Back contact type photovoltaic module

Abstract

The invention discloses a back contact type photovoltaic module, and belongs to the technical field of photovoltaic modules. Comprising at least two battery strings which are arranged at intervals in the first direction, each battery string comprises a first battery piece and a second battery piece which are adjacently arranged in the second direction, and the back face of each battery piece is provided with a first electric connecting piece and a second electric connecting piece which extend in the second direction and are arranged at intervals in the first direction; the insulating piece is arranged on one side, far away from the first battery piece, of the first electric connecting piece and the second electric connecting piece; the first bus bar is arranged on the side, away from the first battery piece, of the insulating part, the projection of the first bus bar on the plane where the first battery piece is located is located in the extending range of the first battery piece in the first direction, and the first bus bar extends in the first direction. The first bus bar comprises a first bus bar body and at least one connecting part protruding out of the first bus bar body in the second direction, and the connecting part at least partially extends out of the insulating piece in the second direction and is electrically connected with the first electric connecting piece.

Description

Technical Field

[0001] This application relates to the field of photovoltaic module technology, specifically to a back-contact photovoltaic module. Background Technology

[0002] Back-contact photovoltaic (PV) modules, as a type of PV module, offer advantages such as high photoelectric conversion efficiency and a more aesthetically pleasing appearance. A back-contact PV module includes at least two cell strings spaced apart along a first direction. Each cell string includes multiple cells spaced apart sequentially along a second direction and a first solder strip and a second solder strip disposed on the back of the cells. At least two adjacent cells are connected in series via the first and second solder strips to form the cell string. A first busbar is also disposed on the back of the cells, extending along the first direction. The first busbar is electrically connected to the first solder strip and insulated from the second solder strip, collecting the charge carriers collected by the first solder strip and transmitting them to an external circuit.

[0003] In related technologies, to prevent the first busbar and the second solder strip from conducting through each other, which could lead to a partial short circuit in the photovoltaic module, an insulating film can be set between the first solder strip and the side of the second solder strip away from the cell and the first busbar. The insulating film blocks the second solder strip and the first busbar, and through holes are set on the insulating film. The through holes are positioned opposite to the first solder strip so that the first solder strip can be electrically connected to the first busbar through the through holes.

[0004] However, during the fabrication of photovoltaic modules, the insulating film is prone to misalignment, and the through-holes on the insulating film may also shift. This prevents the first solder strip from making an electrical connection with the first busbar through the through-holes, thus affecting the reliability of the electrical connection between the first busbar and the first solder strip, and consequently impacting the photoelectric conversion efficiency of the photovoltaic module. Furthermore, during the lamination process of the photovoltaic module, defects such as microcracks and breakage may occur in the solar cells, affecting the process yield of the photovoltaic module. Summary of the Invention

[0005] This application discloses a back-contact photovoltaic module to solve, or at least partially solve, the problems existing in the prior art. During the manufacturing process of photovoltaic modules, the insulating film is prone to displacement, and the through holes on the insulating film will also be misaligned. The first solder strip cannot be electrically connected to the first busbar through the through holes, which affects the reliability of the electrical connection between the first busbar and the first solder strip, and thus affects the photoelectric conversion efficiency of the photovoltaic module. In addition, during the lamination process of the photovoltaic module, the cells are prone to defects such as microcracks and breakage, which affects the process yield of the photovoltaic module.

[0006] To solve the above-mentioned technical problems, this application is implemented as follows: This application discloses a back-contact photovoltaic module, comprising at least two cell strings, the at least two cell strings being arranged at intervals along a first direction, each cell string including a first cell and a second cell arranged adjacent to each other along a second direction, the first cell being disposed at the end of the cell string, and one side of the second cell being pressed against the edge of the first cell; the back of the first cell and / or the second cell is provided with a first electrical connector and a second electrical connector extending along the second direction and arranged at intervals along the first direction, the first electrical connector and the second electrical connector being connected in series with at least two adjacent first cells and second cells, the second direction intersecting the first direction; an insulating member, the insulating member... The components are stacked along the lamination direction of the components on the side of the first electrical connector and the second electrical connector away from the first battery cell to fix the first electrical connector and the second electrical connector to the back of the first battery cell; a first busbar is disposed on the side of the insulating member away from the first battery cell, the projection of the first busbar on the plane of the first battery cell is located within the extension range of the first battery cell along the first direction, the first busbar extends along the first direction, the first busbar includes a first busbar body and at least one connecting portion protruding from the first busbar body along the second direction, the connecting portion at least partially extends out of the insulating member along the second direction and is electrically connected to the first electrical connector.

[0007] In some embodiments, the connecting portion includes a first connecting portion, a second connecting portion, and a third connecting portion arranged sequentially at intervals along the first direction. The projections of the first connecting portion and the second connecting portion onto the plane where the first battery cell is located are located within the same first battery cell, and the projection of the third connecting portion onto the plane where the first battery cell is located is located within an adjacent first battery cell along the first direction. Along the first direction, the distance between the first connecting portion and the second connecting portion is L6, and the distance between the second connecting portion and the third connecting portion is L7, satisfying L6≤L7.

[0008] In some embodiments, along the first direction, the shortest distance between a first electrical connector or a second electrical connector on one of two adjacent first battery cells and a first electrical connector or a second electrical connector on the other first battery cell is L8, and the distance between the two most adjacent sides of two adjacent first battery cells is L9, satisfying L9 < L8 < 2 * L9.

[0009] In some embodiments, along the first direction, on a first battery cell, the distance between adjacent first electrical connectors and second electrical connectors is L10, and the width of the connection portion is L1, satisfying |L8-L10| < L1.

[0010] In some embodiments, along the second direction, the width of the insulating member is L11, and the width of the first busbar body is L12, satisfying L11 > L12.

[0011] In some embodiments, along the thickness direction of the photovoltaic module, the insulating element includes a plurality of sub-insulating elements stacked sequentially.

[0012] In some embodiments, along the first direction, the width of the connecting portion is L1, and the width of the first electrical connector is L2, satisfying L1≥L2.

[0013] In some embodiments, a plurality of first pads are provided on the back side of the first battery cell, the plurality of first pads are arranged at intervals along the second direction and are located between the back side of the first battery cell and the first electrical connector; along the first direction, the width of the connection portion is L1 and the length of the first pad is L3, satisfying L1≥L3.

[0014] In some embodiments, the back side of the first battery cell is further provided with a first main grid extending along the second direction, the first main grid being located between the back side of the first battery cell and the first electrical connector; along the first direction, the width of the connector is L1, and the width of the first main grid is L4, satisfying L1≥L4.

[0015] In some embodiments, the back surface of the first battery cell is further provided with a first fine grid and a second fine grid extending along the first direction and alternately spaced along the second direction. The first electrical connector is electrically connected to the first fine grid, and a first insulating block is disposed between the first electrical connector and the second fine grid. Along the first direction, the width of the connecting portion is L1, and the length of the first insulating block is L5, satisfying L5≥L1. In some embodiments, along the second direction, the first busbar body has a first edge and a second edge disposed opposite to each other, and the connecting portion is connected to the first edge and / or the second edge of the first busbar body.

[0016] In some embodiments, the first pad includes a first sub-pad that is closest to the side of the first cell along the second direction; the projection of the connection portion onto the plane of the first cell is at least partially misaligned with the first sub-pad.

[0017] In some embodiments, the first pad further includes a second sub-pad adjacent to the first sub-pad along the second direction; a projection of the connecting portion on a plane where the first solar cell is located is between the first sub-pad and the second sub-pad.

[0018] In some embodiments, there are multiple second sub-pads, and the multiple second sub-pads are arranged at intervals along the second direction at a position of the first sub-pad away from a side of the first solar cell; the projection of the connecting portion on a plane where the first solar cell is located overlaps with at least a part of the second sub-pads.

[0019] In some embodiments, an edge connection structure is further provided on a back surface of the first solar cell, the edge connection structure is located between the first sub-pad and an edge of the first solar cell, one end of the edge connection structure is connected to the first sub-pad, and the other end extends towards a direction close to the edge of the first solar cell; the projection of the connecting portion on a plane where the first solar cell is located is between the first sub-pad and the edge of the first solar cell, and the projection of the connecting portion on a plane where the first solar cell is located covers at least a part of the edge connection structure.

[0020] In some embodiments, the first pad includes at least two first sub-pads arranged at intervals along the second direction; the connecting portion is provided between two adjacent first sub-pads.

[0021] In some embodiments, the connecting portion at least partially covers the first sub-pad; an area of the connecting portion covering the first sub-pad is greater than or equal to 0.5 mm² and less than or equal to 2 mm².

[0022] In some embodiments, the connecting portion includes at least one of a square connecting portion, a trapezoidal connecting portion, a triangular connecting portion, and an oval connecting portion.

[0023] In some embodiments, the connecting portion includes a first sub-connecting portion extending out of the insulating member along the second direction and a second sub-connecting portion overlapping with the insulating member, a length of the first sub-connecting portion along the second direction is H1, a length of the second sub-connecting portion along the second direction is H2, and H1≥H2; H2>0.

[0024] In some embodiments, along the second direction, a length of the connecting portion is H, and 4 mm≤H≤9 mm; and / or, 2 mm≤H1≤9 mm; and / or, 0 mm<H2≤2 mm; and / or, 0.5≤H1 / H2≤15.

[0025] In some embodiments, along a thickness direction of the photovoltaic module, a height of the first solar cell is less than a height of the second solar cell.

[0026] In some embodiments, the width of the overlapping portion of the first and second battery cells along the second direction is L13, satisfying 0.3mm≤L13≤0.7mm.

[0027] In some embodiments, the first busbar includes at least one of a copper busbar, an aluminum busbar, and a copper-clad aluminum busbar.

[0028] This application discloses a back-contact photovoltaic module, which includes at least two cell strings. The at least two cell strings are spaced apart along a first direction. Each cell string includes a first cell and a second cell arranged adjacent to each other along a second direction. The first cell is located at one end of the cell string, and one side of the second cell is pressed against the edge of the first cell. The back of the first cell and / or the second cell is provided with a first electrical connector and a second electrical connector extending along the second direction and spaced apart along the first direction. The first electrical connector and the second electrical connector are connected in series with at least two adjacent first cells and second cells. The second direction intersects the first direction. An insulating element is also included. The insulating member is disposed on the side of the first electrical connector and the second electrical connector away from the first battery cell, so as to fix the first electrical connector and the second electrical connector to the back of the first battery cell; the first busbar is disposed on the side of the insulating member away from the first battery cell, the projection of the first busbar on the plane of the first battery cell is located within the extension range of the first battery cell along the first direction, the first busbar extends along the first direction, the first busbar includes a first busbar body and at least one connecting portion protruding from the first busbar body along the second direction, the connecting portion at least partially extends out of the insulating member along the second direction and is electrically connected to the first electrical connector.

[0029] The back-contact photovoltaic module disclosed in this application includes a first solar cell and a second solar cell arranged adjacent to each other. The first solar cell is located at the end of the cell string, and one side of the second solar cell is pressed against the edge of the first solar cell. This forms a stacked cell string, where the height of the first solar cell along the thickness direction of the photovoltaic module is lower than the height of the second solar cell. Because the height of the first solar cell is lower, the height of the first busbar is also relatively reduced. Therefore, this avoids the risk of microcracks or breakage of the solar cells during the lamination process, which could affect the manufacturing yield of the photovoltaic module, as the height of the first busbar is too high.

[0030] Furthermore, in the back-contact photovoltaic module disclosed in this application, the connecting portion extends at least partially along the second direction to the outside of the insulating member and contacts and is electrically connected to the first electrical connector to collect the charge carriers gathered by the first electrical connector and transmit the collected charge carriers to the external circuit. The insulating member can insulate and isolate the first busbar body and the second electrical connector, preventing the first busbar body and the second electrical connector from contacting and conducting, which could lead to a partial short circuit in the photovoltaic module and affect its photoelectric conversion efficiency.

[0031] In other words, in this embodiment, the connecting portion extends at least partially along the second direction to the outside of the insulating member, contacts and conducts electricity with the first electrical connector. The connecting portion can collect the charge carriers collected by the first electrical connector and transmit the collected charge carriers to the first busbar body, and then transmit the collected charge carriers to the external circuit through the first busbar body. This ensures the reliability of the electrical connection between the first busbar and the first electrical connector, thereby ensuring the photoelectric conversion efficiency of the photovoltaic module. Attached Figure Description

[0032] Figure 1 This diagram illustrates a partial structure of the back-contact photovoltaic module described in the embodiments of this application. Figure 1 ; Figure 2 This diagram illustrates a partial structure of the back-contact photovoltaic module described in the embodiments of this application. Figure 2 ; Figure 3 This diagram illustrates a partial structure of the back-contact photovoltaic module described in the embodiments of this application. Figure 3 ; Figure 4 This diagram illustrates a partial structure of the back-contact photovoltaic module described in the embodiments of this application. Figure 4 ; Figure 5 This diagram illustrates a partial structure of the back-contact photovoltaic module described in the embodiments of this application. Figure 5 ; Figure 6 This diagram illustrates a partial structure of the back-contact photovoltaic module described in the embodiments of this application. Figure 6 ; Figure 7 This diagram illustrates a partial structure of the back-contact photovoltaic module described in the embodiments of this application. Figure 7 ; Figure 8 This is a schematic diagram of the structure of the back-contact photovoltaic module described in the embodiments of this application; Figure 9 This is a partial cross-sectional view of the back-contact photovoltaic module described in this application embodiment at the location of the first electrical connector along the thickness direction of the photovoltaic module; Figure 10This diagram illustrates the structure of the first electrical connector or the second electrical connector in the embodiments of this application. Figure 1 ; Figure 11 This diagram illustrates the structure of the first electrical connector or the second electrical connector in the embodiments of this application. Figure 2 ; Figure 12 This diagram illustrates the structure of the first electrical connector or the second electrical connector in the embodiments of this application. Figure 3 .

[0033] Figure label: 10: First solar cell; 11: First pad; 111: First sub-pad; 112: Second sub-pad; 12: Edge connection structure; 20: First electrical connection; 30: Second electrical connection; 40: Insulating components; 50: First busbar; 51: First busbar body; 511: First edge; 512: Second edge; 52: Connecting part; 521: First connecting part; 522: Second connecting part; 523: Third connecting part; 524: First sub-connecting part; 525: Second sub-connecting part; 60: First insulating block; 70: Second solar cell; X: First direction; Y: Second direction. Detailed Implementation

[0034] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of the present invention.

[0035] It should be understood that the phrase "one embodiment" or "an embodiment" throughout the specification means that a specific feature, structure, or characteristic related to the embodiment is included in at least one embodiment of the invention. Therefore, "in one embodiment" or "in an embodiment" appearing throughout the specification does not necessarily refer to the same embodiment. Furthermore, these specific features, structures, or characteristics can be combined in any suitable manner in one or more embodiments.

[0036] This application discloses a back-contact photovoltaic module, which includes at least two cell strings arranged at intervals along a first direction X. Each cell string includes a first cell 10 and a second cell 70 arranged adjacent to each other along a second direction Y. The first cell 10 is located at the end of the cell string, and one side of the second cell 70 is pressed against the edge of the first cell 10. A first electrical connector 20 and a second electrical connector 30 extending along the second direction Y and arranged at intervals along the first direction X are provided on the back of the first cell 10 and / or the second cell 70. The first electrical connector 20 and the second electrical connector 30 connect at least two adjacent first cells 10 and second cells 70 in series. The second direction Y intersects the first direction X. An insulating member 40 is also included. 40 is stacked along the component lamination direction on the side of the first electrical connector 20 and the second electrical connector 30 away from the first battery cell 10 to fix the first electrical connector 20 and the second electrical connector 30 to the back of the first battery cell 10; a first busbar 50 is disposed on the side of the insulating member 40 away from the first battery cell 10, the projection of the first busbar 50 on the plane where the first battery cell 10 is located is within the extension range of the first battery cell 10 along the first direction X, the first busbar 50 extends along the first direction X, the first busbar 50 includes a first busbar body 51 and at least one connecting portion 52 protruding from the first busbar body 51 along the second direction Y, the connecting portion 52 at least partially extends out of the insulating member 40 along the second direction Y and is electrically connected to the first electrical connector 20.

[0037] This application discloses a back-contact photovoltaic (PV) module, which has advantages such as high photoelectric conversion efficiency and a more aesthetically pleasing appearance. On the plane of the PV module, the PV module has intersecting first direction X and second direction Y. Exemplarily, the first direction X can be the length direction of the PV module, and the second direction Y can be the width direction of the PV module. Alternatively, the first direction Y can be the width direction of the PV module, and the second direction Y can be the length direction of the PV module. The module lamination direction is the module height direction perpendicular to the first direction X and the second direction Y.

[0038] The back-contact photovoltaic module disclosed in this application includes at least two cell strings, both extending along a second direction Y and spaced apart along a first direction X. Each cell string includes multiple cells arranged sequentially along the second direction Y, including adjacent first cells 10 and second cells 70. For example, in the second direction Y, the first cell 10 can be the outermost cell in the cell string, and the second cell 70 is adjacent to the first cell 10. Of course, the above are merely individual examples of the specific positions of the first cell 10 and the second cell 70 in the cell string and are not intended to limit this application. In practical applications, the first cell 10 and the second cell 70 can be any two adjacent cells in the cell string.

[0039] The following description will use the example of the first solar cell 10 being the outermost cell in the solar cell string, and the second solar cell 70 being adjacent to the first solar cell, to illustrate the back-contact photovoltaic module disclosed in this application. Specifically, as follows... Figure 9 As shown, the first battery cell 10 is located at the end of the battery string, that is, the first battery cell 10 is the outermost battery cell in the battery string. The second battery cell 70 is adjacent to the first battery cell 10, and one side of the second battery cell 70 is pressed against the edge of the first battery cell 10. In this way, a battery string is formed by stacking the cells.

[0040] It should be noted that the battery cell in this embodiment has a front side and a back side arranged opposite to each other, with the front side facing the sunlight and the back side facing away from the sunlight.

[0041] The back-contact photovoltaic module also includes a first electrical connector 20 and a second electrical connector 30. Both the first electrical connector 20 and the second electrical connector 30 extend along a second direction Y and are alternately arranged along a first direction X on the back side of the first cell 10 and / or the second cell 70, and are electrically connected to the first cell 10 and / or the second cell 70. This allows the first electrical connector 20 and the second electrical connector 30 to collect the charge carriers generated by the first cell 10 and / or the second cell 70, and to transmit the collected charge carriers to an external circuit. It can be understood that the first electrical connector 20 and the second electrical connector 30 can be connected in series with adjacent first cells 10 and second cells 70 to form a cell string.

[0042] It should be noted that in this embodiment, the first electrical connector 20 and the second electrical connector 30 have opposite conductivity types. The first electrical connector 20 and the second electrical connector 30 can be solder strips, metal wires, or other types of conductive components. For example, the first electrical connector 20 and the second electrical connector 30 can be rectangular solder strips, circular solder strips, or other irregularly shaped solder strips.

[0043] The back-contact photovoltaic module disclosed in this application also includes an insulating member 40. Exemplarily, the insulating member 40 can be an insulating film, which has insulating properties. The insulating member 40 is stacked on the side of the first electrical connector 20 and the second electrical connector 30 away from the first solar cell 10. Furthermore, the insulating member 40 can be fixed to the back of the first solar cell 10 by means of adhesive bonding or other methods, thereby reliably pressing the first electrical connector 20 and the second electrical connector 30 into their designed positions, effectively preventing the first electrical connector 20 and the second electrical connector 30 from shifting during use or processing, and ensuring the long-term reliability of the photovoltaic module.

[0044] The back-contact photovoltaic module disclosed in this application also includes a first busbar 50. The first busbar 50 is disposed on the side of the insulating member 40 away from the first solar cell 10, and the projection of the first busbar 50 onto the plane where the first solar cell 10 is located is within the extension range of the first solar cell 10 along the first direction X. It can be understood that the first busbar 50 extends along the first direction X and can span at least two first solar cells 10 spaced apart along the first direction X to connect at least two adjacent cell strings in series or parallel, while the first busbar 50 does not extend onto the second solar cell 70.

[0045] In other words, in the stacked battery string formed by pressing the second battery cell 70 against the edge of the first battery cell 10, the height of the first battery cell 10 along the thickness direction of the photovoltaic module is lower than the height of the second battery cell 70. Because the first battery cell 10 is lower, the height of the first busbar 50 is also relatively lower. Therefore, this avoids the risk of microcracks or breakage of the battery cells during the lamination process, which could affect the manufacturing yield of the photovoltaic module, as the height of the first busbar 50 could be too high.

[0046] It should be noted that the first busbar 50 in this embodiment includes a first busbar body 51 and at least one connecting portion 52 connected to the first busbar body 51. The first busbar body 51 is an elongated structure extending along a first direction X and a second direction Y, and has a first edge 511 and a second edge 512 disposed opposite to each other. One end of the connecting portion 52 is connected to the first edge or the second edge of the first busbar body 51, and the other end of the connecting portion 52 extends along the second direction Y in a direction away from the first busbar body 51, so as to form a connecting portion 52 protruding from the first busbar body 51 along the second direction Y on the first edge 511 or the second edge 512 of the first busbar body 51.

[0047] The connecting portion 52 extends at least partially along the second direction Y to the outside of the insulating member 40, and contacts and is electrically connected to the first electrical connector 20 to collect the charge carriers collected by the first electrical connector 20 and transmit the collected charge carriers to the external circuit. The insulating member 40 can insulate and isolate the first busbar body 51 and the second electrical connector 30, preventing the first busbar body 51 and the second electrical connector 30 from contacting and conducting, effectively avoiding partial short circuits in the photovoltaic module and ensuring the photoelectric conversion efficiency of the photovoltaic module.

[0048] In other words, in this embodiment, the connecting portion 52 extends at least partially along the second direction Y to the outside of the insulating member 40, contacting and conducting with the first electrical connector 20. The connecting portion 52 can collect the charge carriers collected by the first electrical connector 20 and transmit the collected charge carriers to the first busbar body 51, and then transmit the collected charge carriers to the external circuit through the first busbar body 51. This ensures the reliability of the electrical connection between the first busbar 50 and the first electrical connector 20, thereby ensuring the photoelectric conversion efficiency of the photovoltaic module.

[0049] In some embodiments, along the second direction Y, the first busbar body 51 has a first edge 511 and a second edge 512 disposed opposite to each other, and the connecting portion 52 is connected to the first edge 511 and / or the second edge 512 of the first busbar body 51.

[0050] In this embodiment, the first busbar body 51 is an elongated structure. The first busbar body 51 extends along a first direction X and a second direction Y. The first busbar body 51 has a first edge 511 and a second edge 512 disposed opposite to each other. The connecting portion 52 is connected to the first edge 511 and / or the second edge 512 of the first busbar body 51.

[0051] For example, one end of the connecting portion 52 is connected to the first edge 511 of the first busbar body 51, and the other end extends in the second direction Y toward a direction away from the first busbar body 51. Alternatively, one end of the connecting portion 52 is connected to the second edge 512 of the first busbar body 51, and the other end extends in the second direction Y toward a direction away from the first busbar body 51. Alternatively, one connecting portion 52 is connected to the first edge 511 of the first busbar body 51, and another connecting portion 52 is connected to the second edge 512 of the first busbar body 51, and the two connecting portions 52 are arranged opposite each other in the second direction Y.

[0052] In this embodiment, by connecting the connecting part 52 to the first edge 511, or the second edge 512, or simultaneously connecting it to the first edge 511 and the second edge 512, the flexibility of the position setting of the connecting part 52 is improved, ensuring that the connecting part 52 can extend out of the insulating member 40, and the orientation of the connecting part 52 can be flexibly selected according to the design, so as to contact and conduct with the first electrical connector 20, thereby ensuring the photoelectric conversion efficiency of the photovoltaic module.

[0053] In some embodiments, along the first direction X, the width of the connecting portion 52 is L1, and the width of the first electrical connector 20 is L2, satisfying L1≥L2.

[0054] In this embodiment, the width L1 of the connecting portion 52 along the first direction X is set to be greater than or equal to the width L2 of the first electrical connector 20 along the first direction X, so that the portion of the connecting portion 52 extending out of the insulating member 40 can cover and contact the first electrical connector 20. This size design ensures that the connecting portion 52 can fully cover the first electrical connector 20, providing sufficient contact area, thereby reducing contact resistance, ensuring the reliability of the electrical connection between the connecting portion 52 and the first electrical connector 20, and ensuring the photoelectric conversion efficiency of the photovoltaic module.

[0055] For example, L1 = L2; or it can be an integer multiple of L2. The specific value can be selected according to actual needs, such as L1 = 2 * L2; or L1 = 3 * L2; or L1 = 4 * L2.

[0056] For example, the width L2 of the first electrical connector 20 along the first direction X can be 1.0mm, 1.2mm, 1.5mm, 1.8mm, 2.0mm, 2.2mm, etc. The width L1 of the connecting portion 52 along the first direction X can be 1.5mm, 2.0mm, 3.0mm, 4.0mm, 5.0mm, 6.0mm, etc.

[0057] In some embodiments, a plurality of first pads 11 are provided on the back side of the first battery cell 10. The plurality of first pads 11 are arranged at intervals along the second direction Y and are located between the back side of the first battery cell 10 and the first electrical connector 20. Along the first direction X, the width of the connection portion 52 is L1 and the length of the first pad 11 is L3, satisfying L1≥L3.

[0058] In this embodiment, a plurality of first pads 11 are provided on the back side of the first battery cell 10. The plurality of first pads 11 are arranged at intervals along the second direction Y, and the plurality of first pads 11 are located between the back side of the first battery cell 10 and the first electrical connector 20. The first electrical connector 20 is soldered to the back side of the first battery cell 10 through the plurality of first pads 11, thereby ensuring the reliability of the electrical connection between the first electrical connector 20 and the first battery cell 10.

[0059] It should be noted that in this embodiment of the application, the width L1 of the connecting part 52 along the first direction X is set to be greater than or equal to the length L3 of the first pad 11 along the first direction X, so as to press the first electrical connector 20 toward the direction close to the first pad 11 through the connecting part 52, thereby ensuring the reliability of the electrical connection between the first electrical connector 20 and the first pad 11, and thus ensuring the photoelectric conversion efficiency of the photovoltaic module.

[0060] For example, the width L1 of the connecting portion 52 along the first direction X can be 1.5mm, 2.0mm, 3.0mm, 4.0mm, 5.0mm, 6.0mm, etc., and the width L3 of the first pad 11 along the first direction X can be 0.8mm, 0.9mm, 1.0mm, 1.1mm, 1.2mm, etc.

[0061] In some embodiments, the back side of the first battery cell 10 is further provided with a first main grid extending along the second direction Y, the first main grid being located between the back side of the first battery cell 10 and the first electrical connector 20; along the first direction X, the width of the connecting portion 52 is L1, and the width of the first main grid is L4, satisfying L1≥L4.

[0062] The back-contact photovoltaic module disclosed in this application can include solar cells with a main grid. That is, a first main grid is provided on the back side of the first solar cell 10, the first main grid extends along the second direction Y, and the first main grid is located between the back side of the first solar cell 10 and the first electrical connector 20. The first main grid collects the charge carriers generated by the first solar cell 10 and transmits the collected charge carriers to an external circuit through the first electrical connector 20.

[0063] Of course, a second main grid can also be provided on the back side of the first solar cell 10. The second main grid extends along the second direction Y and is arranged at intervals from the first main grid along the first direction X. The second main grid is located between the back side of the first solar cell 10 and the second electrical connector 30. The second main grid collects the charge carriers generated by the first solar cell 10 and transmits the collected charge carriers to the external circuit.

[0064] It should be noted that, in this embodiment of the application, the width L1 of the connecting part 52 along the first direction X is set to be greater than or equal to the width L4 of the first main grid along the first direction X, so as to press the first electrical connector 20 toward the first main grid through the connecting part 52, thereby ensuring the reliability of the electrical connection between the first electrical connector 20 and the first main grid, and thus ensuring the photoelectric conversion efficiency of the photovoltaic module.

[0065] For example, the width L1 of the connecting portion 52 along the first direction X can be 1.5mm, 2.0mm, 3.0mm, 4.0mm, 5.0mm, 6.0mm, etc., and the width L4 of the first main gate along the first direction X can be 1.3mm, 1.4mm, 1.5mm, 1.6mm, 1.7mm, etc.

[0066] In some embodiments, the back side of the first battery cell 10 is further provided with a first fine grid and a second fine grid extending along the first direction X and arranged alternately along the second direction Y. The first electrical connector 20 is electrically connected to the first fine grid, and a first insulating block 60 is provided between the first electrical connector 20 and the second fine grid. Along the first direction X, the width of the connecting portion 52 is L1, and the length of the first insulating block 60 is L5, satisfying L5≥L1.

[0067] The back-contact photovoltaic module disclosed in this application can also include a gridless cell. It is understood that the back side of the first cell 10 is provided with only a first and a second fine grid extending along a first direction X and arranged alternately along a second direction Y. The first and second fine grids have opposite conductivity types to collect the charge carriers generated by the first cell 10 through the first and second fine grids.

[0068] The first electrical connector 20 extends along the second direction Y and is electrically connected to multiple first fine grids to collect the charge carriers gathered by the multiple first fine grids and transmit the collected charge carriers to an external circuit. A first insulating block 60 is provided between the first electrical connector 20 and the second fine grid to insulate and isolate the first electrical connector 20 and the second fine grid, preventing the first electrical connector 20 and the second fine grid from conducting and causing a partial short circuit in the photovoltaic module, which would affect the photoelectric conversion efficiency of the photovoltaic module.

[0069] In this embodiment, the second electrical connector 30 extends along the second direction Y and is electrically connected to multiple second fine grids to collect the charge carriers gathered by the multiple second fine grids and transmit the collected charge carriers to an external circuit. A second insulating block is provided between the second electrical connector 30 and the first fine grid to insulate and isolate the second electrical connector 30 and the first fine grid. This prevents the overflow of molten welding material on the surface of the connection portion 52 during the lamination process, avoiding conduction between the second electrical connector 30 and the first fine grid, which could lead to a partial short circuit in the photovoltaic module and affect the photoelectric conversion efficiency of the photovoltaic module. This significantly improves the production yield and long-term reliability of the module.

[0070] It should be noted that in this embodiment, the width L5 of the first insulating block 60 along the first direction X is set to be greater than or equal to the width L1 of the connecting portion 52 along the first direction X. This is to prevent the welding material on the surface of the connecting portion 52 from melting due to heat during the photovoltaic module lamination process, overflowing from the first insulating block 60, and connecting with conductive components of the opposite conductivity type, such as the second grid, which could lead to a partial short circuit in the photovoltaic module.

[0071] Furthermore, the above-mentioned arrangement enables the first insulating block 60 to insulate and isolate the connecting part 52 and the second fine grid, as well as the first electrical connector 20 and the second fine grid, to prevent the connecting part 52, the first electrical connector 20 and the second fine grid from conducting with each other, which would cause a partial short circuit in the photovoltaic module and affect the photoelectric conversion efficiency of the photovoltaic module.

[0072] In some embodiments, the connecting portion 52 includes a first connecting portion 521, a second connecting portion 522, and a third connecting portion 523 arranged sequentially at intervals along a first direction X. The projections of the first connecting portion 521 and the second connecting portion 522 onto the plane where the first battery cell 10 is located are within the same first battery cell 10, and the projection of the third connecting portion 523 onto the plane where the first battery cell 10 is located within adjacent first battery cells 10 along the first direction X. Along the first direction X, the distance between the first connecting portion 521 and the second connecting portion 522 is L6, and the distance between the second connecting portion 522 and the third connecting portion 523 is L7. When the polarities of two adjacent electrical connectors in adjacent first battery cells 10 are the same, L6 < L7 is satisfied, and this spacing difference can adapt to different electrical safety clearance requirements. When the polarities of two adjacent electrical connectors in adjacent first battery cells 10 are opposite, L6 = L7 is satisfied, which facilitates standardized design and manufacturing.

[0073] The photovoltaic module disclosed in this application includes multiple cell strings, which are arranged at intervals along a first direction X and along a second direction Y. The outermost cell in each cell string is a first cell 10. That is, the photovoltaic module includes multiple first cells 10 arranged at intervals along the first direction X. A first busbar 50 extends along the first direction X and is disposed on the back of at least two first cells 10 to connect at least two adjacent first cells 10 in series or in parallel.

[0074] The first busbar 50 includes a first busbar body 51 and a plurality of connecting portions 52 connected to a first edge 511 and / or a second edge 512 of the first busbar body 51. The plurality of connecting portions 52 include a first connecting portion 521, a second connecting portion 522, and a third connecting portion 523 arranged sequentially. In two adjacent first battery cells 10 arranged along the first direction X, the projections of the first connecting portion 521 and the second connecting portion 522 onto the plane of the first battery cell 10 lie within one of the first battery cells 10, and the projection of the third connecting portion 523 onto the plane of the first battery cell 10 lies within the other first battery cell 10.

[0075] When the polarities of the two electrical connectors that are close to each other in two adjacent first battery cells 10 are the same, the distance L7 between the second connection portion 522 and the third connection portion 523 along the first direction X is set to be greater than the distance L6 between the first connection portion 521 and the second connection portion 522 along the first direction X.

[0076] For example, the distance L6 between the first connecting portion 521 and the second connecting portion 522 can be 18mm, and the distance L7 between the second connecting portion 522 and the third connecting portion 523 along the first direction X can be 19.7mm, 19.8mm, 19.9mm, 20.0mm, 20.1mm, 20.2mm, etc. Alternatively, the distance L6 between the first connecting portion 521 and the second connecting portion 522 can be 10.6mm, and the distance L7 between the second connecting portion 522 and the third connecting portion 523 along the first direction X can be 15.4mm, 15.5mm, 15.6mm, 15.7mm, 15.8mm, 15.9mm, etc.

[0077] When two adjacent first solar cells 10 have the same polarity for their two closest electrical connectors, for example, in two adjacent first solar cells 10, the electrical connector on one first solar cell 10 closest to the other is the first electrical connector, and the electrical connector on the other first solar cell 10 closest to that first solar cell 10 is the second electrical connector. The distance L7 between the second connection portion 522 and the third connection portion 523 along the first direction X is set to be equal to the distance L6 between the first connection portion 521 and the second connection portion 522 along the first direction X, thereby improving the ease of photovoltaic module processing and increasing the manufacturing efficiency of photovoltaic modules.

[0078] For example, the distance L6 between the first connecting portion 521 and the second connecting portion 522 can be 18 mm, and the distance L7 between the second connecting portion 522 and the third connecting portion 523 along the first direction X can also be 18 mm. Of course, the above are merely individual examples of the specific distances L6 and L7 in the embodiments of this application and are not intended to limit the application. In practical applications, those skilled in the art can also set the specific distances L6 and L7 as needed. For example, the distance L7 between the second connecting portion 522 and the third connecting portion 523 along the first direction X can be set to be less than the distance L6 between the first connecting portion 521 and the second connecting portion 522 along the first direction X.

[0079] In some embodiments, along the first direction X, the shortest distance between the first electrical connector 20 or the second electrical connector 30 on one of the two adjacent first battery cells 10 and the first electrical connector 20 or the second electrical connector 30 on the other first battery cell 10 is L8, and the distance between the two adjacent sides of the two adjacent first battery cells 10 is L9, satisfying L9 < L8 < 2 * L9.

[0080] In two adjacent first battery cells 10 along the first direction X, the closest distance along the first direction X between the first electrical connector 20 or second electrical connector 30 on one first battery cell 10 that is closest to the other first battery cell 10 and the closest first electrical connector 20 or second electrical connector 30 on the other first battery cell 10 is L8. In other words, in two adjacent first battery cells 10, the closest distance along the first direction X between two closely spaced electrical connectors is L8.

[0081] In this embodiment, the distance between the two closest edges of two adjacent first solar cells 10 along the first direction X is L9. L8 is set to be greater than L9 and less than 2*L9 to ensure that the electrical connector can be disposed on the back side of the first solar cell 10, improving the reliability of the electrical connection between the electrical connector and the first solar cell 10. Furthermore, the electrical connector is close to the edge of the first solar cell 10 to collect charge carriers generated at the edge of the first solar cell 10, ensuring the photoelectric conversion efficiency of the photovoltaic module. This spacing design ensures reliable connection between the electrical connector and the edge of the solar cell, collects edge charge carriers, and also guarantees sufficient insulation distance.

[0082] For example, L9 can be 1mm, 1.2mm, 1.4mm, 1.5mm, 1.6mm, 1.8mm, 2.0mm, etc. L8 can be 3mm, 3.2mm, 3.4mm, 3.6mm, 3.8mm, 4.0mm, etc.

[0083] In some embodiments, along the first direction X, on a first battery cell 10, the distance between adjacent first electrical connectors 20 and second electrical connectors 30 is L10, and the width of the connection portion 52 is L1, satisfying |L8-L10| < L1.

[0084] In this embodiment, on a first battery cell 10, the distance between adjacent first electrical connectors 20 and second electrical connectors 30 along the first direction X is L10. The absolute value of the difference between the shortest distance L8 along the first direction X between two adjacent first battery cells 10 (where the distance between the first electrical connector 20 or second electrical connector 30 on one first battery cell 10 and the distance L10 along the first direction X between adjacent first electrical connectors 20 and second electrical connectors 30 on the other first battery cell 10) and the distance L10 along the first direction X between adjacent first electrical connectors 20 and second electrical connectors 30 on one first battery cell 10 is set to be less than the width L1 of the connecting portion 52 along the first direction X. This design provides a certain tolerance margin, ensuring that even with manufacturing tolerances, the connecting portion 52 can still reliably align and electrically connect with the target electrical connector. To avoid the first electrical connector 20 failing to make contact with the first busbar 50, thus affecting the photoelectric conversion efficiency of the photovoltaic module.

[0085] In some embodiments, the first pad 11 includes a first sub-pad 111 that is closest to the side of the first cell 10 along the second direction Y; the projection of the connection portion 52 onto the plane of the first cell 10 is at least partially misaligned with the first sub-pad 111.

[0086] In this embodiment, the plurality of first pads 11 include first sub-pads 111, wherein the first sub-pad 111 is the first pad 11 closest to the edge of the first battery cell 10 along the second direction Y among the plurality of first pads 11. The projection of the connecting portion 52 onto the plane containing the first battery cell 10 is at least partially misaligned with the first sub-pad 111. That is, the connecting portion 52 does not completely cover the first sub-pad 111.

[0087] In this embodiment, the projection of the connecting part 52 onto the plane where the first battery cell 10 is located is set to be at least partially misaligned with the first sub-pad 111. That is, the connecting part 52 will not completely cover the surface of the first sub-pad 111, thus ensuring the photoelectric conversion efficiency of the photovoltaic module and avoiding local short circuits in the photovoltaic module.

[0088] Because the surface of the connector 52 has a large amount of welding material, during the fabrication of the photovoltaic module, the welding material on the surface of the connector 52 melts due to heat. The first sub-pad 111 also has a large amount of welding material. If the connector 52 covers the surface of the first sub-pad 111, the welding material of both will melt due to heat. This results in an excess of molten welding material, which may overflow to other locations of the first cell 10 and conduct to the second grid or the second electrical connector 30, causing a local short circuit in the photovoltaic module and affecting the photoelectric conversion efficiency of the photovoltaic module. The purpose of this design is to prevent the connector 52 and the first sub-pad 111 from overflowing due to excessive solder melting during lamination, thus reducing the risk of short circuits with adjacent conductive components.

[0089] In some embodiments, the first pad 11 further includes a second sub-pad 112 adjacent to the first sub-pad 111 along the second direction Y; the projection of the connection portion 52 on the plane where the first battery cell 10 is located is between the first sub-pad 111 and the second sub-pad 112.

[0090] The plurality of first pads 11 in this embodiment of the application further includes second sub-pads 112. The second sub-pads 112 are spaced apart from the first sub-pads 111 along the second direction Y. Along the second direction Y, the second sub-pads 112 are located on the side of the first sub-pads 111 away from the side of the first solar cell 10. The projection of the connecting portion 52 onto the plane of the first solar cell 10 is located between the first sub-pads 111 and the second sub-pads 112. That is, the connecting portion 52 neither covers the first sub-pads 111 nor the second sub-pads 112, further controlling the amount of solder to ensure the photoelectric conversion efficiency of the photovoltaic module and avoid local short circuits in the photovoltaic module.

[0091] In some embodiments, the second sub-pad 112 includes a plurality of second sub-pads 112, which are spaced apart along the second direction Y at positions away from the side of the first sub-pad 111 away from the first battery cell 10; the projection of the connecting portion 52 on the plane of the first battery cell 10 overlaps with at least a portion of the second sub-pads 112.

[0092] In this embodiment of the application, the second sub-pad 112 includes a plurality of sub-pads 112, which are spaced apart along the second direction Y on the side of the first sub-pad 111 away from the side of the first battery cell 10, so as to weld the first electrical connector 20 to the surface of the first battery cell 10 through the first sub-pad 111 and the plurality of second sub-pads 112.

[0093] In this design, the first sub-pad 111 is a large pad, and the second sub-pad 112 is a small pad. The projection of the connecting portion 52 onto the plane of the first solar cell 10 overlaps with a portion of the second sub-pad 112, meaning that the connecting portion 52 can cover a portion of the second sub-pad 112. Since the second sub-pad 112 is a small pad, it will not have excessive welding material. The connecting portion 52 covers the surface of the second sub-pad 112. During the photovoltaic module manufacturing process, the welding materials of both will melt due to heat, and the amount of molten welding material will not be excessive. Therefore, it will not affect the photoelectric conversion efficiency of the photovoltaic module, and the reliability of the photovoltaic module remains good.

[0094] It should be noted that, in this embodiment, the area of ​​the overlapping portion of the projection of the connecting portion 52 on the plane of the first battery cell 10 and the second sub-pad 112 is set to be greater than or equal to 0.5 mm² and less than or equal to 1.2 mm². For example, the area of ​​the overlapping portion of the projection of the connecting portion 52 on the plane of the first battery cell 10 and the second sub-pad 112 can be 0.5 mm², 0.7 mm², 0.9 mm², 1.0 mm², 1.1 mm², 1.2 mm², etc. Controllable overlap ensures reliable electrical connection without introducing additional short-circuit risks. In some embodiments, an edge connection structure 12 is further provided on the back side of the first battery cell 10. The edge connection structure 12 is located between the first sub-pad 111 and the edge of the first battery cell 10. One end of the edge connection structure 12 is connected to the first sub-pad 111, and the other end extends toward the edge of the first battery cell 10. The projection of the connection portion 52 on the plane where the first battery cell 10 is located is between the first sub-pad 111 and the edge of the first battery cell 10, and the projection of the connection portion 52 on the plane where the first battery cell 10 is located covers at least part of the edge connection structure 12.

[0095] In this embodiment, an edge connection structure 12 is provided on the back side of the first battery cell 10. Along the second direction Y, the edge connection structure 12 is located between the first sub-pad 111 and the edge of the first battery cell 10, so as to collect charge carriers generated near the edge region of the first battery cell 10. One end of the edge connection structure 12 is connected to the first sub-pad 111, and the other end extends towards the edge of the first battery cell 10. The charge carriers collected by the edge connection structure 12 can be transmitted through the first sub-pad 111 to the first electrical connector 20, and then through the first electrical connector 20 to an external circuit.

[0096] The projection of the connecting portion 52 onto the plane of the first solar cell 10 is located between the first sub-pad 111 and the edge of the first solar cell 10, and the projection of the connecting portion 52 onto the plane of the first solar cell 10 covers a portion of the edge connection structure 12. The connecting portion 52 presses the first electrical connector 20 toward the first solar cell 10, strengthening the electrical contact between the first electrical connector 20 and the edge connection structure 12 and the first sub-pad 111 through the pressure of the connecting portion 52. This improves the reliability of the electrical connection between the first electrical connector 20, the first sub-pad 111, and the edge connection structure 12, enhances the efficiency of current collection in the edge region, and ensures the photoelectric conversion efficiency of the photovoltaic module.

[0097] It should be noted that the edge connection structure 12 in this embodiment includes, but is not limited to, end lines and harpoon-shaped structures. In this embodiment, no excessive restrictions are placed on the specific type of the edge connection structure 12; in practical applications, those skilled in the art can configure it as needed.

[0098] In some embodiments, the first pad 11 includes at least two first sub-pads 111 spaced apart along the second direction Y; the connecting portion 52 is disposed between two adjacent first sub-pads 111.

[0099] In this embodiment of the application, the first sub-pad 111 includes at least two, and the first sub-pad 111 is a large pad. The at least two first sub-pads 111 are spaced apart along the second direction Y and are both located between the back of the first battery cell 10 and the first electrical connector 20, so that the first electrical connector 20 can be soldered to the back of the first battery cell 10 through the at least two first sub-pads 111, thereby improving the reliability of the electrical connection between the first electrical connector 20 and the first battery cell 10.

[0100] The connecting portion 52 is positioned between two adjacent first sub-pads 111, meaning it does not cover the surface of the first sub-pad 111, thus avoiding direct coverage of the large pad. Alternatively, the connecting portion 52 may partially cover the first sub-pad 111, but the coverage area is strictly controlled, for example, greater than or equal to 0.5 mm² and less than or equal to 2 mm², to achieve a balance between connection reliability and solder control. This ensures the photoelectric conversion efficiency of the photovoltaic module and prevents partial short circuits.

[0101] In some embodiments, the connection portion 52 at least partially covers the first sub-pad 111; the area of ​​the connection portion 52 covering the first sub-pad 111 is greater than or equal to 0.5 mm² and less than or equal to 2 mm².

[0102] In this embodiment, the connecting portion 52 is disposed between two adjacent first sub-pads 111, and a portion of the connecting portion 52 covers the first sub-pads 111. It is understood that only a portion of the connecting portion 52 covers the first sub-pads 111. Since the area of ​​the connecting portion 52 covering the first sub-pads 111 is small, although both the connecting portion 52 and the first sub-pads 111 will be heated and melted during the photovoltaic module manufacturing process, the area of ​​the overlapping portion of the connecting portion 52 and the first sub-pads 111 is small. Therefore, the amount of welding material in the molten state will not be excessive, and thus, it will not affect the photoelectric conversion efficiency of the photovoltaic module, and the reliability of the photovoltaic module remains good.

[0103] The area of ​​the connecting portion 52 covering the first sub-pad 111 is greater than or equal to 0.5 mm² and less than or equal to 2 mm². For example, the area of ​​the connecting portion 52 covering the first sub-pad 111 can be 0.5 mm², 0.7 mm², 0.9 mm², 1.1 mm², 1.3 mm², 1.5 mm², 1.7 mm², 1.9 mm², 2.0 mm², etc.

[0104] In some embodiments, the connecting portion 52 includes at least one of a square connecting portion, a trapezoidal connecting portion, a triangular connecting portion, and an elliptical connecting portion.

[0105] In this embodiment, the connecting portion 52 can be a square connecting portion, a trapezoidal connecting portion, a triangular connecting portion, an elliptical connecting portion, or other irregularly shaped connecting portions. In this embodiment, the specific structure of the connecting portion 52 is not subject to excessive restrictions. In practical applications, those skilled in the art can set the specific structure of the connecting portion 52 as needed.

[0106] In this embodiment, the specific structure of the connecting portion 52 is defined to facilitate the fabrication of the first busbar 50. Furthermore, defining the specific structure of the connecting portion 52 improves the reliability of the electrical connection between the connecting portion 52 and the first electrical connector 20, preventing loosening between the connecting portion 52 and the first electrical connector 20 from affecting the photoelectric conversion efficiency of the photovoltaic module.

[0107] It should be noted that when the connecting part 52 is a square connecting part, the square connecting part needs to be chamfered or deburred to avoid the connecting part 52 piercing the insulating part, which would cause a partial short circuit in the photovoltaic module and affect the photoelectric conversion efficiency of the photovoltaic module.

[0108] In some embodiments, the connecting portion 52 includes a first sub-connecting portion 524 extending from the insulating member 40 in the second direction Y and a second sub-connecting portion 525 overlapping with the insulating member 40. The length of the first sub-connecting portion 524 in the second direction Y is H1, and the length of the second sub-connecting portion 525 in the second direction Y is H2, satisfying H1≥H2; H2>0.

[0109] In the embodiments of the present application, the length of the first sub-connecting portion 524 in the second direction Y is set to be greater than or equal to the length of the second sub-connecting portion 525 in the second direction Y. That is to say, the length of the portion of the connecting portion 52 extending from the insulating member 40 in the second direction Y is greater than or equal to the length of the portion of the connecting portion 52 overlapping with the insulating member 40, so as to ensure the reliability of the electrical connection between the connecting portion 52 and the first electrical connector 20 and ensure the photoelectric conversion efficiency of the photovoltaic module.

[0110] And setting the length H2 of the second sub-connecting portion 525 in the second direction Y to be greater than 0 can ensure that the insulating member 40 insulates and isolates the first bus bar 50, the second electrical connector 30 and the second fine grid, and prevents the first bus bar 50, the second electrical connector 30 and the second fine grid from being electrically connected, resulting in a local short-circuit phenomenon in the photovoltaic module and affecting the photoelectric conversion efficiency of the photovoltaic module. At the same time, this not only ensures the suspension length for welding operations but also provides additional mechanical support through the overlapping portion.

[0111] In some embodiments, along the second direction Y, the length of the connecting portion 52 is H, satisfying 4mm≤H≤9mm; and / or, 2mm≤H1≤9mm; and / or, 0mm<H2≤2mm; and / or, 0.5≤H1 / H2≤15.

[0112] In the embodiments of the present application, the length H of the connecting portion 52 in the second direction Y is set to be greater than or equal to 4mm and less than or equal to 9mm, so as to ensure the reliability of the electrical connection between the connecting portion 52 and the first electrical connector 20 while saving the material consumption of the connecting portion 52, controlling the manufacturing cost of the first bus bar 50, and avoiding excessive length of the connecting portion 52, resulting in excessive material consumption of the connecting portion 52 and too high cost of the first bus bar 50.

[0113] Exemplarily, the length H of the connecting portion 52 in the second direction Y can be set to 4mm, 5mm, 6mm, 7mm, 8mm, 9mm, etc.

[0114] In the embodiments of the present application, the length H1 of the first sub-connecting portion 524 in the second direction Y is set to be greater than or equal to 2mm and less than or equal to 9mm, so as to ensure the reliability of the electrical connection between the connecting portion 52 and the first electrical connector 20. And the material consumption of the connecting portion 52 can also be controlled, reducing the manufacturing cost of the first bus bar 50.

[0115] For example, the length H1 of the first sub-connecting part 524 along the second direction Y can be set to 2mm, 4mm, 6mm, 8mm, 9mm, etc.

[0116] In this embodiment, the length H2 of the second sub-connection portion 525 along the second direction Y is set to be greater than 0 mm and less than or equal to 2 mm. This ensures that the insulating member 40 insulates and isolates the first busbar 50, the second electrical connector 30, and the second fine grid, preventing the first busbar 50, the second electrical connector 30, and the second fine grid from conducting, which could lead to a partial short circuit in the photovoltaic module and affect the photoelectric conversion efficiency of the photovoltaic module. Furthermore, the length of the first sub-connection portion 525 along the second direction Y can be controlled to avoid the first sub-connection portion 525 being too long, resulting in excessive material usage for the connection portion 52 and excessively high manufacturing costs for the first busbar 50.

[0117] For example, the length H2 of the second sub-connecting portion 525 along the second direction Y can be set to 0.5mm, 0.7mm, 1mm, 1.2mm, 1.5mm, 2mm, etc.

[0118] In this embodiment, the ratio of the length H1 of the first sub-connector 524 along the second direction Y to the length H2 of the second sub-connector 525 along the second direction Y is set to be greater than or equal to 0.5 and less than or equal to 15. This ensures the reliability of the electrical connection between the connector 52 and the first electrical connector 20, while also saving material usage in the connector 52, controlling the manufacturing cost of the first busbar 50, and preventing the connector 52 from being too long, which would result in excessive material usage and high cost of the first busbar 50.

[0119] For example, the ratio of the length H1 of the first sub-connecting portion 524 along the second direction Y to the length H2 of the second sub-connecting portion 525 along the second direction Y can be set to 0.5, 2, 5, 7, 10, 12, 15, etc.

[0120] In some embodiments, along the second direction Y, the width of the insulating member 40 is L11, and the width of the first busbar body 51 is L12, satisfying L11 > L12.

[0121] In this embodiment, the width L11 of the insulating member 40 along the second direction Y is set to be greater than the width L12 of the first busbar body 51 along the second direction Y. The insulating member 40 insulates and isolates the first busbar body 51 and the second electrical connector 30, as well as the first busbar body 51 and the second fine grid, to ensure that the busbar body is fully insulated and covered, thereby avoiding local short circuits in the photovoltaic module and affecting the photoelectric conversion efficiency of the photovoltaic module.

[0122] In some embodiments, along the thickness direction of the photovoltaic module, the insulating member 40 includes a plurality of sub-insulating members stacked sequentially.

[0123] In this embodiment, along the thickness direction of the photovoltaic module, the insulating member 40 includes multiple sub-insulating members stacked sequentially. These sub-insulating members include, but are not limited to, insulating films and skin films. In other words, the insulating member 40 in this embodiment is a multi-layered composite structure to ensure its insulation and reliability, preventing punctures or insufficient insulation that could lead to partial short circuits in the photovoltaic module and affect its photoelectric conversion efficiency. This multi-layered structure helps improve insulation reliability and mechanical strength.

[0124] In some embodiments, along the thickness direction of the photovoltaic module, the height of the first solar cell 10 is less than the height of the second solar cell 70.

[0125] In this embodiment, the first solar cell 10 is the outermost solar cell in the solar cell string along the second direction Y, and the second solar cell 70 is the solar cell adjacent to the first solar cell 10 along the second direction Y. The edge of the second solar cell 70 is at least partially pressed against the edge of the first solar cell 10 to form a stacked solar cell string, such that the height of the first solar cell 10 along the thickness direction of the photovoltaic module is less than the height of the second solar cell 70. This overlapping design helps to form a compact solar cell string and reduces the risk of microcracks in the solar cells due to height differences during lamination.

[0126] The first busbar 50 is located on the back of the first solar cell 10. During the manufacturing process of the photovoltaic module, since the height of the first solar cell 10 is relatively low, the height of the first busbar 50 will also be relatively low. Therefore, it can avoid the risk of microcracks or breakage of the solar cells during the lamination process, which would affect the process yield of the photovoltaic module, due to the excessive height of the first busbar 50.

[0127] In some embodiments, the width of the overlapping portion of the first battery cell 10 and the second battery cell 70 along the second direction Y is L13, satisfying 0.3mm≤L13≤0.7mm.

[0128] In this embodiment, the width L13 of the stacked portion of the first battery cell 10 and the second battery cell 70 along the second direction Y is set to be greater than or equal to 0.3 mm and less than or equal to 0.7 mm. For example, the width L13 of the stacked portion of the first battery cell 10 and the second battery cell 70 along the second direction Y can be set to 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, etc.

[0129] In this embodiment, the width L13 of the stacked portion of the first solar cell 10 and the second solar cell 80 along the second direction Y is set to be greater than or equal to 0.3 mm and less than or equal to 0.7 mm. This ensures the photoelectric conversion efficiency of the photovoltaic module and prevents the stacked portion of the first solar cell 10 and the second solar cell 70 from being too wide, which would affect the collection of charge carriers and balance the connection strength and power generation area. Furthermore, this setting also ensures that the edge of the second solar cell 70 can overlap the edge of the first solar cell 10, preventing the second solar cell 70 from slipping off the edge of the first solar cell 10 and affecting the reliability of the photovoltaic module.

[0130] In some embodiments, the first busbar 50 includes at least one of a copper busbar, an aluminum busbar, and a copper-clad aluminum busbar.

[0131] The first busbar 50 in this embodiment includes, but is not limited to, pure copper busbars, pure aluminum busbars, copper-clad aluminum busbars, and busbars with pure copper edges and copper-clad aluminum middle sections. In this embodiment, no excessive restrictions are placed on the specific material of the first busbar 50; in practical applications, those skilled in the art can choose according to their needs.

[0132] It should be noted that the various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0133] Although alternative embodiments of the present invention have been described, those skilled in the art, upon learning the basic inventive concept, can make further changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the alternative embodiments as well as all changes and modifications falling within the scope of the embodiments of the present invention.

[0134] Finally, it should be noted that in this document, relational terms such as "first" and "second" are used merely to distinguish one entity from another, and do not necessarily require or imply any such actual relationship or order between these entities. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that an article or terminal device that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such an article or terminal device. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the article or terminal device that includes that element.

[0135] The technical solution provided by the present invention has been described in detail above. Specific examples have been used to illustrate the principle and implementation of the present invention. At the same time, for those skilled in the art, there will be changes in the specific implementation and application scope based on the principle and implementation of the present invention. Therefore, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. A back contact photovoltaic module, characterized by, The application relates to a battery module, comprising: at least two battery strings, the at least two battery strings being arranged in a first direction (X) at intervals, each of the battery strings comprising first battery pieces (10) and second battery pieces (70) arranged adjacently in a second direction (Y), the first battery pieces (10) being arranged at the ends of the battery strings, and one side of the second battery pieces (70) being arranged in pressure contact with the edges of the first battery pieces (10); the back surfaces of the first battery pieces (10) and / or the second battery pieces (70) being provided with first electric connecting pieces (20) and second electric connecting pieces (30) extending in the second direction (Y) and arranged in the first direction (X) at intervals, the first electric connecting pieces (20) and the second electric connecting pieces (30) being connected in series with at least two of the first battery pieces (10) and the second battery pieces (70) adjacently, and the second direction (Y) intersecting the first direction (X); insulating pieces (40) being arranged on the sides of the first electric connecting pieces (20) and the second electric connecting pieces (30) away from the first battery pieces (10) in the lamination direction of the module, so as to fix the first electric connecting pieces (20) and the second electric connecting pieces (30) to the back surfaces of the first battery pieces (10); first bus bars (50) being arranged on the sides of the insulating pieces (40) away from the first battery pieces (10), the projections of the first bus bars (50) in the planes of the first battery pieces (10) being located within the extension ranges of the first battery pieces (10) in the first direction (X), the first bus bars (50) extending in the first direction (X), the first bus bars (50) comprising first bus bar bodies (51) and at least one connecting part (52) protruding from the first bus bar bodies (51) in the second direction (Y), the connecting part (52) extending out of the insulating pieces (40) at least partially in the second direction (Y) and being electrically connected with the first electric connecting pieces (20).

2. The back contact photovoltaic assembly of claim 1, wherein, the connecting part (52) comprising first connecting parts (521), second connecting parts (522) and third connecting parts (523) arranged in the first direction (X) at intervals in sequence, the projections of the first connecting parts (521) and the second connecting parts (522) in the planes of the first battery pieces (10) being located within the same first battery piece (10), and the projection of the third connecting part (523) in the plane of the first battery piece (10) being located within the first battery piece (10) adjacent in the first direction (X); in the first direction (X), the distance between the first connecting part (521) and the second connecting part (522) is L6, the distance between the second connecting part (522) and the third connecting part (523) is L7, and L6<=L7 is satisfied.

3. The back contact photovoltaic assembly of claim 1, wherein, The shortest distance between the first electrical connector (20) or the second electrical connector (30) on one of the first battery pieces (10) and the first electrical connector (20) or the second electrical connector (30) on the other of the first battery pieces (10) is L8, and the distance between the two most adjacent edges of the two adjacent first battery pieces (10) is L9, satisfying L9 < L8 < 2*L9.

4. The back contact photovoltaic assembly of claim 3, wherein, The distance between the first electrical connector (20) and the second electrical connector (30) on one of the first battery pieces (10) is L10, and the width of the connecting portion (52) is L1, satisfying |L8-L10| < L1.

5. The back contact photovoltaic assembly of claim 1, wherein, The width of the insulating piece (40) is L11, and the width of the first bus bar body (51) is L12, satisfying L11 > L12.

6. The back contact photovoltaic assembly of claim 1, wherein, The insulating piece (40) comprises a plurality of sub-insulating pieces arranged in sequence along the thickness direction of the photovoltaic module.

7. The back contact photovoltaic assembly of claim 1, wherein, The width of the connecting portion (52) is L1, and the width of the first electrical connector (20) is L2, satisfying L1 >= L2.

8. The back contact photovoltaic assembly of claim 1, wherein, The back of the first battery piece (10) is provided with a plurality of first pads (11), and the plurality of first pads (11) are arranged at intervals along the second direction (Y) and located between the back of the first battery piece (10) and the first electrical connector (20). The width of the connecting portion (52) is L1, and the length of the first pad (11) is L3, satisfying L1 >= L3.

9. The back contact photovoltaic assembly of claim 1, wherein, The back of the first battery piece (10) is further provided with a first main grid extending along the second direction (Y) and located between the back of the first battery piece (10) and the first electrical connector (20). The width of the connecting portion (52) is L1, and the width of the first main grid is L4, satisfying L1 >= L4.

10. The back contact photovoltaic assembly of claim 1, wherein, The back of the first battery piece (10) is further provided with a first fine grid and a second fine grid extending along the first direction (X) and alternately arranged at intervals along the second direction (Y), the first electrical connector (20) is electrically connected with the first fine grid, and the first electrical connector (20) is provided with a first insulating block (60) between the first fine grid and the second fine grid. The width of the connecting portion (52) is L1, and the length of the first insulating block (60) is L5, satisfying L5 >= L1.

11. The back contact photovoltaic assembly of claim 1, wherein, The first bus bar body (51) has a first edge (511) and a second edge (512) oppositely arranged along the second direction (Y), and the connecting portion (52) is connected to the first edge (511) and / or the second edge (512) of the first bus bar body (51).

12. The back contact photovoltaic assembly of claim 8, wherein, The first pad (11) comprises a first sub-pad (111) closest to the side edge of the first battery piece (10) along the second direction (Y). The projection of the connecting part (52) on the plane where the first battery piece (10) is located is at least partially misaligned with the first sub-pad (111).

13. The back contact photovoltaic assembly of claim 12, wherein, The first pad (11) further comprises a second sub-pad (112) adjacent to the first sub-pad (111) along the second direction (Y); The projection of the connecting part (52) on the plane where the first battery piece (10) is located is located between the first sub-pad (111) and the second sub-pad (112).

14. The back contact photovoltaic assembly of claim 13, wherein, The second sub-pad (112) comprises a plurality of second sub-pads (112) which are arranged at intervals along the second direction (Y) away from the side of the first sub-pad (111) of the first battery piece (10); The projection of the connecting part (52) on the plane where the first battery piece (10) is located overlaps at least part of the second sub-pad (112).

15. The back contact photovoltaic assembly of claim 12, wherein, The back of the first battery piece (10) is further provided with an edge connecting structure (12), which is located between the first sub-pad (111) and the edge of the first battery piece (10), one end of the edge connecting structure (12) is connected to the first sub-pad (111), and the other end extends towards the direction close to the edge of the first battery piece (10); The projection of the connecting part (52) on the plane where the first battery piece (10) is located is located between the first sub-pad (111) and the edge of the first battery piece (10), and the projection of the connecting part (52) on the plane where the first battery piece (10) is located covers at least part of the edge connecting structure (12).

16. The back contact photovoltaic assembly of claim 8, wherein, The first pad (11) comprises at least two first sub-pads (111) arranged at intervals along the second direction (Y); The connecting part (52) is arranged between the two adjacent first sub-pads (111).

17. The back contact photovoltaic assembly of claim 16, wherein, The connecting part (52) at least partially covers the first sub-pad (111); The area of the connecting part (52) covering the first sub-pad (111) is greater than or equal to 0.5mm² and less than or equal to 2mm².

18. The back contact photovoltaic assembly of claim 1, wherein, The connecting part (52) comprises at least one of a square connecting part, a trapezoidal connecting part, a triangular connecting part, and an elliptical connecting part.

19. The back contact photovoltaic assembly of claim 1, wherein, The connecting part (52) comprises a first sub-connecting part (524) extending out of the insulating piece (40) along the second direction (Y) and a second sub-connecting part (525) overlapping the insulating piece (40), the length of the first sub-connecting part (524) along the second direction (Y) is H1, the length of the second sub-connecting part (525) along the second direction (Y) is H2, and H1≥H2 is satisfied; H2>0.

20. The back contact photovoltaic assembly of claim 19, wherein, Along the second direction (Y), the length of the connecting part is H, and 4mm≤H≤9mm is satisfied; And / or, 2mm≤H1≤9mm; And / or, 0mm<H2≤2mm; And / or, 0.5≤H1 / H2≤15.

21. The back contact photovoltaic assembly of claim 1, wherein, Along the thickness direction of the photovoltaic module, the height of the first battery piece (10) is less than the height of the second battery piece (70).

22. The back contact photovoltaic assembly of claim 1, wherein, A width of the first and second battery pieces (10, 70) in the second direction (Y) in the overlapping portion is L13, and 0.3 mm≤L13≤0.7 mm is satisfied.

23. The back contact photovoltaic assembly of claim 1, wherein, The first bus bar (50) includes at least one of a copper bus bar, an aluminum bus bar, and a copper-clad aluminum bus bar.

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