Photovoltaic module and preparation method thereof

Abstract

The invention discloses a photovoltaic module and a preparation method thereof. The photovoltaic module may include: a cover plate; a back plate; packaging the adhesive layer and the battery array; the battery array comprises a battery string, an insulating part and a bus bar; the insulating parts are arranged at the ends of the battery strings respectively, one part of each insulating part is fixed to the outer side edge of the back face of the corresponding end battery piece, and the outer side edges of the back faces of the end battery pieces are located in the extending direction of the battery strings and are perpendicular to the extending direction of the battery strings; the other part of the insulating part extends out of the outer side edge of the end part battery piece, and groove structures are arranged at intervals; the bus bar is laminated on the back surface of the insulator; the bus bar is electrically connected with the front face of the end battery piece through a plurality of bent welding strips, the bent welding strips correspond to the groove structures arranged at intervals, the bent welding strips are embedded in the corresponding groove structures, and the welding strips electrically connected with the back face of the end battery piece and the portions, electrically connected with the bus bar, of the bent welding strips are arranged in a staggered mode. The photovoltaic module can effectively reduce the hidden crack risk of the battery piece and improve the performance.

Description

Technical Field

[0001] The invention relates to a photovoltaic component and a preparation method thereof. Background Art

[0002] At present, a photovoltaic module structure is to fold the busbar in the photovoltaic module to the back of the battery string, so that the busbar cannot be seen from the front of the photovoltaic module, which increases the aesthetics of the photovoltaic module, reduces the string spacing between battery strings in the photovoltaic module, and improves the efficiency of the photovoltaic module. However, for the structure of folding the busbar to the back of the battery string, on the one hand, the folded position of the welding belt will press on the edge of the battery cell, resulting in the risk of hidden cracks at the edge of the battery cell; on the other hand, the welding belt section folded to the back of the battery cell overlaps with the welding belt on the back of the battery cell, further increasing the pressure on the edge of the battery cell, further increasing the risk of hidden cracks at the edge of the battery cell. Summary of the invention

[0003] In view of this, the present invention provides a photovoltaic module and a preparation method thereof, wherein the insulating part of the photovoltaic module has a groove structure matched with a bent welding strip, and the bent welding strip is embedded in the groove structure, which can reduce the pressure brought by the bent welding strip to the edge of the end battery cell. In addition, the welding strip electrically connected to the back of the end battery cell and the portion electrically connected to the busbar in the bent welding strip are staggered to avoid stacking of the welding strip electrically connected to the back of the end battery cell and the bent welding strip, so that the welding strip electrically connected to the back of the end battery cell and the bent welding strip are evenly dispersed at the edge of the end battery cell, reducing the pressure brought by the welding strip and the bent welding strip to the end battery cell, reducing the risk of hidden cracks at the edge of the battery cell, and improving the performance of the module.

[0004] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0005] In a first aspect, the present invention provides a photovoltaic module, comprising:

[0006] Cover plate;

[0007] Back panel;

[0008] Encapsulation glue layer;

[0009] and battery arrays;

[0010] The battery array includes a plurality of battery strings, a plurality of insulating members and a busbar;

[0011] A plurality of insulating members are disposed at ends of a plurality of battery strings, and a portion of the insulating members is fixed to an outer edge of the back side of the end battery cell, wherein the outer edge of the back side of the end battery cell is located in the extension direction of the battery string and is perpendicular to the extension direction of the battery string;

[0012] Another portion of the insulating member extends beyond the outer edge of the end battery sheet and has slot structures arranged at intervals;

[0013] The busbar is stacked on the back of the insulating member;

[0014] At one end of each of the battery strings, one of the busbars is electrically connected to the front side of the end battery cell through a plurality of bent welding strips;

[0015] At the other end of each of the battery strings, another of the busbars is electrically connected to the back of the end battery cell at the other end through a plurality of bent welding strips;

[0016] For each of the end battery cells, the multiple bent welding strips electrically connected to the end battery cell correspond one by one to the slot structures arranged at intervals between the insulating member to which the end battery cell is fixed, and the bent welding strips are embedded in the corresponding slot structures, and the welding strips electrically connected to the back side of the end battery cell are staggered with the parts of the bent welding strips electrically connected to the busbar.

[0017] In a second aspect, an embodiment of the present invention provides a method for preparing a photovoltaic module, comprising:

[0018] Step 1, connecting the battery cells in series, and simultaneously fixing the insulating member to the end battery cell to form a battery string, wherein a portion of the insulating member is fixed to the outer edge of the back side of the end battery cell, and another portion of the insulating member extends out of the outer edge of the end battery cell, and groove structures are arranged at intervals, and the outer edge of the back side of the end battery cell is located in the extension direction of the battery string and is perpendicular to the extension direction of the battery string;

[0019] Step 2: sequentially lay the cover plate and the packaging film, and lay the battery string and the busbar according to the photovoltaic module layout, and connect the end battery cells of the battery string with the busbar through welding ribbons;

[0020] Step 3, folding the busbar toward the back side of the end battery cell, bending the welding ribbon into the groove structure of the insulating member, and pulling the busbar in the length direction of the busbar to form a battery array;

[0021] Step 4, sequentially laying a packaging film and a backplane on the battery array;

[0022] Step 5: Lamination.

[0023] The technical solution of the first aspect of the above invention has the following advantages or beneficial effects:

[0024] The photovoltaic module provided by the embodiment of the present invention is arranged at the end of the battery string through an insulating member, a part of the insulating member is fixed to the outer edge of the back of the end battery cell, and the other part of the insulating member extends out of the outer edge of the end battery cell, so that the bent part of the bending welding strip is away from the edge of the end battery cell, reducing the pressure of the bending welding strip on the edge of the end battery cell. Furthermore, the bending welding strip cooperates with the groove structure of the insulating member so that the groove structure limits the bending welding strip, so that the part of the bending welding strip located on the back of the end battery cell and the part located on the front of the end battery cell can be adjusted independently of each other, that is, the bending welding strip and the welding strip electrically connected to the back of the end battery cell are staggered, while ensuring that the part of the bending welding strip located on the front of the end battery cell will not shift, ensuring the aesthetics and current collection capacity of the bending welding strip on the front of the end battery cell. In addition, the welding ribbon electrically connected to the back side of the end battery cell and the part of the busbar electrically connected in the bent welding ribbon are staggered to avoid stacking of the welding ribbon electrically connected to the back side of the end battery cell and the bent welding ribbon, so that the welding ribbon electrically connected to the back side of the end battery cell and the bent welding ribbon are evenly dispersed at the edge of the end battery cell, reducing the pressure of the welding ribbon and the bent welding ribbon on the end battery cell, reducing the risk of hidden cracks at the edge of the battery cell, and improving the performance of the component.

[0025] Furthermore, a portion of the insulating member is fixed to the outer edge of the back side of the end battery cell, which can prevent the insulating member from moving or deviating, thereby reducing the risk of short circuit caused by folding of the busbar.

[0026] In addition, the welding strips electrically connected to the back of the end battery cells and the parts electrically connected to the busbars in the bent welding strips are staggered, so that the thickness of the photovoltaic module can be thinned after lamination, the stress of the bent welding strips on the battery cells can be reduced, the risk of hidden cracks at the edges of the battery cells can be further reduced, and the reliability of the module can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a schematic cross-sectional structure diagram of the relative relationship between the end battery sheet and the bent welding strip in the photovoltaic module provided by the prior art in the extending direction of the battery string;

[0028] Figure 2 It is a schematic diagram of a cross-sectional structure perpendicular to the extension direction of a battery string, showing the relative relationship between an end battery sheet and a bent welding strip in a photovoltaic module provided according to the prior art;

[0029] Figure 3 is a schematic cross-sectional structure diagram of a first photovoltaic module partial structure in an extending direction of a battery string according to an embodiment of the present invention;

[0030] Figure 4 is a schematic cross-sectional structure diagram of a second photovoltaic module partial structure in the extending direction of a battery string according to an embodiment of the present invention;

[0031] Figure 5is a schematic cross-sectional structure diagram of a third photovoltaic module partial structure in the extending direction of a battery string according to an embodiment of the present invention;

[0032] Figure 6 is a cross-sectional structural schematic diagram of the relative positional relationship between the end battery cell, the bent welding ribbon, the carrier film, the insulating member and the busbar according to an embodiment of the present invention;

[0033] Figure 7 is a bottom view schematically showing a first relative position relationship between the end battery cell, the bent welding ribbon, the insulating member and the busbar according to an embodiment of the present invention;

[0034] Figure 8 is a method according to an embodiment of the present invention corresponding to Figure 7 A bottom view schematic diagram of a second relative position relationship between the end battery cell, the bent welding ribbon, the insulating member and the busbar;

[0035] Fig. 9 is a bottom view schematically showing a third relative position relationship between the end battery cell, the bent welding ribbon, the insulating member and the busbar according to an embodiment of the present invention;

[0036] Fig.10 is a method according to an embodiment of the present invention corresponding to Fig. 9 A bottom view schematically showing a fourth relative position relationship between the end battery cell, the bent welding ribbon, the insulating member and the busbar;

[0037] Fig.11 is a schematic cross-sectional structure diagram of the correlation between the welding strips and the bent welding strips on the front and back sides of the end battery cell according to an embodiment of the present invention;

[0038] Fig.12 is a partial structural schematic diagram of a first structure of an insulating member according to an embodiment of the present invention;

[0039] Fig.13 is a partial structural schematic diagram of a second structure of an insulating member according to an embodiment of the present invention;

[0040] Fig.14 is a partial structural schematic diagram of a third structure of an insulating member according to an embodiment of the present invention;

[0041] Fig.15 is a partial structural schematic diagram of an insulating member according to an embodiment of the present invention;

[0042] Fig.16 is a schematic diagram of the main process of a method for preparing a photovoltaic module according to an embodiment of the present invention;

[0043] Fig.17 It is a schematic diagram of the main process of a battery string in a method for preparing a photovoltaic module according to an embodiment of the present invention;

[0044] Fig.18 It is a schematic diagram of the structural changes in the process of preparing a battery string in the method for preparing a photovoltaic module according to an embodiment of the present invention.

[0045] The reference numerals are as follows:

[0046] 10-cover plate; 20-back plate; 30-encapsulation adhesive layer; 41-battery string; 411-end battery cell; 412-battery cell; 413-carrying film; 42-insulating member; 421-groove structure; 422-adhesive layer; 423-insulating layer; 42'-existing insulating layer; 43-busbar; 44-bent welding strip; 45-welding strip. DETAILED DESCRIPTION

[0047] In the prior art, Figure 1 and Figure 2 As shown, for the existing photovoltaic module structure, the busbar 43 is stacked on the back of the end battery cell 411, and an existing insulating layer 42' is provided between the busbar 43 and the back of the end battery cell 411. Figure 1 As shown, in the conventional photovoltaic module structure, during the process of folding the busbar 43 to the back of the end battery cell 411, the bending welding strip 44 will generate pressure F1 on the edge of the end battery cell 411. In particular, during the lamination process, the pressure F1 will further increase, causing the risk of hidden cracks in the end battery cell 411. On the other hand, Figure 2 As shown, after the bent welding strip 44 is folded to the back of the end battery cell 411, the bent welding strip 44 corresponds to the welding strip 45 on the back of the end battery cell 411, as shown in FIG. Figure 1 As shown, the bent welding strip 44 folded to the back side of the end battery cell 411 generates a relatively concentrated stress F2 on the end battery cell 411 , further increasing the risk of hidden cracks in the end battery cell 411 .

[0048] In addition, for the existing photovoltaic module structure, the existing insulating layer 42' introduced therein is active. During the folding process of the busbar 43, there is a risk that the existing insulating layer 42' will move or shift, causing the busbar 43 to directly contact the back of the end battery cell 411, which may easily cause the photovoltaic module to short-circuit.

[0049] In order to solve the above problems existing in the prior art, an embodiment of the present invention provides a photovoltaic module with a new structure and a preparation method thereof.

[0050] The photovoltaic module involved in the embodiment of the present invention can be any type of photovoltaic module, such as a double-glass module, a single-glass module, etc. Among them, the cell used in the photovoltaic module can be cut from any solar cell with a main grid line or a solar cell without a main grid (such as a silicon-based solar cell, a perovskite solar cell, etc., wherein the silicon-based solar cell can be a cross-finger type, a back contact type, a type with electrodes on both sides, etc.). Preferably, the cell used in the photovoltaic module involved in the embodiment of the present invention is a cell without a main grid.

[0051] The end battery cells 411 involved in the embodiment of the present invention refer to battery cells located at both ends of the battery string 41 in the battery string 41 of the photovoltaic module.

[0052] The bent welding strip 44 involved in the embodiment of the present invention refers to a welding strip located at the end battery cell 411 and electrically connected to the busbar 43, and the welding strip will be folded along the busbar 43 to the insulating member 42 fixed to the back of the end battery cell 411. The bent welding strip 44 can be a welding strip connected to the front of the end battery cell 411, or a welding strip connected to the back of the end battery cell 411.

[0053] in, Figures 3 to 5 Schematic diagrams of cross-sectional structures of partial structures of photovoltaic modules of different structures provided by embodiments of the present invention are respectively shown; Figures 6 to 11 A schematic diagram showing the relative relationship of various components in a photovoltaic module; Figures 12 to 15 Schematic diagrams showing cross-sectional structures of insulating members of different structures; Fig.16 and Fig.17 A schematic diagram showing the main process of the photovoltaic module preparation method; Fig.18 A schematic diagram showing some structural changes during the preparation of photovoltaic modules.

[0054] An embodiment of the present invention provides a photovoltaic module. Figures 3 to 5 As shown, the photovoltaic module may include: a cover plate 10; a back plate 20; a packaging adhesive layer 30; and a battery array.

[0055] Understandably, Figures 3 to 5 Only one battery string in a photovoltaic module is shown as an example. For a battery array, it generally includes multiple battery strings 41, multiple insulating members 42 and busbars 43; in particular, multiple battery strings 41 are connected in series and / or in parallel through busbars 43. The insulating member 42 is used to isolate the busbars 43 from the back of the end battery cell 411 to prevent the busbars 43 from contacting the back of the end battery cell 411.

[0056] Specifically, Figures 3 to 5As shown, a plurality of insulating members 42 are disposed at the ends of a plurality of battery strings 41, and a portion of the insulating member 42 is fixed to the outer edge of the back of the end battery cell 411, wherein the outer edge of the back of the end battery cell 411 is located in the extension direction of the battery string 41 and is perpendicular to the extension direction of the battery string 41; it should be noted that the outer edge of the back of the end battery cell 411 refers to the back of the end battery cell 411, away from the side of the adjacent battery cell 412. By fixing a portion of the insulating member 42 to the outer edge of the back of the end battery cell 411, the insulating member 42 will not shift relative to the end battery cell 411, ensuring the insulation between the busbar 43 and the back of the end battery cell 411, improving the yield of the photovoltaic module, and effectively reducing the difficulty of photovoltaic module production.

[0057] Furthermore, if Figures 3 to 10 As shown, another part of the insulating member 42 extends out of the outer edge of the end battery cell 411, and groove structures 421 are arranged at intervals; wherein, one part and another part of the insulating member 42 refer to two parts in the width direction of the insulating member 42 (the width direction of the insulating member 42 is consistent with the extension direction of the battery string 41). The other part of the insulating member 42 extends out of the outer edge of the end battery cell 411 and the groove structures 421 arranged at intervals can support the bending welding strip 44, reduce or even eliminate the bending pressure of the bending welding strip 44 on the end battery cell 411 ( Figure 1 The pressure F1 shown is used to reduce the risk of hidden cracks in the end battery cell 411.

[0058] Furthermore, if Figures 3 to 5 As shown, the busbar 43 is stacked on the back of the insulating member 42. Figures 3 to 11 As shown, the busbar 43 is electrically connected to the front side of the end battery cell 411 through a plurality of bent welding strips 44. The plurality of bent welding strips 44 correspond one-to-one to the slot structures 421 arranged at intervals, and the bent welding strips 44 are embedded in the corresponding slot structures 421. The welding strip 45 electrically connected to the back side of the end battery cell 411 is staggered with the portion of the bent welding strip 44 electrically connected to the busbar 43.

[0059] On the one hand, the spaced groove structure 421 can support the bent welding strip 44, and on the other hand, the spaced groove structure 421 can limit the bent welding strip 44, that is, the portion of the bent welding strip 44 located on the back side of the end battery cell 411 may shift without affecting the position of the portion of the bent welding strip 44 located on the front side of the end battery cell 411, thereby ensuring the aesthetics of the portion of the bent welding strip 44 located on the front side of the end battery cell 411, and ensuring that the portion of the bent welding strip 44 located on the back side of the end battery cell 411 is staggered with the welding strip 45 electrically connected to the back side of the end battery cell 411, so that the outer edge of the end battery cell 411 is subjected to balanced pressure, thereby further reducing the risk of hidden cracks in the end battery cell 411.

[0060] It is worth mentioning that, for photovoltaic modules, the structure of one end of the battery string is: that is, at one end of each battery string, a busbar 43 is electrically connected to the front side of the end battery cell 411 at one end through a plurality of bent welding strips 44, the plurality of bent welding strips 44 correspond one-to-one to the spaced groove structures 421, and the bent welding strips 44 are embedded in the corresponding groove structures 421, and the welding strips 45 electrically connected to the back side of the end battery cell 411 are staggered with the portion of the bent welding strips 44 electrically connected to the busbar 43.

[0061] like Figures 3 to 5 As shown, the structure of the other end of the battery string: at the other end of each battery string, another bus strap 43 is electrically connected to the back side of the end battery cell 411 at the other end through a plurality of bent welding straps 44; that is, at the other end of each battery string, the bus strap 43 is electrically connected to the back side of the other end battery cell 411 through a plurality of bent welding straps 44, the plurality of bent welding straps 44 correspond one-to-one to the slot structures 421 arranged at intervals, and the bent welding straps 44 are embedded in the corresponding slot structures 421, and the portion of the bent welding strap 44 electrically connected to the back side of the other end battery cell 411 to which the bus strap 43 is electrically connected is staggered with the portion of the bent welding strap 44 electrically connected to the back side of the other end battery cell 411.

[0062] It can be understood that for each end battery cell 411, the multiple bent welding strips 44 electrically connected to the end battery cell 411 correspond one to one with the slot structures 421 arranged at intervals in the insulating member 42 fixed to the end battery cell 411, and the bent welding strips 44 are embedded in the corresponding slot structures 421, and the welding strips 45 electrically connected to the back of the end battery cell 411 are staggered with the portion electrically connected to the busbar 43 in the bent welding strips 44. In addition, one end and the other end of the battery string are relative concepts. It is worth noting that in two adjacent battery strings, one end of one battery string and the other end of the other battery string can be connected in series by connecting the same busbar.

[0063] For the above photovoltaic module, the insulating member is arranged at the end of the battery string, a part of the insulating member is fixed to the outer edge of the back of the end battery cell, and the other part of the insulating member extends out of the outer edge of the end battery cell, so that the bent part of the bending welding strip is away from the edge of the end battery cell, reducing the pressure of the bending welding strip on the edge of the end battery cell. Furthermore, the bending welding strip cooperates with the groove structure of the insulating member, so that the groove structure limits the bending welding strip, so that the part of the bending welding strip located on the back of the end battery cell and the part located on the front of the end battery cell can be adjusted independently of each other, that is, the bending welding strip and the welding strip electrically connected to the back of the end battery cell are staggered, while ensuring that the part of the bending welding strip located on the front of the end battery cell will not shift, ensuring the aesthetics and current collection capacity of the bending welding strip on the front of the end battery cell. In addition, the welding ribbon electrically connected to the back side of the end battery cell and the part of the busbar electrically connected in the bent welding ribbon are staggered to avoid stacking of the welding ribbon electrically connected to the back side of the end battery cell and the bent welding ribbon, so that the welding ribbon electrically connected to the back side of the end battery cell and the bent welding ribbon are evenly dispersed at the edge of the end battery cell, reducing the pressure of the welding ribbon and the bent welding ribbon on the end battery cell, reducing the risk of hidden cracks at the edge of the battery cell, and improving the performance of the component.

[0064] Furthermore, a portion of the insulating member is fixed to the outer edge of the back side of the end battery cell, which can prevent the insulating member from moving or deviating, thereby reducing the risk of short circuit caused by folding of the busbar.

[0065] In addition, the welding strips electrically connected to the back of the end battery cells and the parts electrically connected to the busbars in the bent welding strips are staggered, so that the thickness of the photovoltaic module can be thinned after lamination, the stress of the bent welding strips on the battery cells can be reduced, the risk of hidden cracks at the edges of the battery cells can be further reduced, and the reliability of the module can be improved.

[0066] Before the busbar 43 is folded, the relative positional relationship between the insulating member 42, the end battery cell 411 and the busbar 43 can be as follows: Figure 7 and Fig. 9 As shown. Figure 7 As shown, the welding strip connected to the front side of the end battery cell 411 is a bent welding strip 44, and the bent welding strip 44 is electrically connected to the front side of the busbar 43. Then, after the busbar 43 is folded 180° toward the back side of the end battery cell 411, Figure 8 In the structure shown in the figure, after the bus strip 43 is folded toward the back of the end battery cell 411, the back of the bus strip 43 contacts the insulating member 42, and the front of the bus strip 43 faces away from the insulating member 42. Fig. 9 The force in the direction D1 shown in the figure causes the portion of the bent solder strip 44 located on the back of the end battery cell 411 to be staggered with the solder strip 45 on the back of the end battery cell 411. Fig. 9As shown, the welding strip connected to the front side of the end battery cell 411 is a bent welding strip 44, and the bent welding strip 44 is electrically connected to the back side of the bus strip 43. After the bus strip 43 is folded 180° toward the back side of the end battery cell 411, Fig.10 In the structure shown in the figure, after the busbar 43 is folded toward the back of the end battery cell 411, the back of the busbar 43 contacts the insulating member 42 (that is, the surface of the busbar 43 connected to the bent welding strip 44 contacts the insulating member 42), and the front of the busbar 43 faces away from the insulating member 42, and the busbar 43 is applied with a Fig.10 The force in the direction D2 shown causes the portion of the bent solder strip 44 located on the back of the end battery cell 411 to be staggered with the solder strip 45 on the back of the end battery cell 411. In the process of applying the force in the direction D1 or D2 to the busbar 43, the design of the groove structure 421 can prevent the portion of the bent solder strip 44 located on the front of the end battery cell 411 from shifting, thereby ensuring that the solder strip on the front of the end battery cell 411 maintains its aesthetic appearance.

[0067] After the portion of the bent welding strip 44 located on the back of the end battery cell 411 is displaced, the relative positional relationship between the portion of the bent welding strip 44 located on the back of the end battery cell 411, the portion of the bent welding strip 44 located on the front of the end battery cell 411, and the welding strip 45 on the back of the end battery cell 411 is as follows: Fig.11 As shown, from Fig.11 It can be clearly seen that after the portion of the bent welding strip 44 located on the back side of the end battery cell 411 is displaced, the bent welding strip 44 and the welding strip 45 on the back side of the end battery cell 411 can be evenly distributed on the outward edge of the back side of the end battery cell 411. During the lamination process, the force on the back side of the end battery cell 411 is more balanced, avoiding relatively high pressure on a single point on the end battery cell 411, and further reducing the risk of hidden cracks in the end battery cell 411.

[0068] This structure can ensure that the portion of the bent welding strip 44 located on the front side of the end battery cell 411 does not shift without adding additional tools, making the photovoltaic module preparation process relatively simple and easy to produce.

[0069] The cross section of the groove structure 421 may be one of the following shapes: Fig.13 The rectangle shown; Fig.12 The isosceles trapezoid shown or Fig.14 The combined shape of a rectangle and a circle as shown. With this structural design, the groove structure 421 can limit the bending welding strip 44, and when a force in the direction D1 or D2 is applied to the portion of the bending welding strip 44 located on the back of the end battery cell 411, the portion of the bending welding strip 44 located on the back of the end battery cell 411 is displaced, while ensuring that the portion of the bending welding strip 44 located on the front of the end battery cell 411 will not be displaced.

[0070] Furthermore, there are many specific implementations of fixing the insulating member 42 to the outer edge of the back side of the end battery cell 411 .

[0071] Specifically, Fig.15 As shown, the insulating member 42 may include: a stacked adhesive layer 422 and an insulating layer 423, wherein the adhesive layer 422 is bonded to the outer edge of the end battery cell 411, and the adhesive layer 422 is located between the insulating layer 423 and the outer edge of the end battery cell 411. The insulating layer 423 is bonded to the outer edge of the end battery cell 411 through the adhesive layer 422. The adhesive layer 422 may be an ethylene-vinyl acetate copolymer (EVA) material, a pressure-sensitive adhesive or other adhesives.

[0072] In addition, if Figures 4 to 6 As shown, the battery string 41 may include battery cells 412 connected in series by welding ribbons and a carrier film 413 covering the back of the battery cells 412; the insulating member 42 is disposed below the carrier film 413; the insulating member 42 is adhered to the outer edge of the end battery cell 411 through the carrier film 413. The carrier film 413 may be as follows Figure 4 As shown, only a whole sheet of carrier film 413 is provided on the back of the battery string; Figure 5 As shown, each battery cell 412 in the battery string corresponds to a carrier film 413. The carrier film 413 can be as follows Figure 4 and Figure 5 As shown, it is arranged on the back of the battery cell 412 or the battery string, and can also be Figure 6 As shown, the carrier film 413 is arranged on the back and front of the battery string. The design of the carrier film 413 allows the carrier film 413 to adhere to the insulating member 42 during the heating and serial connection of the battery string, thereby fixing the insulating member 42 to the end battery cell 411. The carrier film 413 may be made of a thermoplastic or thermosetting material, for example, the carrier film 413 may be ethylene-vinyl acetate copolymer (EVA), a polymer of ethylene and butene (POE) or polyolefin (PO), etc.

[0073] The insulating member 42 may include at least one of the following materials: silicone rubber, polyvinyl chloride (PVC), chloroprene rubber and polyurethane (PU). The material itself is relatively soft, which can ensure the insulation of the insulating member 42. At the same time, the insulating member 42 helps to resist the pressure brought to the edge of the end battery cell 411 by the bent welding strip 44, further reducing the risk of hidden cracks in the end battery cell 411 and the risk of hidden cracks at the folding part.

[0074] Further, for the insulating member 42, the width of the groove structure 421 included therein may be 0.8 mm to 1.2 mm, wherein the width of the groove structure 421 is consistent with the length direction of the busbar 43. Fig.12 As shown in d1. For example, the width of the groove structure 421 can be 0.8mm, 0.9mm, 1.0mm, 1.1mm, 1.2mm, etc. Through the width limit of the groove structure 421, the groove structure 421 can provide sufficient support and limit for the part of the bent welding strip 44 trapped therein, ensuring that the part of the bent welding strip 44 located on the front side of the end battery cell 411 does not shift, and can provide sufficient support to shift the part of the bent welding strip 44 located on the back side of the end battery cell 411. Among them, the width of the groove structure 421 generally refers to the width of the widest position of the groove structure 421.

[0075] For the insulating member 42, the depth of the groove structure 421 is 1 mm to 2 mm, wherein the depth of the groove structure 421 is consistent with the width direction of the busbar 43. The depth of the groove structure 421 can be as follows: Fig.12 For example, the depth of the groove structure 421 may be 1.0 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.5 mm, 1.6 mm, 1.7 mm, 1.8 mm, 1.9 mm, 2.0 mm, etc. Through the depth limit of the groove structure 421, the groove structure 421 can provide sufficient support and limit for the portion of the bent welding strip 44 trapped therein, ensuring that the portion of the bent welding strip 44 located on the front side of the end battery cell 411 does not shift, and can provide sufficient support to shift the portion of the bent welding strip 44 located on the back side of the end battery cell 411.

[0076] Furthermore, if Fig.12 As shown, the width d2 of the insulating member 42 can be 10 mm to 15 mm. The direction of the width d2 of the insulating member 42 is consistent with the extension direction of the battery string. For example, the width d2 of the insulating member 42 can be 10 mm, 11 mm, 12 mm, 13 mm, 14 mm, 15 mm, etc. By limiting the width d2 of the insulating member 42, it can be ensured that the insulating member 42 can extend a sufficient width of the end battery cell 411, and the insulating member 42 and the end battery cell 411 form a stable and fixed connection.

[0077] Furthermore, if Fig.11As shown, in the length direction of the end battery cell 411 (the length direction of the end battery cell 411 is perpendicular to the extension direction of the battery string), the spacing d3 between the welding strip 45 electrically connected to the back of the end battery cell 411 and the portion electrically connected to the busbar 43 in the bent welding strip 44 can be 1mm~3mm. For example, the spacing d3 between the welding strip 45 electrically connected to the back of the end battery cell 411 and the portion electrically connected to the busbar 43 in the bent welding strip 44 can be 1mm, 1.2mm, 1.5mm, 1.8mm, 2mm, 2.2mm, 2.4mm, 2.5mm, 2.8mm or 3mm, etc. By controlling the spacing d3, it can be ensured that the edge of the end battery cell 411 is subjected to balanced pressure during the lamination process.

[0078] For the bent welding strip 44, as Fig.11 As shown, the portion of the bent solder strip 44 electrically connected to the busbar 43 is staggered with the portion of the bent solder strip 44 electrically connected to the front side of the end battery cell 411. Fig.11 As shown, in the length direction of the end battery cell 411, the spacing d4 between the portion of the bent welding strip 44 electrically connected to the busbar 43 and the portion of the bent welding strip 44 electrically connected to the busbar 43 can be 1mm~3mm. For example, the spacing d4 can be 1mm, 1.2mm, 1.5mm, 1.8mm, 2mm, 2.2mm, 2.4mm, 2.5mm, 2.8mm or 3mm, etc. By controlling the spacing d4, it can be further ensured that the edge of the end battery cell 411 is subjected to balanced pressure during the lamination process.

[0079] More specifically, the insulating member 42 is fixed to the outer edge of the back side of the end battery cell 411 and is connected in series with each battery cell 412 to form the battery string 41. That is, while the welding ribbon 45 is heated by an infrared light box to form an electrical connection with the battery cell 412, the insulating member 42 is fixed to the end battery cell 411 simultaneously.

[0080] Furthermore, an embodiment of the present invention also provides a method for preparing a photovoltaic module. Fig.16 As shown, the photovoltaic module preparation method may include the following steps:

[0081] Step S1601: Connect each battery cell 412 in series, and simultaneously fix the insulating member 42 to the end battery cell 411 to form a battery string 41, wherein a portion of the insulating member 42 is fixed to the outer edge of the back side of the end battery cell 411, and another portion of the insulating member 42 extends out of the outer edge of the end battery cell 411, and groove structures 421 are arranged at intervals, and the outer edge of the back side of the end battery cell 411 is located in the extension direction of the battery string 41 and is perpendicular to the extension direction of the battery string 41.

[0082] By fixing a portion of the insulating member 42 to the outer edge of the back side of the end battery cell 411, displacement of the insulating member 42 can be avoided during the subsequent folding of the busbar 43, thereby ensuring that the insulating member 42 can provide a better insulation effect, avoiding direct contact between the busbar 43 and the end battery cell 411, and preventing a short circuit in the photovoltaic module.

[0083] Step S1602: Lay the cover plate and the packaging film in sequence, and lay the battery string 41 and the busbar 43 according to the photovoltaic module layout, and connect the end battery cell 411 of the battery string 41 with the busbar 43 through the welding ribbon.

[0084] Step S1603: Fold the busbar 43 toward the back side of the end battery cell 411 so that the welding strip is bent into the groove structure 421 of the insulating member 42, and pull the busbar 43 in the length direction of the busbar 43 to form a battery array.

[0085] Specifically, for Figure 7 The structure shown in the figure is applied to the busbar 43 during the folding process of the busbar 43. Figure 8 The force in the direction D1 shown causes the busbar 43 to drive the portion of the bent solder strip 44 located at the back of the end battery cell 411 to move in the direction D1, while the portion of the bent solder strip 44 located at the front of the end battery cell 411 remains unchanged.

[0086] against Fig. 9 The structure shown in the figure is used to apply a Fig.10 The force in the direction D2 shown causes the busbar 43 to drive the portion of the bent solder strip 44 located at the back of the end battery cell 411 to move in the direction D2, while the portion of the bent solder strip 44 located at the front of the end battery cell 411 remains unchanged.

[0087] Step S1604: sequentially lay a packaging film and a backplane on the battery array.

[0088] Step S1605: Lamination.

[0089] In the above preparation process, a part of the insulating member is fixed to the outer edge of the back of the end battery cell, and another part of the insulating member 42 extends out of the outer edge of the end battery cell 411, so that the bent part of the bent welding strip 44 is away from the edge of the end battery cell 411, reducing the pressure of the bent welding strip 44 on the edge of the end battery cell 411. Further, the bent welding strip 44 cooperates with the groove structure 421 of the insulating member 42, so that the groove structure 421 limits the bent welding strip 44, so that the part of the bent welding strip 44 located on the back of the end battery cell 411 and the part located on the front of the end battery cell 411 can be adjusted independently of each other, that is, the bent welding strip 44 and the welding strip 45 electrically connected to the back of the end battery cell 411 are staggered, while ensuring that the part of the bent welding strip 44 located on the front of the end battery cell 411 will not shift, ensuring the aesthetics and current collection capacity of the bent welding strip 44 on the front of the end battery cell 411. In addition, the welding ribbon 45 electrically connected to the back side of the end battery cell 411 is staggered with the part of the busbar 43 in the bent welding ribbon 44 to avoid stacking of the welding ribbon 45 electrically connected to the back side of the end battery cell 441 and the bent welding ribbon 44, so that the welding ribbon 45 electrically connected to the back side of the end battery cell 411 and the bent welding ribbon 44 are evenly dispersed at the edge of the end battery cell 411, reducing the pressure brought by the welding ribbon 45 and the bent welding ribbon 44 to the end battery cell 411, reducing the risk of hidden cracks at the edge of the battery cell, and improving the performance of the component.

[0090] Furthermore, a portion of the insulating member 42 is fixed to the outer edge of the back side of the end battery cell 411 , which can prevent the insulating member 42 from moving or deviating, thereby reducing the risk of the busbar 43 being folded and causing a short circuit.

[0091] In addition, the welding strip 45 electrically connected to the back side of the end battery cell 411 is staggered with the portion electrically connected to the busbar 43 in the bent welding strip 44, so that the thickness of the photovoltaic module can be thinned after lamination, reducing the stress of the bent welding strip 44 on the battery cell, further reducing the risk of hidden cracks at the edge of the battery cell, and improving the reliability of the module.

[0092] Further, with respect to the above step S1601, if Fig.17 As shown, it may include the following steps:

[0093] Step S1601 - 1 : placing the insulating member 42 .

[0094] Step S1601 - 2 : Covering the edge of the carrier film 413 on a portion of the insulating member 42 .

[0095] Step S1601 - 3 : sequentially laying the solder strip 45 and the end battery cell 411 on the carrier film 413 , wherein the outer edge of the back side of the end battery cell 411 covers a portion of the insulating member 42 .

[0096] Step S1601-4: Circularly lay the carrier film 413, the welding strip and the next battery cell until the last battery cell of the battery string is laid, then place another insulating member 42, cover the edge of the carrier film 413 on a portion of the other insulating member 42, and lay the last battery cell, wherein the outer edge of the back side of the last battery cell covers a portion of the insulating member 42.

[0097] Step S1601 - 5 : The carrier film 413 is heated by infrared so as to connect the soldering ribbon and the battery cells in series, thereby forming a battery string 41 with an insulating member 42 fixed thereto.

[0098] The welding temperature may be 120° C. to 140° C. For example, the welding temperature may be 120° C., 125° C., 130° C., 135° C. or 140° C.

[0099] The diameter of the welding strip or the bent welding strip used in the above embodiments may be 0.15 mm to 0.2 mm. For example, the diameter of the welding strip or the bent welding strip may be 0.15 mm, 0.18 mm, 0.2 mm, etc.

[0100] Above Fig.17 The structure of the battery string 41 prepared in the provided method changes as follows Fig.18 shown.

[0101] The preparation process of photovoltaic modules is described in detail below with two embodiments.

[0102] Embodiment 1:

[0103] S1: Place the insulating member 42 with a groove structure 421 on the machine belt, and then circulate until the last battery cell: place the lower carrier film 413, the welding strip, the battery cell without main grid, the adjacent lower carrier film, the welding strip connecting the adjacent battery cells without main grid, the upper carrier film 413 and the tooling for pressing in sequence, and also place an insulating member 42 with a groove structure 421 on the edge of the back side of the last battery cell without main grid; wherein, the groove structure 421 of the insulating member 42 is oriented toward the outside of the battery string, and the two insulating members 42 on the battery string are respectively located on the back sides of both ends of the battery string.

[0104] S2: The materials placed in step S1 are brought into the infrared light box along with the machine belt, and the carrier film 413 is bonded to the main grid-free battery cell by heating, the welding strip is fixed to form a string, and the insulating member 42 is bonded to the carrier film 413 and fixed at both ends of the battery string.

[0105] S3: Prepare the battery string of this embodiment according to the above steps, layout and stack the battery string according to the layout design, wherein the busbar is folded to the back of the assembly after welding. During the folding process, the welded busbar and welding strip are folded first, and the welding strip passes through the groove structure 421 of the insulating member 42, and then the busbar 43 is translated 2mm along the long side direction of the busbar 43, and the part of the bent welding strip located on the front of the busbar-free battery cell and the part folded to the back of the busbar-free battery cell are staggered and do not overlap. Because the groove structure 421 is fixed, when the busbar 43 is translated, the part of the bent welding strip directly connected to the busbar-free battery cell will not be offset, thereby ensuring the aesthetics of the front of the busbar-free battery cell.

[0106] S4: Lamination, framing, curing, and cleaning to obtain the photovoltaic module of this embodiment.

[0107] Embodiment 2:

[0108] The difference from Example 1 is that the carrier film 413 is omitted, and an insulating member including an adhesive layer and an insulating layer is selected. The insulating member is placed on the back side of both ends of the battery string. During string welding, the insulating member is bonded to the battery string by heating through a light box through the adhesive layer on the insulating member, or a layer of other adhesive materials such as a pressure-sensitive adhesive is provided on the insulating member. During the string welding process, the insulating member is bonded to both ends of the battery string. The other steps are the same as the above-mentioned embodiments.

[0109] The introduction provided in the above steps is only used to help understand the method, structure and core idea of ​​the present invention. For ordinary technicians in this technical field, without departing from the principle of the present invention, several improvements and modifications can be made to the present invention, and these improvements and modifications also belong to the scope of protection of the claims of the present invention.

Claims

1. A photovoltaic module, characterized in that: include: Cover plate (10); Back plate (20); Encapsulation adhesive layer (30); and battery arrays; The battery array comprises a plurality of battery strings (41), a plurality of insulating members (42) and a busbar (43); A plurality of insulating members (42) are disposed at ends of a plurality of battery strings (41), and a portion of the insulating member (42) is fixed to an outer edge of the back side of an end battery sheet (411), wherein the outer edge of the back side of the end battery sheet (411) is located in an extension direction of the battery string (41) and is perpendicular to the extension direction of the battery string (41); Another portion of the insulating member (42) extends beyond the outer edge of the end battery sheet (411), and has slot structures (421) arranged at intervals; The busbar (43) is stacked on the back side of the insulating member (42); At one end of each battery string, a busbar (43) is electrically connected to the front side of the end battery cell (411) at one end through a plurality of bent welding strips (44); At the other end of each battery string, another busbar (43) is electrically connected to the back side of the end battery cell (411) at the other end through a plurality of bent welding strips (44); For each of the end battery cells (411), the plurality of bent welding strips (44) electrically connected to the end battery cell (411) correspond one to one with the slot structures (421) arranged at intervals of the insulating member (42) fixed to the end battery cell (411), and the bent welding strips (44) are embedded in the corresponding slot structures (421), and the welding strips (45) electrically connected to the back of the end battery cell (411) are staggered with the portion of the bent welding strips (44) electrically connected to the busbar (43).

2. The photovoltaic module according to claim 1, characterized in that: The battery string (41) comprises battery cells (412) connected in series via welding ribbons and a carrier film (413) covering the back of the battery cells (412); The insulating member (42) is arranged below the supporting film (413); The insulating member (42) is adhered to the outer edge of the end battery cell (411) via the carrier film (413).

3. The photovoltaic module according to claim 1, characterized in that: The insulating member (42) comprises: an adhesive layer (422) and an insulating layer (423) which are stacked, wherein: The adhesive layer (422) is adhered to the outer edge of the end battery cell (411), and the adhesive layer (422) is located between the insulating layer (423) and the outer edge of the end battery cell (411).

4. The photovoltaic module according to any one of claims 1 to 3, characterized in that: The insulating member (42) is fixed to the outer edge of the back side of the end battery sheet (411) and is connected in series with each battery sheet (412) to form the battery string (41) synchronously.

5. The photovoltaic module according to any one of claims 1 to 3, characterized in that: The portion of the bent welding strip (44) electrically connected to the busbar (43) is staggered with the portion of the bent welding strip (44) electrically connected to the front surface of the end battery cell (411).

6. The photovoltaic module according to any one of claims 1 to 3, characterized in that: The width of the groove structure (421) is 0.8 mm to 1.2 mm, wherein the width of the groove structure (421) is consistent with the length direction of the busbar (43); and / or, The depth of the groove structure (421) is 1 mm to 2 mm, wherein the depth of the groove structure (421) is consistent with the width direction of the busbar (43); and / or, The insulating member (42) has a width of 10 mm to 15 mm; and / or, In the length direction of the end battery cell (411), the spacing between the welding strip (45) electrically connected to the back side of the end battery cell (411) and the portion of the bent welding strip (44) electrically connected to the busbar (43) is 1 mm to 3 mm.

7. The photovoltaic module according to claim 5, characterized in that: In the length direction of the end battery cell (411), the spacing between the portion of the bent welding strip (44) electrically connected to the busbar (43) and the portion of the bent welding strip (44) electrically connected to the busbar (43) is 1 mm to 3 mm.

8. The photovoltaic module according to any one of claims 1 to 3 and 5, characterized in that: The insulating member (42) comprises at least one of the following materials: Silicone rubber, polyvinyl chloride (PVC), chloroprene rubber and polyurethane (PU); and / or, The cross-section of the groove structure (421) is one of the following shapes: rectangle; Isosceles trapezoid; And the combination of rectangle and circle.

9. A method for preparing a photovoltaic module, characterized in that: include: Step 1, connecting the battery cells (412) in series, and simultaneously fixing the insulating member (42) to the end battery cell (411) to form a battery string (41), wherein a portion of the insulating member (42) is fixed to the outer edge of the back side of the end battery cell (411), and another portion of the insulating member (42) extends out of the outer edge of the end battery cell (411), and groove structures (421) are arranged at intervals, and the outer edge of the back side of the end battery cell (411) is located in the extension direction of the battery string (41) and is perpendicular to the extension direction of the battery string (41); Step 2: sequentially laying a cover plate and an upper packaging film, laying the battery string (41) and the busbar (43) according to the photovoltaic module layout, and connecting the end battery sheet (411) of the battery string (41) and the busbar (43) via a welding ribbon; Step 3, folding the busbar (43) toward the back side of the end battery cell (411) so that the welding ribbon is bent and enters the groove structure (421) of the insulating member (42), and pulling the busbar (43) in the length direction of the busbar (43) to form a battery array; Step 4, sequentially laying a packaging film and a backplane on the battery array; Step 5: Lamination.

10. The method for preparing a photovoltaic module according to claim 9, characterized in that: Step 1 includes: Step 11, placing the insulating member (42); Step 12, covering the edge of the carrier film (413) on a portion of the insulating member (42); Step 13, sequentially laying a welding strip (45) and an end battery cell (411) on the carrier film (413), wherein the outer edge of the back side of the end battery cell (411) covers a portion of the insulating member (42); Step 14, cyclically laying the carrier film, the welding ribbon and the next battery cell until the last battery cell of the battery string is laid, placing another insulating member (42), covering the edge of the carrier film on a portion of the other insulating member (42), and laying the last battery cell, wherein the outer edge of the back side of the last battery cell covers a portion of the insulating member (42); Step 15: Infrared heating is used to heat the carrier film so that the welding strip is connected in series with the battery sheet to form a battery string (41) to which the insulating member (42) is fixed.

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