阅读说明：本技术 背板以及光伏组件 (Backboard and photovoltaic module ) 是由 杨志强 宫欣欣 郭志球 于 2021-07-28 设计创作，主要内容包括：本发明实施例提供一种背板以及光伏组件,背板包括：具有承载面的背板本体；第一反光结构位于承载面,第一反光结构远离承载面的顶面为反射面,反射面用于使入射至反射面的光线向远离承载面的方向发生漫反射；第二反光结构位于承载面,第二反光结构位于第一反光结构宽度方向的至少一侧,第二反光结构包括凸起结构,凸起结构背对第一反光结构的侧面为第一侧面,第一侧面为平面或弧形面,且第一侧面朝向靠近第一反光结构的方向倾斜。本发明实施例有利于提高背板将入射至背板上的光线反射至电池片上的概率,以提高电池片对光线的利用率。(The embodiment of the invention provides a backboard and a photovoltaic module, wherein the backboard comprises: a back plate body with a bearing surface; the first light reflecting structure is positioned on the bearing surface, the top surface of the first light reflecting structure, which is far away from the bearing surface, is a reflecting surface, and the reflecting surface is used for enabling light rays incident to the reflecting surface to generate diffuse reflection in the direction far away from the bearing surface; the second light reflecting structure is located on the bearing surface and located on at least one side of the width direction of the first light reflecting structure, the second light reflecting structure comprises a protruding structure, the side, back to the first light reflecting structure, of the protruding structure is a first side face, the first side face is a plane or an arc face, and the first side face inclines towards the direction close to the first light reflecting structure. The embodiment of the invention is beneficial to improving the probability that the backboard reflects the light rays incident on the backboard to the battery piece so as to improve the utilization rate of the battery piece to the light rays.)

1. A backing sheet, comprising:

the back plate body is provided with a bearing surface;

the first light reflecting structure is positioned on the bearing surface, the top surface of the first light reflecting structure, which is far away from the bearing surface, is a reflecting surface, and the reflecting surface is used for enabling light rays incident to the reflecting surface to generate diffuse reflection in the direction far away from the bearing surface;

the second light reflecting structure is located on the bearing surface, the second light reflecting structure is located on at least one side of the width direction of the first light reflecting structure, the second light reflecting structure comprises a protruding structure, the protruding structure faces away from the side face of the first light reflecting structure, the first side face is a plane or an arc-shaped face, and the first side face is close to the direction inclination of the first light reflecting structure.

2. The backing plate of claim 1 wherein the first side surface is planar and the angle between the first side surface and the bearing surface is from 30 ° to 45 °; or the first side surface is an arc-shaped surface and is concave towards the direction close to the first light reflecting structure.

3. The backing sheet of claim 1 wherein the surface of the first side is provided with a saw tooth structure.

4. The backing sheet of claim 1 wherein the number of raised structures is at least two, each raised structure being arranged in a sequence in a direction along the first light reflecting structure toward the second light reflecting structure, and adjacent raised structures having a sequentially decreasing thickness in a direction perpendicular to the bearing surface.

5. The backing plate of claim 1 wherein the angles between the lateral surfaces on both sides of the width direction of the reflecting surface and the supporting surface are less than or equal to 90 °.

6. The backplate of claim 5, wherein the reflective surface is parallel to the bearing surface, and the lateral surfaces of the reflective surface on both sides in the width direction are perpendicular to the bearing surface.

7. The backing sheet of claim 1 wherein the thickness of the first light reflecting structures is not less than the thickness of the second light reflecting structures in a direction perpendicular to the carrying surface.

8. The backsheet according to claim 1, wherein a ratio of a bottom width of the first light reflecting structure to a bottom width of the second light reflecting structure in a direction in which the second light reflecting structure is directed toward the first light reflecting structure is 0.8 to 1.2.

9. The backing sheet of claim 1 further comprising a pyramidal structure on the carrying surface on a side of the second light reflecting structure facing away from the first light reflecting structure.

10. The backing plate of claim 9 wherein the angle between the sides of the pyramidal structures and the carrying surface is from 15 ° to 45 °.

11. The backsheet of claim 1, wherein the backsheet body comprises a fluorine film and a PET film in a laminated arrangement, and wherein the first light reflecting structure and the second light reflecting structure are both print-coated on the carrying surface of the PET film on a side thereof opposite to the fluorine film.

12. The backsheet of claim 1, wherein the material of the first and second light reflecting structures is a mixture of tetrafluoroethylene, titanium dioxide, epoxy resin, light stabilizer, and silane coupling agent, or a mixture of polyvinylidene fluoride, titanium dioxide, epoxy resin, light stabilizer, and silane coupling agent.

13. The backsheet of claim 1, wherein the reflectivity of the first light reflecting structure and the reflectivity of the second light reflecting structure are each greater than the reflectivity of the backsheet body.

14. The backing plate of claim 1 wherein the reflective surface has a roughness Ra of greater than or equal to 5.

15. A photovoltaic module, comprising:

the backing sheet of any one of claims 1 to 14;

the apron and be located the apron with a plurality of battery pieces between the backplate body, the battery piece has directional plain noodles and shady face, and is adjacent have the clearance between the battery piece, first reflection of light structure with second reflection of light structure locates clearance and extending direction with the extending direction in clearance is unanimous.

16. The photovoltaic module of claim 15 wherein an orthographic projection of the first light reflecting structure on the load-supporting surface lies in an orthographic projection of the gap on the load-supporting surface, and an orthographic projection of the second light reflecting structure on the load-supporting surface at least partially overlaps the orthographic projection of the gap on the load-supporting surface.

17. The photovoltaic device of claim 15, wherein the back-light surface has a spacing from the support surface, and wherein a thickness of the first light reflecting structure and a thickness of the second light reflecting structure in a direction perpendicular to the support surface are each not greater than a thickness of the spacing.

18. The photovoltaic module of claim 17, wherein the first light reflecting structure has a thickness of 5um to 20um, and the second light reflecting structure has a thickness not greater than the thickness of the first light reflecting structure.

19. The photovoltaic module according to claim 15, wherein the back-light surface has a space with the carrying surface, and the thickness of the first light reflecting structure and the thickness of the second light reflecting structure in a direction perpendicular to the carrying surface are respectively 2 to 3 times of the thickness of the space.

20. The photovoltaic module of claim 19, wherein the first light reflecting structure and the second light reflecting structure have a thickness equal to each other, ranging from 200um to 3000 um.

21. The pv module according to claim 15 wherein a plurality of said cells are serially connected in a first direction to form a string, at least two of said strings are serially arranged in a second direction intersecting said first direction, a first gap is formed between adjacent strings, said first gap extends along said first direction, and said extending direction of said first reflector and said extending direction of said second reflector are the same as the extending direction of said first gap.

22. The photovoltaic module of claim 21, wherein at least two of the cell strings are further arranged in sequence along the first direction, the cells of adjacent cell strings have a second gap therebetween, the second gap extends along the second direction, and the first and second light reflecting structures further extend along the second direction.

Technical Field

The embodiment of the invention relates to the technical field of solar cells, in particular to a back plate and a photovoltaic module.

Background

With the obvious problems of energy shortage, global temperature rise, increasingly worsened environment and the like, solar energy is receiving more and more attention as a green renewable energy source. A photovoltaic module is a device that converts renewable solar energy into electrical energy.

The generated power of a cell in the photovoltaic module is an important index for measuring the performance of the photovoltaic module, and the utilization efficiency of the photovoltaic module on the light energy is directly reflected. Specifically, the high generated power is beneficial to reducing the cost in the manufacturing process of the photovoltaic module, and under the condition that the generated power of the photovoltaic module is the same, the higher the generated power of the cell is, the smaller the size of the photovoltaic module is, and the lower the weight of the corresponding photovoltaic module is.

However, the probability that the back plate reflects the light incident on the back plate onto the cell in the photovoltaic module is low, which affects the utilization rate of the cell in the photovoltaic module to the light, thereby affecting the power generation power of the cell.

Disclosure of Invention

The technical problem solved by the embodiment of the invention is to provide the back plate and the photovoltaic module, which are beneficial to reflecting the light incident on the back plate to the cell by the back plate so as to ensure the utilization rate of the photovoltaic module to the light and the power generation power.

To solve the above problem, an embodiment of the present invention provides a backplane, including: the back plate body is provided with a bearing surface; the first light reflecting structure is positioned on the bearing surface, the top surface of the first light reflecting structure, which is far away from the bearing surface, is a reflecting surface, and the reflecting surface is used for enabling light rays incident to the reflecting surface to generate diffuse reflection; the second light reflecting structure is located on the bearing surface, the second light reflecting structure is located on at least one side of the width direction of the first light reflecting structure, the second light reflecting structure comprises a protruding structure, the protruding structure faces away from the side face of the first light reflecting structure, the first side face is a plane or an arc-shaped face, and the first side face is close to the direction inclination of the first light reflecting structure.

In addition, the first side surface is a plane, and an included angle between the first side surface and the bearing surface is 30-45 degrees; or the first side surface is an arc-shaped surface and is concave towards the direction close to the first light reflecting structure.

In addition, the first side surface is provided with a sawtooth structure.

In addition, the number of the protruding structures is at least two, the protruding structures are sequentially arranged in the direction of pointing to the second light reflecting structure along the first light reflecting structure, and the thicknesses of the adjacent protruding structures in the direction perpendicular to the bearing surface are sequentially reduced.

In addition, the included angle between the side surfaces at two sides of the reflecting surface in the width direction and the bearing surface is less than or equal to 90 degrees.

In addition, the reflecting surface is parallel to the bearing surface, and the side surfaces on two sides of the reflecting surface in the width direction are vertical to the bearing surface.

In addition, in the direction perpendicular to the bearing surface, the thickness of the first light reflecting structure is not less than that of the second light reflecting structure.

In addition, in the direction that the second light reflecting structure points to the first light reflecting structure, the ratio of the bottom width of the first light reflecting structure to the bottom width of the second light reflecting structure is 0.8-1.2.

In addition, the back sheet further comprises: the pyramid structure is positioned on the bearing surface, the pyramid structure is positioned on one side, back to the first light reflecting structure, of the second light reflecting structure, and the pyramid structure is used for reflecting light rays incident to the pyramid structure to form third reflected light rays, and the third reflected light rays are transmitted towards a direction far away from the pyramid structure and far away from the bearing surface.

In addition, the degree of an acute angle formed between the side surface of the pyramid structure and the bearing surface is 15-45 degrees.

In addition, the backplate body is including range upon range of fluorine membrane and the PET membrane that sets up, first reflection of light structure with the equal printing of second reflection of light structure is scribbled the PET membrane back to fluorine membrane one side on the bearing surface.

In addition, the first reflective structure and the second reflective structure are made of a mixture of tetrafluoroethylene, titanium dioxide, epoxy resin, a light stabilizer and a silane coupling agent, or a mixture of polyvinylidene fluoride, titanium dioxide, epoxy resin, a light stabilizer and a silane coupling agent

In addition, the reflectivity of the first light reflecting structure and the reflectivity of the second light reflecting structure are both larger than the reflectivity of the backboard body.

The surface roughness Ra of the reflecting surface is 50 or more.

Correspondingly, the embodiment of the invention also provides a photovoltaic module, which comprises: the backing sheet of any of the above; the cover plate and the plurality of battery pieces positioned between the cover plate and the backboard body are provided, the battery pieces are provided with opposite light facing surfaces and backlight surfaces, a gap is reserved between the adjacent battery pieces, and the first light reflecting structure is arranged in the gap and the extending direction of the first light reflecting structure is consistent with the extending direction of the gap.

In addition, the orthographic projection of the first light reflecting structure on the bearing surface is positioned in the orthographic projection of the gap on the bearing surface, and the orthographic projection of the second light reflecting structure on the bearing surface is at least partially overlapped with the orthographic projection of the gap on the bearing surface.

In addition, a gap is formed between the backlight surface and the bearing surface, and in the direction perpendicular to the bearing surface, the thickness of the first light reflecting structure and the thickness of the second light reflecting structure are not greater than the thickness of the gap. .

In addition, the thickness of first reflective structure is 5um ~ 20um, just the thickness of second reflective structure is not more than the thickness of first reflective structure.

In addition, an interval is arranged between the backlight surface and the bearing surface, and in the direction perpendicular to the bearing surface, the thickness of the first light reflecting structure and the thickness of the second light reflecting structure are respectively 2-3 times of the thickness of the interval.

In addition, the thickness of first reflection of light structure with the thickness of second reflection of light structure equals, is 200um ~ 3000um respectively.

In addition, it is a plurality of the battery piece is followed first direction concatenates in proper order and constitutes the battery cluster, at least two the battery cluster along with the crossing second direction in first direction arranges in proper order, and is adjacent have first clearance between the battery cluster, first clearance extends along first direction, just first reflection of light structure extend direction the extend direction of second reflection of light structure with the extend direction in first clearance is unanimous.

In addition, at least two the battery cluster still follows first direction is arranged in proper order, and is adjacent the battery cluster have the second clearance between the battery piece, the second clearance is followed the second direction extends, just first light reflecting structure with second light reflecting structure still follows the second direction extends.

Compared with the related art, the technical scheme provided by the embodiment of the invention has the following advantages:

among the above-mentioned technical scheme, set up first reflection of light structure and second reflection of light structure on the loading face of backplate body, the plane of reflection of first reflection of light structure is used for making the light of incidenting to the plane of reflection take place the diffuse reflection in order to form first reflection of light, second reflection of light structure includes protruding structure, the side that protruding structure back to first reflection of light structure is first side, first side is plane or arcwall face, and first side orientation is close to the direction slope of first reflection of light structure, consequently the contained angle towards first reflection of light structure between the tangent plane of any point on the first side and the loading face is the acute angle, make the light of incidenting to first side take place to reflect in order to form second reflection of light, and the direction propagation of first reflection of light structure is kept away from to the second reflection of light orientation.

When the back plate is applied to a photovoltaic module with at least two adjacent battery pieces with gaps, the first light reflecting structure and the second light reflecting structure can act together, on one hand, more light rays incident into the gaps of the adjacent battery pieces are reflected onto the battery pieces through the first light reflecting structure and the second light reflecting structure, and the probability that the back plate reflects the light rays incident onto the back plate onto the battery pieces is improved; on the other hand, compare in level and smooth backplate body, have the first reflection of light structure and the second reflection of light structure of certain thickness, be favorable to reducing the length of the light reflection to the propagation path on the battery piece in the adjacent battery piece clearance of incidenting to improve the light intensity of battery piece received light, both are favorable to improving the utilization ratio of battery piece to light, thereby improve the generating power of battery piece.

In addition, the reflectivity of the first light reflecting structure and the reflectivity of the second light reflecting structure are both larger than the reflectivity of the backboard body, so that the first light reflecting structure and the second light reflecting structure are favorable for ensuring high reflectivity of light rays incident into the gap between the adjacent battery pieces, the probability that the light rays incident into the gap between the adjacent battery pieces are reflected onto the battery pieces through the first light reflecting structure and the second light reflecting structure is further improved, the utilization rate of the battery pieces to the light rays is further improved, and the power generation power of the battery pieces is further improved.

Drawings

One or more embodiments are illustrated by corresponding figures in the drawings, which are not to scale unless specifically noted.

Fig. 1 is a schematic top view of a back plate and a battery piece according to an embodiment of the invention;

FIG. 2 is a schematic cross-sectional view taken along the Y-direction in FIG. 1;

fig. 3 to 11 are schematic views of 9 corresponding partial cross-sectional structures of a back plate and a battery piece according to an embodiment of the invention;

fig. 12 to 14 are schematic views of 3 partial cross-sectional structures of a photovoltaic module according to another embodiment of the present invention;

fig. 15 and 16 are schematic diagrams of 2 top-view structures of a battery string according to another embodiment of the present invention.

Detailed Description

As known from the background art, the probability of reflecting the light incident on the back plate onto the cell needs to be improved, and both the utilization rate of the cell to the light and the power generation power of the cell need to be improved.

The analysis shows that the glaze layer on the surface of the conventional grid back plate is a flat and smooth coating, light rays incident into the gap between adjacent battery pieces are mainly reflected to the glass cover plate positioned above the battery pieces through the grid back plate, then the light rays are reflected to the light facing surface of the battery pieces through the glass cover plate, and the light rays reflected to the backlight surface of the battery pieces through the grid back plate are few and have low probability. In addition, in the conventional grid back plate, an inner-layer bonding layer is arranged between the back plate body and the grid layer, so that the grid back plate is made of more component materials and is higher in preparation cost.

In order to solve the above problems, an embodiment of the present invention provides a back plate, where a first reflective structure and a second reflective structure are disposed on a carrying surface of a back plate body, where a reflective surface of the first reflective structure is used to diffuse light incident on the reflective surface to form a first reflected light, the second reflective structure includes a protrusion structure, a side of the protrusion structure facing away from the first reflective structure is a first side, the first side is a plane or an arc, and the first side is inclined toward a direction close to the first reflective structure, so that an included angle between a tangent plane of any point on the first side and the carrying surface toward the first reflective structure is an acute angle, and the second reflective structure can be used to reflect light incident on the first side to form a second reflected light, and the second reflected light is transmitted toward a direction away from the first reflective structure. When the back plate is applied to a photovoltaic module with at least two adjacent battery pieces with gaps, the first light reflecting structure and the second light reflecting structure can act together, on one hand, more light rays incident into the gaps of the adjacent battery pieces are reflected onto the battery pieces through the first light reflecting structure and the second light reflecting structure, and the probability that the back plate reflects the light rays incident onto the back plate onto the battery pieces is improved; on the other hand, compare in level and smooth backplate body, have the first reflection of light structure and the second reflection of light structure of certain thickness, be favorable to reducing the length of the light reflection to the propagation path on the battery piece in the adjacent battery piece clearance of incidenting to improve the light intensity of battery piece received light, both are favorable to improving the utilization ratio of battery piece to light, thereby improve the generating power of battery piece.

In order to make the objects, technical solutions and advantages of the embodiments of the present invention more apparent, the embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, it will be appreciated by those of ordinary skill in the art that in various embodiments of the invention, numerous technical details are set forth in order to provide a better understanding of the present application. However, the technical solution claimed in the present application can be implemented without these technical details and various changes and modifications based on the following embodiments.

The present invention provides a back plate, which will be described in detail below with reference to the accompanying drawings. Fig. 1 to 11 are schematic structural diagrams of a back plate and a battery piece according to an embodiment of the invention.

Referring to fig. 1 and 2 in combination, the back plate 100 includes: a back plate body 110, wherein the back plate body 110 has a bearing surface c; the first light reflecting structure 120 is located on the bearing surface c, the top surface of the first light reflecting structure 120 away from the bearing surface c is a reflecting surface f, and the reflecting surface f is used for enabling light rays incident to the reflecting surface f to generate diffuse reflection; the second light reflecting structure 130 is located on the bearing surface c, the second light reflecting structure 130 is located on at least one side of the width direction Y of the first light reflecting structure 120, the second light reflecting structure 130 includes a protruding structure 140, a side of the protruding structure 140 opposite to the first light reflecting structure 120 is a first side surface d, the first side surface d is a plane or an arc surface, and the first side surface d is inclined toward a direction close to the first light reflecting structure 120.

The first light reflecting structure 120 has an extending direction X and a width direction Y perpendicular to the extending direction X, the first side surface d of the second light reflecting structure 130 is inclined toward a direction close to the first light reflecting structure 120, an included angle between a tangent plane of any point on the first side surface d and the bearing surface c toward the first light reflecting structure 120 is an acute angle, and when the light incident to the first side surface d is reflected to form a second reflected light, the second reflected light is favorably transmitted toward a direction away from the first light reflecting structure 120.

In some embodiments, the back sheet 100 can be applied to a photovoltaic module having at least two adjacent cells 101 with a gap I, where the cells 101 have opposite light-facing surfaces a and back-light surfaces b, and the bearing surface c is a surface of the back sheet body 110 facing the cells 101; the extending direction X of the first light reflecting structure 120 is consistent with the extending direction of the gap I, and the orthographic projection of the first light reflecting structure 120 on the bearing surface c is located in the orthographic projection of the gap I on the bearing surface c, so that the first reflected light is transmitted to the light facing surface a; and a second light reflecting structure 130 for transmitting the second reflected light to the light facing surface a or the backlight surface b.

In fig. 1 and 2, two adjacent battery pieces 101 with a gap I are taken as an example, and in practical application, a plurality of battery pieces 101 spaced from each other may be arranged in sequence along the width direction Y.

In some embodiments, on the carrying surface c opposite to the gap I of the adjacent battery piece 101, the second light reflecting structures 130 are located on two sides of the first light reflecting structure 120 in the width direction Y, the width direction Y is a direction in which the first light reflecting structure 120 points to the second light reflecting structure 130, the extending direction X is a direction intersecting with the width direction Y, and in one example, the extending direction X is perpendicular to the width direction Y.

Further, for the battery piece 101 located in the edge region, that is, one side of the battery piece 101 along the width direction Y does not have another battery piece 101 adjacent to the one side of the battery piece 101, the second light reflecting structure 130 may be located only on one side of the first light reflecting structure 120 along the width direction Y, and the second light reflecting structure 130 is located on one side of the first light reflecting structure 120 close to the battery piece 101, which is favorable for sufficiently reflecting the light not directly irradiated on the battery piece 101 to the battery piece 101 through the first light reflecting structure 120 and the second light reflecting structure 130, so as to improve the probability that the light not directly irradiated on the battery piece 101 is reflected to the battery piece 101, and thus improve the utilization rate of the battery piece 101 for the light.

In other embodiments, for a single battery piece, the second light reflecting structures may be located around the orthographic projection of the battery piece on the supporting surface, and the first light reflecting structures are located around the second light reflecting structures, so as to increase the probability that light rays which are not directly irradiated on the battery piece are reflected to the battery piece.

The first and second light reflecting structures will be described in detail with reference to fig. 1 to 11. Specifically, the reflectivity of the first light reflecting structure 120 and the reflectivity of the second light reflecting structure 130 are both greater than the reflectivity of the backplane body 110. Therefore, compared with the case that the smooth back plate body 110 is used for reflecting the light to the battery piece 101, the probability that the light incident to the first light reflecting structure 120 and the second light reflecting structure 130 is reflected is increased, so that more light is reflected to the battery piece 101, the utilization rate of the battery piece 101 to the light is further improved, and the power generation power of the battery piece 101 is further improved. Wherein, the reflectivity of the first light reflecting structure 120 and the reflectivity of the second light reflecting structure 130 may be selected to be 70% to 90%.

In some embodiments, the back plate may further comprise: and a reflective film (not shown) disposed on the surface of the first light reflecting structure 120 and the surface of the second light reflecting structure 130 for further improving the reflectivity of the surface of the first light reflecting structure 120 and the surface of the second light reflecting structure 130, so as to further improve the probability of the light incident on the first light reflecting structure 120 and the second light reflecting structure 130 being reflected to the battery piece 101. Wherein, the material of the reflecting film comprises at least one of Polyvinyl chloride (PVC), casting polypropylene or terpolymer (ABS) composed of butadiene-Acrylonitrile-Styrene. Specifically, the material of the reflecting film can be polyvinyl chloride, so that the reflecting film has the characteristics of high strength, strong weather resistance, long service life and strong stability.

In some embodiments, both the first light reflecting structure 120 and the second light reflecting structure 130 are in direct contact with the carrying surface c. In some examples, the backsheet body 110 includes a fluorine film and a PET (Polyethylene Terephthalate) film stacked, and the first and second light reflecting structures 120 and 130 are both printed and coated on a carrying surface c of the PET film on a side opposite to the fluorine film. The PET film may be a material subjected to corona treatment in advance, and the corona treatment is favorable for improving the surface free energy of the bearing surface c, so that the bearing surface c is changed from a non-polar surface to a polar surface, and the adhesion fastness between the back plate body 110 and the first and second light reflecting structures 120 and 130 is improved, compared with a mode of arranging an inner bonding layer between the back plate body and the grid layer, the method is favorable for reducing the constituent materials of the back plate 100, and the preparation cost of the back plate 100 is reduced.

In some embodiments, in the direction in which the second light reflecting structure 130 points to the first light reflecting structure 120, the ratio of the width of the bottom of the first light reflecting structure 120 to the width of the bottom of the second light reflecting structure 130 is 0.8 to 1.2. on one hand, the width of the bottom of the first light reflecting structure 120 is substantially the same as the width of the bottom of the second light reflecting structure 130, which is beneficial to adjust the propagation path of the light incident into the gap I between the adjacent battery plates 101, most of the light rays with the incident point located at the area of the first light reflecting structure 120 can be reflected to the light facing surface a of the battery plate 101 through the first light reflecting structure 120, so as to increase the probability of the light rays incident to the first light reflecting structure 120 being reflected to the light facing surface a, most of the light rays with the incident points located in the area where the second light reflecting structure 130 is located can be reflected to the backlight surface b or the light-facing surface a of the battery piece 101 through the second light reflecting structure 130, so as to improve the probability of the light rays incident on the second light reflecting structure 130 being reflected to the battery piece 101; on the other hand, the bottom width of the first light reflecting structure 120 and the bottom width of the second light reflecting structure 130 are set to be the same value, which is beneficial to reducing the proofing difficulty of the printing templates for preparing the first light reflecting structure 120 and the second light reflecting structure 130, reducing the process difficulty of screen printing, and also beneficial to monitoring the bottom width of the first light reflecting structure 120 and the bottom width of the second light reflecting structure 130 in production.

Further, in the direction Z perpendicular to the carrying surface c, the thickness of the first light reflecting structure 120 may be not less than that of the second light reflecting structure 130. Specifically, referring to fig. 3, the thickness of the first light reflecting structure 120 is greater than that of the second light reflecting structure 130, wherein the thickness of the first light reflecting structure 120 is: the vertical distance between the top end of the first light reflecting structure 120, which is farthest from the bearing surface c, and the bearing surface c in the direction Z perpendicular to the bearing surface c; the thicknesses of the second light reflecting structure 130 are: in the direction Z, the top end of the second light reflecting structure 130 farthest from the bearing surface c is perpendicular to the bearing surface c. As such, the larger the thickness of the first light reflecting structure 120 is, the shorter the propagation distance required for the light incident on the first light reflecting structure 120 to be reflected to the light-facing surface a of the battery piece 101 is, the greater the light intensity of the light when the light is absorbed by the battery piece 101 to the light-facing surface a is, thereby increasing the power generation efficiency of the battery piece 101.

It should be noted that the intensity of light refers to the Luminous intensity (luminosity) of light, which is called light intensity or luminosity in photometry, and is used to represent the physical quantity of light flux in a unit solid angle in a given direction of the light source.

In some embodiments, the first light reflecting structure 120 and the second light reflecting structure 130 may be an integrally formed structure, and the material of the first light reflecting structure 120 is the same as the material of the second light reflecting structure 130, which is beneficial to reducing the manufacturing process steps of the backplane 100 and reducing the manufacturing cost and complexity of the backplane 100. The material of the first reflective structure 120 and the material of the second reflective structure 130 may be a mixture of tetrafluoroethylene, titanium dioxide, epoxy resin, light stabilizer and silane coupling agent, or a mixture of polyvinylidene fluoride, titanium dioxide, epoxy resin, light stabilizer and silane coupling agent. The first light reflecting structure 120 and the second light reflecting structure 130 made of the above materials have strong absorption capacity for ultraviolet light, and when the first light reflecting structure 120 and the second light reflecting structure 130 cover the surface of the back plate body 110 together, the ultraviolet light is prevented from entering the back plate body 110 to damage the back plate body 110, so that the service life of the back plate body 110 is prolonged, and the service life of the back plate 100 is prolonged.

Referring to fig. 2 to 10, the first side d is inclined toward a direction approaching the first light reflecting structure 120. In some embodiments, when the first side surface d is a plane, and an acute angle formed between the first side surface d and the bearing surface c is in a range of 30 ° to 75 °, it is beneficial to ensure that most of light incident on the first side surface d can be reflected to the battery sheet 101.

In some embodiments, referring to fig. 8, the first side surface d is a plane, and the acute angle formed between the first side surface d and the bearing surface c is in a range of 30 ° to 45 °, and when the inclination degree of the first side surface d is in the range, it is favorable to improve the probability that the second reflected light incident on the first side surface d is transmitted to the backlight surface b by primary reflection, that is, when the angle is in the range, most of the second reflected light incident on the backlight surface b can be transmitted to the backlight surface b without secondary reflection by the bearing surface c, and can be directly transmitted to the backlight surface b by primary reflection by the first side surface d, so that the light intensity of the light reaching the backlight surface b is prevented from being reduced due to absorption by the bearing surface c when the light is reflected by the bearing surface c for the second time, and thus it is favorable to improve the intensity of the light absorbed by the backlight surface b of the battery piece 101, and it is favorable to improve the power generation power of the battery piece 101.

In other embodiments, referring to fig. 7, the first side surface d is an arc-shaped surface and is concave toward the direction close to the first light reflecting structure 120. Therefore, the first side surface d is concave, and the width of the top end of the protruding structure 140 away from the bearing surface c is smaller than the width of the bottom end of the protruding structure 140 contacting with the bearing surface c, the first side surface d is favorable for converging the light incident to the first side surface d, the second reflected light incident on the first side surface d can be reflected to the battery piece 101 at a better reflection angle, most of the second reflected light incident on the backlight surface b is directly reflected by the first side surface d for one time without secondary reflection of the bearing surface c, thereby avoiding the reduction of the light intensity reaching the backlight surface b caused by the absorption of the light by the bearing surface c when the light is reflected twice by the bearing surface c, thereby improving the total amount and intensity of the light reflected to the backlight surface b of the battery piece 101, increasing the light intensity absorbed by the backlight surface b of the battery piece 101, so as to improve the utilization rate of the cell 101 to light and improve the power generation power of the cell 101.

In some embodiments, referring to fig. 5, the surface of the first side surface is provided with an uneven sawtooth structure, the sawtooth structure can reflect light incident to the first side surface d from a plurality of different directions to the battery piece 101, so as to improve the probability that light incident at a region where the second light reflecting structure 130 is located reflects the light to the battery piece 101, and further increase the total amount of light absorbed by the battery piece 101, so as to improve the utilization rate of the battery piece 101 to light and improve the power generation power of the battery piece 101.

In other embodiments, referring to fig. 6 and 7, when the first side surface d is a slope or a concave surface, the protrusion structure 140 has a second side surface e opposite to the first side surface d, the second side surface e faces the first light reflecting structure 120, and the second side surface e is perpendicular to the carrying surface c, so that, compared to the second side surface e, more light rays incident on the area where the second light reflecting structure 130 is located will be incident on the first side surface d, that is, more light rays incident on the area where the second light reflecting structure 130 is located will be reflected onto the battery sheet 101 through the first side surface d, which is beneficial to increase the probability that the light rays incident on the second light reflecting structure 130 are reflected onto the battery sheet 101, so as to increase the utilization rate of the battery sheet 101 for the light rays.

It should be noted that, in the above embodiment, the number of the protrusion structures 140 is 2 in each of fig. 2 to fig. 7 as an example, in practical application, the number of the protrusion structures 140 may be 1, or may also be 3 or more than 3, and the number of the protrusion structures 140 is not limited in the above embodiment.

In still other embodiments, referring to fig. 8, the second light reflecting structure 130 includes at least two protruding structures 140, each protruding structure 140 is sequentially arranged in a direction along the first light reflecting structure 120 toward the second light reflecting structure 130, and the thickness of the adjacent protruding structures 140 decreases in a direction perpendicular to the carrying surface c. As shown in fig. 8, such a design can prevent light incident on the first side d of the protruding structure 140 close to the first light reflecting structure 120 from being blocked by the second side e (refer to fig. 7) of the protruding structure 140 far from the first light reflecting structure 120 and being far from the battery sheet 101 in the propagation path of the light reflected to the battery sheet 101, so as to increase the probability that the light incident on the area where the second light reflecting structure 130 is located is reflected to the battery sheet 101, thereby increasing the utilization rate of the battery sheet 101 for the light.

In some embodiments, the roughness Ra of the reflective surface f of the first reflective structure 120 is greater than or equal to 50, so that, compared to a smooth plane with a lower surface roughness, the reflective surface f has an obvious visible concave-convex shape, when light enters the reflective surface f of the first reflective structure 120, due to the rough surface structure of the reflective surface f, the light can be diffusely reflected to the light-facing surface a of the battery plate 101, so as to improve the probability that the light is reflected to the light-facing surface a of the battery plate 101, thereby increasing the total amount of light absorbed by the light-facing surface a of the battery plate 101, so as to improve the utilization rate of the light by the battery plate 101 and improve the power generation power of the battery plate 101, and meanwhile, the surface roughness Ra of the first reflective structure 120 is greater than or equal to 50, which is beneficial to reducing the printing difficulty of the first reflective structure 120.

In some embodiments, the included angle between the lateral surfaces of the first reflective structure 120 and the supporting surface c is less than or equal to 90 °. For example, the first light reflecting structure 120 may have a trapezoidal sectional shape. After the arrangement is adopted, the width of the part, close to the bearing surface c, of the first light reflecting structure 120 is large, so that the part is conveniently and accurately positioned at the preset position on the bearing surface c during laying, and meanwhile, the attaching area of the first light reflecting structure 120 and the bearing surface c is large, so that the mounting stability of the first light reflecting structure 120 on the bearing surface c can be enhanced; and is easier to form compared with the structure with a wide top and a narrow bottom, and is also convenient to be manufactured integrally with the second light reflecting structure 130 and installed on the bearing surface c.

In some embodiments, the reflecting surface f of the first light reflecting structure is parallel to the bearing surface c, which is beneficial to make the probability that the light rays incident to each point on the reflecting surface f are reflected to the light-facing surface a of the battery piece 101 equal, so that the probability that the first light reflecting structure 120 reflects the light rays to the light-facing surface a of the battery piece 101 is integrally increased, the total amount of the light rays absorbed by the light-facing surface a of the battery piece 101 is increased, the utilization rate of the battery piece 101 to the light rays is increased, and the power generation power of the battery piece 101 is increased.

Further, referring to fig. 9, the side surfaces of both sides of the width direction of the reflective surface f of the first light reflecting structure 120 are perpendicular to the bearing surface c, and the first side surface d and the second side surface e of the second light reflecting structure 130 are both inclined surfaces. Thus, the side surfaces of the two sides of the width direction of the reflective surface f are perpendicular to the supporting surface c, and the reflective surface f is parallel to the supporting surface c, i.e. the cross-sectional shape of the first light reflecting structure 120 is rectangular in the plane perpendicular to the supporting surface c. Compared with the first light reflecting structure 120 having an included angle between the side surface and the bearing surface c smaller than 90 ° (for example, the cross-sectional shape of the first light reflecting structure 120 is trapezoidal), the area of the reflecting surface f of the first light reflecting structure 120 away from the bearing surface c is larger, so that more light rays incident on the reflecting surface f are made, and further more light rays incident on the area where the first light reflecting structure 120 is located can be reflected to the light facing surface a of the battery piece 101, so that the total amount of light rays absorbed by the light facing surface a is increased, and the utilization rate of the light rays by the light facing surface a and the power generation power of the battery piece 101 are improved.

Of course, in other embodiments, the included angle between the side surface of the first light reflecting structure and the supporting surface may also be an acute angle, and the area of the reflecting surface f is smaller, which is not limited herein.

It should be noted that fig. 2 illustrates that the top end of the second light reflecting structure 130 away from the supporting surface c and the top surface of the first light reflecting structure 120 away from the supporting surface c are both lower than the backlight surface b, fig. 3 illustrates that the top end of the second light reflecting structure 130 away from the supporting surface c is lower than the backlight surface b, and the top surface of the first light reflecting structure 120 away from the supporting surface c is higher than the backlight surface b, and fig. 10 illustrates that the top end of the second light reflecting structure 130 away from the supporting surface c and the top surface of the first light reflecting structure 120 away from the supporting surface c are both higher than the backlight surface b. In practical applications, the above description is not only applicable to the case that the top end of the second light reflecting structure far from the bearing surface is lower than the backlight surface and/or the top surface of the first light reflecting structure far from the bearing surface is higher than the backlight surface, but also applicable to the case that the top end of the second light reflecting structure far from the bearing surface is not lower than the backlight surface and/or the top surface of the first light reflecting structure far from the bearing surface is not higher than the backlight surface.

The thicknesses of the first and second light reflecting structures in a direction perpendicular to the bearing surface are described in detail in two specific embodiments below.

In some embodiments, the thickness of the second light reflecting structure 130 is not greater than that of the first light reflecting structure 120, and the thickness of the first light reflecting structure 120 in the direction Z perpendicular to the carrying surface c may be 5um to 20 um. Specifically, as the thickness of the first light reflecting structure 120 increases, the shorter the propagation distance required for the light incident on the first light reflecting structure 120 to be reflected to the light-facing surface a of the battery piece 101 is, the reflectivity of the first light reflecting structure 120 increases, the greater the light intensity of the light absorbed by the light-facing surface a of the battery piece 101 is, and thus the power generation capacity of the battery piece 101 is improved. When the thickness of the first light reflecting structure 120 is 20um, the reflectivity of the first light reflecting structure 120 may reach 90%.

In other embodiments, referring to fig. 10, in a direction perpendicular to the carrying surface c, the thickness of the first light reflecting structure 120 is 100um to 3000um, and the thickness of the second light reflecting structure 130 is 100um to 3000 um.

When the second reflective structure 130 is located at a position away from the top end of the supporting surface c, the second reflective light will be reflected to the light-facing surface a of the battery sheet 101 by the second reflective structure 130, and when the second reflective structure 130 is located at a position close to the bottom end of the supporting surface c, the second reflective light will be reflected to the backlight surface b of the battery sheet 101 by the second reflective structure 130. Therefore, the light incident to the second light reflecting structure 130 may be reflected to the backlight surface b and may also be reflected to the light facing surface a, which is beneficial to increase the total amount of light absorbed by the battery piece 101, thereby increasing the power generation power of the battery piece 101.

It should be noted that, in fig. 10, the thickness of the first light reflecting structure 120 is equal to the thickness of the second light reflecting structure 130 as an example, in practical applications, the thickness of the first light reflecting structure may not be equal to the thickness of the second light reflecting structure according to different application scenarios.

It should be noted that, in fig. 2 to fig. 10, an orthographic projection of the second light reflecting structure 130 on the bearing surface c is located in an orthographic projection of the gap I on the bearing surface c, and a combined orthographic projection of the first light reflecting structure 120 and the second light reflecting structure 130 on the bearing surface c is overlapped with the orthographic projection of the gap I on the bearing surface c as an example, in practical application, the second light reflecting structure 130 may be located directly below the battery piece 101.

In other embodiments, referring to fig. 11, the back plate 100 may further include: the pyramid structure 150 is located on the carrying surface c, and the pyramid structure 150 is located on a side of the second light reflecting structure 130 away from the first light reflecting structure 120, the pyramid structure 150 is configured to reflect light incident on the pyramid structure 150 to form a third reflected light, and the third reflected light propagates toward a direction away from the pyramid structure 150 and away from the carrying surface c.

In some embodiments, when the backsheet 100 is applied to a photovoltaic module, the orthographic projection of the pyramid structures 150 on the carrying surface c is located in the orthographic projection of the cell sheet 101 on the carrying surface c, for reflecting the light rays incident on the pyramid structures 150 to the backlight surface b. Specifically, the degree of the acute angle formed between the side surface of the pyramid structure 150 and the bearing surface c is smaller than the degree of the acute angle formed between the first side surface b of the second light reflecting structure 130 and the bearing surface c, which is beneficial to improving the probability that the light incident to the position right below the backlight surface b is reflected to the backlight surface b, so as to further improve the utilization rate of the backlight surface b to the light. In one example, the acute angle formed between the side surface of the pyramid structure 150 and the bearing surface c is 15 ° to 45 °.

The pyramid structure 150 may be a triangular pyramid structure, a rectangular pyramid structure, or a pentagonal pyramid structure, and the number of the side edges of the pyramid structure 150 is not limited in this embodiment.

Specifically, the first light reflecting structure 120, the second light reflecting structure 130 and the pyramid structure 150 may be integrally formed, and the material of the first light reflecting structure 120, the material of the second light reflecting structure 130 and the material of the pyramid structure 150 are the same, which is beneficial to further reducing the manufacturing process steps of the back plate 100 and further reducing the manufacturing cost and complexity of the back plate 100. Among them, the method of forming the first light reflecting structure 120, the second light reflecting structure 130, and the pyramid structure 150 includes screen printing or roll printing.

Further, a reflective film may be further disposed on the surface of the pyramid structure 150 for increasing the reflectivity of the surface of the pyramid structure 150, so as to further increase the probability that the light incident on the pyramid structure 150 is reflected to the backlight surface b of the cell 101.

It should be noted that, in fig. 2 to 11, the degrees of the acute angles between the first side surfaces d of the plurality of protruding structures 140 and the carrying surface c are the same as an example, in practical applications, the degrees of the acute angles between the first side surfaces d of the adjacent protruding structures 140 and the carrying surface c may also be different, and further, in the direction in which the first light reflecting structure 120 points to the second light reflecting structure 130, the degrees of the acute angles formed between the first side surfaces b of the adjacent protruding structures 140 and the carrying surface c may be sequentially decreased. In addition, in fig. 2 to 11, it is exemplified that the bottom portions of the adjacent protruding structures 140 do not have a gap therebetween, in practical applications, the bottom portions of the adjacent protruding structures 140 may have a gap therebetween, and the above embodiment does not limit the size of the gap between the bottom portions of the adjacent protruding structures 140.

In addition, in the above embodiment, taking the elongated structure extending along the extending direction X as an example of the protruding structures 140 in the second light reflecting structure 130 in fig. 1, in practical applications, there may be a plurality of protruding structures 140 in the second light reflecting structure 130 in the extending direction X, and the protruding structures 140 may be arranged in sequence along the extending direction X, that is, the plurality of protruding structures 140 in the second light reflecting structure 130 are arranged in sequence along the width direction Y and/or the plurality of protruding structures 140 are arranged in sequence along the extending direction X.

It should be noted that, in fig. 1, the second light reflecting structures 130 are shown to be located on two sides of the battery piece 101 along the extending direction X, and the first light reflecting structures 120 are also located on two sides of the battery piece 101 along the extending direction X and located between two second light reflecting structures 130, in practical applications, for a single battery piece 101, the second light reflecting structures 130 may be disposed on each side of the battery piece 101, and the first light reflecting structures 120 may also be disposed on each side of the battery piece 101 and located between two second light reflecting structures 130.

In summary, the first light reflecting structure 120 and the second light reflecting structure 130 are disposed on the bearing surface c of the back plate body 110, wherein in the direction Z perpendicular to the bearing surface c, the thickness of the first light reflecting structure 120 is designed and the surface roughness of the top surface of the first light reflecting structure 120 away from the bearing surface c is specified, which is beneficial to improving the probability that the light incident to the first light reflecting structure 120 is reflected to the light facing surface a of the battery piece 101; the angle ranges of the included angles between the first side surface d and the second side surface c of the protruding structure 140 in the second light reflecting structure 130 and the bearing surface c are specified, and the arrangement manner of the protruding structures 140 is designed, which is beneficial to improving the probability that the light incident to the second light reflecting structure 130 is reflected to the light facing surface a and the backlight surface b of the battery piece 101. The first light reflecting structure 120 and the second light reflecting structure 130 cooperate to improve the probability that the back sheet 100 reflects the light incident on the back sheet 100 to the battery sheet 101; on the other hand, compared with the flat and smooth back plate body 110, the first light reflecting structure 120 and the second light reflecting structure 130 with a certain thickness are beneficial to reducing the length of the transmission path of the light rays incident to the gap between the adjacent battery pieces 101 and reflected to the battery pieces 101, so as to improve the light intensity of the light rays received by the battery pieces 101, and both are beneficial to improving the utilization rate of the battery pieces 101 to the light rays, thereby improving the power generation power of the battery pieces 101.

Another embodiment of the present invention provides a photovoltaic device, fig. 12 to 14 are schematic cross-sectional structures of a photovoltaic device according to another embodiment of the present invention, and fig. 15 and 16 are schematic top-view structures of 2 types of battery strings according to another embodiment of the present invention, and the photovoltaic device according to this embodiment will be described in detail below with reference to the drawings, and the same or corresponding portions as those in the above embodiments will not be described in detail below.

Referring to fig. 12 and 14, the photovoltaic module 103 includes: any of the back panels 100 described in the previous embodiments; the light-emitting device comprises a cover plate 102 and a plurality of battery pieces 101 positioned between the cover plate 102 and a back plate body 110, wherein the battery pieces 101 are provided with a light facing surface a and a backlight surface b which are opposite to each other, a gap I is formed between every two adjacent battery pieces 101, and a first light reflecting structure 120 and a second light reflecting structure 130 are arranged in the gap I and have the extending direction consistent with the extending direction of the gap I.

The extending direction X (refer to fig. 1) of the first light reflecting structure 120 is the same as the extending direction of the gap I, and the reflecting surface f of the first light reflecting structure 120 is configured to diffuse light incident on the reflecting surface f in a direction away from the bearing surface c to form a first reflected light, and the first reflected light is transmitted to the surface of the cover plate 102 and reflected to the light facing surface a for a second time; the second light reflecting structure 130 is configured to reflect the light incident on the first side surface d to form a second reflected light, and transmit the second reflected light to the backlight surface b or the light-facing surface a.

The light irradiated into the region without the cell 101 in the photovoltaic module 103 is reflected to the cell 101 through the first light reflecting structure 120 and the second light reflecting structure 130 in the back plate 100, which is beneficial to improving the utilization rate of the cell 101 to the light, thereby improving the power generation power of the cell 101 and improving the power generation power of the photovoltaic module 103.

Specifically, the reflecting surface f of the first reflecting structure 120 transmits the first reflected light to the cover plate 102, and then reflects the first reflected light to the light facing surface a through the cover plate 102, most of the light incident to the first reflecting structure 120 can reach the light facing surface a through twice reflection, the light intensity of the light received by the battery piece 101 is improved by reducing the number of times of reflection that the light reaches the light facing surface a, so that the utilization rate of the light by the battery piece 101 is improved, and the power generation power of the battery piece 101 is improved.

The first side surface d of the second light reflecting structure 130 reflects the incident second reflection light to the backlight surface b or the light-facing surface a, and most of the light incident to the second light reflecting structure 130 can reach the battery piece 101 through reflection, so as to improve the light intensity of the light received by the battery piece 101, thereby being beneficial to improving the utilization rate of the battery piece 101 to the light, and improving the power generation power of the battery piece 101.

The orthographic projection of the first light reflecting structure 120 on the bearing surface c is positioned in the orthographic projection of the gap I on the bearing surface c, and the orthographic projection of the second light reflecting structure 130 on the bearing surface c is at least partially overlapped with the orthographic projection of the gap I on the bearing surface c. In some embodiments, the orthographic projection of the second light reflecting structure 130 on the bearing surface c is located in the orthographic projection of the gap I on the bearing surface c; in other embodiments, the orthographic projection of the second light reflecting structure 130 on the carrying surface c partially overlaps the orthographic projection of the gap I on the carrying surface c, i.e. the orthographic projection of the second light reflecting structure 130 on the carrying surface c is at least partially located in the orthographic projection of the battery piece 101 on the carrying surface c.

Specifically, a space is provided between the backlight surface b and the bearing surface c.

In some embodiments, the thickness of the first light reflecting structure 120 and the thickness of the second light reflecting structure 130 are not higher than the thickness of the space in the direction perpendicular to the carrying surface c. In an example, referring to fig. 12, the thickness of the second light reflecting structure 130 is smaller than the thickness of the gap, and the second light reflecting structure 130 mainly reflects the light incident on the second light reflecting structure 130 to the backlight surface b, which is beneficial to improving the utilization rate of the light by the battery piece 101 and improving the power generation power of the battery piece 101. In practical applications, the thickness of the second light reflecting structure may also be equal to the thickness of the space.

Further, in the direction Z perpendicular to the carrying surface c, the thickness of the first light reflecting structure 120 may be 5um to 20um, and the thickness of the second light reflecting structure 130 is not greater than the thickness of the first light reflecting structure 120. Specifically, as the thickness of the first light reflecting structure 120 increases, the shorter the transmission distance required for the light incident to the first light reflecting structure 120 to be reflected to the light facing surface a of the battery piece 101 is, the reflectivity of the first light reflecting structure 120 increases, and the light intensity absorbed by the light facing surface a of the battery piece 101 is also larger, so as to improve the power generation power of the battery piece 101, specifically, when the thickness of the first light reflecting structure 120 is 20um, the reflectivity of the first light reflecting structure 120 may reach 90%. The thickness of the second light reflecting structure 130 is less than or equal to the thickness of the first light reflecting structure 120, and the thickness is lower, which is more favorable for reflecting light to the backlight surface b.

In other embodiments, the thickness of the first light reflecting structure 120 and the thickness of the second light reflecting structure 130 are greater than the thickness of the space in the direction perpendicular to the carrying surface c.

For example, referring to fig. 13, when a light is obliquely incident toward the first side surface d of the second light reflecting structure 130, the first side surface d of the second light reflecting structure 130 may reflect the incident light to the battery light facing surface a or the backlight surface b. When the reflection point of the second reflected light is located at the top end portion of the second light reflecting structure 130 far away from the supporting surface c, the second reflected light is reflected by the second light reflecting structure 130 to the light facing surface a of the battery sheet 101 for one time, and when the reflection point of the second reflected light is located at the bottom end portion of the second light reflecting structure 130 close to the supporting surface c, the second reflected light is reflected by the second light reflecting structure 130 to the supporting surface c first and then reflected by the supporting surface c to the backlight surface b of the battery sheet 101 for the second time. Thus, the light conversion efficiency of the entire photovoltaic module 103 can be increased. It should be noted that, in fig. 13, only the acute angle formed between the first side surface d and the supporting surface c is greater than 45 °, so that when the reflection point of the second reflected light is located at the bottom portion of the second light reflecting structure 130 close to the supporting surface c, the second reflected light is reflected by the second light reflecting structure 130 to the supporting surface c first, and then reflected by the supporting surface c to the backlight surface b of the battery piece 101 for the second time.

Referring to fig. 14, when light is incident perpendicularly to the first side surface d of the second light reflecting structure 130 at an angle, the first side surface d reflects the light back to the cover plate 102 along the incident light path, and the light is reflected to the light facing surface a by the cover plate 102.

Referring to fig. 13 and 14 in combination, when the thickness of the second light reflecting structure 130 is greater than the thickness of the gap, the second light reflecting structure 130 has the function of reflecting light to the light-facing surface a and the backlight surface b, so that the light reflected by the first side surface d can be absorbed by both the light-facing surface a and the backlight surface b of the battery sheet 101. Moreover, the conversion capability of the light-facing surface a of the cell sheet obtained through actual production and preparation (capability of converting light energy into electric energy) is greater than the conversion capability of the backlight surface b to light, and when the thickness of the first light reflecting structure 120 and the thickness of the second light reflecting structure 130 are respectively 2-3 times of the thickness of the interval, the ratio of the light reflected by the first side surface d and absorbed by the light-facing surface a of the cell sheet 101 is obviously higher, so that the overall light conversion efficiency of the photovoltaic module 103 is improved. When the ratio is greater than 3, the preparation difficulty and the cost are high, and light rays which are normally and directly incident on the surface of the cell 101 are interfered, and the conversion efficiency of the photovoltaic module is reduced. The ratio of the thickness of the first light reflecting structure 120 to the thickness of the interval is also 2-3, the thickness close to that of the second light reflecting structure 130 is maintained, shielding of light rays which are irradiated to the surfaces of the first light reflecting structure and the second light reflecting structure can be reduced, and stable power generation efficiency is guaranteed.

It should be noted that, in the photovoltaic module 103, the EVA adhesive film is filled in the space formed by the first light reflecting structure 120 and the second light reflecting structure 130, the battery piece 101 and the cover plate 102, the thickness of the space between the backlight surface b and the bearing surface c depends on the thickness of the EVA adhesive film, the thickness range of the EVA adhesive film is 100um to 1000um, the thickness range of the space is 100um to 1000um, based on the thickness of the space, when the thickness of the first light reflecting structure 120 and the maximum thickness of the second light reflecting structure 130 are respectively 2 to 3 times of the ratio of the thickness of the space, the thickness of the first light reflecting structure 120 and the thickness of the second light reflecting structure 130 are respectively 200um to 3000 um. The thickness of the first light reflecting structure 120 is equal to that of the second light reflecting structure 130, so that the phenomenon of shielding light rays irradiated to the surfaces of the first light reflecting structure and the second light reflecting structure can be completely eliminated, and the power generation efficiency is high.

In the two embodiments, fig. 12 to 14 all use the thickness of the first light reflecting structure 120 equal to the thickness of the second light reflecting structure 130 as an example, and in practical applications, the thickness of the first light reflecting structure is not limited. In one example, the thickness of the first light reflecting structure may be no greater than the thickness of the space between the backlight surface and the bearing surface; in another example, the first light reflecting structure may have a thickness greater than a thickness of the space between the backlight surface and the support surface.

In addition, in the two embodiments, the first side surface d is inclined toward the direction close to the first light reflecting structure 120, that is, when the first side surface d is an inclined surface, the range of the acute angle formed between the first side surface d and the supporting surface c may be 30 ° to 45 °, and when the inclination degree of the first side surface d is within the range, it is beneficial to improve the probability that the second reflected light ray incident on the first side surface d is directly transmitted to the backlight surface b, that is, most of the second reflected light ray incident on the backlight surface b is directly reflected to the backlight surface b from the first side surface d without the secondary reflection of the supporting surface c, so that the reduction of the light intensity reaching the backlight surface b due to the absorption of the light ray by the supporting surface c during the secondary reflection of the supporting surface c is reduced. Because the number of reflection times required for the light to reach the backlight surface b is reduced, the light intensity of the light received by the cell 101 is improved, the utilization rate of the cell 101 to the light is improved, and the power generation power of the cell 101 is improved.

In some embodiments, referring to fig. 15, the plurality of battery sheets 101 are sequentially connected in series along a first direction to form a battery string 111, at least two battery strings 111 are sequentially arranged along a second direction intersecting the first direction, a first gap f is formed between adjacent battery strings 111, the first gap f extends along the first direction, and an extending direction X of the first light reflecting structure 120 (refer to fig. 12) and an extending direction of the second light reflecting structure 130 (refer to fig. 12) are the same as the extending direction of the first gap, it should be noted that the first direction is generally the extending direction X of the first light reflecting structure 120, and the second direction is generally the width direction Y of the first light reflecting structure 120.

It should be noted that, for a single battery string 111, an orthographic projection of the non-overlapped region of the dashed box m and the dashed box n in the carrying surface c coincides with an orthographic projection of the first light reflecting structure 120 in the carrying surface c, and an orthographic projection of the second light reflecting structure 130 in the carrying surface c is located in an orthographic projection of the dashed box n in the carrying surface c. Specifically, for a single battery string 111, the second light reflecting structure 130 may be disposed on each side of the battery string 111, and the first light reflecting structure 120 may also be disposed on each side of the battery string 111 and between two second light reflecting structures 130.

Further, referring to fig. 16, at least two cell strings 111 are further arranged in sequence along the first direction X, a second gap h is formed between the cell sheets 101 (refer to fig. 12) of the adjacent cell strings 111, the second gap h extends along the second direction, the first light reflecting structure 120 and the second light reflecting structure 130 also extend along the second direction, the first gap f and the second gap h jointly form a gap I (refer to fig. 12), and it should be noted that, for a single cell string 111 in fig. 13, the relative positional relationship among the first light reflecting structure 120, the second light reflecting structure 130 and the cell string 111 is the same as that illustrated in fig. 12.

In fig. 15 and 16, the battery string 111 is taken as an example for description, and in practical applications, a plurality of single battery pieces 101 may be sequentially arranged along the first direction and/or the second direction.

In summary, the first light reflecting structure 120 and the second light reflecting structure 130 in the photovoltaic module 103 are beneficial to increasing the probability of light reflecting to the cell 101, so as to increase the utilization rate of the cell 101 to light, and thus increase the generating power of the cell 101, and increase the generating power of the photovoltaic module 103.

It will be understood by those of ordinary skill in the art that the foregoing embodiments are specific examples for carrying out the invention, and that various changes in form and details may be made therein without departing from the spirit and scope of the invention in practice. Various changes and modifications may be effected therein by one skilled in the art without departing from the spirit and scope of the invention as defined in the appended claims.