Battery string structure and photovoltaic module

Abstract

The utility model discloses a battery string structure and photovoltaic module. The battery string structure can include: a plurality of battery pieces, a plurality of electrical connection structures for connecting the plurality of battery pieces into a string and a plurality of first bearing film layers; each first bearing film layer is fixedly overlapped on the adjacent first edge region of two adjacent battery pieces in the battery string structure, and the first bearing film layer covers part of the electrical connection structure located in the first edge region. The battery string structure can reduce the risk of hidden cracks or broken pieces of the battery pieces.

Description

Technical Field

[0001] This utility model relates to a battery string structure and a photovoltaic module. Background Technology

[0002] Currently, to better secure the solder ribbons connecting the cells in a solar cell string, a carrier film is typically used to cover the entire surface of the cell. By fixing the carrier film to the cell, the solder ribbons are thus secured. However, during the process of fixing the carrier film to the cell, the carrier film undergoes a morphological change: solid → molten state → solid again. When the carrier film is bonded to the cell in a molten state and then cools to a solid state, it shrinks, causing the edges of the cell to warp towards the carrier film. During the photovoltaic module lamination process, this warped cell is prone to microcracks or breakage. Utility Model Content

[0003] In view of this, the present invention provides a battery string structure and a photovoltaic module. The battery string structure improves relative stability while avoiding warping caused by the carrier film, thereby reducing the risk of microcracks or breakage of the battery cells.

[0004] To solve the above-mentioned technical problems, this utility model provides the following technical solution:

[0005] In a first aspect, the present invention provides a battery string structure, comprising: a plurality of battery cells, a plurality of electrical connection structures for connecting the plurality of battery cells into a string, and a plurality of first carrier film layers;

[0006] Each of the first carrier film layers is fixedly overlapped with the first edge region of two adjacent battery cells in the battery string structure, and the first carrier film layer covers the portion of the electrical connection structure located in the first edge region.

[0007] A photovoltaic module includes: a cover plate; a backsheet and an encapsulation film; and one or more cell string structures.

[0008] The encapsulation film layer is used to encapsulate one or more of the battery string structures between the cover plate and the back plate;

[0009] The battery string structure includes: multiple battery cells, multiple electrical connection structures for connecting each adjacent pair of battery cells in series, and multiple first carrier film layers;

[0010] Each of the first carrier film layers is fixedly overlapped with the first edge region of two adjacent battery cells in the battery string structure, and the first carrier film layer covers the portion of the electrical connection structure located in the first edge region.

[0011] The first aspect of the above-mentioned utility model has the following advantages or beneficial effects:

[0012] In the battery string structure provided by this utility model embodiment, each first bearing film layer is fixedly overlapped with the first edge region of two adjacent battery cells. On the one hand, it can relatively fix each pair of adjacent battery cells, thereby making the battery cells in the battery string structure a more stable whole and improving the stability of the battery string structure. On the other hand, the first bearing film layer is only fixedly overlapped with the first edge region of two adjacent battery cells and covers the part of the electrical connection structure located in the first edge region, but does not completely cover the main surface of the battery cell. Even if the first bearing film layer shrinks, it only causes the battery cells to move relatively in the stringing direction of the battery string structure, narrowing the gap between two adjacent battery cells and reducing battery cell warping. That is, it does not provide the battery cells with a force that shrinks from the edge to the middle, which helps to reduce the risk of microcracks or breakage of the battery cells.

[0013] In addition, the improvement of the battery string structure reduces the risk of microcracks or cell breakage caused by lamination during the assembly of the battery string structure into photovoltaic modules, improves the structure of photovoltaic modules, and increases the yield rate of photovoltaic modules. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the back structure of a partial cell string structure containing fully back-contact solar cells in an existing photovoltaic module.

[0015] Figure 2 This is a cross-sectional schematic diagram of a portion of the cell string structure in an existing photovoltaic module;

[0016] Figure 3 This is a partial cross-sectional structural diagram of a photovoltaic module provided according to an embodiment of the present utility model;

[0017] Figure 4 This is a cross-sectional structural diagram of a partial battery string structure including fully back-contact battery cells according to an embodiment of the present utility model;

[0018] Figure 5 This is a schematic diagram of the back structure of a partial battery string structure including fully back-contact battery cells according to an embodiment of the present utility model;

[0019] Figure 6 This is a schematic diagram of the back structure of a fully back-contact battery cell used in a battery string structure according to an embodiment of the present invention.

[0020] The attached figures are labeled as follows:

[0021] 10-Cover plate; 20-Back plate; 30-Encapsulation film layer; 40-Battery string structure; 41-Battery cell; 411-First edge region; 412-Second edge region; 42-Electrical connection structure; 43-First carrier film layer; 43'-Currently used carrier film; 44-Second carrier film layer; 45-Drainage line. Detailed Implementation

[0022] In existing photovoltaic modules or cell strings, to better stabilize the solder ribbons, a carrier film is typically applied to one or both sides of the cell. For example, using... Figure 1 and Figure 2 Taking the existing photovoltaic module or existing cell string structure containing fully back-contact cells as an example, from... Figure 1 and Figure 2 As can be seen, in existing photovoltaic modules or existing cell strings, the currently used carrier film 43' is generally independently covered on the main surface of each cell 41, and the currently used carrier film 43' covering each cell 41 is completely independent. Although the currently used carrier film 43' can fix the electrical connection structure 42 (such as solder ribbon) to the cell 41, the currently used carrier film 43' is generally bonded to the cell by heating from a solid state to a molten state and then cooling from the molten state back to a solid state, and simultaneously fixing the electrical connection structure 42 (such as solder ribbon) to the cell 41.

[0023] Research has found that during the process of recooling the currently used support membrane 43' from a molten state to a solid state, the support membrane 43' will shrink, for example, as shown in the figure. Figure 1 and Figure 2 The carrier film 43' currently used on each of the indicated solar cells will shrink from the edge to the center. Since the coefficient of thermal expansion of the solar cell 41 is significantly smaller than that of the carrier film 43', during the shrinkage process of the carrier film 43', the carrier film 43' will exert a horizontal pulling force on the solar cell 41. That is, the carrier film 43' will apply a pulling force towards the center of the solar cell to the solar cell 41 (e.g., Figure 1 The exemplary tensile forces F1, F2, F3, and F4 indicate that the currently used carrier film 43' pulls the edge of the solar cell 41 towards the center. Additionally, because the thickness of the currently used carrier film 43' varies, it also simultaneously applies a tensile force in the thickness direction to the edge of the solar cell 41 (e.g., ...). Figure 2As shown in F5), the edge cells 41 in the battery string are subjected to more significant horizontal tensile forces, and their edges are also subjected to significant thickness-direction tensile forces. Because the cells 41 are relatively thin, they are less resistant to the tensile forces of the currently used carrier film 43', increasing the risk of edge warping (especially for edge cells 41 in the battery string, where warping is more pronounced). This warping increases the risk of microcracks or fragmentation of the cells 41. Currently, in the photovoltaic module manufacturing process, to address the warping problem of the cells 41 caused by the currently used carrier film 43', the thickness of the encapsulating film between the battery string structure 40 and the backsheet 20 is increased. This allows the thickened encapsulating film between the battery string structure 40 and the backsheet 20 to flatten the warping of the cells 41 during lamination. However, this flattening process also increases the risk of microcracks or fragmentation of the cells 41. Therefore, there is still room for improvement in the battery string structure, the structure of the photovoltaic module, and the production of photovoltaic modules.

[0024] To address the aforementioned problems in existing battery strings and photovoltaic modules, and specifically to resolve the issue of cell warping caused by the supporting film layer in existing battery strings, this invention provides a novel battery string structure and photovoltaic module. In particular, it addresses the structure of battery strings and photovoltaic modules assembled from back-contact solar cells.

[0025] The specific structure of the battery string structure and photovoltaic module provided in the embodiments of this utility model will be described in detail below.

[0026] in, Figure 3 This is a partial cross-sectional structural diagram of a photovoltaic module with a battery string structure provided according to an embodiment of the present utility model; Figure 4 This is a cross-sectional structural diagram of a partial battery string structure including fully back-contact battery cells according to an embodiment of the present utility model; Figure 5 This is a schematic diagram of the back structure of a portion of a photovoltaic module containing fully back-contact solar cells, provided according to an embodiment of the present invention. Figure 6 This is a schematic diagram of the back structure of a fully back-contact battery cell used in a battery string structure according to an embodiment of the present invention.

[0027] Specifically, this utility model embodiment provides a battery string structure 40. Specifically, as... Figures 3 to 5 As shown ( Figure 4 for Figure 3A portion of the provided photovoltaic module's cell string structure 40 may include: a plurality of cells 41, a plurality of electrical connection structures 42 for connecting each adjacent pair of cells 41 in series, and a plurality of first support film layers 43. Each first support film layer 43 is fixedly overlapped with an adjacent first edge region 411 of two adjacent cells 41 in the cell string structure 40, and the first support film layer 43 covers a portion of the electrical connection structure 42 located in the first edge region 411.

[0028] It is worth noting that, although Figures 3 to 5 The exemplary illustration shows a battery string structure 40 and a photovoltaic module assembled from fully back-contact solar cells. However, the structure of the solar cell 41 in the photovoltaic module provided by this utility model is not limited to fully back-contact solar cells. It can also be a solar cell with electrodes on both sides (such as PERC cells, TOPCon cells, etc.). In addition, besides crystalline silicon solar cells, the solar cell 41 can also be an amorphous silicon cell such as a perovskite solar cell.

[0029] Understandably, in the battery string structure 40, each pair of adjacent battery cells 41 is connected in series through multiple electrical connection structures 42. Specifically, for each pair of adjacent battery cells 41, the positive electrode region (e.g., positive grid line) of one battery cell 41 is connected in series with the negative electrode region (e.g., negative grid line) of another battery cell 41 through multiple electrical connection structures 42, or vice versa. This achieves the series connection between battery cells. The positive and negative electrode regions of the same battery cell 41 are connected to different battery cells 41 respectively. For example, as shown... Figure 5 As shown, three battery cells 41 are connected in series to form a battery string structure 40. The negative electrode region of the first battery cell 41 is connected to multiple electrical connection structures 42 and its corresponding busbar. The positive electrode region of the first battery cell 41 and the negative electrode region of the second battery cell 41 are connected in series through multiple electrical connection structures 42. The positive electrode region of the second battery cell 41 and the negative electrode region of the third battery cell 41 are connected in series through multiple electrical connection structures 42. The positive electrode region of the third battery cell 41 is connected in series to the busbar corresponding to the third battery cell 41 through multiple electrical connection structures 42.

[0030] The connection between the grid lines (positive grid lines or negative grid lines) of the battery cell 41 and the electrical connection structure 42 can be achieved by welding, or by pressing the electrical connection structure 42 with the first bearing film layer 43 and the lamination process. The connection between the grid lines (positive grid lines or negative grid lines) of the battery cell 41 and the electrical connection structure 42 is not limited here.

[0031] Furthermore, the battery cell 41 used in this invention can be a battery cell with a main grid, a battery cell without a main grid, or a battery cell 41 without grid lines but connected to the electrical connection structure 42 through a TCO transparent conductive film layer. Preferably, the battery cell 41 used in this invention is a fully back-contact battery cell, that is, both the positive and negative electrode regions of the battery cell 41 are on the back side of the battery cell 41, and the electrical connection structure 42 is connected to the back side of the battery cell 41.

[0032] Understandably, the electrical connection structure 42 can be a solder strip or other existing structures for connecting solar cells in series. The specific structure of the electrical connection structure 42 is not limited here. Any structure of the electrical connection structure 42 is applicable to the photovoltaic module provided by this utility model.

[0033] In addition, such as Figures 3 to 5 As shown, a first carrier film layer 43 is connected only to the adjacent first edge regions 411 of two adjacent battery cells 41, and does not span the entire battery cell. Only one first carrier film layer 43 can be provided in the adjacent first edge regions 411 of two adjacent battery cells 41, or multiple first carrier film layers 43 can be stacked. Preferably, only one first carrier film layer 43 is provided in the adjacent first edge regions 411 of two adjacent battery cells 41.

[0034] Generally, a first bearing film layer 43 is provided in the first edge region 411 of each pair of adjacent battery cells 41 so that each battery cell 41 is relatively stable through the first bearing film layer 43. During the movement of the battery string structure 40, the electrical connection structure 42 between adjacent battery cells 41 will not bulge. Furthermore, during the movement of the battery string structure 40, the battery cells 41 can be prevented from pulling on each other, thereby preventing damage to the battery cells 41 during the movement of the battery string structure 40.

[0035] Furthermore, such as Figure 5 As shown, the first carrier film layer 43 generally covers the area of ​​the electrical connection structure 42 that spans two adjacent battery cells 41, so that the first carrier film layer 43 will not affect the electrical transmission of the electrical connection structure 42, and can better stabilize the electrical connection structure 42, and can also prevent the area of ​​the electrical connection structure 42 that spans two adjacent battery cells 41 from bulging.

[0036] against Figures 3 to 5In the provided battery string structure 40, each first carrier film layer 43 is fixedly overlapped with the first edge region 411 of two adjacent battery cells 41 and covers the portion of the electrical connection structure located in the first edge region. On the one hand, it can relatively fix each pair of adjacent battery cells 41, thereby making the battery cells 41 in the battery string structure 40 a more stable whole and improving the stability of the battery string structure 40. On the other hand, the first carrier film layer 43 is only fixedly overlapped with the first edge region 411 of two adjacent battery cells 41, and does not completely cover the main surface of the battery cell 41. Even if the first carrier film layer 43 shrinks, it only causes the battery cell 41 to move relative to each other in the stringing direction of the battery string structure 40, narrowing the gap between two adjacent battery cells 41. This helps to reduce the warping of the battery cell 41, that is, it does not provide the battery cell 41 with a force that shrinks from the edge to the middle, which helps to reduce the risk of microcracks or breakage of the battery cell 41 and improves the structure of the photovoltaic module made from it.

[0037] In addition, the improvement of the battery string structure reduces the risk of microcracks or cell breakage caused by lamination during the assembly of the battery string structure into photovoltaic modules, improves the structure of photovoltaic modules, and increases the yield rate of photovoltaic modules.

[0038] Furthermore, due to the reduced edge warpage of the solar cell 41, the thickness of the encapsulating film between the cell string structure 40 and the backsheet 20 in the photovoltaic module can be reduced. The photovoltaic module assembled based on this cell string structure 40 is lighter and thinner overall, and the technology is simple to operate, making it suitable for mass production and widespread adoption.

[0039] Furthermore, based on the battery string structure 40 provided in the above embodiments, such as Figures 3 to 5 As shown, the battery string structure 40 may further include: a plurality of second carrier film layers 44, wherein each second carrier film layer 44 is fixed to a second edge region 412 of the end battery cell of the battery string structure 40 away from the adjacent battery cell; the second carrier film layer 44 covers the portion of the electrical connection structure 42 located in the second edge region 412.

[0040] Here, the end cell refers to the cell located at both ends of a battery string structure 40. For the end cell, its second edge region 412 and its first edge region 411 are two opposing edge regions, and the extending directions of the second edge region 412 and the first edge region 411 of the end cell are perpendicular to the extending direction of the battery string structure 40.

[0041] The second carrier film layer 44 generally covers the portion of the electrical connection structure 42 located in the second edge region 412. The second carrier film layer 44 cooperates with the first carrier film layer 43 to better stabilize the electrical connection structure 42.

[0042] Since the second support film layer 44 is only disposed in the second edge region 412, the shrinkage of the second support film layer 44 will not cause the edge of the end cell where it is located to warp.

[0043] In addition, the second carrier film layer 44 cooperates with the first carrier film layer 43 to fix the electrical connection structure 42, so that the electrical connection structure 42 further forms an electrical connection with the cell 41 in the photovoltaic module lamination process, which eliminates the process of welding the electrical connection structure 42 to the cell 41. Therefore, the battery string structure 40 provided by this utility model helps to simplify the production process of photovoltaic modules and improve the production efficiency of photovoltaic modules.

[0044] It is worth noting that the terms "first" and "second" in the first carrier film layer 43, the second carrier film layer 44, the first edge region 411, and the second edge region 412 provided in this embodiment of the invention are used to distinguish carrier film layers and edge regions at different locations, and do not limit the order or number of carrier film layers and edge regions. The first carrier film layer 43 provided in this embodiment of the invention refers to the carrier film layer connecting two adjacent battery cells 41, and the second carrier film layer 44 refers to the carrier film layer disposed in the edge region of the end battery cell in the battery string structure 40. The first edge region 411 refers to the edge region on a battery cell 41 in a battery string structure 40 adjacent to the battery cell 41 connected in series with it; the second edge region 412 refers to the edge region on the end battery cell in a battery string structure 40 away from the adjacent battery cell 41.

[0045] It is worth noting that the materials used for the first carrier film layer 43 and the second carrier film layer 44 in this embodiment of the present invention can be directly selected from existing adhesive materials, such as the materials used for the encapsulation film layer 30 (e.g., transparent POE film, transparent EVA film, transparent EPE film, EP transparent film, colored film, etc.). This is to avoid the materials used for the first carrier film layer 43 and the second carrier film layer 44 affecting the generation of charge carriers inside the battery cell 41, and to avoid the materials used for the first carrier film layer 43 and the second carrier film layer 44 affecting the performance of the battery cell 41 (e.g., stability, photoelectric conversion performance, etc.).

[0046] Furthermore, regarding the first bearing film layer 43 and the second bearing film layer 44, the width of the first bearing film layer 43 overlapping the first edge region 411 (e.g., Figure 5 The width A or width C shown is smaller than the width of the battery cell 41 (e.g., Figure 5 The width E shown is half of the width of the first carrier film layer 43, wherein the width direction of the first carrier film layer 43 and the width direction of the battery cell 41 are aligned with the extension direction of the battery string structure 40. Additionally, the width of the second carrier film layer 44 (as shown) is half of the width of the battery cell 41. Figure 5 The width H shown is also less than half the width of the battery cell 41.

[0047] Among them, the width of the solar cell 41 (e.g.) Figure 5 The width E shown is typically 70mm to 120mm. For example, the width of the solar cell 41 (e.g., Figure 5 The width E shown can be 70mm, 80mm, 85mm, 90mm, 100mm, 110mm or 120mm, etc.

[0048] By controlling the width of the first carrier film layer 43 overlapping the first edge region 411 and the width of the second carrier film layer 44, the edge warping of the battery cell 41 caused by the shrinkage of the first carrier film layer 43 and the second carrier film layer 44 can be effectively avoided.

[0049] Preferably, the width of the first bearing membrane layer 43 overlapping the first edge region 411 (e.g.) Figure 5 The width A or width C shown can be 6mm to 10mm. For example, the width of the first carrier film layer 43 overlapping the first edge region 411 can be 6mm, 7mm, 8mm, 9mm, or 10mm. This can prevent warping of the battery cell 41 edges, effectively stabilize the electrical connection structure 42, prevent bulging in the area spanning adjacent battery cells 41 within the electrical connection structure 42, and better prevent relative movement between the battery cells 41. It can be understood that the width of the same first carrier film layer 43 overlapping two first edge regions 411 (e.g., width A or width C) can be 6mm to 10mm. Figure 5 The widths A and C shown can be the same or different to reduce the difficulty of setting the first carrier film layer 43, ensure that the first carrier film layer 43 has a relatively wide process window, and improve the production yield of the battery string structure 40.

[0050] More preferably, the width of the second carrier film layer 44 can be 6mm to 10mm. For example, the width of the second carrier film layer 44 can be 6mm, 7mm, 8mm, 9mm or 10mm. The width of the second carrier film layer 44 matches the width of the first carrier film layer 43 overlapping the first edge region 411, which can better stabilize the battery string structure 40 and reduce the edge warping of the battery cell 41.

[0051] Furthermore, regarding the battery string structure 40, the relative relationship between the battery cells 41 can be: the spacing between two adjacent battery cells 41 ( Figure 5 The spacing B shown is greater than or equal to 0 mm and less than or equal to 3 mm. For example, Figure 5 The spacing B between two adjacent battery cells 41 shown can be 0mm, 1mm, 1.5mm, 2mm, 2.5mm or 3mm, etc.

[0052] In addition to the relative positional relationship between the battery cells 41 mentioned above, more preferably, the battery cells 41 are full-back contact battery cells with alternating N-regions and P-regions. Specifically, the P-region electrode of the first end full-back contact battery cell in the battery string structure 40 is connected in series with the N-region electrode of its adjacent full-back contact battery cell through an electrical connection structure 42; for each non-end full-back contact battery cell in the battery string structure 40, the P-region electrode of the non-end full-back contact battery cell is connected in series with the N-region electrode of its adjacent full-back contact battery cell on one side through an electrical connection structure 42; the N-region electrode of the non-end full-back contact battery cell is connected in series with the P-region electrode of its adjacent full-back contact battery cell on the other side through an electrical connection structure 42; the N-region electrode of the second end full-back contact battery cell in the battery string structure 40 is connected in series with the P-region electrode of its adjacent full-back contact battery cell through an electrical connection structure 42; and the first carrier film layer 43 is disposed on the back side of the battery string structure 40.

[0053] The P-region electrode is the positive electrode of the solar cell, and the N-region electrode is the negative electrode of the solar cell.

[0054] Furthermore, in the case where the electrical connection structure 42 is a solder strip extending along the extension direction of the battery string structure 40, the relative relationship between the solder strip and the first carrier film layer 43 or the second carrier film layer 44 is as follows: the distance from the end of the solder strip to the edge of the nearest battery cell 41 (e.g., Figure 5 The distance F or distance G shown is generally less than the width of the first carrier film layer 43 overlapping the first edge region 411, or the distance from the end of the solder ribbon to the edge of the adjacent cell 41 is less than the width of the second carrier film layer 44 overlapping the second edge region 412. Preferably, the distance from the end of the solder ribbon to the edge of the adjacent cell 41 is 1mm to 5mm. For example, the distance from the end of the solder ribbon to the edge of the adjacent cell 41 (e.g., distance F or distance G) is generally less than the width of the first carrier film layer 43 overlapping the first edge region 411, or the distance from the end of the solder ribbon to the edge of the adjacent cell 41 is less than the width of the second carrier film layer 44 overlapping the second edge region 412. Figure 5 The distance F or distance G shown can be 1mm, 2mm, 3mm, 4mm or 5mm, etc. By controlling the distance from the end of the solder ribbon to the edge of the adjacent solar cell 41, the electricity generated by the solar cell can be collected better, and the first carrier film layer 43 or the second carrier film layer 44 can cover the end of the solder ribbon to better stabilize the solder ribbon and prevent the solder ribbon from shifting during the lamination process.

[0055] Understandably, such as Figure 5 The width D of the first bearing membrane layer 43 shown above is the width overlapping the two first edge regions 411 (e.g., Figure 5 The widths A and C shown) and the spacing between two adjacent battery cells 41 (as shown) Figure 5 The sum of the spacing B shown (i.e., width A + width C + spacing B = width D of the first bearing membrane layer 43).

[0056] Furthermore, such as Figure 6As shown, the battery string structure 40 may further include: a plurality of guide lines 45 disposed on two opposite edge regions along the length of the battery cell 41, wherein the extension direction of the edge region where the guide lines 45 are located is perpendicular to the extension direction of the battery string structure 40; the guide lines 45 are used to guide the series connection positions of the plurality of electrical connection structures 42. The extension direction of the edge region where the guide lines 45 are located is the length direction of the battery cell 41, which is perpendicular to the extension direction of the battery string structure 40.

[0057] Multiple guide lines 45 are distributed in each edge region. Generally, one guide line 45 is provided at each end of each P region of the solar cell 41, and the extension lines of two guide lines 45 located at the same end of the same P region are on the same straight line. In addition, one guide line 45 is provided at each end of each N region of the solar cell 41, and the extension lines of two guide lines 45 located at the same end of the same N region are on the same straight line. For example, for a fully back-contact solar cell with multiple P regions and multiple N regions arranged alternately, for each edge region, the guide lines 45 provided in the P regions and the guide lines 45 provided in the N regions are arranged alternately in that edge region.

[0058] By distributing multiple drainage lines 45 in each edge area, the electrical connection structure 42 can be positioned and set so that the electrical connection structure 42 can be accurately positioned on the battery cell 41, ensuring the reliability of the connection between the electrical connection structure 42 and the battery cell 41.

[0059] Furthermore, this utility model embodiment also provides a photovoltaic module. Specifically, as shown in the example... Figure 3 As shown, the photovoltaic module provided in this embodiment of the present invention may include: a cover plate 10; a back sheet 20; and an encapsulation film layer 30. In addition, the photovoltaic module may further include: one or more cell string structures 40 provided in any of the above embodiments. The encapsulation film layer 30 is used to encapsulate one or more cell string structures 30 between the cover plate 10 and the back sheet 20.

[0060] It is worth noting that, in addition to the aforementioned structures (cover plate 10, back plate 20, encapsulation film layer 30, and battery string structure 40), the photovoltaic module provided by this utility model may also include other structures such as busbars, current leads, junction boxes, etc. The connection relationship and relative position relationship between the busbars, current leads, junction boxes, etc. and the battery string structure 40 can be understood by those skilled in the art based on the prior art, and the connection relationship and relative position relationship between the other structures and the battery string structure 40 will not be described again here.

[0061] Furthermore, in the photovoltaic module provided by this utility model, the two end cells of the cell string structure 30 are electrically connected to their corresponding busbars (not shown in the figure), and the polarities of the electrode regions of the two end cells connected to the busbars are opposite. More specifically, the negative electrode region of the end cell at the first end of the cell string structure 30 is electrically connected to its corresponding busbar, and the positive electrode region of the end cell at the second end of the cell string structure 30 is electrically connected to its corresponding busbar; or, the positive electrode region of the end cell at the first end of the cell string structure 30 is electrically connected to its corresponding busbar, and the negative electrode region of the end cell at the second end of the cell string structure 30 is electrically connected to its corresponding busbar. For example, as shown... Figure 5 As shown, three battery cells 41 are connected in series to form a battery string structure 40. The negative electrode region of the first battery cell 41 is connected to multiple electrical connection structures 42 and its corresponding busbar. The positive electrode region of the first battery cell 41 and the negative electrode region of the second battery cell 41 are connected in series through multiple electrical connection structures 42. The positive electrode region of the second battery cell 41 and the negative electrode region of the third battery cell 41 are connected in series through multiple electrical connection structures 42. The positive electrode region of the third battery cell 41 is connected in series to the busbar corresponding to the third battery cell 41 through multiple electrical connection structures 42.

[0062] Furthermore, in the case where a photovoltaic module includes multiple cell string structures 40, adjacent cell string structures 40 are connected in series or in parallel via the busbars they are connected to. Whether adjacent cell string structures 40 are connected in series or in parallel can be determined by those skilled in the art based on the photovoltaic module's layout design; the technical solution provided in this utility model does not limit the type of electrical connection between adjacent cell string structures 40.

[0063] The manufacturing process of the battery string structure 40 and the photovoltaic module will be described in detail below. Specifically, multiple battery cells 41 are arranged in the battery string structure 40 according to the set spacing between the battery cells 41. According to the connection relationship between the electrical connection structure 42 and the battery cells 41, the electrical connection structure 42 is placed on the arranged multiple battery cells 41. A first support film layer 43 is placed in the first edge region 411 adjacent to each of two adjacent battery cells 41, so that the first support film layer 43 simultaneously overlaps the first edge region 411 adjacent to the two adjacent battery cells 41 and covers the part of the electrical connection structure 42 located in the first edge region 411. A second support film layer 44 is placed in the second edge region 412 of the end battery cell away from the adjacent battery cell 41, and the second support film layer 44 covers the part of the electrical connection structure 42 located in the second edge region 412. The first and second carrier films 43 and 44 are heated simultaneously to make them melt. After the molten first and second carrier films 43 and 44 are cooled, they are re-solidified. During the solidification process, the first carrier film 43 is bonded to the first edge region 411 it covers, and the second carrier film 44 is bonded to the second edge region 412 it covers, so as to fix the electrical connection structure 42 to the battery cell 41, thus obtaining the battery string structure 40.

[0064] Further, the cover plate 10 and the upper encapsulation film are placed sequentially, and the battery string structure 40 is placed on the upper encapsulation film according to the design pattern of the battery array. The busbar / bus strip is placed in a specific position according to the design structure of the battery array and welded to the electrical connection structure 42 led out from the end battery cell of the battery string structure 40. The lower encapsulation film is covered on the battery array on which the battery string structure 40 is placed, and the back plate 20 is covered on the lower encapsulation film. Through lamination, the upper encapsulation film and the lower encapsulation film form an integral encapsulation film layer 30, and the battery array composed of the battery string structure 40 is encapsulated in the encapsulation film layer 30. This lamination simultaneously forms a stable electrical connection between the electrical connection structure 42 and the battery cell 41, and the encapsulation film layer 30 bonds the cover plate 10 and the back plate 20.

[0065] The following two embodiments illustrate the warpage variation of the photovoltaic module provided by this utility model.

[0066] Example 1: In the cell string structure used in photovoltaic modules, the distance between the end of the solder ribbon and the edge of the cell is 3mm. The first carrier film 43 overlaps with adjacent cells 41 on both sides with a width of 5.5mm, and the spacing between adjacent cells 41 is 1mm, meaning the width of the first carrier film 43 is 12mm. The second carrier film 44 is located at the edge of the end cell, with a width of 5.5mm. The width of the cell 41 is 91mm. Heating the first carrier film 43 and the second carrier film 44 causes them to bond with the cell 41, pressing and fixing the solder ribbon onto the cell 41 to form a cell string structure 40. Measurements show that... Figure 1 and Figure 2 The conventional coated battery string shown has a warpage of 2.5 mm, while the battery string structure provided in this embodiment has a warpage reduced to 0.5 mm.

[0067] Example 2: In the cell string structure used in photovoltaic modules, the distance between the end of the solder ribbon and the edge of the cell is 3mm. The first carrier film 43 overlaps with adjacent cells 41 on both sides with a width of 7.5mm, and the spacing between adjacent cells 41 is 1mm, meaning the width of the first carrier film 43 is 16mm. The second carrier film 44 is located at the edge of the end cell, with a width of 7.5mm. The width of the cell 41 is 91mm. Heating the first carrier film 43 and the second carrier film 44 causes them to bond with the cell 41, pressing and fixing the solder ribbon onto the cell 41 to form a cell string structure 40. Measurements show that the relative... Figure 1 and Figure 2 The conventional coated battery string shown has a warpage of 2.5 mm, while the battery string structure provided in this embodiment has a warpage of 0 mm.

[0068] The above steps are provided only to help understand the method, structure, and core idea of ​​this utility model. For those skilled in the art, various improvements and modifications can be made to this utility model without departing from its principles, and these improvements and modifications also fall within the scope of protection of the claims of this utility model.

Claims

1. A battery string structure, characterized in that, include: Multiple battery cells (41), multiple electrical connection structures (42) for connecting the multiple battery cells (41) in a string, and multiple first carrier film layers (43). Each of the first carrier film layers (43) is fixedly overlapped with the first edge region (411) of two adjacent battery cells (41) in the battery string structure (40), and the first carrier film layer (43) covers the portion of the electrical connection structure (42) located in the first edge region (411).

2. The battery string structure according to claim 1, characterized in that, The width of the first carrier film layer (43) overlapping the first edge region (411) is less than half the width of the battery cell (41); wherein the width direction of the first carrier film layer (43) and the width direction of the battery cell (41) are consistent with the extension direction of the battery string structure (40).

3. The battery string structure according to claim 1, characterized in that, The spacing between two adjacent battery cells (41) is greater than or equal to 0 mm and less than or equal to 3 mm.

4. The battery string structure according to any one of claims 1-3, characterized in that, Also includes: Multiple second bearing membrane layers (44), among which, Each of the second carrier film layers (44) is fixed to the second edge region (412) of the end cell of the battery string structure (40) away from the adjacent cell. The second carrier film layer (44) covers the portion of the electrical connection structure (42) located in the second edge region (412).

5. The battery string structure according to claim 4, characterized in that, The width of the second carrier film layer (44) overlapping the second edge region (412) is less than half the width of the battery cell (41), wherein the width direction of the second carrier film layer (44) and the width direction of the battery cell (41) are consistent with the extension direction of the battery string structure (40).

6. The battery string structure according to claim 5, characterized in that, The width of the first bearing film layer (43) overlapping the first edge region (411) is 6mm~10mm; Or / and, the width of the second carrier film layer (44) overlapping the second edge region (412) is 6mm~10mm.

7. The battery string structure according to claim 4, characterized in that, The battery cell (41) is a back-contact battery cell, and the first carrier film layer (43) and the second carrier film layer (44) are both disposed on the back side of the battery string structure (40).

8. The battery string structure according to claim 4, characterized in that, The electrical connection structure (42) is a solder strip extending along the extension direction of the battery string structure (40). The distance from the end of the solder strip to the edge of the nearby battery cell (41) is less than the width of the first bearing film layer (43) overlapping on the first edge region (411), or the distance from the end of the solder strip to the edge of the nearby battery cell (41) is less than the width of the second bearing film layer (44) overlapping on the second edge region (412).

9. The battery string structure according to claim 8, characterized in that, The distance from the end of the welding strip to the edge of the adjacent battery cell (41) is 1 mm to 5 mm.

10. A photovoltaic module, characterized in that, include: Cover plate (10), back plate (20), battery string structure (40) as described in any one of claims 1-9, and encapsulation film (30). The encapsulation film (30) is used to encapsulate one or more of the battery string structures (40) between the cover plate (10) and the back plate (20).

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