Photovoltaic panels

Abstract

The disclosed embodiments relate to the photovoltaic field and provide a photovoltaic module comprising: a busbar; a cell string electrically connected to the busbar, the cell string comprising a plurality of cells electrically connected in sequence, the plurality of cells including edge cells, the edge cells comprising: a substrate comprising a central region and an edge region; a first main grid located on a surface of the substrate; a first secondary grid electrically connected to the first main grid; a second main grid located on a surface of the substrate and spaced apart from the first main grid; a second secondary grid electrically connected to the second main grid and spaced apart from the first secondary grid; a first insulating structure covering the surface of the second secondary grid; a second insulating structure located in an edge region of the substrate near the busbar and covering at least the surface of the second secondary grid not covered by the first insulating structure; a welding ribbon for electrically connecting the cell string and the busbar; an encapsulating film for covering the surfaces of the cell string, the welding ribbon, and the busbar; and a cover for covering the surface of the encapsulating film away from the cell string. This can improve the reliability of the photovoltaic module.

Description

Technical Field

[0001] The embodiments of the present disclosure relate to the photovoltaic field, and in particular to a photovoltaic module. Background Art

[0002] A solar cell is a thin, photoelectric semiconductor wafer that uses sunlight to generate electricity directly. It's also called a "solar chip" or "photocell." As long as it's illuminated by a certain level of light, it can instantly output voltage and generate current in a circuit. In physics, this is called solar photovoltaics (PV).

[0003] Interdigitated back contact (IBC) solar cells are a type of solar cell that has no electrodes on the front of the cell, and the positive and negative electrodes are located on the back of the cell. This can reduce the shading of the electrodes on the cell, increase the short-circuit current of the cell, and improve the energy conversion efficiency of the cell.

[0004] Photovoltaic modules generally refer to solar cell modules. Since the output voltage of a single solar cell is relatively low, a certain number of single cells must be sealed in series and parallel to form a solar cell module. Summary of the Invention

[0005] The embodiments of the present disclosure provide a photovoltaic module, which can at least improve the reliability of the photovoltaic module.

[0006] According to some embodiments of the present disclosure, on one hand, an embodiment of the present disclosure provides a photovoltaic module, comprising: a bus bar, the bus bar extending along a first direction; a battery string, the battery string being electrically connected to the bus bar, the battery string comprising a plurality of battery cells arranged along a second direction and electrically connected in sequence, the plurality of battery cells including edge battery cells close to the bus bar, the edge battery cells comprising: a substrate, the substrate comprising a central area and edge areas located on opposite sides of the central area along the second direction; a first main grid, the first main grid being located on a surface of the substrate and extending along the second direction; a first auxiliary grid, the first auxiliary grid being electrically connected to the first main grid and extending along the first direction; a second main grid, the second main grid being located on the surface of the substrate surface, spaced from the first main grid along the first direction; a second auxiliary grid, the second auxiliary grid is electrically connected to the second main grid, extends along the first direction, and is spaced from the first auxiliary grid along the second direction; a first insulating structure, the first insulating structure covers the surface of the second auxiliary grid; a second insulating structure, the second insulating structure is located in the edge area of ​​the substrate close to the bus bar, and at least covers the surface of the second auxiliary grid not covered by the first insulating structure; a welding ribbon, the welding ribbon is used to electrically connect the battery string and the bus bar; an encapsulation film, the encapsulation film is used to cover the surface of the battery string, the welding ribbon and the bus bar; a cover plate, the cover plate is used to cover the surface of the encapsulation film away from the battery string.

[0007] In some embodiments, in the first direction, the length of the first insulating structure in contact with the second sub-gate is a first length, the length of the second insulating structure in contact with the second sub-gate is a second length, and the ratio of the second length to the first length is greater than or equal to 50%.

[0008] In some embodiments, in the second direction, a ratio of a width of the second insulating structure to a width of the second secondary gate is greater than or equal to 1.2.

[0009] In some embodiments, the edge battery cell includes: a welding point group connected to the welding strip, the welding point group includes a plurality of welding points arranged along the second direction, the welding strip is connected to the welding point at the edgemost along the second direction, and the second insulation structure is located on the side of the welding point group close to the bus bar.

[0010] In some embodiments, the first insulating structure and the second insulating structure are an integrated structure.

[0011] In some embodiments, in a direction from the battery string toward the bus bar, a length of the second insulation structure in the second direction gradually increases.

[0012] In some embodiments, in the first direction, a thickness of a portion of the second insulating structure close to the first insulating structure is smaller than a thickness of a portion of the second insulating structure far from the first insulating structure.

[0013] In some embodiments, the second insulating structure further covers the entire surface of the edge region.

[0014] In some embodiments, the second insulating structure includes: an insulating layer, the insulating layer covering the surface of the edge region; and a reflective layer, the reflective layer covering the surface of the insulating layer.

[0015] In some embodiments, the battery string further includes a central battery cell away from the bus bar, and the second insulation structure is further located in the edge region of the edge battery cells close to the central battery cell.

[0016] The technical solution provided by the embodiments of the present disclosure has at least the following advantages: the bus bar is used to collect and output the current on the battery string, and the welding ribbon is a structure that electrically connects the bus bar and the battery string. However, during the lamination process, that is, when assembling the packaging film and the cover plate, the welding ribbon is easily crushed, causing the welding ribbon to short-circuit the battery cell. Therefore, this solution increases the insulation area of ​​the second sub-grid surface by setting the first insulation structure and the second insulation structure at the edge area of ​​the battery cell near the edge of the bus bar, so that even if the welding ribbon is crushed, the welding ribbon will not be electrically connected to the first sub-grid and the second sub-grid at the same time, thereby avoiding the occurrence of a short circuit between the first sub-grid and the second sub-grid, thereby improving the reliability of the photovoltaic module. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] 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 stated, the pictures in the drawings do not constitute a scale limitation. In order to more clearly illustrate the embodiments of the present disclosure or the technical solutions in the traditional technology, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present disclosure. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0018] Figure 1 A cross-sectional view of a photovoltaic module provided by an embodiment of the present disclosure;

[0019] Figure 2 A top view of a photovoltaic assembly provided by an embodiment of the present disclosure;

[0020] Figure 3 A top view of a partial structure of a photovoltaic module provided by an embodiment of the present disclosure;

[0021] Figure 4 A partially enlarged perspective view of a photovoltaic assembly provided by an embodiment of the present disclosure;

[0022] Figure 5 A top view of another partial structure of a photovoltaic module provided by an embodiment of the present disclosure;

[0023] Figure 6 A cross-sectional view of the second insulation structure provided in an embodiment of the present disclosure. DETAILED DESCRIPTION

[0024] As can be seen from the background technology, currently, during the lamination process, that is, when assembling the packaging film and the cover plate, the soldering ribbon is easily crushed and deformed. After being crushed, the soldering ribbon will contact the first and second sub-grids at the same time, causing a short circuit between the first and second sub-grids.

[0025] The disclosed embodiment provides a photovoltaic module, wherein a bus bar is used to collect and output the current on a battery string, and a welding ribbon is a structure that electrically connects the bus bar and the battery string. However, during the lamination process, that is, when assembling the packaging film and the cover plate, the welding ribbon is easily crushed, causing the welding ribbon to short-circuit the battery cell. Therefore, the present solution arranges a first insulating structure and a second insulating structure in the edge area of ​​the battery cell near the edge of the bus bar, and increases the insulating area of ​​the second auxiliary grid surface by arranging the first insulating structure and the second insulating structure, so that even if the welding ribbon is crushed, the welding ribbon will not be electrically connected to the first auxiliary grid and the second auxiliary grid at the same time, thereby avoiding the occurrence of a short circuit between the first auxiliary grid and the second auxiliary grid, thereby improving the reliability of the photovoltaic module.

[0026] In the description of the embodiments of this application, the technical terms "first" and "second" are used only to distinguish different objects and should not be understood to indicate or imply relative importance or implicitly specify the quantity, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, the meaning of "plurality" is more than two, unless otherwise clearly and specifically defined.

[0027] References herein to "embodiments" mean that a particular feature, structure, or characteristic described in connection with the embodiments may be included in at least one embodiment of the present application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0028] In the description of the embodiments of this application, the term "and / or" is simply a description of the association relationship between associated objects, indicating that three relationships can exist. For example, A and / or B can represent the following three situations: A exists, A and B exist at the same time, and B exists. In addition, the character " / " in this document generally indicates that the associated objects are in an "or" relationship.

[0029] In the description of the embodiments of the present application, the term "multiple" refers to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).

[0030] In the description of the embodiments of the present application, the technical terms "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 the orientation or position relationship, are based on the orientation or position relationship 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 device or element referred to 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.

[0031] In the description of the embodiments of the present application, unless otherwise expressly specified or limited, technical terms such as "installed," "connected," "connected," and "fixed" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integration; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; internal connections between two components or interactions between two components. Those skilled in the art can understand the specific meanings of the above terms in the embodiments of the present application based on specific circumstances.

[0032] In the accompanying drawings corresponding to the embodiments of the present application, the thickness and area of ​​the layers are exaggerated for better understanding and ease of description. When describing a component (such as a layer, film, region or substrate) on another component or on the surface of another component, the component can be "directly" located on the surface of the other component, or a third component can be present between the two components. Conversely, 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 being "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.

[0033] In the description of the embodiments of the present application, when a component "includes" another component, unless otherwise specified, other components are not excluded, and other components may be further included. In addition, when a component such as a layer, film, region, or plate is referred to as being "on / located on" another component, it can be "directly on" the other component (i.e., located on the surface of the other component with no other components between them), or another component can be present between them. In addition, when a component such as a layer, film, region, or plate is "directly on" another component, or when a component such as a layer, film, region, or plate is located on the surface of another component, it means that no other components are located between them.

[0034] The terms used herein in the description of the various embodiments are intended only to describe the specific embodiments and are not intended to be limiting. As used in the description of the various embodiments and the appended claims, "the component" is intended to include the plural form unless the context clearly indicates otherwise. A component includes a layer, film, region, or plate.

[0035] The following describes various embodiments of the present disclosure in detail with reference to the accompanying drawings. However, those skilled in the art will appreciate that many technical details are provided in the various embodiments of the present disclosure to help readers better understand the embodiments of the present disclosure. However, even without these technical details and the various variations and modifications based on the following embodiments, the technical solutions claimed in the embodiments of the present disclosure can be implemented.

[0036] refer to Figures 1 to 4 , Figure 1 A cross-sectional view of a photovoltaic module provided by an embodiment of the present disclosure; Figure 2 A top view of a photovoltaic assembly provided by an embodiment of the present disclosure; Figure 3 A top view of a partial structure of a photovoltaic module provided by an embodiment of the present disclosure; Figure 4 for Figure 3 The enlarged perspective view of the part in the oval box.

[0037] In some embodiments, the photovoltaic module may include a bus bar 100 extending along a first direction X.

[0038] In some embodiments, the photovoltaic module may further include: a battery string 101, the battery string 101 is electrically connected to the bus bar 100, the battery string 101 includes a plurality of battery cells 111 arranged along the second direction Y and electrically connected in sequence, the plurality of battery cells 111 include an edge battery cell 121 close to the bus bar 100, the edge battery cell 121 includes: a substrate 131, the substrate 131 includes a central area 141 and edge areas 151 located on opposite sides of the central area 141 along the second direction Y; a first main grid 161, the first main grid 161 is located on the surface of the substrate 131 and extends along the second direction Y; a first auxiliary grid 171, the first auxiliary grid 171 is connected to the first main grid 161 is electrically connected and extends along the first direction Y; a second main grid 181, the second main grid 181 is located on the surface of the substrate 131 and is spaced apart from the first main grid 161 along the first direction X; a second auxiliary grid 191, the second auxiliary grid 191 is electrically connected to the second main grid 181, extends along the first direction X, and is spaced apart from the first auxiliary grid 171 along the second direction Y; a first insulating structure 201, the first insulating structure 201 covers the surface of the second auxiliary grid 191; a second insulating structure 211, the second insulating structure 211 is located in the edge area 151 of the substrate 131 close to the busbar 100, and at least covers the surface of the second auxiliary grid 191 not covered by the first insulating structure 201.

[0039] In some embodiments, the photovoltaic module may further include a welding ribbon 102 , which is used to electrically connect the cell string 101 and the bus bar 100 .

[0040] In some embodiments, the packaging film 103 is used to cover the surfaces of the battery string 101 , the welding ribbon 102 , and the bus bar 100 .

[0041] In some embodiments, a cover plate 104 is used to cover the surface of the packaging film 103 away from the battery string 101 .

[0042] In the embodiment of the present disclosure, the busbar 100 is used to collect and output the current on the battery string 101, and the welding ribbon 102 is a structure that electrically connects the busbar 100 and the battery string 101. However, during the lamination process, that is, when assembling the packaging film 103 and the cover plate 104, the welding ribbon 102 is easily crushed, causing the welding ribbon 102 to short-circuit the battery cell 111. Therefore, this solution provides a first insulating structure 201 and a second insulating structure 211 in the edge area 151 of the battery cell 121 near the edge of the busbar 100. By providing the first insulating structure 201 and the second insulating structure 211, the insulation area of ​​the surface of the second auxiliary grid 191 is increased. Therefore, even if the welding ribbon 102 is crushed, the welding ribbon 102 will not be electrically connected to the first auxiliary grid 171 and the second auxiliary grid 191 at the same time, thereby avoiding the occurrence of a short circuit between the first auxiliary grid 171 and the second auxiliary grid 191, thereby improving the reliability of the photovoltaic module.

[0043] In some embodiments, the busbar 100 is generally made of copper or other conductive materials with good electrical conductivity and corrosion resistance.

[0044] In some embodiments, there may be multiple battery strings 101 , and the connections between the multiple battery strings 101 and the bus bar 100 may be in series or in parallel, which can be selected according to actual conditions.

[0045] In some embodiments, the plurality of battery cells 111 may include an edge battery cell 121 close to the bus bar 100 and a center battery cell located on the side of the edge battery cell 121 away from the bus bar 100. The edge battery cell 121 may be the battery cell 111 closest to the bus bar 100 in the battery string 101, and the center battery cell may be all the battery cells 111 except the edge battery cell 121.

[0046] For the edge cell 121, the substrate 131 of the edge cell 121 is used to receive incident light and generate photogenerated carriers. In some embodiments, the substrate 131 may be a semiconductor substrate, such as silicon, germanium, silicon germanium, or silicon on an insulator. In some embodiments, the material of the substrate 131 may be an elemental semiconductor material. Specifically, an elemental semiconductor material is composed of a single element, such as silicon or germanium. Elemental semiconductor materials may be single crystalline, polycrystalline, amorphous, or microcrystalline (a state having both single crystalline and amorphous states is referred to as a microcrystalline state). In some embodiments, the material of the substrate 131 may also be a compound semiconductor material. Common compound semiconductor materials include, but are not limited to, silicon germanium, silicon carbide, gallium arsenide, indium gallium, perovskite, cadmium telluride, copper indium selenide, and other materials. Materials may also include silicon carbide, organic materials, or multi-component compounds.

[0047] In some embodiments, the substrate 131 may include a first doped region and a second doped region arranged in sequence. The first doped region is doped with ions of the same conductivity type as the substrate 131, and the second doped region is doped with ions of a different conductivity type than the substrate. For example, if the substrate is an N-type substrate, the first doped region is an N-type doped region, and the second doped region is a P-type doped region, a PN junction is formed between the second doped region and the substrate 131, effectively shunting carriers.

[0048] The first main grid 161 and the first auxiliary grid 171 can be electrically connected to the first doped region, wherein the first auxiliary grid 171 can be in contact with the first doped region, the first main grid 161 can be in contact with the first auxiliary grid 171, the first auxiliary grid 171 is used to collect and summarize the current of the solar cell, and the first main grid 161 is used to summarize and output the current on the first auxiliary grid 171.

[0049] The second main gate 181 and the second auxiliary gate 191 can be electrically connected to the second doped region, wherein the second auxiliary gate 191 can be in contact with the second doped region, the second main gate 181 can be in contact with the second auxiliary gate 191, the second auxiliary gate 191 is used to collect and summarize the current of the solar cell, and the second main gate 181 is used to summarize and output the current on the second auxiliary gate 191.

[0050] The first auxiliary grid 171 and the second auxiliary grid 191 may be formed by sintering a fire-through paste. The materials of the first auxiliary grid 171 and the second auxiliary grid 191 may be one or more of aluminum, silver, gold, nickel, molybdenum or copper.

[0051] In some embodiments, the first insulating structure 201 may cover the surfaces of the second sub-gates 191 located in the central region 141 and the edge region 151 , that is, the first insulating structure 201 may cover the entire surface of the second sub-gates 191 .

[0052] The second insulating structure 211 at least covers the surface of the second auxiliary grid 191 in the edge area 151 of the substrate 131 close to the busbar 100, and the second insulating structure 211 at least covers the surface of the second auxiliary grid 191 not covered by the first insulating structure 201. In other words, the surface area of ​​the surface of the second auxiliary grid 191 covered by the insulating structure is increased by the second insulating structure 211. In this way, even if the welding ribbon 102 connected to the battery string 101 and the busbar 100 collapses, deforms or shifts, the welding ribbon 102 can still be separated from the second auxiliary grid 191 by the second insulating structure 211, thereby preventing the welding ribbon 102 from being in electrical contact with the first auxiliary grid 171 and the second auxiliary grid 191 at the same time, thereby preventing a short circuit in the battery cell 111.

[0053] In some embodiments, the second auxiliary grid 191 protrudes from the surface of the substrate 131, and the first insulating structure 201 can surround the portion of the second auxiliary grid 191 protruding from the surface of the substrate 131, thereby preventing the soldering ribbon 102 from contacting the side wall of the second auxiliary grid 191. As for the second insulating structure 211, the second insulating structure 211 can also surround the portion of the second auxiliary grid 191 protruding from the surface of the substrate 131, thereby preventing the soldering ribbon 102 from contacting the side wall of the second auxiliary grid 191.

[0054] In some embodiments, the first insulating structure 201 can surround the portion of the second auxiliary grid 191 protruding from the surface of the substrate 131, and the second insulating structure 211 can only cover the top surface of the second auxiliary grid 191. For the second insulating structure 211, the second insulating structure 211 plays a role of supplementary insulation. Therefore, for the second insulating structure 211, covering the top surface of the second auxiliary grid 191 can greatly improve the insulation effect between the second auxiliary grid 191 and the welding strip 102. Therefore, covering only the top surface of the second auxiliary grid 191 can also reduce the amount of material used in the second insulating structure 211 and reduce the cost of the photovoltaic module.

[0055] In some embodiments, the first insulating structure 201 and the second insulating structure 211 are integrally formed. In other words, the first insulating structure 201 and the second insulating structure 211 are formed in the same process step. For example, when printing insulating adhesive, the printing length is increased where the second insulating structure 211 is to be formed, so that the insulating adhesive covers more of the surface of the second auxiliary grid 191, thereby forming the first insulating structure 201 and the second insulating structure 211 in one step. By configuring the first insulating structure 201 and the second insulating structure 211 as an integral structure, the process steps for forming the cell can be reduced, reducing costs, and also improving the contact strength between the first insulating structure 201 and the second insulating structure 211 and the second auxiliary grid 191.

[0056] In some embodiments, part of the first insulating structure 201 is spaced from the second insulating structure 211, and part of the first insulating structure 201 is in contact with the second insulating structure 211. The distance between the first insulating structure 201 and the second insulating structure 211 is calculated and set according to the actual situation. For example, the edge area 151 of the substrate 131 close to the bus bar 100 includes 6 second sub-grids, and in the direction of the bus bar 100 pointing to the edge battery cell 121, the 6 second sub-grids are defined as: the first second sub-grid, the second second sub-grid, and the sixth second sub-grid. During the photovoltaic assembly process, it was found that the position of the welding ribbon 102 on the second second secondary grid was the farthest away. Therefore, we can set the spacing between the second second secondary grid and the first secondary grid corresponding to the second second secondary grid, and the spacing distance is calculated and set according to the actual situation. For example, after testing, it was found that when the spacing distance was set to 3mm, the probability of isolating the welding ribbon 102 and the second secondary grid 191 was above 90%. Therefore, it can be considered that a spacing distance of 3mm is the optimal spacing distance between the second second secondary grid and the first secondary grid corresponding to the second second secondary grid.

[0057] Setting a gap between the partial first insulating structure 201 and the second insulating structure 211 can reduce the amount of the second insulating structure 211 while ensuring the effect of the second insulating structure 211 isolating the welding strip 102 and the second auxiliary grid 191, thereby controlling costs.

[0058] It should be noted that the number and spacing of the second sub-grids are merely illustrations for ease of understanding, and can be adjusted according to actual conditions, and are not limited here.

[0059] In some embodiments, in the first direction X, the length of contact between the first insulating structure 201 and the second auxiliary grid 191 is a first length, the length of contact between the second insulating structure 211 and the second auxiliary grid 191 is a second length, and the ratio of the second length to the first length is greater than or equal to 50%. In other words, for the second auxiliary grid 191, a portion of the surface of the second auxiliary grid 191 covered by the insulating structure has a longer length, while a portion of the surface of the second auxiliary grid 191 covered by the insulating structure has a shorter length. The length of the extended insulating structure is greater than or equal to 150% of the length of the unextended insulating structure. By setting the ratio of the second length to the first length to be greater than or equal to 50%, the reliability of the photovoltaic module enhanced by the second insulating structure 211 can be further improved.

[0060] It should be noted that the lengthened insulating structure refers to the sum of the lengths of the first insulating structure 201 and the second insulating structure 211 , and the non-lengthened insulating structure refers to the insulating structure corresponding to the second sub-gate 191 that only covers the first insulating structure 201 .

[0061] In some embodiments, the ratio of the width of the second insulating structure 211 to the width of the second auxiliary grid 191 in the second direction Y is greater than or equal to 1.2. By setting the ratio of the width of the second insulating structure 211 to the width of the second auxiliary grid 191 to be greater than or equal to 1.2, it can be ensured that the second insulating structure 211 covers the entire top surface of the second auxiliary grid 191, thereby further improving the reliability of the photovoltaic module.

[0062] It is understandable that in the process of forming the second insulating structure 211, the printing of the second insulating structure 211 may be offset. Therefore, setting the ratio of the width of the second insulating structure 211 to the width of the second sub-grid 191 to be greater than or equal to 1.2 can also effectively isolate the solder strip 102 and the second sub-grid 191 when the second insulating structure 211 is printed offset.

[0063] It should be noted that the second insulating structure 211 covering the entire top surface of the second sub-grid 191 mentioned above refers to the surface of the second sub-grid 191 that the second insulating structure 211 needs to cover. For example, the second insulating structure 211 needs to cover 3mm of the second sub-grid 191, and the entire top surface here refers to the entire top surface of the second sub-grid 191 corresponding to the length of this 3mm.

[0064] In some embodiments, the ratio of the width of the first insulating structure 191 to the width of the second auxiliary grid 191 may also be greater than or equal to 1.2. Similarly, by setting the ratio of the width of the first insulating structure 191 to the width of the second auxiliary grid 191 to be greater than or equal to 1.2, it can be ensured that the first insulating structure 201 covers the entire top surface of the second auxiliary grid 191, thereby further improving the reliability of the photovoltaic module.

[0065] In some embodiments, the edge cell 121 includes a solder point group 221 connected to the solder ribbon 102. The solder point group 221 includes a plurality of solder points 231 arranged along the second direction Y. The solder ribbon 102 is connected to the solder point 231 at the edge of the cell 111 along the second direction Y. The second insulating structure 211 is located on the side of the solder point group 221 that is closest to the bus bar 100. It will be appreciated that providing the solder point group 221 on the edge cell 121 can facilitate electrical connection between the cells 111 and between the cell 111 and the bus bar 100. However, for the solder ribbon 102, offset generally occurs between the edgemost solder point 231 and the bus bar 100. Therefore, the second insulating structure 211 is provided on the side of the solder point group 221 that is closest to the bus bar 100, that is, at the offset portion of the solder ribbon 102. This prevents the solder ribbon 102 from being electrically connected to both the first auxiliary grid 171 and the second auxiliary grid 191 at the same time, thereby improving the reliability of the photovoltaic module.

[0066] In some embodiments, the length of the second insulating structure 211 in the second direction Y gradually increases as the cell string 101 approaches the busbar 100. It is understood that the busbar 100 and cell string 101 are typically spaced apart, and the portion of the cell string 101 near the busbar 100, i.e., the middle portion of the welding ribbon 102, is often the most severely deflected or deformed portion of the welding ribbon 102, making it most susceptible to simultaneous electrical connection between the welding ribbon 102 and the first and second auxiliary grids 171 and 191. Therefore, gradually increasing the length of the second insulating structure 211 in the second direction Y can maximize the portion near the edge of the cell string 101. The longer the second insulating structure 211, the stronger the isolation effect provided by the second insulating structure 211. Therefore, by gradually increasing the length of the second insulating structure 211 in the second direction Y as the cell string 101 approaches the busbar 100, the reliability of the photovoltaic module can be further improved.

[0067] In some embodiments, in the first direction X, the thickness of the portion of the second insulating structure 211 near the first insulating structure 201 is thinner than the thickness of the portion of the second insulating structure 211 away from the first insulating structure 201. It is understandable that, as the welding ribbon 102 is squeezed, the thickness of the portion of the welding ribbon 102 closer to the edge of the welding ribbon 102 in the first direction X becomes thinner. That is, in the first direction X, the thickness of the welding ribbon 102 near the first busbar 161 is thicker, and the thickness of the welding ribbon 102 near the second busbar 181 is thinner. Therefore, the thickness of the portion of the second insulating structure 211 near the first insulating structure 201 is thinner, and the thickness of the portion of the second insulating structure 211 away from the first insulating structure 201 is thicker. The second insulating structure 211 compensates for the thickness of the welding ribbon 102, thereby making the top surface of the welding ribbon 102 relatively flat, and the surface of the entire photovoltaic module relatively flat. This can improve the reliability of the photovoltaic module on the one hand, and the aesthetics of the photovoltaic module on the other hand.

[0068] In some embodiments, the cell string 101 further includes a central cell 241 away from the busbar 100, and the second insulating structure 211 is further located in the edge region 151 of the edge cells 121 near the central cell 241. In other words, the second insulating structure 211 is provided in the edge regions 151 on both sides of the central region 141. Thus, even if the edge cell 121 is incorrectly installed and rotated 180° during the process of connecting the cells 111 in series to form the cell string 101, the second insulating structure 211 still isolates the solder ribbon 102 from the second auxiliary grid 191, thereby further improving the reliability of the photovoltaic module.

[0069] In some embodiments, the central cell 241 may also include an edge region and a central region, and the second insulating structure 211 may also be provided in the edge region of the central cell 241. The corresponding description of the second insulating structure 211 provided in the central cell may refer to the description of the edge cell 121. Since the description of the second insulating structure 211 is similar to that of the edge cell 121, it will not be repeated here.

[0070] Combined with reference Figure 3 、 Figure 5 and Figure 6 ,in Figure 5 Another partial structural top view of a photovoltaic module provided in an embodiment of the present disclosure is shown. Figure 6 A cross-sectional view of the second insulating structure provided in the embodiment of the present disclosure. It should be noted that, Figure 5 Only the second insulating structure and Figure 3 The different, same or corresponding parts can be referred to Figure 3 Corresponding content.

[0071] In some embodiments, the second insulating structure 211 also covers the entire surface of the edge region 151. That is, the second insulating structure 211 covers not only the second auxiliary grid 191 but also a portion of the substrate 131, a portion of the first main grid 161, a portion of the first auxiliary grid 171, and a portion of the second main grid 181, thereby enhancing the aesthetics of the entire photovoltaic module.

[0072] In some embodiments, the second insulating structure 211 includes: an insulating layer 251, which covers the surface of the edge region 151; and a reflective layer 261, which covers the surface of the insulating layer 251. The insulating layer 251 is used to insulate the solder ribbon 102 from the second sub-grid 191, and the reflective layer 261 is used to reflect light to the surface of the substrate 131, thereby increasing light utilization.

[0073] In some embodiments, the insulating layer 251 may be made of polyolefin (eg, polypropylene, polyethylene, etc.), and the reflective layer 261 may be made of aluminum.

[0074] In some embodiments, the encapsulation film 103 includes a first encapsulation layer (not shown) and a second encapsulation layer (not shown), the first encapsulation layer covers one of the front side or the back side of the battery cell, and the second encapsulation layer covers the other of the front side or the back side of the battery cell. Specifically, at least one of the first encapsulation layer or the second encapsulation layer can be an organic encapsulation film such as polyvinyl butyral (PVB) film, ethylene-vinyl acetate copolymer (EVA) film, polyethylene octene co-elastomer (POE) film or polyethylene terephthalate (PET) film.

[0075] It can be understood that the first encapsulation layer and the second encapsulation layer have a dividing line before the lamination process. After the lamination process, there will no longer be the concept of the first encapsulation layer and the second encapsulation layer in the formed photovoltaic module, that is, the first encapsulation layer and the second encapsulation layer have formed an integral encapsulation film 103.

[0076] In some embodiments, cover plate 104 may be a light-transmitting cover plate such as a glass cover plate or a plastic cover plate. Specifically, the surface of cover plate 104 facing encapsulation film 103 may have a concave-convex surface to increase the utilization of incident light. Cover plate 104 includes a first cover plate and a second cover plate. The first cover plate is opposite the first encapsulation layer, and the second cover plate is opposite the second encapsulation layer.

[0077] In the embodiment of the present disclosure, the busbar 100 is used to collect and output the current on the battery string 101, and the welding ribbon 102 is a structure that electrically connects the busbar 100 and the battery string 101. However, during the lamination process, that is, when assembling the packaging film 103 and the cover plate 104, the welding ribbon 102 is easily crushed, causing the welding ribbon 102 to short-circuit the battery cell 111. Therefore, this solution provides a first insulating structure 201 and a second insulating structure 211 in the edge area 151 of the battery cell 121 near the edge of the busbar 100. By providing the first insulating structure 201 and the second insulating structure 211, the insulation area of ​​the surface of the second auxiliary grid 191 is increased. Therefore, even if the welding ribbon 102 is crushed, the welding ribbon 102 will not be electrically connected to the first auxiliary grid 171 and the second auxiliary grid 191 at the same time, thereby avoiding the occurrence of a short circuit between the first auxiliary grid 171 and the second auxiliary grid 191, thereby improving the reliability of the photovoltaic module.

[0078] Those skilled in the art will appreciate that the above-described embodiments are specific examples for implementing the present disclosure, and in actual applications, various changes may be made to them in form and detail without departing from the spirit and scope of the embodiments of the present disclosure. Any person skilled in the art may make various changes and modifications without departing from the spirit and scope of the embodiments of the present disclosure. Therefore, the scope of protection of the embodiments of the present disclosure shall be based on the scope defined in the claims.

Claims

1. A photovoltaic module, characterized in that: include: a bus bar extending along a first direction; a battery string, the battery string being electrically connected to the bus bar, the battery string comprising a plurality of battery cells arranged along a second direction and electrically connected in sequence, the plurality of battery cells including edge battery cells adjacent to the bus bar, the edge battery cells comprising: a substrate comprising a central region and edge regions located on opposite sides of the central region along the second direction; a first main grid located on a surface of the substrate and extending along the second direction; a first auxiliary grid electrically connected to the first main grid and extending along the first direction; a second main grid located on a surface of the substrate and spaced apart from the first main grid along the first direction; a second auxiliary grid electrically connected to the second main grid, extending along the first direction, and spaced apart from the first auxiliary grid along the second direction; a first insulating structure covering a surface of the second auxiliary grid; and a second insulating structure located in the edge region of the substrate adjacent to the bus bar and covering at least a surface of the second auxiliary grid not covered by the first insulating structure; a welding ribbon, the welding ribbon being used to electrically connect the battery string and the bus bar; A packaging film, the packaging film is used to cover the surface of the battery string, the welding ribbon and the bus bar; A cover plate is used to cover the surface of the packaging film away from the battery string.

2. The photovoltaic module according to claim 1, characterized in that In the first direction, the length of the first insulating structure in contact with the second auxiliary gate is a first length, the length of the second insulating structure in contact with the second auxiliary gate is a second length, and the ratio of the second length to the first length is greater than or equal to 50%.

3. The photovoltaic module according to claim 1 or 2, characterized in that: In the second direction, a ratio of a width of the second insulating structure to a width of the second auxiliary gate is greater than or equal to 1.

2.

4. The photovoltaic module according to claim 1, characterized in that The edge battery cell includes: a welding point group connected to the welding strip, the welding point group includes a plurality of welding points arranged along the second direction, the welding strip is connected to the welding point at the edgemost edge along the second direction, and the second insulating structure is located on the side of the welding point group close to the bus bar.

5. The photovoltaic module according to claim 1, characterized in that The first insulating structure and the second insulating structure are an integrated structure.

6. The photovoltaic module according to claim 1, characterized in that In a direction from the battery string toward the bus bar, a length of the second insulating structure in the second direction gradually increases.

7. The photovoltaic module according to claim 1 or 6, characterized in that: In the first direction, a thickness of a portion of the second insulating structure close to the first insulating structure is smaller than a thickness of a portion of the second insulating structure far from the first insulating structure.

8. The photovoltaic module according to claim 1, characterized in that The second insulating structure also covers the entire surface of the edge region.

9. The photovoltaic module according to claim 8, characterized in that: The second insulating structure includes: an insulating layer covering a surface of the edge region; A reflective layer covers the surface of the insulating layer.

10. The photovoltaic module according to claim 1, characterized in that: The battery string further includes a central battery cell away from the bus bar, and the second insulation structure is further located in the edge region of the edge battery cells close to the central battery cell.

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