Photovoltaic module

Abstract

The invention relates to the field of photovoltaic technology, in particular to a photovoltaic module. The photovoltaic assembly comprises a back plate, a battery piece assembly on the inner side of the back plate and a plurality of electric connecting wires electrically connected with the battery piece assembly, the back plate comprises a back plate main body and a hole group penetrating through the back plate main body, the hole group comprises a plurality of outgoing line holes, and the outgoing line holes are separated through the back plate main body; each electric connecting wire comprises an electrode leading-out wire which is bent along the direction deviating from the battery piece assembly, and each electrode leading-out wire used for leading out the same electrode respectively penetrates out of each corresponding leading-out wire hole; the width of the electrode leading-out wire is L1, the thickness of the electrode leading-out wire is L2, the size of the leading-out wire hole in the width extension direction of the electrode leading-out wire is A1, the size of the leading-out wire hole in the thickness extension direction of the electrode leading-out wire is A2, (L1 + 4) mm > = A1 > = (L1 + 2) mm, and (L2 + 12.6) mm > = A2 > = (L2 + 2) mm. The photovoltaic module can improve the subfissure performance of the battery piece module and the anti-load performance of the back plate.

Description

Technical Field

[0001] This application relates to the field of photovoltaic technology, and more particularly to a photovoltaic module. Background Technology

[0002] In photovoltaic (PV) modules, leads corresponding to electrodes of the same polarity are typically led out through a single opening on the backsheet. However, as the number of solar cells used in a PV module increases, the number of leads also increases, which negatively impacts the module's yield. This can either increase the risk of microcracks in the solar cells or lead to a decrease in the load-bearing capacity of the backsheet. Summary of the Invention

[0003] This application discloses a photovoltaic module to improve the problems of microcracks in the solar cells and the reduced load-bearing capacity of the backsheet.

[0004] To achieve the above objectives, this application discloses a photovoltaic module, which includes: A backplate, the backplate comprising a backplate body and a hole group penetrating the backplate body, the hole group comprising a plurality of independently arranged lead wire holes, the lead wire holes being separated from each other by the backplate body; A battery cell assembly, wherein the battery cell assembly is disposed on the inside of the back sheet; A plurality of electrical connection wires are electrically connected to the battery cell assembly. Each of the electrical connection wires includes an electrode lead wire bent in a direction away from the battery cell assembly. Each of the electrode leads wires for leading out the same type of electrode is respectively arranged to pass through the corresponding lead wire holes. The width of the electrode lead is L1, the thickness of the electrode lead is L2, the dimension of the lead hole along the width of the electrode lead is A1, and the dimension of the lead hole along the thickness of the electrode lead is A2. (L1+4)mm≥A1≥(L1+2)mm, (L2+12.6)mm≥A2≥(L2+2)mm.

[0005] Furthermore, the cross-sectional shape of the lead-out hole perpendicular to the thickness direction of the back plate is at least one of a circle, an ellipse, a racetrack shape, and a polygon, wherein the polygon has more than or equal to 3 sides.

[0006] Furthermore, L1 is 3 mm to 9 mm, and L2 is 0.1 mm to 0.4 mm.

[0007] Furthermore, the cross-sectional shape of the lead-out hole is circular, and the diameter of the circle is D1, where (L1+4)mm ≥ D1 ≥ (L1+2)mm, (L2+12.6)mm ≥ D1 ≥ (L2+4.9)mm; or, The cross-sectional shape of the lead hole is racetrack-shaped. The racetrack shape is a closed figure composed of two parallel straight line segments of equal length and two circular arc segments of equal length. The straight line segments are parallel to the width direction of the electrode lead. The length of the racetrack shape is L3, and the width of the racetrack shape is L4. (L1+4)mm≥L3≥(L1+2)mm, (L2+4)mm≥L4≥(L2+2)mm.

[0008] Furthermore, the cross-sectional shape of the lead-out hole is circular, and D1 is 5 mm to 13 mm; or, The cross-sectional shape of the lead-out hole is racetrack shaped, with L3 being 5 mm to 13 mm and L4 being 2.1 mm to 4.4 mm.

[0009] Furthermore, the cross-sectional shape of the lead-out hole is racetrack-shaped, and the diameter of the circle corresponding to the arc segment is D2, L4=D2.

[0010] Furthermore, the electrode lead includes a first sub-section and a second sub-section connected along its length direction, wherein the first sub-section is the portion away from the battery cell assembly, and the second sub-section is the portion close to the battery cell assembly; the first sub-section decreases in length along the direction away from the battery cell assembly.

[0011] Furthermore, the battery cell assembly is a four-cell battery cell assembly, the electrode leads include negative leads and positive leads, the number of negative leads is three, the number of positive leads is two, the hole group includes a first hole group and a second hole group, the first hole group includes three lead hole groups, and the second hole group includes two lead hole groups.

[0012] Furthermore, the lines connecting the centers of the three lead-out holes in the first hole group are on a straight line; or, The line connecting the centers of the three lead-out holes in the first hole group forms an equilateral triangle, and the centers of the three lead-out holes are respectively located at the three vertices of the equilateral triangle.

[0013] Furthermore, the straight-line distance between the centers of two adjacent lead holes is greater than or equal to 4.5 mm; and / or, The backsheet material includes at least one of glass, PVF-PET-PVF composite material, PVDF-PET-EVA composite material, PVF-PET-EVA composite material, PVDF-PET-PVDF composite material, and stainless steel; and / or, The material of the electrical connection wire includes at least one of tin-plated copper alloy, tin-plated aluminum alloy, tin-plated iron alloy, or tin-plated alloy; and / or, The yield strength of the electrical connection wire is σ, 60 MPa≤σ≤120 MPa.

[0014] Compared with the prior art, the beneficial effects of this application are as follows: The photovoltaic module of this application improves the problem of microcracks in the cell module, enhances the load resistance of the backsheet, and increases the yield of the photovoltaic module by optimizing the distribution, penetration form, and size relationship between the electrode leads and the lead hole.

[0015] Unlike the previous method where all leads for the same electrode extend from a single opening in the backplate, this application improves the single opening into a group of multiple independently arranged lead holes, replacing the single centralized opening structure with a distributed multi-lead hole structure. Simultaneously, in the electrical connection wires used for electrical connection with the battery cell assembly, leads for the same electrode also extend from their respective lead holes, meaning one lead independently exits from one lead hole. Furthermore, the width of the lead is L1, the thickness is L2, the dimension of the lead hole along the width direction of the lead is A1, and the dimension of the lead hole along the thickness direction of the lead is A2. The dimensions of a single lead hole and the lead extending from it satisfy the following relationships: (L1+4) mm ≥ A1 ≥ (L1+2) mm, (L2+12.6) mm ≥ A2 ≥ (L2+2) mm. This design has two advantages. First, the dispersed and independent exit of each lead effectively avoids bending or compression of multiple Type I electrode leads within the same lead hole, reducing the risk of microcracks in the solar cell module. Second, the lead holes are separated by the backsheet body, reducing the total opening area of ​​the backsheet, ensuring its structural strength, and improving its load-bearing capacity. These two factors combined improve the yield rate of photovoltaic modules. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the electrode leads of the electrical connection wires passing through the backsheet in an existing photovoltaic module; Figure 2 This is a schematic diagram of the structure of the backsheet in the photovoltaic module according to an embodiment of this application; Figure 3This is a schematic diagram of the electrode leads of the electrical connection wires passing through the back sheet in the photovoltaic module of this application embodiment; Figure 4 yes Figure 3 A top view of the photovoltaic module viewed from the back panel side; Figure 5 It is along Figure 4 Schematic diagram of the cross-sectional structure of line AA in the middle; Figure 6 This is a schematic diagram of the deformed structure of the backsheet in the photovoltaic module according to an embodiment of this application; Figure 7 This is a schematic diagram of the structure of the lead-out holes and electrode leads in the photovoltaic module according to an embodiment of this application; Figure 8 These are schematic diagrams of different shapes of racetrack-shaped lead-out holes in the embodiments of this application; Figure 9 yes Figure 4 Enlarged view of region I in the middle; Figure 10 This is a schematic diagram of another modified structure of the backsheet in the photovoltaic module according to an embodiment of this application; Figure 11 yes Figure 10 Enlarged view of region II; Figure 12 This is a schematic diagram of the deformed structure of the electrode lead wire provided in the embodiment of this application; Figure 13 This is a schematic diagram of another modified structure of the backsheet in the photovoltaic module according to an embodiment of this application; Figure 14 This is a top view of the backsheet in the photovoltaic module of Embodiment 6 of this application.

[0018] Explanation of reference numerals in the attached figures: 1. Backplate; 11. Backplate body; 12. Hole group; 12A; First hole group; 12B; Second hole group; 121. Lead wire hole; 2. Solar cell assembly; 21. Solar cell string; 211. Segmented solar cell; 3. Electrical connection wire; 31. Electrode lead wire; 31A. Negative lead wire; 31B. Positive lead wire; 311. First sub-section; 312. Second sub-section; 32. Busbar. Detailed Implementation

[0019] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0020] In this application, the terms "upper," "lower," "left," "right," "front," "rear," "top," "bottom," "inner," "outer," "middle," "vertical," "horizontal," "lateral," and "longitudinal" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. These terms are primarily for the purpose of better describing this application and its embodiments, and are not intended to limit the indicated device, element, or component to having a specific orientation, or to be constructed and operated in a specific orientation.

[0021] Furthermore, some of the aforementioned terms, besides indicating location or positional relationships, may also have other meanings. For example, the term "above" may, in certain circumstances, indicate a dependency or connection. Those skilled in the art can understand the specific meaning of these terms in this application based on the specific circumstances.

[0022] Furthermore, the terms "installation," "setup," "equipped with," "connection," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral structure; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium, or an internal connection between two devices, components, or parts. Those skilled in the art can understand the specific meaning of these terms in this application based on the specific circumstances.

[0023] Furthermore, the terms "first," "second," etc., are primarily used to distinguish different devices, components, or parts (which may be the same or different in specific type and construction), and are not intended to indicate or imply the relative importance or quantity of the indicated devices, components, or parts. Unless otherwise stated, "a plurality of" means two or more.

[0024] Backsheet and leads are crucial components of photovoltaic (PV) modules. Leads, as the conductors of current within the solar cells, must penetrate the backsheet to deliver external power. The backsheet, as the core encapsulation material on the back of the module, provides fixation, insulation, and protection for the leads through its perforated design. The combination of these two elements directly affects the module's electrical performance stability, sealing, and lifespan. Current PV module configurations involve leads for the same type of electrode passing through a single, relatively large lead-out hole.

[0025] like Figure 1As shown, three electrode leads 3 (used to lead out electrodes of the first electrical polarity) simultaneously emerge from the lead-out hole 121 on the left, and two electrode leads 3 (used to lead out electrodes of the opposite electrical polarity) simultaneously emerge from the lead-out hole 121 on the right. However, as the number of cell modules increases, the number of leads in the module also increases, and the above arrangement will cause problems for the backsheet and lead-out arrangement in the photovoltaic module. If the size of a single opening remains unchanged, these leads will have a low hole coverage rate due to insufficient space for arrangement, resulting in bending or local compression, increasing the risk of microcracks in the cell module; if the size of a single opening is increased, the load-bearing capacity of the backsheet will decrease. Therefore, the problems of microcracks in the cell module and the decrease in the load-bearing capacity of the backsheet in the photovoltaic module cannot be improved simultaneously, affecting the yield of the photovoltaic module.

[0026] Based on the analysis of the causes of the above-mentioned technical problems, this application provides a photovoltaic module that improves the problem of microcracks in the cell module and enhances the load resistance of the backsheet by optimizing the distribution and exit form of the electrode leads, thereby increasing the yield of the photovoltaic module.

[0027] The technical solutions provided in this application will be further described below with reference to the embodiments and accompanying drawings.

[0028] This application provides a photovoltaic module, such as... Figures 2-5 As shown, Figure 2 This is a schematic diagram of the structure of the backsheet 1 in the photovoltaic module according to an embodiment of this application. Figure 3 This is a schematic diagram of the electrode lead 31 of the electrical connection line 3 passing through the back plate 1 in the photovoltaic module of this application embodiment. Figure 4 Yes, yes Figure 3 A top view of the photovoltaic module viewed from the back panel 1 side. Figure 5 yes Figure 4 along Figure 4 A cross-sectional view of the AA line shows that the photovoltaic module includes: Back plate 1, back plate 1 includes back plate body 11 and hole group 12 through back plate body 11. Hole group 12 includes a plurality of lead wire holes 121 arranged independently of each other. The lead wire holes 121 are separated by back plate body 11. Battery cell assembly 2, which is located inside the back panel 1; A plurality of electrical connection wires 3 are electrically connected to the battery cell assembly 2. Each electrical connection wire 3 includes an electrode lead wire 31 bent in a direction away from the battery cell assembly 2. Each electrode lead wire 31 for leading out the same type of electrode is respectively arranged to pass through the corresponding lead wire hole 121. The width of the electrode lead 31 is L1, the thickness of the electrode lead 31 is L2, the dimension of the lead hole 121 along the width extension direction of the electrode lead 31 is A1, and the dimension of the lead hole 121 along the thickness extension direction of the electrode lead 31 is A2. (L1+4)mm≥A1≥(L1+2)mm, (L2+12.6)mm≥A2≥(L2+2)mm.

[0029] "Through" means that the lead-out hole 121 penetrates the full thickness of the back plate body 11, so that the lead-out hole 121 forms an unobstructed channel along the thickness direction of the back plate body 11. "Separated by the back plate body 11" means that each lead-out hole 121 is independently arranged on the back plate 1, and the edges of any two lead-out holes 121 do not touch.

[0030] The solar cell assembly 2 can be a structure formed by cutting a whole solar cell into individual solar cells and then electrically connecting several of these individual solar cells. As an optional implementation, several individual solar cells can be connected in series to form a battery string, and then multiple battery strings can be arranged according to the requirements of a parallel circuit to form the solar cell assembly 2. The electrical connection line 3 also includes a bus line 32 extending parallel to the solar cell assembly 2, and the bus line 32 is electrically connected to the solar cell assembly 2.

[0031] The electrode lead 31 can include either a negative lead 31A or a positive lead 31B, or it can include both negative lead 31A and positive lead 31B simultaneously. That is, the electrode lead 31 can be configured in any of the following three ways: (1) such as Figure 6 As shown in (a), the negative lead 31A is provided to pass through each corresponding lead hole 121, and the positive lead 31B is provided to pass through the same lead hole 121. (2) For example Figure 6 As shown in (b), the positive lead 31B is arranged to pass through the corresponding lead hole 121 respectively, and the negative lead 31A is arranged to pass through the same lead hole 121. (3) such as Figure 4 As shown, the negative lead 31A and the positive lead 31B are respectively arranged to pass through the corresponding lead hole 121.

[0032] The structural schematic diagram of lead hole 121 and electrode lead 31 is shown below. Figure 7 As shown, the width of electrode lead 31 is L1 (the direction of the width extension is...). Figure 7 (in the X direction), with a thickness of L2 (the extension direction of the thickness is...) Figure 7 (Y direction). The lead hole extends along the width of the electrode lead ( Figure 7The dimension of the lead hole (in the X direction) is A1, and the lead hole extends along the thickness direction of the electrode lead ( Figure 7 The dimension in the Y direction is A2, (L1+4)mm≥A1≥(L1+2)mm, (L2+12.6)mm≥A2≥(L2+2)mm. For example, A1=(L1+4)mm, A=(L1+3)mm or A=(L1+2)mm; A2=(L2+2)mm, A2=(L2+5)mm, A2=(L2+8)mm or A2=(L2+12.6)mm.

[0033] The photovoltaic module of this application improves the problem of microcracks in the cell module 2 and enhances the load resistance of the backsheet by optimizing the distribution, exit form and dimensional relationship between the electrode lead 31 and the lead hole 121. This also improves the yield of the photovoltaic module.

[0034] and Figure 1 Unlike the previous method where all leads for the same type of electrode extend from a single opening in the back plate 1, this application improves the single opening into a group of holes 12 formed by multiple independently arranged lead holes 121. Figures 2-4 Each lead hole 121 is separated from the back plate body 11 and exists in a dispersed form within the back plate 1. Simultaneously, in the electrical connection wires 3 used for electrical connection with the battery cell assembly 2, each electrode lead 31 also independently exits from its corresponding lead hole 121, i.e., a one-to-one correspondence between one electrode lead 31 and one lead hole 121. Furthermore, the width of the electrode lead 31 is L1, the thickness of the electrode lead 31 is L2, the dimension of the lead hole 121 along the width extension direction of the electrode lead 31 is A1, and the dimension of the lead hole 121 along the thickness extension direction of the electrode lead 31 is A2. The dimensions of a single lead hole 121 and the electrode lead 31 exiting from it satisfy the following relationships: (L1+4) mm ≥ A1 ≥ (L1+2) mm, (L2+12.6) mm ≥ A2 ≥ (L2+2) mm.

[0035] On the one hand, when multiple electrode leads 31 of the same type are set in the same lead hole 121, the multiple electrode leads 31 in one lead hole 121 are prone to mutual compression due to space constraints. Since the photovoltaic module of this application embodiment has each electrode lead 31 dispersed and independently passing through each lead hole 121, and A2≥(L1+2)mm and A2≥(L2+2)mm, the mutual compression of multiple electrode leads 31 can be effectively improved, thereby reducing the stress generated during the compression process. At the same time, the dispersed arrangement allows each electrode lead 31 to bend and turn more gently at the end near the cell module 2, reducing the superposition of bending compressive stress formed when multiple electrode leads 31 bend concentrated in the space of a single lead hole 121, reducing the intensity of stress transmitted to the cell module 2, improving the microcracks of the cell module 2, and improving the yield and stability of the photovoltaic module.

[0036] On the other hand, the backsheet body 11 between each lead hole 121 reduces the total opening area of ​​the backsheet 1. Simultaneously, the dimensional relationships (L1+4)mm≥A1 and (L2+12.6)mm≥A2 further reduce the opening area of ​​the backsheet 1. Since the structural strength of the backsheet 1 is negatively correlated with the opening area, the structural strength of the backsheet 1 is thus improved. Furthermore, the backsheet body 11 serves as a supporting structure for the backsheet 1, further enhancing its structural strength. This structural design enables the backsheet 1 to better resist stress impacts and mechanical loads during the transportation and use of the photovoltaic module, reducing the risk of cracking and delamination due to load, and improving the yield and stability of the photovoltaic module.

[0037] As an optional implementation, the cross-sectional shape of the lead hole 121 is perpendicular to the thickness direction of the back plate 1 (i.e., Figure 2 The shape of the opening on the back plate 1 is at least one of a circle, an ellipse, a racetrack shape, and a polygon, wherein the polygon has three or more sides. For example, the polygon includes triangles, rectangles, pentagons, etc., and this application does not limit the types of polygons.

[0038] The "racetrack shape" refers to a closed figure composed of two straight line segments and two circular arc segments, with each end of the circular arc segment connecting to one of the two straight line segments. Schematic diagrams of different racetrack-shaped lead-out holes 121 in embodiments of this application are shown below. Figure 8 As shown. Figure 8 As shown in (a), two straight line segments are set parallel to each other, and two circular arc segments are tangent to the two straight line segments (i.e., the distance between the two straight line segments is equal to the diameter of the circle corresponding to the circular arc segment); as Figure 8 As shown in (b), the two straight line segments are set in parallel, and the distance between the two straight line segments is less than the diameter of the circle corresponding to the arc segment; as Figure 8As shown in (c), two straight line segments are set parallel to each other, and the distance between the two straight line segments is greater than the diameter of the circle corresponding to the arc segment; as Figure 8 As shown in (d), the two straight line segments are not parallel, and the two arc segments are tangent to the two straight line segments. In this embodiment, when the cross-sectional shape of the lead-out segment hole 121 perpendicular to the thickness direction of the back plate 1 is as described above, the electrode lead-out segment 31 can pass through the lead-out segment hole 121 of the back plate 1 to conduct the current of the battery cell assembly 2 to the outside and realize power supply.

[0039] Preferably, the cross-sectional shape of the lead hole 121 perpendicular to the thickness direction of the back plate 1 is racetrack-shaped. In this embodiment, since the electrode lead 31 is usually a flat strip structure with a width greater than its thickness, the cross-sectional shape of the electrode lead 31 perpendicular to the thickness direction of the back plate 1 is rectangular. When the cross-sectional shape of the lead hole 121 is racetrack-shaped, for the same size electrode lead 31, the area of ​​the lead hole 121 on the back plate 1 is smaller, that is, the area retained by the back plate body 11 is larger, which further improves the load-bearing performance of the back plate 1.

[0040] The dimensional relationship between the lead hole 121 and the electrode lead 31 is explained below.

[0041] Figure 4 Enlarged view of region I in the middle is as follows Figure 9 As shown, the width of electrode lead 31 is L1 (the direction of the width extension is...). Figure 9 (in the X direction), with a thickness of L2 (the extension direction of the thickness is...) Figure 9 (8 directions in the image), L1 is 3 mm to 9 mm, and L2 is 0.1 mm to 0.4 mm. For example, L1 is 3 mm, 5 mm, 7 mm, or 9 mm, and L2 is 0.1 mm, 0.2 mm, 0.3 mm, or 0.4 mm. In this embodiment, when the value of L1 is within the above range, without affecting other performance aspects of the photovoltaic module (such as excessively large L1 causing shading of the cell module 2, or desoldering of the electrical connection line 3 from the cell module 2, affecting electrical connection performance, etc.), the resistance of the electrode lead 31 can be further reduced, improving the photoelectric performance of the photovoltaic module. When the value of L2 is within the above range, while ensuring the electrical performance of the electrical connection line 3, the stress on the electrode lead 31 is reduced, reducing the risk of microcracks in the cell module 2 and improving the yield rate of the photovoltaic module. Preferably, L1 is 6 mm and L2 is 0.15 mm.

[0042] As an optional implementation method, such as Figure 9As shown, the cross-sectional shape of the lead hole 121 is circular, with a diameter of D1, where (L1+4) mm ≥ D1 ≥ (L1+2) mm, and (L2+12.6) mm ≥ D1 ≥ (L2+4.9) mm. In this embodiment, the cross-sectional shape of the lead hole 121 is circular. In this embodiment, when the dimensions of the lead hole 121 and the electrode lead 31 satisfy the above-mentioned relationship, on the one hand, it increases the possibility of a single electrode lead 31 passing through the corresponding lead hole 121, improves the bending or compression of a single electrode lead 31 within the lead hole 121, and reduces the risk of microcracks in the battery cell assembly 2; on the other hand, it avoids the load-bearing performance of the backsheet 1 being affected by excessively large openings.

[0043] Further, D1 is 5 mm to 13 mm, exemplarily 5 mm, 7 mm, 9 mm, 11 mm, or 13 mm. In this embodiment, when D1 is within the above range, it ensures that the electrode lead 31 passes through the lead hole 121 while reducing the opening area on the backsheet 1. This improves the microcrack problem of the solar cell module 2, enhances the load-bearing capacity of the backsheet, and increases the yield of the photovoltaic module. Preferably, D1 is 9 mm.

[0044] As another optional implementation, the cross-sectional shape of the lead hole 121 is racetrack-shaped, and the corresponding structural schematic diagram of the back plate 1 is shown below. Figure 10 As shown, Figure 11 yes Figure 10 An enlarged view of region II shows that the straight segment in the racetrack shape is parallel to the width direction of electrode lead 31, and the length of the racetrack shape is L3 (the length of the racetrack shape extends in the direction of...). Figure 11 (in the X direction), with a width of L4 (the width of the runway shape extends in the X direction). Figure 11 In the Y direction, (L1+4)mm≥L3≥(L1+2)mm, (L2+4)mm≥L4≥(L2+2)mm. In this embodiment, when the cross-sectional shape of the lead hole 121 is racetrack-shaped, and the dimensions of the lead hole 121 and the electrode lead 31 satisfy the above relationship, on the one hand, it increases the possibility of a single electrode lead 31 passing through the corresponding lead hole 121, reduces the bending or compression of a single electrode lead 31 in the lead hole 121, and reduces the risk of microcracks in the battery cell assembly 2. On the other hand, it avoids the load-bearing performance of the back sheet 1 being affected by excessive opening.

[0045] Further, L3 is 5 mm to 13 mm, and L4 is 2.1 mm to 4.4 mm. For example, L3 is 5 mm, 7 mm, 9 mm, 11 mm, or 13 mm, and L4 is 2.1 mm, 3.1 mm, 4 mm, or 4.4 mm. In this embodiment, when L3 and L4 are within the above ranges, it ensures that the electrode lead 31 passes through the lead hole 121 while reducing the opening area on the backsheet 1. This improves the microcrack problem of the solar cell module 2, enhances the load-bearing capacity of the backsheet, and increases the yield of the photovoltaic module. Preferably, L3 is 9 mm and L4 is 3.2 mm.

[0046] Furthermore, the diameter of the circle corresponding to the arc segment in the runway shape is D2, and L4 = D2, as shown in the schematic diagram of the runway shape. Figure 8 (a) and Figure 8 As shown in (b). In this embodiment of the application, the straight segments and circular arc segments in the runway shape are smoothly tangent, the load transfer path is continuous, and there are no abrupt stress concentration points. Therefore, the stress concentration at the lead-out hole 121 in the back plate 1 is small, which further improves the load resistance performance of the back plate 1.

[0047] Furthermore, a schematic diagram of the deformed structure of electrode lead 31 is shown below. Figure 12 As shown, Figure 12 for Figure 2 A side view of the electrode lead 31 in region I along the Y direction. The electrode lead 31 includes a first sub-section 311 and a second sub-section 312 connected along its length direction (i.e., the Z direction). The first sub-section is the portion away from the cell assembly 2 (the portion above the dashed line), and the second sub-section is the portion closer to the cell assembly 2 (the portion below the dashed line). The length L1 of the first sub-section 311 decreases along the direction away from the cell assembly 2. Exemplarily, the shape of the first sub-section 311 can be semi-circular (e.g.,...). Figure 12 (a) shown), trapezoidal (as shown) Figure 12 (b) shown), triangle (as shown) Figure 12 (c) As shown. This application does not limit the shape of the first sub-part 311. Similarly, this application embodiment does not limit the L1 at each position in the second sub-part 312; the L1 of the second sub-part 312 along the direction away from the battery cell assembly 2 can remain constant (e.g., Figure 12 (a) ~ Figure 12 (c) can also show a decreasing trend (e.g.) Figure 12(d) As shown in this embodiment, when the first sub-part 311 of the electrode lead 31 shows a decreasing trend in L1 in the first direction, the possibility of the electrode lead 31 passing through the lead hole 121 is further increased, its hole-passing rate is improved, and the risk of microcracks in the solar cell assembly 2 is reduced. Preferably, the second sub-part 312 has a constant L1 in the direction away from the solar cell assembly 2. At this time, while ensuring that the electrode lead 31 is transmitted through the lead hole 121, the resistance of the electrode lead 31 can be further reduced, and the photoelectric performance of the photovoltaic module can be improved.

[0048] Furthermore, such as Figure 3 As shown, the battery cell assembly 2 is a four-cell battery cell assembly. The electrode leads 31 include negative electrode leads 31A and positive electrode leads 31B. There are three negative electrode leads 31A and two positive electrode leads 31B. The hole group 12 includes a first hole group 12A and a second hole group 12B. The first hole group 12A contains three lead hole holes 121, and the second hole group 12B contains two lead hole holes 121. The two lower negative electrode leads 31A have the same width direction, and the width direction of the upper negative electrode lead 31A is perpendicular to the width direction of the lower negative electrode lead 31A. The two positive electrode leads 31B have the same width direction. In this embodiment, each of the positive electrode lead 31B and the negative electrode lead 31A is dispersed and independently exits from a lead hole 121, which improves the perforation rate of the electrode lead 31 and reduces the risk of microcracks in the battery cell assembly 2; at the same time, it reduces the total opening area of ​​the back sheet 1, ensures the structural strength of the back sheet 1, and improves the load-bearing capacity of the back sheet 1.

[0049] As an optional implementation method, such as Figure 2 and Figure 4 As shown, the line connecting the centers of the three lead-out holes 121 in the first hole group 12A forms an equilateral triangle, and the centers of the three lead-out holes 121 are located at the three vertices of the equilateral triangle, respectively.

[0050] As another alternative implementation, a schematic diagram of another modified structure of the back plate 1 is shown below. Figure 13 As shown, the lines connecting the centers of the three lead holes 121 in the first hole group 12A are on a straight line.

[0051] Preferably, the three lead-out holes 121 in the first hole group 12A are configured according to... Figure 2 and Figure 4In this embodiment, when the lead-out holes 121 in the first hole group 12A are distributed in the manner described above, the stress distribution of the backplate 1 can be further improved, and the load-bearing capacity of the backplate 1 can be further enhanced. Simultaneously, when the negative electrode lead-out wires 31A are distributed according to the lead-out holes 121, it can reduce current interference between the battery strings in the battery cell assembly 2, and also achieve a more compact circuit layout, eliminating the need for additional busbar extensions and reducing resistance loss. Furthermore, the more dispersed distribution of the three negative electrode lead-out wires 31A reduces the possibility of mutual compression between them, thus reducing the possibility of microcracks in the battery cell assembly 2.

[0052] Furthermore, the straight-line distance between the centers of two adjacent lead-out holes 121 is greater than or equal to 4.5 mm. For example, the center distance between two adjacent lead-out holes 121 is 4.5 mm, 5.5 mm, 6.5 mm, or 7.5 mm. In this embodiment, when the straight-line distance between the centers of adjacent lead-out holes 121 is within the above range, the stress distribution of the back plate 1 can be further improved, and the load-bearing capacity of the back plate 1 can be further enhanced.

[0053] Furthermore, the material of the backsheet 1 includes at least one of glass, PVF-PET-PVF composite material, PVF-PET-EVA composite material, PVF-PET-EVA composite material, PVDF-PET-PVDF composite material, and stainless steel. PVF refers to polyvinyl fluoride, PET refers to polyethylene terephthalate, PVDF has the molecular formula -[CH2-HF2]-, and EVA refers to ethylene-vinyl acetate copolymer. In this embodiment, when the backsheet 1 is made of the above-mentioned materials, the backsheet 1 itself possesses properties of water vapor penetration resistance, UV radiation resistance, and insulation. More importantly, it gives the backsheet 1 good mechanical strength and load-bearing capacity, improving the stability of the photovoltaic module. Preferably, the material of the backsheet 1 is glass.

[0054] Furthermore, the material of the electrical connection wire 3 includes at least one of tin-plated copper alloy, tin-plated aluminum alloy, tin-plated iron alloy, or tin alloy. In this embodiment, when the above-mentioned materials are selected for the electrical connection wire 3, they have good electrical and mechanical properties, ensuring the effective transmission of current from the battery cell assembly 2 to the outside.

[0055] Further, the yield strength of the electrical connection wire 3 is σ, where 60 MPa ≤ σ ≤ 120 MPa. For example, the yield strength of the electrical connection wire 3 is 60 MPa, 80 MPa, 100 MPa, or 120 MPa. In this embodiment, when the yield strength of the electrical connection wire 3 is within the above range, the stress at the bend of the electrode lead 31 in the electrical connection wire 3 (i.e., the connection between the electrode lead 31 and the busbar 32) is reduced, decreasing the risk of microcracks in the solar cell module 2 and improving the yield rate of the photovoltaic module. Preferably, the yield strength of the electrical connection wire 3 is 90 MPa.

[0056] Furthermore, photovoltaic modules also include: The front panel of the battery cell assembly 2 is sequentially arranged on the side opposite to the back panel 1; The frame, the front panel away from the surface of the battery cell assembly 2 and the back panel 1 away from the surface of the battery cell assembly 2 are in contact with the frame, while the frame also covers the corresponding area of ​​the battery cell assembly 2. Sealing material filled between the front panel, back panel 1, and frame; The junction box is connected to the end of the electrode lead 31 that is away from the cell assembly 2.

[0057] In this embodiment, the lead holes 121 are separated by the back plate body 11, that is, the back plate body 11 between the lead holes 121 is not removed. Therefore, the phenomenon of sealing material overflowing from the hole group 12 on the back plate 1 is reduced, the air bubbles between the cell assembly 2 and the back plate 1 are reduced, the bonding effect between the two is improved, and the bonding between the electrode lead wires 31 is also reduced, thereby improving the yield of the photovoltaic module.

[0058] Furthermore, the front panel material includes glass; the sealing material includes at least one of EVA and POE. EVA refers to ethylene-vinyl acetate copolymer, and POE refers to polyolefin elastomer.

[0059] The technical solution of this application will be further explained below with reference to more specific embodiments.

[0060] Example 1 This embodiment provides a photovoltaic module with four-cell solar cells, and the method for manufacturing this photovoltaic module includes the following steps: The front panel, sealing material, battery string assembly, electrode connection wires, sealing material, and back panel are arranged and then laminated using a glass laminating machine to obtain a photovoltaic module.

[0061] There are three negative leads and two positive leads. The top view of the backplate is shown below. Figure 2As shown, the cross-section of the lead-out hole is circular, and D1 is 6 mm. The first hole group contains three lead-out holes, and the line connecting the centers of the lead-out holes forms an equilateral triangle, with the centers of the three lead-out holes located at the three vertices of the equilateral triangle. The second hole group contains two lead-out holes. Three negative lead-out wires pass through the three lead-out holes of the first hole group, and two positive lead-out wires pass through the three lead-out holes of the first hole group. The structure of the electrode lead wire is as follows Figure 12 As shown in (b), the L1 of the electrode leads is 4 mm and the L2 is 0.15 mm.

[0062] Example 2 The only difference between this embodiment and Embodiment 1 is that L1 remains unchanged along the extension direction of the electrode lead wire.

[0063] Example 3 The only difference between this embodiment and Embodiment 1 is that the structure of the electrode lead wire is as follows: Figure 12 As shown in (a).

[0064] Example 4 The only difference between this embodiment and Embodiment 1 is that the lines connecting the centers of the three lead-out holes in the first hole group are on a straight line (e.g., ...). Figure 13 (As shown).

[0065] Example 5 The only difference between this embodiment and Embodiment 1 is that the lead-out hole is racetrack-shaped, with dimensions L3=6 mm and D2=L4=2.5 mm (e.g., Figure 10 (As shown).

[0066] Example 6 The only difference between this embodiment and Embodiment 1 is that, Figure 14 As shown, the cross-section of the lead-out hole in the first hole group includes a hybrid design of circular and racetrack shapes, with dimensions D1=6 mm, L3=6 mm, and L4=2.5 mm. The right side contains only one lead-out hole, with a circular cross-section and a dimension D1 of 8 mm.

[0067] Comparative Example 1 The only difference between this comparative example and Example 6 is that, Figure 1 As shown, the first hole group contains only one lead hole. The cross-section of the lead hole is racetrack shaped, with dimensions L3=17 mm and L4=8 mm. The electrode lead is along the extension direction, and L1 remains unchanged.

[0068] Comparative Example 2 The only difference between this comparative example and Comparative Example 1 is that the dimensions of the racetrack-shaped cross-section of the lead-out hole in the first hole group are L3=22 mm and L4=9 mm.

[0069] Performance testing 1. Pore drop rate One hundred photovoltaic modules of Example 1 were prepared, and the number Y of photovoltaic modules without electrode leads was recorded. Hole reduction rate = Y / 100*100%. Hole reduction rates of Examples 2-6 and Comparative Examples 1-2 were obtained using the same method, with 100 modules prepared for each example.

[0070] 2. Microcrack rate in the mesopore One hundred photovoltaic modules of Example 1 were prepared. After the glass bonding step in the preparation process, the number Z of photovoltaic modules with microcracks was recorded. For photovoltaic modules without microcracks in the electroluminescence (EL) test after glass bonding, lamination was performed, and the number W of photovoltaic modules with microcracks in the central hole was recorded after lamination. The microcrack rate of the central hole = (Z+W) / 100*100%. The microcrack rate of the central hole of Examples 2 to 6 and Comparative Examples 1 to 2 was obtained by the same method, wherein the number of modules prepared was 100 in each example.

[0071] 3. Load-bearing performance Examples 1 to 6 and Comparative Examples 1 to 2 were tested according to IEC 61215.

[0072] The structure of performance tests 1-3 is shown in Table 1.

[0073] Table 1 Performance test results of Examples 1 to 6 and Comparative Examples 1 to 2

[0074] Note: "*" indicates the relative magnitude of the load-bearing performance of Examples 1 to 6 and Comparative Examples 1 to 2. The more "*", the better the load-bearing performance.

[0075] By comparing Examples 1-6 and Comparative Examples 1-2, it can be seen that the electrode lead wires in Examples 1-6 of this application, which are arranged to pass through the lead wire holes one-to-one, and the size settings of the electrode lead wires and lead wire holes satisfying (L1+4)mm≥A1≥(L1+2)mm and (L2+12.6)mm≥A2≥(L2+2)mm, can improve the hole coverage rate of the photovoltaic module, alleviate the microcrack problem of the cell module, and enhance the load-bearing performance of the backsheet. Although Comparative Example 2 improved the hole coverage rate and alleviated the microcrack problem of the cell module by increasing the size of a single lead wire hole, it caused a decrease in the load-bearing performance of the photovoltaic module, and could not achieve the effect of the two aspects of improvement in the Examples of this Application.

[0076] Comparing Examples 1 to 3, it can be seen that when the first sub-section L1 in the first direction of the electrode lead wire decreases, the possibility of the electrode lead wire passing through the lead wire hole is further increased, the hole-filling rate is improved, and the risk of microcracks in the battery cell assembly is reduced. Comparing Examples 1 and 4, it can be seen that when the opening area of ​​the backsheet is equal, and the line connecting the centers of the three lead wire holes in the first hole group forms an equilateral triangle, with the centers of the three lead wire holes located at the three vertices of the equilateral triangle, the stress distribution of the backsheet can be further improved, further enhancing the load-bearing capacity. Simultaneously, the distribution of the three negative electrode leads is more dispersed, reducing the possibility of mutual compression between the negative electrode leads and lowering the microcrack rate in the battery cell assembly. Comparing Examples 1 and 5, it can be seen that when the number and distribution of lead wire holes are the same, and the cross-sectional shape of the lead wire holes is racetrack-shaped, the opening area on the backsheet can be further reduced, thereby further improving the load-bearing performance. By comparing Examples 1 and 5-6, it can be seen that when the backplate includes both the first hole group and the second hole group, it has a better effect on improving the microcracks and load resistance performance of the battery cell assembly.

[0077] The technical solutions disclosed in the embodiments of this application have been described in detail above. Specific examples have been used in this article to illustrate the principles and implementation methods of this application. The description of the above embodiments is only for the purpose of helping to understand the technical solutions and core inventive points of the embodiments of this application. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this application. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. A photovoltaic module, characterized in that, The photovoltaic module includes: A backplate, the backplate comprising a backplate body and a hole group penetrating the backplate body, the hole group comprising a plurality of independently arranged lead wire holes, the lead wire holes being separated from each other by the backplate body; A battery cell assembly, wherein the battery cell assembly is disposed on the inside of the back sheet; A plurality of electrical connection wires are electrically connected to the battery cell assembly. Each of the electrical connection wires includes an electrode lead wire bent in a direction away from the battery cell assembly. Each of the electrode leads wires for leading out the same type of electrode is respectively arranged to pass through the corresponding lead wire holes. The width of the electrode lead is L1, the thickness of the electrode lead is L2, the dimension of the lead hole along the width of the electrode lead is A1, and the dimension of the lead hole along the thickness of the electrode lead is A2. (L1+4)mm≥A1≥(L1+2)mm, (L2+12.6)mm≥A2≥(L2+2)mm.

2. The photovoltaic module according to claim 1, characterized in that, The cross-sectional shape of the lead-out hole perpendicular to the thickness direction of the back plate is at least one of a circle, an ellipse, a racetrack shape, and a polygon, wherein the polygon has more than or equal to 3 sides.

3. The photovoltaic module according to claim 2, characterized in that, The L1 is 3 mm to 9 mm, and the L2 is 0.1 mm to 0.4 mm.

4. The photovoltaic module according to claim 3, characterized in that, The cross-sectional shape of the lead-out hole is circular, and the diameter of the circle is D1, where (L1+4)mm≥D1≥(L1+2)mm, (L2+12.6)mm≥D1≥(L2+4.9)mm; or, The cross-sectional shape of the lead hole is racetrack-shaped. The racetrack shape is a closed figure composed of two parallel straight line segments of equal length and two circular arc segments of equal length. The straight line segments are parallel to the width direction of the electrode lead. The length of the racetrack shape is L3, and the width of the racetrack shape is L4. (L1+4)mm≥L3≥(L1+2)mm, (L2+4)mm≥L4≥(L2+2)mm.

5. The photovoltaic module according to claim 4, characterized in that, The cross-sectional shape of the lead-out hole is circular, and D1 is 5 mm to 13 mm; or, The cross-sectional shape of the lead-out hole is racetrack shaped, with L3 being 5 mm to 13 mm and L4 being 2.1 mm to 4.4 mm.

6. The photovoltaic module according to claim 4, characterized in that, The cross-sectional shape of the lead-out hole is racetrack-shaped, and the diameter of the circle corresponding to the arc segment is D2, L4=D2.

7. The photovoltaic module according to claim 1, characterized in that, The electrode lead includes a first sub-section and a second sub-section connected along its length direction, wherein the first sub-section is the part away from the battery cell assembly, and the second sub-section is the part close to the battery cell assembly; the first sub-section decreases in length along the direction away from the battery cell assembly.

8. The photovoltaic module according to claim 1, characterized in that, The battery cell assembly is a four-cell battery cell assembly. The electrode leads include negative leads and positive leads. There are three negative leads and two positive leads. The hole group includes a first hole group and a second hole group. The first hole group contains three lead holes and the second hole group contains two lead holes.

9. The photovoltaic module according to claim 8, characterized in that, The lines connecting the centers of the three lead-out holes in the first hole group are on a straight line; or, The line connecting the centers of the three lead-out holes in the first hole group forms an equilateral triangle, and the centers of the three lead-out holes are respectively located at the three vertices of the equilateral triangle.

10. The photovoltaic module according to any one of claims 1 to 9, characterized in that, The straight-line distance between the centers of two adjacent lead holes is greater than or equal to 4.5 mm; and / or, The backsheet material includes at least one of glass, PVF-PET-PVF composite material, PVDF-PET-EVA composite material, PVF-PET-EVA composite material, PVDF-PET-PVDF composite material, and stainless steel; and / or, The material of the electrical connection wire includes at least one of tin-plated copper alloy, tin-plated aluminum alloy, tin-plated iron alloy, or tin-plated alloy; and / or, The yield strength of the electrical connection wire is σ, 60 MPa≤σ≤120 MPa.

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