阅读说明：本技术 一种背板结构、光伏组件以及制备方法 (Back plate structure, photovoltaic module and preparation method ) 是由 叶玉秋 陈道远 周艳方 于 2020-11-19 设计创作，主要内容包括：本发明公开了一种背板结构、光伏组件以及制备方法。该背板结构包括：背板本体、设置于背板本体一侧的反射层和设置于反射层下方的第一散热层。该背板结构能够有效地降低热斑温度,提高光伏组件的光电性能。(The invention discloses a back plate structure, a photovoltaic module and a preparation method. The back plate structure includes: the back plate comprises a back plate body, a reflecting layer arranged on one side of the back plate body and a first heat dissipation layer arranged below the reflecting layer. The backboard structure can effectively reduce the hot spot temperature and improve the photoelectric performance of the photovoltaic module.)

1. A backsheet construction for a photovoltaic module, comprising: the back plate comprises a back plate body (101), a reflecting layer (102) arranged on one side of the back plate body (101) in the thickness direction, and a first heat dissipation layer (103) arranged below the reflecting layer (102).

2. The backplane structure according to claim 1,

the first heat dissipation layer (103) is arranged between the reflection layer (102) and the backboard body (101).

3. The backplane structure according to claim 1,

the side where the reflecting layer (102) is located is used for bearing the battery unit (201);

the first heat dissipation layer (103) is arranged on the other side of the backboard body (101) in the thickness direction.

4. The backplane structure according to any one of claims 1 to 3,

the reflecting layer (102) and the first heat dissipation layer (103) are both of a grid structure, and the reflecting layer (102) and the first heat dissipation layer (103) are arranged correspondingly.

5. The backplane structure of claim 4, further comprising: a second heat sink layer (105), wherein,

the second heat dissipation layer (105) is in a strip shape;

the second heat dissipation layer (105) is arranged on the hollow-out part (104) and corresponds to the main grid on the back of the battery unit (201).

6. The back plate structure of claim 1, wherein one side of the back plate body (101) in the thickness direction is provided with a first reticular groove (1011);

the first heat dissipation layer (103) and the reflection layer (102) are filled in the first reticular groove (1011).

7. A backplate structure according to claim 1 wherein one side of the backplate body (101) in the thickness direction is provided with a second web-like recess (1012) and the other side of the backplate body (101) in the thickness direction is provided with a third web-like recess (1013);

said second web-like groove (1012) being disposed opposite said third web-like groove (1013);

the first heat dissipation layer (103) is filled in the third reticular groove (1013);

the reflective layer (102) is filled in the second mesh-shaped groove (1012).

8. A photovoltaic module, comprising: a plurality of battery cells (201) and the backsheet construction of any one of claims 1 to 7 wherein,

the plurality of battery cells are arranged in an array on a side of the backplane structure where the reflective layer (102) is disposed.

9. A method of making the backsheet structures of any one of claims 1 to 7 comprising:

respectively coating a reflection layer prefabricated object and a heat dissipation layer prefabricated object on a back plate body, wherein the reflection layer prefabricated object is coated on one side of the back plate body (101) in the thickness direction, and the heat dissipation layer prefabricated object is coated below the reflection layer prefabricated object;

and curing the reflection layer prefabricated object and the heat dissipation layer prefabricated object through a curing process to obtain the reflection layer and the first heat dissipation layer.

10. A method of making a photovoltaic module according to claim 8, comprising:

providing a back-plate structure according to any of claims 1 to 7; and

the plurality of battery cells are arranged in an array and stacked on one side of the back sheet structure including the reflective layer, the stacking being such that at least a portion of the reflective layer and at least a portion of the first heat dissipation layer included in the back sheet structure overlap with a gap between adjacent battery cells in a thickness direction of the photovoltaic module.

Technical Field

The invention relates to a back plate structure, a photovoltaic module and a preparation method.

Background

During the use of the photovoltaic module, the individual cells of the photovoltaic module are shielded and converted from the power generating element to the load element, and the load element generates heat to cause a local temperature increase, which is called a hot spot effect. When the hot spot effect occurs, the shielded battery units not only consume part or all of the energy generated by the battery units with illumination to generate heat, but also further increase the hot spot temperature of the photovoltaic module due to poor heat conduction between the battery units. The increase in hot spot temperature will in severe cases permanently damage the battery cells, even burn the battery cells. Therefore, reducing the hot spot temperature of the photovoltaic module is an urgent problem to be solved.

Disclosure of Invention

In view of the above, the present invention provides a back sheet structure, a photovoltaic module and a method for manufacturing the same, which can effectively reduce the hot spot temperature.

In order to solve the technical problems, the invention provides the following technical scheme:

in a first aspect, the present invention provides a backsheet construction for a photovoltaic module comprising: the backboard comprises a backboard body, a reflecting layer arranged on the thickness direction of one side of the backboard body and a first heat dissipation layer arranged below the reflecting layer.

In a second aspect, the present invention provides a photovoltaic module comprising: a plurality of battery units and the above-mentioned back plate structure, wherein,

the plurality of battery cells are arranged in an array on the side of the backplane structure on which the reflective layer is disposed.

In a third aspect, the present invention provides a method for preparing the above-mentioned back plate structure, including:

respectively coating a reflection layer prefabricated object and a heat dissipation layer prefabricated object on a back plate body, wherein the reflection layer prefabricated object is coated on one side of the back plate body in the thickness direction, and the heat dissipation layer prefabricated object is coated below the reflection layer prefabricated object;

and curing the reflection layer prefabricated object and the heat dissipation layer prefabricated object through a curing process to obtain the grid structure reflection layer and the grid structure first heat dissipation layer.

In a fourth aspect, the present invention provides a method for preparing a photovoltaic module, comprising:

providing the back plate structure; and

the plurality of battery cells are arranged in an array and stacked on one side of the back sheet structure including the reflective layer, the stacking being such that at least a portion of the reflective layer and at least a portion of the first heat dissipation layer included in the back sheet structure overlap with a gap between adjacent battery cells in a thickness direction of the photovoltaic module.

The technical scheme of the first aspect of the invention has the following advantages or beneficial effects: the reflecting layer is arranged on one side of the backboard body, wherein one side of the reflecting layer is used for bearing the battery unit, so that the reflecting layer reflects light energy for the battery unit, the first heat dissipation layer arranged below the reflecting layer is prevented from absorbing the light energy, and the light energy received by the battery unit is improved. Meanwhile, the first heat dissipation layer arranged below the reflection layer absorbs heat of the battery unit and transfers the heat, so that the purpose of reducing the temperature of hot spots is achieved.

Drawings

Fig. 1 is a schematic diagram of a cross-sectional structure of a double-sided battery cell according to an embodiment of the present invention;

FIG. 2 is a schematic view of a planar (front) side of a backplane structure according to one embodiment of the present invention;

FIG. 3 is a schematic diagram of a cross-section of a backplane structure according to one embodiment of the present invention;

FIG. 4 is a schematic diagram of a cross-section of a backplane structure according to another embodiment of the present invention;

FIG. 5 is a schematic view of a reflective layer of a backplane structure reflecting light according to one embodiment of the present disclosure;

FIG. 6 is a schematic view of a reflective layer of a backplane structure according to another embodiment of the present invention reflecting light;

FIG. 7 is a schematic view of a backplane structure heat transfer direction according to one embodiment of the present invention;

FIG. 8 is a schematic view of a planar back plate structure according to another embodiment of the present invention;

FIG. 9 is a schematic diagram of a cross-section of a backplane structure according to yet another embodiment of the present invention;

FIG. 10 is a schematic diagram of a cross-section of a backplane structure according to another embodiment of the present invention;

FIG. 11 is a schematic diagram of a cross-section of a backplane structure according to yet another embodiment of the present invention;

FIG. 12 is a schematic view of a back plate body having a first mesh groove according to one embodiment of the invention;

FIG. 13 is a schematic diagram of a cross-section of a backplane structure according to another embodiment of the present invention;

FIG. 14 is a schematic view of a back plate body having a second mesh groove and a third mesh groove according to an embodiment of the invention;

FIG. 15 is a schematic view of a backplane structure according to another embodiment of the present invention;

FIG. 16 is a schematic view of a back plate body having a first stripe groove according to one embodiment of the present invention;

FIG. 17 is a schematic view of a back plate body according to another embodiment of the invention;

FIG. 18 is a schematic view of a back plate body according to yet another embodiment of the invention;

FIG. 19 is a schematic view of a back plate body according to another embodiment of the invention;

figure 20 is a schematic view of a photovoltaic module in plan (front) view according to one embodiment of the present invention;

FIG. 21 is a schematic illustration of a cross-section of a photovoltaic module according to another embodiment of the present invention;

FIG. 22 is a schematic illustration of a cross-section of a photovoltaic module according to yet another embodiment of the present invention;

FIG. 23 is a schematic illustration of a cross-section of a photovoltaic module according to another embodiment of the present invention;

FIG. 24 is a schematic illustration of a cross-section of a photovoltaic module according to yet another embodiment of the present invention;

FIG. 25 is a schematic illustration of a cross-section of a photovoltaic module according to another embodiment of the present invention;

FIG. 26 is a schematic illustration of a cross-section of a photovoltaic module according to yet another embodiment of the present invention;

FIG. 27 is a schematic illustration of a cross-section of a photovoltaic module according to another embodiment of the present invention;

FIG. 28 is a schematic view of a main flow of a method of manufacturing a backplane structure according to one embodiment of the present invention;

fig. 29 is a schematic view of a main flow of a method of manufacturing a photovoltaic module according to an embodiment of the present invention;

FIG. 30 is a schematic illustration of a groove inner surface configuration according to one embodiment of the present invention.

The reference numbers are as follows:

101 a back plate body;

1011 first net-like groove

1012 second mesh grooves

1013 third reticular groove

1014 first strip groove

1015 second stripe type groove

102 reflective layer

103 first heat dissipation layer

104 hollow part

105 second heat sink layer

201 battery unit

2011 metal front electrode; 2012 front surface antireflection film;

2013 boron doping the emitting layer; 2014 n-type silicon layer;

2015 a phosphorus doped back field (BSF) layer; 2016 a back antireflection film;

2017 metal back electrode

202 cover plate

203 packaging layer

Detailed Description

The photovoltaic module is generally shaped as a plate or sheet, extending substantially in one plane and having a certain thickness. For convenience and clarity in describing the photovoltaic module of the present invention, a direction perpendicular to a plane in which the photovoltaic module extends is defined as a "thickness direction". In the following description and in the appended claims, a feature being "in communication with" or "connected to" another feature includes not only the feature being in a transfer relationship with the other feature (e.g., light reflective transfer, heat transfer, etc.), but also intermediate features between the feature and the other feature through which heat or light energy of the one feature is transferred to the other feature, it being understood that heat transfer includes not only heat conduction, but also various forms of heat transfer such as heat radiation, heat convection, etc. that may occur, and the invention is not limited to any particular form.

In addition, taking fig. 3 to 6, 9 to 11, 13, 15, 21 to 27 as an example, in the thickness direction of the photovoltaic module, the side of each component (such as a cover plate, a battery cell, a back plate structure, etc.) included in the photovoltaic module facing sunlight is above the component, and the side facing away from sunlight is below the component in the present invention, for example, the side facing sunlight is above the back plate structure, and the side facing away from sunlight is below the back plate structure in the thickness direction of the back plate structure included in the photovoltaic module. Thus, one feature disposed or located below another feature may mean that the one feature is located on a side of the another feature facing away from the sun and the one feature is in contact with the side of the another feature facing away from the sun; it may also mean that there is an intermediate feature between the one feature and the other feature, the intermediate feature and the one feature both being located on the side of the other feature facing away from the sun.

A photovoltaic module generally includes a backsheet and a plurality of battery cells disposed on one side of the backsheet, the plurality of battery cells being arranged in an array. The battery unit can be a single-sided battery unit or a double-sided battery unit, and the battery unit can be a single battery piece or a battery string formed by connecting a plurality of battery pieces in series. Among them, a single-sided battery cell is a battery cell that can receive light from only one side and convert the light into electric power. A bifacial cell is a cell that is capable of receiving light from both sides and converting the light into electrical power. The photovoltaic module including the bifacial cell unit can receive not only direct irradiation of sunlight from one side (i.e., the front side) to convert it into electric power, but also light such as reflected light or scattered light from the ground or the like from the other side (i.e., the back side), thereby improving the power generation efficiency of the photovoltaic module. For example, fig. 1 shows a cross-sectional view of a double-sided battery cell. As shown in fig. 1, the bifacial cell includes a metal front electrode 2011, a front surface antireflection film 2012, a boron doped emitter layer 2013, an n-type silicon layer 2014, a phosphorous doped back field (BSF) layer 2015, a back antireflection film 2016, and a metal back electrode 2017. The battery cells may have other configurations, however, the present invention is not limited thereto.

As described above, the photovoltaic module may have hot spots which damage the photovoltaic module, and it is necessary to reduce the temperature of the photovoltaic module when the hot spots occur, thereby improving the reliability of the photovoltaic module. One solution is that the photovoltaic module employs a heat dissipating aluminum backplane structure to dissipate heat, however, because the aluminum is opaque, when the photovoltaic module employs a double-sided cell, the shielding of the aluminum layer will affect the amount of power generated by the back of the double-sided cell of the photovoltaic module.

In addition, in the mode of reducing the hot spot temperature of the photovoltaic module by arranging the heat dissipation layer on the back plate structure, the heat dissipation layer has heat dissipation property but also has strong light absorption property because the heat dissipation material included in the heat dissipation layer is generally dark in color, such as black, gray and the like, so that the reflected light which can be absorbed by the photovoltaic module is reduced, and the photoelectric performance of the photovoltaic module, such as the photoelectric efficiency, is reduced.

Accordingly, the present application provides a back sheet structure for a photovoltaic module as illustrated in fig. 2 to 4, 8 to 11, 13 and 15. Wherein, fig. 2 shows a plan view of a back plate structure according to an embodiment of the present invention from one side (front side/side carrying battery cells), and fig. 3 to 4 respectively show cross-sectional views of the back plate structure, which show two relative positional relationships of a back plate body 101, a reflective layer 102 disposed on one side of the back plate body 101, and a first heat dissipation layer 103 disposed under the reflective layer 102. In fig. 2 to 4, in order to clearly show the relative positional relationship among the back plate body 101, the reflective layer 102 and the first heat dissipation layer 103 in the back plate structure, only the back plate body 101, the reflective layer 102 and the first heat dissipation layer 103 are shown, and other components are omitted.

As shown in fig. 2 to 4, 8 to 11, 13 and 15, the back sheet structure applied to a photovoltaic module according to an embodiment of the present invention may include a back sheet body 101, a reflective layer 102 disposed on one side of the back sheet body 101, and a first heat dissipation layer 103 disposed below the reflective layer 102.

As shown in fig. 3 to 6, the side of the back plate body 101 specifically refers to a side of the back plate body 101 in the thickness direction. In a preferred embodiment, the side of the back plate body 101 where the reflective layer 102 is located is used for carrying the battery unit 201 (shown in fig. 21 and 22).

In one embodiment, as shown in fig. 2 and 7, the reflective layer 102 and the first heat dissipation layer 103 may be both of a mesh structure, and the reflective layer 102 and the first heat dissipation layer 103 are disposed correspondingly. In a preferred embodiment, the hollow part 104 surrounded by the grid structure corresponds to a battery cell 201 (shown in fig. 21 and 22) included in the photovoltaic module.

In the embodiment of the present invention, the hollow part 104 surrounded by the grid structure corresponds to the battery cell 201 included in the photovoltaic module, which may mean that when the back plate structure is applied to the photovoltaic module, the battery cell 201 is filled in the hollow part; when the back sheet structure is applied to a photovoltaic module, a main portion (a portion other than the edge portion) of the battery cell 201 may overlap the hollow portion 104.

Wherein the reflective layer 102 may be positioned in a space between adjacent battery cells, and a portion of the reflective layer may be bonded to an edge of the battery cell 201 by a bonding layer.

The first heat dissipation layer can be in thermal communication with the battery unit, the thermal communication can be that the edge of the first heat dissipation layer is in direct contact with the battery unit, and the first heat dissipation layer and the battery unit are packaged through packaging materials. The thermal communication may also be such that the edge of the first heat sink layer is bonded to the battery cell by an adhesive layer (indirect contact, not shown). The thermal communication may also be the presence of a backplane body between the edge of the first heat spreading layer and the battery cell. No matter which kind of thermal communication, the battery unit based on high temperature directly or indirectly transmits heat to first heat dissipation layer to reach the purpose of cooling.

The back plate body 101 may be a glass back plate, or the like, or the back plate body 101 may be made of other materials, such as a high molecular polymer material.

In the embodiment of the invention, the first heat dissipation layer 103 is disposed below the reflective layer 102, and as shown in fig. 3, the first heat dissipation layer 103 is disposed between the reflective layer 102 and the backplate body 101. As shown in fig. 4, the first heat dissipation layer 103 may be disposed on the other side of the backplane body 101 in the thickness direction.

It should be noted that the pattern of the hollow portion surrounded by the grid structure may be in various forms, such as a rectangular grid, a square grid, a circle, a polygon, and the like, and is not limited herein. The following description mainly takes a rectangular grid as an example.

According to the backboard structure provided by the embodiment of the invention, the reflecting layer is arranged on one side of the backboard body in the thickness direction, wherein the side where the reflecting layer is arranged is used for bearing the battery unit, so that the reflecting layer reflects light energy for the battery unit, and the light energy received by the battery unit is improved. Meanwhile, the first heat dissipation layer absorbs the heat of the battery unit and transfers the heat, so that the purpose of reducing the temperature of hot spots is achieved.

In addition, the reflecting layer and the first heat dissipation layer can be of a grid structure, the reflecting layer and the first heat dissipation layer are correspondingly arranged, so that the back main grid of the double-sided battery unit in the photovoltaic module can absorb light energy through the hollowed-out part surrounded by the grid structure, and the photoelectric performance of the back of the double-sided battery unit is not affected.

In addition, as shown in fig. 5 and 6, in the extending direction of the photovoltaic module, at least a part of the reflective layer 102 and the first heat dissipation layer 103 overlaps with the gap between the adjacent battery cells 201, and the hollow part 104 surrounded by the reflective layer 102 and the hollow part 104 surrounded by the first heat dissipation layer 103 overlap with the battery cells. That is, at least a portion of the reflective layer 102 and at least a portion of the first heat dissipation layer 103 extend along the gap between the adjacent battery cells, while the hollowed-out portions are disposed at the battery cells. Thus, in one aspect, light may be reflected at the reflective layer to re-reflect light to the battery cell, thereby increasing light absorption by the battery cell to enhance the photovoltaic performance of the battery cell/photovoltaic assembly. On the other hand, according to the heat conduction/heat transfer characteristics (high temperature to low temperature), as shown in fig. 7, the first heat dissipation layer 103 adjacent to the battery cell generating the hot spot effect can absorb the heat of the battery cell and then conduct the heat away in a shape of "#" along the extension of the first heat dissipation layer 103, thereby achieving the purpose of cooling. In addition, for the back plate body made of glass or a light-permeable polymer material, light (such as reflected light, scattered light and the like from the ground) can be allowed to pass through the hollow parts surrounded by the grid structures (the reflecting layer and the first heat conducting layer) and be transmitted from the other side (the back surface) of the back plate body to one side (the front surface) of the back plate body so as to be received by the back surface of the battery unit, and the influence on the illumination quantity of the back surface of the photovoltaic module is reduced.

The back generated energy of the photovoltaic module with double-sided power generation is ensured, the front generated energy of the photovoltaic module is improved, meanwhile, the heat at the hot spot of the photovoltaic module is conducted out in time, and the temperature of the photovoltaic cell forming the hot spot is restrained. Therefore, the stability of the photovoltaic module is improved while the power generation efficiency of the photovoltaic module is ensured.

In addition, due to the existence of the reflecting layer, the reflecting layer can prevent the first heat dissipation layer from absorbing light and transmit heat to the first heat dissipation layer, and the first heat dissipation layer can be made of heat dissipation materials with relatively good heat dissipation performance such as black and grey, so that the raw material selectivity for manufacturing the first heat dissipation layer is effectively enlarged. Therefore, the first heat dissipation layer can be made of a high-heat-dissipation, low-cost, deep-color heat dissipation material. For example, a high-heat-dissipation, low-cost, deep-color heat-dissipation material such as one or more of silicon carbide, aluminum nitride, boron carbide, graphite, and graphene.

It should be noted that, although the photovoltaic module according to the embodiment of the present invention is described by taking the bifacial cell unit as an example, the present invention is not limited thereto.

In the embodiment of the invention, a part of the reflecting layer can be overlapped with the edge of the battery unit to better reflect light for the battery unit, thereby improving the photoelectric performance of the battery unit.

In the embodiment of the invention, a part of the first heat dissipation layer can be overlapped with the edge of the battery unit to better reflect light for the battery unit, so that the photoelectric performance of the battery unit is improved.

In the embodiment of the present invention, as shown in fig. 8, which is a plan view of the front surface of the backplane structure, and fig. 9, 10 and 11 which are cross-sectional views, the fig. 9, 10 and 11 show different positional relationships among the reflective layer, the first heat dissipation layer and the second heat dissipation layer in the backplane structure, that is, the backplane structure may further include: a second heat dissipation layer 105, wherein the second heat dissipation layer 105 is in the shape of a bar; the second heat dissipation layer 105 is disposed on the hollow portion 104, corresponds to the main grid on the back surface of the battery cell 201 (i.e., the main grid on the back surface of the battery cell 201 overlaps the corresponding second heat dissipation layer), and is in thermal communication with the main grid on the back surface of the battery cell 201. The second heat dissipation layer corresponds to the main grid on the back of the battery unit, so that the main grid on the back can be cooled. Because the second heat dissipation layer at the position of the main grid on the back of the battery unit is overlapped with the main grid, the heat at the main grid can be quickly conducted out, and the melting phenomenon of local overheating on soldering tin at the main grid can be reduced to the maximum extent. And because the second heat dissipation layer is overlapped with the main grid, the influence of shielding on the back power generation amount is reduced as much as possible.

In a preferred embodiment of the present invention, the first heat dissipation layer 103 is integrally formed with the second heat dissipation layer 105. As shown in fig. 10 or fig. 11, the first heat dissipation layer 103 and the second heat dissipation layer 105 are located on the same side of the backplane body. The manufacturing process of the back plate structure is simplified, and the manufacturing cost of the back plate structure is effectively controlled.

In addition, as shown in fig. 4 and 11, the first heat dissipation layer is in contact with the outside air, so that the first heat dissipation layer directly transmits heat to the outside air, and the heat dissipation of the back plate structure is further improved, thereby further reducing the hot spot temperature of the photovoltaic module of the back plate structure.

It should be noted that the thickness of the second heat dissipation layer may be the same as the thickness of the first heat dissipation layer or the thickness of the reflection layer, or may be different from the thickness of the first heat dissipation layer or the thickness of the reflection layer, and the specific thicknesses of the second heat dissipation layer, the first heat dissipation layer, and the reflection layer may be set according to actual requirements. Therefore, fig. 9 to 11 are merely exemplary of the relative position relationship of the second heat dissipation layer, the first heat dissipation layer and the reflection layer, and do not represent the real size or the real thickness of the second heat dissipation layer, the first heat dissipation layer and the reflection layer.

In one embodiment of the present invention, the thickness of the first heat dissipation layer 103 is in a range of 1-1000 μm. That is, the thickness of the first heat dissipation layer may be any one of 1 to 1000 μm, for example, 1 μm, 10 μm, 20 μm, 50 μm, 80 μm, 100 μm, 200 μm, 300 μm, 500 μm, 600 μm, 700 μm, 800 μm, 900 μm, 1000 μm, and the like. Because the first heat dissipation layer is too thick and is easy to damage, the thickness range of the first heat dissipation layer is controlled within the range of 1-1000 mu m, so that the heat dissipation of the battery unit of the photovoltaic module can be ensured, and meanwhile, the damage to the backboard structure in the transportation process of the backboard structure can be avoided as much as possible.

In one embodiment of the present invention, the thickness of the reflective layer 102 is in a range of 1-1000 μm. That is, the thickness of the reflective layer may be any one of 1 to 1000 μm, for example, 1 μm, 10 μm, 30 μm, 60 μm, 90 μm, 100 μm, 300 μm, 450 μm, 550 μm, 650 μm, 750 μm, 850 μm, 950 μm, 1000 μm, and the like. Because the reflecting layer is too thick and is easy to damage, the thickness range of the first heat dissipation layer is controlled within the range of 1-1000 mu m, so that the light reflection can be effectively improved, and the damage to the backboard structure in the transportation process of the backboard structure can be avoided as much as possible.

In the embodiment of the invention, the width of the first heat dissipation layer 103 ranges from 5mm to 50mm, that is, the width of the first heat dissipation layer 103 can be any value of 5mm to 50mm, for example, 5mm, 8mm, 10mm, 15mm, 20mm, 25mm, 30mm, 35mm, 40mm, 50mm, and the like. The width range can meet the requirement for heat dissipation of the photovoltaic module, and transition blocking of the first heat dissipation layer on the back of the battery unit can be avoided.

In the embodiment of the invention, the width of the reflective layer 102 ranges from 5mm to 50 mm. That is, the width of the reflective layer 102 may be any one of 5 to 50mm, for example, 5mm, 8mm, 12mm, 16mm, 21mm, 25mm, 32mm, 35mm, 45mm, 50mm, etc. The width range can meet the requirement of reflecting light rays for the photovoltaic module, and can avoid transition blocking of the reflecting layer on the back of the battery unit.

In a preferred embodiment, the widths of the first heat dissipation layer and the reflective layer are generally configured such that the edges of the battery cells overlap the widths of the first heat dissipation layer and the reflective layer, i.e., the width of the gap between two adjacent battery cells is generally no greater than the width of the first heat dissipation layer and the width of the reflective layer.

In one embodiment of the present invention, the thickness of the second heat dissipation layer 105 ranges from 1 μm to 100 μm, i.e., the thickness of the second heat dissipation layer is any one of 1 μm to 100 μm, such as 1 μm, 2 μm, 5 μm, 8 μm, 10 μm, 15 μm, 20 μm, 25 μm, 30 μm, 35 μm, 40 μm, 45 μm, and 50 μm. By arranging the second heat dissipation layer within the thickness range, the use of heat dissipation materials can be reduced as much as possible while improving the heat dissipation of the main grid on the back surface of the battery cell, thereby effectively controlling the cost of the back plate structure.

In one embodiment of the present invention, the width of the second heat dissipation layer 105 ranges from 0.1mm to 10mm, i.e., the width of the second heat dissipation layer is any one of 0.1mm to 10mm, such as 0.1mm, 0.2mm, 0.5mm, 0.8mm, 1mm, 1.5mm, 2mm, 2.5mm, 3mm, 4mm, 5mm, 50 μm, etc. Through setting up the second heat dissipation layer in this width scope, when improving for the heat dissipation of the main bars at the battery cell back, can reduce the influence to the back extinction of battery cell as far as possible, guarantee two-sided photovoltaic module's photoelectric property.

In one embodiment of the present invention, the first heat dissipation layer 103 and/or the second heat dissipation layer 105 are cured from a heat dissipation coating preform. Wherein, the curing process can adopt a curing process such as heating calcination, photo-curing or thermal curing. The first heat dissipation layer 103 and/or the second heat dissipation layer 105 can be well attached to the back plate body by curing the heat dissipation coating preform.

Wherein, the heat dissipation coating preform may include: 1-30 parts of heat dissipation filler, 10-70 parts of solvent, 5-40 parts of binder, 0.1-1 part of catalyst and 0.1-1 part of additive. The heat dissipation filler is a heat dissipation main body, and the heat dissipation filler is a basis for realizing heat dissipation of the first heat dissipation layer 103 and/or the second heat dissipation layer 105.

In one embodiment of the present invention, the heat dissipation coating preform may include heat dissipation fillers including: any one or more of silicon carbide, aluminum nitride, boron carbide, graphite, and graphene. The heat dissipation filler has the advantages of low cost and high heat dissipation performance. The heat dissipation filler is a dark material, has strong light absorption, and is not applied to the heat dissipation of photovoltaic modules at present. Because the reflecting layer of the embodiment of the invention exists and the reflecting layer is arranged above the first heat dissipation layer (the first heat dissipation layer is arranged below the reflecting layer), light absorption of dark-colored heat dissipation filler can be avoided, the selectivity of the heat dissipation filler is effectively expanded, and meanwhile, because the heat dissipation filler has the advantages of low cost and high heat dissipation, the manufacturing cost of the backboard structure is reduced and the heat dissipation of the backboard structure is improved.

In one embodiment of the present invention, the particle size of the heat dissipation filler is 10 to 800 nm. That is, the particle size of the heat dissipation filler may be any one of 10 to 800nm, for example, 10nm, 20nm, 25nm, 50nm, 100nm, 150nm, 200nm, 300nm, 400nm, 500nm, 600nm, 700nm, 800nm, etc. This particle size range makes the heat dissipation filler in the heat dissipation layer (first heat dissipation layer, second heat dissipation layer) relatively dense.

In one embodiment of the invention, the heat dissipation filler is spherical, so that the prefabricated object of the heat dissipation layer has a better coating effect, and the heat dissipation effect of the heat dissipation layer is also ensured.

In one embodiment of the present invention, the reflective layer 102 is cured from a reflective coating preform. Wherein, the curing process can adopt a curing process such as heating calcination, photo-curing or thermal curing. The reflective layer 102 can be ensured to be well attached to the backplane body by curing the reflective coating preform.

In one embodiment of the present invention, the reflective coating preform may include: 1-30 parts of reflective filler, 10-70 parts of solvent, 5-40 parts of binder, 0.1-1 part of catalyst and 0.1-1 part of additive.

Wherein the particle size range of the reflective filler is 200-800 nm. Namely, the particle size of the reflective filler can be any value of 200-800 nm, so that the compactness of the reflective layer is ensured, and a better reflective effect is achieved.

The reflective filler is generally a material with a high refractive index (not less than 1.8), such as a white inorganic pigment, preferably one or more of lithopone, titanium dioxide, talc, white lead, mica, calcium carbonate, calcium sulfate, zinc oxide, antimony trioxide, magnesium oxide, magnesium carbonate, iron oxide, silicon dioxide, zirconium dioxide, barium sulfate and aluminum oxide.

Regardless of the heat dissipation coating prefabricated object or the reflection coating prefabricated object, the ductility of the prefabricated object (the heat dissipation coating prefabricated object or the reflection coating prefabricated object) can be effectively ensured by 10-70 parts of solvent, and the ductility of the prefabricated object (the heat dissipation coating prefabricated object or the reflection coating prefabricated object) in a coating process is facilitated. The adhesive can ensure the adhesion among the fillers (heat dissipation fillers or reflective fillers), thereby forming a compact heat dissipation layer or a compact reflective layer and meeting the heat dissipation or light reflection requirements. The 0.1-1 part of catalyst can accelerate and improve the bonding effect generated by the bonding agent, avoid the falling of the filler (heat dissipation filler or reflective filler) and ensure the stability of the heat dissipation layer or the reflective layer. 0.1-1 part of additive can eliminate bubbles generated in the process of preparing the first heat dissipation layer 103 and/or the second heat dissipation layer 105 as much as possible, and can ensure the casting smoothness of the first heat dissipation layer 103 and/or the second heat dissipation layer 105 in the coating process, so that the back plate is relatively smooth and attractive in structure.

Whether a thermal coating precursor or a reflective coating precursor, the solvents that comprise may include: any one or more of water, methanol solvent, ethanol solvent, propanol solvent and butanol solvent. On one hand, the solvent has higher volatility and lower cost, so that the preparation time of the heat dissipation layer and the reflecting layer can be effectively reduced, and the cost is lower.

Whether a thermal coating preform or a reflective coating preform, the binder that it comprises may include: one or more of tetraethyl silicate, sodium silicate, tetrabutyl titanate and zirconium oxychloride. In addition, the binder may be other organic or inorganic salts.

Whether a heat-sink coating precursor or a reflective coating precursor, comprises a catalyst comprising: one or more of citric acid, oxalic acid, acetic acid, hydrochloric acid, sulfuric acid and nitric acid. The catalyst may be other organic acids, other inorganic acids, or the like.

Whether a thermal coating preform or a reflective coating preform, the additives included may include: defoaming agent and leveling agent. Wherein the defoaming agent may include: silicone antifoam and/or polymer antifoam. The leveling agent may include: an organic silicon flatting agent and/or a polyester modified organic silicon flatting agent.

In one embodiment of the present invention, as shown in fig. 12, a first netted groove 1011 is disposed on one side of the back plate body 101 in the thickness direction. As shown in fig. 13, the first heat dissipation layer 103 and the reflective layer 102 are filled in the first mesh-shaped groove 1011. The filling in the first mesh-shaped groove 1011 may specifically be that the sum of the thicknesses of the first heat dissipation layer 103 and the reflection layer 102 is the same as the height of the first mesh-shaped groove 1011, or that the sum of the thicknesses of the first heat dissipation layer 103 and the reflection layer 102 is greater than the height of the first mesh-shaped groove 1011 (i.e., the reflection layer 102 protrudes out of the first mesh-shaped groove 1011), so that the first heat dissipation layer 103 and the reflection layer 102 can be better fixed on the back plate body through the first mesh-shaped groove, thereby facilitating the transportation of the back plate structure and avoiding the collision between the first heat dissipation layer 103 and the reflection layer 102.

In one embodiment of the present invention, as shown in FIG. 14, a second mesh-shaped groove 1012 is formed on one side of the backplate body 101 in the thickness direction, and a third mesh-shaped groove 1013 is formed on the other side of the backplate body 101 in the thickness direction, wherein the second mesh-shaped groove 1012 and the third mesh-shaped groove 1013 are disposed opposite to each other. As shown in fig. 15, the first heat dissipation layer 103 is filled in the third mesh-shaped groove 1013; the reflective layer 102 fills the second mesh-shaped groove 1012. Through the second net-shaped groove and the third net-shaped groove, the first heat dissipation layer 103 and the reflection layer 102 can be better fixed on the back plate body, the transportation of the back plate structure is facilitated, and the collision between the first heat dissipation layer 103 and the reflection layer 102 is avoided.

The arrangement of the first net-shaped groove or the second net-shaped groove and the third net-shaped groove can effectively increase the contact area between the first heat dissipation layer 103 and the reflection layer 102 and the back plate body, thereby ensuring the stability of the first heat dissipation layer 103 and the reflection layer 102.

In one embodiment of the present invention, as shown in fig. 16 and 17, one side in the thickness direction of the back plate body 101 is provided with a first stripe groove 1014. Accordingly, the second heat dissipation layer 105 fills the first stripe-shaped groove 1014 (not shown). Through the first stripe-shaped groove 1014, the contact area between the second heat dissipation layer 105 and the backplate body 101 can be increased, thereby effectively improving the stability of the second heat dissipation layer 105 and reducing the probability of damage to the backplate structure in the transportation process.

In addition to the first stripe groove design, as shown in fig. 18 and 19, a second stripe groove 1015 may be provided on the other side of the back plate body 101 in the thickness direction. Accordingly, the second heat dissipation layer 105 fills the second stripe-shaped groove 1015 (not shown). Through the second stripe-shaped groove 1015, the contact area between the second heat dissipation layer 105 and the backplane body 101 can be increased, so that the stability of the second heat dissipation layer 105 is effectively improved, and the probability of damage to the backplane structure in the transportation process is reduced. In addition, the second heat dissipation layer 105 positioned in the second stripe-shaped groove can be in contact with air, so that the second heat dissipation layer can transfer heat of the main grid on the back surface of the battery unit to the air, and the heat dissipation performance of the back plate structure is improved.

It should be noted that the surfaces of the various grooves (the first mesh-shaped groove, the second mesh-shaped groove, the third mesh-shaped groove, the first stripe-shaped groove, and the second stripe-shaped groove) may be in a zigzag shape as shown in fig. 30, which can increase the contact area, so as to further increase the friction and the adhesion between the reflective layer, the first heat sink layer, the second heat sink layer, and the back plate body, so that the reflective layer, the first heat sink layer, and the second heat sink layer can be more stably disposed on the back plate body.

Fig. 20-25 illustrate a photovoltaic module provided according to an embodiment of the present invention. Fig. 20 is a plan view (front view) of relative position relationship between the back sheet structure and a plurality of battery units after the back sheet structure provided in the above embodiments is applied to a photovoltaic module. FIG. 21 is a cross-sectional view of the back sheet structure of FIG. 3 applied to a photovoltaic module, showing the relative positions of the back sheet structure and a plurality of cells; FIG. 22 is a cross-sectional view of the back sheet structure of FIG. 4 applied to a photovoltaic module, showing the relative positions of the back sheet structure and a plurality of battery cells; FIG. 23 is a cross-sectional view of the back sheet structure of FIG. 13 applied to a photovoltaic module, showing the relative positions of the back sheet structure and a plurality of cells; fig. 25 is a cross-sectional view of the back sheet structure of fig. 15 applied to a photovoltaic module, showing the relative position relationship between the back sheet structure and a plurality of battery cells. Fig. 24 is a relative position relationship between the back sheet structure and a plurality of battery units after the back sheet structure of the variants of fig. 4 and 15 is applied to a photovoltaic module. As shown in fig. 20 to 25, the photovoltaic module may include: a plurality of battery cells 201 and the back plate structure provided in any of the above embodiments. Wherein a plurality of battery cells are arranged in an array at the side of the back plate structure where the reflective layer 102 is provided.

In the embodiment of the invention, for the photovoltaic module, the plurality of battery units 201 correspond to and overlap the reflective layer 102 and the hollow part 104 surrounded by the first heat dissipation layer 103 included in the back plate structure.

In embodiments of the invention, for photovoltaic assemblies, at least a portion of the reflective layer 102 and/or the first heat spreading layer 103 overlaps with the gap between adjacent cells.

In an embodiment of the invention, the reflective layer 102 and the first heat dissipation layer 103 are in communication with the battery cell for a photovoltaic module.

Wherein the reflective layer 102 may be positioned in a space between adjacent battery cells, and a portion of the reflective layer may be bonded to an edge of the battery cell 201 by a bonding layer.

The first heat dissipation layer can be in thermal communication with the battery unit, the thermal communication can be that the edge of the first heat dissipation layer is in direct contact with the battery unit, and the first heat dissipation layer and the battery unit are packaged through packaging materials. The thermal communication may also be such that the edge of the first heat sink layer is bonded to the battery cell by an adhesive layer (indirect contact, not shown). The thermal communication may also be the presence of a backplane body between the edge of the first heat spreading layer and the battery cell. No matter which kind of thermal communication, the battery unit based on high temperature directly or indirectly transmits heat to first heat dissipation layer to reach the purpose of cooling.

In summary, in the extending direction of the photovoltaic module, at least a portion of the reflective layer 102 and the first heat dissipation layer 103 of the back plate structure overlaps with the gap between the adjacent battery cells 201, and the hollow portion 104 surrounded by the reflective layer 102 and the hollow portion 104 surrounded by the first heat dissipation layer 103 overlap with the battery cells. That is, at least a portion of the reflective layer 102 and at least a portion of the first heat dissipation layer 103 extend along the gap between the adjacent battery cells, while the hollowed-out portions are disposed at the battery cells. Thus, in one aspect, light may be reflected at the reflective layer to re-reflect light to the battery cell, thereby increasing light absorption by the battery cell to enhance the photovoltaic performance of the battery cell/photovoltaic assembly. On the other hand, according to the heat conduction/heat transfer characteristics (high temperature to low temperature), the first heat dissipation layer 103 adjacent to the battery unit generating the hot spot effect can absorb the heat of the battery unit, and then conduct the heat away in a shape of "#" along the extension of the first heat dissipation layer 103, thereby achieving the purpose of cooling. In addition, for the back plate body made of glass or a light-permeable polymer material, the back plate body can allow light (such as reflected light, scattered light and the like from the ground) to pass through the hollow parts surrounded by the grid structures (the reflection layer and the first heat conduction layer) and transmit from the other side (the back surface) of the back plate body to one side (the front surface) of the back plate body so as to be received by the back surface of the battery unit, so that the influence on the illumination quantity of the back surface of the photovoltaic module is reduced.

The back generated energy of the photovoltaic module with double-sided power generation is ensured, the front generated energy of the photovoltaic module is improved, meanwhile, the heat at the hot spot of the photovoltaic module is conducted out in time, and the temperature of the photovoltaic cell forming the hot spot is restrained. Therefore, the stability of the photovoltaic module is improved while the power generation efficiency of the photovoltaic module is ensured.

In addition, due to the existence of the reflecting layer, the reflecting layer can block the first heat dissipation layer from absorbing light and transmit heat for the first heat dissipation layer, the first heat dissipation layer can select heat dissipation materials with good heat dissipation performance such as black and grey, the raw material selectivity of manufacturing the first heat dissipation layer is effectively enlarged, and meanwhile, heat dissipation materials with high heat dissipation performance and low cost and deep color can be selected. For example, any one or more of silicon carbide, aluminum nitride, boron carbide, graphite, and graphene is a highly heat-dissipating, low-cost, and deep-colored heat-dissipating material.

In addition, at least a portion of the reflective layer 102 and/or the first heat dissipation layer 103 overlaps with an edge of the battery cell. The reflection performance of the reflecting layer and the heat dissipation effect of the first heat dissipation layer can be further improved, so that the photoelectric performance, the operation stability and the safety of the photovoltaic module are further improved.

In the embodiment of the present invention, as exemplarily shown in fig. 26, the back sheet includes the second heat dissipation layer 105 corresponding to the battery cell 201 back surface main grid and in thermal communication with the battery cell 201 back surface main grid. Through the structure, the heat at the main grid can be quickly conducted out, and the cooling of the main grid on the back of the battery unit is realized, so that the melting phenomenon of local overheating on the soldering tin at the main grid can be reduced to the maximum extent. And because the second heat dissipation layer is overlapped with the main grid, the influence of shielding on the back power generation amount is reduced as much as possible.

In an embodiment of the present invention, as shown in fig. 27, the photovoltaic module may further include: a cover plate 202 and an encapsulation layer 203, wherein the encapsulation layer 203 is used for encapsulating the plurality of battery cells 201 between the cover plate 202 and the backplate structure.

In an embodiment of the present invention, as shown in fig. 28, this embodiment provides a method for preparing a backplane structure according to each of the above embodiments, where the method for preparing the backplane structure includes the following steps:

step S2801: respectively coating a reflection layer prefabricated object and a heat dissipation layer prefabricated object on the back plate body, wherein the reflection layer prefabricated object is coated on one side of the back plate body in the thickness direction, and the heat dissipation layer prefabricated object is coated below the reflection layer prefabricated object;

step S2802: and curing the reflection layer prefabricated object and the heat dissipation layer prefabricated object through a curing process to obtain the reflection layer and the first heat dissipation layer.

Wherein the reflective layer preform may include: 1-30 parts of reflective filler, 10-70 parts of solvent, 5-40 parts of binder, 0.1-1 part of catalyst and 0.1-1 part of additive. The particle size range of the reflective filler is 200-800 nm. Wherein, the heat dissipation coating prefabrication thing includes: 1-30 parts of heat dissipation filler, 10-70 parts of solvent, 5-40 parts of binder, 0.1-1 part of catalyst and 0.1-1 part of additive. The heat dissipation filler may include: any one or more of silicon carbide, aluminum nitride, boron carbide, graphite, and graphene. The particle size of the heat dissipation filler can be 10-800 nm. The reflecting layer prefabricated object and the heat dissipation coating prefabricated object comprise the selection of materials, the selection of the dosage and the size of various materials and the like.

Wherein the solvent included in the first heat dissipation layer, whether it is a reflective coating preform, may include: any one or more of water, methanol solvent, ethanol solvent, propanol solvent and butanol solvent; it should be noted that the water selected as the solvent may be tap water, industrial water, pure water of any grade of high purity, or the like. The solvent can comprise methanol solvent, ethanol solvent, propanol solvent, and butanol solvent with any percentage or purity. Namely, the methanol solvent, the ethanol solvent, the propanol solvent and the butanol solvent can be industrial pure, chemical pure, analytical pure, superior pure and the like. Preferably, any one or more of industrially pure methanol solvent, ethanol solvent, propanol solvent and butanol solvent is selected to reduce the cost of the back plate structure and the manufacturing cost thereof. The binder may include: one or more of tetraethyl silicate, sodium silicate, tetrabutyl titanate and zirconium oxychloride; the catalyst may include: one or more of citric acid, oxalic acid, acetic acid, hydrochloric acid, sulfuric acid and nitric acid; the catalyst can be selected from citric acid, oxalic acid, acetic acid, hydrochloric acid, sulfuric acid and nitric acid with any percentage content or purity. Namely, the citric acid, the oxalic acid, the acetic acid, the hydrochloric acid, the sulfuric acid and the nitric acid can be industrial pure, chemical pure, analytical pure, superior pure and the like. Preferably, any one or more of industrial pure citric acid, oxalic acid, acetic acid, hydrochloric acid, sulfuric acid, nitric acid is selected to reduce the cost of the back plate structure and the manufacturing cost thereof. For example, 30% by mass of industrial hydrochloric acid, 95% by mass of sulfuric acid, 60% by mass of nitric acid, and the like. The additives may include: defoaming agent and leveling agent; the defoaming agent may include: silicone antifoam and/or polymer antifoam; the leveling agent may include: an organic silicon flatting agent and/or a polyester modified organic silicon flatting agent.

In step S2801, the transparent glass or polymer back plate is coated with a coating method, such as screen printing, roll coating, or spray coating, according to a pre-designed layout. The prefabricated reflecting layer and the prefabricated heat dissipation layer used in the step S2801 can be obtained by placing all the raw materials in a reaction container according to the proportion and mechanically stirring for 1-12 hours.

In step S2802, a curing process such as heat calcination, photo-curing, or thermal curing may be used as the curing process. The curing temperature of the curing process is 0-800 ℃, and the heat preservation time is 1-10 min. The selection of the curing temperature and the heat preservation time can not only ensure the completion of curing, but also reduce the energy consumption as much as possible.

The thickness of the reflective layer obtained by the above steps is in the range of 1-1000 μm, i.e. the thickness of the reflective layer can be any value of 1-1000 μm, such as 1 μm, 10 μm, 30 μm, 60 μm, 90 μm, 100 μm, 300 μm, 450 μm, 550 μm, 650 μm, 750 μm, 850 μm, 950 μm, 1000 μm, etc. Because the reflecting layer is too thick and is easy to damage, the thickness range of the first heat dissipation layer is controlled within the range of 1-1000 mu m by the preparation method, so that the light reflection can be effectively improved, and the damage to the backboard structure in the transportation process of the backboard structure can be avoided as much as possible.

The first heat dissipation layer with the width range of 5-50 mm is obtained through the steps, the requirement for heat dissipation of the photovoltaic module can be met by preparing the first heat dissipation layer with the width range, and transition blocking of the first heat dissipation layer to the back of the battery unit can be avoided.

The reflecting layer with the width range of 5-50 mm is obtained through the steps, the requirement for reflecting light rays of the photovoltaic module can be met by preparing the reflecting layer with the width range, and transition blocking of the reflecting layer on the back face of the battery unit can be avoided.

The second heat dissipation layer with the thickness range of 1-100 mu m is obtained through the steps, and the second heat dissipation layer is arranged in the thickness range, so that the heat dissipation of the main grid on the back of the battery unit is improved, meanwhile, the use of heat dissipation materials can be reduced as far as possible, and the cost of the backboard structure is effectively controlled.

The second heat dissipation layer with the width range of 0.1-10 mm is obtained in the steps, and the second heat dissipation layer is arranged in the width range, so that the heat dissipation of the main grid on the back of the battery unit is improved, meanwhile, the influence on light absorption of the back of the battery unit can be reduced as far as possible, and the photoelectric performance of the double-sided photovoltaic module is guaranteed.

In an embodiment of the present invention, as shown in fig. 29, this embodiment provides a method for preparing a photovoltaic module according to each of the above embodiments, and the method for preparing a photovoltaic module may include the following steps:

step S2901: providing a backplane structure according to any of the above embodiments;

step S2902: the plurality of battery cells are arranged in an array and stacked on a side of the backsheet structure including the reflective layer such that at least a portion of the reflective layer and at least a portion of the first heat dissipation layer included in the backsheet structure overlap with a gap between adjacent battery cells in a thickness direction of the photovoltaic module.

In an embodiment of the present invention, a method of making a photovoltaic module can include the steps described in fig. 28 and 29.

Specific preparation processes of the back sheet structure, the photovoltaic module, and the like are specifically described below in each specific example.

Example 1

Adding 30g of silicon carbide ceramic particles into a solvent consisting of 35g of isopropanol and 15g of ethylene glycol, adding 20g of sodium silicate (binder) and 0.3g of hydrochloric acid (catalyst) with the mass fraction of 30%, mixing and stirring at room temperature for 6h, adding 0.3g of BYK-017 (antifoaming agent 017 produced by ByK in Germany) and 0.1g of BYK-307 (leveling agent 307 produced by ByK in Germany), and continuously stirring at room temperature for 12h to obtain a prefabricated product of the heat dissipation coating. And then adding 20g of zirconia ceramic particles into a solvent consisting of 45g of isopropanol and 5g of ethylene glycol, adding 10g of zirconium oxychloride, 15g of sodium silicate (binder) and 0.5g of hydrochloric acid (catalyst) with the mass fraction of 30%, mixing and stirring for 6h at room temperature, adding 0.5g of BYK-017 (antifoaming agent 017 produced by ByK in Germany) and 0.1g of BYK-307 (leveling agent 307 produced by ByK in Germany), and continuously stirring for 12h at room temperature to obtain a prefabricated reflective coating. Wherein, the silicon carbide and the zirconia are both spherical, and the average grain diameter is 500 nm. And sequentially coating the prepared prefabricated objects on the surface of the polymer back plate, which is in contact with the battery, according to the sequence of the prefabricated objects of the heat dissipation coating and the reflective coating by using a spraying method according to the designed grid shape, heating to 120 ℃, and preserving heat for 10min to form the coating with the heat dissipation and light reflection functions. In the obtained back plate structure, the first heat dissipation layer is 300 μm, and the reflection layer is 35 μm.

After the backboard structure is applied to the photovoltaic assembly, when hot spots of battery units in the photovoltaic assembly occur, heat is conducted and diffused to peripheral low-temperature batteries in a shape of '#' through the heat conduction layer with high heat conductivity coefficient, and therefore the temperature of the hot spot batteries is reduced. The reflection layer above the heat dissipation layer increases the refraction of sunlight on the front surface, and the power generation amount on the front surface is improved. The latticed double-coating does not shield the back of the double-sided battery assembly from light at the position without the coating, so that the generating capacity of the back of the assembly is ensured.

Example 2

Adding 20g of aluminum nitride and 30g of boron carbide ceramic particles into a solvent consisting of 40g of high-purity water and 1g of ethylene glycol, adding 10g of zirconium oxychloride, 15g of sodium silicate (binder) and 0.3g of hydrochloric acid (catalyst) with the mass fraction of 30%, mixing and stirring for 6h at room temperature, adding 0.3g of BYK-017 (antifoaming agent 017 produced by ByK, Germany) and 0.1g of BYK-307 (leveling agent 307 produced by ByK, Germany), and continuously stirring for 12h at room temperature to obtain a prefabricated product of the heat dissipation coating. Adding 15g of titanium oxide ceramic particles and 5g of silicon oxide ceramic particles into a solvent consisting of 50g of high-purity water and 5g of isopropanol, adding 23g of tetrabutyl titanate (binder) and 0.8g of citric acid (catalyst), mixing and stirring at room temperature for 8 hours, then adding 0.5g of BYK-014 (defoamer 014 produced by ByK Germany) and 0.1g of BYK-313 (leveling agent 313 produced by ByK Germany) and continuously stirring at room temperature for 12 hours to obtain a prefabricated product of the light-reflecting coating. Wherein the grain diameters of the silicon carbide, the aluminum nitride, the titanium oxide and the silicon oxide ceramic grains are all 500 nm. And (3) coating the heat dissipation coating prefabricated object on the surface of the glass back plate, which is in contact with air, and coating the light reflection coating prefabricated object on the surface of the glass back plate, which is in contact with the battery by adopting a roll coating method according to a designed grid shape. And then heating and calcining, heating to 550 ℃, and preserving heat for 3min to finally obtain the glass back plate with the heat dissipation and light reflection double coatings. In the obtained backboard structure, the first heat dissipation layer is arranged on the surface of the glass backboard, which is in contact with air, and the thickness of the first heat dissipation layer is 800 micrometers; the reflecting layer is arranged on the surface of the glass back plate, which is in contact with the battery, and the thickness of the reflecting layer is 30 mu m.

After the backboard structure is applied to the photovoltaic module, when hot spots of battery units in the photovoltaic module occur, the first heat dissipation layer of the air surface can spread the hot spots in a heat conduction mode at high temperature and then radiate flowing air, so that the temperature of the hot spots is effectively reduced. The reflecting layer on the surface of the battery refracts and reflects the sunlight on the front side and returns to the battery piece again through the reflection on the inner side of the front glass, so that the front power generation amount of the battery is effectively improved.

Example 3

Adding 50g of silicon carbide ceramic particles into a solvent consisting of 30g of high-purity water and 10g of ethylene glycol, adding 25g of sodium silicate (binder) and 0.3g of oxalic acid (catalyst), mixing and stirring at room temperature for 5 hours, adding 0.3g of BYK-017 (antifoaming agent 017 produced by ByK in Germany) and 0.1g of BYK-307 (leveling agent 307 produced by ByK in Germany), and continuously stirring at room temperature for 12 hours to obtain a prefabricated product of the heat dissipation coating. Adding 25g of titanium oxide ceramic particles and 5g of silicon oxide ceramic particles into a solvent consisting of 535 g of isopropanol and 15g of ethylene glycol, adding 20g of tetrabutyl titanate (binder), 0.3g of citric acid and 0.1g of oxalic acid (catalyst), mixing and stirring at room temperature for 8 hours, then adding 0.5g of BYK-014 (defoamer 014 produced by ByK, Germany) and 0.1g of BYK-313 (leveling agent 313 produced by ByK, Germany), and continuing stirring at room temperature for 12 hours to obtain a reflective coating preform. Wherein the grain diameters of the silicon carbide and titanium oxide ceramic grains are both 500 nm. And (3) coating the prefabricated object of the heat dissipation coating on the surface of the glass back plate, which is in contact with the battery, by adopting a screen printing method according to the designed grid mesh shape, wherein the prefabricated object of the heat dissipation coating is coated at the positions of the battery piece gaps, the battery string gaps and the main grids on the back surfaces of the battery pieces. And then coating the reflective coating prefabricated object on the heat dissipation coating prefabricated object except the main grid position. And then heating and calcining, heating to 600 ℃, and keeping the temperature for 2min to finally obtain the grid-shaped glass back plate with the heat dissipation and light reflection double coatings. Wherein the thickness of the first heat dissipation layer and the second heat dissipation layer is 80 μm, and the width of the second heat dissipation layer (namely the width of the main grid) is 0.3 mm; the reflecting layer is 20 μm thick on the surface of the glass back plate contacting the battery.

After the backboard structure is applied to the photovoltaic module, when hot spots of battery units in the photovoltaic module occur, the heat dissipation coating at the position of the main grid is overlapped with the main grid of the battery units, so that heat at the main grid can be quickly conducted out, and the melting phenomenon of local overheating on soldering tin at the main grid can be maximally reduced. And because the heat dissipation coating is overlapped with the main grid, the influence of shielding on the back generated energy is reduced as much as possible.

It should be noted that, in the above embodiments, the reflective coating preform and the heat dissipation coating preform are prepared by weighing. And calculating the volumes of the solvents, the catalysts, the defoaming agents, the flatting agents and the like according to the mass of the solvents, the catalysts, the defoaming agents, the flatting agents and the like, and preparing the prefabricated objects of the reflective coating and the heat dissipation coating by adopting a volume quantity obtaining mode.

In addition, the defoaming agent and the leveling agent of each of the above embodiments may be selected from other commercially available types or manufacturers of silicone leveling agents and/or polyester modified silicone leveling agents, and silicone defoaming agents and/or polymer defoaming agents, in addition to the defoaming agent and the leveling agent produced by BYK, germany.

The application provides the following technical scheme:

technical solution 1. a back sheet structure for a photovoltaic module, comprising: the backboard comprises a backboard body, a reflecting layer arranged on one side of the backboard body in the thickness direction, and a first heat dissipation layer arranged below the reflecting layer.

Technical solution 2. according to the back plate structure of technical solution 1, the first heat dissipation layer is disposed between the reflection layer and the back plate body.

Technical solution 3. according to the back plate structure of technical solution 1, one side of the reflective layer is used for bearing the battery unit;

the first heat dissipation layer is arranged on the other side of the backboard body in the thickness direction.

Technical solution 4. according to any one of the backplate structures of technical solutions 1 to 3, both the reflective layer and the first heat dissipation layer are of a mesh structure, and the reflective layer and the first heat dissipation layer are arranged correspondingly.

Technical solution 5. according to the back sheet structure of the technical solution 4, the hollow portion surrounded by the grid structure corresponds to the battery unit included in the photovoltaic module.

Technical solution 6. according to the technical solution 4, the back plate structure further includes: the second heat dissipation layer is in a strip shape;

the second heat dissipation layer is arranged on the hollow part and corresponds to the main grid on the back of the battery unit.

Technical solution 7. according to the back plate structure of technical solution 1, wherein a first mesh groove is provided on one side of the back plate body in the thickness direction;

the first heat dissipation layer and the reflection layer are filled in the first net-shaped groove.

Technical solution 8. according to the back plate structure of technical solution 1, wherein a second mesh-shaped groove is provided on one side of the back plate body in the thickness direction, and a third mesh-shaped groove is provided on the other side of the back plate body in the thickness direction;

the second reticular groove is opposite to the third reticular groove;

the first heat dissipation layer is filled in the third reticular groove;

the reflective layer is filled in the second mesh groove.

Technical solution 9. according to the back plate structure of technical solution 6, wherein a first bar-shaped groove is formed in one side of the back plate body in the thickness direction;

the second heat dissipation layer is filled in the first strip-shaped groove.

Technical solution 10. according to the back plate structure of technical solution 6, wherein a second stripe-shaped groove is provided on the other side of the back plate body in the thickness direction;

the second heat dissipation layer is filled in the second stripe-shaped groove.

Technical solution 11. the back plate structure according to any one of the technical solutions 1 to 3 and 8, wherein the thickness of the first heat dissipation layer is in a range of 1 to 1000 μm; and/or the presence of a gas in the gas,

the width range of the first heat dissipation layer is 5-50 mm.

Technical solution 12. the back plate structure according to any one of the technical solutions 6, 9 and 10, wherein the thickness of the second heat dissipation layer is in a range of 1 to 100 μm; and/or the presence of a gas in the gas,

the width range of the second heat dissipation layer is 0.1-10 mm.

Technical solution 13 the back plate structure according to any one of the technical solutions 6, 9 and 10, wherein the first heat dissipation layer and/or the second heat dissipation layer is obtained by curing a heat dissipation coating preform.

Technical solution 14 the back plate structure according to claim 6, wherein the first heat dissipation layer and the second heat dissipation layer are integrally formed.

Technical solution 15 the back plate structure according to claim 13, wherein the heat dissipation coating preform includes: 1-30 parts of heat dissipation filler, 10-70 parts of solvent, 5-40 parts of binder, 0.1-1 part of catalyst and 0.1-1 part of additive.

The invention according to claim 16 is the back plate structure according to claim 14, wherein the heat dissipation filler includes: any one or more of silicon carbide, aluminum nitride, boron carbide, graphite, and graphene.

Technical scheme 17. according to the back plate structure of technical scheme 15 or 16, the particle size range of the heat dissipation filler is 10-800 nm.

Claim 18. the back plate structure according to any one of claims 1, 7 and 8, wherein the reflective layer is obtained by curing a reflective coating preform.

Claim 19. the back plate structure of claim 18, wherein the reflective coating preform comprises: 1-30 parts of reflective filler, 10-70 parts of solvent, 5-40 parts of binder, 0.1-1 part of catalyst and 0.1-1 part of additive.

Technical scheme 20. according to the technical scheme 19, the back plate structure, wherein the particle size range of the reflective filler is 200-800 nm.

Claim 21. the back sheet structure of claim 15 or 19, wherein the solvent comprises: any one or more of water, methanol solvent, ethanol solvent, propanol solvent and butanol solvent.

Claim 22 the back plate structure of claim 15 or 19, wherein the adhesive comprises: one or more of tetraethyl silicate, sodium silicate, tetrabutyl titanate and zirconium oxychloride.

Technical solution 23 the back plate structure according to technical solution 15 or 19, wherein the catalyst includes: one or more of citric acid, oxalic acid, acetic acid, hydrochloric acid, sulfuric acid and nitric acid.

Claim 24. the back sheet structure of claim 15 or 19, wherein the additives comprise: defoaming agent and leveling agent.

Technical solution 25 the back plate structure according to claim 24, wherein the defoaming agent includes: silicone antifoam and/or polymer antifoam.

Technical solution 26 the back plate structure according to technical solution 25, wherein the leveling agent includes: an organic silicon flatting agent and/or a polyester modified organic silicon flatting agent.

Technical solution 27 a photovoltaic module, comprising: a plurality of battery cells and the backsheet construction of any one of claims 1 to 26 wherein,

the plurality of battery cells are arranged in an array on the side of the backplane structure on which the reflective layer is disposed.

The photovoltaic module according to claim 28, 27, wherein the plurality of battery cells correspond to and overlap a hollow portion surrounded by the reflective layer and the first heat dissipation layer included in the back sheet structure.

Claim 29 the photovoltaic module of claim 28, wherein at least a portion of the reflective layer and the first heat spreading layer overlap a gap between adjacent ones of the cells.

Claim 30 the photovoltaic module of claim 28 or 29, wherein at least a portion of the reflective layer and/or the first heat sink layer overlaps an edge of the adjacent cell.

Claim 31 the photovoltaic module of claim 28 or 29, wherein the reflective layer and the first heat sink layer are in communication with the battery cell.

The photovoltaic module of claim 32, wherein the backsheet structure includes a second heat spreader layer corresponding to and in thermal communication with the back side primary grid of the cell.

The photovoltaic module according to any one of claims 27 to 29 and 32, further comprising: a cover plate and a packaging layer,

the packaging layer is used for packaging the battery units between the cover plate and the back plate structure.

Technical solution 34 a method for manufacturing a back sheet structure according to any one of technical solutions 1 to 26, comprising the steps of:

respectively coating a reflection layer prefabricated object and a heat dissipation layer prefabricated object on a back plate body, wherein the reflection layer prefabricated object is coated on one side of the back plate body in the thickness direction, and the heat dissipation layer prefabricated object is coated below the reflection layer prefabricated object;

and curing the reflection layer prefabricated object and the heat dissipation layer prefabricated object through a curing process to obtain the reflection layer and the first heat dissipation layer.

Technical solution 35. a method for manufacturing a photovoltaic module according to any one of technical solutions 27 to 33, comprising the steps of:

providing a backplane structure according to any of claims 1 to 26; and

the plurality of battery cells are arranged in an array and stacked on one side of the back sheet structure including the reflective layer, the stacking being such that at least a portion of the reflective layer and at least a portion of the first heat dissipation layer included in the back sheet structure overlap with a gap between adjacent battery cells in a thickness direction of the photovoltaic module.

The above steps are provided only for helping to understand the structure, method and core idea of the present invention. It will be apparent to those skilled in the art that various changes and modifications can be made without departing from the principles of the invention, and these changes and modifications also fall within the scope of the appended claims.