Back contact cell, back contact cell string, cell assembly, and photovoltaic system

Abstract

The invention relates to the technical field of solar cells, and particularly discloses a back contact cell, a back contact cell string, a cell assembly and a photovoltaic system. The back contact cell is provided with a first area and a second area along a second direction; the first area is internally provided with first grid lines and second grid lines which are alternately arranged in the second direction, and first Pad points and second Pad points which are alternately arranged in the first direction, and the second area is internally provided with third grid lines and fourth grid lines which are alternately arranged in the second direction, and fifth grid lines and sixth grid lines which are alternately arranged in the first direction. The fifth grid line and the sixth grid line extend in the second direction and have discontinuous areas, the fifth grid line is arranged on the extension line of the first main grid in the second direction, and the sixth grid line is arranged on the extension line of the second main grid in the second direction. When the back contact battery is tested, the test difficulty is reduced, and the test reliability and stability are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of solar cells, and in particular to a back-contact cell, a back-contact cell string, a cell assembly, and a photovoltaic system. Background Art

[0002] In back-contact solar cells, in order to reduce the use of slurry, the back-contact solar cell adopts a busbar-less design. However, on the one hand, in such a technical solution, due to the busbar-less design on the back side, the difficulty of performing hot spot, EL and other performance tests on the back-contact solar cell is greatly increased. The back-contact solar cell cannot be in stable contact with the test probe, making the test more difficult and the reliability and stability poor. Summary of the invention

[0003] The technical problem to be solved by the present invention is to provide a back-contact battery, aiming to solve the technical problem in the prior art that when testing the back-contact battery, the probe cannot form a stable contact and the reliability and stability of the test are poor.

[0004] The technical problem to be solved by the present invention is also to provide a back-contact battery string, a battery assembly and a photovoltaic system.

[0005] In order to solve the above problems, the present invention provides a back-contact battery, wherein a first region and a second region are provided on the back side of the back-contact battery along a second direction, and first grid lines and second grid lines alternately arranged along the second direction and first pad points and second pad points alternately arranged along the first direction are provided in the first region, the first pad points are connected to a first main grid, the second pad points are connected to a second main grid, the first pad points are connected to the first grid lines in the first region, and the second pad points are connected to the second grid lines in the first region;

[0006] The second region is provided with a third gate line and a fourth gate line alternately arranged along the second direction, the third gate line and the first gate line collect currents of the same polarity, and the fourth gate line and the second gate line collect currents of the same polarity;

[0007] A fifth gate line and a sixth gate line alternately arranged along the first direction are provided in the second area, the fifth gate line is connected to the third gate line, the sixth gate line is connected to the fourth gate line, the fifth gate line and the sixth gate line both extend along the second direction and both have discontinuous areas, a third Pad point is provided on the fifth gate line, a fourth Pad point is provided on the sixth gate line, the fifth gate line is provided in the projection area of ​​the first welding strip on the back side of the back contact battery, and the sixth gate line is provided in the projection area of ​​the second welding strip on the back side of the back contact battery.

[0008] In some embodiments, the area of ​​the third Pad point is smaller than the area of ​​the first Pad point;

[0009] And / or, the area of ​​the fourth Pad point is smaller than the area of ​​the second Pad point.

[0010] In some embodiments, the fifth gate line includes a plurality of first continuous gate lines arranged at intervals along the second direction, a first discontinuous region is provided between two adjacent first continuous gate lines, and a length of the first continuous gate line along the second direction is greater than a length of the first discontinuous region.

[0011] In some embodiments, the first continuous gate line is connected to 3 to 20 of the third gate lines;

[0012] A fourth gate line is disposed in the first discontinuous region.

[0013] In some embodiments, the third Pad point is disposed on the first continuous gate line.

[0014] In some embodiments, a third Pad point is disposed on each of the first continuous gate lines.

[0015] In some embodiments, each of the first continuous gate lines is provided with one third Pad point.

[0016] In some embodiments, the sixth gate line includes a plurality of second continuous gate lines arranged at intervals along the second direction, a second discontinuous region is provided between two adjacent second continuous gate lines, and a length of the second continuous gate line along the second direction is greater than a length of the second discontinuous region.

[0017] In some embodiments, the second continuous gate line is connected to 3 to 20 of the fourth gate lines;

[0018] A third gate line is disposed in the second discontinuous region.

[0019] In some embodiments, the fourth Pad point is located on the second continuous gate line.

[0020] In some embodiments, each of the second continuous grid lines is provided with a fourth Pad point.

[0021] In some embodiments, each of the second continuous grid lines is provided with one fourth Pad point.

[0022] In some embodiments, the first region is disposed near an edge of the back side of the back contact battery, and the second region is disposed at a position away from the edge of the back side of the back contact battery relative to the first region; or

[0023] The first region is disposed at a position close to a cutting region on the back side of the back contact cell, and the second region is disposed at a position farther from the cutting region on the back side of the back contact cell than the first region.

[0024] In some embodiments, along the second direction, the second region is located between two adjacent first regions.

[0025] In some embodiments, a first doping layer is provided under the first gate line, a second doping layer is provided under the second gate line, a third doping layer is provided under the third gate line, a fourth doping layer is provided under the fourth gate line, a fifth doping layer is provided under the fifth gate line, and a sixth doping layer is provided under the sixth gate line. The first doping layer, the third doping layer, and the fifth doping layer have the same polarity, the second doping layer, the fourth doping layer, and the sixth doping layer have the same polarity, and the first doping layer and the second doping layer have opposite polarities.

[0026] In some embodiments, the fifth doping layer is disposed in the third region, and a first spacing region is disposed between adjacent third regions;

[0027] Furthermore, the sixth doping layer is disposed in a fourth region, and a second spacing region is disposed between adjacent fourth regions.

[0028] In some embodiments, an A stack is provided on the fifth doping layer, and the A stack includes a first A stack, the first A stack covers a partial area of ​​the fifth doping layer, and a first A spacing area extending along the second direction is left on the fifth doping layer, the first A stack is connected to the fourth doping layer adjacent to the fifth doping layer, and the first A stack is a doping layer, and the doping polarity of the doping layer is the same as the doping polarity of the fourth doping layer.

[0029] In some embodiments, the A stack also includes a second A stack, the second A stack covers a partial area of ​​the fifth doping layer, and a second A spacing region extending along the second direction is formed between the first A stack and the second A stack, the first A stack and the second A stack are respectively connected to the fourth doping layer adjacent to the fifth doping layer, and the first A stack and the second A stack are doping layers, and the doping polarity of the doping layers is the same as the doping polarity of the fourth doping layer.

[0030] In some embodiments, a width of the first A-spaced region or the second A-spaced region is greater than a width of the fifth gate line.

[0031] In some embodiments, a first dielectric layer is disposed between the A stack and the fifth doped layer.

[0032] In some embodiments, the A stack is disposed in the third region; the A stack is disposed at a position away from a position where the third Pad point is disposed.

[0033] In some embodiments, a B stack is provided on the sixth doping layer, and the B stack includes a first B stack, the first B stack covers a partial area of ​​the sixth doping layer, and a first B spacing area extending along the second direction is left on the sixth doping layer, the first B stack is connected to the third doping layer adjacent to the sixth doping layer, and the first B stack is a doping layer, and the doping polarity of the doping layer is the same as the doping polarity of the third doping layer.

[0034] In some embodiments, the B stack also includes a second B stack, the second B stack covers a partial area of ​​the sixth doping layer, and a second B spacing region extending along the second direction is formed between the first B stack and the second B stack, the first B stack and the second B stack are respectively connected to the third doping layer adjacent to the sixth doping layer, and the first B stack and the second B stack are doping layers, and the doping polarity of the doping layers is the same as the doping polarity of the third doping layer.

[0035] In some embodiments, a width of the first B-spaced region or the second B-spaced region is greater than a width of the sixth gate line.

[0036] In some embodiments, a second dielectric layer is disposed between the B stack and the sixth doped layer.

[0037] In some embodiments, the B stack is disposed in the fourth region; and the B stack is disposed at a position away from a position where the fourth Pad point is disposed.

[0038] In some embodiments, the first region further includes a first edge gate line and a second edge gate line, the first edge gate line is connected to the first gate line, and the second edge gate line is connected to the second gate line.

[0039] In some embodiments, the second region further includes a third edge gate line and a fourth edge gate line, the third edge gate line is connected to the third gate line, and the fourth edge gate line is connected to the fourth gate line.

[0040] In some embodiments, the fifth grid line is not arranged in the vertical direction of the first Pad point closest to the edge of the back contact battery;

[0041] And / or, the sixth grid line is not arranged in the vertical direction of the second Pad point closest to the edge of the back contact cell.

[0042] In some embodiments, the third Pad point and the fourth Pad point are not collinear along the first direction.

[0043] Accordingly, the present invention also provides a back-contact battery string, comprising:

[0044] A plurality of back-contact cells as described above;

[0045] A first welding strip and a second welding strip, the fifth grid line is arranged in the projection area of ​​the first welding strip on the back side of the back contact battery, and the sixth grid line is arranged in the projection area of ​​the second welding strip on the back side of the back contact battery.

[0046] Furthermore, the present invention provides a battery assembly, comprising the back-contact battery string.

[0047] Furthermore, the present invention provides a photovoltaic system, comprising the battery assembly.

[0048] The implementation of the present invention has the following beneficial effects:

[0049] In the back-contact battery and battery assembly disclosed in the present invention, the back side of the back-contact battery is provided with a first area and a second area along the second direction, the first area is provided with a first grid line and a second grid line arranged alternately along the second direction, a first Pad point and a second Pad point arranged alternately along the first direction, the first Pad point is connected to the first main grid, the second Pad point is connected to the second main grid, the first Pad point is connected to the first grid line in the first area, and the second Pad point is connected to the second grid line in the first area. In this way, the first Pad point and the second Pad point are larger in area than a single fine grid, and the first Pad point is electrically connected to the first grid line in the first area, and the second Pad point is electrically connected to the second grid line in the first area. When the back-contact battery is subjected to electrical performance tests (such as IV tests), EL tests, and hot spot tests, the positive and negative probes of the test device can form stable contacts with the first Pad point and the second Pad point, respectively, to reduce the difficulty of the test and improve the reliability and stability of the test.

[0050] Furthermore, the second region is provided with a fifth grid line and a sixth grid line arranged alternately along the first direction, the fifth grid line is connected to the third grid line, the sixth grid line is connected to the fourth grid line, and the fifth grid line and the sixth grid line both extend along the second direction and both have discontinuous regions. In this way, the fifth grid line and the sixth grid line can improve the current transmission efficiency and reduce the resistance loss; and have an anti-break grid effect, further improving the reliability of the battery and the component. The fifth grid line is provided with a third Pad point, the sixth grid line is provided with a fourth Pad point, the fifth grid line is provided in the projection area of ​​the first welding strip on the back of the back contact battery, and the sixth grid line is provided in the projection area of ​​the second welding strip on the back of the back contact battery. In this way, the fifth grid line and the sixth grid line can be used as discontinuous main grids, improve the welding tension of the welding strip, and can reduce welding stress. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Figure 1 is a structural schematic diagram of the back side of the back contact battery provided by the present invention;

[0052] Figure 2 is another structural schematic diagram of the back side of the back contact battery provided by the present invention;

[0053] Figure 3 is a partial enlarged view of the back side of the back contact battery provided by the present invention;

[0054] Figure 4 It is a schematic structural diagram of an A stack on the back side of a back contact battery provided by the present invention;

[0055] Figure 5 It is a schematic structural diagram of another A stacking layer on the back side of the back contact battery provided by the present invention;

[0056] Figure 6 is a schematic structural diagram of the first dielectric layer on the back side of the back contact battery provided by the present invention;

[0057] Figure 7 It is a schematic structural diagram of a B stack on the back side of a back contact battery provided by the present invention;

[0058] Figure 8 It is a schematic structural diagram of another B stack on the back side of the back contact battery provided by the present invention;

[0059] Fig. 9 It is a structural schematic diagram of a battery assembly provided by the present invention;

[0060] Fig.10 It is a structural schematic diagram of the photovoltaic system provided by the present invention. DETAILED DESCRIPTION

[0061] In order to make the purpose, technical scheme and advantages of the present invention clearer, the present invention 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 invention, and should not be construed as limiting the present invention. In addition, it should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0062] In the description of the present invention, it is necessary to understand that the terms "length", "width", "up", "down", "left", "right", "horizontal", "top", "bottom", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention 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 cannot be understood as a limitation on the present invention.

[0063] 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. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0064] In the description of the present invention, 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 the present invention can be understood according to specific circumstances.

[0065] In the present invention, 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.

[0066] The disclosure below provides many different embodiments or examples to realize different structures of the present invention. In order to simplify the disclosure of the present invention, 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 invention. In addition, the present invention can repeat reference numbers and / or reference letters in different examples, and this repetition is for the purpose of simplification and clarity, which itself does not indicate the relationship between the various embodiments and / or settings discussed. In addition, the examples of various specific processes and materials provided by the present invention, but those of ordinary skill in the art can be aware of the application of other processes and / or the use of other materials.

[0067] In the present invention, "preferred" and "better" are only used to describe implementation methods or embodiments with better effects, and it should be understood that they do not constitute a limitation on the scope of protection of the present invention. In the present invention, the technical features described in an open manner include closed technical solutions composed of the listed features, and also include open technical solutions containing the listed features. In the present invention, when involving numerical ranges, unless otherwise specified, the two endpoints of the numerical range are included.

[0068] The present invention provides a back contact battery 100, such as Figure 1 to Figure 3 As shown, the back side of the back contact battery 100 is provided with a first area 110 and a second area 120 along the second direction, the first area 110 is provided with a first grid line 210 and a second grid line 220 alternately arranged along the second direction, and a first pad point 310 and a second pad point 320 alternately arranged along the first direction, the first pad point 310 is connected to the first main grid, the second pad point 320 is connected to the second main grid, the first pad point 310 is connected to the first grid line 210 in the first area 110, and the second pad point 320 is connected to the second grid line 220 in the first area 110;

[0069] The second region 120 is provided with a third gate line 230 and a fourth gate line 240 alternately arranged along the second direction, the third gate line 230 and the first gate line 210 collect currents of the same polarity, and the fourth gate line 240 and the second gate line 220 collect currents of the same polarity;

[0070] The second area 120 is provided with a fifth gate line 250 and a sixth gate line 260 alternately arranged along the first direction, the fifth gate line 250 is connected to the third gate line 230, the sixth gate line 260 is connected to the fourth gate line 240, the fifth gate line 250 and the sixth gate line 260 both extend along the second direction and both have discontinuous areas, the fifth gate line 250 is provided with a third Pad point 330, the sixth gate line 260 is provided with a fourth Pad point 340, the fifth gate line 250 is provided in the projection area of ​​the first welding strip on the back side of the back contact battery, and the sixth gate line 260 is provided in the projection area of ​​the second welding strip on the back side of the back contact battery.

[0071] In some embodiments, the back side of the back-contact battery 100 is provided with a first region 110 and a second region 120 along a second direction. In some embodiments, the first region 110 is disposed close to an edge of the back side of the back-contact battery 100, and the second region 120 is disposed relative to the first region 110 and away from the edge of the back side of the back-contact battery 100; or, the first region 110 is disposed close to a cutting region on the back side of the back-contact battery 100, and the second region 120 is disposed relative to the first region 110 and away from the cutting region on the back side of the back-contact battery 100.

[0072] In some embodiments, along the second direction, the second region 120 is disposed between two adjacent first regions 110. Figure 2 As shown, the back side of the back contact battery 100 is provided with four first regions 110 and two second regions 120, the first regions 110 are provided at the head end and the tail end of the back side of the back contact battery 100 along the second direction, and the second region 120 is provided between the two first regions 110. In some embodiments, the area of ​​the first region 110 is smaller than the area of ​​the second region 120. It should be noted that, Figure 2 In the figure, only the outlines of the fifth grid line, the sixth grid line, the first pad point, and the second pad point are drawn. In reality, the outlines are filled with slurry.

[0073] The structural design in the first area 110 and the second area 120 is described in detail below:

[0074] (I) First area 110

[0075] The first area 110 is provided with a first gate line 210 and a second gate line 220 alternately arranged along the second direction, and a first Pad point and a second Pad point alternately arranged along the first direction, the first Pad point is connected to the first main gate, the second Pad point is connected to the second main gate, the first Pad point is connected to the first gate line 210 in the first area 110, and the second Pad point is connected to the second gate line 220 in the first area 110.

[0076] In some embodiments, the first direction and the second direction intersect; preferably, the first direction and the second direction are perpendicular to each other; more preferably, the first direction is the lateral direction of the back contact battery 100, and the second direction is the longitudinal direction of the back contact battery 100, and the two are perpendicular to each other. Of course, in other embodiments, the first direction and the second direction may also be other directions, and the present invention is not limited thereto.

[0077] In some embodiments, the first region 110 further includes a first edge gate line and a second edge gate line, the first edge gate line is connected to the first gate line 210 , and the second edge gate line is connected to the second gate line 220 .

[0078] In some embodiments, the first edge gate line and the second edge gate line both extend along the second direction.

[0079] In some embodiments, when the first edge gate line is connected to the first gate line 210, a gap is left between the first edge gate line and the second gate line 220, and when the second edge gate line is connected to the second gate line 220, a gap is left between the second edge gate line and the first gate line 210. In this way, contact between opposite gate lines can be avoided and current collection efficiency can be improved.

[0080] It should be noted that, in some embodiments, “the first Pad point is connected to the first gate line 210 in the first area 110” means that, when the back-contact battery 100 is subjected to electrical performance tests (such as IV testing), EL testing, and hot spot testing, some of the first Pad points can be used as test Pad points, and when in contact with the probe of the testing device, all of the first gate lines 210 in the first area 110 can be connected to the probe of the testing device through the first Pad point. The setting method can be that all the first gate lines 210 are directly connected to the first Pad points as a whole or are electrically connected through other structures.

[0081] Similarly, in some embodiments, “the second Pad point is connected to the second gate line 220 in the first area 110” means that when the back-contact battery 100 is subjected to electrical performance tests (such as IV testing), EL testing, and hot spot testing, some of the second Pad points can be used as test Pad points, and when in contact with the probe of the testing device, all of the second gate lines 220 in the first area 110 can be connected to the probe of the testing device through the second Pad point. The arrangement can be that all the second gate lines 220 are directly connected to the second Pad points as a whole or electrically connected through other structures.

[0082] (II) Second Area 120

[0083] The second region 120 is provided with a third gate line 230 and a fourth gate line 240 alternately arranged along the second direction, the third gate line 230 and the first gate line 210 collect currents of the same polarity, and the fourth gate line 240 and the second gate line 220 collect currents of the same polarity;

[0084] The second area 120 is provided with a fifth gate line 250 and a sixth gate line 260 alternately arranged along the first direction, the fifth gate line 250 is connected to the third gate line 230, the sixth gate line 260 is connected to the fourth gate line 240, the fifth gate line 250 and the sixth gate line 260 both extend along the second direction and both have discontinuous areas, the fifth gate line 250 is provided with a third Pad point 330, the sixth gate line 260 is provided with a fourth Pad point 340, the fifth gate line 250 is provided in the projection area of ​​the first welding strip on the back side of the back contact battery, and the sixth gate line 260 is provided in the projection area of ​​the second welding strip on the back side of the back contact battery.

[0085] In some embodiments, the fifth grid line 250 includes a plurality of first continuous grid lines arranged at intervals along the second direction, a first discontinuous region is provided between two adjacent first continuous grid lines, and the length of the first continuous grid line along the second direction is greater than the length of the first discontinuous region. Preferably, the first continuous grid line is connected to 3 to 20 of the third grid lines 230; more preferably, the first continuous grid line is connected to 3 to 5 of the third grid lines 230. In some embodiments, a fourth grid line 240 is provided in the first discontinuous region. Preferably, one fourth grid line 240 is provided in the first discontinuous region. This can not only improve the current transmission efficiency and reduce the resistance loss; it also has an anti-break grid effect, further improving the reliability of the battery and components.

[0086] In some embodiments, the fourth grid line disposed in the first discontinuous region may be continuous and uninterrupted from one end edge of the back side of the solar cell along the first direction to the other end edge of the back side of the solar cell along the first direction.

[0087] In some embodiments, the third Pad point 330 is provided on the first continuous grid line. Preferably, each of the first continuous grid lines is provided with a third Pad point 330. More preferably, each of the first continuous grid lines is provided with one third Pad point 330. The third Pad point 330 is used for welding with the first welding strip, which can increase the welding tension of the welding strip and improve the reliability of the solar module. In some embodiments, the area of ​​the third Pad point 330 is smaller than the area of ​​the first Pad point 310, which is conducive to reducing welding stress, saving slurry, and improving bifaciality.

[0088] In some embodiments, the sixth grid line 260 includes a second continuous grid line and a second discontinuous region arranged alternately along the second direction, and the length of the second continuous grid line along the second direction is greater than the length of the second discontinuous region. Preferably, the second continuous grid line is connected to 3 to 20 of the fourth grid lines 240; more preferably, the second continuous grid line is connected to 3 to 5 of the fourth grid lines 240. In some embodiments, a third grid line 230 is provided in the second discontinuous region; preferably, one third grid line 230 is provided in the second discontinuous region. This can not only improve the current transmission efficiency and reduce the resistance loss; it also has an anti-break grid effect, further improving the reliability of the battery and components.

[0089] In some embodiments, the third grid line disposed in the second discontinuous region may be continuous and uninterrupted from one end edge of the back side of the solar cell along the first direction to the other end edge of the back side of the solar cell along the first direction.

[0090] In some embodiments, the fourth Pad point 340 is provided on the second continuous grid line. Preferably, each of the second continuous grid lines is provided with a fourth Pad point 340. More preferably, each of the second continuous grid lines is provided with one fourth Pad point 340. The fourth Pad point 340 is used for welding with the second welding strip, which can increase the welding tension of the welding strip and improve the reliability of the solar module. In some embodiments, the area of ​​the fourth Pad point 340 is smaller than the area of ​​the second Pad point 320, which is conducive to reducing welding stress.

[0091] In addition, in some embodiments, the fifth grid line is not set in the vertical direction of the first Pad point closest to the edge of the back contact battery; and / or the sixth grid line is not set in the vertical direction of the second Pad point closest to the edge of the back contact battery.

[0092] In some embodiments, the third Pad point and the fourth Pad point are not collinear along the first direction. This can increase welding tension and reduce welding warpage. Further, the second area 120 also includes a third edge grid line and a fourth edge grid line, the third edge grid line is connected to the third grid line 230, and the fourth edge grid line is connected to the fourth grid line 240.

[0093] In some embodiments, the third edge gate line and the fourth edge gate line both extend along the second direction.

[0094] In some embodiments, when the third edge grid line is connected to the third grid line 230, a gap is left between the third edge grid line and the fourth grid line 240, and when the fourth edge grid line is connected to the fourth grid line 240, a gap is left between the fourth edge grid line and the third grid line 230. In this way, contact between opposite-sex grid lines can be avoided and current collection efficiency can be improved.

[0095] In some embodiments, the first direction and the second direction intersect; preferably, the first direction and the second direction are perpendicular to each other; more preferably, the first direction is the lateral direction of the back contact battery 100, and the second direction is the longitudinal direction of the back contact battery 100, and the two are perpendicular to each other. Of course, in other embodiments, the first direction and the second direction may also be other directions, and the present invention is not limited thereto.

[0096] In addition to the above-mentioned gate line structure design, in some embodiments, the following anti-hot spot and reverse leakage designs are also performed, as follows:

[0097] In some embodiments, a first doping layer is disposed under the first gate line 210, a second doping layer is disposed under the second gate line 220, a third doping layer 430 is disposed under the third gate line 230, a fourth doping layer 440 is disposed under the fourth gate line 240, a fifth doping layer 450 is disposed under the fifth gate line 250, and a sixth doping layer 460 is disposed under the sixth gate line 260. The first doping layer, the third doping layer 430, and the fifth doping layer 450 have the same polarity, the second doping layer, the fourth doping layer 440, and the sixth doping layer 460 have the same polarity, and the first doping layer and the second doping layer have opposite polarities. The first doping layer, the second doping layer, the third doping layer, and the fourth doping layer are not labeled in the drawings.

[0098] In some embodiments, the fifth doping layer 450 is disposed in the third region, and a first spacing region is disposed between adjacent third regions; and the sixth doping layer 460 is disposed in the fourth region, and a second spacing region is disposed between adjacent fourth regions. Preferably, the area of ​​the third region is larger than the area of ​​the first spacing region; and the area of ​​the fourth region is larger than the area of ​​the second spacing region.

[0099] On this basis, if Figure 4 As shown, in some embodiments, an A stack 510 is provided on the fifth doping layer 450, and the A stack 510 includes a first A stack 511, the first A stack 511 covers a partial area of ​​the fifth doping layer 450, and a first A spacing area 611 extending along the second direction is left on the fifth doping layer 450, the first A stack 511 is connected to the fourth doping layer 440 adjacent to the fifth doping layer 450, and the first A stack 511 is a doping layer, and the doping polarity of the doping layer is the same as the doping polarity of the fourth doping layer 440.

[0100] It should be noted that, in this embodiment, by introducing the A stack 510, the A stack 510 includes a first A stack 511, the first A stack 511 covers a part of the fifth doping layer 450, and the doping polarity of the A stack 510 is different from the doping polarity of the fifth doping layer 450, thereby forming a leakage contact structure, and the leakage contact structure can improve the leakage capacity of the solar cell and improve the reverse leakage characteristics. In this way, with the improvement of the leakage capacity, at the component end, when the solar cell is blocked, the voltage at both ends of the blocked solar cell will be reduced, and the heating power of the solar cell will be reduced, thereby achieving the purpose of controlling the risk of hot spots. At the same time, the leakage contact structure has a protective effect on the hot spots caused by defects in the silicon wafer itself, which can reduce or even cancel the requirements for the control of defects, and improve the manufacturing capacity of solar cells while reducing the risk of hot spots caused by defects.

[0101] In some embodiments, in the first direction, the width of the first A-spaced region 611 is greater than the width of the fifth gate line 250; and / or the width of the fifth gate line 250 in the first A-spaced region 611 is less than the width of the fifth gate line 250 outside the first A-spaced region 611. In this way, while preparing the leakage contact structure on the fifth doped layer 450, a suitable area is reserved for preparing the fifth gate line 250, so as to prevent the fifth gate line 250 from directly contacting the oppositely doped layer. In some embodiments, as Figure 6As shown, a first dielectric layer 710 is provided between the A stack 510 and the fifth doped layer 450. Here, the fifth doped layer 450, the first dielectric layer 710 and the A stack 510 are connected in sequence. The first dielectric layer includes but is not limited to silicon dioxide, aluminum oxide, and silicon nitride. These materials have a high dielectric constant and excellent passivation performance. The provision of the first dielectric layer plays an important role in improving the efficiency, stability and life of the battery.

[0102] In some embodiments, the A stack 510 is arranged in the third area; the setting position of the A stack avoids the setting position of the third Pad point, so that the probability of leakage can be reduced. In some embodiments, the fifth gate line 250 includes a plurality of first continuous gate lines arranged at intervals along the second direction, and a first discontinuous area is arranged between two adjacent first continuous gate lines; the first continuous gate line is connected to 3 to 20 of the third gate lines. Exemplarily, the first continuous gate line is connected to 3 of the third gate lines, and the first A stack 511 is provided at the intersection of the first continuous gate line and the 3 third gate lines, or the first continuous gate line is provided at the intersection of the first continuous gate line and the 2 third gate lines, or the first A stack 511 is provided at the intersection of the first continuous gate line and 1 of the third gate lines.

[0103] Furthermore, if the coverage area of ​​the A stack 510 on the fifth doping layer 450 is too large, it will cause too much efficiency loss, and if the coverage area of ​​the A stack 510 on the fifth doping layer 450 is too small, it will not have a good reverse leakage effect. Therefore, it is necessary to reasonably design the number of the A stack 510 on the fifth doping layer 450.

[0104] like Figure 5 As shown, in some embodiments, the A stack 510 further includes a second A stack 512, the second A stack 512 covers a portion of the fifth doping layer 450, and a second A spacing region 612 extending along the second direction is formed between the first A stack 511 and the second A stack 512, the first A stack 511 and the second A stack 512 are respectively connected to the fourth doping layer 440 adjacent to the fifth doping layer 450, and the first A stack 511 and the second A stack 512 are doping layers, and the doping polarity of the doping layer is the same as the doping polarity of the fourth doping layer 440. The present invention introduces the second A stack 512 on the basis of the first A stack 511, which can improve the reverse leakage characteristics while avoiding excessive efficiency loss, thereby ensuring the conversion efficiency of the solar cell.

[0105] As above, this embodiment introduces the A stack 510 including the first A stack 511 and the second A stack 512, wherein the first A stack 511 and the second A stack 512 cover a part of the fifth doping layer 450, and the doping polarity of the first A stack 511 and the second A stack 512 is different from the doping polarity of the fifth doping layer 450, thereby forming a leakage contact structure, and the leakage contact structure can improve the leakage capacity of the solar cell and improve the reverse leakage characteristics. In this way, with the improvement of the leakage capacity, at the component end, when the solar cell is shielded, the voltage at both ends of the shielded solar cell will be reduced, and the heating power of the solar cell will be reduced, thereby achieving the purpose of controlling the risk of hot spots. At the same time, the leakage contact structure has a protective effect on the hot spots caused by defects in the silicon wafer itself, which can reduce or even cancel the requirements for the control of defects, and improve the manufacturing capacity of solar cells while reducing the risk of hot spots caused by defects.

[0106] In some embodiments, in the first direction, the width of the second A-spaced region 612 is greater than the width of the fifth gate line 250; and / or the width of the fifth gate line 250 in the second A-spaced region 612 is less than the width of the fifth gate line 250 outside the second A-spaced region 612. In this way, while the leakage contact structure is prepared on the fifth doped layer 450, a suitable area is reserved for preparing the fifth gate line 250, so as to prevent the fifth gate line 250 from directly contacting the oppositely doped layer.

[0107] In some embodiments, a first dielectric layer is provided between the A stack 510 and the fifth doped layer 450. Here, the fifth doped layer 450, the first dielectric layer and the A stack 510 are connected in sequence. The first dielectric layer includes but is not limited to silicon dioxide, aluminum oxide, and silicon nitride. These materials have high dielectric constants and excellent passivation properties. The provision of the first dielectric layer plays an important role in improving the efficiency, stability and life of the battery.

[0108] In some embodiments, the A stack 510 is arranged in the third region; the setting position of the A stack avoids the setting position of the third Pad point, so that the leakage probability can be reduced. In some embodiments, the fifth gate line 250 includes a plurality of first continuous gate lines arranged at intervals along the second direction, and a first discontinuous region is arranged between two adjacent first continuous gate lines; the first continuous gate line is connected to 3 to 20 of the third gate lines. Exemplarily, the first continuous gate line is connected to 3 of the third gate lines, and the first A stack 511 and the second A stack 512 are arranged at the intersection of the first continuous gate line and the 3 third gate lines, or the first continuous gate line and the intersection of 2 third gate lines are provided with the first A stack 511 and the second A stack 512, or the first continuous gate line and the intersection of 1 third gate line are provided with the first A stack 511 and the second A stack 512.

[0109] In addition, the leakage contact structure may be provided on the sixth doping layer 460, as follows:

[0110] In some embodiments, Figure 7 As shown, a B stack 520 is provided on the sixth doping layer 460, and the B stack 520 includes a first B stack 521, the first B stack 521 covers a partial area of ​​the sixth doping layer 460, and a first B spacing area 621 extending along the second direction is left on the sixth doping layer 460, the first B stack 521 is connected to the third doping layer 430 adjacent to the sixth doping layer 460, and the first B stack 521 is a doping layer, and the doping polarity of the doping layer is the same as the doping polarity of the third doping layer 430.

[0111] It should be noted that, in this embodiment, by introducing a B stack 520, the B stack 520 includes a first B stack 521, the first B stack 521 covers a portion of the sixth doping layer 460, and the doping polarity of the B stack 520 is different from the doping polarity of the sixth doping layer 460, thereby forming a leakage contact structure, and the leakage contact structure can improve the leakage capacity of the solar cell and improve the reverse leakage characteristics. In this way, with the improvement of the leakage capacity, at the component end, when the solar cell is shielded, the voltage at both ends of the shielded solar cell will be reduced, and the heating power of the solar cell will be reduced, thereby achieving the purpose of controlling the risk of hot spots. At the same time, the leakage contact structure has a protective effect on the hot spots caused by defects in the silicon wafer itself, which can reduce or even cancel the requirements for the control of defects, and improve the manufacturing capacity of solar cells while reducing the risk of hot spots caused by defects.

[0112] In some embodiments, the width of the first B-spacer region 621 or the second B-spacer region 622 is greater than the width of the sixth gate line 260. And / or, the width of the sixth gate line 260 in the first B-spacer region 621 is less than the width of the sixth gate line 260 outside the first B-spacer region 621. In this way, while the leakage contact structure is prepared on the sixth doping layer 460, a suitable area is reserved for preparing the sixth gate line 260, so as to prevent the sixth gate line 260 from directly contacting the oppositely doped layer.

[0113] In some embodiments, a second dielectric layer is provided between the B stack 520 and the sixth doped layer 460. Here, the sixth doped layer 460, the second dielectric layer and the B stack 520 are connected in sequence. The second dielectric layer includes but is not limited to silicon dioxide, aluminum oxide, and silicon nitride. These materials have a high dielectric constant and excellent passivation performance. The provision of the fourth dielectric layer plays an important role in improving the efficiency, stability and life of the battery.

[0114] In some embodiments, the B stack 520 is arranged in the fourth region; the setting position of the B stack avoids the setting position of the fourth Pad point, so that the leakage probability can be reduced. In some embodiments, the sixth gate line 260 includes a second continuous gate line and a second discontinuous region arranged alternately along the second direction; the second continuous gate line is connected to 3 to 20 of the fourth gate lines. Exemplarily, the second continuous gate line is connected to 3 of the fourth gate lines, and the first B stack 521 is provided at the intersection of the second continuous gate line and the 3 fourth gate lines, or the first B stack 521 is provided at the intersection of the second continuous gate line and 2 of the fourth gate lines, or the second continuous gate line is provided at the intersection of 1 of the fourth gate lines.

[0115] Furthermore, if the coverage area of ​​the B stack 520 on the sixth doping layer 460 is too large, it will cause too much efficiency loss, and if the coverage area of ​​the B stack 520 on the sixth doping layer 460 is too small, it will not have a good reverse leakage effect. Therefore, it is necessary to reasonably design the number of the B stack 520 on the sixth doping layer 460.

[0116] like Figure 8As shown, in some embodiments, the B stack 520 also includes a second B stack 522, the second B stack 522 covers a partial area of ​​the sixth doping layer 460, and a second B spacing region 622 extending along the second direction is formed between the first B stack 521 and the second B stack 522, the first B stack 521 and the second B stack 522 are respectively connected to the third doping layer 430 adjacent to the sixth doping layer 460, and the first B stack 521 and the second B stack 522 are doping layers, and the doping polarity of the doping layer is the same as the doping polarity of the third doping layer 430.

[0117] As above, this embodiment introduces a B stack 520, and the B stack 520 includes a first B stack 521 and a second B stack 522, and the first B stack 521 and the second B stack 522 cover a part of the sixth doping layer 460, and the doping polarity of the first B stack 521 and the second B stack 522 is different from the doping polarity of the sixth doping layer 460, thereby forming a leakage contact structure, and the leakage contact structure can improve the leakage capacity of the solar cell and improve the reverse leakage characteristics. In this way, with the improvement of the leakage capacity, at the component end, when the solar cell is blocked, the voltage at both ends of the blocked solar cell will be reduced, and the heating power of the solar cell will be reduced, thereby achieving the purpose of controlling the risk of hot spots. At the same time, the leakage contact structure has a protective effect on the hot spots caused by defects in the silicon wafer itself, which can reduce or even cancel the requirements for the control of defects, and improve the manufacturing capacity of solar cells while reducing the risk of hot spots caused by defects.

[0118] In some embodiments, the width of the second B spacing region 622 is greater than the width of the sixth gate line 260; and / or the width of the sixth gate line 260 in the second B spacing region 622 is less than the width of the sixth gate line 260 outside the second B spacing region 622. In this way, while the leakage contact structure is prepared on the sixth doping layer 460, a suitable area is reserved for preparing the sixth gate line 260, so as to prevent the sixth gate line 260 from directly contacting the oppositely doped layer.

[0119] In some embodiments, a second dielectric layer is provided between the B stack 520 and the sixth doped layer 460. Here, the sixth doped layer 460, the second dielectric layer and the B stack 520 are connected in sequence. The second dielectric layer includes but is not limited to silicon dioxide, aluminum oxide, and silicon nitride. These materials have a high dielectric constant and excellent passivation performance. The provision of the second dielectric layer plays an important role in improving the efficiency, stability and life of the battery.

[0120] In some embodiments, the B stack 520 is arranged in the fourth region; the setting position of the B stack avoids the setting position of the fourth Pad point, so that the leakage probability can be reduced. In some embodiments, the sixth gate line 260 includes a second continuous gate line and a second discontinuous region arranged alternately along the second direction; the second continuous gate line is connected to 3 to 20 of the fourth gate lines. Exemplarily, the second continuous gate line is connected to 3 of the fourth gate lines, and the first B stack 521 and the second B stack 522 are provided at the intersection of the second continuous gate line and the 3 fourth gate lines, or the first B stack 521 and the second B stack 522 are provided at the intersection of the second continuous gate line and 2 of the fourth gate lines, or the first B stack 521 and the second B stack 522 are provided at the intersection of the second continuous gate line and 1 of the fourth gate lines.

[0121] To sum up, in the back-contact battery 100 provided by the present invention, the first Pad point and the second Pad point are larger in area than a single fine grid, and the first Pad point is electrically connected to the first grid line 210 in the first area 110, and the second Pad point is electrically connected to the second grid line 220 in the first area 110. When the back-contact battery 100 is subjected to electrical performance tests (such as IV tests), EL tests, and hot spot tests, the positive and negative probes of the testing device can form stable contact with the first Pad point and the second Pad point, respectively, thereby reducing the difficulty of testing and improving test reliability and stability.

[0122] Furthermore, the fifth grid line 250 and the sixth grid line 260 can be used as discontinuous main grids to increase the welding tension of the welding strip; at the same time, the current transmission efficiency can be improved and the resistance loss can be reduced; and it has an anti-breaking grid effect, further improving the reliability of the battery and components.

[0123] Furthermore, the present invention is provided with a leakage contact structure in the doping region of the fifth grid line 250 and the sixth grid line 260, namely the A stack 510 and the B stack 520 mentioned above, and the leakage contact structure can improve the leakage capacity of the solar cell and improve the reverse leakage characteristics. In this way, as the leakage capacity is improved, at the component end, when the solar cell is shielded, the voltage at both ends of the shielded solar cell will be reduced, and the heating power of the solar cell will be reduced, thereby achieving the purpose of controlling the risk of hot spots. At the same time, the leakage contact structure has a protective effect on the hot spots caused by defects in the silicon wafer itself, which can reduce or even cancel the requirements for the control of defects, and improve the manufacturing capacity of solar cells while reducing the risk of hot spots caused by defects.

[0124] In addition to the above-mentioned back contact cell 100, Fig. 9 As shown, the present invention also provides a back contact battery 100 string, comprising:

[0125] A plurality of back contact cells 100 as described above;

[0126] A first welding strip and a second welding strip, the fifth grid line is arranged in the projection area of ​​the first welding strip on the back side of the back contact battery, and the sixth grid line is arranged in the projection area of ​​the second welding strip on the back side of the back contact battery.

[0127] The present invention also provides a battery assembly 10, comprising the back contact battery string 100.

[0128] In some embodiments, multiple back-contact solar cells in the battery assembly 10 are connected in series to form a battery string, and each battery string can be connected in series, in parallel, or in a combination of series and parallel to achieve current bus output. For example, the connection between each battery can be achieved by setting a welding bar, and the connection between multiple battery strings can be achieved by a bus bar.

[0129] In some embodiments, the back contact cell 100 is connected via the first welding ribbon and the second welding ribbon, the first pad is connected to the first welding ribbon, and the second pad point is connected to the second welding ribbon.

[0130] In some embodiments, the battery assembly 10 may also include a metal frame, a back plate, photovoltaic glass and an adhesive film. The adhesive film may be filled between the front and photovoltaic glass, the back and the back plate of the back contact solar cell, and the adjacent 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, which may be selected according to actual conditions and is not limited here.

[0131] Photovoltaic glass can cover the adhesive film on the front of the back contact solar cell. 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 solar cell without affecting the efficiency of the back contact solar cell as much as possible. At the same time, the adhesive film can bond the photovoltaic glass and the back contact solar cell together. The presence of the adhesive film can seal and insulate the back contact solar cell and make it waterproof and moisture-proof.

[0132] The backplane can be attached to the adhesive film on the back of the back-contact solar cell. The backplane can protect and support the back-contact solar cell 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. The specific configuration can be made according to the specific situation and is not limited here. The whole composed of the backplane, back-contact solar cell, 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 10 and can stably support and install the battery assembly 10. For example, the battery assembly 10 can be installed at the required location through the metal frame.

[0133] Furthermore, if Fig.10 As shown, the present invention also provides a photovoltaic system 1, which can be used in photovoltaic power stations, such as ground power stations, rooftop power stations, water power stations, etc., and can also be used in 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 1 are not limited to this, that is, the photovoltaic system 1 can be used in all fields that require solar energy to generate electricity. Taking the photovoltaic power generation system network as an example, the photovoltaic system 1 may include a photovoltaic array, a junction box and an inverter. The photovoltaic array can be an array combination of multiple battery assemblies 10. For example, multiple battery assemblies 10 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.

[0134] 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.

[0135] The above disclosure is only a preferred embodiment of the present invention, which certainly cannot be used to limit the scope of the present invention. Therefore, equivalent changes made according to the claims of the present invention are still within the scope of the present invention.

Claims

1. A back contact battery, characterized in that: The back side of the back contact battery is provided with a first area and a second area along a second direction, the first area is provided with a first grid line and a second grid line alternately arranged along the second direction, and a first pad point and a second pad point alternately arranged along the first direction, the first pad point is connected to a first main grid, the second pad point is connected to a second main grid, the first pad point is connected to the first grid line in the first area, and the second pad point is connected to the second grid line in the first area; The second region is provided with a third gate line and a fourth gate line alternately arranged along the second direction, the third gate line and the first gate line collect currents of the same polarity, and the fourth gate line and the second gate line collect currents of the same polarity; A fifth gate line and a sixth gate line alternately arranged along the first direction are provided in the second area, the fifth gate line is connected to the third gate line, the sixth gate line is connected to the fourth gate line, the fifth gate line and the sixth gate line both extend along the second direction and both have discontinuous areas, a third Pad point is provided on the fifth gate line, a fourth Pad point is provided on the sixth gate line, the fifth gate line is provided on the extension line of the first main gate in the second direction, and the sixth gate line is provided on the extension line of the second main gate in the second direction.

2. The back contact cell according to claim 1, characterized in that The area of ​​the third Pad point is smaller than the area of ​​the first Pad point; And / or, the area of ​​the fourth Pad point is smaller than the area of ​​the second Pad point.

3. The back contact cell according to claim 1, characterized in that The fifth gate line includes a plurality of first continuous gate lines arranged at intervals along the second direction, a first discontinuous area is provided between two adjacent first continuous gate lines, and a length of the first continuous gate line along the second direction is greater than a length of the first discontinuous area.

4. The back contact cell according to claim 3, characterized in that The first continuous gate line is connected to 3 to 20 third gate lines; A fourth gate line is disposed in the first discontinuous region.

5. The back contact cell according to claim 3, characterized in that The third Pad point is arranged on the first continuous gate line.

6. The back contact cell according to claim 5, characterized in that A third Pad point is disposed on each of the first continuous grid lines.

7. The back contact cell according to claim 6, characterized in that Each of the first continuous grid lines is provided with a third Pad point.

8. The back contact cell according to claim 1, characterized in that The sixth gate lines include a plurality of second continuous gate lines arranged at intervals along a second direction, a second discontinuous region is arranged between two adjacent second continuous gate lines, and a length of the second continuous gate lines along the second direction is greater than a length of the second discontinuous region.

9. The back contact cell according to claim 8, characterized in that The second continuous grid lines are connected to 3 to 20 fourth grid lines; A third gate line is disposed in the second discontinuous region.

10. The back contact cell according to claim 8, characterized in that The fourth Pad point is located on the second continuous gate line.

11. The back contact cell according to claim 10, characterized in that Each of the second continuous grid lines is provided with a fourth Pad point.

12. The back contact cell according to claim 11, characterized in that Each of the second continuous grid lines is provided with a fourth Pad point.

13. The back contact cell according to claim 1, characterized in that The first region is disposed at a position close to an edge of the back side of the back contact battery, and the second region is disposed at a position far from an edge of the back side of the back contact battery relative to the first region; or, The first region is disposed at a position close to a cutting region on the back side of the back contact cell, and the second region is disposed at a position farther from the cutting region on the back side of the back contact cell than the first region.

14. The back contact cell according to claim 1, characterized in that Along the second direction, the second area is located between two adjacent first areas.

15. The back contact cell according to claim 1, characterized in that A first doping layer is provided under the first gate line, a second doping layer is provided under the second gate line, a third doping layer is provided under the third gate line, a fourth doping layer is provided under the fourth gate line, a fifth doping layer is provided under the fifth gate line, and a sixth doping layer is provided under the sixth gate line. The first doping layer, the third doping layer and the fifth doping layer have the same polarity, the second doping layer, the fourth doping layer and the sixth doping layer have the same polarity, and the first doping layer and the second doping layer have opposite polarities.

16. The back contact cell according to claim 15, characterized in that The fifth doping layer is disposed in the third region, and a first spacing region is disposed between adjacent third regions; Furthermore, the sixth doping layer is disposed in a fourth region, and a second spacing region is disposed between adjacent fourth regions.

17. The back contact cell according to claim 16, characterized in that An A stack is provided on the fifth doping layer, and the A stack includes a first A stack, the first A stack covers a partial area of ​​the fifth doping layer, and a first A spacing area extending along the second direction is left on the fifth doping layer, the first A stack is connected to the fourth doping layer adjacent to the fifth doping layer, and the first A stack is a doping layer, and the doping polarity of the doping layer is the same as the doping polarity of the fourth doping layer.

18. The back contact cell according to claim 17, characterized in that The A stack also includes a second A stack, which covers a partial area of ​​the fifth doping layer, and a second A spacing area extending along the second direction is formed between the first A stack and the second A stack, the first A stack and the second A stack are respectively connected to the fourth doping layer adjacent to the fifth doping layer, and the first A stack and the second A stack are doping layers, and the doping polarity of the doping layers is the same as the doping polarity of the fourth doping layer.

19. The back contact cell according to claim 18, characterized in that A width of the first A-spaced region or the second A-spaced region is greater than a width of the fifth gate line.

20. The back contact cell according to claim 17 or 18, characterized in that A first dielectric layer is disposed between the A stack and the fifth doped layer.

21. The back contact cell according to claim 17 or 18, characterized in that The A stack is arranged in the third region; The arrangement position of the A stack avoids the arrangement position of the third Pad point.

22. The back contact cell according to claim 15, characterized in that A B stack is provided on the sixth doping layer, and the B stack includes a first B stack, the first B stack covers a partial area of ​​the sixth doping layer, and a first B spacing area extending along the second direction is left on the sixth doping layer, the first B stack is connected to the third doping layer adjacent to the sixth doping layer, and the first B stack is a doping layer, and the doping polarity of the doping layer is the same as the doping polarity of the third doping layer.

23. The back contact cell according to claim 22, characterized in that The B stack also includes a second B stack, which covers a partial area of ​​the sixth doping layer, and a second B spacing area extending along the second direction is formed between the first B stack and the second B stack, the first B stack and the second B stack are respectively connected to the third doping layer adjacent to the sixth doping layer, and the first B stack and the second B stack are doping layers, and the doping polarity of the doping layers is the same as the doping polarity of the third doping layer.

24. The back contact cell according to claim 23, characterized in that A width of the first B-spaced region or the second B-spaced region is greater than a width of the sixth gate line.

25. The back contact cell according to claim 22 or 23, characterized in that A second dielectric layer is disposed between the B stack and the sixth doped layer.

26. The back contact cell according to claim 22 or 23, characterized in that The B stack is arranged in the fourth region; The B stack is disposed at a position away from the fourth Pad point.

27. The back contact cell according to claim 1, characterized in that The first region further includes a first edge gate line and a second edge gate line, wherein the first edge gate line is connected to the first gate line, and the second edge gate line is connected to the second gate line.

28. The back contact cell according to claim 1, characterized in that The second region further includes a third edge gate line and a fourth edge gate line, wherein the third edge gate line is connected to the third gate line, and the fourth edge gate line is connected to the fourth gate line.

29. The back contact cell according to claim 1, characterized in that The fifth grid line is not arranged in the vertical direction of the first Pad point closest to the edge of the back contact battery; And / or, the sixth grid line is not arranged in the vertical direction of the second Pad point closest to the edge of the back contact cell.

30. The back contact cell according to claim 1, characterized in that The third Pad point and the fourth Pad point are not collinear along the first direction.

31. A back contact battery string, characterized in that: include: A plurality of back contact cells according to any one of claims 1 to 30; A first welding strip and a second welding strip, the fifth grid line is arranged in the projection area of ​​the first welding strip on the back side of the back contact battery, and the sixth grid line is arranged in the projection area of ​​the second welding strip on the back side of the back contact battery.

32. A battery assembly, characterized in that: Comprising a back-contact cell string as described in claim 31.

33. A photovoltaic system, characterized in that: Comprising a battery assembly as described in claim 32.

Images