area of ​​the first edge welding structure, the cross-sectional area of ​​the first edge welding structure is equal to the cross-sectional area of ​​the second edge welding structure, and the cross-sectional areas of the first middle welding structure, the first edge welding structure, and the second edge welding structure are all parallel to the battery cell body.

[0073] At this time, the shielding area of ​​the first middle welding structure on the battery cell body can be reduced to improve the utilization of light by the solar cell, thereby improving the cell efficiency of the solar cell.

[0074] As a possible implementation, see Figure 2 , the second welding structure 30 further includes a second intermediate welding structure 33 located between the third edge welding structure 31 and the fourth edge welding structure 32. Exemplarily, the number of the second intermediate welding structures 33 is greater than or equal to 5 and less than or equal to 9. For example, it can be 5, 6, 7, 8 or 9. The number of the first intermediate welding structures 23 may be unequal to the number of the second intermediate welding structures 33. Further, when the second welding structure 30 includes a plurality of second intermediate welding structures 33, the plurality of second intermediate welding structures 33 may be arranged at equal intervals or at unequal intervals.

[0075] The height of the second middle welding structure is equal to the height of the third edge welding structure, and the height of the third edge welding structure is equal to the height of the fourth edge welding structure.

[0076] At this time, it can be ensured that the conductive connector is firmly connected to the third edge welding structure, the fourth edge welding structure and the second middle welding structure to ensure the quality of the solar cell. Furthermore, it can also avoid the situation where the conductive connector is raised due to the height of the second middle welding structure being higher than the third edge welding structure and the fourth edge welding structure, thereby avoiding the situation where the solar cell is cracked or broken.

[0077] Furthermore, the cross-sectional area of ​​the second middle welding structure is smaller than the cross-sectional area of ​​the third edge welding structure, the cross-sectional area of ​​the third edge welding structure is equal to the cross-sectional area of ​​the fourth edge welding structure, and the cross-sectional areas of the second middle welding structure, the third edge welding structure and the fourth edge welding structure are all parallel to the battery cell body.

[0078] At this time, the shielding area of ​​the second middle welding structure on the battery cell body can be reduced to improve the utilization of light by the solar cell, thereby improving the cell efficiency of the solar cell.

[0079] The following describes the overlapping relationship between the orthographic projection of the first intermediate welding structure on the battery cell body and the orthographic projection of the second intermediate welding structure on the battery cell body using two possible situations as examples. It should be understood that the following description is only for understanding and is not intended to be a specific limitation.

[0080] Example 1: The first welding structure includes at least two first intermediate welding structures, and the orthographic projections of half of the first intermediate welding structures on the battery cell body do not overlap with the orthographic projections of the second intermediate welding structures on the battery cell body.

[0081] At this time, during the actual welding process, the probability of welding stress concentration occurring in the first welding structure and the second welding structure on the first surface and the second surface of the solar cell can be further reduced, so as to ensure the welding reliability of the final solar module.

[0082] Example 2: The orthographic projections of all first intermediate welding structures on the battery cell body are misaligned with the orthographic projections of the corresponding second intermediate welding structures on the battery cell body.

[0083] In an optional manner, the distance difference between the midpoint of the line connecting the first edge welding structure and the second edge welding structure and the midpoint of the line connecting the third edge welding structure and the fourth edge welding structure is less than 0.5 mm; for example, the distance difference may be 0.49 mm, 0.45 mm, 0.43 mm, 0.38 mm, 0.35 mm, 0.2 mm or 0.1 mm, etc. Or, the midpoint of the line connecting the first edge welding structure and the second edge welding structure passes through one of the first intermediate welding structures. Or, the midpoint of the line connecting the third edge welding structure and the fourth edge welding structure passes through one of the second intermediate welding structures.

[0084] When the above technical solution is adopted, the probability of bending or even cracking of the battery cell body can be reduced while maintaining the reasonable position of the first middle welding structure or the second middle welding structure to ensure the strength and effect of the connection of the conductive connector.

[0085] In a second aspect, the embodiment of the utility model further provides a solar module, which includes a battery string, the battery string includes a plurality of conductive connectors and a plurality of solar cells arranged at intervals as described in the above technical solution, and the conductive connectors connect the plurality of solar cells in series.

[0086] The beneficial effects of the solar cell assembly provided by the embodiment of the utility model are the same as the beneficial effects of the solar cell described in the above technical solution, and will not be described in detail here.

[0087] The conductive connector may be a welding strip or other connector for connecting solar cells. When the conductive connector is a welding strip, the welding strip may be a welding strip with a circular, triangular or rectangular cross section. Preferably, a welding strip with a circular cross section is used. In this case, the mechanical stress at the connection of the solar cell can be dealt with, the problem of hidden cracks in high-density solar modules can be eliminated, and the reliability of the solar modules can be improved.

[0088] As a possible implementation, see Figures 1 to 4 , a plurality of spaced solar cells include adjacent first solar cells 5 and second solar cells 6, and the conductive connector 4 includes a first connection segment 40 located on the first surface 10 of the first solar cell 5, a second connection segment 41 located on the second surface 11 of the second solar cell 6, and a third connection segment 42. The first connection segment 40 has a first end segment 43 and a second end segment 44, the first end segment 43 is welded to the first edge welding structure 21 of the first solar cell 5, and the second end segment 44 is welded to the second edge welding structure 22 of the first solar cell 5. The second connection segment 41 includes a third end segment 45 and a fourth end segment 46, the third end segment 45 is welded to the third edge welding structure 31 of the second solar cell 6, the fourth end segment 46 is welded to the fourth edge welding structure 32 of the second solar cell 6, and the second end segment 44 and the third end segment 45 are connected through the third connection segment 42.

[0089] When the solar cells are welded in a string, the welding ribbon will have shrinkage stress when it cools down later. Since the welding ribbon is welded to the first welding structure 20 and the second welding structure 30 of the solar cell, the shrinkage stress will produce undesirable tension on the first welding structure 20 and the second welding structure 30 of the solar cell, especially for bifacial solar cells. Since the two opposite surfaces of the bifacial solar cell have electrode structures and are welded to the welding ribbon, it is often easier to cause the battery cell body 1 to bend or the tension on the battery cell body 1 to be unevenly distributed, resulting in serious damage to the first welding structure 20 and the second welding structure 30.

[0090] For example, after actual welding, the welding ribbon has a relatively large movable space (for example Figure 4 The B area in the figure), so the welding ribbon can release the shrinkage stress well when cooling. However, on the first surface 10 of the battery cell body 1, the welding ribbon does not have enough space to release the shrinkage stress at the place where the first edge welding structure 21 and the second edge welding structure 22 are close to the inside of the battery cell body 1, and the welding ribbon is fixedly welded to the first edge welding structure 21 and the second edge welding structure 22 and cannot be moved. The first edge welding structure 21 and the second edge welding structure 22 are both subjected to a pulling force toward the inside of the battery cell body (referred to as the first pulling force F1 for the convenience of subsequent description). The first pulling force is large and there is no pulling force balance in the opposite direction. The pulling center of the first pulling force can be simply understood as the center position of the first edge welding structure 21 and the second edge welding structure 22.

[0091] Similarly, on the second surface 11 of the battery cell body 1, the welding strip does not have enough space to release the shrinkage stress at the third edge welding structure 31 and the fourth edge welding structure 32 near the inside of the battery cell body 1, and the welding strip is fixedly welded to the third edge welding structure 31 and the fourth edge welding structure 32 and cannot be moved. The third edge welding structure 31 and the fourth edge welding structure 32 are both subjected to a tensile force toward the inside of the battery cell body (referred to as the second tensile force F2 for the convenience of subsequent description), and the second tensile force is large and there is no tensile force balance in the opposite direction. The center of the second tensile force can be simply understood as the center position of the third edge welding structure 31 and the fourth edge welding structure 32.

[0092] In the prior art, the positions of the four edge welding structures cannot enable the second tension to balance the effect of the first tension on the first surface, which may cause the battery cell body to warp.

[0093] Combined with the above description, it can be known that since the distance between the first edge welding structure and the first edge is smaller than the distance between the third edge welding structure and the first edge, the distance between the second edge welding structure and the second edge is smaller than the distance between the fourth edge welding structure and the second edge. It can be seen that after actual welding, on the first surface of the battery cell body, the first edge welding structure and the second edge welding structure are both subjected to a pulling force toward the inside of the battery cell body (for the convenience of subsequent description, referred to as the first pulling force). On the second surface of the battery cell body, the third edge welding structure and the fourth edge welding structure are both subjected to a pulling force toward the inside of the battery cell body (for the convenience of subsequent description, referred to as the second pulling force). When the above technical solution is adopted, it can be ensured that the perpendicular midline of the line connecting the first edge welding structure 21 and the second edge welding structure 22 and the perpendicular midline of the line connecting the third edge welding structure 31 and the fourth edge welding structure 32 are close and located in the middle area of ​​the battery cell. At this time, the first tension F1 and the second tension F2 can basically offset each other or offset each other, so as to basically balance or balance the influence of the welding strip tension on the first surface and the second surface, so that the influence of the shrinkage of the welding strip (i.e., the conductive connector) on the first surface on the battery cell body and the influence of the shrinkage of the welding strip on the second surface on the battery cell body are balanced as much as possible, thereby reducing or eliminating the probability of bending or even cracking of the battery cell body, so as to ensure the quality of the final solar module.

[0094] As a possible implementation method, when the perpendicular bisector of the line connecting the first edge welding structure 21 and the second edge welding structure 22 and the perpendicular bisector of the line connecting the third edge welding structure 31 and the fourth edge welding structure 32 are infinitely close to or coincide with each other, the first tension F1 and the second tension F2 can be almost completely offset, which can better prevent the battery cell body from bending or even cracking.

[0095] In the description of the above embodiments, specific features, structures, materials or characteristics may be combined in a suitable manner in any one or more embodiments or examples.

[0096] The above is only a specific implementation of the utility model, but the protection scope of the utility model is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed by the utility model, which should be included in the protection scope of the utility model. Therefore, the protection scope of the utility model should be based on the protection scope of the claims.

Claims

1. A solar cell, characterized in that: The solar cell comprises a cell body, the cell body comprises a first surface and a second surface opposite to each other, and a first electrode structure and a second electrode structure respectively formed on the first surface and the second surface; along a first direction, the cell body comprises a first edge and a second edge opposite to each other; The first electrode structure includes at least two first welding structures spaced apart along the first direction; The second electrode structure comprises at least two second welding structures spaced apart along the first direction; The first welding structure comprises: a first edge welding structure close to the first edge, and a second edge welding structure close to the second edge; The second welding structure includes: a third edge welding structure close to the first edge, and a fourth edge welding structure close to the second edge; The distance between the first edge welding structure and the first edge is smaller than the distance between the third edge welding structure and the first edge; A distance between the second edge welding structure and the second edge is smaller than a distance between the fourth edge welding structure and the second edge.

2. The solar cell according to claim 1, characterized in that A difference between a distance between the first edge welding structure and the first edge and a distance between the third edge welding structure and the first edge is equal to a difference between a distance between the second edge welding structure and the second edge and a distance between the fourth edge welding structure and the second edge.

3. The solar cell according to claim 1, characterized in that The distance between the first edge welding structure and the first edge is greater than or equal to 4.5 mm and less than or equal to 8.5 mm; The distance between the second edge welding structure and the second edge is greater than or equal to 5.5 mm and less than or equal to 9.5 mm; The distance between the third edge welding structure and the first edge is greater than or equal to 5 mm and less than or equal to 9 mm; The distance between the fourth edge welding structure and the second edge is greater than or equal to 6.5 mm and less than or equal to 10.5 mm.

4. The solar cell according to claim 1, characterized in that Along the first direction, an overlap rate of an orthographic projection of the first edge welding structure on the battery cell body and an orthographic projection of a corresponding third edge welding structure on the battery cell body is greater than or equal to 0 and less than 70%; Along the first direction, an overlap rate of an orthographic projection of the second edge welding structure on the battery cell body and an orthographic projection of a corresponding fourth edge welding structure on the battery cell body is greater than or equal to 0 and less than 70%.

5. The solar cell according to claim 1, characterized in that: Along the first direction, the overlap rate of the orthographic projection of the first edge welding structure on the battery cell body and the corresponding orthographic projection of the third edge welding structure on the battery cell body, and the overlap rate of the orthographic projection of the second edge welding structure on the battery cell body and the corresponding orthographic projection of the fourth edge welding structure on the battery cell body are equal or unequal.

6. The solar cell according to claim 1, characterized in that Along the first direction, when the overlap rate of the orthographic projection of the first edge welding structure on the battery cell body and the orthographic projection of the corresponding third edge welding structure on the battery cell body is zero, the overlap rate of the orthographic projection of the second edge welding structure on the battery cell body and the orthographic projection of the corresponding fourth edge welding structure on the battery cell body is greater than 50% and less than 100%; or, Along the first direction, when the overlap rate of the orthographic projection of the second edge welding structure on the battery cell body and the orthographic projection of the corresponding fourth edge welding structure on the battery cell body is zero, the overlap rate of the orthographic projection of the first edge welding structure on the battery cell body and the orthographic projection of the corresponding third edge welding structure on the battery cell body is greater than 50% and less than 100%.

7. The solar cell according to claim 1, characterized in that The first welding structure further includes a first intermediate welding structure located between the first edge welding structure and the second edge welding structure; The height of the first middle welding structure is equal to the height of the first edge welding structure; the height of the first edge welding structure is equal to the height of the second edge welding structure; The cross-sectional area of ​​the first intermediate welding structure is smaller than the cross-sectional area of ​​the first edge welding structure; The cross-sectional area of ​​the first edge welding structure is equal to the cross-sectional area of ​​the second edge welding structure; A cross section of the first middle welding structure, a cross section of the first edge welding structure, and a cross section of the second edge welding structure are all parallel to the battery cell body.

8. The solar cell according to claim 7, characterized in that: The second welding structure further includes a second intermediate welding structure located between the third edge welding structure and the fourth edge welding structure; The height of the second middle welding structure is equal to the height of the third edge welding structure; the height of the third edge welding structure is equal to the height of the fourth edge welding structure; The cross-sectional area of ​​the second intermediate welding structure is smaller than the cross-sectional area of ​​the third edge welding structure; The cross-sectional area of ​​the third edge welding structure is equal to the cross-sectional area of ​​the fourth edge welding structure; A cross section of the second middle welding structure, a cross section of the third edge welding structure, and a cross section of the fourth edge welding structure are all parallel to the battery cell body.

9. The solar cell according to claim 8, characterized in that: The first welding structure includes at least two of the first intermediate welding structures; The orthographic projections of half of the first intermediate welding structures on the battery cell body do not overlap with the orthographic projections of the second intermediate welding structures on the battery cell body.

10. The solar cell according to claim 8, characterized in that The orthographic projections of all the first intermediate welding structures on the battery cell body are misaligned with the orthographic projections of the corresponding second intermediate welding structures on the battery cell body.

11. The solar cell according to claim 8, characterized in that The difference in distance between the perpendicular midline of the line connecting the first edge welding structure and the second edge welding structure and the perpendicular midline of the line connecting the third edge welding structure and the fourth edge welding structure is less than 0.5 mm; or, The perpendicular midline of the line connecting the first edge welding structure and the second edge welding structure passes through one of the first intermediate welding structures; or, A perpendicular midline of a line connecting the third edge welding structure and the fourth edge welding structure passes through one of the second intermediate welding structures.

12. A solar panel, characterized in that: The solar module comprises a battery string; the battery string comprises a plurality of conductive connectors and a plurality of solar cells as claimed in any one of claims 1 to 11 arranged at intervals, wherein the conductive connectors connect the plurality of solar cells in series.

13. The solar module according to claim 12, characterized in that The plurality of spaced-apart solar cells include a first solar cell and a second solar cell that are adjacent to each other; the conductive connector includes a first connecting segment located on the first surface of the first solar cell, a second connecting segment located on the second surface of the second solar cell, and a third connecting segment; The first connecting section comprises a first end section and a second end section, the first end section is welded to a first edge welding structure of the first solar cell, and the second end section is welded to a second edge welding structure of the first solar cell; the second connecting section comprises a third end section and a fourth end section, the third end section is welded to a third edge welding structure of the second solar cell, and the fourth end section is welded to a fourth edge welding structure of the second solar cell; the second end section and the third end section are connected via the third connecting section.

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