Back contact battery, battery string, battery assembly and photovoltaic system

Abstract

The invention is suitable for the technical field of solar cells, and provides a back contact cell, a cell string, a cell assembly and a photovoltaic system. The back contact battery comprises a battery piece and a plurality of fine grids. The back face of the battery piece comprises a first edge and a second edge which are oppositely arranged in the first direction and extend in the second direction. The plurality of fine grids on the back surface of the battery piece are arranged at intervals along a first direction and extend along a second direction, the first fine grid close to a first edge along the first direction is a first fine grid, and the first fine grid close to a second edge is a second fine grid; the distance between the first fine grid and the first edge and the distance between the second fine grid and the second edge are both larger than 250 micrometers. Therefore, when the insulation paste is arranged at the positions of the first fine grid and the second fine grid, the insulation paste can be prevented from overflowing to the edge position of the battery piece, so that the insulation paste is prevented from overflowing to a workbench, and the influence on the next batch of battery pieces is avoided.

Description

Technical Field

[0001] The present application belongs to the technical field of solar cells, and in particular relates to a back-contact cell, a cell string, a cell assembly and a photovoltaic system. Background Art

[0002] Solar cell power generation is a sustainable source of clean energy. It uses the photovoltaic effect of semiconductor pn junction to convert sunlight into electrical energy. In the relevant technology, the back contact cell refers to a solar cell with no electrode on the light-facing side of the cell, and the positive and negative electrodes are arranged on the back side of the cell, thereby reducing the shading of the electrode to the cell, increasing the short-circuit current of the cell, and improving the energy conversion efficiency of the cell. In the prior art, the fine grid needs to occupy the back of the back contact cell as much as possible to make full use of the space. However, the fine grid also needs to be provided with corresponding insulating glue, which will overflow to the edge, causing the insulating glue to overflow on the workbench below the cell, and the insulating glue will affect the preparation of the next batch of cells. Summary of the invention

[0003] The present application provides a back-contact battery, a battery string, a battery module and a photovoltaic system, aiming to solve the problem of insulating glue overflow during the preparation of battery cells.

[0004] The back contact battery provided in the present application comprises:

[0005] A battery cell, comprising a front side and a back side facing each other, wherein the back side comprises a first edge and a second edge arranged opposite to each other along a first direction, wherein the first edge and the second edge both extend along a second direction, wherein the second direction intersects the first direction;

[0006] A plurality of fine grids are arranged on the back side, the fine grids are arranged at intervals along the first direction and extend along the second direction, wherein the first fine grid close to the first edge along the first direction is a first fine grid, and the first fine grid close to the second edge along the first direction is a second fine grid;

[0007] The distance between the first fine grid and the first edge is greater than 250 μm, and the distance between the second fine grid and the second edge is greater than 250 μm.

[0008] Furthermore, the fine gates include a plurality of P-type fine gates and a plurality of N-type fine gates, and the plurality of P-type fine gates and the plurality of N-type fine gates are alternately arranged in sequence along the first direction and extend along the second direction.

[0009] Furthermore, the first fine gate is a P-type fine gate, and the second fine gate is an N-type fine gate; or

[0010] The first fine gate is an N-type fine gate, and the second fine gate is a P-type fine gate.

[0011] Furthermore, the back-contact battery further includes a plurality of main grids disposed on the back side, wherein the main grids are arranged at intervals along the second direction and all extend along the first direction.

[0012] Furthermore, the main gate includes a plurality of P-type main gates and a plurality of N-type main gates, and the plurality of P-type main gates and the plurality of N-type main gates are arranged alternately in sequence along the second direction and all extend along the first direction, the P-type fine gate is connected to the P-type main gate and is insulated from the N-type main gate, and the N-type fine gate is connected to the N-type main gate and is insulated from the P-type main gate.

[0013] Furthermore, the battery cell is further formed with a cutting gap region extending along the second direction, the fine grid avoids the cutting gap region, and the cutting gap region is used for cutting the battery cell.

[0014] Furthermore, the width of the cutting gap region along the first direction is greater than 600 μm.

[0015] The battery string provided in the embodiments of the present application includes the back-contact battery described in any of the above embodiments.

[0016] The battery assembly provided in the embodiments of the present application includes the battery string described in the above embodiments.

[0017] The photovoltaic system provided in the embodiments of the present application includes the battery assembly described in the above embodiments.

[0018] In the back contact battery of the embodiment of the present application, the back contact battery includes a battery cell and a plurality of fine grids, the battery cell includes a front side and a back side opposite to each other, the back side includes a first edge and a second edge arranged opposite to each other along a first direction, the first edge and the second edge both extend along a second direction, wherein the second direction intersects with the first direction; a plurality of fine grids are arranged on the back side, the fine grids are arranged at intervals along the first direction, and both extend along the second direction, wherein the first fine grid close to the first edge along the first direction is the first fine grid, and the first fine grid close to the second edge along the first direction is the second fine grid; the distance between the first fine grid and the first edge is greater than 250 μm, and the distance between the second fine grid and the second edge is greater than 250 μm. In this way, the distance between the first fine grid and the first edge is greater than a predetermined distance, and the distance between the second fine grid and the second edge is also greater than a predetermined distance, so that when the insulating glue is arranged at the first fine grid and the second fine grid position, the insulating glue can be prevented from overflowing to the edge position of the battery cell, so as to avoid overflowing onto the workbench, thereby avoiding affecting the next batch of battery cells. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 is a schematic structural diagram of a back contact battery according to an embodiment of the present application;

[0020] Figure 2 is another structural schematic diagram of a back contact battery according to an embodiment of the present application;

[0021] Figure 3 is another structural schematic diagram of a back contact battery according to an embodiment of the present application;

[0022] Figure 4 is another structural schematic diagram of a back contact battery according to an embodiment of the present application;

[0023] Figure 5 is another structural schematic diagram of a back contact battery according to an embodiment of the present application;

[0024] Figure 6 is another structural schematic diagram of a back contact battery according to an embodiment of the present application;

[0025] Figure 7 is another structural schematic diagram of a back contact battery according to an embodiment of the present application;

[0026] Figure 8 is another structural schematic diagram of a back contact battery according to an embodiment of the present application;

[0027] Fig. 9 is another structural schematic diagram of a back contact battery according to an embodiment of the present application;

[0028] Fig.10 is a schematic diagram of the structure of a battery string according to an embodiment of the present application;

[0029] Fig.11 is a schematic structural diagram of a battery assembly according to an embodiment of the present application;

[0030] Fig.12 It is a structural schematic diagram of a photovoltaic system according to an embodiment of the present application.

[0031] Description of main component symbols:

[0032] Back contact battery 100, battery cell 10, first edge 11, second edge 12, third edge 13, fourth edge 14, main grid 20, P-type main grid 21, N-type main grid 22, fine grid 30, P-type fine grid 31, N-type fine grid 32, first fine grid 33, second fine grid 34, third fine grid 35, fourth fine grid 36, insulating glue 40, cutting gap area 50, battery string 200, battery assembly 300, photovoltaic system 400. DETAILED DESCRIPTION

[0033] In order to make the purpose, technical solutions and advantages of the present application clearer, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements with the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application, and should not be construed as limiting the present application. In addition, it should be understood that the specific embodiments described herein are only used to explain the present application and are not intended to limit the present application.

[0034] In the description of the present application, it should be understood that the terms "length", "width", "up", "down", "left", "right", "horizontal", "top", "bottom", etc., indicating the orientation or position relationship are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0035] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of this application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0036] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or mutual communication; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0037] In the present application, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0038] The disclosure below provides many different embodiments or examples to realize the different structures of the present application. In order to simplify the disclosure of the present application, the parts and settings of specific examples are described below. Of course, they are only examples, and the purpose is not to limit the present application. In addition, the present application can repeat reference numbers and / or reference letters in different examples, and this repetition is for the purpose of simplification and clarity, and does not indicate the relationship between the various embodiments and / or settings discussed in itself. In addition, the various specific processes and examples of materials provided by the present application, but those of ordinary skill in the art can be aware of the application of other processes and / or the use scenarios of other materials.

[0039] In the related art, a back-contact cell refers to a solar cell in which the light-facing side of the cell has no electrode, and the positive and negative electrodes are arranged on the back-light side of the cell, thereby reducing the shading of the cell by the electrode, increasing the short-circuit current of the cell, and improving the energy conversion efficiency of the cell. In the prior art, the fine grid needs to occupy the back side of the back-contact cell as much as possible to make full use of the space. However, the fine grid also needs to be provided with corresponding insulating glue, which will overflow toward the edge, causing the insulating glue to overflow on the workbench below the cell, and the insulating glue will affect the preparation of the next batch of cells. In the present application, the distance between the first fine grid and the first edge is greater than the predetermined distance, and the distance between the second fine grid and the second edge is also greater than the predetermined distance, so that when the insulating glue is arranged at the first fine grid and the second fine grid position, the insulating glue can be prevented from overflowing to the edge position of the cell, so as to avoid overflowing onto the workbench, thereby avoiding affecting the next batch of cells.

[0040] Embodiment 1

[0041] See also Figure 1 In the back-contact battery 100 of the embodiment of the present application, the back-contact battery 100 includes a battery cell 10 and a plurality of fine grids 30. The battery cell 10 includes a front side and a back side opposite to each other. The back side includes a first edge 11 and a second edge 12 arranged opposite to each other along a first direction. The first edge 11 and the second edge 12 both extend along a second direction, wherein the second direction intersects with the first direction; a plurality of fine grids 30 are arranged on the back side, the fine grids 30 are arranged at intervals along the first direction, and both extend along the second direction, wherein the first fine grid 30 close to the first edge 11 along the first direction is a first fine grid 33, and the first fine grid 30 close to the second edge 12 along the first direction is a second fine grid 34; the distance between the first fine grid 33 and the first edge 11 is greater than 250 μm, and the distance between the second fine grid 34 and the second edge 12 is greater than 250 μm.

[0042] In the back-contact battery 100 of the embodiment of the present application, the back-contact battery 100 includes a battery cell 10 and a plurality of fine grids 30, the battery cell 10 includes a front side and a back side opposite to each other, the back side includes a first edge 11 and a second edge 12 arranged opposite to each other along a first direction, the first edge 11 and the second edge 12 both extend along a second direction, wherein the second direction intersects with the first direction; the plurality of fine grids 30 are arranged on the back side, the fine grids 30 are arranged at intervals along the first direction, and both extend along the second direction, wherein the first fine grid 30 close to the first edge 11 along the first direction is a first fine grid 33, and the first fine grid 30 close to the second edge 12 along the first direction is a second fine grid 34; the distance between the first fine grid 33 and the first edge 11 is greater than 250 μm, and the distance between the second fine grid 34 and the second edge 12 is greater than 250 μm. In this way, the distance between the first fine grid 33 and the first edge 11 is greater than the predetermined distance, and the distance between the second fine grid 34 and the second edge 12 is also greater than the predetermined distance, so that when the insulating glue 40 is set at the positions of the first fine grid 33 and the second fine grid 34, the insulating glue 40 can be prevented from overflowing to the edge position of the battery cell 10, so as to avoid overflowing onto the workbench, thereby avoiding affecting the next batch of battery cells 10.

[0043] Specifically, in the front and back sides of the cell 10, the front side may be the light-facing side, and the back side may be the back-light-repelling side. The back side of the cell 10 is provided with a plurality of fine grids 30 arranged at intervals along the first direction and extending along the second direction. In this way, the arrangement of the fine grids 30 can make full use of the spatial position of the back side of the cell 10 in the first direction and the second direction, thereby ensuring the photoelectric conversion efficiency of the back contact cell 100.

[0044] Furthermore, the battery cell 10 in the embodiment of the present application may be a rectangular structure, the upper and lower edges of the rectangle extend along the first direction, and the left and right edges of the rectangle extend along the second direction. A first edge 11 and a second edge 12 are provided on the back of the battery cell 10, the first edge 11 and the second edge 12 are two edges arranged opposite to each other along the first direction, and the first edge 11 and the second edge 12 both extend along the second direction, that is, the first edge 11 and the second edge 12 are both parallel to the fine grid 30. For example, the first edge 11 may be the left edge of the rectangular battery cell 10, and the second edge 12 may be the right edge of the rectangular battery cell 10; or, the first edge 11 may be the right edge of the rectangular battery cell 10, and the second edge 12 may be the left edge of the rectangular battery cell 10. The embodiment of the present application does not limit the specific positions of the first edge 11 and the second edge 12 to meet various needs.

[0045] Furthermore, the battery cell 10 is further provided with a first fine grid 33 and a second fine grid 34. When the first edge 11 is the left edge of the battery cell 10 along the first direction, the first fine grid 33 is the fine grid 30 on the left side of the back side of the battery cell 10 along the first direction (that is, the first fine grid 30 counted from the left), and in this case, the second edge 12 is the right edge of the battery cell 10 along the first direction, and the second fine grid 34 is the fine grid 30 on the right side of the back side of the battery cell 10 along the first direction (that is, the first fine grid 30 counted from the right); or, when the first edge 11 is the right edge of the battery cell 10 along the first direction, the first fine grid 33 is the fine grid 30 on the right side of the back side of the battery cell 10 along the first direction, and in this case, the second edge 12 is the left edge of the battery cell 10 along the first direction, and the second fine grid 34 is the fine grid 30 on the left side of the back side of the battery cell 10 along the first direction.

[0046] Furthermore, since the insulating glue 40 is disposed at the first fine grid 33 and the second fine grid 34 , the insulating glue 40 will overflow toward the edge. Therefore, the first fine grid 33 and the second fine grid 34 should maintain an appropriate distance from the first edge 11 and the second edge 12 .

[0047] That is, the distance between the first fine grid 33 and the first edge 11 should be maintained at more than 250 μm, so that after the insulating glue 40 is set at the first fine grid 33, enough space can be left for the overflow of the insulating glue 40. At the same time, the distance between the second fine grid 34 and the second edge 12 should also be maintained at more than 250 μm, so that after the insulating glue 40 is set at the second fine grid 34, enough space can be left for the overflow of the insulating glue 40. In this way, the insulating glue 40 will not overflow outside the edge.

[0048] For example, the distance between the first fine grid 33 and the first edge 11 or the distance between the second fine grid 34 and the second edge 12 can be 260μm, 270μm, 280μm, 290μm, 300μm, 350μm... Of course, the distance between the first fine grid 33 and the second fine grid 34 and the first edge 11 and the second edge 12 should not be too large to avoid wasting the space of the back contact battery 100.

[0049] For example, in actual applications, the amount of insulating glue 40 used at the fine grids 30 of different battery cells 10 may be different, which results in different overflow ranges of the insulating glue 40. If the overflow range of the insulating glue 40 is large, the distances between the first fine grid 33 and the second fine grid 34 and the first edge 11 and the second edge 12 can be large (e.g., both are 300 μm); if the overflow range of the insulating glue 40 is small, the distances between the first fine grid 33 and the second fine grid 34 and the first edge 11 and the second edge 12 can be small (e.g., both are 260 μm).

[0050] It should be noted that the distance between the first fine gate 33 and the first edge 11 and the distance between the second fine gate 34 and the second edge 12 may be the same or different. For example, the distance between the first fine gate 33 and the first edge 11 may be set to 260 μm, while the distance between the second fine gate 34 and the second edge 12 may be 300 μm; or, the distance between the first fine gate 33 and the first edge 11 may be set to 280 μm, while the distance between the second fine gate 34 and the second edge 12 may be 270 μm. The embodiment of the present application does not limit the distances between the first fine gate 33 and the second fine gate 34 and the first edge 11 and the second edge 12 to meet various requirements.

[0051] In addition, the above rectangular structure is only one shape of the battery cell 10, and the battery cell 10 can also be trapezoidal, rhombic, or even circular, as long as the distance between the insulating glue 40 at the fine grid 30 and the edge of the battery cell 10 is greater than 250 μm. The present application does not limit the specific shape of the battery cell 10 to meet various needs.

[0052] Embodiment 2

[0053] See also Figure 1 In some optional embodiments, the fine gate 30 of the back contact battery 100 includes a plurality of P-type fine gates 31 and a plurality of N-type fine gates 32, and the plurality of P-type fine gates 31 and the plurality of N-type fine gates 32 are alternately arranged in sequence along the first direction and extend along the second direction.

[0054] In this way, different types of fine grids 30 are spread throughout the cell 10 , ensuring the photoelectric conversion efficiency of the back contact cell 100 .

[0055] Specifically, a plurality of P-type fine gates 31 and a plurality of N-type fine gates 32 may be arranged in the order of P-type fine gates 31, N-type fine gates 32, P-type fine gates 31, N-type fine gates 32, ... on the cell 10 from left to right along the first direction; or a plurality of P-type fine gates 31 and a plurality of N-type fine gates 32 may be arranged in the order of N-type fine gates 32, P-type fine gates 31, N-type fine gates 32, P-type fine gates 31, .... In this way, the fine gates 30 are distributed throughout the first direction on the back side of the cell 10, making full use of the spatial position of the cell 10 in the first direction, and ensuring the photoelectric conversion efficiency of the back contact cell 100.

[0056] Furthermore, the P-type fine grid 31 and the N-type fine grid 32 are fully extended along the second direction, making full use of the spatial position of the cell 10 in the second direction. In this way, the fine grid 30 can be spread over the back side of the cell 10, ensuring the photoelectric conversion efficiency of the back contact cell 100.

[0057] Embodiment 3

[0058] See also Figure 1In some optional embodiments, the first fine gate 33 of the back contact battery 100 is a P-type fine gate 31, and the second fine gate 34 is an N-type fine gate 31; or

[0059] The first fine gate 33 is an N-type fine gate 31 , and the second fine gate 34 is a P-type fine gate 31 .

[0060] In this way, different types of first fine grids 33 and second fine grids 34 may be provided, thereby obtaining different back contact cells 100 to meet different requirements.

[0061] Specifically, the first fine gate 33 and the second fine gate 34 may be the same type of fine gates 30 , or may be different types of fine gates 30 .

[0062] For example, when the first fine gate 33 is a P-type fine gate 31 , the second fine gate 34 may be a P-type fine gate 31 ;

[0063] Alternatively, when the first fine gate 33 is a P-type fine gate 31 , the second fine gate 34 may be an N-type fine gate 32 ;

[0064] Alternatively, when the first fine gate 33 is an N-type fine gate 32 , the second fine gate 34 may be a P-type fine gate 31 ;

[0065] Alternatively, when the first fine gate 33 is an N-type fine gate 32, the second fine gate 34 may be an N-type fine gate 32. The embodiments of the present application do not limit the specific PN types of the first fine gate 33 and the second fine gate 34 to meet various requirements.

[0066] Embodiment 4

[0067] See also Figure 1 and Figure 2 In some optional embodiments, the back-contact battery 100 further includes a plurality of main grids 20 disposed on the back side of the back-contact battery 100 . The main grids 20 of the back-contact battery 100 are arranged at intervals along the second direction and all extend along the first direction.

[0068] In this way, the distributed main grid 20 is fully connected to the fine grid 30 , and the current in the fine grid 30 is fully collected and transmitted, thereby reducing the resistance loss of the back contact battery 100 and ensuring the photoelectric conversion efficiency of the back contact battery 100 .

[0069] Specifically, the main grid 20 fully extends in the first direction, and cross-connects the fine grids 30 extending in the second direction, so that one main grid 20 can connect multiple fine grids 30, and fully collect and transmit the current in the fine grids 30. At the same time, the main grids 20 are arranged at intervals along the second direction, making full use of the spatial position of the back side of the back contact battery 100, so that multiple main grids 20 can be connected to the same fine grid 30, dispersing the current in the fine grid 30, reducing resistance loss, and ensuring the performance of the back contact battery 100.

[0070] Embodiment 5

[0071] See also Figure 1 and Figure 2 In some optional embodiments, the main grid 20 of the back contact battery 100 includes a plurality of P-type main grids 21 and a plurality of N-type main grids 22, and the plurality of back contact battery 100P-type main grids 21 and the plurality of N-type main grids 22 are alternately arranged in sequence along the second direction and all extend along the first direction, the back contact battery 100P-type fine grid 31 is connected to the P-type main grid 21 of the back contact battery 100 and is insulated from the N-type main grid 22 of the back contact battery 100, and the back contact battery 100N-type fine grid 32 is connected to the N-type main grid 22 of the back contact battery 100 and is insulated from the P-type main grid 21 of the back contact battery 100.

[0072] In this way, the fine gates 30 and the main gate 20 of the same type are connected together, and the fine gates 30 and the main gate 20 of different types are insulated from each other to ensure smooth current flow.

[0073] Specifically, the P-type fine gate 31 and the P-type main gate 21 generally contain holes as positive electrodes, and the N-type fine gate 32 and the N-type main gate 22 generally contain free electrons as negative electrodes. Of course, in the P-type and N-type in the embodiment of the present application, P and N can also be used only to distinguish two different fine gates 30 and main gates 20, without limiting the specific types of the fine gates 30 and main gates 20, so as to meet various needs. For example, the P-type fine gate 31 and the P-type main gate 21 can also be negative electrodes containing free electrons, and the N-type fine gate 32 and the N-type main gate 22 can also be positive electrodes containing holes.

[0074] Further, on the back side of the back contact battery 100, a plurality of P-type busbars 21 and a plurality of N-type busbars 22 are arranged in the order of P-type busbar 21, N-type busbar 22, P-type busbar 21, N-type busbar 22, ... from top to bottom along the second direction; or, a plurality of P-type busbars 21 and a plurality of N-type busbars 22 are arranged in the order of N-type busbar 22, P-type busbar 21, N-type busbar 22, P-type busbar 21, .... In this way, the busbars 20 are distributed in the second direction on the back side of the back contact battery 100, making full use of the spatial position of the back contact battery 100 in the second direction. At the same time, the busbars 20 extend along the first direction, making full use of the spatial position of the back contact battery 100 in the first direction.

[0075] Furthermore, the same type of fine grids 30 and main grids 20 are connected together, and different types of fine grids 30 and main grids 20 are insulated from each other. That is, on the back of the cell 10, the fine grids 30 extend along the second direction, and the two types of main grids 20 are alternately arranged along the second direction, so that two types of main grids 20 (i.e., positive and negative main grids 20) are arranged in the extension direction of a fine grid 30. However, the fine grids 30 can only be electrically connected to the same type of main grids 20, and are insulated from different types of main grids 20.

[0076] For example, in the extension direction of the P-type fine gate 31, a plurality of P-type main gates 21 and N-type main gates 22 are alternately arranged at intervals, the P-type fine gate 31 is only electrically connected to the P-type main gate 21, and is insulated from the N-type main gate 22 using an insulating glue 40; in the extension direction of the N-type fine gate 32, a plurality of P-type main gates 21 and N-type main gates 22 are alternately arranged at intervals, the N-type fine gate 32 is only electrically connected to the N-type main gate 22, and is gate-insulated from the P-type main using an insulating glue 40.

[0077] It should be noted that the insulation materials and insulation methods used for the insulation treatment between different types of fine gates 30 and main gates 20 can be various. The embodiments of the present application do not limit the insulation materials and insulation methods used for the insulation treatment to meet various requirements.

[0078] Embodiment 6

[0079] See also Figures 3 to 9 In some optional embodiments, the back contact battery 100 cell 10 is also formed with a cutting gap area 50 extending along the second direction of the back contact battery 100, and the back contact battery 100 fine grid 30 avoids the back contact battery 100 cutting gap area 50, and the back contact battery 100 cutting gap area 50 is used to cut the back contact battery 100 cell 10.

[0080] In this way, one cell 10 can be cut into two parts by cutting the gap region 50 to form two cells 10. Of course, multiple cutting gap regions 50 can also be provided so that one cell 10 can be cut into multiple parts to form multiple cells 10. In other words, the back contact cell 100 can be divided into two pieces, three pieces, four pieces, etc.

[0081] Specifically, a cutting gap region 50 extending along the second direction can be set in the middle of the battery cell 10 of the back contact battery 100, and the cutting gap region 50 is set between two adjacent fine grids 30 (the third fine grid 35 and the fourth fine grid 36) in the middle of the battery cell 10. That is to say, the setting of the fine grid 30 should avoid the cutting gap region 50, and no fine grid 30 is set in the cutting gap region 50.

[0082] At the same time, the cutting gap region 50 should maintain a certain width along the first direction, that is, a certain distance should be maintained between the third fine grid 35 and the fourth fine grid 36. This ensures that the third fine grid 35 maintains a certain distance from the center line of the cutting gap region 50, and the fourth fine grid 36 also maintains a certain distance from the center line of the cutting gap region 50. In this way, after the insulating glue 40 is provided, the third fine grid 35 and the fourth fine grid 36 adjacent to each other in the middle of the battery cell 10 do not overflow to the vicinity of the center line of the cutting gap region 50, thereby preventing the overflowing insulating glue 40 from affecting the slicing of the battery cell 10.

[0083] Of course, multiple cutting gap regions 50 may be provided at multiple positions of a battery cell 10, and the multiple cutting gap regions 50 all extend along the second direction, so that a battery cell 10 can be cut into multiple battery cells 10. For example, two cutting gap regions 50 may be provided, so that a battery cell 10 can be cut into three battery cells 10; or three cutting gap regions 50 may be provided, so that a battery cell 10 can be cut into four battery cells 10...

[0084] It should be noted that when the cell 10 is cut once, the fine grids 30 on both sides of the cutting gap area 50, that is, the two adjacent fine grids 30 in the middle of the cell 10, are named as the third fine grid 35 and the fourth fine grid 36. Of course, when the cell 10 needs to be cut multiple times, such as twice, there can also be a fifth fine grid and a sixth fine grid; when the cell 10 needs to be cut three times, there can also be a seventh fine grid and an eighth fine grid, and so on. Figures 3 to 9 In the figure, the back contact cell 100 is merely symbolically represented, and the number of the fine grids 30 and the main grid 20 is not specified, nor is the shape and size of the cell 10 cut.

[0085] Embodiment 7

[0086] See also Figures 3 to 9 In some optional embodiments, the width of the cut gap region 50 of the back contact battery 100 along the first direction of the back contact battery 100 is greater than 600 μm. For example, the width of the cut gap region 50 of the back contact battery 100 along the first direction of the back contact battery 100 may be 610 μm, 630 μm, 650 μm, 660 μm, 700 μm, 750 μm, 800 μm, 850 μm, or 900 μm.

[0087] In this way, the setting of the wider cutting gap area 50 ensures that after the insulating glue 40 is set, the insulating glue 40 on the fine grids 30 on both sides of the cutting gap area 50 does not overflow to the center line position of the cutting gap area 50, thereby preventing the overflowing insulating glue 40 from blocking the laser cutting, so that the battery cell 10 can be sliced ​​smoothly.

[0088] Specifically, the overflow range of the insulating glue 40 at the fine grid 30 is generally within 250 μm around the fine grid 30, that is, when the cell 10 is cut, the two new cell 10 cut out each form a new edge at the cutting position, and the new edge of the half of the cell 10 where the third fine grid 35 is located can be the third edge 13, and the distance between the third edge 13 and the third fine grid 35 should be greater than 250 μm. The new edge of the half of the cell 10 where the fourth fine grid 36 is located can be the fourth edge 14, and the distance between the fourth edge 14 and the fourth fine grid 36 should also be greater than 250 μm. In addition, during the laser cutting process of the cell 10, the cutting gap area 50 of the cell 10 also loses some width. Therefore, the width of the cutting gap area 50 is the sum of the three: the distance from the third fine grid 35 to the third edge 13, the distance from the fourth fine grid 36 to the fourth edge 14, and the width lost during the cutting process of the cutting gap area 50. In this way, the width of the cutting gap region 50 of the back contact battery 100 along the first direction of the back contact battery 100 is greater than 600 μm.

[0089] Of course, in actual applications, the amount of insulating glue 40 used at the fine grid 30 of different battery cells 10 may be different, which will result in different overflow ranges of the insulating glue 40. If the amount of insulating glue 40 used is large, so that the overflow range of the insulating glue 40 is large, a larger width cutting gap area 50 (such as 700μm) can be set; if the amount of insulating glue 40 used is small, so that the overflow range of the insulating glue 40 is small, a smaller width cutting gap area 50 (such as 600μm) can be set. The embodiment of the present application does not limit the specific width of the cutting gap area 50 to meet various needs.

[0090] It is understandable that in order not to waste the location space of the back contact battery 100 , the width of the cutting gap area 50 should not be too large.

[0091] Embodiment 8

[0092] See also Figure 1 and Fig.10 The battery string 200 provided in the embodiment of the present application includes the back contact battery 100 of any of the above embodiments.

[0093] In the embodiment of the present application, the battery string 200 can be a shape in which a plurality of sheet-shaped solar cells are connected in series in sequence and connected by welding strips and bus bars. It is understandable that in the battery string 200, the battery string 200 can include two battery cells 10 connected in series, three battery cells 10 connected in series, or other larger numbers of battery cells 10. The specific number of battery cells 10 that need to be connected in series can be determined according to actual usage. In addition, in the embodiment of the present application, the size and type of the solar cell are not limited. The specifications and sizes of adjacent battery cells 10 can be the same or different to meet different needs.

[0094] In the embodiment of the present application, the specific connection method of adjacent battery cells 10 is not limited to meet different needs. In one embodiment, the edges of two adjacent battery cells 10 are at least partially stacked together; in another embodiment, two adjacent battery cells 10 can be arranged at intervals. The spacing between two adjacent battery cells 10 is within a suitable range, which can avoid the small operating space and high welding difficulty caused by too small spacing, and can also avoid the waste of component space and increased costs caused by too large spacing.

[0095] Embodiment 9

[0096] See also Figure 1 , Fig.10 and Fig.11 The battery assembly 300 provided in the embodiment of the present application includes the battery string 200 of the above embodiment.

[0097] In this embodiment, the battery assembly 300 may also include a frame, a back plate, photovoltaic glass and an adhesive film. The adhesive film may be filled between the front and back of the back contact battery 100 and the photovoltaic glass, adjacent battery cells 10, etc. As a filler, it may be a transparent colloid with good light transmission and aging resistance. For example, the adhesive film may be an EVA adhesive film or a POE adhesive film. The specific selection may be based on actual conditions and is not limited here.

[0098] Photovoltaic glass can cover the adhesive film on the front side of the back contact cell 100. The photovoltaic glass can be ultra-white glass, which has high light transmittance, high transparency, and excellent physical, mechanical and optical properties. For example, the light transmittance of ultra-white glass can reach more than 92%, which can protect the back contact cell 100 without affecting the efficiency of the back contact cell 100 as much as possible. At the same time, the adhesive film can bond the photovoltaic glass and the back contact cell 100 together. The presence of the adhesive film can seal and insulate the back contact cell 100 and prevent water and moisture.

[0099] The back plate can be attached to the adhesive film on the back of the back contact battery 100. The back plate can protect and support the back contact battery 100, and has reliable insulation, water resistance and aging resistance. There are multiple options for the back plate, which can usually be tempered glass, organic glass, aluminum alloy TPT composite adhesive film, etc. It can be set according to specific circumstances and is not limited here. The whole composed of the back plate, back contact battery 100, adhesive film and photovoltaic glass can be set on the frame. The frame serves as 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.

[0100] Embodiment 10

[0101] See also Figure 1 , Fig.10 , Fig.11 and Fig.12 The photovoltaic system 400 provided in the embodiment of the present application includes the battery assembly 300 of the above-mentioned embodiment.

[0102] In the back-contact battery 100 of the embodiment of the present application, the back-contact battery 100 includes a battery cell 10 and a plurality of fine grids 30, the battery cell 10 includes a front side and a back side opposite to each other, the back side includes a first edge 11 and a second edge 12 arranged opposite to each other along a first direction, the first edge 11 and the second edge 12 both extend along a second direction, wherein the second direction intersects with the first direction; the plurality of fine grids 30 are arranged on the back side, the fine grids 30 are arranged at intervals along the first direction, and both extend along the second direction, wherein the first fine grid 30 close to the first edge 11 along the first direction is a first fine grid 33, and the first fine grid 30 close to the second edge 12 along the first direction is a second fine grid 34; the distance between the first fine grid 33 and the first edge 11 is greater than 250 μm, and the distance between the second fine grid 34 and the second edge 12 is greater than 250 μm. In this way, the distance between the first fine grid 33 and the first edge 11 is greater than the predetermined distance, and the distance between the second fine grid 34 and the second edge 12 is also greater than the predetermined distance, so that when the insulating glue 40 is set at the positions of the first fine grid 33 and the second fine grid 34, the insulating glue 40 can be prevented from overflowing to the edge position of the battery cell 10, so as to avoid overflowing onto the workbench, thereby avoiding affecting the next batch of battery cells 10.

[0103] In this embodiment, the photovoltaic system 400 can be applied to photovoltaic power stations, such as ground power stations, rooftop power stations, water surface power stations, etc., and can also be applied to equipment or devices that use solar energy to generate electricity, such as user solar power supplies, solar street lights, solar cars, solar buildings, 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 require solar energy to generate electricity. Taking the photovoltaic power generation system network as an example, the photovoltaic system 400 may include a photovoltaic array, a junction box and an inverter. The photovoltaic array may be an array combination of multiple battery assemblies 300. For example, multiple battery assemblies 300 may form multiple photovoltaic arrays. The photovoltaic array is connected to the junction box. The junction box can converge the current generated by the photovoltaic array. The converged current flows through the inverter to convert it into the alternating current required by the mains power grid and then connected to the mains network to realize solar power supply.

[0104] In the description of this specification, the description with reference to the terms "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiments or examples are included in at least one embodiment or example of the present application. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0105] In addition, the above are only preferred embodiments of the present application and are not intended to limit the present application. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present application should be included in the protection scope of the present application.

Claims

1. A back contact battery, characterized in that: include: A battery cell, comprising a front side and a back side facing each other, wherein the back side comprises a first edge and a second edge arranged opposite to each other along a first direction, wherein the first edge and the second edge both extend along a second direction, wherein the second direction intersects the first direction; A plurality of fine grids are arranged on the back side, the fine grids are arranged at intervals along the first direction and extend along the second direction, wherein the first fine grid close to the first edge along the first direction is a first fine grid, and the first fine grid close to the second edge along the first direction is a second fine grid; The distance between the first fine grid and the first edge is greater than 250 μm, and the distance between the second fine grid and the second edge is greater than 250 μm.

2. The back contact cell according to claim 1, characterized in that: The fine gates include a plurality of P-type fine gates and a plurality of N-type fine gates, and the plurality of P-type fine gates and the plurality of N-type fine gates are alternately arranged in sequence along the first direction and extend along the second direction.

3. The back contact battery according to claim 2, characterized in that: The first fine gate is a P-type fine gate, and the second fine gate is an N-type fine gate; or The first fine gate is an N-type fine gate, and the second fine gate is a P-type fine gate.

4. The back contact cell according to claim 3, characterized in that: The back contact battery further comprises a plurality of main grids arranged on the back side, wherein the main grids are arranged at intervals along the second direction and all extend along the first direction.

5. The back contact cell according to claim 4, characterized in that: The main gate includes a plurality of P-type main gates and a plurality of N-type main gates, which are alternately arranged in sequence along the second direction and extend along the first direction. The P-type fine gate is connected to the P-type main gate and is insulated from the N-type main gate, and the N-type fine gate is connected to the N-type main gate and is insulated from the P-type main gate.

6. The back contact cell according to claim 1, characterized in that: The battery cell is further formed with a cutting gap region extending along the second direction, the fine grid avoids the cutting gap region, and the cutting gap region is used for cutting the battery cell.

7. The back contact cell according to claim 6, characterized in that: A width of the cutting gap region along the first direction is greater than 600 μm.

8. A battery string, characterized in that: Comprising a back contact battery as described in any one of claims 1-7.

9. A battery assembly, characterized in that: Comprising the battery string as claimed in claim 8.

10. A photovoltaic system, characterized in that: Comprising the battery assembly as claimed in claim 9.

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