Back contact cell, photovoltaic module and laminated cell

Abstract

The utility model is applicable to the technical field of solar power generation, and provides a back contact cell, a photovoltaic module and a laminated cell, the back contact cell comprises a cell sheet main body, a transparent material and a grid line, the cell sheet main body has a front surface and a back surface which are opposite, the transparent material is arranged on the front surface of the cell sheet main body, and the grid line is arranged on the back surface. And the grid lines are arranged on the back surface of the battery piece main body and are used for being welded with the welding strip, so that the battery piece main body is bent towards the back surface after the welding strip is cooled and contracted. Through the arrangement, the front surface of the battery piece main body is firstly bent through the transparent material, after the welding strip is subsequently welded, the battery piece main body is bent towards the back surface through the contraction of the welding strip and the material for insulation on the back surface, and the flatness of the battery piece main body can be improved after the front surface bending and the back surface bending are mutually counteracted, so that the yield and the precision of the back contact battery are ensured.

Description

Technical Field

[0001] The utility model belongs to the technical field of solar power generation, and in particular relates to a back contact cell, a photovoltaic component and a laminated cell. Background Art

[0002] XBC modules are a general term for various BC (Back Contact) batteries / modules, such as Figure 1 As shown, when preparing the existing XBC components, first Figure 1 The solder strip shown in ② is attached to Figure 1 The grid line surface of the battery cell shown in ① is whole, and then the temperature is increased to combine the welding ribbon and the battery cell, so as to achieve the purpose of welding.

[0003] However, since the solder strips are all located on one side of the battery cell electrode, Figure 1 As shown in ③, the thermal expansion and contraction effect caused by the temperature rise during welding causes the soldering ribbon to shrink, causing the battery cell to arch toward the grid line surface (back side), and the insulating material on the grid line surface will also shrink after heating, further causing the battery cell or battery string to warp severely, such as Figure 1 As shown in ④, it affects the yield and accuracy of the battery cell. Utility Model Content

[0004] The embodiment of the utility model provides a back-contact battery, aiming to solve the problem that the existing back-contact battery has warping after welding the welding strip, which affects the yield and precision of the battery cell.

[0005] The embodiment of the utility model is implemented as follows: a back contact battery comprises a battery cell body, a transparent material and a grid line;

[0006] The battery cell body has a front side and a back side opposite to each other;

[0007] The transparent material is arranged on the front side of the battery cell body, and is used to bend the battery cell body toward the front side after the transparent material solidifies and shrinks;

[0008] The grid line is arranged on the back side of the battery cell body and is used for welding with the welding ribbon so that the battery cell body is bent toward the back side by shrinking after the welding of the welding ribbon.

[0009] Furthermore, the transparent material includes at least one of transparent glue and transparent adhesive strip.

[0010] Furthermore, the transparency of the transparent material is greater than or equal to 80%.

[0011] Furthermore, the transparent material is arranged on a partial area of ​​the front side of the battery cell body.

[0012] Furthermore, the transparent material is arranged in strips on the front side of the battery cell body, and the length direction of the transparent material is parallel to the length direction of the welding strip.

[0013] Furthermore, the transparent material is in a cross shape corresponding to the four corners of the battery cell body.

[0014] Furthermore, the width of the transparent material is 5 mm to 15 mm, and the interval between adjacent transparent materials is 15 mm to 30 mm.

[0015] Furthermore, the thickness of the transparent material is 2 micrometers to 30 micrometers.

[0016] Furthermore, the ratio of the total area of ​​the transparent material to the area of ​​the front side of the battery cell body is 20% to 50%.

[0017] In a second aspect, the present application provides a photovoltaic module, comprising the back contact cell as described above.

[0018] In a third aspect, the present application provides a stacked cell, including a perovskite cell and a back contact cell as described above.

[0019] The beneficial effect of the present application is that the back contact battery of the present application includes a battery cell body, a transparent material and a grid line, wherein the battery cell body has a relative front and back, the transparent material is arranged on the front of the battery cell body, and is used to bend the battery cell body toward the front after the transparent material solidifies and shrinks, and the grid line is arranged on the back of the battery cell body, and is used to be welded with the welding strip, so that the battery cell body shrinks after the welding strip cools and bends the battery cell body toward the back. Through the above arrangement, the front of the battery cell body is first bent by the transparent material, and after the subsequent welding of the welding strip, the battery cell body is bent toward the back by the shrinkage of the welding strip and the insulating material on the back, and the flatness of the battery cell body can be improved after the front bending and the back bending offset each other, thereby ensuring the yield and precision of the back contact battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of the structure during the preparation process of an existing back contact battery;

[0021] Figure 2 It is a structural schematic diagram of the back side of a battery cell body of an embodiment of a back contact battery provided in the present application;

[0022] Figure 3 It is a schematic structural diagram of the front side of a battery cell body of an embodiment of a back contact battery provided in the present application;

[0023] Figure 4 is a side view schematic diagram of an embodiment of a back contact battery provided by the present application;

[0024] Figure 5 is a schematic structural diagram of the front side of a battery cell body of another embodiment of a back contact battery provided in the present application;

[0025] Figure 6 This is a schematic diagram of the structure in which the transparent material is in a cross shape in one embodiment of the back contact battery provided in the present application. DETAILED DESCRIPTION

[0026] In order to make the purpose, technical solution and advantages of the utility model clearer, the utility model is further described in detail below in conjunction with the accompanying drawings and embodiments. Examples of 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 utility model, and cannot be understood as limiting the utility model. In addition, it should be understood that the specific embodiments described herein are only used to explain the utility model and are not used to limit the utility model.

[0027] In the description of the present invention, it should be understood 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. 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 should not be understood as limitations on the present invention.

[0028] 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 technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more features. In the description of the present utility model, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0029] In the description of the present utility model, it should be noted that, unless otherwise clearly specified and limited, the terms "installation", "connection" and "connection" 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 utility model can be understood according to specific circumstances.

[0030] In the present utility model, 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.

[0031] The disclosure below provides many different embodiments or examples for realizing different structures of the utility model. In order to simplify the disclosure of the utility model, the components and settings of specific examples are described below. Of course, they are only examples, and the purpose is not to limit the utility model. In addition, the utility model can repeat reference numbers and / or reference letters in different examples, and this repetition is for the purpose of simplification and clarity, and does not indicate the relationship between the various embodiments and / or settings discussed in itself. In addition, the utility model provides various specific examples of processes and materials, but those of ordinary skill in the art can be aware of the application of other processes and / or the use of other materials.

[0032] The battery cell body comprises a cell body, a transparent material and a grid line, wherein the cell body has a relative front and back, the transparent material is arranged on the front of the cell body, and is used to bend the cell body toward the front after the transparent material solidifies and shrinks, and the grid line is arranged on the back of the cell body, and is used to be welded with the welding strip, so that the cell body shrinks and bends the cell body toward the back after the welding strip cools. Through the above arrangement, the cell body is first bent on the front side by the transparent material, and after the subsequent welding of the welding strip, the cell body is bent toward the back side by the shrinkage of the welding strip and the insulating material on the back side, and the front bending and the back bending offset each other to improve the flatness of the cell body, and ensure the yield and precision of the back contact battery.

[0033] Embodiment 1

[0034] like Figures 2 to 6 As shown, one embodiment of the present application provides a back contact battery, including a battery cell body 100, a transparent material 200 and a grid line 300;

[0035] The battery cell body 100 has a front side 110 and a back side 120 opposite to each other;

[0036] The transparent material 200 is disposed on the front surface 110 of the battery cell body 100, and is used to bend the battery cell body 100 toward the front surface 110 after the transparent material 200 is solidified and shrunk;

[0037] The grid line 300 is disposed on the back side 120 of the cell body 100 for welding with a welding ribbon (not shown) so that the welding ribbon shrinks after cooling to bend the cell body 100 toward the back side 120 .

[0038] During implementation, the battery cell body 100 is in the shape of a sheet or a plate and has a front side 110 and a back side 120. Usually, the front side 110 of the battery cell body 100 can be regarded as the light-receiving side of the back-contact battery, and the back side 120 of the battery cell body 100 can be regarded as the backlight side of the back-contact battery.

[0039] Optionally, a BC cell (back contact cell) refers to a solar cell in which a PN junction and a metal electrode are arranged on the back of the cell, so that there is no electrode blocking the front of the cell, and the cell absorbs sunlight over a larger area, thereby improving conversion efficiency and generating more electricity.

[0040] It should be noted that the back contact cell does not refer to a specific type of cell, but a general platform technology. The back contact cell can be combined with PREC (Passivated Emitter and Rear Cell), TOPCon (Tunnel Oxide Passivating Contact), and HJT (Homojunction Solar Cell), for example, TOPCon+BC=TBC cell, HJT+BC=HBC, to improve the efficiency of solar cells.

[0041] A gate line 300 is provided on the back side 120 of the battery cell body 100 . The gate line 300 is used to be connected to a soldering ribbon by welding. Generally, solder such as solder paste is required to weld the soldering ribbon to the gate line 300 , which will not be described in detail.

[0042] In the traditional XBC component preparation process, the welding ribbon needs to be heated to melt the solder. After the solder cools down, the welding ribbon can be welded to the gate line 300. The temperature change causes the welding ribbon to shrink. At the same time, the insulating material on the back side 120 will also shrink after heating, causing the battery cell or battery string to warp toward the back side 120.

[0043] The back contact battery provided in the present application is provided with a transparent material 200 on the front side 110 of the battery cell body 100. The transparent material 200 includes at least one of transparent glue and transparent adhesive strips, which are not limited. The transparent material 200 will shrink after curing to bend the battery cell body 100 toward the front side 110. The bending of the front side 110 and the bending of the back side 120 of the battery cell body 100 offset each other, thereby reducing or even completely eliminating the warping of the battery cell body 100, and ensuring that the battery cell body 100 is flat.

[0044] Optionally, the transparent glue can be UV glue or other insulating glue, and it can have a certain curing shrinkage without limitation. Similarly, the transparent adhesive strip can also be prepared by using UV glue strip or other insulating glue, and in the subsequent use process, the transparent adhesive strip can be directly attached to the front side 110 of the battery cell body 100.

[0045] In some possible embodiments, the transparent adhesive strip can also be used together with transparent glue. For example, transparent glue is first applied on the front side 110 of the battery cell body 100, and then the transparent adhesive strip is attached to the position coated with the transparent glue, so that the transparent adhesive strip and the front side 110 of the battery cell body 100 fit more firmly, thereby ensuring product quality.

[0046] In some optional embodiments, a transparent material 200 may be first provided on the front side 110 of the battery cell body 100, and the welding strip may be welded to the gate line 300 after the transparent material 200 is solidified. That is to say, the battery cell body 100 is bent toward the front side 110 in advance, so that after the subsequent welding of the welding strip, the battery cell body 100 is bent toward the back side 120 to offset the bending of the front side 110 of the battery cell body 100, thereby making the battery cell body 100 flat.

[0047] In some possible embodiments, the welding strip may be welded to the gate line 300 first, and then the transparent material 200 may be disposed on the front side 110 of the battery cell body 100. That is, the battery cell body 100 may be bent toward the back side 120 due to the shrinkage of the insulating material between the welding strip and the back side 120 after heating, and then the transparent material 200 may be disposed on the front side 110 of the battery cell body 100 to bend the battery cell body 100 toward the front side 110, so as to offset the bending of the back side 120 of the battery cell body 100 and make the battery cell body 100 flat.

[0048] In some possible embodiments, the welding strips may be welded simultaneously during the solidification process of the transparent material 200 , so that the transparent material 200 is solidified simultaneously during the cooling process after the welding step to make the battery cell body 100 flat.

[0049] During the preparation of the XBC assembly, since the front side 110 of the battery cell body 100 is provided with a transparent material 200, the transparent material 200 can be regarded as a protective layer of the front side 110 of the battery cell body 100 after curing, that is, the battery cells can be stacked, which can effectively reduce the sliding scratches between the battery cells, facilitate product preparation while ensuring the conversion efficiency of the battery cells.

[0050] The back contact battery provided in the present application includes a battery cell body 100, a transparent material 200 and a gate line 300, wherein the battery cell body 100 has a front side 110 and a back side 120 opposite to each other, the transparent material 200 is arranged on the front side 110 of the battery cell body 100, and is used to bend the battery cell body 100 toward the front side 110 after the transparent material 200 solidifies and shrinks, and the gate line 300 is arranged on the back side 120 of the battery cell body 100, and is used to be welded with the welding strip, so that the battery cell body 100 shrinks after the welding strip cools and bends the battery cell body 100 toward the back side 120. Through the above arrangement, the front side 110 of the battery cell body 100 is first bent by the transparent material 200, and after the subsequent welding of the welding strip, the battery cell body 100 is bent toward the back side 120 by the shrinkage of the welding strip and the insulating material on the back side 120, and the flatness of the battery cell body 100 can be improved after the bending of the front side 110 and the bending of the back side 120 offset each other, thereby ensuring the yield and precision of the back contact battery.

[0051] In some optional embodiments, the transparency of the transparent material 200 is greater than or equal to 80%. Since the transparent material 200 needs to be arranged on the front side 110 of the battery cell body 100, and the front side 110 of the battery cell body 100 is the light-receiving surface, the high transparency of the transparent material 200 can effectively ensure that light passes through the transparent material 200 to be absorbed by the battery cell, thereby improving the conversion efficiency of the battery cell.

[0052] In some optional embodiments, the transparent material 200 is disposed on a partial area of ​​the front side 110 of the battery cell body 100 .

[0053] During implementation, the transparent material 200 can be set on the entire front side 110 of the battery cell body 100, or can be set on a partial area of ​​the front side 110 of the battery cell body 100. It is preferably set on a partial area of ​​the front side 110 of the battery cell body 100 to reduce the usage of the transparent material 200 and control the cost of the battery cell.

[0054] Optionally, to ensure the flatness of the cell, the area ratio of the transparent material 200 to the cell body 100 can be controlled. If the area ratio is too large, the hardness of the transparent material 200 will be too large after solidification, which will cause the cell body 100 to be severely bent toward the front 110, and the warping and bending cannot be offset after subsequent welding of the welding strip. If the area ratio is too small, the hardness of the transparent material 200 will be low after solidification, which will cause the cell body 100 to have a small warping degree toward the front 110, and the cell body 100 will still be warped toward the back 120 after subsequent welding of the welding strip. Optionally, the ratio of the total area of ​​the transparent material 200 to the area of ​​the front 110 of the cell body 100 is 20% to 50%, such as 25%, 30%, 35%, 40% or 45%, etc., as long as the flatness of the cell body 100 is ensured, and there is no limitation.

[0055] In some optional embodiments, the transparent material 200 is arranged in a strip shape on the front side 110 of the battery cell body 100 , and the length direction of the transparent material 200 is parallel to the length direction of the welding strip.

[0056] In implementation, the transparent material 200 being in strips means that glue is applied in a straight line or in a discontinuous line to form the glue in strips. Of course, in other embodiments, the transparent material 200 may also be a finished transparent adhesive strip, without limitation.

[0057] Optionally, the transparent material 200 may be parallel to the length direction of the welding strip as a whole, for example, the transparent material 200 is independent strips of transparent glue, such as Figure 3 As shown, these transparent materials 200 are parallel to the length direction of the welding strip.

[0058] In some possible embodiments, the transparent material 200 may also be partially parallel to the length direction of the welding strip, for example, the transparent material 200 is in a forked shape, such as Figure 5 As another example, the transparent material 200 can also be arranged in a cross-shaped form, and the cross-shaped transparent material 200 is arranged correspondingly at the four corners of the battery cell body 100, such as Figure 6 Since the back of the cell body 100 is provided with slurry, the cell body 100 may be warped to a certain extent during the curing process of the slurry. By arranging the transparent material 200 in a cross shape, the warping caused by the solder strip and the slurry can be reduced.

[0059] In some other embodiments, the transparent material 200 may also adopt other shapes, as long as the transparent material 200 can achieve the function of bending the battery cell body toward the front after solidification and shrinkage, without limitation.

[0060] Optionally, the width of the transparent material 200 is 5 mm to 15 mm, that is, the width of the transparent materials 200 arranged in parallel, the cross-shaped transparent materials 200 or the transparent materials 200 of other shapes can be set to 5 mm to 15 mm, such as 6 mm, 7 mm, 10 mm or 12 mm. As a way, when the transparent materials 200 are arranged in parallel, the interval between adjacent transparent materials 200 is 15 mm to 30 mm, such as 20 mm, 25 mm, 30 mm or 33 mm, etc., without limitation.

[0061] The length direction of the transparent material 200 is parallel to the direction of the line segment L. Similarly, the length direction of the solder strip is also parallel to the direction of the line segment L, so that the contraction force of the transparent material 200 can better offset the contraction force of the solder strip, further ensuring the flatness of the battery cell body 100.

[0062] In some optional embodiments, the thickness of the transparent material 200 is 2 microns to 30 microns, such as 5 microns, 10 microns, 20 microns, 22 microns or 25 microns, etc., without limitation. Preferably, the thickness of the transparent material 200 is 10 microns to 15 microns, such as 11 microns, 12 microns or 13 microns, etc., without limitation. Through the above settings, the thickness of the transparent material 200 is set within a reasonable range. On the one hand, it is avoided that the transparent material 200 is too thick, resulting in high cost, high hardness and poor light transmittance. On the other hand, it is avoided that the transparent material 200 is too thin, resulting in insufficient hardness, too small curvature of the battery cell body 100 to the front 110, resulting in the inability to offset the curvature of the back 120 of the battery cell body 100 after subsequent welding of the welding strip, thereby ensuring the flatness of the battery cell body 100.

[0063] Embodiment 2

[0064] In some optional embodiments, the present application provides a photovoltaic module, comprising the back contact cell as described above.

[0065] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the structure and implementation principle of the photovoltaic assembly described above can refer to the corresponding structure and implementation principle in the aforementioned embodiment 1, and will not be repeated here.

[0066] The back-contact battery provided in the present application includes a battery cell body 100, a transparent material 200 and a gate line 300, wherein the battery cell body 100 has a relative front side 110 and a back side 120, the transparent material 200 is arranged on the front side 110 of the battery cell body 100, and is used to bend the battery cell body 100 toward the front side 110 after the transparent material 200 solidifies and shrinks, and the gate line 300 is arranged on the back side 120 of the battery cell body 100, and is used to be welded with a welding ribbon, so that the welding ribbon shrinks after cooling and bends the battery cell body 100 toward the back side 120, so as to offset the bending of the front side 110 of the battery cell body 100. Through the above arrangement, the front side 110 of the battery cell body 100 is first bent through the transparent material 200. After the subsequent welding of the welding strip, the welding strip and the insulating material on the back side 120 shrink and bend the battery cell body 100 toward the back side 120. The bending of the front side 110 and the bending of the back side 120 offset each other to improve the flatness of the battery cell body 100, thereby ensuring the yield and accuracy of the back contact battery.

[0067] Embodiment 3

[0068] In some optional embodiments, the present application also provides a stacked battery, including a perovskite battery and a back contact battery as described above.

[0069] In practice, perovskite cells, i.e., perovskite solar cells, are solar cells that use perovskite-type organic metal halide semiconductors as light-absorbing materials. The tandem cells provided in this application are perovskite-silicon-based tandem solar cells. Perovskite-silicon-based tandem cells utilize the wide bandgap structural characteristics of perovskite cell materials, and place perovskite cell materials above silicon-based cells (back contact cells). They can absorb high-energy photons in the short-wave band that are difficult for silicon-based cells to absorb, thereby making greater use of solar incident light, thereby improving the conversion efficiency of photovoltaic cells, and having a higher theoretical efficiency limit, which will not be elaborated on.

[0070] Those skilled in the art can clearly understand that, for the convenience and simplicity of description, the structure and implementation principle of the laminated battery described above can refer to the corresponding structure and implementation principle in the aforementioned embodiments 1 and 2, and will not be repeated here.

[0071] The back-contact battery provided in the present application includes a battery cell body 100, a transparent material 200 and a gate line 300, wherein the battery cell body 100 has a relative front side 110 and a back side 120, the transparent material 200 is arranged on the front side 110 of the battery cell body 100, and is used to bend the battery cell body 100 toward the front side 110 after the transparent material 200 solidifies and shrinks, and the gate line 300 is arranged on the back side 120 of the battery cell body 100, and is used to be welded with a welding ribbon, so that the welding ribbon shrinks after cooling and bends the battery cell body 100 toward the back side 120, so as to offset the bending of the front side 110 of the battery cell body 100. Through the above arrangement, the front side 110 of the battery cell body 100 is first bent through the transparent material 200. After the subsequent welding of the welding strip, the welding strip and the insulating material on the back side 120 shrink and bend the battery cell body 100 toward the back side 120. The bending of the front side 110 and the bending of the back side 120 offset each other to improve the flatness of the battery cell body 100, thereby ensuring the yield and accuracy of the back contact battery.

[0072] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A back contact battery, characterized in that: It includes a battery cell body, a transparent material and a grid line; The battery cell body has a front side and a back side opposite to each other; The transparent material is arranged on the front side of the battery cell body, and is used to bend the battery cell body toward the front side after the transparent material solidifies and shrinks; The grid line is arranged on the back side of the battery cell body and is used for welding with the welding strip, so that the battery cell body is contracted and bent toward the back side after the welding of the welding strip.

2. The back contact cell according to claim 1, characterized in that The transparent material is at least one of transparent glue and transparent adhesive strip.

3. The back contact cell according to claim 1 or 2, characterized in that: The transparency of the transparent material is greater than or equal to 80%.

4. The back contact cell according to claim 1, characterized in that The transparent material is arranged on a partial area of ​​the front side of the battery cell body.

5. The back contact cell according to claim 4, characterized in that The transparent material is arranged in a strip shape on the front side of the battery cell body, and the length direction of the transparent material is parallel to the length direction of the welding strip.

6. The back contact cell according to claim 4, characterized in that The transparent material is in a cross shape with four corners of the battery sheet body being arranged correspondingly.

7. The back contact cell according to claim 4 or 5, characterized in that: The width of the transparent material is 5 mm to 15 mm, and the interval between adjacent transparent materials is 15 mm to 30 mm.

8. The back contact cell according to any one of claims 4 to 6, characterized in that The thickness of the transparent material is 2 micrometers to 30 micrometers.

9. The back contact cell according to any one of claims 4 to 6, characterized in that The ratio of the total area of ​​the transparent material to the area of ​​the front surface of the battery cell body is 20% to 50%.

10. A photovoltaic module, characterized in that: Comprising a back contact cell as claimed in any one of claims 1 to 9.

11. A laminated battery, characterized in that: Comprising a perovskite cell and a back contact cell as claimed in any one of claims 1 to 9.

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