Main-grid-free back contact battery, main-grid-free back contact battery string and battery assembly

Abstract

The utility model discloses a main-grid-free back contact battery and a main-grid-free back contact battery string, the back surface of the main-grid-free back contact battery is provided with positive grid lines and negative grid lines which extend along a first direction, the positive grid lines and the negative grid lines are alternately arranged, the positive grid lines are provided with a plurality of first test Pad points which are arranged along a second direction, and the negative grid lines are provided with a plurality of second test Pad points which are arranged along a third direction. A plurality of first test Pad points arranged along a first direction are arranged on the first grid line, a plurality of second test Pad points arranged along a second direction are arranged on the negative grid line, the first direction intersects with the second direction, and the first test Pad points and the second test Pad points are arranged in a staggered manner in the second direction. The first test-used Pad point and the second test-used Pad point provided by the utility model can be used for testing hot spots, EL and the like of the main-grid-free back contact solar cell, and the first test-used Pad point and the second test-used Pad point can be used as welding points of a positive electrode welding strip and a negative electrode welding strip respectively.

Description

Technical Field

[0001] The utility model relates to the technical field of solar cells, and in particular to a busbar-less back-contact battery, a busbar-less back-contact battery string, and a battery assembly. Background Art

[0002] To reduce the use of slurry, back-contact solar cells adopt a busbar-less design. However, this technical solution significantly increases the difficulty of conducting performance tests such as hot spot and EL on back-contact solar cells due to the busbar-less design. Stable contact between the back-contact solar cell and the test probe is not possible, making testing more difficult and resulting in poor reliability and stability. Related technologies still require the introduction of pad points on the fine grid for performance testing. Utility Model Content

[0003] The technical problem to be solved by the present invention is to provide a main grid-free back contact battery, which introduces a test pad point and uses the test pad point as a welding point for a welding ribbon.

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

[0005] In order to solve the above problems, the utility model provides a main grid-free back contact battery, wherein the back of the main grid-free back contact battery is provided with positive grid lines and negative grid lines extending along a first direction, the positive grid lines and the negative grid lines are arranged alternately, the positive grid lines are provided with a plurality of first test pad points arranged along a second direction, the negative grid lines are provided with a plurality of second test pad points arranged along the second direction, the first direction intersects with the second direction, and the first test pad points and the second test pad points are staggered in the second direction.

[0006] In some embodiments, the first test pad points and the second test pad points are staggered in the first direction.

[0007] In some embodiments, the number of first test pad points provided on the back side of the busbar-less back contact cell is 2 to 40;

[0008] The number of second test pad points provided on the back side of the busbar-less back contact cell is 2 to 40.

[0009] In some embodiments, the distance between adjacent first test pad points along the second direction is 5 mm to 100 mm;

[0010] The distance between adjacent second test Pad points along the second direction is 5 mm to 100 mm.

[0011] In some embodiments, a distance between adjacent first test pad points and second test pad points along the first direction is 3 mm to 230 mm.

[0012] In some embodiments, the first test pad point and the second test pad point are disposed near an edge of the busbar-less back contact cell.

[0013] In some embodiments, the first test pad point and the second test pad point are provided on both sides of the busbar-less back contact cell along the second direction.

[0014] In some embodiments, the positive electrode grid line includes a first positive electrode grid line provided with the first test pad point and a second positive electrode grid line not provided with the first test pad point connection;

[0015] The negative gate lines include a first negative gate line provided with the second test pad point and a second negative gate line not provided with the second test pad point.

[0016] In order to solve the above problems, the present invention further provides a busbar-less back-contact battery string, comprising a plurality of busbar-less back-contact batteries as described above.

[0017] In order to solve the above problems, the present invention further provides a battery assembly, comprising the above-mentioned busbar-free back-contact battery string.

[0018] The implementation of this utility model has the following beneficial effects:

[0019] The present invention discloses a busbar-free back contact battery, wherein the back of the busbar-free back contact battery is provided with a positive grid line and a negative grid line extending along a first direction, the positive grid lines and the negative grid lines are arranged alternately, the positive grid lines are provided with a plurality of first test pad points arranged along a second direction, the negative grid lines are provided with a plurality of second test pad points arranged along the second direction, the first direction intersects with the second direction, and the first test pad points and the second test pad points are staggered in the second direction. The first test pad points and the second test pad points provided by the present invention can be used for hot spot, EL and other tests on busbar-free back contact solar cells, and the first test pad points and the second test pad points can be used as welding points for positive electrode welding strips and negative electrode welding strips, respectively. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1This is a schematic structural diagram of a busbar-free back contact battery provided in Example 1 of the present utility model;

[0021] Figure 2 This is a schematic structural diagram of a busbar-free back contact battery provided in Example 2 of the present utility model. DETAILED DESCRIPTION

[0022] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. Examples of the embodiments are shown in the accompanying drawings, in which 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 are not to 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.

[0023] In the description of the present invention, it should be understood that the terms "upper", "lower", "back surface", "front surface", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they cannot be understood as limitations on the present invention.

[0024] In the present invention, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may include the first and second features being in direct contact, or may include the first and second features being in contact not directly but through another feature between them. Moreover, a first feature being "above," "above," and "above" a second feature may include the first feature being directly above or obliquely above the second feature, or may simply mean that the first feature is higher in level than the second feature. A first feature being "below," "below," and "below" a second feature may include the first feature being directly below or obliquely below the second feature, or may simply mean that the first feature is lower in level than the second feature.

[0025] In the present invention, “preferred” is only used to describe an implementation method or embodiment with better effects. It should be understood that it does not constitute a limitation on the scope of protection of the present invention.

[0026] In the present utility model, 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.

[0027] In the present invention, reference to a numerical range includes both endpoints of the numerical range unless otherwise specified.

[0028] The utility model provides a main grid-free back contact battery. Figures 1 and 2 As shown, the back side of the busbar-less back-contact cell is provided with positive grid lines 100 and negative grid lines 200 extending along a first direction. The positive grid lines 100 and negative grid lines 200 are arranged alternately. The positive grid lines 100 are provided with a plurality of first test pad points 110 arranged along a second direction, and the negative grid lines 200 are provided with a plurality of second test pad points 210 arranged along the second direction. The first direction intersects with the second direction, and the first test pad points 110 and the second test pad points 210 are staggered in the second direction. Preferably, the first direction and the second direction are perpendicular to each other. The first direction can be the lateral direction of the busbar-less back-contact cell, and the second direction can be the longitudinal direction of the busbar-less back-contact cell, and the two directions are perpendicular to each other.

[0029] The first test pad point 110 and the second test pad point 210 provided by the present invention can be used for hot spot, EL, and other tests on solar cells without a main grid back contact. Furthermore, the first test pad point 110 and the second test pad point 210 are arranged in the same direction as the soldering ribbon, allowing the first test pad point 110 to be used as a soldering point for the positive soldering ribbon, and the second test pad point 210 to be used as a soldering point for the negative soldering ribbon. Furthermore, the first test pad point 110 and the second test pad point 210 are staggered in the second direction and spatially insulated from each other, eliminating the need for additional insulation measures.

[0030] In some embodiments, the first test pad points 110 and the second test pad points 210 are staggered in the first direction. This not only reduces the number of test pad points, but also allows the first test pad points 110 and the second test pad points 210 to serve as welding points for the positive electrode welding ribbon and the negative electrode welding ribbon, respectively.

[0031] In some embodiments, the number of first test pad points 110 provided on the back side of the busbarless back contact battery is 2 to 40; the number of second test pad points 210 provided on the back side of the busbarless back contact battery is 2 to 40. Exemplary numbers of the first test pad points 110 or the second test pad points 210 on the back side of the busbarless back contact battery are 5, 10, 15, 20, 25, 30, or 35, but are not limited to the above. It is understood that the number of the first test pad points 110 or the second test pad points 210 provided on the back side of the busbarless back contact battery can be adjusted according to actual conditions. Additionally, in some embodiments, the shape of the first test pad point 110 or the second test pad point 210 is one or a combination of circular, elliptical, square, or rectangular. It is understood that the shape of the first test pad point 110 or the second test pad point 210 can be adjusted according to actual conditions.

[0032] In some embodiments, the spacing distance between adjacent first test pad points 110 along the second direction is 5mm to 100mm; the spacing distance between adjacent second test pad points 210 along the second direction is 5mm to 100mm. Exemplary spacing distances between adjacent first test pad points 110 along the second direction are 10mm, 15mm, 20mm, 25mm, 30mm, 35mm, 40mm, 45mm, 50mm, 55mm, 60mm, 65mm, 70mm, 75mm, 80mm, 85mm, 90mm, and 95mm, but are not limited to the above. It is understood that the spacing distance between adjacent first test pad points 110 along the second direction can be adjusted according to actual conditions. Exemplary spacing distances between adjacent second test pad points 210 along the second direction include, but are not limited to, 10 mm, 15 mm, 20 mm, 25 mm, 30 mm, 35 mm, 40 mm, 45 mm, 50 mm, 55 mm, 60 mm, 65 mm, 70 mm, 75 mm, 80 mm, 85 mm, 90 mm, and 95 mm. It will be appreciated that the spacing distance between adjacent second test pad points 210 along the second direction can be adjusted based on actual conditions.

[0033] In some embodiments, the spacing distance between adjacent first test pad points 110 and second test pad points 210 along the first direction is 3 mm to 230 mm. Exemplary spacing distances between adjacent first test pad points 110 and second test pad points 210 along the first direction are 10 mm, 20 mm, 30 mm, 40 mm, 50 mm, 60 mm, 70 mm, 80 mm, 90 mm, 100 mm, 110 mm, 120 mm, 130 mm, 140 mm, 150 mm, 160 mm, 170 mm, 180 mm, 190 mm, 200 mm, 210 mm, and 220 mm, but are not limited to the above. It is understood that the spacing distance between adjacent first test pad points 110 and second test pad points 210 along the first direction can be adjusted according to actual conditions.

[0034] In one embodiment, the first test pad point 110 and the second test pad point 210 are arranged near the edge of the maingate-free back contact battery. Being arranged at the edge of the silicon wafer can reduce the adverse effect of the test pad point on the carrier collection efficiency. Preferably, the first test pad point 110 and the second test pad point 210 are provided on both sides of the maingate-free back contact battery along the second direction. More preferably, a group of the first test pad point 110 and the second test pad point 210 are provided on one side of the maingate-free back contact battery along the second direction, and a group of the first test pad point 110 and the second test pad point 210 are provided on the other side of the maingate-free back contact battery along the second direction.

[0035] In some embodiments, the positive electrode grid line 100 includes a first positive electrode grid line 100 provided with the first test pad point 110 and a second positive electrode grid line 100 not provided with the first test pad point 110; the negative electrode grid line 200 includes a first negative electrode grid line 200 provided with the second test pad point 210 and a second negative electrode grid line 200 not provided with the second test pad point 210. It should be noted that when setting pad points on the grid lines for performance testing, due to the large contact area of the pad points, it is easy to cause changes in the tension of the fine grid connected to the pad points, resulting in misalignment and deformation of the fine grid, and the large pad point contact area will cause stress concentration points on the surface of the battery, and there is a risk of cracks, fractures, etc. caused by stress concentration. By setting test pad points on part of the grid lines of the positive electrode grid line 100 or the negative electrode grid line 200, the adverse effects of the test pad points on the grid lines can be reduced.

[0036] Accordingly, the present invention further provides a busbar-less back-contact battery string, comprising a plurality of busbar-less back-contact batteries as described above, and a battery assembly, comprising the above busbar-less back-contact battery string.

[0037] In some embodiments, the battery assembly includes a first cover plate, a first adhesive film, at least one busbar-free back contact battery string, a second adhesive film, and a second cover plate, which are stacked in sequence. Specifically, the first cover plate is usually made of a material with high light transmittance and strong weather resistance, including but not limited to glass and polycarbonate. Its main function is to protect the sensitive components inside the battery assembly from the external environment, while providing the necessary mechanical support to ensure the structural integrity of the battery assembly. The first adhesive film is located between the first cover plate and the busbar-free back contact battery string, and mainly plays the role of bonding and sealing to ensure that the battery assembly does not have problems such as delamination or leakage during long-term use. The material of the first adhesive film includes but is not limited to ethylene-vinyl acetate copolymer (EVA) and polyolefin (POE). The second adhesive film is located between the busbar-free back contact battery string and the second cover plate, and has a similar function to the first adhesive film, mainly playing the role of bonding and sealing. The second cover plate is usually made of a material with strong weather resistance, including but not limited to aluminum plate and back plate film. Its main function is to protect the back of the battery assembly from the influence of the external environment and provide additional mechanical support. It can also serve as an insulating layer of the battery assembly to ensure safe use.

[0038] The present invention is further described below with reference to specific embodiments.

[0039] Example 1

[0040] This embodiment provides a busbar-free back contact battery. Figure 1 As shown, the back side of the main grid-less back contact battery is provided with positive grid lines and negative grid lines extending along a first direction, the positive grid lines and the negative grid lines are arranged alternately, the positive grid lines are provided with a plurality of first test pad points arranged along a second direction, the negative grid lines are provided with a plurality of second test pad points arranged along the second direction, the first direction intersects with the second direction, and the first test pad points and the second test pad points are staggered in the second direction.

[0041] Example 2

[0042] This embodiment provides a busbar-free back contact battery. Figure 2As shown, the back side of the busbar-less back contact battery is provided with positive and negative grid lines extending along a first direction, the positive and negative grid lines are arranged alternately, the positive grid lines are provided with a plurality of first test pad points arranged along a second direction, the negative grid lines are provided with a plurality of second test pad points arranged along the second direction, the first direction intersects with the second direction, and the first test pad points and the second test pad points are staggered in the second direction. In some embodiments, the positive grid lines include a first positive grid line provided with the first test pad points and a second positive grid line not connected to the first test pad points; the negative grid lines include a first negative grid line provided with the second test pad points and a second negative grid line not connected to the second test pad points.

[0043] Example 3

[0044] This embodiment provides a busbar-less back-contact battery string, comprising a plurality of busbar-less back-contact batteries as described in Embodiment 1.

[0045] Example 4

[0046] This embodiment provides a battery assembly, including the busbar-less back-contact battery string as described in Example 3.

[0047] Throughout this specification, reference to terms such as "some embodiments," "illustrative embodiments," "examples," "specific examples," or "some examples" means that a specific feature, structure, material, or characteristic described in conjunction with an embodiment or example is included in at least one embodiment or example of the present application. In this specification, the illustrative use of the above terms does not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0048] The above disclosure is only a preferred embodiment of the present invention and certainly cannot be used to limit the scope of rights of the present invention. Therefore, equivalent changes made according to the claims of the present invention are still within the scope covered by the present invention.

Claims

1. A busbar-less back contact battery, characterized in that: The back side of the main-grid-free back-contact battery is provided with positive grid lines and negative grid lines extending along a first direction, the positive grid lines and negative grid lines are arranged alternately, the positive grid lines are provided with a plurality of first test pad points arranged along a second direction, the negative grid lines are provided with a plurality of second test pad points arranged along the second direction, the first direction intersects with the second direction, and the first test pad points and the second test pad points are staggered in the second direction.

2. The busbar-less back contact cell according to claim 1, wherein: The first test pad points and the second test pad points are arranged alternately in the first direction.

3. The busbar-less back contact cell according to claim 1, wherein: The number of first test pad points provided on the back of the busbar-free back contact battery is 2 to 40; The number of second test pad points provided on the back side of the busbar-less back contact cell is 2 to 40.

4. The busbar-less back contact cell according to claim 1, wherein: The distance between adjacent first test pad points along the second direction is 5 mm to 100 mm; The distance between adjacent second test Pad points along the second direction is 5 mm to 100 mm.

5. The busbar-less back contact cell according to claim 1, wherein: The interval between adjacent first test pad points and second test pad points along the first direction is 3 mm to 230 mm.

6. The busbar-less back contact cell according to claim 1, wherein: The first test pad point and the second test pad point are arranged close to the edge of the busbar-less back contact cell.

7. The busbar-less back contact cell according to claim 1, wherein: The first test pad point and the second test pad point are provided on both sides of the busbar-less back contact cell along the second direction.

8. The busbar-less back contact cell according to claim 1, wherein: The positive electrode grid line includes a first positive electrode grid line provided with the first test pad point and a second positive electrode grid line not provided with the first test pad point connection; The negative gate lines include a first negative gate line provided with the second test pad point and a second negative gate line not provided with the second test pad point.

9. A busbar-less back contact battery string, characterized in that: The invention comprises a plurality of busbar-free back contact cells according to any one of claims 1 to 8.

10. A battery assembly, characterized in that: The invention comprises the busbar-less back-contact cell string as claimed in claim 9.

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