Battery string, battery assembly and photovoltaic system

Abstract

The utility model is suitable for the technical field of solar cells, and provides a cell string, a cell assembly and a photovoltaic system. The battery string comprises a plurality of electric connecting pieces and a plurality of back contact batteries, and each back contact battery comprises a silicon substrate and a plurality of auxiliary grid lines; the plurality of auxiliary grid lines comprise a plurality of first auxiliary grids and a plurality of second auxiliary grids; the first auxiliary grid and the second auxiliary grid are arranged on the silicon substrate and extend in the first direction. The first auxiliary grids and the second auxiliary grids are spaced from each other and are alternately arranged along a first direction to form a row of auxiliary grid groups, the plurality of rows of auxiliary grid groups are spaced from each other and are sequentially arranged along a second direction, and the second direction is crossed with the first direction; the plurality of electric connecting pieces are spaced from one another, are arranged along a first direction and extend along a second direction; the electric connecting piece is connected with two adjacent back contact batteries in the second direction, and at least one electric connecting piece is electrically connected with the first auxiliary grid of each row in the plurality of rows of adjacent auxiliary grid groups in one back contact battery and is electrically connected with the second auxiliary grid of each row in the plurality of rows of adjacent auxiliary grid groups in the other back contact battery.

Description

Technical Field

[0001] The present application belongs to the technical field of solar cells, and in particular relates to a battery string, a battery assembly and a photovoltaic system. Background Art

[0002] A solar cell in which electrodes of two polarities are formed on the back of the cell is a back-contact cell. In the back-contact cell of the related art, the two polarities of the sub-grids are usually arranged alternately in sequence in the width direction of the sub-grid, and the sub-grid of each polarity extends in the length direction of the sub-grid. Usually, electrical connectors such as welding strips and conductive wires extending along the width direction of the sub-grid can be used to connect the sub-grid of one polarity in a back-contact cell and the sub-grid of another polarity in an adjacent back-contact cell to form a cell string. In a back-contact cell, an insulating member can be used to electrically isolate the electrical connector from the sub-grid of non-corresponding polarity. However, in this case, the partial absence or offset of the insulating member can easily lead to a short circuit. Moreover, the insulating member provided on the non-corresponding sub-grid is located at a higher position, which can easily lead to an unstable connection between the electrical connector and the sub-grid of the corresponding polarity.

[0003] In the back contact battery of the related art, it is also possible that the insulating glue is not provided at the connection between the electrical connector and the non-corresponding auxiliary grid, but the non-corresponding auxiliary grid is disconnected to prevent the electrical connector from contacting the non-corresponding auxiliary grid. However, in this way, the connection points between the electrical connector and the back contact battery are fewer, the connection tension is smaller, and the risk of unstable connection is higher.

[0004] Based on this, how to reduce the risk of short circuit or unstable connection between the back contact battery and the electrical connector has become an urgent problem to be solved. Utility Model Content

[0005] The present application provides a battery string, a battery assembly and a photovoltaic system, aiming to solve the problem of how to reduce the risk of short circuit or unstable connection between the back contact battery and the electrical connector.

[0006] The battery string provided in the present application includes a plurality of electrical connectors and a plurality of back-contact batteries, wherein the back-contact batteries include a silicon substrate and a plurality of secondary grid lines;

[0007] The plurality of auxiliary gate lines include a plurality of first auxiliary gates and a plurality of second auxiliary gates; the first auxiliary gates and the second auxiliary gates are arranged on the silicon substrate and extend along a first direction; the first auxiliary gates and the second auxiliary gates are spaced from each other and alternately arranged along the first direction to form a row of auxiliary gate groups, and the plurality of rows of the auxiliary gate groups are spaced from each other and sequentially arranged along a second direction, and the second direction intersects the first direction;

[0008] A plurality of the electrical connectors are spaced apart from each other, arranged along the first direction, and extend along the second direction; the electrical connectors connect two adjacent back contact cells in the second direction, and at least one of the electrical connectors is electrically connected to the first sub-grids in each row of several adjacent sub-grid groups in one back contact cell, and is electrically connected to the second sub-grids in each row of several adjacent sub-grid groups in another back contact cell.

[0009] The battery assembly provided in the present application includes any of the battery strings described above.

[0010] The photovoltaic system provided in the present application includes the above-mentioned battery assembly.

[0011] In the battery string, battery assembly and photovoltaic system of the embodiments of the present application, since at least one electrical connector is electrically connected to the first auxiliary grid in each row of several adjacent auxiliary grid groups in one back-contact battery, and is electrically connected to the second auxiliary grid in each row of several adjacent auxiliary grid groups in another back-contact battery, at least one electrical connector is connected to the auxiliary grid of corresponding polarity in each row of the several adjacent auxiliary grid groups, so that the electrical connector has more connection points with the auxiliary grid as a whole, and the overall connection tension between the back-contact battery and the electrical connector is increased. In addition, since there is no need to set an insulating member on the non-corresponding auxiliary grid, the height of the electrical connector will not be raised by the insulating member, thereby reducing the risk of unstable connection between the back-contact battery and the electrical connector. Moreover, in this way, the electrical connector does not need to be electrically isolated from the non-corresponding auxiliary grid by the insulating member, which can reduce the risk of short circuit caused by partial loss or offset of the insulating member. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 is a schematic diagram of the structure of a battery string according to an embodiment of the present application;

[0013] Figure 2 is a schematic structural diagram of a back-contact battery in a battery string according to an embodiment of the present application;

[0014] Figure 3 is a schematic structural diagram of a back-contact battery in a battery string according to an embodiment of the present application;

[0015] Figure 4 is a schematic structural diagram of a back-contact battery in a battery string according to an embodiment of the present application;

[0016] Figure 5 is a schematic structural diagram of a back-contact battery in a battery string according to an embodiment of the present application;

[0017] Figure 6 is a schematic structural diagram of a back-contact battery in a battery string according to an embodiment of the present application;

[0018] Figure 7is a schematic structural diagram of a back-contact battery in a battery string according to an embodiment of the present application;

[0019] Figure 8 is a schematic structural diagram of a back-contact battery in a battery string according to an embodiment of the present application;

[0020] Fig. 9 is a schematic structural diagram of a back-contact battery in a battery string according to an embodiment of the present application;

[0021] Fig.10 is a schematic structural diagram of a back-contact battery in a battery string according to an embodiment of the present application;

[0022] Fig.11 is a schematic structural diagram of a back-contact battery in a battery string according to an embodiment of the present application;

[0023] Fig.12 is a schematic structural diagram of a partial area of ​​a back contact battery in a battery string according to an embodiment of the present application;

[0024] Fig.13 is a schematic structural diagram of a partial area of ​​a back contact battery in a battery string according to an embodiment of the present application;

[0025] Fig.14 is a schematic structural diagram of a partial area of ​​a back contact battery in a battery string according to an embodiment of the present application;

[0026] Fig.15 is a schematic structural diagram of a partial area of ​​a back contact battery in a battery string according to an embodiment of the present application;

[0027] Description of main component symbols:

[0028] A battery string 100, a back contact battery 10, a silicon substrate 101, a first doped region 1001, a second doped region 1002, a tunneling layer 1003, a dielectric film layer 1004, a first sub-gate 11, a first heterosexual overlapping portion 111, a first protruding portion 112, a second heterosexual overlapping portion 113, a second protruding portion 114, a second sub-gate 12, a third heterosexual overlapping portion 121, a third protruding portion 122, a fourth heterosexual overlapping portion 123, a fourth protruding portion 124; a first conductive grid 131, a second conductive grid 132; a first connection area 110, a second connection area 120; a first electrical connector 21, a second electrical connector 22. DETAILED DESCRIPTION

[0029] In order to make the purpose, technical solutions and advantages of the present application clearer, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements with the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application, and should not be construed as limiting the present application. In addition, it should be understood that the specific embodiments described herein are only used to explain the present application and are not intended to limit the present application.

[0030] In the description of the present application, it should be understood that the terms "length", "width", "up", "down", "left", "right", "horizontal", "top", "bottom", etc., indicating the orientation or position relationship are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0031] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of this application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0032] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or mutual communication; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0033] In the present application, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0034] The disclosure below provides many different embodiments or examples to realize the different structures of the present application. In order to simplify the disclosure of the present application, the parts and settings of specific examples are described below. Of course, they are only examples, and the purpose is not to limit the present application. In addition, the present application can repeat reference numbers and / or reference letters in different examples, and this repetition is for the purpose of simplification and clarity, and does not indicate the relationship between the various embodiments and / or settings discussed in itself. In addition, the various specific processes and examples of materials provided by the present application, but those of ordinary skill in the art can be aware of the application of other processes and / or the use scenarios of other materials.

[0035] In the present application, since at least one electrical connector is electrically connected to the first auxiliary grid in each row of several adjacent auxiliary grid groups in one back contact battery, and is electrically connected to the second auxiliary grid in each row of several adjacent auxiliary grid groups in another back contact battery, at least one electrical connector is connected to the auxiliary grid of corresponding polarity in each row of the several adjacent auxiliary grid groups, so that the electrical connector has more connection points with the auxiliary grid as a whole, and the overall connection tension between the back contact battery and the electrical connector is increased. In addition, there is no need to set an insulating member on the non-corresponding auxiliary grid, so the height of the electrical connector will not be raised by the insulating member, thereby reducing the risk of unstable connection between the back contact battery and the electrical connector. Moreover, in this way, the electrical connector does not need to be electrically isolated from the non-corresponding auxiliary grid by the insulating member, which can reduce the risk of short circuit caused by partial loss or offset of the insulating member.

[0036] Embodiment 1

[0037] See also Figure 1 , Figure 2 , Figure 3 , Figure 4 and Figure 5 The battery string 100 of the embodiment of the present application includes a plurality of electrical connectors and a plurality of back-contact batteries 10, and the back-contact batteries 10 include a silicon substrate 101 and a plurality of secondary grid lines;

[0038] The plurality of auxiliary gate lines include a plurality of first auxiliary gates 11 and a plurality of second auxiliary gates 12; the first auxiliary gates 11 and the second auxiliary gates 12 are arranged on the silicon substrate 101 and extend along a first direction; the first auxiliary gates 11 and the second auxiliary gates 12 are spaced from each other and alternately arranged along the first direction to form a row of auxiliary gate groups, and the plurality of rows of auxiliary gate groups are spaced from each other and sequentially arranged along a second direction, and the second direction intersects the first direction;

[0039] A plurality of electrical connectors are spaced apart from each other, arranged along a first direction, and extend along a second direction; the electrical connectors connect two adjacent back contact cells 10 in the second direction, and at least one electrical connector is electrically connected to a first sub-grid 11 in each row of a plurality of adjacent sub-grid groups in one back contact cell 10, and is electrically connected to a second sub-grid 12 in each row of a plurality of adjacent sub-grid groups in another back contact cell 10.

[0040] In the battery string 100 of the embodiment of the present application, since at least one electrical connector is electrically connected to the first auxiliary grid 11 of each row in a plurality of adjacent auxiliary grid groups in one back contact battery 10, and is electrically connected to the second auxiliary grid 12 of each row in a plurality of adjacent auxiliary grid groups in another back contact battery 10, at least one electrical connector is connected to the auxiliary grid of corresponding polarity in each row in the plurality of adjacent auxiliary grid groups, so that the electrical connector has more connection points with the auxiliary grid as a whole, and the overall connection tension between the back contact battery 10 and the electrical connector is increased. In addition, since there is no need to set an insulating member on the non-corresponding auxiliary grid, the height of the electrical connector will not be raised by the insulating member, thereby reducing the risk of unstable connection between the back contact battery 10 and the electrical connector. Moreover, in this way, the electrical connector does not need to be electrically isolated from the non-corresponding auxiliary grid by the insulating member, and the risk of short circuit caused by partial loss or offset of the insulating member can be reduced.

[0041] Specifically, at least one electrical connector is electrically connected to one first sub-grid 11 in each row of several adjacent sub-grid groups in one back-contact cell 10, and is electrically connected to one second sub-grid 12 in each row of several adjacent sub-grid groups in another back-contact cell 10. It can be understood that at least one electrical connector can also be electrically connected to multiple first sub-grids 11 in each row of several adjacent sub-grid groups in one back-contact cell 10, and is electrically connected to multiple second sub-grids 12 in each row of several adjacent sub-grid groups in another back-contact cell 10.

[0042] Specifically, the electrical connector includes a first electrical connector 21 and a second electrical connector 22, and the first electrical connector 21 and the second electrical connector 22 are alternately arranged along the first direction. In a back contact cell 10, the first electrical connector 21 is electrically connected to the first sub-grid 11 of each row in a plurality of adjacent sub-grid groups, and / or the second electrical connector 22 is electrically connected to the second sub-grid 12 of each row in a plurality of adjacent sub-grid groups.

[0043] Please note that the first electrical connector 21 and the second electrical connector 22 are respectively connected to two sub-grids of different polarities in one back-contact cell 10, namely, the first sub-grid 11 and the second sub-grid 12. Therefore, the first electrical connector 21 and the second electrical connector 22 discussed below are all in the case of the same back-contact cell 10. For two adjacent back-contact cells 10, the first electrical connector 21 and the second electrical connector 22 are both connected to the sub-grid of one polarity in one back-contact cell 10 and the sub-grid of another polarity in the other back-contact cell 10. Therefore, the explanation and description of the first electrical connector 21 and the second electrical connector 22 can refer to each other, and the explanation and description of the relationship between the two electrical connectors and the two sub-grids can also refer to each other.

[0044] In this embodiment, the first electrical connection member 21 is electrically connected to the first sub-grid 11 of each row in the several rows of adjacent sub-grid groups, and the second electrical connection member 22 is electrically connected to the second sub-grid 12 of each row in the several rows of adjacent sub-grid groups. Specifically, the first electrical connection member 21 is electrically connected to one first sub-grid 11 in each row of the sub-grid groups, and the second electrical connection member 22 is electrically connected to one second sub-grid 12 in each row of the sub-grid groups. In this way, both electrical connections are electrically connected to one sub-grid of corresponding polarity in each row of the sub-grid groups, which can further increase the number of connection points and further reduce the risk of unstable connection and short circuit.

[0045] It is understood that in other embodiments, the first electrical connector 21 may be electrically connected to the first auxiliary grid 11 of each row in several adjacent auxiliary grid groups, and the second electrical connector 22 may not be electrically connected to the second auxiliary grid 12 of each row in several adjacent auxiliary grid groups; it is also possible that the first electrical connector 21 is not electrically connected to the first auxiliary grid 11 of each row in several adjacent auxiliary grid groups, and / or the second electrical connector 22 is electrically connected to the second auxiliary grid 12 of each row in several adjacent auxiliary grid groups. It is understood that in a back contact battery 10, as long as an electrical connector of one polarity is electrically connected to the auxiliary grid of the corresponding polarity of each row in several adjacent auxiliary grid groups, the risk of unstable connection and the risk of short circuit can be reduced. The electrical connectors of two polarities are electrically connected to an auxiliary grid of the corresponding polarity in each row in several adjacent auxiliary grid groups, respectively, which has a better effect of reducing the risk of unstable connection and the risk of short circuit.

[0046] Specifically, the back contact cell 10 can be a sliced ​​cell formed by cutting a whole cell, such as Figure 1 and Figure 2 As shown; the back contact battery 10 can also be a whole battery that has not been cut, such as Figure 3 and Figure 4 As shown. No limitation is given here. Figure 3 and Figure 4 In the example of , the whole back contact battery 10 can be cut along the cutting line to obtain a sliced ​​battery. Figure 3In the example of , the back contact cell 10 is asymmetrical along the cutting line. Figure 4 In the example shown in FIG. 1 , the back contact cell 10 is symmetrical along the cutting line.

[0047] Specifically, the silicon base 101 may include a silicon substrate, a first doping layer, a second doping layer, and a dielectric film layer 1004 .

[0048] Furthermore, the silicon substrate may be a P-type silicon substrate or an N-type silicon substrate, a single crystal silicon substrate or a polycrystalline silicon substrate. The specific form of the silicon substrate is not limited here.

[0049] Furthermore, the first doped layer and the second doped layer are arranged on the silicon substrate. The first doped layer and the second doped layer have different doping polarities. The two doped layers can be formed by diffusion into the silicon substrate or by depositing a film layer on the silicon substrate.

[0050] It can be understood that in the thickness direction of the back contact battery 10, the first doped layer is stacked on the silicon substrate, and the second doped layer is stacked on the silicon substrate. On the plane perpendicular to the thickness direction of the back contact battery 10, the first doped layer and the second doped layer are distributed in different regions, corresponding to the first doped region 1001 and the second doped region 1002, respectively. Fig.12 , Fig.14 and Fig.15 shown.

[0051] For further information, see Fig.13 , the dielectric film layer 1004 covers the first doping layer and the second doping layer, the first sub-gate 11 passes through the dielectric film layer 1004 to contact the first doping layer, and the second sub-gate 12 passes through the dielectric film layer 1004 to contact the second doping layer. In this way, the dielectric film layer 1004 is used to achieve electrical isolation between the first doping layer and the second doping layer, and the dielectric film layer 1004 can also be used to reduce light reflection and recombination. The dielectric film layer 1004 is also provided between at least one pair of adjacent first doping regions 1001 and second doping regions 1002, and the dielectric film layer 1004 electrically isolates the first doping region 1001 and the second doping region 1002. Please note that in order to better display the first doping region 1001 and the second doping region 1002, Fig.13 The portion of the dielectric film layer 1004 covering the first doping region 1001 and the second doping region 1002 is omitted.

[0052] Specifically, the first sub-gate 11 and the second sub-gate 12 may be distributed in the entire area of ​​the silicon substrate 101. Figure 1 , Figure 2 , Figure 3 As shown; the first sub-gate 11 and the second sub-gate 12 may be distributed in a partial area of ​​the silicon substrate 101, such as Figure 5 As shown. Figure 5In the example, the first sub-gate 11 and the second sub-gate 12 are distributed in the right area of ​​the silicon substrate 101. It can be understood that the left area of ​​the silicon substrate 101 may be distributed with other sub-gates, a main gate, or no gate line.

[0053] Specifically, the first auxiliary gate 11 and the second auxiliary gate 12 have different polarities. The first auxiliary gate 11 corresponds to the first doping layer and the first doping region 1001 , and the second auxiliary gate 12 corresponds to the second doping layer and the second doping region 1002 .

[0054] Specifically, the number of the first sub-grids 11 may be 1, 2, 3, 4 or other numbers. The number of the second sub-grids 12 may be 1, 2, 3, 4 or other numbers. No limitation is made here. The number of the first sub-grids 11 and the number of the second sub-grids 12 may be the same or different.

[0055] Specifically, the first auxiliary grid 11 extends along the first direction, which means that the overall extension direction of the first auxiliary grid 11 is the first direction. This does not represent a limitation on the specific form of the first auxiliary grid 11. In this embodiment, the first auxiliary grid 11 is linear, and the extension direction of the first auxiliary grid 11, that is, the first direction, is the length direction of the first auxiliary grid 11. In other embodiments, the first auxiliary grid 11 may also be wavy, folded, or other forms. In addition, the forms of several first auxiliary grids 11 may be the same or different.

[0056] Similarly, the second auxiliary grid 12 extends along the first direction, which means that the overall extension direction of the second auxiliary grid 12 is the first direction. This does not represent a limitation on the specific form of the second auxiliary grid 12. In this embodiment, the second auxiliary grid 12 is linear, and the extension direction of the second auxiliary grid 12, that is, the first direction, is the length direction of the second auxiliary grid 12. In other embodiments, the second auxiliary grid 12 may also be wavy, folded, or other forms. In addition, the forms of several second auxiliary grids 12 may be the same or different.

[0057] Specifically, “the first sub-grids 11 and the second sub-grids 12 are spaced apart from each other and arranged alternately along the first direction” means that along the first direction, the second sub-grid 12 is arranged between two adjacent first sub-grids 11, the first sub-grid 11 is arranged between two adjacent second sub-grids 12, and a gap is formed between adjacent first sub-grids 11 and second sub-grids 12. In this way, a row of sub-grid groups is formed in the first direction.

[0058] Furthermore, the sub-grids in a row of sub-grid groups have the same width, and the center lines along the first direction are located in the same straight line. In this way, the arrangement of the two sub-grids is more regular, which is convenient for improving the manufacturing efficiency and is also conducive to fully collecting carriers. It can be understood that in other embodiments, the sub-grids in a row of sub-grid groups may have different widths; it may also be that some of the sub-grids in a row of sub-grid groups are located in the same straight line along the center line of the first direction, and the remaining sub-grids are not located on the straight line along the center line of the first direction; it may also be that all the sub-grids in a row of sub-grid groups are not located in the same straight line along the center line of the first direction.

[0059] Furthermore, in a row of sub-gate groups, the spacings between adjacent first sub-gates 11 and second sub-gates 12 are the same. In this way, the arrangement of the two sub-gates is more regular, which is convenient for improving the manufacturing efficiency and is also conducive to fully collecting carriers. It can be understood that in other embodiments, in a row of sub-gate groups, the spacings between adjacent first sub-gates 11 and second sub-gates 12 are different; or in a row of sub-gate groups, the spacings between adjacent first sub-gates 11 and second sub-gates 12 are partially the same, and the remaining spacings are different from the same spacings.

[0060] Specifically, “a plurality of rows of sub-grid groups are spaced apart from each other and sequentially arranged along the second direction” means that a gap is formed between two adjacent rows of sub-grid groups, and a plurality of rows of sub-grid groups are sequentially arranged along the second direction.

[0061] Furthermore, the number of the auxiliary grid groups may be 1 row, 2 rows, 3 rows, 4 rows or other numbers, which are not limited here.

[0062] Furthermore, any pair of adjacent two rows of sub-grid groups have the same spacing. In this way, the arrangement of the sub-grid groups is more regular, which is convenient for improving the manufacturing efficiency and is also conducive to fully collecting carriers. It can be understood that in other embodiments, the spacing between some adjacent two rows of sub-grid groups may be the same, and the spacing between the remaining two adjacent rows of sub-grid groups may be different from the spacing; or any pair of adjacent two rows of sub-grid groups may have different spacings.

[0063] exist Figure 1 and Figure 2In the example, counting from top to bottom in the second direction, the first row of sub-grid groups, that is, the top row of sub-grid groups in the figure, are arranged in sequence from left to right in the first direction with spacing: first sub-grid 11, second sub-grid 12, first sub-grid 11, second sub-grid 12, first sub-grid 11. The second row of sub-grid groups, that is, the sub-grid groups in the row below the first row of sub-grid groups, are arranged in sequence from left to right in the first direction with spacing: second sub-grid 12, first sub-grid 11, second sub-grid 12, first sub-grid 11, second sub-grid 12. The third row of sub-grid groups, that is, the sub-grid groups in the row below the second row of sub-grid groups, are arranged in sequence from left to right in the first direction with spacing: first sub-grid 11, second sub-grid 12, first sub-grid 11, second sub-grid 12, first sub-grid 11... and so on.

[0064] Specifically, the intersection of the first direction and the second direction means that the first direction and the second direction do not overlap, are not the same, and are not opposite. In this embodiment, the first direction and the second direction are perpendicular to each other. The first direction and the second direction are parallel to two adjacent long sides of the silicon substrate 101, respectively. It can be understood that in other embodiments, the first direction and the second direction may also be at an acute angle or an obtuse angle; the first direction and the second direction may also be at an acute angle or an obtuse angle to two adjacent long sides of the silicon substrate 101, respectively. This is not limited here. Please note that the "two adjacent long sides" here refer to the sides other than the corners of the silicon substrate 101, and the arc sides or short sides with rounded corners or chamfers at the corners of the silicon substrate 101 are not considered.

[0065] Specifically, two adjacent rows of auxiliary gate groups are respectively the first group and the second group. The first auxiliary gate 11 in the first group includes a first opposite overlapping portion 111 and a first protruding portion 112. The first auxiliary gate 11 in the second group includes a second opposite overlapping portion 113 and a second protruding portion 114. The adjacent first protruding portion 112 and the second protruding portion 114 form a first connection area 110.

[0066] Specifically, the second sub-gate 12 in the first group includes a third opposite-sex overlap portion 121 and a third protruding portion 122 , and the second sub-gate 12 in the second group includes a fourth opposite-sex overlap portion 123 and a fourth protruding portion 124 . The adjacent third protruding portion 122 and fourth protruding portion 124 form a second connection region 120 .

[0067] Specifically, the first connection area 110 refers to the area where the first electrical connection member 21 is disposed. In other words, the first connection area 110 is the area covered by the projection of the first electrical connection member 21 on the silicon substrate 101. The second connection area 120 refers to the area where the second electrical connection member 22 is disposed. In other words, the second connection area 120 is the area covered by the projection of the second electrical connection member 22 on the silicon substrate 101.

[0068] Specifically, “two adjacent rows of sub-grid groups are respectively the first group and the second group” means that among all the sub-grid groups, any pair of two adjacent rows of sub-grid groups meet the arrangement rule of the first group and the second group, that is, among all the sub-grid groups, any pair of two adjacent rows of sub-grid groups, one is the first group and the other is the second group. In this way, the number of connection points can be increased as much as possible, and the risk of unstable connection can be reduced as much as possible.

[0069] It can be understood that the two polarity sub-gates are spaced from each other and alternately arranged in the first direction to form a gate line row, and multiple rows of gate line rows are spaced from each other and alternately arranged in the second direction. If there are two adjacent rows of gate line rows in all the gate line rows that meet the arrangement rules of the first group and the second group, and the remaining gate line rows do not meet them, then the gate line rows that meet the arrangement rules of the first group and the second group are the sub-gate groups in this article, and the sub-gates therein are the first sub-gates 11 and the second sub-gates 12 in this article. In this case, the first sub-gate 11, the second sub-gate 12 and the sub-gate group are formed in a partial area of ​​the silicon substrate 101. For example, the number of all the gate line rows is 5 rows, and only the adjacent first row of gate line rows and the second row of gate line rows meet the arrangement rules of the first group and the second group, that is, the first row of gate line rows and the second row of gate line rows are the sub-gate groups in this article, one of the first row of gate line rows and the second row of gate line rows is the first group, and the other is the second group, and the sub-gates in the first row of gate line rows and the second row of gate line rows are the first sub-gates 11 and the second sub-gates 12 in this article. In other words, the first sub-gate 11, the second sub-gate 12 and the sub-gate group are distributed in the area where the first gate line row and the second gate line row are located, while the remaining three gate line rows are not the sub-gate group in this article.

[0070] For the convenience of explanation, this paper uses Figure 1 and Figure 2 Take as an example to illustrate, specifically, Figure 1 and Figure 2 The top two rows of sub-grid groups are taken as the first group and the second group for illustration. That is, counting from top to bottom in the second direction, the first row of sub-grid groups, that is, the top row of sub-grid groups in the figure, is taken as the first group; the second row of sub-grid groups, that is, the sub-grid groups in the row below the first row of sub-grid groups, is taken as the second group. It can be understood that this is only an example and does not represent a limitation on the first group and the second group.

[0071] Specifically, the first sub-grid 11 in the first group includes a first opposite-sex overlapping portion 111 and a first protruding portion 112. The first opposite-sex overlapping portion 111 refers to a portion of the first sub-grid 11 of the first group that overlaps with the second sub-grid 12 of the second group in the second direction. The first protruding portion 112 refers to a portion of the first sub-grid 11 of the first group that does not overlap with the second sub-grid 12 of the second group in the second direction. In other words, the first protruding portion 112 refers to a portion of the first sub-grid 11 of the first group that protrudes from the second sub-grid 12 of the second group in the second direction.

[0072] Specifically, the first sub-grid 11 in the second group includes a second opposite-sex overlapping portion 113 and a second protruding portion 114. The second opposite-sex overlapping portion 113 refers to a portion of the first sub-grid 11 of the second group that overlaps with the second sub-grid 12 of the first group in the second direction. The second protruding portion 114 refers to a portion of the first sub-grid 11 of the second group that does not overlap with the second sub-grid 12 of the first group in the second direction. In other words, the second protruding portion 114 refers to a portion of the first sub-grid 11 of the second group that protrudes from the second sub-grid 12 of the first group in the second direction.

[0073] Specifically, the second sub-grid 12 in the first group includes a third opposite-sex overlapping portion 121 and a third protruding portion 122. The third opposite-sex overlapping portion 121 refers to a portion of the second sub-grid 12 of the first group that overlaps with the first sub-grid 11 of the second group in the second direction. The third protruding portion 122 refers to a portion of the second sub-grid 12 of the first group that does not overlap with the first sub-grid 11 of the second group in the second direction. In other words, the third protruding portion 122 refers to a portion of the second sub-grid 12 of the first group that protrudes from the first sub-grid 11 of the second group in the second direction.

[0074] Specifically, the second sub-grid 12 in the second group includes a fourth opposite-sex overlapping portion 123 and a fourth protruding portion 124. The fourth opposite-sex overlapping portion 123 refers to a portion of the second sub-grid 12 of the second group that overlaps with the first sub-grid 11 of the first group in the second direction. The fourth protruding portion 124 refers to a portion of the second sub-grid 12 of the second group that does not overlap with the first sub-grid 11 of the first group in the second direction. In other words, the fourth protruding portion 124 refers to a portion of the second sub-grid 12 of the second group that protrudes from the first sub-grid 11 of the first group in the second direction.

[0075] That is, the first opposite-sex overlapping portion 111 and the fourth opposite-sex overlapping portion 123 overlap in the second direction, have opposite polarities, and are respectively the first sub-grid 11 of the first group and the second sub-grid 12 of the second group. The third opposite-sex overlapping portion 121 and the second opposite-sex overlapping portion 113 overlap in the second direction, have opposite polarities, and are respectively the second sub-grid 12 of the first group and the first sub-grid 11 of the second group.

[0076] That is to say, the first protruding portion 112 and the fourth opposite-sex overlapping portion 123 are staggered in the second direction, or do not overlap. The third protruding portion 122 and the second opposite-sex overlapping portion 113 are staggered in the second direction, or do not overlap. The second protruding portion 114 and the third opposite-sex overlapping portion 121 are staggered in the second direction, or do not overlap. The fourth protruding portion 124 and the first opposite-sex overlapping portion 111 are staggered in the second direction, or do not overlap.

[0077] Specifically, “the adjacent first extension 112 and the second extension 114 form the first connection area 110” means that the first electrical connector 21 can be provided in the first connection area 110 to connect the adjacent first extension 112 and the second extension 114. In other words, the first connection area 110 refers to the area where the first electrical connector 21 is provided. In other words, the first connection area 110 is the area covered by the projection of the first electrical connector 21 on the silicon substrate 101.

[0078] It can be understood that since the first electrical connector 21 is provided in the first connection area 110 for connecting the adjacent first extension 112 and the second extension 114, in the back contact battery 10, as long as the adjacent first extension 112 and the second extension 114 exist, in the process of connecting two adjacent back contact batteries 10 to form the battery string 100, the first electrical connector 21 must be able to be provided in the first extension 112 and the second extension 114 to achieve connection, and the first connection area 110 in the back contact battery 10 must be formed. Therefore, in the back contact battery 10, there is no need to limit, explain or illustrate the specific scope of the first connection area 110.

[0079] Specifically, the “at least one” in “at least one electrical connector is electrically connected to the first sub-grid 11 of each row of several adjacent sub-grid groups in one back-contact battery 10, and is electrically connected to the second sub-grid 12 of each row of several adjacent sub-grid groups in another back-contact battery 10” means that only one electrical connector among all the electrical connectors satisfies the aforementioned content; or multiple or even all of the electrical connectors may satisfy the aforementioned content.

[0080] Specifically, “the electrical connector is electrically connected to the first sub-grid 11 of each row in a plurality of adjacent sub-grid groups in a back-contact cell 10” means that the electrical connector is connected to the first sub-grid of each row in 2 rows, 3 rows or all adjacent sub-grid groups in a back-contact cell 10. In other words, in 2 rows, 3 rows or all adjacent sub-grid groups in a back-contact cell 10, the electrical connector is connected to a first sub-grid of each row.

[0081] Specifically, “and electrically connected to the second sub-grid 12 of each row in several adjacent sub-grid groups in another back-contact cell 10” means that in another back-contact cell 10, the electrical connector connects the second sub-grid of each row in 2 rows, 3 rows or all adjacent sub-grid groups. In other words, in 2 rows, 3 rows or all adjacent sub-grid groups of another back-contact cell 10, the electrical connector is connected to one second sub-grid of each row.

[0082] Specifically, the first electrical connector 21 is electrically connected to one first sub-grid 11 in each row of sub-grid groups in all sub-grid groups of the back-contact battery 10. In this way, compared with the related art in which the electrical connector connects a sub-grid of one polarity to a sub-grid of another polarity every other row, the present application can double the number of connection points between the first electrical connector 21 and the first sub-grid 11, thereby reducing the risk of unstable connection between the back-contact battery 10 and the electrical connector.

[0083] Specifically, the number of the first electrical connectors 21 is 1, 2, 3 or other numbers. When there are multiple first electrical connectors 21, at least one first electrical connector 21 is electrically connected to one first sub-grid 11 in each row of sub-grid groups.

[0084] In this embodiment, there are multiple first electrical connectors 21, and each first electrical connector 21 is electrically connected to one first sub-grid 11 in each row of sub-grid groups in all sub-grid groups of the back-contact battery 10. In this way, the connection points between each first electrical connector 21 and the first sub-grid 11 are doubled, further reducing the risk of unstable connection between the back-contact battery 10 and the electrical connector.

[0085] It is understood that in other embodiments, some of the first electrical connectors 21 may be electrically connected to one first sub-grid 11 in each row of sub-grid groups in all the sub-grid groups of the back-contact battery 10, and the remaining first electrical connectors 21 may not be electrically connected to one first sub-grid 11 in each row of sub-grid groups in all the sub-grid groups of the back-contact battery 10. For example, the remaining first electrical connectors 21 may be electrically connected to one first sub-grid 11 in some rows of sub-grid groups.

[0086] Specifically, the first electrical connection member 21 is spaced apart from the second auxiliary grid 12 in each row of the auxiliary grid group, so as to prevent the first electrical connection member 21 from being electrically connected to the second auxiliary grid 12 of opposite polarity.

[0087] Specifically, the first electrical connector 21 and the first auxiliary grid 11 can be electrically connected by at least one of bonding with conductive adhesive, direct welding, solder paste welding, and physical contact, which is not limited here.

[0088] Please note that an insulating film may be provided on the side of the first electrical connector 21 facing the back contact battery 10. In the case where the first electrical connector 21 is provided with an insulating film, the size of the first electrical connector 21 in the first direction herein refers to the size of the portion without the insulating film, that is, the size of the first electrical connector 21 for effective electrical connection.

[0089] Specifically, the first electrical connector 21 includes at least one of a soldering strip and a conductive wire. This article takes the soldering strip as an example for explanation. It can be understood that when the first electrical connector 21 is a soldering strip, the embodiment of the present application can reduce the risk of cold soldering and desoldering of the back contact battery 10.

[0090] Specifically, “the adjacent third extension 122 and the fourth extension 124 form the second connection area 120” means that the second electrical connector 22 can be provided in the second connection area 120 to connect the adjacent third extension 122 and the fourth extension 124. In other words, the second connection area 120 refers to the area where the second electrical connector 22 is provided. In other words, the second connection area 120 is the area covered by the projection of the second electrical connector 22 on the silicon substrate 101.

[0091] It can be understood that since the second electrical connector 22 is provided in the second connection area 120 for connecting the adjacent third extension part 122 and the fourth extension part 124, in the back contact battery 10, as long as the adjacent third extension part 122 and the fourth extension part 124 exist, in the process of connecting two adjacent back contact batteries 10 to form the battery string 100, the second electrical connector 22 must be able to be provided in the third extension part 122 and the fourth extension part 124 to achieve connection, and the second connection area 120 in the back contact battery 10 must be formed. Therefore, in the back contact battery 10, there is no need to limit, explain or illustrate the specific scope of the second connection area 120.

[0092] Specifically, the second electrical connector 22 is electrically connected to one second sub-grid 12 in each row of sub-grid groups in all sub-grid groups of the back-contact battery 10. Thus, compared with the related art in which the electrical connector connects the sub-grid of one polarity to the sub-grid of another polarity every other row, the present application can double the number of connection points between the second electrical connector 22 and the second sub-grid 12, thereby reducing the risk of unstable connection between the back-contact battery 10 and the electrical connector.

[0093] Specifically, the number of the second electrical connectors 22 is 1, 2, 3 or other numbers. When there are multiple second electrical connectors 22, at least one second electrical connector 22 is electrically connected to one second sub-grid 12 in each row of sub-grid groups.

[0094] In this embodiment, there are multiple second electrical connectors 22, and each second electrical connector 22 is electrically connected to one second sub-grid 12 in each row of sub-grid groups in all sub-grid groups of the back contact battery 10. In this way, the connection points between each second electrical connector 22 and the second sub-grid 12 are doubled, further reducing the risk of unstable connection between the back contact battery 10 and the electrical connector.

[0095] It is understood that in other embodiments, part of the second electrical connections 22 may be electrically connected to one second sub-grid 12 in each row of sub-grid groups, while the remaining second electrical connections 22 may not be electrically connected to one second sub-grid 12 in each row of sub-grid groups. For example, the remaining second electrical connections 22 may be electrically connected to one second sub-grid 12 in some row of sub-grid groups.

[0096] Specifically, the second electrical connection member 22 is spaced apart from the first auxiliary grid 11 in each row of the auxiliary grid group, so as to prevent the second electrical connection member 22 from being electrically connected to the first auxiliary grid 11 of opposite polarity.

[0097] Specifically, the second electrical connection member 22 and the second auxiliary grid 12 can be electrically connected by at least one of bonding with conductive adhesive, direct welding, solder paste welding, and physical contact, which is not limited here.

[0098] Please note that an insulating film may be provided on the side of the first electrical connector 21 facing the back contact battery 10. In the case where the first electrical connector 21 is provided with an insulating film, the size of the first electrical connector 21 in the first direction herein refers to the size of the portion without the insulating film, that is, the size of the first electrical connector 21 for effective electrical connection.

[0099] Specifically, the second electrical connector 22 includes at least one of a soldering strip and a conductive wire. This article takes the second electrical connector 22 as an example of a soldering strip. It can be understood that when the second electrical connector 22 is a soldering strip, the embodiment of the present application can reduce the risk of cold soldering and desoldering of the back contact battery 10.

[0100] In some embodiments, the distance d1 between the endpoints of the adjacent first extension portion 112 and the second extension portion 114 in the first direction is -1 cm to 1 cm, for example -1 cm, -0.8 cm, -0.5 cm, -0.2 cm, 0 cm, 0.2 cm, 0.5 cm, 0.8 cm, 1 cm.

[0101] In this way, the distance d1 between the endpoints of the adjacent first extension portion 112 and the second extension portion 114 in the first direction is within an appropriate range, which can avoid the first extension portion 112 and the second extension portion 114 overlapping too much in the second direction due to a small distance, which is not conducive to collecting carriers of another polarity in the spacing area. It can also avoid the first extension portion 112 and the second extension portion 114 being too far apart in the first direction due to a large distance, which makes the required width of the first electrical connector 21 too large and is not conducive to collecting carriers in the spacing area.

[0102] Specifically, a distance d1 between the endpoints of the adjacent first protruding portion 112 and the second protruding portion 114 in the first direction may be referred to as a first distance d1 .

[0103] Please note that the first distance d1 is a negative number, which means that the adjacent first extension portions 112 and second extension portions 114 overlap in the second direction. Figure 1 The first spacing d1 is a positive number, which means that the adjacent first extension portion 112 and the second extension portion 114 do not overlap in the second direction. Figure 6 The first spacing d1 is 0, which means that the endpoints of the adjacent first extension portion 112 and the second extension portion 114 overlap in the second direction. Figure 7 shown.

[0104] Please note that the back contact cell 10 may include a plurality of pairs of adjacent first extensions 112 and second extensions 114 to form a plurality of first intervals d1, and all first intervals d1 may be the same, being a fixed value within a range of -1 cm to 1 cm, such as Figure 1 , Figure 6 and Figure 7 As shown; it may also be that part of the first spacing d1 is the same, and the rest of the first spacing d1 is different therefrom, such as Fig. 9 As shown; it is also possible that all first intervals d1 are different. In other words, in the back contact battery 10, a plurality of first intervals d1 may fluctuate within a range of -1 cm to 1 cm. This is not limited here.

[0105] See also Figure 1 In some embodiments, the distance d1 between the endpoints of the adjacent first extension portion 112 and the second extension portion 114 in the first direction is -2 mm to 2 mm, for example -2 mm, -1.8 mm, -1.5 mm, -1.2 mm, -1 mm, -0.7 mm, -0.5 mm, -0.3 mm, 0 mm, 0.3 mm, 0.5 mm, 0.7 mm, 1 mm, 1.2 mm, 1.5 mm, 1.8 mm, 2 mm.

[0106] In this way, thinner first electrical connectors 21 can be adapted, and more groups of first electrical connectors 21 can be used when the total amount of first electrical connectors 21 is constant, so that the current transmission path is shorter and the effect of current extraction is better.

[0107] It can be understood that the smaller the absolute value of the distance d1 between the endpoints of the adjacent first extensions 112 and the second extensions 114 in the first direction, the smaller the size of the overlap or the size of the interval between the adjacent first extensions 112 and the second extensions 114, so the required size of the first electrical connector 21 in the first direction can be smaller. The length of the first electrical connector 21 remains substantially unchanged. When the total amount of the first electrical connector 21 is constant, the smaller the size of each first electrical connector 21 in the first direction, the more the number of first electrical connectors 21 can be.

[0108] Specifically, when the first electrical connector 21 is a round welding strip, the size of the first electrical connector 21 in the first direction refers to the diameter of the round welding strip. When the first electrical connector 21 is a flat welding strip, the size of the first electrical connector 21 in the first direction refers to the width of the flat welding strip.

[0109] In some embodiments, the first electrical connector 21 includes a circular welding strip, and the distance d1 between the endpoints of the adjacent first extension portion 112 and the second extension portion 114 in the first direction is -2 mm to 2 mm, and the diameter of the corresponding circular welding strip is 0.2 mm to 3 mm. For example, 0.2 mm, 0.5 mm, 1 mm, 1.6 mm, 2 mm, 2.5 mm, 3 mm. Further, the diameter of the corresponding circular welding strip is preferably 0.2 mm to 0.35 mm. For example, 0.2 mm, 0.21 mm, 0.25 mm, 0.3 mm, 0.32 mm, 0.35 mm.

[0110] In some embodiments, the first electrical connector 21 includes a flat welding strip, and the distance d1 between the endpoints of the adjacent first extension portion 112 and the second extension portion 114 in the first direction is -2mm to 2mm, and the corresponding width of the flat welding strip is 0.6mm to 2.6mm. For example, 0.6mm, 0.8mm, 1mm, 1.2mm, 1.5mm, 2mm, 2.3mm, 2.6mm. Further, the width of the corresponding flat welding strip is preferably 0.6mm to 1mm. For example, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1mm.

[0111] See also Figure 2 In some embodiments, the distance d2 between the endpoints of the adjacent third extension portion 122 and the fourth extension portion 124 in the first direction is -1 cm to 1 cm, for example -1 cm, -0.8 cm, -0.5 cm, -0.2 cm, 0 cm, 0.2 cm, 0.5 cm, 0.8 cm, 1 cm.

[0112] Specifically, a distance d2 between the endpoints of the adjacent third extending portion 122 and the fourth extending portion 124 in the first direction may be recorded as a second distance d2.

[0113] Please note that the second interval d2 may be the same as or different from the first interval d1.

[0114] See also Figure 2In some embodiments, the distance d2 between the endpoints of the adjacent third extension portion 122 and the fourth extension portion 124 in the first direction is -2 mm to 2 mm, for example -2 mm, -1.8 mm, -1.5 mm, -1.2 mm, -1 mm, -0.7 mm, -0.5 mm, -0.3 mm, 0 mm, 0.3 mm, 0.5 mm, 0.7 mm, 1 mm, 1.2 mm, 1.5 mm, 1.8 mm, 2 mm.

[0115] The explanations and descriptions here can be found in the previous text. To avoid redundancy, they will not be repeated here.

[0116] See also Figure 6 In some embodiments, the distance d1 between the endpoints of the adjacent first extension portion 112 and the second extension portion 114 in the first direction is greater than 0 and less than or equal to 1 cm, for example, 0.1 cm, 0.2 cm, 0.5 cm, 0.8 cm, or 1 cm.

[0117] In this way, the projections of the first extension 112 and the second extension 114 in the same plane along the second direction are spaced from each other, which can reduce the amount of gate line paste used and help reduce costs. At the same time, it can avoid that the distance d1 between the endpoints of the adjacent first extension 112 and the second extension 114 in the first direction is too large, resulting in the first extension 112 and the second extension 114 being too far apart in the first direction, and the required first electrical connection member 21 is too wide, which is not conducive to collecting carriers in the spacing area.

[0118] See also Figure 6 In some embodiments, the distance d2 between the endpoints of the adjacent third extension portion 122 and the fourth extension portion 124 in the first direction is greater than 0 and less than or equal to 1 cm, for example, 0.1 cm, 0.2 cm, 0.5 cm, 0.8 cm, or 1 cm.

[0119] In this way, the projections of the third extension portion 122 and the fourth extension portion 124 on the same plane along the second direction are spaced apart from each other, which can reduce the amount of gate line paste used and is conducive to reducing costs. At the same time, it can be avoided that the distance d2 between the endpoints of the adjacent third extension portion 122 and the fourth extension portion 124 in the first direction is too large, resulting in the third extension portion 122 and the fourth extension portion 124 being too far apart in the first direction, and the required second electrical connection member 22 is too large, which is not conducive to collecting carriers in the spacing area.

[0120] See also Figure 1 and Figure 7 In some embodiments, the distance d1 between the endpoints of the adjacent first extension portion 112 and the second extension portion 114 in the first direction is -1 cm to 0 cm, for example -1 cm, -0.8 cm, -0.5 cm, -0.2 cm, or 0 cm.

[0121] In this way, the projections of the first extension 112 and the second extension 114 in the same plane along the second direction are connected or intersected, which can increase the total area of ​​the first extension 112 and the second extension 114 connected to the electrical connector, which is conducive to further reducing the risk of unstable connection between the gate line and the electrical connector. At the same time, it can avoid the first extension 112 and the second extension 114 overlapping too much in the second direction due to the small spacing d1 between the endpoints of the adjacent first extension 112 and the second extension 114 in the first direction, which wastes the gate line paste and is not conducive to collecting carriers of another polarity in the spacing area.

[0122] See also Figure 1 and Figure 7 In some embodiments, the distance d1 between the endpoints of the adjacent first extension portion 112 and the second extension portion 114 in the first direction is -2 mm to 0 mm, for example -2 mm, -1.8 mm, -1.5 mm, -1.2 mm, -1 mm, -0.7 mm, -0.5 mm, -0.3 mm, or 0 mm.

[0123] In this way, the first extension 112 and the second extension 114 overlap, the total area connected with the electrical connector is larger, and the connection is more stable. At the same time, a thinner first electrical connector 21 can be adapted, and more groups of first electrical connectors 21 can be used when the total amount of first electrical connectors 21 is constant, so that the current transmission path is shorter and the effect of current extraction is better.

[0124] In some embodiments, the distance d1 between the endpoints of the adjacent first extension portion 112 and the second extension portion 114 in the first direction is -2 mm to 0 mm, and the corresponding diameter of the circular welding strip is 0.2 mm to 0.35 mm, for example, 0.2 mm, 0.21 mm, 0.25 mm, 0.3 mm, 0.32 mm, 0.35 mm.

[0125] In some embodiments, the distance d1 between the endpoints of the adjacent first extension portion 112 and the second extension portion 114 in the first direction is -2 mm to 0 mm, and the corresponding width of the flat welding strip is 0.6 mm to 1 mm, for example, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, or 1 mm.

[0126] See also Figure 1 and Figure 7 In some embodiments, the distance d2 between the endpoints of the adjacent third extension portion 122 and the fourth extension portion 124 in the first direction is -1 cm to 0 cm, for example -1 cm, -0.8 cm, -0.5 cm, -0.2 cm, or 0 cm.

[0127] See also Figure 1and Figure 7 In some embodiments, the distance d2 between the endpoints of the adjacent third extension portion 122 and the fourth extension portion 124 in the first direction is -2 mm to 0 mm, for example -2 mm, -1.8 mm, -1.5 mm, -1.2 mm, -1 mm, -0.7 mm, -0.5 mm, -0.3 mm, or 0 mm.

[0128] The explanations and descriptions here can be found in the previous text. To avoid redundancy, they will not be repeated here.

[0129] Embodiment 2

[0130] In some embodiments, the ratio of the length of the secondary grid line extending into the electrical connection member to the size of the electrical connection member in the first direction is 0.2-1, for example, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, or 1.

[0131] In this way, the length of the secondary grid line extending into the electrical connector is within an appropriate range, which can avoid the situation where the extension length is too short, resulting in a small connection area with the electrical connector, poor effect in reducing the risk of unstable connection, and being unfavorable for collecting carriers in the spacing area. It can also avoid the situation where the extension length is too long, resulting in excessive use of grid line paste and high cost.

[0132] Specifically, in this embodiment, the size of the electrical connector in the first direction is a constant value. In other words, the size of the electrical connector in the first direction is the same everywhere.

[0133] It is understood that in other embodiments, the size of the electrical connector in the first direction may fluctuate within a certain range. For example, the electrical connector is in a curve or a broken line. In this case, the size of the electrical connector in the first direction required for calculating the aforementioned ratio may be the size of the portion of the electrical connector that is extended by the corresponding secondary grid line in the first direction. In other words, the aforementioned ratio may be calculated based on the portion of the secondary grid line and the electrical connector at the same position in the second direction.

[0134] Please note that “the secondary grid line extends into the electrical connector” means that the secondary grid line extends into the area covered by the electrical connector. In other words, the secondary grid line extends under the electrical connector, rather than the secondary grid line extending into the interior of the electrical connector.

[0135] See also Figure 1 , Figure 2 , Figure 6 and Figure 7 In some embodiments, the ratio of the length w1 of the first auxiliary grid 11 extending into the first electrical connection member 21 to the dimension w2 of the first electrical connection member 21 in the first direction is 0.2-1. Figure 1 , Figure 2 , Figure 6 and Figure 7In some embodiments, the ratio of the length w3 of the second auxiliary grid 12 extending into the second electrical connector 22 to the dimension w4 of the second electrical connector 22 in the first direction is 0.2-1. In some embodiments, the ratio of the length of the first auxiliary grid 11 extending into the second electrical connector 22 to the dimension of the second electrical connector 22 in the first direction is 0.2-1. In some embodiments, the ratio of the length of the second auxiliary grid 12 extending into the first electrical connector 21 to the dimension of the first electrical connector 21 in the first direction is 0.2-1. For the explanation and description of this part, please refer to the previous text, and it will not be repeated here to avoid redundancy.

[0136] Embodiment 3

[0137] In some embodiments, the ratio of the length of the secondary grid line extending into the electrical connection member to the size of the electrical connection member in the first direction is 0.2-0.8, for example, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, or 0.8.

[0138] In this way, the length of the auxiliary grid line extending into the electrical connector is within an appropriate range, which can save grid line paste and reduce costs while ensuring the connection area between the auxiliary grid line and the electrical connector and reducing the risk of unstable connection.

[0139] See also Figure 2 , Figure 6 and Figure 7 In some embodiments, the ratio of the length w1 of the first auxiliary grid 11 extending into the first electrical connection member 21 to the dimension w2 of the first electrical connection member 21 in the first direction is 0.2-0.8. Figure 2 , Figure 6 and Figure 7 In some embodiments, the ratio of the length w3 of the second auxiliary grid 12 extending into the second electrical connector 22 to the dimension w4 of the second electrical connector 22 in the first direction is 0.2-0.8. In some embodiments, the ratio of the length of the first auxiliary grid 11 extending into the second electrical connector 22 to the dimension of the second electrical connector 22 in the first direction is 0.2-0.8. In some embodiments, the ratio of the length of the second auxiliary grid 12 extending into the first electrical connector 21 to the dimension of the first electrical connector 21 in the first direction is 0.2-0.8. For the explanation and description of this part, please refer to the previous text, and it will not be repeated here to avoid redundancy.

[0140] Embodiment 4

[0141] In some embodiments, the ratio of the length of the secondary grid line extending into the electrical connection member to the size of the electrical connection member in the first direction is 0.8-1, for example, 0.8, 0.82, 0.85, 0.88, 0.9, 0.92, 0.95, 0.98, or 1.

[0142] In this way, the length of the secondary grid line extending into the electrical connector is within an appropriate range, which ensures a better connection area between the secondary grid line and the electrical connector and reduces the risk of unstable connection, while facilitating the secondary grid line to collect corresponding charges in the connection area.

[0143] See also Figure 1 , Figure 2 and Figure 7 In some embodiments, the ratio of the length w1 of the first auxiliary grid 11 extending into the first electrical connection member 21 to the dimension w2 of the first electrical connection member 21 in the first direction is 0.8-1. Figure 1 , Figure 2 and Figure 7 In some embodiments, the ratio of the length w3 of the second auxiliary grid 12 extending into the second electrical connector 22 to the dimension w4 of the second electrical connector 22 in the first direction is 0.8-1. In some embodiments, the ratio of the length of the first auxiliary grid 11 extending into the second electrical connector 22 to the dimension of the second electrical connector 22 in the first direction is 0.8-1. In some embodiments, the ratio of the length of the second auxiliary grid 12 extending into the first electrical connector 21 to the dimension of the first electrical connector 21 in the first direction is 0.8-1. For the explanation and description of this part, please refer to the previous text, and it will not be repeated here to avoid redundancy.

[0144] Embodiment 5

[0145] In some embodiments, at least some of the secondary grid lines in at least some of the secondary grid groups extend into the electrical connection component from one side and extend out from the other side of the electrical connection component.

[0146] In this way, a margin is left for the deviation of the electrical connector. When the electrical connector is deviated, the connection area between the electrical connector and the secondary grid line can be guaranteed as much as possible, which is conducive to further reducing the risk of unstable connection.

[0147] Specifically, one, multiple or all of the secondary grid groups may have one, multiple or all of the secondary grid lines in each secondary grid group extending from one side of the electrical connector and extending from the other side of the electrical connector. That is, the secondary grid lines run through the connection area covered by the electrical connector, and the ends of the secondary grid lines are exposed from the electrical connector.

[0148] See also Figure 8 In some embodiments, at least part of the first auxiliary grid 11 in at least part of the auxiliary grid group extends from one side of the first electrical connection member 21 and extends from the other side of the first electrical connection member 21. Figure 8In some embodiments, at least part of the second sub-grid 12 in at least part of the sub-grid group extends from one side of the second electrical connector 22 and extends from the other side of the second electrical connector 22. In some embodiments, at least part of the first sub-grid 11 in at least part of the sub-grid group extends from one side of the second electrical connector 22 and extends from the other side of the first electrical connector 21. In some embodiments, at least part of the second sub-grid 12 in at least part of the sub-grid group extends from one side of the first electrical connector 21 and extends from the other side of the second electrical connector 22. For the explanation and description of this part, please refer to the previous text, and it will not be repeated here to avoid redundancy.

[0149] Embodiment 6

[0150] In some embodiments, the ratio of the length of the secondary grid line extending from the other side of the electrical connector to the size of the electrical connector in the first direction is greater than 0 and less than or equal to 2, for example, 0.1, 0.2, 0.5, 1, 1.2, 1.5, 1.8, 2.

[0151] In this way, the ratio of the length of the secondary grid line extending from the electrical connector to the size of the electrical connector in the first direction is within an appropriate range, which can avoid poor anti-deviation effect caused by a too low ratio and can also avoid being disadvantageous in collecting carriers of another polarity caused by a too high ratio.

[0152] See also Figure 8 In some embodiments, the ratio of the length w5 of the first auxiliary grid 11 extending from the other side of the first electrical connection member 21 to the dimension w2 of the first electrical connection member 21 in the first direction is greater than 0 and less than or equal to 2. Figure 8 In some embodiments, the ratio of the length w6 of the second sub-grid 12 extending from the other side of the second electrical connector 22 to the dimension w4 of the second electrical connector 22 in the first direction is greater than 0 and less than or equal to 2. In some embodiments, the ratio of the length w5 of the first sub-grid 11 extending from the other side of the second electrical connector 22 to the dimension w2 of the second electrical connector 22 in the first direction is greater than 0 and less than or equal to 2. For the explanation and description of this part, please refer to the previous text, and it will not be repeated here to avoid redundancy.

[0153] Embodiment 7

[0154] In some embodiments, in two adjacent rows of secondary grid groups, the sum of the lengths of two adjacent secondary grid lines extending into the same electrical connection member is smaller than the dimension of the electrical connection member in the first direction.

[0155] In this way, the projections of two adjacent auxiliary grid lines in two adjacent rows of auxiliary grid groups along the second direction on the same plane are spaced apart from each other, which can reduce the amount of grid line paste used and help reduce costs.

[0156] See also Figure 6 In some embodiments, in two adjacent rows of sub-grid groups, the sum of the lengths w1 of two adjacent first sub-grids 11 extending into the same first electrical connector 21 is less than the dimension w2 of the first electrical connector 21 in the first direction. In some embodiments, in two adjacent rows of sub-grid groups, the sum of the lengths w1 of two adjacent second sub-grids 12 extending into the same second electrical connector 22 is less than the dimension w4 of the second electrical connector 22 in the first direction. In some embodiments, in two adjacent rows of sub-grid groups, the sum of the lengths of two adjacent first sub-grids 11 extending into the same second electrical connector 22 is less than the dimension of the second electrical connector 22 in the first direction. In some embodiments, in two adjacent rows of sub-grid groups, the sum of the lengths of two adjacent second sub-grids 12 extending into the same second electrical connector 22 is less than the dimension of the first electrical connector 21 in the first direction.

[0157] Embodiment 8

[0158] See also Figure 1 In some embodiments, in the first direction, the secondary gates located at the first end of a row of secondary gate groups have opposite polarities to the secondary gates located at the first end of an adjacent secondary gate group.

[0159] In this way, carriers of two polarities can be better collected at the first end of the sub-gate group, which is beneficial to improving the photoelectric conversion efficiency.

[0160] See also Figure 1 In some embodiments, in the first direction, the secondary gates located at the second end of a row of secondary gate groups have opposite polarities to the secondary gates located at the second end of an adjacent secondary gate group.

[0161] In this way, carriers of two polarities can be better collected at the second end of the sub-gate group, which is beneficial to improving the photoelectric conversion efficiency.

[0162] It can be understood that the first end and the second end are two ends in the first direction respectively. Figure 1 and Figure 2 In the example, the first end may be one of the left end and the right end, and the second end may be the other of the left end and the right end. That is, in two adjacent rows of auxiliary grid groups, the leftmost auxiliary grid has opposite polarity; the rightmost auxiliary grid has opposite polarity.

[0163] Embodiment 9

[0164] See also Fig.10 and Fig.11 In some embodiments, the back contact cell 10 includes a first conductive grid 131 , which has the same polarity as the first auxiliary grid 11 and connects the first auxiliary grids 11 in several rows of adjacent auxiliary grid groups.

[0165] Thus, when detecting reverse bias, the probe for detecting reverse bias can be placed at the intersection of the first conductive grid 131 and the first auxiliary grid 11, which can increase the probability of the probe contacting the auxiliary grid and can more easily align the auxiliary grid, thereby facilitating the detection of reverse bias of the cell.

[0166] Specifically, the first conductive grid 131 connects the first sub-grids 11 in 2 rows, 3 rows, 4 rows, or other numbers of adjacent sub-grid groups.

[0167] Specifically, the first conductive grid 131 can connect the adjacent first extension 112 and the second extension 114. In this way, the connection between the first conductive grid 131 and the first auxiliary grid 11 is more convenient, and there is no need to bypass the second auxiliary grid 12, and there is no need to set an insulating member between the first conductive grid 131 and the second auxiliary grid 12, which can reduce the risk of conduction between the first conductive grid 131 and the second auxiliary grid 12. In addition, the contact area with the electrical connector can be further increased, further reducing the risk of unstable connection.

[0168] Furthermore, there are multiple first conductive grids 131, and the multiple first conductive grids 131 are connected to the same first extension 112 and second extension 114. In this way, the first conductive grids 131, the first extension 112 and the second extension 114 form a grid, which further increases the probability of the probe contacting the secondary grid, and can more easily align the secondary grid.

[0169] Embodiment 10

[0170] See also Fig.10 and Fig.11 In some embodiments, the first conductive gate 131 includes at least one of a gate line and a pad.

[0171] In this way, the gate line as the first conductive gate 131 can enhance the current collection in the silicon substrate 101 region between the adjacent first sub-gates 11 in the second direction while increasing the probability of the probe contacting the sub-gate. The pad as the first conductive gate 131 can enhance the current collection in the silicon substrate 101 region between the adjacent first sub-gates 11 while increasing the probability of the probe contacting the sub-gate, and can further enhance welding and reduce the risk of cold welding and desoldering.

[0172] exist Fig.10 In the example of , the first conductive gate 131 includes a gate line. Fig.11 In the example, the first conductive gate 131 includes a pad.

[0173] Embodiment 11

[0174] See also Fig.10 and Fig.11In some embodiments, the back contact cell 10 includes a second conductive grid 132 , which has the same polarity as the second sub-grid 12 and connects the second sub-grids 12 in several rows of adjacent sub-grid groups.

[0175] The explanations and descriptions here can be found in the previous text. To avoid redundancy, they will not be repeated here.

[0176] Embodiment 12

[0177] See also Fig.10 and Fig.11 In some embodiments, the second conductive gate 132 includes at least one of a gate line and a pad.

[0178] The explanations and descriptions here can be found in the previous text. To avoid redundancy, they will not be repeated here.

[0179] Embodiment 13

[0180] See also Fig.12 , Fig.13 , Fig.14 and Fig.15 In some embodiments, the silicon substrate 101 includes a plurality of first doping regions 1001 and a plurality of second doping regions 1002, the first doping regions 1001 and the second doping regions 1002 extend along a first direction, the first doping regions 1001 and the second doping regions 1002 are alternately arranged along the first direction to form a row of doping region groups, and the plurality of row of doping region groups are sequentially arranged along a second direction; the first sub-gate 11 is arranged on the first doping region 1001, and the second sub-gate 12 is arranged on the second doping region 1002.

[0181] In this way, the arrangement of the two polarity doping regions and the two polarity sub-gates is similar, which facilitates the production of the corresponding polarity sub-gates on the doping regions and the electrical connection between the doping regions and the corresponding polarity sub-gates, thereby reducing process difficulty, improving production efficiency and reducing costs.

[0182] Specifically, the first doping region 1001 and the second doping region 1002 can be formed in the entire region of the silicon substrate 101, so that the first auxiliary gate 11 and the second auxiliary gate 12 are distributed in the entire region of the silicon substrate 101. Figure 1 , Figure 2 , Figure 3 As shown; the first doping region 1001 and the second doping region 1002 can be formed in a partial area of ​​the silicon substrate 101, so that the first auxiliary gate 11 and the second auxiliary gate 12 are distributed in a partial area of ​​the silicon substrate 101, such as Figure 5 As shown. Figure 5 In the example, the first doping region 1001 and the second doping region 1002 are disposed in the right region of the silicon substrate 101 . It can be understood that other doping regions may be disposed in the left region of the silicon substrate 101 .

[0183] Specifically, the polarity of the first doping region 1001 is different from that of the second doping region 1002. The first doping region 1001 corresponds to the first doping layer, and the second doping region 1002 corresponds to the second doping layer.

[0184] Specifically, the number of the first doping regions 1001 may be 1, 2, 3, 4 or other numbers. The number of the second doping regions 1002 may be 1, 2, 3, 4 or other numbers. This is not limited here. The number of the first doping regions 1001 and the number of the second doping regions 1002 may be the same or different.

[0185] Specifically, the first doping region 1001 extends along the first direction, which means that the overall extension direction of the first doping region 1001 is the first direction. This does not represent a limitation on the specific form of the first doping region 1001. In this embodiment, the first doping region 1001 is linear, and the extension direction of the first doping region 1001, that is, the first direction, is the length direction of the first doping region 1001. In other embodiments, the first doping region 1001 may also be wavy, folded, or other forms. In addition, the forms of several first doping regions 1001 may be the same or different.

[0186] Similarly, the second doping region 1002 extends along the first direction, which means that the overall extension direction of the second doping region 1002 is the first direction. This does not represent a limitation on the specific form of the second doping region 1002. In this embodiment, the second doping region 1002 is linear, and the extension direction of the second doping region 1002, that is, the first direction, is the length direction of the second doping region 1002. In other embodiments, the second doping region 1002 may also be wavy, folded, or other forms. In addition, the forms of several second doping regions 1002 may be the same or different.

[0187] Specifically, “the first doping regions 1001 and the second doping regions 1002 are alternately arranged along the first direction” means that, along the first direction, a second doping region 1002 is provided between two adjacent first doping regions 1001, and a first doping region 1001 is provided between two adjacent second doping regions 1002. In this way, a row of doping region groups is formed in the first direction. It can be understood that a gap may be formed between adjacent first doping regions 1001 and second doping regions 1002, they may contact each other, or other film layer structures may be provided.

[0188] Furthermore, the doped regions in a row of doped region groups have the same width, and the center lines along the first direction are located on the same straight line. In this way, the arrangement of the two doped regions is more regular, which is convenient for improving the manufacturing efficiency and is also conducive to fully collecting carriers. It can be understood that in other embodiments, the doped regions in a row of doped region groups may have different widths; it may also be that some of the doped regions in a row of doped region groups are located on the same straight line along the center line of the first direction, and the remaining doped regions are not located on the straight line along the center line of the first direction; it may also be that all the doped regions in a row of doped region groups are not located on the same straight line along the center line of the first direction.

[0189] Further, in the case where a gap is formed between adjacent first doping regions 1001 and second doping regions 1002 or other film structures are provided, in a row of doping region groups, the spacing between adjacent first doping regions 1001 and second doping regions 1002 is the same. In this way, the arrangement of the two doping regions is more regular, which is convenient for improving the manufacturing efficiency and is also conducive to fully collecting carriers. It can be understood that in other embodiments, the spacing between adjacent first doping regions 1001 and second doping regions 1002 in a row of doping region groups may be different.

[0190] Specifically, the number of the doping region groups may be 1 row, 2 rows, 3 rows, 4 rows or other numbers, which are not limited here.

[0191] Furthermore, a gap may be formed between any pair of adjacent rows of doping region groups, the two groups may contact each other, or other film layer structures may be provided.

[0192] Furthermore, in the case where a gap can be formed between two adjacent rows of doped region groups or other film layer structures are provided, the spacing between the two adjacent rows of doped region groups is the same. In this way, the arrangement of the doped region groups is more regular, which is convenient for improving the manufacturing efficiency and is also conducive to fully collecting carriers. It can be understood that in other embodiments, the spacing between some adjacent rows of doped region groups can be the same, and the spacing between the remaining adjacent rows of doped region groups can be different from the spacing; it can also be that the spacing between any pair of adjacent rows of doped region groups is different.

[0193] exist Figure 1 , Figure 2 and Fig.12In the example of , counting from top to bottom in the second direction, the first row of doping area groups, i.e., the top row of doping area groups in the figure, are arranged from left to right in the first direction: the first doping area 1001, the second doping area 1002, the first doping area 1001, the second doping area 1002, and the first doping area 1001. The second row of doping area groups, i.e., the doping area groups in the row below the first row of doping area groups, are arranged from left to right in the first direction: the second doping area 1002, the first doping area 1001, the second doping area 1002, the first doping area 1001, and the second doping area 1002. The third row of doping area groups, i.e., the doping area groups in the row below the second row of doping area groups, are arranged from left to right in the first direction: the first doping area 1001, the second doping area 1002, the first doping area 1001, the second doping area 1002, the first doping area 1001, the second doping area 1002, the first doping area 1001, and the second doping area 1001, and so on.

[0194] Embodiment 14

[0195] See also Fig.13 In some embodiments, a dielectric film layer 1004 is disposed between at least one pair of adjacent first doping regions 1001 and second doping regions 1002 , and the dielectric film layer 1004 electrically isolates the first doping regions 1001 and the second doping regions 1002 .

[0196] In this way, the dielectric film layer 1004 is used to achieve electrical isolation between the first doped layer and the second doped layer, and the refractive index difference and surface passivation effect of the dielectric film layer 1004 can be used to reduce optical loss and carrier recombination.

[0197] Specifically, the dielectric film layer 1004 may be disposed between a pair of adjacent first doping regions 1001 and second doping regions 1002, or between multiple pairs of adjacent first doping regions 1001 and second doping regions 1002. In this embodiment, the dielectric film layer 1004 is disposed between all adjacent first doping regions 1001 and second doping regions 1002.

[0198] Specifically, the dielectric film layer 1004 covers the first doping layer and the second doping layer, the first auxiliary gate 11 passes through the dielectric film layer 1004 to contact the first doping layer, and the second auxiliary gate 12 passes through the dielectric film layer 1004 to contact the second doping layer. Fig.13 The portion of the dielectric film layer 1004 covering the first doping region 1001 and the second doping region 1002 is omitted.

[0199] Specifically, the dielectric film layer 1004 includes at least one of an aluminum oxide layer, a silicon nitride layer, a silicon oxynitride layer, a silicon carbide layer, an amorphous silicon layer, and a silicon oxide layer.

[0200] Embodiment 15

[0201] In some embodiments, a trench is formed between the first doping region 1001 and the second doping region 1002 , and the dielectric film layer 1004 is at least partially disposed in the trench.

[0202] In this way, the first doping region 1001 and the second doping region 1002 can be electrically isolated from each other in the silicon substrate 101 by using the trench, thereby reducing the risk of conduction between the first doping region 1001 and the second doping region 1002 .

[0203] Specifically, “the dielectric film layer 1004 is at least partially disposed in the trench” means that a portion of the dielectric film layer 1004 is disposed in the trench and the remaining portion is disposed outside the trench, or the entire dielectric film layer 1004 is disposed in the trench.

[0204] Specifically, the trench is continuously disposed between the first doping region 1001 and the second doping region 1002. In other words, the first doping region 1001 and the second doping region 1002 are separated by the trench. In this way, it is ensured that the first doping region 1001 and the second doping region 1002 cannot be conductively connected across the trench.

[0205] Embodiment 16

[0206] See also Fig.14 In some embodiments, in the first direction, a tunneling layer 1003 is disposed between at least one pair of adjacent first doping regions 1001 and second doping regions 1002 , and both the first doping regions 1001 and the second doping regions 1002 are in contact with the tunneling layer 1003 .

[0207] In this way, the reverse bias voltage can be reduced, and the heat generation power when the back contact cell 10 is shielded in the assembly and becomes a load can be reduced. In addition, the tunneling layer 1003 can play a passivation role, reducing the recombination at the junction of the first doped region 1001 and the second doped region 1002 in the first direction.

[0208] Specifically, the tunneling layer 1003 includes at least one of a silicon oxide layer, an aluminum oxide layer, and a silicon carbide layer.

[0209] Specifically, the tunneling layer 1003 may be disposed in the entire region of the boundary between the adjacent first doping region 1001 and the second doping region 1002 in the first direction, or may be disposed in a partial region of the boundary between the adjacent first doping region 1001 and the second doping region 1002 in the first direction.

[0210] Specifically, in Fig.14 In the example, a tunneling layer 1003 is provided between all the first doping regions 1001 and the second doping regions 1002 adjacent to each other in the first direction.

[0211] It can be understood that in other embodiments, a tunneling layer 1003 may be provided between one or more pairs of adjacent first doping regions 1001 and second doping regions 1002 in the first direction.

[0212] Specifically, see Fig.15 In the second direction, a tunneling layer 1003 is disposed between at least one pair of adjacent first doping regions 1001 and second doping regions 1002 , and both the first doping regions 1001 and the second doping regions 1002 are in contact with the tunneling layer 1003 .

[0213] In this way, the reverse bias voltage can be reduced, which is beneficial for conducting the current when the back contact cell 10 is blocked, and reducing the risk of hot spots. In addition, the tunneling layer 1003 can play a passivation role, reducing the recombination at the junction of the first doped region 1001 and the second doped region 1002 in the second direction.

[0214] Specifically, the tunneling layer 1003 may be disposed in the entire region of the boundary between the adjacent first doping region 1001 and the second doping region 1002 in the second direction, or may be disposed in a partial region of the boundary between the adjacent first doping region 1001 and the second doping region 1002 in the second direction.

[0215] Specifically, in Fig.15 In the example, a tunneling layer 1003 is provided between all the first doping regions 1001 and the second doping regions 1002 adjacent to each other in the second direction.

[0216] It is understandable that in other embodiments, a tunneling layer 1003 may be provided between one or more pairs of adjacent first doping regions 1001 and second doping regions 1002 in the second direction.

[0217] Embodiment 17

[0218] See also Fig.12 In some embodiments, in the first direction, at least one pair of adjacent first doping regions 1001 and second doping regions 1002 are in contact with each other.

[0219] In this way, the reverse bias voltage can be reduced, and the heat generation power when the back contact battery 10 becomes a load after being shielded in the component can be reduced.

[0220] Specifically, the adjacent first doping region 1001 and the adjacent second doping region 1002 may contact each other in the entire region of the proximity in the first direction, or may contact each other in a partial region of the proximity in the first direction.

[0221] See also Fig.12 In some embodiments, in the second direction, at least one pair of adjacent first doping regions 1001 and second doping regions 1002 are in contact with each other.

[0222] In this way, the reverse bias voltage can be reduced, which is beneficial for conducting the current when the back contact battery 10 is blocked, thereby reducing the risk of hot spots.

[0223] Specifically, the adjacent first doping region 1001 and the adjacent second doping region 1002 may contact each other in the entire region of the adjacent region in the second direction, or may contact each other in a partial region of the adjacent region in the second direction.

[0224] Embodiment 18

[0225] In some embodiments, the projection of the electrical connection element on the silicon substrate 101 is located in the first doped region 1001 . Alternatively, the projection of the electrical connection element on the silicon substrate 101 is located in the second doped region 1002 .

[0226] In this way, the risk of the electrical connector contacting the non-corresponding doped region can be reduced, and carriers of corresponding polarity can be better collected.

[0227] In some embodiments, a projection of the first electrical connection 21 on the silicon substrate 101 is located in the first doped region 1001 .

[0228] Specifically, the first extension portion 112 and the second extension portion 114 are arranged on the first doping region 1001, and the first doping region 1001 is continuously arranged between the first extension portion 112 and the second extension portion 114. In this way, the carriers of corresponding polarity between the first extension portion 112 and the second extension portion 114 can be better collected. At the same time, the risk of the first electrical connection member 21 provided in the first connection region 110 contacting with the opposite doping region can be reduced. Moreover, in this way, the structure required for electrical isolation, such as a groove, can be omitted between the first extension portion and the second extension portion, thereby increasing the passivation contact area, which is conducive to improving the photoelectric conversion efficiency.

[0229] In some embodiments, a projection of the second electrical connection 22 on the silicon substrate 101 is located in the second doped region 1002 .

[0230] The explanations and descriptions here can be found in the previous text. To avoid redundancy, they will not be repeated here.

[0231] Embodiment 19

[0232] In some embodiments, two adjacent rows of auxiliary grid groups are respectively a first group and a second group, the first auxiliary grid 11 in the first group includes a first opposite-sex overlapping portion 111 and a first extending portion 112, the first auxiliary grid 11 in the second group includes a second opposite-sex overlapping portion 113 and a second extending portion 114, the second auxiliary grid 12 in the first group includes a third opposite-sex overlapping portion 121 and a third extending portion 122, and the second auxiliary grid 12 in the second group includes a fourth opposite-sex overlapping portion 123 and a fourth extending portion 124;

[0233] The electrical connector includes a first electrical connector 21 and a second electrical connector 12, and the first electrical connector 21 and the second electrical connector 12 are alternately arranged along a first direction;

[0234] In a back contact cell, at least part of the first electrical connector 21 electrically connects the adjacent first extension 112 and second extension 114 , and at least part of the second electrical connector 12 electrically connects the adjacent third extension 122 and fourth extension 124 .

[0235] In this way, the electrical connector 22 is connected to the corresponding protruding portion, thereby avoiding the overlapping portion, and reducing the risk of the electrical connector being connected to the non-corresponding auxiliary grid.

[0236] In this embodiment, along the second direction, each first electrical connector 21 electrically connects adjacent first extensions 112 and second extensions 114. Figure 1 and Figure 2 In the example, the first electrical connector 21 is electrically connected in sequence from top to bottom along the second direction: the first extending portion 112, the second extending portion 114, the first extending portion 112, the second extending portion 114, and so on.

[0237] It is understandable that in other embodiments, some of the first electrical connectors 21 may electrically connect the adjacent first extension portions 112 and second extension portions 114 , while the remaining first electrical connectors 21 may not electrically connect the adjacent first extension portions 112 and second extension portions 114 .

[0238] Specifically, the first electrical connector 21 may cover a portion or the entire area of ​​the first protruding portion 112 and the second protruding portion 114 in the first direction.

[0239] Specifically, the first electrical connector 21 is staggered with the third opposite-sex overlap portion 121, and staggered with the fourth opposite-sex overlap portion 123. In this way, the first electrical connector 21 is prevented from being connected to the opposite-sex auxiliary grid.

[0240] It can be understood that the first electrical connector 21 can extend in the first direction into the gap between the first extension portion 112 and the adjacent third opposite-sex overlap portion 121. The first electrical connector 21 can extend in the first direction into the gap between the second extension portion 114 and the adjacent fourth opposite-sex overlap portion 123.

[0241] It can be understood that in other embodiments, the first electrical connection member 21 may also cover the second auxiliary grid 12 , and an insulating member is disposed between the first electrical connection member 21 and the second auxiliary grid 12 .

[0242] In this embodiment, the first electrical connector 21 is rectangular, and the first extension portion 112 and the second extension portion 114 adjacent in the second direction extend from the first opposite-sex overlapping portion 111 and the second opposite-sex overlapping portion 121, respectively, to connect the first electrical connector 21. In this way, the first extension portion 112 and the second extension portion 114 can better collect carriers of the first connection area 110.

[0243] It can be understood that in other embodiments, the first electrical connector 21 may include a first body, a first connection end, and a second connection end, and the first connection end and the second connection end extend outward from both sides of the first body, respectively, and respectively connect two first sub-grids 11 adjacent to each other in the second direction in the first group and the second group. In this case, the first sub-grid 11 in the first group may not include an extension portion, and completely overlap with the second sub-grid 12 in the second group in the second direction; the first sub-grid 11 in the second group may not include an extension portion, and completely overlap with the second sub-grid 12 in the first group in the second direction. In other words, the first sub-grid 11 does not extend, and the first electrical connector 21 extends toward the first sub-grid 11.

[0244] Embodiment 20

[0245] The battery assembly of the embodiment of the present application includes the back contact battery 10 of any one of the first to nineteenth embodiments.

[0246] In the battery assembly of the embodiment of the present application, since in the battery string 100, at least one electrical connector is electrically connected to the first auxiliary grid 11 of each row in several rows of adjacent auxiliary grid groups in one back-contact battery 10, and is electrically connected to the second auxiliary grid 12 of each row in several rows of adjacent auxiliary grid groups in another back-contact battery 10, at least one electrical connector is connected to the auxiliary grid of the corresponding polarity in each row in the several rows of adjacent auxiliary grid groups, so that the electrical connector has more connection points with the auxiliary grid as a whole, and the overall connection tension between the back-contact battery 10 and the electrical connector is increased. In addition, since there is no need to set an insulating member on the non-corresponding auxiliary grid, the height of the electrical connector will not be raised by the insulating member, thereby reducing the risk of unstable connection between the back-contact battery 10 and the electrical connector. Moreover, in this way, the electrical connector does not need to be electrically isolated from the non-corresponding auxiliary grid by the insulating member, which can reduce the risk of short circuit caused by partial loss or offset of the insulating member.

[0247] In this embodiment, multiple back-contact batteries 10 in the battery assembly can be connected in series in sequence to form a battery string 100, thereby realizing the series bus output of the current. For example, the series connection of the battery cells can be achieved by setting welding strips (bus bars, interconnecting bars), conductive back plates, etc.

[0248] It is understandable that in such an embodiment, the battery assembly may further include a metal frame, a back plate, a photovoltaic glass and an adhesive film. The adhesive film may be filled between the front and back sides of the back contact battery 10 and the photovoltaic glass, adjacent battery cells, etc. As a filler, it may be a transparent colloid with good light transmittance and aging resistance. For example, the adhesive film may be an EVA adhesive film or a POE adhesive film. The specific selection may be based on actual conditions and is not limited here.

[0249] Photovoltaic glass can cover the adhesive film on the front side of the back contact cell 10. The photovoltaic glass can be ultra-white glass, which has high light transmittance, high transparency, and excellent physical, mechanical and optical properties. For example, the light transmittance of ultra-white glass can reach more than 92%, which can protect the back contact cell 10 without affecting the efficiency of the back contact cell 10 as much as possible. At the same time, the adhesive film can bond the photovoltaic glass and the back contact cell 10 together. The presence of the adhesive film can seal and insulate the back contact cell 10 and make it waterproof and moisture-proof.

[0250] The backplane can be attached to the adhesive film on the back of the back contact battery 10. The backplane can protect and support the back contact battery 10 and has reliable insulation, water resistance and aging resistance. There are multiple options for the backplane, which can usually be tempered glass, organic glass, aluminum alloy TPT composite adhesive film, etc. It can be set according to specific circumstances and is not limited here. The whole composed of the backplane, back contact battery 10, adhesive film and photovoltaic glass can be set on a metal frame. The metal frame serves as the main external support structure of the entire battery assembly and can stably support and install the battery assembly. For example, the battery assembly can be installed at the required location through the metal frame.

[0251] Embodiment 21

[0252] The photovoltaic system of the embodiment of the present application includes the battery assembly of embodiment 20.

[0253] In the photovoltaic system of the embodiment of the present application, since in the battery string 100, at least one electrical connector is electrically connected to the first auxiliary grid 11 of each row in several rows of adjacent auxiliary grid groups in one back contact battery 10, and is electrically connected to the second auxiliary grid 12 of each row in several rows of adjacent auxiliary grid groups in another back contact battery 10, at least one electrical connector is connected to the auxiliary grid of corresponding polarity in each row of the several rows of adjacent auxiliary grid groups, so that the electrical connector has more connection points with the auxiliary grid as a whole, and the overall connection tension between the back contact battery 10 and the electrical connector is increased. In addition, there is no need to set an insulating member on the non-corresponding auxiliary grid, so the height of the electrical connector will not be raised by the insulating member, thereby reducing the risk of unstable connection between the back contact battery 10 and the electrical connector. Moreover, in this way, the electrical connector does not need to be electrically isolated from the non-corresponding auxiliary grid by the insulating member, which can reduce the risk of short circuit caused by partial loss or offset of the insulating member.

[0254] In this embodiment, the photovoltaic system can be applied to photovoltaic power stations, such as ground power stations, rooftop power stations, water power stations, etc., and can also be applied to equipment or devices that use solar energy to generate electricity, such as user solar power supplies, solar street lights, solar cars, solar buildings, etc. Of course, it can be understood that the application scenarios of the photovoltaic system are not limited to this, that is to say, the photovoltaic system can be applied in all fields that require solar energy to generate electricity. Taking the photovoltaic power generation system network as an example, the photovoltaic system may include a photovoltaic array, a junction box and an inverter. The photovoltaic array may be an array combination of multiple battery components. For example, multiple battery components can form multiple photovoltaic arrays. The photovoltaic array is connected to the junction box. The junction box can converge the current generated by the photovoltaic array. The converged current flows through the inverter and is converted into the alternating current required by the mains power grid, and then connected to the mains network to realize solar power supply.

[0255] In the description of this specification, the description with reference to the terms "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiments or examples are included in at least one embodiment or example of the present application. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0256] In addition, the above are only preferred embodiments of the present application and are not intended to limit the present application. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present application should be included in the protection scope of the present application.

Claims

1. A battery string, characterized in that: It comprises a plurality of electrical connectors and a plurality of back contact cells, wherein the back contact cells comprise a silicon substrate and a plurality of secondary grid lines; The plurality of auxiliary gate lines include a plurality of first auxiliary gates and a plurality of second auxiliary gates; the first auxiliary gates and the second auxiliary gates are arranged on the silicon substrate and extend along a first direction; the first auxiliary gates and the second auxiliary gates are spaced from each other and alternately arranged along the first direction to form a row of auxiliary gate groups, and the plurality of rows of the auxiliary gate groups are spaced from each other and sequentially arranged along a second direction, and the second direction intersects the first direction; A plurality of the electrical connectors are spaced apart from each other, arranged along the first direction, and extend along the second direction; the electrical connectors connect two adjacent back contact cells in the second direction, and at least one of the electrical connectors is electrically connected to the first sub-grids in each row of several adjacent sub-grid groups in one back contact cell, and is electrically connected to the second sub-grids in each row of several adjacent sub-grid groups in another back contact cell.

2. The battery string according to claim 1, characterized in that: The ratio of the length of the secondary grid line extending into the electrical connection component to the size of the electrical connection component in the first direction is 0.2-1.

3. The battery string according to claim 2, characterized in that: The ratio of the length of the secondary grid line extending into the electrical connection component to the size of the electrical connection component in the first direction is 0.2-0.

8.

4. The battery string according to claim 2, characterized in that: The ratio of the length of the secondary grid line extending into the electrical connection component to the size of the electrical connection component in the first direction is 0.8-1.

5. The battery string according to claim 1, characterized in that: At least part of the auxiliary grid lines in at least part of the auxiliary grid groups extend into the electrical connection component from one side and extend out from the other side of the electrical connection component.

6. The battery string according to claim 5, characterized in that: The ratio of the length of the secondary grid line extending from the other side of the electrical connection member to the size of the electrical connection member in the first direction is greater than 0 and less than or equal to 2.

7. The battery string according to claim 1, characterized in that: In two adjacent rows of the auxiliary grid groups, the sum of the lengths of two adjacent auxiliary grid lines extending into the same electrical connection member is smaller than the dimension of the electrical connection member in the first direction.

8. The battery string according to claim 1, characterized in that: In the first direction, the auxiliary grids in a row of the auxiliary grid groups located at the first end have opposite polarities to the auxiliary grids in an adjacent auxiliary grid group located at the first end; And / or, in the first direction, the auxiliary grids located at the second end in a row of the auxiliary grid groups have opposite polarities to the auxiliary grids located at the second end in an adjacent auxiliary grid group.

9. The battery string according to claim 1, characterized in that: The back contact battery comprises a first conductive grid, which is of the same nature as the first sub-grid and connects the first sub-grids in several adjacent rows of the sub-grid groups.

10. The battery string according to claim 9, characterized in that: The first conductive gate includes at least one of a gate line and a pad.

11. The battery string according to claim 1, characterized in that: The back contact battery comprises a second conductive grid, which is the same as the second sub-grid and connects the second sub-grids in several adjacent rows of the sub-grid groups.

12. The battery string according to claim 11, characterized in that: The second conductive gate includes at least one of a gate line and a pad.

13. The battery string according to claim 1, characterized in that: The silicon substrate includes a plurality of first doping regions and a plurality of second doping regions, the first doping regions and the second doping regions extend along the first direction, the first doping regions and the second doping regions are alternately arranged along the first direction to form a row of doping region groups, and a plurality of rows of the doping region groups are sequentially arranged along the second direction; the first sub-gate is arranged on the first doping region, and the second sub-gate is arranged on the second doping region.

14. The battery string according to claim 13, characterized in that: A dielectric film layer is provided between at least one pair of adjacent first doping regions and second doping regions, and the dielectric film layer electrically isolates the first doping region from the second doping region.

15. The battery string according to claim 14, characterized in that: A trench is formed between the first doping region and the second doping region, and the dielectric film layer is at least partially disposed in the trench.

16. The battery string according to claim 13, characterized in that: In the first direction, a tunneling layer is disposed between at least one pair of adjacent first doping regions and second doping regions, and both the first doping region and the second doping region are in contact with the tunneling layer.

17. The battery string according to claim 13, characterized in that: In the first direction, at least one pair of adjacent first doping regions and second doping regions are in contact with each other.

18. The battery string according to claim 13, characterized in that: The projection of the electrical connection component on the silicon substrate is located in the first doping region; or the projection of the electrical connection component on the silicon substrate is located in the second doping region.

19. The battery string according to claim 1, characterized in that: The two adjacent rows of the auxiliary grid groups are respectively a first group and a second group, the first auxiliary grid in the first group includes a first opposite-sex overlapping portion and a first extending portion, the first auxiliary grid in the second group includes a second opposite-sex overlapping portion and a second extending portion, the second auxiliary grid in the first group includes a third opposite-sex overlapping portion and a third extending portion, and the second auxiliary grid in the second group includes a fourth opposite-sex overlapping portion and a fourth extending portion; The electrical connector includes a first electrical connector and a second electrical connector, wherein the first electrical connector and the second electrical connector are alternately arranged along the first direction; In one of the back-contact cells, at least part of the first electrical connector electrically connects the adjacent first extension and the second extension, and at least part of the second electrical connector electrically connects the adjacent third extension and the fourth extension.

20. A battery assembly, characterized in that: A battery string comprising any one of claims 1-19.

21. A photovoltaic system, characterized in that: A battery assembly comprising the battery assembly of claim 20.

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