Back contact cell, cell assembly and photovoltaic system

Abstract

The utility model provides a back contact battery, a battery assembly and a photovoltaic system. The back contact battery comprises a battery substrate; the first main grids and the second main grids extend along a first direction and are alternately arranged at intervals along a second direction; the first fine grids and the second fine grids extend along the second direction and are alternately arranged at intervals along the first direction; the first anti-breaking grid lines and the second anti-breaking grid lines are arranged on the battery substrate, in the first direction, the first anti-breaking grid lines are connected with the two adjacent first fine grids, the second anti-breaking grid lines are connected with the two adjacent second fine grids, first insulating parts are arranged between the first anti-breaking grid lines and the second fine grids, and second insulating parts are arranged between the first anti-breaking grid lines and the second fine grids. And a second insulating part is arranged between the second anti-breaking grid line and the first fine grid. Therefore, the situation that local current of the back contact battery cannot be transmitted or collected due to breakage of the grid lines can be avoided, the electrical performance reduction and hot spot risk of the back contact battery are reduced, and the photoelectric conversion efficiency of the back contact battery is improved.

Description

TECHNICAL FIELD

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

[0002] The back contact cell collects current through the grid line. However, in the related art, the grid line of the back contact cell is prone to breakage, which in turn reduces the current collection capacity of the back contact cell, thereby reducing the photoelectric conversion efficiency of the back contact cell.

[0003] Therefore, how to improve the photoelectric conversion efficiency of the back contact cell has become a problem to be solved. SUMMARY

[0004] The utility model provides a kind of back contact cell, battery assembly and photovoltaic system to solve the technical problem of improving the photoelectric conversion efficiency of back contact cell.

[0005] The utility model embodiment is realized as follows: the utility model provides a kind of back contact cell, battery assembly and photovoltaic system. A kind of back contact cell, including cell substrate;First main grid and second main grid are located at the cell substrate, the first main grid and the second main grid extend along the first direction, the first main grid and the second main grid are alternately spaced along the second direction, the polarity of the first main grid and the second main grid is opposite, the first direction and the second direction intersect;First fine grid and second fine grid are located at the cell substrate, the first fine grid and the second fine grid extend along the second direction, the first fine grid and the second fine grid are alternately spaced along the first direction, the polarity of the first fine grid and the second fine grid is opposite, the first fine grid and the first main grid are connected, the second fine grid and the second main grid are connected;First anti-breaking grid line and second anti-breaking grid line are located at the cell substrate, in the first direction, the first anti-breaking grid line is connected with two adjacent first fine grid, the second anti-breaking grid line is connected with two adjacent second fine grid, and first insulating piece is arranged between the first anti-breaking grid line and the second fine grid, second insulating piece is arranged between the second anti-breaking grid line and the first fine grid.

[0006] Further, along the first direction, the cell substrate includes first edge region, middle region arranged in sequence;The first anti-breaking grid line and the second anti-breaking grid line are located in the first edge region.

[0007] Further, along the first direction, the size of first edge region is 20mm to 50mm.

[0008] Further, the battery substrate further comprises a second edge region, the first edge region, the middle region and the second edge region are arranged in sequence along the first direction; the first anti-breaking grid line and the second anti-breaking grid line are located in the second edge region.

[0009] Further, along the first direction, a size of the second edge region is 20mm to 50mm.

[0010] Further, the first conductive connection structure and the second conductive connection structure are further included, the first conductive connection structure is arranged on the first main grid, and the second conductive connection structure is arranged on the second main grid; the first anti-breaking grid line is connected with the first fine grid connected with the first conductive connection structure, and the second anti-breaking grid line is connected with the second fine grid connected with the second conductive connection structure.

[0011] Further, the first anti-breaking grid line and the second anti-breaking grid line are both non-burn-through type grid lines.

[0012] Further, along the first direction, a number of the first anti-breaking grid lines between two adjacent first fine grids is one or more; and / or, along the first direction, a number of the second anti-breaking grid lines between two adjacent second fine grids is one or more.

[0013] Further, along the first direction, at least part of the first anti-breaking grid lines are connected with end portions of two adjacent first fine grids; and / or, along the first direction, at least part of the second anti-breaking grid lines are connected with end portions of two adjacent second fine grids.

[0014] Further, along the second direction, a size of the first anti-breaking grid line is 10um to 500um, and a size of the second anti-breaking grid line is 10um to 500um.

[0015] Further, a size of the first anti-breaking grid line in the second direction is greater than a size of the first fine grid in the first direction; and / or, a size of the second anti-breaking grid line in the second direction is greater than a size of the second fine grid in the first direction.

[0016] The utility model embodiment further provides a battery assembly, the battery assembly includes the back contact battery as described above.

[0017] The utility model embodiment further provides a photovoltaic system, the photovoltaic system includes the battery assembly as described above.

[0018] The utility model discloses a first prevent breaking grid line with two first fine grids adjacent in the first direction is connected, and a second prevent breaking grid line with two second fine grids adjacent in the first direction is connected, when the first fine grid and / or second fine grid line breaks, the current can bypass the breaking point through the first prevent breaking grid line and / or second prevent breaking grid, so that the current can continue transmission, avoids the partial current of back contact battery from being unable to transmit or gather due to the grid line breakage, reduces the back contact battery electric performance decline and hot spot risk, and further improves the photoelectric conversion efficiency of back contact battery. BRIEF DESCRIPTION OF DRAWINGS

[0019] In order to more clearly illustrate the technical scheme in the embodiment of the utility model or prior art, the following will be briefly introduced the drawing needed to be used in the embodiment or prior art description, obviously, the drawing in the following description only is some embodiment of the utility model, for the ordinary skilled person in the art, under the premise of not paying the creative labor, still can obtain other drawing according to these drawings.

[0020] Figure 1 It is the module schematic diagram of photovoltaic system that an embodiment of the utility model provides;

[0021] Figure 2 It is the module schematic diagram of battery assembly that an embodiment of the utility model provides;

[0022] Figure 3 It is the structure schematic diagram of back contact battery that another embodiment of the utility model provides;

[0023] Figure 4 It is the structure schematic diagram of back contact battery that another embodiment of the utility model provides;

[0024] Figure 5 It is the partial structure schematic diagram of back contact battery that still another embodiment of the utility model provides;

[0025] Figure 6 It is the partial structure schematic diagram of back contact battery that still another embodiment of the utility model provides.

[0026] Main element symbol explanation: 1000, photovoltaic system; 1001, battery assembly; 100, back contact cell; 10, cell substrate; 11, first edge region; 12, middle region; 13, second edge region; 21, first main grid; 22, second main grid; 31, first fine grid; 32, second fine grid; 41, first anti-breaking grid line; 42, second anti-breaking grid line; 51, first insulating piece; 52, second insulating piece; 211, first conductive connecting structure; 221, second conductive connecting structure. DETAILED DESCRIPTION

[0027] In order to make the purpose, technical scheme and advantages of the utility model more clearly, the following will be further described in detail in combination with the drawings and examples. The examples described below by referring to the drawings are exemplary and are only used to explain the utility model, and cannot be understood as limiting the utility model. In addition, it should be understood that the specific examples described herein are only used to explain the utility model, and are not used to limit the utility model.

[0028] In the description of the utility model, it should be understood that the terms "length", "width", "upper", "lower", "top", "bottom", "transverse", "longitudinal" and the like indicate the orientation or positional relationship shown in the drawings, which is only for the convenience of describing the utility model and simplifying the description, and does not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, therefore it cannot be understood as limiting the utility model.

[0029] In addition, the terms "first", "second" are only for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features limited by "first", "second" can explicitly or implicitly include one or more of the features. In the description of the utility model, the meaning of "multiple" is two or more, unless otherwise specifically limited.

[0030] In the description of the utility model, it should be noted that, unless otherwise specifically specified and limited, the terms "mounting", "connection", "connection" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected or can communicate with each other; it can be directly connected, or indirectly connected through an intermediate medium; it can be the communication or interaction relationship between two elements. For ordinary skilled in the art, the specific meaning of the above terms in the utility model can be understood according to the specific circumstances.

[0031] The disclosure below provides many different embodiments or examples for implementing different structures of the present application. For the sake of simplicity, the description below refers to specific examples in order to provide a thorough description of the present application. It will be appreciated that these specific examples are only examples and are not intended to limit the present application in any way. Moreover, the present application can employ additional or different features, and the application is therefore not limited to the specific examples described. Furthermore, the present application provides examples of various specific processes and materials, but one skilled in the art will recognize that other processes and / or materials can be used.

[0032] Referring to Figure 1 and Figure 2 The photovoltaic system 1000 in the embodiments of the present application can include the battery assembly 1001 in the embodiments of the present application. The battery assembly 1001 in the embodiments of the present application can include a plurality of back contact cells 100. The plurality of back contact cells 100 can be sequentially connected in series by welding strips to form a cell string. The cell strings in the battery assembly 1001 can be connected in series, in parallel, or in a combination of series and parallel to achieve current bus output. For example, the connection between the cell strings can be achieved by bus bars.

[0033] In the present embodiment, the photovoltaic system 1000 can be applied in a battery assembly 1001 power station, such as a ground power station, a roof power station, a water surface power station, etc. It can also be applied in a device or apparatus that uses solar energy to generate electricity, 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 1000 are not limited to this, that is, the photovoltaic system 1000 can be applied in all fields that need to use solar energy to generate electricity. Taking the battery assembly 1001 power generation system network as an example, the photovoltaic system 1000 can include a battery assembly 1001 array, a bus box, and an inverter. The battery assembly 1001 array can be an array combination of a plurality of battery assemblies 1001. For example, a plurality of battery assemblies 1001 can form a plurality of battery assembly 1001 arrays. The battery assembly 1001 array is connected to the bus box. The bus box can bus the current generated by the battery assembly 1001 array. After the bused current flows through the inverter to convert it into alternating current required by the power grid, it is connected to the power network to achieve solar power supply.

[0034] The drawings provided by the present application are schematic drawings, and some elements are not shown in the drawings. The purpose is to clearly describe the technical solutions and highlight the key points of the present application. It is not intended to limit the technical solutions and does not include these unshown elements. That is, the drawings are only examples and do not represent a specific form of the battery assembly 1001.

[0035] As Figures 3 to 6As shown, the back contact battery 100 in the embodiment of the utility model includes: battery substrate 10;First main grid 21 and second main grid 22 arranged at battery substrate 10, first main grid 21 and second main grid 22 extend along the first direction, first main grid 21 and second main grid 22 are alternately spaced along the second direction, the polarity of first main grid 21 and second main grid 22 is opposite, the first direction and the second direction cross;First fine grid 31 and second fine grid 32 arranged at battery substrate 10, first fine grid 31 and second fine grid 32 extend along the second direction, first fine grid 31 and second fine grid 32 are alternately spaced along the first direction, the polarity of first fine grid 31 and second fine grid 32 is opposite, first fine grid 31 and first main grid 21 are connected, second fine grid 32 and second main grid 22 are connected;First anti-breaking grid line 41 and second anti-breaking grid line 42 are arranged at battery substrate 10, in the first direction, first anti-breaking grid line 41 is connected with the two first fine grid 31 adjacent, second anti-breaking grid line 42 is connected with the two second fine grid 32 adjacent, and first insulating part 51 is arranged between first anti-breaking grid line 41 and second fine grid 32, second insulating part 52 is arranged between second anti-breaking grid line 42 and first fine grid 31.

[0036] In the utility model, through the connection of first anti-breaking grid line 41 and the two first fine grid 31 adjacent in the first direction, through the connection of second anti-breaking grid line 42 and the two second fine grid 32 adjacent in the first direction, when the first fine grid 31 and / or second fine grid 32 line breaks, the current can bypass the breaking point through first anti-breaking grid line 41 and / or second anti-breaking grid line 42, so that the current can continue to transmit, avoid the local current of back contact battery 100 from being unable to transmit or gather due to the breakage of grid line, reduce the risk of back contact battery 100 electric performance decline and hot spot, further improve the photoelectric conversion efficiency of back contact battery 100.

[0037] Meanwhile, first anti-breaking grid line 41 can provide additional support for first fine grid 31, second anti-breaking grid line 42 can provide additional support for second fine grid 32, increase the structural stability of first fine grid 31 and second fine grid 32, reduce the risk of first fine grid 31 and second fine grid 32 breakage, improve the photoelectric conversion efficiency of back contact battery 100, and improve the stability and reliability of back contact battery 100.

[0038] In addition, as Figures 3 to 6 As shown, by insulating first anti-breaking grid line 41 and second fine grid 32 through first insulating part 51, by insulating second anti-breaking grid line 42 and first fine grid 31 through second insulating part 52, the risk of back contact battery 100 short circuit can be avoided.

[0039] It is understood that when the first anti-breakage grid line 41 is connected to two adjacent first fine grids 31 in the first direction, the first anti-breakage grid line 41 will pass through the second fine grid 32 located between the two adjacent first fine grids 31. Therefore, in order to avoid the first anti-breakage grid line 41 contacting the second fine grid 32 and causing a short circuit, in this embodiment of the present invention, a first insulating member 51 is provided in the second fine grid 32. The first insulating member 51 is specifically located between the second fine grid 32 and the first anti-breakage grid line 41, and the first insulating member 51 insulates the second fine grid 32 and the first anti-breakage grid line 41 to prevent the first anti-breakage grid line 41 from conducting with the second fine grid 32.

[0040] It is understandable that when the second anti-breakage grid line 42 is connected to two adjacent second fine grids 32 in the first direction, the second anti-breakage grid line 42 will pass through the first fine grid 31 located between the two adjacent second fine grids 32. Therefore, in order to avoid the second anti-breakage grid line 42 contacting the first fine grid 31 and causing a short circuit, in this embodiment of the present invention, a second insulating member 52 is provided in the first fine grid 31. The second insulating member 52 is specifically located between the first fine grid 31 and the second anti-breakage grid line 42, and the second insulating member 52 insulates the first fine grid 31 and the second anti-breakage grid line 42 to prevent the second anti-breakage grid line 42 from conducting with the first fine grid 31.

[0041] like Figures 2 to 6 As shown, specifically, the battery substrate 10 is the main body of the back contact battery 100. For example, the battery substrate 10 may include a silicon substrate, and may also include a dielectric layer, a doped layer, a passivation layer, etc., which can be set according to the actual situation.

[0042] Specifically, the battery substrate 10 has a first main grid 21 and a second main grid 22, which are arranged alternately along a second direction with opposite polarities. In other words, along the second direction, a second main grid 22 is provided between two adjacent first main grids 21; or, a first main grid 21 is provided between two adjacent second main grids 22. The polarity of one of the first main grids 21 and the second main grid 22 is positive, and the other is negative; this is not limited here.

[0043] Specifically, the battery substrate 10 is provided with first fine grids 31 and second fine grids 32, and the first fine grids 31 and the second fine grids 32 with opposite polarities are alternately and spacedly arranged along a first direction. In other words, along the first direction, one second fine grid 32 is arranged between two adjacent first fine grids 31, or one first fine grid 31 is arranged between two adjacent second fine grids 32. The polarities of one of the first fine grids 31 and the second fine grids 32 are positive, and the polarities of the other are negative, which are not limited herein. The extension directions of the first fine grids 31 and the second fine grids 32 cross the extension directions of the first main grids 21 and the second main grids 22. The first fine grids 31 are connected with the first main grids 21 with the same polarity, and the second fine grids 32 are connected with the second main grids 22 with the same polarity.

[0044] As shown in Figures 2 to 6 In the embodiment of the utility model, the battery substrate 10 is further provided with first anti-breaking grid lines 41 and second anti-breaking grid lines 42, and the first anti-breaking grid lines 41 are connected with two adjacent first fine grids 31 along the first direction, and the second anti-breaking grid lines 42 are connected with two adjacent second fine grids 32. In other words, the two ends of the first anti-breaking grid lines 41 are connected with the first fine grids 31 respectively, and the two ends of the second anti-breaking grid lines 42 are connected with the second fine grids 32 respectively. One or more first anti-breaking grid lines 41 can be connected between two adjacent first fine grids 31, and one or more second anti-breaking grid lines 42 can be connected between two adjacent second fine grids 32, which are not limited herein. The extension directions of the first anti-breaking grid lines 41 and the second anti-breaking grid lines 42 cross the second direction specifically. Alternatively, the first anti-breaking grid lines 41 and the second anti-breaking grid lines 42 can extend along the first direction specifically.

[0045] It can be understood that, since the first fine grids 31 and the second fine grids 32 extend along the second direction, if the first fine grids 31 and the second fine grids 32 are broken at somewhere along the second direction, the current cannot continue to transmit along the fine grids at the broken place. In the embodiment of the utility model, the anti-breaking grid lines are arranged to connect the adjacent fine grids along the first direction. When the first fine grids 31 and / or the second fine grids 32 are broken, the current can bypass the broken point through the first anti-breaking grid lines 41 and / or the second anti-breaking grid lines 42, so that the current can continue to transmit, the local current of the back contact battery 100 caused by the breaking of the grid lines can be avoided, the risk of the decrease of the electrical performance of the back contact battery 100 and the hot spot can be reduced, and the photoelectric conversion efficiency of the back contact battery 100 can be improved.

[0046] Moreover, the grid lines are prone to be broken during the manufacturing or long-term working of the back contact battery 100. Therefore, the anti-breaking grid lines are introduced in the embodiment of the utility model to enhance the mechanical strength of the grid lines in the back contact battery 100, so as to reduce the risk of the breaking of the grid lines in the back contact battery 100.

[0047] It is understood that the polarity of the first anti-breakage grid line 41 is the same as that of the first fine grid 31 and the first main grid 21, and the polarity of the second anti-breakage grid line 42 is the same as that of the second fine grid 32 and the second main grid 22. It is not specified here that one of the first anti-breakage grid line 41 and the second anti-breakage grid line 42 is positive and the other is negative.

[0048] Optionally, a first anti-breakage grid line 41 may be provided between all two adjacent first fine grids 31 in the first direction. Alternatively, the first anti-breakage grid line 41 may be provided between some of the two adjacent first fine grids 31 in the first direction. The specific choice can be made according to the actual situation and is not limited here.

[0049] Optionally, a second anti-breakage grid line 42 may be provided between all two adjacent second fine grids 32 in the first direction. Alternatively, a second anti-breakage grid line 42 may be provided between some of the two adjacent second fine grids 32 in the first direction. The specific choice can be made according to the actual situation and is not limited here.

[0050] like Figures 2 to 6 As shown, in some possible implementations, in the first direction, the number of first anti-breakage grid lines 41 between two adjacent first grids 31 is one or more; and / or, in the first direction, the number of second anti-breakage grid lines 42 between two adjacent second grids 32 is one or more.

[0051] In some embodiments, a plurality of first anti-breakage grid lines 41 may be connected between two adjacent first fine grids 31 in the first direction, and a plurality of second anti-breakage grid lines 42 may be connected between two adjacent second fine grids 32 in the first direction. This further increases the mechanical strength of the grid lines in the back contact battery 100, thereby further reducing the risk of grid line breakage in the back contact battery 100. Simultaneously, even when multiple breakage points occur in the fine grids, current can continue to flow, preventing local current loss or accumulation in the back contact battery 100 due to grid line breakage, reducing the degradation of the electrical performance of the back contact battery 100 and the risk of hot spots, thereby improving the photoelectric conversion efficiency of the back contact battery 100.

[0052] In some embodiments, a first anti-breakage grid line 41 may be connected between two adjacent first fine grids 31 in the first direction, and a second anti-breakage grid line 42 may be connected between two adjacent second fine grids 32 in the first direction. This reduces the manufacturing cost of the back contact battery 100.

[0053] like Figures 2 to 6As shown, in some possible embodiments, in the first direction, at least a portion of the first anti-breakage grid line 41 is connected to the ends of two adjacent first fine grids 31; and / or, in the first direction, at least a portion of the second anti-breakage grid line 42 is connected to the ends of two adjacent second fine grids 32. It is understood that since the first anti-breakage grid line 41 is connected to the ends of the first fine grids 31, the current transmitted to the first fine grids 31 can continue to be transmitted through the first anti-breakage grid line 41 regardless of where the breakage point occurs in the first fine grids 31. Similarly, since the second anti-breakage grid line 42 is connected to the ends of the second fine grids 32, the current transmitted to the second fine grids 32 can continue to be transmitted through the second anti-breakage grid line 42 regardless of where the breakage point occurs in the second fine grids 32. In this way, it is possible to avoid the inability to transmit or collect local current in the back contact battery 100 due to grid line breakage, reducing the degradation of the electrical performance of the back contact battery 100 and the risk of hot spots, thereby improving the photoelectric conversion efficiency of the back contact battery 100.

[0054] It is understood that "at least some of the first anti-breakage grid lines 41 are connected to the ends of two adjacent first fine grids 31" means that some of the first anti-breakage grid lines 41 can be connected to the ends of the first fine grids 31; or all of the first anti-breakage grid lines 41 can be connected to the ends of the first fine grids 31. No limitation is made here.

[0055] It is understood that "at least some of the second anti-breakage grid lines 42 are connected to the ends of two adjacent second fine grids 32" means that some of the second anti-breakage grid lines 42 can be connected to the end of the first fine grid 32; or all of the second anti-breakage grid lines 42 can be connected to the end of the second fine grid 32. No limitation is made here.

[0056] like Figures 2 to 6 As shown, in one possible implementation, the battery substrate 10 includes a first edge region 11 and a middle region 12 arranged sequentially along a first direction; the first anti-breakage grid line 41 and the second anti-breakage grid line 42 are located in the first edge region 11.

[0057] It is understandable that in the back contact battery 100, the stress is more concentrated at the edge, making the grid lines at the edge more prone to breakage. Therefore, in this embodiment, the first anti-breakage grid line 41 and the second anti-breakage grid line 42 are located in the first edge region 11. This prevents current from being unable to be transmitted or collected at the edge of the back contact battery 100 due to grid line breakage, reduces the degradation of the electrical performance of the back contact battery 100 and the risk of hot spots, thereby improving the photoelectric conversion efficiency of the back contact battery 100.

[0058] It is understood that, in the first direction, the first edge region 11 specifically refers to the edge portion of the battery substrate 10. In one possible implementation, the size D1 of the first edge region 11 is 20mm to 50mm. For example, it is 20mm, 25mm, 30mm, 35mm, 40mm, or 50mm.

[0059] like Figure 4 As shown, in some embodiments, a first anti-breakage grid line 41 and a second anti-breakage grid line 42 can be provided in the first edge region 11, while the first anti-breakage grid line 41 and the second anti-breakage grid line 42 are not provided in the middle region 12. Thus, by specifically providing reinforcing grid lines for edge portions prone to breakage, material costs and process complexity can be reduced, unnecessary metal consumables and additional manufacturing steps can be avoided, the electrical performance degradation and hot spot risk of the back contact battery 100 can be reduced, and the photoelectric conversion efficiency of the back contact battery 100 can be improved while reducing the manufacturing cost of the back contact battery 100.

[0060] In one possible implementation, the battery substrate 10 further includes a second edge region 13, with the first edge region 11, the middle region 12, and the second edge region 13 arranged sequentially along a first direction; the first anti-breakage grid line 41 and the second anti-breakage grid line 42 are located in the second edge region 13.

[0061] It is understandable that in the back contact battery 100, the stress is more concentrated at the edge, making the grid lines at the edge more prone to breakage. Therefore, in this embodiment of the invention, the first anti-breakage grid line 41 and the second anti-breakage grid line 42 are disposed in the first edge region 11 and the second edge region 13. This can prevent the current from being unable to be transmitted or collected at the edge of the back contact battery 100 due to grid line breakage, reduce the degradation of the electrical performance of the back contact battery 100 and the risk of hot spots, thereby improving the photoelectric conversion efficiency of the back contact battery 100.

[0062] It is understood that, in the first direction, the first edge region 11 and the second edge region 13 specifically refer to the edge portions of the battery substrate 10. In one possible implementation, the size D2 of the second edge region 13 is 20 mm to 50 mm. For example, it is 20 mm, 25 mm, 30 mm, 35 mm, 40 mm, or 50 mm.

[0063] like Figure 4As shown, in some embodiments, the first breakage prevention grid line 41 and the second breakage prevention grid line 42 can be arranged at the first edge area 11 and the second edge area 13, and not arranged at the middle area 12. In this way, the strengthened grid lines are arranged at the edge parts which are prone to breakage, which can reduce the material cost and the process complexity, avoid unnecessary metal consumption and additional manufacturing process steps, reduce the risk of the electrical performance degradation and hot spot of the back contact battery 100, and improve the photoelectric conversion efficiency of the back contact battery 100 while reducing the manufacturing cost of the back contact battery 100.

[0064] As shown, in some embodiments, the first breakage prevention grid line 41 and the second breakage prevention grid line 42 can be arranged at the first edge area 11 and the second edge area 13, and not arranged at the middle area 12. In this way, the strengthened grid lines are arranged at the edge parts which are prone to breakage, which can reduce the material cost and the process complexity, avoid unnecessary metal consumption and additional manufacturing process steps, reduce the risk of the electrical performance degradation and hot spot of the back contact battery 100, and improve the photoelectric conversion efficiency of the back contact battery 100 while reducing the manufacturing cost of the back contact battery 100. Figures 2 to 6 As shown, in some embodiments, the first breakage prevention grid line 41 and the second breakage prevention grid line 42 can be arranged at the first edge area 11 and the second edge area 13, and not arranged at the middle area 12. In this way, the strengthened grid lines are arranged at the edge parts which are prone to breakage, which can reduce the material cost and the process complexity, avoid unnecessary metal consumption and additional manufacturing process steps, reduce the risk of the electrical performance degradation and hot spot of the back contact battery 100, and improve the photoelectric conversion efficiency of the back contact battery 100 while reducing the manufacturing cost of the back contact battery 100.

[0065] Specifically, the first conductive connection structure 211 is arranged at the first main grid 21, and the second conductive connection structure 221 is arranged at the second main grid 22. The first conductive connection structure 211 and the second conductive connection structure 221 can be a solder pad, a PAD point, a solder point, or the like, which is not limited herein. In the battery assembly 1001, the first conductive connection structure 211 and the second conductive connection structure 221 are specifically used to connect the solder strip.

[0066] It can be understood that in the back contact battery 100, the grid lines near the conductive connection structure will bear greater stress, and the grid lines near the conductive connection structure are more prone to breakage during the manufacture or use of the back contact battery 100. Therefore, by arranging the first anti-breaking grid line 41 connected to the first fine grid 31 connected to the first conductive connection structure 211, and the second anti-breaking grid line 42 connected to the second fine grid 32 connected to the second conductive connection structure 221. When the fine grid connected to the conductive connection structure breaks, the current can continue to be transmitted through the anti-breaking grid line, avoiding the local current of the back contact battery 100 from being unable to transmit or collect due to the breakage of the grid line, reducing the risk of performance degradation and hot spot of the back contact battery 100, and further improving the photoelectric conversion efficiency of the back contact battery 100. At the same time, the arrangement of the first anti-breaking grid line 41 and the second anti-breaking grid line 42 can also enhance the mechanical strength of the fine grid connected to the conductive connection structure in the back contact battery 100, so as to reduce the risk of breakage of the grid line in the back contact battery 100.

[0067] Therefore, the first anti-breaking grid line 41 and the second anti-breaking grid line 42 can be arranged at the edge portion of the back contact battery 100, and / or the first anti-breaking grid line 41 and the second anti-breaking grid line 42 can also be arranged near the first conductive connection structure 211 and the second conductive connection structure 221 in the back contact battery 100, which is not limited herein.

[0068] In a possible implementation, the first anti-breaking grid line 41 and the second anti-breaking grid line 42 are both non-burn-through grid lines. In this way, the first anti-breaking grid line 41 and the second anti-breaking grid line 42 can be separated from the doped layer by the passivation layer in the back contact battery 100, reducing the risk of short circuit of the back contact battery 100.

[0069] It can be understood that the "non-burn-through grid line" is a grid line made of non-burn-through paste, in other words, the first anti-breaking grid line 41 and the second anti-breaking grid line 42 are grid lines made of non-burn-through paste. Compared with the grid line made of burn-through paste, the grid line made of non-burn-through paste has higher stability and is less prone to breakage. Therefore, the first anti-breaking grid line 41 and the second anti-breaking grid line 42 are both non-burn-through grid lines, which can further improve the stability of the first anti-breaking grid line 41 and the second anti-breaking grid line 42, and make the first anti-breaking grid line 41 and the second anti-breaking grid line 42 less prone to breakage.

[0070] In a possible implementation, the size D3 of the first anti-breaking grid line 41 in the second direction is 10 μm to 500 μm, and the size D4 of the second anti-breaking grid line 42 in the second direction is 10 μm to 500 μm. For example, 10 μm, 50 μm, 100 μm, 200 μm, 300 μm, 400 μm, or 500 μm. In this way, the first anti-breaking grid line 41 and the second anti-breaking grid line 42 can disperse more pressure and are less likely to break when stressed, while avoiding excessively high manufacturing costs of the first anti-breaking grid line 41 and the second anti-breaking grid line 42.

[0071] In a possible implementation, the size of the first anti-breaking grid line 41 in the second direction is greater than the size of the first fine grid 31 in the first direction; and / or, the size of the second anti-breaking grid line 42 in the second direction is greater than the size of the second fine grid 32 in the first direction. In this way, by increasing the size of the first anti-breaking grid line 41 and the second anti-breaking grid line 42 in the second direction, the width of the first anti-breaking grid line 41 and the second anti-breaking grid line 42 can be increased, so that the first anti-breaking grid line 41 and the second anti-breaking grid line 42 are less likely to break, and the stability of the first anti-breaking grid line 41 and the second anti-breaking grid line 42 is improved.

[0072] It can be understood that the size of the first anti-breaking grid line 41 and the second anti-breaking grid line 42 in the second direction cannot be too large, so as to avoid excessively high manufacturing costs of the first anti-breaking grid line 41 and the second anti-breaking grid line 42.

[0073] It can be understood that in such an embodiment, the battery assembly 1001 can further include a frame, a back plate, a battery assembly 1001 glass, and a film. The film can be filled between the front and back surfaces of the battery sheet, the battery assembly 1001 glass, and adjacent battery sheets, and can be a transparent adhesive 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 herein.

[0074] The battery assembly 1001 glass can be covered on the film on the front surface of the battery sheet. The battery assembly 1001 glass can be super white glass, which has high light transmittance, high transparency, and superior physical, mechanical, and optical properties. For example, the light transmittance of the super white glass can be 92% or higher, which can protect the battery sheet as much as possible without affecting the efficiency of the battery sheet. At the same time, the film can bond the battery assembly 1001 glass and the battery sheet together, and the presence of the film can seal and insulate the battery sheet and prevent water and moisture.

[0075] The back plate can be attached to the adhesive film on the back of the battery piece. The back plate can protect and support the battery piece, has reliable insulation, water resistance and aging resistance, and the back plate can have multiple choices, which can be tempered glass, organic glass, aluminum alloy TPT composite adhesive film, etc. The specific setting can be made 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 battery assembly 1001 glass can be arranged on the frame. The frame is the main external support structure of the whole battery assembly 1001, and can stably support and install the battery assembly 1001. For example, the battery assembly 1001 can be installed at the required installation position through the frame.

[0076] In the description of the present specification, the description referring to the terms "some embodiments", "illustrative 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 application. In the present specification, the illustrative 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.

[0077] In addition, the above only describes the preferred embodiments of the present application and does not limit the present application. Any modification, equivalent replacement and improvement made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A back contact cell, characterized in that, The battery substrate comprises: a first main grid and a second main grid arranged on the battery substrate, the first main grid and the second main grid extend along a first direction, the first main grid and the second main grid are alternately and spacedly arranged along a second direction, the first main grid and the second main grid are opposite in polarity, the first direction intersects the second direction; a first fine grid and a second fine grid arranged on the battery substrate, the first fine grid and the second fine grid extend along the second direction, the first fine grid and the second fine grid are alternately and spacedly arranged along the first direction, the first fine grid and the second fine grid are opposite in polarity, the first fine grid is connected with the first main grid, and the second fine grid is connected with the second main grid; a first anti-breaking grid line and a second anti-breaking grid line arranged on the battery substrate, in the first direction, the first anti-breaking grid line is connected with two adjacent first fine grids, the second anti-breaking grid line is connected with two adjacent second fine grids, and a first insulating member is arranged between the first anti-breaking grid line and the second fine grid, and a second insulating member is arranged between the second anti-breaking grid line and the first fine grid. In the first direction, the battery substrate comprises a first edge region, an intermediate region, and a second edge region arranged in sequence.

2. The back contact cell of claim 1, wherein, The first anti-breaking grid line and the second anti-breaking grid line are located in the first edge region. In the first direction, the size of the first edge region is 20mm to 50mm.

3. The back contact cell of claim 2, wherein, The battery substrate further comprises a second edge region, and the first edge region, the intermediate region, and the second edge region are arranged in sequence along the first direction.

4. The back contact cell of claim 2, wherein, The first anti-breaking grid line and the second anti-breaking grid line are located in the second edge region. In the first direction, the size of the second edge region is 20mm to 50mm.

5. The back contact cell of claim 4, wherein, Further comprising a first conductive connection structure and a second conductive connection structure, the first conductive connection structure is arranged on the first main grid, and the second conductive connection structure is arranged on the second main grid; 6. The back contact cell of claim 1, wherein, The first anti-breaking grid line is connected with the first fine grid connected with the first conductive connection structure, and the second anti-breaking grid line is connected with the second fine grid connected with the second conductive connection structure. The first anti-breaking grid line and the second anti-breaking grid line are both non-burn-through grid lines.

7. The back contact cell of claim 1, wherein, In the first direction, the number of first anti-breaking grid lines between two adjacent first fine grids is one or more; and / or, in the first direction, the number of second anti-breaking grid lines between two adjacent second fine grids is one or more.

8. The back contact cell of claim 1, wherein In the first direction, at least part of the first anti-breaking grid lines are connected with the end portions of two adjacent first fine grids; and / or, 9. The back contact cell of claim 1, wherein In the first direction, at least part of the second anti-breaking grid lines are connected with the end portions of two adjacent second fine grids. In the second direction, the size of the first anti-breaking grid line is 10μm to 500μm, and the size of the second anti-breaking grid line is 10μm to 500μm.

10. The back contact cell of claim 1, wherein, ​ 11. The back contact cell of claim 1, wherein, The first break-proof grid line has a dimension in the second direction that is greater than a dimension of the first fine grid in the first direction; and / or, the second break-proof grid line has a dimension in the second direction that is greater than a dimension of the second fine grid in the first direction.

12. A battery assembly characterized by, The battery assembly comprises a back-contacted cell as claimed in any of claims 1 to 11.

13. A photovoltaic system characterized by, The photovoltaic system comprises a battery assembly as claimed in claim 12.

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