Solar cell, cell string, cell assembly, and photovoltaic system

Abstract

The present disclosure is applicable to the technical field of solar cells, and provides a solar cell, a cell string, a cell assembly, and a photovoltaic system. The solar cell comprises a cell substrate, a first finger, a second finger, a junction structure, and a first bending structure. The junction structure is disposed on the cell substrate. At least a part of the first finger is connected to the junction structure. The first bending structure is connected to the first finger and the junction structure. The first bending structure extends in a first direction and is at least partially bent in a second direction. The width of a contact portion between the junction structure and the first bending structure in the second direction is greater than the width of the first finger in the second direction. In this way, the first finger is connected to the junction structure by means of the first bending structure, so that the junction structure has a certain margin for movement on the plane of the cell substrate. The width of the contact portion between the first bending structure and the junction structure in the second direction is greater than the width of the first finger in the second direction, thereby further improving connection stability.

Description

Solar cell, cell string, cell module and photovoltaic system

[0001] Cross-reference to Related Applications

[0002] The present disclosure claims priority to the Chinese patent application No. 202411105279.X, filed on August 12, 2024, entitled "Solar cell, cell string, cell module and photovoltaic system", the entire content of which is incorporated herein by reference. TECHNICAL FIELD

[0003] The present disclosure belongs to the technical field of solar cells, and particularly relates to a solar cell, a cell string, a cell module and a photovoltaic system. BACKGROUND

[0004] At present, a solar cell is a kind of semiconductor device that directly converts the energy of sunlight into electrical energy. The solar cell utilizes the photovoltaic effect to excite electrons by absorbing photons, and guides these electrons out to generate current through the built-in electric field. At this time, the grid lines can collect and transmit the current, thereby realizing the conversion of light energy into electrical energy. However, in the related technology, stress concentration is prone to occur at the connection position of the grid lines and the pads, and when the bonding wire or the laminating process is set, the grid lines are often broken at this position. SUMMARY

[0005] The present disclosure provides a solar cell, a cell string, a cell module and a photovoltaic system, which aims to solve the problem that the fine grid and the pad of the photovoltaic cell are prone to be disconnected during preparation and use.

[0006] The present disclosure provides a solar cell, which comprises a cell piece substrate, a first fine grid, a second fine grid, a bus structure and a first bending structure. The first fine grid is arranged on the cell piece substrate and extends along a first direction. The second fine grid is arranged on the cell piece substrate, and the first fine grid and the second fine grid are distributed along a second direction. The bus structure is arranged on the cell piece substrate, and at least part of the first fine grid is connected to the bus structure. The first bending structure connects the first fine grid and the bus structure, extends along the first direction and at least partially bends towards the second direction. The width of the contact part of the bus structure and the first bending structure in the second direction is greater than the width of the first fine grid in the second direction.

[0007] In the solar cell of the embodiments of the present disclosure, the solar cell comprises a cell piece substrate, a first fine grid, a second fine grid, a busbar structure and a first bending structure, the first fine grid is arranged on the cell piece substrate, the first fine grid extends along a first direction, the second fine grid is arranged on the cell piece substrate, the first fine grid and the second fine grid are distributed along a second direction, the busbar structure is arranged on the cell piece substrate, at least part of the first fine grid is connected to the busbar structure, the first bending structure connects the first fine grid and the busbar structure, the first bending structure extends along the first direction and is at least partially bent towards the second direction, and the width of the contact part of the busbar structure with the first bending structure in the second direction is greater than the width of the first fine grid in the second direction. In this way, the first fine grid and the busbar structure are connected through the first bending structure, so that the busbar structure has a certain movement allowance in the plane of the cell piece substrate, the first bending structure can elastically change when the solder strip is connected to the busbar structure, and the connection stability is ensured. At the same time, the width of the contact part of the first bending structure with the busbar structure in the second direction is greater than the width of the first fine grid in the second direction, which further improves the connection stability and avoids stress concentration to break the first fine grid.

[0008] In some embodiments, the maximum bending distance of the first bending structure relative to the first fine grid in the second direction is 100 μm-400 μm.

[0009] In some embodiments, the height of the first bending structure in the third direction is 35 μm-200 μm, wherein the third direction is perpendicular to both the first direction and the second direction.

[0010] In some embodiments, the solar cell further comprises a second fine grid and a third fine grid arranged on the cell piece substrate, the second fine grid, the first fine grid and the third fine grid all extend along the first direction and are distributed along the second direction, and in the second direction, the second fine grid and the third fine grid are adjacent to the first fine grid.

[0011] The first bending structure comprises a first bending segment and a second bending segment, the first bending segment is bent relative to the first fine grid towards the direction close to the second fine grid, and the second bending segment is bent relative to the first fine grid towards the direction close to the third fine grid.

[0012] In some embodiments, the maximum bending distance of the first bending segment relative to the first fine grid in the second direction is less than the distance between the first fine grid and the second fine grid.

[0013] The maximum bending distance of the second bending segment relative to the first fine grid in the second direction is less than the distance between the first fine grid and the third fine grid.

[0014] In some embodiments, the first bending segments and the second bending segments are arranged alternately along the first direction.

[0015] In some embodiments, the first bending structure is in a wave shape.

[0016] In some embodiments, the solar cell further comprises main busbars arranged on the cell substrate, the busbar connecting structure is formed on the main busbars, and a plurality of the main busbars extend along the second direction and are distributed along the first direction.

[0017] The first fine busbar is connected to the main busbar or the busbar connecting structure.

[0018] The second fine busbar and the third fine busbar are disconnected at the main busbar.

[0019] In some embodiments, the solar cell further comprises a second bending structure, the second bending structure connecting the main busbar and the busbar connecting structure, and the second bending structure extends along the second direction and is at least partially bent towards the first direction.

[0020] In some embodiments, the maximum bending distance of the second bending structure relative to the main busbar in the first direction is 100 μm-400 μm.

[0021] The height of the second bending structure in the third direction is 35 μm-200 μm, wherein the third direction is perpendicular to both the first direction and the second direction.

[0022] The battery string provided by the embodiments of the present disclosure comprises the solar cell as described in any one of the above embodiments.

[0023] The battery assembly provided by the embodiments of the present disclosure comprises the battery string as described in the above embodiments.

[0024] The photovoltaic system provided by the embodiments of the present disclosure comprises the battery assembly as described in the above embodiments.

[0025] In the solar cell, the cell string, the cell module and the photovoltaic system of the embodiments of the present disclosure, the solar cell comprises a cell substrate, a first fine grid, a second fine grid, a busbar structure and a first bending structure, the first fine grid is arranged on the cell substrate, the first fine grid extends along a first direction, the second fine grid is arranged on the cell substrate, the first fine grid and the second fine grid are distributed along a second direction, the busbar structure is arranged on the cell substrate, at least part of the first fine grid is connected with the busbar structure, the first bending structure connects the first fine grid and the busbar structure, the first bending structure extends along the first direction and is at least partially bent towards the second direction, and the width of the contact part of the busbar structure with the first bending structure in the second direction is greater than the width of the first fine grid in the second direction. In this way, the first fine grid and the busbar structure are connected through the first bending structure, so that the busbar structure has a certain movement allowance in the plane of the cell substrate, the first bending structure can elastically change when the solder strip is connected with the busbar structure, and the connection stability is ensured. At the same time, the width of the contact part of the first bending structure with the busbar structure in the second direction is greater than the width of the first fine grid in the second direction, which further improves the connection stability and avoids the first fine grid being pulled off due to stress concentration. BRIEF DESCRIPTION OF DRAWINGS

[0026] Fig. 1 is a schematic diagram of a partial structure of a solar cell according to an embodiment of the present disclosure;

[0027] Fig. 2 is a schematic diagram of another partial structure of a solar cell according to an embodiment of the present disclosure;

[0028] Fig. 3 is a schematic diagram of still another partial structure of a solar cell according to an embodiment of the present disclosure;

[0029] Fig. 4 is a schematic diagram of still another partial structure of a solar cell according to an embodiment of the present disclosure;

[0030] Fig. 5 is a schematic diagram of still another partial structure of a solar cell according to an embodiment of the present disclosure;

[0031] Fig. 6 is a schematic diagram of a module structure of a cell string according to an embodiment of the present disclosure;

[0032] Fig. 7 is a schematic diagram of a module structure of a cell module according to an embodiment of the present disclosure;

[0033] Fig. 8 is a schematic diagram of a module structure of a photovoltaic system according to an embodiment of the present disclosure.

[0034] Main element symbol explanation: 100, solar cell; 10, cell substrate; 20, first fine grid; 30, second fine grid; 40, third fine grid; 50, busbar structure; 60, first bending structure; 61, first bending segment; 62, second bending segment; 70, main grid line; 80, second bending structure; 200, cell string; 300, cell module; 400, photovoltaic system. DETAILED DESCRIPTION

[0035] In order to make the purposes, technical solutions and advantages of the present disclosure clearer, the present disclosure will be further described in detail below with reference to the drawings and embodiments. The examples of the embodiments are shown in the drawings, wherein the same or similar notations denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by reference to the drawings are exemplary and are only used to explain the present disclosure, and should not be understood as limiting the present disclosure. In addition, it should be understood that the specific embodiments described herein are only used to explain the present disclosure and should not be used to limit the present disclosure.

[0036] In the description of the present disclosure, it should be understood that the terms "length", "width", "upper", "lower", "left", "right", "horizontal", "top", "bottom" and the like indicate the orientation or positional relationship shown in the drawings, and are only used to facilitate the description of the present disclosure and simplify the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present disclosure.

[0037] In addition, the terms "first", "second" are only for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined with "first", "second" can explicitly or implicitly include one or more of the features. In the description of the present disclosure, the meaning of "a plurality of" is two or more, unless otherwise explicitly specified and limited.

[0038] In the description of the present disclosure, it should be noted that unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connection" should be understood in a broad sense, for example, can be fixedly connected, can be detachably connected, or integrally connected; can be mechanically connected, or electrically connected or can communicate with each other; can be directly connected, or indirectly connected through an intermediate medium, can be the internal communication of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the present disclosure can be understood according to the specific circumstances.

[0039] In the present disclosure, unless specifically defined and limited otherwise, the "on" or "under" of a first feature to a second feature can include that the first and second features are in direct contact, or that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, the "on", "above" and "above" of the first feature to the second feature includes that the first feature is directly above and obliquely above the second feature, or only indicates that the first feature is higher than the second feature in horizontal height. The "under", "below" and "below" of the first feature to the second feature includes that the first feature is directly below and obliquely below the second feature, or only indicates that the first feature is less than the second feature in horizontal height.

[0040] The disclosure below provides many different embodiments or examples for implementing different structures of the present disclosure. In order to simplify the disclosure of the present disclosure, the components and settings of specific examples are described below. Of course, they are only examples, and the purpose is not to limit the present disclosure. In addition, the present disclosure can repeatedly refer to numbers and / or letters in different examples, and such repetition is for the purpose of simplification and clarity, which itself does not indicate the relationship between the various embodiments and / or settings discussed. In addition, the present disclosure provides examples of various specific processes and materials, but those of ordinary skill in the art can realize the application of other processes and / or the use of other materials.

[0041] In the related art, solar cells use the photovoltaic effect to excite electrons by absorbing photons, and guide these electrons out to generate current through the built-in electric field. However, stress concentration is prone to occur at the connection position of the grid line and the pad, and the grid line is often broken at this position when the bonding wire is set or laminated. In the embodiment of the present disclosure, the first fine grid and the bus structure are connected through the first bending structure, so that the bus structure has a certain movement allowance in the plane of the cell substrate, and the first bending structure can elastically change when the bonding wire is connected with the bus structure, ensuring stable connection; At the same time, the width of the contact part of the first bending structure and the bus structure in the second direction is greater than the width of the first fine grid in the second direction, which further improves the connection stability and avoids the first fine grid from being broken by stress concentration.

[0042] Embodiment one

[0043] Referring to FIG. 1, FIG. 2 and FIG. 3, the solar cell 100 provided by the embodiment of the present disclosure includes a cell substrate 10, a first fine grid 20, a second fine grid 30, a busbar structure 50 and a first bending structure 60. The first fine grid 20 is arranged on the cell substrate 10 and extends along a first direction. The second fine grid 30 is arranged on the cell substrate 10 and is arranged along a second direction together with the first fine grid 20. The busbar structure 50 is arranged on the cell substrate 10 and is connected to the first fine grid 20 at least partially. The first bending structure 60 connects the first fine grid 20 and the busbar structure 50, extends along the first direction and bends at least partially towards the second direction. The width of the contact part of the busbar structure 50 with the first bending structure 60 in the second direction is greater than the width of the first fine grid 20 in the second direction.

[0044] In the solar cell 100 provided by the embodiment of the present disclosure, the solar cell 100 includes a cell substrate 10, a first fine grid 20, a second fine grid 30, a busbar structure 50 and a first bending structure 60. The first fine grid 20 is arranged on the cell substrate 10 and extends along a first direction. The second fine grid 30 is arranged on the cell substrate 10 and is arranged along a second direction together with the first fine grid 20. The busbar structure 50 is arranged on the cell substrate 10 and is connected to the first fine grid 20 at least partially. The first bending structure 60 connects the first fine grid 20 and the busbar structure 50, extends along the first direction and bends at least partially towards the second direction. The width of the contact part of the busbar structure 50 with the first bending structure 60 in the second direction is greater than the width of the first fine grid 20 in the second direction. In this way, the first fine grid 20 and the busbar structure 50 are connected through the first bending structure 60, so that the busbar structure 50 has a certain moving allowance in the plane of the cell substrate 10. The first bending structure 60 can change elastically when the solder strip is connected to the busbar structure 50, so as to ensure the stability of the connection. At the same time, the width of the contact part of the first bending structure 60 with the busbar structure 50 in the second direction is greater than the width of the first fine grid 20 in the second direction, so as to further improve the stability of the connection and avoid the stress concentration from breaking the connection between the first fine grid 20 and the busbar structure 50.

[0045] Specifically, the first fine grid 20 and the busbar structure 50 are connected through the first bending structure 60, so that the busbar structure 50 has a certain moving allowance in the plane of the cell substrate 10. That is, when the busbar structure 50 moves slightly relative to the cell substrate 10, the first bending structure 60 can be pulled to change elastically and move slightly, so as to avoid breaking the connection between the first fine grid 20 and the busbar structure 50 in the process of preparation, and improve the stability of the connection.

[0046] Further, in the second direction, the width of the busbar structure 50 is greater than the width of the first bending structure 60 and the first fine grid 20, and the first bending structure 60 is bent downward in the second direction relative to the first fine grid 20, that is, the first bending structure 60 has a certain slope relative to the first fine grid 20. In this way, the contact part of the busbar structure 50 with the first bending structure 60 in the second direction has a width greater than that of the first fine grid 20 in the second direction. The first bending structure 60 has a larger connection area with the busbar structure 50, which can improve the stability of the connection between the first bending structure 60 and the busbar structure 50, eliminate the problem of stress concentration, and avoid the problem of stress concentration breaking the first fine grid 20.

[0047] It can be understood that when the first fine grid 20 and the busbar structure 50 and the first bending structure 60 are arranged on the battery piece substrate 10, the relative positions of the first fine grid 20 and the busbar structure 50 and the first bending structure 60 and the battery piece substrate 10 do not change. However, during the connection of the busbar structure 50 with the solder strip, stress concentration often occurs, causing the busbar structure 50 to have a tendency to move relative to the first fine grid 20. At this time, at least part of the first bending structure 60 has a slope relative to the first fine grid 20 and is connected with the busbar structure 50, and can move with the busbar structure 50. In this way, the first bending structure 60 has a very small movement distance relative to the battery piece substrate 10, which can eliminate the problem of stress concentration. At the same time, the first bending structure 60 has a larger connection area with the busbar structure 50, which can effectively reduce the tension pressure and further avoid the problem of stress concentration.

[0048] In some embodiments, the first bending structure 60 effectively disperses stress during the welding and lamination of the battery piece substrate 10, reduces the risk of fine grid breakage, and thus improves the overall reliability and service life of the solar cell 100. Not only improves the mechanical properties of the solar cell 100, but also improves the electrical properties of the solar cell 100, ensuring higher power generation efficiency and longer service life.

[0049] In the embodiments of the present disclosure, the polarity of the first fine grid 20 and the second fine grid 30 is not limited, and the polarity between the first fine grid 20 and the second fine grid 30 is opposite, which can meet different needs. For example, the first fine grid 20 is a positive grid line, and the second fine grid 30 is a negative grid line. The first fine grid 20 can be connected to the busbar structure 50, and the busbar structure 50 can be connected to the solder strip to connect an external load, thereby realizing the action of generating electricity. The solder strip can be connected to multiple busbar structures 50, thereby converging the current of multiple first fine grids 20. Of course, the first fine grid 20 can also be a negative grid line, and the second fine grid 30 can be a positive grid line.

[0050] It can be understood that the "first" and "second" in the first fine grid 20 and the second fine grid 30 are relative concepts, which refer to two different grid lines.

[0051] In addition, in the embodiments of the present disclosure, the specific material type of the first bending structure 60 is not limited to meet different needs. In one example, the first bending structure 60 can be a part of the busbar structure 50, that is, the busbar structure 50 and the first bending structure 60 are prepared at the same time on the battery piece substrate 10, and the first bending structure 60 is made of the same material as the busbar structure 50. When the busbar structure 50 is tin paste, the first bending structure 60 can be prepared by tin paste, further increasing the stability of the connection between the first bending structure 60 and the busbar structure 50. In another example, the first bending structure 60 can be a part of the first fine grid 20, that is, the first fine grid 20 and the first bending structure 60 are prepared at the same time on the battery piece substrate 10, and the first bending structure 60 is made of the same material as the first fine grid 20.

[0052] In the present embodiment, the solar cell 100 can be a main grid-free cell, and the fine grid directly conducts current to the solder strip through the busbar structure 50, and the solder strip conducts current to the external load to perform the action of generating electricity.

[0053] In addition, in the embodiments of the present disclosure, the corresponding relationship between the first fine grid 20 and the first bending structure 60 is not limited, for example, part of the first fine grid 20 is not connected with the busbar structure 50, and therefore the end of this part of the first fine grid 20 is not provided with the first bending structure 60, to meet different needs.

[0054] In some embodiments, the first bending structure 60 can be selectively provided at the end of part of the first fine grid 20, and the end of another part of the first fine grid 20 is not provided with the first bending structure 60. In other embodiments, the first bending structure 60 can be provided at one end of the first fine grid 20, and the other end is not provided with the first bending structure 60. In still other embodiments, the first bending structure 60 can be provided at both ends of the first fine grid 20.

[0055] Embodiment Two

[0056] Referring to FIG. 1 and FIG. 2, in some optional embodiments, the maximum bending distance of the first bending structure 60 relative to the first fine grid 20 in the second direction is 100 μm-400 μm. For example, the maximum bending distance of the first bending structure 60 relative to the first fine grid 20 in the second direction can be 100 μm, 110 μm, 120 μm, 130 μm, 140 μm, 150 μm, 160 μm, 170 μm, 180 μm, 190 μm, 200 μm, 210 μm, 220 μm, 230 μm, 240 μm, 250 μm, 260 μm, 270 μm, 280 μm, 290 μm, 300 μm, 310 μm, 320 μm, 330 μm, 340 μm, 350 μm, 360 μm, 370 μm, 380 μm, 390 μm, 400 μm.

[0057] In this way, the maximum bending distance of the first bending structure 60 relative to the first fine grid 20 in the second direction is set in this range, which can not only ensure that the current collecting structure 50 has a certain activity margin to avoid disconnection between the current collecting structure 50 and the first bending structure 60, but also can avoid the influence of the first bending structure 60 on other fine grids.

[0058] For example, the maximum bending distance of the first bending structure 60 relative to the first fine grid 20 in the second direction can be 200 μm, which can not only ensure that the current collecting structure 50 has sufficient activity margin to avoid disconnection between the current collecting structure 50 and the first bending structure 60 due to stress or external force, but also can effectively avoid the interference or influence of the first bending structure 60 on adjacent fine grids.

[0059] Further, in the process of preparation, the solder strip needs to be welded with the current collecting structure 50, so as to connect the plurality of first fine grids 20 by the solder strip and realize the current convergence. However, in the process of connecting the solder strip with the current collecting structure 50, the problem of stress concentration often occurs, and even the connection between the first fine grid 20 and the current collecting structure 50 is broken or disconnected. The current collecting structure 50 of the embodiment of the present disclosure can be connected with the first fine grid 20 through the first bending structure 60, which ensures the flexibility and adaptability of the current collecting structure 50 on the battery piece substrate 10 and improves the stability of the connection between the first fine grid 20 and the current collecting structure 50. In this way, by reasonably controlling the bending distance of the first bending structure 60, the mechanical strength and flexibility of the connection part with the current collecting structure 50 can be better balanced, thereby improving the reliability in the process of welding and use and prolonging the service life of the solar cell 100.

[0060] Of course, the distance between the first fine grid 20 and the second fine grid 30 should be greater than the maximum bending distance of the first bending structure 60 relative to the first fine grid 20 in the second direction, so as to avoid the problem of short circuit.

[0061] Embodiment three

[0062] Referring to FIG. 1 and FIG. 2, in some optional embodiments, the height of the first bending structure 60 in the third direction is 35 μm-200 μm, wherein the third direction is perpendicular to both the first direction and the second direction. For example, the height of the first bending structure 60 in the third direction can be 35 μm, 40 μm, 50 μm, 60 μm, 70 μm, 80 μm, 90 μm, 100 μm, 110 μm, 120 μm, 130 μm, 140 μm, 150 μm, 160 μm, 170 μm, 180 μm, 190 μm, 200 μm.

[0063] In this way, the height of the first bending structure 60 in the third direction relative to the solar cell substrate 10 is set in this range, which can not only ensure the stable connection between the first fine grid 20 and the bus structure 50, but also avoid the influence of the height of the first bending structure 60 on the thickness of the battery assembly 300.

[0064] For example, the height of the first bending structure 60 in the third direction can be 80 μm. By setting the height of the first bending structure 60 to be 80 μm, the stability of the connection between the first fine grid 20 and the bus structure 50 can be ensured, and the overall thickness of the battery assembly 300 can be avoided due to the excessive height of the first bending structure 60.

[0065] Further, the height of the first fine grid 20 in the third direction can also be 35 μm-200 μm, and the height of the first fine grid 20 and the first bending structure 60 in the third direction can be the same to ensure the stability of the connection between the first fine grid 20 and the first bending structure 60. In this embodiment, the height of the first fine grid 20 and the first bending structure 60 in the third direction can be 80 μm, which can maximize the reduction of the influence on the thickness of the battery assembly 300 while ensuring the reliability of the mechanical connection, and is helpful to optimize the overall performance and appearance of the battery assembly 300.

[0066] Embodiment Four

[0067] Referring to FIG. 1 and FIG. 2, in some optional embodiments, the solar cell 100 further comprises a second fine grid 30 and a third fine grid 40 arranged on the solar cell substrate 10, the second fine grid 30, the first fine grid 20 and the third fine grid 40 all extend along the first direction and are arranged along the second direction, and in the second direction, the second fine grid 30 and the third fine grid 40 are adjacent to the first fine grid 20.

[0068] The first bending structure 60 comprises a first bending section 61 and a second bending section 62, the first bending section 61 bends relative to the first fine grid 20 towards the direction close to the second fine grid 30, and the second bending section 62 bends relative to the first fine grid 20 towards the direction close to the third fine grid 40.

[0069] Thus, the second fine grid 30 and the third fine grid 40 are arranged on both sides of the first fine grid 20 respectively, and a section of the second fine grid 30 close to the first fine grid 20 is a first bending section 61, and a section of the third fine grid 40 close to the first fine grid 20 is a second bending section 62, and the first bending section 61 and the second bending section 62 can be alternately connected. In this way, the maximum bending distance in the second direction is not increased, and the moving allowance of the first bending structure 60 on the plane of the battery piece substrate 10 can be improved, and the connection stability of the busbar structure 50 and the first fine grid 20 is ensured.

[0070] In the embodiment, the second fine grid 30 and the third fine grid 40 can be arranged on both sides of the first fine grid 20 respectively and adjacent to each other. The first bending structure 60 is composed of the first bending section 61 and the second bending section 62, wherein the first bending section 61 is bent towards the second fine grid 30 relative to the first fine grid 20, and the second bending section 62 is bent towards the third fine grid 40 relative to the first fine grid 20. Dividing the first bending structure 60 into the first bending section 61 and the second bending section 62 can increase the bending length of the first bending structure 60 and avoid affecting other fine grids.

[0071] In one example, the first fine grid 20 is a positive electrode fine grid, and at this time, the second fine grid 30 and the third fine grid 40 are both negative electrode fine grids, so that the positive electrode fine grid and the negative electrode fine grid can be alternately arranged along the second direction. In addition, the first fine grid 20, the second fine grid 30 and the third fine grid 40 only limit the relative positional relationship. For example, please refer to FIG. 1, the number of the first fine grid 20, the second fine grid 30 and the third fine grid 40 is multiple, in this case, the second fine grid 30 is on the upper side of the first fine grid 20, and the fine grid on the lower side of the first fine grid 20 is the third fine grid 40, and this fine grid is also the second fine grid 30 of the second first fine grid 20, and so on, forming a form of one positive electrode fine grid and one negative electrode fine grid alternately arranged.

[0072] Embodiment five

[0073] Please refer to FIG. 1 and FIG. 2, in some optional embodiments, the maximum bending distance of the first bending section 61 relative to the first fine grid 20 in the second direction is less than the distance between the first fine grid 20 and the second fine grid 30;

[0074] The maximum bending distance of the second bending section 62 relative to the first fine grid 20 in the second direction is less than the distance between the first fine grid 20 and the third fine grid 40.

[0075] Thus, the first bending structure 60 is connected between the first fine grid 20 and the busbar structure 50, and the maximum bending distance of the first bending segment 61 and the second bending segment 62 is less than the distance from other fine grids, so that the first bending segment 61 and the second bending segment 62 are prevented from being short-circuited with other fine grids, and the connection stability of the first fine grid 20 and the busbar structure 50 is improved.

[0076] Specifically, the maximum bending distance of the first bending segment 61 relative to the first fine grid 20 in the second direction is less than the distance between the first fine grid 20 and the second fine grid 30, and the maximum bending distance of the second bending segment 62 relative to the first fine grid 20 in the second direction is less than the distance between the first fine grid 20 and the third fine grid 40. In this way, not only is the possibility of short-circuiting between the bending segments and other fine grids avoided, but the connection stability between the first fine grid 20 and the busbar structure 50 is also enhanced, and the range of the movement allowance of the busbar structure 50 is improved, which helps to improve the structural reliability and conductive performance of the overall battery piece.

[0077] Of course, in other embodiments, insulating glue can be arranged between the first bending structure 60 and the second fine grid 30, and insulating glue can be arranged between the first bending structure 60 and the third fine grid 40, so that the first fine grid 20 is prevented from being short-circuited with other fine grids through the first bending structure 60.

[0078] Embodiment six

[0079] Referring to FIGS. 1 and 2, in some optional embodiments, the plurality of first bending segments 61 and the plurality of second bending segments 62 are arranged alternately along the first direction.

[0080] Thus, the plurality of first bending segments 61 and the plurality of second bending segments 62 are arranged alternately along the first direction, which not only avoids short-circuiting with other fine grids, but also increases the movement allowance of the busbar structure 50, thereby ensuring the connection stability of the first fine grid 20 and the busbar structure 50.

[0081] Exemplarily, the number of the first bending segments 61 and the second bending segments 62 is two, and in the process of the first fine grid 20 approaching the busbar structure 50, the first first bending segment 61 is connected with the first second bending segment 62, the first second bending segment 62 is connected with the second first bending segment 61, the second first bending segment 61 is connected with the second second bending segment 62, and the second second bending segment 62 is finally connected with the busbar structure 50. In this way, the plurality of first bending segments 61 and the second bending segments 62 are alternately distributed in the first direction, which not only significantly increases the moving allowance of the busbar structure 50 in the plane of the battery piece substrate 10, but also effectively disperses the stress in the process of welding and heat treatment. The alternating arrangement further improves the connection stability between the first fine grid 20 and the busbar structure 50, ensures the durability and conductivity of the battery piece in actual use, reduces the risk of fracture caused by stress concentration, and improves the overall reliability and service life of the solar cell 100.

[0082] Embodiment Seven

[0083] Please refer to FIG. 1 and FIG. 2, in some optional embodiments, the first bending structure 60 is in a wave shape.

[0084] In this way, the first bending structure 60 can be bent up and down in a wave shape, which improves the moving allowance of the busbar structure 50 without increasing the maximum bending distance, thereby ensuring the stable connection between the first fine grid 20 and the busbar structure 50.

[0085] Specifically, the first bending structure 60 is in a wave shape, that is, the connection positions of the first bending segments 61 and the second bending segments 62 can be provided with rounded corners, avoiding the problem of stress concentration caused by the abrupt change of the connection positions of the first bending segments 61 and the second bending segments 62.

[0086] Further, the first bending segments 61 and the second bending segments 62 themselves are also arc-shaped, which significantly improves the moving allowance of the busbar structure 50 without increasing the maximum bending distance. This wave-shaped structure can better buffer the stress changes generated in the process of welding and heat treatment, avoid the fracture between the first bending segments 61 and the second bending segments 62 or the first bending segments 61 and the second bending segments 62 themselves, thereby effectively ensuring the connection stability between the first fine grid 20 and the busbar structure 50.

[0087] Embodiment Eight

[0088] Please refer to FIG. 3 and FIG. 4, in some optional embodiments, the solar cell 100 further comprises a plurality of main grid lines 70 arranged on the battery piece substrate 10, and the busbar structure 50 is formed on the main grid lines 70, and the plurality of main grid lines 70 extend along the second direction and are distributed along the first direction;

[0089] The first fine grid 20 is connected with the main grid line 70 or the busbar structure 50.

[0090] The second fine grid 30 and the third fine grid 40 are disconnected at the main grid line 70.

[0091] In this way, the first fine grid 20 can be connected to the main grid line 70 through the first bending structure 60 and the busbar structure 50 to conduct the collected current to an external load through the main grid line 70 and the solder strip, thereby realizing the action of generating electricity.

[0092] Specifically, the polarities of the second fine grid 30 and the third fine grid 40 can be the same, and thus need to be disconnected at the position of the main grid line 70 to avoid short-circuiting with the main grid line 70. The main grid line 70 can be connected to and collect the current on the plurality of first fine grids 20, while the busbar structure 50 is formed on the main grid line 70, and part of the first fine grids 20 can be connected to the busbar structure 50 through the first bending structure 60, thereby converging the current of all the first fine grids 20 on the main grid line 70. The solder strip can be connected to the busbar structure 50 by soldering and extend along the direction of the main grid line 70, thereby conducting the current of the main grid line 70 to an external load.

[0093] It can be understood that there is another main grid connected to the second fine grid 30 and the third fine grid 40, and the first fine grid 20 is disconnected at this position, and the main grid can also be provided with other busbar structures and solder strips. In addition, in the embodiments of the present disclosure, the shape of the busbar structure 50 is not limited to meet different needs.

[0094] Of course, in some embodiments, the polarities of the second fine grid 30 and the third fine grid 40 are the same, the polarity of the first fine grid 20 is the same as that of the main grid line 70, and an insulating adhesive can be provided between the second fine grid 30 and the third fine grid 40 and the main grid line 70 to avoid the problem of short-circuiting.

[0095] Example Nine

[0096] Please refer to FIG. 3 and FIG. 4, in some optional embodiments, the solar cell 100 further comprises a second bending structure 80, the second bending structure 80 connects the main grid line 70 and the busbar structure 50, and the second bending structure 80 extends along a second direction and at least partially bends towards a first direction.

[0097] In this way, the main grid line 70 is connected to the busbar structure 50 through the second bending structure 80, so that the busbar structure 50 has a certain movement allowance in the plane of the cell substrate 10, and the second bending structure 80 can elastically change when the solder strip is connected to the busbar structure 50, thereby ensuring stable connection; at the same time, the width of the contact part of the second bending structure 80 and the busbar structure 50 in the first direction is greater than the width of the main grid line 70 in the first direction, thereby further improving the connection stability and avoiding stress concentration to break the main grid line 70.

[0098] In the embodiment, the second bending structure 80 is also formed between the main grid line 70 and the busbar structure 50, further increasing the moving allowance of the busbar structure 50 on the plane of the cell substrate 10. That is, when the busbar structure 50 is slightly moved relative to the cell substrate 10, the second bending structure 80 can be slightly moved by elastic change, so as to avoid breaking the connection between the main grid line 70 and the busbar structure 50 during the process preparation, and improve the stability of the connection.

[0099] Further, in the first direction, the width of the busbar structure 50 is greater than the width of the second bending structure 80 and the main grid line 70, and the second bending structure 80 is bent left and right relative to the main grid line 70 in the first direction, that is, the second bending structure 80 has a certain slope relative to the main grid line 70. In this way, the width of the contact part of the busbar structure 50 and the second bending structure 80 in the first direction is greater than the width of the main grid line 70 in the first direction. The second bending structure 80 has a larger connection area with the busbar structure 50, which can improve the stability of the connection between the second bending structure 80 and the busbar structure 50, eliminate the problem of stress concentration, and avoid breaking the main grid line 70 due to stress concentration.

[0100] Please refer to FIG. 5, in some embodiments, the second bending structure 80 can be in a wave shape.

[0101] In addition, in the embodiments of the present disclosure, the corresponding relationship between the main grid line 70 and the second bending structure 80 is not limited, so as to meet different needs. In some embodiments, the second bending structure 80 can be selectively arranged at the end of part of the main grid line 70, and the end of another part of the main grid line 70 is not provided with the second bending structure 80. In another embodiment, the second bending structure 80 can be arranged at one end of the main grid line 70, and the other end is not provided with the second bending structure 80. In yet another embodiment, the second bending structure 80 can be arranged at both ends of the main grid line 70.

[0102] Embodiment ten

[0103] Please refer to FIG. 3 to FIG. 5, in some optional embodiments, the maximum bending distance of the second bending structure 80 relative to the main grid line 70 in the first direction is 100 μm-400 μm.

[0104] The height of the second bending structure 80 in the third direction is 35 μm-200 μm, wherein the third direction is perpendicular to the first direction and the second direction.

[0105] Therefore, the maximum bending distance of the second bending structure 80 relative to the main grid line 70 in the first direction is set within this range, which can ensure that the busbar structure 50 has a certain margin of activity to avoid the disconnection of the busbar structure 50 and the second bending structure 80, and can also avoid the influence of the second bending structure 80 on other fine grids. At the same time, the height of the second bending structure 80 relative to the battery piece substrate 10 in the third direction is set within this range, which can ensure the stable connection between the main grid line 70 and the busbar structure 50, and also avoid the height of the second bending structure 80 being too high to affect the thickness of the battery assembly 300.

[0106] For example, the maximum bending distance of the second bending structure 80 relative to the main grid line 70 in the first direction can be 100 μm, 110 μm, 120 μm, 130 μm, 140 μm, 150 μm, 160 μm, 170 μm, 180 μm, 190 μm, 200 μm, 210 μm, 220 μm, 230 μm, 240 μm, 250 μm, 260 μm, 270 μm, 280 μm, 290 μm, 300 μm, 310 μm, 320 μm, 330 μm, 340 μm, 350 μm, 360 μm, 370 μm, 380 μm, 390 μm, 400 μm.

[0107] For another example, the height of the second bending structure 80 in the third direction can be 35 μm, 40 μm, 50 μm, 60 μm, 70 μm, 80 μm, 90 μm, 100 μm, 110 μm, 120 μm, 130 μm, 140 μm, 150 μm, 160 μm, 170 μm, 180 μm, 190 μm, 200 μm.

[0108] For example, the maximum bending distance of the second bending structure 80 relative to the main grid line 70 in the first direction can be 300 μm, and at the same time, the height of the second bending structure 80 in the third direction can be 100 μm. In this way, it can be ensured that the busbar structure 50 has sufficient movement margin in the plane of the battery piece substrate 10. The problem of disconnection of the busbar structure 50 and the second bending structure 80 caused by stress concentration can be effectively avoided. In addition, appropriate control of the bending distance can also prevent the second bending structure 80 from interfering with or affecting the normal function of other fine grids or main grids. At the same time, the height of the second bending structure 80 in the third direction is controlled within a reasonable range, which can not only ensure the stability of the connection between the main grid line 70 and the busbar structure 50, but also prevent the height of the bending structure from being too high, thereby affecting the overall thickness and structural integrity of the battery assembly 300.

[0109] Embodiment eleven

[0110] Referring to FIG. 1 and FIG. 6, the battery string 200 provided by the embodiment of the present disclosure includes the solar cell 100 as any one of the above embodiments.

[0111] In the solar cell 100 and the cell string 200 of the embodiment of the present disclosure, the solar cell 100 comprises a cell substrate 10, a first fine grid 20, a second fine grid 30, a busbar structure 50 and a first bending structure 60, the first fine grid 20 is arranged on the cell substrate 10, the first fine grid 20 extends along a first direction, the second fine grid 30 is arranged on the cell substrate 10, the first fine grid 20 and the second fine grid 30 are arranged along a second direction, the busbar structure 50 is arranged on the cell substrate 10, the busbar structure 50 is connected to the first fine grid 20 at least partially, the first bending structure 60 connects the first fine grid 20 and the busbar structure 50, the first bending structure 60 extends along the first direction and bends to the second direction at least partially, and the width of the contact part of the busbar structure 50 and the first bending structure 60 in the second direction is greater than the width of the first fine grid 20 in the second direction. In this way, the first fine grid 20 and the busbar structure 50 are connected through the first bending structure 60, so that the busbar structure 50 has a certain moving allowance in the plane of the cell substrate 10, the first bending structure 60 can elastically change when the solder strip is connected to the busbar structure 50, so as to ensure the stability of the connection; at the same time, the width of the contact part of the first bending structure 60 and the busbar structure 50 in the second direction is greater than the width of the first fine grid 20 in the second direction, which further improves the stability of the connection and avoids the stress concentration to break the first fine grid 20.

[0112] It can be understood that in the cell string 200, the cell string 200 can comprise two cell substrates connected in series, three cell substrates connected in series or more cell substrates connected in series, and the number of cell substrates connected in series can be determined according to actual use. In addition, in the embodiment of the present disclosure, the size and type of the cell substrate are not limited, and the specifications and sizes of adjacent cell substrates can be the same or different to meet different needs.

[0113] Embodiment twelve

[0114] Please refer to FIG. 1 and FIG. 7, the battery assembly 300 provided by the embodiment of the present disclosure comprises the cell string 200 of the above-mentioned embodiment.

[0115] In the solar cell 100, the cell string 200 and the cell module 300 of the embodiments of the present disclosure, the solar cell 100 comprises a cell substrate 10, a first fine grid 20, a second fine grid 30, a busbar structure 50 and a first bending structure 60, the first fine grid 20 is arranged on the cell substrate 10 and extends along a first direction, the second fine grid 30 is arranged on the cell substrate 10, the first fine grid 20 and the second fine grid 30 are arranged along a second direction, the busbar structure 50 is arranged on the cell substrate 10, the busbar structure 50 is connected to at least part of the first fine grid 20, the first bending structure 60 connects the first fine grid 20 and the busbar structure 50, the first bending structure 60 extends along the first direction and is at least partially bent towards the second direction, and the width of the contact part of the busbar structure 50 with the first bending structure 60 in the second direction is greater than the width of the first fine grid 20 in the second direction. In this way, the first fine grid 20 and the busbar structure 50 are connected through the first bending structure 60, so that the busbar structure 50 has a certain movement allowance in the plane of the cell substrate 10, the first bending structure 60 can elastically change when the solder strip is connected to the busbar structure 50, and the connection stability is ensured. At the same time, the width of the contact part of the first bending structure 60 with the busbar structure 50 in the second direction is greater than the width of the first fine grid 20 in the second direction, which further improves the connection stability and avoids stress concentration to break the first fine grid 20.

[0116] It can be understood that in such embodiments, the cell module 300 can further comprise a frame, a back plate, photovoltaic glass and a film. The film can be filled between the front and back surfaces of the cell substrate 10, the photovoltaic glass and the adjacent cells, as a filler, which can be a transparent gel with good light transmission performance and aging resistance, for example, the film can use EVA film or POE film, which can be selected according to actual conditions, and is not limited here.

[0117] The photovoltaic glass can be covered on the film on the front surface of the cell substrate 10, and the photovoltaic glass can be super white glass, which has high light transmittance, high transparency, and excellent physical, mechanical and optical properties. For example, the light transmittance of super white glass can reach more than 92%, which can protect the cells as much as possible without affecting the efficiency of the cells. At the same time, the film can bond the photovoltaic glass and the cells together, and the presence of the film can seal and insulate the cells and prevent water and moisture.

[0118] The back plate can be attached to the adhesive film on the back of the battery piece base body 10. The back plate can protect and support the battery piece, has reliable insulation, water resistance and aging resistance, and can have multiple options, such as tempered glass, organic glass, aluminum alloy TPT composite adhesive film, etc. The specific configuration can be set according to the specific situation, which is not limited here. The whole composed of the back plate, the battery piece, the adhesive film and the photovoltaic glass can be arranged on the frame. The frame is the main external support structure of the entire battery assembly 300, and can stably support and install the battery assembly 300. For example, the battery assembly 300 can be installed at the required installation position through the frame.

[0119] Example XIII

[0120] Please refer to FIG. 1 and FIG. 8, the photovoltaic system 400 provided by the embodiment of the present disclosure includes the battery assembly 300 of the above-mentioned embodiment.

[0121] In the solar cell 100, the battery string 200, the battery assembly 300 and the photovoltaic system 400 of the embodiment of the present disclosure, the solar cell 100 includes a battery piece base body 10, a first fine grid 20, a second fine grid 30, a busbar structure 50 and a first bending structure 60. The first fine grid 20 is arranged on the battery piece base body 10 and extends along a first direction. The second fine grid 30 is arranged on the battery piece base body 10, and the first fine grid 20 and the second fine grid 30 are arranged along a second direction. The busbar structure 50 is arranged on the battery piece base body 10, and at least part of the first fine grid 20 is connected to the busbar structure 50. The first bending structure 60 connects the first fine grid 20 and the busbar structure 50, and extends along the first direction and at least partially bends towards the second direction. The width of the contact part of the busbar structure 50 and the first bending structure 60 in the second direction is greater than the width of the first fine grid 20 in the second direction. In this way, the first fine grid 20 and the busbar structure 50 are connected through the first bending structure 60, so that the busbar structure 50 has a certain movement allowance in the plane of the battery piece base body 10. The first bending structure 60 can elastically change when the solder strip is connected to the busbar structure 50, ensuring stable connection. At the same time, the width of the contact part of the first bending structure 60 and the busbar structure 50 in the second direction is greater than the width of the first fine grid 20 in the second direction, further improving the stability of the connection and avoiding stress concentration to break the first fine grid 20.

[0122] In the present embodiment, the photovoltaic system 400 can be applied in a photovoltaic power station, such as a ground power station, a roof power station, a water surface power station, etc., and can also be applied in a device or apparatus that utilizes solar energy to generate power, such as a user solar power source, a solar street lamp, a solar car, a solar building, etc. Of course, it can be understood that the application scenarios of the photovoltaic system 400 are not limited to this, that is, the photovoltaic system 400 can be applied in all fields that need to utilize solar energy to generate power. Taking a photovoltaic power generation system network as an example, the photovoltaic system 400 can include a photovoltaic array, a combiner box, and an inverter, the photovoltaic array can be an array combination of a plurality of cell assemblies 300, for example, a plurality of cell assemblies 300 can constitute a plurality of photovoltaic arrays, the photovoltaic arrays are connected to the combiner box, the combiner box can combine the current generated by the photovoltaic arrays, the combined current flows through the inverter to convert into alternating current required by a power grid, and then is connected to a power network to realize solar power supply.

[0123] In the description of the present specification, the description referring to the terms "some embodiments", "exemplary embodiments", "examples", "specific examples", or "some examples" and the like means that the specific features, structures, materials or characteristics described in connection with the embodiments or examples are included in at least one embodiment or example of the present disclosure. In the present specification, the exemplary description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0124] In addition, the above are only the preferred embodiments of the present disclosure, and are not intended to limit the present disclosure. Any modification, equivalent replacement and improvement made within the spirit and principle of the present disclosure shall be included in the protection scope of the present disclosure.

Claims

1. A solar cell, characterized by, The solar cell comprises: a cell substrate; a first fine grid disposed on the cell substrate, the first fine grid extending along a first direction; a second fine grid disposed on the cell substrate, the first fine grid and the second fine grid being distributed along a second direction; a bus structure disposed on the cell substrate, at least part of the first fine grid being connected to the bus structure; a first bending structure connecting the first fine grid and the bus structure, the first bending structure extending along the first direction and bending at least partially towards the second direction, a contact portion of the bus structure with the first bending structure having a width in the second direction greater than a width of the first fine grid in the second direction.

2. The solar cell according to claim 1, characterized in that, The first bending structure has a maximum bending distance in the second direction relative to the first fine grid of 100-400 μm.

3. The solar cell according to claim 1, characterized in that, The first bending structure has a height in a third direction of 35-200 μm, wherein the third direction is perpendicular to both the first direction and the second direction.

4. The solar cell of claim 1, wherein The solar cell further comprises a second fine grid disposed on the cell substrate, the second fine grid, the first fine grid and a third fine grid all extending along the first direction and being distributed along the second direction, the second fine grid and the third fine grid being adjacent to the first fine grid in the second direction. The first bending structure comprises a first bending segment and a second bending segment, the first bending segment bending relative to the first fine grid towards the second fine grid, and the second bending segment bending relative to the first fine grid towards the third fine grid.

5. The solar cell according to claim 4, characterized in that, The first bending segment has a maximum bending distance in the second direction relative to the first fine grid less than a distance between the first fine grid and the second fine grid. The second bending segment has a maximum bending distance in the second direction relative to the first fine grid less than a distance between the first fine grid and the third fine grid.

6. The solar cell of claim 4, wherein, The first bending segment and the second bending segment are alternately disposed along the first direction.

7. The solar cell of claim 4, wherein The first bending structure is in a wave shape.

8. The solar cell of claim 4, wherein, The solar cell further comprises a main grid line disposed on the cell substrate, the bus structure being formed on the main grid line, a plurality of the main grid lines extending along the second direction and being distributed along the first direction. The first fine grid is connected to the main grid line or the bus structure. The second fine grid and the third fine grid are disconnected at the main grid line.

9. The solar cell of claim 8, wherein, The solar cell further comprises a second bending structure connecting the main grid line and the bus structure, the second bending structure extending along the second direction and bending at least partially towards the first direction.

10. The solar cell of claim 9, wherein, The second bending structure has a maximum bending distance in the first direction relative to the main grid line of 100-400 μm. The second bending structure has a height in a third direction of 35-200 μm, wherein the third direction is perpendicular to both the first direction and the second direction.

11. A battery string, characterized by The solar cell as claimed in any one of claims 1-10.

12. A battery assembly characterized by, The cell string as claimed in claim 11.

13. A photovoltaic system characterized by, A battery assembly comprising the battery assembly of claim 12.

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