Battery sheet, photovoltaic module and screen printing plate

Abstract

The embodiment of the present disclosure relates to the photovoltaic field, and provides a cell, a photovoltaic module and a printing glue screen plate, wherein the cell comprises: a substrate, the substrate comprises two edge regions arranged along a first direction and a center region located between the edge regions; a plurality of row glue point structures arranged along the first direction, each row glue point structure comprises a plurality of glue points arranged at intervals along a second direction, and the glue points in each row glue point structure are used for fixed contact with the same solder strip; wherein the total area of the orthographic projection of all the glue points in each row edge glue point structure on the surface of the substrate is greater than the total area of the orthographic projection of all the glue points in each row center glue point structure on the surface of the substrate, and in the first direction, the length of the glue points in the edge glue point structure is greater than or equal to the length of the glue points in the center glue point structure, and / or in the second direction, the width of the glue points in the edge glue point structure is greater than or equal to the width of the glue points in the center glue point structure, so that the reliability of the cell can be improved.

Description

Technical Field

[0001] This disclosure relates to the photovoltaic field, and particularly to a solar cell, a photovoltaic module, and a printing screen. Background Technology

[0002] Photovoltaic modules are components that generate electricity using the photovoltaic effect. They are typically composed of solar cells, encapsulant film, glass, and cover plate. Solar cells are a major component of the module, and the welding performance of the solar cells at the module end directly affects the module's power generation performance and power.

[0003] 0BB (Busbarless) technology eliminates the main busbar lines at the cell end, retaining only fine busbars. Solder ribbons are connected to the cells via adhesive bonding, followed by lamination for fusion bonding. Therefore, 0BB technology reduces silver paste consumption while increasing the cell's light-receiving area and reducing optical losses, effectively improving module power. Furthermore, the absence of pads and main busbars results in a more uniform and aesthetically pleasing cell surface color, representing one of the solutions the industry is constantly seeking to achieve through technological breakthroughs.

[0004] There is currently a need to provide a battery cell to increase the reliability of the connection between the battery cell and the solder strip. Summary of the Invention

[0005] This disclosure provides a solar cell, a photovoltaic module, and a printing stencil, which can at least improve the reliability of the connection between the solar cell and the solder ribbon.

[0006] According to some embodiments of this disclosure, one aspect of this disclosure provides a battery cell, comprising: a substrate, the substrate including two edge regions arranged along a first direction and a central region located in the middle of the edge regions; a multi-row adhesive dot structure arranged along the first direction, each row of the adhesive dot structure including a plurality of adhesive dots arranged at intervals along a second direction, the adhesive dots in each row of the adhesive dot structure being used for fixed contact with the same solder strip; wherein, the multi-row adhesive dot structure includes at least one row of edge adhesive dot structures located in each of the edge regions, and further includes at least one row of center adhesive dot structures located in the central region, the total area of ​​the orthographic projection of all the adhesive dots in each row of the edge adhesive dot structures onto the substrate surface is greater than the total area of ​​the orthographic projection of all the adhesive dots in each row of the center adhesive dot structures onto the substrate surface, and in the first direction, the length of the adhesive dots in the edge adhesive dot structures is greater than or equal to the length of the adhesive dots in the center adhesive dot structures, and / or, in the second direction, the width of the adhesive dots in the edge adhesive dot structures is greater than or equal to the width of the adhesive dots in the center adhesive dot structures.

[0007] In some embodiments, the edge adhesive dot structure is multi-row, and the area of ​​all the adhesive dots in the edge adhesive dot structure projected onto the substrate surface increases in the direction from the edge region to the center region.

[0008] In some embodiments, the number of adhesive dots in the edge adhesive dot structure is greater than the number of adhesive dots in the center adhesive dot structure.

[0009] In some embodiments, the edge adhesive dot structure is in multiple rows, the center adhesive dot structure is in multiple rows, and the spacing between adjacent edge adhesive dot structures is smaller than the spacing between adjacent center adhesive dot structures.

[0010] In some embodiments, the substrate includes a first side and a second side arranged along the second direction, and in the same row of adhesive dots, the length of the adhesive dots closer to the second side is greater than the length of the adhesive dots closer to the first side.

[0011] In some embodiments, the substrate includes a first side and a second side arranged along the second direction, wherein the density of the adhesive dots near the second side is greater than the density of the adhesive dots near the first side.

[0012] In some embodiments, along the second direction, the width of the adhesive dot structure located in the edge region on the side away from the center region is greater than the width on the side closer to the center region.

[0013] In some embodiments, the substrate includes a first side and a second side arranged along the second direction, a portion of the adhesive dots located in the central region near the first side are aligned along the first direction, a portion of the adhesive dots located in the central region near the second side are aligned along the first direction, and the remaining adhesive dots located in the central region and in the same column along the first direction are staggered.

[0014] According to some embodiments of this disclosure, another aspect of this disclosure also provides a photovoltaic module, including: a battery string, formed by connecting a plurality of battery cells as described above; an encapsulating film for covering the surface of the battery string; and a cover plate for covering the surface of the encapsulating film facing away from the battery string.

[0015] According to some embodiments of this disclosure, another aspect of this disclosure also provides a printing screen for dispensing adhesive onto solar cells, comprising: a main body, the main body including two first regions arranged along a first direction and a second region located between the first regions; multiple rows of dispensing mesh structures arranged along the first direction, each row of the dispensing mesh structures including a plurality of through holes arranged at intervals along a second direction, through which adhesive is printed onto the surface of the solar cell; wherein, the multiple rows of dispensing mesh structures include at least one row of edge mesh structures located in each of the first regions, and at least one row of center mesh structures located in the second region, the total area of ​​all the through holes in each row of the edge mesh structures projected onto the main body surface is greater than the total area of ​​all the through holes in each row of the center mesh structures projected onto the main body surface, and in the first direction, the length of the through holes in the edge mesh structures is greater than or equal to the length of the through holes in the center mesh structures, and / or, in the second direction, the width of the through holes in the edge mesh structures is greater than or equal to the width of the through holes in the center mesh structures.

[0016] The technical solution provided by the embodiments of this disclosure has at least the following advantages: For the edge area of ​​the battery cell, the solder ribbon is more likely to detach from the battery cell. Therefore, the embodiments of this disclosure set the total area of ​​all adhesive dots in each row of edge adhesive dots to be greater than the sum of the total areas of all adhesive dots in each row of center adhesive dots, thereby increasing the contact area between the edge adhesive dots and the solder ribbon, thereby improving the connection reliability between the solder ribbon and the battery cell in the edge area. In addition, the disclosure also sets the through hole length of the edge mesh structure to be no less than the through hole length in the center mesh structure, and / or the width of the edge mesh structure to be no less than the through hole width in the center mesh structure, so that the contact length and / or contact width between the solder ribbon and each adhesive dot will not decrease in the first direction and / or the second direction, thereby avoiding affecting the connection reliability between the solder ribbon and each adhesive dot. Attached Figure Description

[0017] One or more embodiments are illustrated by way of example with corresponding pictures in the accompanying drawings. These illustrations do not constitute a limitation on the embodiments. Unless otherwise stated, the pictures in the accompanying drawings do not constitute a limitation on scale. In order to more clearly illustrate the technical solutions in the embodiments of this disclosure or the conventional technology, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this disclosure. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 A top view of a battery cell is provided for one embodiment of this disclosure;

[0019] Figure 2 Another top view of a battery cell provided in an embodiment of this disclosure;

[0020] Figure 3 This is a schematic diagram of the structure of a photovoltaic module provided in one embodiment of the present disclosure;

[0021] Figure 4 A cross-sectional view of a photovoltaic module provided in an embodiment of this disclosure;

[0022] Figure 5 This is a schematic diagram of the structure of a printing screen according to an embodiment of the present disclosure. Detailed Implementation

[0023] As can be seen from the background technology, the elimination of the main busbar connection line and pads in OBB technology has led to a decrease in the welding reliability between the solder ribbon and the cell, especially in the edge area of ​​the cell. When printing adhesive dots in the edge area of ​​the cell, there may be missed printing, making the edge area of ​​the cell the main area where the solder ribbon and cell connection fails.

[0024] This disclosure provides a solar cell, a photovoltaic module, and a printing screen. In the solar cell, the edge area is more prone to solder ribbon detachment. Therefore, in this embodiment, the total area of ​​all adhesive dots in each row of edge adhesive dots is greater than the sum of the total areas of all adhesive dots in each row of center adhesive dots. This increases the contact area between the edge adhesive dots and the solder ribbon, thereby improving the connection reliability between the solder ribbon and the solar cell in the edge area. Furthermore, this disclosure also provides that the length of the through holes in the edge mesh structure is not less than the length of the through holes in the center mesh structure, and / or that the width of the edge mesh structure is not less than the width of the through holes in the center mesh structure. This ensures that the contact length and / or contact width between the solder ribbon and each adhesive dot does not decrease in the first and / or second directions, thus avoiding affecting the connection reliability between the solder ribbon and each adhesive dot.

[0025] In the description of the embodiments of this disclosure, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary or secondary relationship of the indicated technical features. In the description of the embodiments of this disclosure, "a plurality of" means two or more, unless otherwise explicitly defined.

[0026] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this disclosure. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0027] In the description of the embodiments of this disclosure, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent three cases: A exists, A and B exist simultaneously, and B exists. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.

[0028] In the description of the embodiments of this disclosure, the term "multiple" refers to two or more (including two), similarly, "multiple groups" refers to two or more (including two groups), and "multiple pieces" refers to two or more (including two pieces).

[0029] In the description of the embodiments of this disclosure, the technical terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of this disclosure and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this disclosure.

[0030] In the description of the embodiments of this disclosure, unless otherwise expressly specified and limited, technical terms such as "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; 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; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of this disclosure according to the specific circumstances.

[0031] In the accompanying drawings corresponding to the embodiments of this disclosure, the thickness and area of ​​the layers are enlarged for better understanding and ease of description. When describing a component (such as a layer, film, region, or substrate) on or on the surface of another component, the component may be "directly" located on the surface of the other component, or there may be a third component between the two components. Conversely, when describing a component on the surface of another component, or when another component is formed or disposed on the surface of a component, it indicates that there is no third component between the two components. Furthermore, when describing a component as being "generally" formed on another component, it means that the component is not formed on the entire surface (or front surface) of the other component, nor is it formed on a portion of the edge of the entire surface.

[0032] In the description of embodiments of this disclosure, when a component "includes" another component, other components are not excluded unless otherwise stated, and may be further included. Furthermore, when a component such as a layer, film, region, or plate is referred to as being "on / located" on another component, it can be "directly" on the other component (i.e., located on the surface of the other component with no other components between them), or another component may be present therein. Additionally, when a component such as a layer, film, region, or plate is "directly located" on another component, or when a component such as a layer, film, region, or plate is located on the surface of another component, it indicates that no other components are located therein.

[0033] The terminology used in the description of the various embodiments herein is for the purpose of describing particular embodiments only and is not intended to be limiting. As used in the description of the various embodiments and the appended claims, the term "component" is also intended to include the plural form unless the context clearly indicates otherwise. Components include layers, films, regions, or plates, etc.

[0034] The embodiments of this disclosure will now be described in detail with reference to the accompanying drawings. However, those skilled in the art will understand that many technical details have been provided in the embodiments of this disclosure to facilitate a better understanding of the disclosure. However, the technical solutions claimed in this disclosure can be implemented even without these technical details and various variations and modifications based on the following embodiments.

[0035] refer to Figure 1 , Figure 1 A top view of a battery cell is provided for one embodiment of this disclosure.

[0036] In some embodiments, the battery cell may include a substrate 100, which includes two edge regions 110 arranged along a first direction X and a central region 120 located in the middle of the edge regions 110.

[0037] The battery cell may further include: multiple rows of adhesive dots 101 arranged along a first direction X, each row of adhesive dots 101 including a plurality of adhesive dots 111 arranged at intervals along a second direction Y, and the adhesive dots 111 in each row of adhesive dots 101 being used for fixed contact with the same solder strip 102.

[0038] The multi-row adhesive dot structure 101 includes at least one row of edge adhesive dot structures 121 located in each edge region 110, and at least one row of center adhesive dot structures 131 located in the center region 120. The total area of ​​all adhesive dots 111 in each row of edge adhesive dot structures 121 projected onto the surface of the substrate 100 is greater than the total area of ​​all adhesive dots 111 in each row of center adhesive dot structures 131 projected onto the surface of the substrate 100. In the first direction X, the length of adhesive dots 111 in the edge adhesive dot structure 121 is greater than or equal to the length of adhesive dots 111 in the center adhesive dot structure 131, and / or, in the second direction Y, the width of adhesive dots 111 in the edge adhesive dot structure 121 is greater than or equal to the width of adhesive dots 111 in the center adhesive dot structure 131.

[0039] In the battery cell, the edge region 110 is more prone to the solder ribbon 102 detaching from the battery cell. Therefore, in this embodiment, the total area of ​​all adhesive dots 111 in each row of edge adhesive dot structures 121 is greater than the sum of the total areas of all adhesive dots 111 in each row of center adhesive dot structures 131. This increases the contact area between the edge adhesive dot structure 121 and the solder ribbon 102, thereby improving the connection reliability between the solder ribbon 102 and the battery cell in the edge region 110. Furthermore, this disclosure also sets the length of the through hole 211 in the edge mesh structure 221 to be no less than the length of the through hole 211 in the center mesh structure 231, and / or the width of the edge mesh structure 221 to be no less than the width of the through hole 211 in the center mesh structure 231. This ensures that the contact length and / or contact width between the solder ribbon 102 and each adhesive dot 111 in the first direction X and / or the second direction Y will not decrease, thus avoiding affecting the connection reliability between the solder ribbon 102 and each adhesive dot 111.

[0040] In some embodiments, the solar cells include, but are not limited to, one or any combination of PERC cells (Passivated Emitter RearCell), IBC cells (Interdigitated Back Contact), TOPCon cells (Tunnel Oxide Passivated Contact), HIT / HJT cells (Heterojunction Technology), thin-film solar cells, and tandem solar cells. Thin-film solar cells include, but are not limited to, perovskite thin-film solar cells, copper indium selenide (CIGS) thin-film solar cells, gallium arsenide (GaAs) thin-film solar cells, and cadmium sulfide (CdS) thin-film solar cells. Tandem solar cells include, but are not limited to, perovskite cells stacked with crystalline silicon cells, perovskite cells stacked with perovskite cells, and perovskite cells stacked with thin-film cells.

[0041] Depending on the type of solar cell, the substrate 100 can have a corresponding structure. Taking TOPCon solar cells as an example, the substrate 100 of the solar cell can be a substrate 100 that has already formed a front emitter, a front passivation layer, a front electrode, a back oxide layer, a back doped conductive layer, a back passivation layer, and a back electrode.

[0042] Regarding the edge region 110 and the center region 120, the edge region 110 may be the area where the base 100 is located along the first direction X edge 1 / 5, and the center region 120 may be the area where the base 100 is located along the first direction X center 3 / 5. In other embodiments, the edge region 110 and the center region 120 may also have other proportions, and the area of ​​the base 100 included in the edge region 110 and the center region 120 can be set according to requirements.

[0043] For the adhesive dot structure 101, the adhesive dot structure 101 can be printed conductive adhesive or insulating adhesive. When the adhesive dot structure 101 is conductive adhesive, by setting the total area of ​​the true projection of the edge adhesive dot structure 121 on the surface of the substrate 100 to be larger, the contact resistance between the solder ribbon 102 in the edge region 110 of the substrate 100 and the adhesive dot structure 101 can be reduced, thereby reducing the carrier transmission loss in the edge region 110. When the adhesive dot structure 101 is insulating adhesive, by setting the total area of ​​the true projection of the edge adhesive dot structure 121 on the surface of the substrate 100 to be larger, the reliability of the connection between the solder ribbon 102 in the edge region 110 of the substrate 100 and the adhesive dot structure 101 can be increased, thereby avoiding abnormalities such as solder ribbon 102 misalignment or solder ribbon 102 detachment, thereby increasing the reliability of the battery cells connected in series to form a battery string.

[0044] In some embodiments, the adhesive dot structure 101 is a conductive adhesive, and the morphology of the edge adhesive dot structure 121 can be: small at both ends and large in the middle along the first direction X, similar to an olive shape. For the solder ribbon 102, the solder ribbon 102 is usually connected to the middle part of the conductive adhesive. Therefore, setting the edge adhesive dot structure 121 to be olive-shaped can increase the contact area between the edge adhesive dot structure 121 and the solder ribbon 102, thereby increasing the reliability of the connection between the edge adhesive dot structure 121 and the solder ribbon 102 while reducing the contact resistance, thereby improving the performance of the battery cell.

[0045] In some embodiments, the adhesive dot structure 101 is an insulating adhesive, and the morphology of the edge adhesive dot structure 121 can be: larger at both ends and smaller in the middle along the first direction X, similar to an hourglass shape. For the solder ribbon 102, the solder ribbon 102 is prone to displacement in the edge region 110. In order to avoid the solder ribbon 102 from being electrically connected to other structures that should not be electrically connected after displacement, the edge adhesive dot structure 121 is set to be hourglass-shaped so that even if the solder ribbon 102 is displaced, there is still insulating adhesive to isolate it, thereby further improving the reliability of the battery cell.

[0046] In some embodiments, along the second direction Y, the width of the adhesive dot structure 101 located in the edge region 110 on the side away from the center region 120 is greater than the width on the side closer to the center region 120. The closer to the edge region 110, the higher the possibility of connection failure between the adhesive dot structure 101 and the solder ribbon 102. Therefore, by setting the width of the adhesive dot structure 101 located in the edge region 110 on the side away from the center region 120 to be greater than the width on the side closer to the center region 120, the possibility of connection between the adhesive dot structure 101 and the solder ribbon 102 can be improved. Moreover, for the process of forming the adhesive dot structure 101, it is necessary to form the width of the adhesive dot structure 101 located in the edge region 110 on the side away from the center region 120 to be greater than the width on the side closer to the center region 120. Then, the corresponding adhesive printing process will increase the amount of adhesive on the side away from the center region 120. At this time, even if there is a case of missing adhesive printing, the projected area of ​​the adhesive dot structure 101 projected onto the surface of the substrate 100 will still increase, thereby increasing the reliability of the connection between the adhesive dot structure 101 and the solder ribbon 102.

[0047] In some embodiments, the edge adhesive dot structure 121 is multi-row, and the area of ​​the orthographic projection of all adhesive dots 111 in the edge adhesive dot structure 121 onto the surface of the substrate 100 tends to increase in the direction from the edge region 110 to the center region 120. In other words, the closer the adhesive dots 111 are to the edge region 110, the smaller the area of ​​the orthographic projection onto the surface of the substrate 100. On the one hand, this can reduce the difficulty of the process. For the edge region 110 of the battery cell, the closer to the edge of the battery cell, the more difficult it is to print the adhesive dot structure 101. By reducing the area of ​​the adhesive dots 111 near the edge, the difficulty of the process can be reduced. On the other hand, under the premise that the total area of ​​the orthographic projection of any edge adhesive dot structure 121 onto the surface of the substrate 100 is greater than the total area of ​​the true projection of any center adhesive dot structure 131 onto the surface of the substrate 100, controlling the area of ​​the orthographic projection of the adhesive dots 111 in the edge adhesive dot structure 121 onto the surface of the substrate 100 can further increase the reliability of the connection between the solder ribbon 102 of the edge region 110 and the battery cell, thereby improving the reliability of the subsequent battery cells being connected in series to form a battery string.

[0048] It should be noted that the increasing trend here can refer to the fact that the closer the adhesive dots 111 are to the edge area 110, the larger the area of ​​their orthogonal projection on the surface of the substrate 100. It can also refer to the overall increasing trend, in which the area of ​​some adhesive dots 111 projected onto the surface of the substrate 100 remains unchanged or decreases slightly. As long as the overall trend is increasing, it can be regarded as an increasing trend.

[0049] In some embodiments, the number of adhesive dots 111 in the edge adhesive dot structure 121 is greater than the number of adhesive dots 111 in the central adhesive dot structure 131. By setting a larger number of adhesive dots 111 in the edge adhesive dot structure 121, the total area of ​​all adhesive dots 111 projected onto the surface of the substrate 100 can also be increased. Furthermore, provided that the length of the adhesive dots 111 in the edge adhesive dot structure 121 is not less than the length of the adhesive dots 111 in the central adhesive dot structure 131, and / or the width of the adhesive dots 111 in the edge adhesive dot structure 121 is not less than the width of the adhesive dots 111 in the central adhesive dot structure 131, the increased adhesive dots 111 also have a certain contact area with the solder ribbon 102, thereby increasing the reliability of the connection between the solder ribbon 102 and the battery cell while ensuring a certain contact area and connection reliability between each adhesive dot 111 and the solder ribbon 102.

[0050] In some embodiments, the edge adhesive dot structures 121 are arranged in multiple rows, the center adhesive dot structures 131 are arranged in multiple rows, and the spacing between adjacent edge adhesive dot structures 121 is smaller than the spacing between adjacent center adhesive dot structures 131. In other words, the adhesive dot structures 101 located in the edge region 110 are arranged more densely. By controlling the arrangement of the adhesive dot structures 101 in the edge region 110 to be more dense, the tightness of the connection between the solder ribbon 102 in the edge region 110 and the substrate 100 can be improved, thereby further improving the reliability of the solar cell.

[0051] In some embodiments, provided that the length of the adhesive dots 111 in the edge adhesive dot structure 121 is greater than or equal to the length of the adhesive dots 111 in the center adhesive dot structure 131, and / or, in the second direction Y, the width of the adhesive dots 111 in the edge adhesive dot structure 121 is greater than or equal to the width of the adhesive dots 111 in the center adhesive dot structure 131, the spacing between adjacent edge adhesive dot structures 121 is less than the spacing between adjacent center adhesive dot structures 131. This will further increase the proportion of the area covered by the adhesive dot structures 101 on the surface of the substrate 100 of the edge region 110, thereby increasing the contact area of ​​the intersection structure between the solder ribbon 102 and the edge region 110, and thus improving the reliability of the solar cell.

[0052] In some embodiments, the substrate 100 includes a first side 130 and a second side 140 arranged along the second direction Y. In the same row of adhesive dots 101, the length of the adhesive dots 111 near the second side 140 is greater than the length of the adhesive dots 111 near the first side 130. The area near the second side 140 is actually near the edge where the battery cell is connected in series with an adjacent battery cell. During the process of connecting the battery cells into a battery string, the solder ribbon 102 inevitably undergoes bending and other changes. During bending, the solder ribbon 102 moves in the first direction X. Therefore, by setting the length of the adhesive dots 111 near the second side 140 to be greater than the length of the adhesive dots 111 near the first side 130, even if the solder ribbon 102 shifts in the first direction X, it will still contact the adhesive dots 111, thereby increasing the reliability of the battery cells in subsequent string welding.

[0053] In some embodiments, the substrate 100 includes a front side and a back side. In the same row of adhesive dot structures 101 on the front side, the length of adhesive dots 111 near the second side 140 is greater than the length of adhesive dots 111 near the first side 130. In the same row of adhesive dot structures 101 on the back side, the length of adhesive dots 111 near the first side 130 is greater than the length of adhesive dots 111 near the second side 140. It can be understood that for the front side of the substrate 100, the side of the front side near the second side 140 is the connection side for connecting with adjacent solar cells in series. However, for the back side of the substrate 100, the side of the back side near the first side 130 is the connection side for connecting with adjacent solar cells in series. Therefore, setting the length of adhesive dots 111 near the second side 140 on the front side and the length of adhesive dots 111 near the first side 130 on the back side can adapt to different connection situations on the front and back sides.

[0054] In some embodiments, the width of the adhesive dots 111 near the first side 130 and near the second side 140 can be greater than the width located between the first side 130 and the second side 140. For the adhesive dots 111 near the first side 130 and near the second side 140, these adhesive dots 111 also belong to the adhesive dots 111 on the edge of the battery cell. Therefore, setting the width of the adhesive dots 111 near the first side 130 and near the second side 140 to be larger can also increase the reliability of the battery cell.

[0055] In some embodiments, the substrate 100 includes a first side 130 and a second side 140 arranged along a second direction Y. The density of adhesive dots 111 near the second side 140 is greater than the density of adhesive dots 111 near the first side 130. Similarly, for the adhesive dot structure 101 near the second side 140, these adhesive dots 111 are close to the edge where the solar cell is connected in series with adjacent solar cells. During the process of connecting solar cells into a battery string, the solder ribbon 102 may be bent or displaced under stress. Therefore, by increasing the density of adhesive dots 111, the tightness of the connection between adhesive dots 111 and solder ribbon 102 is improved, the stress resistance between adhesive dots 111 and solder ribbon 102 is enhanced, and the possibility of disconnection between solder ribbon 102 and adhesive dots 111 is reduced, thereby improving the reliability of the solar cell.

[0056] In some embodiments, the substrate 100 includes a first side 130 and a second side 140 arranged along a second direction Y. A portion of adhesive dots 111 located in the central region 120 near the first side 130 are aligned along the first direction X. A portion of adhesive dots 111 located in the central region 120 near the second side 140 are also aligned along the first direction X. The remaining adhesive dots 111 located in the same column along the first direction X and in the central region 120 are staggered. In other words, the adhesive dots 111 located in the middle portion of the central region 120 and in the same column are staggered along the first direction X. This prevents all adhesive dots 111 from being printed in the wrong position simultaneously. For example, if the central region 120 contains five rows of central adhesive dot structures, and these five rows are named the first row of central adhesive dot structures, the second row of central adhesive dot structures, and so on, the printing position of the first row of central adhesive dot structures may be misaligned, thus improving the printing accuracy of the adhesive dots 111.

[0057] In some embodiments, in the first direction X, the length of the adhesive dots 111 in the edge adhesive dot structure 121 is 1.3mm to 2mm, for example, 1.4mm, 1.5mm, 1.6mm, 1.7mm, 1.8mm or 1.9mm, etc., and the length of the adhesive dots 111 in the center adhesive dot structure 131 is 0.8mm to 1.8mm, for example, 1mm, 1.1mm, 1.3mm, 1.6mm or 1.7mm, etc. For the edge adhesive dot structure 121, the longer the edge adhesive dot structure 121 is, the higher the reliability of the connection between the battery cell and the solder ribbon 102. The longer the edge adhesive dot structure 121 is, the less the spacing between adjacent rows of edge adhesive dot structures 121 will be. If the edge adhesive dot structure 121 is a conductive structure, the reduction in spacing may cause short circuits between adjacent rows of edge adhesive dot structures 121. Therefore, setting the length of the adhesive dots 111 in the edge adhesive dot structure 121 to 1.3mm to 2mm can improve the reliability of the connection between the edge adhesive dot structure 121 and the solder ribbon 102 while avoiding abnormalities in the battery cell. For the center adhesive dot structure 131, the center adhesive dot structure 131 does not need to improve the reliability of the connection. On the contrary, maintaining the spacing is more beneficial to the structure of the central area 120. Therefore, setting the length of the adhesive dots 111 in the center adhesive dot structure 131 to 0.8mm to 1.8mm can better adapt to the structure of the battery cell.

[0058] In some embodiments, in the first direction X, the difference between the length of the adhesive dots 111 in the edge adhesive dot structure 121 and the length of the adhesive dots 111 in the center adhesive dot structure 131 is 0.1 mm to 0.3 mm, for example, 0.15 mm, 0.2 mm, or 0.25 mm, etc. By controlling the difference between the length of the adhesive dots 111 in the edge adhesive dot structure 121 and the length of the adhesive dots 111 in the center adhesive dot structure 131, excessive increases in the edge adhesive dot structure 121 can be avoided, thereby improving the reliability of forming battery strings from solar cells while avoiding waste of adhesive dots 111.

[0059] refer to Figure 2 , Figure 2 Another top view of a battery cell provided in an embodiment of this disclosure.

[0060] In some embodiments, the extension direction of the adhesive dots 111 in the edge adhesive dot structure 121 can be at an angle to the first direction X. In other words, the extension direction of the adhesive dots 111 is inclined. Thus, compared to the structure in the edge adhesive dot structure 121 where the extension direction of the adhesive dots 111 is parallel to the first direction X, the adhesive dots 111 with the extension direction inclined can be closer to the central region 120. For example, if the distance between the adhesive dots 111 with the extension direction parallel to the first direction X and the edge of the battery cell is 5mm everywhere, then the distance between the adhesive dots 111 with the extension direction inclined and the edge of the battery cell is only 5mm at one point, and the distances of the remaining parts to the edge of the battery cell are all less than 5mm. This makes the edge adhesive dot structure 121 as close to the central region 120 as possible. In this way, on the one hand, the possibility of missing printing of the edge adhesive dot structure 121 can be reduced during the formation of adhesive dots 111, and on the other hand, the contact area between the adhesive dots 111 and the solder ribbon 102 is not reduced.

[0061] It should be noted that the 5mm mentioned above is just an example for ease of understanding and does not limit the distance between the adhesive dot and the edge of the battery cell to 5mm. Other distances are also possible and can be adjusted according to the actual situation.

[0062] In this embodiment of the present disclosure, for the edge region 110 of the battery cell, the solder ribbon 102 is more likely to detach from the battery cell. Therefore, this embodiment of the present disclosure sets the total area of ​​all adhesive dots 111 in each row of edge adhesive dot structures 121 to be greater than the sum of the total areas of all adhesive dots 111 in each row of center adhesive dot structures 131. This can increase the contact area between the edge adhesive dot structure 121 and the solder ribbon 102, thereby improving the connection reliability between the solder ribbon 102 and the battery cell in the edge region 110. In addition, this disclosure also sets the length of the through hole 211 of the edge mesh structure 221 to be no less than the length of the through hole 211 in the center mesh structure 231, and / or the width of the edge mesh structure 221 to be no less than the width of the through hole 211 in the center mesh structure 231. This ensures that the contact length and / or contact width between the solder ribbon 102 and each adhesive dot 111 in the first direction X and / or the second direction Y will not decrease, thereby avoiding affecting the connection reliability between the solder ribbon 102 and each adhesive dot 111.

[0063] Another embodiment of this disclosure also provides a photovoltaic module, which may include the solar cells in some or all of the above embodiments. The following will describe a photovoltaic module provided by the present disclosure in conjunction with the accompanying drawings. It should be noted that the parts that are the same as or similar to the above embodiments can be referred to the above embodiments, and will not be repeated hereafter.

[0064] refer to Figure 3 and Figure 4 , Figure 3 This is a schematic diagram of the structure of a photovoltaic module provided in one embodiment of the present disclosure. Figure 4 For along Figure 3 Cross-sectional view along the MM1 direction.

[0065] Photovoltaic modules include: a battery string, which is composed of a plurality of battery cells 40 as described in all or part of the above embodiments; an encapsulating film 41 for covering the surface of the battery string; and a cover plate 42 for covering the surface of the encapsulating film 41 facing away from the battery string.

[0066] It is worth noting that the solar cells 40 are electrically connected to form multiple cell strings, which are electrically connected in series and / or parallel. The solar cells 40 may include sliced ​​solar cells, which are formed by dividing a whole solar cell. In this way, the power loss of the photovoltaic module can be improved by reducing the current of the sliced ​​solar cells, thereby improving the photoelectric conversion efficiency of the photovoltaic module.

[0067] In some embodiments, the encapsulating film 41 includes a first encapsulating layer and a second encapsulating layer. The first encapsulating layer covers one of the front or back of the battery cell, and the second encapsulating layer covers the other of the front or back of the battery cell. Specifically, at least one of the first encapsulating layer or the second encapsulating layer can be an organic encapsulating film such as polyvinyl butyral (PVB) film, ethylene-vinyl acetate copolymer (EVA) film, polyvinyl octene coelastomer (POE) film, or polyethylene terephthalate (PET) film.

[0068] In some cases, the first encapsulation layer and the second encapsulation layer still have a boundary line before lamination. After lamination, the photovoltaic module will no longer have the concept of a first encapsulation layer and a second encapsulation layer. That is, the first encapsulation layer and the second encapsulation layer have formed an integral encapsulation film 41.

[0069] In some embodiments, the cover plate 42 can be a glass cover plate, a plastic cover plate, or other cover plate with light-transmitting function. Specifically, the surface of the cover plate 42 facing the encapsulating film 41 can be an uneven surface, thereby increasing the utilization rate of incident light. The cover plate 42 includes a first cover plate and a second cover plate, the first cover plate being opposite to the first encapsulation layer, and the second cover plate being opposite to the second encapsulation layer.

[0070] Another embodiment of this disclosure also provides a printing screen, which can be used to form the adhesive dot structure 101 in the above-mentioned battery cell embodiment. The printing screen provided by this disclosure will be described below with reference to the accompanying drawings. It should be noted that the parts that are the same as or similar to the above embodiments can be referred to the above embodiments, and will not be repeated below.

[0071] refer to Figure 5 , Figure 5 This is a schematic diagram of the structure of a printing screen according to an embodiment of the present disclosure.

[0072] In some embodiments, the printing screen may include a body 200, which includes two first regions 210 arranged along a first direction X and a second region 220 located between the first regions 210.

[0073] The printing screen may also include: a multi-row dispensing mesh structure 201 arranged along the first direction X, each row of dispensing mesh structure 201 including a plurality of through holes 211 arranged at intervals along the second direction Y, through which adhesive is printed onto the surface of the solar cell.

[0074] The multi-row dispensing mesh structure 201 includes at least one row of edge mesh structures 221 located in each first region 210, and at least one row of center mesh structures 231 located in the second region 220. The total area of ​​all through holes 211 in each row of edge mesh structures 221 projected onto the surface of the main body 200 is greater than the total area of ​​all through holes 211 in each row of center mesh structures 231 projected onto the surface of the main body 200. In the first direction X, the length of the through holes 211 in the edge mesh structures 221 is greater than or equal to the length of the through holes 211 in the center mesh structures 231, and / or, in the second direction Y, the width of the through holes 211 in the edge mesh structures 221 is greater than or equal to the width of the through holes 211 in the center mesh structures 231.

[0075] By setting the total area of ​​all through holes 211 in each row of edge mesh structure 221 projected onto the surface of the main body 200 to be greater than the total area of ​​all through holes 211 in each row of center mesh structure 231 projected onto the surface of the main body 200, even if there is a printing misprint in the edge mesh structure 221, a glue dot structure with a certain surface area can still be formed on the surface of the solar cell. This ensures the reliability of the glue dot structure formed by the printing screen on the surface of the solar cell. Furthermore, by setting the length of the through holes 211 in the edge mesh structure 221 to be greater than or equal to the length of the through holes 211 in the center mesh structure 231, and / or setting the width of the through holes 211 in the edge mesh structure 221 to be greater than or equal to the width of the through holes 211 in the center mesh structure 231, the contact area between the solder ribbon and the glue dots formed by the printing screen can be guaranteed, thereby avoiding affecting the reliability of the connection between the solder ribbon and each glue dot.

[0076] In some embodiments, the main body 200 includes two opposing sides arranged along the second direction Y, wherein the density of through holes 211 on one side is greater than the density of through holes 211 on the other side. It is understood that the opposing sides of the main body 200 arranged along the second direction Y correspond to the surface of the solar cell, i.e., the two sides of the solar cell used to connect with adjacent cells. During the process of connecting cells in series to form a battery string, the solder ribbon may bend or shift under stress. Therefore, setting the density of through holes 211 on one side to be greater than the density of through holes 211 on the other side allows for a greater density of adhesive dots formed on the surface of the cell, thereby improving the reliability of the connection between the solder ribbon and adhesive dots on one side of the cell.

[0077] In some embodiments, the main body 200 includes two opposite sides arranged along the second direction Y. A portion of the through holes 211 near the sides are aligned along the first direction X, while the remaining through holes in the same column along the first direction X and located in the second region 220 are staggered. For example, there are a total of five rows of central mesh structures 231, namely the first row, the second row, and the fifth row. The first row and the second row are staggered. Therefore, if there is a deviation in the printing of adhesive dots in the first row of central mesh structures, printing can be performed using the second row. Similarly, if there is a deviation in the printing of adhesive dots in the second row of central mesh structures, printing can be performed using the first row, thereby improving the accuracy of the printing screen printing adhesive dots.

[0078] In some embodiments, the structure of the through hole 211 can correspond to the structure of the adhesive dots in the above-described battery cell embodiments. For example, in the direction from the first region 210 to the second region 220, the area of ​​the through hole 211 in the edge mesh structure 221 projected onto the surface of the main body 200 tends to increase, etc. The same or corresponding content can be referred to the description of the adhesive dot structure in the above-described embodiments, and will not be repeated here.

[0079] In some embodiments, in the first direction X, the length of the through holes 211 in the edge mesh structure 221 is 1.3mm to 2mm, for example, 1.4mm, 1.5mm, 1.6mm, 1.7mm, 1.8mm, or 1.9mm, etc., and the length of the through holes 211 in the center mesh structure 231 is 0.8mm to 1.8mm, for example, 1mm, 1.1mm, 1.3mm, 1.6mm, or 1.7mm, etc. In this way, adhesive dots of corresponding sizes can be formed on the surface of the solar cell, thereby improving the reliability of the connection between the edge adhesive dots 111 of the solar cell and the solder ribbon 102.

[0080] The difference between the length of the through hole 211 in the edge mesh structure 221 and the length of the through hole 211 in the center mesh structure 231 can be 0.1mm to 0.3mm, for example, 0.15mm, 0.2mm or 0.25mm, etc., so as to avoid wasting glue when printing glue dots 111 on the surface of the battery cell, while ensuring increased reliability.

[0081] In some embodiments, the extension direction of the through hole 211 in the edge mesh structure 221 may also be at an angle to the first direction X, so that the extension direction of the adhesive dots formed on the surface of the battery cell is at an angle to the first direction X. The same or corresponding description can be referred to the description of the battery cell above, and will not be repeated here.

[0082] Those skilled in the art will understand that the above embodiments are specific examples of implementing this disclosure, and in practical applications, various changes in form and detail may be made without departing from the spirit and scope of the embodiments of this disclosure. Any person skilled in the art can make various modifications and alterations without departing from the spirit and scope of the embodiments of this disclosure; therefore, the scope of protection of the embodiments of this disclosure should be determined by the scope defined in the claims.

Claims

1. A battery sheet, characterized by, The application relates to a solar cell sheet, comprising: a substrate, the substrate comprising two edge regions arranged along a first direction and a central region located between the edge regions; a plurality of glue point structures arranged along the first direction, each row of the glue point structures comprising a plurality of glue points arranged at intervals along a second direction, the glue points in each row of the glue point structures being used to be fixedly contacted with the same solder strip; wherein the plurality of glue point structures comprises at least one row of edge glue point structures located in each of the edge regions and at least one row of central glue point structures located in the central region, the total area of the glue points in each row of the edge glue point structures in the surface projection of the substrate being greater than the total area of the glue points in each row of the central glue point structures in the surface projection of the substrate, and in the first direction, the length of the glue points in the edge glue point structures is greater than or equal to the length of the glue points in the central glue point structures, and / or in the second direction, the width of the glue points in the edge glue point structures is greater than or equal to the width of the glue points in the central glue point structures; the glue points located in the middle part of the central region and in the same column are staggered with each other along the first direction.

2. The battery sheet of claim 1, wherein, The edge glue point structures are multiple rows, and the area of the glue points in the edge glue point structures in the surface projection of the substrate presents an increasing trend from the direction of the edge region to the central region.

3. The battery sheet of claim 1, wherein, The number of the glue points in the edge glue point structures is greater than the number of the glue points in the central glue point structures.

4. The battery sheet of claim 1, wherein, The edge glue point structures are multiple rows, and the central glue point structures are multiple rows, the interval between adjacent edge glue point structures being smaller than the interval between adjacent central glue point structures.

5. The battery sheet of claim 1, wherein, The substrate comprises a first side and a second side arranged along the second direction, and in the same row of the glue point structures, the length of the glue points close to the second side is greater than the length of the glue points close to the first side.

6. The battery sheet according to claim 1 or 5, wherein The substrate comprises a first side and a second side arranged along the second direction, and the arrangement density of the glue points close to the second side is greater than the arrangement density of the glue points close to the first side.

7. The battery sheet of claim 1, wherein, In the second direction, the width of the glue point structures located in the edge region away from the side of the central region is greater than the width close to the side of the central region.

8. The battery sheet of claim 1, wherein, The substrate comprises a first side and a second side arranged along the second direction, and the glue points located in the central region close to the first side are aligned along the first direction, and the glue points located in the central region close to the second side are aligned along the first direction.

9. A photovoltaic module, characterized by The application relates to a solar cell string, comprising: a plurality of solar cell sheets as claimed in any one of claims 1 to 8; an encapsulating adhesive film used for covering the surface of the solar cell string; a cover plate used for covering the surface of the encapsulating adhesive film away from the solar cell string.

10. An adhesive screen printing plate for dispensing an adhesive on a solar cell, characterized in that, The application relates to a solar cell sheet, comprising: a substrate, the substrate comprising two edge regions arranged along a first direction and a central region located between the edge regions; a plurality of glue point structures arranged along the first direction, each row of the glue point structures comprising a plurality of glue points arranged at intervals along a second direction, the glue points in each row of the glue point structures being used to be fixedly contacted with the same solder strip; wherein the plurality of glue point structures comprises at least one row of edge glue point structures located in each of the edge regions and at least one row of central glue point structures located in the central region, the total area of the glue points in each row of the edge glue point structures in the surface projection of the substrate being greater than the total area of the glue points in each row of the central glue point structures in the surface projection of the substrate, and in the first direction, the length of the glue points in the edge glue point structures is greater than or equal to the length of the glue points in the central glue point structures, and / or in the second direction, the width of the glue points in the edge glue point structures is greater than or equal to the width of the glue points in the central glue point structures; the glue points located in the middle part of the central region and in the same column are staggered with each other along the first direction. The edge glue point structures are multiple rows, and the area of the glue points in the edge glue point structures in the surface projection of the substrate presents an increasing trend from the direction of the edge region to the central region. The number of the glue points in the edge glue point structures is greater than the number of the glue points in the central glue point structures. The edge glue point structures are multiple rows, and the central glue point structures are multiple rows, the interval between adjacent edge glue point structures being smaller than the interval between adjacent central glue point structures. The substrate comprises a first side and a second side arranged along the second direction, and in the same row of the glue point structures, the length of the glue points close to the second side is greater than the length of the glue points close to the first side. The substrate comprises a first side and a second side arranged along the second direction, and the arrangement density of the glue points close to the second side is greater than the arrangement density of the glue points close to the first side. In the second direction, the width of the glue point structures located in the edge region away from the side of the central region is greater than the width close to the side of the central region. The substrate comprises a first side and a second side arranged along the second direction, and the glue points located in the central region close to the first side are aligned along the first direction, and the glue points located in the central region close to the second side are aligned along the first direction. The application relates to a solar cell string, comprising: a plurality of solar cell sheets as claimed in any one of claims 1 to 8; an encapsulating adhesive film used for covering the surface of the solar cell string; a cover plate used for covering the surface of the encapsulating adhesive film away from the solar cell string. The multi-row dispensing grid structure comprises at least one row of edge grid structures in each of the first regions, and at least one row of center grid structures in the second region. The total area of the orthographic projection of all the through holes in each row of the edge grid structures on the main body surface is greater than the total area of the orthographic projection of all the through holes in each row of the center grid structures on the main body surface. In the first direction, the length of the through holes in the edge grid structures is greater than or equal to the length of the through holes in the center grid structures, and / or in the second direction, the width of the through holes in the edge grid structures is greater than or equal to the width of the through holes in the center grid structures. The through holes in the same column in the intermediate part of the second region are staggered in the first direction.

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