Photovoltaic module

Abstract

The application discloses a photovoltaic module, which comprises at least two cell pieces arranged at intervals in a first direction. A plurality of first conductive wires are arranged at intervals in a second direction on a first surface of the cell piece, and a plurality of second conductive wires are arranged at intervals in the second direction on a second surface of the cell piece. A busbar is arranged on the edge of the first surface of the cell piece in the first direction to connect the first conductive wires. The second conductive wire of another cell piece protrudes from the edge of the cell piece to be overlapped with the busbar of the cell piece. In the solar module disclosed by the application, the busbar is formed on the first surface of the cell piece by silver paste, and no busbar is arranged. When the second conductive wire of another cell piece is overlapped with the first surface of the cell piece, each second conductive wire can be directly connected with the busbar to transmit current, and each second conductive wire will not be affected by the thickness of the second conductive wire itself and the thickness of the busbar, so that the virtual connection of the conductive wire caused by the electrical connection of the two cell pieces is avoided, and the current transmission efficiency between the two cell pieces is improved.

Description

Technical Field

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

[0002] In the photovoltaic industry, with technological advancements, products such as back-contact modules, shingled modules, and multi-cell modules have emerged. In shingled modules, taking the overlap of two cells as an example, the conductive wires of one cell are connected to the conductive wires of the other cell via a busbar along the thickness direction of the cell. When this busbar is connected to multiple conductive wires on the other cell, due to manufacturing errors, the thickness of the conductive wires may be inconsistent. The thicker conductive wires connect to the busbar first, while the thinner conductive wires may have difficulty making contact, potentially leading to incomplete connections between the thinner conductive wires and the busbar, thus affecting the current transmission efficiency between the cells. Utility Model Content

[0003] This application discloses a photovoltaic module for improving the problem of loose connections when connecting conductive wires between adjacent cells.

[0004] To achieve the above objectives, this application discloses a photovoltaic module, comprising:

[0005] At least two battery cells are provided, the two battery cells are spaced apart along a first direction, each battery cell has a first surface and a second surface along its thickness direction, a busbar is formed on the first surface, the busbar is disposed near the edge of the first surface in the first direction;

[0006] Multiple first conductive wires are spaced apart on the first surface along a second direction. The first conductive wires extend along the first direction, and all of the multiple first conductive wires are connected to the bus grid line so that the bus grid line collects the current of the first conductive wires.

[0007] Multiple second conductive wires are spaced apart on the second surface along the second direction, and the second conductive wires extend along the first direction and protrude from the edge of the second surface;

[0008] The busbar is configured to connect in the first direction to the portion of the second conductive wire of the adjacent battery cell that protrudes from the second surface;

[0009] The first direction intersects with the second direction.

[0010] As some alternative embodiments, the battery cell comprises, along its thickness direction, the following components arranged sequentially:

[0011] silicon substrate;

[0012] Doped layers; and,

[0013] Functional layer;

[0014] The silicon substrate has a second surface, the functional layer has a first surface, and the bus gate is at least partially embedded in the functional layer.

[0015] As some alternative implementations, the first surface, the busbar, and the first conductive wire are arranged sequentially along the thickness direction of the battery cell, such that the first conductive wire overlaps the busbar.

[0016] As some alternative implementations, the battery cell has a first edge and a second edge disposed opposite to each other along a first direction, the second edge being spaced apart from and adjacent to the first edge of another battery cell, and the busbar being disposed adjacent to the second edge;

[0017] Along the first direction, the width of the busbar is W1, and the distance from the busbar to the second edge is d1, satisfying: 25 < d1 / W1 < 100.

[0018] As some alternative implementations, the width W1 of the busbar satisfies: 2μm≤W1≤6μm.

[0019] As some optional implementations, a plurality of pads are also provided on the first surface. Along the second direction, each pad is located between two adjacent first conductive wires, and the pad is located at the connection between the busbar and the second conductive wire of another adjacent battery cell.

[0020] Along the first direction, the width of the busbar is W1, and the width of the pad is W2, satisfying: 1.4 < W2 / W1 < 4.

[0021] As some alternative implementations, the shape of the cross-section of the pad along the thickness direction of the battery cell is square;

[0022] The dimension of the pad in the second direction is L, which satisfies: 1.4 < L / W2 < 10.

[0023] As some alternative implementations, W2 is 10μm-60μm; and / or,

[0024] L is 40μm-80μm.

[0025] As some optional implementations, the photovoltaic module further includes:

[0026] An adhesive layer is disposed at the connection between the pad and the second conductive wire of the adjacent other battery cell, and the adhesive layer extends along the second direction to cover each of the pads;

[0027] The dimension of the adhesive layer along the first direction is W3, which satisfies: 1 < W3 / W2 < 5.

[0028] As some alternative implementations, W3 is 80μm-150μm; and / or,

[0029] Along the thickness direction of the battery cell, the thickness of the adhesive layer is h, where h is 1μm-2μm.

[0030] Compared with the prior art, the beneficial effects of this application are as follows:

[0031] This application discloses a photovoltaic module comprising at least two solar cells interconnected along a first direction. The two solar cells are spaced apart along the first direction when connected. A second conductive wire on the second surface of one solar cell protrudes from the edge of the cell, allowing it to overlap the first surface of the adjacent solar cell. Simultaneously, a busbar is formed on the first surface of the adjacent solar cell near the edge of one of the solar cells. This busbar connects to the first conductive wire on the first surface of the adjacent solar cell to achieve current collection. Since the second conductive wire of one solar cell is connected to the busbar, the two solar cells are electrically connected using the busbar. In this application, the busbar is formed on the first surface, then the first conductive wire is placed on the first surface, and finally the second conductive wire of the other solar cell overlaps the first surface and connects to the busbar. Because the first conductive wire and the second conductive wire of the other solar cell are sequentially and individually connected to the busbar, each first conductive wire and each second conductive wire can directly connect to the busbar. In other words, each first conductive wire and each second conductive wire are directly connected to the busbar individually during installation. This avoids the thicker conductive wire affecting the connection between the thinner conductive wire and the busbar, preventing the conductive wire and the busbar from causing a loose connection. This allows two adjacent solar cells to form an effective electrical connection, which helps improve the current transmission efficiency between the two solar cells. Attached Figure Description

[0032] To more clearly illustrate the technical solutions in the embodiments of this application, the 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.

[0033] Figure 1This is a schematic diagram of the structure of the photovoltaic module disclosed in the embodiments of this application;

[0034] Figure 2 This is a schematic diagram of the structure of a battery cell disclosed in an embodiment of this application;

[0035] Figure 3 This is a schematic diagram of a photovoltaic module disclosed in an embodiment of this application;

[0036] Figure 4 for Figure 3 A magnified view of a section at point A in the middle;

[0037] Figure 5 This is a schematic diagram of another structure of the photovoltaic module disclosed in the embodiments of this application;

[0038] Figure 6 for Figure 5 A magnified view of a section at point B in the middle;

[0039] Figure 7 This is a schematic diagram of another structure of the battery cell disclosed in the embodiments of this application.

[0040] Explanation of reference numerals in the attached figures:

[0041] 100. Photovoltaic module; 1. Solar cell; 11. Silicon substrate; 12. Doped layer; 13. Functional layer; 1a. First side; 1b. Second side; 1c. First edge; 1d. Second edge; 1e. First solar cell; 1f. Second solar cell; 2. Busbar; 3. First conductive wire; 4. Second conductive wire; 5. Pad; 6. Adhesive layer. Detailed Implementation

[0042] 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.

[0043] In this application, the terms "front," "back," "upper," "lower," etc., 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.

[0044] Furthermore, in addition to indicating location or positional relationship, some of the aforementioned terms may also have other meanings. For example, the term "above" may also be used in some cases to indicate a certain dependency or connection relationship. Those skilled in the art can understand the specific meaning of these terms in this application based on the specific circumstances.

[0045] 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.

[0046] Furthermore, the terms "first," "second," etc., are primarily used to distinguish different devices, elements, or components (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, elements, or components. Unless otherwise stated, "a plurality of" means two or more.

[0047] In the photovoltaic industry, with technological advancements, products such as back-contact modules, shingled modules, and multi-cell modules have emerged. In shingled modules, taking the overlap of two solar cells as an example, the conductive wires of one cell are connected to the conductive wires of the other cell via a busbar along the thickness direction of the cell. When this busbar is connected to multiple conductive wires on the other cell, due to manufacturing errors, the thickness of the conductive wires may be inconsistent. Thicker conductive wires connect to the busbar first, while thinner conductive wires may have difficulty making contact, potentially leading to incomplete connections between the thinner wires and the busbar. This not only affects the current transmission efficiency between the cells but also compromises the stability of the connection between the cells.

[0048] This application discloses a photovoltaic module in which, during the cell arrangement, a busbar is formed on a first surface, followed by a first conductive wire on the first surface, and finally, a second conductive wire from another cell is connected to the first surface and the busbar. Since the first and second conductive wires are individually and sequentially connected to the busbar, each first and second conductive wire can directly connect to the busbar. This individual connection avoids the thicker conductive wire affecting the connection between the thinner conductive wire and the busbar, preventing incomplete connections and ensuring an effective electrical connection between adjacent cells, thus improving current transfer efficiency between the two cells. Furthermore, the connection stability between the conductive wire and the busbar is enhanced by adding pads and adhesive layers on the busbar, further improving the stability of the electrical connection between the cells.

[0049] The technical solution of this application will be further described below with reference to the embodiments and accompanying drawings.

[0050] Please see Figure 1 This application discloses a photovoltaic module 100, including at least two solar cells 1, which are spaced apart along a first direction. Each solar cell 1 has a first surface 1a and a second surface 1b along its thickness direction. A busbar 2 is formed on the first surface 1a and is disposed near the edge of the first surface 1a in the first direction.

[0051] It is understood that the busbar 2 can be made of silver paste, which is applied or printed on the edge of the first surface 1a of the cell 1 to form the busbar 2.

[0052] It is understandable that either the first side 1a or the second side 1b can be the light-facing side, and the other side can be the shadow-facing side; this application does not make any specific restrictions here.

[0053] Exemplarily, the solar cell 1 includes a silicon substrate 11 and a doped layer 12, the doped layer being disposed on the surface of the silicon substrate 11. The silicon substrate 11 can be an N-type silicon substrate or a P-type silicon substrate. The doped layer 12 can be a diffusion layer, such as a boron diffusion layer or a phosphorus diffusion layer, or a polycrystalline silicon layer, such as a P-type doped polycrystalline silicon layer or an N-type doped polycrystalline silicon layer, or an amorphous silicon layer, such as a P-type doped amorphous silicon layer or an N-type doped amorphous silicon layer.

[0054] It is understandable that cell 1 is a solar cell, and the cell type can be passivated contact solar cell (TOPCon solar cell), back contact solar cell (BC solar cell), heterojunction solar cell (HJT solar cell), or emitter and back passivated solar cell (PERC solar cell).

[0055] Please see also Figure 1 and Figure 2 Typically, the solar cell 1 is a square sheet. Therefore, in solar cell 1, the first direction X can be the length direction of solar cell 1, and the second direction Y can be the width direction of solar cell 1. Alternatively, the first direction X can also be the width direction of solar cell 1, and the second direction Y can also be the length direction of solar cell 1. The first and second directions intersect. Figure 1 In the example, X indicates the first direction X, and Y indicates the second direction Y. Figure 1 In the example, Z indicates the thickness direction Z of the battery cell 1.

[0056] It is understood that the square sheet can be a square sheet with the same length and width, or a rectangular sheet with different length and width. This application does not make any specific limitation here.

[0057] In some embodiments, the photovoltaic module 100 further includes a plurality of first conductive wires 3 and a plurality of second conductive wires 4. The plurality of first conductive wires 3 are spaced apart along a second direction on a first surface 1a and extend along the first direction. Each of the first conductive wires 3 is connected to a busbar 2 so that the busbar 2 collects the current of the first conductive wires 3. The plurality of second conductive wires 4 are spaced apart along the second direction on a second surface 1b and extend along the first direction, protruding beyond the edge of the second surface 1b. The busbar 2 is configured to connect in the first direction to the portion of the second conductive wire 4 of an adjacent cell 1 that protrudes beyond the second surface 1b.

[0058] In the photovoltaic module disclosed in this application, after a busbar 2 is formed on the first surface 1a of a cell 1 using silver paste, a first conductive wire 3 needs to be connected to the first surface 1a by welding. Thus, the first conductive wire 3 is simultaneously welded to the busbar 2, forming a stable connection. The second conductive wire 4 of another cell 1, with its protruding edge overlapping the edge of the first surface 1a of that cell 1, connects to the busbar 2 of that cell 1. In other words, the connection between the first conductive wire 3 and the second conductive wire 4 of the two cells 1 is achieved through the busbar 2. Since the busbar 2 is first set on the first surface 1a, and the first conductive wire 3 and the second conductive wire 4 of the other cell 1 are subsequently connected to the busbar 2, both the first conductive wire 3 and the second conductive wire 4 can form an effective connection with the busbar 2. This avoids the thickness of the busbar and the thickness of the conductive wire itself affecting the connection, prevents incomplete connections, and improves the stability of current transmission between the cells 1.

[0059] Please see Figure 2In some embodiments, the solar cell 1 includes a silicon substrate 11, a doped layer 12, and a functional layer 13 disposed sequentially along its thickness direction. The silicon substrate 11 has a second surface 1b, the functional layer has a first surface 1a, and the busbar 2 is at least partially embedded in the functional layer 13.

[0060] In this application, when setting the busbar 2, the busbar 2 can be partially embedded into the functional layer 13 by printing. This way, when setting the first conductive wire 3, the first conductive wire 3 will overlap the top of the busbar 2 in the thickness direction of the battery cell 1, thus forming an effective connection between the busbar 2 and the first conductive wire 3. Subsequently, when the second conductive wire 4 of another battery cell 1 overlaps the edge of the first surface 1a of that battery cell 1, it will also overlap the top of the busbar 2, unaffected by the thickness of the second conductive wire 4 itself. Furthermore, the thickness difference between the various second conductive wires 4 will not affect the connection between the thinner second conductive wire 4 and the busbar 2. The second conductive wire 4 can form an effective electrical connection with the busbar 2, avoiding any loose connection between the conductive wire and the busbar 2. Of course, in other embodiments, the busbar 2 can also be formed on the first surface 1a by, for example, coating with silver paste.

[0061] Taking the formation of the busbar 2 on the first surface 1a by printing as an example, the busbar 2 can be formed on the first surface 1a by, for example, silver paste printing. During the fabrication of the solar cell 1, a functional layer 13 can be formed on the doped layer 12. The functional layer 13 has a first surface 1a, and the busbar is printed on the first surface 1a using silver paste.

[0062] It is understood that the silicon substrate 11 can be a P-type silicon substrate or an N-type silicon substrate, and a doped layer 12, a functional layer 13, etc. can also be disposed on the side of the silicon substrate 11 with the second surface 1b.

[0063] It is understandable that the doped layer 12 can be divided into phosphorus doped layer or boron doped layer, etc., depending on the different doping elements.

[0064] It is understood that the functional layer 13 may be a passivation layer and / or an antireflection layer, etc. The materials of the passivation layer and the antireflection layer may be alumina, silicon nitride, etc., and this application does not make specific limitations here.

[0065] In some embodiments, along the thickness direction of the battery cell 1, the first surface 1a, the busbar 2, and the first conductive wire 3 are arranged sequentially so that the first conductive wire 3 overlaps the busbar 2.

[0066] As described above, when setting the busbar 2, the busbar 2 can be formed on the first surface 1a by means of printing, for example. In this way, when setting the first conductive wire 3, the first conductive wire 3 will overlap the top of the busbar 2 in the thickness direction of the battery cell 1, so that the busbar 2 and the first conductive wire 3 form an effective connection. When the second conductive wire 4 of another battery cell 1 overlaps the edge of the first surface 1a of the battery cell 1, it will also overlap the top of the busbar 2, and will not be affected by the thickness of the second conductive wire 4 itself. The second conductive wire 4 can form an effective electrical connection with the busbar 2, avoiding the situation of a loose connection between the conductive wire and the busbar 2.

[0067] For ease of understanding and explanation, this application will use two adjacent solar cells 1 as an example, namely the first solar cell 1e and the second solar cell 1f. It is understood that the photovoltaic module 100 can also be formed by connecting three, four or more solar cells 1 in sequence, which will not be elaborated here.

[0068] Please see also Figure 3 and Figure 4 In some embodiments, the first battery cell 1e has a first edge 1c and a second edge 1d disposed opposite each other along a first direction. The second edge 1d is spaced apart from and adjacent to the first edge 1c of the first battery cell 1e, and the busbar 2 is disposed adjacent to the second edge 1d. In the first direction, the width of the busbar 2 is W1, and the distance from the busbar 2 to the second edge 1d is d1, satisfying: 25 < d1 / W1 < 100.

[0069] It should be noted that d1 refers to the distance from the center line of the busbar 2 in the first direction to the second edge 1d. Since d1 keeps the distance between the center line of the busbar 2 and the edge of the cell 1 constant, when W1 is larger, the ratio of d1 / W1 is smaller, and the edge of the busbar 2 is closer to the second edge 1d. Conversely, when W1 is smaller, the ratio of d1 / W1 is larger, and the edge of the busbar 2 is farther away from the second edge 1d.

[0070] It is understandable that the busbar has a certain width W1 in the first direction, and the center line of the busbar in the first direction should be at or near the midpoint of W1.

[0071] When the busbar 2 is fabricated near the second edge 1d, stress concentration occurs at the edge of the solar cell 1. If the distance is too close, damage such as microcracks may occur at the edge of the solar cell 1. In other words, this application controls the distance between the busbar 2 and the second edge 1d of the solar cell 1 to prevent damage to the solar cell 1. On the other hand, it also avoids the printing position of the busbar 2 being too far from the second edge 1d of the solar cell 1. If the busbar 2 is too far from the second edge 1d of the first solar cell 1e, the portion of the second conductive wire 4 protruding from the edge of the first solar cell 1e needs to be longer to form an effective connection with the busbar, affecting the connection stability between the two adjacent solar cells 1. Therefore, controlling the distance between the busbar 2 and the second edge 1d of the first solar cell 1e can also improve the connection stability between the two adjacent solar cells 1.

[0072] For example, d1 / W1 can be 25-35, 35-45, 45-55, 55-65, 65-75, 75-85, 85-100, etc. For instance, d1 / W1 can be 26, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, or 99, etc.

[0073] Optionally, the width W1 of the busbar 2 satisfies: 2μm ≤ W1 ≤ 6μm. On the one hand, when the first surface 1a is the light-facing surface of the solar cell 1, the width of the busbar 2 needs to consider its shading effect on the solar cell 1. Therefore, when the busbar 2 is located on the light-facing surface of the solar cell 1, controlling the width of the busbar 2 helps avoid the problem of the busbar 2 shading the solar cell 1 and affecting its efficiency.

[0074] On the other hand, since the busbar 2 is formed on the cell 1 using silver paste, this application can reduce the amount of silver paste used during the forming process by limiting the width of the busbar 2 to 2μm-6μm, thereby saving the production cost of the cell 1.

[0075] For example, W1 can be 2μm-3μm, 3μm-4μm, 4μm-5μm, 5μm-6μm, etc. For instance, W1 can be 2μm, 2.5μm, 3μm, 3.5μm, 4μm, 4.5μm, 5μm, 5.5μm, or 6μm, etc.

[0076] Please see also Figure 3 and Figure 4In some embodiments, a plurality of pads 5 are also formed on the first surface 1a. Along the second direction, each pad 5 is located between two adjacent first conductive wires 3, and the pad 5 is located at the connection between the busbar 2 and the second conductive wire 4 of the adjacent battery cell 1. Along the first direction, the width of the busbar 2 is W1, and the width of the pad 5 is W2, satisfying: 1.4 < W2 / W1 < 4.

[0077] Considering the narrow width of the busbar 2, when the second conductive wire 4 of an adjacent first battery cell 1e is connected to the busbar 2, it may affect the stability of the connection between the second conductive wire 4 and the busbar 2. To address this, this application provides a solder pad 5 at the connection point between the busbar 2 and the second conductive wire 4 to increase the soldering area between the second conductive wire 4 and the busbar 2, thereby improving the connection stability.

[0078] Based on the above, by controlling the width ratio between the pad 5 and the busbar 2, it is possible to prevent the width of the pad 5 from being too small relative to the busbar 2, which would affect the welding area between the pad and the second conductive wire 4 and potentially cause the second conductive wire 4 to have difficulty forming an effective connection with the pad 5. Furthermore, when setting the pad 5, it is also considered that the pad 5 may block light from the solar cell 1 on the light-facing surface. Therefore, by controlling the width ratio between the pad 5 and the busbar 2, it is possible to avoid the situation where the width of the pad 5 is too large and blocks light from the solar cell 1.

[0079] For example, W2 / W1 can be 1.4-1.6, 1.6-1.8, 1.8-2, 2-2.2, 2.2-2.4, 2.4-2.6, 2.6-2.8, 2.8-3, 3-3.2, 3.2-3.4, 3.4-3.6, 3.6-3.8, 3.8-4, etc. For example, W2 / W1 can be 1.5, 1.6, 1.7, 1.8, 1.9, 2, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9, 3, 3.1, 3.2, 3.3, 3.4, 3.5, 3.6, 3.7, 3.8, or 3.9, etc.

[0080] In some embodiments, when the pad 5 is disposed on the first surface 1a, it can be disposed integrally with the busbar 2. The material of the pad 5 can also be silver. Therefore, controlling the width of the pad 5 is beneficial to saving production costs.

[0081] For example, when printing silver paste to form busbars 2, when printing silver paste to form busbars 2 on the first surface 1a of the battery cell 1, the shape of pads 5 can be printed on the busbars 2 at the same time. In this way, the busbars 2 and pads 5 can be integrated, which is beneficial to improving production efficiency.

[0082] In some embodiments, the shape of the cross section of the pad 5 along the thickness direction of the battery cell 1 is square, that is, the shape of the pad 5 is square when viewed from the thickness direction of the battery cell 1.

[0083] Because the pad 5 is square, the relative contact area between the second conductive wire 4 of the other battery cell 1 and the pad 5 in the first direction is approximately the same. For example, when the second conductive wire 4 shifts relative to the pad 5, the contact area between the second conductive wire 4 and the pad 5 remains relatively unchanged. If the pad 5 is circular, the relative contact area between the second conductive wire 4 and the pad 5 will only be large when the second conductive wire 4 is connected to the position where the diameter of the pad 5 is located, which places higher requirements on the connection. However, when the pad 5 is square, it not only helps to improve the stability of the connection but also improves the ease of soldering the second conductive wire 4 onto the pad 5.

[0084] Please see Figure 4 In some embodiments, the pad 5 has a dimension L in the second direction, satisfying: 1.4 < L / W2 < 10.

[0085] In other words, the pad 5 is relatively long in the second direction. When the second conductive wire 4 of another cell 1 is connected to the pad 5, the second conductive wire 4 can effectively maintain its connection with the pad 5 even if it shifts in the second direction, thus preventing the second conductive wire 4 from detaching from the pad 5.

[0086] For example, L / W2 can be 1.4-2, 2-3, 3-4, 4-5, 5-6, 6-7, 7-8, 8-9, 9-10, etc. For instance, L / W2 can be 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5, 6, 6.5, 7, 7.5, 8, 8.5, 9, or 9.5, etc.

[0087] In some embodiments, W2 can be 10μm-60μm.

[0088] This application controls the width of the pad 5 to be between 10μm and 60μm. On the one hand, this avoids the situation where the width of the pad 5 is too small, which would affect the connection stability between the second conductive wire 4 of the other battery cell 1 and the pad 5. On the other hand, since there are a large number of pads 5, this avoids the pads 5 being too wide, reducing the amount of silver used when forming the pads 5, which helps to reduce production costs.

[0089] For example, W2 can be 10μm-20μm, 20μm-30μm, 30μm-40μm, 40μm-50μm, 50μm-60μm, etc. For instance, W2 can be 10μm, 15μm, 20μm, 25μm, 30μm, 35μm, 40μm, 45μm, 50μm, 55μm, or 60μm, etc.

[0090] In some embodiments, L can be 40μm-80μm.

[0091] On the one hand, the pad 5 should not be too long in the second direction. If L is too long, the pad 5 may easily overlap with two adjacent first conductive wires 3 in the second direction, causing a short circuit. Therefore, the pad 5 should not be too long in the second direction to prevent short circuits in the battery cell 1. On the other hand, when the second conductive wire 4 of another battery cell 1 is connected to the pad 5, if the pad 5 is too short, the second conductive wire 4 may overlap outside the pad 5 when it is offset in the second direction, affecting the connection of the battery cell 1. Therefore, the pad 5 should not be too short to avoid affecting the effective connection of the second conductive wire 4 of the other battery cell 1 on the pad 5.

[0092] For example, L can be 40μm-50μm, 50μm-60μm, 60μm-70μm, 70μm-80μm, etc. For instance, L can be 40μm, 45μm, 50μm, 55μm, 60μm, 65μm, 70μm, 75μm, or 80μm, etc.

[0093] When pad 5 is connected to the junction of busbar 2 and the second conductive wire 4 of another cell 1, it is also necessary to increase the connection stability between pad 5, busbar 2, and the second conductive wire 4. Please refer to [link / reference]. Figure 5 In some embodiments, the photovoltaic module further includes an adhesive layer 6, which is disposed at the connection between the pad 5 and the second conductive wire 4 of the adjacent cell 1, and extends along a second direction to cover each pad 5.

[0094] This application enhances the connection strength between battery cells 1 by adhering an adhesive layer 6. For example, the adhesive layer 6 is applied by applying glue or sticking tape at the connection point between the pad 5 and the second conductive wire 4 of the adjacent battery cell 1, so that the adhesive layer 6 is stably connected to the pad 5 and the second conductive wire 4 of the other battery cell 1, preventing the second conductive wire 4 from falling off the pad 5. This helps to improve the connection stability between two adjacent battery cells 1.

[0095] For example, when the adhesive layer 6 is formed by applying adhesive, a light-curing adhesive can be used to cure the adhesive to form the adhesive layer 6.

[0096] This application uses a light-curing adhesive, which is cured by light, thus reducing damage to the solar cell 1 and improving product yield.

[0097] Please see Figure 6 In some embodiments, the dimension of the adhesive layer 6 along the first direction is W3, satisfying: 1 < W3 / W2 < 5.

[0098] It is understandable that the width of the adhesive layer 6 is set to be wider than that of the pad 5, so that the adhesive layer 6 can better cover the pad 5 and the second conductive wire 4 of the other battery cell 1, so that the two adjacent battery cells 1 can be stably connected.

[0099] For example, W3 / W2 can be 1-2, 2-3, 3-4, 4-5, etc. For instance, W3 / W2 can be 1.1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, or 4.9, etc.

[0100] By controlling the width ratio between W3 and W2, the adhesive layer 6 can effectively cover the solder pad 5 and the second conductive wire 4. Simultaneously, the width of the adhesive layer 6 is limited to prevent it from becoming too large. This is because if too much adhesive is applied during the formation of the adhesive layer 6, resulting in an overly wide layer, the excess adhesive may overflow from the edges of the solar cell 1, affecting its production. Therefore, controlling the width of the adhesive layer 6 facilitates its formation at the edges of the solar cell 1.

[0101] In some embodiments, W3 can be 80μm-150μm.

[0102] Exemplarily, W3 may be 80 μm-90 μm, 90 μm-100 μm, 100 μm-110 μm, 110 μm-120 μm, 120 μm-130 μm, 130 μm-140 μm, 140 μm-150 μm, etc. For example, W3 can be 80 μm, 85 μm, 90 μm, 95 μm, 100 μm, 105 μm, 110 μm, 115 μm, 120 μm, 125 μm, 130 μm, 135 μm, 140 μm, 145 μm or 150 μm, etc.

[0103] On the one hand, because the pad 5 is relatively wide, when the adhesive layer 6 is placed on the pad 5 to cover it, a relatively wide adhesive layer 6 is beneficial for covering the pad 5, thus improving the stability of the pad 5 on the cell 1. On the other hand, to prevent the adhesive layer 6 from being too wide, if too much adhesive is applied during the adhesive layer 6 formation process, the excess adhesive may overflow from the edge of the cell 1, affecting the production of the cell 1. Therefore, controlling the width of the adhesive layer 6 is beneficial for its formation at the edge of the cell 1.

[0104] Please see Figure 7 In some embodiments, the thickness of the adhesive layer 6 along the thickness direction of the battery cell 1 is h, where h can be 1μm-2μm.

[0105] For example, h can be 1μm-1.2μm, 1.2μm-1.4μm, 1.4μm-1.6μm, 1.6μm-1.8μm, 1.8μm-2μm, etc. For instance, h can be 1μm, 1.1μm, 1.2μm, 1.3μm, 1.4μm, 1.5μm, 1.6μm, 1.7μm, 1.8μm, 1.9μm, or 2μm, etc.

[0106] Since the adhesive layer 6 is positioned along the thickness direction of the battery cell 1, if the adhesive layer 6 is formed by applying adhesive, and the adhesive is applied but not yet fully formed, a thin adhesive layer may cause the pads 5, the second conductive wire 4, and the first conductive wire 3 located below the adhesive layer 6 to be exposed through the adhesive layer 6, which is detrimental to the protection of the pads 5, the first conductive wire 3, and the second conductive wire 4 by the adhesive layer 6. Furthermore, if the thickness of the adhesive layer 6 is set too thick, the edges of the battery cell 1 may be relatively uneven, which is not conducive to the placement and stacking of the battery cell 1. Therefore, controlling the thickness of the adhesive layer 6 to 1μm-2μm allows the adhesive layer 6 to effectively cover the first conductive wire 3, the second conductive wire 4, and the pads 5, while also preventing unevenness at the edges of the battery cell 1, thus facilitating the placement and stacking of the battery cell 1.

[0107] The photovoltaic modules disclosed in the embodiments of this application have been described in detail above. Specific examples have been used 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 photovoltaic modules and their core ideas 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, include: At least two battery cells are provided, the two battery cells are spaced apart along a first direction, each battery cell has a first surface and a second surface along its thickness direction, a busbar is formed on the first surface, the busbar is disposed near the edge of the first surface in the first direction; Multiple first conductive wires are spaced apart on the first surface along a second direction. The first conductive wires extend along the first direction, and all of the multiple first conductive wires are connected to the bus grid line so that the bus grid line collects the current of the first conductive wires. Multiple second conductive wires are spaced apart on the second surface along the second direction, and the second conductive wires extend along the first direction and protrude from the edge of the second surface; The busbar is configured to connect in the first direction to the portion of the second conductive wire of the adjacent battery cell that protrudes from the second surface; The first direction intersects with the second direction.

2. The photovoltaic module according to claim 1, characterized in that, The battery cell comprises, along its thickness direction, the following components arranged sequentially: silicon substrate; Doped layers; and, Functional layer; The silicon substrate has a second surface, the functional layer has a first surface, and the bus gate is at least partially embedded in the functional layer.

3. The photovoltaic module according to claim 1, characterized in that, Along the thickness direction of the battery cell, the first surface, the busbar, and the first conductive wire are arranged sequentially, so that the first conductive wire overlaps the busbar.

4. The photovoltaic module according to any one of claims 1-3, characterized in that, The battery cell has a first edge and a second edge disposed opposite to each other along a first direction, the second edge being spaced apart from and adjacent to the first edge of another battery cell, and the busbar being disposed near the second edge; Along the first direction, the width of the busbar is W1, and the distance from the busbar to the second edge is d1, satisfying: 25 < d1 / W1 < 100.

5. The photovoltaic module according to claim 4, characterized in that, The width W1 of the busbar satisfies: 2μm≤W1≤6μm.

6. The photovoltaic module according to any one of claims 1-3, characterized in that, The first surface is also provided with a plurality of pads. Along the second direction, each pad is located between two adjacent first conductive wires, and the pad is located at the connection between the busbar and the second conductive wire of another adjacent battery cell. Along the first direction, the width of the busbar is W1, and the width of the pad is W2, satisfying: 1.4 < W2 / W1 < 4.

7. The photovoltaic module according to claim 6, characterized in that, The shape of the cross-section of the pad along the thickness direction of the battery cell is square; The dimension of the pad in the second direction is L, which satisfies: 1.4 < L / W2 < 10.

8. The photovoltaic module according to claim 7, characterized in that, W2 is 10μm-60μm; and / or, L is 40μm-80μm.

9. The photovoltaic module according to claim 6, characterized in that, The photovoltaic module also includes: An adhesive layer is disposed at the connection between the pad and the second conductive wire of the adjacent other battery cell, and the adhesive layer extends along the second direction to cover each of the pads; The dimension of the adhesive layer along the first direction is W3, which satisfies: 1 < W3 / W2 < 5.

10. The photovoltaic module according to claim 9, characterized in that, W3 is 80μm-150μm; and / or, Along the thickness direction of the battery cell, the thickness of the adhesive layer is h, where h is 1μm-2μm.

Images