CN220367922U

CN220367922U - Back contact battery, battery pack and photovoltaic system

Info

Publication number: CN220367922U
Application number: CN202321247885.6U
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: 2024-01-19
Anticipated expiration: 2033-05-22

Abstract

The application is applicable to the technical field of solar cells and provides a back contact battery, a battery assembly and a photovoltaic system. The back contact battery comprises a battery substrate and an insulating piece, wherein the back surface of the battery substrate is provided with auxiliary grids with two polarities which are distributed in a staggered mode, the back surface of the battery substrate comprises a series connection piece electric connection area, the series connection piece electric connection area is an area where the back contact battery is electrically connected with the series connection piece, and the insulating piece surrounds the series connection piece electric connection area. Therefore, the insulating piece surrounds the electric connection area of the serial piece, so that the conductive material can be prevented from flowing from the electric connection area of the serial piece to the opposite auxiliary grid of the serial piece, the serial piece and the opposite auxiliary grid are prevented from being conducted, normal operation of the back contact battery can be ensured, and the risk of short circuit of the back contact battery is reduced. Meanwhile, the situation that the conductive material flows from the electric connection area of the serial connection piece to the homopolar auxiliary grid of the serial connection piece to cause the conductive material to be lower can be avoided, and poor connection with the serial connection piece is avoided.

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 battery, a battery 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 battery of the related art, the secondary grids of two polarities are distributed in a staggered manner, and a series element is generally connected with the grid line to lead out the current of the back contact battery. However, the conductive material provided when the series connection member is connected has fluidity and easily flows onto the opposite auxiliary gate, so that the series connection member is conducted with the opposite auxiliary gate, thereby causing 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 application 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 an insulating piece, wherein auxiliary grids with two polarities are formed on the back of the battery substrate in a staggered mode, the back of the battery substrate comprises a series connection piece electric connection area, the series connection piece electric connection area is an area where the back contact battery is electrically connected with the series connection piece, and the insulating piece surrounds the series connection piece electric connection area.

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

Optionally, the top surface of the insulator and the top surface of the electrical connector differ in height by more than 20 μm.

Optionally, the insulating parts are closed and are continuously distributed at the periphery of the electric connection area of the serial parts.

Optionally, the width of the insulator is greater than 100 μm.

Optionally, the series electrical connection region includes a pad region.

Optionally, the area of the electrical connection area of the serial connection element is 2mm ² -6mm ² 。

Optionally, the number of the electrical connection areas of the serial connection parts is 30-300, and the number of the insulating parts is 30-300.

Optionally, the insulating member is a transparent insulating member.

Optionally, the 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 comprises the battery assembly.

According to the back contact battery, the battery assembly and the photovoltaic system, the insulating piece surrounds the electric connection area of the serial connection piece, so that the conductive material can be prevented from flowing onto the opposite auxiliary grid of the serial connection piece from the electric connection area of the serial connection piece, the serial connection piece and the opposite auxiliary grid are prevented from being conducted, normal operation of the back contact battery can be guaranteed, and the risk of short circuit of the back contact battery is reduced. Meanwhile, the conductive material can be prevented from flowing from the electric connection area of the serial connection piece to the homopolar auxiliary grid of the serial connection piece, so that the conductive material is prevented from being low in height, and poor connection with the serial connection piece is avoided.

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 structural 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 structural 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 structural view of a partial region of a back contact battery according to an embodiment of the present application;

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

fig. 9 is a schematic structural 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 view of the structure of a back contact cell 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 non-series electrical connection region 102, 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 insulator 20, the first insulator 21, and the second insulator 22.

Detailed Description

In order to make the objects, technical solutions and advantages of the present application more apparent, the present application will be further described in detail with reference to the accompanying drawings and examples. 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 exemplary only for the purpose of explaining the present application and are not to be construed as limiting the present 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 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 orientations or positional relationships illustrated in the drawings, merely to facilitate description of the present application and simplify description, and do not indicate or imply that the devices or elements being referred to must have a particular orientation, be configured and operated in a particular orientation, and are therefore not to 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 terms in this application will be understood by those of ordinary skill in the art as the case may be.

In this 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, and may also include the first and second features not being in direct contact but being in contact with each other by way of 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 disclosure of the present application, the components and arrangements of specific examples are described below. Of course, they are merely examples and are not intended to limit the present 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 in 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 may recognize applications of other processes and/or usage scenarios for other materials.

In the application, the insulating piece surrounds the electric connection area of the serial piece, so that the electric conduction material can be prevented from flowing from the electric connection area of the serial piece to the opposite auxiliary grid of the serial piece, the serial piece and the opposite auxiliary grid are prevented from being communicated, normal operation of the back contact battery can be ensured, and the risk of short circuit of the back contact battery is reduced. Meanwhile, the conductive material can be prevented from flowing from the electric connection area of the serial connection piece to the homopolar auxiliary grid of the serial connection piece, so that the conductive material is prevented from being low in height, and poor connection with the serial connection piece is avoided.

Example 1

Referring to fig. 1, 2 and 3, the back contact battery 100 in the embodiment of the present application includes a battery substrate 10 and an insulating member 20, wherein the back surface of the battery substrate 10 is formed with two polarity sub-grids distributed in a staggered manner, the back surface includes a series electrical connection area 101, the series electrical connection area 101 is an area where the back contact battery 100 is electrically connected to the series, and the insulating member 20 surrounds the series electrical connection area 101.

In the back contact battery 100 of the embodiment of the present application, since the insulating member 20 surrounds the electrical connection region 101 of the serial connection member, the conductive material can be prevented from flowing from the electrical connection region 101 of the serial connection member to the opposite auxiliary grid of the serial connection member, so that the serial connection member and the opposite auxiliary grid are prevented from being conducted, the 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. Meanwhile, the conductive material can be prevented from flowing from the electric connection area 101 of the serial connection piece to the homopolar auxiliary grid of the serial connection piece, so that the conductive material is prevented from being low in height, and poor connection with the serial connection piece is avoided.

Meanwhile, when a plurality of back contact cells 100 are stacked, the sub-grid may be prevented from scratching another back contact cell 100 by the insulating member 20 at the region covered with the insulating member 20. Also, since the insulating member 20 has a certain thickness, a gap may be formed between the region not covered with the insulating member 20 and the other back contact battery 100, thereby preventing the sub-gate from scratching the other back contact battery 100 in the region not covered with the insulating member 20. 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.

Specifically, the series electrical connection region 101 is located in the bus region 13. The serial connection element is electrically connected with the back contact battery 100 in the serial connection element electrical connection area 101, and is connected with other back contact batteries 100 in series to form a battery string.

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 serial electrical connection region 101 exposes a gate line of one polarity. It will be appreciated that if the serial electrical connection region 101 exposes two polarities of gate lines, a short circuit is likely to occur when electrically connected to the serial.

Specifically, the back surface of the back contact battery 100 includes a non-serial electrical connection region 102, and the non-serial electrical connection region 102 is located at a region of the back surface except for the serial electrical connection region 101. In other words, the non-series electrical connection region 102 includes the bus region 13 and the non-bus region 14 except for the series electrical connection region 101.

Specifically, the serial connection member is, for example, a solder strip, a conductive wire, a conductive sheet, a conductive plate, or the like. The serial connection is taken as a welding strip for illustration, but the serial connection is not limited by the serial connection.

Referring to fig. 1 and 3, the insulating member 20 surrounds the series electrical connection region 101. Thus, the conductive material is prevented from flowing out of the electrical connection region 101 of the serial connection member, so that short circuit or poor connection with the serial connection member is avoided.

In the example of fig. 1 and 3, the series electrical connection region 101 is rectangular, and the insulating member 20 is rectangular. Thus, the insulating member 20 is regular in shape and convenient to install. Moreover, the configuration of the serial connection part electrical connection area 101 and the insulation part 20 is matched, so that the effect of blocking the conductive material from flowing out is better.

It will be appreciated that in other embodiments, the pattern formed by the inner edges of the insulator 20 may be circular, oval, square, triangular or other configurations. In other embodiments, the outer edge of the insulator 20 may be formed in a circular, oval, square, triangular or other configuration. In other embodiments, the pattern formed on the inner side of the insulator 20 may be the same as or different from the pattern formed on the outer side of the insulator 20. In other embodiments, the pattern formed on the inner or outer edge of the insulating member 20 may be the same as or different from the pattern formed on the electrical connection region 101 of the serial member. The specific form of the insulating member 20 and the relationship with the series electrical connection region 101 are not limited herein.

Specifically, the insulating member 20 is disposed at the interface between the serial electrical connection region 101 and the non-serial electrical connection region 102. Thus, the insulating member 20 abuts against the electrical connection region 101 of the serial member, so that the conductive material can be limited in the electrical connection region 101 of the serial member as much as possible.

In the example of fig. 1 and 3, all of the series electrical connection regions 101 are identical in shape and size. Thus, the serial connection part electrical connection area 101 is convenient to set, and the production efficiency is improved.

It will be appreciated that in other embodiments, all of the series electrical connection regions 101 may be the same in shape and different in size; alternatively, all the serial electrical connection areas 101 may have different shapes; alternatively, some of the serial electrical connection regions 101 may have different shapes, and the other serial electrical connection regions 101 may have the same shape. The relationship between the configurations of the plurality of series electrical connection regions 101 is not limited.

Referring to fig. 1 and 3, in some alternative embodiments, the insulating member 20 partially covers the non-tandem connection region 102. Thus, the coverage area of the insulating member 20 is smaller, the amount of the insulating member 20 can be reduced, and the cost can be reduced. Specifically, "locally covering" refers to the insulating member 20 covering a portion, but not all, of the non-series electrical connection region 102.

Referring to fig. 4, in some alternative embodiments, the insulating member 20 entirely covers the non-series electrical connection region 102. Thus, the process for setting the insulating member 20 is simpler, which is advantageous for improving the production efficiency. Specifically, "full coverage" refers to the insulator 20 covering the entire non-series electrical connection region 102.

Example two

In some alternative embodiments, the thickness of the insulator 20 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 insulating member 20 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 insulator 20 is 20 μm to 30 μm. Thus, the overall effect of insulation and economy is best.

Note that the thickness of the insulating member 20 may be a constant value within 10 μm to 50 μm or may fluctuate within 10 μm to 50 μm.

Example III

In some alternative embodiments, the top surface of the insulator 20 is level different from the top surface of the electrical connector by more than 20 μm. For example, 20.1 μm, 21 μm, 25 μm, 30 μm, 50 μm.

Thus, the height difference between the top surface of the insulating member 20 and the top surface of the electrical connector is in a suitable range, so that the conductive material caused by the too small height difference can be prevented from flowing out of the electrical connection region 101 of the serial connection member.

Specifically, the electrical connector is formed by curing a conductive material, and connects the back contact battery 100 and the serial connection member.

Preferably, the height difference is 21 μm to 30 μm. Therefore, not only can the conductive material flowing out from the electric connection area 101 of the serial connection piece caused by too small height difference be avoided, but also the material waste and the cost increase caused by too large height difference can be avoided, and the overall effect is best.

Note that the difference in height between the top surface of the insulating member 20 and the top surface of the electrical connector may be a constant value greater than 20 μm or may fluctuate within greater than 20 μm.

Example IV

Referring to fig. 1 and 3, in some alternative embodiments, the insulating member 20 is closed and continuously distributed around the periphery of the electrical connection region 101 of the serial member.

Thus, the insulating member 20 is closed, and continuously surrounds the electrical connection region 101 of the serial member, so that the conductive material can be prevented from flowing out from the notch of the insulating member 20.

It is understood that the insulating members 20 are closed, and are continuously distributed around the periphery of the electrical connection area 101 of the serial member, that is, the insulating members 20 are annular.

In the example of fig. 1 and 3, the insulator 20 is a rectangular ring. It will be appreciated that in other examples, the insulator 20 may be annular, elliptical, triangular, or any other form of ring. The specific form of the insulator 20 is not limited herein.

Example five

Referring to fig. 3, in some alternative embodiments, the width D of the insulator 20 is greater than 100 μm. For example, 100.1 μm, 101 μm, 125 μm, 130 μm, 150 μm.

Thus, the width of the insulating member 20 is in a suitable range, so that the conductive material can be prevented from flowing out of the electrical connection region 101 of the serial member due to the too small width.

Specifically, the width D of the insulating member 20 refers to the distance between the inner edge and the outer edge of the insulating member 20.

Preferably, the width of the insulator 20 is 101 μm to 130 μm. Thus, not only the conductive material flowing out from the series element electrical connection region 101 caused by too small width of the insulating element 20 can be avoided, but also the waste of materials and the increase of cost caused by too large width of the insulating element 20 can be avoided, so that the overall effect is best.

Note that the width of the insulating member 20 may be a constant value greater than 100 μm or may fluctuate within greater than 100 μm.

Example six

In some alternative embodiments, the series electrical connection region 101 includes a pad region and/or a conductive paste region.

In this manner, the back contact battery 100 and the series connection member may be connected by pad welding and/or conductive adhesive bonding.

In other words, the serial electrical connection area 101 may be connected to the serial via soldering; 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.

Further, the pad region may be provided with a conductive material. The conductive material is, for example, solder paste.

Further, the conductive adhesive area may be provided with conductive adhesive.

Example seven

In some alternative embodiments, the area of the electrical connection region 101 of the serial connection element is 2mm ² -6mm ² 。

For exampleIs 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.

Example eight

In some alternative embodiments, the number of the series electrical connection regions 101 is 30-300, and the number of the insulating members 20 is 30-300. For example 30, 40, 50, 100, 120, 150, 200, 280, 300.

In this way, the number of the series element electrical connection regions 101 and the number of the insulating elements 20 are in a proper range, so that unstable connection between the back contact battery 100 and the series element caused by too small number can be avoided, and lower efficiency and higher cost caused by too large number can also be avoided.

Specifically, the number of the series electrical connection areas 101 is the same as the number of the insulating elements 20. In this way, each serial connection element is ensured to have a corresponding insulating element 20 to block the conductive material from flowing out. It is understood that in other embodiments, the number of insulating members 20 may be different from the number of serial members, for example, the non-serial member electrical connection region 102 covers one insulating member 20.

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.

Referring to fig. 1, 2 and 3, in some alternative embodiments, a main gate is formed on the back surface, and the electrical connection area 101 of the serial connection element is an area where the main gate is electrically connected to the serial connection element.

In this way, the main grid is used for converging the auxiliary grid and is connected with the serial connection piece, so that the current of the back contact battery 100 is conveniently led out.

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.

Referring to fig. 5, in some alternative embodiments, the back contact battery 100 is a battery without main grids, a portion of each sub-grid is located in the series electrical connection region 101, and the other portion of each sub-grid is located in the non-series electrical connection region 102, where the series electrical connection region 101 is a region where the sub-grid is electrically connected to the series.

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.

Referring to FIG. 5, in some alternative embodiments, the area of the series electrical connection region 101 is 0.02mm ² -0.6mm ² . Example(s)Such as 0.02mm ² 、0.03mm ² 、0.375mm ² 、0.4mm ² 、0.5mm ² 、0.6mm ² 。

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.

Referring to fig. 5, in some alternative embodiments, the number of the series electrical connection regions 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.

Specifically, the number of the series electrical connection areas 101 is different from the number of the insulating elements 20, the number of the series electrical connection areas 101 is plural, and the whole surface of the non-series electrical connection area 102 is covered with one insulating element 20. In this way, the efficiency of disposing the insulating member 20 is high. It will be appreciated that in other embodiments, the number of insulating members 20 may be the same as the number of series members, so that each series member has a corresponding insulating member 20 to block the flow of conductive material.

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.

Referring to fig. 6 and 7, in some alternative embodiments, the back contact battery 100 includes a first insulator 21, where the first insulator 21 is disposed continuously along the extending direction of the bus region 13 at the edge of the non-bus region 14, and covers a portion of the non-bus region 14 near the bus region 13. In this way, the auxiliary grid can be prevented from being close to the edge of the bus region 13 in the non-bus region 14, and is 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 circuit of the back contact battery 100 is reduced.

Specifically, the first insulator 21 and the insulator 20 may overlap or may be connected.

The "edge" in the "first insulator 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 insulator 21 is near the edge of the bus bar region 13 at the non-bus bar region 14. The "extending direction" in the "first insulator 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 insulators 21 at the edges of the non-bus region 14 along the extending direction of the bus region 13" means that the first insulators 21 are not disconnected.

That is, the first insulator 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. 6 and 7, the first insulator 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 insulator 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 insulator 21 are not limited here.

The width w of the first insulator 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 insulator 21 at the edge of the non-bus region 14 is in a proper 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 insulator 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 insulator 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.

Referring to fig. 8 and 9, in some alternative embodiments, the back contact battery 100 includes a second insulator 22, where the second insulator 22 is disposed continuously from the first insulator 21 along the extension direction of the sub-grids in the non-bus region 14, and at least partially covers the sub-grids having the opposite polarity to the corresponding bus region 13.

In this way, conduction of the sub-gate covered by the second insulator 22 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, it is in contact with the sub-gate covered by the second insulator 22, and it is not conducted with the sub-gate covered by the second insulator 22 having the opposite polarity, so that 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 second insulator 22 is not broken. That is, the second insulator 22 is continuously provided in the non-bus region 14 from the first insulator 21 along the longitudinal direction of the sub-gate.

In particular, "at least partially" refers to a portion or all. In other words, the second insulator 22 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.

In some alternative embodiments, the ratio of the sum of the lengths of the second insulators 22 corresponding to adjacent two sub-gates to the length 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 second insulators 22 corresponding to the two adjacent sub-gates to the length of the non-confluence region 14 is in a proper range, so that the short-circuit risk is reduced, and meanwhile, the waste of materials and the increase of cost caused by the overlarge ratio can be 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 second insulator 22 must have a certain length, the ratio of the sum of the lengths of the second insulators 22 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 second insulator 22 refers to the dimension of the second insulator 22 in the length direction of the sub-gate.

Specifically, the length of the non-bus region 14 refers to the dimension of the non-bus region 14 in the length direction of the sub-gate.

In the example of fig. 8, the ratio of the sum of the lengths of the second insulators 22 corresponding to the adjacent two sub-gates to the length of the non-bus region 14 is 50%. In the example of fig. 9, the ratio of the sum of the lengths of the second insulators 22 corresponding to the adjacent two sub-gates to the length 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. 8 and 9, the lengths of the second insulators 22 corresponding to the adjacent two sub-gates are the same. It will be appreciated that in other examples, the lengths of the second insulators 22 corresponding to adjacent two sub-gates may be different.

Referring to fig. 8, in some alternative embodiments, the second insulator 22 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 second insulator 22 is in a proper range, so that the problem that the sub-gate is difficult to cover due to too small width and the insulation effect is poor can be avoided, and the waste of materials and the increase of cost due to too large width can be avoided.

Preferably, the width d of the second insulator 22 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 d of the second insulator 22 may be a constant value within 50 μm to 500 μm or may fluctuate within 50 μm to 500 μm.

In some alternative embodiments, the difference between the widths of the second insulator 22 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 second insulator 22 and the corresponding sub-gate is in a proper range, which can avoid the difficulty in covering the sub-gate and poor insulation effect caused by too small difference between the widths of the second insulator 22 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 second insulator 22 and the corresponding sub-gate.

Preferably, the difference between the widths of the second insulator 22 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 insulator 20 and a first insulator 21. As another example, in fig. 11 and 12, the back contact battery 100 includes a battery substrate 10, an insulator 20, a first insulator 21, and a second insulator 22. For another example, in fig. 11, the ratio of the sum of the lengths of the second insulators 22 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 second insulators 22 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 nine

In some alternative embodiments, the insulator 20 is a transparent insulator.

In this way, the shielding of sunlight by the insulator 20 can be reduced, so that more sunlight is absorbed by the back contact battery 100, which is advantageous for improving the photoelectric conversion efficiency.

Note that transparent means that the transmittance of the insulating member 20 to visible light at a thickness of 20 μm is 70% or more.

It will be appreciated that in other embodiments, the insulator 20 may be non-transparent. The description is not limited thereto.

Examples ten

In some alternative embodiments, the insulator 20 is a transparent fluorescent insulator.

In this way, the insulating member 20 emits light under the irradiation of the light source with the corresponding wavelength, so that the position of the insulating member 20 can be conveniently detected, and the accuracy of the back contact battery 100 for arranging the insulating member 20 can be improved.

In this embodiment, the transparent fluorescent insulator is made of transparent insulating glue.

Specifically, the transparent insulating paste includes: 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%. In this way, the mass percentage of the resin component is in a proper range, so that the brittleness of the insulating member 20 formed by curing the insulating glue can be reduced, and the bending resistance and impact resistance strength of the insulating member 20 can be 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. Furthermore, the resin component can reduce brittleness of the insulating member 20 formed by curing the transparent insulating paste, and improve bending and impact strength of the insulating member 20.

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.

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, e.g. fluorescent whitening agents-OB, zinc oxide, zinc sulfide, calcium sulfide, strontium aluminate, calcium chlorate, barium aluminate,Rare earth fluorescent material, fluorescent brightening agent BC, fluorescent brightening agent JD-3, fluorescent brightening agent BR, fluorescent brightening agent-EBF, fluorescent brightening agent R, fluorescent brightening agent ER, 1, 8-naphthalimide fluorescent compound, polyphenyl, polythiophene, polyfluorene, polytriphenylamine derivative, polycarbazole, polypyrrole and derivative thereof, copolymer, N-dimethylamino benzylidene dinitrile compound, 8-hydroxyquinoline aluminum and europium metal complex, when the mass percentage is more than or equal to 0.1% and less than 1%, the gray value range of the characteristic fluorescent effect is 100-300, the viscosity value range of the characteristic printability is 150-300, and the light transmittance range is 85-90%. 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, the back contact battery 100 may be irradiated with at least one light of green light, blue light, infrared light, ultraviolet light, and white light, so that the insulating member 20 formed by curing the transparent insulating paste emits fluorescence, thereby precisely detecting the position of the transparent insulating paste.

Example eleven

The battery assembly of the embodiment of the present application includes the back contact battery 100 of any one of the embodiment one to embodiment ten.

In this way, in the back contact battery 100, the insulating member 20 surrounds the serial member electrical connection region 101, so that the conductive material can be prevented from flowing from the serial member electrical connection region 101 to the opposite auxiliary grid of the serial member, thereby avoiding the conduction between the serial member and the opposite auxiliary grid, ensuring the normal operation of the back contact battery 100, and reducing the risk of short circuit of the back contact battery 100. Meanwhile, the conductive material can be prevented from flowing from the electric connection area 101 of the serial connection piece to the homopolar auxiliary grid of the serial connection piece, so that the conductive material is prevented from being low in height, and poor connection with the serial connection piece is avoided.

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 pieces may be realized by providing a welding strip (bus bar, interconnection bar), a conductive back plate, 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 twelve

The photovoltaic system of the present application includes the battery assembly of embodiment eleven.

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 present 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 invention is provided for the purpose of illustration only, and is not intended to limit the invention 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 invention.

Claims

1. The back contact battery is characterized by comprising a battery substrate and an insulating piece, wherein auxiliary grids with two polarities are formed on the back surface of the battery substrate in a staggered mode, the back surface comprises a serial piece electric connection area, the serial piece electric connection area is an area where the back contact battery is electrically connected with the serial piece, and the insulating piece surrounds the serial piece electric connection area.

2. The back contact battery of claim 1, wherein the insulator has a thickness of 10 μm to 50 μm.

3. The back contact battery of claim 1, wherein the difference in height between the top surface of the insulator and the top surface of the electrical connector is greater than 20 μm.

4. The back contact battery of claim 1, wherein the insulating member is closed and continuously distributed around the periphery of the electrical connection region of the series member.

5. The back contact battery of claim 4, wherein the width of the insulator is greater than 100 μm.

6. The back contact battery of claim 1, wherein the series electrical connection region comprises a pad region and/or a conductive paste region.

7. The back contact battery of claim 1, wherein the area of the series electrical connection region is 2mm ² -6mm ² 。

8. The back contact battery of claim 1, wherein the number of series electrical connection areas is 30-300 and the number of insulators is 30-300.

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

10. The back contact battery of claim 9, wherein the insulator is a transparent fluorescent insulator.

11. A battery assembly comprising the back contact battery of any one of claims 1 to 10.

12. A photovoltaic system comprising the cell assembly of claim 11.