A photovoltaic module

Abstract

This disclosure relates to the photovoltaic field, and more particularly to a photovoltaic module. The photovoltaic module includes: a cell string composed of multiple cells, the multiple cells including alternating first and second cells, each first and second cell having a first surface and a second surface; wherein the direction in which the first surface of the first cell points to the second surface is the same as the direction in which the second surface of the second cell points to the first surface; a first solder strip located on the first surface of one first cell and the second surface of another second cell, electrically connecting the first and second cells; and a second solder strip located on the first surface of a second cell and the second surface of another first cell, electrically connecting the second cell and a corresponding first cell; wherein the cross-sectional area of ​​the first solder strip is smaller than the cross-sectional area of ​​the second solder strip, which can at least improve the performance of the photovoltaic module and save manufacturing costs.

Description

Technical Field

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

[0002] As fossil fuels are gradually depleted, solar energy is becoming increasingly widely used as a new energy alternative. A solar cell is a device that converts sunlight into electrical energy. Solar cells utilize the photovoltaic principle to generate charge carriers, which are then extracted using electrodes, thus facilitating the efficient use of electrical energy.

[0003] Photovoltaic modules are crucial devices for converting solar energy into electrical energy. Improving the performance of photovoltaic modules is a pressing issue that needs to be addressed. Summary of the Invention

[0004] This disclosure provides a photovoltaic module that can at least improve the performance of the photovoltaic module and save manufacturing costs.

[0005] This disclosure provides a photovoltaic module, comprising: a battery string consisting of a plurality of battery cells, wherein the plurality of battery cells include alternating first battery cells and second battery cells, both the first battery cell and the second battery cell having a first surface and a second surface; wherein the direction in which the first surface of the first battery cell points to the second surface is the same as the direction in which the second surface of the second battery cell points to the first surface; a first solder strip located on the first surface of one first battery cell and the second surface of another second battery cell, and electrically connecting the first battery cell and the second battery cell; a second solder strip located on the first surface of another second battery cell and the second surface of another first battery cell, and electrically connecting the second battery cell and a corresponding first battery cell; wherein the cross-sectional area of ​​the first solder strip is smaller than the cross-sectional area of ​​the second solder strip.

[0006] Optionally, the ratio of the cross-sectional area of ​​the first solder strip to the cross-sectional area of ​​the second solder strip is 0.1 to 0.99.

[0007] Optionally, the first solar cell includes: a first main grid located on the first surface; a second main grid located on the second surface; the cross-sectional area of ​​the first main grid is smaller than the cross-sectional area of ​​the second main grid; and / or, the second solar cell includes: a third main grid located on the first surface; a fourth main grid located on the second surface; the cross-sectional area of ​​the third main grid is larger than the cross-sectional area of ​​the fourth main grid.

[0008] Optionally, in the first direction, the ratio of the width of the first main gate to the width of the first solder strip is 0.5 to 1.5; and / or, in the first direction, the ratio of the width of the second main gate to the width of the second solder strip is 0.5 to 1.5; and / or, in the first direction, the ratio of the width of the third main gate to the width of the second solder strip is 0.5 to 1.5; and / or, in the first direction, the ratio of the width of the fourth main gate to the width of the first solder strip is 0.5 to 1.5; wherein, the first direction is defined as the direction perpendicular to the extension direction of the first main gate.

[0009] Optionally, for the same first battery cell or the same second battery cell, the first solder strip and the second solder strip are arranged in a staggered manner.

[0010] Optionally, the first solder strip includes a first body portion and a first solder layer wrapped around the surface of the first body portion, and the second solder strip includes a second body portion and a second solder layer wrapped around the surface of the second body portion; wherein the resistivity of the first body portion is less than the resistivity of the second body portion, and / or the thickness of the first solder layer is less than the thickness of the second solder layer.

[0011] Optionally, the material of the first body portion includes at least one of copper, silver, or a copper-silver alloy.

[0012] Optionally, the second main body includes a first part and a second part wrapped around the surface of the first part, wherein the material of the first part includes aluminum and the material of the second part includes copper.

[0013] Optionally, the cross-sectional shape of the first solder strip includes a circle, a triangle, a rectangle, or a trapezoid, and / or the cross-sectional shape of the second solder strip includes a circle, a triangle, a rectangle, or a trapezoid.

[0014] Optionally, the photovoltaic module includes: a first encapsulating film located on one side of the first surface of the first solar cell in the battery string; and a second encapsulating film located on one side of the second surface of the first solar cell in the battery string; wherein the thickness of the first encapsulating film is less than or equal to the thickness of the second encapsulating film.

[0015] The technical solution provided in this disclosure has at least the following advantages: In the photovoltaic module disclosed herein, first and second solar cells are arranged alternately, with the first surface of the first solar cell and the second surface of the second solar cell facing the same direction, and the second surface of the first solar cell and the first surface of the second solar cell facing the same direction. A first solder strip electrically connects the first surface of the first solar cell to the second surface of an adjacent second solar cell, and a second solder strip electrically connects the first surface of the second solar cell to the second surface of an adjacent first solar cell. The cross-sectional area of ​​the first solder strip is smaller than that of the second solder strip. The smaller cross-sectional area of ​​the first solder strip helps to save on the manufacturing cost of the first solder strip, thereby saving on the manufacturing cost of the photovoltaic module; the larger cross-sectional area of ​​the second solder strip helps to reduce current transmission loss, thereby improving the performance of the photovoltaic module. Attached Figure Description

[0016] One or more embodiments are illustrated by way of example with reference numerals in the accompanying drawings. These illustrations do not constitute a limitation on the embodiments. Elements with the same reference numerals in the drawings are denoted as similar elements. Unless otherwise stated, the figures in the drawings are not to be limited by scale.

[0017] Figure 1 This is a partial structural diagram of a battery string provided in an embodiment of the present disclosure; Figure 2 A partial structural side view of a battery string provided in an embodiment of this disclosure; Figure 3 A structural side view of a first battery cell provided in an embodiment of this disclosure; Figure 4 A side view of the structure of a second battery cell provided in an embodiment of this disclosure; Figure 5 A partial structural side view of a first battery cell provided in an embodiment of this disclosure; Figure 6 A cross-sectional view of a first solder strip provided in an embodiment of this disclosure; Figure 7 A cross-sectional view of a second solder strip provided in an embodiment of this disclosure; Figure 8 A partial structural side view of another first battery cell provided in an embodiment of this disclosure; Figure 9 A partial structural side view of another first battery cell provided in an embodiment of this disclosure.

[0018] Explanation of reference numerals in the attached figures: Battery string 1, first solder strip 2, second solder strip 3, first battery cell 11, second battery cell 12, first surface 101, second surface 102, first main grid 111, second main grid 112, third main grid 121, fourth main grid 122, first main body 21, first solder layer 22, second main body 31, second solder layer 32, first part 311, second part 312. Detailed Implementation

[0019] In existing photovoltaic module manufacturing, multiple TOPCon cells are typically arranged with the same orientation, for example, all cells have their p-type doped regions facing upwards, and adjacent cells are connected in series by solder ribbons. In this module structure, the solder ribbons used on the front and back of the module are exactly the same, making it impossible to design differently according to the functional requirements of the two sides: the front solder ribbon cannot be made thin to reduce shading, and the back solder ribbon cannot be made thick to reduce resistance, resulting in a difficulty in achieving both optical and electrical performance.

[0020] Further analysis revealed that the root cause of the problem lies in the fact that existing solder strip production processes are unable to continuously manufacture segmented solder strips with cross-sectional areas varying along the length direction.

[0021] To address the aforementioned technical problems, this disclosure creatively proposes a photovoltaic module in which first and second solar cells are arranged alternately, with the first side of the first solar cell and the second side of the second solar cell facing the same side and electrically connected by a first solder strip with a small cross-sectional area, thereby reducing material usage and lowering the manufacturing cost of the photovoltaic module. Furthermore, by arranging the first side of the second solar cell and the second side of the adjacent first solar cell to face the same side and electrically connected by a second solder strip with a larger cross-sectional area, current transmission loss is reduced, thereby improving the performance of the photovoltaic module.

[0022] 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, "multiple" means two or more, unless otherwise explicitly defined. Similarly, "multiple sets" refers to two or more sets (including two sets), and "multiple pieces" refers to two or more pieces (including two pieces).

[0023] 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.

[0024] 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.

[0025] 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," etc., indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings and are only for the convenience of describing the embodiments of this disclosure and simplifying the description. They do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the embodiments of this disclosure. For example, if the device or element in the illustration is inverted, then the element described as "below," "under," "below," or "bottom" of other elements or features will be oriented "above" or "top" of said other elements or features. Therefore, the term "below" may, depending on the context in which the term is used, encompass both above and below orientations, which will be obvious to those skilled in the art. Materials may be oriented in other ways (e.g., rotated 90 degrees, inverted, flipped), and the spatial relative descriptive terms used herein may be interpreted accordingly.

[0026] 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.

[0027] In the accompanying drawings corresponding to the embodiments of this disclosure, the thickness and / or area of ​​layers, films, panels, regions, etc., are enlarged for better understanding and ease of description. Throughout the specification, the same reference numerals denote the same elements. It should be understood that 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 an intermediate component between the two components. Conversely, when describing a component on the surface of another component, or a component "directly" on another component, or a component surface on which another component is formed or disposed, it indicates that there is no intermediate component between the two components. Furthermore, when describing a component as "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.

[0028] In the description of the embodiments of this disclosure, when a component "includes" another component, other components are not excluded unless otherwise stated, and may be further included. The formation or placement of a second component above or on a first component, or on the surface of a first component, or on one side of a first component, may include embodiments where the first and second components are in direct contact, and may also include embodiments where an additional component may be placed between the first and second components, thereby preventing direct contact between the first and second components. For simplicity and clarity, various components may be drawn at different scales. In the drawings, some layers / components may be omitted for simplicity. Unless otherwise specified, the formation or placement of a second component on the surface of a first component refers to direct contact between the first and second components. The term "component" can refer to a layer, film, region, portion, structure, etc.

[0029] 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.

[0030] 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.

[0031] refer to Figure 1 and Figure 2A photovoltaic module includes: a cell string 1 consisting of multiple cells, a first solder strip 2, and a second solder strip 3.

[0032] The battery cells include alternating first battery cells 11 and second battery cells 12, each having a first surface 101 and a second surface 102. The direction in which the first surface 101 of the first battery cell 11 points to the second surface 102 is the same as the direction in which the second surface 102 of the second battery cell 12 points to the first surface 101. A first solder strip 2 is located on the first surface 101 of one first battery cell 11 and the second surface 102 of the second battery cell 12, and electrically connects the first battery cell 11 and the second battery cell 12. A second solder strip 3 is located on the first surface 101 of the second battery cell 12 and the second surface 102 of another first battery cell 11, and electrically connects the second battery cell 12 and the corresponding first battery cell 11. The cross-sectional area of ​​the first solder strip 2 is smaller than the cross-sectional area of ​​the second solder strip 3.

[0033] Photovoltaic modules are used to convert solar energy into electrical energy.

[0034] The solar cell can be one or any combination of BC (Back Contact) cells, PERC (Passivated Emitter Rear Cell) cells, TOPCON (Tunnel Oxide Passivated Contact) cells, heterojunction cells, thin-film solar cells, and tandem 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 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. In this embodiment, a TOPCON cell is used as an example for illustration.

[0035] Solar cells can be either whole cells or sliced ​​cells. Sliced ​​cells refer to cells formed from a single, whole cell through a cutting process. Sliced ​​cells can be halved, tertiary, or quadrilateral, etc.

[0036] In some embodiments, the battery cell is a single-sided battery, in which case the first side 101 can serve as the light-receiving surface for receiving sunlight, and the second side 102 serves as the backlight surface. In some embodiments, the battery cell is a double-sided battery, in which case both the first side 101 and the second side 102 can serve as light-receiving surfaces and can both be used to receive sunlight.

[0037] The solar cell has a front and a back side. The conductive polarities of the front and back sides are different. For example, in some embodiments, the front side can be a P-type doped region and the back side can be an N-type doped region; in other embodiments, the front side can be an N-type doped region and the back side can be a P-type doped region. The specific polarity configuration depends on the cell structure type, such as TOPCon (Tunnel Oxide Passivated Contact) cells, PERC (Passivated Emitter Rear Cell) cells, or HJT (Heterojunction with Intrinsic Thin Layer) cells, etc.

[0038] It should be noted that, in the embodiments of this disclosure, the first surface 101 and the second surface 102 may correspond to the front or back of the battery cell, respectively, depending on the specific implementation. For example, in some embodiments, the first surface 101 may be the front of the battery cell and the second surface 102 may be its back; in other embodiments, the first surface 101 may be the back and the second surface 102 may be the front.

[0039] The first solder strip 2 and the second solder strip 3 are responsible for current transmission.

[0040] Placing the first solder strip 2 with a smaller cross-sectional area on the first surface 101 of the first cell 11 and the second surface 102 of the adjacent second cell 12 helps to reduce the shading area of ​​the first solder strip 2 on the first surface 101 of the first cell 11 and the second surface 102 of the adjacent second cell 12, thereby improving the performance of the photovoltaic module.

[0041] It should be noted that the electrical connection between the two actually means that both are made of conductive materials and are directly connected or connected through other conductive materials. Therefore, when the photovoltaic cell is generating electricity, there is an electrical connection between the two.

[0042] In the photovoltaic module provided in this disclosure, first solar cells 11 and second solar cells 12 are arranged alternately, with the first surface 101 of the first solar cell 11 and the second surface 102 of the second solar cell 12 facing the same direction, and the second surface 102 of the first solar cell 11 and the first surface 101 of the second solar cell 12 facing the same direction. A first solder ribbon 2 electrically connects the first surface 101 of the first solar cell 11 and the second surface 102 of the adjacent second solar cell 12, and a second solder ribbon 3 electrically connects the first surface 101 of the second solar cell 12 and the second surface 102 of the adjacent first solar cell 11. The cross-sectional area of ​​the first solder ribbon 2 is smaller than that of the second solder ribbon 3. The smaller cross-sectional area of ​​the first solder ribbon 2 helps to save the manufacturing cost of the first solder ribbon 2, thereby saving the manufacturing cost of the photovoltaic module; the larger cross-sectional area of ​​the second solder ribbon 3 helps to reduce current transmission loss, thereby improving the performance of the photovoltaic module.

[0043] The embodiments of this disclosure will now be described in more detail with reference to the accompanying drawings.

[0044] In some embodiments, the ratio of the cross-sectional area of ​​the first solder strip 2 to the cross-sectional area of ​​the second solder strip 3 is 0.1 to 0.99; for example, it can be 0.1 to 0.35, 0.35 to 0.7, or 0.7 to 0.99, etc.

[0045] In some embodiments, the ratio of the cross-sectional area of ​​the first solder strip 2 to the cross-sectional area of ​​the second solder strip 3 can be 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, or 0.99, etc.

[0046] It is understandable that cross-sectional area refers to the cross-sectional area of ​​the weld strip perpendicular to its length, which is usually a geometric cross-sectional area of ​​a circle, a flat rectangle, or a triangle.

[0047] The ratio of the cross-sectional area of ​​the first solder strip 2 to the cross-sectional area of ​​the second solder strip 3 is not less than 0.1, which ensures that the first solder strip 2 has basic electrical conductivity and mechanical strength; at the same time, the ratio is not greater than 0.99, which ensures that the first solder strip 2 and the second solder strip 3 have distinguishable differences in size, and avoids that the two are substantially the same.

[0048] By limiting the ratio to the range of 0.1 to 0.99, it is possible to ensure that the first solder ribbon 2 is thin enough to reduce its shading area on the first surface 101 of the first solar cell 11 and the second surface 102 of the adjacent second solar cell 12, thereby improving the performance of the photovoltaic module and reducing costs, while also ensuring the conductivity reliability of the first solder ribbon 2. At the same time, the second solder ribbon 3 maintains a relatively large cross-sectional area, which is beneficial for effectively reducing series resistance and current transmission loss. This ratio range balances optical performance optimization and electrical performance stability.

[0049] refer to Figures 3 to 4In some embodiments, the first battery cell 11 includes: a first main grid 111 located on a first surface 101; a second main grid 112 located on a second surface 102; the cross-sectional area of ​​the first main grid 111 is smaller than the cross-sectional area of ​​the second main grid 112; and / or, the second battery cell 12 includes: a third main grid 121 located on the first surface 101; a fourth main grid 122 located on the second surface 102; the cross-sectional area of ​​the third main grid 121 is larger than the cross-sectional area of ​​the fourth main grid 122.

[0050] In some embodiments, only the first solar cell 11 may employ a differentiated main grid design. Specifically, the first solar cell 11 has a first main grid 111 on its first surface 101 and a second main grid 112 on its second surface 102, and the cross-sectional area of ​​the first main grid 111 is smaller than that of the second main grid 112. The third main grid 121 and the fourth main grid 122 of the second solar cell 12 may have the same cross-sectional area, or their dimensional relationship may not be particularly limited, to meet conventional electrical connection requirements.

[0051] In other embodiments, only the second battery cell 12 may employ a differentiated main grid design. Specifically, the second battery cell 12 has a third main grid 121 on its first surface 101 and a fourth main grid 122 on its second surface 102, and the cross-sectional area of ​​the third main grid 121 is larger than that of the fourth main grid 122. The first main grid 111 and the second main grid 112 of the first battery cell 11 may have the same cross-sectional area, or their dimensional relationship may not be particularly limited, to meet conventional electrical connection requirements.

[0052] In some embodiments, both the first battery cell 11 and the second battery cell 12 may employ differentiated main grid designs. Specifically, the cross-sectional area of ​​the first main grid 111 is smaller than that of the second main grid 112; simultaneously, the cross-sectional area of ​​the third main grid 121 is larger than that of the fourth main grid 122. This embodiment achieves synergistic optimization of the main grid structure, enabling better matching of solder strips with different cross-sectional areas, and balancing light suppression and improved conductivity.

[0053] By co-optimizing the busbar and solder strip dimensions of the first solar cell 11 and / or the second solar cell 12, a smaller cross-sectional area first busbar 111 and / or fourth busbar 122 are used on the side where the first solder strip 2 is located, in conjunction with the smaller cross-sectional area of ​​the first solder strip 2, further reducing the shading area and cost. On the side where the second solder strip 3 is located, a larger cross-sectional area second busbar 112 and / or third busbar 121 are used in conjunction with the second solder strip 3, to further reduce contact resistance and current transmission loss, thereby improving the performance of the photovoltaic module.

[0054] In some embodiments, the first battery cell 11 includes: a first fine grid located on a first surface 101; a second fine grid located on a second surface 102; the cross-sectional area of ​​the first fine grid is smaller than the cross-sectional area of ​​the second fine grid; and / or, the second battery cell 12 includes: a third fine grid located on the first surface 101; a fourth fine grid located on the second surface 102; the cross-sectional area of ​​the third fine grid is larger than the cross-sectional area of ​​the fourth fine grid.

[0055] It is understandable that using a first and / or fourth fine grid with a smaller cross-sectional area in conjunction with a first solder strip 2 with a smaller cross-sectional area can further reduce the shading area and lower costs. Using a second and / or third fine grid with a larger cross-sectional area in conjunction with a second solder strip 3 can further reduce contact resistance and current transmission loss, thereby improving the performance of the photovoltaic module.

[0056] In some embodiments, in the first direction X, the ratio of the width of the first main gate 111 to the width of the first solder strip 2 is 0.5 to 1.5; and / or, in the first direction X, the ratio of the width of the second main gate 112 to the width of the second solder strip 3 is 0.5 to 1.5; and / or, in the first direction X, the ratio of the width of the third main gate 121 to the width of the second solder strip 3 is 0.5 to 1.5; and / or, in the first direction X, the ratio of the width of the fourth main gate 122 to the width of the first solder strip 2 is 0.5 to 1.5; wherein, the first direction X is defined as a direction perpendicular to the extension direction of the first main gate 111.

[0057] In some embodiments, in the first direction X, the ratio of the width of the first main gate 111 to the width of the first solder strip 2 is 0.5~0.8, 0.8~1.2, or 1.2~1.5; for example, in the first direction X, the ratio of the width of the first main gate 111 to the width of the first solder strip 2 is 0.5, 0.6, 0.7, 0.8, 0.9, 1, 1.1, 1.2, 1.3, 1.4, or 1.5.

[0058] When the ratio is not less than 0.5, the first solder strip 2 can effectively cover the first main gate 111 to ensure reliable electrical connection; when the ratio is not greater than 1.5, the first main gate 111 will not extend excessively beyond the edge of the first solder strip 2, which can reduce silver paste consumption and avoid unnecessary light shading.

[0059] In some embodiments, in the first direction X, the ratio of the width of the second main gate 112 to the width of the second solder strip 3 is 0.5~0.8, 0.8~1.2, or 1.2~1.5; for example, in the first direction X, the ratio of the width of the second main gate 112 to the width of the second solder strip 3 is 0.5, 0.6, 0.7, 0.8, 0.9, 1, 1.1, 1.2, 1.3, 1.4, or 1.5.

[0060] When the ratio is not less than 0.5, the second solder strip 3 can effectively cover the second main gate 112 to ensure reliable electrical connection; when the ratio is not greater than 1.5, the second main gate 112 will not extend excessively beyond the edge of the second solder strip 3, which can reduce silver paste consumption and avoid unnecessary shading.

[0061] In some embodiments, in the first direction X, the ratio of the width of the third main gate 121 to the width of the second solder strip 3 is 0.5~0.8, 0.8~1.2, or 1.2~1.5; for example, in the first direction X, the ratio of the width of the third main gate 121 to the width of the second solder strip 3 is 0.5, 0.6, 0.7, 0.8, 0.9, 1, 1.1, 1.2, 1.3, 1.4, or 1.5.

[0062] When the ratio is not less than 0.5, the second solder strip 3 can effectively cover the third main gate 121 to ensure reliable electrical connection; when the ratio is not greater than 1.5, the third main gate 121 will not extend excessively beyond the edge of the second solder strip 3, which can reduce silver paste consumption and avoid unnecessary shading.

[0063] In some embodiments, in the first direction X, the ratio of the width of the fourth main gate 122 to the width of the first solder strip 2 is 0.5~0.8, 0.8~1.2, or 1.2~1.5; for example, in the first direction X, the ratio of the width of the fourth main gate 122 to the width of the first solder strip 2 is 0.5, 0.6, 0.7, 0.8, 0.9, 1, 1.1, 1.2, 1.3, 1.4, or 1.5.

[0064] When the ratio is not less than 0.5, the first solder strip 2 can effectively cover the fourth main gate 122 to ensure reliable electrical connection; when the ratio is not greater than 1.5, the fourth main gate 122 will not extend excessively beyond the edge of the first solder strip 2, which can reduce silver paste consumption and avoid unnecessary light shading.

[0065] refer to Figure 5 In some embodiments, for the same first battery cell 11 or the same second battery cell 12, the first solder strip 2 and the second solder strip 3 are arranged in a staggered manner.

[0066] Misaligned arrangement means that, in the thickness direction of the battery cell, the projection position of the first solder strip 2 on the first surface 101 of the first battery cell 11 does not completely coincide with the projection position of the second solder strip 3 on the second surface 102 of the first battery cell 11; or, the projection position of the first solder strip 2 on the second surface 102 of the second battery cell 12 does not completely coincide with the projection position of the second solder strip 3 on the first surface 101 of the second battery cell 12.

[0067] By staggering the first solder strip 2 and the second solder strip 3 connecting opposite sides of the same cell, the concentrated stress caused by thermal expansion or mechanical load can be effectively dispersed, and the local stress superposition caused by the alignment of the first solder strip 2 and the second solder strip 3 can be avoided, thereby reducing the risk of cell microcracks, fragmentation or solder strip detachment.

[0068] refer to Figures 6 to 7 In some embodiments, the first solder strip 2 includes a first body portion 21 and a first solder layer 22 wrapped around the surface of the first body portion 21, and the second solder strip 3 includes a second body portion 31 and a second solder layer 32 wrapped around the surface of the second body portion 31; wherein the resistivity of the first body portion 21 is less than the resistivity of the second body portion 31, and / or the thickness of the first solder layer 22 is less than the thickness of the second solder layer 32.

[0069] The first main body 21 has a lower resistivity, which helps to reduce the bulk resistance of the first solder strip 2, offsetting the increase in resistance caused by the smaller cross-sectional area, and maintaining the overall electrical performance balance.

[0070] By controlling the thickness of the first solder layer 22 to be relatively thin, it is beneficial to form a smoother and denser welding interface, improve the current distribution, thereby reducing the overall effective resistance of the first solder strip 2 and further improving the performance of the photovoltaic module.

[0071] The material of the first solder layer 22 can be tin or a tin alloy, and the material of the second solder layer 32 can be tin or a tin alloy.

[0072] In some embodiments, the material of the first body portion 21 includes at least one of copper, silver, or a copper-silver alloy.

[0073] The first main body 21 is a conductive core inside the first welding strip 2 that is used to carry out the main current transmission function.

[0074] Copper has high electrical conductivity, good mechanical strength and low cost; silver has better electrical conductivity and oxidation resistance, but higher cost; copper-silver alloys can achieve a balance between electrical conductivity, corrosion resistance and manufacturing cost.

[0075] By selecting copper, silver, or a copper-silver alloy as the material of the first main body 21, a low volume resistance can be maintained even when the cross-sectional area of ​​the first solder strip 2 is small, effectively compensating for the decrease in conductivity caused by the small cross-sectional area.

[0076] refer to Figure 7 In some embodiments, the second body portion 31 includes a first portion 311 and a second portion 312 wrapped around the surface of the first portion 311. The material of the first portion 311 includes aluminum, and the material of the second portion 312 includes copper.

[0077] The second main body 31 is a conductive core inside the second welding strip 3 that is used to carry out the main current transmission function. It consists of an inner first part 311 and an outer second part 312.

[0078] The first part 311 serves as the core and is made of aluminum or aluminum alloy, which has the advantages of low density and low cost. The second part 312 covers the outer periphery of the first part 311 and is made of copper or copper alloy, which helps to provide good conductivity and solderability.

[0079] In some embodiments, the second solder strip 3 may be a copper-aluminum composite solder strip. The second solder layer 32 is wrapped around the surface of the second part 312.

[0080] Using a copper-aluminum composite structure as the second main body 31 can further reduce material costs while ensuring that the second welding strip 3 has sufficient conductivity and welding reliability.

[0081] In some embodiments, the cross-sectional shape of the first solder strip 2 includes a circle, a triangle, a rectangle, or a trapezoid, and / or, the cross-sectional shape of the second solder strip 3 includes a circle, a triangle, a rectangle, or a trapezoid.

[0082] In some embodiments, the cross-sectional shapes of the first solder strip 2 and the second solder strip 3 can be arbitrarily combined. For example, refer to... Figure 8 The first solder strip 2 can have a circular cross-section to reduce the light-shielding area, while the second solder strip 3 can have a rectangular cross-section to provide a larger contact area and higher current-carrying capacity, reducing series resistance; or, refer to Figure 9 The first solder strip 2 has a triangular cross-section, and the second solder strip 3 has a rectangular cross-section. By flexibly configuring the cross-sectional shapes of the first solder strip 2 and the second solder strip 3, the synergistic optimization of the optical and electrical performance of the photovoltaic module can be achieved.

[0083] In some embodiments, the photovoltaic module includes: a first encapsulating film located on the side where the first surface 101 of the first cell 11 in the battery string 1 is located; and a second encapsulating film located on the side where the second surface 102 of the first cell 11 in the battery string 1 is located; wherein the thickness of the first encapsulating film is less than or equal to the thickness of the second encapsulating film.

[0084] Understandably, the first adhesive film directly covers the first solder ribbon 2 and the surface of the battery on which it is located, and its thickness must be designed to at least cover the highest point of the first solder ribbon 2 to achieve reliable encapsulation. Since the cross-sectional area of ​​the first solder ribbon 2 is small and its height is low, the minimum thickness requirement for the first adhesive film is correspondingly reduced.

[0085] The second adhesive film covers the surface of the second solder strip 3. Because the second solder strip 3 has a larger cross-sectional area and a higher height, the second adhesive film needs to be thicker to ensure complete filling and sealing.

[0086] Therefore, by making the thickness of the first adhesive film less than or equal to the thickness of the second adhesive film, the amount of the first adhesive film can be reduced while meeting the requirements of encapsulation reliability, thereby saving manufacturing costs.

[0087] In some embodiments, for the same first battery cell 11 or the same second battery cell 12, the ratio of the number of first solder strips 2 to the number of second solder strips 3 is 0.5 to 2; for example, the ratio of the number of first solder strips 2 to the number of second solder strips 3 can be 0.5 to 1, 1 to 1.5 or 1.5 to 2, etc.

[0088] In some embodiments, for the same first battery cell 11 or the same second battery cell 12, the ratio of the number of first solder strips 2 to the number of second solder strips 3 can be 0.5, 0.6, 0.7, 0.8, 0.9, 1, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9 or 2, etc.

[0089] By limiting the ratio of the first solder ribbon 2 to the second solder ribbon 3 to a range of 0.5 to 2, a smaller number of first solder ribbons 2 helps to reduce the shading area of ​​the first solder ribbon 2 on the first surface 101 of the first solar cell 11 and the second surface 102 of the adjacent second solar cell 12, thereby improving the performance of the photovoltaic module and reducing costs. A larger number of second solder ribbons 3 helps to effectively reduce series resistance and current transmission loss. This ratio range balances optical performance optimization with electrical performance stability.

[0090] In some embodiments, in the first direction X, the distance between adjacent first solder strips 2 is 5mm to 20mm; for example, the distance between adjacent first solder strips 2 can be 5mm to 10mm, 10mm to 15mm, or 15mm to 20mm, etc. In the first direction X, the distance between adjacent second solder strips 3 can be 5mm to 20mm; for example, the distance between adjacent second solder strips 3 can be 5mm to 10mm, 10mm to 15mm, or 15mm to 20mm, etc.

[0091] In some embodiments, the distance between adjacent first solder strips 2 in the first direction X can be 5mm, 6mm, 7mm, 8mm, 9mm, 10mm, 11mm, 12mm, 13mm, 14mm, 15mm, 16mm, 17mm, 18mm, 19mm, or 20mm, etc. Similarly, the distance between adjacent second solder strips 3 in the first direction X can be 5mm, 6mm, 7mm, 8mm, 9mm, 10mm, 11mm, 12mm, 13mm, 14mm, 15mm, 16mm, 17mm, 18mm, 19mm, or 20mm, etc.

[0092] By limiting the spacing between adjacent first solder strips 2 and adjacent second solder strips 3 in the first direction X to between 5mm and 20mm, a good balance can be achieved between light-shielding loss and electrical performance.

[0093] In some embodiments, for the same first battery cell 11 or the same second battery cell 12, the total cross-sectional area of ​​the first solder strips 2 is less than or equal to the total cross-sectional area of ​​the second solder strips 3; wherein, the total cross-sectional area is defined as the product of the cross-sectional area of ​​a single solder strip and its quantity.

[0094] The smaller total cross-sectional area of ​​the first solder strip 2 helps reduce the shading area of ​​the first solder strip 2 on the first surface 101 of the first solar cell 11 and the second surface 102 of the adjacent second solar cell 12, thereby improving the performance of the photovoltaic module and reducing costs. The larger total cross-sectional area of ​​the second solder strip 3 helps to effectively reduce series resistance and current transmission loss. This ratio range balances optical performance optimization with electrical performance stability.

[0095] In some embodiments, a reflective portion is provided on the side of the first solder strip 2 away from the battery string 1.

[0096] The side away from the battery string 1 refers to the direction of the first solder strip 2 away from the battery cell, that is, the side facing the outside of the module encapsulation layer.

[0097] The reflective part is a structure or coating with high reflectivity disposed on the surface of the first solder strip 2 away from the battery string 1. The material of the reflective part may include silver, aluminum, titanium dioxide, silicon dioxide multilayer dielectric film or other functional layers with visible light or near-infrared light reflectivity.

[0098] In some embodiments, the reflective portion can be formed directly on the surface of the first solder strip 2, or it can be integrated by attaching, coating or vapor deposition, and its position corresponds one-to-one with the first solder strip 2.

[0099] By setting a reflective part on the side of the first solder strip 2 away from the battery string 1, the incident light that was originally blocked by the first solder strip 2 can be reflected back to the surface of the battery cell, thereby partially compensating for the current loss caused by the first solder strip 2 blocking the light, effectively improving the light utilization rate, increasing the short-circuit current and the overall power generation efficiency.

[0100] In some embodiments, the spacing between adjacent battery cells in battery string 1 is -10mm to 10mm.

[0101] It is understandable that when the spacing is negative, it means that the adjacent cells partially overlap, and its absolute value is the overlap length.

[0102] Limiting the spacing between adjacent cells to -10mm to 10mm avoids both the increase in ineffective area caused by excessive gaps and the risk of microcracks or shading losses caused by excessive overlap. This optimizes photoelectric conversion efficiency and manufacturing costs while ensuring module yield and long-term reliability.

[0103] In the photovoltaic module provided in this disclosure, by alternating the arrangement of first and second solar cells, with the first side of the first solar cell and the second side of the second solar cell facing the same side, and electrically connected by a first solder strip with a small cross-sectional area, the amount of material used is reduced, thereby lowering the manufacturing cost of the photovoltaic module. Furthermore, by arranging the first side of the second solar cell and the second side of the adjacent first solar cell to face the same side, and electrically connecting them by a second solder strip with a larger cross-sectional area, current transmission loss is reduced, thereby improving the performance of the photovoltaic module. Moreover, the dimensions of the main grid and solder strip of the first and / or second solar cells are optimized synergistically. On the side where the first solder strip is located, a first main grid / / or a fourth main grid with a smaller cross-sectional area is used in conjunction with the first solder strip, further reducing the shading area and cost. On the side where the second solder strip is located, a second main grid and / or a third main grid with a larger cross-sectional area is used in conjunction with the second solder strip, further reducing contact resistance and current transmission loss, thereby improving the performance of the photovoltaic module. Furthermore, by staggering the first and second solder strips connecting opposite sides of the same solar cell, concentrated stress caused by thermal expansion or mechanical loads can be effectively dispersed, avoiding localized stress superposition due to alignment of the first and second solder strips. This reduces the risk of microcracks, fragmentation, or solder strip detachment in the solar cell. It is worth noting that by having a lower resistivity for the first body portion than for the second body portion, and / or a thinner first solder layer than for the second solder layer, the bulk resistance of the first solder strip can be reduced, offsetting the increase in resistance due to the smaller cross-sectional area and maintaining overall electrical performance balance.

[0104] 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 this disclosure. Any person skilled in the art can make various alterations and modifications without departing from the spirit and scope of this disclosure; therefore, the scope of protection of this disclosure should be determined by the scope defined in the claims.

Claims

1. A photovoltaic module, characterized by, include: A battery string consisting of multiple battery cells, wherein the multiple battery cells include alternating first battery cells and second battery cells, and both the first battery cell and the second battery cell have a first surface and a second surface; wherein the direction in which the first surface of the first battery cell points to the second surface is the same as the direction in which the second surface of the second battery cell points to the first surface. The first solder strip is located on the first side of the first battery cell and the second side of the second battery cell, and electrically connects the first battery cell and the second battery cell. The second solder strip is located on the first side of the second battery cell and the second side of another first battery cell, and electrically connects the second battery cell and the corresponding first battery cell. Wherein, the cross-sectional area of ​​the first solder strip is smaller than the cross-sectional area of ​​the second solder strip.

2. The photovoltaic module according to claim 1, characterized in that, The ratio of the cross-sectional area of ​​the first solder strip to the cross-sectional area of ​​the second solder strip is 0.1 to 0.

99.

3. The photovoltaic module of claim 1, wherein, The first battery cell includes: The first main gate is located on the first surface; the second main gate is located on the second surface; The cross-sectional area of ​​the first main gate is smaller than the cross-sectional area of ​​the second main gate; And / or, the second battery cell includes: The third main gate is located on the first surface; the fourth main gate is located on the second surface. The cross-sectional area of ​​the third main gate is larger than that of the fourth main gate.

4. The photovoltaic module of claim 3, wherein, In the first direction, the ratio of the width of the first main gate to the width of the first solder strip is 0.5 to 1.5; and / or, in the first direction, the ratio of the width of the second main gate to the width of the second solder strip is 0.5 to 1.5; and / or, in the first direction, the ratio of the width of the third main gate to the width of the second solder strip is 0.5 to 1.5; and / or, in the first direction, the ratio of the width of the fourth main gate to the width of the first solder strip is 0.5 to 1.

5. The first direction is defined as the direction perpendicular to the extension direction of the first main gate.

5. The photovoltaic module according to any one of claims 1 to 4, characterized in that, For the same first battery cell or the same second battery cell, the first solder strip and the second solder strip are arranged in a staggered manner.

6. The photovoltaic module according to claim 1, characterized in that, The first solder strip includes a first body portion and a first solder layer wrapped around the surface of the first body portion, and the second solder strip includes a second body portion and a second solder layer wrapped around the surface of the second body portion; wherein the resistivity of the first body portion is less than the resistivity of the second body portion, and / or the thickness of the first solder layer is less than the thickness of the second solder layer.

7. The photovoltaic module of claim 6, wherein, The material of the first main body includes at least one of copper, silver, or a copper-silver alloy.

8. The photovoltaic module of claim 6, wherein, The second main body includes a first part and a second part that wraps around the surface of the first part. The material of the first part includes aluminum, and the material of the second part includes copper.

9. The photovoltaic module according to claim 1, characterized in that, The cross-sectional shape of the first solder strip includes a circle, a triangle, a rectangle, or a trapezoid, and / or the cross-sectional shape of the second solder strip includes a circle, a triangle, a rectangle, or a trapezoid.

10. The photovoltaic module of claim 1, wherein, The photovoltaic module includes: a first encapsulating film located on one side of the first surface of the first cell in the battery string; and a second encapsulating film located on one side of the second surface of the first cell in the battery string. The thickness of the first adhesive film is less than or equal to the thickness of the second adhesive film.

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