Photovoltaic module

Abstract

The invention provides a photovoltaic module. The assembly comprises a plurality of battery strings, each battery string at least comprises a first battery piece and a second battery piece, the first battery piece and the second battery piece are provided with front faces and back faces, the front faces and / or the back faces are provided with grooves, the grooves extend in the first direction, the first battery piece and the second battery piece comprise a plurality of fine grids, and the fine grids are distributed on the front faces and the back faces at intervals. The fine grids extend along a second direction, and the second direction is perpendicular to the first direction; at least part of the welding strips are located in the grooves, and the welding strips are connected with the front face of the first battery piece and the back face of the second battery piece; by optimizing the connection mode between the battery pieces, better assembly welding performance is obtained, the stress between the battery pieces and the welding strip is reduced, the stability and the power generation efficiency of the assembly are improved, and the overall performance of the photovoltaic assembly is further improved.

Description

Technical Field

[0001] The present application relates to the field of photovoltaic manufacturing technology, and in particular, to a photovoltaic module. Background Art

[0002] As the battery size in the industry gradually increases, the size of the component end is unified. The current mainstream chip spacing of 182 modules is 1.5mm, and the mainstream chip spacing of 210 is 0.8mm. During welding, due to a certain deviation in the placement of the chips, the minimum chip spacing may reach 0.5mm. The smaller the chip spacing, the greater the angle between the welding ribbon and the battery, the higher the height of the welding ribbon bending during lamination, and the stress of the welding ribbon on the edge of the battery at the interconnection increases, resulting in lamination breakage, which in turn causes component degradation.

[0003] Several existing technologies and products for photovoltaic modules currently have their shortcomings. Photovoltaic modules are components that use the photovoltaic effect to generate electricity. They are usually composed of cells, films, glass, and cover plates. Cells are an important component of the main components. The welding performance of cells at the module end directly affects the power generation performance and power of the module. Since the current module cell spacing is small, generally less than 1.5mm, there is a certain deviation in the placement position during welding, and the minimum cell spacing may reach 0.5mm. Summary of the invention

[0004] The present application provides a photovoltaic module to solve the problem in the related art that the spacing between the cells is small, resulting in an increase in the height of the bending of the welding strip and the breakage of the cells during lamination.

[0005] According to one aspect of the present application, a photovoltaic module is provided, comprising: a plurality of battery strings, each of the battery strings comprising at least a first battery cell and a second battery cell, the first battery cell and the second battery cell having a front side and a back side, a groove being provided on the front side and / or the back side, the groove extending along a first direction, the first battery cell and the second battery cell comprising a plurality of fine grids, the fine grids being spaced apart on the front side and the back side, the fine grids extending along a second direction, the second direction being perpendicular to the first direction; a plurality of welding strips, at least some of the welding strips being located in the grooves, the welding strips connecting the front side of the first battery cell and the back side of the second battery cell.

[0006] Optionally, the front side and the back side are both provided with a plurality of grooves distributed at intervals.

[0007] Optionally, the first battery cell and the second battery cell further include a plurality of main grids, at least some of the main grids are located in the grooves in a one-to-one correspondence, and the welding strip is located on a side of the main grid away from the groove.

[0008] Optionally, the first cell and / or the second cell includes multiple sub-cells, and the welding ribbon also connects the main grids of multiple sub-cells in the first cell and / or the welding ribbon also connects the main grids of multiple sub-cells in the second cell.

[0009] Optionally, the photovoltaic assembly further includes a buffer structure, and the buffer structure is located between the groove wall of the groove and the welding strip.

[0010] Optionally, the buffer structure is located in edge regions of the first battery cell and the second battery cell, and the edge regions are located at two ends of the groove in the length direction.

[0011] Optionally, the minimum distance between the edge area and two ends of the groove is 1 mm to 3 mm.

[0012] Optionally, the maximum width of the buffer structure in the first direction is 0.3 mm to 1.5 mm, the maximum width in the second direction is 1 mm to 5 mm, and the thickness of the buffer structure is 0.05 mm to 0.3 mm.

[0013] Optionally, the buffer structure comprises an adhesive material.

[0014] Optionally, the maximum depth of the groove is 5 μm to 10 μm, and the width of the groove is 0.20 mm to 0.30 mm.

[0015] Through the technical solution of the present application, a photovoltaic module is provided, which includes: multiple battery strings and multiple welding strips, wherein each battery string includes at least a first battery cell and a second battery cell, a groove is provided on the front and / or back of the first battery cell and the second battery cell, the extension direction of the groove is perpendicular to the extension direction of the fine grid of the battery cell, at least part of the multiple welding strips are located in the groove, the welding strip connects the front of the first battery cell and the back of the second battery cell, and by providing the groove on the front and / or back of the above-mentioned battery cell and arranging the welding strip in the groove, the minimum thickness of the battery cell becomes smaller, so that when the welding strip connects the front and back of multiple battery cells, the bending angle of the welding strip is smaller and more gentle, thereby reducing the stress between the battery cell and the welding strip, making the connection between the battery cell and the welding strip more stable and reliable. The problem of small spacing between battery cells in the related art, resulting in increased bending height of the welding strip and broken battery cells during lamination is solved. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The drawings constituting a part of the present application are used to provide a further understanding of the present application. The illustrative embodiments and descriptions of the present application are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0017] Figure 1is a schematic diagram of battery interconnection provided according to an embodiment of the present application;

[0018] Figure 2 is a schematic diagram of a cross-sectional structure of a photovoltaic module provided according to an embodiment of the present application;

[0019] Figure 3 A partial enlarged schematic diagram of the interconnection side of a photovoltaic module provided according to an embodiment of the present application;

[0020] Figure 4 is a schematic diagram of a three-dimensional structure of a photovoltaic module provided according to an embodiment of the present application;

[0021] Figure 5 It is a schematic diagram of the cross-sectional structure of another photovoltaic module provided according to an embodiment of the present application.

[0022] The above drawings include the following reference numerals:

[0023] 1. Battery string; 111. First battery cell; 112. Second battery cell; 2. Welding strip; 3. Groove; 4. Fine grid; 5. Buffer structure. DETAILED DESCRIPTION

[0024] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0025] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present application.

[0026] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so as to describe the embodiments of the present application described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0027] In related technologies, as the size of batteries in the industry gradually increases, the size of the component end is unified. The current mainstream chip spacing of 182 components is 1.5mm, and the mainstream chip spacing of 210 is 0.8mm. During welding, due to a certain deviation in the placement of the chips, the minimum chip spacing may reach 0.5mm. The smaller the chip spacing, the greater the angle between the welding ribbon and the battery, the higher the height of the welding ribbon bending during lamination, and the stress of the welding ribbon on the edge of the battery at the interconnection increases, resulting in lamination breakage, which in turn causes component degradation.

[0028] Several existing technologies and products currently have their shortcomings. Photovoltaic modules are components that use the photovoltaic effect to generate electricity. They are usually composed of cells, films, glass, and cover plates. Cells are an important component of the main components. The welding performance of cells at the component end directly affects the power generation performance and power of the component. Since the current component cell spacing is small, generally less than 1.5mm, there is a certain deviation in the placement position during welding, and the minimum cell spacing may reach 0.5mm.

[0029] Therefore, in view of the above problems, a photovoltaic module is provided in the embodiment of the present application, such as Figure 1 to Figure 2 As shown, it includes: a plurality of battery strings 1, each battery string 1 includes at least a first battery cell 111 and a second battery cell 112, the first battery cell 111 and the second battery cell 112 have a front side and a back side, a groove 3 is provided on the front side and / or the back side, the groove 3 extends along a first direction, the first battery cell 111 and the second battery cell 112 include a plurality of fine grids 4, the fine grids 4 are spaced apart on the front side and the back side, the fine grids 4 extend along a second direction, and the second direction is perpendicular to the first direction; a plurality of welding strips 2, at least part of the welding strips 2 are located in the grooves 3, and the welding strips 2 connect the front side of the first battery cell 111 and the back side of the second battery cell 112.

[0030] By providing grooves on the front and / or back of the above-mentioned battery cell and arranging welding strips in the grooves, the minimum thickness of the battery cell becomes smaller, so that when the welding strips are used to connect the front and back of multiple battery cells, the bending angle of the welding strips is smaller and more gentle, thereby reducing the stress between the battery cell and the welding strips, making the connection between the battery cell and the welding strips more stable and reliable, so as to obtain better component welding performance, improve the stability and power generation efficiency of the component, and thus improve the overall performance of the photovoltaic component. The problem of small spacing between battery cells in the related art, which leads to increased bending height of the welding strips and battery cell breakage during lamination is solved.

[0031] In the above optional implementation, if Figure 1 As shown, the photovoltaic module includes a plurality of battery strings 1 and a plurality of welding strips 2, wherein the plurality of battery strings 1 include a first battery cell 111 and a second battery cell 112, that is, the battery string 1 includes at least the first battery cell 111 and the second battery cell 112. Figure 2As shown, the welding strip 2 and the groove 3 are distributed on the surface of the battery along the first direction, and the welding strip 2 can be partially located in the groove 3 or completely located in the groove 3. When the welding strip 2 is completely located in the groove 3, the bending height of the welding strip 2 when connecting adjacent battery cells is the smallest, which can better reduce the stress between the battery cell and the welding strip. Thus, the voltage and power output of the photovoltaic module are improved, the groove 3 can increase the light absorption area and improve the conversion efficiency of the photovoltaic module, and the fine grid 4 can reduce the recombination loss of the charge and improve the current output of the photovoltaic module.

[0032] In the above optional embodiment, the first cell and the second cell are usually made of silicon material, among which the most common types are monocrystalline silicon, polycrystalline silicon and amorphous silicon. The conversion and utilization of solar energy is achieved by converting light energy into electrical energy. Under lighting conditions, light energy will excite the electrons inside the cell to generate current, thereby generating electrical energy. It is the most core component in the photovoltaic module and the key to achieving solar energy conversion.

[0033] In the above optional embodiment, the welding ribbon is usually a strip material made of aluminum or copper, which connects the battery cells with brackets, cables and other components to form the circuit of the photovoltaic module. It has good conductivity and corrosion resistance, and can ensure that the electrical connection of the photovoltaic module is stable and reliable. At the same time, it can also withstand certain mechanical loads to ensure the stability and safety of the photovoltaic module during use. The material selection and processing quality of the welding ribbon have a great influence on the performance and life of the photovoltaic module. Therefore, special attention needs to be paid to the quality control of the welding ribbon.

[0034] In the above optional embodiment, the fine grid is usually made of metal wire or semiconductor material and is arranged on the surface of the solar cell. The fine grid and the main grid or welding strip form a grid structure, which can help the transmission of photons inside the solar cell and guide the photons to the photoelectric conversion layer, thereby improving the photoelectric conversion efficiency. In addition, the fine grid can also reduce reflection and scattering, increase the absorption rate of light, and enable the solar panel to effectively generate electricity even in a weak light environment.

[0035] In some optional embodiments, such as Figure 2 and Figure 3 As shown, the front and back surfaces are both provided with a plurality of grooves 3 distributed at intervals.

[0036] In the above optional implementation, if Figure 2 and Figure 3As shown, when multiple battery cells are connected in parallel using welding ribbons 2, the welding ribbons 2 may melt when heated and may come into contact with the welding ribbons 2 on the back of the battery, thereby causing a short circuit between the battery cells. When grooves 3 are provided on both the front and back sides of the battery cell, the positions of the grooves 3 on the front and back sides may be staggered; the positions of the grooves 3 on the front and back sides may also be provided in a one-to-one correspondence. This arrangement may minimize the distance between the welding ribbon 2 located in the front groove 3 and the welding ribbon 2 located in the back groove 3, thereby minimizing the bending degree of the welding ribbon when connecting different battery cells.

[0037] In some optional embodiments, the first battery cell and the second battery cell further include a plurality of main grids, at least some of the main grids are located in the grooves in a one-to-one correspondence, and the welding strip is located on a side of the main grid away from the groove.

[0038] In the above optional embodiment, the battery cell of the photovoltaic module with a main grid is provided with the above main grid in the groove, and then the main grids of multiple battery cells are electrically connected by a welding strip. The above main grid is usually composed of a conductive silver wire or aluminum wire. The main grid can converge the current of multiple fine grids to form a current path between the battery cells. The design and arrangement of the main grid have an important influence on the performance and efficiency of the photovoltaic module, and can affect the output power and stability of the photovoltaic module.

[0039] like Figure 2 and Figure 3 As shown, a groove 3 is provided at the main grid position of the front and back sides of the battery cell in the battery string 1. During welding, the welding strip 2 is partially inserted into the groove 3. Through this welding method, the relative height between the batteries is reduced, and the angle between the welding strip 2 on the front side of the previous piece and the welding strip 2 on the back side of the next piece can be increased, that is, the welding strip 2 becomes flatter, reducing the stress of the welding strip 2 on the battery and reducing hidden cracks in the battery.

[0040] It should be noted that the above-mentioned battery cell can have or without a main grid. In the case of no main grid, the welding strip replaces the main grid to gather the current in multiple fine grids, wherein the extension direction of the groove is limited to a first direction, which is perpendicular to the extension direction of the fine grid in a second direction, and the main grid is parallel to the welding strip.

[0041] In some optional embodiments, the first battery cell and / or the second battery cell includes multiple sub-batteries, and the welding ribbon is also connected to the main grid of the multiple sub-batteries in the first battery cell and / or the welding ribbon is also connected to the main grid of the multiple sub-batteries in the second battery cell.

[0042] In the above optional embodiment, the above-mentioned first battery cell and / or the second battery cell can also be a small battery string, which divides the above-mentioned first battery cell and / or the second battery cell into multiple sub-battery cells and connects the main grids of these sub-battery cells with welding ribbons, so as to improve the electrical connection between the battery cells, ensure that the current can effectively flow between the various sub-battery cells, thereby improving the overall efficiency and performance of the photovoltaic module. The welding ribbon directly affects the quality of the electrical connection between the battery cells. If the welding ribbon is not firmly connected or there is poor contact, it may cause current transmission to be obstructed. The above-mentioned welding ribbon is precisely designed to effectively connect the main grids of each sub-battery cell, ensuring that the welding ribbon plays a good role in the photovoltaic module.

[0043] In some optional embodiments, such as Figure 1 and Figure 4 As shown, the photovoltaic assembly further includes a buffer structure 5 , and the buffer structure 5 is located between the groove wall of the groove and the welding strip 2 .

[0044] In the above optional implementation, if Figure 4 As shown, a buffer structure 5 is provided at the battery interconnection, i.e., near the edge of the battery cell. The order of laying the buffer structure 5 and the welding tape 2 can be: the buffer structure 5 is pre-set on the battery cell interconnection side, and the welding tape 2 is laid for welding after the buffer structure 5 is set. Due to the buffer structure 5, the stress between the welding tape 2 and the battery is buffered, and the risk of hidden cracks in the battery due to excessive stress between the welding tape 2 and the battery cell is reduced. By further providing the buffer structure 5 in the above-mentioned groove, the hidden crack rate of the photovoltaic module in the production process is further reduced, thereby improving the module yield.

[0045] like Figure 3 and Figure 4 As shown, the above-mentioned welding strip 2 is located on the front and / or back side of the battery string 1, and the part located at the edge of the battery can be directly placed on the buffer structure 5, and the buffer structure 5 is elastic when heated, and can wrap the welding strip 2 to disperse the stress acting on the welding strip 2.

[0046] It should be noted that the buffer structure may be an adhesive film, the material of the adhesive film may be one of a light-curing adhesive and a thermosetting adhesive, and the thickness of the buffer structure may be 0.01 mm to 0.3 mm.

[0047] In some optional embodiments, such as Figure 4 As shown, the buffer structure 5 is located in the edge regions of the first battery cell and the second battery cell, and the edge regions are located at both ends of the groove in the length direction.

[0048] In the above optional implementation, if Figure 4As shown, the above-mentioned buffer structure 5 is located at the edge of the photovoltaic module, and is used to protect the edge of the module from the influence of the external environment. It also plays a role in reducing the stress on the edge of the module and increasing the strength and stability of the module. It is usually made of silicone or other elastic materials, and has good weather resistance and heat resistance. It can resist the erosion of the external environment such as ultraviolet rays, high temperature, humidity, etc. to the module. In addition, the edge buffer structure 5 can also absorb and disperse the pressure on the edge of the module, reducing the risk of module damage caused by external force.

[0049] In some optional embodiments, the minimum distance between the edge area and both ends of the groove is 1 mm to 3 mm.

[0050] In the above optional embodiment, the buffer structure is located 1 to 3 mm away from the edge of the battery. By maintaining the minimum distance between the edge area and the groove, it can be ensured that the photovoltaic module will not be cracked or damaged due to stress concentration during use, thereby improving the stability and reliability of the module.

[0051] In some optional embodiments, the maximum width of the buffer structure in the first direction is 0.3 mm to 1.5 mm, the maximum width in the second direction is 1 mm to 5 mm, and the thickness of the buffer structure is 0.05 mm to 0.3 mm.

[0052] In the above optional embodiment, the length of the buffer structure is in the range of 1 to 5 mm, and the width is in the range of 0.3 to 1.5 mm, so that the buffer structure has a smaller size and a smaller thickness, ensuring the overall lightweight of the photovoltaic module while providing sufficient support and stability to the welding strip.

[0053] In some optional embodiments, the buffer structure includes an adhesive material.

[0054] In the above optional embodiment, the above buffer structure may include adhesive materials such as silicone, polyurethane glue, photocurable glue and acrylic glue, which have good bonding properties and weather resistance, can effectively fix and seal the edges of the photovoltaic modules, prevent the intrusion of water vapor and dust, and improve the stability and durability of the photovoltaic modules.

[0055] In some optional embodiments, the buffer structure further includes elastic material.

[0056] In the above optional embodiment, the above buffer structure may also include elastic materials such as rubber, silicone and foam plastic, which have good elasticity and wear resistance, provide buffering and protection, and can effectively reduce the impact of external shocks on photovoltaic modules and extend their service life.

[0057] In some optional embodiments, such as Figure 5As shown, the maximum depth d of the groove is 5 μm to 10 μm, and the width D of the groove is 0.20 mm to 0.30 mm.

[0058] In the above optional implementation, if Figure 5 As shown, the depth of the groove is d, the dimension d should meet the requirement of 5-10 μm, and the width is D, the dimension D should meet the requirement of 0.20-0.30 mm.

[0059] The photovoltaic module obtained by the above-mentioned battery interconnection method adopts the technology of setting a buffer structure at the interconnection of the battery cells. The above-mentioned buffer structure is composed of photocurable adhesive, thermosetting adhesive or adhesive film. The position and size of the above-mentioned buffer structure are precisely controlled, which effectively reduces the stress between the welding strip and the battery, reduces the hidden cracks of the battery, and improves the module yield. At the same time, grooves are set at the main grid positions on the front and back sides of the battery cell, and the welding strip is partially inserted into the grooves, which reduces the relative height between the batteries and the stress of the welding strip on the battery, further reducing the hidden crack rate, so that the stability and reliability of the photovoltaic module in the production process are improved, the module has better welding performance, reduces production costs, and improves the overall performance and power generation efficiency of the module.

[0060] The technical solution of the present application can be used for passivated emitter rear contact cells (PERC), tunnel oxide passivated contact cells (TOPCON), heterojunction cells (HJT), back contact cells (BC), perovskite cells (PSC), etc. with busbar-free technology (0BB, Zero Busbar) or multi-busbar technology (MBB, MULTI-BUSBAR).

[0061] The above photovoltaic module of the present application will be described in detail below in combination with specific embodiments and comparative examples.

[0062] Example 1

[0063] This embodiment provides a photovoltaic assembly, including:

[0064] The first battery cell and the second battery cell, the front surface is provided with a groove, the groove extends along the first direction, the first battery cell and the second battery cell include a plurality of fine grids, the fine grids are spaced and distributed on the front surface and the back surface, the fine grids extend along the second direction, the second direction is perpendicular to the first direction, the spacing between the groove and the edge area of ​​the first battery cell and the second battery cell is 1mm, the depth of the groove is 5μm, and the width is 0.2mm;

[0065] A plurality of welding strips, part of which is located in the groove, and the welding strips connect the front side of the first battery cell and the back side of the second battery cell.

[0066] Example 2

[0067] This embodiment provides a photovoltaic assembly, including:

[0068] The first battery cell and the second battery cell, the front surface is provided with a groove, the groove extends along the first direction, the first battery cell and the second battery cell include a plurality of fine grids, the fine grids are spaced and distributed on the front surface and the back surface, the fine grids extend along the second direction, the second direction is perpendicular to the first direction, the spacing between the groove and the edge area of ​​the first battery cell and the second battery cell is 1mm, the depth of the groove is 8μm, and the width is 0.2mm;

[0069] A plurality of welding strips, part of which is located in the groove, and the welding strips connect the front side of the first battery cell and the back side of the second battery cell.

[0070] Example 3

[0071] This embodiment provides a photovoltaic assembly, including:

[0072] The first battery cell and the second battery cell, the front surface is provided with a groove, the groove extends along the first direction, the first battery cell and the second battery cell include a plurality of fine grids, the fine grids are spaced and distributed on the front surface and the back surface, the fine grids extend along the second direction, the second direction is perpendicular to the first direction, the spacing between the groove and the edge area of ​​the first battery cell and the second battery cell is 1mm, the depth of the groove is 10μm, and the width is 0.2mm;

[0073] A plurality of welding strips, part of which is located in the groove, and the welding strips connect the front side of the first battery cell and the back side of the second battery cell.

[0074] Example 4

[0075] This embodiment provides a photovoltaic assembly, including:

[0076] The first battery cell and the second battery cell, the front surface is provided with a groove, the groove extends along the first direction, the first battery cell and the second battery cell include a plurality of fine grids, the fine grids are spaced and distributed on the front surface and the back surface, the fine grids extend along the second direction, the second direction is perpendicular to the first direction, the spacing between the groove and the edge area of ​​the first battery cell and the second battery cell is 1mm, the depth of the groove is 5μm, and the width is 0.25mm;

[0077] A plurality of welding strips, part of which is located in the groove, and the welding strips connect the front side of the first battery cell and the back side of the second battery cell.

[0078] Example 5

[0079] This embodiment provides a photovoltaic assembly, including:

[0080] The first battery cell and the second battery cell, the front surface is provided with a groove, the groove extends along the first direction, the first battery cell and the second battery cell include a plurality of fine grids, the fine grids are spaced and distributed on the front surface and the back surface, the fine grids extend along the second direction, the second direction is perpendicular to the first direction, the spacing between the groove and the edge area of ​​the first battery cell and the second battery cell is 1mm, the depth of the groove is 5μm, and the width is 0.3mm;

[0081] A plurality of welding strips, part of which is located in the groove, and the welding strips connect the front side of the first battery cell and the back side of the second battery cell.

[0082] Example 6

[0083] This embodiment provides a photovoltaic assembly, including:

[0084] The first battery cell and the second battery cell, the front surface is provided with a groove, the groove extends along the first direction, the first battery cell and the second battery cell include a plurality of fine grids, the fine grids are spaced and distributed on the front surface and the back surface, the fine grids extend along the second direction, the second direction is perpendicular to the first direction, the spacing between the groove and the edge area of ​​the first battery cell and the second battery cell is 1mm, the depth of the groove is 5μm, and the width is 0.3mm;

[0085] A plurality of welding strips, part of which is located in the groove, and the welding strips connect the front surface of the first battery cell and the back surface of the second battery cell;

[0086] The buffer structure is located in the edge area of ​​the first battery cell and the second battery cell, and is located at both ends of the above-mentioned groove in the extension direction. The width of the buffer structure in the above-mentioned first direction is 1 mm, the width in the above-mentioned second direction is 3 mm, the thickness of the above-mentioned buffer structure is 0.2 mm, and the material of the buffer structure is thermosetting adhesive.

[0087] Example 7

[0088] This embodiment provides a photovoltaic assembly, including:

[0089] The first battery cell and the second battery cell, the front surface is provided with a groove, the groove extends along the first direction, the first battery cell and the second battery cell include a plurality of fine grids, the fine grids are spaced and distributed on the front surface and the back surface, the fine grids extend along the second direction, the second direction is perpendicular to the first direction, the spacing between the groove and the edge area of ​​the first battery cell and the second battery cell is 1mm, the depth of the groove is 2μm, and the width is 0.1mm;

[0090] A plurality of welding strips, part of which is located in the groove, and the welding strips connect the front side of the first battery cell and the back side of the second battery cell.

[0091] Example 8

[0092] This embodiment provides a photovoltaic assembly, including:

[0093] The first battery cell and the second battery cell, the front surface is provided with a groove, the groove extends along the first direction, the first battery cell and the second battery cell include a plurality of fine grids, the fine grids are spaced and distributed on the front surface and the back surface, the fine grids extend along the second direction, the second direction is perpendicular to the first direction, the spacing between the groove and the edge area of ​​the first battery cell and the second battery cell is 1mm, the depth of the groove is 5μm, and the width is 0.3mm;

[0094] A plurality of welding strips, part of which is located in the groove, and the welding strips connect the front side of the first battery cell and the back side of the second battery cell.

[0095] Example 9

[0096] A photovoltaic module is provided, comprising:

[0097] a first battery cell and a second battery cell;

[0098] A plurality of welding strips, part of which is located in the groove, and the welding strips connect the front surface of the first battery cell and the back surface of the second battery cell;

[0099] The buffer structure is located in the edge area of ​​the first battery cell and the second battery cell, and is located at both ends of the above-mentioned groove in the extension direction. The width of the buffer structure in the above-mentioned first direction is 0.3mm, the width in the above-mentioned second direction is 1mm, the thickness of the above-mentioned buffer structure is 0.05mm, and the material of the buffer structure is thermosetting adhesive.

[0100] Comparative Example 1

[0101] This embodiment provides a photovoltaic assembly, including:

[0102] A first battery cell and a second battery cell, wherein the first battery cell and the second battery cell include a plurality of fine grids, and the fine grids are distributed at intervals on the front surface and the back surface;

[0103] A plurality of welding strips are provided, wherein the welding strips are connected to the front surface of the first battery cell and the back surface of the second battery cell.

[0104] The performance of the photovoltaic modules in the above-mentioned Examples 1 to 9 and Comparative Example 1 was tested, and the test results are as follows:

[0105] Table 1

[0106] Hidden crack rate% Example 1 5％ Example 2 3.8％ Example 3 3.2％ Example 4 4％ Example 5 3.6％ Example 6 3.5％ Example 7 5.7％ Example 8 4.0％ Example 9 3.9％ Comparative Example 1 10.0％

[0107] From the experimental data in the above table, it can be seen that the hidden crack rate in Examples 1 to 6 is significantly higher than that in Examples 7 to 9, indicating that the limitation of the groove depth and width in the present application can significantly improve the hidden crack rate of the battery; the hidden crack rate in Examples 1 to 9 is significantly higher than that in Comparative Example 1, indicating that the technical solution of designing grooves on the battery cell in the present application can significantly improve the influence of the stress generated by the interconnection between batteries in the prior art on the battery cell. From the above experimental data, it can be seen that the hidden crack rate of the battery cell of the photovoltaic module in the present application is low, thereby ensuring the integrity of the battery cell structure and improving the performance of the photovoltaic module.

[0108] From the above description, it can be seen that the above embodiments of the present application achieve the following technical effects:

[0109] 1) The photovoltaic module of the embodiment of the present application is provided with grooves on the front and / or back of the cell, and welding strips are arranged in the grooves, so that the minimum thickness of the cell becomes smaller, so that when the welding strips are used to connect the front and back of multiple cells, the bending angle of the welding strips is smaller and more gentle, thereby reducing the stress between the cell and the welding strips, making the connection between the cell and the welding strips more stable and reliable. The problem of small spacing between cells in the related art, which leads to an increase in the bending height of the welding strips and the breakage of the cell during lamination, is solved.

[0110] 2) The photovoltaic module of the embodiment of the present application is provided with buffer structures at both ends of the groove extension direction, which can further disperse the stress acting on the welding strip and the edge of the battery cell and reduce the risk of hidden cracks in the battery cell.

[0111] It should also be noted that the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, commodity or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, commodity or device. In the absence of more restrictions, the elements defined by the sentence "comprises a ..." do not exclude the existence of other identical elements in the process, method, commodity or device including the elements.

[0112] The above are only embodiments of the present application and are not intended to limit the present application. For those skilled in the art, the present application may have various changes and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included within the scope of the claims of the present application.

Claims

1. A photovoltaic module, characterized in that: include: A plurality of battery strings, each of the battery strings at least comprising a first battery cell and a second battery cell, the first battery cell and the second battery cell having a front side and a back side, the front side and / or the back side being provided with a groove, the groove extending along a first direction, the first battery cell and the second battery cell comprising a plurality of fine grids, the fine grids being spaced apart and distributed on the front side and the back side, the fine grids extending along a second direction, the second direction being perpendicular to the first direction; A plurality of welding strips, at least part of which is located in the groove, and the welding strips connect the front side of the first battery cell and the back side of the second battery cell.

2. The photovoltaic module according to claim 1, characterized in that: The front side and the back side are both provided with a plurality of grooves distributed at intervals.

3. The photovoltaic module according to claim 1, characterized in that: The first battery cell and the second battery cell further include a plurality of main grids, at least some of which are located in the grooves in a one-to-one correspondence, and the welding strip is located on a side of the main grid away from the groove.

4. The photovoltaic module according to claim 1, characterized in that: The first cell and / or the second cell includes a plurality of sub-cells, and the welding ribbon further connects the main grids of the plurality of sub-cells in the first cell and / or the welding ribbon further connects the main grids of the plurality of sub-cells in the second cell.

5. The photovoltaic module according to any one of claims 1 to 4, characterized in that: The photovoltaic assembly further includes a buffer structure, and the buffer structure is located between the groove wall of the groove and the welding strip.

6. The photovoltaic module according to claim 5, characterized in that: The buffer structure is located in edge regions of the first battery cell and the second battery cell, and the edge regions are located at two ends of the groove in the length direction.

7. The photovoltaic module according to claim 6, characterized in that: The minimum distance between the edge area and two ends of the groove is 1 mm to 3 mm.

8. The photovoltaic module according to claim 5, characterized in that: The maximum width of the buffer structure in the first direction is 0.3 mm to 1.5 mm, the maximum width in the second direction is 1 mm to 5 mm, and the thickness of the buffer structure is 0.05 mm to 0.3 mm.

9. The photovoltaic module according to claim 5, characterized in that: The cushioning structure includes a bonding material.

10. The photovoltaic module according to claim 1, characterized in that: The maximum depth of the groove is 5 μm to 10 μm, and the width of the groove is 0.20 mm to 0.30 mm.

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