CN219800861U

CN219800861U - Back contact battery, battery pack and photovoltaic system

Info

Publication number: CN219800861U
Application number: CN202321247872.9U
Authority: CN
Inventors: 谭理想; 王永谦; 张宁; 宋易; 陈刚
Original assignee: Zhejiang Aiko Solar Energy Technology Co Ltd; Guangdong Aiko Technology Co Ltd; Tianjin Aiko Solar Energy Technology Co Ltd; Zhuhai Fushan Aixu Solar Energy Technology Co Ltd
Current assignee: Zhejiang Aiko Solar Energy Technology Co Ltd; Guangdong Aiko Technology Co Ltd; Tianjin Aiko Solar Energy Technology Co Ltd; Zhuhai Fushan Aixu Solar Energy Technology Co Ltd
Priority date: 2023-05-22
Filing date: 2023-05-22
Publication date: 2023-10-03
Anticipated expiration: 2033-05-22

Abstract

The application is suitable for the technical field of solar cells, and provides a back contact cell, a cell assembly and a photovoltaic system. The back contact battery comprises a battery substrate and a first insulating piece, wherein secondary grids of two polarities which are distributed in a staggered way are formed on the back surface of the battery substrate, and the back surface comprises a bus area and a non-bus area which are distributed in a staggered way; the first insulating piece is arranged continuously along the extending direction of the bus area at the edge of the non-bus area and covers the part of the auxiliary grid, which is positioned in the non-bus area and is close to the bus area. Therefore, the first insulating piece is continuously arranged at the edge of the non-bus area along the extending direction of the bus area, and the auxiliary grid is covered on the part of the non-bus area close to the bus area, so that the auxiliary grid can be prevented from being conducted with the bus piece with opposite polarity at the edge of the non-bus area close to the bus area, the normal operation of the back contact battery can be ensured, and the risk of short circuit of the back contact battery is reduced.

Description

Back contact battery, battery pack and photovoltaic system

Technical Field

The application belongs to the technical field of solar cells, and particularly relates to a back contact cell, a cell assembly and a photovoltaic system.

Background

Solar cell power generation is a sustainable clean energy source that uses the photovoltaic effect of semiconductor p-n junctions to convert sunlight into electrical energy.

In the back contact cell of the related art, the sub-gates of two polarities are alternately distributed. When the sub-gate is converged by the converging member, the sub-gate is easily conducted with the converging member of the opposite type, thereby causing a short circuit.

Based on this, how to reduce the risk of shorting back contact cells becomes a problem to be solved.

Disclosure of Invention

The utility model provides a back contact battery, a battery assembly and a photovoltaic system, and aims to solve the problem of reducing the risk of short circuit of the back contact battery.

The back contact battery comprises a battery substrate and a first insulating piece, wherein secondary grids of two polarities which are distributed in a staggered mode are formed on the back face of the battery substrate, and the back face comprises a confluence area and a non-confluence area which are distributed in a staggered mode; the first insulating piece is arranged at the edge of the non-bus area and is continuously arranged along the extending direction of the bus area, and the part, close to the bus area, of the non-bus area, of the auxiliary grid is covered.

Optionally, the thickness of the first insulator is 10 μm to 50 μm.

Optionally, the width of the first insulating member at the edge of the non-bus region is 100 μm to 1000 μm.

Optionally, the back surface is formed with a main gate, and the main gate is disposed in the bus region and exposed from the first insulating member.

Optionally, the ratio of the coverage area of the first insulating member to the total area of the back contact battery is 10% -20%.

Optionally, the back contact battery is a battery without a main grid, a part of each auxiliary grid is located in the converging area, the rest of each auxiliary grid is located in the non-converging area, the converging area is used for arranging a serial connection piece, and the corresponding converging area of each serial connection piece exposes auxiliary grids with the same polarity.

Optionally, the bus region is provided with the sub-gate of one polarity, and the bus region is entirely exposed from the first insulating member.

Optionally, the bus region is provided with the secondary grids with two polarities, and the back contact battery comprises a second insulating member, and the second insulating member covers the secondary grids with the polarities opposite to those of the corresponding series connection members in the bus region.

Optionally, the ratio of the sum of the coverage areas of the first and second insulating members to the total area of the back contact battery is 5% -15%.

Optionally, the back contact battery includes a third insulating member disposed continuously from the first insulating member in the extending direction of the sub-grids in the non-bus region, at least partially covering the sub-grids having a polarity opposite to that of the corresponding bus region.

Optionally, the ratio of the sum of the lengths of the third insulating pieces corresponding to the two adjacent auxiliary grids to the distance between the first insulating pieces at two ends of the non-confluence region is less than or equal to 150%.

Optionally, the ratio of the sum of the lengths of the third insulating pieces corresponding to the two adjacent auxiliary grids to the distance between the first insulating pieces at two ends of the non-confluence region is 100% or more and 120% or less.

Optionally, the width of the third insulator is 50 μm to 500 μm.

Optionally, the difference between the widths of the third insulating member and the corresponding sub-gate is 20 μm to 200 μm.

Optionally, the first insulating member is a transparent insulating member.

Optionally, the first insulating member is a transparent fluorescent insulating member.

The battery assembly provided by the application comprises the back contact battery of any one of the above.

The photovoltaic system provided by the application comprises the battery assembly.

According to the back contact battery, the battery assembly and the photovoltaic system, the first insulating piece is continuously arranged at the edge of the non-bus area along the extending direction of the bus area, and the part, close to the bus area, of the non-bus area is covered by the auxiliary grid, so that the auxiliary grid can be prevented from being conducted with the bus piece with opposite polarity at the edge, normal operation of the back contact battery can be guaranteed, and the risk of short circuit of the back contact battery is reduced.

Drawings

Fig. 1 is a schematic structural view of a back contact battery according to an embodiment of the present application;

fig. 2 is a schematic view of the structure of a battery substrate of a back contact battery according to an embodiment of the present application;

fig. 3 is a schematic view of a partial region of a back contact battery according to an embodiment of the present application;

fig. 4 is a schematic structural view of a partial region of a back contact battery according to an embodiment of the present application;

fig. 5 is a schematic view of a partial region of a back contact battery according to an embodiment of the present application;

fig. 6 is a schematic structural view of a partial region of a back contact battery according to an embodiment of the present application;

fig. 7 is a schematic view of a partial region of a back contact battery according to an embodiment of the present application;

fig. 8 is a schematic view of a partial region of a back contact battery according to an embodiment of the present application;

Fig. 9 is a schematic view of a partial region of a back contact battery according to an embodiment of the present application;

fig. 10 is a schematic structural view of a back contact battery according to an embodiment of the present application;

fig. 11 is a schematic structural view of a back contact battery according to an embodiment of the present application;

fig. 12 is a schematic structural view of a back contact battery according to an embodiment of the present application;

description of main reference numerals:

the back contact battery 100, the battery substrate 10, the series electrical connection region 101, the first sub-gate 111, the first main gate 112, the first series electrical connection region 1120, the second sub-gate 121, the second main gate 122, the second series electrical connection region 1220, the bus region 13, the non-bus region 14, the first insulating member 21, the second insulating member 22, the third insulating member 23, and the stopper 24.

Detailed Description

The present application will be described in further detail with reference to the drawings and examples, in order to make the objects, technical solutions and advantages of the present application more apparent. Examples of the embodiments are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to like or similar elements throughout or elements having like or similar functionality. The embodiments described below by referring to the drawings are illustrative only and are not to be construed as limiting the application. Furthermore, it should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the scope of the present application.

In the description of the present application, it should be understood that the terms "length," "width," "upper," "lower," "left," "right," "horizontal," "top," "bottom," and the like indicate orientations or positional relationships based on the orientation or positional relationships shown in the drawings, are merely for convenience in describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be configured and operated in a specific orientation, and thus should not be construed as limiting the present application.

Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include one or more of the described features. In the description of the present application, the meaning of "a plurality" is two or more, unless explicitly defined otherwise.

In the description of the present application, it should be noted that, unless explicitly specified and limited otherwise, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be either fixedly connected, detachably connected, or integrally connected, for example; can be mechanically connected, electrically connected or can be communicated with each other; can be directly connected or indirectly connected through an intermediate medium, and can be communicated with the inside of two elements or the interaction relationship of the two elements. The specific meaning of the above terms in the present application can be understood by those of ordinary skill in the art according to the specific circumstances.

In the present application, unless expressly stated or limited otherwise, a first feature "above" or "below" a second feature may include both the first and second features being in direct contact, as well as the first and second features not being in direct contact but being in contact with each other through additional features therebetween. Moreover, a first feature being "above," "over" and "on" a second feature includes the first feature being directly above and obliquely above the second feature, or simply indicating that the first feature is higher in level than the second feature. The first feature being "under", "below" and "beneath" the second feature includes the first feature being directly under and obliquely below the second feature, or simply means that the first feature is less level than the second feature.

The following disclosure provides many different embodiments, or examples, for implementing different structures of the application. In order to simplify the present disclosure, components and arrangements of specific examples are described below. They are, of course, merely examples and are not intended to limit the application. Furthermore, the present application may repeat reference numerals and/or letters in the various examples, which are for the purpose of brevity and clarity, and which do not themselves indicate the relationship between the various embodiments and/or arrangements discussed. In addition, the present application provides examples of various specific processes and materials, but one of ordinary skill in the art will recognize applications of other processes and/or usage scenarios for other materials.

In the application, the first insulating piece is continuously arranged at the edge of the non-bus area along the extending direction of the bus area, and the auxiliary grid is covered on the part of the non-bus area close to the bus area, so that the auxiliary grid can be prevented from being conducted with the bus piece with opposite polarity at the edge of the non-bus area close to the bus area, the normal operation of the back contact battery can be ensured, and the risk of short circuit of the back contact battery is reduced.

Example 1

Referring to fig. 1, 2 and 3, a back contact battery 100 according to an embodiment of the present application includes a battery substrate 10 and a first insulating member 21, wherein a back surface of the battery substrate 10 is formed with sub-grids of two polarities which are alternately distributed, and the back surface includes an alternately distributed bus region 13 and a non-bus region 14; the first insulating member 21 is provided continuously along the extending direction of the bus bar region 13 at the edge of the non-bus bar region 14, covering the portion of the sub-gate located near the bus bar region 13 of the non-bus bar region 14.

In the back contact battery 100 of the embodiment of the present application, since the first insulating member 21 is continuously disposed along the extending direction of the bus region 13 at the edge of the non-bus region 14, and covers the portion of the sub-gate near the bus region 13 of the non-bus region 14, the sub-gate near the edge of the bus region 13 of the non-bus region 14 can be prevented from being conducted with the bus member with opposite polarity, so that the normal operation of the back contact battery 100 can be ensured, and the risk of short-circuiting of the back contact battery 100 can be reduced.

Meanwhile, when a plurality of back contact cells 100 are stacked, it is possible to prevent the sub-grid from scratching another back contact cell 100 by the first insulating member 21 at the region where the first insulating member 21 is covered. Also, since the first insulating member 21 has a certain thickness, a gap may be formed between the region not covered with the first insulating member 21 and the other back contact cell 100, thereby preventing the sub-gate from scratching the other back contact cell 100 in the region not covered with the first insulating member 21. In this way, it is possible to reduce damage to the back contact battery 100 when the back contact batteries 100 are stacked, and to dispense with a separator provided between two adjacent back contact batteries 100, thereby reducing the cost of transporting or storing the back contact batteries 100.

Specifically, the back contact battery 100 may be a single battery piece, or may be a half piece, a third piece, or other ratio of battery pieces formed by dividing a single battery piece. For clarity of the drawing, the back contact cell 100 is shown in fig. 1 and 2 as a half-piece divided from a single piece of cell. Other proportions of the back contact battery 100 are similar to those of fig. 1 and 2, and reference is made to fig. 1 and 2, and no further description is given here. Fig. 3 to 9 show a partial region of the back contact battery 100, and other regions of the back contact battery 100 are similar to those of fig. 3 to 9, and reference may be made to fig. 3 to 9, which are not repeated herein. That is, the drawings are merely examples, and do not represent a limitation on the specific form of the back contact battery 100.

Specifically, the back surface of the battery substrate 10 is formed with sub-grids of two polarities, a first sub-grid 111 and a second sub-grid 121, which are alternately distributed, respectively.

Further, the battery substrate 10 includes a front surface facing the sun, which mainly receives direct sunlight, and a back surface facing the mounting surface of the battery assembly, which mainly receives sunlight reflected by the mounting surface, such as a floor, a roof, and the like. Alternatively, the back surface is a surface of the back contact battery 100 provided with the gate line.

Further, the staggered distribution means that one second sub-gate 121 is disposed between two adjacent first sub-gates 111, and one first sub-gate 111 is disposed between two adjacent second sub-gates 121. Further, one of the first sub-gate 111 and the second sub-gate 121 is a positive sub-gate, and the other of the first sub-gate 111 and the second sub-gate 121 is a negative sub-gate.

Specifically, the back surface includes bus regions 13 and non-bus regions 14 that are alternately distributed. In other words, one non-bus region 14 is formed between two adjacent bus regions 13, and one bus region 13 is formed between two adjacent non-bus regions 14.

Further, the staggered arrangement direction of the bus bar regions 13 and the non-bus bar regions 14 is perpendicular to the staggered arrangement direction of the first sub-gate 111 and the second sub-gate 121. It will be appreciated that in other embodiments, the staggered arrangement direction of the bus regions 13 and the non-bus regions 14 may be at an angle to the staggered arrangement direction of the first sub-gate 111 and the second sub-gate 121, which is not limited herein.

Further, the polarity of the bus area 13 is two, namely a first bus area and a second bus area, which are staggered. In other words, one second bus region is formed between two adjacent first bus regions, and one first bus region is formed between two adjacent second bus regions. Further, one of the first bus region and the second bus region is a positive electrode bus region, and the other of the first bus region and the second bus region is a negative electrode bus region.

Further, the staggered arrangement direction of the first and second bus regions is perpendicular to the staggered arrangement direction of the first and second sub-gates 111 and 121. It is to be understood that, in other embodiments, the direction of the staggered arrangement of the first bus bar region and the second bus bar region may be at an angle to the direction of the staggered arrangement of the first sub-gate 111 and the second sub-gate 121, which is not limited herein.

In the examples of fig. 1, 2 and 3, the first and second bus regions are formed with first and second main gates 112 and 122, respectively. In other words, in the examples of fig. 1, 2 and 3, the sub-gates of the same polarity are converged by the main gates of the same polarity. Further, one of the first main gate 112 and the second main gate 122 is a positive main gate, and the other of the first main gate 112 and the second main gate 122 is a negative main gate.

It is to be understood that in other embodiments, the first and second convergence regions may be used to provide the first and second series, respectively. That is, the same polarity of the sub-grids are converged by the same polarity of the series connection. In other embodiments, it is also possible that part of the bus regions 13 are connected via the main gate and the remaining bus regions 13 are connected via the series connection. The specific manner of the sub-gate bus is not limited herein.

The serial connection element is an electric conductor for connecting the back contact battery 100 in series to form a battery string. The serial connection member is, for example, a serial connection member, a conductive wire, a conductive sheet, a conductive plate, etc. The serial connection is described by taking the serial connection as an example, but the serial connection is not limited by the serial connection.

Referring to fig. 1 and 3, the first insulating member 21 is disposed continuously along the extending direction of the bus region 13 at the edge of the non-bus region 14, covering the portion of the sub-gate near the bus region 13 of the non-bus region 14. In this way, the portion of the sub-grid close to the bus bar region 13, whether the same or opposite polarity as the bus bar region 13, is covered by the first insulating member 21, and the risk of shorting the back contact battery 100 can be minimized. Further, the polarity of the sub-gate and the bus bar region 13 is not required to be considered when the first insulating member 21 is provided, which is advantageous in that the efficiency of providing the first insulating member 21 is improved. Furthermore, the first insulating member 21 is continuously covered without avoiding the sub-gate having the same polarity as the bus bar region 13, and the process of disposing the first insulating member 21 is simpler, which is also advantageous in improving the efficiency of disposing the first insulating member 21.

As described above, the bus bar regions 13 and the non-bus bar regions 14 are alternately arranged. Therefore, "the edge" in the "the first insulating member 21 is continuously provided along the extending direction of the bus bar region 13 at the edge of the non-bus bar region 14" means that the first insulating member 21 is near the edge of the bus bar region 13 at the non-bus bar region 14. The "extending direction" in the "first insulating member 21 is provided continuously along the extending direction of the bus bar region 13 at the edge of the non-bus bar region 14" means the direction of the boundary line between the non-bus bar region 14 and the bus bar region 13. The "continuous arrangement" in the "continuous arrangement of the first insulating member 21 at the edge of the non-bus region 14 along the extending direction of the bus region 13" means that the first insulating member 21 is not broken.

That is, the first insulating member 21 is continuously provided near the edge of the bus bar region 13 in the non-bus bar region 14 along the boundary line between the non-bus bar region 14 and the bus bar region 13.

Referring to fig. 1 and 3, the first insulating member 21 covers the sub-gate at a portion of the non-bus region 14 near the bus region 13, and covers the sub-gates of two polarities. It will be appreciated that in other embodiments, the non-bus region 14 may be near the edge of the bus region 13, only the sub-gate having the same polarity as the bus region 13 is formed, and the sub-gate having the opposite polarity to the bus region 13 is not formed, and the first insulating member 21 covers the sub-gate at the portion of the non-bus region 14 near the bus region 13, and covers the sub-gate having the same polarity as the bus region 13. The specific polarity and the number of polarities of the sub-gates covered by the first insulating member 21 are not limited here.

Referring to fig. 1 and 3, the outer edge of the first insulating member 21 is a straight line or a broken line. It will be appreciated that in other embodiments, the outer edge of the first insulating member 21 may be curved. The specific form of the outer edge of the first insulating member 21 is not limited here.

Example two

In some alternative embodiments, the thickness of the first insulator 21 is 10 μm to 50 μm. For example, 10 μm, 12 μm, 15 μm, 17 μm, 20 μm, 25 μm, 28 μm, 30 μm, 35 μm, 40 μm, 42 μm, 45 μm, 49 μm, 50 μm.

Thus, the thickness of the first insulating member 21 is in a proper range, so that poor insulating effect caused by too small thickness can be avoided, and waste of materials and cost increase caused by too large thickness can be avoided.

Preferably, the thickness of the first insulating member 21 is 20 μm to 30 μm. Thus, the overall effect of insulation and economy is best.

Note that the thickness of the first insulating member 21 may be a constant value within 10 μm to 50 μm or may fluctuate within 10 μm to 50 μm.

Example III

Referring to fig. 3, in some alternative embodiments, the width w of the first insulating member 21 at the edge of the non-bus region 14 is 100 μm to 1000 μm. For example 100 μm, 102 μm, 110 μm, 200 μm, 250 μm, 300 μm, 400 μm, 500 μm, 600 μm, 900 μm, 990 μm, 1000 μm.

In this way, the width of the first insulating member 21 at the edge of the non-bus region 14 is in a suitable range, so that poor insulating effect and high risk of short circuit of the back contact battery 100 due to too small width can be avoided, and waste of materials and cost increase due to too large width can also be avoided.

Preferably, the width w of the first insulating member 21 at the edge of the non-bus region 14 is 400 μm to 600 μm. Thus, the overall effect of insulation and economy is best.

Note that the width w of the first insulating member 21 at the edge of the non-bus region 14 may be a constant value within 100 μm to 1000 μm, or may fluctuate within 100 μm to 1000 μm.

Example IV

Referring to fig. 3, in some alternative embodiments, a main gate is formed on the back surface, and the main gate is disposed in the bus region 13 and is exposed from the first insulating member 21.

In this way, the current of the back contact battery 100 is easily drawn out by the main gate and the sub-gate. Further, the main grid is exposed from the first insulating member 21, is not shielded by the first insulating member 21, and is easily connected to the series member to form a battery string.

Specifically, the back surface is formed with main gates of two polarities which are alternately distributed, namely, a first main gate 112 and a second main gate 122, respectively, and sub-gates of two polarities, namely, a first sub-gate 111 and a second sub-gate 121, respectively, are converged. Further, the staggered distribution means that one second main gate 122 is disposed between two adjacent first main gates 112, and one first main gate 112 is disposed between two adjacent second main gates 122. Still further, one of the first main gate 112 and the second main gate 122 is a positive main gate, and the other of the first main gate 112 and the second main gate 122 is a negative main gate.

It will be appreciated that in other embodiments, the back surface may be formed with two types of main grids, and each of the two types of main grids is used for converging a part of the auxiliary grids with corresponding polarities, and the rest of the auxiliary grids are converged by the serial connection member; in other embodiments, the back side may be formed with a primary gate of one polarity, a secondary gate of the same polarity, the secondary gate of the other polarity being converged by the cascade. The specific form in which the sub-gates are converged by the main gate is not limited herein.

Example five

Referring to fig. 1, in some alternative embodiments, the ratio of the coverage area of the first insulating member 21 to the total area of the back contact battery 100 is 10% -20%. For example, 10%, 11%, 15%, 18%, 20%.

In this way, the ratio of the coverage area of the first insulating member 21 to the total area of the back contact battery 100 is in a suitable range, so that the situation that the coverage area of the first insulating member 21 is smaller and the risk of short circuit of the back contact battery 100 is higher due to the too small ratio can be avoided, and the material waste and the cost improvement caused by the too large ratio can also be avoided.

Preferably, the ratio of the coverage area of the first insulating member 21 to the total area of the back contact battery 100 is 15%. Thus, the overall effect of insulation and economy is best.

Example six

Referring to fig. 4, in some alternative embodiments, the back contact battery 100 is a battery without a main grid, a portion of each sub-grid is located in the bus region 13, and the other portion of each sub-grid is located in the non-bus region 14, where the bus region 13 is used to provide a series connection, and the bus region 13 corresponding to each series connection exposes sub-grids with the same polarity.

In this way, the back contact battery 100 has no main grid, and the series element is used for converging the auxiliary grid, so that the slurry of the main grid can be omitted, and the cost can be reduced.

Specifically, the serial connection parts have two polarities, and the auxiliary grids with the same polarity are respectively converged.

Specifically, the serial connection member is an electrical conductor that connects back contact cells 100 in series to form a cell string. The serial connection member is, for example, a serial connection member, a conductive wire, a conductive sheet, a conductive plate, etc. The serial connection is described by taking the serial connection as an example, but the serial connection is not limited by the serial connection.

Example seven

Referring to fig. 4, in some alternative embodiments, the bus region 13 is provided with a sub-gate of one polarity, and the bus region 13 is fully exposed from the first insulating member 21.

Therefore, the serial connection piece can be directly arranged in the converging area 13, and auxiliary grids with different polarities from those of the serial connection piece are not required to be shielded, so that the production efficiency is improved, and the cost is reduced.

Example eight

Referring to fig. 5, in some alternative embodiments, the bus region 13 is provided with two polarity sub-grids, and the back contact battery 100 includes a second insulating member 22, where the second insulating member 22 covers the sub-grids with opposite polarity to the corresponding series members in the bus region 13.

In this way, the secondary grids of one polarity can be shielded in the bus region 13, and the secondary grids of the other polarity are exposed to be connected with the serial connection member so as to be connected in a bus manner, and the risk of short circuit of the battery string can be reduced.

Specifically, the second insulating member 22 completely covers the sub-grid of opposite polarity to the corresponding series member in the bus region 13. In this way, it is ensured that the secondary grid of opposite polarity to the series is not exposed in the junction region 13, minimizing the risk of short circuits.

It is understood that the serial connection member does not have a polarity, but the auxiliary grid to be converged by the serial connection member has a polarity, so the polarity of the serial connection member refers to the polarity of the auxiliary grid to be converged by the serial connection member.

Example nine

Referring to fig. 5, in some alternative embodiments, the ratio of the sum of the coverage areas of the first insulating member 21 and the second insulating member 22 to the total area of the back-contact battery 100 is 5% -15%. For example, 5%, 6%, 8%, 10%, 11%, 13%, 15%.

In this way, the ratio of the sum of the coverage areas of the first insulating member 21 and the second insulating member 22 to the total area of the back contact battery 100 is in a suitable range, so that the situation that the total coverage area of the first insulating member 21 and the second insulating member 22 is smaller and the risk of short circuit of the back contact battery 100 is higher due to the excessively small ratio can be avoided, and the material waste and the cost increase due to the excessively large ratio can also be avoided.

Preferably, the ratio of the sum of the coverage areas of the first and second insulating members 21 and 22 to the total area of the back-contact battery 100 is 10%. Thus, the overall effect of insulation and economy is best.

Referring to fig. 6, in some alternative embodiments, the battery substrate 10 is formed with a serial electrical connection region 101 and a non-serial electrical connection region 102, and the back contact battery 100 includes a limiting member 24, where the limiting member 24 is connected to the first insulating member 21, and surrounds the serial electrical connection region 101.

In this way, the conductive material can be prevented from flowing from the electric connection area 101 of the serial connection element to the opposite auxiliary grid of the serial connection element, so that the conduction between the serial connection element and the auxiliary grid with opposite polarity is avoided, and the risk of short circuit of the back contact battery 100 can be reduced. Meanwhile, the conductive material can be prevented from flowing from the electric connection area 101 of the serial connection part to the auxiliary grid with the same polarity as the serial connection part, so that the lower height of the conductive material is avoided, and poor connection is avoided.

Specifically, the electrical connection area 101 includes a first electrical connection area 1120 and a second electrical connection area 1220 with opposite polarities. The polarity of the first serial electrical connection region 1120 is the same as the first sub-gate 111, and the polarity of the second serial electrical connection region 1220 is the same as the second sub-gate 121.

Specifically, the limiting member 24 may be an insulating member. In this way, the limiting piece 24 can insulate while limiting, and the risk of short circuit is reduced.

In the example of fig. 6, a main grid is formed on the back surface of the battery substrate 10, and a series electrical connection region 101 and a non-series electrical connection region 102 are formed on the main grid, wherein the series electrical connection region 101 is a region where the main grid is electrically connected with the series.

Specifically, the electrical connection area 101 of the serial connection element includes a pad area and/or a conductive adhesive area. Further, the pad region may be provided with a conductive material. The conductive material is solder such as solder paste. Further, the conductive adhesive area may be provided with conductive adhesive. In other words, the serial part electrical connection area 101 of the main gate can be connected with the serial part by welding; the serial connection parts can also be electrically bonded and connected through conductive adhesive; the serial connection parts can also be connected through welding and bonding of conductive adhesive.

Specifically, the area of the electrical connection region 101 of the serial connection element is 2mm ² -6mm ² . For example 2mm ² 、3mm ² 、3.75mm ² 、4mm ² 、5mm ² 、6mm ² . Thus, the area of the electrical connection region 101 of the serial connection element is in a proper range, so that unstable connection between the back contact battery 100 and the serial connection element caused by too small area can be avoided, and waste of conductive material and poor insulation effect caused by too large area can be avoided. Preferably, the area of the electrical connection area 101 of the serial connection element is 3.75mm ² Rectangular, with a width of 1.5mm and a length of 2.5mm. Thus, the connection between the back contact battery 100 and the serial connection member, the saving of conductive materials and the insulation are combined, and the overall effect is the best.

Specifically, the number of the series electrical connection areas 101 is 30-300. For example 30, 40, 50, 100, 120, 150, 200, 280, 300. In this way, the number of the electrical connection areas 101 of the serial connection element is in a proper range, so that unstable connection between the back contact battery 100 and the serial connection element caused by too small number can be avoided, and lower efficiency and higher cost caused by too large number can also be avoided.

Note that the number of the 30-300 cells corresponds to the back contact cell 100 being a single cell. It is understood that in the case where the back contact battery 100 is a half, a third, or other ratio of battery pieces divided from a single battery piece, the number of the series electrical connection regions 101 may be determined based on the dividing ratio and the range of 30 to 300. For example, in the case where the back contact battery 100 is a half-piece divided from a single battery piece, the number of the series electrical connection regions 101 is 15 to 150.

It is understood that in other examples, the back contact battery 100 may be a non-main-grid battery, and the back surface of the back contact battery 100 includes a series electrical connection region 101 and a non-series electrical connection region 102, a portion of each sub-grid is located in the series electrical connection region 101, and the rest of each sub-grid is located in the non-series electrical connection region 102, and the series electrical connection region 101 is a region where the sub-grid is electrically connected to the series. In this way, the secondary grids of the cells without the primary grids are converged by the series element. It will be appreciated that, whether the back contact battery 100 has a main grid or not, the battery strings are connected through the series connection member, and the limiting member 24 can surround the series connection member electrical connection region 101 together with the first insulating member 21, so as to avoid the conductive material flowing from the series connection member electrical connection region 101 to the opposite auxiliary grid of the series connection member.

Specifically, the width of the electrical connection region 101 of the serial connection element may be greater than or equal to the spacing between the first insulating elements 21 on two sides at the non-electrical connection region 102 of the serial connection element. Thus, the area of the electrical connection area 101 of the serial connection element is larger, and more conductive materials can be arranged, so that the connection between the back contact battery 100 and the serial connection element such as the serial connection element is more stable. In other embodiments, the width of the electrical connection region 101 of the serial connection element may be smaller than the spacing between the first insulating elements 21 at the non-serial connection region 102.

Specifically, the area of the electrical connection region 101 of the serial connection element is 0.02mm ² -0.6mm ² . For example 0.02mm ² 、0.03mm ² 、0.375mm ² 、0.4mm ² 、0.5mm ² 、0.6mm ² . Thus, the area of the electrical connection region 101 of the serial connection element is in a proper range, so that unstable connection between the back contact battery 100 and the serial connection element caused by too small area can be avoided, and waste of conductive material and poor insulation effect caused by too large area can be avoided. Preferably, the area of the electrical connection region 101 of the serial connection element is 0.375mm ² Rectangular with a width of 0.15mm and a length of 0.25mm. Thus, the connection between the back contact battery 100 and the serial connection member, the saving of conductive materials and the insulation are combined, and the overall effect is the best.

Specifically, the number of the series electrical connection areas 101 is 1000-4000. For example 1000, 1500, 2000, 2500, 3000, 3500, 3800, 4000. In this way, the number of the electrical connection areas 101 of the serial connection element is in a proper range, so that unstable connection between the back contact battery 100 and the serial connection element caused by too small number can be avoided, and lower efficiency and higher cost caused by too large number can also be avoided.

Note that the number ranges from 1000 to 4000, corresponding to the back contact cell 100 being a single unitary cell. It is understood that in the case where the back contact battery 100 is a half, a third, or other ratio of battery pieces divided from a single battery piece, the number of the series electrical connection regions 101 may be determined based on the dividing ratio and the range of 1000 to 4000. For example, in the case where the back contact battery 100 is a half-piece divided from a single battery piece, the number of the series electrical connection regions 101 is 500 to 2000.

Examples ten

Referring to fig. 7, 8 and 9, in some alternative embodiments, the back contact battery 100 includes a third insulating member 23, where the third insulating member 23 is disposed continuously from the first insulating member 21 along the extending direction of the sub-grids in the non-bus region 14, and at least partially covers the sub-grids having the polarity opposite to that of the corresponding bus region 13.

In this way, conduction of the sub-gate covered by the third insulator 23 and the adjacent sub-gate having opposite polarity by the conductive foreign matter such as tin slag can be avoided, and the risk of shorting the back contact battery 100 can be reduced. Meanwhile, even if the bus bar is offset, the bus bar is in contact with the sub-gate covered by the third insulating member 23, and is not conducted with the sub-gate covered by the third insulating member 23 having the opposite polarity, the risk of shorting the back contact battery 100 can be reduced.

Specifically, the "extending direction of the sub-gate" refers to the length direction of the sub-gate. By "continuously disposed" is meant that the third insulating member 23 is not broken. That is, the third insulating member 23 is continuously provided in the non-bus region 14 from the first insulating member 21 along the longitudinal direction of the sub-grid.

In particular, "at least partially" refers to a portion or all. In other words, the third insulator 23 covers a part of the sub-gate having the opposite polarity to the corresponding bus region 13 or covers the entire sub-gate having the opposite polarity to the corresponding bus region 13 in the non-bus region 14.

Example eleven

Referring to fig. 7, 8 and 9, in some alternative embodiments, the ratio of the sum of the lengths of the third insulating members 23 corresponding to two adjacent sub-grids to the spacing between the first insulating members 21 at both ends of the non-bus region 14 is less than or equal to 150%. For example, 150%, 145%, 140%, 100%, 90%, 50%, 10%, 5%, 1%, 0.1%.

In this way, the ratio of the sum of the lengths of the third insulating members 23 corresponding to the two adjacent auxiliary grids to the distance between the first insulating members 21 at the two ends of the non-converging region 14 is in a proper range, so that the risk of short circuit is reduced, and meanwhile, the waste of materials and the increase of cost caused by overlarge ratio are avoided. In this way, it is advantageous to reduce the risk of short circuits and to reduce costs.

It will be appreciated that since the third insulating member 23 must have a certain length, the ratio of the sum of the lengths of the third insulating members 23 corresponding to the adjacent two sub-gates to the length of the non-bus region 14 is greater than 0.

Specifically, the length of the third insulating member 23 refers to the dimension of the third insulating member 23 in the length direction of the sub-gate.

Specifically, the pitch of the first insulating members 21 at both ends of the non-bus region 14 refers to the distance between the adjacent two boundary lines of the first insulating members 21 at both ends of the non-bus region 14 in the longitudinal direction of the sub-gate.

For example, in the example of fig. 7, the lengths of the third insulating members 23 corresponding to the adjacent two sub-grids are w1 and w2, respectively, and the intervals of the first insulating members 21 at both ends of the non-bus region 14 are w0, and the ratio (w1+w2)/w 0 is less than or equal to 150%.

In the example of fig. 7, the ratio of the sum of the lengths of the third insulating members 23 corresponding to the adjacent two sub-gates to the pitch of the first insulating members 21 at both ends of the non-bus region 14 is 50%. In the example of fig. 8, the ratio of the sum of the lengths of the third insulating members 23 corresponding to the adjacent two sub-gates to the pitch of the first insulating members 21 at both ends of the non-bus region 14 is 100%. In the example of fig. 9, the ratio of the sum of the lengths of the third insulating members 23 corresponding to the adjacent two sub-gates to the pitch of the first insulating members 21 at both ends of the non-bus region 14 is 110%. This is merely an example and is not meant to be limiting of the specific ratios.

Specifically, in the examples of fig. 7, 8 and 9, the lengths of the third insulating members 23 corresponding to the adjacent two sub-gates are the same. It will be appreciated that in other examples, the lengths of the third insulating members 23 corresponding to the adjacent two sub-gates may be different.

Referring to fig. 8 and 9, in some alternative embodiments, the third insulating members 23 covering adjacent two sub-gates are distributed in succession in the non-bus region 14. In this way, conduction of two adjacent auxiliary grids with opposite polarities through conductive foreign matters such as tin slag can be avoided, normal operation of the back contact battery 100 can be ensured, and the risk of short circuit of the back contact battery 100 is reduced.

Specifically, the third insulating members 23 covered on the adjacent two sub-gates are sequentially distributed, that is, the third insulating members 23 covered on the adjacent two sub-gates are sequentially distributed in the length direction of the sub-gate. Alternatively, the area of one sub-gate not covered with the third insulating member 23 is overlapped with the area of the adjacent sub-gate covered with the third insulating member 23 or is located within the area of the adjacent sub-gate covered with the third insulating member 23 in the width direction of the sub-gate.

It will be understood that, in other embodiments, the third insulating members 23 covered on the adjacent two sub-grids are distributed continuously, which may also mean that the third insulating members 23 covered on the adjacent two sub-grids are distributed continuously in the width direction of the sub-grids; in other embodiments, the third insulating members 23 covered on the adjacent two sub-gates are distributed continuously, or the third insulating members 23 covered on the adjacent two sub-gates may be distributed continuously in a direction other than the longitudinal direction and the width direction of the sub-gate. The specific direction in which the third insulating members 23, which are covered on the adjacent two sub-gates, are sequentially distributed is not limited.

Referring to fig. 8, in some alternative embodiments, the edges of the third insulating member 23 overlying adjacent two sub-gates are aligned at the junction.

In this way, the third insulating member 23 covered on two adjacent sub-gates is just connected in the width direction of the sub-gate, so that the coverage area of the third insulating member 23 can be reduced, which is beneficial to reducing the cost.

Specifically, each third insulating member 23 includes a first side, which is a side of the third insulating member 23 extending along the sub-gate, and a second side, which is a side adjacent to the first side. For example, in fig. 3, the third insulator 23 has a rectangular shape, and the long side of the rectangle is the first side and the short side is the second side. It will be appreciated that in other embodiments, the third insulator 23 may also be parallelogram-shaped or otherwise shaped.

Specifically, the adjacent two third insulating members 23 are located on the two first sides between the adjacent two sub-grids, and the connection line of the end points at the connection points is perpendicular to the length direction of the sub-grids. In this way, the third insulating member 23 covered on the two adjacent auxiliary grids is guaranteed to be just connected, and the short circuit risk is reduced.

Specifically, two second edges of two adjacent auxiliary grids at the joint are positioned on the same straight line. In this way, the third insulating member 23 covered on the two adjacent auxiliary grids is guaranteed to be just connected, and the short circuit risk is reduced. In other embodiments, two second sides of two adjacent sub-grids at the junction may not be in the same straight line.

Referring to fig. 9, in some alternative embodiments, edges of the third insulating member 23 covering adjacent two sub-gates are staggered at the junction.

In this way, the third insulating members 23 covering the adjacent two sub-gates partially overlap in the width direction of the sub-gates, and the risk of short circuits can be further reduced.

Specifically, each third insulating member 23 includes a first side, which is a side of the third insulating member 23 extending along the sub-gate, and a second side, which is a side adjacent to the first side. For example, in fig. 4, the third insulator 23 has a rectangular shape, and the long side of the rectangle is a first side and the short side is a second side. It will be appreciated that in other embodiments, the third insulator 23 may also be parallelogram-shaped or otherwise shaped.

Specifically, the second side of the third insulating member 23 covered on one sub-gate is located within the area covered with the third insulating member 23 on the adjacent sub-gate, along the width direction of the sub-gate, projected on the adjacent sub-gate. In this way, the third insulating members 23 covering adjacent two auxiliary grids are ensured to be staggered at the joint, and the short circuit risk is reduced.

Referring to fig. 8 and 9, in some alternative embodiments, the third insulating members 23 covered by two adjacent sub-gates are the same length. It will be appreciated that in alternative embodiments, the third insulating member 23 covered by two adjacent sub-grids may be of different lengths. It is not limited herein.

Example twelve

Referring to fig. 8 and 9, in some alternative embodiments, the ratio of the sum of the lengths of the third insulating members 23 corresponding to two adjacent sub-grids to the spacing between the first insulating members 21 at the two ends of the non-bus region 14 is 100% or more and 120% or less. For example, 100%, 105%, 110%, 112%, 115%, 118%, 120%.

In this way, the ratio of the sum of the lengths of the third insulating members 23 corresponding to the two adjacent auxiliary grids to the distance between the first insulating members 21 at the two ends of the non-converging region 14 is in a more proper range, so that the short-circuit risk is further reduced, and the overall effect of short-circuit prevention and cost reduction is better.

Example thirteen

Referring to fig. 7, in some alternative embodiments, the third insulator 23 has a width d of 50 μm to 500 μm. For example 50 μm to 500 μm. For example 50 μm, 55 μm, 80 μm, 100 μm, 200 μm, 250 μm, 300 μm, 400 μm, 500 μm.

In this way, the width of the third insulating member 23 is in a proper range, so that it is possible to avoid the difficulty in covering the sub-gate due to the too small width and poor insulating effect, and also to avoid the waste of materials and the increase of cost due to the too large width.

Preferably, the width d of the third insulator 23 is 200 μm to 300 μm. Thus, the insulation effect and the cost are considered, and the overall effect is best.

Note that the width of the third insulating member 23 may be a constant value within 50 μm to 500 μm or may fluctuate within 50 μm to 500 μm.

Examples fourteen

Referring to fig. 7, in some alternative embodiments, the difference between the widths of the third insulating member 23 and the corresponding sub-gate is 20 μm to 200 μm. For example 20 μm, 25 μm, 30 μm, 50 μm, 80 μm, 100 μm, 150 μm, 180 μm, 200 μm.

In this way, the difference between the widths of the third insulating member 23 and the corresponding sub-gate is in a proper range, which can avoid the difficulty in covering the sub-gate and poor insulating effect caused by too small difference between the widths of the third insulating member 23 and the corresponding sub-gate, and can also avoid the waste of materials and increase in cost caused by too large difference between the widths of the third insulating member 23 and the corresponding sub-gate.

Preferably, the difference between the widths of the third insulating member 23 and the corresponding sub-gate is 100 μm to 150 μm. Thus, the insulation effect and the cost are considered, and the overall effect is best.

Referring to fig. 10, 11, and 12, specific features, structures, materials, or characteristics of back-contact battery 100 described herein may be combined in any suitable manner in any one or more embodiments or examples. For example, in fig. 10, the back contact battery 100 includes a battery substrate 10, a first insulating member 21, and a stopper 24. As another example, in fig. 11 and 12, the back contact battery 100 includes a battery substrate 10, a first insulating member 21, a third insulating member 23, and a stopper 24. For another example, in fig. 11, the ratio of the sum of the lengths of the third insulators 23 corresponding to the adjacent two sub-gates to the length of the non-bus region 14 is 50%, and in fig. 12, the ratio of the sum of the lengths of the third insulators 23 corresponding to the adjacent two sub-gates to the length of the non-bus region 14 is 100%.

In one example, referring to fig. 10, the insulating pattern of fig. 10 is printed on the battery substrate 10, and the insulating paste is cured using a thermal curing process, wherein the weight of the cured insulating paste is 0.28g, and the ratio of the series short circuit is 0.51%. Obviously, the risk of shorting back contact battery 100 may be reduced.

In one example, referring to fig. 11, the insulating pattern of fig. 11 is printed on the battery substrate 10, and the insulating paste is cured using a thermal curing process, wherein the weight of the cured insulating paste is 0.45g, and the ratio of the series short circuit is 0.2%. Obviously, the risk of shorting back contact battery 100 may be reduced.

In one example, referring to fig. 12, the insulating pattern of fig. 12 is printed on the battery substrate 10, and the insulating paste is cured using a thermal curing process, wherein the weight of the cured insulating paste is 0.65g, and the ratio of the series short circuit is 0.12%. Obviously, the risk of shorting back contact battery 100 may be reduced.

Note that the data of the above three examples are based on the back contact battery 100 being a single piece of battery.

Example fifteen

In some alternative embodiments, the first insulating member 21 is a transparent insulating member.

In this way, the shielding of the first insulating member 21 from sunlight can be reduced, so that more sunlight is absorbed by the back contact battery 100, which is advantageous in improving the photoelectric conversion efficiency.

Note that transparent means that the first insulating member 21 has a transmittance of 70% or more for visible light at a thickness of 20 μm.

It will be appreciated that in other embodiments, the first insulating member 21 may be a non-transparent insulating member. The description is not limited thereto.

Specifically, the second insulating member 22 is a transparent insulating member. Therefore, the shielding of the insulating piece to sunlight can be further reduced, and the photoelectric conversion efficiency is further improved.

Specifically, the third insulating member 23 is a transparent insulating member. Therefore, the shielding of the insulating piece to sunlight can be further reduced, and the photoelectric conversion efficiency is further improved.

Note that the explanation and description of the second insulating member 22 and the third insulating member 23 as transparent insulating members are similar to those of the first insulating member 21, and reference is made to the relevant contents of the first insulating member 21, and thus, the description thereof will not be repeated.

Examples sixteen

In some alternative embodiments, the first insulating member 21 is a transparent fluorescent insulating member.

In this way, the first insulating member 21 emits light under the irradiation of the light source with the corresponding wavelength, so that the position of the first insulating member 21 can be conveniently detected, and the accuracy of the back contact battery 100 for arranging the first insulating member 21 can be improved.

In this embodiment, the second insulating member 22 is a transparent fluorescent insulating member. In this way, the second insulating member 22 emits light under the irradiation of the light source with the corresponding wavelength, so that the position of the second insulating member 22 can be conveniently detected, and the accuracy of the back contact battery 100 for arranging the second insulating member 22 can be improved.

In the present embodiment, the third insulating member 23 is a transparent fluorescent insulating member. In this way, the third insulating member 23 emits light under the irradiation of the light source with the corresponding wavelength, so that the position of the third insulating member 23 can be conveniently detected, and the accuracy of the back contact battery 100 for arranging the third insulating member 23 can be improved.

Note that the explanation and description of the second insulating member 22 and the third insulating member 23 as transparent fluorescent insulating members are similar to those of the first insulating member 21, and reference is made to the relevant contents of the first insulating member 21, which are not repeated here.

Example seventeen

In some alternative embodiments, the transparent fluorescent insulation is made of a transparent insulating gel comprising: 60-80% of resin component by mass percent; the inorganic filler accounts for 5-15% of the total mass of the material; 5-15% of curing agent; the mass percentage of the solvent is less than 10%; the mass percentage of the fluorescent agent is more than or equal to 0.1 percent and less than 1 percent.

In this way, since the insulating adhesive is a transparent insulating member, shielding of sunlight can be reduced, so that more sunlight is absorbed by the back contact battery 100, which is advantageous for improving photoelectric conversion efficiency. Meanwhile, the transparent insulating adhesive comprises the fluorescent agent with the mass percentage of more than or equal to 0.1% and less than 1%, so that the transparent insulating adhesive can emit light under the irradiation of the light source with the corresponding wavelength, thereby being convenient for detecting the position of the transparent insulating adhesive and being beneficial to improving the accuracy of the back contact battery 100 in setting the transparent insulating adhesive.

Specifically, the transparent insulating paste may be provided on the back contact battery 100 by screen printing, spray valve, coating, or the like.

Specifically, the coverage area ratio of the transparent insulating paste in the back contact battery 100 is greater than 10%.

Specifically, the mass percentage of the resin component is, for example, 60%, 62%, 65%, 70%, 73%, 75%, 78%, 80%. Therefore, the mass percentage of the resin component is in a proper range, so that the brittleness of the insulating part formed by solidification of the insulating glue can be reduced, and the bending resistance and impact resistance strength of the insulating part are improved.

Specifically, the mass percentage of the inorganic filler is, for example, 5%, 6%, 8%, 10%, 11%, 14%, 15%. Thus, the use amount of the resin component can be reduced by using the cheaper inorganic filler, thereby reducing the cost of the transparent insulating adhesive. Moreover, the inorganic filler can enhance the mechanical property of the transparent insulating glue, so that the insulating glue is easier to set and adhere.

Specifically, the mass percentage of the curing agent is, for example, 5%, 8%, 10%, 11%, 14%, 15%. In this way, the transparent insulating paste is allowed to cure within a predetermined process time.

Specifically, the mass percentage of the solvent is, for example, 9.99%, 9%, 7%, 5%, 4%, 2%, 0.1%. Thus, other materials in the transparent insulating glue can be dissolved, and the viscosity of the transparent insulating glue can be adjusted.

Specifically, the mass percentage of the fluorescent agent is, for example, 0.99%, 0.95%, 0.8%, 0.6%, 0.5%, 0.3%, 0.1%. The fluorescent agent can whiten, and the light transmittance of the transparent insulating adhesive can be influenced by the mass percentage of the fluorescent agent being more than or equal to 1%. And the mass percentage of the fluorescent agent is more than or equal to 0.1% and less than 1%, so that the light transmittance of the insulating adhesive is better, and the photoelectric conversion efficiency is guaranteed. In addition, the mass percentage of the fluorescent agent is more than or equal to 0.1% and less than 1%, so that the cost is not excessively high, and the fluorescent agent is beneficial to ensuring the normal operation of the solar photocell and reducing the cost of the back contact battery 100 while ensuring that the insulating adhesive can be detected.

In some alternative embodiments, the resin component includes at least one of a modified polyacrylate, a modified polyurethane, a modified polyamide, a modified polyesteramide, a modified polycarbonate, a modified silicone ester, a modified styrene ester, polystyrene, polytetrafluoroethylene, polyoxymethylene, a modified phenolic, a modified polyester, a modified polyamide, a modified epoxy resin. Therefore, the resin component in various forms is provided, more actual production scenes and actual production requirements can be met, and the production efficiency of the transparent insulating adhesive can be improved. In addition, the resin component can reduce the brittleness of the insulating piece formed by solidification of the transparent insulating glue and improve the bending resistance and impact resistance strength of the insulating piece.

In some alternative embodiments, the inorganic filler comprises talc. Therefore, cheaper talcum powder can be utilized, and the consumption of resin components is reduced, so that the cost of the transparent insulating adhesive is reduced. In addition, the talcum powder can enhance the heat stability and corrosion resistance of the transparent insulating glue, so that the quality of the transparent insulating glue is better. In addition, talcum powder has insulativity, and can improve the insulating performance of transparent insulating glue.

In some alternative embodiments, the talc includes at least one of barium sulfate, calcium carbonate, and titanium dioxide. Therefore, the talcum powder in various forms is provided, more actual production scenes and actual production requirements can be met, and the production efficiency of the transparent insulating adhesive can be improved.

In some alternative embodiments, the curing agent comprises an imidazole derivative. Thus, the imidazole derivative is used as a curing agent, so that the curing speed of the insulating adhesive can be increased, and the curing cost can be reduced.

In some alternative embodiments, the imidazole derivative includes at least one of an aliphatic amine, an aromatic, and an anhydride curing agent. Therefore, the curing agent in various forms is provided, more actual production scenes and actual production requirements can be met, and the production efficiency of the transparent insulating adhesive can be improved. In particular, the fatty amine comprises ethylenediamine and/or xylylenediamine. For example, fatty amines include ethylenediamine; as another example, the fatty amine includes xylylenediamine; for another example, the fatty amine includes ethylenediamine and xylylenediamine. Specifically, the aromatic group includes m-phenylenediamine and/or diaminodiphenylmethane. For example, aromatics include meta-phenylenediamine; as another example, aromatics include diaminodiphenyl methane; for another example, the aromatic group includes m-phenylenediamine and diaminodiphenylmethane. In particular, the anhydride curing agent comprises phthalic anhydride and/or hexahydrophthalic anhydride. For example, the anhydride curing agent includes phthalic anhydride; as another example, the anhydride curing agent includes hexahydrophthalic anhydride; for another example, the anhydride curing agent includes phthalic anhydride and hexahydrophthalic anhydride.

In some alternative embodiments, the solvent comprises at least one of dimethyl adipate, dimethyl succinate, dimethyl glutarate, dimethyl malonate, diethyl adipate, diethyl succinate, diethyl glutarate, dibutyl succinate, dibutyl glutarate, DBE-3, DBE-4, DBE-6, DBE-9, DBE-IB, and DBE-ME. In this way, the dibasic acid ester can better play a role in dissolution, can react with the resin component to form a chain-shaped or cyclic polymer, and can form a stable solid compound after volatilization. In addition, the dibasic acid ester in various forms is provided, so that the method can adapt to more actual production scenes and actual production requirements, and is beneficial to improving the production efficiency of the insulating adhesive.

Example eighteen

In some alternative embodiments, the fluorescent agent comprises at least one of fluorescent whitening agent OB-1, fluorescent whitening agent-OB, alumina, zinc oxide, zinc sulfide, calcium sulfide, strontium aluminate, calcium chlorate, barium aluminate, rare earth fluorescent material, fluorescent whitening agent BC, fluorescent whitening agent JD-3, fluorescent whitening agent BR, fluorescent whitening agent-EBF, fluorescent whitening agent R, fluorescent whitening agent ER, 1, 8-naphthalimide fluorescent compound, polyphenyl, polythiophene, polyfluorene, polytriphenylamine derivative, polycarbazole, polypyrrole, polyphenylporphyrin and derivatives, copolymers thereof, N-dimethylaminobenzylidene dinitrilide compound, 8-hydroxyquinoline aluminum, europium metal complex.

Therefore, the fluorescent agent in various forms is provided, more actual production scenes and actual production requirements can be met, and the production efficiency of the transparent insulating adhesive can be improved.

Specifically, the rare earth fluorescent material refers to a fluorescent material containing a rare earth element. Namely, a fluorescent material containing at least one rare earth element selected from europium, samarium, erbium and neodymium.

In one example, the fluorescent agent is fluorescent whitening agent OB-1. When ultraviolet light irradiates the insulating glue with fluorescent agent being fluorescent whitening agent OB-1, the visual fluorescent color is blue, and the visual effect is stronger.

In the following table, the resin component, curing agent and solvent of the transparent insulating adhesive are respectively: 70% of phenolic epoxy resin, 10% of imidazole derivative and 5% of anisole. The fluorescent agents are fluorescent whitening agents OB-1, and the inorganic fillers are barium sulfate. The mass percentages of OB-1 and barium sulfate are shown in the following table.

The following table shows the fluorescence gray scale value, viscosity value and transmittance of the transparent insulating glue at a thickness of 20 microns for each added amount of fluorescent whitening agent OB-1. It is understood that the fluorescence gray value may characterize the fluorescence effect. The viscosity value characterizes printability, with the viscosity value being the best between 150 dpa.s and 250 dpa.s. It is apparent that, in the case that the mass percentage of the fluorescent agent is greater than or equal to 1%, although the fluorescent effect of the transparent insulating paste is strong, both printability and light transmittance are poor. When the mass percentage of the fluorescent agent is 0.1% or more and less than 1%, the fluorescence of the transparent insulating adhesive is sufficient to be detected, and the printability and the light transmittance are both good. Therefore, the mass percentage of the fluorescent agent is more than or equal to 0.1% and less than 1%, the detectability, the fluorescent effect and the printability can be ensured, and the overall effect of the transparent insulating adhesive is better.

In another example, the fluorescent agent is alumina. When the ultraviolet light irradiates the insulating adhesive with aluminum oxide as the fluorescent agent, the visual fluorescent color is light blue, and the visual effect is strong.

In the following table, the resin component, curing agent and solvent of the transparent insulating adhesive are respectively: 70% of phenolic epoxy resin, 10% of imidazole derivative and 5% of anisole. The fluorescent agents are all aluminum oxide, and the inorganic fillers are all barium sulfate. The mass percentages of alumina and barium sulfate are shown in the following table.

The following table shows the fluorescence gray value, viscosity value and transmittance of the transparent insulating glue at a thickness of 20 microns for each added amount of alumina. It is apparent that, in the case that the mass percentage of the fluorescent agent is greater than or equal to 1%, although the fluorescent effect of the transparent insulating paste is strong, both printability and light transmittance are poor. When the mass percentage of the fluorescent agent is 0.1% or more and less than 1%, the fluorescence of the transparent insulating adhesive is sufficient to be detected, and the printability and the light transmittance are both good. Therefore, the mass percentage of the fluorescent agent is more than or equal to 0.1% and less than 1%, the detectability, the fluorescent effect and the printability can be ensured, and the overall effect of the transparent insulating adhesive is better.

Note that specific data for fluorescent agent being fluorescent whitening agent OB-1 and specific data for fluorescent agent being alumina are given herein. Other fluorescent agents, such as fluorescent whitening agent-OB, zinc oxide, zinc sulfide, calcium sulfide, strontium aluminate, calcium chlorate, barium aluminate, rare earth fluorescent materials, fluorescent whitening agent BC, fluorescent whitening agent JD-3, fluorescent whitening agent BR, fluorescent whitening agent-EBF, fluorescent whitening agent R, fluorescent whitening agent ER, 1, 8-naphthalimide fluorescent compounds, polyphenyl, polythiophene, polyfluorene, polytriphenylamine derivatives, polycarbazole, polypyrrole, polyphenylporphyrin and derivatives, copolymers thereof, N-dimethylamino benzylidene dinitrilides, 8-hydroxyquinoline aluminum, europium metal complexes, the range of gray values characterizing the fluorescent effect is 100-300, the range of viscosity values characterizing the printability is 150-300, and the range of light transmittance is 85-90% when the mass percentage is more than or equal to 0.1%. To avoid redundancy, further description is omitted here.

In other embodiments, the fluorescent agent may comprise an optical brightener-OB; in other embodiments, the fluorescent agent may include barium aluminate, rare earth fluorescent material, fluorescent whitening agent BC, fluorescent whitening agent JD-3; in other embodiments, the fluorescent agent may include fluorescent whitening agent-EBF, fluorescent whitening agent R, fluorescent whitening agent ER, 1, 8-naphthalimide fluorescent compound. The specific form of the fluorescent agent is not limited herein.

Specifically, at least one light selected from green light, blue light, infrared light, ultraviolet light, and white light may be irradiated to the back contact battery 100, so that the insulating member formed by curing the transparent insulating paste emits fluorescence, thereby precisely detecting the position of the transparent insulating paste.

Examples nineteenth

The battery assembly of the embodiment of the application includes the back contact battery 100 of any one of the first to the eighteenth embodiments.

In this way, in the back contact battery 100, the first insulating member 21 is continuously disposed along the extending direction of the bus region 13 at the edge of the non-bus region 14, and covers the portion of the sub-gate near the bus region 13 of the non-bus region 14, so that the sub-gate near the edge of the bus region 13 of the non-bus region 14 can be prevented from being conducted with the opposite-polarity bus member, thereby ensuring the normal operation of the back contact battery 100 and reducing the risk of short circuit of the back contact battery 100.

In this embodiment, a plurality of back contact batteries 100 in the battery assembly may be serially connected in sequence to form a battery string, so as to realize serial bus output of current, for example, serial connection of battery sheets may be realized by providing serial connection members (bus bars, interconnection bars), conductive back plates, and the like.

It will be appreciated that in such embodiments, the battery assembly may also include a metal frame, a back sheet, photovoltaic glass, and a glue film. The adhesive film may be filled between the front and back surfaces of the back contact battery 100 and the photovoltaic glass, adjacent battery pieces, etc., and as a filler, it may be a transparent adhesive with good light transmittance and aging resistance, for example, the adhesive film may be an EVA adhesive film or a POE adhesive film, and may be specifically selected according to practical situations, which is not limited herein.

The photovoltaic glass may be coated on the adhesive film on the front surface of the back contact battery 100, and the photovoltaic glass may be ultra-white glass having high light transmittance, high transparency, and excellent physical, mechanical, and optical properties, for example, the ultra-white glass may have a light transmittance of 92% or more, which may protect the back contact battery 100 without affecting the efficiency of the back contact battery 100 as much as possible. Meanwhile, the adhesive film can bond the photovoltaic glass and the back contact battery 100 together, and the back contact battery 100 can be sealed and insulated and waterproof and moistureproof by the adhesive film.

The back plate can be attached to the adhesive film on the back of the back contact battery 100, can protect and support the back contact battery 100, has reliable insulativity, water resistance and aging resistance, can be selected multiple times, and can be toughened glass, organic glass, an aluminum alloy TPT composite adhesive film and the like, and the back plate can be specifically set according to specific conditions without limitation. The whole of the back plate, the back contact battery 100, the adhesive film and the photovoltaic glass may be disposed on a metal frame, which serves as a main external support structure of the whole battery assembly, and may stably support and mount the battery assembly, for example, the battery assembly may be mounted at a desired mounting position through the metal frame.

Example twenty

The photovoltaic system of the embodiment of the application comprises the battery component of the nineteenth embodiment.

In this embodiment, the photovoltaic system may be applied to a photovoltaic power station, such as a ground power station, a roof power station, a water power station, or the like, and may also be applied to a device or apparatus that uses solar energy to generate power, such as a user solar power source, a solar street lamp, a solar car, a solar building, or the like. Of course, it is understood that the application scenario of the photovoltaic system is not limited thereto, that is, the photovoltaic system may be applied to all fields where solar energy is required to generate electricity. Taking a photovoltaic power generation system network as an example, the photovoltaic system can comprise a photovoltaic array, a junction box and an inverter, wherein the photovoltaic array can be an array combination of a plurality of battery assemblies, for example, the plurality of battery assemblies can form a plurality of photovoltaic arrays, the photovoltaic array is connected with the junction box, the junction box can conduct junction on current generated by the photovoltaic array, and the junction box is connected with a commercial power network after the junction current flows through the inverter and is converted into alternating current required by the commercial power network so as to realize solar power supply.

In the description of the present specification, reference to the terms "some embodiments," "illustrative embodiments," "examples," "specific examples," or "some examples," etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiments or examples is included in at least one embodiment or example of the application. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiments or examples. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

Furthermore, the foregoing description of the preferred embodiment of the application is provided for the purpose of illustration only, and is not intended to limit the application to the particular form disclosed, but on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the application.

Claims

1. The back contact battery is characterized by comprising a battery substrate and a first insulating piece, wherein the back surface of the battery substrate is provided with auxiliary grids with two polarities which are distributed in a staggered way, and the back surface comprises a confluence area and a non-confluence area which are distributed in a staggered way; the first insulating piece is arranged at the edge of the non-bus area and is continuously arranged along the extending direction of the bus area, and the part, close to the bus area, of the non-bus area, of the auxiliary grid is covered.

2. The back contact battery of claim 1, wherein the first insulator has a thickness of 10 μιη -50 μιη.

3. The back contact battery of claim 1, wherein the width of the first insulating member at the edge of the non-bus region is 100 μιη -1000 μιη.

4. The back contact battery of claim 1, wherein the back surface is formed with a main grid provided in the bus region and exposed from the first insulating member.

5. The back contact battery of claim 4, wherein the ratio of the covered area of the first insulator to the total area of the back contact battery is 10% -20%.

6. The back contact battery of claim 1, wherein the back contact battery is a cell without a primary grid, a portion of each secondary grid is located in the bus region, the remaining portion of each secondary grid is located in the non-bus region, the bus region is used for providing a series connection, and the bus region corresponding to each series connection exposes secondary grids of the same polarity.

7. The back contact battery of claim 6, wherein the bus region is provided with the sub-grid of one polarity, the bus region being fully exposed from the first insulating member.

8. The back contact battery of claim 6, wherein the bussing region is provided with the secondary grid of two polarities, the back contact battery comprising a second insulating member covering the secondary grid of opposite polarity to the corresponding series member at the bussing region.

9. The back contact battery of claim 8, wherein the ratio of the sum of the coverage areas of the first and second insulators to the total area of the back contact battery is 5% -15%.

10. The back contact battery of claim 1, comprising a third insulating member disposed continuously from the first insulating member in the extending direction of the sub-grids in the non-bus region, at least partially covering the sub-grids having a polarity opposite to that of the corresponding bus region.

11. The back contact battery of claim 10, wherein the ratio of the sum of the lengths of the third insulating members corresponding to the adjacent two sub-grids to the spacing of the first insulating members at both ends of the non-bus region is 150% or less.

12. The back contact battery of claim 11, wherein the ratio of the sum of the lengths of the third insulating members corresponding to the adjacent two sub-grids to the spacing of the first insulating members at both ends of the non-bus region is 100% or more and 120% or less.

13. The back contact battery of claim 10, wherein the width of the third insulator is 50-500 μm.

14. The back contact battery of claim 10, wherein the difference between the widths of the third insulating member and the corresponding sub-gate is 20-200 μm.

15. The back contact battery of claim 1, wherein the first insulator is a transparent insulator.

16. The back contact battery of claim 15, wherein the first insulator is a transparent fluorescent insulator.

17. A battery assembly comprising the back contact battery of any one of claims 1 to 16.

18. A photovoltaic system comprising the cell assembly of claim 17.