Solar battery and manufacturing method for the same, and photovoltaic module

Abstract

To provide a solar battery and a manufacturing method for the same, and a photovoltaic module.SOLUTION: In a solar battery, a first welding point group of a plurality of columns and a second welding point group of at least one column are distributed along a first direction on a back surface of a battery cell. The second welding point group is distributed in a region that is adjacent to a cutting end or a bevelling end of the battery cell, and the first welding point group is distributed in a region where it is separated from the cutting end or the bevelling end of the battery cell. In the first direction, an interval distance between at least one welding point in the second welding point group and a welding point in the first welding point group that is adjacent thereto is larger than an interval distance between the welding points in the first welding point group adjacent to each other. In the solar battery according to the present application, a distance between the adjacent welding points in the adjacent battery cell can be reduced by moving the welding point of at least one part in the second welding point group in the region adjacent to the cutting end or the bevelling end in the battery cell to the outside, and can prevent generation of a phenomenon such as deviation or twisting in a welding strip.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] This application relates to the technical field of photovoltaic power generation, and particularly to solar cells, their manufacturing methods, and photovoltaic modules.

Background Art

[0002] A back-contact type battery refers to a battery cell in which both the metal grid lines of the two electrodes (including the main grid lines of the two electrodes and the fine grid lines of the two electrodes) and the PN junction are both located on the back surface of the battery cell, and the metal grid lines of the two electrodes are distributed alternately at intervals. A back-contact type battery with such a structure has no shielding due to structures such as metal grid lines of the two electrodes on the front surface (light conversion surface) of the battery cell, so it can reduce optical losses, has a higher short-circuit current Jsc, and allows wide metal grid lines of the two electrodes on the back surface of the battery cell to reduce the series resistance Rs of the battery cell, thereby improving the fill factor FF. In addition, by adding the front field of the battery cell and the open-circuit voltage gain due to a good passivation effect, the output power of the back-contact type battery is increased. Furthermore, because the conversion efficiency of the back-contact type battery is high, the back-contact type battery has good commercialization prospects.

[0003] Conventional back-contact type batteries include a plurality of battery cells, and the battery cells are connected to each other by welding strips to form a battery string to obtain a high-efficiency output module. However, since the welding points are provided on the back surface of the battery cell and the interval between adjacent welding points is large in adjacent battery cells, the welding strips connecting the welding points are likely to shift or twist during the processes of welding and lamination.

Summary of the Invention

Problems to be Solved by the Invention

[0004] In view of this, the present application provides a solar cell, a method for manufacturing the same, and a photovoltaic module. By moving at least a part of the weld points in the second weld point group to the outside in a region close to the cut end or chamfered end in the battery cell, the yield of manufacturing the photovoltaic module is improved.

Means for Solving the Problems

[0005] According to a first aspect, the present application provides a solar cell. On the back surface of the battery cell of the solar cell, a plurality of rows of first weld point groups and at least one row of second weld point groups are distributed along a first direction. The second weld point group is distributed in a region close to the cut end or chamfered end of the battery cell, and the first weld point group is distributed in a region away from the cut end or chamfered end of the battery cell. In the first direction, the distance between at least a part of the weld points in the second weld point group and the weld points in the first weld point group adjacent thereto is greater than the distance between the weld points in the adjacent first weld point groups.

[0006] In the above technical solution, in the solar cell according to the present application, by moving at least a part of the weld points in the second weld point group to the outside in a region close to the cut end or chamfered end of the battery cell, the distance between adjacent weld points in adjacent battery cells can be shortened. When adjacent weld points of adjacent battery cells are connected by a welding strip, it is possible to prevent phenomena such as displacement and torsion of the welding strip from occurring during the processes of welding and lamination, and the yield of manufacturing the photovoltaic module is high.

[0007] In accordance with the first aspect, in the first direction, the distance a between at least a part of the weld points in the second weld point group and the weld points in the first weld point group adjacent thereto, and the distance b between the weld points in the adjacent first weld point groups satisfy a - b = (2 mm to 6 mm).

[0008] In accordance with the first aspect, in the first direction, the distance between at least some of the weld points in the second weld point group and the cut end or chamfered end of the battery cell is 5 mm to 12 mm.

[0009] In accordance with the first aspect, in the region adjacent to the cut end of the battery cell, a row of the second weld point group is distributed. The distance between the weld points in the adjacent second weld point group and the first weld point group is greater than the distance between the weld points in the adjacent first weld point group.

[0010] In accordance with the first aspect, in the region adjacent to the cut end of the battery cell, two rows of the second weld point group are distributed. The two rows of the second weld point group are the third weld point group and the fourth weld point group respectively. The fourth weld point group is closer to the cut end than the third weld point group. The distance between the weld points in the adjacent third weld point group and the first weld point group is equal to the distance between the weld points in the adjacent first weld point group, and the distance between the weld points in the adjacent first weld point group and the fourth weld point group is greater than the distance between the weld points in the adjacent first weld point group.

[0011] In accordance with the first aspect, in the region adjacent to the chamfered end of the battery cell, two rows of the second weld point group are distributed. The two rows of the second weld point group are the fifth weld point group and the sixth weld point group respectively. The sixth weld point group is closer to the chamfered end than the fifth weld point group. The distance between the weld points in the adjacent fifth weld point group and the first weld point group is equal to the distance between the weld points in the adjacent first weld point group, and the distance between the weld points in the adjacent first weld point group and the sixth weld point group is greater than the distance between the weld points in the adjacent first weld point group.

[0012] In accordance with the first aspect, the weld points in the third weld point group and the weld points in the fourth weld point group are distributed at intervals alternately.

[0013] According to the first aspect, the battery cell is a one-Nth cut cell formed by cutting a full cell, where 1 ≤ N ≤ 4.

[0014] According to the second aspect, the present application provides a method for manufacturing a solar cell. The manufacturing method includes providing a plurality of welding points on the main grid line on the back surface of the battery cell along a first direction, and forming a plurality of rows of first welding point groups arranged and distributed and at least one row of second welding point groups. The second welding point group is distributed in a region close to the cut end or chamfered end of the battery cell, and the first welding point group is distributed in a region away from the cut end or chamfered end of the battery cell. In the first direction, the distance between at least some of the welding points in the second welding point group and the welding points in the adjacent first welding point group is greater than the distance between the welding points in the adjacent first welding point group.

[0015] According to the third aspect, the present application provides a photovoltaic module. The photovoltaic module includes a photovoltaic glass, a first adhesive film, a battery string, a second adhesive film, and a photovoltaic backplate. The battery string includes a plurality of solar cells manufactured by the solar cell according to any one of the first aspects or the manufacturing method of the solar cell according to the second aspect. Adjacent solar cells in the battery string are connected by a welding strip. Among the adjacent welding points for welding the welding strip in the adjacent solar cells, the distance between the second welding point groups at the ends of the adjacent solar cells is 9 mm to 25 mm.

Brief Description of the Drawings

[0016]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Embodiments for Carrying Out the Invention

[0017] To better understand the technical solution of the present application, the embodiments of the present application will be described in detail below with reference to the drawings.

[0018] It should be clear that the described embodiments are only some embodiments of the present application, not all embodiments. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the protection scope of the present application.

[0019] The terms used in the embodiments of the present application are only for the purpose of explaining specific embodiments and are not intended to limit the present application. The singular forms "one", "the foregoing", and "said" used in the embodiments of the present application and the appended claims are intended to include the plural forms as well, unless the context clearly indicates otherwise.

[0020] The term "and / or" used in this specification simply describes the relationship between related objects and means that three relationships may exist. For example, A and / or B can represent three cases: when A exists alone, when A and B exist simultaneously, and when B exists alone. Note that the character " / " used in this specification generally represents that the related objects before and after are in an "or" relationship.

[0021] Note that the orientation terms such as "upper", "lower", "left", and "right" described in the embodiments of the present application are described from the angles shown in the drawings and should not be understood as limitations to the embodiments of the present application. Further, in the context, when it is mentioned that an element is connected "above" or "below" another element, the element may be directly connected "above" or "below" the other element, or may be indirectly connected "above" or "below" the other element via an intermediate element.

[0022] In some embodiments, referring to FIG. 1, the configuration of the photovoltaic module includes a laminate member and a frame. The laminate member includes a photovoltaic glass 4, a first adhesive film 5, a plurality of sets of battery strings, a second adhesive film 6, and a photovoltaic backplate 7. Further, each battery string includes a plurality of battery cells installed in series, and the battery cell is a full cell or a cut cell that is one-Nth of the full cell, where 1 ≤ N ≤ 4. That is, the battery cell may be a full cell, a half cut cell, a one-third cut cell, a one-fourth cut cell, etc., and the type of the battery cell can be selected according to actual needs and is not limited herein. The photovoltaic glass 4, the first adhesive film 5, the plurality of sets of battery strings, the second adhesive film 6, and the photovoltaic backplate 7 undergo a lamination process to obtain the laminate member, and at this time, the laminate member is assembled with the frame to form a photovoltaic module.

[0023] Furthermore, the battery cell used in the present application may be a single-sided light conversion battery cell or a double-sided light conversion battery cell. Also, the single-sided light conversion battery cell refers to a battery cell that receives light only from the front side and converts the light into electric power, and the double-sided light conversion battery cell refers to a battery cell that receives light from both sides and converts the light into electric power. That is, the battery cell can not only receive direct sunlight irradiation from the front side and convert the sunlight into electric power, but also receive light such as reflected light or scattered light from the ground, etc. from the back side, thereby improving the power generation efficiency of the photovoltaic module. Battery cells in other light conversion regions may be selected, or the light conversion type of the battery cell may be selected according to actual needs and is not limited herein.

[0024] Furthermore, both the metal grid lines of the two electrodes in the battery cell (including the main grid lines of the two electrodes and the fine grid lines of the two electrodes) and the PN junction are located on the back surface of the battery cell. That is, in the solar cell according to the present application, a back-contact battery cell is adopted. The main grid lines of the two electrodes of the back-contact battery cell include a first main grid line and a second main grid line. The plurality of first main grid lines and the second main grid line both extend along the first direction, and the two are alternately distributed along the second direction.

[0025] In the present application, the first direction refers to the length direction of the battery string, that is, the series connection direction of the battery cells in the battery string, and the second direction refers to the width direction of the battery cell, that is, the parallel connection direction of the plurality of battery strings. Further, along the second direction, the first main grid line may be the first main grid line or the second main grid line according to actual needs, and is not limited here.

[0026] On the back surface of the battery cell, there are further included a first fine grid line and a second fine grid line extending along the second direction. That is, the first main grid line, the second main grid line, the first fine grid line, and the second fine grid line are all located on the back surface of the battery cell. Specifically, the first fine grid line and the second fine grid line are alternately arranged along the first direction. Also, the first fine grid line is connected to the first main grid line, the second fine grid line is connected to the second main grid line, and the first fine grid line has the same polarity as the first main grid line, and the second fine grid line has the same polarity as the second main grid line. As can be understood, the first main grid line may be selected as the positive electrode main grid line, and the second main grid line may be selected as the negative electrode main grid line, or the second main grid line may be selected as the positive electrode main grid line, and the first main grid line may be selected as the negative electrode main grid line, which can be selected according to actual needs and is not limited here. At this time, through the cooperation of the first fine grid line and the first main grid line, and the cooperation of the second fine grid line and the second main grid line, the current converted from light can be collected by the first main grid line and the second main grid line through the first fine grid line and the second fine grid line.

[0027] For the back contact battery in which the metal grid lines of both electrodes (including the main grid lines of both electrodes and the fine grid lines of both electrodes) and the PN junction are all located on the back surface of the battery cell, since there is no shielding by structures such as the metal grid lines of both electrodes on the front surface (light conversion surface) of the battery cell, optical loss can be reduced, it has a higher short-circuit current Jsc, and on the back surface of the battery cell, wide metal grid lines of both electrodes are allowed, and by reducing the series resistance Rs of the battery cell, the fill factor FF can be improved, and adding the open-circuit voltage gain due to the front field of the battery cell and a good passivation effect, the output power of the back contact type battery can be increased, and furthermore, the conversion efficiency of the back contact type battery is high.

[0028] In some embodiments, battery cells according to the present application can form a battery string through combined connection of welding strips 3 and welding points, and an efficient output module can be obtained. The conventional welding point arrangement method is generally as follows. That is, after the first main grid line and the second main grid line extending along the first direction are alternately provided on the back surface of the battery cell, the distribution positions of the welding points are specified on the first main grid line and the second main grid line respectively. That is, all the welding points of the back contact battery are also provided on the back surface of the battery cell. A plurality of welding points on the first main grid line and the second main grid line are all distributed at equal intervals, and the interval distance between adjacent welding points in the battery cell is equal to the interval distance between the outermost welding point of the battery cell and the edge of the end of the battery cell. This interval distance b = 7 mm to 18 mm. Optionally, the interval distance b may specifically be 7 mm, 9 mm, 11 mm, 13 mm, 15 mm, 17 mm, 18 mm, etc., or other numerical values within the range, and can be selected according to actual needs, and is not limited here. When adjacent battery cells need to be connected by welding strips, the interval distance c between adjacent welding points at the ends of adjacent battery cells is c≥2b = 16 mm to 33 mm. Optionally, the interval distance c may specifically be 16 mm, 18 mm, 21 mm, 24 mm, 27 mm, 29 mm, 31 mm or 33 mm, etc., or other numerical values within the range, and may also be selected according to actual needs, and is not limited here. As can be understood, due to the installation method of welding points at equal interval distances on the first main grid line and the second main grid line, and the interval distance c≥2b = 16 mm to 33 mm, the length of the welding strip 3 required for connecting adjacent welding points in adjacent battery cells becomes longer. A welding strip 3 that is too long is likely to shift or twist during the processes of welding and laminating.

[0029] In view of this, the present application provides a solar cell. Referring to FIGS. 2 to 8, on the back surface of the battery cell of the solar cell, a plurality of rows of first welding point groups 1 and at least one row of second welding point groups 2 are distributed along a first direction. The second welding point group 2 is distributed in a region close to the cutting end or chamfered end of the battery cell, and the first welding point group 1 is distributed in a region away from the cutting end or chamfered end of the battery cell. Also, in the first direction, the distance a between at least some of the welding points in the second welding point group 2 and the welding points in the adjacent first welding point group 1 is greater than the distance b between the welding points in the adjacent first welding point group 1.

[0030] In the above technical solution, for the solar cell according to the present application, by moving at least some of the welding points in the second welding point group 2 in the region close to the cutting end or chamfered end of the battery cell outward, the distance between adjacent welding points in adjacent battery cells can be shortened. When adjacent welding points are connected to adjacent battery cells by the welding strip 3, it is possible to prevent phenomena such as displacement and torsion of the welding strip 3 from occurring during the processes of welding and lamination, and the production yield of the photovoltaic module is high.

[0031] As can be understood, compared with providing welding points at equal distances on the first main grid line and the second main grid line in the prior art, in the technical solution of the present application, since at least some of the welding points are moved outward closer to the cutting end or chamfered end, when adjacent battery cells need to be connected by a welding strip, if the battery cells are connected at the adjacent cutting ends, the distance between adjacent welding points at the adjacent cutting ends is smaller than 2b, and if the battery cells are connected at the chamfered ends, the distance between adjacent welding points in the adjacent battery cells is also smaller than 2b. That is, the length of the welding strip 3 required to connect adjacent welding points in adjacent battery cells is reduced, thereby reducing the problem of displacement or torsion of the welding strip 3 occurring during the processes of welding and lamination.

[0032] In some embodiments, in the first direction, the spacing distance a between the welding points in the first welding point group 1 adjacent to at least some of the welding points in the second welding point group 2 and the spacing distance b between the welding points in the adjacent first welding point group 1 satisfy a - b = (2 mm to 6 mm), that is, the value of a may be 9 mm to 24 mm. Optionally, the value of a may specifically be 9 mm, 11 mm, 13 mm, 15 mm, 17 mm, 19 mm, 21 mm, 24 mm, etc., or other numerical values within the range, and can be selected according to actual needs, and is not limited here. Preferably, it is 12 mm to 21 mm, and more preferably, it is 15 mm to 18 mm.

[0033] Optionally, the value of a - b may specifically be 2 mm, 3 mm, 4 mm, 5 mm, 6 mm, etc., or other numerical values within the range, and can be selected according to actual needs, and is not limited here. If the value of a - b is too small, the outward movement distance of the welding point is insufficient, and the spacing between the adjacent welding points of the adjacent battery cells is still too large, and the welding or lamination requirements of the welding strip 3 cannot be met. If the value of a - b is too large, the outward movement distance of the welding point is too large, and the spacing between the adjacent welding points in the battery cell is too large, and it is necessary to increase the length of the welding strip 3 connecting the adjacent welding points in the battery cell, and phenomena such as displacement and torsion are likely to occur during the welding and lamination processes. Preferably, the value of a - b is 3 mm to 5 mm, and more preferably, the value of a - b is 4 mm to 4.5 mm.

[0034] In some embodiments, in the first direction, the spacing distance d between at least some of the welding points of the second welding point group 2 and the cut end or chamfered end of the battery cell is 5 mm to 12 mm, that is, the spacing distance d of the outermost welding point of the battery cell from the battery cell edge is 5 mm to 12 mm. Optionally, the spacing distance d may specifically be 5 mm, 6 mm, 7 mm, 8 mm, 9 mm, 10 mm, 11 mm, 12 mm, etc., or other numerical values within the range, and can be selected according to actual requirements, and is not limited here. If the spacing distance of the outermost welding point of the battery cell from the battery cell edge is too large, that is, if the moving distance of the welding point outward is insufficient, the spacing between adjacent welding points in the adjacent battery cell is still too large, and the requirements for welding or laminating the welding strip 3 cannot be met. If the spacing distance of the outermost welding point of the battery cell from the battery cell edge is too small, the moving distance of the welding point outward is too large, that is, the spacing between adjacent welding points in the battery cell is too large, and it is necessary to increase the length of the welding strip 3 connecting the adjacent welding points in the battery cell, and phenomena such as displacement and torsion are likely to occur during the welding and laminating processes.

[0035] In some embodiments, the second welding point group 2 having the above distance from the battery cell edge is distributed in a region close to the cut end or chamfered end of the battery cell, and the first welding point group 1 is distributed in a region away from the cut end or chamfered end of the battery cell, that is, the first welding point group 1 is provided in the middle region of the battery cell, and the second welding point group 2 is provided in the end region of the battery cell. In the middle region, multiple rows of the first welding point group 1 are provided, and the spacing distance b between the welding points in the adjacent first welding point groups 1 is the same. The number of installations of the second welding point group 2 can be selected according to the chamfered end or cut end in the end region.

[0036] In addition, when the battery cell of the solar cell used in this application is a full cell, the battery cell includes two chamfered ends and does not have a cut end. When the battery cell is a 1 / N cut cell, the battery cell includes at least one cut end. Exemplarily, it includes one cut end and one chamfered end, or both ends of the battery cell are cut ends. In this application, the type of the battery cell is not limited and can be selected according to actual needs.

[0037] In some embodiments, the second solder joint group 2 may be provided at the cut end.

[0038] As an alternative technical solution of this application, continuing to refer to FIG. 2, in the region close to the cut end of the battery cell, a row of second solder joint groups 2 are distributed. Among them, the spacing distance a between the solder joints of the adjacent second solder joint group 2 and the first solder joint group 1 is larger than the spacing distance b between the solder joints of the adjacent first solder joint group 1. That is, the solder joints of the second solder joint group 2 located in the region close to the cut end have all moved outward.

[0039] As yet another alternative technical solution of this application, continuing to refer to FIG. 3, in the region close to the cut end of the battery cell, two rows of second solder joint groups 2 are distributed. The two rows of second solder joint groups 2 are the third solder joint group 21 and the fourth solder joint group 22 respectively. The fourth solder joint group 22 is closer to the cut end than the third solder joint group 21. Also, the spacing distance between the solder joints of the adjacent third solder joint group 21 and the first solder joint group 1 is equal to the spacing distance between the solder joints of the adjacent first solder joint group 1, and the spacing distance a between the solder joints of the adjacent first solder joint group 1 and the fourth solder joint group 22 is larger than the spacing distance b between the solder joints of the adjacent first solder joint group 1. That is, the solder joints of the second solder joint group 2 located in the region close to the cut end have partially moved outward. Note that the solder joints that have moved outward may be the solder joints located on the first main grid line or the solder joints located on the second main grid line, and can be selected according to actual needs and are not limited here.

[0040] In some embodiments, when the second weld point group 2 is provided at the chamfered end, due to the special structure of the chamfered end, the chamfered end includes two rows of the second weld point group 2, and the two rows of the second weld point group 2 are the fifth weld point group 25 and the sixth weld point group 26 respectively. The sixth weld point group 26 is closer to the chamfered end than the fifth weld point group 25.

[0041] In the present application, the chamfering angle of the chamfered end is 40 - 45°. Optionally, the chamfering angle may specifically be 40°, 41°, 42°, 43°, 44°, 45°, etc., or other numerical values within the range, and can be selected according to actual needs, without limitation here. As can be understood, when the chamfering angle is within the above range, the stress at the corner can be minimized. Preferably, the chamfering angle of the chamfered end is 41° - 44°, and more preferably, the chamfering angle of the chamfered end is 42° - 43°.

[0042] As an alternative technical solution of the present application, referring to FIG. 2 or FIG. 3 continuously, the chamfered end includes two chamfered areas. The fifth weld point group 25 is provided only in the chamfered area. Except for the weld points located in the chamfered area, all the remaining weld points of the second weld point group 2 move outward to form the sixth weld point group 26.

[0043] As yet another alternative technical solution of the present application, referring to FIG. 4 or FIG. 5 continuously, some weld points of the second weld point group 2 are displaced to form the sixth weld point group 26. Here, the weld points that move outward are all the weld points on the first main grid line or all the weld points on the second main grid line, and can be selected according to actual needs, without limitation here.

[0044] In the above two technical solutions, the spacing distance between the weld points in the adjacent fifth weld point group 25 and the first weld point group 1 is equal to the spacing distance b between the weld points in the adjacent first weld point group 1, and the spacing distance a between the weld points in the adjacent first weld point group 1 and the sixth weld point group 26 is greater than the spacing distance b between the weld points in the adjacent first weld point group 1.

[0045] In addition, when the number of welding points in the third welding point group 21 and the number of welding points in the fourth welding point group 22 are added together, it becomes equal to the number of the first welding point group 1 in one row. When the number of welding points in the fifth welding point group 25 and the number of welding points in the sixth welding point group 26 are added together, it also becomes equal to the number of the first welding point group 1 in one row.

[0046] In the process of manufacturing, first, along the first direction, a plurality of welding points are provided on the main grid lines on the back surface of the battery cell to form a plurality of rows of the first welding point group 1 and at least one row of the second welding point group 2 that are arranged and distributed. Among them, the second welding point group 2 is distributed in the area close to the cut end or chamfered end of the battery cell, and the first welding point group 1 is distributed in the area away from the cut end or chamfered end of the battery cell. Also, in the first direction, the distance a between at least some of the welding points in the second welding point group 2 and the welding points in the adjacent first welding point group 1 is greater than the distance b between the welding points in the adjacent first welding point group 1. That is, a solar cell with a welding point spacing distance that meets the requirements can be obtained.

[0047] In addition, when adjacent battery cells are connected by an overlapping welding method, the distance e between the welding points in the adjacent second welding point group 2 at the ends of the adjacent solar cells is less than 2d. When adjacent battery cells are connected by a non - overlapping welding method, the distance e between the welding points in the adjacent second welding point group 2 at the ends of the adjacent solar cells is greater than or equal to 2d. The connection method of adjacent battery cells can be selected according to actual requirements, and it is not limited here.

[0048] Referring to FIG. 6, FIG. 7 or FIG. 8, FIG. 6, FIG. 7 or FIG. 8 shows different connection forms of different welding strips of adjacent battery cells when the form of the movement of the welding point to the outside is different. The spacing distance e between the welding points in the second welding point group 2 adjacent to the ends of the adjacent solar cells after the welding strips are connected is 9 mm to 25 mm. Optionally, the spacing distance e between the welding points in the second welding point group 2 adjacent to the ends of the adjacent battery cells may specifically be 9 mm, 12 mm, 15 mm, 18 mm, 21 mm, 24 mm, 25 mm, etc., or other numerical values within the range, and can be selected according to actual requirements without limitation here. If the spacing distance between the welding points in the second welding point group 2 of the adjacent battery cells is too large, the movement distance of the welding point to the outside is insufficient, and the spacing between the adjacent welding points of the adjacent battery cells is still too large, and the welding or lamination requirements of the welding strip 3 cannot be satisfied. If the spacing distance between the welding points in the second welding point group 2 of the adjacent battery cells is too small, the movement distance of the welding point to the outside is too large, the spacing between the adjacent welding points in the battery cell is too large, and it is necessary to increase the length of the welding strip 3 connecting the adjacent welding points in the battery cell, and phenomena such as displacement and torsion are likely to occur during the welding and lamination processes. Preferably, the spacing distance e may be 12 mm to 21 mm, and more preferably, the spacing distance e may be 16 mm to 17 mm.

[0049] In some embodiments, the battery string with the connection by the welding strip 3 can undergo a lamination process with other elements. Since the battery cells are very fragile during the lamination process and are easily damaged when subjected to pressure, and the photovoltaic glass 4 and the photovoltaic backplate 7 cannot be directly attached onto the battery cells, the first adhesive film 5 and the second adhesive film 6 are required to act as a medium for the adhesion. In actual use, the first adhesive film 5 and the second adhesive film 6 are used to seal the battery strings arranged at intervals. Specifically, after laminating the first adhesive film 5, the battery string, and the second adhesive film 6 to obtain a combination, the combination is heated to a certain temperature to melt the first adhesive film 5 and the second adhesive film 6 and adhere them to the battery cells.

[0050] It should be noted that the first adhesive film 5 and the second adhesive film 6 used in the present application may be ethylene-vinyl acetate copolymer (EVA) adhesive films, polyethylene octene copolymer (POE) adhesive films, or polyethylene terephthalate (PET) adhesive films, and may also be polyvinyl butyral (PVB) adhesive films, ethylene propylene elastomer (EPE) adhesive films (three-layer coextruded adhesive films of EVA and POE), ethylene propylene (EP) adhesive films (two-layer coextruded adhesive films of EVA and POE), or other types of adhesive films, and can be selected according to actual needs and are not limited herein. Preferably, the first adhesive film 5 and the second adhesive film 6 used in the present application are EVA adhesive films. The EVA adhesive film has no viscosity at room temperature, has good winding property, transparency, and surface glossiness, has stable chemical properties, excellent anti-aging and ozone resistance, is non-toxic, and undergoes melt adhesion and crosslinking curing when hot-pressed under certain conditions. The cured adhesive film has excellent light transmittance, adhesion strength, thermal stability, airtightness, and anti-aging performance, and does not affect the light conversion performance of the photovoltaic module when sealing multiple sets of battery strings.

[0051] The photovoltaic glass 4 is provided on the side away from the battery cell of the first adhesive film 5. The photovoltaic glass 4, also called "photoelectric glass", has good light transmittance and high hardness. When coated on the first adhesive film 5, it can adapt to large day-night temperature differences and bad weather environments and can play a protective role for the battery cell. The photovoltaic glass 4 used in this application may be ultra-white photovoltaic embossed glass, ultra-white processed float glass, TCO glass, etc., or other types of photovoltaic glass 4, and can be selected according to actual needs, and is not limited here.

[0052] The photovoltaic backplate 7 is provided on the side away from the battery cell of the second adhesive film 6. Similarly, the photovoltaic backplate 7 can play a protective and supporting role for the battery cell, and has good weather resistance, water shielding property, corrosion resistance, insulation property, etc. It can isolate the photovoltaic module from the surrounding photovoltaic environment and effectively protect and support the battery cell, thereby improving the impact resistance strength of the photovoltaic module. The photovoltaic backplate 7 used in this application may be glass, rolled glass or ultra-white rolled glass.

[0053] After the adhesion of the laminate member is completed, the photovoltaic module can be assembled by a frame, and finally, the photovoltaic module is fixed to the bracket by a pressing block and used. The bracket is a special frame designed and installed to support, fix, and rotate the photovoltaic module. It can be divided into a fixed bracket and a tracking bracket according to its structure. The fixed bracket has a fixed direction and a low manufacturing cost. The tracking bracket can rotate the angle of the photovoltaic module according to the light irradiation intensity, reduce the angle between the module and the direct sunlight of the sun, obtain more solar irradiation, and effectively improve the power generation efficiency. However, the manufacturing cost is high. Also, according to the material, it can be divided into an aluminum alloy bracket, a carbon steel bracket, a stainless steel bracket, etc. The structure and material of the bracket can be selected according to the actual needs, and it is not limited here. When actually used, the photovoltaic bracket can fix the photovoltaic module in a certain direction, arrangement method, and interval based on the conditions of the terrain, climate, and solar energy resources. As can be understood, when the photovoltaic module is fixed through the bracket, it can receive sunlight better.

[0054] Hereinafter, the technical solution of the present application will be described with reference to specific embodiments. Installation of Samples Sample 1: Move at least some of the weld points in the second weld point group at the end of the battery cell 2 mm to 6 mm outward. The distance between the outermost weld point and the end of the battery cell is 5 mm to 12 mm. Connect the adjacent outermost weld points in the adjacent battery cells using a welding strip, and observe the warping height of the welding strip.

[0055] Sample 2: All weld points are provided at equal intervals. The distance between the outermost weld point and the end of the battery cell is 8 mm to 16.5 mm. Connect the adjacent outermost weld points in the adjacent battery cells using a welding strip, and observe the warping height of the welding strip.

[0056] The number of samples 1 and 2 installed is 100 each. After assembling the battery cells, photovoltaic glass, first adhesive film, second adhesive film, photovoltaic backplate, etc. of samples 1 and 2 into a photovoltaic module through steps such as lamination, observe the torsional situation of the welding strip.

[0057] The test results are as follows.

Table 1

[0058] As can be seen from the above test results, for the solar cell and the photovoltaic module according to the present application, by moving at least a part of the welding points of the second welding point group 2 in the region close to the cut end or chamfered end in the battery cell to the outside, the distance between adjacent welding points in adjacent battery cells can be shortened. When the adjacent welding points of adjacent battery cells are connected by the welding strip 3, the number of cases where the warp height of the welding strip of the present application is too high is lower than that of the prior art, and most of them are concentrated in 2 - 4 mm. After going through the lamination process, no torsional phenomenon occurs in the welding strip, and the production yield of the photovoltaic module is high.

[0059] Based on the embodiments shown in the drawings above, the structure, features, and effects of the present invention have been described in detail. However, the above are only preferred embodiments of the present invention, and the present invention is not limited to the embodiments shown in the drawings. It is an equivalent embodiment modified by changes made based on the concept of the present invention or equivalent deformations, and as long as it does not exceed the spirit included in the description and the illustration, all are within the protection scope of the present invention.

Explanation of Reference Numerals

[0060] 1 First welding point group, 2 Second welding point group, 21 Third welding point group, 22 Fourth welding point group, 25 Fifth welding point group, 26 Sixth welding point group, 3 Welding strip, 4 Photovoltaic glass, 5 First adhesive film, 6 Second adhesive film, 7 Photovoltaic backplate

Claims

1. A solar cell comprising: a back surface of a battery cell of the solar cell has a plurality of rows of first welding points and at least one row of second welding points distributed along a first direction, the second welding points being distributed in an area close to a cut edge or a chamfered edge of the battery cell, and the first welding points being distributed in an area away from the cut edge or the chamfered edge of the battery cell; A solar cell characterized in that, in a first direction, a distance between at least some of the welding points in the second group of welding points and adjacent welding points in the first group of welding points is greater than a distance between adjacent welding points in the first group of welding points.

2. The solar cell according to claim 1, characterized in that, in a first direction, a distance a between at least a portion of the welding points in the second welding point group and an adjacent welding point in the first welding point group, and a distance b between adjacent welding points in the first welding point group, satisfy a-b = (2 mm to 6 mm).

3. 2. The solar cell according to claim 1, wherein a distance in the first direction between at least some of the welds in the second group of welds and the cut edge or chamfered edge of the battery cell is 5 mm to 12 mm.

4. a row of the second welding points is distributed in an area adjacent to the cut end of the battery cell; 2 . The solar cell according to claim 1 , wherein a distance between adjacent welding points in the second welding point group and the first welding point group is greater than a distance between adjacent welding points in the first welding point group.

5. two rows of second welding point groups are distributed in an area adjacent to the cut end of the battery cell, the two rows of second welding point groups being a third welding point group and a fourth welding point group, respectively, the fourth welding point group being closer to the cut end than the third welding point group; 2. The solar cell according to claim 1, wherein a spacing distance between the welding points in the adjacent third welding point group and the adjacent first welding point group is equal to a spacing distance between the welding points in the adjacent first welding point group, and a spacing distance between the welding points in the adjacent first welding point group and the adjacent fourth welding point group is greater than a spacing distance between the welding points in the adjacent first welding point group.

6. two rows of second welding point groups are distributed in an area of ​​the battery cell adjacent to the chamfered end, the two rows of second welding point groups being a fifth welding point group and a sixth welding point group, respectively, the sixth welding point group being closer to the chamfered end than the fifth welding point group; 6. The solar cell according to claim 5, wherein a spacing distance between the welding points in the adjacent fifth welding point group and the adjacent first welding point group is equal to a spacing distance between the welding points in the adjacent first welding point group, and a spacing distance between the welding points in the adjacent first welding point group and the adjacent sixth welding point group is greater than a spacing distance between the welding points in the adjacent first welding point group.

7. 7. The solar cell according to claim 6, wherein the welds in the third group of welds and the welds in the fourth group of welds are alternately distributed at intervals.

8. 8. The solar cell according to claim 1, wherein the battery cell is a 1 / Nth cut cell obtained by cutting a full cell, where 1≦N≦4.

9. A method for manufacturing a solar cell, comprising the steps of: the manufacturing method includes providing a plurality of welding points on main grid lines on a back surface of a battery cell along a first direction to form a plurality of rows of a first group of welding points and at least one row of a second group of welding points that are arranged and distributed, the second group of welding points being distributed in an area close to a cut edge or a chamfered edge of the battery cell, and the first group of welding points being distributed in an area away from the cut edge or the chamfered edge of the battery cell, and a distance between at least some of the welding points in the second group of welding points and an adjacent welding point in the first group of welding points in the first direction is greater than a distance between adjacent welding points in the first group of welding points.

10. 1. A photovoltaic module comprising: The photovoltaic module includes a photovoltaic glass, a first adhesive film, a battery string, a second adhesive film, and a photovoltaic back plate, and the battery string includes a plurality of solar cells manufactured by the solar cell manufacturing method according to any one of claims 1 to 8 or claim 9; the adjacent solar cells in the cell string are connected by a welding strip, and among the adjacent welding points for welding the welding strips in the adjacent solar cells, a spacing distance between the second welding point group at the ends of the adjacent solar cells is 9 mm to 25 mm.

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