Back contact cells, stacked cells and photovoltaic modules

Abstract

The embodiment of the present application relates to the photovoltaic field, and provides a back contact cell, a laminated cell and a photovoltaic module, the back contact cell comprises: a first busbar line and a first pad which are arranged at intervals in a first direction, the first busbar line extends along a second direction; a first connecting busbar line is located in a first reserved area and extends along the first direction, so as to connect the first busbar line and the first pad, the first reserved area is an area located between the first pad and the first busbar line in the first direction; a plurality of first bus lines and a plurality of second bus lines are alternately and spacedly arranged along the second direction and extend along the first direction, and the first bus line is electrically connected with the first busbar line or the first bus line is electrically connected with the first pad, the second bus line is arranged outside the first reserved area and is arranged to be insulated from the first busbar line and the first pad respectively. The back contact cell provided by the embodiment of the present application can at least improve the reliability of the cell.

Description

Technical Field

[0001] This application relates to the photovoltaic field, and in particular to a back contact cell, a tandem cell, and a photovoltaic module. Background Technology

[0002] In traditional photovoltaic cell design, to improve current collection efficiency, the cell surface typically features fine grid lines and busbars perpendicular to these fine grid lines. The fine grid lines directly contact the PN junction of the cell and collect photogenerated carriers, while the busbars collect the photogenerated current collected by the fine grid lines. The pads are crucial for connecting the cell to external circuitry; their primary function is to collect the photogenerated current generated on the cell surface. Specifically, the fine grid lines on the cell surface converge at the pads via the busbars, and then the current is connected to the solder ribbon or busbar, ultimately delivering the current to the external circuitry of the solar module.

[0003] Photovoltaic cells are susceptible to mechanical stress during production, handling, and use, which can lead to microcracks. To prevent these microcracks from affecting current transmission, the pads often need to be shifted towards the center of the cell. However, the fine grid lines on the cell surface are frequently affected by this inward shift of the pads, resulting in broken grids. This directly impacts the effective collection and conduction of current, potentially leading to partial or even complete cell failure. Summary of the Invention

[0004] This application provides a back-contact battery, a tandem battery, and a photovoltaic module, which at least solves the hot spot problem caused by the formation of "islands" in the doped regions that are in contact with the broken grid.

[0005] According to some embodiments of this application, one aspect of this application provides a back contact battery, the back contact battery including: a first busbar and a first pad, the first busbar and the first pad being spaced apart in a first direction, and the first busbar extending along a second direction, the first direction intersecting the second direction; a first connecting gate, the first connecting gate being located in a first reserved area and extending along the first direction to connect the first busbar and the first pad, the first reserved area being located between the first pad and the first busbar, and the orthographic projection of the first pad on the first busbar and the first reserved area on the first busbar... The orthographic projections overlap; multiple gate lines, multiple gate lines and the first pad are located on the same side of the first bus gate line, the gate lines include first gate lines and second gate lines with opposite polarities, multiple first gate lines and multiple second gate lines are alternately spaced along the second direction and extend along the first direction, and the first gate lines are electrically connected to the first bus gate line or the first gate line is electrically connected to the first pad, the second gate lines are arranged outside the first reserved area and are respectively insulated from the first bus gate line and the first pad; a doped layer, the doped layer includes a first doped layer and a second doped layer spaced apart, the first reserved area is a part of the surface of the first doped layer.

[0006] In some embodiments, the back contact battery further includes: a second busbar and a second pad, the second busbar and the second pad being spaced apart in a first direction, the second busbar extending in a second direction, multiple busbars and the second pad being located on the same side of the second busbar, and the first pad and the second pad being spaced apart between the first busbar and the second busbar in the first direction; a second connecting busbar, the second connecting busbar being located in a second reserved area and extending in the first direction to connect the second busbar and the second pad, the second reserved area being located between the second pad and the second busbar, and the orthographic projection of the second pad on the second busbar partially overlapping the orthographic projection of the second reserved area on the second busbar; a first busbar being disposed outside the second reserved area and insulated from the second busbar and the second pad respectively, the second busbar being electrically connected to the second busbar or the second pad being electrically connected to the second pad.

[0007] In some embodiments, the first grid line is disposed outside the first reserved area.

[0008] In some embodiments, a first pad has a first side and a second side opposite to each other in a first direction, and the first side is located between the first bus gate and the second side in the first direction. A first connecting gate connects the first side and the first bus gate. A plurality of first gate lines include first sub-gate lines and second sub-gate lines. In a second direction, a plurality of first sub-gate lines are arranged on both sides of the first pad and connected to the first bus gate in the first direction. The second sub-gate lines are arranged on the side of the first pad away from the first bus gate and connected to the second side in the first direction. A plurality of second gate lines include third sub-gate lines and fourth sub-gate lines. In a second direction, a plurality of third sub-gate lines are arranged on both sides of the first pad and spaced apart from the first bus gate in the first direction. The fourth sub-gate lines are arranged on the side of the first pad away from the first bus gate and spaced apart from the second side in the first direction. In a second direction, a plurality of first sub-gate lines and a plurality of third sub-gate lines are alternately spaced apart, and a plurality of second sub-gate lines and a plurality of fourth sub-gate lines are alternately spaced apart.

[0009] In some embodiments, the back contact battery further includes: a third connecting grid line, which extends along a second direction and connects to the first sub-grid line and the first pad respectively.

[0010] In some embodiments, at least two first grid lines are disposed in the first reserved area and are respectively disposed at intervals on both sides of the first connecting grid line in the second direction.

[0011] In some embodiments, the first pad has opposing first and second sides in a first direction, with the first side located between the first busbar and the second side in the first direction, and a first connecting gate connecting the first side and the first busbar; multiple first gates include fifth sub-gates, sixth sub-gates, and seventh sub-gates, with multiple fifth sub-gates arranged on both sides of the first pad in a second direction and connected to the first busbar in the first direction, the sixth sub-gates arranged on the side of the first pad away from the first busbar and connected to the second side, and multiple seventh sub-gates arranged... Within the first reserved area, the seventh sub-gate line is connected to the first bus gate line and the first side respectively; multiple second gate lines include an eighth sub-gate line and a ninth sub-gate line. In the second direction, multiple eighth sub-gate lines are arranged on both sides of the first pad and spaced apart from the first bus gate line in the first direction. The ninth sub-gate line is arranged on the side of the first pad away from the first bus gate line and spaced apart from the second side in the first direction. In the second direction, multiple fifth sub-gate lines and multiple eighth sub-gate lines are alternately spaced apart, and multiple sixth sub-gate lines and multiple ninth sub-gate lines are alternately spaced apart.

[0012] In some embodiments, the back contact battery further includes: a fourth connecting grid line, which extends along a second direction and connects to a fifth sub-grid line and a first pad, respectively.

[0013] In some embodiments, the first pad has a first side and a second side opposite to each other in a first direction, and the first side is located between the first busbar and the second side in the first direction. The first connecting gate connects the first side and the first busbar. The plurality of first gates include a tenth sub-gate, an eleventh sub-gate, a twelfth sub-gate, and a thirteenth sub-gate. In a second direction, the plurality of tenth sub-gates are arranged on both sides of the first pad and connected to the first busbar in the first direction. In the second direction, the eleventh sub-gate is arranged between the tenth sub-gate and the first pad and is spaced apart from the first busbar in the first direction. The twelfth sub-gate is arranged on the side of the first pad away from the first busbar and is connected to the second side in the first direction. The plurality of thirteenth sub-gates are arranged in a first reserved area and are respectively connected to the first busbar and the first side. The back contact battery further includes a fifth connecting gate, which extends along the second direction and connects the eleventh sub-gate and the first pad.

[0014] In some embodiments, the plurality of second gate lines include a fourteenth sub-gate line and a fifteenth sub-gate line. The fourteenth sub-gate line is disposed on both sides of the first pad in the second direction and is spaced apart from the first bus gate line in the first direction. The fourteenth sub-gate line has a bend at one end near the first bus gate line in the first direction, and the bend extends from the end of the fourteenth sub-gate line near the first bus gate line along the second direction toward the first reserved area. The bend separates the first bus gate line and the eleventh sub-gate line in the first direction. The fifteenth sub-gate line is disposed on the side of the first pad away from the first bus gate line and is spaced apart from the second side in the first direction. In the second direction, the portion of the fourteenth sub-gate line other than the bend is located between the tenth sub-gate line and the eleventh sub-gate line, and a plurality of twelfth sub-gate lines and a plurality of fifteenth sub-gate lines are alternately spaced apart in the second direction.

[0015] According to some embodiments of this application, another aspect of this application provides a stacked battery, including a first battery and a second battery stacked together, wherein one of the first battery and the second battery is a back contact battery as described above.

[0016] According to some embodiments of this application, another aspect of this application provides a photovoltaic module, including: a battery string, which is formed by connecting a plurality of back-contact batteries as described above or stacked batteries 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 away from the battery string.

[0017] The technical solution provided in this application has at least the following advantages:

[0018] Using the technical solution of this application, the back contact battery includes: a first busbar and a first pad, the first busbar and the first pad being spaced apart in a first direction, and the first busbar extending along a second direction, the first direction intersecting the second direction; a first connecting grid line, the first connecting grid line being located in a first reserved area and extending along the first direction to connect the first busbar and the first pad, the first reserved area being located between the first pad and the first busbar, and the orthographic projection of the first pad on the first busbar partially overlapping the orthographic projection of the first reserved area on the first busbar; Multiple gate lines are located on the same side of the first bus gate line as the first pad. The gate lines include first gate lines and second gate lines with opposite polarities. The multiple first gate lines and multiple second gate lines are alternately arranged along the second direction and extend along the first direction. The first gate lines are electrically connected to the first bus gate line or to the first pad. The second gate lines are arranged outside the first reserved area and are respectively insulated from the first bus gate line and the first pad. A doped layer is included, which includes a first doped layer and a second doped layer arranged at intervals. The first reserved area is a portion of the surface of the first doped layer.

[0019] In this application, the first busbar extends along the second direction, is spaced apart from the first pad in the first direction and connected by the first connecting grid line. The first direction intersects the second direction, and multiple grid lines are located on the same side of the first busbar. In this way, the first pad is moved inward, that is, the first pad is moved towards the center area of ​​the cell. Since the center area is a more stable location with a lower risk of microcracks compared to the area where the first busbar is located, the problem of microcracks in the cell caused by the first solder joint being located on the first busbar is solved by moving the first pad inward. The grid lines of the back contact battery include a first grid line. Since the first grid line is electrically connected to the first bus grid line or the first grid line is electrically connected to the first pad, the first bus grid line and the first pad have the same polarity as the first grid line and opposite polarity to the second grid line. Furthermore, the first bus grid line and the first pad are connected by a first connecting grid line extending along a first direction. Thus, the photogenerated carriers collected by the first grid line can be gathered at the first pad through the first bus grid line or can be directly gathered at the first pad. This ensures that the current collected by the first grid line on the battery cell can be output through the first pad, thus ensuring that the first grid line can effectively collect and transmit current. Furthermore, the aforementioned first connecting gate line is located in the first reserved area. Further, the gate line of the back contact battery also includes a second gate line with the opposite polarity to the first gate line. The second gate line is insulated from both the first bus gate line and the first pad. Multiple first gate lines and multiple second gate lines are alternately spaced along the second direction and extend along the first direction. The second gate line is located outside the first reserved area. Based on this, the doped layer includes a first doped layer and a second doped layer spaced apart. Since the aforementioned first reserved area is a portion of the surface of the first doped layer, the area corresponding to the first reserved area will not consider the setting of the second doped layer. This directly avoids the possibility of setting the second gate line in the first reserved area, thus preventing the occurrence of an "island" corresponding to the second doped layer in the first reserved area due to a broken gate line (for example, in...). Figure 1 If the "doped region corresponding to the second gate line 42 located between the first pad 10 and the first bus gate line 20" is not connected to "other second gate lines 42 that have not experienced gate breakage", then... Figure 1The doped region corresponding to the second gate line 42 located between the first pad 10 and the first busbar 20 is referred to as an "island". This directly avoids the hot spot problem caused by the "island", thus solving the hot spot problem caused by the formation of an "island" by the doped region in contact with the broken gate. Furthermore, since the second gate line of opposite polarity is no longer laid in the first reserved area, the first pad will not occupy the space set for the second gate line. Therefore, even if the first pad moves inward, it will not cause the second gate line to break. This ensures that all the second gate lines in this application can effectively collect current and effectively deliver it to the corresponding busbar (i.e., the second busbar), which improves the reliability of the cell and promotes the improvement of cell efficiency. Attached Figure Description

[0020] One or more embodiments are illustrated by way of example with reference to the accompanying drawings. These illustrations do not constitute a limitation on the embodiments. Unless otherwise stated, the drawings 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 application or in the conventional art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 A partial schematic diagram of the back grid lines of a back-contact battery provided in the prior art;

[0022] Figure 2 This is a partial schematic diagram of the back grid lines of a back contact battery provided in an embodiment of this application;

[0023] Figure 3 A partial schematic diagram of another back-contact battery back grid line provided in an embodiment of this application is shown;

[0024] Figure 4 A partial schematic diagram of another back contact battery back grid line provided in an embodiment of this application is shown.

[0025] The above figures include the following reference numerals:

[0026] 10. First pad; 20. First bus gate; 30. First connecting gate; 102. First reserved area; 40. Gate line; 400. Spacer region; 410. First doped layer; 41. First gate line; 411. First sub-gate line; 412. Second sub-gate line; 413. Fifth sub-gate line; 414. Sixth sub-gate line; 415. Seventh sub-gate line; 416. Tenth sub-gate line; 417. Eleventh sub-gate line ; 418, Twelfth sub-gate line; 419, Thirteenth sub-gate line; 420, Second doped layer; 42, Second gate line; 421, Third sub-gate line; 422, Fourth sub-gate line; 423, Eighth sub-gate line; 424, Ninth sub-gate line; 425, Fourteenth sub-gate line; 4251, Bend section; 426, Fifteenth sub-gate line; 50, Third connecting gate line; 60, Fourth connecting gate line; 70, Fifth connecting gate line. Detailed Implementation

[0027] As the background technology knows, solder pads are critical connection points between solar cells and external circuits. To prevent microcracks in the solar cells, the solder pads are often moved towards the center of the cell. However, in existing technologies, inward movement of the solder pads can cause breakage of the fine grid lines on the surface of the solar cell (e.g., ...). Figure 1 As shown, the grid lines 40 on the surface of the solar cell include first grid lines 41 and second grid lines 42. Multiple first grid lines 41 are connected to the first bus grid line 20, and multiple second grid lines 42 are broken on both sides of the first pad 10, causing the doped regions corresponding to the broken grids to form "islands" (for example, in...). Figure 1 If the "doped region corresponding to the second gate line 42 located between the first pad 10 and the first bus gate line 20" is not connected to "other second gate lines 42 that have not experienced gate breakage", then... Figure 1 The doped region corresponding to the second gate line 42 located between the first pad 10 and the first busbar 20 is called an "island". This affects the effective collection and conduction of current, which in turn leads to the failure of part or even the entire cell.

[0028] This application provides a back contact battery, such as... Figures 2 to 4As shown, the back contact battery includes: a first busbar 20 and a first pad 10, the first busbar 20 and the first pad 10 being spaced apart in a first direction A, and the first busbar 20 extending along a second direction B, the first direction A intersecting the second direction B; a first connecting gate 30, the first connecting gate 30 being located within a first reserved area 102 and extending along the first direction A to connect the first busbar 20 and the first pad 10, the first reserved area 102 being located between the first pad 10 and the first busbar 20, and the orthographic projection of the first pad 10 on the first busbar 20 partially overlapping the orthographic projection of the first reserved area 102 on the first busbar 20; and multiple gate lines 40. Multiple gate lines 40 are located on the same side of the first bus gate 20 as the first pad 10. Each gate line 40 includes a first gate line 41 and a second gate line 42 with opposite polarities. The multiple first gate lines 41 and the multiple second gate lines 42 are alternately spaced along the second direction B and extend along the first direction A. The first gate lines 41 are electrically connected to the first bus gate 20 or to the first pad 10. The second gate lines 42 are located outside the first reserved area 102 and are insulated from both the first bus gate 20 and the first pad 10. A doped layer is included, comprising a first doped layer 410 and a second doped layer 420 spaced apart. The first reserved area 102 is a portion of the surface of the first doped layer 410. The orthographic projection of the first pad 10 onto the first bus gate 20 can lie within the orthographic projection of the first reserved area 102 onto the first bus gate 20.

[0029] In this application, the first busbar 20 extends along the second direction B, is spaced apart from the first pad 10 in the first direction A, and is connected by the first connecting grid line 30. The first direction A intersects the second direction B, and multiple grid lines are located on the same side of the first busbar 20 as the first pad 10. In this way, the first pad 10 is moved inward, that is, the first pad 10 is moved towards the center region of the battery cell. Since the center region is a more stable location with a lower risk of microcracks compared to the region where the first busbar 20 is located, the inward movement of the first pad 10 solves the problem that the solder joint located on the first busbar 20 is prone to causing microcracks in the battery cell. The grid line 40 of the back contact battery includes a first grid line 41. Since the first grid line 41 is electrically connected to the first bus grid line 20 or the first grid line 41 is electrically connected to the first pad 10, the first bus grid line 20 and the first pad 10 have the same polarity as the first grid line 41 and opposite polarity to the second grid line 42. Furthermore, the first bus grid line 20 and the first pad 10 are connected by a first connecting grid line 30 extending along the first direction A. Thus, the photogenerated carriers collected by the first grid line 41 can be gathered at the first pad 10 through the first bus grid line 20 or can be directly gathered at the first pad 10, so that the current collected by the first grid line 41 on the battery cell can be output through the first pad 10, ensuring that the first grid line 41 can effectively collect and transmit current. Furthermore, the aforementioned first connecting gate line 30 is located in the first reserved area 102. Further, the gate line 40 on the back contact battery also includes a second gate line 42 with the opposite polarity to the first gate line 41. The second gate line 42 is insulated from both the first bus gate line 20 and the first pad 10. Multiple first gate lines 41 and multiple second gate lines 42 are alternately arranged along the second direction B and extend along the first direction A. The second gate line 42 is located outside the first reserved area 102. Based on this, the doped layer includes a first doped layer 410 and a second doped layer 420 arranged at intervals. Since the aforementioned first reserved area 102 is a portion of the surface of the first doped layer 410, the area corresponding to the first reserved area 102 will not consider the setting of the second doped layer 420. This directly avoids the possibility of setting the second gate line 42 in the first reserved area 102, thus preventing the occurrence of an "island" corresponding to the second doped layer 420 in the first reserved area 102 due to a break in the second gate line 42 (for example, in...). Figure 1 If the "doped region corresponding to the second gate line 42 located between the first pad 10 and the first bus gate line 20" is not connected to "other second gate lines 42 that have not experienced gate breakage", then... Figure 1The doped region corresponding to the second grid line 42 located between the first pad 10 and the first busbar 20 is referred to as an "island". This directly avoids the hot spot problem caused by the "island", thus solving the hot spot problem caused by the formation of an "island" by the doped region in contact with the broken grid. Furthermore, since the first reserved area 102 no longer has the second grid line 42 of opposite polarity laid, the first pad 10 will not occupy the space provided by the second grid line 42. Therefore, even if the first pad 10 moves inward, it will not cause the second grid line 42 to break. This ensures that all the second grid lines 42 in this application can effectively collect current and effectively deliver it to the corresponding busbar (i.e., the second busbar), which improves the reliability of the cell and promotes the improvement of cell efficiency.

[0030] In the description of the embodiments of this application, 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 and secondary relationship of the indicated technical features. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly defined.

[0031] 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 application. 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.

[0032] In the description of the embodiments in this application, 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. In addition, the character " / " in this document generally indicates that the related objects before and after it have an "or" relationship.

[0033] In the description of the embodiments of this application, the term "multiple" refers to two or more (including two), similarly, "multiple sets" refers to two or more (including two sets), and "multiple pieces" refers to two or more (including two pieces).

[0034] In the description of the embodiments of this application, 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 application 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 application.

[0035] In the description of the embodiments of this application, unless otherwise expressly specified and limited, the 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. For those skilled in the art, the specific meaning of the above terms in the embodiments of this application can be understood according to the specific circumstances.

[0036] In the accompanying drawings corresponding to the embodiments of this application, 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.

[0037] In the description of the embodiments of this application, when a component "includes" another component, other components are not excluded unless otherwise stated, and other components 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. Moreover, 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.

[0038] 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 word "part" is also intended to include the plural form, unless the context clearly indicates otherwise. Components include layers, films, regions, or plates, etc.

[0039] The embodiments of this application 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 application to facilitate a better understanding of the application. However, the technical solutions claimed in this application can be implemented even without these technical details and various variations and modifications based on the following embodiments.

[0040] like Figures 2 to 4 As shown, the first grid line 41 and the second grid line 42 can be fine grid lines of the back contact battery. Specifically, the first grid line 41 can be the positive electrode of the back contact battery, and the second grid line 42 can be the negative electrode of the back contact battery; or, the first grid line 41 can be the negative electrode of the back contact battery, and the second grid line 42 can be the positive electrode of the back contact battery.

[0041] The aforementioned back contact battery can be a multi-busbar battery (MBB battery) or a zero-busbar battery (OBB battery). When the back contact battery is an MBB battery, it may include a plurality of main busbars spaced apart in a first direction A and extending along a second direction B. Each main busbar includes the aforementioned first busbar 20, which is one of the outermost main busbars located in the first direction A. When the back contact battery is an OBB battery, the aforementioned first busbar 20 is one of the edge busbars located at the edge of the battery cell and connected to a plurality of first busbars 41, extending along the second direction B.

[0042] It should be noted that the first pad 10 is relatively large, meaning it can have a certain width in the second direction B, thus allowing the first reserved area 102 between the first pad 10 and the first busbar 20 in the first direction A. However, the width of the first pad 10 in the second direction B can be reasonably selected according to actual design needs, and is not specifically limited here.

[0043] In some optional embodiments, the back contact battery further includes: a second busbar and a second pad, the second busbar and the second pad being spaced apart in a first direction A, the second busbar extending along a second direction B, multiple busbars and the second pad being located on the same side of the second busbar, and the first pad and the second pad being spaced apart between the first busbar and the second busbar in the first direction A; a second connecting busbar, the second connecting busbar being located within a second reserved area and extending along the first direction A to connect the second busbar and the second pad, the second reserved area being located between the second pad and the second busbar, and the orthographic projection of the second pad on the second busbar partially overlapping the orthographic projection of the second reserved area on the second busbar; a first busbar being disposed outside the second reserved area and insulated from the second busbar and the second pad respectively, the second busbar being electrically connected to the second busbar or the second pad being electrically connected to the second pad. It should be noted that the second reserved area is a portion of the surface of the second doped layer. Optionally, the orthographic projection of the second pad on the second busbar is located within the orthographic projection of the second reserved area on the first busbar.

[0044] In the above embodiment, the second busbar extends along the second direction B, is spaced apart from the second pad in the first direction A and connected by the second connecting grid line. Multiple grid lines and the second pad are located on the same side of the second busbar. In this way, the second pad is moved inward, that is, the second pad is moved towards the center area of ​​the cell. Since the center area is a more stable location with a lower risk of microcracks compared to the area where the second busbar is located, the problem of microcracks in the cell caused by the second pad being located on the second busbar is solved by moving the second pad inward. Since the second grid line in contact with the cell is electrically connected to the second bus grid line or the second grid line is electrically connected to the second pad, the second bus grid line and the second pad have the same polarity as the second grid line but opposite to that of the first grid line. Furthermore, the second bus grid line and the second pad are connected by a second connecting grid line extending along the first direction A. Thus, the photogenerated carriers collected by the second grid line can be gathered at the second pad through the second bus grid line or directly gathered at the second pad. This ensures that the current collected by the second grid line on the cell can be output through the second pad, further ensuring that the second grid line can effectively collect and transmit the current. Furthermore, the aforementioned second busbar is located in the second reserved area. Further, the first busbar, the second busbar, and the second pad are all insulated from each other. Since the second reserved area is a portion of the surface of the second doped layer, the area corresponding to the second reserved area does not take into account the first doped layer. This directly avoids the possibility of placing the first busbar in the second reserved area, thus preventing the formation of an "island" phenomenon in the second reserved area due to a broken first busbar. This directly avoids the hot spot problem caused by "islands," thus solving the problem of hot spots caused by "islands" formed by doped areas in contact with broken busbars. Furthermore, since the second reserved area no longer has a first busbar of opposite polarity, the second pad will not occupy the space provided by the first busbar. Therefore, even if the second pad moves inward, it will not cause the first busbar to break. This ensures that the first busbar can effectively collect current and effectively deliver it to the corresponding busbar (i.e., the first busbar), further improving the reliability of the cell and further promoting the improvement of cell efficiency.

[0045] Optionally, when the back contact battery is an MBB battery, the second busbar is another main busbar located at the outermost edge of the plurality of main busbars in the first direction A and opposite to the first busbar in the first direction A. When the back contact battery is an OBB battery, the second busbar is another edge busbar located at the edge of the cell, connected to the plurality of second busbars, and disposed opposite to the first busbar in the first direction A.

[0046] In some alternative implementations, such as Figure 2As shown, the first gate line 41 is located outside the first reserved area 102. Thus, the position near the first pad 10 where the second gate line 42 would normally be located is hollowed out; that is, within the first reserved area 102, besides the aforementioned first connecting gate line 30, no other gate lines (first gate line 41 or second gate line 42) are present. This directly avoids the occurrence of gate breakage near the first pad 10. Furthermore, since no gate lines other than the aforementioned first connecting gate line 30 can be provided within the first reserved area 102, the number of gate lines is reduced. This indirectly simplifies the process steps before forming the gate lines of the back contact cell, including but not limited to the step of forming a doped layer and laser grooving, thereby reducing the complexity of the entire back contact cell fabrication and reducing the generation of process defects.

[0047] In some alternative implementations, such as Figure 2 As shown, the first pad 10 has a first side and a second side opposite to each other in the first direction A, and the first side is located between the first bus gate 20 and the second side in the first direction A. The first connecting gate 30 connects the first side and the first bus gate 20. Multiple first gate lines 41 include first sub-gate lines 411 and second sub-gate lines 412. In the second direction B, multiple first sub-gate lines 411 are arranged on both sides of the first pad 10 and connected to the first bus gate 20 in the first direction A. The second sub-gate lines 412 are arranged on the side of the first pad 10 away from the first bus gate 20 and connected to the first bus gate 20 in the first direction A. The second side is connected; multiple second gate lines 42 include third sub-gate lines 421 and fourth sub-gate lines 422. In the second direction B, multiple third sub-gate lines 421 are arranged on both sides of the first pad 10 and spaced apart from the first bus gate line 20 in the first direction A. The fourth sub-gate line 422 is arranged on the side of the first pad 10 away from the first bus gate line 20 and spaced apart from the second side in the first direction A. In the second direction B, multiple first sub-gate lines 411 and multiple third sub-gate lines 421 are alternately spaced apart, and multiple second sub-gate lines 412 and multiple fourth sub-gate lines 422 are alternately spaced apart.

[0048] In the above embodiment, the first sub-gate line 411, the second sub-gate line 412, the third sub-gate line 421, and the fourth sub-gate line 422 are all disposed outside the first reserved area 102. That is, by foregoing the placement of the first gate line 41 and the second gate line 42 within the first reserved area 102, the possibility of gate line breakage in or near this area is directly avoided, effectively improving the reliability of the solar cell. Specifically, any one of the first sub-gate lines 411 extends in the first direction A and is electrically connected to the first bus gate line 20, while the first bus gate line 20 is electrically connected to the first pad 10 via the first connecting gate line 30. This allows the photogenerated carriers collected by any one of the first sub-gate lines 411 to converge at the first pad 10 via the first bus gate line 20 and the first connecting gate line 30. Similarly, any one of the second sub-gate lines 412 extends in the first direction A and is electrically connected to the first pad 10, allowing the photogenerated carriers collected by any one of the second sub-gate lines 412 to directly converge at the first pad 10. In this way, an effective electrical connection is achieved between the first pad 10 and the first gate line 41, ensuring the effective transmission of the current collected by the first gate line 41. Furthermore, since multiple first sub-gate lines 411 are located on opposite sides of the first pad 10 in the second direction B, and multiple second sub-gate lines 412 are located on the side of the first pad 10 away from the first busbar 20 in the first direction A, the multiple first sub-gate lines 411 and multiple second sub-gate lines 412 form a highly efficient current collection network, improving the current collection efficiency of the solar cell.

[0049] Furthermore, in the above embodiment, any third sub-gate line 421 extends in the first direction A and is insulated from the first bus gate line 20 by a gap. This third sub-gate line 421 is also located on one side of the first pad 10 in the second direction B and is spaced apart from the first sub-gate line 411. This effectively prevents direct contact between the third sub-gate line 421 and the first bus gate line 20, as well as between the third sub-gate line 421 and the first sub-gate line 411, thereby effectively preventing direct contact between the first gate line 41 and the second gate line 42 and avoiding short circuits. Furthermore, multiple first sub-gate lines 411 and multiple third sub-gate lines 421 are alternately arranged in the second direction B, further optimizing the layout of the first gate line 41 and the second gate line 42, forming a more reasonable current path, making the current flow inside the cell more balanced, and effectively suppressing the effects of hot spot effect and potential induced degradation (PID) effect.

[0050] Similarly, in the above embodiments, any fourth sub-gate line 422 extends in the first direction A, is located on the side of the first pad 10 away from the first busbar 20 in the first direction A, and is insulated from the first pad 10 by a gap, and is insulated from the second sub-gate line 412 by a gap in the second direction B. This effectively prevents direct contact between the fourth sub-gate line 422 and the first pad 10, and between the fourth sub-gate line 422 and the second sub-gate line 412, thereby effectively preventing direct contact between the first gate line 41 and the second gate line 42, and avoiding short circuits. Furthermore, multiple fourth sub-gate lines 422 and multiple second sub-gate lines 412 are alternately arranged in the second direction B, which further optimizes the layout of the first gate line 41 and the second gate line 42, forming a more reasonable current path, making the current flow inside the cell more balanced, and effectively suppressing the effects of hot spot effect and potential induced degradation (PID) effect.

[0051] It should be noted that the first busbar 20, the first gate line 41, the second gate line 42, and the second busbar are all formed on the back side of the back contact cell (i.e., the backlight surface). The back side of the back contact cell may also include a doped layer.

[0052] It is understandable that, such as Figures 2 to 4 As shown, the doped layer includes a first doped layer 410 and a second doped layer 420 with opposite doping types, and the first doped layer 410 and the second doped layer 420 are insulated from each other by a spacer region 400. The first gate line 41 may be located on and in contact with the first doped layer 410, and the second gate line 42 may be located on and in contact with the second doped layer 420. The first gate line 41 is insulated from the second doped layer 420, and the second gate line 42 is insulated from the first doped layer 410.

[0053] Optionally, the first doped layer 410 is P-type and the second doped layer 420 is N-type; or, the first doped layer 410 is N-type and the second doped layer 420 is P-type.

[0054] In some alternative implementations, such as Figure 2 As shown, the back contact battery also includes: a third connecting grid line 50, which extends along the second direction B and connects to the first sub-grid line 411 and the first pad 10 respectively.

[0055] In the above embodiments, the electrical connection between the first sub-gate line 411 and the first pad 10 can be achieved not only through the first busbar line 20 and the first connecting gate line 30, but also through the third connecting gate line 50. That is, the two ends of the third connecting gate line 50 in the second direction B are electrically connected to the first sub-gate line 411 and the first pad 10, respectively. This not only shortens the current transmission path of the first sub-gate line 411, but also further enhances the overall current collection capability of the solar cell by adding additional connection points.

[0056] In some alternative implementations, such as Figure 3 and Figure 4 As shown, at least two first grid lines 41 are arranged in the first reserved area 102 and are respectively arranged at intervals on both sides of the first connecting grid line 30 in the second direction B.

[0057] In the above embodiment, the position near the first pad 10 where the second gate line 42 was originally provided is only provided with the first gate line 41. That is, in the first reserved area 102, in addition to the first connecting gate line 30, only the first gate line 41 connected to the first bus gate line 20 is provided. This means that there is no second gate line 42 with the opposite polarity to the first bus gate line 20 in the first reserved area 102. In this way, the risk of gate breakage caused by the opposite gate line is avoided, thereby simplifying the production process, reducing production costs, and improving the overall performance of the cell. In addition, this also means that only one type of charge carrier needs to be collected near the first reserved area 102. Therefore, it can be understood that only one type of doped layer needs to be formed at the position corresponding to the first reserved area 102 on the back side of the back contact cell. This effectively reduces the complexity of the entire back contact cell manufacturing process.

[0058] Furthermore, in the above embodiment, by providing at least two first grid lines 41 in the first reserved area 102, the current collection and transmission path of the first reserved area 102 is increased, thereby improving the photoelectric conversion efficiency of the back contact battery.

[0059] In some alternative implementations, such as Figure 3As shown, the first pad 10 has a first side and a second side opposite to each other in the first direction A, and the first side is located between the first bus gate 20 and the second side in the first direction A. The first connecting gate 30 connects the first side and the first bus gate 20. Multiple first gate lines 41 include a fifth sub-gate line 413, a sixth sub-gate line 414 and a seventh sub-gate line 415. In the second direction B, multiple fifth sub-gate lines 413 are arranged on both sides of the first pad 10 and connected to the first bus gate 20 in the first direction A. The sixth sub-gate line 414 is arranged on the side of the first pad 10 away from the first bus gate 20 and connected to the second side. Multiple seventh sub-gate lines 415 are arranged in the first reserved area. Within domain 102, the seventh sub-gate line 415 is connected to the first bus gate line 20 and the first side respectively; multiple second gate lines 42 include an eighth sub-gate line 423 and a ninth sub-gate line 424. In the second direction B, multiple eighth sub-gate lines 423 are arranged on both sides of the first pad 10 and are spaced apart from the first bus gate line 20 in the first direction A. The ninth sub-gate line 424 is arranged on the side of the first pad 10 away from the first bus gate line 20 and is spaced apart from the second side in the first direction A; in the second direction B, multiple fifth sub-gate lines 413 and multiple eighth sub-gate lines 423 are alternately spaced apart, and multiple sixth sub-gate lines 414 and multiple ninth sub-gate lines 424 are alternately spaced apart.

[0060] In the above embodiment, the eighth sub-grid line 423 and the ninth sub-grid line 424 are both located outside the first reserved area 102. That is, by abandoning the setting of the second grid line 42 in the first reserved area 102, the situation that the second grid line 42 will break in the first reserved area 102 and the vicinity of the first reserved area 102 is directly avoided, which effectively improves the reliability of the solar cell. In this configuration, any fifth sub-gate line 413 extends in the first direction A and is electrically connected to the first bus gate line 20. The first bus gate line 20 is electrically connected to the first pad 10 via the first connecting gate line 30. This allows photogenerated carriers collected by any fifth sub-gate line 413 to converge at the first pad 10 via the first bus gate line 20 and the first connecting gate line 30. Any sixth sub-gate line 414 extends in the first direction A and is electrically connected to the first pad 10. This allows photogenerated carriers collected by any sixth sub-gate line 414 to converge directly at the first pad 10. Any seventh sub-gate line 415 is disposed within the first reserved area 102 and is electrically connected to the first pad 10. This provides a collection path for photogenerated carriers within the first reserved area 102 and allows photogenerated carriers collected by any seventh sub-gate line 415 to converge at the first pad 10. Thus, an effective electrical connection is achieved between the first pad 10 and the first gate line 41, ensuring the effective transmission of the current collected by the first gate line 41. Furthermore, since multiple fifth sub-grid lines 413 are located on opposite sides of the first pad 10 in the second direction B, and multiple sixth sub-grid lines 414 are located on the side of the first pad 10 away from the first busbar 20 in the first direction A, multiple fifth sub-grid lines 413, multiple sixth sub-grid lines 414 and multiple seventh sub-grid lines 415 form a highly efficient current collection network, thereby improving the current collection efficiency of the solar cell.

[0061] Furthermore, in the above embodiment, any eighth sub-gate line 423 extends in the first direction A and is insulated from the first busbar 20 by a gap. This eighth sub-gate line 423 is also located on one side of the first pad 10 in the second direction B and is insulated from the fifth sub-gate line 413 by a gap. This effectively prevents direct contact between the eighth sub-gate line 423 and the first busbar 20, and between the eighth sub-gate line 423 and the fifth sub-gate line 413, thereby effectively preventing direct contact between the first gate line 41 and the second gate line 42 and avoiding short circuits. Furthermore, multiple fifth sub-gate lines 413 and multiple eighth sub-gate lines 423 are alternately arranged in the second direction B, further optimizing the layout of the first gate line 41 and the second gate line 42, forming a more reasonable current path, making the current flow inside the cell more balanced, and effectively suppressing the effects of hot spot effect and PID effect.

[0062] Similarly, in the above embodiments, any ninth sub-gate line 424 extends in the first direction A, is located on the side of the first pad 10 away from the first busbar 20 in the first direction A, and is insulated from the first pad 10 by a gap, and is insulated from the sixth sub-gate line 414 by a gap in the second direction B. This effectively prevents direct contact between the ninth sub-gate line 424 and the first pad 10, and between the ninth sub-gate line 424 and the sixth sub-gate line 414, thereby effectively preventing direct contact between the first gate line 41 and the second gate line 42, and avoiding short circuits. Furthermore, multiple ninth sub-gate lines 424 and multiple sixth sub-gate lines 414 are alternately arranged in the second direction B, which further optimizes the layout of the first gate line 41 and the second gate line 42, forming a more reasonable current path, making the current flow inside the cell more balanced, and effectively suppressing the effects of hot spot effect and PID effect.

[0063] Optionally, the first gate line 41 located in the first reserved area 102 may have a first extension line in the first direction A, and the second sub-gate line 412 located on the side of the first pad 10 away from the first bus gate line 20 may have a second extension line in the first direction A, with each first extension line having a second extension line overlapping it.

[0064] In some alternative implementations, such as Figure 3 As shown, the back contact battery also includes: a fourth connecting grid line 60, which extends along the second direction B and connects to the fifth sub-grid line 413 and the first pad 10 respectively.

[0065] In the above embodiments, the electrical connection between the fifth sub-gate line 413 and the first pad 10 can be achieved not only through the first busbar line 20 and the fourth connecting gate line 60, but also through the fourth connecting gate line 60. That is, the two ends of the fourth connecting gate line 60 in the second direction B are electrically connected to the fifth sub-gate line 413 and the first pad 10, respectively. This not only shortens the current transmission path of the fifth sub-gate line 413, but also further enhances the overall current collection capability of the solar cell by adding additional connection points.

[0066] In some alternative implementations, such as Figure 4As shown, the first pad 10 has a first side and a second side opposite to each other in the first direction A, and the first side is located between the first bus gate line 20 and the second side in the first direction A. The first connecting gate line 30 connects the first side and the first bus gate line 20. Multiple first gate lines 41 include a tenth sub-gate line 416, an eleventh sub-gate line 417, a twelfth sub-gate line 418, and a thirteenth sub-gate line 419. In the second direction B, multiple tenth sub-gate lines 416 are arranged on both sides of the first pad 10 and connected to the first bus gate line 20 in the first direction A. In the second direction B, the eleventh sub-gate line 417... The 10th sub-gate line 416 is disposed between the 10th sub-gate line 416 and the 10th pad, and is spaced apart from the 1st busbar line 20 in the first direction A. The 12th sub-gate line 418 is disposed on the side of the 10th pad away from the 1st busbar line 20 and is connected to the second side in the first direction A. Multiple 13th sub-gate lines 419 are disposed in the first reserved area 102, and the 13th sub-gate lines 419 are respectively connected to the 10th busbar line 20 and the first side. The back contact battery also includes: a fifth connecting gate line 70, which extends along the second direction B and connects the 11th sub-gate line 417 and the 10th pad.

[0067] In the above embodiment, only a thirteenth sub-grid line 419 with the same polarity as the first busbar line 20 is provided in the first reserved area 102. In contrast, there is no second grid line 42 with the opposite polarity to the first busbar line 20 in the first reserved area 102. In this way, the risk of grid breakage caused by the opposite grid line is avoided, thereby simplifying the production process, reducing production costs, and improving the overall performance of the battery cell. In this configuration, any tenth sub-gate line 416 extends in the first direction A and is electrically connected to the first bus gate line 20. The first bus gate line 20 is electrically connected to the first pad 10 via the first connecting gate line 30. This ensures that photogenerated carriers collected by any tenth sub-gate line 416 will converge to the first pad 10 via the first bus gate line 20 and the first connecting gate line 30. Any eleventh sub-gate line 417 extends in the first direction A, is spaced apart from the first bus gate line 20 in the first direction A, and is electrically connected to the first pad 10 in the second direction B via the fifth connecting gate line 70. This ensures that the eleventh sub-gate line 417 and the first pad 10... Based on the effective electrical connection, a certain space is reserved between the eleventh sub-gate line 417 and the first bus gate line 20 in the first direction A; any twelfth sub-gate line 418 extends in the first direction A and is electrically connected to the first pad 10, which allows the photogenerated carriers collected by any twelfth sub-gate line 418 to directly converge at the first pad 10; any thirteenth sub-gate line 419 is arranged in the first reserved area 102 and is electrically connected to the first pad 10, which provides a collection path for the photogenerated carriers in the first reserved area 102 and allows the photogenerated carriers collected by any thirteenth sub-gate line 419 to converge at the first pad 10. In this way, the effective electrical connection between the first pad 10 and the first gate line 41 is achieved, ensuring the effective transmission of the current collected by the first gate line 41. Furthermore, since multiple tenth sub-grid lines 416 and multiple eleventh sub-grid lines 417 are located on opposite sides of the first pad 10 in the second direction B, and multiple twelfth sub-grid lines 418 are located on the side of the first pad 10 away from the first busbar 20 in the first direction A, multiple tenth sub-grid lines 416, multiple eleventh sub-grid lines 417, multiple twelfth sub-grid lines 418 and multiple thirteenth sub-grid lines 419 form a highly efficient current collection network, thereby improving the current collection efficiency of the solar cell.

[0068] In some optional embodiments, the multiple second gate lines 42 include a fourteenth sub-gate line 425 and a fifteenth sub-gate line 426. The fourteenth sub-gate line 425 is disposed on both sides of the first pad 10 in the second direction B and spaced apart from the first bus gate line 20 in the first direction A. In the first direction A, the fourteenth sub-gate line 425 has a bend 4251 at one end near the first bus gate line 20, and the bend 4251 extends from the end of the fourteenth sub-gate line 425 near the first bus gate line 20 along the second direction B towards the first reserved area 10. 2. In the first direction A, the bending portion 4251 separates the first bus gate line 20 and the eleventh sub-gate line 417. The fifteenth sub-gate line 426 is arranged on the side of the first pad 10 away from the first bus gate line 20 and is spaced apart from the second side in the first direction A. In the second direction B, the portion of the fourteenth sub-gate line 425 other than the bending portion 4251 is located between the tenth sub-gate line 416 and the eleventh sub-gate line 417. In the second direction B, multiple twelfth sub-gate lines 418 and multiple fifteenth sub-gate lines 426 are alternately spaced.

[0069] In the above embodiment, any fourteenth sub-gate line 425, excluding the bend 4251, extends in the first direction A and is insulated from the first busbar 20 by a gap. Furthermore, the fourteenth sub-gate line 425 is located on one side of the first pad 10 in the second direction B and is insulated from the tenth sub-gate line 416 by a gap. This effectively prevents direct contact between the fourteenth sub-gate line 425 and the first busbar 20, as well as between the fourteenth sub-gate line 425 and the tenth sub-gate line 416, avoiding short circuits. Furthermore, multiple tenth sub-gate lines 416 and multiple fourteenth sub-gate lines 425 are alternately arranged in the second direction B, further optimizing the layout of the first gate line 41 and the second gate line 42, forming a more reasonable current path, making the current flow inside the cell more balanced, and effectively suppressing the effects of hot spot and PID effects.

[0070] Furthermore, the bend 4251 of any fourteenth sub-gate line 425 extends from the end of the fourteenth sub-gate line 425 near the first busbar 20 along the second direction B towards the first reserved area 102. Given that a certain space is reserved between the eleventh sub-gate line 417 and the first busbar 20 in the first direction A, the bend 4251 can be located within this reserved space, that is, the bend 4251 in the first direction A separates the first busbar 20 and the eleventh sub-gate line 417. Thus, while ensuring that the photogenerated carriers collected by the first gate line 41 can be effectively collected at the first pad 10, this embodiment, by providing the bend 4251 to the fourteenth sub-gate line 425, increases the carrier collection area corresponding to the second gate line 42 near the first reserved area 102, thereby further enhancing the uniformity of current collection, avoiding current loss due to edge effects, and improving the overall electrical performance and reliability of the solar cell.

[0071] It should be noted that both the first busbar 20 and the eleventh sub-busbar 417 can be located on and in contact with the first doped layer 410, and the bending portion 4251 can be located on and in contact with the second doped layer 420 of the back contact battery. The first doped layer 410 and the second doped layer 420 are insulated by the spacer region 400. Therefore, when the bending portion 4251 is located in a certain space reserved in the first direction A between the eleventh sub-busbar 417 and the first busbar 20, the reserved space can include the spacer region 400 between the first doped layer 410 and the second doped layer 420. Thus, it can be considered that the bending portion 4251 separates the first busbar 20 and the eleventh sub-busbar 417 in the first direction A.

[0072] In some alternative embodiments, a stacked battery is provided, comprising a first battery and a second battery stacked together, wherein one of the first battery and the second battery is a back contact battery as described above.

[0073] In the above embodiments, since the stacked battery includes any of the aforementioned back contact batteries, and the aforementioned back contact batteries do not consider the setting of the second doped layer in the area corresponding to the first reserved area, the possibility of setting the second gate line in the first reserved area is directly avoided. Thus, the phenomenon of "island" corresponding to the second doped layer in the first reserved area due to the second gate line breaking in the first reserved area is avoided. In this way, the hot spot problem caused by the "island" is directly avoided, thereby solving the hot spot problem caused by the doped area in contact with the broken gate forming an "island". Therefore, the stacked battery has high reliability.

[0074] For example, the above-mentioned stacked battery is a crystalline silicon-perovskite battery, that is, one of the first battery and the second battery is a crystalline silicon battery and the other is a perovskite battery, and the crystalline silicon battery is any of the above-mentioned back contact batteries.

[0075] For example, when the first battery is any of the aforementioned back-contact batteries, the second battery is a perovskite battery; when the second battery is any of the aforementioned back-contact batteries, the first battery is a perovskite battery.

[0076] In some alternative embodiments, a photovoltaic module is provided, comprising: a battery string consisting of a plurality of back-contact batteries as described above or stacked batteries 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.

[0077] Similarly, in the above embodiments, since the photovoltaic module includes any of the aforementioned back contact cells or a stacked cell including any of the aforementioned back contact cells, and the aforementioned back contact cells do not take into account the setting of the second doped layer in the area corresponding to the first reserved area, the possibility of setting the second grid line in the first reserved area is directly avoided. Thus, the phenomenon of "island" corresponding to the second doped layer in the first reserved area due to the second grid line breaking in the first reserved area will not occur. In this way, the hot spot problem caused by the "island" is directly avoided, thereby solving the hot spot problem caused by the doped area in contact with the broken grid forming an "island". Therefore, the photovoltaic module has high reliability.

[0078] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0079] Those skilled in the art will understand that the above embodiments are specific examples of implementing this application, and in practical applications, various changes in form and detail can be made without departing from the spirit and scope of this application. Any person skilled in the art can make various alterations and modifications without departing from the spirit and scope of this application; therefore, the scope of protection of this application should be determined by the scope defined in the claims.

Claims

1. A back-contact battery, characterized in that, The back contact battery includes: A first bus gate and a first pad are provided at intervals in a first direction, and the first bus gate extends along a second direction, the first direction intersecting the second direction; A first connecting gate line is located within a first reserved area and extends along the first direction to connect the first bus gate line and the first pad. The first reserved area is located between the first pad and the first bus gate line, and the orthographic projection of the first pad on the first bus gate line is located within the orthographic projection of the first reserved area on the first bus gate line. Multiple gate lines are provided, with the gate lines and the first pad located on the same side of the first bus gate line. Each gate line includes a first gate line and a second gate line with opposite polarities. The multiple first gate lines and the multiple second gate lines are alternately spaced along the second direction and extend along the first direction. The first gate lines are electrically connected to the first bus gate line or to the first pad. The second gate lines are provided outside the first reserved area and are insulated from the first bus gate line and the first pad, respectively. Alternatively, the first gate lines are provided outside the first reserved area, or at least two first gate lines are provided within the first reserved area and spaced apart on both sides of the first connecting gate line in the second direction. The first gate lines provided within the first reserved area correspond one-to-one with the first gate lines located on the side of the first pad away from the first bus gate line and are collinear. The doped layer includes a first doped layer and a second doped layer spaced apart, wherein the first reserved area is a portion of the surface of the first doped layer.

2. The back contact battery according to claim 1, characterized in that, The back contact battery also includes: The second bus gate and the second pad are spaced apart in the first direction. The second bus gate extends along the second direction. Multiple gates and the second pad are located on the same side of the second bus gate. The first pad and the second pad are spaced apart between the first bus gate and the second bus gate in the first direction. The second connecting gate line is located within the second reserved area and extends along the first direction to connect the second bus gate line and the second pad. The second reserved area is located between the second pad and the second bus gate line, and the orthographic projection of the second pad on the second bus gate line partially overlaps with the orthographic projection of the second reserved area on the second bus gate line. The first gate line is located outside the second reserved area and is insulated from the second bus gate line and the second pad respectively. The second gate line is electrically connected to the second bus gate line or the second gate line is electrically connected to the second pad.

3. The back contact battery according to claim 1, characterized in that, The first grid line is laid outside the first reserved area; The first pad has a first side and a second side opposite each other in the first direction, and the first side is located between the first bus gate and the second side in the first direction, and the first connecting gate connects the first side and the first bus gate; The plurality of first gate lines include first sub-gate lines and second sub-gate lines. In the second direction, the plurality of first sub-gate lines are arranged on both sides of the first pad and connected to the first bus gate line in the first direction. The second sub-gate lines are arranged on the side of the first pad away from the first bus gate line and connected to the second side in the first direction. The multiple second gate lines include third sub-gate lines and fourth sub-gate lines. In the second direction, the multiple third sub-gate lines are arranged on both sides of the first pad and are spaced apart from the first bus gate line in the first direction. The fourth sub-gate lines are arranged on the side of the first pad away from the first bus gate line and are spaced apart from the second side in the first direction. In the second direction, multiple first sub-gate lines and multiple third sub-gate lines are alternately spaced, and multiple second sub-gate lines and multiple fourth sub-gate lines are alternately spaced.

4. The back contact battery according to claim 3, characterized in that, The back contact battery further includes: a third connecting grid line, which extends along the second direction and connects to the first sub-grid line and the first pad respectively.

5. The back contact battery according to claim 1, characterized in that, At least two of the first grid lines are arranged in the first reserved area and are respectively spaced apart on both sides of the first connecting grid line in the second direction; The first pad has a first side and a second side opposite each other in the first direction, and the first side is located between the first bus gate and the second side in the first direction, and the first connecting gate connects the first side and the first bus gate; The multiple first gate lines include a fifth sub-gate line, a sixth sub-gate line, and a seventh sub-gate line. In the second direction, the multiple fifth sub-gate lines are arranged on both sides of the first pad and connected to the first bus gate line in the first direction. The sixth sub-gate line is arranged on the side of the first pad away from the first bus gate line and connected to the second side. The multiple seventh sub-gate lines are arranged in the first reserved area, and the seventh sub-gate lines are respectively connected to the first bus gate line and the first side. The multiple second gate lines include an eighth sub-gate line and a ninth sub-gate line. In the second direction, the multiple eighth sub-gate lines are arranged on both sides of the first pad and are spaced apart from the first bus gate line in the first direction. The ninth sub-gate line is arranged on the side of the first pad away from the first bus gate line and is spaced apart from the second side in the first direction. In the second direction, multiple fifth sub-gate lines and multiple eighth sub-gate lines are alternately spaced, and multiple sixth sub-gate lines and multiple ninth sub-gate lines are alternately spaced.

6. The back contact battery according to claim 5, characterized in that, The back contact battery further includes: a fourth connecting grid line, which extends along the second direction and connects to the fifth sub-grid line and the first pad respectively.

7. The back contact battery according to claim 1, characterized in that, The first pad has a first side and a second side opposite each other in the first direction, and the first side is located between the first bus gate and the second side in the first direction, and the first connecting gate connects the first side and the first bus gate; The multiple first gate lines include a tenth sub-gate line, an eleventh sub-gate line, a twelfth sub-gate line, and a thirteenth sub-gate line. In the second direction, the multiple tenth sub-gate lines are arranged on both sides of the first pad and connected to the first bus gate line in the first direction. In the second direction, the eleventh sub-gate line is arranged between the tenth sub-gate line and the first pad and is spaced apart from the first bus gate line in the first direction. The twelfth sub-gate line is arranged on the side of the first pad away from the first bus gate line and is connected to the second side in the first direction. The multiple thirteenth sub-gate lines are arranged in the first reserved area, and the thirteenth sub-gate lines are respectively connected to the first bus gate line and the first side. The back contact battery also includes: The fifth connecting gate line extends along the second direction and connects the eleventh sub-gate line and the first pad.

8. The back contact battery according to claim 7, characterized in that, The multiple second gate lines include a fourteenth sub-gate line and a fifteenth sub-gate line. In the second direction, the fourteenth sub-gate line is arranged on both sides of the first pad and is spaced apart from the first bus gate line in the first direction. In the first direction, the fourteenth sub-gate line has a bend at one end near the first bus gate line, and the bend extends from the end of the fourteenth sub-gate line near the first bus gate line along the second direction toward the first reserved area. In the first direction, the bend separates the first bus gate line and the eleventh sub-gate line. The fifteenth sub-gate line is arranged on the side of the first pad away from the first bus gate line and is spaced apart from the second side in the first direction. In the second direction, the portion of the fourteenth sub-grid line excluding the bend is located between the tenth sub-grid line and the eleventh sub-grid line, and in the second direction, multiple twelfth sub-grid lines and multiple fifteenth sub-grid lines are alternately spaced.

9. A stacked battery, characterized in that, It includes a first battery and a second battery stacked together, wherein the first battery is a back contact battery as described in any one of claims 1 to 8, and the second battery is a perovskite battery.

10. A photovoltaic module, characterized in that, include: A battery string is formed by connecting multiple back-contact batteries as described in any one of claims 1 to 8 or stacked batteries as described in claim 9; An encapsulating film is used to cover the surface of the battery string; A cover plate is used to cover the surface of the encapsulating film that faces away from the battery string.

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