Back contact type battery piece and photovoltaic module

Abstract

The utility model relates to a back contact type battery piece and a photovoltaic assembly, which are applied to the field of photovoltaic power generation, the back contact type battery piece comprises a battery piece, a fixing piece, a welding strip and insulation paste, and the battery piece comprises positive electrode grid lines and negative electrode grid lines which are alternately arranged and arranged in parallel; the welding strips are arranged on the fixing piece in a reciprocating and penetrating manner, and each welding strip is used for connecting all the positive grid lines or all the negative grid lines on a single battery piece; when the welding strip is connected with the positive electrode grid line, the insulation paste coats the negative electrode grid line located below the covering position of the fixing piece. And when the welding strip is connected with the cathode grid line, the insulation paste coats the anode grid line below the covering position of the fixing piece. By adopting the scheme, the welding strip is connected with the positive grid line or the negative grid line through the position of the protruding fixing piece, so that the problems that in the prior art, the reliability is poor due to the fact that the welding strip is directly fixed to the battery piece in a dispensing mode, and glue films are prone to flowing into the position below the welding strip to cause pseudo soldering during lamination welding are solved; and the problem of high cost caused by fixing the welding strip and the battery piece by adopting a hot melt adhesive is also avoided.

Description

Technical Field

[0001] The utility model relates to the technical field of photovoltaic cells, in particular to a back-contact type cell sheet and a photovoltaic assembly. Background Art

[0002] Back-contact photovoltaic modules shift the cell's contact points (i.e., positive and negative electrodes) from the traditional front to the back. This design leaves the front of the cell more complete and unobstructed, allowing it to receive more sunlight, thereby improving photovoltaic conversion efficiency. Existing back-contact photovoltaic modules primarily feature a busbar design, but busbar-free designs are also available. Busbar-free back-contact cells eliminate the busbar and solder joints, significantly reducing silver consumption and are becoming a research hotspot.

[0003] The busbar-less design of back-contact cells primarily utilizes a staggered, through-hole arrangement of positive and negative fine grids. Insulation paste is applied along the original busbar arrangement direction to insulate one of the same-polarity grid lines (either all positive or all negative grids). A soldering ribbon is then overlapped and secured to the other busbar line along the busbar direction. The main methods for securing the soldering ribbon include direct lamination and dispensing. Direct lamination involves using a hot-melt adhesive film applied to the cell surface to secure the ribbon to the cell to form a cell string. The cell string is then stacked and laminated to form a module. However, the use of hot-melt adhesive can be costly. The main process of fixing the solder ribbon by dispensing glue is to design the dispensing position on the battery cell, apply UV glue and place the solder ribbon, use ultraviolet lamp to cure the UV glue to fix the solder ribbon, and then use lamination welding to weld the solder ribbon to the battery cell. The main problems with this method are: first, the reliability of UV glue fixing the solder ribbon is poor, and the tensile force of the glue point is very small; second, there is easily an adhesive film under the solder ribbon, which makes it easy for the adhesive film to flow into the solder ribbon position during the lamination process, resulting in component cold soldering. Utility Model Content

[0004] Based on this, a back-contact cell and photovoltaic module are provided to solve the problem of high cost caused by using hot-melt film when adopting direct lamination technology in the prior art, or the problem of cold soldering caused by using UV glue when fixing the solder strip by dispensing glue.

[0005] In one aspect, a back-contact solar cell is provided for use in the field of photovoltaic power generation, comprising:

[0006] The battery body includes positive electrode grid lines and negative electrode grid lines arranged alternately and in parallel on the backlight surface of the battery body;

[0007] A fixing member, wherein a first adhesive layer is provided on one side of the fixing member and the fixing member is bonded to the battery body through the first adhesive layer;

[0008] Welding strips are reciprocatingly threaded onto the fixing member, and each welding strip is used to connect all the positive grid lines or all the negative grid lines on a single battery body;

[0009] Insulating glue, which is coated on the positive electrode grid wire or the negative electrode grid wire and used for insulation;

[0010] When the welding ribbon is connected to the positive grid line, the insulating glue is coated on the negative grid line below the covering position of the fixing piece; when the welding ribbon is connected to the negative grid line, the insulating glue is coated on the positive grid line below the covering position of the fixing piece.

[0011] On the basis of the above technical solution, the present invention can also be improved as follows.

[0012] In one implementation, the fixing member includes:

[0013] Middle grassroots,

[0014] A first adhesive layer is located on one side of the intermediate base layer and is used for bonding with the battery body;

[0015] The second adhesive layer is located on the other side of the middle base layer and is used to bond with the upper adhesive film.

[0016] In one implementation, the fixing member includes:

[0017] The welding belt hole is used for the reciprocating insertion of the welding belt, and a plurality of welding belt holes are provided.

[0018] In one implementation, the fixing member further includes:

[0019] Laser holes, which are alternately provided with welding tape holes, are used to weld the welding tape to the positive electrode grid line or the negative electrode grid line by laser.

[0020] When the welding ribbon is connected to the positive grid lines, the laser holes at least correspond to the positive grid lines one by one; when the welding ribbon is connected to the negative grid lines, the laser holes at least correspond to the negative grid lines one by one.

[0021] In one implementation, the welding ribbon hole is a flat hole, and the laser hole is a round hole or an elliptical hole.

[0022] In one implementation, the width of the laser hole is not less than the width of the welding ribbon hole;

[0023] and / or, the length of the laser hole is not less than the length of the welding ribbon hole;

[0024] The width direction is the direction in which the welding strip passes through, and the length direction is the direction perpendicular to the direction in which the welding strip passes through.

[0025] In one implementation, the positive and negative grid lines are evenly spaced, and the welding holes and the laser holes are evenly alternated.

[0026] When the welding ribbon is connected to the positive electrode grid line, the laser holes correspond to the positive electrode grid lines one by one, and the welding ribbon holes are located between two adjacent positive electrode grid lines; when the welding ribbon is connected to the negative electrode grid line, the laser holes correspond to the negative electrode grid lines one by one, and the welding ribbon holes are located between two adjacent negative electrode grid lines;

[0027] Alternatively, the welding strip is connected to the positive grid line or the negative grid line, the laser holes correspond to the positive grid lines and the negative grid lines one by one, and the welding strip holes are located between adjacent positive grid lines and negative grid lines.

[0028] In one implementation, there are multiple welding ribbons that are arranged parallel to each other;

[0029] There is one fixing member, which is provided with multiple rows of through holes. The number of rows of through holes is the same as the number of solder strips. Each row of through holes includes laser holes and solder strip holes that are alternately arranged.

[0030] Alternatively, there are multiple fixing members, one fixing member corresponds to one welding strip, each fixing member is provided with a row of through holes, and each row of through holes includes laser holes and welding strip holes that are alternately arranged.

[0031] In one implementation, the battery body further includes:

[0032] The left grid line is located on one side of the battery body and is used to connect one end of all the positive grid lines and does not contact the negative grid line;

[0033] The right grid line is located on the other side of the battery body. The right grid line is used to connect one end of all the negative grid lines and does not contact the positive grid line;

[0034] The left grid line and the right grid line are arranged in parallel, and the left grid line and the positive grid line are perpendicular to each other.

[0035] On the other hand, the present invention further provides a photovoltaic assembly, which, in one implementation, includes a plurality of back-contact solar cells.

[0036] The beneficial effects of the present invention are as follows: the welding ribbon is wound by setting a fixing piece, and then the fixing piece is fixed to the battery body by the first adhesive coating layer, thereby fixing the position of the welding ribbon on the battery body. At this time, since the welding ribbon is reciprocated on the fixing piece, the position where the welding ribbon needs to be connected to the positive grid line or the negative grid line protrudes from the fixing piece, so that the welding ribbon will connect to the positive grid line or the negative grid line through the position of the protruding fixing piece, thereby avoiding the poor reliability caused by directly fixing the welding ribbon on the battery body in a spot glue manner in the prior art, and the problem that the adhesive film is easy to flow under the welding ribbon during lamination welding to cause cold welding, and also avoids the high cost problem caused by using hot melt adhesive to fix the welding ribbon and the battery body; in addition, since the insulating adhesive is provided, the insulating adhesive is used to fix the welding ribbon under the fixing piece and does not need to be fixed. The positive grid lines or negative grid lines connected to the welding strips on the fixed part are coated to insulate and isolate any one of the positive grid lines or negative grid lines, thereby improving the stability when welding the welding strips. Since the width of the fixed part is larger than the welding strips in actual use, when using insulating glue to coat the target grid lines, only the target grid lines covered in the local position or all positions in the width direction of the fixed part can be coated. For example, the target grid lines covered in the width direction of the fixed part are fully coated with insulating glue, so that the welding strips and the target grid lines that are not welded can be separated; or the range of coating the insulating glue on the target grid lines is set to that the size coated along the width direction of the welding strips is 1.2 times to 1.5 times the width of the welding strips, and the size of the protruding welding strips on both sides of the insulating glue on the target grid lines is equal, thereby ensuring the isolation effect between the welding strips and the target grid lines. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 A schematic structural diagram of a back-contact battery cell in one embodiment;

[0038] Figure 2 for Figure 1 The schematic diagram of the structure after enlarging A in the middle;

[0039] Figure 3 for Figure 1 The schematic diagram of the structure after enlarging at B in the middle;

[0040] Figure 4 A schematic structural diagram of a cross section of a back-contact type battery cell during installation in one embodiment;

[0041] Figure 5 for Figure 4 The enlarged structural diagram of point C in the middle;

[0042] Figure 6 This is a schematic structural diagram of a cross section of a fixing member in an embodiment;

[0043] Figure 7 Schematic diagram of the length direction structure of the fixing member in the embodiment;

[0044] Figure 8 Schematic diagram of the structure of welding ribbon hole and laser hole.

[0045] In the accompanying drawings, the components represented by the reference numerals are as follows:

[0046] 10. Battery body; 11. Positive electrode grid line; 12. Negative electrode grid line; 13. Left grid line; 14. Right grid line; 15. Positioning part;

[0047] 20. Welding strip; 21. First raised portion; 22. Second raised portion;

[0048] 30. Fixing piece; 31. Welding hole; 32. Laser hole; 33. First adhesive layer; 34. Intermediate base layer; 35. Second adhesive layer. DETAILED DESCRIPTION

[0049] In order to make the purpose, technical solutions and advantages of this application more clear, the following further describes this application in detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not intended to limit this application.

[0050] See also Figure 1 A back-contact cell refers to a photovoltaic module in which the electrode grid lines of the cell body 10 are all located on the back side of the cell body 10, forming a cross-back contact structure. This design leaves the front of the photovoltaic module completely unobstructed, allowing light to directly reach the active area of ​​the cell body 10, thereby maximizing photoelectric conversion efficiency. This application elaborates on the structure of a back-contact cell.

[0051] A back contact battery cell, see Figure 1 、 Figure 2 and Figure 4 , used in the field of photovoltaic power generation, including a battery body 10, a fixing part 30, a welding strip 20 and an insulating glue, the backlight surface of the battery body 10 includes positive grid lines 11 and negative grid lines 12 arranged alternately and in parallel; a first glue layer 33 is provided on one side of the fixing part 30, and is bonded to the battery body 10 through the first glue layer 33; the welding strip 20 is reciprocated on the fixing part 30, and each welding strip 20 is used to connect all the positive grid lines 11 or all the negative grid lines 12 on a single battery body 10; the insulating glue is coated on the positive grid lines 11 or the negative grid lines 12 and is used for insulation; when the welding strip 20 is connected to the positive grid lines 11, the insulating glue is coated on the negative grid lines 12 below the covering position of the fixing part 30; when the welding strip 20 is connected to the negative grid lines 12, the insulating glue is coated on the positive grid lines 11 below the covering position of the fixing part 30.

[0052] Using the above solution, see Figure 4, by setting a fixing piece 30 to wrap the welding ribbon 20, and then fixing the fixing piece 30 on the battery body 10 through the first coating layer 33, thereby fixing the position of the welding ribbon 20 on the battery body 10. At this time, since the welding ribbon 20 is reciprocated on the fixing piece 30, the position where the welding ribbon 20 needs to be connected to the positive grid line 11 or the negative grid line 12 protrudes from the fixing piece 30, so that the welding ribbon 20 will be connected to the positive grid line 11 or the negative grid line 12 through the position of the protruding fixing piece 30, thereby avoiding the poor reliability caused by directly fixing the welding ribbon 20 on the battery body 10 in the prior art by dispensing glue, and the problem that the adhesive film is easy to flow under the welding ribbon 20 during lamination welding to cause cold welding, and also avoids the high cost problem caused by using hot melt adhesive to fix the welding ribbon 20 and the battery body 10; in addition, since the insulating glue is provided, the insulating glue is used to fix the welding ribbon 20 below the fixing piece 30 and does not need to be passed through The positive grid line 11 or the negative grid line 12 connected to the welding strip 20 on the fixing part 30 is coated to insulate and isolate any one of the positive grid line 11 or the negative grid line 12, thereby improving the stability when welding the welding strip 20. Since the width of the fixing part 30 is larger than the welding strip 20 in actual use, when using the insulating glue to coat the target grid line, it is possible to coat only the target grid line covered by the local position or the entire position in the width direction of the fixing part 30. For example, the target grid line covered by the width direction of the fixing part 30 is fully coated with the insulating glue, so that the welding strip 20 and the target grid line that is not welded can be separated; or the range of coating the insulating glue on the target grid line is set to that the size coated along the width direction of the welding strip 20 is 1.2 times to 1.5 times the width of the welding strip 20, and the size of the insulating glue protruding from the welding strip 20 on both sides of the target grid line is equal, thereby ensuring the isolation effect of the welding strip 20 and the target grid line.

[0053] The above-mentioned “target grid line” means the grid line that is not welded to the welding strip 20 . For example, when the welding strip 20 is used to weld the positive grid line 11 , the target grid line is the negative grid line 12 ; when the welding strip 20 is used to weld the negative grid line 12 , the target grid line is the positive grid line 11 .

[0054] For details, see Figure 4 After being applied, the insulating glue is cured at high temperature and has good stability and temperature resistance. Therefore, even if lamination or laser welding is used subsequently, the insulating glue will not melt, that is, the insulating glue will not flow under the welding strip 20 and will not affect the welding position of the welding strip 20.

[0055] For details, see Figure 1 and Figure 4Because the positive and negative grid lines 11 and 12 are arranged in parallel, and a single welding ribbon 20 needs to connect all of the positive or negative grid lines 11 or 12, the welding ribbon 20 is reciprocated through the fixing member 30, which is bonded to the battery body 10. Therefore, the fixing member 30 needs to be set at a certain angle to the positive grid lines 11, and similarly, the fixing member 30 needs to be set at a certain angle to the negative grid lines 12 to ensure that the welding ribbon 20 can simultaneously connect all of the positive or negative grid lines 11 or 12 on a battery body 10. Optionally, the fixing member 30 can be set perpendicular to both the positive and negative grid lines 11, 12 to reduce the length of the welding ribbon 20 and simplify the application range of the insulating adhesive.

[0056] In some embodiments, see Figure 6 The fixing member 30 includes: an intermediate base layer 34, a first adhesive layer 33, and a second adhesive layer 35. The first adhesive layer 33 is located on one side of the intermediate base layer 34 and is used to bond to the battery body 10; the second adhesive layer 35 is located on the other side of the intermediate base layer 34 and is used to bond to the adhesive film above. In this way, the fixing member 30 is configured as a three-layer structure. The intermediate base layer 34 forms the main body of the fixing member 30, and the first adhesive layer 33 is used to adhere the fixing member 30 to the battery body 10, thereby fixing the relative position of the welding ribbon 20 and the battery body 10, thereby assisting the welding ribbon 20 and the corresponding positive electrode grid line 11 to be tightly attached, or assisting the welding ribbon 20 and the corresponding negative electrode grid line 12 to be tightly attached; the second adhesive layer 35 is used to bond the adhesive film located later on.

[0057] For details, see Figure 4 and Figure 6 The first adhesive layer 33 and the second adhesive layer 35 are respectively located on both sides of the middle base layer 34. The two adhesive layers can be glue applied subsequently. For example, the welding ribbon 20 can be first passed through the fixing part 30, and then the first adhesive layer 33 can be applied to the side of the fixing part 30 facing the battery body 10 to help the fixing part 30 to be tightly attached to the battery body 10, thereby preliminarily fixing the position of the welding ribbon 20 and the battery body 10; when applying the second adhesive layer 35, the welding ribbon 20 can also be passed back and forth through the fixing part 30 before applying it; or, the welding ribbon 20 can be first passed through the fixing part 30, and then the first adhesive layer 33 can be applied on the fixing part 30, and then the fixing part 30 can be fixed on the battery body 10 through the first adhesive layer 33, and the welding ribbon 20 and the battery body 10 can be welded or laminated, and then the second adhesive layer 35 can be applied.

[0058] In the embodiment, see Figure 6Because the first adhesive layer 33 is a coating layer made of a heat-resistant glue, such as one that can withstand temperatures of 150°C, the coating layer will not flow under the soldering ribbon 20 during lamination. This ensures the stability of the connection between the soldering ribbon 20 and the battery body 10 during lamination and prevents the occurrence of cold solder joints. The intermediate base layer 34 can be made of any of PET, PC, and PS. The first and second adhesive layers 33, 35 can be made of any of acrylate glue, epoxy resin glue, or organic silicone glue.

[0059] In some embodiments, see Figure 7 The fixing member 30 includes a welding hole 31 for reciprocating insertion of the welding ribbon 20. A plurality of welding holes 31 are provided. The provision of the welding hole 31 facilitates the reciprocating insertion of the welding ribbon 20 through the fixing member 30 and facilitates positioning of the insertion position of the welding ribbon 20. After the welding ribbon 20 is inserted through the fixing member 30, it forms a wavy shape along the length of the fixing member 30. This allows only the portion of the welding ribbon 20 that mates with the positive grid line 11 or the negative grid line 12 to protrude from the fixing member 30. This facilitates contact between the welding ribbon 20 and the portion where the positive grid line 11 or the negative grid line 12 is to be welded, thereby facilitating welding of the welding ribbon 20.

[0060] For details, see Figure 4 and Figure 5 The welding strip 20 is passed back and forth on the fixing member 30, so that multiple positions in the length direction of the fixing member 30 are provided with protruding welding strips 20. When the welding strip 20 is used to connect the positive electrode grid line 11 on the battery body 10, the protruding position of the welding strip 20 on the fixing member 30 is not less than the number of the positive electrode grid lines 11 on the battery body 10, and the protruding welding strip 20 forms a one-to-one correspondence and fits with the positive electrode grid lines 11, so that all the positive electrode grid lines 11 can be connected through the welding strip 20; when the welding strip 20 is used to connect the negative electrode grid lines 12 on the battery body 10, the protruding position of the welding strip 20 on the fixing member 30 is not less than the number of the negative electrode grid lines 12 on the battery body 10, and forms a one-to-one correspondence and fits with the negative electrode grid lines 12, so that all the negative electrode grid lines 12 can be connected through the welding strip 20.

[0061] When only the welding ribbon hole 31 is provided on the fixing member 30 , the welding ribbon 20 can be welded to the corresponding position on the battery body 10 by lamination welding; or the welding ribbon 20 can be welded to the corresponding position on the battery body 10 by laser welding.

[0062] Specifically, the fixing member 30 is a narrow strip structure, or the fixing member 30 can also be a wider strip structure. The fixing member 30 is provided with alternatingly arranged welding tape holes 31 and laser holes 32. The welding tape holes 31 and laser holes 32 extending along the same length direction and alternatingly arranged are a group of welding auxiliary holes. At least one group of welding auxiliary holes can be set on each fixing member 30, and each group of welding auxiliary holes is used to connect a welding tape 20. Therefore, only one welding tape 20 can be passed through each fixing member 30, or multiple welding tapes 20 can be passed through each fixing member 30, which is beneficial to reduce the number of fixing members 30.

[0063] In some embodiments, see Figure 7 The fixing member 30 also includes: laser holes 32, which are alternately opened with the welding ribbon holes 31. The laser holes 32 are used to weld the welding ribbon 20 to the positive electrode grid line 11 or the negative electrode grid line 12 by laser. When the welding ribbon 20 is connected to the positive electrode grid line 11, the laser holes 32 at least correspond to the positive electrode grid line 11; when the welding ribbon 20 is connected to the negative electrode grid line 12, the laser holes 32 at least correspond to the negative electrode grid line 12. In this way, since the laser holes 32 and the welding tape holes 31 are opened alternately, the laser holes 32 are arranged between adjacent welding tape holes 31, so that the opening position of the laser holes 32 corresponds to the position where the welding tape 20 protrudes from the fixing part 30. Therefore, the welding tape 20 can be welded by laser from the laser hole 32, and the welding tape 20 located on one side of the fixing part 30 is laser welded through the laser hole 32, so that the welding tape 20 is fixed to the corresponding positive grid line 11 or negative grid line 12; specifically, when the welding tape 20 is used to connect the positive grid line 11, the laser holes 32 correspond to the positive grid line 11 one by one, thereby facilitating the welding of the positive grid line 11 and the welding tape 20 together from the laser hole 32; when the welding tape 20 is used to connect the negative grid line 12, the laser holes 32 correspond to the negative grid line 12 one by one, thereby facilitating the welding of the negative grid line 12 and the welding tape 20 together from the laser hole 32.

[0064] Specifically, the positive grid lines 11 and the negative grid lines 12 can be arranged at equal intervals, and the distance between adjacent laser holes 32 is equal to the distance between adjacent positive grid lines 11 and negative grid lines 12. Therefore, the position of the laser hole 32 can be completely corresponding to the position of the positive grid line 11 or the negative grid line 12, so that when laser welding is performed, it can be ensured that the welding strip 20 is welded to the corresponding positive grid line 11 or negative grid line 12, so as to accurately complete the welding of the welding strip 20.

[0065] In some embodiments, see Figure 7The welding hole 31 is a flat hole, and the laser hole 32 is a round hole or an elliptical hole. Setting the welding hole 31 as a flat hole facilitates the insertion of the welding ribbon 20 and can position the angle of the welding ribbon 20. The flat hole can also reduce the bending of the welding ribbon 20, thereby effectively avoiding localized excessive stress or fracture of the welding ribbon 20 caused by bending. Setting the laser hole 32 as a larger hole, such as a round hole or an elliptical hole, facilitates the penetration of the laser and welding during laser welding.

[0066] In specific use, it is sufficient to set the circular hole or elliptical hole as a wide hole with a certain length and width, so as to facilitate the laser to pass through and weld. Therefore, the laser hole 32 can be not only a circular hole or an elliptical hole, but also a square hole, etc.

[0067] In some embodiments, the width of the laser hole 32 is not less than the width of the soldering hole 31; and / or the length of the laser hole 32 is not less than the length of the soldering hole 31. The width is the direction in which the soldering ribbon is threaded, and the length is perpendicular to the direction in which the soldering ribbon is threaded. In this way, rationally sizing the laser hole 32 and the soldering hole 31 facilitates the threading of the soldering ribbon 20 back and forth through the multiple soldering holes 31, improving the stability of the soldering ribbon 20 during threading.

[0068] In some embodiments, the positive grid lines 11 and the negative grid lines 12 are evenly spaced, and the welding tape holes 31 and the laser holes 32 are evenly alternately arranged; when the welding tape 20 is connected to the positive grid lines 11, the laser holes 32 correspond one-to-one to the positive grid lines 11, and the welding tape holes 31 are located between two adjacent positive grid lines 11; when the welding tape 20 is connected to the negative grid lines 12, the laser holes 32 correspond one-to-one to the negative grid lines 12, and the welding tape holes 31 are located between two adjacent negative grid lines 12; or, when the welding tape 20 is connected to the positive grid lines 11 or the negative grid lines 12, the laser holes 32 correspond one-to-one to both the positive grid lines 11 and the negative grid lines 12, and the welding tape holes 31 are located between adjacent positive grid lines 11 and negative grid lines 12. In this way, when using the welding ribbon 20 to connect the positive electrode grid line 11, since the negative electrode grid line 12 located below the fixing member 30 is coated with insulating glue, it is only necessary to set the welding ribbon hole 31 between two adjacent positive electrode grid lines 11; similarly, when using the welding ribbon 20 to connect the negative electrode grid line 12, since the positive electrode grid line 11 located below the fixing member 30 is coated with insulating glue, it is only necessary to set the welding ribbon hole 31 between two adjacent negative electrode grid lines 12.

[0069] In some embodiments, there are multiple soldering ribbons 20 arranged parallel to each other; there is a single fixing member 30, which is provided with multiple rows of through holes. The number of rows of through holes is the same as the number of soldering ribbons 20, and each row of through holes includes alternating laser holes 32 and soldering ribbon holes 31. Alternatively, there are multiple fixing members 30, one fixing member 30 corresponding to each soldering ribbon 20, and each fixing member 30 is provided with a row of through holes, each row of through holes including alternating laser holes 32 and soldering ribbon holes 31. In this way, when the soldering ribbon 20 and the fixing member 30 are connected together, the fixing member 30 can be in a one-to-one correspondence with the soldering ribbon 20, or multiple soldering ribbons 20 can be passed through a single fixing member 30, thereby improving the integration of the overall structure.

[0070] In the embodiment, see Figure 1 、 Figure 2 and Figure 3 The battery body 10 also includes a positioning portion 15, which is provided on one side of the battery body 10 and is used to guide the direction in which the welding ribbon 20 extends from the battery body 10. Since the welding ribbon 20 needs to extend out of the battery body 10, it is necessary to determine which end of the battery body 10 the welding ribbon 20 extends from in order to determine the correct laying direction of the welding ribbon 20. The positioning portion 15 facilitates guiding the placement of the welding ribbon 20 when laying the fixing member 30 and the welding ribbon 20, thereby preventing the welding ribbon 20 from being placed upside down.

[0071] For details, see Figure 1 、 Figure 2 and Figure 3 When laying the positioning portion 15 and the welding strip 20, it is necessary to conduct the electricity of the battery body 10, so the positioning portion 15 can be used to position the direction of the conduction; when in use, the positioning portion 15 can be set on one side of the battery body 10 and the side is parallel to the positive grid line 11 and the negative grid line 12. When the welding strip 20 extends in a direction perpendicular to the positive grid line 11 and the negative grid line 12, that is, the side is perpendicular to the welding strip 20, and thus the positioning portion 15 can be set on the side to indicate the direction in which the welding strip 20 extends out of the battery, such as setting one end of the positioning portion 15 as the direction in which the welding strip 20 connected to the positive grid line 11 extends, and correspondingly, the end opposite to the positioning portion 15 is the direction in which the welding strip 20 connected to the negative grid line 12 extends; the direction setting can also be reversed, as long as it can play a role in positioning the direction in which the welding strip 20 extends out.

[0072] In the embodiment, see Figure 1 、 Figure 2 and Figure 3The positioning portion 15 is located at both ends of a side of the battery body 10, with each end having a triangular notch. Placing the positioning portion 15 on the side of the battery body 10 notches notches a triangular shape. This provides positioning while reducing the number of right-angled edges on the battery body 10, protecting operators and preventing bending or other damage to the battery body 10 that might occur if the positioning portion 15 were located in the middle of the battery body 10.

[0073] For details, see Figure 1 、 Figure 2 and Figure 3 The battery body 10 is rectangular and has two notches on one side. The side is parallel to the positive grid line 11 and the negative grid line 12. The two notches are symmetrically arranged along the length direction of the grid lines and are respectively arranged at both ends of the side.

[0074] In the embodiment, see Figure 4 The positive grid lines 11 and the negative grid lines 12 are evenly spaced, and the welding strips 20 are provided in multiple pieces and arranged parallel to each other. This facilitates the placement of the welding strips and simplifies the way the welding strips 20 connect to the positive grid lines 11 or the negative grid lines 12.

[0075] Specifically, the welding strip 20 is divided into a first welding strip and a second welding strip. The first welding strip is used to connect all the positive electrode grid lines 11 on a single battery body 10, and the second welding strip is used to connect all the negative electrode grid lines 12 on a single battery body 10. There are multiple first welding strips and second welding strips and they are arranged parallel to each other. By providing multiple first welding strips and connecting the first welding strips to all positive grid lines 11 on a single battery body 10, and by providing multiple second welding strips and connecting the second welding strips to all negative grid lines 12 on a single battery body 10, that is, by providing multiple first welding strips and second welding strips to connect the battery body 10, the following effects are achieved: improving the shunt effect, providing multiple connected welding strips 20 for the positive grid lines 11 and the negative grid lines 12 respectively, which can disperse and conduct the current, reduce the current density of a single welding strip 20, and thus reduce resistance loss and heat generation; improving the reliability of the photovoltaic cell body 10, even if a certain welding strip 20 is broken or has poor contact, the other welding strips 20 can continue to conduct current, thereby improving the overall reliability of the system; facilitating assembly and maintenance, the design of multiple welding strips 20 makes the assembly and maintenance of photovoltaic cell modules more convenient and flexible; enhancing the mechanical strength, the connection between the welding strips 20 and the grid lines not only plays a conductive role, but the welding strips 20 can also serve as reinforcement ribs to improve the structural stability of the battery body 10.

[0076] Specifically, when arranging a plurality of first welding strips and a plurality of second welding strips, since the first welding strips are arranged in parallel with the second welding strips, the positions of the first welding strips and the second welding strips can be set according to needs. The following describes possible arrangements of the first welding strips and the second welding strips:

[0077] The first method is to arrange all the first welding strips close together, and all the second welding strips close together. Since "when the welding strip 20 is connected to the positive electrode grid line 11, the insulating glue is applied to the negative electrode grid line 12 below the cover position of the fixing member 30; when the welding strip 20 is connected to the negative electrode grid line 12, the insulating glue is applied to the positive electrode grid line 11 below the cover position of the fixing member 30", this arrangement of the first welding strips and the second welding strips can conveniently improve the efficiency of applying the insulating glue, for example, it can effectively prevent the insulating lateral glue that needs to cover the positive electrode grid line 11 from extending to the position of the negative electrode grid line 12;

[0078] Secondly, the first welding strips and the second welding strips may be arranged alternately.

[0079] In the embodiment, see Figure 1 The number of the first welding strips and the second welding strips can be set to be equal, for example, the number of each welding strip 20 can be between 5 and 10.

[0080] In some embodiments, see Figure 1 The battery body 10 further includes a left grid line 13 and a right grid line 14. The left grid line 13 is located on one side of the battery body 10 and is used to connect one end of all the positive grid lines 11 without contacting the negative grid line 12. The right grid line 14 is located on the other side of the battery body 10 and is used to connect one end of all the negative grid lines 12 without contacting the positive grid line 11. The left grid line 13 and the right grid line 14 are arranged in parallel, and the left grid line 13 and the positive grid lines 11 are perpendicular to each other. In this way, the battery body 10 is provided with a left grid line 13 and a right grid line 14. The left grid line 13 is used to connect one end of all the positive grid lines 11, and the right grid line 14 is used to connect one end of all the negative grid lines 12. The left grid line 13 and the right grid line 14 are used to converge current, that is, the left grid line 13 converges all the positive grid lines 11, and the right grid line 14 converges all the negative grid lines 12, thereby preventing current mismatch.

[0081] A photovoltaic module includes a plurality of back-contact type cells.

[0082] For the back-contact battery cell of the present application, there are at least two welding methods for fixing the welding ribbon 20 and the battery body 10 together, including laser welding and lamination welding. The following describes the two welding methods in detail.

[0083] Example 1:

[0084] When laser welding is used in this application, see Figure 1 and Figure 4The photovoltaic module includes a battery body 10, a welding ribbon 20, a fixing part 30 and an insulating glue. The battery body 10 includes positive grid lines 11 and negative grid lines 12 arranged alternately and in parallel. The fixing part 30 is provided with welding ribbon holes 31 and laser holes 32 arranged alternately. The welding ribbon holes 31 are used to facilitate the passage of the welding ribbon 20 and fix the position of the welding ribbon 20. The laser holes 32 are used to facilitate the passage of the laser and facilitate the welding ribbon 20 and the positive grid line 11 or the welding ribbon 20 and the negative grid line 12. Welding; when using laser welding, it is best to meet the requirements that "the positive grid lines 11 and the negative grid lines 12 are arranged at equal intervals, the distance between adjacent laser holes 32 is equal to the distance between adjacent positive grid lines 11 and negative grid lines 12; the laser holes 32 are used to laser weld the welding strip 20 to the positive grid lines 11 or the negative grid lines 12", thereby simplifying the setting of the positions of the welding strip holes 31 and the laser holes 32, and it is only necessary to set the welding strip holes 31 and the laser holes 32 at equal intervals to meet the requirements.

[0085] For the above structure, when using it, see Figure 4 and Figure 5 When the first welding tape is used to connect the positive electrode grid line 11, the first welding tape is passed back and forth in the welding tape hole 31, so that the first welding tape is arranged in a wavy shape relative to the fixing member 30, and the first welding tape forms a first protrusion 21 and a second protrusion 22 on both sides of the fixing member 30, respectively. The first protrusion 21 and the second protrusion 22 arranged along the length direction are arranged alternately, wherein the first protrusion 21 is used to fit with the positive electrode grid line 11, and the second protrusion 22 is located on the side of the fixing member 30 facing away from the battery body 10. The first protrusion 21 and the second protrusion 22 are arranged on the fixing member The positions extending from the upper portion 30 all coincide with the laser holes 32. During laser welding, the first protrusion 21 is welded by passing the welding laser through the laser hole 32 corresponding to the first protrusion 21, so as to weld the first protrusion 21 to the positive electrode grid line 11. It can also be seen from the above that, among any two adjacent laser holes 32, only one laser hole 32 is used for the laser to pass through. Therefore, when setting the positional relationship between the welding ribbon hole 31 and the laser hole 32, it is also possible not to set the laser hole 32 corresponding to the second protrusion 22. This setting reduces the position of the laser hole 32 by half.

[0086] Correspondingly, when the second welding tape is used to connect the negative electrode grid line 12, the second welding tape also has corresponding third and fourth raised portions, wherein the third raised portion corresponds to the first raised portion 21, and the fourth raised portion corresponds to the second raised portion 22. Therefore, the understanding of the third and fourth raised portions and the operation during laser welding can refer to the above-mentioned first and second raised portions 21, 22, and will not be repeated here.

[0087] Example 2:

[0088] When lamination welding is used in this application, see Figure 1 and Figure 7 The photovoltaic module includes a battery body 10, a welding ribbon 20, a fixing part 30 and an insulating adhesive. The battery body 10 includes alternating and parallel positive grid lines 11 and negative grid lines 12. The fixing part 30 is provided with evenly arranged welding ribbon holes 31. The welding ribbon holes 31 are used to facilitate the passage of the welding ribbon 20 and fix the position of the welding ribbon 20. Since the laser hole 32 is not required for lamination welding, whether the laser hole 32 is provided on the fixing part 30 has no effect when used for lamination welding; however, if the laser hole 32 is provided, the laser hole 32 can be used to assist in checking whether the welding ribbon 20 is placed correctly and whether the welding ribbon 20 is in contact with the corresponding positive grid line 11 or negative grid line 12. Since the welding ribbon 20 is passed back and forth on the fixing part 30, after the welding ribbon 20 is wrapped around the fixing part 30, the preparatory operations before lamination welding include:

[0089] See also Figure 4 and Figure 5 When the first welding tape is used to connect the positive electrode grid line 11, the first welding tape is passed back and forth through the welding tape hole 31, so that the first welding tape is arranged in a wavy shape relative to the fixing member 30, and the first welding tape forms a first protrusion 21 and a second protrusion 22 on both sides of the fixing member 30, respectively. The first protrusion 21 and the second protrusion 22 are arranged alternately along the length direction, wherein the first protrusion 21 is used to fit with the positive electrode grid line 11, and the second protrusion 22 is located on the side of the fixing member 30 facing away from the battery body 10. When laminating and welding, ensure that all the first protrusions 21 are aligned with the positive electrode grid line 11 to perform laminating and welding, thereby fixing the first welding tape to the positive electrode grid line 11;

[0090] Correspondingly, when the second welding tape is used to connect the negative electrode grid line 12, the second welding tape also has corresponding third and fourth protrusions, wherein the third protrusion corresponds to the first protrusion 21, and the fourth protrusion corresponds to the second protrusion 22. Therefore, the understanding of the third and fourth protrusions and the operation during lamination welding can refer to the above; that is, by passing the second welding tape back and forth in the welding tape hole 31, the second welding tape is arranged in a wavy shape relative to the fixing member 30, and the second welding tape forms a third protrusion and a fourth protrusion on both sides of the fixing member 30, respectively, and the third and fourth protrusions are arranged alternately along the length direction, wherein the third protrusion is used to fit with the negative electrode grid line 12, and the fourth protrusion is located on the side of the fixing member 30 facing away from the battery body 10. When lamination welding is performed, ensure that all the third protrusions are aligned with the negative electrode grid line 12 to perform lamination welding, thereby fixing the second welding tape on the negative electrode grid line 12.

[0091] In the embodiment, laser welding requires the use of laser, so the welding strip 20 can be a high-temperature welding strip 20, and the adhesive film can be a conventional adhesive film; the laminated welding can be laminated low-temperature welding, and the laminated low-temperature welding needs to match the low-temperature welding strip 20, and the adhesive film is also a conventional adhesive film. During the lamination process, the low-temperature welding strip 20 is alloyed with the metal grid line for welding.

[0092] In the embodiment, see Figure 7 and Figure 8 The sizes of the laser hole 32 and the welding tape hole 31 on the fixing member 30 correspond to the sizes of the welding tape 20. Specifically, the length of the laser hole 32 is a and the width is b, and the length of the welding tape hole 31 is c and the width is d. The relationship can be: a≥c, b≥d, c>the width of the welding tape, d>the thickness of the welding tape.

[0093] It should be noted that the illustrations provided in this embodiment are only used to schematically illustrate the basic concept of the present invention. Therefore, the illustrations only show components related to the present invention and are not drawn according to the number, shape and size of components in actual implementation. In actual implementation, the type, quantity and proportion of each component can be changed at will, and the component layout type may also be more complicated.

[0094] The structures, proportions, sizes, etc. illustrated in the drawings in this specification are only used to match the contents disclosed in the specification so as to facilitate understanding and reading by persons familiar with the art. They are not intended to limit the conditions under which the present invention can be implemented and therefore have no substantive technical significance. Any structural modifications, changes in proportions, or adjustments in sizes shall still fall within the scope of the technical contents disclosed in this utility model without affecting the efficacy and objectives that can be achieved by the present utility model.

[0095] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like to indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation to the present invention.

[0096] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature specified as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of this utility model, "plurality" means at least two, such as two, three, etc., unless otherwise specifically defined.

[0097] In this utility model, unless otherwise specified or limited, the terms "installed," "connected," "connect," "fixed," etc. should be understood in a broad sense. For example, they can refer to fixed connection, detachable connection, or integration; mechanical connection, electrical connection; direct connection, or indirect connection through an intermediate medium; internal communication between two components, or interaction between two components, unless otherwise specified. Those skilled in the art will understand the specific meanings of the above terms in this utility model based on specific circumstances.

[0098] In the present invention, unless otherwise expressly specified or limited, when a first feature is "above" or "below" a second feature, it may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediary. Furthermore, when a first feature is "above," "above," or "above" a second feature, it may mean that the first feature is directly above or diagonally above the second feature, or simply means that the first feature is at a higher level than the second feature. When a first feature is "below," "below," or "below" a second feature, it may mean that the first feature is directly below or diagonally below the second feature, or simply means that the first feature is at a lower level than the second feature.

[0099] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification and features of different embodiments or examples without contradiction.

[0100] The above-described embodiments merely represent several implementation methods of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the utility model patent. It should be noted that a person skilled in the art could make various modifications and improvements without departing from the spirit of the present application, all of which fall within the scope of protection of the present application. Therefore, the scope of protection of the present patent application shall be determined by the appended claims.

Claims

1. A back-contact solar cell, used in the field of photovoltaic power generation, characterized in that: include: A battery body (10), wherein the backlight surface of the battery body (10) includes positive electrode grid lines (11) and negative electrode grid lines (12) that are alternately arranged and arranged in parallel; A fixing member (30), wherein a first adhesive layer (33) is provided on one side of the fixing member (30) and the fixing member (30) is bonded to the battery body (10) via the first adhesive layer (33); Welding strips (20), the welding strips (20) being reciprocally threaded on the fixing member (30), each welding strip (20) being used to connect all the positive electrode grid lines (11) or all the negative electrode grid lines (12) on the battery body (10); Insulating glue, the insulating glue is coated on the positive electrode grid line (11) or the negative electrode grid line (12) and is used for insulation; When the welding strip (20) is connected to the positive grid line (11), the insulating glue is applied to the negative grid line (12) located below the covering position of the fixing member (30); when the welding strip (20) is connected to the negative grid line (12), the insulating glue is applied to the positive grid line (11) located below the covering position of the fixing member (30).

2. The back contact battery cell according to claim 1, characterized in that: The fixing member (30) comprises: Intermediate base (34), The first adhesive layer (33), the first adhesive layer (33) is located on one side of the intermediate base layer (34) and is used for bonding with the battery body (10); A second adhesive layer (35), the second adhesive layer (35) is located on the other side of the intermediate base layer (34) and is used for bonding with the upper adhesive film.

3. The back contact battery sheet according to claim 1, characterized in that: The fixing member (30) comprises: A welding belt hole (31), wherein the welding belt hole (31) is used for reciprocating insertion of the welding belt (20), and a plurality of welding belt holes (31) are provided.

4. The back contact battery sheet according to claim 3, characterized in that: The fixing member (30) further comprises: Laser holes (32), the laser holes (32) and the welding strip holes (31) being alternately opened, the laser holes (32) being used to weld the welding strip (20) to the positive electrode grid line (11) or the negative electrode grid line (12) by laser welding; When the welding strip (20) is connected to the positive grid line (11), the laser holes (32) correspond to at least the positive grid line (11) one-to-one; when the welding strip (20) is connected to the negative grid line (12), the laser holes (32) correspond to at least the negative grid line (12) one-to-one.

5. The back contact battery sheet according to claim 4, characterized in that: The welding belt hole (31) is a flat hole, and the laser hole (32) is a circular hole or an elliptical hole.

6. The back contact battery sheet according to claim 5, characterized in that: The width of the laser hole (32) is not less than the width of the welding strip hole (31); and / or, the length of the laser hole (32) is not less than the length of the welding strip hole (31); The width direction is the direction in which the welding strip is passed through, and the length direction is a direction perpendicular to the direction in which the welding strip is passed through.

7. The back contact battery sheet according to any one of claims 4 to 6, characterized in that: The positive electrode grid lines (11) and the negative electrode grid lines (12) are evenly spaced, and the welding holes (31) and the laser holes (32) are evenly and alternately arranged; When the welding strip (20) is connected to the positive grid line (11), the laser holes (32) correspond to the positive grid lines (11) one by one, and the welding strip holes (31) are located between two adjacent positive grid lines (11); when the welding strip (20) is connected to the negative grid line (12), the laser holes (32) correspond to the negative grid lines (12) one by one, and the welding strip holes (31) are located between two adjacent negative grid lines (12); Alternatively, the welding strip (20) is connected to the positive grid line (11) or the negative grid line (12), the laser holes (32) correspond one-to-one to the positive grid line (11) and the negative grid line (12), and the welding strip holes (31) are located between adjacent positive grid lines (11) and negative grid lines (12).

8. The back contact battery sheet according to any one of claims 4 to 6, characterized in that: The welding strips (20) are provided in plurality and are arranged parallel to each other; There is one fixing member (30), and a plurality of rows of through holes are provided on the fixing member (30), the number of rows of through holes being the same as the number of the welding strips (20), and each row of through holes comprising the laser holes (32) and the welding strip holes (31) arranged alternately; Alternatively, there are multiple fixing members (30), one fixing member (30) corresponds to one welding strip (20), each fixing member (30) is provided with a row of through holes, and each row of through holes includes the laser holes (32) and the welding strip holes (31) that are alternately arranged.

9. The back contact battery sheet according to claim 1, characterized in that: The battery body (10) further includes: a left grid line (13), the left grid line (13) being located on one side of the battery body (10), the left grid line (13) being used to connect one end of all the positive grid lines (11) and not being in contact with the negative grid line (12); a right grid line (14), the right grid line (14) being located on the other side of the battery body (10), the right grid line (14) being used to connect one end of all the negative grid lines (12) and not in contact with the positive grid line (11); The left grid line (13) and the right grid line (14) are arranged in parallel, and the left grid line (13) and the positive grid line (11) are perpendicular to each other.

10. A photovoltaic module, characterized in that: The invention comprises a plurality of back-contact battery sheets according to any one of claims 1 to 9.

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