Back contact battery, battery assembly and photovoltaic system
By optimizing the grid line design of the back contact battery, sufficient spacing between the grid line area and the edge of the silicon substrate is ensured during laser cutting, solving the problem that the cutting area design cannot meet the yield requirements and improving the performance and reliability of the back contact battery.
Patent Information
- Application Number
- CN202511720585.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-11-21
- Publication Date
- 2026-02-27
AI Technical Summary
In existing technologies, the size design of the cutting area cannot meet the yield requirements of the back contact battery, resulting in problems such as leakage damage and cutting misalignment.
By setting the distance between the first edge fine gate and the cutting center line to be greater than the distance between the second edge fine gate and the nearest first edge, and limiting the distance relationship between adjacent gate line areas, it is ensured that there is a sufficient gap between the gate line area and the edge of the silicon substrate during laser cutting, thus avoiding paste printing to the edge and cutting offset.
This improved the yield of back-contact batteries, avoided leakage damage and cutting misalignment, reduced the probability of edge defects after cutting, and enabled more efficient electron collection and space utilization.
Smart Images
Figure CN121586331A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of solar energy, and in particular to a back contact cell, a cell module and a photovoltaic system. BACKGROUND
[0002] A back contact cell is a device that converts sunlight into electricity using the photoelectric effect. It is mainly made of photovoltaic materials such as silicon, which excites electrons by absorbing photons to form an electric current. The cell includes a front electrode, a photovoltaic layer, and a back electrode, which can generate electricity under sunlight and is widely used in power generation systems and various electronic devices.
[0003] In the prior art, the size of the cutting area cannot meet the yield requirements of the back contact cell. SUMMARY
[0004] The present application provides a back contact cell, a cell module and a photovoltaic system to improve the yield of the back contact cell.
[0005] According to one aspect of the present application, a back contact cell is provided, characterized in that it comprises:
[0006] A silicon substrate, the silicon substrate comprising at least one cutting area and at least two grid line areas, the cutting area being arranged between two adjacent grid line areas, the grid line area comprising a plurality of first fine grids and a plurality of second fine grids, the plurality of first fine grids and the plurality of second fine grids being arranged alternately along a first direction and extending along a second direction, the second direction intersecting the first direction; along the first direction, the silicon substrate has two opposite first edges;
[0007] Along the first direction, the distance between the first edge fine grid and the cutting center line is greater than the distance between the second edge fine grid and the nearest first edge; wherein the first edge fine grid is the fine grid closest to the cutting area in the grid line area; the cutting center line is the connecting line of the midpoint of the cutting area in the first direction along the second direction; the second edge fine grid is the fine grid closest to the first edge in the grid line area; the edge fine grid is at least one of the first fine grid and the second fine grid.
[0008] Further, the distance between the first edge fine grid and the cutting center line is greater than half the distance between the two adjacent first fine grids in the grid line area.
[0009] Further, the distance between the first edge fine grid and the cutting center line is greater than half the distance between the two adjacent second fine grids in the grid line area.
[0010] Further, the distance between the adjacent first fine grid and the second fine grid in the grid line area is equal.
[0011] Further, the distance between the second edge fine grid and the first edge is greater than half the distance between the two adjacent first fine grids in the grid line area.
[0012] Further, the distance between the second edge fine grid and the first edge is greater than half of the distance between two adjacent second fine grids in the grid line region.
[0013] Further, the distance between the first edge fine grid and the cutting center line is greater than or equal to 0.25mm and less than 1.5mm.
[0014] Further, the distance between the second edge fine grid and the first edge is greater than or equal to 0.15mm and less than 1.5mm.
[0015] According to another aspect of the present application, a battery assembly is provided, comprising the back contact battery according to any of the embodiments of the present application.
[0016] According to another aspect of the present application, a photovoltaic system is provided, comprising the battery assembly according to any of the embodiments of the present application.
[0017] The back contact battery provided by the embodiments of the present application can ensure that, when the cutting deviates along the cutting center line in the second direction, the first grid line and the second grid line in the grid line region and the edge of the silicon substrate have enough space left between them on the side where the cutting deviates, so as to avoid the screen expansion to print the paste to the edge of the silicon substrate, and thus effectively avoid the occurrence of the electric leakage damage, and improve the yield of the back contact battery.
[0018] It should be understood that the description in this section is not intended to identify key or critical features of the embodiments of the present application or to limit the scope of the present application. Other features of the present application will become apparent from the following description. BRIEF DESCRIPTION OF DRAWINGS
[0019] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed in the embodiment description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative effort.
[0020] Figure 1 is a structural schematic diagram of a back contact battery provided by the embodiments of the present application;
[0021] Figure 2 is Figure 1 is an enlarged structural schematic diagram of the A-A region in
[0022] Figure 3 isFigure 1 Structure enlarged schematic view of the middle B-B region. DETAILED DESCRIPTION
[0023] In order to better understand the technical scheme of the present application, the technical scheme in the embodiments of the present application will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work should fall within the scope of protection of the present application.
[0024] It should be noted that the terms "first", "second" and the like in the description and claims of the present application and the above-mentioned accompanying drawings are used to distinguish similar objects, and do not necessarily indicate a specific order or sequence. It should be understood that the data thus used can be interchanged under appropriate circumstances, so that the embodiments of the present application described herein can be implemented in an order other than that illustrated or described herein. In addition, the terms "comprise" and "have" and any variations thereof are intended to cover non-exclusive inclusion, for example, a process, method, system, product or device comprising a series of steps or units does not necessarily limit to those steps or units clearly listed, but can include other steps or units not clearly listed or inherent to these processes, methods, products or devices.
[0025] The embodiment of the present application provides a back contact battery, Figure 1 is a structural schematic view of a back contact battery provided by the embodiment of the present application, Figure 2 is Figure 1 Structure enlarged schematic view of the middle A-A region, Figure 3 is Figure 1 Structure enlarged schematic view of the middle B-B region, referring to Figures 1-3 The back contact battery comprises:
[0026] A silicon substrate 1, the silicon substrate 1 comprises at least one cutting region 2 and at least two grid line regions 3, the cutting region 2 is arranged between two adjacent grid line regions 3, the grid line region 3 comprises a plurality of first fine grids 31 and a plurality of second fine grids 32, the plurality of first fine grids 31 and the plurality of second fine grids 32 are alternately arranged along a first direction X and extend along a second direction Y, the second direction Y intersects with the first direction X; along the first direction X, the silicon substrate 1 has two opposite first edges 4;
[0027] In the first direction X, the distance d1 between the first edge fine grid 51 and the cutting center line 21 is greater than the distance d2 between the second edge fine grid 52 and the nearest first edge 4; wherein the first edge fine grid 51 is the fine grid closest to the cutting area 2 in the grid line area 3; the cutting center line 21 is the connecting line of the midpoint of the cutting area 2 in the first direction X along the second direction Y; the second edge fine grid 52 is the fine grid closest to the first edge 4 in the grid line area 3; and the edge fine grid is at least one of the first fine grid 31 and the second fine grid 32.
[0028] Wherein the silicon substrate 1 has a front surface and a back surface, the front surface is the light receiving surface when the back contact cell is working, and the back surface is the back light surface when the back contact cell is working. The silicon substrate 1 can be a single crystal silicon wafer or a polycrystalline silicon wafer, which can be a P-type silicon wafer or an N-type silicon wafer, and the specific embodiments are not limited herein. And the silicon substrate 1 is provided with a doped layer and a passivation layer arranged in layers, and the doped layer can establish ohmic contact with the grid line. At least one can be understood as one or more, and at least two can be understood as two or more. For example, the silicon substrate 1 includes one or more cutting areas 2 and two or more grid line areas 3. The grid line area 3 is arranged on the back surface of the silicon substrate 1, and the first fine grid 31 in the grid line area 3 can be a positive grid line, and the second fine grid 32 can be a negative grid line; or the first fine grid 31 in the grid line area 3 can be a negative grid line, and the second fine grid 32 can be a positive grid line. The embodiments of the present application do not limit this.
[0029] Specifically, the cutting area 2 refers to the position reserved for cutting and slicing in the back contact solar cell. The back contact cell provided by the embodiments of the present application can be divided into a plurality of cell pieces according to the cutting area 2. For example, the back contact cell can be divided according to the cutting center line 21 along the second direction Y, and therefore, in the first direction X, the distance d1 between the first edge fine grid 51 and the cutting center line 21 is greater than the distance d2 between the second edge fine grid 52 and the nearest first edge 4. When cutting occurs along the cutting center line 21 along the second direction Y by laser, it can be ensured that on the side where the cutting offset occurs, the first grid line 31 and the second grid line 32 in the grid line area 3 and the edge of the silicon substrate 1 have sufficient spacing, so as to avoid that the screen extends to print the paste to the edge of the silicon substrate 1, thereby effectively avoiding the occurrence of the damage caused by the electric leakage.
[0030] The back contact battery provided by the embodiment of the present application sets the distance d1 between the first edge fine grid 51 and the cutting center line 21 to be greater than the distance d2 between the second edge fine grid 52 and the nearest first edge 4, which indicates that the distance d1 between the first edge fine grid 51 and the cutting center line 21 is relatively large, and when cutting deviation occurs in the cutting according to the cutting center line 21 along the second direction Y by laser, it can be ensured that on the side where the cutting deviation occurs, there is enough space between the first grid line 31 and the second grid line 32 in the grid line area 3 and the edge of the silicon substrate 1, so as to avoid that the screen expansion causes the paste to be printed to the edge of the silicon substrate 1, and thus the occurrence of the electric leakage damage is effectively avoided, and the yield of the back contact battery is improved.
[0031] Further, with reference to Figures 1-3 , the distance d1 between the first edge fine grid 51 and the cutting center line 21 is greater than half of the distance between the two adjacent first fine grids 31 in the grid line area 3.
[0032] Specifically, the distance d1 between the first edge fine grid 51 and the cutting center line 21 is set to be greater than half of the distance between the two adjacent first fine grids 31 in the grid line area 3, so that when cutting according to the cutting center line 21 along the second direction Y by laser, the edge of the grid line area 3 can be prevented from being defective due to laser cutting deviation.
[0033] Further, with reference to Figures 1-3 , the distance d1 between the first edge fine grid 51 and the cutting center line 21 is greater than half of the distance between the two adjacent second fine grids 32 in the grid line area 3.
[0034] Specifically, on the basis of setting the distance d1 between the first edge fine grid 51 and the cutting center line 21 to be greater than half of the distance between the two adjacent first fine grids 31 in the grid line area 3, the distance d1 between the first edge fine grid 51 and the cutting center line 21 is also set to be greater than half of the distance between the two adjacent second fine grids 32 in the grid line area 3, which further limits the distance d1 between the first edge fine grid 51 and the cutting center line 21, so that the distance d1 between the first edge fine grid 51 and the cutting center line 21 is large enough and more in line with the design requirements, and thus when cutting according to the cutting center line 21 along the second direction Y by laser, the probability of the edge of the grid line area 3 being defective due to laser cutting deviation can be further reduced.
[0035] Further, with reference to Figure 2 , the distance between the adjacent first fine grid 31 and the second fine grid 32 in the grid line area 3 is equal.
[0036] Specifically, the distance between the adjacent first fine grid 31 and the second fine grid 32 in the grid line area 3 is equal, which can avoid the short circuit of the first fine grid 31 and the second fine grid 32 caused by the fine slag generated by cutting the solder strip due to the close distance between the first fine grid 31 and the second fine grid 32 in one or more of the first fine grid 31 and the second fine grid 32; at the same time, it can also avoid the lap joint of the first fine grid 31 and the second fine grid 32 caused by the close distance between the first fine grid 31 and the second fine grid 32 in one or more of the first fine grid 31 and the second fine grid 32 when printing the first fine grid 31 and the second fine grid 32, thereby improving the yield of the back contact battery.
[0037] Further, with reference to Figures 1-3 , the distance d2 between the second edge fine grid 52 and the nearest first edge 4 is greater than half the distance between the adjacent two first fine grids 31 in the grid line area 3.
[0038] Specifically, the edge area is arranged on the side of the grid line area 3 away from the cutting area 2 near the edge of the silicon substrate 1, so that the first grid line 31 and the second grid line 32 in the grid line area 3 have a certain interval with the first edge 4 of the silicon substrate 1, which can effectively avoid the printing of the paste to the edge of the silicon substrate 1 caused by the extension of the screen plate, and avoid the occurrence of leakage damage. And the distance d2 between the second edge fine grid 52 and the nearest first edge 4 is greater than half the distance between the adjacent two first fine grids 31 in the grid line area 3, which effectively realizes the collection of the electrons at the edge position and prevents the waste of a large area of space in the back contact battery caused by the too large distance between the second edge fine grid 52 and the nearest first edge 4.
[0039] Further, with reference to Figures 1-3 , the distance d2 between the second edge fine grid 52 and the nearest first edge 4 is greater than half the distance between the adjacent two second fine grids 32 in the grid line area 3.
[0040] Specifically, under the condition that the distance d2 between the second edge fine grid 52 and the nearest first edge 4 is greater than half the distance between the adjacent two first fine grids 31 in the grid line area 3, the distance d2 between the second edge fine grid 52 and the nearest first edge 4 is also greater than half the distance between the adjacent two second fine grids 32 in the grid line area 3, which further limits the distance d2 between the second edge fine grid 52 and the nearest first edge 4, so that the distance d2 between the second edge fine grid 52 and the nearest first edge 4 meets the design requirements, thereby further effectively realizing the collection of the electrons at the edge position and further effectively preventing the waste of a large area of space in the back contact battery caused by the too large distance d2 between the second edge fine grid 52 and the nearest first edge 4.
[0041] Further, with reference to Figure 2The distance d1 between the first edge fine grid 51 and the cutting center line 21 is greater than or equal to 0.25 mm and less than 1.5 mm.
[0042] Specifically, the distance d1 between the first edge fine grid 51 and the cutting center line 21 is greater than or equal to 0.25 mm, so that when the cutting deviates along the cutting center line 21 in the second direction Y, the first grid line 31 and the second grid line 32 in the grid line area 3 on the side where the cutting deviates can have sufficient spacing with the edge of the silicon substrate 1 to avoid the screen expansion to print the paste to the edge of the silicon substrate 1, thereby effectively avoiding the occurrence of the electric leakage damage, and effectively preventing the edge defects caused by the laser cutting deviation. The distance d1 between the first edge fine grid 51 and the cutting center line 21 is less than 1.5 mm, which can avoid the edge position area being too large after cutting, and effectively collect the electrons at the edge position.
[0043] Further, referring to Figure 3 The distance d2 between the second edge fine grid 52 and the nearest first edge 4 is greater than or equal to 0.15 mm and less than 1.5 mm.
[0044] Specifically, the distance d2 between the second edge fine grid 52 and the nearest first edge 4 is greater than or equal to 0.15 mm, so that the first grid line 31 and the second grid line 32 in the grid line area 3 have a certain spacing with the edge of the silicon substrate 1, which can effectively avoid the screen expansion to print the paste to the edge of the silicon substrate 1, thereby avoiding the occurrence of the electric leakage damage. The distance d2 between the second edge fine grid 52 and the nearest first edge 4 is less than 1.5 mm, which can avoid the area waste caused by the edge area 4 being too large, and effectively collect the electrons at the edge area 4.
[0045] The embodiment of the present application also provides a battery assembly comprising the back contact battery according to any of the embodiments of the present application.
[0046] The embodiment of the present application also provides a photovoltaic system comprising the battery assembly according to any of the embodiments of the present application.
[0047] It should be understood that the various forms of flow shown above can be reordered, added to, or deleted from. For example, the steps described in the present application can be executed in parallel, in sequence, or in different orders, as long as the desired results of the technical solutions of the present application can be achieved, which are not limited herein.
[0048] The above detailed description does not limit the scope of the application. Various modifications, combinations, sub-combinations and alternatives can be made to the detailed description. Any modification, equivalent replacement and improvement etc. made within the spirit and principle of the application shall be included in the scope of the application.
Claims
1. A back-contact battery, characterized in that, include: A silicon substrate, the silicon substrate including at least one diced region and at least two gate line regions, the diced region being disposed between two adjacent gate line regions, the gate line regions including a plurality of first fine gates and a plurality of second fine gates, the plurality of first fine gates and the plurality of second fine gates being alternately arranged along a first direction and extending along a second direction, the second direction intersecting the first direction; Along the first direction, the silicon substrate has two opposing first edges; Along the first direction, the distance between the first edge grid and the cutting center line is greater than the distance between the second edge grid and the nearest first edge; wherein, the first edge grid is the grid closest to the cutting area within the grid line region; the cutting center line is the line connecting the midpoint of the cutting area in the first direction along the second direction; the second edge grid is the grid closest to the first edge within the grid line region; the edge grid is at least one of the first grid and the second grid.
2. The back contact battery according to claim 1, characterized in that, The distance between the first edge grid and the cutting center line is greater than half the distance between two adjacent first grids in the grid region.
3. The back contact battery according to claim 2, characterized in that, The distance between the first edge grid and the cutting center line is greater than half the distance between two adjacent second grids in the grid region.
4. The back contact battery according to claim 3, characterized in that, The distance between adjacent first and second fine grids in the grid region is equal.
5. The back contact battery according to claim 1, characterized in that, The distance between the second edge fine grid and the first edge is greater than half the distance between two adjacent first fine grids in the grid line region.
6. The back contact battery according to claim 5, characterized in that, The distance between the second edge fine grid and the first edge is greater than half the distance between two adjacent second fine grids in the grid line region.
7. The back contact battery according to claim 1, characterized in that, The distance between the first edge grid and the cutting center line is greater than or equal to 0.25 mm and less than 1.5 mm.
8. The back contact battery according to claim 1, characterized in that, The distance between the second edge fine grid and the first edge is greater than or equal to 0.15 mm and less than 1.5 mm.
9. A battery assembly, characterized in that, Includes the back contact battery as described in any one of claims 1-8.
10. A photovoltaic system, characterized in that, Includes the battery assembly as described in claim 9.