Back contact battery assembly and photovoltaic system

Abstract

The utility model discloses a back contact cell assembly and a photovoltaic system, and belongs to the technical field of solar cells. The back contact battery assembly comprises a first battery piece, a second battery piece, an insulating part, a first welding strip, a bus bar and a second welding strip, wherein the first battery piece and the second battery piece are distributed along a first direction; the insulating part is arranged on the back surface of the second battery piece; the first welding strip is arranged on the back face of the second battery piece and electrically connected with the second battery piece, and the insulating part and the first welding strip are arranged side by side in the first direction; the bus bar is arranged on the side, away from the second battery piece, of the insulating part, and the bus bar and the first welding strip are insulated through the insulating part; the two ends of the second welding strip are electrically connected with the bus bar and the first battery piece respectively. According to the back contact battery assembly, the condition of subfissure of the battery pieces in the laminating process can be avoided, so that the quality and the use performance of the finished battery assembly are ensured. According to the photovoltaic system, by applying the back contact battery assembly, the quality and the use performance can be improved.

Description

Technical Field

[0001] This utility model relates to the field of solar cell technology, specifically to a back-contact battery module and photovoltaic system. Background Technology

[0002] A photovoltaic (PV) system is a clean energy system that directly converts solar energy into electrical energy using the photovoltaic effect. A back-contact solar module is a solar cell where the light-facing side of the cell has no electrodes, and both the positive and negative electrodes are located on the back-facing side of the cell. This design reduces shading of the cells by the electrodes, increases the short-circuit current, and improves the energy conversion efficiency of the cells.

[0003] Figure 1 A partial cross-sectional structural diagram of a back-contact battery assembly provided by related technologies is shown. For example... Figure 1 As shown, the back-contact battery assembly includes a battery string 100', a first solder ribbon 201', a second solder ribbon 202', an insulating member 300', and a busbar 400'. The battery string 100' includes a first battery cell 101' and a second battery cell 102' distributed along a first direction. The first solder ribbon 201' is disposed on the second battery cell 102' and the two are electrically connected. The insulating member 300' is disposed at one end of the first solder ribbon 201' near the first battery cell 101'. The busbar 400' is disposed on the side of the insulating member 300' away from the first solder ribbon 201'. The second solder ribbon 202' is used to electrically connect the busbar 400' and the first battery cell 101'. (Reference) Figure 1 Taking the partial stacking of the first battery cell 101' and the second battery cell 102' as an example, in the above configuration, the distance between the busbar 400' and the first battery cell 101' is equal to the sum of the thickness of the second battery cell 102', the thickness of the first solder strip 201', and the thickness of the insulating component 300'. This makes it easy for the battery cells to develop microcracks during lamination, affecting the performance of the finished battery module.

[0004] Therefore, there is an urgent need for a back-contact battery assembly to solve the above problems. Utility Model Content

[0005] The purpose of this invention is to provide a back-contact battery module and photovoltaic system that can prevent microcracks in the battery cells during the lamination process, thereby ensuring the quality and performance of the finished battery module.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A back-contact battery assembly, comprising:

[0008] The first and second solar cells are distributed along the first direction;

[0009] An insulating element is disposed on the back side of the second battery cell;

[0010] The first solder strip is disposed on the back of the second battery cell and is electrically connected to the second battery cell. The insulating component and the first solder strip are arranged side by side along the first direction.

[0011] A busbar is disposed on the side of the insulating member opposite to the second battery cell, and the busbar and the first solder strip are insulated by the insulating member;

[0012] The second solder strip has its two ends electrically connected to the busbar and the first battery cell, respectively.

[0013] As a preferred embodiment of the back contact battery assembly provided by this utility model, the contact area between the insulating member and the second battery cell accounts for 40% to 60% of the total area of ​​the insulating member facing the second battery cell.

[0014] As a preferred embodiment of the back contact battery assembly provided by this utility model, the width of the busbar is less than or equal to the width of the insulating member.

[0015] As a preferred embodiment of the back contact battery assembly provided by this utility model, the difference between the width of the insulating member and the width of the busbar is 3mm to 5mm.

[0016] As a preferred embodiment of the back contact battery assembly provided by this utility model, the insulating component abuts against the first welding strip.

[0017] As a preferred embodiment of the back contact battery assembly provided by this utility model, there is a gap between the insulating component and the first solder strip.

[0018] As a preferred embodiment of the back contact battery assembly provided by this utility model, the busbar is an end busbar or an intermediate busbar.

[0019] As a preferred embodiment of the back contact battery assembly provided by this utility model, the first battery cell and the second battery cell are partially stacked.

[0020] As a preferred embodiment of the back contact battery assembly provided by this utility model, the first battery cell and the second battery cell are disposed on the same plane.

[0021] To achieve the above objectives, this utility model also provides a photovoltaic system, characterized in that it includes a back contact battery assembly as described above.

[0022] The beneficial effects of this utility model are as follows:

[0023] The back contact battery assembly provided by this utility model reduces the gap between the busbar and the first battery cell by arranging the first solder strip and the insulating component side by side along the first direction on the second battery cell, thereby improving the structural stability of the entire back contact battery assembly. This avoids microcracks in the battery cells during lamination, thus ensuring the quality and performance of the finished battery assembly.

[0024] The photovoltaic system provided by this utility model, through the aforementioned back-contact battery module, can avoid microcracks in the battery cells during the lamination process, thus ensuring the quality and performance of the finished battery module. Attached Figure Description

[0025] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the description of the embodiments of this utility model will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the content of the embodiments of this utility model and these drawings without creative effort.

[0026] Figure 1 This is a partial cross-sectional structural diagram of the back contact battery assembly provided by related technologies;

[0027] Figure 2 This is a schematic diagram of the planar structure of the back contact battery assembly provided in Embodiment 1 of this utility model;

[0028] Figure 3 This is a partial cross-sectional structural diagram of the back contact battery assembly provided in Embodiment 1 of this utility model;

[0029] Figure 4 This is a partial cross-sectional structural diagram of the back contact battery assembly provided in Embodiment 2 of this utility model.

[0030] Figure label:

[0031] 100', Battery string; 101', First battery cell; 102', Second battery cell;

[0032] 201', First weld strip; 202', Second weld strip;

[0033] 300', Insulating components;

[0034] 400', Busbar;

[0035] 11. First solar cell; 12. Second solar cell;

[0036] 20. Insulating components;

[0037] 30. Busbar;

[0038] 41. First weld strip; 42. Second weld strip. Detailed Implementation

[0039] Before explaining any embodiment of the present invention in detail, it should be understood that the present invention is not limited to its application to the structural details and component arrangements set forth in the following description or shown in the above drawings.

[0040] In this invention, the terms "comprising," "including," "having," or any other variations thereof are intended to cover a 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 a process, method, article, or apparatus. Without further limitation, 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.

[0041] In this invention, the term "and / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent three situations: A exists alone, A and B exist simultaneously, and B exists alone. Additionally, in this invention, the character " / " generally indicates that the preceding and following related objects have an "and / or" relationship.

[0042] In this invention, the terms "connection," "combination," "coupling," and "installation" can refer to direct connection, combination, coupling, or installation, or indirect connection, combination, coupling, or installation. For example, a direct connection refers to two parts or components being connected together without the need for an intermediary, while an indirect connection refers to two parts or components each being connected to at least one intermediary, with the connection achieved through the intermediary. Furthermore, "connection" and "coupling" are not limited to physical or mechanical connections or couplings, but can also include electrical connections or couplings.

[0043] In this invention, those skilled in the art will understand that relative terms (e.g., “about,” “approximately,” “basically,” etc.) used in conjunction with quantities or conditions are to include the value and have the meaning indicated by the context. For example, such relative terms include at least the degree of error associated with the measurement of a particular value, tolerances associated with the particular value due to manufacturing, assembly, use, etc. Such terms should also be considered as disclosing a range defined by the absolute values ​​of the two endpoints. Relative terms may refer to a certain percentage (e.g., 1%, 5%, 10% or more) of the indicated value. Numerical values ​​not using relative terms should also be disclosed as specific values ​​with tolerances. Furthermore, “basically” when expressing relative angular relationships (e.g., substantially parallel, substantially perpendicular) may refer to a certain degree (e.g., 1 degree, 5 degrees, 10 degrees or more) added to or subtracted from the indicated angle.

[0044] In this invention, those skilled in the art will understand that the function performed by a component can be performed by one component, multiple components, one part, or multiple parts. Similarly, the function performed by a part can be performed by one part, one component, or a combination of multiple parts.

[0045] In this utility model, the directional terms "upper," "lower," "left," "right," "front," and "rear" are used to describe the orientation and positional relationships shown in the accompanying drawings and should not be construed as limiting the embodiments of this utility model. Furthermore, in the context, it should be understood that when one element is mentioned as being connected "upper" or "lower" to another element, it can be directly connected to the other element "upper" or "lower," or indirectly connected through an intermediate element. It should also be understood that directional terms such as upper side, lower side, left side, right side, front side, and rear side not only represent the direct orientation but can also be understood as the lateral orientation. For example, "below" can include directly below, lower left, lower right, lower front, and lower rear.

[0046] Example 1

[0047] Figure 2 A schematic diagram of the planar structure of the back contact battery assembly provided in this embodiment is shown. Figure 3 A partial cross-sectional structural diagram of the back contact battery assembly provided in this embodiment is shown. Figures 2-3As shown, this embodiment provides a back-contact battery assembly, which includes a first battery cell 11, a second battery cell 12, an insulating member 20, a first solder ribbon 41, a second solder ribbon 42, and a busbar 30. The first battery cell 11 and the second battery cell 12 are distributed along a first direction. The insulating member 20 is disposed on the back side of the second battery cell 12. The first solder ribbon 41 is disposed on the back side of the second battery cell 12 and is electrically connected to the second battery cell 12. The insulating member 20 and the first solder ribbon 41 are arranged side by side along the first direction. The busbar 30 is disposed on the side of the insulating member 20 away from the second battery cell 12. The busbar 30 and the first solder ribbon 41 are insulated by the insulating member 20. The two ends of the second solder ribbon 42 are electrically connected to the busbar 30 and the first battery cell 11, respectively. By arranging the first solder strip 41 and the insulating component 20 side by side on the second battery cell 12 along the first direction, the distance between the busbar 30 and the first battery cell 11 can be reduced, thereby improving the structural stability of the entire back contact battery module. This avoids the occurrence of microcracks in the battery cells during lamination, thus ensuring the quality and performance of the finished battery module.

[0048] It should be noted that, compared to the related technology where the insulating element 300' is placed on the first solder strip 201' (see reference...), Figure 1 In this embodiment, during the processing of the back contact battery assembly, the length of the first solder strip 41 corresponding to the busbar 30 can be reduced, so that the busbar 30 is placed on the second battery cell 12. This arrangement can improve the structural stability of the entire battery assembly while reducing the material used for the first solder strip 41, thereby reducing the processing cost of the battery assembly to a certain extent.

[0049] In this embodiment, as Figure 3 As shown, the first solar cell 11 and the second solar cell 12 are partially stacked to eliminate the gap between them, thereby obtaining a larger light-receiving area and improving the power generation efficiency of the back-contact solar module. Compared with the prior art, the distance between the busbar 30 and the first solar cell 11 is reduced by the thickness of a first solder strip 41. Experimental verification has shown that this effectively avoids microcracks in the solar cells during lamination of the solar module.

[0050] like Figure 3As shown, the contact area between the insulating member 20 and the second battery cell 12 accounts for 40% to 60% of the total area of ​​the insulating member 20 facing the second battery cell 12. This design ensures that the insulating member 20 is stably supported on the second battery cell 12, ensuring the structural stability of the entire battery assembly. For example, the percentage of the contact area between the insulating member 20 and the second battery cell 12 relative to the total area of ​​the insulating member 20 facing the second battery cell 12 can be 42%, 44%, 45%, 46%, 48%, 50%, 52%, 54%, 55%, 56%, 58%, etc. Of course, the percentage of the contact area between the insulating member 20 and the second battery cell 12 relative to the total area of ​​the insulating member 20 facing the second battery cell 12 is not limited to the above values; designers can adjust these values ​​according to actual processing requirements.

[0051] In some embodiments, the insulating element 20 abuts against the first solder strip 41. This arrangement can mutually restrict each other to prevent the insulating element 20 or the first solder strip 41 from shifting during the manufacturing process of the battery assembly, which could lead to the first solder strip 41 contacting the busbar 30 and causing a short circuit, thereby ensuring the safety of the battery assembly.

[0052] In some embodiments, a gap exists between the insulating element 20 and the first solder strip 41. This arrangement can further reduce the length of the first solder strip 41, thereby reducing material costs. In this embodiment, the specific value of the gap between the insulating element 20 and the first solder strip 41 is not limited; designers can adjust it according to actual usage requirements.

[0053] like Figure 2 As shown, in this embodiment, both the insulating member 20 and the busbar 30 extend along the second direction to cover the entire first battery cell 11 and the second battery cell 12 along the second direction. The first and second directions are perpendicular to each other.

[0054] To ensure the safety of the battery assembly, the width of the busbar 30 is less than or equal to the width of the insulator 20. This is to prevent the insulator 20 from being too narrow, causing the sides of the busbar 30 to be exposed and potentially leading to a short circuit due to contact between the busbar 30 and the first solder strip 41. Optionally, the difference between the width of the insulator 20 and the width of the busbar 30 is 3mm to 5mm. This width difference range allows for safe use of the battery assembly while minimizing the width of the insulator 20, thereby reducing material costs. For example, the difference between the width of the insulator 20 and the width of the busbar 30 can be 3.1mm, 3.2mm, 3.3mm, 3.4mm, 3.5mm, 3.6mm, 3.7mm, 3.8mm, 3.9mm, 4.0mm, 4.1mm, 4.2mm, 4.3mm, 4.4mm, 4.5mm, 4.0mm, 4.6mm, 4.7mm, 4.8mm, 4.9mm, etc. Of course, in other embodiments, the difference between the width of the insulating member 20 and the width of the busbar 30 is not limited to the above range. Designers can adjust the above values ​​according to the model of the battery assembly, usage requirements, etc.

[0055] Understandably, when assembling the battery assembly, the busbar 30 should be placed in the middle of the insulator 20 as much as possible, so that both sides of the insulator 20 extend beyond the busbar 30, thereby ensuring the safe use of the battery assembly.

[0056] It should be noted that the busbar 30 can be an end busbar or an intermediate busbar. When processing the back contact battery assembly, only the end busbar and its corresponding first solder strip 41 can be arranged side by side, or only the intermediate busbar and its corresponding first solder strip 41 can be arranged side by side, or both the end busbar and its corresponding first solder strip 41 and the intermediate busbar and its corresponding first solder strip 41 can be arranged side by side, in order to further reduce the risk of microcracks in the battery cells during the lamination process.

[0057] Example 2

[0058] This embodiment provides a back contact battery assembly. The specific structure of the back contact battery assembly is roughly the same as that of the back contact battery assembly in Embodiment 1, except that the arrangement of the first battery cell 11 and the second battery cell 12 is different.

[0059] Figure 4 A partial cross-sectional structural diagram of the back contact battery assembly provided in this embodiment is shown. Figure 4As shown, in this embodiment, the first battery cell 11 and the second battery cell 12 are disposed on the same plane and arranged at intervals. With this arrangement, the insulating member 20 can be simultaneously supported on the first battery cell 11 and the second battery cell 12, further improving the structural stability of the battery assembly and reducing the risk of microcracks in the battery cells during the lamination process.

[0060] Example 3

[0061] This embodiment provides a photovoltaic system including a back-contact battery module, wherein the back-contact battery module can be any one of Embodiment 1 or Embodiment 2. By applying the above-mentioned back-contact battery module, microcracks in the battery cells can be avoided during the lamination process, ensuring the quality and performance of the finished battery module.

[0062] Specifically, this photovoltaic system can be applied to photovoltaic power plants, such as ground-mounted power plants, rooftop power plants, and floating power plants; it can also be applied to equipment or devices that utilize solar energy to generate electricity, such as user solar power supplies, solar streetlights, solar cars, and solar buildings. It is understood that the application scenarios of photovoltaic systems are not limited to the above scope; they can also be applied to all other fields that require solar energy for power generation.

[0063] Taking a photovoltaic power generation system grid as an example, the photovoltaic system includes a combiner box, an inverter, and a photovoltaic array composed of multiple back-contact battery modules. The photovoltaic array is connected to the combiner box, which can combine the current generated by the photovoltaic array. The combined current flows through the inverter and is converted into AC power required by the mains power grid before being connected to the mains power grid to realize solar power supply.

[0064] The foregoing has shown and described the basic principles, main features, and advantages of this utility model. Those skilled in the art should understand that the above embodiments do not limit this utility model in any way, and all technical solutions obtained by equivalent substitution or equivalent transformation fall within the protection scope of this utility model.

Claims

1. A back contact cell assembly, characterized by, The back contact battery assembly comprises: a first cell sheet (11) and a second cell sheet (12) distributed along a first direction; an insulation piece (20) arranged on the back of the second cell sheet (12); a first solder strip (41) arranged on the back of the second cell sheet (12) and electrically connected with the second cell sheet (12), the insulation piece (20) and the first solder strip (41) being arranged side by side along the first direction; a bus bar (30) arranged on the side of the insulation piece (20) away from the second cell sheet (12), the bus bar (30) and the first solder strip (41) being insulated by the insulation piece (20); a second solder strip (42) with two ends electrically connected with the bus bar (30) and the first cell sheet (11) respectively.

2. The back contact solar cell assembly of claim 1, wherein, The contact area between the insulation piece (20) and the second cell sheet (12) accounts for 40-60% of the total area of the side of the insulation piece (20) facing the second cell sheet (12).

3. The back contact cell assembly of claim 1, wherein, The width of the bus bar (30) is less than or equal to the width of the insulation piece (20).

4. The back contact solar cell assembly of claim 3, wherein, The difference between the width of the insulation piece (20) and the width of the bus bar (30) is 3-5 mm.

5. The back contact solar cell assembly of claim 1 wherein, The insulation piece (20) abuts against the first solder strip (41).

6. The back contact cell assembly of claim 1, wherein, There is a gap between the insulation piece (20) and the first solder strip (41).

7. The back contact solar cell assembly of any one of claims 1-6, wherein, The bus bar (30) is an end bus bar or a middle bus bar.

8. The back contact solar cell assembly of any one of claims 1-6, wherein, The first cell sheet (11) and the second cell sheet (12) are partially laminated.

9. The back contact solar cell assembly of any one of claims 1-6, wherein, The first cell sheet (11) and the second cell sheet (12) are arranged on the same plane.

10. A photovoltaic system characterized by, The back contact battery assembly comprises any one of claims 1-9.

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