Photovoltaic module and photovoltaic system

Abstract

The photovoltaic module comprises a plurality of battery pieces, each battery piece comprises a plurality of fine gate electrodes, and each fine gate electrode comprises a first section and a second section which are alternately arranged and connected together; the second section is wider than the first section; the top surfaces of the first section and the second section in a fine gate electrode are flush with each other; the at least one second section comprises a first part and a second part, and the second part is connected with the first part and the first section; and the width of the second part is gradually increased in the direction from the first section to the first part. According to the photovoltaic module provided by the embodiment of the invention, the pulling-out force between the interconnection piece and the battery piece can be ensured.

Description

Technical Field

[0001] The present invention relates to the technical field of photovoltaic technology, and particularly to a photovoltaic module and a photovoltaic system. Background Art

[0002] A photovoltaic module includes solar cells and solder tapes. The solar cells have grid lines, and the solder tapes are used for interconnecting the solar cells.

[0003] In conventional solar cells, the grid lines on the solar cells, that is, the electrodes, are effectively connected to the solder tapes through solder pads.

[0004] However, it is easy to have a pull-off phenomenon between the solder pad and the solder tape, that is, it is difficult to ensure the pull-off force between the solar cell and the solder tape. Summary of the Invention

[0005] The present invention provides a photovoltaic module and a photovoltaic system, aiming to at least solve the technical problem that it is difficult to ensure the pull-off force between the solar cell and the solder tape in the prior art.

[0006] An embodiment of the present invention provides a photovoltaic module, including a plurality of solar cells. The solar cells include a plurality of fine grid electrodes extending along a first direction and arranged along a second direction. The first direction intersects the second direction. One of the fine grid electrodes includes a first section and a second section that are alternately arranged and connected together; the width of the second section is greater than the width of the first section;

[0007] The top surfaces of the first section and the second section in one of the fine grid electrodes are flush;

[0008] At least one of the second sections includes a first part and a second part, and the second part connects the first part and the first section;

[0009] In the direction from the first section to the first part, the width of the second part increases.

[0010] In an embodiment of the present invention, the second section includes a first part and a second part. The second part connects the first part and the first section, and the width of the second part increases. Through the setting of the increasing width of the second part, the stress concentration at the end of the second section can be reduced. The second section serves as a connection base of the interconnecting member on the solar cell. After the width of the second section on the solar cell body increases and the stress concentration at the end of the second section is reduced, the risk of the fine grid electrode breaking between the first section and the second section and the second section detaching can be reduced, thereby ensuring the pull-off force between the interconnecting member and the solar cell. In addition, for each fine grid electrode, it can transmit current to the interconnecting member through the second section, which can shorten the current transmission distance and improve the current transmission efficiency.

[0011] The above description is only an overview of the technical solution of the present invention. In order to understand the technical means of the present invention more clearly, it can be implemented according to the content of the specification. And in order to make the above and other objects, features and advantages of the present invention more obvious and understandable, the specific embodiments of the present invention are hereinafter specifically exemplified. Description of the Drawings

[0012] Figure 1 Partial structural schematic of the layout of the cell and the insulator in the photovoltaic module provided by the embodiment of the present invention Figure 1 ;

[0013] Figure 2 Partial structural schematic of the layout of the cell, the bonding layer layout, and the insulator layout in the photovoltaic module provided by the embodiment of the present invention Figure 1 ;

[0014] Figure 3 Structural schematic diagram of the second section in the cell of the photovoltaic module provided by the embodiment of the present invention;

[0015] Figure 4 Partial structural schematic of the layout of the cell, the bonding layer layout, and the insulator layout in the photovoltaic module provided by the embodiment of the present invention Figure 2 ;

[0016] Figure 5 Partial structural schematic of the layout of the cell, the bonding layer layout, and the insulator layout in the photovoltaic module provided by the embodiment of the present invention Figure 3 ;

[0017] Figure 6 Partial structural schematic of the layout of the cell and the insulator in the photovoltaic module provided by the embodiment of the present invention Figure 2 ;

[0018] Figure 7 Partial structural schematic diagram of the connection between the cell and the interconnector in the photovoltaic module provided by the embodiment of the present invention.

[0019] Reference Numerals:

[0020] 1 - cell, 11 - fine grid electrode, 111 - first section, 112 - second section, 1121 - first part, 1122 - second part, 12 - positive electrode, 13 - negative electrode, 2 - bonding layer, 21 - first bonding layer, 22 - second bonding layer, 3 - insulator, 4 - barrier, 5 - interconnector. Detailed Embodiments

[0021] Exemplary embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Although the exemplary embodiments of the present invention are shown in the drawings, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided so that the present invention can be more thoroughly understood and the scope of the present invention can be completely conveyed to those skilled in the art.

[0022] Referring to Figures 1 to 3 、 Figure 7 ,an embodiment of the present invention discloses a photovoltaic module, including a plurality of cell wafers 1. The cell wafer 1 includes a plurality of fine grid electrodes 11 extending along a first direction and arranged along a second direction. The first direction intersects the second direction. A fine grid electrode 11 includes a first segment 111 and a second segment 112 which are alternately arranged and connected together. The width of the second segment 112 is greater than the width of the first segment 111. The top surfaces of the first segment 111 and the second segment 112 in a fine grid electrode 11 are flush. At least one second segment 112 includes a first portion 1121 and a second portion 1122. The second portion 1122 connects the first portion 1121 and the first segment 111. In the direction from the first segment 111 to the first portion 1121, the width of the second portion 1122 increases.

[0023] Among them, the cell wafer 1 can be a main-gridless cell wafer. The main-gridless cell wafer only includes the fine grid electrodes 11. Since the main grid lines are removed, the amount of metal paste can be reduced and the cost of cell wafer metallization can be lowered. Of course, along the second direction, connection electrodes can be provided between the fine grid electrodes of the same polarity. The connection electrodes can be connected to the first segment of the fine grid electrode or the second segment. The plurality of connection electrodes connecting the second segments of the fine grid electrodes can be collinear in the second direction. The cell wafer 1 can also be a back-contact cell wafer or a cell wafer with double-sided fine grid electrodes. The front side of the back-contact cell wafer has no fine grid electrodes, and has the characteristics of low light-shielding loss and beautiful appearance. When the cell wafer 1 is a main-gridless cell wafer and a back-contact cell wafer, the weight of the metal paste on a single side of the cell wafer 1 can be reduced.

[0024] The cell wafer 1 includes a cell wafer body, and the fine grid electrodes 11 are disposed on the cell wafer body. The length direction of the fine grid electrodes 11 can refer to Figure 1 、 Figure 2 、 Figure 4 and Figure 5In the direction indicated by arrow A, the width direction of the fine grid electrode 11 may refer to the direction indicated by arrow B. The width direction of the fine grid electrode 11 is preferably perpendicular to the length direction of the fine grid electrode 11. The width of the second segment 112 here specifically refers to the width at any position on the second segment 112; or the width of the second segment 112 refers to the width at any position on the second segment 112 except for the end point position in contact with the first segment. It should be understood that the lengths of the fine grid electrode 11 and its included first segment 111, second segment 112, first part 1121, and second part 1122 in the second segment 112 are parallel to the first direction, and the width direction is perpendicular to the length direction.

[0025] That the top surfaces of the first segment 111 and the second segment 112 in a fine grid electrode 11 are flush means that the top surfaces of the first segment 111 and the second segment 112 are in the same plane in the theoretical design state, that is, the height difference is zero. This top surface is the top surface of the fine grid electrode 11 facing away from the battery cell 1. Considering the process errors in the actual processing, a slight height difference between the top surface of the first segment 111 and the top surface of the second segment 112 is allowed. The height of the first segment 111 can be set according to actual needs, for example, it can be 10 micrometers - 20 micrometers.

[0026] The photovoltaic module may further include an interconnector 5 connecting two adjacent battery cells 1. The interconnector 5 extends along the second direction and is fixed to the second segment 112. The second segment 112 is specifically welded or conductively bonded to the interconnector 5. Multiple battery cells 1 are connected in series through the interconnector 5. The interconnector 5 can be a solder ribbon or a coated solder ribbon. Among them, the solder ribbon is a flat solder ribbon or a round solder ribbon, and the solder ribbon can also be set to other shapes according to actual needs. When the battery cell 1 is a back-contact battery cell, the interconnector 5 is preferably a flat solder ribbon. The length direction of the interconnector is parallel to the second direction, and the width direction is perpendicular to the length direction.

[0027] Specifically, the first part 1121 is connected to the interconnector 5. A second segment 112 specifically includes two second parts 1122, and the two second parts 1122 are located on both sides of the first part 1121 along the first direction. The increase in the width of the second part 1122 can be understood as the width of the second part 1122 gradually increasing, increasing step by step, increasing equally or unequally. The increase in the width of the second part 1122 can be linearly increasing or non-linearly increasing. Along the second direction, a second part 1122 can have two transition contour lines arranged oppositely along the second direction, and the transition contour lines can be oblique straight lines, arcs, curves, etc.

[0028] In this embodiment, the second section 112 includes a first part 1121 and a second part 1122. The second part 1122 connects the first part 1121 and the first section 111, and the width of the second part 1122 increases. By setting the width of the second part 1122 to increase, the stress concentration at the end of the second section 112 can be reduced. The second section 112 serves as the connection base of the interconnect 5 on the solar cell 1. After the width of the second section 112 on the solar cell body increases and the stress concentration at the end of the second section 112 is reduced, the risk of the fine grid electrode 11 breaking between the first section 111 and the second section 112 and the second section 112 detaching can be reduced, thereby ensuring the pull-off force between the interconnect 5 and the solar cell 1. Herein, the pull-off force between the interconnect 5 and the solar cell 1 refers to the force required to pull the interconnect 5 off the solar cell 1.

[0029] In some embodiments, a plurality of fine grid electrodes 11 include a plurality of positive electrodes 12 and a plurality of negative electrodes 13. The top surfaces of the second section 112 and the first section 111 included in the positive electrode 12 are flush, and the top surfaces of the second section 112 and the first section 111 included in the negative electrode 13 are flush. In the back contact solar cell, the plurality of positive electrodes 12 and the plurality of negative electrodes 13 are alternately arranged in the second direction. Since the top surfaces of the second section 112 and the first section 111 of the same-sex electrodes are flush, when the interconnect 5 connects a plurality of same-sex electrodes, the connection failure caused by the height difference of the second section 112 can be reduced, and thus the connection quality of the interconnect 5 can be improved.

[0030] In some embodiments, the height difference between the positive electrode 12 and the negative electrode 13 is less than or equal to 3 microns. At this time, the height difference between the positive and negative electrodes on the same solar cell 1 is small, and the placement height and processing height differences of the interconnect 5 corresponding to the solar cell 1 are small, thereby improving the processing yield and welding consistency.

[0031] In some embodiments, a plurality of solar cells 1 include a first solar cell and a second solar cell connected in series. The height difference between a fine grid electrode 11 on the first solar cell and a fine grid electrode 11 on the second solar cell is less than or equal to 5 microns, and the polarities of the two fine grid electrodes are opposite. At this time, the interconnect 5 connects the positive electrode of the previous solar cell 1 and the negative electrode of the subsequent solar cell 1. When the height difference is within the above range, the bending and undulation of the interconnect 5 can be reduced, and the connection quality between the interconnect 5 and the solar cell 1 can be improved. Herein, the height difference between a fine grid electrode 11 on the first solar cell and a fine grid electrode 11 on the second solar cell can be 0 micron, 1 micron, 2 microns, 3 microns, 4 microns, 5 microns, etc.

[0032] In some embodiments, the material of the first section 111 in the same fine grid electrode 11 is the same as that of the second section 112. The material can be low-temperature flake silver paste, nano-silver paste, silver-coated copper flake paste, copper paste, etc.; it can also be high-temperature silver paste. The same material for the first section 111 and the second section 112 can avoid the interface resistance between different materials.

[0033] In some embodiments, the materials of the positive electrode 12 and the negative electrode 13 on the battery cell 1 are the same. The materials of the respective fine grid electrodes 11 are the same, and their physical and chemical properties are similar, which can reduce the design and processing difficulties of the fine grid electrodes 11 on the battery cell 1.

[0034] In some embodiments, a plurality of battery cells 1 include a first battery cell and a second battery cell connected in series. The material of a fine grid electrode 11 on the first battery cell is the same as that of a fine grid electrode 11 on the second battery cell, which can ensure the consistency of current transmission of the series-connected battery cells.

[0035] In some embodiments, a fine grid electrode 11 is a strip-shaped continuous fine grid electrode, and the number of overlapping nodes in the fine grid electrode 11 is zero. The first section 111 and the second section 112 in the fine grid electrode 11 are integrally printed on the battery cell body. Integral printing can avoid the overlapping nodes between the first section 111 and the second section 112, thereby avoiding the interface resistance at the overlapping nodes.

[0036] In some embodiments, along the first direction, the second part 1122 has a first end and a second end. The width of the first end is equal to the width of the first section 111, and the width of the second end is equal to the width of the first part 1121.

[0037] When the width of the first section 111 in the negative electrode 13 is 75 μm - 85 μm, the width of the first end of the second part 1122 in the negative electrode 13 is 75 μm - 85 μm, preferably both are equal and both are 80 μm. When the width of the first section 111 in the positive electrode 12 is 115 μm - 125 μm, the width of the first end of the second part 1122 in the positive electrode 12 is 115 μm - 125 μm, preferably both are equal and both are 120 μm. In this embodiment, the width of the first end of the second part 1122 is equal to the width of the first section 111, and the width of the second end of the second part 1122 is equal to the width of the first part 1121, so that the first section 111 and the first part 1121 can have a smooth transition, and the stress caused by width mutation can be reduced.

[0038] In some embodiments, the width of the second end of the second portion 1122 is 1.8 to 3.5 times the width of the first end. Among them, the width of the second end of the second portion 1122 can be 1.8 times, 2 times, 2.1 times, 2.2 times, 2.5 times, 3 times, 3.5 times, etc. the width of the first end. The width of the first portion 1121 in the negative electrode 13 can be 0.2 mm, and the width of the first portion 1121 in the positive electrode 12 can be 0.26 mm. In this embodiment, the width change at both ends of the second portion 1122 is not too large, and the transition effect of the second portion 1122 is good.

[0039] In some embodiments, referring to Figure 3 , a second portion 1122 has two transition contour lines; taking the center point of the second section 112 as the origin to establish an XY coordinate system, the X-axis in the XY coordinate system is parallel to the first direction, and the Y-axis in the XY coordinate system is perpendicular to the X-axis. One transition contour line in the negative electrode 13 satisfies: Y = -0.08X + 0.16; one transition contour line in the positive electrode 12 satisfies: Y = -7 / 75X + 0.2.

[0040] Among them, the positive directions of the X-axis and the Y-axis both face the transition contour line. For example, for Figure 3 the upper left corner transition contour line indicated by SI in, when establishing the XY coordinate system, the positive direction of the X-axis faces left, and the positive direction of the Y-axis faces up. Similarly, for Figure 3 the lower left corner transition contour line in, when establishing the XY coordinate system, the positive direction of the X-axis faces left, and the positive direction of the Y-axis faces down. In this embodiment, the transition contour line is relatively gentle, and the transition effect of the second portion 1122 is good.

[0041] In some embodiments, referring to Figure 3 , in a fine grid electrode 11, the angle between the transition contour line and the adjacent first section 111 is 140° - 179°. Among them, in a fine grid electrode 11, the angle between the transition contour line and the adjacent first section 111 can refer to Figure 3 the α shown in, α is 140° - 179°, for example, 140°, 150°, 160°, 165°, 170°, 175°, 179°, etc. In this embodiment, the angle between the transition contour line and the adjacent first section 111 is relatively large, the transition contour line is relatively gentle, and the stress dispersion effect of the second portion 1122 is good.

[0042] In some embodiments, the transition contour line is a curve or an oblique straight line. When the transition contour line is an oblique straight line, it can take into account both stress dispersion and the area of the second portion 1122. When the transition contour line is a curve, the curve can be convex or concave. The convex curve can increase the area of the second portion 1122, and the concave curve can further make the smooth transition between the second portion 1122 and the first section 111.

[0043] In some embodiments, relative to the straight line connecting the two end points of the transition contour line, a transition contour line protrudes at least partially outward from the second segment 112 and / or depresses inwardly into the second segment 112.

[0044] In some embodiments, the interconnecting member 5 is fixedly connected to the second segment 112, and the widths of the portions of the second segment 112 covered by the interconnecting member 5 are the same, ensuring that the current at the connection between the second segment 112 and the interconnecting member 5 can be uniformly transmitted to the interconnecting member 5.

[0045] In some embodiments, the length of a second segment 112 is less than the length of the first segment 111 adjacent thereto and having two ends respectively connected to two second segments 112; in a second segment 112, the length of a second portion 1122 is 0.3 times to 1 times the length of a first portion 1121. Among them, the length of the second portion 1122 can be 0.3 times, 0.4 times, 0.5 times, 0.7 times, 1 times, etc. the length of the first portion 1121. The length of the first portion 1121 can be 1.5 mm, and the length of the second portion 1122 can be 0.75 mm. In this embodiment, the length of the second segment 112 with a larger width is less than the length of the first segment 111 having two ends respectively connected to two second segments 112, which can reduce light shielding and improve the light utilization rate of the battery cell 1.

[0046] In some embodiments, the length of the first portion 1121 is 1.8 times to 3 times the width of the interconnecting member 5; the length of the second segment 112 is 3 times to 15 times the width of the interconnecting member 5.

[0047] Among them, the length of the first portion 1121 can be 1.8 times, 2 times, 2.5 times, 2.7 times, 3 times, etc. the width of the interconnecting member 5. The length of the second segment 112 can be 3 times, 4 times, 5 times, 6 times, 10 times, 15 times, etc. the width of the interconnecting member 5. The width of the interconnecting member 5 can be 0.6 mm, the length of the first portion 1121 can be 1.5 mm, and the length of the second segment 112 can be 3 mm. In this embodiment, when the interconnecting member 5 is fixed to the first portion 1121, the entire width region of the interconnecting member 5 can be connected to the first portion 1121. At the same time, sufficient laying space can be reserved for the bonding layer 2 between the second segment 112 and the interconnecting member 5, improving the current transmission rate between the second segment 112, the bonding layer 2, and the interconnecting member 5.

[0048] In some embodiments, referring to Figure 2 , Figure 4 and Figure 5 , a bonding layer 2 is provided on the second segment 112, and the second segment 112 and the interconnecting member 5 are fixed and electrically connected through the bonding layer 2.

[0049] Among them, the bonding layer 2 can be a conductive adhesive or a conductive paste. During the welding process of the second section 112 and the interconnecting member 5, the conductive adhesive or the conductive paste can play a role in fixing and conducting electricity. The number of the bonding layers 2 is several, and the several bonding layers 2 correspond to the several second sections 112 one by one. The shape of the bonding layer 2 can be square, square with rounded corners, trapezoidal, kidney-shaped, oval, etc. The length direction and the width direction of the bonding layer 2 are consistent with those of the fine grid electrode 11. In this embodiment, by arranging the bonding layer 2, the bonding force and the fixing effect between the interconnecting member 5 and the battery cell 1 can be improved, so that the pull-off force between the interconnecting member 5 and the battery cell 1 can be increased.

[0050] In some embodiments, at least a portion of the bonding layers 2 cover 37%-80% of the area of the second section 112; or, at least a portion of the bonding layers 2 cover 25%-35% of the area of the second section 112.

[0051] Among them, at least a portion of the bonding layers 2 cover 37%, 40%, 45%, 50%, 60%, 70%, 80%, etc. of the area of the second section 112. At least a portion of the bonding layers 2 cover 25%, 27%, 28%, 30%, 35%, etc. of the area of the second section 112.

[0052] The several bonding layers 2 include a plurality of first bonding layers 21 and second bonding layers 22, and the area of the first bonding layer 21 is larger than that of the second bonding layer 22. Along the first direction, the length of the first bonding layer 21 is greater than that of the second bonding layer 22. The first bonding layer 21 covers 37%-80% of the area of the second section 112, and the second bonding layer 22 covers 25%-35% of the area of the second section 112. Preferably, the first bonding layer 21 covers 40%-50% of the area of the second section 112. When the bonding layer 2 covers 37%-80% of the area of the second section 112, the covering area of the bonding layer 2 is relatively large, which can provide a better fixing effect for the interconnecting member 5, and the bonding force between the bonding layer 2 and the second section 112 will increase.

[0053] For a column of bonding layers 2 arranged along the second direction, including a plurality of first bonding layers 21 and a plurality of second bonding layers 22, the plurality of first bonding layers 21 are preferably located at both ends of the battery cell 1 along the second direction, and the plurality of second bonding layers 22 are located between the plurality of first bonding layers 21 on both sides. For a column of bonding layers 2 arranged along the second direction, there can be 1-20 bonding layers 2 as the first bonding layer 21.

[0054] In some embodiments, at least a portion of the bonding layers 2 cover 37%-80% of the area of the second section 112, and at least a portion of the bonding layers 2 cover 25%-35% of the area of the second section 112. Under this scheme, on the basis of ensuring the pull-off force between the interconnecting member 5 and the main-gridless battery cell 1, the wet weight and cost of the battery cell 1 can be reduced.

[0055] In some embodiments, the bonding layer 2 is disposed on the first portion 1121 in the second segment 112. Among them, the first portion 1121 is the portion where the second segment 112 is connected to the interconnect 5. Disposing the bonding layer 2 on the first portion 1121 can provide a relatively wide extension range for the bonding layer 2 and can reduce the risk of the bonding layer 2 overflowing the second segment 112 in the second direction.

[0056] In some embodiments, the length of at least a portion of the bonding layers 2 is 1.5 times to 2.8 times the width of the interconnect 5; or, the length of at least a portion of the bonding layers 2 is 0.85 times to 2.3 times the width of the interconnect 5.

[0057] Among them, the length of at least a portion of the bonding layers 2 is 1.5 times, 1.7 times, 1.8 times, 2 times, 2.5 times, 2.8 times, etc. of the width of the interconnect 5. The length of at least a portion of the bonding layers 2 is 0.85 times, 1 time, 1.2 times, 1.5 times, 1.8 times, 2.3 times, etc. of the width of the interconnect 5. The length of the first bonding layer 21 is 1.5 times to 2.8 times the width of the interconnect 5, and the length of the second bonding layer 22 is 0.85 times to 2.3 times the width of the interconnect 5. When the width of the interconnect 5 is 0.6 mm, the length of the first bonding layer 21 is 0.9 mm to 1.68 mm, and the length of the first bonding layer 21 is preferably 1.2 mm to 1.3 mm. When the width of the interconnect 5 is 0.6 mm, the length of the second bonding layer 22 is 0.6 mm to 1.38 mm, and the length of the second bonding layer 22 is preferably 0.8 mm to 1 mm.

[0058] In this embodiment, for the bonding layer 2 with a length of 1.5 times to 2.8 times the width of the interconnect 5, the length of the bonding layer 2 is greater than the width of the interconnect 5, so that the entire width region of the interconnect 5 can be fixed to the second segment 112 through the bonding layer 2, and the fixing effect between the interconnect 5 and the second segment 112 can be improved. In addition, for the bonding layer 2 with a length of 1.5 times to 2.8 times the width of the interconnect 5, even if there are errors in the position of the bonding layer 2 or the position of the interconnect 5, it can be ensured that the entire width region of the interconnect 5 can be fixed to the second segment 112 through the bonding layer 2.

[0059] In some embodiments, the length of at least a portion of the bonding layers 2 is 1.5 times to 2.8 times the width of the interconnect 5, and the length of at least a portion of the bonding layers 2 is 0.85 times to 2.3 times the width of the interconnect 5. Under this scheme, on the basis of ensuring that the entire width region of the interconnect 5 can be fixed to the second segment 112 through the bonding layer 2, the wet weight and cost of the battery cell 1 can be reduced.

[0060] In some embodiments, the interconnecting member 5 has two side surfaces oppositely arranged along its width direction, and at least a partial number of bonding layers 2 fix the bottom of the interconnecting member 5 and the two side surfaces of the interconnecting member 5. Preferably, all the bonding layers 2 fix the bottom of the interconnecting member 5 and the two side surfaces of the interconnecting member 5. In this solution, the fixing area between the bonding layer 2 and the interconnecting member 5 can be increased and a wrapping effect can be presented, thereby improving the fixing effect between the bonding layer 2 and the interconnecting member 5.

[0061] In some embodiments, the bonding layer 2 is disposed in the middle of the second section 112. The width at the middle of the second section 112 is the large-width portion. The bonding layer 2 is disposed in the middle of the second section 112, which can increase the fixing area between the bonding layer 2 and the second section 112.

[0062] In some embodiments, along the first direction, for a bonding layer 2 from the edge of the interconnecting member 5 to the end of the bonding layer 2, the width first decreases and then increases. At this time, more material of the bonding layer 2 accumulates at the bottom and periphery of the interconnecting member 5, which can enhance the fixing of the interconnecting member 5. It should be noted that for the bonding layer 2 that has not been welded to the interconnecting member 5, the width of the bonding layer 2 can be uniform.

[0063] In some embodiments, along the second direction, the length of the bonding layer 2 near the edge of the cell is greater than the length of the bonding layer 2 far from the edge of the cell. The closer to the edge of the cell 1, the greater the swing and position error of the interconnecting member 5. In this embodiment, the length of the bonding layer 2 near the edge of the cell 1 is greater, which can effectively ensure that the entire width region of the portion of the interconnecting member 5 near the edge of the cell 1 can be fixed to the second section 112 through the bonding layer 2.

[0064] In some embodiments, referring to Figure 1 , all the second sections 112 in a cell 1 include a second part 1122. The fixing effect at the connection between the interconnecting member 5 and all the second sections 112 is good, which can improve the pull-off force between the interconnecting member 5 and the main-gridless cell 1.

[0065] In some embodiments, referring to Figure 5 , along the second direction, at least one second section 112 at at least one end of the cell 1 includes a second part 1122. Preferably, a partial number of the second sections 112 include the second part 1122, and a partial number of the second sections 112 do not include the second part 1122. On the basis of ensuring the pull-off force between the interconnecting member 5 and the main-gridless cell 1, the wet weight and cost of the cell 1 can be reduced. The number of the second sections 112 including the second part 1122 can be less than the number of the second sections 112 not including the second part 1122.

[0066] In some embodiments, referring to Figure 6, along the second direction, the second segment 112 in the fine grid electrode 11 closest to the edge of the cell is asymmetrically designed; along the second direction, the second segment 112 located in the middle is symmetrically designed.

[0067] Among them, along the width direction of the fine grid electrode 11, the second segment 112 in the fine grid electrode 11 closest to the edge of the cell 1 is divided into a first sub - part and a second sub - part with the center line of the first segment 111 as the boundary. The first sub - part is located on the side of the center line of the first segment 111 close to the edge of the cell 1, and the second sub - part is located on the side of the center line of the first segment 111 far from the edge of the cell 1. The width of the first sub - part is less than the width of the second sub - part. The center line of the first segment 111 can refer to Figure 6 the dotted line shown by Z in

[0068] The width of the first part 1121 in the second segment 112 of the fine grid electrode 11 closest to the edge of the cell 1 is greater than 0.26 mm, and can be 0.35 mm - 0.37 mm. The width of the second segment 112 in the fine grid electrode 11 closest to the edge of the cell 1 is greater than the width of the second segment 112 in other fine grid electrodes 11, which can improve the fixing effect between the edge of the cell 1 and the interconnector 5.

[0069] In some embodiments, referring to Figure 6 , along the second direction, a blocking member 4 is provided between the second segment 112 of the fine grid electrode 11 closest to the edge of the cell 1 and the edge of the cell 1.

[0070] Among them, the blocking member 4 can be an insulating material. The width of the blocking member 4 is less than the width of the adjacent second segment 112. The height of the blocking member 4 can be equal to the height of the insulating member 3. In this embodiment, through the setting of the blocking member 4, it is possible to prevent the bonding layer 2 on the second segment 112 of the fine grid electrode 11 closest to the edge of the cell 1 from overflowing, thereby avoiding short - circuit and soiling of the cell 1 caused by the splashing of the bonding layer 2.

[0071] In some embodiments, referring to Figure 2 and Figure 4 , the upper surface area per unit length of the negative electrode 13 is not equal to the upper surface area per unit length of the positive electrode 12; the upper surface area of the second segment 112 in the negative electrode 13 is not equal to the upper surface area of the second segment 112 in the positive electrode 12. For an N - type silicon wafer, the upper surface area per unit of the positive electrode 12 can be larger to balance carrier collection.

[0072] Among them, the back-contact battery cell has N-type regions and P-type regions that are alternately and spaced apart. The negative electrode 13 is disposed in the N-type region, and the positive electrode 12 is disposed in the P-type region. The unit length can refer to 1 mm, 1 cm, etc.

[0073] The width of the first segment 111 in the negative electrode 13 can be 75 μm - 85 μm, and the width of the first segment 111 in the positive electrode 12 can be 115 μm - 125 μm. The difference between the width of the first segment 111 in the negative electrode 13 and the width of the first segment 111 in the positive electrode 12 can be 0.35 times - 1 times the width of the first segment 111 in the negative electrode 13.

[0074] The width of the first part 1121 in the negative electrode 13 is less than the width of the first part 1121 in the positive electrode 12. The difference between the width of the first part 1121 in the negative electrode 13 and the width of the first part 1121 in the positive electrode 12 can be 0.2 times - 0.5 times the width of the first part 1121 in the negative electrode 13.

[0075] In some embodiments, the peel force between the interconnect 5 and the second segment 112 of the negative electrode 13 is F1, and the peel force between the interconnect 5 and the second segment 112 of the positive electrode 12 is F2; F1 is less than F2; and / or, the difference between F1 and F2 is 0.5 times - 1 times F1.

[0076] F1 can be about 0.5 N, and F2 can be about 1 N - 1.2 N. The difference between F1 and F2 can be 0.5 times, 0.8 times, 0.9 times, 1 times, etc. of F1. In this embodiment, the difference in the peel force between the second segment 112 of the negative electrode 13 and the second segment 112 of the positive electrode 12 in the battery cell 1 and the interconnect 5 is 0.5 times - 1 times the peel force between the interconnect 5 and the second segment 112 of the negative electrode 13, which can avoid the imbalance of mechanical properties caused by too large a difference in peel force.

[0077] In some embodiments, referring to Figure 1 、 Figure 2 、 Figures 4 to 6 , there is an insulating member 3 provided between the interconnect 5 and the fine grid electrode 11 of the opposite sex; along the second direction, the insulating member 3 is spaced apart from the adjacent second segment 112. Along the first direction, the length difference between the second segment 112 and the insulating member 3 is 0.01 mm - 1 mm.

[0078] Among them, the insulating member 3 can be insulating glue. The shape of the insulating member 3 can be square, square with rounded corners, trapezoidal, kidney-shaped, oval, etc. Along the first direction, the length of the insulating member 3 can be 3 mm. By providing the insulating member 3, insulation between the interconnect 5 and the fine grid electrode 11 of the opposite sex can be achieved.

[0079] In the second direction, the distance between the insulating member 3 and the adjacent second segment 112 can be set according to actual requirements. For example, it can be set to 40 micrometers - 50 micrometers. In the second direction, the distance between the insulating member 3 and the adjacent second segment 112 is preferably 45 micrometers. The insulating member 3 is spaced apart from the adjacent second segment 112, which can prevent the insulating member 3 from extending to the adjacent second segment 112, thereby avoiding the connection between the second segment 112 and the bonding layer 2 from being affected, and further avoiding the soldering between the second segment 112 and the interconnecting member 5 from being affected. It should be noted that the middle part of the bonding layer 2 can be in contact with the side surface of the adjacent insulating member 3. The end part in the bonding layer 2 is not in contact with the adjacent insulating member 3.

[0080] The welding method between the solar cell 1 and the interconnecting member 5 can be infrared welding, such as low-temperature infrared welding.

[0081] In some embodiments, a part of the fine grid electrode 11 has an oxide layer, and the oxide layer can be silver oxide, copper oxide, etc. After the solar cell 1 is encapsulated, the oxide layer will not expand further and can protect the inside of the fine grid electrode 11.

[0082] In some embodiments, the solar cell 1 further includes a connecting line extending in the second direction, and the connecting line connects the second segment 112 or the first segment 111 of the fine grid electrodes 11 with the same polarity. As an example, the connecting line is only located at the end of the solar cell 1 in the second direction, or the connecting line connects the first part 1121 of the adjacent second segments 112 with the same polarity, or the connecting line connects the second part 1122 of the adjacent second segments 112 with the same polarity. The connecting line can assist in current collection, and after multiple fine grid electrodes 11 with the same polarity are connected, it can play a role in balancing the current magnitude.

[0083] The embodiment of the present invention also provides a photovoltaic system, and the photovoltaic system includes a photovoltaic module according to any one of the above embodiments or a combination of multiple embodiments.

[0084] It should be noted that in this article, the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements not only includes those elements, but also includes other elements not explicitly listed, or further includes elements inherent to this process, method, article or device. Without more limitations, an element defined by the statement "including one..." does not exclude the existence of another identical element in the process, method, article or device including that element.

[0085] The embodiments of the present invention have been described above in conjunction with the accompanying drawings. However, the present invention is not limited to the above specific embodiments. The above specific embodiments are merely illustrative and not restrictive. Under the inspiration of the present invention, those of ordinary skill in the art can also make many forms without departing from the purpose and scope of the present invention. All of these are within the protection scope of the present invention.

Claims

1. A photovoltaic module, characterized in that: A plurality of battery cells are included, each of which includes a plurality of fine grid electrodes extending along a first direction and arranged along a second direction, wherein the first direction intersects the second direction; the fine grid electrodes include a first segment and a second segment which are alternately arranged and connected together; the width of the second segment is greater than the width of the first segment; The top surfaces of the first section and the second section of the fine gate electrode are flush with each other; at least one of the second segments comprises a first portion and a second portion, the second portion connecting the first portion and the first segment; The width of the second portion increases gradually from the first section toward the first portion.

2. The photovoltaic module according to claim 1, characterized in that: The plurality of fine gate electrodes include a plurality of positive electrodes and a plurality of negative electrodes, the top surfaces of the second segment and the first segment of the positive electrodes are flush, and the top surfaces of the second segment and the first segment of the negative electrodes are flush.

3. The photovoltaic module according to claim 2, characterized in that: A height difference between the positive electrode and the negative electrode is less than or equal to 3 micrometers.

4. The photovoltaic module according to claim 1, characterized in that: The plurality of cells include a first cell and a second cell connected in series, a height difference between a fine gate electrode on the first cell and a fine gate electrode on the second cell is less than or equal to 5 microns, and the two fine gate electrodes have opposite polarities.

5. The photovoltaic module according to claim 1, characterized in that: The material of the first segment and the material of the second segment in the same fine gate electrode are the same.

6. The photovoltaic module according to claim 1, characterized in that: The plurality of fine grid electrodes include a plurality of positive electrodes and a plurality of negative electrodes, and the material of a positive electrode and a negative electrode on the battery cell is the same.

7. The photovoltaic module according to claim 1, characterized in that: The plurality of battery cells include a first battery cell and a second battery cell connected in series, and a fine gate electrode on the first battery cell is made of the same material as a fine gate electrode on the second battery cell.

8. The photovoltaic module according to claim 1, characterized in that: The fine gate electrode is a strip-shaped continuous fine gate electrode, and the number of overlapping nodes in the fine gate electrode is zero.

9. The photovoltaic module according to claim 1, characterized in that: Along the first direction, the second portion has a first end and a second end, the width of the first end is equal to the width of the first segment, and the width of the second end is equal to the width of the first portion.

10. The photovoltaic module according to claim 9, characterized in that: The width of the second end of the second portion is 1.8 to 3.5 times the width of the first end.

11. The photovoltaic module according to claim 1, characterized in that: The second portion has two transition contour lines; the plurality of fine grid electrodes include a plurality of positive electrodes and a plurality of negative electrodes; An XY coordinate system is established with the center point of the second segment as the origin, the X axis in the XY coordinate system is parallel to the first direction, the Y axis in the XY coordinate system is perpendicular to the X axis, and a transition contour line in the negative electrode satisfies: Y=-0.08X+0.16; and / or, a transition contour line in the positive electrode satisfies: Y=-7 / 75X+0.

2.

12. The photovoltaic module according to claim 1, characterized in that: - the second portion has two transition contours; In one of the fine gate electrodes, the angle between the transition contour line and the adjacent first segment is 140°-179°.

13. The photovoltaic module according to claim 1, characterized in that: The second portion has two transition contour lines, and the transition contour lines are curves or oblique straight lines.

14. The photovoltaic module according to claim 1, characterized in that: The photovoltaic assembly further includes an interconnection member connecting two adjacent solar cells, the interconnection member is fixedly connected to the second section, and the width of the portion of the second section covered by the interconnection member is consistent.

15. The photovoltaic module according to any one of claims 1 to 14, characterized in that: - the length of the second segment is shorter than the length of the first segment adjacent to it and connected to two second segments at both ends; In the second section, a length of the second portion is 0.3 to 1 times the length of the first portion.

16. The photovoltaic module according to any one of claims 1 to 14, characterized in that: The photovoltaic module further includes an interconnection member connecting two adjacent solar cells, and the length of the first portion is 1.8 to 3 times the width of the interconnection member; And / or, the length of the second segment is 3 times to 15 times the width of the interconnect.

17. The photovoltaic module according to any one of claims 1 to 14, characterized in that: The photovoltaic assembly also includes an interconnection member connecting two adjacent solar cells. A bonding layer is provided on the second section, and the second section is fixed and electrically connected to the interconnection member through the bonding layer.

18. The photovoltaic module according to claim 17, characterized in that: At least a partial amount of the bonding layer covers 37% to 80% of the area of ​​the second segment; Alternatively, at least a partial amount of the bonding layer covers 25%-35% of the area of ​​the second section.

19. The photovoltaic module according to claim 17, characterized in that: The length of at least a portion of the bonding layers is 1.5 to 2.8 times the width of the interconnect; Alternatively, the length of at least a portion of the bonding layers is 0.85 times to 2.3 times the width of the interconnect.

20. The photovoltaic module according to claim 17, characterized in that: The bonding layer is disposed in the middle of the second section; and / or, along the second direction, the length of the bonding layer close to the edge of the battery cell is greater than the length of the bonding layer far from the edge of the battery cell; And / or, the photovoltaic module further comprises an interconnection member connecting two adjacent solar cells, and along the first direction, the width of the bonding layer first decreases and then increases from the edge of the interconnection member to the end of the bonding layer.

21. The photovoltaic module according to any one of claims 1 to 14, characterized in that: All the second sections in the battery sheet have the second portion; Alternatively, along the second direction, at least one of the second segments located at an end of the battery sheet has a second portion.

22. The photovoltaic module according to any one of claims 1 to 14, characterized in that: An asymmetric design of the second section of the fine grid electrode closest to the edge of the cell along the second direction; Along the second direction, the second section located in the middle is symmetrically designed.

23. The photovoltaic module according to any one of claims 1 to 14, characterized in that: Along the second direction, a blocking member is arranged between the second segment of the fine gate electrode closest to the edge of the battery cell and the edge of the battery cell.

24. The photovoltaic module according to any one of claims 1 to 14, characterized in that: The plurality of fine grid electrodes include a plurality of positive electrodes and a plurality of negative electrodes, and the upper surface area per unit length of the negative electrodes is not equal to the upper surface area per unit length of the positive electrodes; The upper surface area of ​​the second section in the negative electrode is not equal to the upper surface area of ​​the second section in the positive electrode.

25. The photovoltaic module according to any one of claims 1 to 14, characterized in that: The photovoltaic assembly further includes an interconnection member connecting two adjacent solar cells, wherein the interconnection member extends along the second direction and is fixed to the second section; The plurality of fine grid electrodes include a plurality of positive electrodes and a plurality of negative electrodes, the peeling force between the interconnector and the second segment of the negative electrode is F1, and the peeling force between the interconnector and the second segment of the positive electrode is F2; F1 is smaller than F2; and / or, the difference between F1 and F2 is 0.5 to 1 times of F1.

26. The photovoltaic module according to any one of claims 1 to 14, characterized in that: The plurality of fine grid electrodes include a plurality of positive electrodes and a plurality of negative electrodes, and the photovoltaic module further includes an interconnection member connecting two adjacent cells, and an insulating member is provided between the interconnection member and the fine grid electrodes of opposite sex; Along the second direction, the insulating member is spaced apart from the adjacent second segment; And / or, along the first direction, a length difference between the second section and the insulating member is 0.01 mm-1 mm.

27. The photovoltaic module according to any one of claims 1 to 14, characterized in that: Part of the fine gate electrode has an oxide layer; And / or, the battery cell further includes a connecting line extending along the second direction, the connecting line connecting the second section or the first section of the fine gate electrode with the same polarity.

28. A photovoltaic system, characterized in that: A photovoltaic module comprising any one of claims 1 to 27.

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