Interconnecting strip, solar cell, preparation method of interconnection strip, preparation method of solar cell, preparation method of solar cell and photovoltaic module

Abstract

The embodiment of the invention provides an interconnection strip, a solar cell, preparation methods of the interconnection strip and the solar cell, and a photovoltaic module, and relates to the technical field of photovoltaic equipment. The interconnecting strip comprises a base body, a first connecting part and a second connecting part. Wherein the base body has electrical conductivity; the base body comprises a first surface and a second surface which are opposite to each other. The first connecting part and the second connecting part are arranged on the first surface and the second surface. Wherein the first connecting part and the second connecting part have electrical conductivity and pressure-sensitive adhesion. The interconnection strip can avoid the interconnection of the battery pieces in a high-temperature state, thereby reducing the adverse effect on the solar battery, especially the solar battery made of a perovskite material, when the battery pieces are interconnected through the interconnection strip, improving the performance of the solar battery, and prolonging the service life of the solar battery.

Description

Technical Field

[0001] The present application relates to the technical field of photovoltaic equipment, and in particular to an interconnection strip, a solar cell and respective preparation methods, and a photovoltaic module. Background Art

[0002] Perovskite photovoltaic modules include solar cells that use perovskite materials to achieve photoelectric conversion. They use organic-inorganic hybrid metal halides with perovskite crystal structures as light-absorbing layers, and have high photoelectric conversion efficiency and low preparation cost.

[0003] However, photovoltaic modules, especially perovskite photovoltaic modules, are sensitive to temperature. Excessively high temperatures can cause the perovskite material to decompose, leading to performance degradation or even failure of the perovskite photovoltaic modules, limiting the further development and application of perovskite photovoltaic modules. Summary of the Invention

[0004] The embodiments of the present application provide an interconnection strip, a solar cell, their respective preparation methods, and a photovoltaic module, aiming to provide an interconnection strip that can avoid high-temperature preparation of solar cells, thereby reducing the adverse effects of interconnection strips on solar cells, especially solar cells made of perovskite materials, when cell sheets are interconnected, and improving the performance and service life of solar cells.

[0005] To achieve the above objectives, the embodiments of the present application adopt the following technical solutions:

[0006] In a first aspect, an interconnection bar is provided. The interconnection bar includes a base, a first connecting portion, and a second connecting portion.

[0007] The substrate is conductive and includes a first surface and a second surface facing each other. The first connecting portion and the second connecting portion are disposed on the first surface and the second surface. Both the first connecting portion and the second connecting portion are conductive and pressure-sensitive adhesive.

[0008] In the interconnection strip provided in the embodiment of the present application, the first connection portion and the second connection portion are respectively arranged on two surfaces of the substrate facing each other, so that the two surfaces of the substrate facing each other are adhesive without affecting the conductivity of the substrate, thereby making the formed interconnection strip have double-sided adhesion, and at the same time can also realize electrical connection between the two structures located on both sides of the interconnection strip (the side where the first surface is located and the side where the second surface is located).

[0009] In addition, the first connection part and the second connection part of the interconnection strip have pressure-sensitive adhesion, thereby achieving decoupling between the connection effect of the interconnection strip and high temperature, that is, there is no need to increase the connection temperature (such as the welding temperature, high-temperature curing temperature, etc. in other embodiments) to ensure the excellent connection effect between the interconnection strip and other electrical structures (such as battery cells), but a better connection effect of the interconnection strip can be achieved only by applying pressure, thereby avoiding the limitation of temperature on the application scenarios of the interconnection strip, so that the interconnection strip can be used in the connection scenarios of some electrical structures that are sensitive to temperature.

[0010] In some embodiments, the first connecting portion includes a plurality of first sub-portions, and the second connecting portion includes a plurality of second sub-portions; along the extension direction of the base body, two adjacent first sub-portions are spaced apart, and two adjacent second sub-portions are spaced apart;

[0011] Wherein, along the extension direction of the base body, a plurality of first sub-sections and a plurality of second sub-sections are alternately arranged in sequence, and a gap exists between adjacently arranged first sub-sections and second sub-sections in the extension direction of the base body.

[0012] In some embodiments, the first subsection and the second subsection each include multiple components, and adjacent components are spaced apart, and the spacing between two adjacent components is smaller than the spacing between two adjacent first subsections or two adjacent second subsections.

[0013] In some embodiments, the plurality of components are sequentially spaced apart along the extension direction of the substrate.

[0014] In some embodiments, both the first connecting portion and the second connecting portion extend along an extension direction of the substrate, and the first connecting portion covers the first surface, while the second connecting portion covers the second surface.

[0015] In some embodiments, the first connecting portion and the second connecting portion both include a pressure-sensitive adhesive and a conductive filler, and the conductive filler is mixed with the pressure-sensitive adhesive.

[0016] In some embodiments, the pressure-sensitive adhesive accounts for 40% to 60%, and the conductive filler accounts for 20% to 40%.

[0017] In some embodiments, the thickness of the first connecting portion and the second connecting portion are both 3 μm to 100 μm.

[0018] In some embodiments, the width of the first connecting portion and the second connecting portion are both 0.1 mm to 3 mm.

[0019] In some embodiments, the interconnection strip further includes an adhesive layer, which is disposed between the first connection portion and the substrate, and between the second connection portion and the substrate, and has adhesive properties.

[0020] In a second aspect, a method for preparing an interconnection strip is provided, the method comprising:

[0021] The substrate is unwound; the substrate is conductive; the substrate includes a first surface and a second surface facing each other. A first connecting portion and a second connecting portion are formed on the first surface and the second surface, respectively; the first connecting portion and the second connecting portion are both conductive and pressure-sensitive adhesive. The substrate with the first connecting portion and the second connecting portion is rewound.

[0022] The technical effects brought about by the method for preparing the interconnection strips in the second aspect can be referred to the technical effects brought about by the design method of the interconnection strips in the first aspect, and will not be repeated here.

[0023] In some embodiments, forming the first connecting portion and the second connecting portion on the first surface and the second surface, respectively, comprises:

[0024] The first surface of the unwound substrate passes through the gluing structure to form a first connecting portion; the material for the first connecting portion is placed in the gluing structure, with the first surface facing the gluing structure. The substrate is rewound and unwound again, swapping the positions of the first and second surfaces. The second surface of the unwound substrate passes through the gluing structure to form a second connecting portion; the material for the second connecting portion is placed in the gluing structure, with the second surface facing the gluing structure.

[0025] In some embodiments, after forming the first connection portion and after forming the second connection portion, the method further includes: passing the substrate provided with the first connection portion and / or the second connection portion through a hot drying tunnel.

[0026] In some embodiments, the baking temperature in the hot baking tunnel is 50° C. to 300° C., and the baking time is 1 minute to 60 minutes.

[0027] In a third aspect, a solar cell is provided, comprising a plurality of cells and a plurality of interconnecting bars as described in any embodiment of the first aspect, wherein two adjacent cells are electrically connected via the interconnecting bars.

[0028] The technical effects brought about by the design of the solar cell in the third aspect can be referred to the technical effects brought about by the design of the interconnection strip in the first aspect, and will not be repeated here.

[0029] In a fourth aspect, a method for preparing a solar cell is provided, the method comprising:

[0030] Multiple battery cells and multiple interconnecting bars are laid in a string; the interconnecting bars are placed at the positions of two adjacent battery cells that need to be electrically connected to the interconnecting bars. A pressure treatment is performed to bond the interconnecting bars to the two adjacent battery cells.

[0031] In the preparation method of solar cells provided in the embodiment of the present application, the conductivity and pressure-sensitive adhesion of the interconnecting strips are utilized, and the interconnection between the cell and the interconnecting strip can be achieved by simply applying pressure, without the need for high-temperature curing to achieve the connection between the two, thereby avoiding problems such as damage to the cell (especially the cell made of perovskite material) caused by the high temperature environment during the cell interconnection process, optimizing the efficiency of the solar cell and extending its service life.

[0032] In addition, in the embodiments of the present application, the obtained interconnecting strips have both electrical conductivity and pressure-sensitive adhesion, so the electrical connection between the interconnecting strips and the battery cells can be achieved by directly physically connecting the interconnecting strips and the battery cells without the need for additional gluing or glue alignment processing, thereby speeding up the preparation of solar cells.

[0033] In a fifth aspect, a photovoltaic assembly is provided, comprising a packaging structure and a plurality of solar cells according to the embodiment of the third aspect. The plurality of solar cells are electrically connected and packaged within the packaging structure.

[0034] The technical effects brought about by the design of the photovoltaic components in the fifth aspect can be referred to the technical effects brought about by the design of the interconnection strips in the first aspect, and will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] To more clearly illustrate the technical solutions of this application, the following briefly introduces the drawings required for use in some embodiments of this application. Obviously, the drawings described below are only drawings of some embodiments of this application. For those skilled in the art, other drawings can also be obtained based on these drawings. In addition, the drawings described below can be regarded as schematic diagrams and do not represent the actual dimensions of the products or the actual processes of the methods involved in the embodiments of this application.

[0036] Figure 1 A schematic diagram of the structure of an interconnection strip provided in an embodiment of the present application;

[0037] Figure 2 Another structural diagram of the interconnection strip provided in an embodiment of the present application;

[0038] Figure 3 Another structural diagram of the interconnection strip provided in an embodiment of the present application;

[0039] Figure 4 Another structural diagram of the interconnection strip provided in an embodiment of the present application;

[0040] Figure 5 A flow chart for preparing interconnection strips provided in an embodiment of the present application;

[0041] Figure 6A schematic diagram of the process for preparing the interconnection strips provided in an embodiment of the present application;

[0042] Figure 7 A three-dimensional diagram of a solar cell provided in an embodiment of the present application;

[0043] Figure 8 for Figure 7 A local enlarged view of the structure in circle C;

[0044] Figure 9 for Figure 8 A local enlarged view of the structure in circle D;

[0045] Figure 10 A cross-sectional view of a solar cell provided in an embodiment of the present application;

[0046] Figure 11 for Figure 10 A local enlarged view of the structure in circle E;

[0047] Figure 12 for Figure 11 A local enlarged view of the structure in circle F;

[0048] Figure 13 A cross-sectional view of a battery cell provided in an embodiment of the present application;

[0049] Figure 14 A flow chart of the preparation of a solar cell provided in an embodiment of the present application;

[0050] Figure 15 A schematic diagram of the structure of a photovoltaic module provided in an embodiment of the present application. DETAILED DESCRIPTION

[0051] The following will be combined with the accompanying drawings to clearly and completely describe the technical solutions in some embodiments of the present application. Obviously, the embodiments described are only some embodiments of the present application, not all embodiments. Based on the embodiments provided in this application, all other embodiments obtained by ordinary technicians in this field are within the scope of protection of this application.

[0052] In the description of this application, it should be understood that the terms "center", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on this application.

[0053] Unless the context requires otherwise, throughout the specification and claims, the term "including" is to be interpreted as having an open, inclusive meaning, that is, "including, but not limited to." In the description of the specification, the terms "one embodiment," "some embodiments," "exemplary embodiments," "exemplarily," or "some examples" are intended to indicate that specific features, structures, materials, or characteristics associated with the embodiment or example are included in at least one embodiment or example of the present application. The schematic representation of the above terms does not necessarily refer to the same embodiment or example. In addition, the aforementioned specific features, structures, materials, or characteristics may be included in any one or more embodiments or examples in any appropriate manner.

[0054] The terms "first," "second," etc. are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of the technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the embodiments of this application, unless otherwise specified, "plurality" means two or more.

[0055] Connection, connected: can refer to a mechanical connection relationship or a physical connection relationship, that is, A and B are connected or A and B are connected, which can mean that there is a fastening component (such as a screw, bolt, rivet, etc.) between A and B, or A and B are in contact with each other and A and B are difficult to separate, wherein A and B can be fixedly connected, detachably connected, or integrated; can be directly connected, or indirectly connected through an intermediate medium.

[0056] As used herein, "parallel", "perpendicular", and "equal" include the situations described and situations similar to the situations described, and the range of the similar situations is within an acceptable deviation range, wherein the acceptable deviation range is as determined by a person of ordinary skill in the art taking into account the measurement in question and the errors associated with the measurement of the specific quantity (i.e., the limitations of the measurement system). For example, "parallel" includes absolute parallelism and approximate parallelism, wherein the acceptable deviation range of approximate parallelism can be, for example, a deviation within 5°; "perpendicular" includes absolute perpendicularity and approximate perpendicularity, wherein the acceptable deviation range of approximate perpendicularity can also be, for example, a deviation within 5°. "Equal" includes absolute equality and approximate equality, wherein the acceptable deviation range of approximate equality can be, for example, that the difference between the two equals is less than or equal to 5% of either one.

[0057] Exemplary embodiments are described herein with reference to cross-sectional and / or plan views that are idealized exemplary drawings. In the drawings, the thicknesses of layers and regions are exaggerated for clarity. Therefore, variations in shape relative to the drawings due to, for example, manufacturing techniques and / or tolerances are contemplated. Therefore, the exemplary embodiments should not be construed as limited to the shapes of the regions shown herein, but rather include deviations in shape due to, for example, manufacturing. Therefore, the regions shown in the drawings are schematic in nature, and their shapes are not intended to illustrate the actual shape of regions of the device and are not intended to limit the scope of the exemplary embodiments.

[0058] In addition, the scenarios described in the embodiments of the present application are intended to more clearly illustrate the technical solutions of the embodiments of the present application, and do not constitute a limitation on the technical solutions provided in the embodiments of the present application. A person of ordinary skill in the art will know that with the emergence of new scenarios, the technical solutions provided in the embodiments of the present application are also applicable to similar technical problems.

[0059] The embodiment of the present application provides an interconnection bar 10, Figure 1 、 Figure 2 and Figure 3 All of them are structural schematic diagrams of the interconnection bar 10 provided in the embodiments of the present application, wherein each figure includes a three-dimensional view and a cross-sectional view of the interconnection bar 10.

[0060] like Figure 1 、 Figure 2 and Figure 3 As shown, the interconnection strip 10 includes a base 1 , a first connecting portion 21 and a second connecting portion 22 .

[0061] The substrate 1 is conductive so as to provide a basis for the conductive performance of the interconnection strip 10 .

[0062] For example, the material of the substrate 1 may include copper, silver, aluminum and other materials having conductive properties.

[0063] For example, the substrate 1 can be a structure with good electrical conductivity such as tinned copper strip and whose surface is not easily oxidized, or it can be other structures that do not require a metal layer but have good electrical conductivity and are not easily oxidized. The embodiments of the present application do not limit this.

[0064] See Figure 1 、 Figure 2 and Figure 3 The substrate 1 includes a first surface 1a and a second surface 1b facing each other. For example, the first surface 1a and the second surface 1b may be two surfaces arranged in the thickness direction of the substrate 1.

[0065] For example, Figure 1 、 Figure 2 and Figure 3Based on the orientation of the cross-sectional view in FIG, the upper surface of the substrate 1 may be the first surface 1 a, and the lower surface of the substrate 1 may be the second surface 1 b.

[0066] See Figure 1 、 Figure 2 and Figure 3 The first connecting portion 21 and the second connecting portion 22 are respectively provided on the first surface 1a and the second surface 1b.

[0067] For example, the first connection portion 21 is disposed on the first surface 1 a , and the second connection portion 22 is disposed on the second surface 1 b .

[0068] The first connection portion 21 and the second connection portion 22 both have electrical conductivity and pressure-sensitive adhesive properties.

[0069] Exemplarily, both the first connection portion 21 and the second connection portion 22 may be pressure-sensitive conductive adhesives, that is, both may be adhesives that are sensitive to pressure and have adhesive properties and can conduct electricity when subjected to pressure.

[0070] In the interconnection bar 10 provided in the embodiment of the present application, the first connection part 21 and the second connection part 22 are respectively arranged on two surfaces of the substrate 1 facing each other, so that the two surfaces of the substrate 1 facing each other are adhesive without affecting the conductivity of the substrate 1, thereby making the formed interconnection bar 10 have double-sided adhesion, and at the same time can also realize electrical connection between the two structures located on both sides of the interconnection bar 10 (the side where the first surface 1a is located and the side where the second surface 1b is located).

[0071] In addition, the first connection part 21 and the second connection part 22 of the interconnection bar 10 have pressure-sensitive adhesion, thereby achieving decoupling between the connection effect of the interconnection bar 10 and high temperature, that is, there is no need to increase the connection temperature (such as the welding temperature, high-temperature curing temperature, etc. in other embodiments) to ensure the excellent connection effect between the interconnection bar 10 and other electrical structures (such as battery cells), but the better connection effect of the interconnection bar 10 can be achieved only by applying pressure, thereby avoiding the temperature limitation of the application scenario of the interconnection bar 10, so that the interconnection bar 10 can be used in the connection scenarios of some electrical structures that are sensitive to temperature.

[0072] In addition, the interconnection strip 10 in the embodiment of the present application can also solve the problem of being unable to rework after conductive glue interconnection. At the same time, the interconnection strip 10 does not need to be stored at low temperatures and can be used for a long time at room temperature, and has a wide range of application scenarios.

[0073] In some embodiments, the interconnection bar 10 may further include a protective layer, which may be disposed on a side of the first connection portion 21 and the second connection portion 22 away from the substrate 1, so as to ensure the adhesion of the first connection portion 21 and the second connection portion 22 before the interconnection bar 10 is connected to other electrical structures, thereby preventing both from being damaged or contaminated, resulting in a decrease in adhesion.

[0074] Illustratively, the protective layer may be a release film.

[0075] In some embodiments, see Figure 1 The first connecting portion 21 includes a plurality of first sub-portions 2A, and the second connecting portion 22 includes a plurality of second sub-portions 2B. Along the extension direction of the substrate 1, two adjacent first sub-portions 2A are spaced apart, and two adjacent second sub-portions 2B are spaced apart.

[0076] Each first subsection 2A and each second subsection 2B can be used to connect one electrical structure respectively. Multiple first subsections 2A can be used to connect multiple electrical structures, and multiple second subsections 2B can also be used to connect multiple electrical structures.

[0077] Among them, see Figure 1 Along the extension direction of the base 1, a plurality of first sub-sections 2A and a plurality of second sub-sections 2B are alternately arranged in sequence.

[0078] That is, see Figure 1 The first sub-section 2A is arranged on the other side surface of the substrate 1 opposite to the gap between the two adjacent second sub-sections 2B. For example, the orthographic projection of the first sub-section 2A on the substrate 1 can be located between the orthographic projections of the two adjacent second sub-sections 2B on the substrate 1.

[0079] Similarly, see Figure 1 The second sub-section 2B is arranged on the other side surface of the substrate 1 opposite to the gap between the two adjacent first sub-sections 2A. For example, the orthographic projection of the second sub-section 2B on the substrate 1 can be located between the orthographic projections of the two adjacent first sub-sections 2A on the substrate 1.

[0080] By arranging multiple first sub-sections 2A and multiple second sub-sections 2B alternately in sequence, the positions available for fixed connection on both sides of the interconnection bar 10 can be controlled to be staggered in the thickness direction. Therefore, when multiple other electrical structures (such as battery cells) are connected on both sides of the interconnection bar 10, the other multiple electrical structures can be dispersed in the thickness direction, avoiding the problem of poor heat dissipation after the other multiple electrical structures are stacked.

[0081] See Figure 1 The adjacent first sub-section 2A and the second sub-section 2B have a gap in the extending direction of the base 1 .

[0082] For example, see Figure 1 The size of the orthographic projection of two adjacent second sub-sections 2B on the substrate 1 is larger than the size of the orthographic projection of the first sub-section 2A on the substrate 1, so as to cover the orthographic projection of the first sub-section 2A on the substrate 1, that is, the size of the gap between two adjacent second sub-sections 2B in the extension direction of the substrate 1 is larger than the size of the first sub-section 2A in the extension direction of the substrate 1, so that there is a gap between the adjacent first sub-sections 2A and second sub-sections 2B between their close boundaries. Similarly, the size of the gap between two adjacent first sub-sections 2A is also larger than the size of the second sub-section 2B.

[0083] That is, see Figure 1 , so that at least a portion of the substrate 1 (between the adjacent first sub-portions 2A and the second sub-portions 2B) has neither the first sub-portion 2A nor the second sub-portion 2B on its surface, that is, this portion only has the conductive effect of the substrate 1 but no adhesion effect, thereby facilitating deformation of this portion, so that the interconnection bar 10 is suitable for a variety of different application scenarios. For example, the portion of the substrate 1 without the first connecting portion 21 and the second connecting portion 22 can be folded in an S shape, so that the two electrical structures interconnected with the interconnection bar 10 and arranged on both sides of the interconnection bar 10 can be located in the same space in the thickness direction, that is, share the same design space in the thickness direction, avoiding excessive thickness after interconnection (see subsequent Figure 12 ).

[0084] In some embodiments, see Figure 2 Each first sub-section 2A and second sub-section 2B includes multiple components M, and adjacent components M are spaced apart, and the spacing between adjacent components M is smaller than the spacing between adjacent first sub-sections 2A or adjacent second sub-sections 2B.

[0085] That is, each first sub-section 2A and each second sub-section 2B are divided into a plurality of small blocks (ie, component parts M), so that the stress of each first sub-section 2A after being bonded to other electrical structures is small.

[0086] For example, the multiple components M may be evenly dispersed so that the stress distribution after the first sub-part 2A is bonded to other electrical structures is more uniform, thereby improving the connection effect between the interconnection bar 10 and the electrical structure.

[0087] For example, see Figure 2 The multiple components M are arranged in sequence along the extension direction of the substrate 1, that is, the arrangement direction of the multiple components M is consistent with the arrangement direction of the multiple first sub-parts 2A and the multiple second sub-parts 2B, so that the overall stress of the interconnection bar 10 is more coordinated, thereby extending the service life of the interconnection bar 10.

[0088] Alternatively, for example, the plurality of components M may be arranged in an array in the extension direction and width direction of the substrate 1 , or arranged along other directions, and this embodiment of the present application does not impose any limitation thereto.

[0089] In some embodiments, see Figure 3 The first connection portion 21 and the second connection portion 22 both extend along the extension direction of the substrate 1 , and the first connection portion 21 covers the first surface 1 a , and the second connection portion 22 covers the second surface 1 b .

[0090] That is, see Figure 3 The first connecting portion 21 and the second connecting portion 22 can both be provided on the entire surface, so that any position of the substrate 1 has conductivity and pressure-sensitive adhesion. On the one hand, the connection position of the interconnection bar 10 and other electrical structures can be flexibly adjusted. On the other hand, it can ensure that there is strong adhesion between the interconnection bar 10 and other electrical structures to ensure the connection effect.

[0091] In some embodiments, the first connection portion 21 and the second connection portion 22 both include pressure-sensitive adhesive and conductive filler, and the conductive filler is mixed with the pressure-sensitive adhesive so that the first connection portion 21 and the second connection portion 22 both have conductivity and pressure-sensitive adhesive properties.

[0092] Exemplarily, the pressure-sensitive adhesive accounts for 40% to 60%, and the conductive filler accounts for 20% to 40%.

[0093] For example, the proportion of the pressure-sensitive adhesive may be 40%, 45.6%, 48.45% or 60%, and the proportion of the conductive filler may be 20%, 23.5%, 28.67%, 35.892% or 40%.

[0094] Exemplarily, the materials of pressure-sensitive adhesives may include acrylates (such as butyl acrylate, isooctyl acrylate, good transparency and aging resistance), rubbers (such as natural rubber, SBS elastomer, high initial viscosity, suitable for low temperature environment), and silicone resins (resistant to high temperatures, but relatively high cost), so as to make it have adhesion and flexibility.

[0095] Exemplarily, the material of the conductive filler may include metal powder, such as silver powder (best conductivity), copper powder (needs to be protected from oxidation), nickel powder (low cost), or the material of the conductive filler may include carbon-based materials, such as carbon black (low cost, but high resistance), graphene (high performance, difficult to disperse), or the material of the conductive filler may include composite fillers, such as silver-coated copper powder (balancing cost and performance).

[0096] It is understandable that the pressure-sensitive adhesive and the conductive filler can be prepared by selecting different material components and using different proportions according to different requirements of different application scenarios.

[0097] In some embodiments, the thickness of the first connection portion 21 and the second connection portion 22 are both 3 μm to 100 μm, for example, 3 μm to 19 μm, 20 μm, 21 μm to 35 μm, 40 μm, 45.5 μm, 50 μm to 80 μm, 92.75 μm, or 100 μm.

[0098] In some embodiments, the width of the first connection portion 21 and the second connection portion 22 are both 0.1 mm to 3 mm, for example, 0.1 mm to 0.29 mm, 0.3 mm, 0.31 mm to 1.7 mm, 1.8 mm, or 1.879 mm to 3 mm.

[0099] Exemplarily, the first connecting portion 21 and the second connecting portion 22 may further include a tackifying resin (eg, accounting for 10-30%) to enhance initial adhesion and peel strength, and the material thereof may include at least one of rosin resin, petroleum resin, and terpene resin.

[0100] Exemplarily, the first connecting portion 21 and the second connecting portion 22 may further include a plasticizer (eg, a proportion of 5-15%) to improve flexibility and coating performance, and the material thereof may include at least one of phthalates and liquid rubber.

[0101] Exemplarily, the first connecting portion 21 and the second connecting portion 22 may further include a solvent or diluent to adjust the viscosity for easy coating, and the material may include at least one of toluene, ethyl acetate (solvent-based system) and deionized water (aqueous system).

[0102] Exemplarily, the first connecting portion 21 and the second connecting portion 22 may further include a functional additive (e.g., a proportion of 1-5%). For example, a stabilizer and / or an antioxidant (e.g., BHT) may be included to prevent aging, or a dispersant may be included to prevent agglomeration of the conductive filler (e.g., a silane coupling agent), or a cross-linking agent may be included to improve temperature resistance (e.g., isocyanate).

[0103] Figure 4 Another cross-sectional view of the interconnection bar 10 provided in an embodiment of the present application.

[0104] In some embodiments, see Figure 4 The interconnection strip 10 also includes an adhesive layer 3, which has adhesive properties. The adhesive layer 3 is arranged between the first connecting part 21 and the substrate 1, and between the second connecting part 22 and the substrate 1, so as to increase the adhesion between the first connecting part 21 and the substrate 1, and between the second connecting part 22 and the substrate 1.

[0105] Exemplarily, the adhesive layer 3 can be ordinary glue, such as solvent-based glue, reactive adhesive, hot melt glue, etc., that is, before the interconnection bar 10 is connected to the external electrical structure, it may not be restricted by temperature. For example, high temperature can be used to achieve a good connection effect between the substrate 1 and the connecting part (the first connecting part 21 and the second connecting part 22). It can ensure the adhesion between the substrate 1 and the connecting part and prevent the connecting part from falling off. The high-temperature process can also be completed before the interconnection bar 10 is connected to the electrical structure. Similarly, the high-temperature process will not cause damage to the electrical structure, or affect the connection effect between the connecting part and the electrical structure. The connection part and the electrical structure are still bonded using pressure-sensitive properties.

[0106] The embodiment of the present application also provides a method for preparing the interconnection bar 10 .

[0107] Figure 5 This is a flow chart for preparing the interconnection bar 10 provided in an embodiment of the present application. This preparation method can prepare the interconnection bar 10 in the aforementioned embodiment.

[0108] See Figure 5 The preparation method comprises:

[0109] S1: Unwinding the substrate 1.

[0110] The substrate 1 is conductive and includes a first surface 1 a and a second surface 1 b facing each other.

[0111] For example, the thickness of the substrate 1 may be 3 μm to 500 μm.

[0112] S2: Forming the first connection portion 21 and the second connection portion 22 on the first surface 1 a and the second surface 1 b , respectively.

[0113] The first connection portion 21 and the second connection portion 22 both have electrical conductivity and pressure-sensitive adhesive properties.

[0114] For example, the first connecting portion 21 and the second connecting portion 22 can be formed simultaneously or in different steps. For example, the pressure-sensitive conductive adhesive can be applied to both sides of the substrate 1 simultaneously during the unwinding process of the substrate 1. Alternatively, as described in subsequent embodiments, the pressure-sensitive conductive adhesive can be applied separately.

[0115] For example, the coating of the first connection portion 21 and the second connection portion 22 may be achieved by using a blade coating or a gravure coating method.

[0116] S3: Rolling up the base body 1 provided with the first connecting portion 21 and the second connecting portion 22 .

[0117] The technical effects brought about by the method for preparing the interconnection bar 10 can be found in the technical effects brought about by the design of the interconnection bar 10 in the aforementioned embodiment, and will not be described in detail here.

[0118] Figure 6 A schematic diagram of a preparation process of the interconnection bar 10 provided in an embodiment of the present application.

[0119] In some embodiments, see Figure 6 , the aforementioned step S2 includes:

[0120] S21 : The first surface 1 a of the unrolled substrate 1 is passed through the adhesive coating structure W to form a first connecting portion 21 .

[0121] In this step, the material of the first connection portion 21 is placed in the glue-coated structure W, and the first surface 1 a faces the glue-coated structure W.

[0122] S22: The substrate 1 is rewound and unwound again, so that the positions of the first surface 1 a and the second surface 1 b are interchanged.

[0123] S23 : The second surface 1 b of the unwound substrate 1 (which now carries the first connecting portion 21 ) is passed through the glue coating structure W to form the second connecting portion 22 .

[0124] In this step, the material of the second connection portion 22 is placed in the glue-coated structure W, and the second surface 1 b faces the glue-coated structure W.

[0125] Exemplarily, the materials placed in the glue-coated structure W in step S21 and step S22 may be the same.

[0126] For example, before proceeding to step S1, the materials to be placed in the adhesive structure W can be prepared. For example, pre-mixing can be performed: for example, the pressure-sensitive adhesive materials, such as the base polymer, tackifying resin, plasticizer, and solvent, can be mixed using a planetary mixer or a high-speed disperser and stirred until a uniform adhesive solution is obtained. The conductive filler can then be added, for example, by adding the conductive filler in batches and using high-shear dispersion (e.g., a three-roll mill). During this process, a coupling agent (e.g., KH-550) can be used to pre-treat the surface of the conductive filler to enhance its bonding with the pressure-sensitive adhesive.

[0127] In some embodiments, see Figure 6 After forming the first connecting portion 21 and after forming the second connecting portion 22, the preparation method further includes:

[0128] S4: passing the substrate 1 provided with the first connecting portion 21 and / or the second connecting portion 22 through a hot drying tunnel.

[0129] This step can remove excess moisture from the first connecting part 21 and the second connecting part 22 coated on the substrate 1, or when the interconnection strip 10 includes an adhesive layer 3, this step can also allow temperature to act on the adhesive layer 3 to achieve high-strength bonding between the substrate 1 and the first connecting part 21 and the second connecting part 22.

[0130] Illustratively, the baking temperature in the hot drying tunnel is 50° C. to 300° C., and the baking time is 1 minute to 60 minutes.

[0131] For example, in any of the aforementioned winding steps, the provision of a protective layer can be simultaneously achieved so that the protective layer wraps around the first connecting portion 21 and the second connecting portion 22 on the side away from the substrate 1 to prevent both from being damaged or contaminated.

[0132] In some embodiments, see Figure 6 , the preparation method may further comprise:

[0133] S5: Slitting: Slitting the rolled structure into widths of 0.1-3 mm as required, ultimately forming interconnection strips 10 with pressure-sensitive conductive properties.

[0134] The embodiment of the present application further provides a solar cell 100, Figure 7 A three-dimensional diagram of a solar cell 100 provided in an embodiment of the present application. Figure 8 for Figure 7 The local enlarged view of the structure in circle C, Figure 9 for Figure 8 The local enlarged view of the structure in circle D in the figure, Figure 10 A cross-sectional view of a solar cell 100 provided in an embodiment of the present application is shown. Figure 11 for Figure 10 The local enlarged picture corresponding to the structure in circle E, Figure 12 for Figure 11 A local enlarged view of the structure corresponding to circle F in FIG.

[0135] See Figures 7 to 12 The solar cell 100 includes a plurality of cells 20 and a plurality of interconnecting bars 10 as in any embodiment of the first aspect.

[0136] For example, see Figure 7 The plurality of cells 20 may be arranged in an array, see Figure 8 and Figure 9 , two adjacent battery cells 20 are spaced apart to avoid unexpected electrical connection and electrical interference between the two adjacent battery cells 20.

[0137] For example, see Figure 10 , multiple cells 20 can be connected in series along a preset direction, see Figure 11 and Figure 12 , each two battery cells 20 can be interconnected (including physical and electrical connections) through an interconnection bar 10 .

[0138] For example, see Figure 11 and Figure 12 An interconnection bar 10 may include only one first connection portion 21 and one second connection portion, which are disposed on both sides of the substrate 1, so that the two battery cells 20 connected by the interconnection bar 10 can be disposed on both sides of the interconnection bar 10 to achieve series connection.

[0139] For example, see Figure 12 The portion of the base 1 in the interconnection bar 10 where the first connection portion 21 and the second connection portion 22 are not provided can be bent in an S-shape so that the two battery cells 20 connected by the interconnection bar 10 can share the same design space in the thickness direction, thereby making the obtained solar cell 100 in a sheet shape, which is convenient for heat dissipation and receiving solar energy.

[0140] Figure 13 A cross-sectional view of a battery cell 20 provided in an embodiment of the present application, and a structural material distribution diagram corresponding to the battery cell 20.

[0141] For example, see Figure 13 , the cell 20 can be a perovskite stacked cell.

[0142] See Figure 13 The perovskite stacked cell may include a core film layer: a perovskite layer, and an electron transport layer and a hole transport layer arranged on both sides of the perovskite layer facing each other.

[0143] For example, see Figure 13 The cell 20 may also include two electrodes (top TCO and silicon bottom cell) at both ends, as well as a buffer layer and a composite layer, which are in contact with the electron transport layer and the hole transport layer respectively, so as to optimize the transport effect of the electron transport layer and the hole transport layer.

[0144] For example, see Figure 12 and Figure 13 The battery cell 20 may further include a metal grid line, which covers the surface of the electrode and is used to realize external connection of the electrode. The metal grid lines of two adjacent battery cells 20 are interconnected through the aforementioned interconnection bar 10.

[0145] Related research has shown that rising temperatures can cause perovskite materials to decompose. The effect of temperature on perovskite stability varies depending on the testing environment of each laboratory, resulting in different specific temperature parameters. However, the overall conclusion is that at 100°C (within 30 minutes), MAPbI3 shows no obvious decay. At 140-200°C, XRD observation of perovskite shows a clear PbI2 peak, which is a typical characteristic of temperature perovskite decay. The temperature of the cell 20 during interconnection welding and packaging processes must be less than 120°C.

[0146] In addition, the perovskite stacked battery is also chemically sensitive. The I in the perovskite material - Iodide ions are reducing and easily oxidized. During the interconnection process of multiple battery cells 20 , if the connection material (eg, the interconnection bar 10 ) contains peroxide, it will affect the power generation of the battery cells 20 .

[0147] In the solar cell 100 provided in the embodiment of the present application, the interconnection of multiple battery cells 20 is achieved through the interconnection bar 10, so that the conductivity and pressure-sensitive adhesion of the first connecting part 21 and the second connecting part 22 in the interconnection bar 10 can be utilized to achieve the connection between the interconnection bar 10 and the battery cell 20 only by applying pressure, without the need to adopt a high-temperature process, thereby avoiding damage to the battery cell 20, especially the perovskite stacked battery cell 20, caused by the high-temperature environment, thereby ensuring the efficiency and service life of the solar cell 100.

[0148] In addition, in the embodiment of the present application, before the interconnecting bar 10 is connected to the battery cell 20, the first connecting portion 21 and the second connecting portion 22 have already achieved a cross-linking reaction with the substrate 1, so there is no peroxide residue. Therefore, when the interconnecting bar 10 is connected to the battery cell 20, the interconnecting bar 10 will not damage the perovskite in the battery cell 20, further extending the service life of the battery cell 20.

[0149] The present invention also provides a method for preparing a solar cell 100. Figure 14 This is a flow chart of the preparation of the solar cell 100 provided in an embodiment of the present application.

[0150] See Figure 14 , the preparation method may include:

[0151] K1: Laying multiple battery cells 20 and multiple interconnection bars 10 in series.

[0152] The interconnection bar 10 is placed at positions of two adjacent battery cells 20 that need to be electrically connected to the interconnection bar 10 .

[0153] K2: Performing a pressurization process to bond the interconnection bar 10 to two adjacent battery cells 20 .

[0154] Exemplarily, pressurizing refers to applying pressure, for example, so that the interconnection strip 10 is squeezed and thus has adhesion.

[0155] For example, the pressurization time may be 3 minutes to 15 minutes.

[0156] In the preparation method of the solar cell 100 provided in the embodiment of the present application, the conductivity and pressure-sensitive adhesion of the interconnection bar 10 are utilized, and the interconnection between the cell 20 and the interconnection bar 10 can be achieved by simply applying pressure (pressurization), without the need for high-temperature curing (for example, a curing process of 3 minutes to 5 minutes and 120°C to 140°C) to achieve the connection between the two, thereby avoiding problems such as damage to the cell 20 (especially the cell 20 made of perovskite material) caused by the high temperature environment during the interconnection of the cell 20, optimizing the efficiency of the solar cell 100 and extending its service life.

[0157] In addition, in the embodiment of the present application, the obtained interconnection bar 10 has both conductivity and pressure-sensitive adhesion, so the electrical connection between the interconnection bar 10 and the battery cell 20 can be achieved by directly physically connecting the interconnection bar 10 and the battery cell 20 without the need for additional gluing or glue alignment processing, thereby speeding up the preparation of solar cells.

[0158] For example, see Figure 14 The preparation method may further include battery sorting, battery string welding and subsequent steps, which are not limited in the embodiments of the present application.

[0159] The embodiment of the present application further provides a photovoltaic assembly 1000, Figure 15 A schematic structural diagram of a photovoltaic assembly 1000 provided in an embodiment of the present application.

[0160] See Figure 15 The photovoltaic module 1000 includes a packaging structure 200 and a plurality of solar cells 100 as described in the above embodiments. The plurality of solar cells 100 are electrically connected and packaged in the packaging structure 200.

[0161] Exemplarily, the photovoltaic component 1000 can be a small power supply, a household rooftop grid-connected power generation system, a photovoltaic water pump, power supply equipment in the transportation field, power supply equipment in the communications field, power supply equipment in the petroleum, marine and meteorological fields, a household lighting power supply, a photovoltaic power station, a solar car / electric car, a battery charging device, a car air conditioner, a ventilation fan, a cold drink box, a solar hydrogen production and fuel cell regenerative power generation system, seawater desalination power supply equipment, and satellites, spacecraft, space solar power stations, etc. The embodiments of the present application do not limit the specific form of the photovoltaic power generation equipment.

[0162] The above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that a person skilled in the art can conceive within the technical scope disclosed in this disclosure should be included within the scope of protection of the present application. Therefore, the scope of protection of the present application should be based on the scope of protection of the claims.

Claims

1. An interconnection strip, characterized in that: include: A substrate having electrical conductivity; the substrate includes a first surface and a second surface facing each other; A first connecting portion and a second connecting portion are respectively provided on the first surface and the second surface; Wherein, both the first connecting portion and the second connecting portion have electrical conductivity and pressure-sensitive adhesive properties.

2. The interconnection strip according to claim 1, characterized in that: The first connecting portion includes a plurality of first sub-portions, and the second connecting portion includes a plurality of second sub-portions; along the extension direction of the base body, two adjacent first sub-portions are spaced apart, and two adjacent second sub-portions are spaced apart; Wherein, along the extension direction of the base body, the plurality of first sub-sections and the plurality of second sub-sections are alternately arranged in sequence, and there is a gap between the adjacently arranged first sub-sections and second sub-sections in the extension direction of the base body.

3. The interconnection strip according to claim 2, characterized in that: The first subsection and the second subsection each include a plurality of components, and adjacent components are spaced apart from each other. The spacing between the adjacent components is smaller than the spacing between two adjacent first subsections or two adjacent second subsections.

4. The interconnection strip according to claim 3, characterized in that: The plurality of components are sequentially arranged at intervals along the extending direction of the base.

5. The interconnection strip according to claim 1, characterized in that: The first connecting portion and the second connecting portion both extend along an extension direction of the base body, and the first connecting portion covers the first surface, while the second connecting portion covers the second surface.

6. The interconnection strip according to claim 1, characterized in that: The first connecting portion and the second connecting portion both include pressure-sensitive adhesive and conductive filler, and the conductive filler is mixed with the pressure-sensitive adhesive.

7. The interconnection strip according to claim 6, characterized in that: The pressure-sensitive adhesive accounts for 40% to 60%, and the conductive filler accounts for 20% to 40%.

8. The interconnection strip according to claim 1, characterized in that: The thickness of the first connecting portion and the second connecting portion are both 3 μm to 100 μm.

9. The interconnection strip according to claim 1, characterized in that: The width of the first connecting portion and the second connecting portion are both 0.1 mm to 3 mm.

10. The interconnection strip according to claim 1, characterized in that: Also includes: The adhesive layer is provided between the first connection portion and the base, and between the second connection portion and the base, and has adhesiveness.

11. A method for preparing an interconnection strip, characterized in that: include: Unwinding the substrate; The substrate is conductive; the substrate includes a first surface and a second surface facing each other; forming a first connecting portion and a second connecting portion on the first surface and the second surface respectively; the first connecting portion and the second connecting portion both have electrical conductivity and pressure-sensitive adhesive properties; The base body provided with the first connecting portion and the second connecting portion is rolled up.

12. The preparation method according to claim 11, characterized in that The forming of the first connecting portion and the second connecting portion on the first surface and the second surface respectively comprises: The first surface of the unwound substrate passes through a gluing structure to form the first connecting portion; the material of the first connecting portion is placed in the gluing structure, with the first surface facing the gluing structure; Rewinding and unwinding the substrate so that the positions of the first surface and the second surface are interchanged; The second surface of the substrate after re-unwinding is passed through a glue coating structure to form the second connecting portion; the material of the second connecting portion is placed in the glue coating structure, and the second surface faces the glue coating structure.

13. The preparation method according to claim 12, characterized in that After forming the first connection portion and after forming the second connection portion, the method further includes: The base body provided with the first connecting portion and / or the second connecting portion is passed through a hot drying tunnel.

14. The preparation method according to claim 13, characterized in that The baking temperature in the hot baking tunnel is 50° C. to 300° C., and the baking time is 1 minute to 60 minutes.

15. A solar cell, characterized in that: include: A plurality of interconnecting strips according to any one of claims 1 to 10; Two adjacent battery cells are electrically connected via the interconnection bar.

16. A method for preparing a solar cell, characterized in that: include: Laying a plurality of battery cells and a plurality of interconnection bars in a string; placing the interconnection bars at positions where two adjacent battery cells need to be electrically connected to the interconnection bars; A pressurizing process is performed to bond the interconnection strip to two adjacent battery cells.

17. A photovoltaic module, characterized in that: include: A plurality of solar cells according to claim 15, wherein the plurality of solar cells are electrically connected; A packaging structure, wherein the plurality of solar cells are packaged in the packaging structure.

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