CN219917177U

CN219917177U - Main-grid-free back contact battery, battery assembly and photovoltaic system

Info

Publication number: CN219917177U
Application number: CN202321248035.8U
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: 2023-10-27
Anticipated expiration: 2033-05-22

Abstract

The application is suitable for the technical field of solar cells, and provides a non-main-grid back contact cell, a cell assembly and a photovoltaic system. The non-main grid back contact battery comprises a battery substrate, a first insulating piece and a conductive piece, wherein the back surface of the battery substrate is provided with auxiliary grids with two polarities which are distributed in a staggered way, the back surface of the battery substrate comprises a bus area and a non-bus area which are distributed in a staggered way, part of each auxiliary grid is positioned in the bus area, and the rest part of each auxiliary grid is positioned in the non-bus area; the converging region comprises a series element electric connection region, the first insulating element is arranged in the converging region and covers the auxiliary grid with the polarity opposite to that of the converging region, and the series element electric connection region is exposed; the conductive piece is arranged in the electric connection area of the serial piece. Therefore, the conduction of the auxiliary grid and the welding strip with opposite polarities is avoided in the bus area by the first insulating piece, and the risk of short circuit of the battery without the main grid back contact is reduced. Meanwhile, the auxiliary grid and the serial connection piece with the same polarity are connected by the conductive piece, so that the serial connection piece connects the non-main grid back contact battery into a battery string in series.

Description

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

Technical Field

The application belongs to the technical field of solar cells, and particularly relates to a non-main-grid 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 related art non-main gate back contact cell, the sub-gates of two polarities are alternately distributed. When the cascade piece is used for converging the auxiliary grid, the auxiliary grid is easy to be conducted with the opposite cascade piece, so that short circuit is caused.

Based on this, how to reduce the risk of shorting the non-main gate back contact battery becomes a problem to be solved.

Disclosure of Invention

The utility model provides a non-main grid 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 non-main grid back contact battery.

The utility model provides a non-main-grid back contact battery, which comprises a battery substrate, a first insulating piece and a conductive piece, wherein secondary grids with two polarities are formed on the back surface of the battery substrate in a staggered mode, the back surface comprises a bus area and a non-bus area which are distributed in a staggered mode, part of each secondary grid is located in the bus area, and the rest part of each secondary grid is located in the non-bus area; the first insulating piece is arranged in the converging area and covers the auxiliary grid with the polarity opposite to that of the converging area, and the electric connection area of the connecting piece is exposed; the conductive piece is arranged in the electric connection area of the serial piece.

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

Optionally, the length of the first insulating member is 1mm-3mm.

Optionally, the width of the first insulating member is 0.2mm to 0.6mm.

Optionally, the height of the conductive element is 30 μm to 100 μm.

Optionally, the area of the electrical connection area of the serial connection piece is 0.02mm ² -0.6mm ² 。

Optionally, the number of the electrical connection areas of the serial connection element is 1000-4000.

Optionally, the non-main gate back contact battery includes a second insulating member, where the second insulating member connects two adjacent first insulating members, and the second insulating member and the adjacent first insulating members enclose the series connection member electrical connection region.

Optionally, the width of the second insulating member is 1mm-3mm.

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 non-main grid back contact battery.

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

According to the non-main grid back contact battery, the battery assembly and the photovoltaic system, the first insulating piece is arranged in the converging area and covers the auxiliary grid with the polarity opposite to that of the converging area, so that conduction between the auxiliary grid with the polarity opposite to that of the welding strip in the converging area can be avoided, and the risk of short circuit of the non-main grid back contact battery is reduced. Meanwhile, the conductive piece is arranged in the electric connection area, so that the auxiliary grid and the serial piece with the same polarity are convenient to connect, the serial piece connects the non-main grid back contact battery into a battery string in series, and the current of the non-main grid back contact battery is led out. In addition, as the main grid is not arranged, the main grid slurry can be omitted, and the cost is reduced.

Drawings

Fig. 1 is a schematic structural view of a partial region of a non-main gate back contact cell according to an embodiment of the present application;

fig. 2 is a schematic view of the structure of a battery substrate without a main gate back contact battery according to an embodiment of the present application;

fig. 3 is a schematic view of a part of the structure of a non-main gate back contact battery according to an embodiment of the present application;

fig. 4 is a schematic view of a part of the structure of a non-main gate back contact battery according to an embodiment of the present application;

fig. 5 is a schematic structural view of a partial region of a non-main gate back contact cell according to an embodiment of the present application;

description of main reference numerals:

the battery 100 without main gate back contact, the battery substrate 10, the series element electric connection area 101, the non-series element electric connection area 102, the first auxiliary gate 111, the first series element electric connection area 1120, the second auxiliary gate 121, the second series element electric connection area 1220, the converging area 13, the non-converging area 14, the first insulating element 21, the second insulating element 22 and the conductive element 30.

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 arranged in the converging region and covers the auxiliary grid with the polarity opposite to that of the converging region, so that the auxiliary grid with the polarity opposite to that of the converging region can be prevented from being conducted with the welding strip, and the risk of short circuit of the battery without the main grid back contact is reduced. Meanwhile, the conductive piece is arranged in the electric connection area, so that the auxiliary grid and the serial piece with the same polarity are convenient to connect, the serial piece connects the non-main grid back contact battery into a battery string in series, and the current of the non-main grid back contact battery is led out. In addition, as the main grid is not arranged, the main grid slurry can be omitted, and the cost is reduced.

Example 1

Referring to fig. 1, 2, 3, 4 and 5, a non-main-grid back-contact battery 100 according to an embodiment of the present application includes a battery substrate 10, a first insulating member 21 and a conductive member, 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 bus region 13 and a non-bus region 14 distributed in a staggered manner, a part of each sub-grid is located in the bus region 13, and the rest of each sub-grid is located in the non-bus region 14; the bus region 13 includes a serial connection element electrical connection region 101, and the first insulating element 21 is disposed in the bus region 13 and covers the auxiliary gate opposite to the polarity of the bus region 13 to expose the serial connection element electrical connection region 101; the conductive member is disposed in the serial electrical connection area 101.

In the non-main gate back contact battery 100 of the embodiment of the application, since the first insulating member 21 is disposed in the bus region 13 and covers the auxiliary gate having the polarity opposite to that of the bus region 13, conduction between the auxiliary gate having the polarity opposite to that of the bus region 13 and the solder strip can be avoided, thereby reducing the risk of short circuit of the non-main gate back contact battery 100. Meanwhile, the conductive member is arranged in the electrical connection area, so that the auxiliary grid and the serial member with the same polarity are convenient to connect, the serial member connects the non-main grid back contact battery 100 in series into a battery string, and the current of the non-main grid back contact battery 100 is led out. In addition, as the main grid is not arranged, the main grid slurry can be omitted, and the cost is reduced.

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

Specifically, the non-main-grid 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 no-main-gate back-contact cell 100 shown in fig. 1, 2, 3 and 4 is a single block of five-piece no-main-gate back-contact cells 100 with two piece areas. The configuration of the remaining areas of the five-piece no-main-gate back-contact battery 100, and the configuration of the no-main-gate back-contact battery 100 of other piece ratios, similar to those of fig. 1, 2, 3 and 4, may be referred to in fig. 1, 2, 3 and 4, and will not be described again. Fig. 5 shows a partial region of the non-main gate back contact battery 100, and other regions of the non-main gate back contact battery 100 are similar to those of fig. 5, and reference is made to fig. 5, and a detailed description thereof is omitted. That is, the drawings are merely examples, and do not represent a limitation on the specific form of the non-main gate 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 the surface of the non-main gate back contact cell 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.

Note that the bus regions 13 of two polarities are alternately distributed in the length direction of the sub-gate, and one or more rows of the divided regions may be formed in the width direction of the sub-gate, each row of the divided regions including the bus regions 13 and the non-bus regions 14 alternately distributed in the length direction of the sub-gate. The non-primary gate back contact cell 100 may include an insulating strip that covers the secondary gate at the boundary of adjacent two cell regions. Therefore, the single-chip current can be reduced by utilizing the slicing technology, the power loss of the same battery piece packaged into the photovoltaic module is reduced, and the module efficiency is improved. It can be understood that after dicing, the monolithic current becomes smaller, heat loss can be reduced, resistance becomes larger, and transmission loss can be reduced. In this embodiment, the non-main gate back contact cell is a five-piece cell. It will be appreciated that in other embodiments, the non-primary-grid back contact cell may also be a two-piece cell, a three-piece cell, a four-piece cell, or a six-piece cell, as not limited herein.

Preferably, the main grid back contact cell is a three-piece cell and a four-piece cell. Thus, the increase of the cutting loss is lower, the reduction of the single-chip power loss is higher, the complexity of the process is lower, the whole effect is best, and the power is optimal.

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.

Specifically, the first converging region and the second converging region are respectively used for arranging a first serial connection piece and a second serial connection piece. That is, the same polarity of the sub-grids are converged by the same polarity of the series connection.

Specifically, the bus region 13 includes a series electrical connection region 101. The serial connection element is electrically connected with the non-main grid back contact battery 100 in the serial connection element electrical connection area 101 and is connected with other non-main grid 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 series electrical connection region 101 exposes the sub-gates with two polarities, and the first insulating member 21 is disposed in the bus region 13 and covers the sub-gates with the polarity opposite to that of the bus region 13. In this way, conduction of the secondary grid and the solder strip of opposite polarity can be avoided in the bus region 13, thereby reducing the risk of shorting the non-primary grid back contact cell 100.

Specifically, the non-serial electrical connection region 102 is located in a region of the battery substrate 10 other than 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.

In some alternative embodiments, the series electrical connection region 101 includes at least one of a pad region, a conductive paste region, and an electronic paste region. In other words, the series electrical connection region 101 includes one or more of a pad region, a conductive paste region and an electronic paste region.

As such, the non-main gate back contact battery 100 and the series may be connected by at least one of pad bonding, conductive paste, and electronic paste.

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.

Specifically, the serial connection member is, for example, a solder strip, a conductive wire, a conductive tape, 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.

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

Referring to fig. 1, 2, 3 and 4, the first insulating member 21 is disposed in the bus region 13, covers the sub-gate opposite to the bus region 13, and exposes the series electrical connection region 101; the conductive member is disposed in the serial electrical connection area 101.

Specifically, the first insulating element 21 covers the second sub-gate 121 in the first bus region, exposing the series element electrical connection region 101 of the first bus region; the first insulating member 21 covers the first sub-gate 111 in the second bus region, exposing the series electrical connection region 101 of the second bus region.

Specifically, the first insulating member 21 covers the entire surface of the bus region 13 with the sub-gate having the polarity opposite to that of the bus region 13. In other words, the sub-gate having the polarity opposite to that of the bus bar region 13 is covered by the first insulator 21 in all portions of the bus bar region 13. In this way, the sub-gate and the series of opposite polarity are insulated as much as possible.

Specifically, one or both ends of the first insulating member 21 may also extend from the bus region 13 toward the non-bus region 14 along the length direction of the corresponding sub-gate. In this way, in case of a serial offset, the risk of conduction of the sub-gate with opposite polarity can be reduced.

Specifically, the conductive element locally covers the serial element electrical connection region 101. Specifically, "locally covering" refers to the conductive element covering a portion, but not all, of the electrical connection region 101 of the series element. Thus, the coverage area is smaller, and the cost is reduced.

It is understood that in other embodiments, the conductive element may also entirely cover the series electrical connection region 101. Specifically, "full coverage" refers to the conductive element covering all of the series element electrical connection area 101. Therefore, the setting process of the conductive piece is simpler, and the production efficiency is improved.

Further, the center of the conductive member overlaps the center of the electrical connection region 101 of the serial member. In this way, the conductive member is located at the center of the electrical connection region 101 of the serial member, so that the connection between the serial member and the battery 100 without the main grid back contact is more stable.

Specifically, the conductive member may be conductive adhesive, and is fixed in the serial member electrical connection area 101 after curing. The conductive member may be adhered to the serial member electrical connection area 101 by a glue. The conductive member may also be formed by solidification after soldering. The specific manner in which the conductive member is disposed in the serial electrical connection region 101 is not limited herein.

Specifically, the serial electrical connection area 101 is rectangular. It is understood that in other embodiments, the electrical connection area 101 of the serial connection element may have a circular shape, a square shape, a triangular shape, or other shapes. The specific configuration of the electrical connection region 101 of the serial connection element is not limited herein.

Specifically, the contact surface between the conductive element and the electrical connection area 101 of the serial element is rectangular. It is understood that in other embodiments, the contact surface between the conductive element and the electrical connection region 101 of the serial element may have a circular, square, triangular or other shape. The specific form of the contact surface between the conductive element and the electrical connection region 101 of the serial element is not limited herein.

Specifically, the form of the electrical connection region 101 of the serial connection element may be the same as or different from the form of the contact surface between the conductive element and the electrical connection region 101 of the serial connection element.

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. 5, in some alternative embodiments, the length d of the first insulating member 21 is 1mm-3mm. For example, 1mm, 1.1mm, 1.5mm, 1.8mm, 2mm, 2.2mm, 2.5mm, 2.9mm, 3mm.

Thus, the length of the first insulating member 21 is in a suitable range, so that the opposite auxiliary grid which cannot completely cover the bus region 13 due to too small length can be avoided, the insulating effect is poor, and the waste of materials and the increase of cost due to too large length can be avoided.

Preferably, the length d of the first insulating member 21 is 1.5mm-2.5mm. Thus, the overall effect of insulation and economy is best.

Note that the length of the first insulating member 21 may be a constant value within 1.5mm to 2.5mm, and may also fluctuate within 1.5mm to 2.5mm.

Example IV

In some alternative embodiments, the width w of the first insulating member 21 is 0.2mm-0.6mm. For example 0.2mm, 0.3mm, 0.4mm, 0.5mm, 0.6mm.

Thus, the width w of the first insulating member 21 is in a suitable range, which can avoid the situation that the auxiliary gate cannot be covered due to too small width, has poor insulating effect, and can avoid the waste of materials and increase the cost due to too large width.

Preferably, the width w of the first insulator 21 is 0.4mm. Thus, the overall effect of insulation and economy is best.

Note that the width w of the first insulating member 21 may be a constant value within 0.2mm to 0.6mm, and may also fluctuate within 0.2mm to 0.6 mm.

Example five

In some alternative embodiments, the height of the conductive element is 30 μm to 100 μm. For example 30 μm, 32 μm, 35 μm, 40 μm, 60 μm, 70 μm, 90 μm, 95 μm, 100 μm.

Therefore, the height of the conductive piece is in a proper range, so that the conductive piece is difficult to connect with the serial piece due to the too small height can be avoided, and the waste of materials and the cost increase due to the too large height can be avoided.

Preferably, the height of the conductive member is 60 μm to 70 μm. Thus, the overall effect is best.

Note that the height of the conductive member may be a constant value within 30 μm to 100 μm or may fluctuate within 30 μm to 100 μm.

Example six

Referring to FIG. 5, in some alternative embodiments, the area of the series electrical connection region 101 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 。

In this way, the area of the electric connection region 101 of the serial connection member is in a proper range, so that unstable connection between the non-main-grid back contact battery 100 and the serial connection member caused by too small area can be avoided, and waste of conductive material and poor insulation effect caused by too large area can also 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 of the non-main-grid back contact battery 100 and the serial connection part, the saving of conductive materials and the insulation are considered, and the overall effect is the best.

Example seven

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 regions 101 of the serial connection member is in a suitable range, so that unstable connection between the non-main-grid back contact battery 100 and the serial connection member 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 1000-4000 corresponds to the cell 100 without the main gate back contact being a single piece. It will be appreciated that in the case where the non-primary-grid back-contact battery 100 is a half, a third, or other ratio of battery pieces divided from a single battery piece, the number of series electrical connection regions 101 may be determined based on the division ratio and the range of 1000 to 4000. For example, in the case where the non-main-gate back-contact battery 100 is a half-piece divided from a single battery piece, the number of the series-connection electrical connection regions 101 is 500 to 2000.

Example eight

Referring to fig. 5, in some alternative embodiments, the non-main-gate back-contact battery 100 includes a second insulating member 22, wherein the second insulating member 22 connects two adjacent first insulating members 21, and encloses a series electrical connection area 101 with the adjacent first insulating members 21.

In this way, the first insulating member 21 and the second insulating member 22 that are connected together enclose the serial connection member electrical connection region 101, and the conductive material that can be blocked flows from the serial connection member electrical connection region 101 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 battery 100 without the main grid back contact can be ensured, and the risk of short circuit of the battery 100 without the main grid back contact 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 height of the conductive piece formed by solidifying the conductive material is low, and poor connection with the serial connection piece is avoided.

Specifically, the two first insulating members 21 and the two second insulating members 22 may enclose a rectangular series connection member electrical connection region 101, where the two first insulating members 21 are respectively located at two opposite sides of the rectangle, and the two second insulating members 22 are respectively located at two other opposite sides of the rectangle.

It should be understood that in other embodiments, the number of the second insulating elements 22 corresponding to each of the series electrical connection regions 101 may be 3, 4, 5 or other numbers, and the first insulating elements 21 and the second insulating elements 22 may enclose the series electrical connection regions 101 into other shapes, and specific surrounding shapes of the first insulating elements 21 and the second insulating elements 22 are not limited.

Example nine

Referring to fig. 5, in some alternative embodiments, the width x of the second insulator 22 is 1mm-3mm. For example, 1mm, 1.2mm, 1.5mm, 2mm, 2.3mm, 2.5mm, 2.7mm, 3mm.

In this way, the width x of the second insulating member 22 is in a suitable range, so that the problem that the conductive material cannot be blocked due to too small width can be avoided, and the waste of materials and the increase of cost due to too large width can be avoided.

Preferably, the width x of the second insulator 22 is 2mm. Thus, the overall effect of insulation and economy is best.

Note that the width x of the second insulating member 22 may be a constant value within 1mm to 3mm, or may fluctuate within 1mm to 3mm.

Examples ten

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 backcontact cell 100 without the main grid, which is advantageous for 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.

In some alternative embodiments, 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.

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

Example eleven

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 arranging the first insulating member 21 of the non-main-grid back contact battery 100 can be improved.

In some alternative embodiments, the second insulator 22 is a transparent fluorescent insulator. 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 for arranging the second insulating member 22 can be improved.

Note that the explanation and description of the second insulating member 22 as a transparent fluorescent insulating member is similar to the first insulating member 21, and reference is made to the relevant content of the first insulating member 21, which is not repeated here.

Example twelve

In some alternative embodiments, the transparent fluorescent insulation is made of transparent insulating glue. The transparent insulating adhesive comprises: 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 non-main-grid back contact battery 100, which is beneficial to 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 setting the transparent insulating adhesive for the battery 100 without the main grid back contact.

Specifically, the transparent insulating paste may be provided on the non-main-grid back-contact battery 100 by screen printing, valve spraying, coating, or the like.

Specifically, the coverage area ratio of the transparent insulating paste on the non-main gate back contact battery 100 is more 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 suitable range, so that the brittleness of the first insulating member 21 formed by curing the insulating gel can be reduced, and the bending and impact resistance strength of the first insulating member 21 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 method is beneficial to ensuring the normal operation of the solar photocell and reducing the cost of the non-main grid 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. Further, the resin component can reduce brittleness of the first insulating member 21 formed by curing the transparent insulating gel, and improve bending and impact strength of the first insulating member 21.

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 thirteen

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, the non-main gate 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 first insulating member 21 formed by curing the transparent insulating paste emits fluorescence, thereby precisely detecting the position of the transparent insulating paste.

Examples fourteen

The battery assembly of the embodiment of the application includes the no-main-gate back-contact battery 100 of any one of the first to thirteenth embodiments.

In this way, in the non-main-gate back-contact battery 100, the first insulating member 21 is disposed in the bus region 13 and covers the sub-gate having the opposite polarity to the bus region 13, so that conduction between the sub-gate having the opposite polarity and the solder strip in the bus region 13 can be avoided, thereby reducing the risk of short circuit of the non-main-gate back-contact battery 100. Meanwhile, the conductive member is arranged in the electrical connection area, so that the auxiliary grid and the serial member with the same polarity are convenient to connect, the serial member connects the non-main grid back contact battery 100 in series into a battery string, and the current of the non-main grid back contact battery 100 is led out. In addition, as the main grid is not arranged, the main grid slurry can be omitted, and the cost is reduced.

In this embodiment, a plurality of non-main-grid 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 can be filled between the front and back surfaces of the non-main-grid back-contact battery 100 and the photovoltaic glass, adjacent battery pieces and the like, and can be a transparent colloid with good light transmittance and ageing resistance, for example, the adhesive film can be an EVA adhesive film or a POE adhesive film, and the adhesive film can be specifically selected according to practical situations and is not limited.

The photovoltaic glass may be coated on the adhesive film of the front surface of the non-main gate 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 non-main gate back contact battery 100 without affecting the efficiency of the non-main gate back contact battery 100 as much as possible. Meanwhile, the photovoltaic glass and the non-main-grid back contact battery 100 can be bonded together by the adhesive film, and the non-main-grid 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 non-main-grid back-contact battery 100, can protect and support the non-main-grid 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 can be specifically set according to specific conditions without limitation. The whole of the back plate, the non-main-grid 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 fifteen

The photovoltaic system of the embodiment of the application comprises the battery assembly of the fourteen 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 without the main grid is characterized by comprising a battery substrate, a first insulating piece and a conductive piece, wherein the back surface of the battery substrate is provided with auxiliary grids with two polarities which are distributed in a staggered way, the back surface comprises a confluence area and a non-confluence area which are distributed in a staggered way, part of each auxiliary grid is positioned in the confluence area, and the rest part of each auxiliary grid is positioned in the non-confluence area; the first insulating piece is arranged in the converging area and covers the auxiliary grid with the polarity opposite to that of the converging area, and the electric connection area of the connecting piece is exposed; the conductive piece is arranged in the electric connection area of the serial piece.

2. The backcontact cell of claim 1, wherein the first insulator has a thickness of 10 μm to 50 μm.

3. The backcontact cell of claim 1, wherein the first insulator has a length of 1mm-3mm.

4. The backcontact cell of claim 1, wherein the first insulator has a width of 0.2mm to 0.6mm.

5. The backcontact cell of claim 1, wherein the conductive member has a height of 30 μm to 100 μm.

6. The backcontact cell of claim 1, wherein the area of the series electrical connection region is 0.02mm ² -0.6mm ² 。

7. The backcontact cell of claim 1, wherein the number of the series electrical connection regions is 1000-4000.

8. The backcontact cell of claim 1, wherein the backcontact cell comprises a second insulator connecting adjacent two of the first insulators and surrounding the series electrical connection region with adjacent first insulators.

9. The backcontact cell of claim 8, wherein the second insulator has a width of 1mm to 3mm.

10. The backcontact cell of claim 1, wherein the first insulator is a transparent insulator.

11. The backcontact cell of claim 10, wherein the first insulator is a transparent fluorescent insulator.

12. A battery assembly comprising the backcontact cell without primary grid of any one of claims 1 to 11.

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