Reinforcing structure for electrical connection of battery pieces in photovoltaic module

Abstract

The utility model discloses a reinforcing structure for electrical connection of battery pieces in a photovoltaic module, which is characterized in that electrical connection and connection strength of two action factors of internal connection of the photovoltaic module are separated, and the two action factors are respectively responsible for an electrical connection material and a bonding material; the electric connection material mainly plays a role in electric connection, and the binding power of the electric connection material can be reduced or even zero; the bonding material mainly plays a role in bonding. The electrical connection and the bonding strength do not need to be considered by one material, the electrical connection material and the bonding material only need to meet one requirement, two requirements do not need to be met at the same time, the selection range of the electrical connection material and the bonding material is wider, the manufacturing process window is larger, and the manufacturing and production difficulty is reduced. The performance of the electric connection material and the performance of the bonding material can be independently adjusted, the requirement for the electric conductivity or bonding strength of the independent performance is controllable, and the independent performance is more convenient to adjust. The utility model is very suitable for small-area contact electrical connection.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of photovoltaic, in particular to a reinforcing method for electrical connection of cell pieces in a photovoltaic module. BACKGROUND

[0002] In the existing crystalline silicon cell module, the cell pieces are connected in series by metal welding wire. The connection between the welding wire and the cell pieces has two main functions: ① forming an electrical path to transmit current; ② having a certain connection force to connect the cell pieces into a string. Through the welding means to form an alloy, the electrical connection generally meets the current transmission requirements, but different types of cell pieces, different cell paste, different material welding strip and different welding process will lead to different connection strength of the connection site. For example, HJT cells use solidified low-temperature silver paste and low-temperature welding, and the pull-off force of the welding site formed is much lower than that of PERC sintered high-temperature silver paste. Again, the slight temperature difference in the welding temperature process control causes a great difference in the welding form.

[0003] In addition, in the tile assembly, the cell pieces are connected in series by overlapping a part of the area of the cell pieces above and below each other. The connection between the overlapping areas of the cell pieces generally uses conductive glue to form a connection, which also needs to meet the requirements of electrical connection and connection strength. In general, the connection strength of the conductive glue is lower than that of the welding.

[0004] The need to simultaneously meet the requirements of electrical connection and fixed connection strength also makes soldering the preferred choice for the connection process, which greatly limits the selection of electrical connection materials.

[0005] The metal wire and the cell piece form an electrical connection in the photovoltaic module. When the connection strength between the wire and the cell piece is too small, the cell piece or the cell string is easily peeled off from the cell piece during operation, or is separated from the cell piece during the lamination process of the module manufacturing, is extruded by the encapsulation glue film, or is naturally peeled off during operation. Or the electrical connection strength between the cell pieces is too small, and the cell pieces are peeled off. The present application mainly solves the above peeling problem. SUMMARY

[0006] To solve the defects of the prior art, the present application provides a reinforcing method for electrical connection of cell pieces in a photovoltaic module, which makes the cell pieces in the photovoltaic module adopt flat series connection or laminated series connection.

[0007] In the flat series connection, the adjacent two cell pieces are connected by a metal wire, and the metal wire and the cell piece form an electrical connection through an electrical connection material, and the metal wire and the cell piece form a fixed connection through an adhesive material, and the connection strength (adhesion strength, peeling strength) of the fixed connection between the metal wire and the cell piece is greater than the connection strength (adhesion strength, peeling strength) of the electrical connection between the metal wire and the cell piece.

[0008] When the laminated strings are connected in series, the laminated strings are overlapped with two adjacent battery pieces, and the two battery pieces are electrically connected by the electric connection material, and the two battery pieces are fixedly connected by the adhesive material, and the connection strength (adhesion strength, peeling strength) of the fixed connection between the two battery pieces is greater than the connection strength (adhesion strength, peeling strength) of the electrical connection between the two battery pieces.

[0009] Preferably, the electric connection material is metal, alloy, metal paste or conductive adhesive tape, etc.

[0010] Preferably, the adhesive material is conductive adhesive material or insulating adhesive material.

[0011] Preferably, the adhesive material is transparent adhesive material or high-reflective adhesive material.

[0012] Preferably, the adhesive material is light-curing adhesive material or heat-curing adhesive material.

[0013] Preferably, the adhesive material is fast-UV-curing transparent adhesive, fast-heat-sensitive-curing transparent adhesive, fast-curing high-reflective adhesive, high-molecular melting adhesive, adhesive with certain conductivity (such conductive adhesive can be used on ITO battery to increase the adhesion strength and improve the conductivity), and other adhesive materials with strong adhesion and good anti-aging property.

[0014] Preferably, when the laminated strings are connected in series, the adhesive material is coated on the battery pieces, and the adhesive material is continuously coated on one side or both sides of the metal wire to bond the metal wire and the battery pieces together.

[0015] Preferably, when the laminated strings are connected in series, the adhesive material is coated on the battery pieces, and the adhesive material is discontinuously coated on one side or both sides of the metal wire to bond the metal wire and the battery pieces together.

[0016] Preferably, when the laminated strings are connected in series, the adhesive material is coated on the battery pieces, and the adhesive material is coated on the metal wire on the battery pieces to bond the metal wire and the battery pieces together.

[0017] Preferably, when the laminated strings are connected in series, the electric connection material between the metal wire and the battery pieces is discontinuously arranged, and the adhesive material is discontinuously coated on the battery pieces, and the adhesive material is coated between two adjacent electric connection materials to bond the metal wire and the battery pieces together.

[0018] Preferably, the adhesive material is prepared into an adhesive film; when the laminated strings are connected in series, the adhesive film is covered on a single or several metal wires and battery pieces to bond the single or several metal wires and the battery pieces together.

[0019] Preferably, the adhesive film is transparent adhesive film.

[0020] Preferably, the adhesive film is a strip-shaped adhesive film and / or a sheet-shaped adhesive film.

[0021] Preferably, the cross-sectional shape of the metal wire is triangular, circular, rectangular, trapezoidal or zigzag, etc.

[0022] Preferably, the battery piece is a PERC battery piece, a TOPCon battery piece, an HJT battery piece, an IBC battery piece or an MWT battery piece.

[0023] A reinforcing structure for electrical connection of battery pieces in a photovoltaic module, the battery pieces in the photovoltaic module are connected in parallel or stacked in series:

[0024] When connected in parallel, it includes adjacent laid battery pieces, the battery pieces are connected by metal wires, the metal wires and the battery pieces are electrically connected by electrical connection material, and the metal wires and the battery pieces are fixedly connected by adhesive material;

[0025] When connected in series, it includes adjacent stacked battery pieces, the battery pieces are connected by electrical connection material and adhesive material, the stacked battery pieces are electrically connected by electrical connection material, and the stacked battery pieces are fixedly connected by adhesive material.

[0026] Preferably, the connection strength of the fixed connection is greater than the connection strength of the electrical connection.

[0027] Preferably, when connected in parallel, the adhesive material is arranged on one side or both sides of the metal wire or wrapped inside the metal wire.

[0028] Preferably, when connected in parallel, the adhesive material is arranged to be continuous or discontinuous.

[0029] Preferably, when connected in parallel, the metal wire and the battery piece are spaced apart and provided with electrical connection material and adhesive material.

[0030] Preferably, when connected in parallel, the cross-sectional shape of the metal wire is triangular, circular, rectangular, trapezoidal or zigzag.

[0031] The advantages and beneficial effects of the present application are:

[0032] The present application considers electrical connection and connection strength as two elements, the electrical connection material is responsible for forming an electrical path between the metal wire and the battery piece (parallel connection) or between the battery pieces (stacked connection), the adhesive material is responsible for forming a fixed connection between the metal wire and the battery piece (parallel connection) or between the battery pieces (stacked connection), the metal wire and the battery piece (parallel connection) or the battery pieces (stacked connection) are tightly bonded together, which enhances the bonding strength and does not affect the electrical connection between the metal wire and the battery piece (parallel connection) or between the battery pieces (stacked connection).

[0033] The present application is suitable for small contact surface applications; with the development of photovoltaic technology, such as multi-busbar, busbar-less module, shingled module, the electrical connection surface is getting smaller and smaller, the connection width is even less than 0.1mm, and the connection area can be less than 0.01mm 2 The smaller the contact area, the smaller the bonding strength; when the electrical contact area is too small, it is difficult for traditional connection process to simultaneously meet the electrical connection and high-strength bonding, the present application increases the bonding area between the metal wire and the cell (tiled series) or between the cell and the cell (stacked series), which can realize electrical and strength connection in the case of small contact area, and the present application has a great advantage in small area connection. The outer diameter of the metal wire used in the present application can be less than 0.1mm, and even the outer diameter can be as thin as 0.01mm. The contact surface width of the metal wire and the cell can be less than 0.1mm, and even the width can be as narrow as 0.01mm.

[0034] The cross-sectional shape structure of the metal wire of the present application is various, which can be triangular, circular, rectangular, trapezoidal, sawtooth type, etc.

[0035] The electrical connection material of the present application is selected from a variety of materials, as long as it meets the electrical connection requirements of the photovoltaic module, and the selection is wide.

[0036] The bonding material of the present application is also selected from a variety of materials, which can be transparent bonding material, high-reflective bonding material, light-curable bonding material, heat-curable bonding material, etc.

[0037] The coating method of the bonding material of the present application is various, as long as the bonding site is not easy to detach.

[0038] The present application separates the two factors of internal connection of photovoltaic module, electrical connection and connection strength (bonding strength, peeling strength), which are respectively responsible for two materials, electrical connection material and bonding material: the electrical connection material mainly plays the role of electrical communication, and the bonding force of the electrical connection material can be reduced or even zero; the bonding material mainly plays the role of adhesion, and the bonding material can be insulating bonding material or bonding material with low electrical conductivity.

[0039] The electrical connection and bonding strength of the present application do not need to be considered by one material, and the electrical connection material and the bonding material only need to meet one requirement, without meeting two requirements at the same time, so the selection of the electrical connection material and the bonding material is wider, the process window is larger, and the production difficulty is reduced.

[0040] The performance of the electrical connection material and the bonding material of the present application can be adjusted separately, and the conductivity or bonding strength requirement of the separate performance can be controlled, and the separate performance adjustment is more convenient.

[0041] The bonding strength of the connection point of the present application is improved, which is not easy to detach during the operation of the cell or the cell string, reduces the repair and other defects, and improves the process yield.

[0042] The present application is suitable for all battery sheet assembly packaging applications, including PERC, TOPCon, HJT, IBC, MWT, etc. BRIEF DESCRIPTION OF DRAWINGS

[0043] Figure 1 is a side view schematic diagram of the connection between the metal wire and the battery sheet;

[0044] Figure 2 is a side view schematic diagram of the connection between two battery sheets;

[0045] Figure 3 is a top view schematic diagram of continuous coating of the bonding material on both sides of the metal wire;

[0046] Figure 4 is a top view schematic diagram of intermittent coating of the bonding material on both sides of the metal wire;

[0047] Figure 5 is a side view schematic diagram of the bonding material covering the metal wire on the battery sheet;

[0048] Figure 6 is a side view schematic diagram of the bonding material coated between the adjacent two electrical connection materials;

[0049] Figure 7 is a top view schematic diagram of the bonding material pre-prepared into a film and covered on multiple metal wires and battery sheets. DETAILED DESCRIPTION

[0050] The specific embodiments of the present application will be further described below in conjunction with the drawings and examples. The following examples are only used to more clearly illustrate the technical solutions of the present application, and cannot be used to limit the protection scope of the present application.

[0051] The technical solutions of the specific embodiments of the present application are as follows:

[0052] The present application provides a reinforcing method for electrical connection of battery sheets in a photovoltaic assembly, so that the battery sheets in the photovoltaic assembly are connected in parallel or stacked in series;

[0053] As shown in Figure 1 , when connected in parallel, the adjacent two battery sheets are connected by a metal wire, and the metal wire and the battery sheet are electrically connected by an electrical connection material, and the metal wire and the battery sheet are fixedly connected by a bonding material, and the connection strength (bonding strength, peeling strength) of the fixed connection between the metal wire and the battery sheet is greater than the connection strength (bonding strength, peeling strength) of the electrical connection between the metal wire and the battery sheet;

[0054] As shown in Figure 2As shown, when the laminates are connected in series, the two adjacent laminates are overlapped, the overlapping parts of the two laminates are connected by the electric connection material, the two laminates are fixedly connected by the adhesive material, and the connection strength (adhesion strength, peeling strength) of the fixed connection between the two laminates is greater than the connection strength (adhesion strength, peeling strength) of the electrical connection between the two laminates.

[0055] Specifically:

[0056] The cross-sectional shape of the metal wire used in the present application can be various shapes such as triangular, circular, rectangular, trapezoidal or zigzag, etc. The outer diameter of the metal wire used in the present application can be less than 0.1 mm, and even the outer diameter can be as thin as 0.01 mm. The width of the contact surface of the metal wire and the laminates can be less than 0.1 mm, and even the width can be as narrow as 0.01 mm.

[0057] The electric connection material used in the present application is selected from a variety of materials, as long as it meets the electrical connection requirements of the photovoltaic module, and has a wide selection range. More specifically, the electric connection material can be metal, alloy, metal paste or conductive tape, etc.

[0058] The adhesive material used in the present application is also selected from a variety of materials:

[0059] Regarding the electrical conductivity, the adhesive material used in the present application can be conductive adhesive material or insulating adhesive material;

[0060] Regarding the reflectivity, the adhesive material used in the present application can be transparent adhesive material or high-reflectivity adhesive material;

[0061] Regarding the curing method, the adhesive material used in the present application can be light-curable adhesive material or heat-curable adhesive material;

[0062] More specifically, the adhesive material used in the present application can be fast-UV-curable transparent adhesive, fast-heat-sensitive-curable transparent adhesive, fast-curable high-reflectivity adhesive, adhesive with certain electrical conductivity (such conductive adhesive can be used on ITO cells to increase the adhesion strength and improve the electrical conductivity), and other adhesive materials with strong adhesion and good anti-aging properties.

[0063] The application method (setting method) of the adhesive material used in the present application can be various, as long as it has sufficient adhesion strength to prevent the metal wire and the laminates or the laminates from being easily peeled off.

[0064] More specifically:

[0065] As shown in the drawings, when the laminates are connected in series, the two adjacent laminates are overlapped, the overlapping parts of the two laminates are connected by the electric connection material, the two laminates are fixedly connected by the adhesive material, and the connection strength (adhesion strength, peeling strength) of the fixed connection between the two laminates is greater than the connection strength (adhesion strength, peeling strength) of the electrical connection between the two laminates. Figure 3

[0066] As shown in the drawings, when the laminates are connected in series, the two adjacent laminates are overlapped, the overlapping parts of the two laminates are connected by the electric connection material, the two laminates are fixedly connected by the adhesive material, and the connection strength (adhesion strength, peeling strength) of the fixed connection between the two laminates is greater than the connection strength (adhesion strength, peeling strength) of the electrical connection between the two laminates. Figure 4 ​As shown in the figure, when the parallel connection is carried out, the bonding material is coated on the battery sheet, and the bonding material is discontinuously coated on one side or both sides of the metal wire to bond the metal wire and the battery sheet together.

[0067] As shown in the figure, when the parallel connection is carried out, the bonding material is coated on the battery sheet, and the bonding material is discontinuously coated on one side or both sides of the metal wire to bond the metal wire and the battery sheet together. Figure 5 As shown in the figure, when the parallel connection is carried out, the bonding material is coated on the battery sheet, and the bonding material is discontinuously coated on one side or both sides of the metal wire to bond the metal wire and the battery sheet together.

[0068] As shown in the figure, when the parallel connection is carried out, the bonding material is coated on the battery sheet, and the bonding material is discontinuously coated on one side or both sides of the metal wire to bond the metal wire and the battery sheet together. Figure 6 As shown in the figure, when the parallel connection is carried out, the bonding material is coated on the battery sheet, and the bonding material is discontinuously coated on one side or both sides of the metal wire to bond the metal wire and the battery sheet together.

[0069] Figure 7 As shown in the figure, when the parallel connection is carried out, the bonding material is coated on the battery sheet, and the bonding material is discontinuously coated on one side or both sides of the metal wire to bond the metal wire and the battery sheet together.

[0070] The above only describes the preferred embodiments of the present application, and it should be noted that those skilled in the art can make some improvements and refinements without departing from the technical principles of the present application, and these improvements and refinements should also be considered as the protection scope of the present application.​

Claims

1. A reinforcing structure for electrical connection of cells in a photovoltaic module, characterized in that: when the cells are connected in series by laying, the cells are adjacent to each other and connected by metal wires, the metal wires and the cells are electrically connected by electrical connection material, and the cells are fixedly connected by adhesive material; when the cells are connected in series by stacking, the cells are overlapped by adjacent cells, the overlapped cells are provided with electrical connection material and adhesive material, the overlapped cells are electrically connected by the electrical connection material, and the overlapped cells are fixedly connected by the adhesive material.

2. The reinforcement structure for electrical connection of cells in a photovoltaic module according to claim 1, characterized in that, The fixed connection has a greater connection strength than the electrical connection.

3. The reinforcement structure for electrical connection of cells in a photovoltaic module according to claim 1, characterized in that, When the cells are connected in series by laying, the adhesive material is arranged on one side or both sides of the metal wires or wrapped inside the metal wires.

4. A reinforcing structure for electrical connection of cells in a photovoltaic module according to claim 1 or 3, characterized in that, When the cells are connected in series by laying, the adhesive material is arranged continuously or discontinuously.

5. The reinforcement structure for electrical connection of cells in a photovoltaic module according to claim 1, characterized in that, When the cells are connected in series by laying, the electrical connection material and the adhesive material are arranged between the metal wires and the cells.

6. The reinforcement structure for electrical connection of cells in a photovoltaic module according to claim 1, characterized in that, When the cells are connected in series by laying, the cross-sectional shape of the metal wires is triangular, circular, rectangular, trapezoidal, or sawtooth-shaped.

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