Main-grid-free back contact battery, battery assembly and photovoltaic system

Abstract

The utility model provides a main-grid-free back contact battery, a battery assembly and a photovoltaic system. The main-grid-free back contact battery comprises a battery substrate; the fine grids are arranged on the battery substrate; each first fixing section comprises a plurality of first welding spot parts which are arranged at intervals in the first direction, the first welding spot parts are arranged on the fine grids, and the areas of the first welding spot parts are gradually reduced in the first direction; each second fixing section comprises a plurality of second welding spot parts which are arranged at intervals in the first direction, the second welding spot parts are arranged on the fine grids, and the areas of every two adjacent second welding spot parts are the same in the first direction; the battery substrate further comprises a plurality of conductive adhesive areas, the conductive adhesive areas are used for arranging conductive adhesives, and in the second direction, the conductive adhesive areas and the second fixing sections are arranged at intervals. Due to the arrangement of the first fixed section and the conductive adhesive region, the welding strip is prevented from being aligned with the central positions of welding spots on the battery pieces one by one during arrangement, and the arrangement difficulty of the welding strip is reduced.

Description

TECHNICAL FIELD

[0001] The utility model relates to photovoltaic technology field especially relates to a kind of main gridless back contact cell, battery pack and photovoltaic system. BACKGROUND

[0002] In battery pack, adjacent cell piece is connected by welding band.In related technology, in order to prevent welding band from deviating, welding band needs to be aligned with the center position of soldering point on cell piece one by one when setting welding band.This makes the setting difficulty of welding band greater.

[0003] Therefore, how to reduce the setting difficulty of welding band has become a problem to be solved urgently. SUMMARY

[0004] The utility model provides a kind of main gridless back contact cell, battery pack and photovoltaic system to solve the technical problem of how to reduce the setting difficulty of welding band.

[0005] The utility model embodiment is realized as follows, the utility model provides a kind of main gridless back contact cell, battery pack and photovoltaic system.A kind of main gridless back contact cell, comprising: cell substrate, the cell substrate includes the first edge and the second edge along the first direction arrangement, the first edge and the second edge are oppositely arranged;Several thin grids, set in the cell substrate, the thin grid along the first direction arrangement, the thin grid extends along the second direction, the first direction and the second direction intersect, the first direction is the first edge of the cell substrate towards the center of the cell substrate direction;Several first fixed sections, the distance of the first fixed section along the first direction to the first edge is less than to the second edge, the first fixed section includes the first soldering point part along the first direction interval arrangement, the first soldering point part is set in the thin grid, along the first direction, the area of the first soldering point part gradually decreases;

[0006] Several second fixed sections, the distance of the second fixed section along the first direction to the first edge is less than to the second edge, the first fixed section and the second fixed section along the first direction sequentially arranged, the second fixed section includes the second soldering point part along the first direction interval arrangement, the second soldering point part is set in the thin grid, along the first direction, the area of adjacent two second soldering point parts is same, along the first direction, the second fixed section is located between two second fixed sections.

[0007] The cell substrate further includes several conductive glue regions, and the conductive glue regions are used to set conductive glue, and the conductive glue regions and the first fixed section and / or the second fixed section are spaced apart in the second direction.

[0008] Further, along the first direction, each of the second solder point portions has the same length in the second direction.

[0009] Further, along the first direction, a center point of each of the second solder point portions in the second fixed segment is on a first straight line, the first straight line extending along the first direction.

[0010] Further, the second solder point portion comprises a first boundary line extending along the first direction, along the first direction, each of the first boundary lines in the second fixed segment is on a second straight line, the second straight line extending along the first direction.

[0011] Further, the second solder point portion further comprises a second boundary line extending along the first direction, the second boundary line oppositely arranged with the first boundary line, along the first direction, each of the second boundary lines in the second fixed segment is on a third straight line, the third straight line extending along the first direction.

[0012] Further, along the first direction, a line connecting the center points of all the second solder point portions in two adjacent second fixed segments is a first fold line.

[0013] Further, the first fold line comprises a plurality of first straight line segments. Further, the back contact cell without main grid further comprises a third solder point portion, the third solder point portion not comprising the conductive adhesive area along two side edges in the second direction; along the first direction, a center point of each of the first solder point portions in the first fixed segment is on a fourth straight line, the fourth straight line extending along the first direction; in the first direction, the center point of the third solder point portion is between two adjacent first fixed segments; in the second direction, the center point of the third solder point portion is between two fourth straight lines formed by two adjacent first fixed segments; or, in the first direction, the center point of the third solder point portion is between two adjacent second fixed segments; in the second direction, the center point of the third solder point portion is between two first straight lines formed by two adjacent second fixed segments; or, in the first direction, the center point of the third solder point portion is between the adjacent first fixed segment and the second fixed segment; in the second direction, the center point of the third solder point portion is between the fourth straight line formed by the adjacent first fixed segment and the first straight line formed by the second fixed segment.

[0014] Further, the back contact cell without main grid further comprises a plurality of first welding sections, the first fixed section, the second fixed section and the first welding section are arranged in sequence along the first direction; an edge of the first welding section along the second direction does not comprise the conductive adhesive area; the first welding section comprises a plurality of fourth soldering point parts arranged at the fine grid, and the area of the fourth soldering point part gradually decreases along the first direction.

[0015] Further, the area of the first soldering point part with the smallest area is greater than or equal to the area of the second soldering point part.

[0016] Further, the area of the fourth soldering point part with the largest area is less than or equal to the area of the second soldering point part.

[0017] Further, the first direction, the second fixed section is located between two second fixed sections.

[0018] The utility model embodiment further provides a battery assembly, the battery assembly includes the back contact cell without main grid as described above.

[0019] Further, the battery assembly further comprises a solder strip and conductive adhesive, the solder strip is connected with the fine grid through the conductive adhesive and the soldering point part, and the conductive adhesive is arranged in the conductive adhesive area; the soldering point part comprises at least one of a plurality of first soldering point parts, a plurality of second soldering point parts, a plurality of third soldering point parts and a plurality of fourth soldering point parts.

[0020] Further, the solder strip covers the soldering point part and the conductive adhesive.

[0021] Further, the soldering point part comprises a first edge point, the first edge point is the point on the soldering point part farthest from the conductive adhesive area in the second direction; the conductive adhesive area comprises a second edge point, the second edge point is the point on the conductive adhesive area farthest from the soldering point part in the second direction; in the second direction, the interval between the first edge point and the second edge point is a first size; in the second direction, the width of the solder strip is a second size; the second size is greater than or equal to the first size.

[0022] The utility model embodiment further provides a photovoltaic system, the photovoltaic system includes the battery assembly as described above.

[0023] The back contact cell without main grid in the embodiment of the utility model, due to being provided with the first fixed section, the second fixed section and the conductive glue area, and then the solder strip can be positioned through the conductive glue area when setting the solder strip, the solder strip is prevented from deviating, and then the soldering is carried out through the first soldering point part in the first fixed section and the second soldering point part in the second fixed section, so that the solder strip needs to be aligned with the center position of the soldering point on the cell piece one by one when setting is avoided, and the setting difficulty of the solder strip is reduced. BRIEF DESCRIPTION OF DRAWINGS

[0024] In order to more clearly illustrate the technical scheme in the embodiments of the utility model or the prior art, the drawings needed to be used in the embodiment or the prior art description will be briefly introduced below, and obviously, the drawings in the following description are only some embodiments in the utility model, and for those skilled in the art, other drawings can be obtained according to these drawings without creating labor.

[0025] Figure 1 It is the module schematic diagram of the photovoltaic system provided by an embodiment of the utility model;

[0026] Figure 2 It is the module schematic diagram of the battery assembly provided by an embodiment of the utility model;

[0027] Figure 3 It is the schematic diagram of the back contact cell without main grid provided by an embodiment of the utility model;

[0028] Figure 4 It is the partial structure schematic diagram of the back contact cell without main grid provided by an embodiment of the utility model;

[0029] Figure 5 It is the partial structure schematic diagram of the back contact cell without main grid provided by another embodiment of the utility model;

[0030] Figure 6 It is the partial structure schematic diagram of the back contact cell without main grid provided by another embodiment of the utility model;

[0031] Figure 7 It is the partial structure schematic diagram of the back contact cell without main grid provided by another embodiment of the utility model;

[0032] Figure 8 It is the partial structure schematic diagram of the back contact cell without main grid provided by another embodiment of the utility model;

[0033] Figure 9Part structure schematic diagram of back contact cell without main grid provided by another embodiment of the utility model;

[0034] Figure 10 Part structure schematic diagram of back contact cell without main grid provided by another embodiment of the utility model;

[0035] Figure 11 Part structure schematic diagram of battery assembly provided by still another embodiment of the utility model.

[0036] Main element symbol explanation: 1000, photovoltaic system;1001, battery assembly;100, back contact cell without main grid;200, solder strip;300, conductive glue;10, battery substrate;11, first edge;12, second edge;13, conductive glue area;20, fine grid;30, first fixed section;40, solder point part;50, second fixed section;60, first soldering section;80, third fixed section;41, first solder point part;42, second solder point part;43, third solder point part;44, fourth solder point part;45, fifth solder point part;401, first edge point;411, first boundary line;412, second boundary line;71, first straight line;72, first fold line;73, second straight line;74, third straight line;75, fourth straight line;721, first straight line section. DETAILED DESCRIPTION

[0037] In order to make the purpose, technical scheme and advantages of the utility model more clearly, the following will be further described in detail by combining with the drawings and embodiments. The embodiments described below by referring to the drawings are exemplary, and are only used to explain the utility model, and cannot be understood as the limitation of the utility model. In addition, it should be understood that the specific embodiments described herein are only used to explain the utility model, and are not used to limit the utility model.

[0038] In the description of the utility model, it should be understood that the orientation or position relationship indicated by the terms "length", "width", "upper", "lower", "top", "bottom", "transverse", "longitudinal" and the like is based on the orientation or position relationship shown in the drawings, and is only for the convenience of describing the utility model and simplifying the description, and therefore cannot be understood as indicating or implying that the indicated device or element must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the utility model.

[0039] In addition, the terms "first", "second" are only used for description purpose, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features limited by "first", "second" can explicitly or implicitly include one or more of the features. In the description of the utility model, the meaning of "multiple" is two or more, unless otherwise specifically limited.

[0040] In the description of the utility model, it needs to explain, unless another explicit provision and limitation, term " install " " link " " connection " should do broad sense understanding, for example, can be fixed connection, also can be detachable connection, or integrally connected, can be mechanical connection, also can be electric connection or can communicate with each other, can be directly connected, also can be indirectly connected through intermediate medium, can be the communication of two elements or the interaction of two elements. For ordinary skilled in the art, the above-mentioned terms can be understood according to the specific meaning of the utility model.

[0041] The following disclosure provides many different embodiments or examples for implementing different structures of the utility model. In order to simplify the disclosure of the utility model, the components and settings of specific examples are described below. Of course, they are only examples, and the purpose is not to limit the utility model. In addition, the utility model can refer to the same number and / or reference letter in different examples, and this repetition is for the purpose of simplification and clarity, which itself does not indicate the relationship between the various embodiments and / or settings discussed. In addition, the utility model provides various specific examples of processes and materials, but those skilled in the art can realize the application of other processes and / or the use of other materials.

[0042] Please refer to Figure 1 And Figure 2 The photovoltaic system 1000 in the embodiment of the utility model can include the battery assembly 1001 in the embodiment of the utility model, and the battery assembly 1001 in the embodiment of the utility model can include a plurality of main gridless back contact cells 100. The plurality of main gridless back contact cells 100 can be sequentially connected in series through the welding strip 200 to form a battery string. Each battery string in the battery assembly 1001 can be connected in series, parallel, or a combination of series and parallel to realize the current bus output, for example, the connection between each battery string can be realized through the bus bar.

[0043] As Figures 3 to 10 Indicated in the embodiment of the utility model, the main gridless back contact cell 100 includes a battery substrate 10, a plurality of fine grids 20, a plurality of first fixed segments 30, and a plurality of second fixed segments 50. The battery substrate 10 includes a first edge 11 and a second edge 12 arranged along a first direction, and the first edge 11 and the second edge 12 are oppositely arranged. The plurality of fine grids 20 are arranged on the back surface of the battery substrate 10, the fine grids 20 are arranged along the first direction, the fine grids 20 extend along the second direction, the first direction and the second direction intersect, and the first direction is from the first edge 11 to the second edge 12.

[0044] Exemplarily, the battery substrate 10 can include a silicon substrate, and can further include a dielectric layer, a doped layer, a passivation layer, etc., which can be set according to actual conditions.

[0045] As shown in Figures 3 to 10 The first fixed section 30 has a distance to the first edge 11 smaller than a distance to the second edge 12 along the first direction; the first fixed section 30 includes a plurality of first solder point portions 41 arranged at intervals along the first direction, and the first solder point portions 41 are arranged on the fine grid 20, and the area of the first solder point portions 41 gradually decreases along the first direction.

[0046] The second fixed section 50 has a distance to the first edge 11 smaller than a distance to the second edge 12 along the first direction, and the first fixed section 30 and the second fixed section 50 are arranged in sequence along the first direction; the second fixed section 50 includes a plurality of second solder point portions 42 arranged at intervals along the first direction, and the second solder point portions 42 are arranged on the fine grid 20, and the area of adjacent two second solder point portions 42 is the same along the first direction.

[0047] The battery substrate 10 further includes a plurality of conductive glue areas 13 for arranging conductive glue 300, and the conductive glue areas 13 are arranged at intervals with the first fixed section 30 and / or the second fixed section 50 along the second direction.

[0048] The main-free grid back contact battery 100 in the embodiment of the utility model, because setting has the first fixed section 30, the second fixed section 50 and the conductive glue area 13, then can position the solder strip 200 through the conductive glue area 13 when setting the solder strip 200, prevent the solder strip 200 from deviating, and then weld through the first solder point portion 41 in the first fixed section 30 and the second solder point portion 42 in the second fixed section 50, thereby avoiding the need to align the center position of the solder point on the battery piece one by one when setting the solder strip 200, and reducing the setting difficulty of the solder strip 200.

[0049] Meanwhile, the area of the first solder point portion 41 gradually decreases along the first direction, thereby increasing the tension of the solder strip 200 at the edge part of the main-free grid back contact battery 100, improving the firmness of the soldering of the solder strip 200, stabilizing the soldering of the solder strip 200, and reducing the risk of virtual welding of the solder strip 200.

[0050] Specifically, the main-free grid back contact battery 100 can be a whole battery piece, or can be a half piece, a one-third piece or other proportion of battery piece divided from a whole battery piece. In order to make the drawings clearer, Figure 3 The main-free grid back contact battery 100 shown is a half piece divided from a whole battery piece. Figures 4 to 10 The main-free grid back contact battery 100 shown is a half piece divided from a whole battery piece. Figures 4 to 10 The main-free grid back contact battery 100 shown is a half piece divided from a whole battery piece. Figures 4 to 10Here, no longer elaborated. That is to say, the drawings are only examples, and do not represent a specific form of the ownerless grid back contact cell 100.

[0051] Specifically, the back of the cell substrate 10 is formed with two polarities of fine grids 20 staggered, which can be positive fine grids 20 and negative fine grids 20 respectively.

[0052] Further, the cell substrate 10 includes a front surface and a back surface, the front surface faces the sun and mainly receives direct sunlight, and the back surface faces the mounting surface of the battery assembly 1001, such as the ground, the roof, etc. Or, the back surface is the surface of the ownerless grid back contact cell 100 provided with grid lines.

[0053] Further, the staggered distribution means that one negative fine grid 20 is provided between two adjacent positive fine grids 20, and one positive fine grid 20 is provided between two adjacent negative fine grids 20.

[0054] Specifically, the ownerless grid back contact cell 100 has a first fixed section 30, a second fixed section 50 and a conductive glue area 13. The first fixed section 30, the second fixed section 50 and the conductive glue area 13 cooperate to set the solder strip 200. The first fixed section 30 includes a plurality of first soldering point parts 41, which can be PAD points, soldering points or solder pads.

[0055] Therefore, solder paste can be provided on the first soldering point part 41 to realize the welding of the first soldering point part 41 and the solder strip 200. The second fixed section 50 includes a plurality of second soldering point parts 42, which can be PAD points, soldering points or solder pads. Solder paste can be provided on the second soldering point part 42 to realize the welding of the second soldering point part 42 and the solder strip 200.

[0056] Specifically, the conductive glue area 13 is provided corresponding to the first fixed section 30 and / or the second fixed section 50. The conductive glue area 13 is used to set the conductive glue 300. When the solder strip 200 is set, the conductive glue 300 can be set in the conductive glue area 13. In turn, the positioning can be realized in advance by the conductive glue 300 when the solder strip 200 is set. At the same time, the solder strip 200 is fixed by the conductive glue 300, the first soldering point part 41 and the second soldering point part 42 at the same time, which can also improve the stability of the conductive connection between the solder strip 200 and the fine grid 20, and prevent the solder strip 200 from being falsely soldered.

[0057] Further, the conductive glue area 13 is specifically spaced apart from the first fixed section 30 and / or the second fixed section 50 in the second direction. In this way, when the conductive glue 300 is set, the conductive glue 300 can avoid contaminating the second soldering point part 42, which affects the welding effect of the second soldering point part 42.

[0058] Specifically, as shown in FIG. 1, the ownerless grid back contact cell 100 has a first fixed section 30, a second fixed section 50 and a conductive glue area 13. Figures 3 to 10As shown, the first direction and the second direction can be longitudinal direction and transverse direction of the back contact cell 100 respectively, of course, in other embodiments, the first direction and the second direction can also be other directions, for example, both can be diagonal direction of the cell substrate 10, and the specific limitation is not made here.

[0059] Specifically, as Figures 3 to 10 The first direction is the same as the direction of the first edge 11 of the cell substrate 10 towards the center of the cell substrate 10.

[0060] Specifically, for the specific structure of the cell substrate 10, the cell substrate 10 has a first edge 11 and a second edge 12, the first edge 11 and the second edge 12 are arranged along the first direction, and both extend along the second direction.

[0061] It can be understood that the first edge 11 and the second edge 12 are two opposite edge lines of the cell substrate 10, or in other words, the first edge 11 and the second edge 12 are two opposite boundary lines of the cell substrate 10. In the embodiment of the utility model, the center of the cell substrate 10 can be understood as the geometric center of the cell substrate 10, or as the center line of the cell piece.

[0062] Specifically, along the first direction, the distance from the first fixed section 30 to the first edge 11 is less than the distance from the first fixed section 30 to the second edge 12. Therefore, in the first direction, the first fixed section 30 is closer to the first edge 11.

[0063] It is worth noting that the area of the first solder joint part 41 gradually decreases. It means that in the first fixed section 30, the area of the first solder joint part 41 gradually decreases along the first direction. Or in other words, in the first direction, the area of the first solder joint part 41 closer to the first edge 11 is larger, and the area of the first solder joint part 41 farther away from the first edge 11 is smaller.

[0064] Further, in the back contact cell 100, because the stress of the edge part is more concentrated, the soldering tension of the solder strip 200 in this part is insufficient, and false welding is prone to occur. And the closer to the edge of the back contact cell 100, the stronger the stress, the more difficult it is to stably weld the solder strip 200, and the more prone to false welding.

[0065] And in the embodiment of the utility model, along the first direction, the area of the first solder joint part 41 gradually decreases. Further, the area of the first solder joint part 41 close to the first edge 11 of the back contact cell 100 can be increased to increase the soldering tension of the solder strip 200 and the fine grid 20 of the edge part of the back contact cell 100, so as to improve the soldering tension of the solder strip 200 of the edge part of the back contact cell 100, improve the firmness of the soldering of the solder strip 200, and reduce the risk of false welding of the solder strip 200.

[0066] Specifically, the overall external profile of the first fixed section 30 can be set as a trapezoidal shape, a circular shape, etc. When the overall external profile of the first fixed section 30 is a trapezoidal shape, optionally, the external profile of the first fixed section 30 can be a trapezoidal shape with the short side away from the first edge 11 and the long side close to the first edge 11.

[0067] For the gradually decreasing area of the first solder joint part 41, there can be multiple cases, for example, there are 6 first solder joint parts 41 arranged in the first direction in turn, and the areas of the first solder joint parts 41 are X1, X2, X3, X4, X5, X6 in turn. It can be X1>X2>X3>X4>X5>X6 so that the areas of the first solder joint parts 41 gradually decrease, or it can also be X1=X2>X3=X4>X5=X6 so that the areas of the first solder joint parts 41 gradually decrease, which is not limited here.

[0068] Please refer to Figure 3 In some embodiments, along the first direction, the difference between the lengths of the second direction of the two adjacent first solder joint parts 41 is 0.05mm to 0.15mm. For example, 0.05mm, 0.06mm, 0.07mm, 0.08mm, 0.09mm, 0.10mm, 0.11mm, 0.12mm, 0.13mm, 0.14mm, 0.15mm. In this way, the size of the first solder joint part 41 close to the first edge 11 of the back contact cell 100 without busbars can be increased to increase the welding tension of the ribbon 200 and the fine grid 20 of the edge part of the back contact cell 100 without busbars, so as to improve the welding tension of the ribbon 200 of the edge part of the back contact cell 100 without busbars, improve the firmness of the welding of the ribbon 200, and reduce the risk of false welding of the ribbon 200.

[0069] It can be understood that along the first direction, the difference between the sizes of the second direction of the two adjacent first solder joint parts 41 is greater than 0.05mm to 0.15mm. For example, 0.05mm, 0.06mm, 0.07mm, 0.08mm, 0.09mm, 0.10mm, 0.11mm, 0.12mm, 0.13mm, 0.14mm, 0.15mm. In this way, the difference between the lengths of the second direction of the two adjacent first solder joint parts 41 is within the above range, which can avoid the difference between the lengths of the second direction of the two adjacent first solder joint parts 41 being too large, reduce the change range of the welding tension of the two adjacent first solder joint parts 41, and thus reduce the probability of warping of the cell sheet.

[0070] In addition, the closer to the first edge 11, the larger the size of the first solder joint part 41 in the second direction, so as to match the gradually increasing stress of the edge part of the cell substrate 10.

[0071] Meanwhile, the conductive adhesive area 13 can be arranged corresponding to the first fixed section 30, that is, in the second direction, the conductive adhesive area 13 can also be arranged corresponding to the first fixed section 30, which is not limited herein.

[0072] Of course, in other embodiments, the first fixed section 30 or the second fixed section 50 can not include the conductive adhesive area 13 on the two side edges in the second direction, that is, the conductive adhesive area 13 is on the two side edges of the first fixed section 30 or the second fixed section 50 in the second direction. In order to save the arrangement cost of the conductive adhesive 300. Which is not limited herein.

[0073] For the specific structure of the second fixed section 50, the first fixed section 30 and the second fixed section 50 are arranged in sequence along the first direction. The distance from the second fixed section 50 to the first edge 11 is less than the distance from the second fixed section 50 to the second edge 12. Therefore, in the first direction, the second fixed section 50 is closer to the first edge 11.

[0074] Along the first direction, the areas of two adjacent second solder point parts 42 are the same. That is, the areas of all second solder point parts 42 in the second fixed section 50 are the same. In this way, the arrangement of each second solder point part 42 in the second fixed section 50 can be facilitated, and the difficulty of setting the second solder point part 42 can be simplified. At the same time, it can also make the stress consistency when the solder strip 200 remains connected to the position of the second fixed section 50.

[0075] Please refer to Figures 4 to 9 In some embodiments, along the first direction, the length of each second solder point part 42 in the second direction is the same. In this way, the arrangement of each second solder point part 42 in the second fixed section 50 can be further simplified, and the difficulty of setting the second solder point part 42 can be simplified. At the same time, it can also make the stress consistency when the solder strip 200 remains connected to the position of the second fixed section 50.

[0076] Please refer to Figure 4 In some embodiments, along the first direction, the center point of each second solder point part 42 in the second fixed section 50 is on the first straight line 71, and the first straight line 71 extends along the first direction. In this way, the welding precision when the solder strip 200 is welded with each first solder point part 41 can be improved.

[0077] It can be understood that the center point of each second solder point part 42 in the second fixed section 50 is on the first straight line 71. That is, the center point of each second solder point part 42 is flush. So that when the solder strip 200 is laid, it can be more accurate to align each first solder point part 41, so as to improve the welding precision and stability of the solder strip 200.

[0078] Please refer to Figure 5In some embodiments, the second solder joint part 42 comprises a first boundary line 411 extending along the first direction, and along the first direction, the first boundary line 411 of each second solder joint part 42 in the second fixed section 50 is on a second straight line 73 extending along the first direction. In this way, the welding precision of the solder strip 200 when welded with each first solder joint part 41 can be improved.

[0079] It can be understood that the first boundary line 411 of each second solder joint part 42 in the second fixed section 50 is on the second straight line 73. That is, each first boundary line 411 is flush. In this way, when the solder strip 200 is laid, each second solder joint part 42 can be more accurately aligned, so as to improve the welding precision and stability of the solder strip 200.

[0080] Please refer to Figure 5 In some embodiments, the second solder joint part 42 further comprises a second boundary line 412 extending along the first direction, and the second boundary line 412 is oppositely arranged with the first boundary line 411 along the second direction. Along the first direction, the second boundary line 412 of each second solder joint part 42 in the second fixed section 50 is on a third straight line 74 extending along the first direction. In this way, the welding precision of the solder strip 200 when welded with each first solder joint part 41 can be improved.

[0081] It can be understood that the second boundary line 412 of each second solder joint part 42 in the second fixed section 50 is on the third straight line 74. That is, each second boundary line 412 is flush. In this way, when the solder strip 200 is laid, each second solder joint part 42 can be more accurately aligned, so as to improve the welding precision and stability of the solder strip 200.

[0082] Meanwhile, the first boundary line 411 and the second boundary line 412 of each second solder joint part 42 are flush. That is, the two side edges of the second solder joint part 42 along the second direction are flush. In this way, when the solder strip 200 is laid, each second solder joint part 42 can be more accurately aligned, so as to further improve the welding precision and stability of the solder strip 200.

[0083] Please refer to Figure 6 and Figure 7 In some embodiments, the number of the second fixed sections 50 can be multiple, and along the first direction, the line connecting the center points of all the second solder joint parts 42 in the two adjacent second fixed sections 50 is a first fold line 72. In this way, during the welding of the solder strip 200, the solder paste can be arranged on the second solder joint part 42, and the conductive adhesive 300 can be arranged on the conductive adhesive area 13.

[0084] Since the connecting line of the center points of all the first soldering points 41 in the two adjacent second fixed segments 50 is the first fold line 72, the spacing between the conductive adhesive area 13 and the second fixed segment 50 is increased, and the connecting line of the center points of all the second soldering points 42 in the two adjacent second fixed segments 50 is the first fold line 72, so that the spacing between the conductive adhesive area 13 and the second fixed segment 50 spaced from the conductive adhesive area 13 is increased, even if the height of the conductive adhesive 300 is higher than the height of the solder paste on the second soldering point 42, the farther spacing between them can effectively avoid the occurrence of false welding in the subsequent welding process. At the same time, the adhesion of the conductive adhesive area 13 to the solder strip 200 can be ensured, and the stability of the pre-fixing of the solder strip 200 can be ensured. Specifically, the first fold line 72 includes a plurality of first straight line segments 721. The first straight line segment 721 corresponds to the second fixed segment 50.

[0085] In addition, in some embodiments, the connecting line of the center points of all the second soldering points 42 in the two adjacent second fixed segments 50 can also be in other forms, for example, the connecting line of the center points of all the second soldering points 42 in the two adjacent second fixed segments 50 can also be a wavy line, that is, in the first direction, the arrangement profile of the second soldering points 42 is wavy, which is not limited here.

[0086] Please refer to Figure 7 and Figure 8 In some embodiments, the back contact cell 100 without main grid further includes a third soldering point 43, and the third soldering point 43 does not include a conductive adhesive area 13 along the two side edges in the second direction. In the first direction, the center point of each first soldering point 41 in the first fixed segment 30 is on the fourth straight line 75, and the fourth straight line 75 extends in the first direction.

[0087] In the first direction, the center point of the second soldering point 42 is located between the two adjacent first fixed segments 30; in the second direction, the center point of the second soldering point 42 is located between the two fourth straight lines 75 formed by the two adjacent first fixed segments 30. In this way, when the conductive adhesive 300 is arranged in the conductive adhesive area 13, the conductive adhesive 300 can avoid contaminating the first soldering points 41 of the first fixed segments 30 located on both sides of the third soldering point 43, so as to improve the welding stability of the solder strip 200 and prevent false welding.

[0088] Alternatively, in the first direction, the center point of the third soldering point 43 is located between the two adjacent second fixed segments 50; in the second direction, the center point of the third soldering point 43 is located between the two first straight lines 71 formed by the two adjacent second fixed segments 50. In this way, when the conductive adhesive 300 is arranged in the conductive adhesive area 13, the conductive adhesive 300 can avoid contaminating the second soldering points 42 of the second fixed segments 50 located on both sides of the third soldering point 43, so as to improve the welding stability of the solder strip 200 and prevent false welding.

[0089] Alternatively, in the first direction, the center point of the third solder joint part 43 is located between the adjacent first fixed section 30 and the second fixed section 50; in the second direction, the center point of the third solder joint part 43 is located between the fourth straight line 75 formed by the adjacent first fixed section 30 and the first straight line 71 formed by the second fixed section 50. In this way, when the conductive adhesive 300 is arranged in the conductive adhesive area 13, the conductive adhesive 300 can avoid contaminating the first solder joint part 41 and the second solder joint part 42 located on both sides of the third solder joint part 43, thereby improving the soldering stability of the solder strip 200 and preventing false welding.

[0090] Notably, the number of third solder joint parts 43 can be one or more. The two side edges of the third solder joint part 43 in the second direction do not include the conductive adhesive area 13, i.e., the conductive adhesive area 13 avoids the two side edges of the third solder joint part 43 in the second direction. When the conductive adhesive 300 is arranged, the two side edges of the third solder joint part 43 in the second direction are not provided with insulating adhesive. In this way, the interference of the conductive adhesive 300 on the soldering process can be reduced, thereby ensuring the accuracy and stability of the soldering process.

[0091] Specifically, the third solder joint part 43 can be a PAD point, a solder joint, or a solder pad. Solder paste can be arranged on the first solder joint part 41 to realize the soldering of the third solder joint part 43 and the solder strip 200.

[0092] Please refer to Figure 9 In some embodiments, the back contact cell 100 without a main grid further includes a first soldering section 60, the first fixed section 30, the second fixed section 50, and the first soldering section 60 are arranged in sequence along the first direction; the edge of the first soldering section 60 in the second direction does not include the conductive adhesive area 13; the first soldering section 60 includes a plurality of fourth solder joint parts 44 arranged on the fine grid 20, the fourth solder joint parts 44 are arranged in sequence along the first direction, and the area of the fourth solder joint part 44 gradually decreases along the first direction.

[0093] In this way, while ensuring the stable connection of the solder strip 200, the amount of conductive adhesive 300 can be reduced to achieve the effect of saving costs. At the same time, the tensile force of the solder strip 200 at the edge of the back contact cell 100 without a main grid can be further increased, the firmness of the soldering of the solder strip 200 can be improved, the soldering of the solder strip 200 can be stabilized, and the risk of false welding of the solder strip 200 can be reduced.

[0094] It can be understood that the edge of the first soldering section 60 in the second direction does not include the conductive adhesive area 13, i.e., the conductive adhesive area 13 avoids the two side edges of the first soldering section 60 in the second direction, or in other words, the two side edges of the first soldering section 60 are not provided with the conductive adhesive area 13. Further, when the conductive adhesive 300 is arranged, the conductive adhesive 300 can be arranged only near the second fixed section 50 to reduce the amount of conductive adhesive 300 and save costs.

[0095] Meanwhile, the first fixed section 30, the second fixed section 50 and the first solder section 60 are arranged in sequence along the first direction. The first solder section 60 comprises a plurality of fourth soldering point portions 44 provided on the fine grid 20, and the area of the fourth soldering point portion 44 gradually decreases along the first direction. Thus, the tensile force of the solder ribbon 200 at the edge portion of the back contact cell 100 without busbars can be further increased, the soldering firmness of the solder ribbon 200 can be improved, the soldering of the solder ribbon 200 can be stabilized, and the risk of false welding of the solder ribbon 200 can be reduced, so as to disperse and resist the stress gradually increasing as the back contact cell 100 without busbars is closer to the first edge 11, so as to improve the tensile force of the solder ribbon 200 at the edge portion, improve the soldering firmness of the solder ribbon 200, stabilize the soldering of the solder ribbon 200, and reduce the risk of false welding of the solder ribbon 200.

[0096] Specifically, the fourth soldering point portion 44 can be a PAD point, a soldering point or a soldering pad. Solder paste can be provided on the fourth soldering point portion 44 to realize the soldering of the fourth soldering point portion 44 and the solder ribbon 200.

[0097] Specifically, the area of the first soldering point portion 41 with the smallest area is greater than or equal to the area of the second soldering point portion 42. In this way, the soldering point portions 40 in the first fixed section 30 and the second fixed section 50 for soldering with the solder ribbon 200 can have a trend of gradually decreasing in area along the first direction as a whole. Thus, the stress gradually increasing as the back contact cell 100 without busbars is closer to the edge can be dispersed and resisted, so as to improve the tensile force of the solder ribbon 200 at the edge portion of the back contact cell 100 without busbars, improve the soldering firmness of the solder ribbon 200, stabilize the soldering of the solder ribbon 200, and reduce the risk of false welding of the solder ribbon 200. Meanwhile, the use of materials can be optimized and the cost can be reduced under the premise of ensuring the soldering strength of the solder ribbon 200.

[0098] In a possible implementation, as shown in Figure 10 the second fixed section 50 is located between two first fixed sections 30 along the first direction. In this way, the tensile force of the solder ribbon 200 at the edge portion of the back contact cell 100 without busbars can be further increased, the soldering firmness of the solder ribbon 200 can be improved, the soldering of the solder ribbon 200 can be stabilized, and the risk of false welding of the solder ribbon 200 can be reduced.

[0099] Specifically, the second fixed section 50 is located between two first fixed sections 30 along the first direction. In other words, one first fixed section 30, one second fixed section and one first fixed section can be arranged in sequence along the first direction. In this way, the flexibility of the arrangement of the second fixed section 50 can be improved.

[0100] In a possible implementation, as shown in Figure 3As shown, the back contact cell 100 without main grid in the embodiment of the utility model can further include a third fixed section 80, the distance from the third fixed section 80 to the second edge 12 is less than the distance from the third fixed section 80 to the first edge 11 along the first direction; the third fixed section 80 includes a plurality of first soldering point parts 41 arranged at intervals along the first direction, the first soldering point part 41 is arranged at the fine grid 20, and the area of at least part of the first soldering point part 41 in the plurality of first soldering point parts 41 gradually increases along the first direction.

[0101] It can be understood that the arrangement mode and overall structure of each first soldering point part 41 in the third fixed section 80 can refer to the first fixed section 30, and will not be repeated here.

[0102] In a possible implementation, as shown in Figure 3 As shown, the back contact cell 100 without main grid in the embodiment of the utility model can further include a fourth fixed section 90, the fourth fixed section and the third fixed section are arranged in sequence along the first direction, the distance from the fourth fixed section 90 to the second edge 12 is less than the distance from the fourth fixed section 90 to the first edge 11 along the first direction; the fourth fixed section 90 includes a plurality of second soldering point parts 42 arranged at intervals along the first direction, the second soldering point part 42 is arranged at the fine grid 20, and the area of the plurality of second soldering point parts 42 does not change along the first direction.

[0103] In a possible implementation, the back contact cell 100 without main grid in the embodiment of the utility model can further include a plurality of fifth soldering point parts 45 arranged at intervals along the first direction, as shown in Figure 3 As shown, the fifth soldering point part 45 is arranged near the center line of the back contact cell 100 without main grid, and the area of the plurality of fifth soldering point parts 45 does not change along the first direction.

[0104] In the second direction, the conductive adhesive area 13 is arranged at intervals with the fifth soldering point part 45. The area of the fifth soldering point part 45 is less than the area of the first soldering point part 41, the area of the second soldering point part 42, the area of the third soldering point part 43 and the area of the fourth soldering point part 44.

[0105] In this way, the setting of the fifth soldering point part 45 can provide a stable welding area for the middle part of the back contact cell 100 without main grid, ensure that the middle part of the back contact cell 100 without main grid has uniform mechanical strength and stability, and also achieve the effects of optimizing the use of materials and reducing costs.

[0106] It can be understood that the arrangement mode and overall structure of the fifth soldering point part 45 can refer to the second fixed section 50, and will not be repeated here.

[0107] Please refer to Figure 11The battery assembly 1001 provided by the utility model embodiment. The battery assembly 1001 comprises the back contact battery 100 without main grid described above.

[0108] Please refer to Figure 11 In some embodiments, the battery assembly 1001 further comprises a solder strip 200 and conductive glue 300, the solder strip 200 is connected with the fine grid 20 through the conductive glue 300 and the solder joint part 40, the conductive glue 300 is arranged in the conductive glue area 13; the solder joint part 40 comprises at least one of a plurality of first solder joint parts 41, a plurality of second solder joint parts 42, a plurality of third solder joint parts 43, a plurality of fourth solder joint parts 44 and a plurality of fifth solder joint parts 45. In this way, when the solder strip 200 is arranged, the solder strip 200 can be positioned through the conductive glue 300, so that the solder strip 200 is prevented from deviating, and then welding is carried out through the solder joint part 40, so that the solder strip 200 needs to be aligned with the center positions of the solder joints on the battery piece one by one when arranged, and the arrangement difficulty of the solder strip 200 is reduced.

[0109] Meanwhile, the solder strip 200 is also fixed through the conductive glue 300 and the solder joint part 40, so that the conductive connection stability of the solder strip 200 and the fine grid 20 can be improved, and the solder strip 200 is prevented from being false-welded.

[0110] Please refer to Figure 11 In some embodiments, the solder strip 200 covers the solder joint part 40 and the conductive glue 300. In this way, the stable connection of the solder strip 200 and the fine grid 20 can be realized.

[0111] It can be understood that "the solder strip 200 covers the solder joint part 40 and the conductive glue 300" means that the solder strip 200 partially covers the solder joint part 40 and the solder strip 200 partially covers the conductive glue 300. It can also mean that the solder strip 200 partially covers the solder joint part 40 and the solder strip 200 completely covers the conductive glue 300. It can also mean that the solder strip 200 completely covers the solder joint part 40 and the solder strip 200 partially covers the conductive glue 300. It can also mean that the solder strip 200 completely covers the solder joint part 40 and the solder strip 200 completely covers the conductive glue 300. This is not limited here.

[0112] Optionally, the solder strip 200 can be arranged to completely cover the solder joint part 40. In this way, the solder joint part 40 can be prevented from being exposed, so that the solder joint part 40 is prevented from being contaminated, the connection effect of the solder joint part 40 and the solder strip 200 is prevented from being affected, and the solder joint part 40 is prevented from being short-circuited.

[0113] Optionally, the solder strip 200 can be arranged to completely cover the conductive glue 300. In this way, the conductivity and the connection stability of the solder strip 200 are improved.

[0114] Please refer to Figure 11In some embodiments, the solder joint portion 40 comprises a first edge point 401, which is a point on the solder joint portion 40 farthest from the conductive adhesive area 13 in the second direction; the conductive adhesive area 13 comprises a second edge point 131, which is a point on the conductive adhesive area 13 farthest from the solder joint portion 40 in the second direction.

[0115] In the second direction, the distance between the first edge point 401 and the second edge point 131 is a first size D2; in the second direction, the width of the solder strip 200 is a second size D3; the second size D3 is greater than or equal to the first size D2. In this way, the solder strip 200 can completely cover the solder joint portion 40 while ensuring the conductivity and connection stability of the solder strip 200, avoiding the exposure of the solder joint portion 40, thereby avoiding the contamination of the solder joint portion 40, affecting the connection effect of the solder joint portion 40 and the solder strip 200, and even short-circuiting the solder joint portion 40.

[0116] It can be understood that the first edge point 401 refers to a point on the solder joint portion 40 farthest from the conductive adhesive area 13 in the second direction. Specifically, the first edge point 401 is located at the edge of the solder joint portion 40 away from the conductive adhesive area 13.

[0117] It can be understood that the second edge point 131 refers to a point on the conductive adhesive area 13 farthest from the solder joint portion 40 in the second direction. Specifically, the second edge point 131 is located at the edge of the solder joint portion 40 away from the conductive adhesive area 13.

[0118] It can be understood that in such embodiments, the battery assembly 1001 can further comprise a frame, a back plate, photovoltaic glass, and a film. The film can be filled between the front and back of the cell sheet, photovoltaic glass, adjacent cell sheets, etc., as a filler, which can be a transparent gel with good light transmission performance and aging resistance, for example, the film can use EVA film or POE film, which can be selected according to actual conditions, which is not limited here.

[0119] The photovoltaic glass can be covered on the film on the front of the cell sheet, and the photovoltaic glass can be super white glass, which has high light transmittance, high transparency, and superior physical, mechanical, and optical properties, for example, the light transmittance of super white glass can reach more than 92%, which can protect the cell sheet as much as possible without affecting the efficiency of the cell sheet. At the same time, the film can bond the photovoltaic glass and the cell sheet together, and the presence of the film can seal and insulate the cell sheet and prevent water and moisture.

[0120] The back plate can be attached to the adhesive film on the back of the battery piece. The back plate can protect and support the battery piece, has reliable insulation, water resistance and aging resistance, and the back plate can have multiple choices, which can be tempered glass, organic glass, aluminum alloy TPT composite adhesive film, etc. It can be set according to the specific situation, which is not limited here. The whole composed of the back plate, the battery piece, the adhesive film and the photovoltaic glass can be arranged on the frame. The frame is the main external support structure of the whole battery assembly 1001, and can stably support and install the battery assembly 1001. For example, the battery assembly 1001 can be installed at the required installation position through the frame.

[0121] In the description of the present specification, the description referring to the terms "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" and the like means that the specific features, structures, materials or characteristics described in connection with the embodiments or examples are included in at least one embodiment or example of the present application. In the present specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0122] In addition, the above only describes the preferred embodiments of the present application and does not limit the present application. Any modification, equivalent replacement and improvement made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A back contact cell with no busbars, characterized in that, The battery substrate comprises a first edge and a second edge arranged opposite to each other along a first direction; a plurality of fine grids arranged along the first direction, the fine grids extending along a second direction, the first direction and the second direction intersecting, the first direction being a direction in which the first edge of the battery substrate faces the center of the battery substrate; a plurality of first fixed segments, the distance from the first fixed segment to the first edge along the first direction being less than the distance to the second edge, the first fixed segment comprising a plurality of first solder point portions arranged along the first direction, the first solder point portions being arranged on the fine grids, the area of the first solder point portions gradually decreasing along the first direction; a plurality of second fixed segments, the distance from the second fixed segment to the first edge along the first direction being less than the distance to the second edge, the first fixed segment and the second fixed segment being arranged along the first direction, the second fixed segment comprising a plurality of second solder point portions arranged along the first direction, the second solder point portions being arranged on the fine grids, the area of adjacent two second solder point portions being the same along the first direction; the battery substrate further comprises a plurality of conductive adhesive regions for arranging conductive adhesive, the conductive adhesive regions being arranged apart from the first fixed segment and / or the second fixed segment along the second direction. The length of each second solder point portion in the second direction is the same along the first direction.

2. The no-lead back-contact cell of claim 1, wherein, The center points of each second solder point portion in the second fixed segment are on a first straight line along the first direction.

3. The gridless back contact cell of claim 1, wherein, The second solder point portion comprises a first boundary line extending along the first direction, each first boundary line in the second fixed segment is on a second straight line along the first direction.

4. The eni -main grid back contact cell of claim 1, wherein, The second solder point portion further comprises a second boundary line extending along the first direction, the second boundary line being arranged opposite to the first boundary line, each second boundary line in the second fixed segment is on a third straight line along the first direction.

5. The eni -main grid back contact cell of claim 4, wherein, The connecting line of the center points of all second solder point portions in adjacent two second fixed segments along the first direction is a first fold line.

6. The eni -main grid back contact cell of claim 1, wherein, The first fold line comprises a plurality of first straight line segments.

7. The eni -main grid back contact cell of claim 6, wherein, The battery substrate further comprises a third solder point portion, the two side edges of the third solder point portion along the second direction do not comprise the conductive adhesive region; 8. The gridless back contact cell of claim 3, wherein, The center points of each first solder point portion in the first fixed segment are on a fourth straight line along the first direction. The center point of the third solder point portion is located between adjacent two first fixed segments along the first direction, the center point of the third solder point portion is located between two fourth straight lines formed by adjacent two first fixed segments along the second direction, or ​ In the first direction, the center point of the third soldering point part is located between two adjacent second fixed segments; in the second direction, the center point of the third soldering point part is located between two first straight lines formed by two adjacent second fixed segments; or, In the first direction, the center point of the third soldering point part is located between the first fixed segment and the second fixed segment; in the second direction, the center point of the third soldering point part is located between the fourth straight line formed by the first fixed segment and the first straight line formed by the second fixed segment.

9. The gridless back contact cell of claim 1 wherein, The back contact cell without main grid further comprises a plurality of first soldering segments, the first fixed segment, the second fixed segment and the first soldering segment are arranged in sequence along the first direction; The edge of the first soldering segment along the second direction does not include the conductive adhesive area; The first soldering segment comprises a plurality of fourth soldering point parts arranged in the fine grid, and the area of the fourth soldering point part gradually decreases along the first direction.

10. The gridless back contact cell of claim 1, wherein, The area of the first soldering point part with the smallest area is greater than or equal to the area of the second soldering point part.

11. The gridless back-contact cell of claim 9, wherein, The area of the fourth soldering point part with the largest area is less than or equal to the area of the second soldering point part.

12. The gridless back contact cell of claim 1, wherein, Along the first direction, the first fixed segment is located between two second fixed segments.

13. A battery assembly characterized by, The battery assembly comprises the back contact cell without main grid according to any one of claims 1 to 12.

14. The battery assembly of claim 13, wherein, The battery assembly further comprises a solder strip and conductive adhesive, the solder strip is connected with the fine grid through the conductive adhesive and soldering point part, and the conductive adhesive is arranged in the conductive adhesive area; The soldering point part comprises at least one of a plurality of first soldering point parts, a plurality of second soldering point parts, a plurality of third soldering point parts and a plurality of fourth soldering point parts.

15. The battery assembly of claim 14, wherein, The solder strip covers the soldering point part and the conductive adhesive.

16. The battery assembly of claim 15, wherein, The soldering point part comprises a first edge point, which is the point on the soldering point part farthest from the conductive adhesive area in the second direction; the conductive adhesive area comprises a second edge point, which is the point on the conductive adhesive area farthest from the soldering point part in the second direction; In the second direction, the distance between the first edge point and the second edge point is a first size; In the second direction, the width of the solder strip is a second size; The second size is greater than or equal to the first size.

17. A photovoltaic system characterized by, The battery assembly comprises the battery assembly according to any one of claims 13 to 16. The battery assembly comprises the battery assembly according to any one of claims 13 to 16.

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