Back contact foil covered cell string

Abstract

The application discloses a back contact film-coated battery string, a plurality of film pieces, a plurality of battery pieces and a plurality of welding strip groups, the back light surfaces of the plurality of battery pieces are connected in series along a first direction through the plurality of welding strip groups, the plurality of film pieces are covered on the back light surfaces of the plurality of battery pieces, and the area of the film piece is greater than the area of the covered battery piece. The technical scheme can solve the problem that in the EL detection of the back contact film-coated battery string, the side edges of each battery piece in the back contact film-coated battery string are not fixed by the adhesive film, and the corresponding area in the image formed by the electroluminescence is prone to appear shadow, thereby causing the poor EL detection effect.

Description

Technical Field

[0001] This utility model relates to the field of battery string technology, and in particular to a back-contact coated battery string. Background Technology

[0002] The back contact coated battery string is fixedly connected to the solder strip and the back contact battery cell by low-temperature bonding with glue or film.

[0003] To mitigate the stress on solar cells caused by excessive EVA film melting during the lamination process, besides thinning the EVA film in photovoltaic modules to prevent microcracks, related technologies reduce the area of ​​the encapsulant film. This means the encapsulant film only needs to cover the area where the solder ribbon overlaps the center of the solar cell to ensure the relative position between the solder ribbon and the cell. However, in EL inspection, the side of each solar cell in the string is not fixed to the solder ribbon by the encapsulant film, causing shadows to appear in the corresponding area in the electroluminescence image, resulting in poor EL inspection results. Utility Model Content

[0004] The purpose of this invention is to provide a back-contact coated battery string to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a back-contact coated battery string, comprising multiple films, multiple battery cells, and multiple solder ribbon groups, wherein the backlight surfaces of the multiple battery cells are connected in series along a first direction through the multiple solder ribbon groups, and the multiple films cover the backlight surfaces of the multiple battery cells, wherein the area of ​​the films is larger than the area of ​​the battery cells.

[0006] Preferably, each of the two opposite sides of the diaphragm extends out to the sides of the corresponding attached battery sheet, or one of the two opposite sides of the diaphragm extends out to the side of one side of the battery sheet.

[0007] Preferably, when each of the two opposite sides of the membrane extends to the sides of the corresponding attached battery cell, a gap is formed between any two adjacent battery cells, and the sides of two adjacent membranes facing the gap are stacked on top of each other.

[0008] Preferably, along the first direction, one side of each of the multiple membranes extending in the same direction is stacked on top of an adjacent one.

[0009] Preferably, along the first direction, the side edges of any one of the odd-numbered or even-numbered membranes respectively cover the two adjacent side edges of two adjacent membranes.

[0010] Preferably, along the vertical direction, a gap is formed between any two adjacent cells of the plurality of cells, and the sides of the two films correspondingly attached to the two adjacent cells are spliced ​​together towards the gap.

[0011] Preferably, when the two opposite sides of the corresponding film attached to each of the battery cells extend beyond the side of the battery cell, a gap is formed between any two adjacent battery cells, and the spacing of the gap is greater than the spacing between the sides of two adjacent films facing the gap (A).

[0012] Preferably, the two sides of the two battery cells that are furthest apart are covered or flush with the sides of the two films corresponding to them.

[0013] Preferably, among the plurality of battery cells, the two sides of the two battery cells that are furthest apart are respectively covered by the side of the two membranes, one of which is covered by the side of the corresponding membrane, and the other is covered flush with the side of the corresponding membrane.

[0014] Preferably, the membrane includes a first sub-membrane and a second sub-membrane, which are spliced ​​together to cover the battery cell. One side of the first sub-membrane and one side of the second sub-membrane extend beyond the sides of both sides of the battery cell. Alternatively, one side of the first sub-membrane and one side of the second sub-membrane extend beyond one side of the battery cell, while the other side is flush with the other side of the battery cell.

[0015] Preferably, along the second direction, each of the two opposing sides of the diaphragm extends beyond the sides of the corresponding attached battery sheet on both sides, or, one of the two opposing sides of each diaphragm extends beyond the side of one side of the battery sheet, and the other is flush with the side of the other side of the corresponding attached battery sheet, wherein the second direction is perpendicular to the first direction.

[0016] Preferably, along the first direction, the side edges of any one of the odd-numbered or even-numbered membranes respectively cover the two adjacent side edges of two adjacent membranes.

[0017] The technical solution adopted in this application can achieve the following beneficial effects:

[0018] In a back-contact coated battery string disclosed in this application, there are multiple films, multiple battery cells and multiple sets of solder ribbons. The back surfaces of the multiple battery cells are connected in series along a first direction through multiple sets of solder ribbons. The multiple films cover the back surfaces of the multiple battery cells one by one. Along the first direction, the two opposite sides of each film extend out to the sides of the corresponding bonded battery cell, or, one of the two opposite sides of each film extends out to the side of one side of the battery cell, and the other side is flush with the side of the other side of the corresponding bonded battery cell.

[0019] Since multiple solder ribbon groups in the back-contact battery string are electrically connected on the back side of the battery cell, multiple solder ribbons in the solder ribbon group will overlap the sides of the battery cell. In the above structure, the two opposite sides of the corresponding film attached to each battery cell extend beyond the sides of the battery cell, or, one of the two opposite sides of the corresponding film attached to each battery cell extends beyond one side of the battery cell, and the other is flush with the other side of the opposite battery cell. This allows the film to control the solder ribbon groups on the corresponding battery cell, thereby ensuring that in EL detection, the corresponding area of ​​each side of the battery cell in the back-contact battery string will not be shadowed in the image formed by electroluminescence, thus ensuring the EL detection effect. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0021] Figure 1 This is a partial top view of the back-contact coated battery string disclosed in an embodiment of this application;

[0022] Figure 2 This is a partial top view of the battery cell and film assembly disclosed in the embodiments of this application, wherein the sides of the film are stacked.

[0023] Figure 3 This is a partial cross-sectional view of the battery cell and film assembly disclosed in the embodiments of this application, and the side splicing of the film.

[0024] Figure 4 This is a partial cross-sectional view of the battery cell and film assembly disclosed in the embodiments of this application, wherein the film is spaced apart on its sides;

[0025] Figure 5 This is a partial cross-sectional view of the side-stacked membranes in a back-contact coated battery string disclosed in an embodiment of this application;

[0026] Figure 6This is a partial cross-sectional view of the side splicing of the membrane in the back-contact coated battery string disclosed in an embodiment of this application;

[0027] Figure 7 This is a partial cross-sectional view showing the side spacing of the membrane in the back-contact coated battery string disclosed in an embodiment of this application;

[0028] Figure 8 This application discloses a partial cross-sectional view of a back-contact coated battery string, which includes a first sub-film and a second sub-film.

[0029] Figure 9 This is a partial cross-sectional view of the side of the battery cell in the back-contact coated battery string, which is disclosed in an embodiment of this application.

[0030] In the diagram: 100, membrane; 101, first sub-membrane; 102, second sub-membrane; 200, solar cell; 300, welding strip assembly; A, gap. Detailed Implementation

[0031] To facilitate understanding of this utility model, a more complete description will be given below with reference to the accompanying drawings. The drawings illustrate preferred embodiments of this utility model. However, this utility model can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of the disclosure of this utility model.

[0032] It should be noted that when a component is said to be "set on" another component, it can be directly on the other component or there may be an intervening component. When a component is said to be "connected to" another component, it can be directly connected to the other component or there may be an intervening component.

[0033] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

[0034] like Figures 1 to 9 As shown, this application discloses a back-contact coated battery string. The disclosed back-contact coated battery string includes multiple films 100, multiple battery cells 200, and multiple solder ribbon groups 300. The backlight surfaces of the multiple battery cells 200 are connected in series along a first direction through the multiple solder ribbon groups 300. The multiple films 100 cover the backlight surfaces of the multiple battery cells 200, wherein the area of ​​the film 100 is larger than the area of ​​the battery cell 200.

[0035] When multiple sets of solder ribbons 300 are laid on the cell string, the distribution of solder ribbons is relatively large. The side of the film 100 extending from the cell 200 corresponds to a large area of ​​the solder ribbon sets 300 on the cell 200, covering the entire surface of the cell 200 to stably adhere all the solder ribbon sets 300 to the surface of the cell 200. Furthermore, because the film 100 extending from the cell 200 serves as a filler in the gaps between the cells 200 in the photovoltaic module, after being laminated and heated to melt, it fills the gaps between the cells 200, thus preventing voids within the photovoltaic module and preventing air bubbles from affecting the performance of the photovoltaic module or causing module burn-out, thereby improving conversion efficiency.

[0036] Along the first direction, both opposite sides of the diaphragm 100 extend beyond the sides of the corresponding attached battery cell 200, or one of the opposite sides of the diaphragm 100 extends beyond one side of the battery cell 200, and the other side is flush with the other side of the corresponding attached battery cell 200.

[0037] Since multiple solder ribbon groups 300 of the back contact battery string are electrically connected on the back surface of the battery cell 200, multiple solder ribbons in the solder ribbon group 300 will overlap the sides of both sides of the battery cell 200. In the above structure, the two opposite sides of the corresponding film 100 attached to each battery cell 200 extend out of the sides of both sides of the battery cell 200, or one of the two opposite sides of the corresponding film 100 attached to each battery cell 200 extends out of the side of one side of the battery cell 200. This allows the film 100 to control the solder ribbon group 300 on the corresponding battery cell 200, thereby ensuring that in EL detection, the corresponding area of ​​the side of each battery cell 200 in the back contact battery string will not be shadowed in the image formed by electroluminescence, thus ensuring the EL detection effect.

[0038] In addition, each film 100 has two opposing sides that extend beyond the sides of the corresponding attached solar cell 200. Alternatively, one of the two opposing sides of each film 100 extends beyond one side of the solar cell 200, while the other side is flush with the other side of the corresponding attached solar cell 200. In both cases, the side of the film 100 extending beyond the solar cell 200 can fill the gap A between two adjacent solar cells 200 in the subsequent lamination process of photovoltaic module manufacturing. This reduces the stress on the solder ribbon caused by excessive flow of EVA film in the photovoltaic module, except in the direction of gravity. This ensures the relative fixation between the solder ribbon group 300 and the solar cell 200 and avoids the problem of poor electrical connection of the back contact film-coated cell string caused by solder ribbon misalignment.

[0039] In this embodiment of the application, when each diaphragm 100 extends from the two opposite sides of the corresponding attached battery cell 200, a gap A is formed between any two adjacent battery cells 200, and the sides of two adjacent diaphragms 100 facing the gap A can be stacked on top of each other.

[0040] In the above structure, the two films 100 attached to the adjacent cells 200 facing the gap A can mutually control the sides of the two films 100 and simultaneously control the portion of the solder ribbon group 300 on the sides of the adjacent cells 200. The portion of the solder ribbon group 300 on the sides of the adjacent cells 200 further improves the fixing effect, thereby enabling multiple films 100 in the back-contact coated cell string to form a whole, providing a guarantee for the subsequent photovoltaic module manufacturing, avoiding the solder ribbon between the two adjacent cells 200 from being deflected by the molten adhesive during the lamination process. At the same time, the sides of the two films 100 facing the gap A can fill the gap A after melting.

[0041] Furthermore, in an alternative embodiment, multiple phase films 100 are stacked on one side extending in the same direction along a first direction on an adjacent one.

[0042] In the above structure, in the back-contact coated battery string, the two sides of the film 100 to which each battery cell 200 is attached are stacked on the side of the adjacent film 100 on one side in the same direction, and the other side is stacked on top of the side of the adjacent film 100, which is neat and beautiful.

[0043] In another alternative scheme, along the first direction, the side edges of any one of the odd-numbered or even-numbered diaphragms 100 can respectively cover the two adjacent side edges of two adjacent diaphragms 100.

[0044] In one alternative, a gap A is formed between any two adjacent cells 200 in the vertical direction, and the sides of two films 100 attached to the adjacent cells 200 are spliced ​​together with respect to the gap A.

[0045] In the above structure, multiple films 100 in the back-contact coated battery string are spliced ​​together to form a whole. Compared with the two films 100 that are attached to two adjacent battery cells 200 and can be stacked on the side facing the gap A, this application reduces the overall area of ​​the films 100. In other words, it saves costs while meeting the overall control of multiple solder ribbon groups 300.

[0046] In another alternative scheme, when the two opposite sides of the corresponding film 100 attached to each battery cell 200 extend beyond the side of the battery cell 200, a gap A is formed between any two adjacent batteries 200, and the spacing of gap A is greater than the spacing between the sides of two adjacent films 100 facing gap A.

[0047] In the above structure, compared to the two films 100 that are attached to the adjacent two battery cells 200, which can be stacked on each other with their sides facing the gap A, the films 100 can control the solder ribbon groups 300 corresponding to both sides of the battery cell 200, and also avoid contact between multiple films 100 and mutual interference, further reducing the overall area of ​​the films 100. In other words, while meeting the overall control of multiple solder ribbon groups 300, further cost savings are achieved.

[0048] In one alternative scheme, the two sides of the two furthest battery cells 200 can be extended to cover or flush with the sides of the two films 100, thereby ensuring that the solder ribbon groups 300 at both ends of the back-contact coated battery string are controlled by the corresponding films 100.

[0049] The above structure can control the overall control of the solder strip group on the cells at both ends of the back-contact coated battery string through the diaphragm 100. The two sides of the two cells 200 that are furthest apart among the multiple cells 200 can be extended to cover the two sides of the two diaphragms 100, and the extended sides of the diaphragms 100 can fill the gaps in the lamination process. The two sides of the two diaphragms 100 that are furthest apart among the multiple cells 200 can be flush with each other, reducing the area and saving costs.

[0050] In another alternative scheme, the two sides of the two furthest solar cells 200 are respectively covered by the sides of two membranes 100, one of which is covered by the side of the corresponding membrane 100, and the other is covered flush with the side of the corresponding membrane 100.

[0051] In this embodiment of the application, the diaphragm 100 may include a first sub-diaphragm 101 and a second sub-diaphragm 102. Specifically, the first sub-diaphragm 101 and the second sub-diaphragm 102 are spliced ​​to cover the battery cell 200. The side edge of the first sub-diaphragm 101 and the side edge of the second sub-diaphragm 102 both extend to the side edges of the battery cell 200. Alternatively, one of the side edges of the first sub-diaphragm 101 and the side edge of the second sub-diaphragm 102 extends to the side edge of the battery cell 200, and the other is flush with the side edge of the other side of the battery cell 200.

[0052] In the above structure, the membrane 100 can be formed by splicing the first sub-membrane 101 and the second sub-membrane 102. In the preparation process of the back contact coated battery string, the first sub-membrane 101 and the second sub-membrane 102 are laid simultaneously or one by one. Compared with the whole membrane laying, the number of air bubbles between the membrane and the battery cell 200 can be reduced. Along the first direction, the side length of the first sub-membrane 101 and the second sub-membrane 102 is shorter than that of the membrane 100, and the path of air bubble discharge is also shorter, which facilitates rapid discharge.

[0053] In this embodiment of the application, along the second direction, each diaphragm 100 can extend from the two opposite sides of its corresponding attached battery sheet 200 to the sides of both sides, or, one of the two opposite sides of each diaphragm 100 can extend from the side of one side of the battery sheet 200, and the other can be flush with the side of the other side of its corresponding attached battery sheet 200, wherein the second direction is perpendicular to the first direction.

[0054] In the above structure, along the second direction, each film 100 extends a side edge of at least one side of the corresponding attached solar cell 200, which can fill the gap between back-contact coated cell strings in the photovoltaic module lamination process.

[0055] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A back-contact coated battery string, characterized in that, It includes multiple films (100), multiple battery cells (200), and multiple ribbon groups (300). The backlight surfaces of the multiple battery cells (200) are connected in series along a first direction through the multiple ribbon groups (300). The multiple films (100) cover the backlight surfaces of the multiple battery cells (200), and the area of ​​the films (100) is larger than the area of ​​the battery cells (200).

2. The back-contact coated battery string according to claim 1, characterized in that, Along the first direction, both opposite sides of the diaphragm (100) extend out to the sides of the corresponding attached battery sheet (200), or one of the opposite sides of the diaphragm (100) extends out to the side of one side of the battery sheet (200).

3. The back-contact coated battery string according to claim 1, characterized in that, With each of the two opposite sides of the membrane (100) extending outwards from the sides of the corresponding attached battery cell (200), a gap (A) is formed between any two adjacent battery cells (200), and the sides of two adjacent membranes (100) facing the gap (A) are stacked on top of each other.

4. The back-contact coated battery string according to claim 3, characterized in that, Along the first direction, one side of each of the multiple membranes (100) extending in the same direction is stacked on top of an adjacent one.

5. The back-contact coated battery string according to claim 3, characterized in that, Along the first direction, the side edges of any one of the odd-numbered or even-numbered membranes (100) respectively cover the two adjacent side edges of two adjacent membranes (100).

6. The back-contact coated battery string according to claim 2, characterized in that, A gap (A) is formed between any two adjacent cells (200) of the plurality of cells, and the sides of the two films (100) that are attached to the adjacent cells (200) are spliced ​​together with the gap (A).

7. The back-contact coated battery string according to claim 2, characterized in that, When the two opposite sides of the corresponding film (100) attached to each of the battery cells (200) extend beyond the side of the battery cell (200), a gap (A) is formed between any two adjacent battery cells (200), and the spacing of the gap (A) is greater than the spacing between the sides of two adjacent films (100) facing the gap (A).

8. The back-contact coated battery string according to claim 2, characterized in that, The two sides of the two battery cells (200) that are furthest apart from each other are covered or flush with the sides of the two films (100).

9. The back-contact coated battery string according to claim 2, characterized in that, Among the plurality of battery cells (200), the two sides of the two battery cells (200) that are furthest apart are respectively covered by the side of the two membranes (100), one of which is covered by the side of the corresponding membrane (100) and the other is covered flush with the side of the corresponding membrane (100).

10. The back-contact coated battery string according to claim 1, characterized in that, The membrane (100) includes a first sub-membrane and a second sub-membrane. The first sub-membrane and the second sub-membrane are spliced ​​to cover the battery cell (200). One side of the first sub-membrane and one side of the second sub-membrane extend out to the sides of both sides of the battery cell (200). Alternatively, one side of the first sub-membrane and one side of the second sub-membrane extend out to the side of one side of the battery cell (200), and the other side is flush with the side of the other side of the battery cell (200).

11. The back-contact coated battery string according to claim 1, characterized in that, Along the second direction, each of the two opposite sides of the diaphragm (100) extends beyond the sides of the corresponding attached battery sheet (200), or, one of the two opposite sides of each of the diaphragm (100) extends beyond one side of the battery sheet (200), and the other is flush with the other side of the corresponding attached battery sheet (200), wherein the second direction is perpendicular to the first direction.

12. The back-contact coated battery string according to claim 1, characterized in that, Along the first direction, the side edges of any one of the odd-numbered or even-numbered membranes (100) respectively cover the two adjacent side edges of two adjacent membranes (100).

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