Solar cell, cell assembly and photovoltaic system

Abstract

The utility model provides a solar cell, a cell assembly and a photovoltaic system. The solar cell includes: a cell substrate including a doped layer; the fine grid is arranged on the battery substrate; wherein the thin grid comprises a first conductive part arranged on the cell substrate and a plurality of spaced second conductive parts, the first conductive part extends along a first direction, the first conductive part is connected with the plurality of second conductive parts, the second conductive parts are silver conductive parts, and the second conductive parts are electrically connected with the doping layer. In the first direction, the ratio of the size of the second conductive portion to the size of the first conductive portion is 0.2 to 0.9. Therefore, according to the utility model, the first conductive part of the fine grid is connected with the plurality of spaced second conductive parts which are made of silver and connected with the doping layer in the fine grid, so that the use amount of silver in the solar cell can be greatly reduced and the cost can be reduced while current carriers of the doping layer are collected.

Description

TECHNICAL FIELD

[0001] The utility model relates to photovoltaic technology field especially relates to a solar cell, battery assembly and photovoltaic system. BACKGROUND

[0002] Solar cell usually contacts with doped layer through fine grid to collect current. However, in the related art, a large amount of silver paste needs to be used in the process of manufacturing fine grid, and the manufacturing cost is high. Therefore, how to reduce the manufacturing cost of fine grid has become a problem to be solved. SUMMARY

[0003] The utility model provides a solar cell, battery assembly and photovoltaic system to solve the technical problem of how to reduce the manufacturing cost of fine grid.

[0004] The utility model embodiment is realized in this way, and the utility model provides a solar cell, battery assembly and photovoltaic system. A solar cell, the solar cell includes: cell base, the cell base includes doped layer;Fine grid is located at the cell base;Wherein, the fine grid includes the first conductive part and a plurality of interval second conductive parts located at the cell base, the first conductive part extends along the first direction, the first conductive part is connected with a plurality of second conductive parts, the second conductive part is silver conductive part, the second conductive part electrically connects the doped layer, in the first direction, the size ratio of the second conductive part and the size of the first conductive part is 0.2 to 0.9.

[0005] Further, a plurality of the second conductive parts are arranged at intervals along the first direction, and in the first direction, the interval between two adjacent second conductive parts is greater than 0 and less than 10 mm.

[0006] Further, the total area of all the second conductive parts is greater than 0 and less than 8 mm 2 .

[0007] Further, the extension direction of at least part of the second conductive parts intersects the first direction.

[0008] Further, all the second conductive parts extend along the first direction.

[0009] Further, the second conductive parts are located on the side of the first conductive part facing the cell base.

[0010] Further, the second conductive parts are located on the side of the first conductive part facing the cell base.

[0011] Further, the first conductive part comprises a first edge and a second edge in the second direction, the first edge and the second edge extending along the first direction; the second conductive part is arranged on a side of the first edge away from the second edge, and / or the second conductive part is arranged on a side of the second edge away from the first edge.

[0012] Further, the second conductive part is a line segment-shaped conductive part, a circular conductive part, a rectangular conductive part, or a rhombic conductive part.

[0013] The utility model embodiment further provides a battery assembly, the battery assembly includes the solar cell above described.

[0014] The utility model embodiment further provides a photovoltaic system, the photovoltaate system includes the battery assembly as described above.

[0015] Therefore, the utility model can utilize the first conductive part of the fine grid to connect the multiple spaced second conductive parts of the silver conductive part in the fine grid and connect the doped layer, so that the use amount of silver in the solar cell can be greatly reduced while collecting the carriers of the doped layer, and the cost is reduced. BRIEF DESCRIPTION OF DRAWINGS

[0016] In order to more clearly illustrate the technical scheme in the embodiments of the utility model or the prior art, the drawings needed to be used in the embodiment or the prior art description will be briefly introduced below, and obviously, the drawings in the following description are only some embodiments of the utility model, and for those skilled in the art, other drawings can also be obtained according to these drawings without creative labor.

[0017] Figure 1 It is the module schematic diagram of the photovoltaic system provided by an embodiment of the utility model;

[0018] Figure 2 It is the structural schematic diagram of the battery assembly provided by an embodiment of the utility model;

[0019] Figure 3 It is the structural schematic diagram of the solar cell provided by an embodiment of the utility model;

[0020] Figure 4 It is the structural schematic diagram of the solar cell provided by another embodiment of the utility model;

[0021] Figure 5 It is the structural schematic diagram of the fine grid in the solar cell provided by an embodiment of the utility model;

[0022] Figure 6 It is the structural schematic diagram of the fine grid in the solar cell provided by another embodiment of the utility model;

[0023] Figure 7 This is a schematic diagram of the fine grid structure in a solar cell provided in another embodiment of the present invention;

[0024] Figure 8 This is a schematic diagram of the fine grid structure in a solar cell provided in another embodiment of the present invention;

[0025] Figure 9 This is a schematic diagram of the fine grid structure in a solar cell provided in another embodiment of the present invention;

[0026] Figure 10 This is a schematic diagram of the fine grid structure in a solar cell provided in another embodiment of the present invention;

[0027] Figure 11 This is a partial cross-sectional structural diagram of a solar cell provided in one embodiment of the present invention.

[0028] Explanation of key component symbols: 1000, photovoltaic system; 1001, battery module; 100, solar cell; 10, battery substrate; 11, doped layer; 20, fine grid; 21, first conductive part; 22, second conductive part; 211, first edge; 212, second edge. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present utility model, and should not be construed as limiting the present utility model. Furthermore, it should be understood that the specific embodiments described herein are merely for explaining the present utility model and are not intended to limit the present utility model.

[0030] In the description of this utility model, it should be understood that the terms "length", "width", "upper", "lower", "top", "bottom", "lateral", "longitudinal", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0031] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the stated features. In the description of this utility model, "a plurality of" means two or more, unless otherwise explicitly specified.

[0032] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection, an electrical connection, or a connection that allows for communication; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0033] The following disclosure provides numerous different embodiments or examples for implementing various structures of the present invention. To simplify the disclosure, specific examples of components and arrangements are described below. These are merely examples and are not intended to limit the scope of the invention. Furthermore, reference numerals and / or letters may be repeated in different examples; such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed. In addition, examples of various specific processes and materials are provided in this invention; however, those skilled in the art will recognize the application of other processes and / or the use of other materials.

[0034] Please see Figure 1 and Figure 2 The photovoltaic system 1000 in this embodiment of the present invention may include a battery module 1001. The battery module 1001 may include a plurality of solar cells 100. The plurality of solar cells 100 may be connected in series to form a battery string. The battery strings in the battery module 1001 may be connected in series, in parallel, or in a series-parallel combination to achieve current collection and output. For example, the connection between the battery strings may be achieved by a bus bar.

[0035] In this embodiment, the photovoltaic system 1000 can be applied in photovoltaic power plants, such as ground-mounted power plants, rooftop power plants, and floating power plants. It can also be applied to equipment or devices that utilize solar energy for power generation, such as user solar power supplies, solar streetlights, solar cars, and solar buildings. Of course, it is understood that the application scenarios of the photovoltaic system 1000 are not limited to these; that is, the photovoltaic system 1000 can be applied in all fields that require solar energy for power generation. Taking a photovoltaic power generation system network as an example, the photovoltaic system 1000 may include a photovoltaic array, a combiner box, and an inverter. The photovoltaic array may be an array combination of multiple battery modules 1001. For example, multiple battery modules 1001 can form multiple photovoltaic arrays. The photovoltaic array is connected to the combiner box, which can collect the current generated by the photovoltaic array. The collected current flows through the inverter and is converted into AC power required by the mains power grid before being connected to the mains power grid to achieve solar power supply.

[0036] The accompanying drawings provided in this utility model are schematic diagrams, and some elements are not shown in the drawings. The purpose is to clearly describe the technical solution and highlight the key points of the utility model. It is not intended to limit the technical solution to exclude these unshown elements. That is to say, the drawings are merely examples and do not represent a limitation on the specific form of the back contact battery.

[0037] like Figures 3 to 11 As shown, the solar cell 100 in this embodiment of the present invention includes a cell substrate 10 and a fine grid 20 disposed on the cell substrate 10. The cell substrate 10 includes a doped layer 11; the fine grid 20 extends along a first direction. The fine grid 20 includes a first conductive portion 21 disposed on the cell substrate 10 and a plurality of spaced second conductive portions 22. The first conductive portion 21 connects to the plurality of second conductive portions 22. The second conductive portions 22 are silver conductive portions and are electrically connected to the doped layer 11. In the first direction, the ratio of the size D1 of the second conductive portion 22 to the size D3 of the first conductive portion 21 is 0.2 to 0.9.

[0038] Thus, this invention can utilize the first conductive part 21 of the fine grid 20 to connect the second conductive parts 22 of the fine grid 20, which are made of silver and connect the multiple intervals of the doped layer 11. Therefore, while collecting the charge carriers of the doped layer 11, the amount of silver used in the solar cell 100 can be greatly reduced, thereby reducing the cost.

[0039] Specifically, the battery substrate 10 is the main body of the solar cell 100. For example, the battery substrate 10 may include a silicon substrate, and may also include a dielectric layer, a passivation layer, etc., which can be configured according to actual conditions. The passivation layer is stacked on the doped layer 11. The second conductive portions 22 in the fine grid 20 are silver conductive portions made of silver. Each second conductive portion 22 can burn through the passivation layer and contact the doped layer 11, achieving an electrical connection between the second conductive portion 22 and the doped layer 11, thereby allowing the second conductive portion 22 to collect charge carriers in the doped layer 11. Furthermore, the first conductive portion 21 is connected to the second conductive portion 22, allowing the first conductive portion 21 to collect the charge carriers collected by the second conductive portion 22. Thus, the fine grid 20 can collect charge carriers in the doped layer 11 through the second conductive portion 22 and the first conductive portion 21.

[0040] Specifically, the solar cell 100 can be either a grid-connected solar cell 100 or a gridless solar cell 100, and is not limited thereto. Furthermore, the second conductive part 22 can be made of silver paste.

[0041] It is understood that the fine grid 20 in the prior art is usually made of silver. In this embodiment of the present invention, the second conductive part 22 of the silver conductive part is intermittently arranged, and the entire fine grid 20 does not need to be made entirely of silver. Only a part of the fine grid 20 is made of silver, thereby saving silver material in the manufacturing process of the fine grid 20, and thus reducing the manufacturing cost of the solar cell 100.

[0042] Moreover, since charge carriers can be directly collected through the silver-made second conductive part 22, while the first conductive part 21 acts as a convergence part, the fine grid 20 provided in this embodiment of the present invention can reduce the dependence on the amount of silver paste while ensuring the collection of charge carriers.

[0043] Furthermore, the first conductive portion 21 can be made of aluminum paste or copper paste. For example, the first conductive portion 21 is a copper conductive portion; or, the first conductive portion 21 is an aluminum conductive portion. This further reduces the amount of silver used in the solar cell 100, thus lowering costs.

[0044] Specifically, in the solar cell 100, the fine grid 20 provided by this invention can be one or more, and there is no limitation here. Each fine grid 20 includes a first conductive part 21 and a plurality of second conductive parts 22, and each second conductive part 22 is connected to the first conductive part 21.

[0045] Furthermore, the first conductive portion 21 is the main body of the fine gate 20, and the first conductive portion 21 extends along a first direction. Specifically, the first direction can be a horizontal direction, and the first conductive portion 21 extends in the horizontal direction; or, the first direction can be an inclined direction, and the extension direction of the first conductive portion 21 has a certain angle with the horizontal direction, which is not limited here.

[0046] like Figure 5 As shown, the fine grid 20 further includes a plurality of second conductive portions 22, each of which is connected to a first conductive portion 21. In the first direction, the ratio of the size D1 of a single second conductive portion 22 to the size D3 of the first conductive portion 21 is 0.2 to 0.9, for example, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, or 0.9. This effectively reduces the carrier transport path between the second conductive portion 22 and the doped layer 11, thereby improving carrier transport efficiency and increasing the photoelectric conversion efficiency of the solar cell 100. It is understood that when the ratio of the size D1 of the second conductive portion 22 to the size D3 of the first conductive portion 21 is too small, the effective contact area between the second conductive portion 22 and the doped layer 11 is insufficient, thus failing to collect enough carriers from the doped layer 11; when the ratio of the size D1 of the second conductive portion 22 to the size D3 of the first conductive portion 21 is too large, it leads to excessive silver paste usage, thus failing to effectively reduce the cost of using the solar cell 100.

[0047] In this embodiment of the invention, the second conductive portion 22 has a certain size D1, and the second conductive portion 22 is generally in the shape of a line segment. Compared with other solutions where the second conductive portion 22 is in the shape of a point, in the first direction, the ratio of the size D1 of the second conductive portion 22 to the size D3 of the first conductive portion 21 is 0.2 to 0.9, which can effectively reduce the carrier transport path between the second conductive portion 22 and the doped layer 11, thereby improving the carrier transport efficiency and increasing the photoelectric conversion efficiency of the solar cell 100.

[0048] like Figure 5As shown, in one possible implementation, a plurality of second conductive portions 22 are arranged at intervals along a first direction, wherein the distance D2 between two adjacent second conductive portions 22 in the first direction is greater than 0 and less than 10 mm. For example, it is 0.5 mm, 2 mm, 5 mm, 8 mm, 9 mm, or 9.5 mm. It is understood that if the distance D2 between two adjacent second conductive portions 22 in the first direction is too small, it will increase the amount of silver used in the solar cell 100, thereby increasing the manufacturing cost of the solar cell 100; at the same time, if the distance D2 between two adjacent second conductive portions 22 in the first direction is too large, it will increase the carrier transport path between the second conductive portion 22 and the doped layer 11, thereby reducing the carrier transport efficiency and lowering the photoelectric conversion efficiency of the solar cell 100. Thus, setting the distance D2 between two adjacent second conductive portions 22 in the first direction to be greater than 0 and less than 10 mm can reduce the manufacturing cost of the solar cell 100 while ensuring the photoelectric conversion efficiency of the solar cell 100.

[0049] like Figures 5 to 9 As shown, in one possible implementation, the total area of ​​all the second conductive portions 22 is greater than 0 and less than 8 mm². 2 For example, 1mm, 3mm 2 4mm 2 5mm 2 7mm 2 7.28mm 2 Understandably, if the area of ​​the second conductive portion 22 is too large, it will increase the amount of silver used in the solar cell 100, thereby increasing the manufacturing cost of the solar cell 100; at the same time, if the area of ​​the second conductive portion 22 is too small, it will increase the carrier transport path between the second conductive portion 22 and the doped layer 11, thereby reducing the carrier transport efficiency. Therefore, the total area of ​​all the second conductive portions 22 is set to be greater than 0 and less than 8 mm². 2 This can reduce the manufacturing cost of solar cell 100 while ensuring the photoelectric conversion efficiency of solar cell 100.

[0050] like Figures 7 to 9 As shown, in one possible embodiment, at least a portion of the extension direction of the second conductive portion 22 intersects the first direction. This allows the second conductive portion 22 to cover a wider area, thereby increasing the effective contact area between the second conductive portion 22 and the doped layer 11, and consequently increasing the photoelectric conversion efficiency of the solar cell 100.

[0051] It is understood that "at least a portion of the extension direction of the second conductive part 22 intersects the first direction" means that a portion of the extension direction of the second conductive part 22 intersects the first direction, or that all the extension directions of the second conductive part 22 intersect the first direction.

[0052] like Figure 9 As shown, for example, a portion of the second conductive portion 22 may form a certain angle with the first direction. The second conductive portion 22 may simultaneously include a portion whose extending direction intersects the first direction and a portion whose extending direction is parallel to the first direction.

[0053] like Figures 7 to 9 As shown, for example, all of the second conductive portion 22 may form a certain angle with the first direction. In other words, the second conductive portion 22 may be inclined relative to the first conductive portion 21.

[0054] like Figure 5 and Figure 6 As shown, in one possible implementation, the entire second conductive portion 22 extends along the first direction. This helps maintain the consistency in the fabrication of the second conductive portion 22 and the first conductive portion 21, thereby reducing the process complexity of the fine grid 20 and improving the yield and stability of the solar cell 100 production.

[0055] like Figure 5 and Figure 11 As shown, in one possible implementation, the second conductive portion 22 is disposed on the side of the first conductive portion 21 facing the battery substrate 10. Thus, the first conductive portion 21 can provide an additional protective layer for the silver-based second conductive portion 22, helping to reduce the impact of external mechanical stress on the second conductive portion 22 and improving the stability of the electrical connection between the second conductive portion 22 and the doped layer 11.

[0056] Specifically, the second conductive portion 22 is disposed on the side of the first conductive portion 21 facing the battery substrate 10. In other words, the second conductive portion 22 can be stacked on top of the first conductive portion 21. When fabricating the fine grid 20, the position of the second conductive portion 22 can be accurately positioned by the first conductive portion 21, which facilitates the placement of the second conductive portion 22.

[0057] like Figure 7 and Figure 8 As shown, in one possible implementation, the second conductive portion 22 can be in the shape of a triangular wave or a sine wave. For example, the second conductive portion 22 can be a triangular waveform conductive portion or a sine wave conductive portion. Specifically, the structure of the second conductive portion 22 can be adjusted by adjusting its period or amplitude.

[0058] like Figure 10As shown, in one possible implementation, the second conductive portion 22 can be in the shape of a line segment, a circle, a rectangle, or a rhombus. For example, the second conductive portion 22 can be a line segment conductive portion, a circular conductive portion, a rectangular conductive portion, or a rhombus conductive portion. Specifically, the structure of the second conductive portion 22 can be adjusted to correspond to the arrangement of fine grids 20 of different sizes.

[0059] like Figure 6 As shown, in one possible implementation, the first conductive portion 21 includes a first edge 211 and a second edge 212 in a second direction, the first edge 211 and the second edge 212 extending along the first direction; the second conductive portion 22 is disposed on the side of the first edge 211 facing away from the second edge 212, and / or, the second conductive portion 22 is disposed on the side of the second edge 212 facing away from the first edge 211. Thus, in this embodiment of the present invention, the second conductive portion 22 can also be disposed on the edge of the first conductive portion 21, and when setting the fine grid 20, the second conductive portion 22 can be printed simultaneously with the first conductive portion 21, thereby simplifying the manufacturing process of the fine grid 20.

[0060] It is understood that the first edge 211 and the second edge 212 are the two boundary lines of the first conductive portion 21 in the second direction. The second conductive portion 22 can be disposed outside the first edge 211 and / or the second edge 212. Preferably, the second conductive portion 22 and the first conductive portion 21 can be disposed in the same plane, thereby enabling the use of co-mold printing, co-mold electroplating, or co-layer deposition, reducing process steps, improving production efficiency and yield, and further simplifying the fabrication process of the fine grid 20.

[0061] It is understood that in such an embodiment, the battery assembly 1001 may also include a frame, a backsheet, photovoltaic glass, and an encapsulating film. The encapsulating film may be filled between the front and back surfaces of the solar cells 100, the photovoltaic glass, adjacent solar cells 100, etc. As a filler, it may be a transparent colloid with good light transmittance and aging resistance. For example, the encapsulating film may be an EVA film or a POE film, and the specific choice can be made according to the actual situation, without limitation.

[0062] Photovoltaic glass can be applied to the encapsulating film on the front side of the solar cell 100. This photovoltaic glass can be ultra-clear glass, possessing high light transmittance, high transparency, and superior physical, mechanical, and optical properties. For example, ultra-clear glass can achieve a light transmittance of over 92%, protecting the solar cell 100 while minimizing impact on its efficiency. Simultaneously, the encapsulating film bonds the photovoltaic glass and the solar cell 100 together, providing sealing, insulation, and waterproofing / moisture protection for the solar cell 100.

[0063] The backsheet can be attached to the adhesive film on the back side of the solar cell 100. The backsheet provides protection and support for the solar cell 100, and possesses reliable insulation, water resistance, and aging resistance. Multiple options are available for the backsheet, typically including tempered glass, acrylic glass, aluminum alloy TPT composite adhesive film, etc., and the specific choice is determined based on the specific circumstances and is not limited here. The backsheet, solar cell 100, adhesive film, and photovoltaic glass can be integrated into a frame. The frame serves as the main external support structure for the entire battery module 1001, providing stable support and installation for the battery module 1001. For example, the battery module 1001 can be installed at the desired location via the frame.

[0064] In the description of this specification, references to terms such as "some embodiments," "illustrative embodiments," "examples," "specific examples," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with an embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0065] Furthermore, the above description is merely a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A solar cell, characterized in that, include: A battery substrate, the battery substrate including a doped layer; Fine grids disposed on the battery substrate; The fine grid includes a first conductive portion disposed on the battery substrate and a plurality of spaced second conductive portions. The first conductive portion extends along a first direction and is connected to a plurality of second conductive portions. The second conductive portions are silver conductive portions and are electrically connected to the doped layer. In the first direction, the ratio of the size of the second conductive portion to the size of the first conductive portion is 0.2 to 0.

9.

2. The solar cell according to claim 1, characterized in that, Multiple second conductive parts are arranged at intervals along the first direction, and the distance between two adjacent second conductive parts in the first direction is greater than 0 and less than 10 mm.

3. The solar cell according to claim 1, characterized in that, The total area of ​​all the second conductive parts is greater than 0 and less than 8 mm. 2 .

4. The solar cell according to claim 1, characterized in that, The first conductive part is a copper conductive part; or, the first conductive part is an aluminum conductive part.

5. The solar cell according to claim 1, characterized in that, At least a portion of the second conductive portion extends in a direction that intersects the first direction.

6. The solar cell according to claim 1, characterized in that, The entire second conductive portion extends along the first direction.

7. The solar cell according to claim 1, characterized in that, The second conductive portion is disposed on the side of the first conductive portion facing the battery substrate.

8. The solar cell according to claim 1, characterized in that, The first conductive portion includes a first edge and a second edge in a second direction, the first edge and the second edge extending along the first direction; The second conductive portion is disposed on the side of the first edge facing away from the second edge, and / or the second conductive portion is disposed on the side of the second edge facing away from the first edge.

9. The solar cell according to claim 1, characterized in that, The second conductive part is a line segment conductive part, a circular conductive part, a rectangular conductive part, or a rhomboid conductive part.

10. A battery assembly, characterized in that, The battery assembly includes a solar cell as described in any one of claims 1 to 9.

11. A photovoltaic system, characterized in that, The photovoltaic system includes the battery module as described in claim 10.

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