Back contact photovoltaic module

Abstract

The embodiment of the invention relates to the field of photovoltaic technology, and provides a back contact photovoltaic module, which at least can improve the efficiency of the back contact photovoltaic module. The back contact photovoltaic module comprises a battery body and an insulating part, a first surface of the battery body is provided with a plurality of main grids and a plurality of fine grids, and the plurality of fine grids comprise first fine grids and second fine grids which extend along a first direction and are alternately distributed along a second direction; the plurality of main grids comprise first main grids and second main grids which extend along the second direction and are alternately distributed along the first direction, and each main grid comprises a main grid body and a welding part which are alternately connected; the insulating parts are located on the first surface and at least cover the ends, close to the second main grids, of the first fine grids and the ends, close to the first main grids, of the second fine grids, and the insulating parts located on the two sides of the main grid body in the first direction and closest to the welding parts are first insulating parts. The rest of the insulating parts located on the two sides of the main grid body in the first direction are second insulating parts, and the distance between the first insulating parts is smaller than the distance between the second insulating parts in the second direction.

Description

Technical Field

[0001] The embodiments of the present application relate to the field of photovoltaic technology, and in particular to a back-contact photovoltaic module. Background Art

[0002] At present, with the gradual depletion of fossil energy, solar cells are becoming more and more widely used as a new energy alternative. Solar cells are devices that convert sunlight into electrical energy. Solar cells use the photovoltaic principle to generate carriers, and then use electrodes to lead the carriers out, thereby facilitating the effective use of electrical energy.

[0003] IBC cell (Interdigitated Back Contact) refers to a back-junction back-contact solar cell structure in which the positive and negative metal electrodes are arranged in an interdigitated manner on the back side of the cell, where the back junction refers to the pn junction located on the back of the cell.

[0004] IBC cells are one of the photovoltaic cells with the highest conversion efficiency at present. The cell is based on single crystal silicon, and the pn junction and metal electrode are located on the back of the cell. There is no metal electrode shading on the front, which can obtain very high short-circuit current and conversion efficiency. However, in the process of preparing IBC cells, there are still many factors that affect the cell performance of IBC cells, which in turn limits the further improvement of the photoelectric conversion efficiency of IBC cells. Summary of the invention

[0005] The embodiments of the present application provide a back-contact photovoltaic module, which is at least beneficial to improving the efficiency of the back-contact photovoltaic module.

[0006] According to some embodiments of the present application, on one hand, the embodiments of the present application provide a back-contact photovoltaic module, including: a battery body, a first surface of the battery body having a plurality of main grids and a plurality of fine grids, the plurality of fine grids including a first fine grid and a second fine grid extending along a first direction and alternately distributed along a second direction, the first direction intersects with the second direction, and the polarities of the first fine grid and the second fine grid are different; the plurality of main grids including a first main grid and a second main grid extending along the second direction and alternately distributed along the first direction, the first main grid is in electrical contact with the plurality of first fine grids, and the second main grid is in electrical contact with the plurality of second fine grids, the main grid including an alternately connected main grid body and a welding portion, the main grid body extending along the second direction, and the size of the welding portion is larger than the size of the main grid body along the first direction; an insulating portion, the insulating portion being located on the first surface, the insulating portion at least covering an end portion of the first fine grid close to the second main grid and an end portion of the second fine grid close to the first main grid, the insulating portions located on both sides of the main grid body along the first direction and closest to the welding portion 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, and along the second direction, the spacing between the first insulating portions is smaller than the spacing between the second insulating portions.

[0007] In some embodiments, between adjacent welding portions, along the second direction, the intervals between different second insulating portions first increase and then decrease.

[0008] In some embodiments, among the multiple welding portions corresponding to the main grid, the spacing between different second insulating portions gradually increases in the direction from the outermost welding portion to the edge of the corresponding battery body.

[0009] 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 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.

[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 spacing between the third insulating portions and adjacent fine grids is greater than the spacing between the first insulating portions and adjacent fine grids.

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

[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 spacing between one side end of the first insulating portion close to the main gate body and the corresponding fine gate end is greater than the spacing between one side end of the third insulating portion close to the welding portion and the corresponding fine gate end.

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

[0014] 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 first direction, the length of the widened portion of the third insulating portion is smaller than the length of the widened portion of the first insulating portion.

[0015] In some embodiments, it also includes: a welding strip, which is used to connect adjacent battery bodies. The welding 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 welding strip is 0.9 to 1.1.

[0016] The technical solution provided by the embodiments of the present application has at least the following advantages:

[0017] In the back-contact photovoltaic module provided by the embodiment of the present application, the surface of the battery body has multiple main grids and multiple fine grids, and the fine grids include a first fine grid and a second fine grid with different polarities, so that the first fine grid can be used to collect one of the electrons or holes in the battery body, and the second fine grid can be used to collect the other of the electrons or holes in the battery body; the main grid includes a first main grid and a second main grid, and along the 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, so that the first main grid can collect the carriers collected by the multiple first fine grids arranged along the second direction, and the second main grid is used to collect the carriers collected by the multiple second fine grids arranged along the second direction. Wherein, the main grid includes a main grid body and a welding portion, and along the first direction, the size of the welding portion is larger than the size of the main grid body, so when a welding strip is set on the main grid, the welding portion can have a larger contact area with the welding strip than the main grid body, so as to improve the welding stability of the welding strip and the main grid. The end of the first fine grid close to the second main grid and the end of the second fine grid close to the first main grid are covered with an insulating part. The insulating part can prevent the fine grid of another polarity that is not connected to the main grid on both sides of the main grid from contacting with the welding strip and causing a short circuit, which is beneficial to improving the stability of the back contact photovoltaic module. Among them, the insulating parts located on both sides of the main grid body along the first direction and closest to the welding part are the first insulating parts, and the remaining insulating parts located on both sides of the main grid body along the first direction are the second insulating parts. In the second direction, the spacing between the first insulating parts is smaller than the spacing between the second insulating parts. In this way, the spacing between the first insulating parts is small, which can make the first insulating parts on both sides of the welding part along the second direction play a role of clamping the welding strip, avoiding the problem of welding misalignment caused by the deviation of the welding strip during or after welding; the spacing between the second insulating parts is large, so that the insulating part is not easy to flow to the middle to cover the main grid body, resulting in the problem that the welding strip cannot contact the main grid body, and the contact possibility between the welding strip and the main grid body is improved. The back-contact photovoltaic module provided in the embodiment of the present application can, on the one hand, improve the welding stability between the welding strip and the welding part, and on the other hand, improve the contact possibility between the welding strip and the main grid body, thereby comprehensively improving the carrier transmission efficiency, reducing power loss, and improving the overall efficiency of the back-contact photovoltaic module. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] One or more embodiments are exemplarily illustrated by the pictures in the corresponding drawings. These exemplified descriptions do not constitute a limitation on the embodiments. Unless otherwise specified, the pictures in the drawings do not constitute a scale limitation. In order to more clearly illustrate the embodiments of the present application or the technical solutions in the traditional technology, the drawings required for use in the embodiments are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0019] Figure 1 A top view corresponding to a cell body of a back-contact photovoltaic module provided in an embodiment of the present application;

[0020] Figure 2 for Figure 1 A is a schematic diagram of a partially enlarged structure shown in the dotted box in FIG.

[0021] Figures 3 to 5 A schematic diagram of the partially enlarged structure of various battery bodies provided in the embodiments of the present application. DETAILED DESCRIPTION

[0022] As can be seen from the background technology, in the process of preparing IBC batteries, there are still many factors that affect the battery performance of IBC batteries, which in turn limits the further improvement of the photoelectric conversion efficiency of IBC batteries.

[0023] The back-contact photovoltaic module provided in the embodiment of the present application can, on the one hand, improve the welding stability between the welding strip and the welding part, and on the other hand, improve the contact possibility between the welding strip and the main grid body, thereby comprehensively improving the carrier transmission efficiency, reducing power loss, and improving the overall efficiency of the back-contact photovoltaic module.

[0024] In the description of the embodiments of the present application, technical terms such as "first" and "second" are only used to distinguish different objects and cannot be understood 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 the present application, “plurality” means more than two, unless otherwise clearly and specifically defined.

[0026] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0027] In the description of the embodiments of the present application, the term "and / or" is only a description of the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can represent: A exists, A and B exist at the same time, and B exists. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0028] In the description of the embodiments of the present application, technical terms such as "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are only for the convenience of describing the embodiments of the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the embodiments of the present application.

[0029] In the description of the embodiments of the present application, unless otherwise clearly specified and limited, technical terms such as "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the internal connection of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0030] In the accompanying drawings corresponding to the embodiments of the present application, the thickness and area of ​​the layer are magnified 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 a third component may be present between the two components. On the contrary, when describing a component on the surface of another component or when another component is formed or provided on the surface of a component, it means that there is no third component between the two components. In addition, when describing a component as "substantially" 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 partial edge of the entire surface.

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

[0032] The terms used in the description of the various described embodiments herein are used only to describe specific embodiments and are not intended to be limiting. As used in the description of the various described embodiments and the appended claims, "components" are also intended to include plural forms unless the context clearly indicates otherwise.

[0033] The following will describe the various embodiments of the present application in detail with reference to the accompanying drawings. However, it will be appreciated by those skilled in the art that in the various embodiments of the present application, many technical details are provided in order to enable the reader to better understand the present application. However, even without these technical details and various changes and modifications based on the following embodiments, the technical solution claimed in the present application can be implemented.

[0034] Figure 1 A top view corresponding to a cell body of a back-contact photovoltaic module provided in an embodiment of the present application; Figure 2 for Figure 1 The partially enlarged structural diagram shown in the dotted box in A. Figure 1 The insulating portion 130 in FIG. 1 is in a transparent state.

[0035] refer to Figure 1 and Figure 2 The back-contact photovoltaic module provided by the embodiment of the present application includes: a battery body 100 and an insulating portion 130 located on the first surface 101 of the battery body 100. The first surface 101 of the battery body 100 has a plurality of main grids 110 and a plurality of fine grids 120. The plurality of fine grids 120 include a first fine grid 121 and a second fine grid 122 extending along a first direction X and alternately distributed along a second direction Y. The first direction X intersects with the second direction Y. The first fine grid 121 and the second fine grid 122 have different polarities. The plurality of main grids 110 include a first main grid 111 and a second main grid 112 extending along the second direction Y and alternately distributed along the first direction X. The first main grid 111 is in electrical contact with the plurality of first fine grids 121, and the second main grid 112 is in electrical contact with the plurality of second fine grids 122. The main grid 110 includes a main grid body 114 and a welding portion 113 that are alternately connected. The main grid body 114 extends along the second direction Y. In the first direction X, the size of the welding portion 113 is larger than the size of the main grid body 114. The insulating portion 130 at least covers the end of the first fine grid 121 close to the second main grid 112 and the end of the second fine grid 122 close to the first main grid 111. The insulating portions 130 located on both sides of the main grid body 114 along the first direction X and closest to the welding portion 113 are first insulating portions 131, and the remaining insulating portions 130 located on both sides of the main grid body 114 along the first direction X are second insulating portions 132. In 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 the embodiment of the present application, the surface of the battery body 100 has multiple main grids 110 and multiple fine grids 120, and the fine grids 120 include a first fine grid 121 and a second fine grid 122 with different polarities. The first fine grid 121 can be used to collect one of the electrons or holes in the battery body 100, and the second fine grid 122 can be used to collect the other of the electrons or holes in the battery body 100; the main grid 110 includes a first main grid 111 and a second main grid 112. Along the second direction Y, multiple first fine grids 121 are electrically contacted with the same first main grid 111, and multiple second fine grids 122 are electrically contacted with the same second main grid 112. In this way, the first main grid 111 can collect carriers collected by multiple first fine grids 121 arranged along the second direction Y, and the second main grid 112 is used to collect carriers collected by 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. In the first direction X, the size of the welding portion 113 is larger than that of the main grid body 114. When a welding strip is provided on the main grid 110, the welding portion 113 can have a larger contact area with the welding strip than the main grid body 114, so as to improve the welding stability between the welding strip and the main grid 110. The end of the first fine grid 121 close to the second main grid 112 and the end of the second fine grid 122 close to the first main grid 111 are covered with an insulating portion 130. The insulating portion 130 can prevent the fine grid 120 of another polarity that is not connected to the main grid 110 on both sides of the main grid 110 from contacting with the welding strip and causing a short circuit, which is beneficial to improving the stability of the back contact photovoltaic module. Among them, the insulating parts 130 located on both sides of the main grid body 114 along the first direction X and closest to the welding part 113 are the first insulating parts 131, and the other insulating parts 130 located on both sides of the main grid body 114 along the first direction X are the second insulating parts 132. Along the second direction Y, the spacing L1 between the first insulating parts 131 is smaller than the spacing L2 between the second insulating parts 132. In this way, the spacing L1 between the first insulating parts 131 is small, so that the first insulating parts 131 can play the role of clamping the welding strip on both sides of the welding part 113 along the second direction Y, avoiding the problem of welding misalignment caused by the displacement of the welding strip during or after welding; the spacing L2 between the second insulating parts 132 is large, so that the insulating part 130 is not easy to flow to the middle to cover the main grid body 114, resulting in the problem that the welding strip cannot contact the main grid body 114, thereby improving the contact possibility between the welding strip and the main grid body 114. The back-contact photovoltaic module provided in the embodiment of the present application can, on the one hand, improve the welding stability between the welding strip and the welding portion 113, and on the other hand, improve the contact possibility between the welding strip and the main grid body 114, thereby comprehensively improving the carrier transmission 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 connection line 141 and a first penetration line 143, wherein the first connection line 141 extends along the second direction Y and is located at one side edge of the battery body 100 along the first direction X, and in the second direction Y, a plurality of first fine grids 121 located at the edge of the battery body 100 are in electrical contact with the first connection line 141; the first penetration line 143 extends along the first direction X and is located at one side edge of the battery body 100 along the second direction Y, and in the first direction X, the ends of a plurality of first main grids 111 are in electrical contact with the first penetration line 143, and the ends of the first connection line 141 are in electrical contact with the ends of the first penetration line 143. In this way, the first fine grid 121 located at the edge of the battery body 100 can be electrically connected to the first main grid 111 located at the middle of the battery body 100 through the first connection line 141 and the first penetration line 143, so as to realize the collection of carriers on the first fine grid 121 at the edge of the battery body 100.

[0038] refer to Figure 1 The back-contact photovoltaic module may further include: a second connection line 142 and a second penetration line 144, the second connection line 142 extends along the second direction Y and is located at the other side edge of the battery body 100 along the first direction X, and along the second direction Y, a plurality of second fine grids 122 located at the edge of the battery body 100 are in electrical contact with the second connection line 142; the second penetration line 144 extends along the first direction X and is located at the other side edge of the battery body 100 along the second direction Y, and along the first direction X, the ends of a plurality of second main grids 112 are in electrical contact with the second penetration line 144, and the ends of the second connection line 142 are in electrical contact with the ends of the second penetration line 144. In this way, the second fine grid 122 located at the edge of the battery body 100 can be electrically connected to the second main grid 112 located at the middle position of the battery body 100 through the second connection line 142 and the second penetration line 144, so as to realize the collection of carriers on the second fine grid 122 at the edge of the battery body 100.

[0039] exist Figure 1 In the embodiment, the number of main grids 110 is an even number, so that the polarities of the fine grids 120 located at the two side edges of the battery body 100 along the first direction X are different, and the corresponding battery body 100 is respectively provided with a first connecting line 141 and a second connecting line 143 at the two side edges along the first direction X, and the battery body 100 is respectively provided with a first through line 142 and a second through line 144 at the two side edges along the second direction Y. In other embodiments, the number of main grids may be an odd number, so that the polarities of the fine grids located at the two side edges of the battery body along the first direction are the same, and the corresponding battery body may be provided with a first connecting line or a second connecting line at both side edges along the first direction, and the battery body is provided with a first through line at least on one side edge along the second direction.

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

[0041] The back contact photovoltaic module may also include: a welding strip (not shown in the figure), which is used to connect adjacent battery bodies 100, and is located on the main grid 110, and is welded to the welding portion 113. In the first direction X, the ratio of the spacing L1 between the first insulating portions 131 and the width of the welding strip 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. In other words, the spacing L1 between the first insulating portions 131 is close to the width of the welding strip, so that the first insulating portion 131 can be just clamped with the welding strip, so as to avoid the problem of welding misalignment caused by the deviation of the welding strip during or after welding.

[0042] refer to Figure 2 In some embodiments, between adjacent welding portions 113, along the second direction Y, the spacing L2 between different second insulating portions 132 increases first and then decreases. That is, the spacing L2 between the second insulating portions 132 that are farther from the welding portion 113 is larger, so that the second insulating portions 132 that are closer to the welding portion 113 can play a role in assisting the clamping welding strip, further improving the welding stability between the welding strip and the welding portion 113; the spacing between the second insulating portions 132 that are farther away from the welding portion 113 is larger, which can be beneficial to improving the contact possibility between the welding strip and the main grid body 114, further improving the carrier transmission efficiency, reducing power loss, and improving the overall efficiency of the back contact photovoltaic module.

[0043] exist Figure 2 In the embodiment, between adjacent welding portions 113, along the second direction Y, the spacing L2 between different second insulating portions 132 increases first and then decreases as a gradual change trend, that is, the spacing L2 between any two adjacent groups of second insulating portions 132 along the second direction Y are not equal. In other embodiments, the spacing L2 between different second insulating portions 132 increases first and then decreases as a step-wise change trend, 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 some other embodiments, between adjacent welding portions 113 , the intervals L2 between different second insulating portions 132 may be equal.

[0045] Continue to refer Figure 2In some embodiments, among the multiple welding parts 113 corresponding to the main grid 110, the spacing L2 between different second insulating parts 132 gradually increases in the direction from the outermost welding part 113 to the edge of the corresponding battery body 100. That is to say, in the direction from the first or last welding part 113 arranged along the second direction Y corresponding to the main grid 110 to the edge of the battery body 100, the farther the distance between the second insulating parts 132 from the welding part 113 is, the larger the spacing is. In this way, for the edge of the battery body 100, the welding strip has enough space for movement, so as to avoid the problem that the welding strip interferes with the second insulating part 132 at the edge of the battery body 100, resulting in stress concentration and causing the battery body 100 to break.

[0046] exist Figure 2 In the embodiment, among the multiple welding portions 113 corresponding to the main grid 110, in the direction from the outermost welding portion 113 to the edge of the corresponding battery body 100, the variation trend of the spacing L2 between different second insulating portions 132 gradually increasing is taken as a gradual variation, that is, the spacing L2 between any two adjacent groups of second insulating portions 132 along the second direction Y are not equal. In other embodiments, the variation trend of the spacing L2 between different second insulating portions 132 gradually increasing can be a step-wise variation, 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 multiple welding portions 113 corresponding to the main grid 110 , the intervals L2 between different second insulating portions 132 in the direction from the outermost welding portion 113 to the corresponding edge of the battery body 100 may 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 third insulating portions 133 .

[0049] refer to Figure 2 In some embodiments, along the first direction X, the distance a between the third insulating portion 133 and the welding portion 113 is greater than the distance b between the first insulating portion 131 and the main grid body 114. If the distance between the third insulating portion 133 and the welding portion 113 along the first direction X is relatively close, the organic solvent in the third insulating portion 133 may easily flow to the welding portion 113 during the welding process, thereby causing abnormal curing of the solder paste and reducing the welding tension between the welding strip and the welding portion 113. Setting a larger distance between the third insulating portion 133 and the welding portion 113 can avoid such problems, thereby improving the welding stability between the welding strip and the welding portion 113.

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

[0052] refer to Figure 2 In some embodiments, along the second direction Y, the spacing c between the third insulating portion 133 and the adjacent fine grid 120 is greater than the spacing d between the first insulating portion 131 and the adjacent fine grid 120. If the distance between the third insulating portion 133 and the adjacent fine grid 120 along the second direction Y is relatively close, during the welding process, the organic solvent in the third insulating portion 133 may easily flow to the adjacent fine grid 120, and then extend to the welding portion 113 along the extension direction of the fine grid 120, thereby causing abnormal curing of the solder paste, and reducing the welding tension between the solder ribbon and the welding portion 113. Setting a larger distance between the third insulating portion 133 and the adjacent fine grid 120 can avoid such problems, thereby improving the welding stability between the solder ribbon and the welding portion 113.

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

[0054] In some embodiments, the distance between the fine gate 120 and the third insulating portion 133 on either side of the third insulating portion 133 in the second direction Y is greater than the distance between the fine gate 120 and the first insulating portion 131 on either side of the first insulating portion 131 in the second direction Y. For example, when the fine gates 120 of different polarities are arranged at equal intervals in the second direction Y, the width of the third insulating portion 133 in the second direction Y is set to be smaller than the width of the first insulating portion 131 in the second direction Y, so that the spacing between the fine gate 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 spacing between the fine gate 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 between the fine gates 120 on both sides of the third insulating portion 133 in the second direction Y can be adjusted so that the spacing between the fine gate 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 spacing between the fine gate 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, along the first direction X, the length of the third insulating portion 133 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 spacing d between the first insulating portion 131 and the adjacent fine grid 120 is greater than the spacing e between the second insulating portion 132 and the adjacent fine grid 120. Since the first insulating portion 131 is the insulating portion 130 closest to the welding portion 113 on both sides of the main grid body 114 along the first direction X, during the welding process, the organic solvent in the first insulating portion 131 may flow to the adjacent fine grid 120, and then extend to the welding portion 113 along the extension direction of the fine grid 120, thereby causing abnormal curing of the solder paste, resulting in a decrease in the welding tension between the soldering ribbon and the welding portion 113. Setting a larger distance between the first insulating portion 131 and the adjacent fine grid 120 can avoid such problems, thereby improving the welding stability between the soldering ribbon and the welding portion 113.

[0057] In the second direction Y, the intervals between the fine gates 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 spacing between the fine gate 120 and the first insulating portion 131 on either side of the first insulating portion 131 in the second direction Y is greater than the spacing between the fine gate 120 and the second insulating portion 132 on either side of the second insulating portion 132 in the second direction Y. For example, when the fine gates 120 of different polarities are arranged at equal intervals in the second direction Y, the width of the first insulating portion 131 in the second direction Y is set to be smaller than the width of the second insulating portion 132 in the second direction Y, so that the distance between the fine gate 120 on either side of the first insulating portion 131 in the second direction Y and the first insulating portion 131 is greater than the distance between the fine gate 120 and the second insulating portion 132 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 distance between the fine gates 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 gate 120 on either side of the first insulating portion 131 in the second direction Y and the first insulating portion 131 is greater than the distance between the fine gate 120 and the second insulating portion 132 on either side of the second insulating portion 132 in the second direction Y.

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

[0060] refer to Figure 2 In some embodiments, the spacing f between the end of the first insulating portion 131 close to the main grid body 114 and the end of the corresponding fine grid 120 is greater than the spacing g between the end of the third insulating portion 133 close to the welding portion 113 and the end of the corresponding fine grid 120. In this way, the problem of the welding strip short-circuiting with the heterogeneous fine grid 120 after the welding strip deviates on both sides of the main grid body 114 can be avoided. Since the welding portion 113 is welded and fixed to the welding strip, the possibility of the welding strip deviating at the welding portion 113 is smaller than the possibility of the welding strip deviating on both sides of the main grid body 114. Therefore, the spacing between the end of the third insulating portion 133 close to the welding portion 113 and the end of the corresponding fine grid 120 can be smaller.

[0061] Figure 3 A schematic diagram of a partially enlarged structure of a battery body provided in an embodiment of the present application.

[0062] refer to Figure 3In some embodiments, the insulating portion 130 includes a main 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 main body portion 134 is located on the side of the widened portion 135 away from the main grid 110. In the second direction Y, the width of the widened portion 135 is greater than the width of the main body portion 134. In other words, the insulating portion 130 is provided with the widened portion 135 at the end close to the main grid 110. On the one hand, the widened portion 135 can further reduce the risk of short-circuiting between the welding strip and the end of the heterogeneous fine grid 120, thereby improving the stability of the back-contact photovoltaic module; on the other hand, the smaller width of the main 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 part 130 includes the main body part 134 and the widened part 135 , along the second direction Y, the spacing L1 between the first insulating parts 131 is equal to the spacing between the widened parts 135 corresponding to the first insulating parts 131 ; the spacing L2 between the second insulating parts 132 is equal to the spacing between the widened parts 135 corresponding to the second insulating parts 132 .

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

[0065] When the insulating portion 130 includes a main body portion 134 and a widened portion 135, along the second direction Y, a spacing c between the third insulating portion 133 and an adjacent fine gate 120 is greater than a spacing d between the first insulating portion 131 and an adjacent fine gate 120, which means that a spacing between a widened portion 135 corresponding to the third insulating portion 133 and an adjacent fine gate 120 is greater than a spacing between a widened portion 135 corresponding to the first insulating portion 131 and an adjacent fine gate 120.

[0066] When the insulating portion 130 includes a main body portion 134 and a widened portion 135, along the second direction Y, a spacing d between the first insulating portion 131 and an adjacent fine gate 120 is greater than a spacing e between the second insulating portion 132 and an adjacent fine gate 120, which means that a spacing between the widened portion 135 corresponding to the first insulating portion 131 and an adjacent fine gate 120 is greater than a spacing between the widened portion 135 corresponding to the second insulating portion 132 and an adjacent fine gate 120.

[0067] When the insulating part 130 includes a main body part 134 and a widened part 135, a spacing f between an end portion of the first insulating part 131 close to a side of the main grid body 114 and an end portion of the corresponding fine grid 120 is greater than a spacing g between an end portion of the third insulating part 133 close to a side of the welding part 113 and an end portion of the corresponding fine grid 120, which means that a spacing between an end portion of the widened part 135 corresponding to the first insulating part 131 close to a side of the main grid body 114 and an end portion of the corresponding fine grid 120 is greater than a spacing between an end portion of the widened part 135 corresponding to the third insulating part 133 close to a side of the welding part 113 and an end portion of the corresponding fine grid 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 fixed to the welding strip by welding, the possibility of the welding strip being offset at the welding portion 113 is smaller than the possibility of the welding strip being offset on both sides of the main grid body 114. 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, which can reduce the risk of short-circuiting between the welding strip and the end of the heterogeneous fine grid 120, and can also save the use cost of the insulating portion 130.

[0069] Figure 4 A schematic diagram of a partially enlarged structure of another battery body provided in an embodiment of the present application.

[0070] refer to Figure 4 In some embodiments, the first insulating portion 131 and the second insulating portion 132 are connected to each other as a whole. For the third insulating portion 133 and the first insulating portion 131 near the welding portion 113, they need to be separated from the fine grid 120 connected to the welding portion 113 to prevent the organic solvent in the third insulating portion 133 or the first insulating portion 131 from extending along the fine grid 120 to the welding portion 113, thereby avoiding the problem of abnormal solder paste curing; for the second insulating portion 132 on both sides of the main grid body 114, the distance between the second insulating portion 132 and the welding portion 113 is relatively far, and it is not easy for the organic solvent to flow to the welding portion 113. Connecting the first insulating portion 131 and the second insulating portion 132 to each other as a whole can facilitate 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, in a direction perpendicular to the first surface 101 of the battery body 100, the height of the first insulating portion 131 is greater than the height of the main grid 110. In this way, after the welding strip is welded, the first insulating portion 131 is located on both sides of the welding strip to play the role of clamping the welding strip to fix the relative position of the welding strip and improve the stability of the welding strip during and after welding.

[0072] refer to Figure 4 When the first insulating portion 131 includes a main body portion 134 and a widened portion 135, the height of the widened portion 135 may be greater than the height of the main body portion 134 in a 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. In this way, on the one hand, after the welding strip is welded, the widened portions 135 of the first insulating portion 131 are located on both sides of the welding strip to play a role of clamping the welding strip, so as to fix the relative position of the welding strip and improve the stability of the welding strip during and after welding; on the other hand, the large height of the widened portion 135 can avoid the problem of the insulating portion 130 shrinking after solidification to expose the end of the fine grid 120.

[0073] Figure 5 A schematic diagram of a partially enlarged structure of another battery body provided in an embodiment of the present 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 grids 110 and greater than 1 / 2 of the spacing between adjacent main grids 110. In this way, the insulating portion 130 covers a longer length of the fine grid 120, which can further reduce the risk of short circuit between the welding strip and the heterogeneous fine grid 120.

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

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

[0077] In some embodiments, the type of the battery body 100 can be a monocrystalline silicon solar cell, a polycrystalline silicon solar cell, an amorphous silicon solar cell or a multi-compound solar cell. The multi-compound solar cell can specifically 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 also includes: an encapsulation layer, which covers the surface of the battery body. The material of the encapsulation layer can be an organic encapsulation film such as ethylene-vinyl acetate copolymer (EVA) film, polyethylene octene co-elastomer (POE) film or polyvinyl butyral (PVB) film.

[0079] In some embodiments, the back contact photovoltaic module further comprises: a cover plate, which is located on the surface of the encapsulation layer away from the battery body, and the cover plate can be a glass cover plate, a plastic cover plate or other light-transmitting cover plate. In some embodiments, the surface of the cover plate facing the encapsulation layer can be a concave-convex surface, thereby increasing the utilization rate of the incident light.

[0080] In the back-contact photovoltaic module provided in the embodiment of the present application, the surface of the battery body 100 has multiple main grids 110 and multiple fine grids 120, and the fine grids 120 include a first fine grid 121 and a second fine grid 122 with different polarities. The first fine grid 121 can be used to collect one of the electrons or holes in the battery body 100, and the second fine grid 122 can be used to collect the other of the electrons or holes in the battery body 100; the main grid 110 includes a first main grid 111 and a second main grid 112. Along the second direction Y, multiple first fine grids 121 are electrically contacted with the same first main grid 111, and multiple second fine grids 122 are electrically contacted with the same second main grid 112. In this way, the first main grid 111 can collect carriers collected by multiple first fine grids 121 arranged along the second direction Y, and the second main grid 112 is used to collect carriers collected by 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. In the first direction X, the size of the welding portion 113 is larger than that of the main grid body 114. When a welding strip is provided on the main grid 110, the welding portion 113 can have a larger contact area with the welding strip than the main grid body 114, so as to improve the welding stability between the welding strip and the main grid 110. The end of the first fine grid 121 close to the second main grid 112 and the end of the second fine grid 122 close to the first main grid 111 are covered with an insulating portion 130. The insulating portion 130 can prevent the fine grid 120 of another polarity that is not connected to the main grid 110 on both sides of the main grid 110 from contacting with the welding strip and causing a short circuit, which is beneficial to improving the stability of the back contact photovoltaic module. Among them, the insulating parts 130 located on both sides of the main grid body 114 along the first direction X and closest to the welding part 113 are the first insulating parts 131, and the other insulating parts 130 located on both sides of the main grid body 114 along the first direction X are the second insulating parts 132. Along the second direction Y, the spacing L1 between the first insulating parts 131 is smaller than the spacing L2 between the second insulating parts 132. In this way, the spacing L1 between the first insulating parts 131 is small, so that the first insulating parts 131 can play the role of clamping the welding strip on both sides of the welding part 113 along the second direction Y, avoiding the problem of welding misalignment caused by the displacement of the welding strip during or after welding; the spacing L2 between the second insulating parts 132 is large, so that the insulating part 130 is not easy to flow to the middle to cover the main grid body 114, resulting in the problem that the welding strip cannot contact the main grid body 114, thereby improving the contact possibility between the welding strip and the main grid body 114. The back-contact photovoltaic module provided in the embodiment of the present application can, on the one hand, improve the welding stability between the welding strip and the welding portion 113, and on the other hand, improve the contact possibility between the welding strip and the main grid body 114, thereby comprehensively improving the carrier transmission efficiency, reducing power loss, and improving the overall efficiency of the back-contact photovoltaic module.

[0081] Those skilled in the art will appreciate that the above-mentioned embodiments are specific examples for implementing the present application, and in practical applications, various changes may be made to the embodiments in form and detail without departing from the spirit and scope of the present application. Any person skilled in the art may make various changes and modifications without departing from the spirit and scope of the present application, and therefore the scope of protection of the present application shall be subject to the scope defined in the claims.

Claims

1. A back contact photovoltaic module, characterized in that: include: A battery body, wherein a first surface of the battery body has a plurality of main grids and a plurality of fine grids, wherein the plurality of fine grids include a first fine grid and a second fine grid extending along a first direction and alternately distributed along a second direction, wherein the first direction intersects the second direction, and the first fine grid and the second fine grid have different polarities; The plurality of main grids include a first main grid and a second main grid extending along the second direction and alternately distributed along the first direction, the first main grid is in electrical contact with the plurality of the first fine grids, the second main grid is in electrical contact with the plurality of the second fine grids, the main grid includes a main grid body and a welding portion connected alternately, the main grid body extends along the second direction, and along the first direction, the size of the welding portion is larger than the size of the main grid body; An insulating portion, wherein the insulating portion is located on the first surface, and the insulating portion at least covers an end portion of the first fine grid close to the second main grid and an end portion of the second fine grid close to the first main grid. The insulating portions located on both sides of the main grid body along the first direction and closest to the welding portion are first insulating portions, and the remaining insulating portions located on both sides of the main grid body along the first direction are 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 welding portions, along the second direction, the intervals between different second insulating portions first increase and then decrease.

3. The back contact photovoltaic module according to claim 1 or 2, characterized in that: Among the plurality of welding portions corresponding to the main grid, the spacing between different second insulating portions gradually increases in the direction from the outermost welding portion to the corresponding edge of the battery body.

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 third insulating portions. Along the first direction, a distance between the third insulating portion and the welding portion is greater than a 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 third insulating portions. Along the second direction, a distance between the third insulating portion and adjacent fine grids is greater than a distance between the first insulating portion and adjacent fine grids.

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

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

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

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

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

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