Back-contact batteries, battery modules, and photovoltaic systems

Abstract

This application is applicable to the field of solar cell technology and provides a back-contact battery (100), a battery module, and a photovoltaic power generation system. The back-contact battery (100) includes a battery substrate (10) and a first insulating member (21), wherein two types of subgrids of intersecting polarity are formed on the back surface of the battery substrate (10), and the back surface includes intersecting confluence areas (13) and non-confluence areas (14); the first insulating member (21) is provided continuously along the extending direction of the confluence area (13) at the edge of the non-confluence area (14) and covers the portion of the subgrid of the non-confluence area (14) that is close to the confluence area (13).

Description

Cross-reference of related applications

[0001] This application was filed with the State Intellectual Property Administration of China on May 22, 2023, with application number 2023105805203, claiming priority to a Chinese patent application titled "Back Contact Battery, Battery Module and Photovoltaic Power Generation System," the entire contents of which are incorporated into this application by reference. [Technical Field]

[0002] This application relates to the field of solar cell technology, and more specifically to back-contact batteries, battery modules, and photovoltaic power generation systems. [Background technology]

[0003] Solar cell power generation is one of the sustainable and clean energy sources, and it can convert sunlight into electrical energy by utilizing the photovoltaic effect of semiconductor pn junctions.

[0004] In back-contact batteries, a related technology, sub-grids with two different polarities are distributed in an intersecting manner. When the sub-grids are merged using busbars, the sub-grids are more likely to conduct electricity with busbars of the opposite polarity, which can cause a short circuit. [Overview of the project] [Problems that the invention aims to solve]

[0005] Reducing the risk of short circuits in back-contact batteries is an urgent issue that needs to be addressed. [Means for solving the problem]

[0006] This application provides a back-contact battery, a battery module, and a photovoltaic power generation system to solve the problem of how to reduce the risk of short circuits in back-contact batteries.

[0007] The back contact battery provided in this application includes a battery substrate and a first insulating member, wherein two types of subgrids of polarity are formed on the back surface of the battery substrate, and the back surface includes a converging area and a non-converging area, which are also distributed in an intersecting manner; the first insulating member is provided continuously along the edge of the non-converging area and along the direction of extension of the converging area, and covers the portion of the subgrid of the non-converging area that is close to the converging area.

[0008] The battery module provided in this application includes any of the back-contact batteries described above.

[0009] The photovoltaic power generation system provided in this application includes the above-mentioned battery module. [Effects of the Invention]

[0010] In the embodiment of this application, the back contact battery, battery module, and photovoltaic power generation system are provided with the first insulating member continuously along the extending direction of the converging area at the edge of the non-converging area, covering the portion of the subgrid in the non-converging area that is close to the converging area. This prevents the subgrid from making contact with a busbar of opposite polarity at the edge of the non-converging area that is close to the converging area, ensuring the normal operation of the back contact battery and reducing the risk of short circuits in the back contact battery. [Brief explanation of the drawing]

[0011] [Figure 1] This is a schematic diagram of the structure of a back-contact battery according to one embodiment of the present application. [Figure 2] This is a schematic diagram of the structure of the battery substrate of a back-contact battery according to one embodiment of this application. [Figure 3] This is a schematic diagram of the structure of a portion of a back contact battery according to one embodiment of the present application. [Figure 4] This is a schematic diagram of the structure of a portion of a back contact battery according to one embodiment of the present application. [Figure 5] This is a schematic diagram of the structure of a portion of a back contact battery according to one embodiment of the present application. [Figure 6]It is a structural schematic diagram of a partial area of a back-contact battery according to an embodiment of the present application. [Figure 7] It is a structural schematic diagram of a partial area of a back-contact battery according to an embodiment of the present application. [Figure 8] It is a structural schematic diagram of a partial area of a back-contact battery according to an embodiment of the present application. [Figure 9] It is a structural schematic diagram of a partial area of a back-contact battery according to an embodiment of the present application. [Figure 10] It is a structural schematic diagram of a back-contact battery according to an embodiment of the present application. [Figure 11] It is a structural schematic diagram of a back-contact battery according to an embodiment of the present application. [Figure 12] It is a structural schematic diagram of a back-contact battery according to an embodiment of the present application.

Embodiments for Carrying out the Invention

[0012] To make the objectives, technical solutions, and advantages of the present application clearer, the present application will be described in more detail below with reference to the drawings and embodiments. The above embodiments are shown in the drawings, and the same or similar reference numerals throughout the drawings indicate the same or similar elements, or elements having the same or similar functions. It should be understood that the embodiments described below with reference to the drawings are exemplary only and are merely for the purpose of interpreting the present application and not intended to limit the present application. Also, it should be understood that the specific embodiments described herein are merely for the purpose of interpreting the present application and not for the purpose of limiting the present application.

[0013] In the description of the present application, the orientation or positional relationship indicated by terms such as "length", "width", "upper", "lower", "left", "right", "horizontal", "top", "bottom", etc. is the orientation or positional relationship based on the drawings, and is merely for facilitating the description of the present application and simplifying the description, and does not indicate or imply that the indicated device or element must have a specific orientation and be configured and operated in a specific orientation. Therefore, it should not be understood as a limitation to the present application.

[0014] Furthermore, the terms “first” and “second” are used solely for descriptive purposes and should not be understood as indicating or implying relative importance, or implicitly indicating the number of technical features being referred to. Thus, features limited by “first” and “second” may explicitly or implicitly include one or more of the aforementioned features. In the description of this application, unless otherwise clearly and specifically defined, “multiple” refers to two or more.

[0015] In the description of this application, unless explicitly stated or limited, the terms “attachment,” “connection,” and “connection” should be interpreted broadly, for example, meaning that connections may be fixed, detachably connected, or integrally connected; mechanically connected, electrically connected, or communicating with each other; directly connected, indirectly connected via an intermediary, or internal communication between two elements or an interaction relationship between two elements. Those skilled in the art will be able to understand the specific meaning of the above terms in this application depending on the specific case.

[0016] In this application, unless otherwise explicitly stated and limited, the description of a first feature being "above" or "below" a second feature includes cases where the first and second features are in direct contact, and cases where they are in contact via another feature between them without direct contact. Furthermore, the description of a first feature being "above," "above," and "above" a second feature includes cases where the first feature is directly above or diagonally above the second feature, or simply where the horizontal height of the first feature is greater than that of the second feature. The description of a first feature being "below," "below," and "below" a second feature includes cases where the first feature is directly below or diagonally below the second feature, or simply where the horizontal height of the first feature is lower than that of the second feature.

[0017] The following disclosure provides many different examples or embodiments for realizing the different structures of this application. To simplify the disclosure of this application, the components and installations in specific examples are described below. Of course, these are merely examples and are not intended to limit this application. Furthermore, for the sake of simplification and clarity, this application may repeatedly use reference figures and / or reference letters in different examples, and these themselves do not indicate relationships between the various embodiments and / or installations discussed. Furthermore, while this application provides examples of various specific processes and materials, those skilled in the art will be able to recognize the application of other processes and / or usage scenarios for other materials. [Examples]

[0018] Referring to Figures 1, 2, and 3, the back contact battery 100 according to an embodiment of the present application includes a battery substrate 10 and a first insulating member 21, wherein two types of subgrids of polarity are formed on the back surface of the battery substrate 10 and the back surface includes a confluence area 13 and a non-confluence area 14 that are distributed in an intersecting manner; the first insulating member 21 is provided continuously along the extending direction of the confluence area 13 at the edge of the non-confluence area 14 and covers the portion of the subgrid of the non-confluence area 14 that is close to the confluence area 13.

[0019] In the embodiment of the present application, the back contact battery 100 has a first insulating member 21 that is continuously provided along the extending direction of the merging area 13 at the edge of the non-merging area 14, and covers the portion of the subgrid of the non-merging area 14 that is close to the merging area 13. This prevents the subgrid from making contact with a busbar of opposite polarity at the edge of the non-merging area 14 that is close to the merging area 13, thereby ensuring the normal operation of the back contact battery 100 and reducing the risk of short circuits in the back contact battery 100.

[0020] Furthermore, when multiple back contact batteries 100 are stacked, the first insulating member 21 prevents the subgrid from damaging other back contact batteries 100 in the area covered by the first insulating member 21. Also, since the first insulating member 21 has a certain thickness, a gap can be formed between the area not covered by the first insulating member 21 and other back contact batteries 100, thereby preventing the subgrid from damaging other back contact batteries 100 in the area not covered by the first insulating member 21. As a result, when back contact batteries 100 are stacked, damage to the back contact batteries 100 can be reduced, the separator paper provided between two adjacent back contact batteries 100 can be omitted, and the transportation and storage costs of the back contact batteries 100 can be reduced.

[0021] Optionally, the back contact battery 100 may be a single battery cell, or it may be a half-cell, a one-third cell, or a battery cell of other proportions obtained by dividing a single battery cell. For clarity in the drawings, the back contact battery 100 shown in Figures 1 and 2 is a half-cell obtained by dividing a single battery cell. The forms of back contact batteries 100 of other proportions are similar to those in Figures 1 and 2, and can be referred to; a detailed explanation is omitted here. Figures 3 to 9 show only parts of the back contact battery 100; other parts of the back contact battery 100 are similar to those in Figures 3 to 9, and can be referred to; a detailed explanation is omitted here. In other words, the drawings are merely examples and do not limit the specific form of the back contact battery 100.

[0022] Optionally, two types of sub-grids with alternating polarities are formed on the back surface of the battery substrate 10, which are the first sub-grid 111 and the second sub-grid 121, respectively.

[0023] Optionally, the battery substrate 10 has a front and back surface facing each other, the front surface facing the sun and mainly receiving direct sunlight, and the back surface facing the mounting surface of the battery module and mainly receiving sunlight reflected from the mounting surface, which is, for example, the ground or a roof. Alternatively, the back surface is the surface on which the grid lines of the back contact battery 100 are provided.

[0024] Arbitrarily, an intersecting distribution means that one second sub-grid 121 is placed between two adjacent first sub-grids 111, and one first sub-grid 111 is placed between two adjacent second sub-grids 121. Arbitrarily, one of the first sub-grids 111 and the second sub-grids 121 is a positive sub-grid, and the other of the first sub-grids 111 and the second sub-grids 121 is a negative sub-grid.

[0025] Optionally, the reverse side includes intersecting confluence zones 13 and non-confluence zones 14. In other words, one non-confluence zone 14 is formed between two adjacent confluence zones 13, and one confluence zone 13 is formed between two adjacent non-confluence zones 14.

[0026] Optionally, the orientation in which the confluence zone 13 and non-confluence zone 14 are distributed intersectingly is perpendicular to the orientation in which the first sub-grid 111 and second sub-grid 121 are distributed intersectingly. In other embodiments, the orientation in which the confluence zone 13 and non-confluence zone 14 are distributed intersectingly and the orientation in which the first sub-grid 111 and second sub-grid 121 are distributed intersectingly may be at an angle, and this is not limited here.

[0027] 13 can be arbitrarily divided into two polarities: a first confluence area and a second confluence area, which are distributed in an intersecting manner. In other words, one second confluence area is formed between two adjacent first confluence areas, and one first confluence area is formed between two adjacent second confluence areas. 13 can be arbitrarily divided into positive and negative confluence areas, and one of the first and second confluence areas is negative confluence area.

[0028] Optionally, the orientation in which the first and second confluence areas are distributed intersectingly is perpendicular to the orientation in which the first sub-grid 111 and the second sub-grid 121 are distributed intersectingly. In other embodiments, the orientation in which the first and second confluence areas are distributed intersectingly and the orientation in which the first sub-grid 111 and the second sub-grid 121 are distributed intersecting may be at an angle, and this is not limited here.

[0029] In the examples shown in Figures 1, 2, and 3, a first main grid 112 and a second main grid 122 are formed in the first and second confluence areas, respectively. In other words, in the examples shown in Figures 1, 2, and 3, subgrids of the same polarity are confluenced by main grids of the same polarity. Optionally, one of the first main grid 112 and the second main grid 122 is a positive-electrode main grid, and the other is a negative-electrode main grid.

[0030] In other embodiments, the first and second merging areas may be used to install the first and second series connecting members, respectively. That is, it is understood that sub-grids of the same polarity are merged by series connecting members of the same polarity. In other embodiments, some merging areas 13 are merged by the main grid, and the remaining merging areas 13 are merged by series connecting members. The specific form of sub-grid merging is not limited here.

[0031] The series connection member is a conductor that connects the back contact batteries 100 in series to form a battery string. The series connection member is, for example ba guide These include electric wires, conductive sheets, conductive plates, etc. In this application, a series connection member is used. While examples have been given to illustrate this point, the series connecting members of this application are not limited to these.

[0032] Referring to Figures 1 and 3, the first insulating member 21 is provided continuously along the edge of the non-merging area 14, along the extending direction of the merging area 13, and covers the portion of the subgrid of the non-merging area 14 that is close to the merging area 13. As a result, the portion of the subgrid close to the merging area 13 is covered by the first insulating member 21, regardless of whether it has the same polarity as or opposite to the polarity of the merging area 13, thereby minimizing the risk of short-circuiting the back contact battery 100. Furthermore, when installing the first insulating member 21, it is not necessary to consider the polarity of the subgrid and the merging area 13, which is advantageous in improving the installation efficiency of the first insulating member 21. In addition, because the first insulating member 21 provides continuous coverage, it is not necessary to avoid subgrids with the same polarity as the merging area 13, making the installation process of the first insulating member 21 simpler and also advantageous in improving the installation efficiency of the first insulating member 21.

[0033] As described above, the confluence zone 13 and the non-confluence zone 14 are distributed in an intersecting manner. Therefore, in the statement "the first insulating member 21 is provided continuously along the extending direction of the confluence zone 13 at the edge of the non-confluence zone 14," "edge" refers to the edge of the non-confluence zone 14 that is close to the confluence zone 13. In the statement "the first insulating member 21 is provided continuously along the extending direction of the confluence zone 13 at the edge of the non-confluence zone 14," "extending direction" refers to the direction of the boundary line between the non-confluence zone 14 and the confluence zone 13. In the statement "the first insulating member 21 is provided continuously along the extending direction of the confluence zone 13 at the edge of the non-confluence zone 14," "provided continuously" means that the first insulating member 21 is not interrupted.

[0034] In other words, the first insulating member 21 is continuously provided along the edge of the non-merging area 14 closest to the merging area 13, in the direction of the boundary line between the non-merging area 14 and the merging area 13.

[0035] Referring to Figures 1 and 3, the portion of the subgrid of the non-merging area 14 of the first insulating member 21 that is close to the merging area 13 is covered, and the covered portion consists of subgrids of two different polarities. In other embodiments, only subgrids of the same polarity as the merging area 13 are formed at the edge of the non-merging area 14 that is close to the merging area 13, and subgrids of the opposite polarity to the merging area 13 are not required to be formed. In this case, it is understood that the first insulating member 21 covers the portion of the subgrid of the non-merging area 14 that is close to the merging area 13, and the covered portion consists of subgrids of the same polarity as the merging area 13. Here, the specific polarity and number of polarities of the subgrids covered by the first insulating member 21 are not limited.

[0036] Referring to Figures 1 and 3, the outer edge of the first insulating member 21 is straight or broken. In other embodiments, it will be understood that the outer edge of the first insulating member 21 may be curved. Hereinafter, the specific form of the outer edge of the first insulating member 21 is not limited. [Examples]

[0037] In some arbitrary embodiments, the thickness of the first insulating member 21 is 10 μm to 50 μm. For example, 10 μm, 12 μm, 15 μm, 17 μm, 20 μm, 25 μm, 28 μm, 30 μm, 35 μm, 40 μm, 42 μm, 45 μm, 49 μm, and 50 μm.

[0038] This ensures that the thickness of the first insulating member 21 is within an appropriate range, avoiding a decrease in insulating effect due to insufficient thickness, and also avoiding material waste and increased costs due to excessive thickness.

[0039] Preferably, the thickness of the first insulating member 21 is 20 μm to 30 μm. This maximizes the overall effect of insulation and energy saving.

[0040] The thickness of the first insulating member 21 may be a constant value within the range of 10 μm to 50 μm, or it may vary within the range of 10 μm to 50 μm. [Examples]

[0041] Referring to Figure 3, in some arbitrary embodiments, the width w at the edge of the non-converging area 14 of the first insulating member 21 is 100 μm to 1000 μm. For example, 100 μm, 102 μm, 110 μm, 200 μm, 250 μm, 300 μm, 400 μm, 500 μm, 600 μm, 900 μm, 990 μm, and 1000 μm.

[0042] This ensures that the width of the first insulating member 21 at the edge of the non-merging area 14 is within an appropriate range, avoiding a decrease in insulating effect due to an insufficient width and an increased risk of short-circuiting the back contact battery 100, as well as avoiding material waste and increased costs due to an insufficient width.

[0043] Preferably, the width w of the first insulating member 21 at the edge of the non-merging area 14 is 400 μm to 600 μm. This maximizes the overall effect of insulation and energy saving.

[0044] Furthermore, the width w at the edge of the non-converging area 14 of the first insulating member 21 may be a constant value within the range of 100 μm to 1000 μm, or it may vary within the range of 100 μm to 1000 μm. [Examples]

[0045] Referring to Figure 3, in some arbitrary embodiments, a main grid is formed on the back surface, and the main grid is located in the confluence area 13 and is exposed from the first insulating member 21. "Exposure" means that the orthographic projection of the main grid onto the battery substrate does not overlap with the orthographic projection of the first insulating member onto the battery substrate.

[0046] This makes it easier to draw current from the back contact battery 100 by merging the sub-grid with the main grid. In addition, the main grid is exposed from the first insulating member 21 and is not obstructed by the first insulating member 21, which facilitates the formation of a battery string by connecting it with the series connecting member.

[0047] Optionally, two types of polarity main grids are formed on the reverse side, distributed in an intersecting manner, namely the first main grid 112 and the second main grid 122, and two types of polarity sub-grids, namely the first sub-grid 111 and the second sub-grid 121, are joined to each other. Optionally, "distributed in an intersecting manner" means that one second main grid 122 is provided between two adjacent first main grids 112, and one first main grid 112 is provided between two adjacent second main grids 122. Optionally, one of the first main grids 112 and the second main grids 122 is the positive electrode main grid, and the other of the first main grids 112 and the second main grids 122 is the negative electrode main grid.

[0048] In other embodiments, two types of main grids of polarity may be formed on the back surface, with some sub-grids of the corresponding polarity being joined to each, and the remaining sub-grids being joined by a series connecting member; in other embodiments, one type of main grid of polarity may be formed on the back surface, with sub-grids of this polarity being joined to each, and the sub-grids of the other polarity being joined by a series connecting member. Herein, the specific form of joining of sub-grids by the main grid is not limited. [Examples]

[0049] Referring to Figure 1, in some arbitrary embodiments, the ratio of the covering area of ​​the first insulating member 21 to the total area of ​​the back contact battery 100 is 10% to 20%. For example, 10%, 11%, 15%, 18%, and 20%.

[0050] This ensures that the ratio of the covering area of ​​the first insulating member 21 to the total area of ​​the back contact battery 100 is within an appropriate range, avoiding the increased risk of short circuits in the back contact battery 100 due to a ratio that is too small, and also avoiding material waste and increased costs due to a ratio that is too large. Preferably, the ratio of the covering area of ​​the first insulating member 21 to the total area of ​​the back contact battery 100 is 15%. This provides the greatest overall effect in insulation and energy saving. [Examples]

[0051] Referring to Figure 4, in some arbitrary embodiments, the back-contact battery 100 is a main grid-free battery, where a portion of each sub-grid is located in a merging area 13, the remainder of each sub-grid is located in a non-merging area 14, the merging area 13 is used to install series connection members, and each series connection member has a corresponding merging area 13 with a sub-grid of the same polarity exposed.

[0052] As a result, the back contact battery 100 does not have a main grid, and the sub-grids are merged by a series connecting member, eliminating the slurry of the main grid and thus contributing to cost reduction.

[0053] Optionally, there are two types of polarity for the series connection members, and each is used to merge sub-grids with the same polarity.

[0054] Optionally, the series connection member is a conductor that connects back contact batteries 100 in series to form a battery string. The series connection member is, for example ba guide These include electric wires, conductive sheets, conductive plates, etc. In this application, a series connection member is used. While examples have been given to illustrate this point, the series connecting members of this application are not limited to these. [Examples]

[0055] Referring to Figure 4, in some arbitrary embodiments, the confluence area 13 is provided with a sub-grid of one polarity, and the confluence area 13 is fully exposed from the first insulating member 21. "Exposure" means that the orthographic projection of the confluence area onto the battery substrate does not overlap with the orthographic projection of the first insulating member onto the battery substrate.

[0056] This eliminates the need to separate the series connection member from the sub-grid with a different polarity, allowing the series connection member to be installed directly in the merging area 13, which is advantageous for improving production efficiency and reducing costs. [Examples]

[0057] Referring to Figure 5, in some arbitrary embodiments, the confluence area 13 is provided with sub-grids of two different polarities, and the back contact battery 100 includes a second insulating member 22, which covers the confluence area 13 with sub-grids of opposite polarity to the corresponding series connection members.

[0058] This allows the sub-grid of one polarity to be blocked in the merging area 13, while the sub-grid of the other polarity is exposed and connected to the series connection member for merging, thereby reducing the risk of short circuits in the battery string.

[0059] Optionally, the second insulating member 22 completely covers the sub-grid with opposite polarity to the corresponding series connection member in the merging area 13. This ensures that the sub-grid with opposite polarity to the series connection member is not exposed in the merging area 13, minimizing the risk of short circuits.

[0060] While the series connecting members themselves do not possess polarity, the sub-grids into which the series connecting members merge do possess polarity. Therefore, it is understood that the polarity of the series connecting members refers to the polarity of the sub-grids into which the series connecting members merge. [Examples]

[0061] Referring to Figure 5, in some arbitrary embodiments, the ratio of the total covering area of ​​the first insulating member 21 and the second insulating member 22 to the total area of ​​the back contact battery 100 is 5% to 15%. For example, 5%, 6%, 8%, 10%, 11%, 13%, and 15%.

[0062] This ensures that the ratio of the total covering area of ​​the first insulating member 21 and the second insulating member 22 to the total area of ​​the back contact battery 100 is within an appropriate range. This avoids the risk of short-circuiting the back contact battery 100 due to a ratio that is too small, which would result in a smaller total covering area of ​​the first insulating member 21 and the second insulating member 22. It also avoids the waste of materials and increased costs caused by a ratio that is too large.

[0063] Preferably, the ratio of the total covering area of ​​the first insulating member 21 and the second insulating member 22 to the total area of ​​the back contact battery 100 is 10%. This maximizes the overall effect of insulation and energy saving.

[0064] Referring to Figure 6, in some arbitrary embodiments, the battery substrate 10 has an electrical connection area 101 for series-connected members and an electrical connection area 102 for non-series-connected members, and the back-contact battery 100 includes a displacement limiting member 24, which is connected to a first insulating member 21 and surrounds the electrical connection area 101 for series-connected members.

[0065] This prevents the conductive material from flowing from the electrical connection region 101 of the series connection member onto the sub-grid of the opposite polarity of the series connection member, thereby avoiding conduction between the series connection member and the sub-grid of the opposite polarity and reducing the risk of short circuits in the back contact battery 100. It also prevents the conductive material from flowing from the electrical connection region 101 of the series connection member onto the sub-grid of the same polarity as the series connection member, thus avoiding a decrease in the height of the conductive material and thus avoiding connection failures.

[0066] Optionally, the electrical connection region 101 of the series connecting member includes the electrical connection region 1120 of the first series connecting member and the electrical connection region 1220 of the second series connecting member, which have opposite polarity. The polarity of the electrical connection region 1120 of the first series connecting member is the same as that of the first sub-grid 111, and the polarity of the electrical connection region 1220 of the second series connecting member is the same as that of the second sub-grid 121.

[0067] Optionally, the displacement limiting member 24 may be an insulating material. This allows the displacement limiting member 24 to perform both displacement limiting and insulation, thereby reducing the risk of short circuits.

[0068] In the example of FIG. 6, a main grid is formed on the back surface of the battery substrate 10, and an electrical connection region 101 of a series connection member and an electrical connection region 102 of a non-series connection member are formed on the main grid. The electrical connection region 101 of the series connection member is an area where the main grid and the series connection member are electrically connected.

[0069] Optionally, the electrical connection region 101 of the series connection member includes a pad section and / or a conductive adhesive section. Optionally, a conductive material may be installed in the pad section. The conductive material is, for example, solder such as tin paste. Optionally, a conductive adhesive may be installed in the conductive adhesive section. In other words, the electrical connection region 101 of the series connection member of the main grid may connect the series connection member by welding; may electrically adhesively connect the series connection member by a conductive adhesive; or may connect the series connection member by the adhesion of welding and a conductive adhesive.

[0070] Optionally, the area of the electrical connection region 101 of the series connection member is 2 mm 2 ~6 mm 2 . For example, 2 mm 2 , 3 mm 2 , 3.75 mm 2 , 4 mm 2 , 5 mm 2 , 6 mm 2 . Thereby, the area of the electrical connection region 101 of the series connection member is within an appropriate range, and it is possible to avoid the destabilization of the connection between the back contact battery 100 and the series connection member due to the area being too small, and it is also possible to avoid the waste of conductive materials and the reduction of the insulation effect due to the area being too large. Preferably, the area of the electrical connection region 101 of the series connection member is 3.75 mm 2 . It is rectangular, with a width of 1.5 mm and a length of 2.5 mm. Thereby, it is possible to achieve both the connection between the back contact battery 100 and the series connection member, the saving of conductive materials, and insulation, and the overall effect is the best.

[0071] The number of electrical connection areas 101 of the series connection member can be arbitrarily between 30 and 300. For example, 30, 40, 50, 100, 120, 150, 200, 280, or 300. This ensures that the number of electrical connection areas 101 of the series connection member is within an appropriate range, avoiding instability in the connection between the back contact battery 100 and the series connection member due to too few connection areas, and avoiding low efficiency and high costs due to too many connection areas.

[0072] The range of 30 to 300 corresponds to the case where the back contact battery 100 is a single battery cell. When the back contact battery 100 is a half cell, a one-third cell, or a battery cell of other proportions obtained by dividing a single battery cell, it is understood that the number of electrical connection areas 101 of the series connection member can be determined based on the division ratio and the range of 30 to 300. For example, when the back contact battery 100 is a half cell obtained by dividing a single battery cell, the number of electrical connection areas 101 of the series connection member is 15 to 150.

[0073] In other examples, the back-contact battery 100 may be a main grid-free battery, and the back surface of the back-contact battery 100 includes an electrical connection area 101 of the series connection member and an electrical connection area 102 of the non-series connection member, with a portion of each sub-grid located in the electrical connection area 101 of the series connection member and the remainder of each sub-grid located in the electrical connection area 102 of the non-series connection member, and the electrical connection area 101 of the series connection member being the area where the sub-grids and the series connection member are electrically connected. Thus, the sub-grids of the main grid-free battery are joined by the series connection member. Regardless of whether the back-contact battery 100 has a grid or not, it is understood that it can be connected by the series connection member to form a battery string, and the displacement limiting member 24, together with the first insulating member 21, can surround the electrical connection area 101 of the series connection member, thereby preventing conductive material from flowing from the electrical connection area 101 of the series connection member to the opposite polarity sub-grids of the series connection member.

[0074] Optionally, the width of the electrical connection area 101 of the series connection member may be greater than or equal to the distance between the electrical connection areas 102 of the non-series connection members of the first insulating members 21 on both sides. This increases the area of ​​the electrical connection area 101 of the series connection member, allowing more conductive material to be provided, thereby connecting the back contact battery 100 to the series connection part Material and The connection becomes more stable. In other embodiments, the width of the electrical connection area 101 of the series connection member may be smaller than the distance between the first insulating members 21 on both sides in the electrical connection area 102 of the non-series connection member.

[0075] Optionally, the area of ​​the electrical connection region 101 of the series connection members is 0.02 mm². 2 ~0.6mm 2 For example, 0.02 mm 2 , 0.03mm 2 , 0.375mm 2 , 0.4mm 2 , 0.5mm 2 , 0.6mm 2 This ensures that the area of ​​the electrical connection region 101 of the series connection member is within an appropriate range, avoiding instability in the connection between the back contact battery 100 and the series connection member due to an area that is too small, and also avoiding wasted conductive material and reduced insulation effect due to an area that is too large. Preferably, the area of ​​the electrical connection region 101 of the series connection member is 0.375 mm². 2 It has a rectangular shape, with a width of 0.15 mm and a length of 0.25 mm. This allows for the connection of the back contact battery 100 to the series connection member, saving conductive material and providing insulation, resulting in the best overall effect.

[0076] The number of electrical connection areas 101 of the series connection member can be arbitrarily between 1,000 and 4,000. For example, 1,000, 1,500, 2,000, 2,500, 3,000, 3,500, 3,800, or 4,000. This ensures that the number of electrical connection areas 101 of the series connection member is within an appropriate range, avoiding instability in the connection between the back contact battery 100 and the series connection member due to too few connection areas, and avoiding low efficiency and high costs due to too many connection areas.

[0077] The range of 1,000 to 4,000 corresponds to the case where the back contact battery 100 is a single battery cell. When the back contact battery 100 is a half cell, a one-third cell, or a battery cell of other proportions obtained by dividing a single battery cell, it is understood that the number of electrical connection areas 101 of the series connection member can be determined based on the division ratio and the range of 1,000 to 4,000. For example, when the back contact battery 100 is a half cell obtained by dividing a single battery cell, the number of electrical connection areas 101 of the series connection member is 500 to 2,000. [Examples]

[0078] Referring to Figures 7, 8, and 9, in some arbitrary embodiments, the back contact battery 100 includes a third insulating member 23 which is provided in a non-merging area 14, continuously from the first insulating member 21 along the direction of extension of the subgrid, and at least partially covers the subgrid which is opposite in polarity to the corresponding merging area 13.

[0079] This prevents electrical conductivity between the sub-grid covered by the third insulating member 23 and the adjacent sub-grid of the opposite polarity via conductive foreign matter such as tin slag, thereby reducing the risk of short-circuiting the back contact battery 100. Furthermore, even if the busbar shifts and comes into contact with the sub-grid covered by the third insulating member 23, it will not make electrical conductivity with the sub-grid of the opposite polarity covered by the third insulating member 23, further reducing the risk of short-circuiting the back contact battery 100.

[0080] Optionally, "extension direction of the subgrid" refers to the longitudinal direction of the subgrid. "Provided continuously" means that the third insulating member 23 is not interrupted. That is, the third insulating member 23 is provided continuously in the non-merging area 14, along the longitudinal direction of the subgrid from the first insulating member 21.

[0081] Optionally, "at least partially" means part or all. In other words, the third insulating member 23 covers either a portion of the subgrid with opposite polarity to the corresponding merging area 13 in the non-merging area 14, or covers all of the subgrid with opposite polarity to the corresponding merging area 13. [Examples]

[0082] Referring to Figures 7, 8, and 9, in some arbitrary embodiments, the ratio of the sum of the lengths of the third insulating member 23 corresponding to two adjacent subgrids to the spacing of the first insulating member 21 at both ends of the non-merging area 14 is 150% or less. For example, 150%, 145%, 140%, 100%, 90%, 50%, 10%, 5%, 1%, and 0.1%.

[0083] This ensures that the ratio of the sum of the lengths of the third insulating members 23 corresponding to two adjacent subgrids to the spacing of the first insulating members 21 at both ends of the non-merging area 14 is within an appropriate range, reducing the risk of short circuits and avoiding material waste and increased costs due to an excessively large ratio. This is advantageous in reducing the risk of short circuits and lowering costs.

[0084] Of course, since the third insulating member 23 has a certain length, it is understood that the ratio of the sum of the lengths of the third insulating members 23 corresponding to two adjacent subgrids to the length of the non-merging area 14 is greater than 0.

[0085] Optionally, the length of the third insulating member 23 refers to the dimension of the sub-grid of the third insulating member 23 in the longitudinal direction.

[0086] Optionally, the spacing between the first insulating members 21 at both ends of the non-merging area 14 refers to the distance in the longitudinal direction of the subgrid between two adjacent boundary lines of the first insulating members 21 at both ends of the non-merging area 14.

[0087] For example, in the example shown in Figure 7, if the lengths of the third insulating member 23 corresponding to two adjacent subgrids are w1 and w2, respectively, and the distance between the first insulating members 21 at both ends of the non-merging area 14 is w0, then the ratio (w1+w2) / w0 is 150% or less.

[0088] In the example in Figure 7, the ratio of the sum of the lengths of the third insulating members 23 corresponding to two adjacent subgrids to the spacing of the first insulating members 21 at both ends of the non-merging area 14 is 50%. In the example in Figure 8, the ratio of the sum of the lengths of the third insulating members 23 corresponding to two adjacent subgrids to the spacing of the first insulating members 21 at both ends of the non-merging area 14 is 100%. In the example in Figure 9, the ratio of the sum of the lengths of the third insulating members 23 corresponding to two adjacent subgrids to the spacing of the first insulating members 21 at both ends of the non-merging area 14 is 110%. These are merely examples and do not limit the specific values ​​of the ratios.

[0089] Optionally, in the examples of Figures 7, 8, and 9, the lengths of the third insulating member 23 corresponding to two adjacent subgrids are the same. In other examples, it is understood that the lengths of the third insulating member 23 corresponding to two adjacent subgrids may be different.

[0090] Referring to Figures 8 and 9, in some arbitrary embodiments, the third insulating member 23 covering two adjacent subgrids is continuously distributed in the non-merging area 14. This prevents two adjacent subgrids of opposite polarity from conducting through conductive foreign matter such as tin slag, ensuring the normal operation of the back contact battery 100 and reducing the risk of short circuits in the back contact battery 100.

[0091] When we say that the third insulating member 23 covering two adjacent subgrids is continuously distributed, we mean that the third insulating member 23 covering two adjacent subgrids is continuously distributed in the longitudinal direction of the subgrid. Alternatively, the projection of an area on one subgrid that is not covered by the third insulating member 23 onto an adjacent subgrid along the width direction of the subgrid overlaps with the area on the adjacent subgrid that is covered by the third insulating member 23, or lies within the area on the adjacent subgrid that is covered by the third insulating member 23.

[0092] In other embodiments, the continuous distribution of the third insulating member 23 covering two adjacent subgrids may mean that the third insulating member 23 covering two adjacent subgrids is continuously distributed in the width direction of the subgrid; and in other embodiments, the continuous distribution of the third insulating member 23 covering two adjacent subgrids may mean that the third insulating member 23 covering two adjacent subgrids is continuously distributed in directions other than the longitudinal and width directions of the subgrid. Here, the specific direction in which the third insulating member 23 covering two adjacent subgrids is continuously distributed is not limited.

[0093] Referring to Figure 8, in some arbitrary embodiments, the edges of the third insulating member 23 covering two adjacent subgrids are aligned at the connection point.

[0094] As a result, the third insulating member 23 covering two adjacent sub-grids is perfectly continuous in the width direction of the sub-grids, reducing the covering area of ​​the third insulating member 23, which is advantageous for cost reduction.

[0095] Optionally, each third insulating member 23 includes a first side and a second side, the first side being the side extending along the subgrid of the third insulating member 23, and the second side being the side adjacent to the first side. For example, in Figure 3, the third insulating member 23 is rectangular, with the longer side being the first side and the shorter side being the second side. In other embodiments, it is understood that the third insulating member 23 may be a parallelogram or have other shapes.

[0096] Optionally, two adjacent third insulating members 23 are located on the two first sides between two adjacent subgrids, and the connection lines at the endpoints of the connection points are perpendicular to the longitudinal direction of the subgrids. This ensures that the third insulating members 23 covering the two adjacent subgrids are tightly connected, reducing the risk of short circuits.

[0097] Optionally, the two second edges at the connection point of two adjacent subgrids are located on the same straight line. This ensures that the third insulating member 23 covering the two adjacent subgrids is tightly connected, reducing the risk of short circuits. In other embodiments, the two second edges at the connection point of two adjacent subgrids do not have to be located on the same straight line.

[0098] Referring to Figure 9, in some arbitrary embodiments, the edges of the third insulating member 23 covering two adjacent subgrids intersect at the connection point.

[0099] As a result, the third insulating member 23 covering two adjacent sub-grids partially overlaps in the width direction of the sub-grids, thereby further reducing the risk of short circuits.

[0100] Optionally, each third insulating member 23 includes a first side and a second side, the first side being the side extending along the subgrid of the third insulating member 23, and the second side being the side adjacent to the first side. For example, in Figure 4, the third insulating member 23 is rectangular, with the longer side being the first side and the shorter side being the second side. In other embodiments, it is understood that the third insulating member 23 may be a parallelogram or have other shapes.

[0101] Optionally, the projection of the second edge of a third insulating member 23 covering one sub-grid onto an adjacent sub-grid, along the width direction of the sub-grid, is located within the area where the third insulating member 23 covers the adjacent sub-grid. This ensures that the third insulating members 23 covering two adjacent sub-grids intersect at the connection point, thereby reducing the risk of short circuits.

[0102] Referring to Figures 8 and 9, in some arbitrary embodiments, the third insulating member 23 covering two adjacent subgrids is of the same length. In some arbitrary other embodiments, it is understood that the third insulating member 23 covering two adjacent subgrids is of different lengths. This is not limited here. [Examples]

[0103] Referring to Figures 8 and 9, in some arbitrary embodiments, the ratio of the sum of the lengths of the third insulating member 23 corresponding to two adjacent subgrids to the spacing of the first insulating member 21 at both ends of the non-merging area 14 is between 100% and 120%. For example, 100%, 105%, 110%, 112%, 115%, 118%, and 120%.

[0104] This results in a more appropriate ratio between the sum of the lengths of the third insulating members 23 corresponding to two adjacent sub-grids and the spacing of the first insulating members 21 at both ends of the non-merging area 14, further reducing the risk of short circuits and resulting in a greater overall effect of short-circuit prevention and cost reduction. [Examples]

[0105] Referring to Figure 7, in some arbitrary embodiments, the width d of the third insulating member 23 is 50 μm to 500 μm. Example. For example, these are 50 μm, 55 μm, 80 μm, 100 μm, 200 μm, 250 μm, 300 μm, 400 μm, and 500 μm.

[0106] This ensures that the width of the third insulating member 23 is within an appropriate range, avoiding difficulties in covering the subgrid and a decrease in insulation effect due to a width that is too small, and also avoiding material waste and increased costs due to a width that is too large.

[0107] Preferably, the width d of the third insulating member 23 is 200 μm to 300 μm. This balances insulation effect and cost, resulting in the best overall performance.

[0108] The width of the third insulating member 23 may be a constant value within the range of 50 μm to 500 μm, or it may vary within the range of 50 μm to 500 μm. [Examples]

[0109] Referring to Figure 7, in some arbitrary embodiments, the difference between the width of the third insulating member 23 and the corresponding subgrid is 20 μm to 200 μm. For example, 20 μm, 25 μm, 30 μm, 50 μm, 80 μm, 100 μm, 150 μm, 180 μm, and 200 μm.

[0110] This ensures that the difference between the width of the third insulating member 23 and the corresponding sub-grid is within an appropriate range, avoiding difficulties in covering the sub-grid and a decrease in insulation effect due to a difference that is too small, and also avoiding material waste and increased costs due to a difference that is too large.

[0111] Preferably, the difference between the width of the third insulating member 23 and the corresponding sub-grid is 100 μm to 150 μm. This balances insulation effectiveness and cost, resulting in the best overall performance.

[0112] Referring to Figures 10, 11, and 12, the specific features, structure, materials, or properties of the back-contact battery 100 described in this application can be combined in an appropriate manner in any one or more embodiments or examples. For example, in Figure 10, the back-contact battery 100 includes a battery substrate 10, a first insulating member 21, and a displacement limiting member 24. For example, in Figures 11 and 12, the back-contact battery 100 includes a battery substrate 10, a first insulating member 21, a third insulating member 23, and a displacement limiting member 24. For example, in Figure 11, the ratio of the sum of the lengths of the third insulating member 23 corresponding to two adjacent subgrids to the length of the non-merging area 14 is 50%, and in Figure 12, the ratio of the sum of the lengths of the third insulating member 23 corresponding to two adjacent subgrids to the length of the non-merging area 14 is 100%.

[0113] In one example, referring to Figure 10, the insulating pattern shown in Figure 10 is printed onto the battery substrate 10, and the insulating adhesive is cured using a thermosetting process. The weight of the insulating adhesive after curing is 0.28 g, and the series short-circuit ratio is 0.51%. Clearly, the risk of short-circuiting the back contact battery 100 can be reduced.

[0114] In one example, referring to Figure 11, the insulating pattern shown in Figure 11 is printed onto the battery substrate 10, and the insulating adhesive is cured using a thermosetting process. The weight of the insulating adhesive after curing is 0.45 g, and the series short-circuit ratio is 0.2%. Clearly, the risk of short-circuiting the back contact battery 100 can be reduced.

[0115] In one example, referring to Figure 12, the insulating pattern shown in Figure 12 is printed on the battery substrate 10, and the insulating adhesive is cured using a thermosetting process. The weight of the insulating adhesive after curing is 0.65 g, and the series short-circuit ratio is 0.12%. Clearly, the risk of short-circuiting the back contact battery 100 can be reduced.

[0116] Note that the data for the three examples above is based on the assumption that the back contact battery 100 is a single battery cell. [Examples]

[0117] In some arbitrary embodiments, the first insulating member 21 is a transparent insulating member.

[0118] This reduces the shielding of sunlight by the first insulating member 21, allowing more sunlight to be absorbed by the back contact battery 100, which is advantageous for improving photoelectric conversion efficiency.

[0119] Furthermore, "transparent" refers to a light transmittance of 70% or more for visible light at a thickness of 20 μm of the first insulating member 21.

[0120] In other embodiments, the first insulating member 21 may be an opaque insulating member. This is not limited to the present invention.

[0121] Optionally, the second insulating member 22 is a transparent insulating member. This further reduces the shielding of sunlight by the insulating material, which is advantageous in improving the photoelectric conversion efficiency.

[0122] Optionally, the third insulating member 23 is a transparent insulating member. This further reduces the shielding of sunlight by the insulating material, which is advantageous in improving photoelectric conversion efficiency.

[0123] The interpretation and explanation regarding the fact that the second insulating member 22 and the third insulating member 23 are transparent insulating members are similar to those for the first insulating member 21, and the relevant information for the first insulating member 21 can be found there. A detailed explanation is therefore omitted here. [Examples]

[0124] In some arbitrary embodiments, the first insulating member 21 is a transparent fluorescent insulating member.

[0125] As a result, the first insulating member 21 can emit light when irradiated with a light source of the corresponding wavelength, making it easier to detect the position of the first insulating member 21, which is advantageous in improving the accuracy of installing the first insulating member 21 on the back contact battery 100.

[0126] In this embodiment, the second insulating member 22 is a transparent fluorescent insulating member. As a result, the second insulating member 22 can emit light when irradiated with a light source of a corresponding wavelength, making it easier to detect the position of the second insulating member 22, which is advantageous in improving the accuracy of installing the second insulating member 22 on the back contact battery 100.

[0127] In this embodiment, the third insulating member 23 is a transparent fluorescent insulating member. As a result, the third insulating member 23 can emit light when irradiated with a light source of a corresponding wavelength, making it easier to detect the position of the third insulating member 23, which is advantageous in improving the accuracy of installing the third insulating member 23 on the back contact battery 100.

[0128] The interpretation and explanation regarding the fact that the second insulating member 22 and the third insulating member 23 are transparent fluorescent insulating members are similar to those for the first insulating member 21, and the relevant information for the first insulating member 21 can be found therein; therefore, a detailed explanation is omitted here. [Examples]

[0129] In some arbitrary embodiments, the transparent fluorescent insulating member comprises a transparent insulating adhesive comprising: a resin component in mass percentage of 60% to 80%; an inorganic filler in mass percentage of 5% to 15%; a curing agent in mass percentage of 5% to 15%; a solvent in mass percentage of less than 10%; and a fluorescent agent in mass percentage of 0.1% to less than 1%.

[0130] As a result, since the insulating adhesive is a transparent insulating material, it can reduce the shielding of sunlight, allowing more sunlight to be absorbed by the back contact battery 100, which is advantageous for improving photoelectric conversion efficiency. In addition, since the transparent insulating adhesive contains a fluorescent agent at a mass percentage of 0.1% to less than 1%, it can emit light when irradiated with a light source of the corresponding wavelength, which makes it easier to detect the position of the transparent insulating adhesive and is advantageous for improving the accuracy of installing the transparent insulating adhesive on the back contact battery 100.

[0131] Optionally, the transparent insulating adhesive can be applied to the back contact battery 100 by methods such as screen printing, spraying, or coating.

[0132] Optionally, the coverage area ratio of the transparent insulating adhesive on the back contact battery 100 is greater than 10%.

[0133] The mass percentage of the resin component can be, for example, 60%, 62%, 65%, 70%, 73%, 75%, 78%, or 80%. This ensures that the mass percentage of the resin component is within an appropriate range, reducing the brittleness of the insulating material formed by the curing of the insulating adhesive and improving the bending and impact resistance of the insulating material.

[0134] The mass percentage of the inorganic filler can be, for example, 5%, 6%, 8%, 10%, 11%, 14%, or 15%. This allows for a reduction in the cost of the transparent insulating adhesive by utilizing relatively inexpensive inorganic fillers to reduce the amount of resin components used. Furthermore, the inorganic fillers can improve the mechanical properties of the transparent insulating adhesive, making the installation and adhesion of the insulating adhesive easier.

[0135] Optionally, the mass percentage of the curing agent can be, for example, 5%, 8%, 10%, 11%, 14%, or 15%. This allows the transparent insulating adhesive to cure within a predetermined process time.

[0136] Optionally, the mass percentage of the solvent can be, for example, 9.99%, 9%, 7%, 5%, 4%, 2%, or 0.1%. This allows for the dissolution of other materials in the transparent insulating adhesive and the adjustment of its viscosity.

[0137] The mass percentage of the fluorescent agent can be, for example, 0.99%, 0.95%, 0.8%, 0.6%, 0.5%, 0.3%, or 0.1%. The fluorescent agent has the effect of increasing whiteness, and if the mass percentage is 1% or more, it affects the light transmittance of the transparent insulating adhesive itself. On the other hand, if the mass percentage of the fluorescent agent is between 0.1% and 1%, the light transmittance of the insulating adhesive itself is good, which is advantageous for ensuring photoelectric conversion efficiency. Furthermore, if the mass percentage of the fluorescent agent is between 0.1% and 1%, the cost will not increase excessively, ensuring the detection of the insulating adhesive while guaranteeing the normal operation of the solar cell and reducing the cost of the back contact cell 100.

[0138] In some optional embodiments, the resin component includes at least one of modified polyacrylic acid esters, modified polyurethanes, modified polyamides, modified polyesteramides, modified polycarbonates, modified silicone esters, modified styrene esters, polystyrene, polytetrafluoroethylene, polyoxymethylene, modified phenolic resins, modified polyesters, modified polyamide resins, and modified epoxy resins. This provides a variety of resin component forms, which can meet more real-world production scenarios and needs, and is advantageous in increasing the production efficiency of transparent insulating adhesives. Furthermore, the resin component can reduce the brittleness of the insulating material formed when the transparent insulating adhesive cures, and improve the strength of the insulating material against bending and impact.

[0139] In some optional embodiments, the inorganic filler includes talc powder. This allows for a reduction in the cost of the transparent insulating adhesive by utilizing relatively inexpensive talc powder to reduce the amount of resin component used. In addition, talc powder can improve the thermal stability and corrosion resistance of the transparent insulating adhesive, thereby improving its quality. Furthermore, talc powder has insulating properties, which can enhance the insulating performance of the transparent insulating adhesive.

[0140] In some arbitrary embodiments, the talc powder comprises at least one of barium sulfate, calcium carbonate, and titanium dioxide. This provides various forms of talc powder, which can meet more real-world production scenarios and actual production needs and is advantageous in enhancing transparent insulating adhesives.

[0141] In some optional embodiments, the curing agent includes an imidazole derivative. This allows for an increased curing speed of the insulating adhesive and a reduction in curing costs when an imidazole derivative is used as the curing agent.

[0142] In some optional embodiments, the imidazole derivative comprises at least one of an aliphatic amine, an aromatic, and an acid anhydride curing agent. This provides various forms of curing agents, which can meet more real-world production scenarios and actual production needs and is advantageous in enhancing transparent insulating adhesives. Optionally, the aliphatic amine comprises ethylenediamine and / or xylylenediamine. For example, the aliphatic amine comprises ethylenediamine; for example, the aliphatic amine comprises xylylenediamine; for example, the aliphatic amine comprises ethylenediamine and xylylenediamine. Optionally, the aromatic comprises m-phenylenediamine and / or diaminodiphenylmethane. For example, the aromatic comprises m-phenylenediamine; for example, the aromatic comprises diaminodiphenylmethane; for example, the aromatic comprises m-phenylenediamine and diaminodiphenylmethane. Optionally, the acid anhydride curing agent comprises phthalic anhydride and / or hexahydrophthalic anhydride. For example, the acid anhydride curing agent contains phthalic anhydride; for example, the acid anhydride curing agent contains hexahydrophthalic anhydride; for example, the acid anhydride curing agent contains phthalic anhydride and hexahydrophthalic anhydride.

[0143] In some optional embodiments, the solvent comprises at least one of dimethyl adipate, dimethyl succinate, dimethyl glutarate, dimethyl malonate, diethyl adipate, diethyl succinate, diethyl glutarate, dibutyl succinate, dibutyl glutarate, DBE, DBE-3, DBE-4, DBE-6, DBE-9, DBE-IB, and DBE-ME. This allows the dibasic acid ester to exhibit better dissolving action, react with the resin component to form a chain-like or cyclic polymer, and form a stable solid compound after volatilization. Furthermore, this provides various forms of dibasic acid esters, which can meet more practical production scenarios and actual production needs, and is advantageous for improving the production efficiency of insulating adhesives. [Examples]

[0144] In some optional embodiments, the fluorescent agent includes at least one of the following: fluorescent whitening agent OB-1, fluorescent whitening agent-OB, aluminum oxide, zinc oxide, zinc sulfide, calcium sulfide, strontium sulfide, strontium aluminate, calcium chlorate, barium aluminate, rare earth fluorescent materials, fluorescent whitening agent BC, fluorescent whitening agent JD-3, fluorescent whitening agent BR, fluorescent whitening agent-EBF, fluorescent whitening agent R, fluorescent whitening agent ER, 1,8-naphthaleneimide-based fluorescent compounds, polyphenyls, polythiophenes, polyfluorenes, polytriphenylamines, polytriphenylamine derivatives, polycarbazoles, polypyrroles, porphyrins and their derivatives, copolymers, N,N-dimethylaminobenzylidene dinitrile-based compounds, 8-hydroxyquinoline aluminum, and europium metal complexes.

[0145] This allows us to offer various forms of fluorescent agents, enabling us to meet a wider range of real-world production scenarios and needs, which is advantageous in enhancing transparent insulating adhesives.

[0146] Optionally, rare earth fluorescent materials refer to fluorescent materials containing rare earth elements. That is, fluorescent materials containing at least one rare earth element from europium, samarium, erbium, and neodymium.

[0147] In one example, the fluorescent agent is the fluorescent whitening agent OB-1. When ultraviolet light is shone on an insulating adhesive containing the fluorescent whitening agent OB-1, the visible fluorescence color is blue, and the visual effect is strong.

[0148] In the table below, the resin component, curing agent, and solvent of the transparent insulating adhesive are 70% phenol epoxy resin, 10% imidazole derivative, and 5% anisole, respectively. The fluorescent agent is the fluorescent whitening agent OB-1 in all cases, and the inorganic filler is barium sulfate in all cases. The mass percentages of OB-1 and barium sulfate are as shown in the table below.

[0149] The table below shows the fluorescence grayscale, viscosity, and light transmittance of transparent insulating adhesives with a thickness of 20 μm and the addition of fluorescent whitening agent OB-1 at various amounts. The fluorescence grayscale is understood to represent the fluorescence effect. The viscosity value represents the printability, and the best printability was observed when the viscosity value was between 150 dpa·s and 250 dpa·s. It was found that when the mass percentage of the fluorescent agent was 1% or more, the fluorescence effect of the transparent insulating adhesive was strong, but the printability and light transmittance were poor. When the mass percentage of the fluorescent agent was between 0.1% and less than 1%, the fluorescence of the transparent insulating adhesive was sufficiently detectable, and the printability and light transmittance were good. Therefore, when the mass percentage of the fluorescent agent is between 0.1% and less than 1%, detectability, fluorescence effect, and printability can be ensured, and the overall effect of the transparent insulating adhesive can be further enhanced.

[0150] [Table 1]

[0151] In another example, the fluorescent agent is aluminum oxide. When ultraviolet light is shone on an insulating adhesive containing aluminum oxide as the fluorescent agent, the visible fluorescence is pale blue, and the visual effect is strong.

[0152] In the table below, the resin component, curing agent, and solvent of the transparent insulating adhesive are 70% phenol epoxy resin, 10% imidazole derivative, and 5% anisole, respectively. The fluorescent agent is aluminum oxide, and the inorganic filler is barium sulfate. The mass percentages of aluminum oxide and barium sulfate are as shown in the table below.

[0153] The table below shows the fluorescence grayscale, viscosity, and light transmittance of transparent insulating adhesives with a thickness of 20 μm and varying amounts of aluminum oxide added. It was found that when the mass percentage of the fluorescent agent was 1% or more, the fluorescence effect of the transparent insulating adhesive was strong, but the printability and light transmittance were poor. When the mass percentage of the fluorescent agent was between 0.1% and less than 1%, the fluorescence of the transparent insulating adhesive was sufficiently detectable, and the printability and light transmittance were good. Therefore, when the mass percentage of the fluorescent agent is between 0.1% and less than 1%, detectability, fluorescence effect, and printability can be ensured, and the overall effect of the transparent insulating adhesive can be further enhanced.

[0154] [Table 2]

[0155] Here, we will show specific data for cases where the fluorescent agent is the fluorescent whitening agent OB-1, and specific data for cases where the fluorescent agent is aluminum oxide. Other fluorescent agents, such as fluorescent whitening agent-OB, zinc oxide, zinc sulfide, calcium sulfide, strontium sulfide, strontium aluminate, calcium chlorate, barium aluminate, rare earth fluorescent materials, fluorescent whitening agent BC, fluorescent whitening agent JD-3, fluorescent whitening agent BR, fluorescent whitening agent-EBF, fluorescent whitening agent R, fluorescent whitening agent ER, 1,8-naphthaleneimide-based fluorescent compounds, polyphenyls, polythiophenes, polyfluorenes, polytriphenylamine, polytriphenylamine derivatives, polycarbazoles, polypyrroles, porphyrins and their derivatives, copolymers, N,N-dimethylaminobenzylidene dinitrile-based compounds, 8-hydroxyquinoline aluminum, and europium metal complexes, when their mass percentage was between 0.1% and less than 1%, exhibited a grayscale range of 100-300 for the fluorescence effect, a viscosity range of 150-300 for the printability, and a light transmittance range of 85-90%. To avoid redundancy, a detailed explanation will be omitted here.

[0156] In other embodiments, the fluorescent agent may include fluorescent whitening agent-OB; in other embodiments, the fluorescent agent may include barium aluminate, rare earth fluorescent material, fluorescent whitening agent BC, fluorescent whitening agent JD-3; in other embodiments, the fluorescent agent may include fluorescent whitening agent-EBF, fluorescent whitening agent R, fluorescent whitening agent ER, and 1,8-naphthaleneimide-based fluorescent compounds. The specific form of the fluorescent agent is not limited here.

[0157] By optionally irradiating the back contact battery 100 with at least one type of light ray—green light, blue light, infrared light, ultraviolet light, or white light—fluorescence is generated in the insulating material formed by the curing of the transparent insulating adhesive, making it possible to accurately detect the position of the transparent insulating adhesive. [Examples]

[0158] The battery module according to the embodiment of this application includes a back contact battery 100 of any of Embodiments 1 to 18.

[0159] As a result, in the back contact battery 100, the first insulating member 21 is continuously provided along the extending direction of the merged area 13 at the edge of the non-merging area 14, and covers the portion of the subgrid of the non-merging area 14 that is close to the merged area 13. This prevents the subgrid from making contact with a busbar of opposite polarity at the edge of the non-merging area 14 that is close to the merged area 13, thereby ensuring the normal operation of the back contact battery 100 and reducing the risk of short circuits in the back contact battery 100.

[0160] In this embodiment, a battery string can be formed by sequentially connecting multiple back-contact batteries 100 in a battery module in series, thereby realizing series connection, merging, and output of current. For example, series connection of battery cells can be achieved by installing series connection members (bus bars, interconnection strips) or conductive backplanes.

[0161] In such embodiments, it is understood that the battery module may further include a metal frame, a backplane, photovoltaic glass, and an adhesive film. The adhesive film may be filled between the front and back surfaces of the back contact battery 100, and between the photovoltaic glass, adjacent battery cells, etc. The filler may be a transparent colloid having good light transmittance and aging resistance. For example, the adhesive film may be an EVA adhesive film or a POE adhesive film, and can be specifically selected according to the circumstances, and is not limited here.

[0162] The photovoltaic glass can cover the adhesive film on the front of the back contact battery 100. The photovoltaic glass may be an ultra-white glass with high light transmittance, high transparency, and excellent physical, mechanical, and optical performance. For example, ultra-white glass can achieve a light transmittance of 92% or more, protecting the back contact battery 100 with minimal impact on its efficiency. The adhesive film can bond the photovoltaic glass to the back contact battery 100, and the presence of the adhesive film enables sealed insulation and waterproof / moisture-proof protection of the back contact battery 100.

[0163] The backplane can be attached to the adhesive film on the back of the back contact battery 100. The backplane can protect and support the back contact battery 100 and has reliable insulation, water repellency, and aging resistance. Multiple types of backplanes can be selected, and they may typically be tempered glass, organic glass, aluminum alloy TPT composite adhesive film, etc. Specifically, they can be installed according to the circumstances and are not limited here. The whole structure consisting of the backplane, back contact battery 100, adhesive film, and photovoltaic glass can be mounted on a metal frame. The metal frame serves as the main external support structure for the entire battery module, enabling stable support and mounting of the battery module. For example, the metal frame can be used to mount the battery module in a desired position. [Examples]

[0164] The photovoltaic power generation system according to the embodiment of this application includes a battery module according to Embodiment 19. As a result, in the back contact battery 100, the first insulating member 21 is continuously provided along the extending direction of the merged area 13 at the edge of the non-merging area 14 and covers the portion of the subgrid of the non-merging area 14 that is close to the merged area 13. This prevents the subgrid from making contact with a busbar of opposite polarity at the edge of the non-merging area 14 that is close to the merged area 13, ensuring the normal operation of the back contact battery 100 and reducing the risk of short circuits in the back contact battery 100.

[0165] In this embodiment, the photovoltaic power generation system can be applied to solar power plants such as ground-based power plants, rooftop power plants, and floating power plants, and can also be applied to equipment or devices that generate electricity using sunlight, such as user solar power sources, solar streetlights, solar-powered automobiles, and solar-powered buildings. Of course, the application scenes of the photovoltaic power generation system are not limited to these, meaning that it is understood that the photovoltaic power generation system can be applied to any field where solar power generation is required. Taking a photovoltaic power generation system network as an example, the photovoltaic power generation system may include a photovoltaic array, a junction box, and an inverter, and the photovoltaic array may be a combination of arrays of multiple battery modules, for example, multiple battery modules may constitute multiple photovoltaic arrays, the photovoltaic arrays may be connected to a junction box, the junction box may combine the currents generated by the photovoltaic arrays, convert the combined current into the AC current required by the commercial power grid via an inverter, and then connect to the commercial power grid to realize solar power supply.

[0166] In this specification, any reference terms such as “several examples,” “exemplary examples,” “examples,” “specific examples,” or “several examples” mean that the specific features, structures, materials, or characteristics described with reference to the examples are included in at least one example of this application. In this specification, exemplary expressions of the above terms do not necessarily mean the same examples. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any one or more examples in appropriate form.

[0167] The above description is merely a preferred embodiment of the present application and does not limit it. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present application are all included within the scope of protection of this application. [Explanation of Symbols]

[0168] 100 Back Contact Battery 10 Battery board 101 Electrical connection area of ​​series connection member 111 First Sub-Grid 112 First Main Grid 1120 Electrical connection area of ​​the first series connecting member 121 Second Sub-Grid 122 Second main grid 1220 Electrical connection area of ​​the second series connecting member 13 Confluence area 14 Non-merging area 21 First insulating member 22 Second insulating member 23 Third insulating member 24 Displacement limiting section

Claims

1. A back contact battery including a battery substrate and a first insulating member, A back contact battery characterized in that two types of sub-grids of polarity are formed on the back surface of the battery substrate, the back surface includes a confluence area and a non-confluence area, the confluence area and the non-confluence area are formed on the back surface of the battery substrate, the first insulating member is provided continuously along the extending direction of the confluence area at the edge of the non-confluence area, and covers the portion of the sub-grid of the non-confluence area that is close to the confluence area.

2. The back contact battery according to claim 1, characterized in that the thickness of the first insulating member is 10 μm to 50 μm.

3. The back contact battery according to claim 1, characterized in that the width of the first insulating member at the edge of the non-merging area is 100 μm to 1000 μm.

4. The back contact battery according to claim 1, characterized in that a main grid is formed on the back surface, the main grid is provided in the confluence area and is exposed from the first insulating member.

5. The back contact battery according to claim 4, characterized in that the ratio of the covering area of ​​the first insulating member to the total area of ​​the back contact battery is 10% to 20%.

6. The back contact battery according to claim 1, wherein the back contact battery is a main grid-free battery, a portion of each sub-grid is located in the merging area, the remaining portion of each sub-grid is located in the non-merging area, the merging area is used for installing series connecting members, and each series connecting member has a sub-grid of the same polarity exposed in the corresponding merging area.

7. The back contact battery according to claim 6, characterized in that the merging area is provided with a sub-grid of one type of polarity, and the merging area is fully exposed from the first insulating member.

8. The back contact battery according to claim 6, wherein the merging area is provided with sub-grids of two different polarities, the back contact battery includes a second insulating member, and the second insulating member covers the merging area with sub-grids having opposite polarity to the corresponding series connecting member.

9. The back contact battery according to claim 8, characterized in that the ratio of the total covering area of ​​the first insulating member and the second insulating member to the total area of ​​the back contact battery is 5% to 15%.

10. The back contact battery according to claim 1, wherein the back contact battery includes a third insulating member, the third insulating member is provided continuously in the non-merging area along the direction of extension of the sub-grid from the first insulating member, and at least partially covers the sub-grid having opposite polarity to the corresponding merging area.

11. The back contact battery according to claim 10, characterized in that the ratio of the sum of the lengths of the third insulating member corresponding to two adjacent subgrids to the distance between the first insulating members at both ends of the non-merging area is 150% or less.

12. The back contact battery according to claim 11, characterized in that the ratio of the sum of the lengths of the third insulating member corresponding to two adjacent sub-grids to the distance between the first insulating members at both ends of the non-merging area is 100% or more and 120% or less.

13. The back contact battery according to claim 10, characterized in that the width of the third insulating member is 50 μm to 500 μm.

14. The back contact battery according to claim 10, characterized in that the difference between the width of the third insulating member and the width of the corresponding sub-grid is 20 μm to 200 μm.

15. The back contact battery according to claim 1, characterized in that the first insulating member is a transparent insulating member.

16. The back contact battery according to claim 15, characterized in that the first insulating member is a transparent fluorescent insulating member.

17. The transparent fluorescent insulating member is made of a transparent insulating adhesive, and the transparent insulating adhesive is Resin components with a mass percentage of 60% to 80%, Inorganic fillers with a mass percentage of 5% to 15%, A hardening agent with a mass percentage of 5% to 15%. Solvents with a mass percentage of less than 10%, The back contact battery according to claim 15, characterized by containing a fluorescent agent in a mass percentage of 0.1% or more and less than 1%.

18. The back contact battery according to claim 17, characterized in that the fluorescent agent comprises at least one of the following: fluorescent whitening agent OB-1, fluorescent whitening agent -OB, aluminum oxide, zinc oxide, zinc sulfide, calcium sulfide, strontium sulfide, strontium aluminate, calcium chlorate, barium aluminate, rare earth fluorescent material, fluorescent whitening agent BC, fluorescent whitening agent JD-3, fluorescent whitening agent BR, fluorescent whitening agent -EBF, fluorescent whitening agent R, fluorescent whitening agent ER, 1,8-naphthaleneimide-based fluorescent compound, polyphenyl, polythiophene, polyfluorene, polytriphenylamine, polytriphenylamine derivative, polycarbazole, polypyrrole, porphyrin and its derivatives, copolymer, N,N-dimethylaminobenzylidene dinitrile-based compound, 8-hydroxyquinoline aluminum, and europium metal complex.

19. A battery module characterized by including a back contact battery according to any one of claims 1 to 18.

20. A solar power generation system characterized by including the battery module described in claim 19.

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