Solar cell piece assembly and cell string

Abstract

The utility model provides a solar cell sheet assembly and a cell string, the solar cell sheet assembly comprises a cell sheet and a plurality of solder strips, two side surfaces of the cell sheet are provided with fine auxiliary grid lines, and the solder strips are arranged in parallel at intervals. The welding strip comprises a first section electrically connected with thin auxiliary grid lines on the first side face of the battery piece and a second section extending out of the first side face, at least two glue points are arranged in the length direction of the first section at intervals, and the first side face is covered with the glue points so that the first section can be fixedly connected with the battery piece. The positions, located on the avoiding glue points, of the first sections are covered with welding strip protection films, and the welding strip protection films cover the first sections of the multiple welding strips at the same time. According to the utility model, during the use process of the corresponding photovoltaic module panel, when the local temperature of the hot spot effect is too high to cause the secondary fusion of the welding strip and the welding spot, the position of the welding strip is kept unchanged, the ohmic contact between the welding strip and the thin auxiliary grid line is kept, the aging speed of the photovoltaic module panel is delayed, and the service life of a battery string is prolonged.

Description

Technical Field

[0001] The utility model relates to the technical field of photovoltaic component processing, in particular to a solar cell sheet component and a battery string. Background Art

[0002] The conventional cell string structures of photovoltaic modules include main-grid-free and XBC. In the main-grid-free cell string (composed of multiple adjacent cells connected by welding ribbons), the surface of the corresponding cell is covered with silver fine grid lines (also known as fine auxiliary grid lines) for collecting current and outputting it to the adjacent cell through the welding ribbons. The welding ribbon and the silver fine grid lines of the cell are welded to form an alloyed contact to ensure the conduction effect of the current. When this welding structure is put into use in the later stage of photovoltaic panels, the unstable shadow on the surface of the photovoltaic panels will cause severe local heating of the cell. This severe heating phenomenon will melt the welded part between the welding ribbon and the silver fine grid lines. Once melted, the welding ribbon will easily detach from the silver fine grid lines on the surface of the cell. After the temperature returns to normal, the original alloyed contact effect will be significantly reduced compared with before, which also leads to the problem of increased resistance of the welding ribbon connection and lower service life of the photovoltaic panel. Utility Model Content

[0003] The solar cell assembly and battery string designed in the present invention can at least partially solve the above problems.

[0004] The utility model aims to provide a solar cell module, comprising a cell and a plurality of welding strips, wherein both side surfaces of the cell are provided with thin auxiliary grid lines, and each of the welding strips is arranged in parallel and at intervals, wherein the welding strip comprises a first section electrically connected to the thin auxiliary grid line on the first side surface of the cell and a second section extending beyond the first side surface, and at least two glue points are arranged at intervals along the length direction of the first section, and each of the glue points covers the first side surface to achieve a fixed connection between the first section and the cell, and each of the first sections is covered with a welding strip protective film at a position avoiding the glue point, and the welding strip protective film simultaneously covers the first sections of a plurality of welding strips.

[0005] In some embodiments, the at least two glue dots include a first glue dot and a second glue dot, and the first glue dot and the second glue dot are respectively located at two end positions of each of the first segments.

[0006] In some embodiments, the solder strip protective film is a hot melt adhesive film; or,

[0007] The solder strip protection film is an adhesive film, and a side of the adhesive film facing the first side surface has an adhesive layer.

[0008] In some embodiments, a third glue dot is further provided between the first glue dot and the second glue dot.

[0009] In some embodiments, a plurality of annular conductive members are further formed on the first side surface, and each of the annular conductive members is disposed around the glue point of each first section so as to electrically connect each of the fine secondary grid lines adjacent to the glue point with the welding strip.

[0010] In some embodiments, the annular conductive member is surrounded by thin auxiliary grid lines, and the inner area thereof is not provided with the thin auxiliary grid lines.

[0011] In some embodiments, the annular conductive member is formed by silver paste printing.

[0012] In some embodiments, the first side surface is correspondingly attached with the solder ribbon protective film, and the solder ribbon protective film is provided with a glue point avoidance hole for avoiding the glue point position; or, each of the first sections is attached and positioned by a plurality of the solder ribbon protective films, and each of the solder ribbon protective films is perpendicular to the extension direction of the solder ribbon and is located at a position to avoid the glue point.

[0013] In some embodiments, when the at least two glue points are a first glue point located at two ends of the battery sheet, a second glue point, and a third glue point located between the first glue point and the second glue point:

[0014] The solder strip protective film is a single piece and a evacuation hole for evading the third glue point is provided in the middle thereof, and two sides of the solder strip protective film stop at positions adjacent to the first glue point and the second glue point respectively.

[0015] In some embodiments, when the at least two glue points are a first glue point located at two ends of the battery sheet, a second glue point, and a third glue point located between the first glue point and the second glue point:

[0016] The solder strip protective film consists of two pieces, and the two pieces of the solder strip protective film are respectively arranged between the first glue point and the third glue point, and between the second glue point and the third glue point. The two pieces of the solder strip protective film extend in a direction perpendicular to the solder strip and can cover multiple solder strips at the same time.

[0017] The utility model also provides a battery string, which is formed by a plurality of adjacent battery cell assemblies connected in series, wherein the battery cell assembly is the above-mentioned solar cell assembly, and the front and back sides of the battery cell are provided with glue points for fixing the welding ribbon at the corresponding side positions and a welding ribbon protective film arranged to avoid the glue point position and used to attach the welding ribbon to the surface of the battery cell.

[0018] The solar cell module and battery string of the utility model:

[0019] At least two glue points are arranged at intervals in the length direction of the first section so that the first section can be kept in a straightened state. When the solder joints of the solder strips are melted for the second time due to the excessive local temperature of the hot spot effect during the use of the corresponding photovoltaic module board, even if the connection points (i.e., solder joints) between the solder strips and the corresponding thin auxiliary grid lines are melted for the second time and lose the connection strength, the solder strips will not change position due to the positioning effect of the glue points at both ends, thereby maintaining the ohmic contact between the solder strips and the thin auxiliary grid lines, effectively delaying the aging speed of the photovoltaic module board and improving the service life of the battery string; in addition, the solder strip protective film that covers multiple solder strips at the same time forms a covering protection for the solder strips in the form of a larger sheet, which can further improve the reliability of the ohmic contact between the solder strips and the thin auxiliary grid lines and realize the pre-fixation of the first sections of the solder strips, and can also directly contact the solder strips with force after the filling film layer between the battery string and the glass plate is melted under the hot spot effect during the use of the photovoltaic module board, causing the position of the solder strips to change, that is, it plays its role in protecting the solder strips and further reduces the probability of the position of the solder strips changing. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a three-dimensional structural diagram of a solar cell assembly of an embodiment of the utility model

[0021] Figure 2 It is a three-dimensional structural schematic diagram of a solar cell panel assembly according to another embodiment of the utility model, and shows that two solder strip protective films are arranged on the first side surface of the solar cell panel.

[0022] Figure 3 It is a schematic diagram of the three-dimensional structure of a solar cell panel assembly of another embodiment of the utility model with the soldering ribbon protection film omitted.

[0023] Figure 4 yes Figure 3 A local enlarged view of point A in the figure.

[0024] Figure 5 It is a three-dimensional structural schematic diagram of a battery string according to an embodiment of the utility model.

[0025] Figure 6 yes Figure 5 A partial enlarged view of point B in the middle;

[0026] Figure 7 This is a schematic diagram of the three-dimensional structure of a solar cell assembly according to another embodiment of the utility model.

[0027] In the figure:

[0028] 1. Battery cell; 11. Thin secondary grid line; 2. Solder ribbon; 21. First section; 22. Second section; 3. Glue point; 4. Solder ribbon protective film; 41. Glue point avoidance hole; 5. Ring-shaped conductive part. DETAILED DESCRIPTION

[0029] Example embodiments will now be described more fully with reference to the accompanying drawings. However, example embodiments can be implemented in a variety of forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that the present invention will be comprehensive and complete and fully convey the concepts of the example embodiments to those skilled in the art. In the drawings, the thickness of regions and layers are exaggerated for clarity. The same reference numerals in the drawings represent the same or similar structures, and thus their detailed description will be omitted.

[0030] The described features, structures or characteristics may be combined in one or more embodiments in any suitable manner. In the following description, many specific details are provided to provide a full understanding of the embodiments of the present invention. However, those skilled in the art will appreciate that the technical solution of the present invention may be practiced without one or more of the specific details, or other methods, components, materials, etc. may be used. In other cases, known structures, materials or operations are not shown or described in detail to avoid blurring the various aspects of the present invention.

[0031] The following example describes a solar cell module and a battery string of the utility model. This example is only a part of the embodiments of the utility model, but the protection scope of the utility model is not limited to this. All other embodiments obtained by ordinary technicians in this field without creative work should be included in the protection scope of the utility model.

[0032] Please refer to Figures 1 to 7According to an embodiment of the utility model, a solar cell assembly is provided, comprising a cell 1 and a plurality of welding strips 2, wherein thin auxiliary grid lines 11 are provided on both sides of the cell 1, and the welding strips 2 are arranged in parallel and spaced apart, wherein the welding strips 2 comprise a first section 21 electrically connected to the thin auxiliary grid lines 11 on a first side surface of the cell 1 and a second section 22 extending beyond the first side surface, and at least two glue dots 3 are arranged at intervals along the length direction of the first section 21, and each of the glue dots 3 is covered on the first side surface to achieve a fixed connection between the first section 21 and the cell 1, and each of the first sections 21 is covered with a welding strip protective film 4 at a position avoiding the glue dots 3 (i.e., a position where no glue is applied), and the welding strip protective film 4 simultaneously covers the first sections 21 of a plurality of welding strips 2, and in a specific embodiment, the welding strip protective film 4 covers the first sections 21 of each welding strip 2 across the width of the cell 1. It can be understood that the heat-resistant temperature of the aforementioned glue dots 3 should be higher than the melting point of the aforementioned soldering tape 2, and the electrical connection between the aforementioned soldering tape 2 and the thin auxiliary grid lines 11 can be a welding connection, for example, it can be achieved by lamination melting after the batteries are strung together, and the soldering tape 2 is electrically connected to all the thin auxiliary grid lines 11 on the battery cell 1. In specific implementation, the aforementioned glue dots 3 are specifically dispensed at corresponding positions by a dispensing device and then subsequent curing operations are performed according to the curing characteristics of the colloid.

[0033] In this technical solution, at least two glue spots 3 are arranged at intervals in the length direction of the first section 21 so that the first section 21 can be kept in a straightened state. When the corresponding photovoltaic module panel is in use and the local temperature is too high due to the hot spot effect, resulting in secondary melting of the solder joint of the soldering ribbon, even if the connection point (i.e., the soldering point) between the soldering ribbon 2 and the corresponding thin auxiliary grid line 11 is melted for the second time and loses the connection strength, the soldering ribbon 2 will not change position due to the positioning effect of the glue spots 3 at both ends, thereby maintaining the ohmic contact between the soldering ribbon 2 and the thin auxiliary grid line 11, effectively delaying the aging speed of the photovoltaic module panel and improving the service life of the battery string. It should be noted that the heat resistance temperature of the aforementioned glue point 3 being higher than the melting point of the welding strip 2 is only the most basic requirement. In theory, the heat resistance temperature of the glue point 3 should preferably not be lower than the maximum value of the local temperature when the battery cell produces a hot spot effect during use, so as to ensure that the glue point 3 can reliably straighten the fixed welding strip 2. In actual application, based on the consideration of the material selection of the glue point 3 and the cost consideration, a curing glue with a heat resistance temperature higher than the melting point of the welding strip 2 can be selected, which can meet the straightening and positioning requirements of the secondary molten welding strip in most cases; in addition, the welding strip protection film 4 that covers multiple welding strips 2 at the same time forms a covering protection for the welding strip 2 in the form of a larger sheet. On the one hand, it can further improve the reliability of the ohmic contact between the welding strip 2 and the thin auxiliary grid line 11, and realize the pre-fixation of each first section 21 of the welding strip 2. On the other hand, during the use of the photovoltaic module board, the filling film layer between the battery string and the glass plate can be directly contacted with the welding strip 2 after melting under the hot spot effect, resulting in a change in the position of the welding strip 2, that is, it plays its role in protecting the welding strip, and further reduces the probability of the position change of the welding strip 2.

[0034] In a specific embodiment, the glue dots 3 are formed by curing with a thermosetting adhesive. The aforementioned thermosetting adhesive can specifically be a thermosetting resin commonly used on the market, such as epoxy resin, unsaturated polyester resin, phenolic resin, polyurethane, etc. The heat resistance temperature of these thermosetting resins can generally reach above 100°C. According to actual needs, a thermosetting resin with a heat resistance temperature of not less than 150°C, such as epoxy resin, can be further selected.

[0035] In another specific embodiment, the glue dots 3 are formed by curing with a photocuring glue. The photocuring glue can specifically be UV glue (also known as ultraviolet curing glue) commonly used on the market, and its thermal decomposition temperature, that is, the heat resistance temperature, can be as high as 250°C-300°C. It has high thermal stability and can significantly reduce manufacturing costs.

[0036] As a preferred embodiment, the at least two glue points 3 include a first glue point (not labeled in the figure) and a second glue point (not labeled in the figure), and the first glue point and the second glue point are respectively located at the two end positions of each of the first sections 21. In another preferred embodiment, other glue points 3 are further arranged between the first glue point and the second glue point, and the number can be reasonably selected according to the length of the battery cell. In theory, the more glue points 3 there are, the more conducive it is to prevent the occurrence of poor connection caused by the hot spot effect, but the cost will also increase accordingly.

[0037] In this technical solution, the first glue point and the second glue point at the ends of the first section 21 can straighten the solder strip while preventing the ends of the solder strip from melting due to the hot spot effect and flowing into the gap between two adjacent battery cells 1 connected in series. If the tin-lead at the ends flows into the gap between the battery cells, it is easy to cause poor contact or short circuit, and it will also affect the normal use of the photovoltaic module in the later stage. By dispensing glue on the ends, the flow of the melted ends of the solder strip can be effectively blocked, which is more conducive to extending the service life of the component board.

[0038] In some embodiments, the solder strip protective film 4 is a hot melt adhesive film, which is covered on the solder strip of the battery cell and then fixed after being cured by a certain degree of hot melt. This film is usually non-sticky, which can facilitate the smooth execution of processing, cutting, laminating and other actions; in a preferred embodiment, the hot melt adhesive film can be made of the same material as the laminating film in the back-end lamination process, such as EVA, POE, PET or EPE, etc. This material can be melted simultaneously with the laminating film during lamination, which can ensure the uniformity between the film media and is conducive to better absorption of sunlight.

[0039] In other embodiments, the solder strip protective film 4 is an adhesive film, and the side of the adhesive film facing the first side surface has an adhesive layer, that is, this type of adhesive film uses a sticky protective film, the melting point of which needs to be at least higher than the melting point of the laminating film in the back-end lamination process, and can form a protective layer for the solder strip during lamination; for soldering the solder strip through the lamination process, it can ensure the accuracy of the solder strip position, and for the prepared photovoltaic modules, it can also provide good protection for the solder strip when a hot spot effect occurs in the later stage.

[0040] It should be noted that the welding between the soldering ribbon 2 and each thin auxiliary grid line 11 can be reserved for welding in the back-end lamination process, and of course, it can also be welded and fixed on the side of the battery cell before covering the soldering ribbon protection film 4.

[0041] See Figure 2 and Figure 3As shown, in some embodiments, a third glue point (not marked in the figure) is further provided between the first glue point and the second glue point, thereby achieving multi-point fixation of the end and middle portion of the first section 21, ensuring the straightening and positioning effect of the welding strip 2 during the secondary melting.

[0042] In some embodiments, a plurality of annular conductive members 5 are further formed on the first side surface, and each of the annular conductive members 5 is arranged around the glue point 3 of each of the first sections 21 so as to be able to electrically connect the each of the fine auxiliary grid lines 11 adjacent to the glue point 3 with the welding tape 2. The annular conductive members 5 may be square, circular or other irregular shapes. In principle, any shape is acceptable as long as the each of the fine auxiliary grid lines 11 near the glue point 3 can be electrically connected in the circumferential direction around the glue point 3.

[0043] In this technical solution, by arranging an annular conductive member 5 around the glue point 3, when the soldering tape 2 is wrapped and fixed on the side of the battery cell 1 by the glue point 3, the thin auxiliary grid line 11 at the avoidance position of the soldering tape can form a loop and form a good contact with the soldering tape 2. Even after the glue point 3 is solidified, the two sides of the soldering tape 2 can still be welded with the thin auxiliary grid line 11 to form an alloy connection, so that the glue point action and the subsequent welding action no longer interfere with each other, which is conducive to the normal use of the solar cell module in the later stage and ensures the normal use of the EL detection. It can be understood that if such an annular conductive member 5 is not designed, after the soldering tape 2 is fixed by the glue point 3 after the glue point is solidified, the glue point 3 will wrap and fix the soldering tape 2. When the soldering tape is welded to form an ohmic contact with the thin auxiliary grid line 11 between the battery cells in the lamination process, the wrapping effect of the glue point 3 will not allow the soldering tape to directly form a welding structure with the silver auxiliary grid line, so that the soldering tape and the silver fine grid line at the position of the glue point 3 solidification point still have a large resistance, which not only affects the normal use of the subsequent photovoltaic module, but also causes undesirable phenomena when performing EL detection.

[0044] The aforementioned annular conductive member 5 is preferably arranged on the periphery of the glue point in the middle area of ​​the welding strip 2. For the glue points 3 at the two ends of the welding strip 2, since the two sides of the battery cell adopt a secondary grid line structure with better contact effect, the aforementioned annular conductive member 5 may not be arranged on the glue point positions on both sides of the battery cell. Of course, this does not necessarily mean that the aforementioned annular conductive member 5 is not arranged at the two end positions of the battery cell 1.

[0045] In a preferred embodiment, the annular conductive member 5 is surrounded by the thin auxiliary grid lines 11 and the thin auxiliary grid lines 11 are not arranged in the inner area thereof, that is, each thin auxiliary grid line 11 is electrically connected to the annular conductive member 5 from the outer side of the annular conductive member 5, thereby being able to reduce the usage of the thin auxiliary grid lines 11 to a certain extent and reduce the component manufacturing cost.

[0046] In a feasible embodiment, the annular conductive member 5 is formed by printing silver paste, which is convenient for the production of the annular conductive member 5. Specifically, the annular silver paste is printed on the basis of the battery cell (multiple uniformly parallel silver thin secondary grid lines) so that the position of the glue point 3 can form an alloy contact during the subsequent lamination process.

[0047] In some embodiments, see Figure 7 As shown, the first side surface is correspondingly attached with the solder strip protective film 4, and the solder strip protective film 4 is provided with a glue point avoidance hole 41 for avoiding the glue point position, that is, a whole piece of film with the aforementioned glue point avoidance hole 41 is used corresponding to one side of the battery cell 1, and the production is very convenient. Specifically, when the at least two glue points 3 are the first glue point, the second glue point and the third glue point located at both ends of the battery cell: the solder strip protective film 4 is a piece and the middle part of the solder strip protective film 4 is provided with an avoidance hole for avoiding the third glue point, and the two sides of the solder strip protective film 4 stop at the positions adjacent to the first glue point and the second glue point respectively.

[0048] As another feasible implementation, each of the first sections 21 is attached and positioned by a plurality of the solder strip protective films 4, each of the solder strip protective films 4 is perpendicular to the extension direction of the solder strip 2 and is located at a position to avoid the glue point 3. Specifically, see Figure 2 As shown, when the at least two glue points 3 are the first glue point, the second glue point and the third glue point located at both ends of the battery cell: the solder strip protective film 4 is two pieces, and the two pieces of the solder strip protective film 4 are respectively arranged at the positions between the first glue point and the third glue point, and the second glue point and the third glue point, and the two pieces of the solder strip protective film 4 extend in a direction perpendicular to the solder strip 2 and can cover multiple solder strips 2 at the same time.

[0049] According to the embodiments of the present invention, see Figure 5 and Figure 6 As shown, a battery string is also provided, which is formed by connecting a plurality of adjacent battery cell assemblies in series, wherein the battery cell assembly is the above-mentioned solar cell assembly, and the front and back sides of the battery cell 1 are provided with glue points 3 for fixing the welding ribbon 2 at the corresponding side positions and a welding ribbon protective film 4 arranged to avoid the glue point position and used to attach the welding ribbon 2 to the surface of the battery cell.

[0050] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may be subject to various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A solar cell assembly, comprising a cell (1) and a plurality of welding strips (2), wherein both sides of the cell (1) are provided with thin secondary grid lines (11), and the welding strips (2) are arranged in parallel and at intervals, characterized in that: The soldering strip (2) comprises a first section (21) electrically connected to a thin secondary grid line (11) on a first side surface of a battery cell (1) and a second section (22) extending out of the first side surface, at least two glue points (3) are arranged at intervals along the length direction of the first section (21), each of the glue points (3) covers the first side surface to achieve a fixed connection between the first section (21) and the battery cell (1), each of the first sections (21) is covered with a soldering strip protective film (4) at a position avoiding the glue point (3), and the soldering strip protective film (4) simultaneously covers the first sections (21) of a plurality of soldering strips (2).

2. The solar cell assembly according to claim 1, characterized in that: The at least two glue spots (3) include a first glue spot and a second glue spot, wherein the first glue spot and the second glue spot are respectively located at two end positions of each of the first sections (21).

3. The solar cell assembly according to claim 1 or 2, characterized in that: The welding strip protective film (4) is a hot melt adhesive film; or, The solder strip protective film (4) is an adhesive film, and the side of the adhesive film facing the first side surface has an adhesive layer.

4. The solar cell assembly according to claim 2, characterized in that: A third glue point is further provided between the first glue point and the second glue point.

5. The solar cell assembly according to claim 1, characterized in that: A plurality of annular conductive members (5) are also formed on the first side surface, and each of the annular conductive members (5) is arranged around the glue point (3) of each of the first sections (21) so as to be able to electrically connect each of the fine secondary grid lines (11) adjacent to the glue point (3) with the welding strip (2).

6. The solar cell assembly according to claim 5, characterized in that: The annular conductive member (5) is formed by surrounding the thin auxiliary grid line (11), and the inner area thereof is not provided with the thin auxiliary grid line (11).

7. The solar cell assembly according to claim 5 or 6, characterized in that: The annular conductive element (5) is formed by silver paste printing.

8. The solar cell assembly according to claim 1, characterized in that: The solder strip protective film (4) is attached to the first side surface in correspondence, and the solder strip protective film (4) is provided with a glue point avoidance hole (41) for avoiding the glue point position; or, each of the first sections (21) is attached and positioned by a plurality of the solder strip protective films (4), and each of the solder strip protective films (4) is perpendicular to the extension direction of the solder strip (2) and is located at a position to avoid the glue point (3).

9. The solar cell assembly according to claim 4, characterized in that: When the at least two glue points (3) are a first glue point located at two ends of the battery cell, a second glue point, and a third glue point located between the first glue point and the second glue point: The solder strip protective film (4) is a single piece and has an avoidance hole in the middle thereof for avoiding the third glue point. Both sides of the solder strip protective film (4) stop at positions adjacent to the first glue point and the second glue point respectively.

10. The solar cell assembly according to claim 4, characterized in that: When the at least two glue points (3) are a first glue point located at two ends of the battery cell, a second glue point, and a third glue point located between the first glue point and the second glue point: The solder strip protective film (4) consists of two pieces, and the two pieces of the solder strip protective film (4) are respectively arranged between the first glue point and the third glue point, and between the second glue point and the third glue point. The two pieces of the solder strip protective film (4) extend in a direction perpendicular to the solder strip (2) and can cover a plurality of the solder strips (2) at the same time.

11. A battery string, characterized in that: The invention relates to a solar cell assembly formed by connecting a plurality of adjacent cell assemblies in series, wherein the cell assembly is a solar cell assembly according to any one of claims 1 to 10, wherein both the front and back sides of the cell (1) are provided with glue points (3) for fixing the welding strip (2) at corresponding side positions and a welding strip protective film (4) arranged to avoid the glue point position and used for attaching the welding strip (2) to the surface of the cell.

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