A back contact cell assembly

Abstract

The application discloses a back contact battery assembly, which comprises a battery body, a plurality of first fine grids, a plurality of second fine grids, an edge connecting line, an edge solder strip and a solder strip, the plurality of second fine grids are arranged in an interlaced manner with the plurality of first fine grids; the edge connecting line is connected with the plurality of second fine grids respectively; the edge solder strip is connected with the plurality of second fine grids respectively; the solder strip is vertically arranged at the middle part of the plurality of first fine grids and the plurality of second fine grids, and the solder strip is alternately connected with the first fine grid and the second fine grid. The edge connecting line is arranged at the edge position of the battery body and connected with the plurality of second fine grids, so that the current can be smoothly conducted from the second fine grid to the edge solder strip. The design not only avoids the use of insulating glue and simplifies the production steps, but also reduces the risk of edge solder strip deviation by arranging the wide solder strip at the edge, reduces the battery hidden crack, and the solder strip extending out of the battery edge can also be used as a reflective strip, thereby improving the reliability and efficiency of the whole assembly.

Description

Technical Field

[0001] This application relates to the field of photovoltaic module technology, and in particular to a back-contact battery module. Background Technology

[0002] Back contact batteries are a type of high-efficiency crystalline silicon battery. Their electrode grid lines are all located on the back of the battery. Therefore, the positive and negative fine grids are arranged alternately on the surface of the battery. The solder ribbons are arranged vertically with the fine grids, so they will cross the other fine grid. In order to avoid short circuit problems, insulating adhesive is usually printed on the surface of the other fine grid at the location where the solder ribbons are fixed.

[0003] Currently, by designing the fine grids to be disconnected while ensuring the precise positioning of the solder ribbon, the use of insulating adhesive can be eliminated. However, for the outermost fine grid, since the solder ribbon can only collect positive or negative current, the current of the negative or positive grid lines near the edge of the battery cannot be collected. Currently, there are two methods to solve this problem: (1) Print a connecting line perpendicular to the fine grid along the edge of the battery to connect all the fine grids that cannot contact the solder ribbon, and extend it along the edge of the battery to the secondary edge main grid. However, this will cause the outermost solder ribbon to contact the outermost fine grid, so insulating adhesive needs to be printed, and the outermost main grid cannot be printed on the outermost fine grid; (2) Disconnect all the fine grids from the edge main grid, and then add solder ribbons along the edge of the battery to collect the fine grid current. However, when adding solder ribbons along the edge of the battery, there is a risk of microcracks at the edge of the battery due to the proximity to the edge (within 1mm). At the same time, the closer to the edge of the battery, the easier it is for the solder ribbon to shift under the push of the adhesive film during the lamination process. For the two battery types mentioned above, the urgent problem to be solved is how to meet the current collection requirements while avoiding the use of insulating adhesive and without affecting the yield of the components. Utility Model Content

[0004] The main objective of this application is to provide a back-contact battery assembly that addresses the issues of edge grid current collection and the need for printed insulating adhesive in existing back-contact battery assembly grid disconnect patterns.

[0005] To achieve the above objectives, this application provides a back-contact battery assembly, comprising: a battery body, a plurality of first fine grids, a plurality of second fine grids, an edge connecting line, an edge solder strip, and a solder strip, wherein the plurality of first fine grids are disposed on the surface of the battery body; the plurality of second fine grids are disposed on the surface of the battery body, and the plurality of second fine grids are arranged alternately with the plurality of first fine grids; the edge connecting line is disposed at the edge of the battery body, and the edge connecting line is connected to the plurality of second fine grids respectively; the edge solder strip is disposed on the edge connecting line and is connected to the plurality of second fine grids respectively; the solder strip is disposed in the middle of the plurality of first fine grids and the plurality of second fine grids.

[0006] Optionally, the edge connecting line is 0.2mm to 0.5mm away from the edge of the battery body.

[0007] Optionally, the edge welding strip protrudes 0.5mm to 2mm from the edge of the battery body.

[0008] Optionally, the distance from each of the first fine gates to the edge connection line is 0.3 mm to 1 mm.

[0009] Optionally, the width of the edge weld strip is 0.7mm to 3mm, and the thickness of the edge weld strip is 0.05mm to 0.2mm.

[0010] Optionally, the edge solder strip is made of copper.

[0011] Optionally, the edge solder strip is made of a composite material consisting of a central copper core and an outer tin layer.

[0012] Optionally, the thickness of the outer tin layer is between 2 μm and 5 μm.

[0013] Optionally, the edge solder strip includes a copper layer and an aluminum layer, the copper layer being bonded to the battery body.

[0014] Optionally, the first and second fine grids are alternately disconnected at the solder strip connection to avoid short circuits, and the disconnection distance is greater than the width of the solder strip.

[0015] This application proposes a back-contact solar cell module. By placing edge connecting lines at the edge of the cell body and connecting them to multiple second fine grids, it ensures smooth current conduction from the second fine grids to the edge solder strips, while the multiple first fine grids are not connected to the edge solder strips. This design not only avoids the use of insulating adhesive, simplifying the production process and reducing costs, but also improves the reliability and efficiency of the module. Moreover, the back-contact solar cell module provided in this application solves the current collection problem of the edge fine grids in existing back-contact solar cell module open-grid designs through the design of edge connecting lines and edge solder strips. This module is not only simple in structure and easy to manufacture, but also has excellent current collection capability and reliability, making it suitable for various photovoltaic application scenarios.

[0016] This application uses edge solder strips instead of reflective strips, saving the cost of reflective strips and reducing the steps involved in laying reflective strips on the module, making the back contact battery module simpler and effectively reducing costs. The use of thin and wide edge solder strips avoids edge solder strip misalignment and microcracks at the battery edges. Attached Figure Description

[0017] Figure 1 A schematic diagram illustrating the structure for adding edge solder strips and solder strips to a solar cell; Figure 2This is a schematic diagram showing the connection relationship of the multiple back contact battery components involved in this application; Figure 3 A back-contact battery assembly with a main grid assembly is provided as an embodiment of this application; Figure 4 This is a schematic diagram of the overall structure of the back contact battery assembly involved in this application.

[0018] In the diagram, 1 is the battery body; 2 is the first fine grid; 3 is the second fine grid; 4 is the edge connecting line; 5 is the edge solder strip; and 6 is the solder strip.

[0019] The realization of the purpose, functional features and advantages of this application will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0020] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0021] It should be noted that all directional indicators (such as up, down, left, right, front, back, etc.) in this utility model embodiment are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicator will also change accordingly.

[0022] In this utility model, unless otherwise explicitly specified and limited, the terms "connection," "fixing," etc., should be interpreted broadly. For example, "fixing" can mean a fixed connection, a detachable connection, or an integral part; it can mean a mechanical connection or an electrical connection; it can mean a direct connection or an indirect connection through an intermediate medium; it can mean the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0023] Furthermore, if the embodiments of this utility model involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the meaning of "and / or" throughout the text includes three parallel solutions; for example, "A and / or B" includes solution A, solution B, or a solution where both A and B are satisfied simultaneously. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this utility model.

[0024] Please see Figures 1 to 4 This application provides a back-contact battery assembly, which may include: a battery body 1, a plurality of first fine grids 2, a plurality of second fine grids 3, an edge connecting line 4, an edge solder strip 5, and a solder strip 6. The plurality of first fine grids 2 are disposed on the surface of the battery body 1; the plurality of second fine grids 3 are disposed on the surface of the battery body 1, and the plurality of second fine grids 3 are arranged alternately with the plurality of first fine grids 2; the edge connecting line 4 is disposed at the edge of the battery body 1, and the edge connecting line 4 is connected to the plurality of second fine grids 3 respectively; the edge solder strip 5 is disposed on the edge connecting line 4 and is connected to the plurality of second fine grids 3 respectively; the solder strip 6 is vertically disposed in the middle of the plurality of first fine grids 2 and the plurality of second fine grids 3, and intersects the first fine grids 2 and the second fine grids 3 alternately and perpendicularly.

[0025] In this embodiment, by placing the edge connection line 4 at the edge of the battery body 1 and connecting it to multiple second fine grids 3, it is ensured that current can be smoothly conducted from the second fine grids 3 to the edge solder strip 5, and the multiple first fine grids 2 are not connected to the edge solder strip 5. This design not only avoids the use of insulating adhesive, simplifies the production process and reduces costs, but also improves the overall reliability and efficiency of the module. Moreover, the back contact battery module provided in this application embodiment solves the problem of edge fine grid current collection in existing back contact battery module open grid designs through the design of the edge connection line 4 and the edge solder strip 5. This module is not only simple in structure and easy to manufacture, but also has excellent current collection capability and reliability, making it suitable for various photovoltaic application scenarios.

[0026] Additionally, it should be noted that existing photovoltaic (PV) modules incorporate reflective strips between the cell strings. These strips primarily reflect incident light onto the cells, thereby improving the PV module's light utilization and power generation efficiency. The reflective strips are typically aluminum-containing reflective film strips, placed between the cell strings during the layout process after manufacturing. This application uses edge solder strips 5 instead of reflective strips, saving on the cost of the strips and reducing the steps involved in laying them on the module. This simplifies the back-contact cell module design and effectively reduces costs. The edge solder strips 5 are thin and wide, preventing edge solder strip misalignment and microcracks at the cell edges.

[0027] It should be further noted that the ends of the edge solder strips 5 and 6 protrude from the battery body 1 to facilitate connection with another battery body 1. The first fine grid 2 is interrupted at the edge solder strip 5 to avoid contact with the edge solder strip 5; similarly, the second fine grid 3 is interrupted at the solder strip 6 to avoid contact with the solder strip 6.

[0028] Furthermore, in some possible implementations, the edge connection line 4 is 0.2mm to 0.5mm away from the edge of the battery body 1.

[0029] In specific embodiments, the distance between the edge connection line 4 and the edge of the battery body 1 can be 0.2mm, 0.3mm, 0.4mm, or 0.5mm. Specifically, the setting of the edge connection line 4 not only ensures smooth current conduction but also optimizes the overall structure of the battery assembly. The precise control of its distance from the edge of the battery body 1 avoids potential damage from direct contact with the battery edge while ensuring sufficient connection stability and current transmission efficiency.

[0030] Furthermore, in some possible implementations, the edge welding strip 5 protrudes 0.5mm to 2mm from the edge of the battery body 1.

[0031] In this embodiment, the edge welding strip 5 protruding from the edge of the battery body 1 can be 0.5mm, 1mm, 1.5mm, 2mm, etc. Designing the edge welding strip 5 to protrude 0.5mm to 2mm from the edge of the battery body 1 ensures reliable connection with the edge connecting line 4 and the second fine grid 3, while also facilitating subsequent assembly and connection operations. Simultaneously, this design also considers mechanical stress and environmental factors in practical applications, ensuring the long-term stability and reliability of the battery assembly. That is to say, if the edge welding strip 5 protrudes too little from the edge of the battery body 1, it will not serve a reflective function; the distance of the edge welding strip 5 protruding from the edge of the battery body 1 should not exceed half the spacing between the battery strings, otherwise the edge welding strips of two parallel battery strings will overlap, causing a short circuit. Furthermore, the protruding edge of the edge welding strip 5 is parallel to the edge of the battery body 1.

[0032] Furthermore, in some possible implementations, the distance from each first fine gate 2 to the edge connection line 4 is 0.3 mm to 1 mm.

[0033] Specifically, the distance from each first fine grid 2 to the edge connection line 4 can be: 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, or 1mm. Regarding the design of the distance between the first fine grid 2 and the edge connection line 4, this application provides a specific range for each first fine grid 2. That is, the distance from each first fine grid 2 to the edge connection line 4 is 0.3mm to 1mm. This design ensures effective connection between the first fine grid 2 and the solder strip 6 while avoiding the risk of short circuits that may result from excessive proximity to the edge connection line 4. In other words, if the first fine grid 2 is too close to the edge connection line 4, it is prone to short circuits; if the first fine grid 2 is too far from the edge connection line 4, it will be unable to properly collect the edge current of the battery, leading to a decrease in battery efficiency.

[0034] Furthermore, in some possible implementations, the width of the edge solder strip 5 is 0.7 mm to 3 mm, and the thickness of the edge solder strip 5 is 0.05 mm to 0.2 mm.

[0035] Specifically, the edge solder strip 5 is designed as a flat solder strip, with a width of 0.7mm, 1.5mm, 2.3mm, 3mm, etc., and a thickness of 0.05mm, 0.1mm, 0.15mm, 0.2mm, etc. Designing the width of the edge solder strip 5 to be 0.7mm–3mm and the thickness to be 0.05mm–0.2mm ensures both sufficient current carrying capacity and the flexibility and ease of handling of the solder strip.

[0036] Furthermore, in some possible implementations, the edge solder strip 5 is made of copper.

[0037] In this embodiment, the edge solder strip 5 is made of copper, mainly because copper has good electrical conductivity and mechanical strength, which can meet the operating requirements of the back contact battery module under high current density. The copper edge solder strip 5 can effectively reduce resistance and improve current transmission efficiency, and can also serve as a reflective strip to reflect light between the batteries.

[0038] Furthermore, in some possible implementations, the edge solder strip 5 is made of a composite material with copper in the center and tin on the outer layer.

[0039] Specifically, the outer tin layer is primarily designed to improve the corrosion resistance and weldability of the edge solder strip 5. The tin layer prevents the copper layer from directly contacting the external environment, thereby reducing copper oxidation and corrosion and extending the service life of the edge solder strip 5. Simultaneously, the tin layer also provides excellent weldability, making it easier and more reliable to connect the edge solder strip 5 to other components. This composite material design ensures both the conductivity of the edge solder strip 5 and enhances its corrosion resistance and weldability, resulting in a more stable and reliable back-contact battery assembly.

[0040] In other embodiments, the edge solder strip 5 may also be a composite material of copper and other metals, such as aluminum, nickel, bismuth, lead, etc. Specifically, the center is copper, and the outer layer is tin, tin-lead, or tin-lead-bismuth, or a layered composite, such as copper-aluminum, or copper-aluminum-copper layered composite. Alternatively, after layered composite, a tin, tin-lead, or tin-lead-bismuth layer may be formed outside the copper layer.

[0041] Furthermore, in some possible implementations, the thickness of the outer tin layer is between 2 μm and 5 μm.

[0042] The thickness of the outer tin layer can be 2μm, 3μm, 4μm, or 5μm. Controlling the thickness of the outer tin layer within the range of 2μm to 5μm ensures sufficient protection of the copper layer, preventing oxidation and corrosion, without adding unnecessary costs and processing difficulties due to an excessively thick tin layer. This design is both economical and practical, meeting the long-term stable operation requirements of back-contact battery modules in various environments.

[0043] Furthermore, in some possible implementations, the edge solder strip 5 includes a copper layer and an aluminum layer, with the copper layer bonded to the battery body 1.

[0044] In this embodiment, the edge solder strip 5 adopts a composite structure of copper and aluminum layers. The copper layer is tightly bonded to the battery body 1, while the aluminum layer is located outside the copper layer. The copper layer has good electrical conductivity, ensuring efficient current transmission, while the aluminum layer has excellent corrosion resistance and is much cheaper than copper. This significantly reduces the cost of the solder strip while improving the overall performance and service life of the edge solder strip 5.

[0045] Furthermore, in some possible implementations, the first fine gate 2 and the second fine gate 3 are alternately disconnected at the connection of the solder strip 6, and the disconnection distance is greater than the width of the solder strip 6.

[0046] The alternating break between the first grid 2 and the second grid 3 at the connection point of the solder strip 6 is designed to be wider than the solder strip 6. This is primarily to avoid direct contact between the grid and the solder strip 6, thus preventing potential short-circuit risks. Simultaneously, this design ensures that the current on the second grid 3 can be smoothly collected through the edge connection line 4 and the edge solder strip 5, improving the current collection efficiency and overall performance of the battery module. By precisely controlling the break distance of the second grid 3, the effect of eliminating the need for insulating adhesive can be achieved. Short circuits are avoided solely through the grid break design, saving on the use of insulating adhesive and simplifying the battery cell production process.

[0047] Compared with the prior art, the back contact battery assembly involved in this application has significant advantages, specifically: the edge solder strip 5 is designed as a flat solder strip, which can effectively reduce the risk of displacement during lamination compared with the round solder strip. The test data is as follows: compared with the round solder strip, the flat solder strip can effectively improve the displacement problem, and as the width of the solder strip increases, the displacement after lamination decreases significantly.

[0048]

[0049] It should be noted that when the first fine gate 2 is the positive fine gate, the second fine gate 3 is the negative fine gate; similarly, when the first fine gate 2 is the negative fine gate, the second fine gate 3 is the positive fine gate.

[0050] The above are merely preferred embodiments of this application and do not limit the patent scope of this application. Any equivalent structural or procedural transformations made using the content of this application's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this application.

Claims

1. A back-contact battery assembly, characterized in that, include: Battery body (1); Multiple first fine grids (2) are disposed on the surface of the battery body (1); Multiple second fine grids (3) are disposed on the surface of the battery body (1), and the multiple second fine grids (3) are arranged alternately with the multiple first fine grids (2); An edge connecting line (4) is provided at the edge of the battery body (1), and the edge connecting line (4) is connected to a plurality of second fine grids (3); Edge solder strips (5) are disposed on the edge connecting line (4) and are respectively connected to a plurality of second fine grids (3); The solder strip (6) is vertically disposed in the middle of a plurality of first fine grids (2) and a plurality of second fine grids (3), and the solder strip (6) is alternately connected to the first fine grids (2) and the second fine grids (3).

2. The back contact battery assembly according to claim 1, characterized in that, The edge connecting line (4) is 0.2mm to 0.5mm away from the edge of the battery body (1).

3. The back contact battery assembly according to claim 1, characterized in that, The edge welding strip (5) protrudes 0.5mm to 2mm from the edge of the battery body (1).

4. The back contact battery assembly according to claim 1, characterized in that, The distance from each of the first fine grids (2) to the edge connecting line (4) is 0.3 mm to 1 mm.

5. The back contact battery assembly according to claim 1, characterized in that, The edge welding strip (5) has a width of 0.7mm to 3mm and a thickness of 0.05mm to 0.2mm.

6. The back contact battery assembly according to claim 5, characterized in that, The edge solder strip (5) is made of copper.

7. The back contact battery assembly according to claim 5, characterized in that, The edge solder strip (5) is made of a composite material with copper in the center and tin on the outer layer.

8. The back contact battery assembly according to claim 7, characterized in that, The thickness of the outer tin layer is between 2μm and 5μm.

9. The back contact battery assembly according to claim 5, characterized in that, The edge solder strip (5) includes a copper layer and an aluminum layer, the copper layer being bonded to the battery body (1).

10. The back contact battery assembly according to claim 1, characterized in that, The first fine grid (2) and the second fine grid (3) are alternately disconnected at the connection of the solder strip (6), and the disconnection distance is greater than the width of the solder strip (6).

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