Back contact photovoltaic modules

Abstract

This application relates to the field of photovoltaic technology, providing a back-contact photovoltaic module that can at least improve the efficiency of the back-contact photovoltaic module. The back-contact photovoltaic module includes: a cell body and an insulating portion. The first surface of the cell body has multiple main grids and multiple fine grids. The multiple fine grids include first fine grids and second fine grids extending along a first direction and alternately distributed along a second direction. The multiple main grids include first main grids and second main grids extending along a second direction and alternately distributed along the first direction. Each main grid includes alternatingly connected main grid bodies and welding portions. The insulating portion is located on the first surface and at least covers the ends of the first fine grids near the second main grids and the ends of the second fine grids near the first main grids. The insulating portions located on both sides of the main grid body along the first direction and closest to the welding portions are the first insulating portions, and the remaining insulating portions located on both sides of the main grid body along the first direction are the second insulating portions. Along the second direction, the spacing between the first insulating portions is smaller than the spacing between the second insulating portions.

Description

Technical Field

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

[0002] Currently, with the gradual depletion of fossil fuels, solar cells are becoming increasingly widely used as a new energy alternative. A solar cell is a device that converts sunlight into electrical energy. Solar cells utilize the photovoltaic principle to generate charge carriers, which are then extracted using electrodes, thus facilitating the efficient utilization of electrical energy.

[0003] IBC (Interdigitated Back Contact) cells refer to a type of solar cell structure in which the front and back metal electrodes are arranged in an interdigitated manner on the back side of the cell. The back junction refers to the pn junction being located on the back side of the cell.

[0004] IBC cells are among the most efficient photovoltaic cells currently available. Using monocrystalline silicon as the substrate, the pn junction and metal electrodes are located on the back of the cell, with no metal electrodes on the front to block light, resulting in very high short-circuit current and conversion efficiency. However, many factors still affect the performance of IBC cells during fabrication, thus limiting further improvements in their photoelectric conversion efficiency. Summary of the Invention

[0005] This application provides a back-contact photovoltaic module, which at least helps to improve the efficiency of the back-contact photovoltaic module.

[0006] According to some embodiments of this application, one aspect of this application provides a back-contact photovoltaic module, including: a cell body, a first surface of the cell body having multiple main grids and multiple fine grids, the multiple fine grids including first fine grids and second fine grids extending along a first direction and alternately distributed along a second direction, the first direction intersecting the second direction, the first fine grids and second fine grids having different polarities; multiple main grids including first main grids and second main grids extending along the second direction and alternately distributed along the first direction, the first main grids being in electrical contact with multiple first fine grids, the second main grids being in electrical contact with multiple second fine grids, the main grids including alternatingly connected main grid bodies and welding portions, the main grid bodies extending along the second direction, the size of the welding portions being larger than the size of the main grid bodies along the first direction; an insulating portion located on the first surface, the insulating portion at least covering the ends of the first fine grids near the second main grids and the ends of the second fine grids near the first main grids, the insulating portions located on both sides of the main grid body along the first direction and closest to the welding portions are the first insulating portions, the remaining insulating portions located on both sides of the main grid body along the first direction are the second insulating portions, the spacing between the first insulating portions is smaller than the spacing between the second insulating portions along the second direction.

[0007] In some embodiments, the spacing between adjacent welded portions and between different second insulating portions along the second direction first increases and then decreases.

[0008] In some embodiments, among the plurality of welded portions corresponding to the main grid, the spacing between the outermost welded portion and the corresponding battery body edge gradually increases.

[0009] In some embodiments, the insulating portions located on both sides of the welding portion along the first direction are third insulating portions, and the distance between the third insulating portion and the welding portion along the first direction is greater than the distance between the first insulating portion and the main gate body.

[0010] In some embodiments, the insulating portions located on both sides of the welding portion along the first direction are third insulating portions, and along the second direction, the distance between the third insulating portion and the adjacent fine grid is greater than the distance between the first insulating portion and the adjacent fine grid.

[0011] In some embodiments, along the second direction, the spacing between the first insulating portion and the adjacent fine gate is greater than the spacing between the second insulating portion and the adjacent fine gate.

[0012] In some embodiments, the insulating portions located on both sides of the welding portion along the first direction are third insulating portions, and the distance between the end of the first insulating portion near the main gate body and the corresponding fine gate end is greater than the distance between the end of the third insulating portion near the welding portion and the corresponding fine gate end.

[0013] In some embodiments, the insulating portion includes a body portion and a widening portion connected to each other. The widening portion is located at the end of the fine grid, and the body portion is located on the side of the widening portion away from the main grid. Along the second direction, the width of the widening portion is greater than the width of the body portion.

[0014] In some embodiments, the insulating portions located on both sides of the weld portion along the first direction are third insulating portions, and the length of the widened portion of the third insulating portion is less than the length of the widened portion of the first insulating portion along the first direction.

[0015] In some embodiments, the device further includes: a solder strip for connecting adjacent battery bodies, the solder strip being located on the main grid and welded to a welding portion, wherein the ratio of the spacing between the first insulating portions to the width of the solder strip is 0.9 to 1.1 along the first direction.

[0016] The technical solution provided in this application has at least the following advantages:

[0017] In the back-contact photovoltaic module provided in this application embodiment, the surface of the cell body has multiple main grids and multiple fine grids. The fine grids include first fine grids and second fine grids with different polarities. The first fine grids can be used to collect either electrons or holes within the cell body, and the second fine grids can be used to collect either electrons or holes within the cell body. The main grids include first main grids and second main grids. Along a second direction, multiple first fine grids are in electrical contact with the same first main grid, and multiple second fine grids are in electrical contact with the same second main grid. Thus, the first main grids can collect the charge carriers collected by the multiple first fine grids arranged along the second direction, and the second main grids are used to collect the charge carriers collected by the multiple second fine grids arranged along the second direction. The main grid includes a main grid body and a welding portion. Along a first direction, the size of the welding portion is larger than the size of the main grid body. Therefore, when solder strips are provided on the main grid, the welding portion can have a larger contact area with the solder strips compared to the main grid body, thereby improving the welding stability between the solder strips and the main grid. Insulating portions are provided on the ends of the first fine grid near the second main grid and the ends of the second fine grid near the first main grid. These insulating portions prevent short circuits caused by contact between the fine grids of the opposite polarity on both sides of the main grid and the solder strip, thus improving the stability of the back-contact photovoltaic module. Specifically, the insulating portions located on both sides of the main grid body along the first direction and closest to the solder joint are designated as the first insulating portions, while the remaining insulating portions on both sides of the main grid body along the first direction are designated as the second insulating portions. Along the second direction, the spacing between the first insulating portions is smaller than the spacing between the second insulating portions. This smaller spacing allows the first insulating portions to engage the solder strip on both sides of the solder joint along the second direction, preventing misalignment during or after soldering. The larger spacing between the second insulating portions prevents the insulating portions from flowing into the middle and obscuring the main grid body, thus increasing the likelihood of contact between the solder strip and the main grid body. The back-contact photovoltaic module provided in this application can improve the welding stability of the solder strip and the welding part, and increase the contact possibility between the solder strip and the main grid body. This comprehensively improves the carrier transport efficiency, reduces power loss, and improves the overall efficiency of the back-contact photovoltaic module. Attached Figure Description

[0018] One or more embodiments are illustrated by way of example with corresponding pictures in the accompanying drawings. These illustrations do not constitute a limitation on the embodiments. Unless otherwise stated, the pictures in the accompanying drawings do not constitute a limitation on scale. In order to more clearly illustrate the technical solutions in the embodiments of this application or in the conventional technology, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This application provides a top view of the cell body of a back-contact photovoltaic module according to an embodiment of the present application.

[0020] Figure 2 for Figure 1 A magnified schematic diagram of the partial structure shown in the dashed box in section A;

[0021] Figures 3 to 5 This is a partially enlarged structural diagram of various battery bodies provided in the embodiments of this application. Detailed Implementation

[0022] As can be seen from the background technology, there are still many factors that affect the performance of IBC cells during the fabrication process, which limits the further improvement of the photoelectric conversion efficiency of IBC cells.

[0023] The back-contact photovoltaic module provided in this application can improve the welding stability of the solder strip and the welding part, and increase the contact possibility between the solder strip and the main grid body. This comprehensively improves the carrier transport efficiency, reduces power loss, and improves the overall efficiency of the back-contact photovoltaic module.

[0024] In the description of the embodiments of this application, the technical terms "first", "second", etc. are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features.

[0025] In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0026] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0027] In the description of the embodiments in this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent three cases: A exists, A and B exist simultaneously, and B exists. In addition, the character " / " in this document generally indicates that the related objects before and after it have an "or" relationship.

[0028] In the description of the embodiments of this application, technical terms such as "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of this application and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this application.

[0029] In the description of the embodiments of this application, unless otherwise expressly specified and limited, technical terms such as "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. For those skilled in the art, the specific meaning of the above terms in the embodiments of this application can be understood according to the specific circumstances.

[0030] In the accompanying drawings corresponding to the embodiments of this application, the thickness and area of ​​the layers are enlarged for better understanding and ease of description. When describing a component on another component or on the surface of another component, the component may be "directly" located on the surface of the other component, or there may be a third component between the two components. Conversely, when describing a component on the surface of another component, or when another component is formed or disposed on the surface of a component, it indicates that there is no third component between the two components. Furthermore, when describing a component as being "generally" formed on another component, it means that the component is not formed on the entire surface (or front surface) of the other component, nor is it formed on a portion of the edge of the entire surface.

[0031] In the description of the embodiments of this application, when a component "includes" another component, other components are not excluded unless otherwise stated, and other components may be further included.

[0032] The terminology used in the description of the various embodiments herein is for the purpose of describing particular embodiments only and is not intended to be limiting. As used in the description of the various embodiments and the appended claims, the term "component" is also intended to include the plural form unless the context clearly indicates otherwise.

[0033] The embodiments of this application will now be described in detail with reference to the accompanying drawings. However, those skilled in the art will understand that many technical details have been provided in the embodiments of this application to facilitate a better understanding of the application. However, the technical solutions claimed in this application can be implemented even without these technical details and various variations and modifications based on the following embodiments.

[0034] Figure 1 This application provides a top view of the cell body of a back-contact photovoltaic module according to an embodiment of the present application. Figure 2 for Figure 1 A magnified schematic diagram of the partial structure shown in the dashed box in section A. Among them, Figure 1 The insulating part 130 is transparent.

[0035] refer to Figure 1 and Figure 2 The back-contact photovoltaic module provided in this application embodiment includes: a cell body 100 and an insulating portion 130 located on a first surface 101 of the cell body 100. The first surface 101 of the cell body 100 has multiple main grids 110 and multiple fine grids 120. The multiple fine grids 120 include first fine grids 121 and second fine grids 122 that extend along a first direction X and are alternately distributed along a second direction Y. The first direction X intersects the second direction Y, and the first fine grids 121 and second fine grids 122 have different polarities. The multiple main grids 110 include first main grids 111 and second main grids 112 that extend along the second direction Y and are alternately distributed along the first direction X. The first main grids 111 are in electrical contact with the multiple first fine grids 121, and the second main grids 112 are in electrical contact with the multiple second fine grids 122. The main gate 110 includes alternating main gate bodies 114 and welded portions 113. The main gate bodies 114 extend along a second direction Y. Along a first direction X, the welded portions 113 are larger than the main gate bodies 114. Insulating portions 130 at least cover the ends of the first fine gates 121 near the second main gate 112 and the ends of the second fine gates 122 near the first main gate 111. The insulating portions 130 located on both sides of the main gate bodies 114 along the first direction X and closest to the welded portions 113 are the first insulating portions 131, and the remaining insulating portions 130 located on both sides of the main gate bodies 114 along the first direction X are the second insulating portions 132. Along the second direction Y, the spacing L1 between the first insulating portions 131 is smaller than the spacing L2 between the second insulating portions 132.

[0036] In the back-contact photovoltaic module provided in this application embodiment, the surface of the cell body 100 has multiple main grids 110 and multiple fine grids 120. The fine grids 120 include first fine grids 121 and second fine grids 122 with different polarities. The first fine grids 121 can be used to collect one of electrons or holes in the cell body 100, and the second fine grids 122 can be used to collect the other of electrons or holes in the cell body 100. The main grids 110 include first main grids 111 and second main grids 112. Along the second direction Y, multiple first fine grids 121 are in electrical contact with the same first main grid 111, and multiple second fine grids 122 are in electrical contact with the same second main grid 112. Thus, the first main grids 111 can collect the charge carriers collected by the multiple first fine grids 121 arranged along the second direction Y, and the second main grids 112 are used to collect the charge carriers collected by the multiple second fine grids 122 arranged along the second direction Y. The main grid 110 includes a main grid body 114 and a welding portion 113. Along the first direction X, the size of the welding portion 113 is larger than the size of the main grid body 114. Therefore, when solder strips are placed on the main grid 110, the welding portion 113 can have a larger contact area with the solder strip compared to the main grid body 114, thereby improving the welding stability between the solder strip and the main grid 110. An insulating portion 130 covers the end of the first fine grid 121 near the second main grid 112 and the end of the second fine grid 122 near the first main grid 111. The insulating portion 130 can prevent short circuits caused by contact between the other polarity fine grids 120 on both sides of the main grid 110 that are not connected to the main grid 110 and the solder strip, which is beneficial for improving the stability of the back-contact photovoltaic module. The insulating portions 130 located on both sides of the main gate body 114 along the first direction X and closest to the welding portion 113 are the first insulating portions 131, and the remaining insulating portions 130 located on both sides of the main gate body 114 along the first direction X are the second insulating portions 132. Along the second direction Y, the distance L1 between the first insulating portions 131 is smaller than the distance L2 between the second insulating portions 132. Thus, the smaller distance L1 between the first insulating portions 131 allows the first insulating portions 131 to act as a retainer for the solder ribbon on both sides of the welding portion 113 along the second direction Y, preventing the solder ribbon from shifting during or after welding and causing welding misalignment. The larger distance L2 between the second insulating portions 132 prevents the insulating portions 130 from flowing into the middle and blocking the main gate body 114, thus increasing the possibility of contact between the solder ribbon and the main gate body 114. The back-contact photovoltaic module provided in this application embodiment can improve the welding stability between the solder strip and the welding part 113, and increase the contact possibility between the solder strip and the main grid body 114, thereby comprehensively improving the carrier transport efficiency, reducing power loss, and improving the overall efficiency of the back-contact photovoltaic module.

[0037] refer to Figure 1The back-contact photovoltaic module may further include: a first connecting line 141 and a first through line 143. The first connecting line 141 extends along the second direction Y and is located at one edge of the cell body 100 along the first direction X. Along the second direction Y, multiple first fine grids 121 located at the edge of the cell body 100 are electrically in contact with the first connecting line 141. The first through line 143 extends along the first direction X and is located at one edge of the cell body 100 along the second direction Y. Along the first direction X, the ends of multiple first main grids 111 are electrically in contact with the first through line 143, and the ends of the first connecting line 141 are electrically in contact with the ends of the first through line 143. In this way, the first fine grids 121 located at the edge of the cell body 100 can be electrically connected to the first main grids 111 located in the middle of the cell body 100 through the first connecting line 141 and the first through line 143 to achieve the collection of charge carriers on the first fine grids 121 at the edge of the cell body 100.

[0038] refer to Figure 1 The back-contact photovoltaic module may further include: a second connecting line 142 and a second through line 144. The second connecting line 142 extends along a second direction Y and is located on the other side edge of the cell body 100 along a first direction X. Along the second direction Y, multiple second fine grids 122 located at the edge of the cell body 100 are electrically in contact with the second connecting line 142. The second through line 144 extends along the first direction X and is located on the other side edge of the cell body 100 along the second direction Y. Along the first direction X, the ends of multiple second main grids 112 are electrically in contact with the second through line 144, and the ends of the second connecting line 142 are electrically in contact with the ends of the second through line 144. In this way, the second fine grids 122 located at the edge of the cell body 100 can be electrically connected to the second main grids 112 located in the middle of the cell body 100 through the second connecting line 142 and the second through line 144 to achieve the collection of charge carriers on the second fine grids 122 at the edge of the cell body 100.

[0039] exist Figure 1 In some embodiments, taking an even number of main grids 110 as an example, the fine grids 120 located on both sides of the battery body 100 along the first direction X have different polarities. Correspondingly, the battery body 100 has a first connecting line 141 and a second connecting line 143 on both sides of the first direction X, and a first through line 142 and a second through line 144 on both sides of the battery body 100 along the second direction Y. In other embodiments, the number of main grids can be odd. In this case, the fine grids located on both sides of the battery body along the first direction have the same polarity. Correspondingly, the battery body can have either a first connecting line or a second connecting line on both sides of the first direction, and a first through line on at least one side of the battery body along the second direction.

[0040] In the accompanying drawings provided in this embodiment, the number of fine gates 120 and the number of main gates 110 can be adjusted according to actual conditions, and do not constitute a limitation on the number of fine gates 120 and the number of main gates 110 in this embodiment. Correspondingly, the number of welding portions 113 on the main gate 110 can be adjusted according to actual conditions.

[0041] The back-contact photovoltaic module may further include: a solder ribbon (not shown in the figure), which is used to connect adjacent cell bodies 100. The solder ribbon is located on the main grid 110 and is welded to the welding portion 113. Along the first direction X, the ratio of the spacing L1 between the first insulating portions 131 to the width of the solder ribbon is 0.9 to 1.1, for example, it can be 0.9, 0.95, 1, 1.03, 1.06, 1.08 or 1.1. That is, the spacing L1 between the first insulating portions 131 is close to the width of the solder ribbon. This facilitates the first insulating portions 131 to precisely engage with the solder ribbon, thereby avoiding the problem of welding misalignment caused by the solder ribbon shifting during or after welding.

[0042] refer to Figure 2 In some embodiments, the spacing L2 between adjacent weld portions 113 and between different second insulating portions 132 along the second direction Y first increases and then decreases. That is, the spacing L2 between the second insulating portions 132 farther away from the weld portion 113 is larger. Thus, the second insulating portions 132 closer to the weld portion 113 can play an auxiliary role in engaging the solder strip, further improving the welding stability between the solder strip and the weld portion 113; the larger spacing between the second insulating portions 132 farther away from the weld portion 113 can help increase the contact possibility between the solder strip and the main grid body 114, further improving the carrier transport efficiency, reducing power loss, and improving the overall efficiency of the back contact photovoltaic module.

[0043] exist Figure 2 In one embodiment, the spacing L2 between adjacent welded portions 113 along the second direction Y first increases and then decreases, taking as an example a gradual change. That is, the spacing L2 between any two adjacent groups of second insulating portions 132 along the second direction Y is not equal. In other embodiments, the spacing L2 between different second insulating portions 132 can be stepped, for example, the spacing L2 between every two, three, or four adjacent groups of second insulating portions 132 along the second direction Y is equal.

[0044] In other embodiments, the spacing L2 between adjacent welded portions 113 and between different second insulating portions 132 can be equal.

[0045] Continue to refer to Figure 2In some embodiments, among the plurality of welded portions 113 corresponding to the main grid 110, the spacing L2 between different second insulating portions 132 gradually increases in the direction from the outermost welded portion 113 to the edge of the corresponding battery body 100. That is, in the direction from the first or last welded portion 113 arranged along the second direction Y corresponding to the main grid 110 to the edge of the battery body 100, the spacing between the second insulating portions 132 farther away from the welded portion 113 is larger. In this way, the solder strip has sufficient room to move for the edge of the battery body 100, thus avoiding the problem of stress concentration caused by interference between the solder strip and the second insulating portion 132 at the edge of the battery body 100, which could lead to fragmentation of the battery body 100.

[0046] exist Figure 2 In the main grid 110, among the multiple welded portions 113, the outermost welded portion 113, in the direction from its origin to the edge of the corresponding battery body 100, exhibits a gradual increase in the spacing L2 between different second insulating portions 132, exemplified by this gradual increase. This means that the spacing L2 between any two adjacent groups of second insulating portions 132 along the second direction Y is not equal. In other embodiments, the gradual increase in the spacing L2 between different second insulating portions 132 can be step-like; for example, the spacing L2 between every two, three, or four adjacent groups of second insulating portions 132 along the second direction Y is equal.

[0047] In other embodiments, among the plurality of welded portions 113 corresponding to the main grid 110, the spacing L2 between different second insulating portions 132 in the direction from the outermost welded portion 113 to the edge of the corresponding battery body 100 can be equal.

[0048] refer to Figure 2 The insulating portions 130 located on both sides of the welding portion 113 along the first direction X are the third insulating portions 133.

[0049] refer to Figure 2 In some embodiments, the distance 'a' between the third insulating portion 133 and the solder portion 113 along the first direction X is greater than the distance 'b' between the first insulating portion 131 and the main gate body 114. If the distance between the third insulating portion 133 and the solder portion 113 along the first direction X is too close, the organic solvent in the third insulating portion 133 is prone to flow onto the solder portion 113 during the soldering process, which can lead to abnormal solder paste curing and a decrease in the soldering pull force between the solder strip and the solder portion 113. Setting a larger distance between the third insulating portion 133 and the solder portion 113 can avoid such problems and improve the soldering stability between the solder strip and the solder portion 113.

[0050] Along the first direction X, the spacing between the third insulating portions 133 on both sides of the weld portion 113 and the weld portion 113 may be equal or unequal. Along the first direction X, the spacing between the first insulating portions 131 on both sides of the main gate body 114 and the main gate body 114 may be equal or unequal.

[0051] In some embodiments, the distance between the third insulating portion 133 and the welding portion 113 on either side of the first direction X is smaller than the distance between the first insulating portion 131 and the main gate body 114 on either side of the first direction X.

[0052] refer to Figure 2 In some embodiments, along the second direction Y, the distance c between the third insulating portion 133 and the adjacent fine gate 120 is greater than the distance d between the first insulating portion 131 and the adjacent fine gate 120. If the distance between the third insulating portion 133 and the adjacent fine gate 120 along the second direction Y is too close, the organic solvent in the third insulating portion 133 is prone to flow onto the adjacent fine gate 120 during the soldering process, and then extend along the extension direction of the fine gate 120 to the solder portion 113, which leads to abnormal solder paste curing and a decrease in the soldering pull force between the solder strip and the solder portion 113. Setting a larger distance between the third insulating portion 133 and the adjacent fine gate 120 can avoid such problems, thereby improving the soldering stability between the solder strip and the solder portion 113.

[0053] Along the second direction Y, the spacing between the fine grids 120 on both sides of the third insulating portion 133 and the third insulating portion 133 may be equal or unequal. Along the second direction Y, the spacing between the fine grids 120 on both sides of the first insulating portion 131 and the first insulating portion 131 may be equal or unequal.

[0054] In some embodiments, the distance between the third insulating portion 133 and the fine gate 120 on either side of the second direction Y is greater than the distance between the first insulating portion 131 and the fine gate 120 on either side of the second direction Y. For example, when fine grids 120 of different polarities are equally spaced in the second direction Y, setting the width of the third insulating portion 133 in the second direction Y to be smaller than the width of the first insulating portion 131 in the second direction Y can make the distance between the fine grids 120 and the third insulating portion 133 on either side of the third insulating portion 133 in the second direction Y smaller than the distance between the fine grids 120 and the first insulating portion 131 on either side of the first insulating portion 131 in the second direction Y; or, when the width of the third insulating portion 133 in the second direction Y is equal to the width of the first insulating portion 131 in the second direction Y, the spacing of the fine grids 120 on both sides of the third insulating portion 133 in the second direction Y can be adjusted so that the distance between the fine grids 120 and the third insulating portion 133 on either side of the third insulating portion 133 in the second direction Y is smaller than the distance between the fine grids 120 and the first insulating portion 131 on either side of the first insulating portion 131 in the second direction Y.

[0055] In some embodiments, the length of the third insulating portion 133 along the first direction X may be equal to or unequal to the length of the first insulating portion 131.

[0056] refer to Figure 2 In some embodiments, along the second direction Y, the distance d between the first insulating portion 131 and the adjacent fine gate 120 is greater than the distance e between the second insulating portion 132 and the adjacent fine gate 120. Since the first insulating portion 131 is the insulating portion 130 of the main gate body 114 closest to the solder portion 113 on both sides along the first direction X, during the soldering process, the organic solvent in the first insulating portion 131 may flow to the adjacent fine gate 120 and then extend along the extension direction of the fine gate 120 to the solder portion 113, thereby causing abnormal solder paste curing and reducing the soldering pull force between the solder strip and the solder portion 113. Setting a larger distance between the first insulating portion 131 and the adjacent fine gate 120 can avoid such problems, thereby improving the soldering stability between the solder strip and the solder portion 113.

[0057] Along the second direction Y, the spacing between the fine grids 120 on both sides of the second insulating portion 132 and the second insulating portion 132 may be equal or unequal.

[0058] In some embodiments, the distance between the first insulating portion 131 and the fine gate 120 on either side of the second direction Y and the first insulating portion 131 is greater than the distance between the second insulating portion 132 and the fine gate 120 on either side of the second direction Y and the second insulating portion 132. For example, when fine grids 120 of different polarities are equally spaced in the second direction Y, setting the width of the first insulating portion 131 in the second direction Y to be smaller than the width of the second insulating portion 132 in the second direction Y can make the distance between the fine grid 120 on either side of the first insulating portion 131 and the first insulating portion 131 in the second direction Y greater than the distance between the fine grid 120 on either side of the second insulating portion 132 in the second direction Y; or, when the width of the first insulating portion 131 in the second direction Y is equal to the width of the second insulating portion 132 in the second direction Y, the spacing of the fine grids 120 on both sides of the first insulating portion 131 in the second direction Y can be adjusted so that the distance between the fine grid 120 on either side of the first insulating portion 131 and the first insulating portion 131 in the second direction Y is greater than the distance between the fine grid 120 on either side of the second insulating portion 132 in the second direction Y.

[0059] In some embodiments, the length of the first insulating portion 131 and the length of the second insulating portion 132 may be equal or unequal along the first direction X.

[0060] refer to Figure 2 In some embodiments, the distance f between the end of the first insulating portion 131 near the main gate body 114 and the end of the corresponding fine gate 120 is greater than the distance g between the end of the third insulating portion 133 near the welding portion 113 and the end of the corresponding fine gate 120. This avoids the problem of short-circuiting between the solder strip and the irregular fine gate 120 after the solder strip shifts on both sides of the main gate body 114. Since the welding portion 113 is welded and fixed to the solder strip, the possibility of the solder strip shifting at the welding portion 113 is smaller than the possibility of the solder strip shifting on both sides of the main gate body 114. Therefore, the distance between the end of the third insulating portion 133 near the welding portion 113 and the end of the corresponding fine gate 120 can be smaller.

[0061] Figure 3 This is a partially enlarged structural diagram of a battery body provided in an embodiment of this application.

[0062] refer to Figure 3In some embodiments, the insulating portion 130 includes a body portion 134 and a widened portion 135 connected to each other. The widened portion 135 is located at the end of the fine grid 120, and the body portion 134 is located on the side of the widened portion 135 away from the main grid 110. Along the second direction Y, the width of the widened portion 135 is greater than the width of the body portion 134. That is, the insulating portion 130 has a widened portion 135 at the end near the main grid 110. On the one hand, the widened portion 135 can further reduce the risk of short circuit between the solder strip and the end of the irregular fine grid 120, thereby improving the stability of the back contact photovoltaic module. On the other hand, the smaller width of the body portion 134 can help reduce the material cost of the insulating portion 130, thereby reducing the manufacturing cost of the back contact photovoltaic module.

[0063] When the insulating portion 130 includes the body portion 134 and the widened portion 135, along the second direction Y, the spacing L1 between the first insulating portions 131 is equal to the spacing between the widened portions 135 corresponding to the first insulating portions 131; the spacing L2 between the second insulating portions 132 is equal to the spacing between the widened portions 135 corresponding to the second insulating portions 132.

[0064] When the insulating portion 130 includes the body portion 134 and the widening portion 135, along the first direction X, the distance a between the third insulating portion 133 and the welding portion 113 is equal to the distance between the widening portion 135 and the welding portion 113 corresponding to the third insulating portion 133; the distance b between the first insulating portion 131 and the main gate body 114 is equal to the distance between the widening portion 135 and the main gate body 114 corresponding to the first insulating portion 131.

[0065] When the insulating portion 130 includes the body portion 134 and the widened portion 135, in the second direction Y, the distance c between the third insulating portion 133 and the adjacent fine grid 120 is greater than the distance d between the first insulating portion 131 and the adjacent fine grid 120. This means that the distance between the widened portion 135 corresponding to the third insulating portion 133 and the adjacent fine grid 120 is greater than the distance between the widened portion 135 corresponding to the first insulating portion 131 and the adjacent fine grid 120.

[0066] When the insulating portion 130 includes the body portion 134 and the widened portion 135, in the second direction Y, the distance d between the first insulating portion 131 and the adjacent fine grid 120 is greater than the distance e between the second insulating portion 132 and the adjacent fine grid 120. This means that the distance between the widened portion 135 corresponding to the first insulating portion 131 and the adjacent fine grid 120 is greater than the distance between the widened portion 135 corresponding to the second insulating portion 132 and the adjacent fine grid 120.

[0067] When the insulating portion 130 includes the body portion 134 and the widened portion 135, the distance f between the end of the first insulating portion 131 near the main gate body 114 and the end of the corresponding fine gate 120 is greater than the distance g between the end of the third insulating portion 133 near the welding portion 113 and the end of the corresponding fine gate 120. This means that the distance between the end of the widened portion 135 corresponding to the first insulating portion 131 near the main gate body 114 and the end of the corresponding fine gate 120 is greater than the distance between the end of the widened portion 135 corresponding to the third insulating portion 133 near the welding portion 113 and the end of the corresponding fine gate 120.

[0068] In some embodiments, along the first direction X, the length of the widened portion 135 corresponding to the third insulating portion 133 is less than the length of the widened portion 135 corresponding to the first insulating portion 131. Since the welding portion 113 is welded and fixed to the welding strip, the possibility of the welding strip shifting at the welding portion 113 is smaller than the possibility of the welding strip shifting on both sides of the main gate body 114. The shorter length of the widened portion 135 corresponding to the third insulating portion 133 compared to the first insulating portion 131 reduces the risk of short circuit between the welding strip and the end of the irregular fine gate 120, and also saves on the cost of using the insulating portion 130.

[0069] Figure 4 This is a partially enlarged structural diagram of another battery body provided in an embodiment of this application.

[0070] refer to Figure 4 In some embodiments, the first insulating portion 131 and the second insulating portion 132 are connected as a single unit. For the third insulating portion 133 and the first insulating portion 131 near the solder portion 113, they need to be separated from the fine grid 120 connecting the solder portion 113 to prevent organic solvents in the third insulating portion 133 or the first insulating portion 131 from extending along the fine grid 120 onto the solder portion 113, thereby avoiding abnormal solder paste curing. For the second insulating portions 132 on both sides of the main grid body 114, the distance between the second insulating portion 132 and the solder portion 113 is relatively large, making it less likely for organic solvents to flow onto the solder portion 113. Connecting the first insulating portion 131 and the second insulating portion 132 as a single unit facilitates the integrated printing of the first insulating portion 131 and the second insulating portion 132, thereby improving the manufacturing efficiency of the back contact photovoltaic module.

[0071] In some embodiments, the height of the first insulating portion 131 is greater than the height of the main grid 110 in the direction perpendicular to the first surface 101 of the battery body 100. Thus, when the solder strip is welded, the first insulating portion 131 is located on both sides of the solder strip and plays a role in locking the solder strip to fix the relative position of the solder strip and improve the stability of the solder strip welding process and after welding.

[0072] refer to Figure 4 When the first insulating portion 131 includes a body portion 134 and a widened portion 135, the height of the widened portion 135 can be greater than the height of the body portion 134 in the direction perpendicular to the first surface 101 of the battery body 100, and the height of the widened portion 135 is greater than the height of the main grid 110. Thus, on the one hand, after the solder strip is welded, the widened portion 135 of the first insulating portion 131, located on both sides of the solder strip, acts to engage the solder strip, fixing its relative position and improving the stability of the solder strip welding process and after welding; on the other hand, the greater height of the widened portion 135 can avoid the problem of the insulating portion 130 shrinking and exposing the ends of the fine grid 120 after solidification.

[0073] Figure 5 This is a partially enlarged structural diagram of another battery body provided in an embodiment of this application.

[0074] refer to Figure 5 In some embodiments, along the first direction X, the length of the insulating portion 130 may be less than the spacing between adjacent main gates 110, but greater than half the spacing between adjacent main gates 110. Thus, the insulating portion 130 covers a longer length of the fine gate 120, which can further reduce the risk of short circuits between the solder strip and the irregular fine gate 120.

[0075] In some embodiments, in conjunction with reference Figure 3 and Figure 5 When the insulating portion 130 includes the body portion 134 and the widened portion 135, the length of the body portion 134 along the first direction X can be less than the spacing between adjacent main gates 110 and greater than 1 / 2 of the spacing between adjacent main gates 110, so as to further reduce the risk of short circuit between the solder strip and the irregular fine gate 120.

[0076] In some embodiments, the battery body 100 may be an IBC battery (Interdigitated Back Contact), an HPBC battery (Hybrid Passivated Back Contact), a TBC battery that combines TOPCon (Tunnel Oxide Passivated Contact) technology and IBC technology, or an HBC battery that combines HIT / HJT (Heterojunction Technology) technology and IBC technology. Of course, it may also be other types of back contact batteries.

[0077] In some embodiments, the battery body 100 may be a monocrystalline silicon solar cell, a polycrystalline silicon solar cell, an amorphous silicon solar cell, or a multi-component compound solar cell. Specifically, the multi-component compound solar cell may be a cadmium sulfide solar cell, a gallium arsenide solar cell, a copper indium selenide solar cell, or a perovskite solar cell.

[0078] In some embodiments, the back-contact photovoltaic module further includes an encapsulation layer that covers the surface of the battery body. The encapsulation layer may be made of organic encapsulation films such as ethylene-vinyl acetate copolymer (EVA) film, polyvinyl octene coelastomer (POE) film, or polyvinyl butyral (PVB) film.

[0079] In some embodiments, the back-contact photovoltaic module further includes a cover plate located on the surface of the encapsulation layer away from the cell body. The cover plate can be a glass cover plate, a plastic cover plate, or other cover plate with light-transmitting function. In some embodiments, the surface of the cover plate facing the encapsulation layer can be an uneven surface, thereby increasing the utilization rate of incident light.

[0080] In the back-contact photovoltaic module provided in this application embodiment, the surface of the cell body 100 has multiple main grids 110 and multiple fine grids 120. The fine grids 120 include first fine grids 121 and second fine grids 122 with different polarities. The first fine grids 121 can be used to collect one of electrons or holes in the cell body 100, and the second fine grids 122 can be used to collect the other of electrons or holes in the cell body 100. The main grids 110 include first main grids 111 and second main grids 112. Along the second direction Y, multiple first fine grids 121 are in electrical contact with the same first main grid 111, and multiple second fine grids 122 are in electrical contact with the same second main grid 112. Thus, the first main grids 111 can collect the charge carriers collected by the multiple first fine grids 121 arranged along the second direction Y, and the second main grids 112 are used to collect the charge carriers collected by the multiple second fine grids 122 arranged along the second direction Y. The main grid 110 includes a main grid body 114 and a welding portion 113. Along the first direction X, the size of the welding portion 113 is larger than the size of the main grid body 114. Therefore, when solder strips are placed on the main grid 110, the welding portion 113 can have a larger contact area with the solder strip compared to the main grid body 114, thereby improving the welding stability between the solder strip and the main grid 110. An insulating portion 130 covers the end of the first fine grid 121 near the second main grid 112 and the end of the second fine grid 122 near the first main grid 111. The insulating portion 130 can prevent short circuits caused by contact between the other polarity fine grids 120 on both sides of the main grid 110 that are not connected to the main grid 110 and the solder strip, which is beneficial for improving the stability of the back-contact photovoltaic module. The insulating portions 130 located on both sides of the main gate body 114 along the first direction X and closest to the welding portion 113 are the first insulating portions 131, and the remaining insulating portions 130 located on both sides of the main gate body 114 along the first direction X are the second insulating portions 132. Along the second direction Y, the distance L1 between the first insulating portions 131 is smaller than the distance L2 between the second insulating portions 132. Thus, the smaller distance L1 between the first insulating portions 131 allows the first insulating portions 131 to act as a retainer for the solder ribbon on both sides of the welding portion 113 along the second direction Y, preventing the solder ribbon from shifting during or after welding and causing welding misalignment. The larger distance L2 between the second insulating portions 132 prevents the insulating portions 130 from flowing into the middle and blocking the main gate body 114, thus increasing the possibility of contact between the solder ribbon and the main gate body 114. The back-contact photovoltaic module provided in this application embodiment can improve the welding stability between the solder strip and the welding part 113, and increase the contact possibility between the solder strip and the main grid body 114, thereby comprehensively improving the carrier transport efficiency, reducing power loss, and improving the overall efficiency of the back-contact photovoltaic module.

[0081] Those skilled in the art will understand that the above embodiments are specific examples of implementing this application, and in practical applications, various changes in form and detail can be made without departing from the spirit and scope of this application. Any person skilled in the art can make various alterations and modifications without departing from the spirit and scope of this application; therefore, the scope of protection of this application should be determined by the scope defined in the claims.

Claims

1. A back-contact photovoltaic module, characterized in that, include: The battery body has a first surface with multiple main grids and multiple fine grids. The multiple fine grids include first fine grids and second fine grids that extend along a first direction and are alternately distributed along a second direction. The first direction and the second direction intersect. The first fine grids and the second fine grids have different polarities. The plurality of main gates include a first main gate and a second main gate that extend along the second direction and are alternately distributed along the first direction. The first main gate is electrically contacted with a plurality of first fine gates, and the second main gate is electrically contacted with a plurality of second fine gates. The main gate includes an alternately connected main gate body and a welded portion. The main gate body extends along the second direction, and along the first direction, the size of the welded portion is larger than the size of the main gate body. An insulating portion is located on the first surface. The insulating portion covers at least the end of the first fine gate near the second main gate and the end of the second fine gate near the first main gate. The insulating portion located on both sides of the main gate body along the first direction and closest to the weld portion is the first insulating portion. The remaining insulating portions located on both sides of the main gate body along the first direction are the second insulating portions. Along the second direction, the spacing between the first insulating portions is smaller than the spacing between the second insulating portions.

2. The back-contact photovoltaic module according to claim 1, characterized in that, Between adjacent welded portions, the spacing between different second insulating portions along the second direction first increases and then decreases.

3. The back-contact photovoltaic module according to claim 1 or 2, characterized in that, Among the multiple welded portions corresponding to the main grid, the distance between the outermost welded portion and the corresponding edge of the battery body gradually increases in the direction from which the second insulating portion is located.

4. The back-contact photovoltaic module according to claim 1, characterized in that, The insulating portions located on both sides of the welding portion along the first direction are the third insulating portions. Along the first direction, the distance between the third insulating portion and the welding portion is greater than the distance between the first insulating portion and the main gate body.

5. The back-contact photovoltaic module according to claim 1, characterized in that, The insulating portions located on both sides of the welding portion along the first direction are the third insulating portions. Along the second direction, the distance between the third insulating portion and the adjacent fine grid is greater than the distance between the first insulating portion and the adjacent fine grid.

6. The back-contact photovoltaic module according to claim 5, characterized in that, Along the second direction, the spacing between the first insulating portion and the adjacent fine gate is greater than the spacing between the second insulating portion and the adjacent fine gate.

7. The back-contact photovoltaic module according to claim 1, characterized in that, The insulating portions located on both sides of the welding portion along the first direction are the third insulating portions. The distance between the end of the first insulating portion near the main gate body and the corresponding end of the fine gate is greater than the distance between the end of the third insulating portion near the welding portion and the corresponding end of the fine gate.

8. The back-contact photovoltaic module according to claim 1, characterized in that, The insulating portion includes a body portion and a widening portion connected to each other. The widening portion is located at the end of the fine grid, and the body portion is located on the side of the widening portion away from the main grid. Along the second direction, the width of the widening portion is greater than the width of the body portion.

9. The back-contact photovoltaic module according to claim 8, characterized in that, The insulating portions located on both sides of the welded portion along the first direction are the third insulating portions, and the length of the widened portion of the third insulating portion is less than the length of the widened portion of the first insulating portion along the first direction.

10. The back-contact photovoltaic module according to claim 1, characterized in that, Also includes: A solder strip is used to connect adjacent battery bodies. The solder strip is located on the main grid and is welded to the welding part. Along the first direction, the ratio of the spacing between the first insulating parts to the width of the solder strip is 0.9 to 1.1.

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