Main-grid-free back contact battery, battery assembly and photovoltaic system

Abstract

The utility model is suitable for the technical field of main-grid-free back contact cells, and provides a main-grid-free back contact cell, a cell assembly and a photovoltaic system. The main-grid-free back contact battery comprises a main grid line area and a plurality of edge grid line areas, wherein the main grid line area is positioned between two edge grid line areas; the fine grid in the edge grid line area is provided with a plurality of first insulating glue and a plurality of first connecting structures, the first connecting structures electrically connect the fine grid with the welding strip, and the first insulating glue electrically isolates the fine grid from the welding strip; wherein the area of the single first insulation paste is larger than that of the single first connection structure. According to the main-grid-free back contact battery, the area of the first insulation paste in the edge grid line area is larger than the area of the first connection structure, so that larger electrical isolation is provided for the grid lines and the welding strips in the edge grid line area, the short circuit problem is prevented, and the effect of improving the stability of the main-grid-free back contact battery is achieved.

Description

Technical Field

[0001] The utility model relates to the technical field of photovoltaic, in particular to a main-gridless back-contact battery, a battery module and a photovoltaic system. Background Art

[0002] A main-gridless back-contact battery is a device that converts sunlight into electrical energy by using the photovoltaic effect. It is mainly made of photovoltaic materials (such as silicon), and electrons are excited by absorbing photons to form an electric current. The battery includes a front electrode, a photovoltaic layer and a back electrode, and can generate electricity under sunlight irradiation, and is widely used in power generation systems and various electronic devices.

[0003] In the prior art, the solder joints or conductive parts in the edge area of the main-gridless back-contact battery are easy to contact with other electrical components, and the solder joints or conductive parts in the edge area are more susceptible to heat and stress, resulting in the melting (liquefaction) of the solder joints or conductive parts in the edge area, so that the adjacent fine grids and solder tapes are short-circuited, and further causing the short circuit of the main-gridless back-contact battery, resulting in the problem of damage to the main-gridless back-contact battery. Summary of the Utility Model

[0004] The utility model provides a main-gridless back-contact battery, a battery module and a photovoltaic system to solve the problem that the main-gridless back-contact battery in the prior art is easily damaged.

[0005] The embodiment of the utility model is implemented as follows. The utility model provides a main-gridless back-contact battery, a battery module and a photovoltaic system. The main-gridless back-contact battery includes: a silicon substrate; a plurality of fine grids arranged on the silicon substrate; the fine grids include a first fine grid and a second fine grid, the first fine grid and the second fine grid are arranged at intervals along a first direction and extend along a second direction, and the first fine grid and the second fine grid have opposite polarities; the silicon substrate is further provided with a plurality of solder tapes, the solder tapes include a first solder tape and a second solder tape, the first solder tape and the second solder tape are arranged at intervals along the second direction and extend along the first direction, and the first solder tape and the second solder tape have opposite polarities; the first direction intersects with the second direction; the main-gridless back-contact battery includes a main grid line area and a plurality of edge grid line areas, and the main grid line area is located between the two edge grid line areas; the first fine grid and the second fine grid in the edge grid line area are provided with a plurality of first insulating adhesives and a plurality of first connection structures; the first connection structure electrically connects the first fine grid with the first solder tape, and the first insulating adhesive electrically isolates the second fine grid from the first solder tape; the first connection structure electrically connects the second fine grid with the second solder tape, and the first insulating adhesive electrically isolates the first fine grid from the second solder tape; wherein, the area of a single first insulating adhesive is larger than the area of a single first connection structure.

[0006] Furthermore, along the first direction, the area of the first insulating adhesive is larger than the area of the first connection structure adjacent to the first insulating adhesive.

[0007] Furthermore, along the first direction, the length of the first insulating adhesive is greater than the length of the first connection structure adjacent to the first insulating adhesive.

[0008] Furthermore, along the first direction, the width of the first insulating adhesive is smaller than the spacing between the two first connection structures adjacent to the first insulating adhesive.

[0009] Furthermore, a plurality of second insulating adhesives and a plurality of second connection structures are provided on the first fine grid and the second fine grid in the main grid line region; wherein, the area of a single first insulating adhesive is larger than the area of a single second insulating adhesive.

[0010] Furthermore, the area of a single first connection structure is larger than the area of a single second connection structure.

[0011] Furthermore, the area range of a single first insulating adhesive is 45000 μm 2 to 300000 μm 2 .

[0012] Furthermore, the area range of a single second insulating adhesive is 30000 μm 2 to 60000 μm 2 .

[0013] Furthermore, the width range of a single first insulating adhesive is 90 μm to 110 μm.

[0014] Furthermore, the length range of a single first insulating adhesive is 500 μm to 2000 μm.

[0015] Furthermore, the ratio of the sum of the total areas of the plurality of first insulating adhesives and the plurality of second insulating adhesives to the total area of the main-gridless back-contact battery is 5% to 15%.

[0016] An embodiment of the present invention also provides a battery assembly, and the battery assembly includes the main-gridless back-contact battery as described above.

[0017] An embodiment of the present invention also provides a photovoltaic system, and the photovoltaic system includes the battery assembly as described above.

[0018] An embodiment of the present utility model provides a main-gridless back-contact battery, a battery module, and a photovoltaic system. The main-gridless back-contact battery includes: a silicon substrate; a plurality of fine grids disposed on the silicon substrate; the fine grids include a first fine grid and a second fine grid, the first fine grid and the second fine grid are arranged at intervals along a first direction and extend along a second direction, and the first fine grid and the second fine grid have opposite polarities; the silicon substrate is further provided with a plurality of solder tapes, the solder tapes include a first solder tape and a second solder tape, the first solder tape and the second solder tape are arranged at intervals along the second direction and extend along the first direction, and the first solder tape and the second solder tape have opposite polarities; the first direction intersects the second direction; the main-gridless back-contact battery includes a main grid line area and a plurality of edge grid line areas, and the main grid line area is located between the two edge grid line areas; the first fine grid and the second fine grid in the edge grid line area are provided with a plurality of first insulating adhesives and a plurality of first connection structures; the first connection structure electrically connects the first fine grid to the first solder tape, and the first insulating adhesive electrically isolates the second fine grid from the first solder tape; the first connection structure electrically connects the second fine grid to the second solder tape, and the first insulating adhesive electrically isolates the first fine grid from the second solder tape; wherein, the area of a single first insulating adhesive is larger than the area of a single first connection structure. In the present utility model, the main-gridless back-contact battery is provided with the area of the first insulating adhesive in the edge grid line area being larger than the area of the first connection structure, so as to provide greater electrical isolation for the grid lines and the solder tapes in the edge grid line area, prevent short-circuit problems, and achieve the effect of improving the stability of the main-gridless back-contact battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions in the embodiments of the present utility model or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments recorded in the present utility model. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0020] Figure 1 is a module schematic diagram of the photovoltaic system provided by the embodiment of the present utility model;

[0021] Figure 2 is a module schematic diagram of the battery module provided by the embodiment of the present utility model;

[0022] Figure 3 is a structural schematic diagram of the main-gridless back-contact battery provided by the embodiment of the present utility model;

[0023] Figure 4 For Figure 3Schematic diagram of the local structure at location A in the main-gridless back-contact battery described in

[0024] Figure 5 is Figure 3 Schematic diagram of the structure of the main-gridless back-contact battery described in when a solder tab is provided;

[0025] Figure 6 is Figure 5 Schematic diagram of the cross-sectional structure at location B in the main-gridless back-contact battery described in .

[0026] Description of the main component symbols: 1000, photovoltaic system; 1001, battery module; 100, main-gridless back-contact battery; 200, fine grid; 210, first fine grid; 220, second fine grid; 300, solder tab; 310, first solder tab; 320, second solder tab; 101, silicon substrate; 10, main grid line area; 20, edge grid line area; 11, first insulating adhesive; 12, first connection structure; 21, second insulating adhesive; 22, second connection structure. Detailed implementation manners

[0027] In order to make the objectives, technical solutions and advantages of the present utility model clearer and more understandable, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. The embodiments described below by referring to the accompanying drawings are exemplary and are only used to explain the present utility model, and should not be construed as a limitation to the present utility model. In addition, it should be understood that the specific embodiments described herein are only used to explain the present utility model and are not used to limit the present utility model.

[0028] In the description of the present utility model, it should be understood that the orientation or positional relationships indicated by the terms "length", "width", "upper", "lower", "top", "bottom", "lateral", "longitudinal", etc. are based on the orientation or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present utility model 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 thus should not be construed as a limitation to the present utility model.

[0029] In addition, the terms "first" and "second" are only used for descriptive purposes and should not be construed as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of the described features. In the description of the present utility model, "a plurality of" means two or more, unless otherwise specifically defined.

[0030] In the description of the present utility model, it should be noted that unless otherwise clearly specified and defined, the terms "installed", "connected", and "coupled" 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 a connection that allows mutual communication; it can be a direct connection, or an indirect connection through an intermediate medium, and it can be the internal communication between two components or the interaction relationship between two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.

[0031] In the present utility model, unless otherwise clearly specified and defined, the first feature being "above" or "below" the second feature may include the direct contact between the first and second features, or may include the situation where the first and second features are not in direct contact but in contact through other features therebetween. Moreover, the first feature being "above", "over", and "on top of" the second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the horizontal height of the first feature is higher than that of the second feature. The first feature being "under", "beneath", and "underneath" the second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the horizontal height of the first feature is lower than that of the second feature.

[0032] The following disclosure provides many different embodiments or examples for implementing different structures of the present utility model. To simplify the disclosure of the present utility model, the components and settings of specific examples are described below. Of course, they are merely examples and are not intended to limit the present utility model. In addition, the present utility model may repeat reference numerals and / or reference letters in different examples. This repetition is for the purpose of simplification and clarity, and does not itself indicate the relationship between the various embodiments and / or settings discussed. In addition, the present utility model provides examples of various specific processes and materials, 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.

[0033] Please refer to Figure 1 and Figure 2 , the photovoltaic system 1000 in the embodiment of the present utility model may include the battery module 1001 in the embodiment of the present utility model. The battery module 1001 in the embodiment of the present utility model may include a plurality of battery strings, and the battery strings may include a plurality of main-gridless back-contact batteries 100 in the embodiment of the present utility model. In the present utility model, a plurality of main-gridless back-contact batteries 100 in the battery module 1001 can be sequentially connected in series through welding tapes 300 to form a battery string. Each battery string in the battery module 1001 can be connected in series, in parallel, or in a series-parallel combination to achieve the current collection output. For example, the connection between each battery string can be achieved through busbars.

[0034] Please refer to Figure 3, Figure 4 , Figure 5 and Figure 6 . Figure 4 is Figure 3 a partial enlarged schematic view at A, Figure 6 is Figure 5 a sectional structure schematic view at B. The main-gridless back-contact battery 100 in the embodiment of the present invention includes a silicon substrate 101 and a plurality of fine grids 200 disposed on the silicon substrate 101; the fine grids 200 include a first fine grid 210 and a second fine grid 220, the first fine grid 210 and the second fine grid 220 are arranged at intervals along a first direction and extend along a second direction, and the polarities of the first fine grid 210 and the second fine grid 220 are opposite. The silicon substrate 101 is further provided with a plurality of welding tapes 300, the welding tapes 300 include a first welding tape 310 and a second welding tape 320, the first welding tape 310 and the second welding tape 320 are arranged at intervals along the second direction and extend along the first direction, and the polarities of the first welding tape 310 and the second welding tape 320 are opposite; the first direction intersects with the second direction.

[0035] The first fine grid 210 and the second fine grid 220 can specifically be positive fine grids 200 or negative fine grids 200, that is, the first fine grid 210 can be set as a positive fine grid 200 and the second fine grid 220 can be set as a negative fine grid 200; or the first fine grid 210 can be set as a negative fine grid 200 and the second fine grid 220 can be set as a positive fine grid 200.

[0036] The first welding tape 310 and the second welding tape 320 can specifically be positive welding tapes 300 or negative welding tapes 300, that is, the first welding tape 310 can be set as a positive welding tape 300 and the second welding tape 320 can be set as a negative welding tape 300; or the first welding tape 310 can be set as a negative welding tape 300 and the second welding tape 320 can be set as a positive welding tape 300.

[0037] The main-gridless back-contact battery 100 includes a main grid line area 10 and a plurality of edge grid line areas 20, the main grid line area 10 is located between two edge grid line areas 20; the first fine grid 210 and the second fine grid 220 of the edge grid line area 20 are provided with a plurality of first insulating adhesives 11 and a plurality of first connection structures 12, the first connection structure 12 electrically connects the first fine grid 210 with the first welding tape 310, and the first insulating adhesive 11 electrically isolates the second fine grid 220 from the first welding tape 310; the first connection structure 12 electrically connects the second fine grid 220 with the second welding tape 320, and the first insulating adhesive 11 electrically isolates the first fine grid 210 from the second welding tape 320. Among them, the area of a single first insulating adhesive 11 is larger than the area of a single first connection structure 12.

[0038] Specifically, in the embodiments of the present utility model, the first direction specifically refers to the width direction of the fine grid 200, and the second direction specifically refers to the length direction of the fine grid 200. Of course, in other embodiments, the first direction and the second direction can also be set as the diagonal direction.

[0039] Among them, the main-gridless back-contact battery 100 specifically includes a main grid line region 10 that occupies most of the main-gridless back-contact battery 100 and edge grid line regions 20 arranged on both sides of the main grid line region 10 along the first direction. The edge grid line region 20 is the edge part of the main-gridless back-contact battery 100. In the embodiments of the present utility model, the ratio of the area of one edge grid line region 20 to the total area of the main-gridless back-contact battery 100 is 5% to 12%.

[0040] A plurality of fine grids 200 are arranged in both the main grid line region 10 and several edge grid line regions 20. The fine grid 200 specifically includes a first fine grid 210 and a second fine grid 220.

[0041] A plurality of first insulating adhesives 11 and a plurality of first connection structures 12 are provided on both the first fine grid 210 and the second fine grid 220 in the edge grid line region 20. The fine grid 200 is insulated from the solder tapes 300 with different polarities through the first insulating adhesives 11, and the fine grid 200 is connected to the solder tapes 300 with the same polarity through the first connection structures 12. The first connection structure 12 can specifically be a PAD point. Solder can be provided on the first connection structure 12 to weld the solder tape 300, or glue can be applied on the first connection structure 12 to connect the solder tape 300.

[0042] Since the edge grid line region 20 is the edge part of the main-gridless back-contact battery 100, the first connection structure 12 arranged in the edge grid line region 20 is likely to come into contact with other electrical components, and the first connection structure 12 is also likely to be affected by heat and stress, resulting in the melting (liquefaction) of the first connection structure 12, causing short circuits between adjacent fine grids 200 and / or solder tapes 300, and further leading to the short circuit of the main-gridless back-contact battery 100 and the problem of damage to the main-gridless back-contact battery 100.

[0043] Therefore, by setting the area of the first insulating adhesive 11 in the edge grid line region 20 to be larger than the area of the first connection structure 12, greater electrical isolation is provided for the grid lines and the solder tapes 300 in the edge grid line region 20 to prevent short circuit problems, achieving the effect of improving the stability of the main-gridless back-contact battery 100; and in the edge grid line region 20, setting the area of the first insulating adhesive 11 to exceed the area of the first connection structure 12 can effectively prevent the contact problem of the fine grid 200 caused by the position error of the first connection structure 12 or changes during the production process.

[0044] In the embodiment of the present utility model, the areas of the first connection structure 12 and the first insulating glue 11 refer to the covering areas of the first connection structure 12 and the first insulating glue 11. Among them, the area of a single first insulating glue 11 being larger than the area of a single first connection structure 12 can mean that the area of one first insulating glue 11 is larger than the area of an adjacent first connection structure 12, or it can mean that the area of any first insulating glue 11 is larger than the area of any first connection structure 12, and no limitation is made here.

[0045] Further, in a possible implementation manner, along the first direction, the area of the first insulating glue 11 is larger than the area of the first connection structure 12 adjacent to the first insulating glue 11.

[0046] Specifically, for the area of a single first insulating glue 11, along the first direction, two first connection structures 12 are arranged on both sides of one first insulating glue 11. Therefore, the area of the first insulating glue 11 should be smaller than the areas of the two first connection structures 12 adjacent to the first insulating glue 11. Because when the area of the first insulating glue 11 is too small, when the first connection structure 12 melts (liquefies), the first insulating glue 11 cannot block the melted first connection structure 12, and as a result, the adjacent fine grid 200 and the welding strip 300 will be short-circuited, and the main-gridless back-contact battery 100 will be short-circuited, causing damage to the main-gridless back-contact battery 100. Therefore, when the first connection structure 12 arranged in the edge grid line area 20 melts (liquefies), the first insulating glue 11 can block the first connection structure 12 to provide necessary protection and isolation for the main-gridless back-contact battery 100, achieving the effect of improving the stability of the main-gridless back-contact battery 100.

[0047] Optionally, the area range of a single first insulating glue 11 is 45000μm 2 to 300000μm 2 . Specifically, when the area of the first insulating glue 11 is too small, the fine grid 200 may not be able to effectively insulate from the welding strip 300 with different polarities, and when the area of the first insulating glue 11 is too small, it may also be impossible to accurately position the first insulating glue 11; while when the area of the first insulating glue 11 is too large, it will cause waste of cost. Therefore, by setting the area range of the first insulating glue 11 to be 45000μm 2 to 300000μm 2 within this range, the first insulating glue 11 can achieve the effects of effective insulation and cost waste reduction.

[0048] In such an embodiment, the area of the first insulating glue 11 can be, for example, 45000μm 2 , 50000μm 2 , 55000μm2 , 60,000 μm 2 , 65,000 μm 2 , 70,000 μm 2 , 80,000 μm 2 , 90,000 μm 2 , 100,000 μm 2 , 200,000 μm 2 , 250,000 μm 2 , 300,000 μm 2 or 45,000 μm 2 to 300,000 μm 2 Any value between. Preferably, the area of the first insulating adhesive 11 is 80,000 μm 2 , so that the first insulating adhesive 11 has the best insulation and overall saving effect.

[0049] Further, in a possible implementation, along the first direction, the width of the first insulating adhesive 11 is less than the spacing of the first connecting structure 12 arranged adjacent to the first insulating adhesive 11.

[0050] For the width of a single first insulating adhesive 11, along the first direction, two first connecting structures 12 are arranged on both sides of a first insulating adhesive 11. Therefore, the width of the first insulating adhesive 11 should be less than the spacing of the two first connecting structures 12 arranged adjacent to the first insulating adhesive 11. Because when the width of the first insulating adhesive 11 is too large, the first insulating adhesive 11 will be stacked on the first connecting structure 12, thereby affecting the normal connection between the first connecting structure 12 and the solder strip 300. In this way, by setting the width of the first insulating adhesive 11 to be less than the spacing of the two first connecting structures 12 arranged adjacent to the first insulating adhesive 11, the effect of preventing the first insulating adhesive 11 from affecting the connection between the first connecting structure 12 and the solder strip 300 can be achieved.

[0051] Optionally, the width range of a single first insulating adhesive 11 is 90 μm to 110 μm. Specifically, when the width of the first insulating adhesive 11 is too small, the fine grid 200 may not be able to effectively insulate between the solder strips 300 with different polarities, and when the width of the first insulating adhesive 11 is too small, it may also be impossible to accurately position the first insulating adhesive 11; while when the width of the first insulating adhesive 11 is too large, it will occupy the effective space of the first connecting structure 12 and cause waste of cost. Therefore, by setting the width range of the first insulating adhesive 11 within the range of 90 μm to 110 μm, the first insulating adhesive 11 can achieve the effects of effective insulation and reduction of cost waste.

[0052] In such an embodiment, the width of the first insulating adhesive 11 can be, for example, 90μm, 95μm, 100μm, 105μm, 110μm, or any value between 90μm and 110μm. Preferably, the width of the first insulating adhesive 11 is 100μm, so that the first insulating adhesive 11 has the best insulation and overall cost-saving effect.

[0053] Furthermore, in a possible implementation manner, along the first direction, the length of the first insulating adhesive 11 is greater than the length of the first connection structure 12 arranged adjacent to the first insulating adhesive 11.

[0054] Specifically, for the length of a single first insulating adhesive 11, along the first direction, two first connection structures 12 are arranged on both sides of a first insulating adhesive 11. Therefore, the length of the first insulating adhesive 11 should be less than the lengths of the two first connection structures 12 arranged adjacent to the first insulating adhesive 11. Because when the length of the first insulating adhesive 11 is too small, when the first connection structure 12 melts (liquefies), the first insulating adhesive 11 cannot block the melted first connection structure 12, and then the adjacent fine grid 200 and the solder strip 300 will be short-circuited, resulting in a short circuit of the main-gridless back-contact battery 100 and causing damage to the main-gridless back-contact battery 100. Therefore, by setting the length of the first insulating adhesive 11 to be greater than the length of the first connection structure 12 arranged adjacent to the first insulating adhesive 11, the first insulating adhesive 11 can achieve the effects of effective insulation and cost waste reduction.

[0055] Optionally, the length range of a single first insulating adhesive 11 is 500μm to 2000μm. Specifically, when the length of the first insulating adhesive 11 is too short, the fine grid 200 may not be able to effectively insulate between the solder strips 300 with different polarities; when the length of the first insulating adhesive 11 is too long, the first insulating adhesive 11 may affect the heat dissipation of the solder strip 300 and the first connection structure 12, and also cause cost waste. Therefore, by setting the length range of the first insulating adhesive 11 within the range of 500μm to 2000μm, the first insulating adhesive 11 can achieve the effects of effective insulation and cost waste reduction.

[0056] In such an embodiment, the length of the first insulating adhesive 11 can be, for example, 500μm, 550μm, 600μm, 650μm, 700μm, 800μm, 900μm, 1000μm, 15000μm, 2000μm, or any value between 500μm and 2000μm. Preferably, the length of the first insulating adhesive 11 is 800μm, so that the first insulating adhesive 11 has the best insulation and overall cost-saving effect.

[0057] Further, in a possible implementation, a plurality of second insulating adhesives 21 and a plurality of second connection structures 22 are provided on the first fine grid 210 and the second fine grid 220 in the main grid line area 10; wherein, the area of a single first insulating adhesive 11 is larger than the area of a single second insulating adhesive 21.

[0058] Further, please refer to Figure 3 , Figure 4 , Figure 5 and Figure 6 , in addition to the fact that the fine grid 200 in the edge grid line area 20 is provided with an insulating adhesive and a connection structure, for the main grid line area 10. A plurality of second insulating adhesives 21 and a plurality of second connection structures 22 are provided on the fine grid 200 line in the main grid line area 10; wherein, the area of a single first insulating adhesive 11 is larger than the area of a single second insulating adhesive 21. In the main grid line area 10, the second connection structure 22 electrically connects the first fine grid 210 to the first solder strip 310, and the second insulating adhesive 21 electrically isolates the second fine grid 220 from the first solder strip 310; the second connection structure 22 electrically connects the second fine grid 220 to the second solder strip 320, and the second insulating adhesive 21 electrically isolates the first fine grid 210 from the second solder strip 320. That is, in the main grid line area 10, the fine grid 200 is insulated from the solder strips 300 with different polarities through the second insulating adhesive 21, and the fine grid 200 is connected to the solder strips 300 with the same polarity through the second connection structure 22. The second connection structure 22 may specifically be a PAD point, solder can be provided on the second connection structure 22 to connect the solder strip 300, and glue can also be applied on the second connection structure 22 to connect the solder strip 300.

[0059] In the embodiment of the present utility model, the areas of the second connection structure 22 and the second insulating adhesive 21 refer to the covering areas of the second connection structure 22 and the second insulating adhesive 21. Among them, the area of a single first insulating adhesive 11 being larger than the area of a single second insulating adhesive 21 may mean that the area of any one first insulating adhesive 11 is larger than the area of any one first connection structure 12, and no limitation is made here.

[0060] Similarly, since the edge grid line area 20 is the edge part of the back-contact battery 100 without a main grid, the first connection structure 12 provided in the edge grid line area 20 is likely to come into contact with other electrical components, and the first connection structure 12 is also more likely to be affected by heat and stress, resulting in the melting (liquefaction) of the first connection structure 12, causing short circuits between adjacent fine grids 200 or between adjacent solder strips 300, and further leading to a short circuit of the back-contact battery 100 without a main grid, resulting in damage to the back-contact battery 100 without a main grid.

[0061] Therefore, by setting the area of the first insulating glue 11 in the edge grid line area 20 to be larger than the area of the second connection structure 22 in the main grid line area 10, greater electrical isolation is provided for the fine grid 200 and the solder strip 300 in the edge grid line area 20 to prevent short - circuit problems, achieving the effect of improving the stability of the main - grid - free back - contact battery 100; it can effectively prevent the contact problem of the fine grid 200 caused by the position error of the first connection structure 12 or changes during the production process.

[0062] And for the main grid line area 10, the second connection structure 22 arranged in the main grid line area 10 is not as easy to contact other electrical components as the first connection structure 12. Therefore, by setting the area of the first insulating glue 11 to be larger than the area of the second insulating glue 21, that is, the area of the second insulating glue 21 is smaller than the area of the first insulating glue 11, the effect of cost saving can also be achieved.

[0063] Furthermore, for the main grid line area 10, please refer to Figure 3 、 Figure 4 、 Figure 5 and Figure 6 , in a possible implementation manner, the area of a single first connection structure 12 is larger than the area of a single second connection structure 22.

[0064] Specifically, along the first direction, the edge grid line area 20 is specifically arranged at the two - side edges of the main grid line area 10. For the main - grid - free back - contact battery 100, the stress and tensile force at the two - side edge parts of the main - grid - free back - contact battery 100 are relatively large. Therefore, problems such as connection and false soldering will occur in the solder strip 300 connected to the edge of the main - grid - free back - contact battery 100.

[0065] Therefore, in the present utility model, by setting the area of the first connection structure 12 in the edge grid line area 20 to be larger than the area of the second connection structure 22 in the main grid line area 10, the contact area between the first connection structure 12 and the solder strip 300 in the edge grid line area 20 is increased to enhance the tensile force on the solder strip 300 at the edge grid line area 20, which can effectively cope with the high - stress and large - tensile - force problems at the edge part of the main - grid - free back - contact battery 100, further improving the welding stability of the solder strip 300 and the overall reliability of the main - grid - free back - contact battery 100.

[0066] Optionally, the area range of a single second insulating glue 21 is 30000μm 2 to 60000μm 2Specifically, when the area of the second insulating adhesive 21 is too small, the fine grid 200 may not be able to effectively insulate from the solder tape 300 with a different polarity, and when the area of the second insulating adhesive 21 is too small, it may also be impossible to accurately position the first insulating adhesive 11; while when the area of the first insulating adhesive 11 is too large, it will cause waste of cost. Therefore, by setting the area range of the second insulating adhesive 21 to be 30,000 μm 2 to 60,000 μm 2 within this range, the first insulating adhesive 11 can achieve the effects of effective insulation and cost waste reduction.

[0067] In such an embodiment, the area of the second insulating adhesive 21 can be, for example, 30,000 μm 2 , 35,000 μm 2 , 45,000 μm 2 , 50,000 μm 2 , 55,000 μm 2 , 60,000 μm 2 or any value between 45,000 μm 2 and 300,000 μm 2 Preferably, the area of the first insulating adhesive 11 is 60,000 μm 2 , so that the second insulating adhesive 21 has the best insulation and overall saving effect.

[0068] Furthermore, for the first insulating adhesive 11 and the second insulating adhesive 21, in a possible implementation manner, the ratio of the total area of several first insulating adhesives 11 and the total area of several second insulating adhesives 21 to the total area of the main-gridless back-contact battery 100 is 5% to 15%.

[0069] Specifically, the number of both the first insulating adhesive 11 and the second insulating adhesive 21 can be one or more. The ratio of the total area of several first insulating adhesives 11 and the total area of several second insulating adhesives 21 to the total area of the main-gridless back-contact battery 100 is 5% - 15%. For example, it can be 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%.

[0070] In this way, the ratio of the first insulating adhesive 11 and the second insulating adhesive 21 to the total area of the main-gridless back-contact battery 100 is within a suitable range, which can avoid the small coverage area of the first insulating adhesive 11 and the second insulating adhesive 21 and the high short-circuit risk of the main-gridless back-contact battery 100 caused by too small a ratio, and can also avoid waste of materials and increased cost caused by too large a ratio. Preferably, the ratio of the first insulating adhesive 11 and the second insulating adhesive 21 to the total area of the main-gridless back-contact battery 100 is 10%. In this way, the overall insulation and saving effect is the best.

[0071] In the description of this specification, the descriptions referring to terms such as "some embodiments", "schematic embodiments", "examples", "specific examples", or "some examples", etc., mean 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 this application. In this specification, the schematic expressions of the above terms do not necessarily refer to the same embodiments or examples. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.

[0072] In addition, the above are only the preferred embodiments of this application and are not intended to limit this application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of this application shall be included within the protection scope of this application.

Claims

1. A back-contact cell without main grid, characterized in that, Comprising: A silicon substrate; A plurality of fine grids disposed on the silicon substrate; the fine grids include a first fine grid and a second fine grid, the first fine grid and the second fine grid are arranged at intervals in a first direction and extend in a second direction, and the first fine grid and the second fine grid have opposite polarities; A plurality of solder tapes are further disposed on the silicon substrate, the solder tapes include a first solder tape and a second solder tape, the first solder tape and the second solder tape are arranged at intervals in the second direction and extend in the first direction, and the first solder tape and the second solder tape have opposite polarities; the first direction intersects the second direction; The main-gridless back-contact battery includes a main grid line region and a plurality of edge grid line regions, and the main grid line region is located between the two edge grid line regions; A plurality of first insulating adhesives and a plurality of first connection structures are provided on the first fine grid and the second fine grid in the edge grid line region; The first connection structure electrically connects the first fine grid to the first solder tape, and the first insulating adhesive electrically isolates the second fine grid from the first solder tape; The first connection structure electrically connects the second fine grid to the second solder tape, and the first insulating adhesive electrically isolates the first fine grid from the second solder tape; Wherein, the area of a single first insulating adhesive is larger than the area of a single first connection structure.

2. The back-contact cell without main grid according to claim 1, wherein Along the first direction, the area of the first insulating adhesive is larger than the area of the first connection structure adjacent to the first insulating adhesive.

3. The back-contact cell without main grid according to claim 2, wherein, Along the first direction, the length of the first insulating adhesive is greater than the length of the first connection structure adjacent to the first insulating adhesive.

4. The back-contact cell without main grid according to claim 2, wherein Along the first direction, the width of the first insulating adhesive is less than the spacing between two adjacent first connection structures.

5. The back-contact cell without main grid according to claim 1, wherein A plurality of second insulating adhesives and a plurality of second connection structures are provided on the first fine grid and the second fine grid in the main grid line region; Wherein, the area of a single first insulating adhesive is larger than the area of a single second insulating adhesive.

6. The back-contact cell without main grid according to claim 5, characterized in that, The area of a single first connection structure is larger than the area of a single second connection structure.

7. The back-contact cell without main grid according to claim 1, characterized in that The area range of each of the first insulating adhesives is 45000μm 2 to 300000μm 2 .

8. The back-contact cell without main grid according to claim 5, characterized in that, The area range of each of the second insulating adhesives is 30000 μm 2 to 60000 μm 2 .

9. The back-contact cell without main grid according to claim 1, wherein The width range of a single first insulating adhesive is 90μm to 110μm.

10. The back-contact cell without main grid according to claim 1, wherein, The length range of a single first insulating adhesive is 500μm to 2000μm.

11. The back-contact cell without main grid according to claim 5, characterized in that, The ratio of the total area of a plurality of first insulating adhesives and the total area of a plurality of second insulating adhesives to the total area of the main-gridless back-contact battery is 5% to 15%.

12. A battery assembly, characterized in that, Including the main-gridless back-contact battery according to any one of claims 1 to 11.

13. A photovoltaic system, characterized in that, Including the battery assembly according to claim 12.

Images