Photovoltaic module

Abstract

Disclosed in the present application is a photovoltaic module, comprising a reflective structure and a cell string group, wherein the cell string group comprises a plurality of cells, and gaps are provided between the plurality of cells; the orthographic projection of the reflective structure on the cell string group covers at least the gaps between the plurality of cells; and the reflective structure comprises a first reflective layer close to the cells and a second reflective layer stacked with the first reflective layer, the first reflective layer is an organic material layer, and the second reflective layer is a metal layer. In the embodiments of the present application, infrared light that is incident on the gaps between the plurality of cells is reflected by the reflective structure, so that the infrared light re-irradiates the cells, enabling the cells to absorb the infrared light and convert same into electric energy, thereby increasing the generation power of the photovoltaic module.

Description

Photovoltaic module TECHNICAL FIELD

[0001] The present application relates to the field of photovoltaic technology, in particular to a photovoltaic module. BACKGROUND

[0002] In order to meet the requirements of users on the appearance of photovoltaic modules, it is usually necessary to make the photovoltaic modules black.

[0003] At present, the backboard of the black photovoltaic module is black, and ordinary black paint is used. However, the black backboard will absorb sunlight and generate heat, and compared with the white photovoltaic module, the power generation is lower, the reflectivity is lower, and the temperature of the module is higher. SUMMARY

[0004] The present application provides a photovoltaic module, which aims to solve the technical problems of the low power generation, low reflectivity and high temperature of the black photovoltaic module in the prior art.

[0005] The present application provides a photovoltaic module, which includes a light reflection structure and a cell string group, the cell string group includes a plurality of cell pieces, and the plurality of cell pieces have gaps therebetween, and the orthographic projection of the light reflection structure on the cell string group covers at least the gaps between the plurality of cell pieces.

[0006] The light reflection structure includes a first light reflection layer close to the cell pieces and a second light reflection layer stacked with the first light reflection layer, the first light reflection layer is an organic material layer, and the second light reflection layer is a metal layer.

[0007] Optionally, the reflectivity of the first light reflection layer to infrared light is greater than the reflectivity of the second light reflection layer to infrared light, and the first light reflection layer can transmit part of infrared light.

[0008] Optionally, the photovoltaic module further includes an insulating layer stacked with the plurality of cell pieces, the light reflection structure is arranged between the insulating layer and the cell pieces, and the first light reflection layer, the second light reflection layer and the insulating layer are sequentially stacked; or the light reflection structure is embedded in the insulating layer, and the first light reflection layer and the second light reflection layer are in contact and stacked.

[0009] Optionally, the photovoltaic module further includes an insulating layer stacked with the plurality of cell pieces, the first light reflection layer is located on a side of the insulating layer away from the cell pieces, and the insulating layer is provided with light transmission grooves corresponding to the gaps between the plurality of cell pieces.

[0010] Optionally, the material of the insulating layer is different from the material of the first light reflection layer.

[0011] Optionally, the insulating layer and the first light-reflecting layer are in an integrated structure, and the first light-reflecting layer is arranged at a position corresponding to the gap between the plurality of the battery pieces.

[0012] Optionally, the insulating layer comprises a slot corresponding to the gap between the plurality of the battery pieces, and the first light-reflecting layer is embedded in the slot of the insulating layer.

[0013] Optionally, the battery piece is a back contact battery piece.

[0014] Optionally, a metal interconnection layer is further included, and the plurality of the battery pieces are electrically connected through the metal interconnection layer.

[0015] Optionally, the second light-reflecting layer and the metal interconnection layer are arranged in the same layer, or the second light-reflecting layer is the metal interconnection layer.

[0016] Optionally, the metal interconnection layer comprises a plurality of conductive groups arranged in an array, each of the conductive groups comprises a plurality of metal conductive parts extending along a first direction and arranged at intervals along a second direction intersecting the first direction.

[0017] The metal interconnection layer further comprises an isolation gap for isolating two adjacent metal conductive parts in the same conductive group.

[0018] Optionally, the material of the first light-reflecting layer comprises black pigment.

[0019] Optionally, the battery string group comprises a plurality of battery strings arranged at intervals, each of the battery strings is formed by the battery pieces arranged at intervals along a first direction, and the gap between the plurality of the battery pieces comprises a piece gap between two adjacent battery pieces in the same battery string and a string gap between two adjacent battery strings.

[0020] In the embodiments of the present application, the first light-reflecting layer can transmit and reflect infrared light, the second light-reflecting layer can reflect infrared light, and the light-reflecting structure covers the gap between the plurality of the battery pieces. Therefore, the infrared light incident on the gap between the plurality of the battery pieces will be reflected by the light-reflecting structure, so that the infrared light is re-irradiated on the battery pieces, so that the battery pieces absorb and convert the infrared light into electric energy, thereby improving the power generation of the photovoltaic module. In addition, in addition to the second light-reflecting layer being able to reflect infrared light, the first light-reflecting layer can also reflect infrared light, thereby improving the reflection and utilization rate of infrared light by the photovoltaic module. In addition, the second light-reflecting layer is a metal layer, and the reflection effect of metal is good. In addition, the infrared light reflected by the light-reflecting structure will be absorbed by the battery pieces and converted into electric energy, thereby avoiding the temperature rise of the photovoltaic module due to the absorption of sunlight by the black back plate to generate heat, reducing the temperature of the photovoltaic module during power generation, thereby prolonging the service life of the photovoltaic module.

[0021] The above description is only a summary of the technical solutions of the present application. In order to make the technical means of the present application more clearly understood, the present application can be implemented according to the content of the description, and in order to make the above and other purposes, characteristics and advantages of the present application more obvious and easy to understand, the specific embodiments of the present application are described below. BRIEF DESCRIPTION OF DRAWINGS

[0022] Fig. 1 is a structural schematic diagram of a photovoltaic module provided by an embodiment of the present application;

[0023] Fig. 2 is a structural schematic diagram of a light reflection structure provided by an embodiment of the present application;

[0024] Fig. 3 is a structural schematic diagram of a light reflection structure provided by an embodiment of the present application;

[0025] Fig. 4 is a top view structural schematic diagram of a light reflection structure and a cell provided by an embodiment of the present application;

[0026] Fig. 5 is a structural schematic diagram of a photovoltaic module provided by an embodiment of the present application;

[0027] Fig. 6 is a structural schematic diagram of a photovoltaic module provided by an embodiment of the present application;

[0028] Fig. 7 is a structural schematic diagram of a photovoltaic module provided by an embodiment of the present application;

[0029] Fig. 8 is a structural schematic diagram of a cell, an insulating layer and a metal interconnection layer provided by an embodiment of the present application;

[0030] Fig. 9 is a structural schematic diagram of a metal interconnection layer provided by an embodiment of the present application;

[0031] Fig. 10 is a structural schematic diagram of an insulating layer provided by an embodiment of the present application;

[0032] Fig. 11 is a structural schematic diagram of an insulating layer and a first light reflection layer provided by an embodiment of the present application;

[0033] Fig. 12 is a structural schematic diagram of a cell, an insulating layer, a first light reflection layer and a metal interconnection layer provided by an embodiment of the present application;

[0034] Fig. 13 is a reflection principle schematic diagram of a light reflection structure in a photovoltaic module provided by an embodiment of the present application;

[0035] Fig. 14 is a reflection principle schematic diagram of the inside of a light reflection structure provided by an embodiment of the present application.

[0036] Fig. 1: 1 - light-reflecting structure, 11 - first light-reflecting layer, 12 - second light-reflecting layer, 13 - support layer, 2 - battery piece, 3 - insulating layer, 31 - opening, 32 - light-transmitting groove, 4 - metal interconnection layer, 41 - conductive group, 411 - metal conductive part, 42 - isolation gap, 5 - first adhesive film, 6 - back plate, 7 - second adhesive film, 8 - glass cover plate, 9 - inter-piece gap. DETAILED DESCRIPTION

[0037] Exemplary embodiments of the present application will be described in greater detail below with reference to the accompanying drawings. Although exemplary embodiments of the present application are shown in the drawings, it is understood that the present application can be implemented in various forms and should not be limited by the embodiments set forth herein. Rather, these embodiments are provided so that this application will be thoroughly and completely understood, and will fully convey the scope of the application to those skilled in the art.

[0038] Referring to FIGS. 1, 2, 5 to 7, the present application discloses a photovoltaic module, which includes a light-reflecting structure 1 and a battery string group, the battery string group including a plurality of battery pieces 2, the plurality of battery pieces 2 having gaps therebetween, and the light-reflecting structure 1 having a positive projection on the battery string group covering at least the gaps between the plurality of battery pieces 2; the light-reflecting structure 1 including a first light-reflecting layer 11 close to the battery pieces 2 and a second light-reflecting layer 12 laminated with the first light-reflecting layer 11, the first light-reflecting layer 11 being an organic material layer, and the second light-reflecting layer 12 being a metal layer, the first light-reflecting layer 11 being configured to transmit and reflect infrared light, and the second light-reflecting layer 12 being configured to reflect infrared light.

[0039] Specifically, the battery piece 2 includes a light-receiving surface and a back surface, and the light-receiving surface and the back surface of the battery piece 2 can both be provided with electrodes. The light-receiving surface of the battery piece 2 can not be provided with electrodes, and only the back surface of the battery piece 2 is provided with electrodes, in which case the battery piece 2 is a back contact (BC) battery piece. The battery piece 2 can specifically be a back contact battery of a PERC (Passivated Emitter and Rear Cell) battery, a TOPCon (Tunnel Oxide Passivating Contacts) battery, an HJT (Hetero-junction with Intrinsic Thin-layer) battery, or a hybrid back contact battery of any two or more of the above-mentioned batteries.

[0040] The battery pieces 2 in the photovoltaic module can be connected in series through interconnection strips to form a battery string. When the battery pieces 2 are back contact battery pieces, the battery pieces 2 can also be electrically connected through a conductive back plate. The light-reflecting structure 1 is preferably located below the plurality of battery pieces 2.

[0041] The photovoltaic module further comprises a second adhesive film 7 and a glass cover plate 8 laminated on the plurality of cell pieces 2. Referring to FIG. 13, the light reflection structure 1 is configured to reflect the infrared light incident to the gap between the plurality of cell pieces 2, and the infrared light reflected by the light reflection structure 1 is reflected again by the glass cover plate 8 to the light receiving surface of the cell piece 2, or the infrared light reflected by the light reflection structure 1 is received by the back surface of the cell piece 2, so that the cell piece 2 absorbs and converts the infrared light into electric energy, thereby improving the power generation of the photovoltaic module.

[0042] The cell string group comprises a plurality of cell strings spaced apart from each other, each of the cell strings being formed by the cell pieces 2 arranged in a first direction. In one embodiment, referring to FIG. 4, the gap between the plurality of cell pieces 2 comprises a piece gap 9 between two adjacent cell pieces 2 in the same cell string and a string gap between two adjacent cell strings. The width of the light reflection structure 1 corresponding to the piece gap 9 is greater than or equal to the width of the piece gap 9, and the width of the light reflection structure 1 corresponding to the string gap is greater than or equal to the width of the string gap.

[0043] In one embodiment, there can be an overlap between two adjacent cell pieces 2 in the same cell string, and in this case, the gap between the plurality of cell pieces 2 does not comprise the piece gap between the two adjacent cell pieces in the same cell string, but only comprises the string gap between the two adjacent cell strings.

[0044] The photovoltaic module further comprises a frame, and referring to FIG. 4, the light reflection structure 1 can also cover an edge gap between the plurality of cell pieces 2 and the inner edge of the frame. The width of the light reflection structure 1 corresponding to the edge gap is greater than or equal to the width of the edge gap.

[0045] Referring to FIGS. 1 and 2, in one embodiment, the second light reflection layer 12 can be integrally formed on the first light reflection layer 11, and in this case, the photovoltaic module can use a common back plate or a conductive back plate. The conductive back plate comprises an insulating layer 3, a metal interconnection layer 4, a first adhesive film 5 and a back plate 6. Referring to FIGS. 5 to 7, in one embodiment, the first light reflection layer 11 and the second light reflection layer 12 are in a split structure, and when the photovoltaic module uses a conductive back plate, the second light reflection layer 12 can be the metal interconnection layer 4 in the conductive back plate.

[0046] The material of the first light reflection layer 11 includes black pigment. The material of the first light reflection layer 11 can also include resin, or the material of the first light reflection layer 11 can also include water and water-based dispersant, or the material of the first light reflection layer 11 can also include solvent and oil-based dispersant. The black pigment can include at least one of perylene-3,4,9,10-tetracarboxamide derivative, inorganic chromium black series, and phthalocyanine series. When the material of the first light reflection layer 11 includes black pigment, the first light reflection layer 11 is black, and the first light reflection layer 11 is close to the plurality of battery pieces 2, so that the appearance of the photovoltaic module presents a uniform black color.

[0047] The second light reflection layer 12 is a metal layer, and the average reflectivity for the infrared wave band of 750-1100 nm is about 20% higher than that of the conventional white substrate layer. The material of the second light reflection layer 12 includes at least one of gold, silver, copper, and aluminum. Preferably, the material of the second light reflection layer 12 includes any one of gold, silver, copper, and aluminum. When the material of the second light reflection layer 12 is selected from the above materials, the reflection effect on infrared light is good.

[0048] The photovoltaic module can effectively convert solar energy of sunlight with a wavelength of 300-1200 nm into electrical energy. The sunlight with a wavelength of 720-2500 nm is near-infrared light. The first light reflection layer 11 is specifically used for transmitting and reflecting near-infrared light, and the second light reflection layer 12 is specifically used for reflecting near-infrared light. The reflectivity of the first light reflection layer 11 to infrared light is greater than that of the second light reflection layer 12 to infrared light, and the first light reflection layer 11 can transmit part of the infrared light.

[0049] In the embodiment of the present application, the first light reflection layer 11 can transmit and reflect infrared light, the second light reflection layer 12 can reflect infrared light, and the light reflection structure 1 covers the gap between the plurality of battery pieces 2. Therefore, the infrared light incident to the gap between the plurality of battery pieces 2 will be reflected by the light reflection structure 1, so that the infrared light is irradiated on the battery piece 2 again, so that the battery piece 2 absorbs and converts the infrared light into electrical energy, thereby improving the power generation of the photovoltaic module. In addition, referring to FIG. 14, in addition to the second light reflection layer 12 being able to reflect infrared light, the first light reflection layer 11 is also able to reflect infrared light, thereby improving the reflection and utilization of infrared light by the photovoltaic module. In addition, the second light reflection layer 12 is a metal layer, and the reflection effect of the metal is good. In addition, the infrared light reflected by the light reflection structure 1 will be absorbed by the battery piece 2 and converted into electrical energy, thereby avoiding the temperature rise of the photovoltaic module due to the absorption of sunlight by the black back plate to generate heat, reducing the temperature of the photovoltaic module during power generation, thereby prolonging the service life of the photovoltaic module.

[0050] Referring to FIGS. 6 and 7, the photovoltaic module provided by the embodiment of the present application further comprises an insulating layer 3 which is arranged in layers with the plurality of cell pieces 2, and the light reflection structure 1 is arranged between the insulating layer 3 and the cell pieces 2, and the first light reflection layer 11, the second light reflection layer 12 and the insulating layer 3 are arranged in layers in sequence; or the light reflection structure 1 is embedded in the insulating layer 3, and the first light reflection layer 11 and the second light reflection layer 12 are in contact and arranged in layers.

[0051] Specifically, the cell piece 2 comprises a plurality of main grid lines and a plurality of auxiliary grid lines, and the insulating layer 3 is used to separate the cell pieces 2 and the metal interconnection layer 4, so as to prevent the positive and negative poles of the cell pieces from being short-circuited. The color of the insulating layer 3 can be white, which has certain light reflection characteristics, so as to improve the utilization rate of part of light. The material of the insulating layer 3 can be set according to actual requirements, such as polyimide (PI), polyethylene naphthalate (PEN), polyethylene terephthalate (PET), polypropylene (PP), polyethylene foam plastic (EPE) and the like.

[0052] In FIG. 6, the thickness of the first light reflection layer 11 is less than or equal to the thickness of the insulating layer 3. Before lamination, the first light reflection layer 11, the second light reflection layer 12 and the insulating layer 3 are arranged in layers in sequence. After lamination, the first light reflection layer 11 is embedded in the insulating layer 3.

[0053] Referring to FIG. 7, when the first light reflection layer 11 is embedded in the insulating layer 3, the thickness of the first light reflection layer 11 is less than or equal to the thickness of the insulating layer 3. The bottom surface of the first light reflection layer 11 away from the cell piece is preferably flush with the bottom surface of the insulating layer 3 away from the cell piece. When the first light reflection layer 11 is embedded in the insulating layer 3, the height difference caused by the first light reflection layer 11 being located on one side of the insulating layer 3 can be avoided.

[0054] In an implementation manner, the first light reflection layer 11 can also cover the plurality of cell pieces 2, at this time, the insulating layer is not required to be arranged, and the first light reflection layer 11 also simultaneously plays an insulating role.

[0055] Referring to FIG. 5, the photovoltaic module provided by the embodiment of the present application further comprises an insulating layer 3 which is arranged in layers with the plurality of cell pieces 2, and the first light reflection layer 11 is located on one side of the insulating layer 3 away from the cell pieces 2, and the insulating layer 3 is provided with a light transmission groove 32 corresponding to the gap between the plurality of cell pieces 2.

[0056] The infrared light incident to the gap between the plurality of cell pieces 2 is irradiated on the first light reflection layer 11 through the light transmission groove 32. The width of the light transmission groove 32 is greater than or equal to the width of the gap between the plurality of cell pieces 2. Through the arrangement of the light transmission groove 32, the infrared light incident to the gap between the plurality of cell pieces 2 can be irradiated on the first light reflection layer 11.

[0057] The material of the insulating layer 3 is different from the material of the first light reflection layer 11.

[0058] Specifically, the material of the first light reflection layer 11 includes a pigment having infrared reflection and infrared transmission functions. The material of the first light reflection layer 11 can include at least one of perylene-3,4,9,10-tetracarboxamide derivatives, inorganic chromium black series, and phthalocyanine series. The material of the insulating layer 3 can be an insulating material, for example, polyimide (PI), polyethylene naphthalate (PEN), polyethylene terephthalate (PET), polypropylene (PP), polyethylene foam plastic (EPE), etc., without the need to have infrared reflection and infrared transmission functions, so as to save costs. The color of the insulating layer 3 is different from the color of the first light reflection layer 11, and the color of the insulating layer 3 can be white, and the color of the first light reflection layer 11 can be black.

[0059] Referring to FIG. 7, the insulating layer 3 and the first light reflection layer 11 are in an integrated structure, and the first light reflection layer 11 is arranged at a position corresponding to the gap between the plurality of cell pieces 2. When the insulating layer 3 and the first light reflection layer 11 are in an integrated structure, only one layer of the integrated insulating layer 3 and the first light reflection layer 11 needs to be laid during laying, without the need to lay the insulating layer 3 and the first light reflection layer 11 in sequence, so the process is simple.

[0060] The insulating layer 3 is provided with a slot 31 corresponding to the gap between the plurality of cell pieces 2, and the first light reflection layer 11 is embedded in the slot 31 of the insulating layer 3.

[0061] The width of the slot 31 is greater than or equal to the width of the gap between the plurality of cell pieces 2. It should be noted that the portion of the metal interconnection layer 4 corresponding to the slot 31 is preferably not subjected to a patterning process. The portion of the metal interconnection layer 4 corresponding to the slot 31 can also be subjected to a small amount of patterning.

[0062] The cell piece 2 is a back contact cell piece. The light receiving surface of the back contact cell piece is free of electrodes, and the positive and negative electrodes are arranged on the back surface of the cell piece, so as to reduce the shielding of the light receiving surface of the cell piece by the electrodes, increase the light receiving area of the light receiving surface of the cell piece, and improve the energy conversion efficiency of the cell piece.

[0063] Referring to FIGS. 1, 5 to 8, the photovoltaic module provided by the embodiment of the application further includes a metal interconnection layer 4, and the plurality of cell pieces 2 are electrically connected through the metal interconnection layer 4.

[0064] Specifically, different cell strings are connected in parallel through the metal interconnection layer 4, and the plurality of cell pieces 2 in the same cell string are connected in series through the metal interconnection layer 4. When the photovoltaic module adopts a conductive back plate, the conductive back plate includes the insulating layer 3, the metal interconnection layer 4, the first adhesive film 5, and the back plate 6. The insulating layer 3 is located below the cell piece 2, and the metal interconnection layer 4 is located below the insulating layer 3. The material of the metal interconnection layer 4 can be at least one of copper, silver, aluminum, nickel, magnesium, iron, titanium, molybdenum, and tungsten. The material of the metal interconnection layer 4 is preferably copper or aluminum.

[0065] The insulating layer 3 is located between the battery piece 2 and the metal interconnection layer 4, and a plurality of through holes can be formed in the insulating layer 3, and a conductive part is arranged in each through hole, and the battery piece 2 is electrically connected to the metal interconnection layer 4 through the conductive part. The conductive part can be conductive glue. The shape of the through hole can be circular or square.

[0066] In the embodiment of the present application, by arranging the metal interconnection layer 4 with low resistivity, compared with using a traditional interconnection strip, the series resistance of the back contact battery piece can be reduced, so as to reduce the ohmic loss of the photovoltaic module and improve the photoelectric conversion efficiency of the photovoltaic module.

[0067] When the metal interconnection layer 4 is arranged and the color of the insulating layer 3 is white, the infrared light at the back light surface of the battery piece 2 will also be reflected by the insulating layer 3 and the metal interconnection layer 4 to the back light surface of the battery piece 2, so as to be absorbed by the battery piece 2 and converted into electric energy.

[0068] The second light reflecting layer 12 and the metal interconnection layer 4 are arranged in the same layer, or referring to FIGS. 5 to 7, the second light reflecting layer 12 is the metal interconnection layer 4.

[0069] Specifically, when the second light reflecting layer 12 and the metal interconnection layer 4 are arranged in the same layer, the second light reflecting layer 12 is the part in the layer corresponding to the gap between the plurality of battery pieces 2, and the metal interconnection layer 4 is the part in the layer except the second light reflecting layer 12.

[0070] The metal interconnection layer 4 is a structure in the conductive back plate, which is beneficial to the metal interconnection layer 4 as the second light reflecting layer 12, so that the second light reflecting layer 12 does not need to be additionally arranged, and only the first light reflecting layer 11 needs to be arranged, thereby saving the cost.

[0071] Referring to FIG. 9, the metal interconnection layer 4 includes a plurality of conductive groups 41 arranged in an array, each conductive group 41 includes a plurality of metal conductive parts 411 extending along a first direction and arranged at intervals along a second direction intersecting the first direction, the first direction can refer to the direction shown by the A arrow in FIGS. 4, 9 and 12, and the second direction can refer to the direction shown by the B arrow in FIG. 9; and the metal interconnection layer 4 is further provided with isolation gaps 42 for separating adjacent two metal conductive parts 411 in the same conductive group 41.

[0072] The position of each conductive group 41 corresponds to the position of the battery piece 2. The structure of the insulating layer 3 can refer to FIG. 10, the position of the first light reflecting layer 11 relative to the insulating layer 3 can refer to FIG. 11, and the correspondence between the insulating layer 3 and the metal interconnection layer 4 can refer to FIG. 12, in which the conductive part arranged in the through hole in the insulating layer 3 is electrically connected to the metal conductive part 411 in the metal interconnection layer 4.

[0073] By the isolation gap 42, the positive and negative electrodes of the same battery piece 2 can be insulated from the electrical connection of the metal interconnection layer 4, and the adjacent positive and negative electrodes of the two adjacent battery strings can be insulated from the electrical connection of the metal interconnection layer 4.

[0074] Referring to FIG. 2, the first light reflection layer 11 is integrally formed on the second light reflection layer 12.

[0075] Specifically, the light reflection structure 1 is located on the side of the insulating layer 3 close to the battery piece 2. When the second light reflection layer 12 is integrally formed on the first light reflection layer 11, the reflectivity of the infrared waveband above 1050nm is higher.

[0076] When the material of the first light reflection layer 11 includes resin and black pigment, the first light reflection layer 11 can be obtained by means of curtain coating, flow casting, blow molding, etc., and the resin includes at least one of polyethylene, polypropylene, ethylene-propylene copolymer, ethylene-butene copolymer, ethylene-octene copolymer, ethylene-vinyl acetate copolymer, polyvinyl chloride, and chlorinated ethylene. Preferably, polyethylene: polypropylene: ethylene-butene copolymer = 1:0.1:0-1:1:1. When the material of the first light reflection layer 11 includes resin and black pigment, the thickness of the first light reflection layer 11 can be 10-200 microns. The thickness of the first light reflection layer 11 is preferably 35-60 microns.

[0077] When the material of the first light reflection layer 11 includes water, water-based dispersant and black pigment, the first light reflection layer 11 is arranged on the second light reflection layer 12 or the insulating layer 3 or the metal interconnection layer 4 by means of coating or printing. When the material of the first light reflection layer 11 includes water, water-based dispersant and black pigment, the thickness of the first light reflection layer 11 can be 0.1-20 microns. The thickness of the first light reflection layer 11 is preferably 3-10 microns.

[0078] The second light reflection layer 12 can be prepared by means of evaporation, coating, calendering, etc.

[0079] When the second light reflection layer 12 is prepared by means of evaporation or coating, the thickness of the second light reflection layer 12 can be 0.1-10 microns, and is preferably 0.3-1 micron. At this time, referring to FIG. 3, the light reflection structure 1 further includes a support layer 13 between the first light reflection layer 11 and the second light reflection layer 12. The support layer 13 has a certain stiffness, and the thickness of the support layer 13 can be 10-100 microns, and is preferably 15-35 microns. The material of the support layer 13 can include at least one of polyethylene terephthalate, polybutylene terephthalate, poly-1,4-cyclohexane dimethyl terephthalate, polycarbonate, polyamide, and polystyrene.

[0080] When the second light-reflecting layer 12 is prepared by a calendering process, the first light-reflecting layer 11 can be prepared on the second light-reflecting layer 12 by a coating process, a spraying process or the like. In this case, the first light-reflecting layer 11 comprises black pigments and resin, or water, a water-based dispersant and black pigments.

[0081] Referring to Table 1, Table 1 shows the near-infrared light reflectivity, surface temperature and power generation efficiency of photovoltaic modules corresponding to the light-reflecting schemes in different embodiments of the present application and prior art.

[0082] Table 1

[0083] In Table 1, the materials of the first light-reflecting layer 11, the second light-reflecting layer 12 and the support layer 13 are the materials shown in the foregoing. The white material used in the light-reflecting layer in prior art is rutile titanium dioxide. The surface temperature in Table 1 refers to the temperature after irradiation of a simulated sunlight source for 1 h. It should be noted that the photovoltaic module can be a non-standard version. A hot spot test box can be used to simulate the sunlight source, in which the light intensity can be 1000 W / m 2 .

[0084] Table 2 shows the near-infrared light reflectivity, surface temperature and power generation efficiency of photovoltaic modules corresponding to different photovoltaic modules in prior art.

[0085] Table 2

[0086] The surface temperature in Table 2 refers to the temperature after irradiation of a simulated sunlight source for 1 h. It should be noted that the photovoltaic module can be a non-standard version. A hot spot test box can be used to simulate the sunlight source, in which the light intensity can be 1000 W / m 2 .

[0087] In the embodiments of the present application, the light-reflecting structure 1 reflects the infrared light incident to the gaps between the plurality of cell pieces 2, the infrared light reflected by the light-reflecting structure 1 is reflected again by the glass cover plate 8 to the light-receiving surface of the cell piece 2, or the infrared light reflected by the light-reflecting structure 1 is received by the back light surface of the cell piece 2, so that the cell piece 2 absorbs and converts the infrared light into electric energy, thereby improving the power generation power of the photovoltaic module. Meanwhile, when the metal interconnection layer 4 is provided and the color of the insulating layer 3 is white, the infrared light at the back light surface of the cell piece 2 is also reflected by the insulating layer 3 and the metal interconnection layer 4 to the back light surface of the cell piece 2, so as to be absorbed and converted into electric energy by the cell piece 2.

[0088] It should be noted that, in this document, the terms "comprising", "comprises" or any other variation thereof are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but can also include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element preceded by "comprises a" does not, without more limitations, foreclose the existence of additional identical elements in the process, method, article, or apparatus that comprises the recited element.

[0089] The embodiments of the present application are described above with reference to the accompanying drawings, but the present application is not limited to the specific embodiments described above, which are merely illustrative and not restrictive, and a person of ordinary skill in the art can make many forms under the inspiration of the present application without departing from the purpose of the present application and the scope protected by the claims.

Claims

1. A photovoltaic module, comprising a light reflection structure and a cell string group, the cell string group comprising a plurality of cell pieces with gaps between the plurality of cell pieces, a normal projection of the light reflection structure on the cell string group covering at least the gaps between the plurality of cell pieces; the light reflection structure comprising a first light reflection layer close to the cell pieces and a second light reflection layer laminated with the first light reflection layer, the first light reflection layer being an organic material layer, and the second light reflection layer being a metal layer.

2. The photovoltaic module of claim 1, wherein, The reflectivity of the first light reflection layer to infrared light is greater than the reflectivity of the second light reflection layer to infrared light, and the first light reflection layer can transmit part of infrared light.

3. The photovoltaic module of claim 1, wherein, Further comprising an insulating layer laminated with the plurality of cell pieces, the light reflection structure being arranged between the insulating layer and the cell pieces, and the first light reflection layer, the second light reflection layer and the insulating layer being laminated in sequence; or the light reflection structure being embedded in the insulating layer, and the first light reflection layer and the second light reflection layer being in contact and laminated.

4. The photovoltaic module of claim 1, wherein, Further comprising an insulating layer laminated with the plurality of cell pieces, the first light reflection layer being located on a side of the insulating layer away from the cell pieces, and the insulating layer being provided with light transmission grooves corresponding to the gaps between the plurality of cell pieces.

5. The photovoltaic module of claim 3 or 4, wherein, The material of the insulating layer is different from the material of the first light reflection layer.

6. The photovoltaic assembly of claim 3, wherein, The insulating layer and the first light reflection layer are an integral structure, and the first light reflection layer is arranged at a position corresponding to the gaps between the plurality of cell pieces.

7. The photovoltaic module of claim 3, wherein, The insulating layer comprises grooves corresponding to the gaps between the plurality of cell pieces, and the first light reflection layer is embedded in the grooves of the insulating layer.

8. The photovoltaic module of claim 1, wherein, The cell pieces are back contact cell pieces.

9. The photovoltaic module of claim 8, wherein, Further comprising a metal interconnection layer, and the plurality of cell pieces are electrically connected through the metal interconnection layer.

10. The photovoltaic module of claim 9, wherein, The second light reflection layer and the metal interconnection layer are arranged in the same layer, or the second light reflection layer is the metal interconnection layer.

11. The photovoltaic module of claim 9, wherein, The metal interconnection layer comprises a plurality of arrayed conductive groups, each of the conductive groups comprising a plurality of metal conductive parts extending along a first direction and spaced apart along a second direction intersecting the first direction. The metal interconnection layer is further provided with isolation gaps for isolating adjacent two metal conductive parts in the same conductive group.

12. The photovoltaic module of claim 1, wherein, The material of the first light reflection layer comprises black pigment.

13. The photovoltaic module of claim 1, wherein, The cell string group comprises a plurality of spaced-apart cell strings, each of the cell strings being formed by the cell pieces spaced apart along a first direction, and the gaps between the plurality of cell pieces comprising piece gaps between adjacent two cell pieces in the same cell string and string gaps between adjacent two cell strings.

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