Back contact cells and photovoltaic modules

Abstract

The application provides a back contact cell and a photovoltaic module. The back contact cell comprises a cell body, a plurality of first sub-grids and a plurality of second sub-grids located on the cell body, the first sub-grids and the second sub-grids extend along a first direction and are alternately and spacedly arranged along a second direction, the distance between two adjacent sub-grid segments along the first direction is a first distance, a plurality of first insulation parts are located on the side of the plurality of sub-grid segments away from the cell body and are spacedly arranged along the first direction, the distance between the projections of the end portions of the sub-grid segments on the cell body along the first direction is a second distance, a plurality of welding parts are located on the side of the sub-grid segments away from the cell body, the difference between the first distance and the second distance is greater than or equal to 0.3 mm, and the difference between the second distance and the width of the welding part in the first direction is greater than or equal to 0.3 mm, so as to avoid the problems of offset, splitting or incomplete shape of the solidified solder and ensure the welding reliability.

Description

Technical Field

[0001] This application relates to the field of solar energy technology, and more specifically, to a back contact battery and a photovoltaic module. Background Technology

[0002] In the current manufacturing process of back contact batteries, there are problems such as displacement, splitting, or incomplete shape after the solder paste or glue has cured, resulting in poor welding reliability. Summary of the Invention

[0003] The main objective of this application is to provide a back-contact battery and a photovoltaic module to at least solve the problem of poor soldering reliability of solder paste or gray glue for back-contact batteries in the prior art.

[0004] To achieve the above objectives, according to one aspect of this application, a back-contact battery is provided, comprising: a battery body; a plurality of first sub-grids and a plurality of second sub-grids located on the battery body, the first sub-grids and second sub-grids extending along a first direction and alternately spaced along a second direction, the first sub-grids and second sub-grids having different polarities, the first direction intersecting the second direction, each of the first sub-grids and second sub-grids including a plurality of sub-grid segments spaced along the first direction, the distance between two adjacent sub-grid segments along the first direction being a first distance; a plurality of first insulating portions located on the side of the plurality of sub-grid segments away from the battery body, spaced along the first direction, the projection of the end of a sub-grid segment on the battery body falling within the projection of the first insulating portion on the battery body, the distance between two adjacent first insulating portions along the first direction being a second distance; a plurality of welded portions located on the side of the sub-grid segments away from the battery body, the welded portions being located between two adjacent first insulating portions along the first direction; the difference between the first distance and the second distance is greater than or equal to 0.3 mm, and the difference between the second distance and the width of the welded portion in the first direction is greater than or equal to 0.3 mm.

[0005] Optionally, the sub-gate segments correspond one-to-one with the first insulating portion, the distance between two adjacent sub-gate segments along the second direction is the third distance, the distance between the edge of the first insulating portion and the corresponding sub-gate segment is the fourth distance, and the difference between the third distance and the fourth distance is greater than or equal to 0.15mm.

[0006] Optionally, the first insulating portion is axially symmetrical about the sub-gate segment.

[0007] Optionally, the width of the first insulating portion in the second direction is 0.2 to 0.6 mm.

[0008] Optionally, the back contact battery further includes: a plurality of main grids extending along the second direction and spaced apart along the first direction, the main grids being located between two adjacent sub-grid segments along the first direction, and the welded portion covering a portion of the main grids.

[0009] Optionally, the polarity of the main grid is the same as that of the first sub-grid, the sub-grid segment of the second sub-grid is the second sub-grid segment, and the back contact battery further includes: a plurality of second insulating portions extending along the first direction and spaced apart along the second direction, the sub-grid segments, the second insulating portions and the main grid are arranged along a direction away from the battery body, the projections of the ends of two adjacent second sub-grid segments along the first direction on the battery body are located in the projection of the second insulating portion on the battery body, and the projection of the main grid on the battery body overlaps with the projection of the second insulating portion on the battery body.

[0010] Optionally, the plurality of second insulating portions include a plurality of edge insulating portions and a plurality of non-edge insulating portions, wherein the minimum distance between the edge insulating portion and the surface edge of the battery body is less than the minimum distance between the non-edge insulating portion and the surface edge.

[0011] Optionally, the widths of the edge insulating portion, the non-edge insulating portion, and the first insulating portion decrease sequentially in the first direction.

[0012] Optionally, the width of the edge insulating portion in the first direction is 3 to 20 mm, and the width of the non-edge insulating portion in the first direction is 2 to 20 mm.

[0013] To achieve the above objectives, according to one aspect of this application, a photovoltaic module is provided, comprising: a back contact battery as described in any of the above.

[0014] By applying the technical solution of this application, the dimensional relationship between the sub-grid segments, the first insulating part, and the welding part is quantified in the screen design. The difference between the first distance and the second distance is limited to be greater than or equal to 0.3 mm, and the difference between the second distance and the width of the welding part in the first direction is greater than or equal to 0.3 mm. The first distance is the distance between two adjacent sub-grid segments along the first direction, and the second distance is the distance between two adjacent first insulating parts along the first direction. This ensures that the welded part has a good shape after curing and avoids problems such as solder displacement, splitting, or incomplete shape after curing, thus ensuring good welding reliability. Attached Figure Description

[0015] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application. The illustrative embodiments and descriptions of this application are used to explain this application and do not constitute an undue limitation of this application. In the drawings:

[0016] Figure 1 A schematic diagram of a local structure of a back contact battery according to an embodiment of this application is shown;

[0017] Figure 2 A schematic diagram of a local structure of another back-contact battery provided according to an embodiment of this application is shown;

[0018] Figure 3 A schematic diagram of the welding effect of a comparative example 1 of a back contact battery provided according to an embodiment of this application is shown;

[0019] Figure 4 A schematic diagram of the welding effect of another back contact battery provided according to an embodiment of this application is shown;

[0020] Figure 5 A schematic diagram showing the welding effect of Embodiment 1 of a back contact battery provided according to an embodiment of this application is illustrated;

[0021] Figure 6 A schematic diagram of the welding effect of another embodiment 2 of the back contact battery provided according to an embodiment of this application is shown.

[0022] The above figures include the following reference numerals:

[0023] 1. Battery body; 2. First sub-grid; 3. Second sub-grid; 4. Sub-grid segment; 5. First insulating part; 6. Welded part; 7. Main grid; 42. First sub-grid segment; 43. Second sub-grid segment; 8. Second insulating part; 81. Edge insulating part; 82. Non-edge insulating part. Detailed Implementation

[0024] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0025] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort should fall within the scope of protection of the present application.

[0026] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate for the embodiments of this application described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0027] As described in the background section, the soldering reliability of solder paste or gray glue for back contact batteries is poor in the prior art. To solve this technical problem, embodiments of this application provide a back contact battery and a photovoltaic module.

[0028] This application provides a back contact battery, such as... Figure 1 As shown, the aforementioned back contact battery includes:

[0029] Battery body 1;

[0030] Multiple first sub-gates 2 and multiple second sub-gates 3 are located on the battery body 1. The first sub-gates 2 and the second sub-gates 3 extend along the first direction x and are arranged alternately along the second direction y. The first sub-gates 2 and the second sub-gates 3 have different polarities. The first direction x and the second direction y intersect. Both the first sub-gates 2 and the second sub-gates 3 include multiple sub-gate segments 4 arranged at intervals along the first direction x. The distance between two adjacent sub-gate segments 4 along the first direction x is the first distance a.

[0031] Multiple first insulating portions 5 are located on the side of multiple sub-grid segments 4 away from the battery body 1 and are arranged at intervals along the first direction x. The projection of the end of the sub-grid segment 4 on the battery body 1 is located in the projection of the first insulating portion 5 on the battery body 1. The distance between two adjacent first insulating portions 5 along the first direction x is the second distance c.

[0032] Multiple welded portions 6 are located on the side of the sub-grid segment 4 away from the battery body 1, and the welded portions 6 are located between two adjacent first insulating portions 5 along the first direction x.

[0033] The difference between the first distance a and the second distance c is greater than or equal to 0.3 mm. For example, ac = 0.3 mm, or ac = 0.5 mm, or ac = 0.7 mm, or ac = 0.9 mm, etc. The difference between the second distance c and the width b of the welding part 6 in the first direction x is greater than or equal to 0.3 mm. For example, cb = 0.3 mm, or cb = 0.6 mm, cb = 0.9 mm, or cb = 1.1 mm.

[0034] Through the above embodiments, the dimensional relationship between the sub-grid segments, the first insulating part, and the welding part is quantified in the screen design. The difference between the first distance and the second distance is limited to be greater than or equal to 0.3mm, and the difference between the second distance and the width of the welding part in the first direction is greater than or equal to 0.3mm. The first distance is the distance between two adjacent sub-grid segments along the first direction, and the second distance is the distance between two adjacent first insulating parts along the first direction. This ensures that the welded part has a good shape after curing and avoids problems such as solder displacement, splitting, or incomplete shape after curing, thus ensuring good welding reliability.

[0035] Back-contact solar cells, also known as interdigitated back-contact (IBC) cells, are a novel type of solar cell structure. Their most significant feature is that the PN junction and both the positive and negative electrodes are located on the back of the cell, creating an unobstructed area on the front. Because the front is unobstructed, IBC cells can absorb sunlight more effectively, resulting in higher photoelectric conversion efficiency. In IBC cells, P-type and N-type regions are alternately arranged on the back of the cell, and these regions are isolated from each other.

[0036] In some alternative implementations, the polarity of one of the first sub-gate 2 and the second sub-gate 3 is positive, and the polarity of the other of the first sub-gate 2 and the second sub-gate 3 is negative.

[0037] In some alternative embodiments, the first sub-gate 2 and the second sub-gate 3 can be sintered from a burn-through paste, and a metal paste can be printed on the surface of a portion of the passivation layer using a screen printing process. The metal paste may include at least one of silver, aluminum, copper, tin, or nickel, and is used for conductivity and support. The first insulating portion 5 can isolate the different electrodes.

[0038] In some alternative embodiments, the welding portion 6 can realize the electrical connection between components in the back contact battery, specifically the electrical connection between the main grid and the sub-grid with the same polarity as the main grid. The material of the welding portion 6 can be aluminum, tin, or gray glue, but is not limited to the above types. Those skilled in the art can also reasonably select the material for the welding portion according to actual needs, and this application does not make specific limitations.

[0039] In some alternative embodiments, the first insulating portion 5 can achieve insulation between components in the back contact battery, specifically isolating the main gate and the sub-gate with a different polarity from the main gate, thus preventing short circuits caused by the main gate and the sub-gate with a different polarity from being connected. The first insulating portion 5 can be made of silicone or insulating adhesive, but is not limited to the above types. Those skilled in the art can also reasonably select the material for the first insulating portion according to actual needs, and this application does not make specific limitations.

[0040] In some alternative implementations, such as Figure 1 As shown, the sub-gate segments 4 correspond one-to-one with the first insulating portion 5. The distance between two adjacent sub-gate segments 4 along the second direction y is the third distance s / 2, that is, the distance between two sub-gate segments with different polarities is the third distance s / 2. The distance between the edge of the first insulating portion 5 and the corresponding sub-gate segment 4 is the fourth distance h / 2. The difference between the third distance s / 2 and the fourth distance h / 2 is greater than or equal to 0.15mm. For example, s / 2-h / 2 = 0.15mm, or s / 2-h / 2 = 0.3mm, or s / 2-h / 2 = 0.45mm, or s / 2-h / 2 = 0.6mm, or s / 2-h / 2 = 0.7mm, etc. In the above embodiments, due to the material properties of the first insulating part, it is prone to flow during printing. Setting s / 2-h / 2≥0.15mm can ensure that the first insulating part effectively covers the corresponding sub-gate segment, and can also prevent the first insulating part from covering non-corresponding sub-gate segments due to offset. This ensures that the first insulating part can achieve its isolation effect and avoids problems such as offset, splitting or incomplete shape after curing that affect its isolation effect.

[0041] In some alternative implementations, such as Figure 1 As shown, the first insulating portion 5 is symmetrical about the sub-gate segment 4. That is, the distances from the sub-gate segment 4 to the two opposite edges of the first insulating portion 5 are the same. This arrangement provides the same margin for the offset of the first insulating portion in both directions (positive y-direction and negative y-direction), which can further avoid the problem that the first insulating portion cannot cover the corresponding sub-gate segment after curing due to the fluidity of the first insulating portion, or that the first insulating portion covers a non-corresponding sub-gate segment after curing, thereby further ensuring a better effect after the first insulating portion is cured.

[0042] In some alternative implementations, such as Figure 1As shown, the width of the first insulating portion 5 in the second direction y is 0.2 to 0.6 mm. For example, the width of the first insulating portion 5 can be set to 0.2 mm, 0.3 mm, 0.4 mm, or 0.6 mm, etc. Setting the width of the first insulating portion in the second direction within this range can avoid the problem of wasting screen printing area due to the first insulating portion being too wide, and can also avoid the problem of short circuit caused by the first insulating portion being too narrow, which would result in the inability to effectively isolate the main gate and the sub-gate segment with different characteristics from the main gate.

[0043] In some alternative implementations, such as Figure 1 and Figure 2 As shown, the aforementioned back contact battery further includes: a plurality of main grids 7 extending along a second direction y and spaced apart along a first direction x. The main grids 7 are located between two adjacent sub-grid segments 4 along the first direction x, and a welding portion 6 covers a portion of the main grids 7. In the above embodiment, the main grids are electrically connected to sub-grids of the same polarity via the welding portion, and the main grids are electrically isolated from sub-grids of opposite polarity via an insulating portion.

[0044] Specifically, the main gate 7 can be located on the side of the welded portion 6 away from the sub-gate segment 4.

[0045] In some alternative implementations, such as Figure 2 As shown, the polarity of the main grid 7 is the same as that of the first sub-grid 2. The sub-grid segment 4 of the second sub-grid 3 is the second sub-grid segment 43. The back contact battery also includes: a plurality of second insulating portions 8, extending along the first direction x and spaced apart along the second direction y. The sub-grid segments 4, the second insulating portions 8, and the main grid 7 are arranged in a direction away from the battery body 1. The projections of the ends of two adjacent second sub-grid segments 43 along the first direction x onto the battery body are located in the projections of the second insulating portions 8 onto the battery body 1. The projections of the main grid 7 onto the battery body 1 overlap with the projections of the second insulating portions 8 onto the battery body 1. In this embodiment, the polarities of the main grid and the second sub-grid are different. The second insulating portion is located between the sub-grid line and the main grid, which can isolate the main grid and the second sub-grid to avoid short circuit problems. Furthermore, the second sub-grid segment is broken at the second insulating portion, which can prevent the main grid and the second sub-grid from being electrically connected in the event of problems such as offset, splitting, or incomplete shape of the second insulating portion, thus avoiding short circuit problems.

[0046] like Figure 2 As shown, the sub-gate segment 4 of the first sub-gate 2 is the first sub-gate segment 42. One second insulating part 8 corresponds to two sub-gate segments 4.

[0047] In some alternative implementations, such as Figure 2As shown, the aforementioned plurality of second insulating portions 8 include a plurality of edge insulating portions 81 and a plurality of non-edge insulating portions 82. The minimum distance between the edge insulating portion 81 and the surface edge of the battery body 1 is smaller than the minimum distance between the non-edge insulating portion 82 and the surface edge. That is, compared to the second insulating portion located at the non-edge position of the back contact battery, the second insulating portion located at the edge position of the back contact battery is wider. This can prevent the head and tail solder strips from shifting with the adhesive film to the non-insulating portion coverage area during the lamination process of the battery string, resulting in overlapping of the non-insulating sub-grids and causing a short circuit.

[0048] In some alternative implementations, such as Figure 2 As shown, the widths of the edge insulating portion 81, the non-edge insulating portion 82, and the first insulating portion 5 decrease sequentially in the first direction x. The edge insulating portion, the non-edge insulating portion, and the first insulating portion are arranged in a direction from the edge of the battery body to the center of the battery body. By setting the width of the insulating portion to increase from the center region to the edge region, the problem of edge warping in the back contact battery can be avoided.

[0049] In some alternative implementations, such as Figure 2 As shown, the width of the edge insulating portion 81 in the first direction x is 3 to 20 mm. For example, the width of the edge insulating portion 81 can be 3 mm, 5 mm, 10 mm, 16 mm, or 20 mm, etc.; the width of the non-edge insulating portion 82 in the first direction x is 2 to 20 mm. For example, the width of the non-edge insulating portion 82 can be 2 mm, 5 mm, 10 mm, 15 mm, or 20 mm, etc. In this embodiment, setting the width of the edge insulating portion in the first direction to 3 to 20 mm can provide sufficient insulation protection for the sub-gate located at the edge of the back contact battery and with a polarity different from the main gate, which is beneficial to the overall stability of the back contact battery, and can also avoid the problem of wasting screen printing area due to excessive width. Setting the width of the non-edge insulating portion in the first direction to 2 to 20 mm can provide sufficient insulation protection for the sub-gate located at the non-edge position of the back contact battery and with a polarity different from the main gate, which is beneficial to the overall stability of the back contact battery, and can also avoid the problem of wasting screen printing area due to excessive width. Furthermore, the design of the gradually changing width can reduce the warping of the battery cell.

[0050] Embodiments of this application also provide a photovoltaic module, including: any of the back contact cells described above.

[0051] Through the above embodiments, the dimensional relationship between the sub-grid segments, the first insulating portion, and the welding portion in the back contact cell of the photovoltaic module is quantified. The difference between the first distance and the second distance is limited to be greater than or equal to 0.3 mm, and the difference between the second distance and the width of the welding portion in the first direction is greater than or equal to 0.3 mm. The first distance is the distance between two adjacent sub-grid segments along the first direction, and the second distance is the distance between two adjacent first insulating portions along the first direction. This ensures that the welded portion has a good shape after curing, avoids problems such as solder displacement, splitting, or incomplete shape after curing, and ensures good welding reliability, thereby ensuring good overall stability of the photovoltaic module.

[0052] The back contact battery of this application will be described in detail below with reference to specific embodiments and comparative examples.

[0053] Example 1

[0054] This embodiment provides a back contact battery, including:

[0055] Battery body 1;

[0056] Multiple first sub-gates 2 and multiple second sub-gates 3 are located on the battery body 1. The first sub-gates 2 and the second sub-gates 3 extend along the first direction x and are arranged alternately along the second direction y. The first sub-gates 2 and the second sub-gates 3 have different polarities. The first direction x and the second direction y intersect. Both the first sub-gates 2 and the second sub-gates 3 include multiple sub-gate segments 4 arranged at intervals along the first direction x. The distance between two adjacent sub-gate segments 4 along the first direction x is the first distance a.

[0057] Multiple first insulating portions 5 are located on the side of multiple sub-grid segments 4 away from the battery body 1 and are arranged at intervals along the first direction x. The projection of the end of the sub-grid segment 4 on the battery body 1 is located in the projection of the first insulating portion 5 on the battery body 1. The distance between two adjacent first insulating portions 5 along the first direction x is the second distance c.

[0058] Multiple welded portions 6 are located on the side of the sub-grid segment 4 away from the battery body 1, and the welded portions 6 are located between two adjacent first insulating portions 5 along the first direction x.

[0059] The sub-gate segments 4 and the first insulating portion 5 correspond one-to-one. The distance between two adjacent sub-gate segments 4 along the second direction y is the third distance s / 2, that is, the distance between two sub-gate segments with different polarities is the third distance s / 2. The distance between the edge of the first insulating portion 5 and the corresponding sub-gate segment 4 is the fourth distance h / 2.

[0060] The difference between the first distance a and the second distance c is 0.3 cm, the difference between the second distance c and the width b of the welded part 6 in the first direction x is 0.3 mm, and the difference between the third distance s / 2 and the fourth distance h / 2 is 0.15 mm.

[0061] Example 2

[0062] This embodiment provides a back contact battery. The only difference between this back contact battery and Embodiment 1 is that the difference between the first distance a and the second distance c is 0.5 cm, and the difference between the second distance c and the width b of the welding part 6 in the first direction x is 0.6 mm.

[0063] Example 3

[0064] This embodiment provides a back contact battery, the only difference between this back contact battery and Embodiment 1 is that the difference between the third distance s / 2 and the fourth distance h / 2 is 0.3 mm.

[0065] Comparative Example 1

[0066] This embodiment provides a back contact battery. The only difference between this back contact battery and Embodiment 1 is that the difference between the first distance a and the second distance c is 0.6 cm, and the difference between the second distance c and the width b of the welding part 6 in the first direction x is 0.1 mm.

[0067] Comparative Example 2

[0068] This embodiment provides a back contact battery. The only difference between this back contact battery and Embodiment 1 is that the difference between the first distance a and the second distance c is 0.2 cm, and the difference between the second distance c and the width b of the welding part 6 in the first direction x is 0.16 mm.

[0069] Comparative Example 3

[0070] This embodiment provides a back contact battery, the only difference between this back contact battery and Embodiment 1 is that the difference between the third distance s / 2 and the fourth distance h / 2 is 0.09 mm.

[0071] The welding effect of the back contact battery using the methods described in Example 1, Example 2, and Comparative Example 1 was tested, and the test results are shown in Table 1.

[0072] Table 1

[0073]

[0074]

[0075] The experimental data above show that the welding effect of the welded parts in Examples 1 to 3 is significantly better than that in Comparative Examples 1 to 2, indicating that the welding reliability of the back contact battery of this application is better; the curing effect of the first insulating part in Examples 1 to 3 is significantly better than that in Comparative Example 3, indicating that the insulation reliability of the back contact battery of this application is better.

[0076] For example, the welding effect diagram corresponding to Comparative Example 1 is as follows: Figure 3 As shown, the welded area after curing exhibits an incomplete shape. The welding effect diagram corresponding to Comparative Example 2 is shown below. Figure 4 As shown, the welded part after curing exhibits a splitting problem; the welding effect diagram corresponding to Example 1 is shown below. Figure 5 As shown, the welding effect diagram corresponding to Example 2 is as follows. Figure 6 As shown, the welded parts after curing in Examples 1 and 2 do not have problems such as displacement, splitting, or incomplete shape after curing, and the welding effect is good.

[0077] Welding performance tests were conducted on 1000 back-contact batteries manufactured using the screen design dimensions described in this application. The results showed that the abnormality rate of the welded parts after curing was 0%. This indicates that this application has a significant effect on optimizing the welding reliability of the welded parts after curing.

[0078] As can be seen from the above description, the embodiments of this application achieve the following technical effects:

[0079] 1) In the back contact battery of this application, the dimensional relationship between the sub-grid segments, the first insulating part and the welding part is quantified in the screen design. The difference between the first distance and the second distance is limited to be greater than or equal to 0.3mm, and the difference between the second distance and the width of the welding part in the first direction is greater than or equal to 0.3mm. The first distance is the distance between two adjacent sub-grid segments along the first direction, and the second distance is the distance between two adjacent first insulating parts along the first direction. This ensures that the shape of the welding part after curing is good and avoids problems such as solder displacement, splitting or incomplete shape after curing, thus ensuring good welding reliability.

[0080] 2) In the back contact cell of the photovoltaic module of this application, the dimensional relationship between the sub-busbar segments, the first insulating part and the welding part is quantified, and the difference between the first distance and the second distance is limited to be greater than or equal to 0.3mm, and the difference between the second distance and the width of the welding part in the first direction is greater than or equal to 0.3mm. The first distance is the distance between two adjacent sub-busbar segments along the first direction, and the second distance is the distance between two adjacent first insulating parts along the first direction. This ensures that the shape of the welding part after curing is good, avoids problems such as solder displacement, splitting or incomplete shape after curing, and ensures good welding reliability, thereby ensuring good overall stability of the photovoltaic module.

[0081] It should also be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0082] The above are merely preferred embodiments of this application and are not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A back-contact battery, characterized in that, include: Battery body; Multiple first sub-gates and multiple second sub-gates are located on the battery body. The first sub-gates and the second sub-gates extend along a first direction and are alternately spaced along a second direction. The first sub-gates and the second sub-gates have different polarities. The first direction and the second direction intersect. Both the first sub-gates and the second sub-gates include multiple sub-gate segments spaced along the first direction. The distance between two adjacent sub-gate segments along the first direction is a first distance. Multiple first insulating portions are located on the side of the multiple sub-grid segments away from the battery body and are arranged at intervals along the first direction. The projection of the end of the sub-grid segment on the battery body is located in the projection of the first insulating portion on the battery body. The distance between two adjacent first insulating portions along the first direction is the second distance. Multiple welded portions are located on the side of the sub-grid segment away from the battery body, and the welded portions are located between two adjacent first insulating portions along the first direction; The difference between the first distance and the second distance is greater than or equal to 0.3 mm, and the difference between the second distance and the width of the welded portion in the first direction is greater than or equal to 0.3 mm. A plurality of second insulating portions extend along the first direction and are spaced apart along the second direction. The projection of the ends of the sub-gate segments of two adjacent second sub-gates along the first direction onto the battery body is located in the projection of the second insulating portion onto the battery body. The plurality of second insulating portions include a plurality of edge insulating portions and a plurality of non-edge insulating portions. The minimum distance between the edge insulating portion and the surface edge of the battery body is less than the minimum distance between the non-edge insulating portion and the surface edge.

2. The back contact battery according to claim 1, characterized in that, The sub-gate segments correspond one-to-one with the first insulating portion. The distance between two adjacent sub-gate segments along the second direction is the third distance. The distance between the edge of the first insulating portion and the corresponding sub-gate segment is the fourth distance. The difference between the third distance and the fourth distance is greater than or equal to 0.15 mm.

3. The back contact battery according to claim 1, characterized in that, The first insulating portion is axially symmetrical about the sub-gate segment.

4. The back contact battery according to claim 1, characterized in that, The width of the first insulating portion in the second direction is 0.2~0.6mm.

5. The back contact battery according to any one of claims 1 to 4, characterized in that, The back contact battery also includes: Multiple main gates extend along the second direction and are spaced apart along the first direction. The main gates are located between two adjacent sub-gate segments along the first direction, and the welded portion covers a portion of the main gates.

6. The back contact battery according to claim 5, characterized in that, The polarity of the main grid is the same as that of the first sub-grid. The sub-grid segment of the second sub-grid is the second sub-grid segment. The sub-grid segment, the second insulating portion, and the main grid are arranged in a direction away from the battery body. The projection of the main grid on the battery body overlaps with the projection of the second insulating portion on the battery body.

7. The back contact battery according to claim 1, characterized in that, The widths of the edge insulating portion, the non-edge insulating portion, and the first insulating portion increase sequentially in the first direction.

8. The back contact battery according to claim 1, characterized in that, The width of the edge insulating portion in the first direction is 3~20mm, and the width of the non-edge insulating portion in the first direction is 2~20mm.

9. A photovoltaic module, characterized in that, include: The back contact battery according to any one of claims 1 to 8.

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