Photovoltaic module

Abstract

This disclosure relates to a photovoltaic module, comprising: a plurality of cell strings (1), each cell string (1) including a plurality of cell sheets (12) arranged along a first direction (X) and connected by solder strips (11); a plurality of first busbars (21) extending along a second direction (Y) perpendicular to the first direction (X), respectively connected to the solder strips (11) at both ends and the middle of each cell string (1), the first busbars (21) being located on the back side of the cell sheets (12) of each cell string (1); the solder strips (11) between adjacent cell sheets (12) connected to the first busbar (21) located in the middle are uninterrupted. In this disclosure, the solder strips between adjacent cell sheets located in the middle do not need to be cut, and a stable and reliable connection can be achieved between the solder strips and the first busbars, reducing the occurrence of poor soldering and helping to improve the yield of the photovoltaic module.

Description

Technical Field

[0001] This disclosure relates to a photovoltaic module. Background Technology

[0002] In photovoltaic modules, the main purpose of busbars and solder ribbons is to transmit the current generated by a single cell string to the busbar through the solder ribbon and connect the busbar to other cell strings, so that the current generated by all cell strings can be transmitted to the external circuit through the lead-out terminals of the busbar.

[0003] In related technologies, such as CN114649435A and CN113782628A, the solder ribbon is connected through the busbar, and then the busbar is folded to the back side of the cell string to increase the front light-receiving area. However, the solder ribbon located in the middle of the cell string needs to be cut before it can be connected to the busbar, which increases the process time in photovoltaic module manufacturing and results in low production efficiency. In addition, after the solder ribbon is cut, it is welded to both sides of the busbar and then folded. During the folding process, the solder ribbon may detach from the busbar, resulting in poor soldering and affecting the yield of photovoltaic modules. Utility Model Content

[0004] In view of this, the present disclosure provides a photovoltaic module that is beneficial to improving product yield.

[0005] In one aspect of this disclosure, a photovoltaic module is provided, comprising:

[0006] Multiple battery strings, each battery string comprising multiple battery cells arranged along a first direction and connected by solder strips;

[0007] Multiple first busbars extend along a second direction perpendicular to the first direction and are connected to the solder strips at both ends and the middle of each battery string, respectively. The first busbars are located on the back of the battery cells of each battery string.

[0008] The solder strips between adjacent battery cells connected to the first busbar in the middle are uninterrupted.

[0009] In some embodiments, the solder strip between adjacent cells is configured to be partially folded over the back of the cell, and a first busbar is connected to the folded portion of the solder strip.

[0010] In some embodiments, the front and back sides of the first busbar located in the middle are connected to the folded portion of the solder strip.

[0011] In some embodiments, the photovoltaic module further includes:

[0012] A first buffer section, disposed between the front side of the battery cell connected to the first busbar and the solder strip, is configured to melt during the welding and / or lamination process.

[0013] In some embodiments, a first buffer portion is disposed at the end of the battery cell along a first direction. The first buffer portion extends along the first direction and a third direction perpendicular to both the first and second directions, so as to wrap the solder strip located on the front side of the battery cell and between adjacent battery cells.

[0014] In some embodiments, the first buffer portion includes any one of: an adhesive film formed from ethylene-vinyl acetate copolymer, an adhesive film formed from polyethylene octene coelastomer, a co-extruded structure formed from ethylene-vinyl acetate copolymer and polyethylene octene coelastomer, an ultraviolet curable adhesive, and a thermosetting adhesive.

[0015] In some embodiments, the solder strips between adjacent cells are configured to be connected to the back side of the cell in which the first busbar is provided and the front side of another cell, respectively.

[0016] In some embodiments, the folded portion of the solder strip does not overlap with other solder strips on the back side of the cell where the first busbar is located.

[0017] In some embodiments, the first busbar is configured to connect to the side of the cell away from the solder strip on the back side of the cell.

[0018] In some embodiments, the photovoltaic module further includes:

[0019] The second buffer section is located on the back of the battery cell connected to the first busbar and is connected to the solder strip.

[0020] In some embodiments, the solder strips on the front side of the solar cell are folded over the back side of the solar cell, and the second buffer portion is an insulating element.

[0021] In some embodiments, the plurality of battery strings are spaced apart along a second direction;

[0022] The photovoltaic module also includes a second busbar extending along a first direction. The second busbar is connected to the first busbar located at both ends of the cell string. The second busbar is connected in series with a bypass diode.

[0023] In some embodiments, the photovoltaic module further includes: two battery modules, each battery module including a plurality of battery strings connected in parallel via a first busbar;

[0024] Among them, the two first busbars located at the first end of the battery string in the two battery modules are connected in series, and the first busbars located in the middle of the battery string in the two battery modules are connected through a bypass diode;

[0025] The positive electrode of the photovoltaic module is located on the side of one of the battery modules near the second end of the battery string, and the negative electrode of the photovoltaic module is located on the side of another battery module near the second end of the battery string.

[0026] In some embodiments, the number of bypass diodes is two, which are respectively disposed on both sides of the first busbar located in the middle of the battery string;

[0027] The positive electrode of the photovoltaic module is located at the first busbar at the first end of the battery string, or between the first end of the second busbar and the bypass diode near the first end of the battery string.

[0028] The negative electrode of the photovoltaic module is located at the first busbar at the second end of the battery string, or between the second end of the second busbar and the bypass diode near the second end of the battery string.

[0029] In some embodiments, the photovoltaic module further includes:

[0030] The second buffer section is located between the second busbar and the battery cell.

[0031] Therefore, according to the embodiments of this disclosure, a stable and reliable connection can be achieved between the uncut, uninterrupted solder strip and the first busbar, reducing the occurrence of poor soldering due to the separation of the first busbar and the solder strip, which helps to improve the yield of photovoltaic modules. Attached Figure Description

[0032] Figure 1 These are schematic diagrams illustrating the structure of photovoltaic modules according to some embodiments of the present disclosure;

[0033] Figure 2 yes Figure 1 A partial schematic diagram of the battery string located in the middle;

[0034] Figure 3 yes Figure 1 A partial schematic diagram of the battery string located at one end;

[0035] Figure 4 These are schematic diagrams of the structure of photovoltaic modules according to other embodiments of the present disclosure;

[0036] Figure 5 yes Figure 4 A partial schematic diagram of the battery string located in the middle;

[0037] Figure 6 yes Figure 4 A partial schematic diagram of the battery string located at one end;

[0038] Figure 7 These are schematic diagrams illustrating the structure of photovoltaic modules according to further embodiments of the present disclosure;

[0039] Figure 8 yes Figure 7 A partial schematic diagram of the battery string located in the middle;

[0040] Figure 9 yes Figure 8 A bottom view;

[0041] Figure 10 This is a schematic diagram of the structure of the photovoltaic module's cell string stacking according to the present disclosure;

[0042] Figure 11 yes Figure 10 A partial schematic diagram of the battery string located in the middle;

[0043] Figure 12 yes Figure 11 A bottom view;

[0044] Figure 13 These are schematic diagrams of some embodiments of photovoltaic modules according to this disclosure;

[0045] Figure 14 These are schematic diagrams of other embodiments of photovoltaic modules according to this disclosure.

[0046] In the picture:

[0047] 1. Battery string; 11. Solder strip; 12. Battery cell;

[0048] 21. First busbar; 22. Second busbar;

[0049] 3. First buffer section;

[0050] 4. Second buffer section;

[0051] 5. Bypass diode;

[0052] 61. Positive electrode; 62. Negative electrode;

[0053] 7. Photovoltaic modules;

[0054] X, first direction; Y, second direction; Z, third direction.

[0055] It should be understood that the dimensions of the various parts shown in the accompanying drawings are not drawn to actual scale. Furthermore, the same or similar reference numerals denote the same or similar components. Detailed Implementation

[0056] Various exemplary embodiments of this disclosure will now be described in detail with reference to the accompanying drawings.

[0057] The photovoltaic modules involved in the embodiments of this invention can be any type of photovoltaic module, such as double-glass modules, single-glass modules, etc. The solar cells used in the photovoltaic modules can be any type of solar cell with main grid lines or a gridless solar cell (such as silicon-based solar cells, perovskite solar cells, etc., wherein silicon-based solar cells can be of the cross-type, back-contact type, or type with electrodes on both sides, etc.) cut from.

[0058] One aspect of this disclosure provides a photovoltaic module that can improve product yield.

[0059] Figure 1 These are schematic diagrams illustrating the structure of photovoltaic modules according to some embodiments of the present disclosure. Figure 2 yes Figure 1 A partial schematic diagram of the battery string located in the middle. Figure 3 yes Figure 1 A partial schematic diagram of the battery string located at one end, for reference. Figures 1-3 The photovoltaic module includes multiple cell strings 1 and a first busbar 21.

[0060] Each of the multiple battery strings 1 includes multiple battery cells 12 arranged along a first direction X and connected by solder strips 11. A first busbar 21 extends along a second direction Y perpendicular to the first direction X, and is connected to the solder strips 11 of each battery string 1 at both ends and the middle of each battery string 1. The first busbar 21 is located on the back side of the battery cells 12 of each battery string 1. A third direction Z is perpendicular to both the first direction X and the second direction Y, including but not limited to the thickness direction parallel to the battery cell 12. The front and back sides of the battery cell 12 are two surfaces opposite each other along the third direction Z.

[0061] The solder strips 11 connecting the adjacent battery cells 12 to the first busbar 21 located in the middle are uninterrupted. The two ends and the middle of the battery string 1 refer to the two ends and the middle position of the battery string 1 along the first direction X.

[0062] Multiple battery cells 12 are connected in series along the first direction X by solder strips 11 to form a battery string 1. A first busbar 21 extending along the second direction Y is connected to the solder strips 11 at both ends and the middle of the battery string 1.

[0063] The first busbar 21 located in the middle of the battery string 1 can act as a bypass when a cell 12 in the photovoltaic module has a hot spot or is damaged, so that other cells 12 can carry current to maintain the overall power of the photovoltaic module.

[0064] The solder strip 11 between two adjacent cells 12 in the middle of the battery string 1 is directly welded to the first busbar 21 without being cut or interrupted. This ensures that the first busbar 21 can form a reliable and stable connection with the solder strip 11 on both sides along the first direction X, reducing the possibility of the solder strip 11 detaching from the first busbar 21 due to poor soldering, and improving the quality of the photovoltaic module.

[0065] Furthermore, when a cell 12 in the photovoltaic module fails, the reliable connection between the solder ribbon 11 and the first busbar 21 located in the middle can reduce the risk that current cannot be transmitted to the first busbar 21 for bypassing, thus preventing other normal cells 12 from outputting current, which is beneficial to maintaining the overall power of the photovoltaic module. Since the solder ribbon 11 does not require trimming, it can also reduce the number of manufacturing steps in the photovoltaic module, shorten processing time, and improve manufacturing efficiency.

[0066] The solder strips 11 between adjacent battery cells 12 include, but are not limited to, being directly soldered to the first busbar 21 on the back side of the battery cell 12, or being first soldered to the first busbar 21 on the front side of the battery cell 12 and then folded together with the first busbar 21 to the back side of the battery cell 12.

[0067] The first busbar 21 is hidden on the back of the solar cell 12, which can increase the front light-receiving area of ​​the photovoltaic module. With the same area layout, more solar cells 12 can be added to improve the power generation efficiency of the photovoltaic module.

[0068] The solar cell 12 has pads for welding with the solder ribbon 11. The pads can collect and conduct current. The solder ribbon 11 is welded to the pads on the solar cell 12. The diameter of the solder ribbon 11 is between 0.1 mm and 0.3 mm to prevent the solder ribbon 11 from being too large, which would cause greater concentrated stress on the solar cell 12 during the lamination process, leading to cracking or microcracks in the solar cell 12.

[0069] In this embodiment, by setting the solder ribbon 11 between adjacent solar cells 12 connected to the first busbar 21 located in the middle to be continuous and uninterrupted, a stable and reliable connection can be achieved between the uncut solder ribbon 11 and the first busbar 21. This reduces the occurrence of poor soldering due to separation between the first busbar 21 and the solder ribbon 11, which helps to improve the yield of photovoltaic modules. Furthermore, the solder ribbon 11 does not need to be cut, which can reduce the number of photovoltaic module manufacturing processes and time, and improve the efficiency of photovoltaic module manufacturing.

[0070] Figure 4 These are schematic diagrams of the structure of photovoltaic modules according to other embodiments of the present disclosure. Figure 5 yes Figure 4 A partial schematic diagram of the battery string located in the middle. Figure 6 yes Figure 4 A partial schematic diagram of the battery string located at one end, for reference. Figures 1-6 In some embodiments, the first busbar 21 is configured to connect to the side of the solder strip 11 away from the cell 12 on the back side of the cell 12.

[0071] The solder ribbon 11 is connected to the front side of one of the adjacent solar cells 12 and the back side of the other solar cell 12, respectively. The first busbar 21 is directly connected to the solder ribbon 11 on the back side of the solar cell 12, eliminating the need to fold the first busbar 21 and the solder ribbon 11 from the front side to the back side of the solar cell 12. This reduces the possibility of the first busbar 21 separating from the solder ribbon 11 during the folding process, which could lead to poor soldering and improve the yield of photovoltaic modules. Since the first busbar 21 does not need to be folded, the solar cell 12 will not be at risk of cracking due to excessive stress during the lamination process.

[0072] For two adjacent battery cells 12, the first busbar 21 can be connected to the back solder strip 11 of the battery cell 12 located on the left or right side. The first busbar 21 is positioned close to the gap between adjacent battery cells 12, and both sides of the first busbar 21 are welded to the solder strip 11 along the first direction. This increases the number of welds and reduces the risk of incomplete welding caused by individual solder strips 11 not being welded to the first busbar 21, which is beneficial to improving the welding quality.

[0073] The first busbar 21 is connected to the back solder strip 11 of the left-hand battery cell 12 among the two adjacent battery cells 12, as shown in the following case. Figure 2 As shown, the first busbar 21 is connected to the back solder strip 11 of the right-hand cell 12 among the two adjacent cell cells 12. Figure 5 As shown. When the first busbar 21 is connected to the back solder strip 11 of the battery cell 12 located on the right side, the first busbar 21 can be conveniently placed and operated because it is connected to the end of the solder strip 11 along the first direction X.

[0074] In this embodiment, the first busbar 21 is directly connected to the solder strip 11 located on the back of the cell 12. This helps to reduce the possibility of poor soldering between the solder strip 11 and the first busbar 21, and reduces the risk of the solder strip 11 detaching from the first busbar 21. Since there is no need to fold, it also reduces the risk of the cell 12 cracking due to excessive stress during lamination. This improves the installation reliability of the first busbar 21 and shortens the photovoltaic module manufacturing time, which helps to improve the yield and manufacturing efficiency of the photovoltaic module.

[0075] Figure 7 These are structural schematic diagrams of photovoltaic modules according to further embodiments of the present disclosure. Figure 8 yes Figure 7 A partial schematic diagram of the battery string located in the middle, for reference. Figure 1 , Figure 3 , Figure 4 , Figure 7 and Figure 8In some embodiments, the solder ribbon 11 is configured to be partially folded over the back of the battery cell 12. The first busbar 21 is connected to the folded portion of the solder ribbon 11.

[0076] refer to Figure 1 , Figure 3 , Figure 4 and Figure 7 The solder strip 11 on the front side of the battery cell 12 located at the end of the battery string 1 can be bent along the end of the battery cell 12 to the back side of the battery cell 12. The first busbar 21 is located between the solder strip 11 on the back side and the back side of the battery cell 12 along the third direction Z.

[0077] refer to Figure 1 and Figure 7 The solder strip 11 on the back of the battery cell 12 located at the end of the battery string 1 can be folded on the back of the battery cell 12, and the first busbar 21 is located between the two folded solder strips 11 along the third direction Z.

[0078] refer to Figure 7 and Figure 8 The solder strip 11 on the back of the battery cell 12 located in the middle of the battery string 1 can be folded on the back of the battery cell 12, and the first busbar 21 is located between the two folded solder strips 11 along the third direction Z. Both surfaces of the first busbar 21 located in the middle are connected to the folded portion of the solder strip 11 along the third direction Z.

[0079] In this embodiment, by folding the first busbar 21 to the back of the battery string 1 and connecting the first busbar 21 to the folded part of the solder strip 11, the welding reliability of the first busbar 21 and the solder strip 11 can be increased while increasing the power generation area of ​​the photovoltaic module, which is beneficial to maintaining a relatively stable current transmission state of the photovoltaic module.

[0080] refer to Figure 7 , Figure 8 In some embodiments, the front and back sides of the first busbar 21 located in the middle are connected to the folded portion of the solder strip 11. The front and back sides of the first busbar 21 are two surfaces opposite each other along the third direction Z.

[0081] The solder strip 11 on the back of the battery cell 12 located in the middle of the battery string 1 can be folded on the back of the battery cell 12, and the first busbar 21 is located between the two folded solder strips 11 along the third direction Z.

[0082] For the battery cell 12 located in the middle of the battery string 1, the solder strip 11 between adjacent battery cells 12 is configured to be folded over the back of one of the battery cells 12. The front and back of the first busbar 21 located in the middle are connected to the folded portion of the solder strip 11. For the battery cells 12 located at the ends of the battery string 1, the solder strip 11 is bent towards the back of the battery cell 12, and the first busbar 21 is connected to the folded portion of the solder strip 11.

[0083] The first busbar 21 located in the middle has two surfaces along the third direction Z connected to the folded portion of the welding strip 11, which can further increase the welding quantity and area of ​​the welding strip 11 and the first busbar 21, thereby improving the connection reliability of the welding strip 11 and the first busbar 21 and reducing the risk of the welding strip 11 and the first busbar 21 separating during the folding process.

[0084] Since the solder strips 11 between adjacent battery cells 12 are uninterrupted and the folds of the solder strips 11 are continuously arranged, if one side of the first busbar 21 is separated from the solder joint of the solder strip 11, the first busbar 21 can still ensure the transmission of current through the connection of the other side with the solder strip 11.

[0085] In this embodiment, by connecting both surfaces of the first busbar 21 along the third direction Z to the folded portion of the welding strip 11, the number of welds on the first busbar 21 and the welding reliability are increased, which helps to maintain a relatively stable current transmission state of the photovoltaic module and ensure the power generation performance of the photovoltaic module.

[0086] refer to Figure 1 , Figure 2 , Figure 3 , Figure 7 and Figure 8 In some embodiments, the solder strip 11 between adjacent battery cells 12 is configured to be connected to the back side of the battery cell 12 in which the first busbar 21 is provided and the front side of another battery cell 12, respectively.

[0087] In adjacent solar cells 12, such as Figure 1 , Figure 2 , Figure 3 , Figure 7 and Figure 8 The solar cell 12 located on the left is the first solar cell, and the solar cell 12 located on the right is the second solar cell. The solder ribbon 11 is connected to the back of the first solar cell and the front of the second solar cell. The first busbar 21 is welded to the back of the first solar cell. This reduces the possibility of short circuits caused by direct contact between the front solder ribbon 11 and the back solder ribbon 11 of the first solar cell after the solder ribbon 11 between adjacent solar cells 12 is folded to the back of the first solar cell. This improves the safety and reliability of the photovoltaic module.

[0088] In this embodiment, by connecting the solder strips 11 between the solar cells 12 to the back side of the solar cell 12 with the first busbar 21 and the front side of another solar cell 12 respectively, the risk of short circuit caused by direct contact between the solder strips 11 on the front side of the same solar cell 12 and the solder strips 11 on the back side of the same solar cell 12 can be reduced, thereby improving the safety of the photovoltaic module.

[0089] refer to Figures 1-8 In some embodiments, the photovoltaic module further includes a first buffer portion 3. The first buffer portion 3 is disposed between the front side of the cell 12 connected to the first busbar 21 and the solder strip 11, and is configured to melt during the welding and / or lamination process.

[0090] The first buffer part 3 is disposed between the front side of the battery cell 12 and the solder strip 11. For the stacked structure where the solder strip 11 and the first busbar 21 are folded, the first buffer part 3 can melt during the welding process to wrap the solder strip 11, and then cool down and solidify, so as to isolate the contact between the solder strip 11 on the front side of the battery cell 12 and the battery cell 12 during the folding process of the solder strip 11 and the first busbar 21, and reduce the squeezing damage to the battery cell 12 caused by the bending of the solder strip 11.

[0091] For the laminated structure where the solder strip 11 and the first busbar 21 are folded, the first buffer part 3 is provided on the same side of the folded part of the solder strip 11 and the first busbar 21, so as to reduce the risk of the laminated structure cracking due to stress concentration during the lamination process.

[0092] During the lamination and photovoltaic module use, because the first buffer part 3 is relatively soft and has a large contact surface with the cell 12, it can play a buffering role between the cell 12 and the solder ribbon 11, making the force applied to the cell 12 more uniform, preventing the concentrated stress generated when the front solder ribbon 11 contacts the cell 12, and reducing the occurrence of cell cracking and microcracks in the cell 12.

[0093] The first buffer part 3 is strip-shaped or strip-shaped and has the characteristic of softening at high temperature. At the lamination temperature, the first buffer part 3 softens, separating the solder ribbon 11 from the battery cell 12 while preventing stress damage to the battery cell 12.

[0094] In this embodiment, by setting the first buffer part 3, the risk of cracking and microcracks occurring during the welding, lamination and use of photovoltaic modules can be reduced. In particular, for photovoltaic modules where the solder strip 11 and the first busbar 21 are folded, the risk of cracking caused by stress concentration can be reduced, thereby improving the yield of photovoltaic modules.

[0095] refer to Figures 1-8 In some embodiments, a first buffer portion 3 is disposed at the end of the battery cell 12 along the first direction X. The first buffer portion 3 extends along the first direction X and a third direction Z perpendicular to both the first direction X and the second direction Y, so as to wrap the solder strip 11 located on the front side of the battery cell 12 and between adjacent battery cells 12.

[0096] The first buffer portion 3 forms a complete wrap around the front and sides of the battery cell 12, transforming the point contact between the solder ribbon 11 and the battery cell 12 into a surface contact between the first buffer portion 3 and the battery cell 12. This allows the battery cell 12 to be subjected to more uniform stress during the lamination process, reducing the risk of battery cell cracking or microcracks.

[0097] For the stacked structure where the solder strip 11 and the first busbar 21 are folded, the first buffer part 3 can reduce the contact between the solder strip 11 and the battery cell 12 between adjacent battery cells 12 during the folding process of the solder strip 11 and the first busbar 21, thereby reducing the squeezing damage to the battery cell 12 caused by the bending of the solder strip 11.

[0098] In this embodiment, the first buffer portion 3 extends along the front and side of the cell 12 at the end of the cell 12, forming a comprehensive and reliable buffer between the cell 12 and the solder strips 11 located on the front and side, which helps to reduce the risk of cell cracking during the lamination process and improve the yield of photovoltaic modules.

[0099] In some embodiments, the first buffer portion 3 includes any one of the following: an adhesive film formed by ethylene-vinyl acetate copolymer, an adhesive film formed by polyethylene octene coelastomer, a co-extruded structure formed by ethylene-vinyl acetate copolymer and polyethylene octene coelastomer, an ultraviolet curable adhesive, and a thermosetting adhesive.

[0100] The first buffer section 3 can be formed by melting transparent films such as ethylene-vinyl acetate copolymer film, polyethylene octene co-elastomer film, ethylene-vinyl acetate copolymer, and polyethylene octene co-elastomer co-extruded structure at high temperature. The transparent film has light transmittance, which can reduce the shading of the battery cell 12 and increase the light-receiving area of ​​the battery cell 12.

[0101] The first buffer section 3 uses ultraviolet curable adhesive or thermosetting adhesive. The ultraviolet curable adhesive or thermosetting adhesive can sink and cure at high temperature, relieving the pressure brought by the solder strip 11 to the end of the battery cell 12 during lamination.

[0102] In this embodiment, the first buffer part 3 is made of the above-mentioned material, which can help reduce the pressure on the battery cell 12 during the lamination process, especially the stress concentration generated at the fold of the solder strip 11 and the first busbar 21, and reduce the occurrence of microcracks or cracks in the battery cell 12.

[0103] refer to Figures 1-8 In some embodiments, the photovoltaic module further includes a second buffer 4, which is disposed on the back side of the cell 12 connected to the first busbar 21 and connected to the solder strip 11.

[0104] If the solder strip 11 located on the front side of the battery cell 12 is folded to the back side of the battery cell 12, the second buffer portion 4 on the back side of the battery cell 12 can be set as an insulating part to reduce the overall short circuit risk.

[0105] For example Figure 1 , Figure 2 , Figure 3 , Figure 7 and Figure 8 The solder strip 11 located on the front side of the solar cell 12 is folded to the back side of another solar cell 12. Due to the lower risk of short circuit, the second buffer portion 4 does not need to be an insulating component and can be made thinner to reduce the thickness of the photovoltaic module. In this embodiment, the second buffer portion 4 is disposed on the back side of the solar cell 12 to provide buffering, which can reduce the stress concentration on the solar cell 12 caused by the protruding part on the back side of the solar cell 12 during the lamination process. The second buffer portion 4, together with the first buffer portion 3, can comprehensively improve the yield of the photovoltaic module.

[0106] refer to Figure 1 , Figure 3 , Figure 4 , Figure 7 In some embodiments, the solder strip 11 located on the front side of the battery cell 12 is folded over the back side of the battery cell 12, and the second buffer portion 4 is an insulating component. The second buffer portion 4 can provide high-temperature insulation to prevent thermal stress damage to the battery cell 12 caused by excessively high temperatures when the first busbar 21 is heated and soldered on the battery cell 12.

[0107] The second buffer part 4 is strip-shaped or strip-shaped. The side that contacts the battery cell 12 can be softened at high temperature, and the side that contacts the first busbar 21 can be insulated and resistant to high temperature. While playing a role in high temperature insulation, it ensures the softness of the contact surface with the battery cell 12 and prevents the concentrated stress on the battery cell 12 from being damaged by the protrusion at the welding position of the first busbar 21 and the welding strip 11 on the back of the battery cell 12 during the lamination process.

[0108] In this embodiment, the second buffer part 4 can provide high-temperature insulation, reduce thermal stress damage during welding, and improve the safety and reliability of photovoltaic module manufacturing and use.

[0109] Figure 10 This is based on the structural schematic diagram of the photovoltaic module's cell string stacking in this disclosure. Figure 11 yes Figure 10 A partial schematic diagram of the battery string located in the middle, for reference. Figures 1-11 Each battery cell 12 of the battery string 1 is located in the same plane perpendicular to the third direction Z, or at least some adjacent battery cells 12 of the battery string 1 are stacked along the third direction Z. The third direction Z is perpendicular to both the first direction X and the second direction Y.

[0110] Each battery cell 12 in the battery string 1 can be located on the same height plane, with adjacent battery cells 12 spaced apart along the first direction X. The battery cells 12 can also be arranged in a stacked manner, with adjacent battery cells 12 partially stacked along the third direction Z and the first direction X.

[0111] In the stacking of the battery cells 12, the solder strip 11 is not limited to being folded on the back of the battery cells 12, and the folded portion of the solder strip 11 is connected to both the front and back of the first busbar 21.

[0112] Figure 9 yes Figure 8 The bottom view, Figure 12 yes Figure 11 A bottom view, for reference Figure 9 and Figure 12 In some embodiments, the folded portions of the solder ribbon 11 do not overlap with other solder ribbons 11 on the back side of the cell 12 where the first busbar 21 is disposed. The folded portions of the solder ribbon 11 that fold along with the first busbar 21 to the back side of the cell 12 are not overlapped with other solder ribbons 11 on the back side of the cell 12, but are staggered to reduce the stacking thickness of the solder ribbon 11 in the third direction Z, thereby reducing the risk of cell cracking during lamination.

[0113] Each solar cell 12 is connected to, but is not limited to, multiple solder strips 11, with the solder strips 11 on the back of the solar cell 12 spaced apart along the second direction Y. The folds between adjacent solar cells 12 folded to the back of the solar cell 12 include, but are not limited to, being inclined relative to the first direction X, so as to stagger the solder strips 11 on the back of the solar cell 12, thereby reducing the thickness of the photovoltaic module.

[0114] Figure 13 These are schematic diagrams of some embodiments of photovoltaic modules according to this disclosure. Figure 14 These are schematic diagrams of other embodiments of the photovoltaic module disclosed herein, with reference to... Figure 13 and Figure 14 In some embodiments, multiple battery strings 1 are spaced apart along the second direction Y.

[0115] The photovoltaic module also includes a second busbar 22 extending along the first direction X, which is connected to the first busbar 21 located at both ends of the cell string 1. The second busbar 22 is connected in series with a bypass diode 5. The bypass diode 5 can be installed in a bypass junction box.

[0116] In this embodiment, by setting a second busbar 22 extending along the first direction X and setting a bypass diode 5 thereon, compared to the situation in related technologies where the bypass junction box would bypass all the preceding solar cells 12 when the solar cells 12 are damaged, resulting in a serious drop in the overall power of the photovoltaic module, the second busbar 22 can bypass the damaged solar cells 12, allowing the undamaged solar cells 12 to carry current through the bypass diode 5. This avoids the situation where other solar cells 12 are bypassed due to the damage of a few solar cells 12, which helps to maintain the power of the photovoltaic module and improve the reliability of the photovoltaic module.

[0117] refer to Figure 13In some embodiments, the photovoltaic module further includes two battery modules, each battery module including multiple battery strings 1 connected in parallel via a first busbar 21.

[0118] The two first busbars 21 located at the first end of the battery string 1 in the two battery modules are connected in series, and the first busbars 21 located in the middle of the battery string 1 in the two battery modules are connected through a bypass diode 5.

[0119] The positive electrode of the photovoltaic module is located on the side of one of the battery modules near the second end of the battery string 1, and the negative electrode of the photovoltaic module is located on the side of another battery module near the second end of the battery string 1.

[0120] Each battery module includes, but is not limited to, three battery strings 1 connected in parallel via the first busbar 21. For example... Figure 13 The left end of battery string 1 is the second end of battery string 1 in this embodiment, as shown below. Figure 13 The right end of the battery string 1 is the first end of the battery string 1 in this embodiment. The first busbar 21 of the two battery modules located at the first end of the battery string 1 is conductive so as to connect the two battery modules in series to form a photovoltaic module.

[0121] Each second busbar 22 is connected in series with two bypass diodes 5, which are spaced apart on both sides of the central first busbar 21. The first bypass diode is closer to the first end of the battery string 1, and the second bypass diode is closer to the second end of the battery string 1.

[0122] The positive electrode 61 of the photovoltaic module includes, but is not limited to, being disposed in, such as Figure 9 The battery module is located at the top, and the first busbar 21 is disposed near the second end of the battery string 1, or the second busbar 22 is disposed between the end of the second busbar 22 near the second end of the battery string 1 and the second bypass diode.

[0123] The negative electrode 62 of the photovoltaic module includes, but is not limited to, being disposed in, such as Figure 9 The battery module is located below the battery module, and the first busbar 21 is disposed near the second end of the battery string 1, or the second busbar 22 is disposed between the end of the second busbar 22 near the second end of the battery string 1 and the second bypass diode.

[0124] The positive electrode 61 and negative electrode 62 of the photovoltaic module can be provided with separate junction boxes, or they can share a junction box with the bypass diode 5 on the second busbar 22, so as to reduce the manufacturing cost of the photovoltaic module.

[0125] When a battery cell 12 is damaged, current is transmitted through the first and second busbars 22 and the bypass diode 5, and after passing through two battery modules connected in series, the current is finally output at the negative terminal 62.

[0126] In this embodiment, a larger output current can be achieved by connecting the two battery modules in series. When a battery cell 12 is damaged, the second busbar 22 can smoothly output the current of the other battery cells 12, ensuring the power of the photovoltaic module.

[0127] refer to Figure 14 In some embodiments, there are two bypass diodes 5, respectively located on both sides of the first busbar 21 in the middle of the battery string 1. Figure 14 The left end of battery string 1 is the first end of battery string 1 in this embodiment, as shown below. Figure 14 The right end of the battery string 1 is the second end of the battery string 1 in this embodiment.

[0128] The positive electrode 61 of the photovoltaic module is disposed at the first busbar 21 located at the first end of the battery string 1, or disposed between the first end of the second busbar 22 and the bypass diode 5 near the first end of the battery string 1.

[0129] The negative electrode 62 of the photovoltaic module is disposed at the first busbar 21 located at the second end of the battery string 1, or disposed between the second end of the second busbar 22 and the bypass diode 5 near the second end of the battery string 1.

[0130] A first busbar 21 located at the first and second ends of the battery string 1 connects multiple battery strings 1 in parallel. A second busbar 22 is connected to the first busbar 21 located at the first and second ends of the battery string 1 respectively to provide bypass protection in the event of damage to the battery cell 12.

[0131] The positive electrode 61 and negative electrode 62 of the photovoltaic module can be provided with separate junction boxes, or they can share a junction box with the bypass diode 5 on the second busbar 22, so as to reduce the manufacturing cost of the photovoltaic module.

[0132] In this embodiment, the parallel connection of the battery string 1 along the second direction Y can achieve a larger resistance. When a battery cell 12 is damaged, the second busbar 22 and the first busbar 21 located in the middle can smoothly output the current of the other battery cells 12, ensuring the power of the photovoltaic module.

[0133] In some embodiments, the photovoltaic module further includes a second buffer portion 4 disposed between the second busbar 22 and the solar cell 12. When the solder strip 11 on the front side of the solar cell 12 is folded to the back side of the solar cell 12, the second buffer portion 4 may be configured as an insulating element.

[0134] In this embodiment, a buffer is achieved by providing an insulating second buffer portion 4 between the second busbar 22 and the battery cell 12, thereby reducing the risk of microcracks caused by the second busbar 22 squeezing the battery cell 12 during lamination.

[0135] The following provides a process flow for the manufacturing method of photovoltaic modules, including steps S1 to S2.

[0136] Multiple battery cells 12 are connected along the first direction X to form a battery string 1 by soldering ribbon 11.

[0137] Photovoltaic modules 7 are formed by connecting solder strips 11 at both ends and the middle of each battery string 1 through a first busbar 21 perpendicular to the first direction X and the second direction Y.

[0138] The first busbar 21 is located on the back of the battery cell 12 of each battery string 1, and the solder strip 11 between the adjacent battery cells 12 in the middle and connected to the first busbar 21 in the middle is uninterrupted.

[0139] The solder strip 11 between two adjacent cells 12 in the middle of the battery string 1 is directly welded to the first busbar 21 without being cut or interrupted. This ensures that the first busbar 21 can form a reliable and stable connection with the solder strip 11 on both sides along the first direction X, reducing the possibility of the solder strip 11 detaching from the first busbar 21 due to poor soldering, and improving the quality of the photovoltaic module.

[0140] Furthermore, when a cell 12 in the photovoltaic module fails, the reliable connection between the solder ribbon 11 and the first busbar 21 located in the middle can reduce the risk that current cannot be transmitted to the first busbar 21 for bypassing, thus preventing other normal cells 12 from outputting current, which is beneficial to maintaining the overall power of the photovoltaic module. Since the solder ribbon 11 does not require trimming, it can also reduce the number of manufacturing steps in the photovoltaic module, shorten processing time, and improve manufacturing efficiency.

[0141] In this embodiment, by hiding the first busbar 21 behind the solar cell 12, the front light-receiving area of ​​the photovoltaic module can be increased. With a uniform area layout, more solar cells 12 can be added, thereby improving the power generation efficiency of the photovoltaic module. Furthermore, the solder ribbons 11 connecting the adjacent solar cells 12 to the centrally located first busbar 21 are continuous, eliminating the need for trimming. This reduces the number of manufacturing steps and time required for the photovoltaic module, improving its manufacturing efficiency. The untrimmed solder ribbons 11 ensure a stable and reliable connection with the first busbar 21, reducing the likelihood of separation between the first busbar 21 and the solder ribbons 11, which could lead to poor soldering and ultimately improve the yield rate of the photovoltaic module.

[0142] In some embodiments, the operation of connecting the solder strips 11 of multiple battery strings 1 through the first busbar 21 specifically includes:

[0143] The first busbar 21 is connected to the back of the cell 12 and the side of the solder strip 11 away from the cell 12.

[0144] In this embodiment, the first busbar 21 is directly connected to the solder strip 11 located on the back of the cell 12. This helps to reduce the possibility of poor soldering between the solder strip 11 and the first busbar 21, and reduces the risk of the solder strip 11 detaching from the first busbar 21. Since there is no need to fold, it also reduces the risk of the cell 12 cracking due to excessive stress during lamination. This improves the installation reliability of the first busbar 21 and shortens the photovoltaic module manufacturing time, which helps to improve the yield and manufacturing efficiency of the photovoltaic module.

[0145] In some embodiments, connecting the first busbar 21 to the back side of the battery cell 12 and the solder strip 11 on the side away from the battery cell 12 further includes the following steps:

[0146] The first busbar 21 is connected to the solder strip 11 on the front side of the battery cell 12;

[0147] Fold the solder strip 11 between adjacent battery cells 12 and the first busbar 21 to the back of the battery cell 12.

[0148] In this embodiment, by folding the first busbar 21 to the back of the battery string 1, the first busbar 21 does not need to be placed in the gap between the battery cells 12, thereby reducing the surface area occupied by the photovoltaic module and improving the power generation efficiency of the photovoltaic module.

[0149] The description of exemplary embodiments is merely illustrative and is in no way intended to limit the scope of this disclosure or its application or use. This disclosure may be implemented in many different forms and is not limited to the embodiments described herein. These embodiments are provided to make this disclosure thorough and complete, and to fully express the scope of this disclosure to those skilled in the art. It should be noted that, unless specifically stated otherwise, the relative arrangement of components and steps, the composition of materials, numerical expressions, and values ​​set forth in these embodiments should be interpreted as exemplary only and not as limiting.

[0150] The terms "first," "second," and similar words used in this disclosure do not indicate any order, quantity, or importance, but are merely used to distinguish different parts. Words such as "including" or "contains" mean that the element preceding the word encompasses the element listed after it, and do not exclude the possibility of encompassing other elements as well. Terms such as "above," "below," "left," and "right" are used only to indicate relative positional relationships; when the absolute position of the described object changes, this relative positional relationship may also change accordingly.

[0151] In this disclosure, when a specific device is described as being located between a first device and a second device, an intermediary device may or may not be present between the specific device and the first or second device. When a specific device is described as being connected to other devices, the specific device may be directly connected to the other devices without an intermediary device, or it may be not directly connected to the other devices but have an intermediary device.

[0152] All terms used in this disclosure (including technical or scientific terms) have the same meaning as understood by one of ordinary skill in the art to which this disclosure pertains, unless otherwise specifically defined. It should also be understood that terms defined in a general dictionary, such as a dictionary, should be interpreted as having a meaning consistent with their meaning in the context of the relevant art, and not as having an idealized or highly formalized meaning, unless expressly defined herein.

[0153] Techniques, methods, and equipment known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and equipment should be considered part of the specification.

[0154] The embodiments of this disclosure have now been described in detail. To avoid obscuring the concept of this disclosure, some details known in the art have not been described. Those skilled in the art can fully understand how to implement the technical solutions disclosed herein based on the above description.

[0155] While specific embodiments of this disclosure have been described in detail by way of examples, those skilled in the art should understand that the examples are for illustrative purposes only and not intended to limit the scope of this disclosure. Those skilled in the art should understand that modifications can be made to the above embodiments or equivalent substitutions can be made to some technical features without departing from the scope and spirit of this disclosure. The scope of this disclosure is defined by the appended claims.

Claims

1. A photovoltaic module, characterized in that, include: Multiple battery strings (1), each of the battery strings (1) includes multiple battery cells (12) arranged along a first direction (X) and connected by solder strips (11); Multiple first busbars (21) extend along a second direction (Y) perpendicular to the first direction (X) and are connected to the solder strips (11) at both ends and the middle of each battery string (1). The first busbars (21) are located on the back of the battery cells (12) of each battery string (1). The solder strip (11) between adjacent battery cells (12) connected to the first busbar (21) located in the middle is uninterrupted.

2. The photovoltaic module as described in claim 1, characterized in that, The solder strip (11) between adjacent battery cells (12) is configured to be partially folded over the back of the battery cell (12), and the first busbar (21) is connected to the folded portion of the solder strip (11).

3. The photovoltaic module as described in claim 2, characterized in that, The front and back sides of the first busbar (21) located in the middle are connected to the folded portion of the welding strip (11).

4. The photovoltaic module as described in claim 1, characterized in that, Also includes: A first buffer section (3) is disposed between the front side of the battery cell (12) connected to the first busbar (21) and the solder strip (11), and is configured to melt during welding and / or lamination.

5. The photovoltaic module as described in claim 4, characterized in that, The first buffer portion (3) is disposed at the end of the battery cell (12) along the first direction (X). The first buffer portion (3) extends along the first direction (X) and a third direction (Z) that is perpendicular to both the first direction (X) and the second direction (Y) to wrap the solder strip (11) located on the front side of the battery cell (12) and between adjacent battery cells (12).

6. The photovoltaic module as described in claim 4, characterized in that, The first buffer section (3) includes any one of the following: a film formed by ethylene-vinyl acetate copolymer, a film formed by polyethylene octene co-elastomer, a co-extruded structure formed by ethylene-vinyl acetate copolymer and polyethylene octene co-elastomer, an ultraviolet curable adhesive, and a thermosetting adhesive.

7. The photovoltaic module as described in claim 2, characterized in that, The solder strip (11) between adjacent battery cells (12) is configured to connect to the back side of the battery cell (12) in which the first busbar (21) is provided and the front side of another battery cell (12), respectively.

8. The photovoltaic module as described in claim 2, characterized in that, The fold of the solder strip (11) does not overlap with the other solder strips (11) on the back of the battery cell (12) on which the first busbar (21) is disposed.

9. The photovoltaic module as described in claim 1, characterized in that, The first busbar (21) is configured to connect to the side of the solder strip (11) away from the battery cell (12) on the back side of the battery cell (12).

10. The photovoltaic module as described in claim 1, characterized in that, Also includes: The second buffer section (4) is disposed on the back side of the battery cell (12) connected to the first busbar (21) and connected to the solder strip (11).

11. The photovoltaic module as described in claim 10, characterized in that, The solder strip (11) located on the front side of the battery cell (12) is folded over the back side of the battery cell (12), and the second buffer part (4) is an insulating part.

12. The photovoltaic module as described in claim 1, characterized in that, Multiple battery strings (1) are spaced apart along the second direction (Y); The photovoltaic module further includes a second busbar (22) extending along the first direction (X), the second busbar (22) being connected to the first busbar (21) located at both ends of the battery string (1), and the second busbar (22) being connected in series with a bypass diode (5).

13. The photovoltaic module as described in claim 12, characterized in that, Also includes: Two battery modules, each battery module comprising multiple battery strings (1) connected in parallel via the first busbar (21); Among them, the two first busbars (21) located at the first end of the battery string (1) in the two battery modules are connected in series, and the first busbars (21) located in the middle of the battery string (1) in the two battery modules are connected by a bypass diode (5). The positive electrode (61) of the photovoltaic module is located on one side of one of the battery modules near the second end of the battery string (1), and the negative electrode (62) of the photovoltaic module is located on the other side of the battery module near the second end of the battery string (1).

14. The photovoltaic module as described in claim 12, characterized in that, The number of bypass diodes (5) is two, which are respectively disposed on both sides of the first busbar (21) located in the middle of the battery string (1); The positive electrode (61) of the photovoltaic module is disposed at the first busbar (21) located at the first end of the battery string (1), or disposed between the first end of the second busbar (22) and the bypass diode (5) near the first end of the battery string (1). The negative electrode (62) of the photovoltaic module is disposed at the first busbar (21) located at the second end of the battery string (1), or disposed between the second end of the second busbar (22) and the bypass diode (5) near the second end of the battery string (1).

15. The photovoltaic module as described in claim 12, characterized in that, Also includes: The second buffer section (4) is disposed between the second busbar (22) and the battery cell (12).

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