Conductive interconnection strip, preparation method thereof and photovoltaic cell module

Abstract

The invention belongs to the field of photovoltaic technology, particularly provides a conductive interconnection strip and a preparation method thereof, and a photovoltaic cell module, and aims to solve the problems that the existing interconnection strip can shield a cell piece during welding, the light receiving area of the cell piece is influenced, the welding temperature in the welding process is easy to damage the cell piece, and the module efficiency is influenced. Therefore, the conductive interconnection strip comprises a transparent substrate and a transparent pressure-sensitive conductive adhesive with conductivity, an infiltration structure is arranged in the transparent substrate, and the transparent pressure-sensitive conductive adhesive forms a first conductive adhesive layer and a second conductive adhesive layer on the front surface and the back surface of the transparent substrate respectively; and the transparent pressure-sensitive conductive adhesive is also positioned in the infiltration structure so as to electrically connect the first conductive adhesive layer and the second conductive adhesive layer. The conductive interconnection strip is fully transparent, the battery pieces are not shielded when the battery pieces are connected in series, and the light receiving area of the battery pieces is not affected.

Description

Technical Field

[0001] The present application belongs to the field of photovoltaic technology, and specifically provides a conductive interconnection strip and a preparation method thereof, and a photovoltaic cell assembly. Background Art

[0002] The structure of a photovoltaic power generation device primarily includes a frame, glass cover, encapsulant film, photovoltaic module array, backsheet, and junction box. The components also include cells, interconnects, and busbars. Adjacent photovoltaic modules are connected by interconnects to form a string, integrating the wiring with the photovoltaic module array and conserving space.

[0003] However, existing interconnecting strips will block the front and back of the cell, affecting the light-receiving area of ​​the cell and ultimately affecting the efficiency of the module.

[0004] Accordingly, this field requires a new technical solution to solve the above technical problems. Summary of the Invention

[0005] The present application aims to solve the above-mentioned technical problems, namely, to solve the problem that the existing interconnection strips will block the battery cells during welding, affecting the light-receiving area of ​​the battery cells, and the welding temperature during the welding process will easily cause damage to the battery cells, thereby affecting the efficiency of the components.

[0006] In a first aspect, the present application provides a conductive interconnection strip, which includes a transparent substrate and a transparent pressure-sensitive conductive adhesive with conductive properties. The transparent substrate has an infiltration structure, and the transparent pressure-sensitive conductive adhesive forms a first conductive adhesive layer and a second conductive adhesive layer on the front and back sides of the transparent substrate, respectively. The transparent pressure-sensitive conductive adhesive is also located in the infiltration structure to electrically connect the first conductive adhesive layer and the second conductive adhesive layer.

[0007] In the preferred technical solution of the above conductive interconnection strip, the wetting structure is a gap or a hole.

[0008] In the preferred technical solution of the above conductive interconnection strip, the transparent substrate is a transparent strip, the infiltration structure is a plurality of through holes provided on the transparent strip, and the through holes penetrate the transparent strip along the thickness direction of the transparent strip.

[0009] In the preferred technical solution of the above conductive interconnection strip, the plurality of through holes are distributed at intervals along the length direction of the transparent strip; or, the plurality of through holes are distributed in a matrix along the length direction and width direction of the transparent strip.

[0010] In the preferred technical solution of the above-mentioned conductive interconnection strip, the transparent substrate further includes a first conductive metal wire, which is arranged on the front and / or back side of the transparent substrate; or, the transparent substrate further includes a first conductive metal wire, which is sequentially inserted into the plurality of through holes along the length direction of the transparent strip, so that the same first conductive metal wire can be simultaneously located on the front side of the transparent substrate, on the back side of the transparent substrate and in the through hole.

[0011] In the preferred technical solution of the above conductive interconnection strip, the transparent substrate is a transparent woven cloth, and the impregnation structure is a woven gap of the transparent woven cloth.

[0012] In the preferred technical solution of the above conductive interconnection strip, the transparent substrate further includes second conductive metal wires, and the second conductive metal wires are woven together with a transparent woven material to form the transparent woven cloth.

[0013] In the preferred technical solution of the above-mentioned conductive interconnection strip, the width of the transparent substrate is 0.1 to 3 mm, and the thickness of the transparent substrate is 0.01 to 1 mm; and / or the width of the first conductive adhesive layer is the same as the width of the transparent substrate, and the thickness of the first conductive adhesive layer is 3 to 500 μm; and / or the width of the second conductive adhesive layer is the same as the width of the transparent substrate, and the thickness of the second conductive adhesive layer is 3 to 500 μm.

[0014] In the preferred technical solution of the above-mentioned conductive interconnection strip, the material of the transparent substrate is one or more of polyolefins, polyesters, olefin copolymers, fluororesins, and polyamides; and / or the transparent pressure-sensitive conductive adhesive includes the following components in parts by weight: 60 to 120 parts of resin matrix material, 10 to 50 parts of conductive filler, 60 to 100 parts of solvent, 10 to 40 parts of tackifying resin, and 0.1 to 0.5 parts of cross-linking agent.

[0015] In the preferred technical solution of the above-mentioned conductive interconnection strip, the transparent pressure-sensitive conductive adhesive includes the following components in parts by weight: 80-90 parts of a resin matrix material, 12-18 parts of a conductive filler, 75-90 parts of a solvent, 15-25 parts of a tackifying resin, and 0.2-0.4 parts of a cross-linking agent; and / or, the resin matrix material includes one or more of acrylates and acrylic acid; and / or, the conductive filler includes one or more of liquid metal nanoparticles, transparent metal oxides, and composite conductive materials; and / or, the solvent includes one or more of ethyl acetate, toluene, and cyclohexanone; and / or, the tackifying resin includes hydrogenated rosin, preferably, the hydrogenated rosin is hydrogenated rosin KR-610; and / or, the cross-linking agent includes an isocyanate compound.

[0016] In a second aspect, the present application provides a method for preparing a conductive interconnection strip, which is used to prepare the above-mentioned conductive interconnection strip, and the preparation method includes the following steps: (1) providing a transparent substrate; (2) providing a transparent pressure-sensitive conductive adhesive; (3) unwinding the transparent substrate and applying the transparent pressure-sensitive conductive adhesive to one side of the transparent substrate; (4) baking the coated transparent substrate to dry the coating to form a first conductive adhesive layer; (5) coating the outer side of the first conductive adhesive layer with a protective film and then rewinding the substrate to obtain a first coated substrate; (6) unwinding the first coated substrate and applying the transparent pressure-sensitive conductive adhesive to the other side of the transparent substrate of the first coated substrate; (7) baking the coated first coated substrate to dry the coating to form a second conductive adhesive layer; (8) coating the outer side of the second conductive adhesive layer with a protective film and then rewinding the substrate to obtain a second coated substrate; (9) slitting the second coated substrate according to a preset width to obtain a plurality of conductive interconnections.

[0017] In the preferred technical solution of the above-mentioned method for preparing the conductive interconnection strip, a hot drying tunnel is used for baking in steps (4) and (7), the baking temperature of the hot drying tunnel is 50 to 300° C., and the time for the substrate to move from the inlet end to the outlet end of the hot drying tunnel is 1 to 60 minutes.

[0018] In a third aspect, the present application provides a photovoltaic cell assembly, wherein the photovoltaic cell assembly includes a cell string, and the cell string includes a plurality of cell sheets connected by the above-mentioned conductive interconnection strips.

[0019] When the above technical solution is adopted, the conductive interconnection strip of the present application includes a transparent substrate and a transparent pressure-sensitive conductive adhesive with conductive properties. The transparent substrate has an infiltration structure. The transparent pressure-sensitive conductive adhesive forms a first conductive adhesive layer and a second conductive adhesive layer on the front and back of the transparent substrate, respectively. The transparent pressure-sensitive conductive adhesive is also located in the infiltration structure to electrically connect the first conductive adhesive layer and the second conductive adhesive layer. With this arrangement, the conductive interconnection strip is completely transparent and will not block the battery cells when the battery cells are connected in series, and will not affect the light-receiving area of ​​the battery cells. In addition, the conductive interconnection strip does not require welding when connecting the battery cells in series, avoiding the impact and damage of the welding temperature on the stability of the battery cells. Because the first conductive adhesive layer and the second conductive adhesive layer are both conductive and transparent pressure-sensitive conductive adhesives, when connecting the battery strings, only pressure is required to connect. This connection method is not limited by temperature and can ensure adhesion, which can effectively improve the reliability of the interconnection. In addition, the width of the conductive interconnection strip can be adjusted as needed during use to better improve the series connection effect of the battery strings without affecting the light-receiving area of ​​the battery cells.

[0020] Furthermore, the infiltration structure is set as a gap or hole to facilitate the penetration of the transparent pressure-sensitive conductive adhesive so as to electrically connect the first conductive adhesive layer with the second conductive adhesive layer, and then connect the positive and negative poles of the two battery cells in series when the battery cells are connected in series, thereby achieving better electrical conduction.

[0021] Furthermore, the transparent substrate is set as a transparent strip, and the infiltration structure is set as a plurality of through holes located in the thickness direction of the transparent strip. This setting makes it easier to electrically connect the first conductive adhesive layer and the second conductive adhesive layer. At the same time, setting multiple through holes to form multiple electrical connection points can improve the current carrying capacity of the conductive interconnection strip.

[0022] Furthermore, arranging the first conductive metal wire on the transparent substrate can further improve the current carrying capacity of the conductive interconnection strip.

[0023] Furthermore, the transparent substrate is set as a transparent woven cloth, and the impregnation structure is the woven gaps of the transparent woven cloth. This setting method can be prepared by weaving and molding, and the preparation process is simple without punching.

[0024] Furthermore, the transparent substrate also includes a second conductive metal wire, which is woven together with the transparent woven material to form a transparent woven cloth. By setting the second conductive metal wire, the conductivity between the first conductive adhesive layer and the second conductive adhesive layer can be improved, thereby improving the current carrying capacity of the conductive interconnection strip.

[0025] Furthermore, the width of the transparent substrate is set to 0.1-3 mm, and the thickness of the transparent substrate is set to 0.01-1 mm, so that the conductive interconnection strip has sufficient width and thickness, thereby facilitating assembly and use.

[0026] Furthermore, the thickness of the first conductive adhesive layer is set to 3-500 μm, so as to maintain good connection stability and conductivity, thereby improving the current carrying capacity of the conductive interconnection strip.

[0027] Furthermore, the thickness of the second conductive adhesive layer is set to 3-500 μm, so as to maintain good connection stability and conductivity, thereby improving the current carrying capacity of the conductive interconnection strip.

[0028] Furthermore, the transparent pressure-sensitive conductive adhesive includes, by weight, 60 to 120 parts of a resin matrix material, 10 to 50 parts of a conductive filler, 60 to 100 parts of a solvent, 10 to 40 parts of a tackifying resin, and 0.1 to 0.5 parts of a cross-linking agent, so that the transparent pressure-sensitive conductive adhesive has good light transmittance, adhesion, and conductivity, and is also easy to store and can be used for a long time at room temperature.

[0029] Furthermore, making the conductive filler include one or more of liquid metal nanoparticles, transparent metal oxides, and composite conductive materials can not only effectively improve the conductivity of the transparent pressure-sensitive conductive adhesive, but also avoid reducing the transmittance of the transparent pressure-sensitive conductive adhesive due to the addition of conductive fillers.

[0030] Furthermore, setting the tackifying resin to hydrogenated rosin can effectively improve the viscosity of the transparent pressure-sensitive conductive adhesive. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The preferred embodiments of the present application are described below with reference to the accompanying drawings, in which:

[0032] Figure 1 1 is a schematic structural diagram of a first embodiment of a conductive interconnection strip of the present application;

[0033] Figure 2 yes Figure 1 Cross-sectional view in the AA direction;

[0034] Figure 3 is a structural diagram of a second embodiment of the conductive interconnection strip of the present application;

[0035] Figure 4 yes Figure 3 Cross-sectional view in the middle BB direction;

[0036] Figure 5 This is a schematic structural diagram of a third embodiment of the conductive interconnection strip of the present application;

[0037] Figure 6 yes Figure 5 Cross-sectional view in CC direction;

[0038] Figure 7 is a structural diagram of a fourth embodiment of the conductive interconnection strip of the present application;

[0039] Figure 8 yes Figure 7 Cross-sectional view in the middle DD direction;

[0040] Figure 9 is a structural diagram of a fifth embodiment of the conductive interconnection strip of the present application;

[0041] Figure 10 is a flow chart of a method for preparing a conductive interconnection bar of the present application;

[0042] Figure 11 is a top view of the battery string of Experimental Example 2 of the present application;

[0043] Figure 12 This is a front view of a battery string in Test Example 2 of the present application.

[0044] List of reference numerals:

[0045] 1. Transparent substrate; 101. First conductive metal wire;

[0046] 2. Infiltration structure;

[0047] 3. The first conductive adhesive layer;

[0048] 4. Second conductive adhesive layer;

[0049] 5. Battery cells; 6. Interconnect strips. DETAILED DESCRIPTION

[0050] The preferred embodiments of the present application are described below with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are only used to explain the technical principles of the present application and are not intended to limit the scope of protection of the present application.

[0051] In this application, the term "and / or" describes the relationship between associated objects, indicating that three possible relationships exist. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. A and B can be singular or plural. The character " / " generally indicates that the associated objects are in an "or" relationship.

[0052] In this application, "at least one" means one or more, and "more than one" means two or more. "At least one of the following" or similar expressions refers to any combination of these items, including any combination of single items or plural items. For example, "at least one of a, b, or c", or "at least one of a, b, and c" can all mean: a, b, c, ab (i.e., a and b), ac, bc, or abc, where a, b, and c can be single or multiple.

[0053] It should be understood that in the various embodiments of the present application, the size of the serial numbers of the above-mentioned processes does not mean the order of execution. Some or all of the steps can be executed in parallel or sequentially. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0054] The terms used in the embodiments of the present application are for the purpose of describing specific embodiments only and are not intended to limit the present application. The singular forms "a", "an", "the" and "the" used in the embodiments of the present application and the appended claims are also intended to include plural forms unless the context clearly indicates otherwise.

[0055] The weights of the relevant components mentioned in the examples of this application may not only refer to the specific content of each component, but also represent the weight ratio between the components. Therefore, as long as the content of the relevant components is proportionally enlarged or reduced according to the examples of this application, it is within the scope disclosed in the examples of this application. Specifically, the mass described in the examples of this application may be a mass unit known in the chemical industry, such as μg, mg, g, kg, etc.

[0056] The terms "first" and "second" are used solely for descriptive purposes to distinguish objects, such as substances, from one another and should not be understood to indicate or imply relative importance or to implicitly specify the quantity of the technical features being referred to. For example, without departing from the scope of the embodiments of this application, a first XX may also be referred to as a second XX, and similarly, a second XX may also be referred to as a first XX. Thus, features defined as "first" or "second" may explicitly or implicitly include one or more of such features.

[0057] The experimental methods in the following examples are conventional methods unless otherwise specified. The materials, reagents, etc. used in the following examples are commercially available unless otherwise specified.

[0058] As pointed out in the background technology, existing interconnecting strips will block the battery cells during welding, affecting the light-receiving area of ​​the battery cells, and the welding temperature during the welding process will easily damage the battery cells, thereby affecting the efficiency of the module.

[0059] The present application provides a conductive interconnection strip that is fully transparent and does not obstruct the cells when connecting them in series, nor does it affect the light-receiving area of ​​the cells. Furthermore, the conductive interconnection strip does not require soldering when connecting the cells in series, thus avoiding the impact of soldering temperatures on the stability of the cells. Because the first and second conductive adhesive layers are both conductive and transparent, pressure-sensitive conductive adhesives, the cells can be connected together using only pressure. This connection method is not restricted by temperature and can ensure adhesion, effectively improving interconnect reliability. Furthermore, the width of the conductive interconnection strip can be adjusted as needed during use to further improve the series connection effect of the cell strings without affecting the light-receiving area of ​​the cells.

[0060] In the first aspect, the present application provides a conductive interconnection strip. Specifically, please refer to Figures 1 to 9 The conductive interconnection strip of the present application includes a transparent substrate 1 and a transparent pressure-sensitive conductive adhesive with conductive properties. The transparent substrate 1 has an infiltration structure 2. The transparent pressure-sensitive conductive adhesive forms a first conductive adhesive layer 3 and a second conductive adhesive layer 4 on the front and back sides of the transparent substrate 1, respectively. The transparent pressure-sensitive conductive adhesive is also located in the infiltration structure 2 to electrically connect the first conductive adhesive layer 3 and the second conductive adhesive layer 4.

[0061] The conductive interconnection strip of the present application, by providing an impregnation structure 2 within a transparent substrate 1, can allow the transparent pressure-sensitive conductive adhesive to penetrate into the impregnation structure 2 when preparing the first conductive adhesive layer 3 and the fourth conductive adhesive layer 4, thereby electrically connecting the first conductive adhesive layer 3 and the second conductive adhesive layer 4, thereby enabling the conductive interconnection strip to have good conductivity and current-carrying capacity. The conductive interconnection strip of the present application does not require welding when connecting the battery cells in series, thus avoiding the impact and damage of the welding temperature on the stability of the battery cells. Because the first conductive adhesive layer 3 and the second conductive adhesive layer 4 are both conductive and transparent pressure-sensitive conductive adhesives, when connecting the battery strings, only pressure is required to connect. This connection method is not limited by temperature and can ensure adhesion, which can effectively improve the reliability of the interconnection. In addition, the width of the conductive interconnection strip can be adjusted as needed during use to better improve the series connection effect of the battery strings without affecting the light-receiving area of ​​the battery cells.

[0062] Preferably, the wetting structure 2 is a gap or a hole.

[0063] In some embodiments, please also refer to Figures 1 to 9 The transparent substrate 1 is a transparent strip, and the infiltration structure 2 is a plurality of through holes provided on the transparent strip, and the through holes penetrate the transparent strip along the thickness direction of the transparent strip.

[0064] It should be noted that this application does not impose any restrictions on the specific arrangement of the multiple through-holes. In actual applications, those skilled in the art can customize the arrangement of the through-holes according to actual needs. Any adjustments and changes to the specific arrangement of the through-holes do not deviate from the basic principles of this application and should be limited to the scope of protection of this application.

[0065] In some specific embodiments, please also refer to Figure 1 and Figure 2 , multiple through holes are distributed at intervals along the length direction of the transparent strip.

[0066] In some specific embodiments, please also refer to Figure 3 and Figure 4 , multiple through holes are distributed in a matrix along the length and width directions of the transparent strip.

[0067] In some preferred embodiments, please also refer to Figures 5 to 8 The transparent substrate 1 further includes a first conductive metal wire 101 , which is arranged on the front and / or back side of the transparent substrate 1 .

[0068] In some preferred embodiments, see Figure 9 The transparent substrate 1 also includes a first conductive metal wire 101, which is sequentially inserted into a plurality of through holes along the length direction of the transparent strip, so that the same first conductive metal wire 101 can be simultaneously located in the first conductive adhesive layer 3, the second conductive adhesive layer 4 and the through hole.

[0069] It should be noted that this application does not impose any restrictions on the number and placement of the first conductive metal wires 101. In actual applications, those skilled in the art can adjust the number and placement of the first conductive metal wires 101 according to actual needs. Any adjustments and changes to the number and placement of the first conductive metal wires 101 do not deviate from the basic principles of this application and are within the scope of protection of this application.

[0070] In some embodiments, please also refer to Figure 5 and Figure 6 The number of the first conductive metal wire 101 is one, and the first conductive metal wire 101 is arranged on the front side of the transparent substrate 1 , that is, between the transparent substrate 1 and the first conductive adhesive layer 3 .

[0071] In some embodiments, the number of the first conductive metal wire 101 is one, and the first conductive metal wire 101 is disposed on the back side of the transparent substrate 1 , that is, between the transparent substrate 1 and the second conductive adhesive layer 4 .

[0072] In some embodiments, please also refer to Figure 7 and Figure 8 There are two first conductive metal wires 101, and the two first conductive metal wires 101 are respectively located on the back and front of the transparent substrate 1, that is, respectively located between the transparent substrate 1 and the first conductive adhesive layer 3 and between the transparent substrate 1 and the second conductive adhesive layer 4.

[0073] In some embodiments, there are multiple first conductive metal wires 101, at least two first conductive metal wires 101 are spaced apart along the width direction between the transparent substrate 1 and the first conductive adhesive layer 3, and at least two first conductive metal wires 101 are spaced apart along the width direction between the transparent substrate 1 and the second conductive adhesive layer 4.

[0074] In some embodiments, see Figure 9 The number of the first conductive metal wire 101 is one, and the first conductive metal wire 101 is sequentially interspersed with multiple through holes along the length direction of the transparent strip, so that the same first conductive metal wire 101 can be simultaneously located on the front side of the transparent substrate 1, the back side of the transparent substrate 1, and in the through hole, thereby electrically connecting the first conductive adhesive layer 3 and the second conductive adhesive layer 4 to improve the conductivity of the conductive interconnection strip.

[0075] It should be noted that this application does not impose any restrictions on the shape of the first conductive metal wire 101. In actual applications, those skilled in the art can customize the shape of the first conductive metal wire 101 based on actual needs. For example, the first conductive metal wire 101 can be configured as a looped wire, a triangular wire, a square wire, etc. Adjustments and changes to the shape of the first conductive metal wire 101 do not deviate from the basic principles of this application and are intended to be within the scope of protection of this application.

[0076] Preferably, the first conductive metal wire 101 is a tinned copper wire.

[0077] In some embodiments, the through hole has a diameter of 0.001 to 2 mm.

[0078] In some embodiments, the transparent substrate 1 is a transparent woven cloth, and the infiltrated structure 2 is a woven gap of the transparent woven cloth.

[0079] The transparent substrate 1 is set as a transparent woven cloth, and the impregnated structure 2 is the woven gap of the transparent woven cloth. This setting method can be prepared by weaving and molding. The preparation process is simple and does not require punching.

[0080] In some embodiments, the transparent substrate 1 further includes second conductive metal wires, and the second conductive metal wires are woven together with the transparent woven material to form the transparent woven cloth.

[0081] The transparent substrate 1 also includes a second conductive metal wire, which is woven together with the transparent braided material to form a transparent woven cloth. The second conductive metal wire can improve the conductivity between the first conductive adhesive layer 3 and the second conductive adhesive layer 4, thereby improving the current carrying capacity of the conductive interconnection strip.

[0082] It should be noted that this application does not impose any restrictions on the shape of the second conductive metal wire. In actual applications, those skilled in the art may customize the shape of the second conductive metal wire based on actual needs. For example, the second conductive metal wire may be configured as a looped wire, a triangular wire, a square wire, etc. Adjustments and changes to the shape of the second conductive metal wire do not deviate from the basic principles of this application and are intended to be within the scope of protection of this application.

[0083] Preferably, the second conductive metal wire is a tinned copper coil wire.

[0084] In actual applications, those skilled in the art can determine the width and thickness of the transparent substrate 1 according to actual needs so as to smoothly connect the cells in series. For example, the width of the transparent substrate 1 can be 0.1 mm and the thickness can be 0.01 mm; or the width of the transparent substrate 1 can be 3 mm and the thickness can be 1 mm; or the width of the transparent substrate 1 can be 1 mm and the thickness can be 0.5 mm. Any adjustment or change in the width and thickness of the transparent substrate 1 does not deviate from the basic principles of this application and should be within the scope of protection of this application.

[0085] Preferably, the width of the transparent substrate 1 is 0.1-3 mm, and the thickness of the transparent substrate 1 is 0.01-1 mm.

[0086] The width of the transparent substrate 1 is controlled to be 0.1-3 mm so that its conductive interconnection strips have sufficient width to smoothly connect the cells in series. The thickness of the transparent substrate 1 is controlled to be 0.01-1 mm so as to facilitate coating and preparing the first conductive adhesive layer 3 and the second conductive adhesive layer 4.

[0087] Preferably, the width of the first conductive adhesive layer 3 is the same as the width of the transparent substrate 1 , and the thickness of the first conductive adhesive layer 3 is 3-500 μm.

[0088] Preferably, the width of the second conductive adhesive layer 4 is the same as the width of the transparent substrate 1 , and the thickness of the second conductive adhesive layer 4 is 3-500 μm.

[0089] In some preferred embodiments, the thickness of the conductive interconnection strip is 0.2-0.3 mm.

[0090] In some specific embodiments, the thickness of the conductive interconnection strip is 0.3 mm, wherein the thickness of the transparent substrate 1 is 0.1 mm, the thickness of the first conductive adhesive layer 3 is 0.1 mm, and the thickness of the second conductive adhesive layer 3 is 0.1 mm.

[0091] Preferably, the material of the transparent substrate 1 is one or more of polyolefins, polyesters, olefin copolymers, fluororesins, and polyamides.

[0092] The transparent substrate 1 is prepared by selecting polyolefins, polyesters, olefin copolymers, fluororesins, and polyamides, which can maintain high light transmittance of the transparent substrate 1 .

[0093] Preferably, the transparent pressure-sensitive conductive adhesive comprises the following components in parts by weight: 60-120 parts of resin matrix material, 10-50 parts of conductive filler, 60-100 parts of solvent, 10-40 parts of tackifying resin, and 0.1-0.5 parts of cross-linking agent.

[0094] Further preferably, the transparent pressure-sensitive conductive adhesive comprises the following components in parts by weight: 80-90 parts of resin matrix material, 12-18 parts of conductive filler, 75-90 parts of solvent, 15-25 parts of tackifying resin, and 0.2-0.4 parts of cross-linking agent.

[0095] In some specific embodiments, the transparent pressure-sensitive conductive adhesive includes the following components in parts by weight: 85 parts of a resin matrix material, 15 parts of a conductive filler, 80 parts of a solvent, 18 parts of a tackifying resin, and 0.3 parts of a cross-linking agent.

[0096] Preferably, the resin matrix material includes one or more of acrylate and acrylic acid.

[0097] Specifically, the acrylic acid ester includes one or more of butyl acrylate, isooctyl acrylate, methyl methacrylate, and hydroxyethyl methacrylate.

[0098] Preferably, the conductive filler includes one or more of liquid metal nanoparticles, transparent metal oxides, and composite conductive materials.

[0099] The liquid metal nanoparticles include one or more of gallium-indium alloy nanoparticles and gallium-indium-tin alloy nanoparticles, and the particle size is less than 50 nm.

[0100] The transparent metal oxide includes one or more of indium tin oxide nanoparticles and silver nanowires, with a diameter less than 50 nm and an aspect ratio greater than 100.

[0101] The composite conductive material includes one or more of polystyrene@silver core-shell microspheres and graphene / polymer composites.

[0102] In some specific embodiments, the conductive filler is a mixture of gallium-indium alloy nanoparticles and silver nanowires, wherein the mass ratio of the gallium-indium alloy nanoparticles to the silver nanowires is 3:1.

[0103] Preferably, the solvent includes one or more of ethyl acetate, toluene, and cyclohexanone.

[0104] Preferably, the tackifying resin comprises hydrogenated rosin.

[0105] More preferably, the hydrogenated rosin is hydrogenated rosin KR-610.

[0106] Preferably, the cross-linking agent comprises an isocyanate compound, wherein the isocyanate compound comprises isophorone diisocyanate.

[0107] In a second aspect, the present application provides a method for preparing a conductive interconnection bar, which is used to prepare the conductive interconnection bar provided in the first aspect.

[0108] See also Figure 10The method for preparing the conductive interconnection strip of the present application comprises the following steps:

[0109] S1: providing a transparent substrate 1.

[0110] S2: Provides transparent pressure-sensitive conductive adhesive.

[0111] S3: unwinding the transparent substrate 1 and applying a transparent pressure-sensitive conductive adhesive to one side of the transparent substrate 1 .

[0112] S4: baking the coated transparent substrate to dry the coating to form the first conductive adhesive layer 3. The coating method is blade coating or gravure coating.

[0113] S5: After coating the outer side of the first conductive adhesive layer 3 with a protective film, the first coated substrate is rolled up to obtain a first coated substrate.

[0114] S6: unwinding the first coated substrate, and applying the transparent pressure-sensitive conductive adhesive to the other side of the transparent base 1 of the first coated substrate.

[0115] S7: baking the coated first coating substrate to dry the coating to form a second conductive adhesive layer 4.

[0116] S8: After coating the outer side of the second conductive adhesive layer 4 with a protective film, the substrate is rolled up to obtain a second coated substrate.

[0117] S9: cutting the second coated substrate into sections according to a preset width to obtain a plurality of conductive interconnecting strips.

[0118] Preferably, a hot drying tunnel is used for baking in step S4 and step S7, the baking temperature of the hot drying tunnel is 50-300° C., and the time for the substrate to move from the inlet end to the outlet end of the hot drying tunnel is 1-60 minutes.

[0119] In practical applications, there is a negative correlation between the baking temperature of the hot drying tunnel and the movement of the substrate from the inlet end to the outlet end of the hot drying tunnel, that is, the higher the baking temperature of the hot drying tunnel, the shorter the movement time of the substrate from the inlet end to the outlet end of the hot drying tunnel.

[0120] In some specific embodiments, the baking temperature of the hot drying tunnel in step S4 and step S7 is 200° C., and the time for the substrate to move from the inlet end to the outlet end of the hot drying tunnel is 30 minutes.

[0121] In a third aspect, the present application provides a photovoltaic cell assembly, which includes a cell string. The cell string includes a plurality of cells connected by the conductive interconnection strips provided in the first aspect.

[0122] The conductive interconnection strips of the present application are described in detail below through several specific embodiments.

[0123] Example 1

[0124] The structure of the conductive interconnection strip in this embodiment is as follows Figure 1 and Figure 2 As shown, it includes a transparent substrate 1, a transparent pressure-sensitive conductive adhesive forming a first conductive adhesive layer 3 on the front side of the transparent substrate 1, and a transparent pressure-sensitive conductive adhesive forming a second conductive adhesive layer 4 on the back side of the transparent substrate 1. The transparent substrate 1 has an infiltration structure, which is a through hole penetrating the transparent substrate 1. The through hole has a transparent pressure-sensitive conductive adhesive and connects the first conductive adhesive layer 3 and the second conductive adhesive layer 4.

[0125] The transparent substrate 1 is a PET film with a thickness of 0.1 mm and a width of 3 mm. The first conductive adhesive layer 3 is 3 mm wide and 100 μm thick. The second conductive adhesive layer 4 is 3 mm wide and 100 μm thick. The through-holes are circular with a diameter of 2 mm. Multiple through-holes are spaced along the length of the transparent substrate 1, and the distance between adjacent through-holes (the distance between adjacent edges) is 1 mm.

[0126] The transparent pressure-sensitive conductive adhesive of this embodiment is composed of the following components: 85 parts of a resin matrix material, 15 parts of a conductive filler, 80 parts of a solvent, 18 parts of a tackifying resin, and 0.3 parts of a crosslinking agent. The resin matrix material is 60 parts of butyl acrylate, 20 parts of methyl methacrylate, and 5 parts of acrylic acid; the conductive filler is a mixture of gallium-indium alloy nanoparticles and silver nanowires, with a mass ratio of 3:1; the solvent is ethyl acetate; the tackifying resin is hydrogenated rosin KR-610; and the crosslinking agent is isophorone diisocyanate.

[0127] The conductive interconnection strips of this embodiment are prepared by the following steps:

[0128] S1: Providing a transparent substrate 1: purchasing or preparing a 1 mm thick PET film through an extrusion process, and punching the PET film to obtain a transparent substrate 1 having a plurality of through holes.

[0129] S2: Provide transparent pressure-sensitive conductive adhesive: Mix the base resin material, tackifying resin, cross-linking agent and solvent, use a planetary mixer or high-speed disperser to stir until the adhesive liquid is uniform, then add conductive fillers in batches, and cooperate with shear dispersion to make the conductive fillers evenly dispersed in the adhesive liquid to obtain a transparent pressure-sensitive conductive adhesive.

[0130] S3: The transparent substrate 1 is unwound and a transparent pressure-sensitive conductive adhesive is applied to one side of the transparent substrate 1 using a doctor blade. The substrate is then passed through a hot drying oven to dry the coating and form a 100 μm thick first conductive adhesive layer 3. The drying oven temperature is 200°C, and the substrate travels from the entrance to the exit of the hot drying oven for 30 minutes.

[0131] S4: After coating the outer side of the first conductive adhesive layer 3 with a protective film, the first coated substrate is rolled up to obtain a first coated substrate.

[0132] S5: The first coated substrate is unwound, and a transparent pressure-sensitive conductive adhesive is applied to the other side of the transparent substrate 1 using a doctor blade. The substrate is then passed through a hot drying tunnel for drying to form a 100 μm thick second conductive adhesive layer 4. The drying tunnel temperature is 200°C, and the substrate travels from the entrance to the exit of the hot drying tunnel for 30 minutes.

[0133] S6: After coating the outer side of the second conductive adhesive layer 4 with a protective film, a second coated substrate is obtained.

[0134] S7: Cut the second coated substrate into pieces according to a preset width (3 mm) to obtain a plurality of conductive interconnecting strips.

[0135] Example 2

[0136] The structure of the conductive interconnection strip in this embodiment is as follows Figure 3 and Figure 4 As shown, it includes a transparent substrate 1, a transparent pressure-sensitive conductive adhesive forming a first conductive adhesive layer 3 on the front side of the transparent substrate 1, and a transparent pressure-sensitive conductive adhesive forming a second conductive adhesive layer 4 on the back side of the transparent substrate 1. The transparent substrate 1 has an infiltration structure, which is a through hole penetrating the transparent substrate 1. The through hole has a transparent pressure-sensitive conductive adhesive and connects the first conductive adhesive layer 3 and the second conductive adhesive layer 4.

[0137] The transparent substrate 1 is a PET film with a thickness of 0.1 mm and a width of 3 mm. The first conductive adhesive layer 3 is 3 mm wide and 100 μm thick. The second conductive adhesive layer 4 is 3 mm wide and 100 μm thick. The through-holes are circular with a diameter of 1 mm and are arranged in two rows. The distance between adjacent through-holes along the length of the transparent substrate 1 (the distance between adjacent edges) is 1 mm, and the distance between the two rows of through-holes along the width of the transparent substrate 1 is 0.5 mm.

[0138] The formula of the transparent pressure-sensitive conductive adhesive of this embodiment is the same as that of Example 1, and the preparation method of the conductive interconnection strip is the same as that of Example 1.

[0139] Example 3

[0140] The structure of the conductive interconnection strip in this embodiment is as follows Figure 5 and Figure 6As shown, it includes a transparent substrate 1, a transparent pressure-sensitive conductive adhesive forming a first conductive adhesive layer 3 on the front side of the transparent substrate 1, and a transparent pressure-sensitive conductive adhesive forming a second conductive adhesive layer 4 on the back side of the transparent substrate 1. The transparent substrate 1 has an infiltration structure, which is a through hole penetrating the transparent substrate 1. The through hole has a transparent pressure-sensitive conductive adhesive and connects the first conductive adhesive layer 3 and the second conductive adhesive layer 4.

[0141] The transparent substrate 1 is a PET film with a thickness of 0.1 mm and a width of 3 mm. The first conductive adhesive layer 3 is 3 mm wide and 100 μm thick. The second conductive adhesive layer 4 is 3 mm wide and 100 μm thick. The through-holes are circular and 2 mm in diameter. Multiple through-holes are spaced along the length of the transparent substrate 1, with the distance between adjacent through-holes (the distance between adjacent edges) being 1 mm. The transparent substrate 1 also includes a first conductive wire 102, specifically a tinned copper wire with a diameter of 0.05 mm. The first conductive wire 102 is located on the side of the transparent substrate 1 near the first conductive adhesive layer 3.

[0142] The formula of the transparent pressure-sensitive conductive adhesive of this embodiment is the same as that of Example 1.

[0143] The method for preparing the conductive interconnection bar of this embodiment is the same as that of embodiment 1. The difference from embodiment 1 is that in step S1, the first conductive metal wire 102 is disposed on one side of the transparent substrate 1 after punching.

[0144] Example 4

[0145] The structure of the conductive interconnection strip in this embodiment is as follows Figure 7 and Figure 8 As shown, it includes a transparent substrate 1, a transparent pressure-sensitive conductive adhesive forming a first conductive adhesive layer 3 on the front side of the transparent substrate 1, and a transparent pressure-sensitive conductive adhesive forming a second conductive adhesive layer 4 on the back side of the transparent substrate 1. The transparent substrate 1 has an infiltration structure, which is a through hole penetrating the transparent substrate 1. The through hole has a transparent pressure-sensitive conductive adhesive and connects the first conductive adhesive layer 3 and the second conductive adhesive layer 4.

[0146] The transparent substrate 1 is a PET film with a thickness of 0.1 mm and a width of 3 mm. The first conductive adhesive layer 3 is 3 mm wide and 100 μm thick. The second conductive adhesive layer 4 is 3 mm wide and 100 μm thick. The through-holes are circular holes with a diameter of 2 mm. Multiple through-holes are spaced along the length of the transparent substrate 1, and the distance between adjacent through-holes (the distance between adjacent edges) is 1 mm. The transparent substrate 1 also includes two first conductive metal wires 102, specifically tinned copper wires with a diameter of 0.05 mm. One of the first conductive metal wires 102 is located on the side of the transparent substrate 1 closest to the first conductive adhesive layer 3, and the other is located on the side of the transparent substrate 1 closest to the second conductive adhesive layer 4.

[0147] The formula of the transparent pressure-sensitive conductive adhesive of this embodiment is the same as that of Example 1.

[0148] The method for preparing the conductive interconnection bars of this embodiment is the same as that of embodiment 1. The difference from embodiment 1 is that in step S1, the first conductive metal wires 102 are arranged on two side surfaces of the transparent substrate 1 after punching.

[0149] Example 5

[0150] The structure of the conductive interconnection strip in this embodiment is as follows Figure 9 As shown, it includes a transparent substrate 1, a transparent pressure-sensitive conductive adhesive forming a first conductive adhesive layer 3 on the front side of the transparent substrate 1, and a transparent pressure-sensitive conductive adhesive forming a second conductive adhesive layer 4 on the back side of the transparent substrate 1. The transparent substrate 1 has an infiltration structure, which is a through hole penetrating the transparent substrate 1. The through hole has a transparent pressure-sensitive conductive adhesive and connects the first conductive adhesive layer 3 and the second conductive adhesive layer 4.

[0151] The transparent substrate 1 is a PET film with a thickness of 0.1 mm and a width of 3 mm. The first conductive adhesive layer 3 is 3 mm wide and 100 μm thick. The second conductive adhesive layer 4 is 3 mm wide and 100 μm thick. The through-holes are circular and 2 mm in diameter. Multiple through-holes are spaced along the length of the transparent substrate 1, with the distance between adjacent through-holes (the distance between adjacent edges) being 1 mm. The transparent substrate 1 also includes a first conductive wire 102, specifically a tinned copper wire with a diameter of 0.05 mm. The first conductive wire 102 is sequentially interspersed through the multiple through-holes along the length of the transparent substrate 1.

[0152] The formula of the transparent pressure-sensitive conductive adhesive of this embodiment is the same as that of Example 1.

[0153] The method for preparing the conductive interconnection bar of this embodiment is the same as that of embodiment 1. The difference from embodiment 1 is that in step S1, after punching, a puncher is used to insert the first conductive metal wire 102 into the through hole of the transparent substrate 1.

[0154] Example 6

[0155] The conductive interconnection strip of this embodiment includes a transparent substrate 1, a transparent pressure-sensitive conductive adhesive forming a first conductive adhesive layer 3 on the front side of the transparent substrate 1, and a transparent pressure-sensitive conductive adhesive forming a second conductive adhesive layer 4 on the back side of the transparent substrate 1. The transparent substrate 1 has an infiltration structure, and the transparent substrate 1 is a transparent woven cloth. The infiltration structure is the weaving gap of the transparent woven cloth. The weaving gap has a transparent pressure-sensitive conductive adhesive and connects the first conductive adhesive layer 3 and the second conductive adhesive layer 4.

[0156] The transparent woven fabric has a thickness of 0.1 mm and a width of 3 mm; the first conductive adhesive layer 3 has a width of 3 mm and a thickness of 100 μm; and the second conductive adhesive layer 4 has a width of 3 mm and a thickness of 100 μm.

[0157] The formula of the transparent pressure-sensitive conductive adhesive of this embodiment is the same as that of Example 1.

[0158] The method for preparing the conductive interconnection strips of this embodiment is the same as that of embodiment 1, and the only difference from embodiment 1 is that step S1 prepares a transparent woven cloth by a weaving process to obtain a transparent substrate 1 .

[0159] Example 7

[0160] The structure of the conductive interconnection strips of this embodiment is the same as that of embodiment 6. The difference between this embodiment and embodiment 6 is that the transparent woven fabric contains second conductive metal wires, and each conductive interconnection strip includes three second conductive metal wires.

[0161] The formula of the transparent pressure-sensitive conductive adhesive of this embodiment is the same as that of Example 6.

[0162] The method for preparing the conductive interconnection strips of this embodiment is the same as that of embodiment 6, and the only difference from embodiment 6 is that a second conductive metal wire is added when preparing the transparent woven cloth through a weaving process in step S1.

[0163] Example 8

[0164] The structure of the conductive interconnection strip of this embodiment is the same as that of embodiment 5, and the preparation method thereof is also the same as that of embodiment 5.

[0165] The difference between this embodiment and embodiment 5 lies in the different formula of the transparent pressure-sensitive conductive adhesive.

[0166] Specifically, the transparent pressure-sensitive conductive adhesive of this embodiment is composed of the following components: 60 parts of a resin matrix material, 10 parts of a conductive filler, 60 parts of a solvent, 10 parts of a tackifying resin, and 0.1 parts of a crosslinking agent. The resin matrix material is butyl acrylate; the conductive filler is a mixture of gallium-indium alloy nanoparticles and silver nanowires, with a mass ratio of 3:1; the solvent is ethyl acetate; the tackifying resin is hydrogenated rosin KR-610; and the crosslinking agent is isophorone diisocyanate.

[0167] Example 9

[0168] The structure of the conductive interconnection strip of this embodiment is the same as that of embodiment 5, and the preparation method thereof is also the same as that of embodiment 5.

[0169] The difference between this embodiment and embodiment 5 lies in the different formula of the transparent pressure-sensitive conductive adhesive.

[0170] Specifically, the transparent pressure-sensitive conductive adhesive of this embodiment is composed of the following components: 80 parts of a resin matrix material, 12 parts of a conductive filler, 75 parts of a solvent, 15 parts of a tackifying resin, and 0.2 parts of a crosslinking agent. The resin matrix material is 60 parts of butyl acrylate and 20 parts of methyl methacrylate; the conductive filler is a mixture of gallium-indium alloy nanoparticles and silver nanowires, with a mass ratio of 3:1; the solvent is ethyl acetate; the tackifying resin is hydrogenated rosin KR-610; and the crosslinking agent is isophorone diisocyanate.

[0171] Example 10

[0172] The structure of the conductive interconnection strip of this embodiment is the same as that of embodiment 5, and the preparation method thereof is also the same as that of embodiment 5.

[0173] The difference between this embodiment and embodiment 5 lies in the different formula of the transparent pressure-sensitive conductive adhesive.

[0174] Specifically, the transparent pressure-sensitive conductive adhesive of this embodiment is composed of the following components: 90 parts of a resin matrix material, 18 parts of a conductive filler, 90 parts of a solvent, 25 parts of a tackifying resin, and 0.4 parts of a crosslinking agent. The resin matrix material is 60 parts of butyl acrylate, 20 parts of methyl methacrylate, and 10 parts of acrylic acid; the conductive filler is a mixture of gallium-indium alloy nanoparticles and silver nanowires, with a mass ratio of 3:1; the solvent is ethyl acetate; the tackifying resin is hydrogenated rosin KR-610; and the crosslinking agent is isophorone diisocyanate.

[0175] Example 11

[0176] The structure of the conductive interconnection strip of this embodiment is the same as that of embodiment 5, and the preparation method thereof is also the same as that of embodiment 5.

[0177] The difference between this embodiment and embodiment 5 lies in the different formula of the transparent pressure-sensitive conductive adhesive.

[0178] Specifically, the transparent pressure-sensitive conductive adhesive of this embodiment is composed of the following components: 120 parts of a resin matrix material, 50 parts of a conductive filler, 100 parts of a solvent, 40 parts of a tackifying resin, and 0.5 parts of a crosslinking agent. The resin matrix material is 80 parts of butyl acrylate and 40 parts of methyl methacrylate; the conductive filler is a mixture of gallium-indium alloy nanoparticles and silver nanowires, with a mass ratio of 3:1; the solvent is ethyl acetate; the tackifying resin is hydrogenated rosin KR-610; and the crosslinking agent is isophorone diisocyanate.

[0179] Example 12

[0180] The structure of the conductive interconnection strip of this embodiment is the same as that of embodiment 5, and the preparation method thereof is also the same as that of embodiment 5.

[0181] The difference between this embodiment and embodiment 5 lies in the different formula of the transparent pressure-sensitive conductive adhesive.

[0182] Specifically, the transparent pressure-sensitive conductive adhesive of this embodiment is composed of the following components: 85 parts of a resin matrix material, 15 parts of a conductive filler, 80 parts of a solvent, 18 parts of a tackifying resin, and 0.3 parts of a crosslinking agent. The resin matrix material is 20 parts of butyl acrylate, 20 parts of methyl methacrylate, 40 parts of hydroxyethyl methacrylate, and 5 parts of acrylic acid; the conductive filler is indium tin oxide nanoparticles; the solvent is ethyl acetate; the tackifying resin is hydrogenated rosin KR-610; and the crosslinking agent is isophorone diisocyanate.

[0183] Comparative Example

[0184] The interconnection bar in this comparative example is a tinned copper strip interconnection bar with a thickness of 0.23 mm and a width of 1 mm.

[0185] Test Example 1

[0186] The conductive interconnecting strips of Examples 1 to 12 were tested for light transmittance, current carrying capacity, and adhesion. The test results are shown in Table 1.

[0187] The light transmittance detection method is: using a spectrophotometer to detect the light transmittance of the interconnection strip at a wavelength of 380 to 1200 nm.

[0188] The current carrying capacity of the interconnection strip is tested by calculating the current carrying capacity of the interconnection strip through a temperature rise test and a contact resistance test.

[0189] The method for testing the bonding strength of the interconnecting strips is as follows: using a universal tensile testing machine to test the bonding strength of the interconnecting strips.

[0190] Table 1 Transmittance, current carrying capacity and adhesion data of Examples 1 to 12

[0191] From the experimental data in Table 1, we can see that:

[0192] The conductive interconnecting strips of Examples 1 to 12 all have good light transmittance, current carrying capacity and adhesion. It can be seen that the conductive interconnecting strips of the present application will not block the light-receiving surface of the battery cells when connecting the battery cells to form a battery string, and can effectively increase the light-receiving area of ​​the battery string. The good adhesion can ensure the connection strength with the battery cells.

[0193] Comparing Examples 1 to 7, the current carrying capacity of Examples 3, 4 and 5 is better than that of Examples 1 and 2, and the current carrying capacity of Example 7 is better than that of Example 6. It can be seen that adding conductive metal wires to the conductive interconnection strips can effectively improve the conductivity of the conductive interconnection strips. Combined with the transmittance after adding the conductive metal wires, the setting method of Example 5 is most preferred, so that the conductive metal wires are sequentially interspersed with multiple through holes along the length direction of the transparent substrate, which can not only ensure a high transmittance, but also maximize the current carrying capacity. When used in photovoltaic modules, it can effectively improve the photoelectric conversion efficiency of the battery string.

[0194] Test Example 2

[0195] Examples 1 to 12 and the comparative example were carried out as follows Figure 11 and Figure 12 Six cells were connected in series to form a 2×3 string, forming Group A modules. The photovoltaic conversion efficiency of Group A modules was tested, and the test results are shown in Table 2. In Group A modules, each cell had seven busbars, connecting two adjacent cells via seven interconnects. The cells were perovskite tandem cells, each measuring 210 mm x 105 mm. The soldering parameters for the tinned copper ribbon interconnects used in the comparative example were: a soldering temperature of 270°C.

[0196] Example 1, Example 2 and Example 6 were carried out as follows Figure 11 and Figure 12 The connection structure shown in the figure connects six cells in series into a 2×3 cell string to form Group B modules. The photoelectric conversion efficiency of Group B modules was tested, and the test results are shown in Table 2. In Group B modules, each cell has 10 busbars, connecting two adjacent cells via 10 interconnects. The cells are perovskite stacked cells, and each cell measures 210 mm × 105 mm.

[0197] Table 2 Photoelectric conversion efficiency of small modules in Group A and Group B

[0198] From the experimental data in Table 2, we can see that:

[0199] Comparing Examples 3 to 5 and Examples 7 to 12 of Group A's small components with the comparative examples, it is found that the photoelectric conversion efficiency of Examples 3 to 5 and Examples 7 to 12 is higher than that of the comparative example. It can be seen that when the conductive interconnection strips of the present application are applied to photovoltaic modules, since the conductive interconnection strips are fully transparent, the light-receiving area of ​​the battery string is effectively increased, which can effectively improve the photoelectric conversion efficiency of the module and enhance the performance of the battery string.

[0200] Comparing Examples 1, 2 and 6 of Group A's small components with Examples 1, 2 and 6 of Group B's small components, the photoelectric conversion efficiency of Group B's small components is higher than that of Group A's small components. It can be seen that when using the same conductive interconnection bars to connect the battery cells in series, the conductivity of the battery string can be improved by adjusting the number of conductive interconnection bars, thereby improving the photoelectric conversion efficiency of the components and enhancing the performance of the battery string.

[0201] Thus far, the technical solutions of the present application have been described in conjunction with the preferred embodiments shown in the accompanying drawings. However, it is readily understood by those skilled in the art that the scope of protection of the present application is obviously not limited to these specific embodiments. Without departing from the principles of the present application, those skilled in the art may make equivalent changes or substitutions to the relevant technical features, and the technical solutions after such changes or substitutions will fall within the scope of protection of the present application.

Claims

1. A conductive interconnection strip, characterized in that: The conductive interconnection strip comprises a transparent substrate (1) and a transparent pressure-sensitive conductive adhesive having conductive properties, wherein the transparent substrate (1) has an impregnation structure (2). The transparent pressure-sensitive conductive adhesive forms a first conductive adhesive layer (3) and a second conductive adhesive layer (4) on the front and back sides of the transparent substrate (1), respectively, and the transparent pressure-sensitive conductive adhesive is also located in the infiltration structure (2) to electrically connect the first conductive adhesive layer (3) and the second conductive adhesive layer (4).

2. The conductive interconnection strip according to claim 1, wherein: The infiltration structure (2) is a gap or a hole.

3. The conductive interconnection strip according to claim 2, wherein: The transparent substrate (1) is a transparent strip, and the infiltration structure (2) is a plurality of through holes provided on the transparent strip, wherein the through holes penetrate the transparent strip along the thickness direction of the transparent strip.

4. The conductive interconnection strip according to claim 3, wherein: The plurality of through holes are spaced apart and distributed along the length direction of the transparent strip; Alternatively, the plurality of through holes are distributed in a matrix along the length direction and the width direction of the transparent strip.

5. The conductive interconnection strip according to claim 4, wherein: The transparent substrate (1) further comprises a first conductive metal wire (101), wherein the first conductive metal wire (101) is arranged on the front side and / or the back side of the transparent substrate (1); Alternatively, the transparent substrate (1) further comprises a first conductive metal wire (101), wherein the first conductive metal wire (101) is sequentially inserted into the plurality of through holes along the length direction of the transparent strip, so that the same first conductive metal wire (101) can be simultaneously located on the front side of the transparent substrate (1), the back side of the transparent substrate (1), and in the through hole.

6. The conductive interconnection strip according to claim 2, wherein: The transparent substrate (1) is a transparent woven cloth, and the infiltration structure (2) is a woven gap of the transparent woven cloth.

7. The conductive interconnection strip according to claim 6, wherein: The transparent substrate (1) further comprises a second conductive metal wire, and the second conductive metal wire is woven together with the transparent woven material to form the transparent woven cloth.

8. The conductive interconnection strip according to claim 1, wherein: The width of the transparent substrate (1) is 0.1 to 3 mm, and the thickness of the transparent substrate (1) is 0.01 to 1 mm; And / or, the width of the first conductive adhesive layer (3) is the same as the width of the transparent substrate (1), and the thickness of the first conductive adhesive layer (3) is 3 to 500 μm; And / or, the width of the second conductive adhesive layer (4) is the same as the width of the transparent substrate (1), and the thickness of the second conductive adhesive layer (4) is 3 to 500 μm.

9. The conductive interconnection strip according to any one of claims 1 to 8, characterized in that: The material of the transparent substrate (1) is one or more of polyolefins, polyesters, olefin copolymers, fluororesins, and polyamides; And / or, the transparent pressure-sensitive conductive adhesive comprises the following components in parts by weight: 60-120 parts of resin matrix material, 10-50 parts of conductive filler, 60-100 parts of solvent, 10-40 parts of tackifying resin, and 0.1-0.5 parts of cross-linking agent.

10. The conductive interconnection strip according to claim 9, wherein: The transparent pressure-sensitive conductive adhesive comprises the following components in parts by weight: 80-90 parts of a resin matrix material, 12-18 parts of a conductive filler, 75-90 parts of a solvent, 15-25 parts of a tackifying resin, and 0.2-0.4 parts of a cross-linking agent; And / or, the resin matrix material includes one or more of acrylate and acrylic acid; And / or, the conductive filler includes one or more of liquid metal nanoparticles, transparent metal oxides, and composite conductive materials; and / or, the solvent comprises one or more of ethyl acetate, toluene, and cyclohexanone; And / or, the tackifying resin comprises hydrogenated rosin, preferably the hydrogenated rosin is hydrogenated rosin KR-610; And / or, the cross-linking agent includes an isocyanate compound.

11. A method for preparing a conductive interconnection bar, for preparing the conductive interconnection bar according to any one of claims 1 to 10, characterized in that: The preparation method comprises the following steps: (1) providing a transparent substrate (1); (2) Providing transparent pressure-sensitive conductive adhesive; (3) unwinding the transparent substrate (1) and applying the transparent pressure-sensitive conductive adhesive to one side of the transparent substrate (1); (4) baking the coated transparent substrate (1) to dry the coating to form a first conductive adhesive layer (3); (5) coating the outer side of the first conductive adhesive layer (3) with a protective film and then rolling it up to obtain a first coated substrate; (6) unwinding the first coated substrate and applying the transparent pressure-sensitive conductive adhesive to the other side of the transparent base (1) of the first coated substrate; (7) baking the coated first coating substrate to dry the coating to form a second conductive adhesive layer (4); (8) coating the outer side of the second conductive adhesive layer (4) with a protective film and then rolling it up to obtain a second coated substrate; (9) Cutting the second coated substrate into sections according to a preset width to obtain a plurality of conductive interconnecting strips.

12. The method for preparing a conductive interconnection strip according to claim 11, wherein: In step (4) and step (7), a hot drying tunnel is used for baking. The baking temperature of the hot drying tunnel is 50 to 300° C., and the time for the substrate to move from the inlet end to the outlet end of the hot drying tunnel is 1 to 60 minutes.

13. A photovoltaic cell assembly, characterized in that: The battery string comprises a plurality of battery cells connected by a conductive interconnection bar, wherein the conductive interconnection bar is the conductive interconnection bar according to any one of claims 1 to 10.

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