CN111732901B

CN111732901B - Adhesive film, photovoltaic module and manufacturing method thereof

Info

Publication number: CN111732901B
Application number: CN202010550354.9A
Authority: CN
Inventors: 陶武松; 徐涛; 王路闯; 郭志球; 金浩
Original assignee: Jingke Green Energy Shanghai Management Co ltd; Zhejiang Jinko Solar Co Ltd
Current assignee: Jingke Green Energy Shanghai Management Co ltd; Zhejiang Jinko Solar Co Ltd
Priority date: 2020-06-16
Filing date: 2020-06-16
Publication date: 2022-05-20
Anticipated expiration: 2040-06-16
Also published as: CN111732901A

Abstract

The embodiment of the invention provides an adhesive film, a photovoltaic module and a manufacturing method thereof, wherein the adhesive film is used for packaging a battery string in the photovoltaic module, the battery string comprises a plurality of battery pieces, adjacent battery pieces are provided with overlapping areas, the adhesive film is provided with a first surface facing the battery string and a second surface opposite to the first surface, and the adhesive film is characterized by comprising: at least one groove extending from the first face to the second face, the position of each groove being directly opposite to the position of at least one of the overlapping regions. The embodiment of the invention is beneficial to improving the yield of the photovoltaic module while improving the module efficiency of the photovoltaic module.

Description

Adhesive film, photovoltaic module and manufacturing method thereof

Technical Field

The embodiment of the invention relates to the technical field of solar cells, in particular to an adhesive film, a photovoltaic module and a manufacturing method of the 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 module efficiency is an important index for measuring the performance of the photovoltaic module, and directly reflects the utilization efficiency of the photovoltaic module to the light energy. Particularly, the high assembly efficiency is not only beneficial to reducing the cost in the manufacturing process of the photovoltaic assembly, but also beneficial to reducing the occupied area required by the power station in the operation stage; in addition, under the condition that the module power of the photovoltaic module is the same, the higher the module efficiency, the lower the size of the photovoltaic module, and the lower the weight of the corresponding photovoltaic module.

However, while improving the device efficiency of the photovoltaic device, the yield of the photovoltaic device is reduced.

Disclosure of Invention

The technical problem solved by the embodiment of the invention is to provide an adhesive film, a photovoltaic module and a manufacturing method thereof, and solve the problem of low yield of the photovoltaic module.

In order to solve the above problem, an embodiment of the present invention provides an adhesive film for encapsulating a cell string in a photovoltaic module, where the cell string includes a plurality of cells, and adjacent cells have an overlapping region, the adhesive film has a first surface facing the cell string and a second surface opposite to the first surface, and the adhesive film includes: at least one groove extending from the first face to the second face, the position of each groove directly opposing the position of at least one of the overlapping regions.

In addition, the same groove spans a plurality of the overlapping regions.

In addition, the adjacent battery pieces are provided with connecting lines in the overlapping area, and the length direction of the groove is the same as the extending direction of the connecting lines.

In addition, the first surface comprises a central area and a peripheral area positioned outside the central area, the grooves are positioned in the peripheral area, and the position of each groove is opposite to the position of at least one overlapping area.

In addition, the groove is also positioned in the central area, the volume of the groove opposite to each overlapping area positioned in the peripheral area is a first volume, the volume of the groove opposite to each overlapping area positioned in the central area is a second volume, and the first volume is larger than the second volume.

In addition, in the direction parallel to the arrangement direction of the plurality of battery pieces in the same battery string, the cross-sectional area of the groove in the peripheral area is larger than that of the groove in the central area.

In addition, the depth of the grooves of the peripheral region is greater than the depth of the grooves of the central region; or, in the direction parallel to the arrangement direction of the plurality of battery pieces in the same battery string, the cross-sectional width of the groove in the peripheral region is greater than the cross-sectional width of the groove in the central region.

In addition, the same groove spans the central region and the peripheral region; alternatively, the grooves in the peripheral region and the grooves in the central region are separated from each other.

In addition, the first face is rectangular, the central area and the peripheral area both cross the short side of the first face, and the peripheral area is distributed on two opposite sides of the central area; alternatively, the first face is square or circular in shape, and the peripheral region surrounds the central region.

In addition, the depth of the groove is less than or equal to 1/2 of the thickness of the adhesive film.

In addition, in the direction parallel to the arrangement direction of the plurality of battery pieces in the same battery string, the cross section of the groove is in a shape of an arc, an inverted trapezoid, a square or an inverted triangle.

In addition, still include: and the plurality of convex structures are positioned on the surface of the groove.

Correspondingly, the embodiment of the invention also provides a photovoltaic module, which comprises the adhesive film.

Correspondingly, the embodiment of the invention also provides a manufacturing method of the photovoltaic module, which comprises the following steps: sequentially stacking a first cover plate, a first adhesive film, a battery string, a second adhesive film and a second cover plate, wherein at least one of the first adhesive film or the second adhesive film adopts the adhesive film, the battery string comprises a plurality of battery pieces, the adjacent battery pieces are provided with overlapping areas, and the position of each groove is opposite to the position of at least one overlapping area; and carrying out lamination treatment to form the laminated photovoltaic module.

In addition, the first adhesive film is the adhesive film of the previous embodiment, and the first adhesive film is provided with a groove; the second adhesive film is the adhesive film of the embodiment, the second adhesive film is provided with a groove, and in the stacking process, the groove in the second adhesive film is opposite to the groove in the first adhesive film, or the groove in the second adhesive film and the groove in the first adhesive film are staggered.

In addition, the second adhesive film adopts the adhesive film of the previous embodiment, and the second adhesive film is provided with a groove; and applying pressure to the surface of the second cover plate far away from the second adhesive film in the laminating process.

In addition, the glue film with the groove is manufactured by designing a calendering roller with a protruding structure.

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

the adhesive film provided by the embodiment of the invention is provided with a first surface and a second surface which are opposite, at least one groove extends from the first surface to the second surface, the groove is positioned in a peripheral area, and the position of each groove is opposite to the position of at least one overlapping area. In the laminating stage of manufacturing the photovoltaic module by adopting the adhesive film, the grooves can buffer the laminating pressure on the overlapping area of the battery pieces, and the effect of reducing the hidden crack and fragment risk of the overlapping area is achieved, so that the assembly efficiency of the photovoltaic module is improved, and the yield of the photovoltaic module is improved.

In addition, the first surface is provided with a central area and a peripheral area, the groove is located in the peripheral area, the groove can buffer the laminating pressure applied to the cell overlapping area of the peripheral area, the effect of reducing the hidden crack and the fragment risk of the overlapping area is achieved, and the yield of the photovoltaic module is improved.

In addition, the groove is also positioned in the central area, the volume of the groove opposite to each overlapping area positioned in the peripheral area is a first volume, the volume of the groove opposite to each overlapping area positioned in the central area is a second volume, and the first volume is larger than the second volume. Therefore, the overlapping area of the central area and the peripheral area can be prevented from being subjected to hidden cracking or fragmentation, and the groove in the central area is relatively small, so that the adhesive film with the groove still has enough quantity, the adhesive film is guaranteed to have a good packaging effect, the yield of the photovoltaic module is further improved, and the service life of the photovoltaic module is prolonged.

Correspondingly, in the manufacturing method of the photovoltaic module provided by the embodiment of the invention, the adhesive film is adopted, so that the yield of the photovoltaic module is improved, the groove can also play a role in positioning the battery piece, and the manufacturing difficulty of the photovoltaic module is reduced.

Drawings

One or more embodiments are illustrated by corresponding figures in the drawings, which are not to be construed as limiting the embodiments, unless expressly stated otherwise, and the drawings are not to scale.

Fig. 1 to 4 are schematic structural views of a glue film according to a first embodiment of the invention;

FIG. 5 is a schematic top view illustrating a glue film according to a second embodiment of the present invention;

FIG. 6 is a schematic top view illustrating a glue film according to a third embodiment of the present invention;

FIG. 7 is a schematic structural diagram of a glue film according to a fourth embodiment of the invention;

fig. 8 to 10 are schematic structural views of an adhesive film according to a fifth embodiment of the present invention;

fig. 11 and 12 are schematic structural views of a glue film according to a sixth embodiment of the invention;

FIG. 13 is a schematic structural view of a glue film according to a seventh embodiment of the invention;

FIG. 14 is a schematic top view illustrating a glue film according to an eighth embodiment;

fig. 15 is a schematic cross-sectional view of a photovoltaic device according to an embodiment of the present invention;

FIG. 16 is a schematic cross-sectional view of a photovoltaic module after lamination;

fig. 17 is a schematic cross-sectional view of a photovoltaic module according to another embodiment of the present invention;

fig. 18 is a schematic cross-sectional structure view of a photovoltaic module according to still another embodiment of the present invention.

Detailed Description

Known from the background art, the prior art faces the problem that the yield of the photovoltaic module becomes low while the module efficiency of the photovoltaic module is improved.

In order to improve the assembly efficiency of the photovoltaic module, a stitch welding technology can be adopted to eliminate the gaps of the battery pieces, namely, in the battery string of the photovoltaic module, an overlapping area is formed between the adjacent battery pieces, and in the overlapping area, the overlapping area is provided with an overlapping part between the adjacent battery pieces and a welding strip for electrically connecting the adjacent battery pieces. In the production process of the photovoltaic module, in the lamination stage, the overlapped areas have higher hidden crack or fragment risks under the action of lamination pressure than other areas, so that the yield of the manufactured photovoltaic module is influenced.

In order to solve the above problems, the embodiment of the invention provides an adhesive film, in which a groove is arranged, the groove is opposite to an overlapping area between battery pieces of a battery string, and can buffer pressure applied to the overlapping area in a manufacturing process of a photovoltaic module, so that the yield of the photovoltaic module is improved.

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.

Fig. 1 to 4 are schematic structural diagrams of an adhesive film according to a first embodiment of the invention, fig. 1 is a schematic top-view structural diagram of the adhesive film, fig. 2 is a schematic cross-sectional structural diagram along the AA1 direction in fig. 1, fig. 3 is a schematic cross-sectional structural diagram of a single groove in various different cross-sectional configurations, and fig. 4 is a schematic top-view structural diagram of the adhesive film in another embodiment.

Referring to fig. 1 to 3, an adhesive film 101 is used for encapsulating a cell string in a photovoltaic module, the cell string includes at least a plurality of cell pieces, adjacent cell pieces have an overlapping region, the adhesive film 101 has a first side facing the cell string and a second side opposite to the first side; at least one groove 102 extending from the first face to the second face, each groove 102 being located directly opposite the location of the at least one overlap region.

The adhesive film provided in the present embodiment will be described in detail below with reference to the accompanying drawings.

The adhesive film 101 can be an EVA adhesive film or a POE adhesive film; the adhesive film 101 may be a roll or a sheet.

In this embodiment, the first surface is rectangular, and the same groove 102 penetrates the long side of the first surface. The same groove 102 spans multiple overlapping regions. Specifically, adjacent battery pieces are provided with connecting lines in the overlapping regions, and in the extending direction of the connecting lines, the same groove 102 spans the overlapping regions, so that when the photovoltaic module is formed, the same groove 102 can be over against the overlapping regions of at least 2 battery strings, which is beneficial to reducing the number of the grooves 102 and reducing the manufacturing difficulty and the production cost of the adhesive film 101. The connecting line direction is perpendicular to the arrangement direction of the plurality of battery pieces in the same battery string. The extending direction of the same groove 102 is the same as the extending direction of the connecting line in the overlapping region of the adjacent battery plates of the same battery string, and the length direction of the groove 102 is the same as the extending direction of the connecting line.

The arrangement direction of the grooves 102 is related to the arrangement position of the cell strings. In this embodiment, the same groove 102 extends in the transverse direction, and different grooves 102 are arranged at intervals in the longitudinal direction, the transverse direction refers to the long side direction of the first surface, and the longitudinal direction refers to the short side direction of the first surface; correspondingly, when the photovoltaic module is formed, the cells are arranged in the way that the cells in the same cell string are arranged along the longitudinal direction, and the extending direction of the connecting lines in the overlapping region in the same cell string extends along the transverse direction. The adhesive film 101 is suitable for a non-gap type between battery strings or a gap type between battery strings.

In other embodiments, as shown in fig. 4, the adhesive film 101 has a plurality of mutually discrete grooves 102 in the extending direction of the connecting lines in the overlapping region of the adjacent battery pieces along the same battery string, and the spacing between the adjacent grooves 102 is the same as the spacing between the adjacent battery strings, i.e. the adhesive film 101 can be applied to the gap type between the battery strings. Since the plurality of grooves 102 are separated from each other, different grooves 102 can be set to have different sizes, so that matching of cell strings with different sizes is facilitated, and structural flexibility of the photovoltaic module is improved. In addition, compared with the scheme that the adjacent grooves are communicated, the adhesive film 101 material is arranged between the adjacent grooves 102 in the extending direction of the connecting line, so that the material quantity of the adhesive film 101 can be increased under the condition that the thickness of the adhesive film 101 is not changed, and the adhesive film 101 has a good packaging effect in the manufacturing process of the photovoltaic module.

The grooves 102 are positioned opposite to the overlapping region, and the distance between the adjacent grooves 102 is matched with the size of the battery piece. Specifically, the larger the cell size, the larger the spacing between adjacent grooves 102; the smaller the cell size, the smaller the spacing between adjacent grooves 102. In this embodiment, the adjacent grooves 102 are arranged at equal intervals. In other embodiments, the spacing between adjacent grooves may be different. Wherein, the size of the battery piece can be 150mm-250 mm.

In this embodiment, the cross-sectional width of the groove 102 is 5mm to 20mm, for example, 6mm, 10mm, 12mm, 15mm, and 18mm, in the direction parallel to the arrangement direction of the plurality of battery pieces in the same battery string, i.e., in the cross-sectional direction perpendicular to the connecting lines.

As shown in fig. 2, the adjacent battery pieces have connecting lines in the overlapping region, and in this embodiment, the cross-sectional shape of the groove 102 is a circular arc in the direction parallel to the arrangement direction of the plurality of battery pieces in the same battery string, i.e., in the cross-sectional direction perpendicular to the connecting lines. In other embodiments, the cross-sectional shape of the groove may also be an inverted trapezoid, a square or an inverted triangle in the direction parallel to the arrangement direction of the plurality of battery pieces in the same battery string.

In the arrangement direction of the adjacent cells parallel to the same cell string, the width of the groove 102 is greater than or equal to the width of the overlapping area, which is beneficial to further ensuring that the pressure on each area of the overlapping area is small, thereby further reducing the risk of cracking or breaking of the overlapping area. Specifically, the orthographic projection of the overlapping area on the first surface is a first projection, the orthographic projection of the groove 102 on the first surface is a second projection, and in the arrangement direction of the plurality of battery pieces parallel to the same battery string, the boundary of the first projection overlaps with the boundary of the second projection, or the boundary of the first projection is located within the boundary of the second projection.

The depth of the groove 102 is less than or equal to 1/2 of the thickness of the adhesive film 101. Therefore, the depth of the groove 102 occupies the thickness of the adhesive film 101 in a moderate proportion, so that the adhesive film 101 in the area where the groove 102 is located still has a thick thickness, and the area where the groove 102 is located is ensured to have a good packaging effect. The depth of the groove 102 may also be greater than 1/6 of the thickness of the adhesive film 101, for example, the depth of the groove 102 is 1/3, 1/4 or 1/5 of the thickness of the adhesive film 101, in which range the groove 102 has a larger volume, so that the groove 102 has a better effect of relieving or eliminating pressure.

As shown in fig. 3, the adhesive film 101 may further include: a plurality of raised structures 112 located on the surface of the recess 102. The shape of the protruding structure 112 may be a triangular prism shape, a semicircular shape, or the like. These raised structures are beneficial to further relieve the pressure on the overlapped area in the lamination stage, and are beneficial to increase the contact area between the adhesive film 101 and the cover plate so as to enhance the packaging strength between the cover plate and the adhesive film 101.

In addition, the adhesive film 101 may further include: and the burr structures 113 are positioned between the adjacent grooves, and the shape of the burr structures 113 can be triangular prism, semicircular and the like. The size of burr structure 113 is less than the size of protruding structure 112, and the setting of this burr structure 113 not only is favorable to increasing the frictional force between range upon range of stage glued membrane 101 and apron, and still is favorable to alleviating the lamination pressure that glued membrane 101 received to be favorable to further improving photovoltaic module's yield.

The adhesive film 101 provided by the embodiment can be manufactured by a calendering roller provided with a periodic protruding structure; when the adhesive film passes through the calender roll having the convex structure, the portion of the adhesive film 101 in contact with the convex structure is pressed out of the periodic grooves 102.

In the production process of the photovoltaic module, the groove 102 is opposite to the overlapping area of the cell string, and due to the arrangement of the groove 102, a gap is reserved between the adhesive film 101 and the overlapping area before the lamination stage; in the laminating stage, the pressure applied to the adhesive film 101 is eliminated or reduced after passing through the groove 102, so that the pressure applied to the overlapping region corresponding to the groove 102 is reduced, thereby greatly reducing the risk of subfissure and breakage of the overlapping region.

The second embodiment of the present invention further provides a glue film, which is substantially the same as the glue film provided in the previous embodiment, and the main difference is that the same groove extends along the longitudinal direction in the second embodiment, and different grooves are arranged at intervals in the transverse direction. Fig. 5 is a schematic top view of a glue film according to a second embodiment of the invention. The adhesive film provided in the present embodiment will be described in detail below with reference to the accompanying drawings.

Referring to fig. 5, the adhesive film 201 has a first side facing the battery string and a second side opposite to the first side; at least one groove 202 extending from the first face to the second face, each groove 202 being located directly opposite the location of the at least one overlap region. Wherein, first face includes neighbouring long limit and minor face, and long limit extending direction is horizontal, and the minor face extending direction is vertical, and same recess 202 is along longitudinal extension, and different recesses 202 are at horizontal interval arrangement.

Correspondingly, when the photovoltaic module is formed, the cells are arranged in the way that the cells in the same cell string are arranged along the transverse direction, and the extending direction of the connecting line in the overlapping region in the same cell string extends along the longitudinal direction. In one example, as shown in the upper diagram of fig. 5, the same groove 202 penetrates the width of the adhesive film 201 in the longitudinal direction, and the adhesive film 201 may be applied to a non-gap type between battery strings or a gap type between battery strings. In another example, as shown in the lower diagram of fig. 5, the adhesive film 201 may be applied to a type in which a plurality of grooves 202 are separated from each other in the longitudinal direction, and the distance between adjacent grooves 202 is the same as the gap between the battery strings.

In the transverse direction, the adjacent grooves 201 may be arranged at equal intervals, or the intervals between the adjacent grooves 201 may be different.

The third embodiment of the present invention further provides an adhesive film, which is different from the previous embodiment in that the groove comprises a groove extending along the transverse direction and a groove extending along the longitudinal direction. Fig. 6 is a schematic top view of a glue film according to a third embodiment of the present invention, and reference may be made to the detailed description of the glue film according to the embodiment for the same or corresponding parts as those in the previous embodiment.

Referring to fig. 6, the adhesive film 301 has a first face and a second face, and has a groove 302 extending from the first face to the second face, the groove 302 including a plurality of grooves 302 extending in a long side direction of the first face, and further including a plurality of grooves 302 extending along a short side of the first face.

The grooves 302 include grooves 302 extending in the lateral direction (i.e., the long-side direction of the first face) and grooves 302 extending in the longitudinal direction (i.e., the short-side direction of the first face), and the corresponding battery string includes: the first battery string is arranged along the longitudinal direction of each battery piece, and the second battery is arranged along the transverse direction of each battery piece.

The adhesive film 301 provided in this embodiment can simultaneously form a photovoltaic module with the cell strings of the cell sheets arranged in the transverse direction and the cell strings of the cell sheets arranged in the longitudinal direction.

The fourth embodiment of the present invention further provides an adhesive film, wherein the first surface includes a central area and a peripheral area located outside the central area, and the main difference between the adhesive film and the previous embodiment is that the grooves are located in the peripheral area, and the position of each groove is opposite to the position of at least one overlapping area. The adhesive film provided by the fourth embodiment of the present invention will be described in detail below with reference to the accompanying drawings.

Fig. 7 is a schematic structural diagram of an adhesive film according to a fourth embodiment of the invention, in which an upper diagram of fig. 7 is a schematic structural diagram viewed from above, and a lower diagram is a schematic structural diagram of a cross-section cut along the direction aa1 in the upper diagram.

Referring to fig. 7, an adhesive film 401 is used for encapsulating a cell string in a photovoltaic module, the cell string includes a plurality of cell pieces, adjacent cell pieces have an overlapping region, the adhesive film 401 has a first face Front facing the cell string and a second face Back opposite to the first face; at least one groove 402 extending from the first face to the second face, each groove 402 being located directly opposite to the location of the at least one overlap region.

The inventor of the invention researches and discovers that the photovoltaic module is provided with a central area and a peripheral area positioned outside the central area, and the risk of subfissure or fragment in the overlapping area of the peripheral area is higher than that in the overlapping area of the peripheral area.

Further analysis has revealed that the causes of this problem include: the manufacturing steps of the photovoltaic module comprise a laminating stage and a laminating stage; in the laminating stage, a back plate, a lower adhesive film, a battery string, an upper adhesive film and a front plate are sequentially laminated to form a laminated structure; during the lamination stage, firstly, air exhaust treatment is carried out to exhaust air among layers of the laminated structure, and pressurization treatment is carried out after the air exhaust treatment; in the process of or after the air-extracting process, the peripheral region is warped, and the heating process is performed on the laminated structure in the process of or after the air-extracting process, which also can improve the warping degree of the peripheral region to a certain extent. To eliminate the lifting of the peripheral zone, the pressure applied to the peripheral zone may be higher than the pressure applied to the central zone during the lamination phase, which however would lead to a greater risk of hidden cracking or chipping of the overlapping zones of the peripheral zone; alternatively, to eliminate the lifting of the peripheral region, even if the pressure applied to the peripheral region in the lamination stage is the same as the pressure applied to the central region, the deformation of the back plate and the front plate of the peripheral region under the pressure in the lamination stage is larger than that of the back plate and the front plate of the central region under the pressure, which may cause the risk that the overlapping region of the peripheral region is more prone to subfissure or chipping than the central region.

The peripheral region II may be located on opposite sides of the central region I; alternatively, the peripheral region II may surround the central region I.

The width of the peripheral region II may be at least the width across one cell string; thus, the peripheral region II is directly opposite to at least one cell string when the photovoltaic module is constructed. Or the width of the peripheral region II can also be 1/N of the width of a single battery string, and N is greater than 1; thus, the peripheral region II faces 1/N cell strings when the photovoltaic module is constructed. Or, the width of the peripheral region II may also be the width of N battery strings and 1/N width of a single battery string, where N is a natural number greater than or equal to 1; thus, the peripheral region II faces the N +1/N cell strings when the photovoltaic module is constructed. The width refers to a width in a direction perpendicular to the arrangement direction of the plurality of battery pieces in the same battery string.

It is understood that the width of the peripheral zone II is related to the size of the first face Front, and the width of the peripheral zone II may be reasonably set according to the size of the first face Front. Specifically, when the size of the first face Front is larger, the peripheral area II, which has a correspondingly larger area, is prone to warping, and the width of the corresponding peripheral area II is larger; the smaller the size of the first face Front, the smaller the area of the region in which the warpage problem correspondingly occurs, the larger the width of the corresponding peripheral region II.

It is also noted that the positional relationship between the peripheral region II and the central region I is related to the shape of the first face Front. For example, in the embodiment, the first face Front is rectangular, the central region I and the peripheral region II both span the short side of the first face Front and are arranged along the long side of the first face Front, and the peripheral regions II are respectively located at two opposite sides of the central region I. In other embodiments, the first face is rectangular or circular in shape, and the peripheral region surrounds the central region.

In the present embodiment, the width of the peripheral region II in the longitudinal direction along the first face Front is 10mm to 20mm, for example, 12mm, 15mm, 17 mm.

It is understood that, in other embodiments, the shape of the first surface may also be a triangle, a trapezoid, a regular polygon, an irregular shape, or the like, and an area prone to be lifted up may be reasonably expected according to the shape of the first surface, and accordingly, the area prone to be lifted up is the peripheral area. For example, if the first face is triangular in shape, the peripheral regions are located at the three corners of the first face, and the first face has a central region and three peripheral regions.

Because the peripheral area II is provided with the groove 402, in the laminating process of manufacturing the photovoltaic module by utilizing the adhesive film 401, a gap is formed between the adhesive film 401 and the overlapping area, so that the pressure applied to the overlapping area opposite to the groove 402 is reduced or eliminated, the risk of hidden cracking or fragment of the overlapping area of the peripheral area II is greatly reduced, and the yield of the photovoltaic module is improved; in addition, in the laminating stage, the adhesive film at the groove 402 is heated to melt and fill the groove 402, and the flowable area of the adhesive film is increased, so that the pressure applied to the overlapping area by the adhesive film is reduced, and the yield of the photovoltaic module can be improved to a certain extent.

The extending direction of the same groove 402 is the same as the extending direction of the connecting line of the adjacent battery piece in the overlapping region; or, the extending direction of the same groove 402 is the same as the arrangement direction of the plurality of battery pieces in the same battery string. That is, the arrangement direction of the grooves is related to the arrangement position of the cell strings. In this embodiment, the same groove 402 extends in the transverse direction, and different grooves 402 are arranged at intervals in the longitudinal direction, the transverse direction refers to the long side direction of the first surface, and the longitudinal direction refers to the short side direction of the first surface; correspondingly, when the photovoltaic module is formed, the arrangement of the cell pieces on the peripheral area II is that the cell pieces in the same cell string are longitudinally arranged, and the extending direction of the connecting line in the overlapping area in the same cell string is transversely extended. In other embodiments, the same groove may also extend in the longitudinal direction, and different grooves are arranged at intervals in the transverse direction; correspondingly, when the photovoltaic module is formed, the arrangement of the cell pieces on the peripheral area is that each cell piece in the same cell string is arranged along the transverse direction, and the extending direction of the connecting line of the overlapping area in the same cell string is along the longitudinal direction. In yet another embodiment, the grooves include a first groove extending in the transverse direction and a second groove extending in the longitudinal direction, and the corresponding battery string includes: the first cell string is arranged along the longitudinal direction of each cell piece and the second cell string is arranged along the transverse direction of each cell piece.

In addition, in this embodiment, in the extending direction of the connecting lines in the overlapping regions of the adjacent battery pieces along the same battery string, and in the direction perpendicular to the arrangement direction of the plurality of battery pieces in the same battery string, the same peripheral region II has a groove 402, and the groove 402 may be directly opposite to an overlapping region of a battery string, or may be directly opposite to an overlapping region of at least 2 battery strings, that is, the adhesive film 401 may be applied to a zero-gap type between battery strings or a gap type between battery strings. In other embodiments, in the extending direction of the connecting line in the overlapping region of the adjacent battery pieces along the same battery string, the same peripheral region may also have at least 2 grooves, and the distance between adjacent grooves is the same as the distance between adjacent battery strings, i.e. the adhesive film may be suitable for the gap type between battery strings.

The grooves 402 are positioned opposite to the overlapping region, and the distance between adjacent grooves 402 is matched with the size of the battery plate. Specifically, the larger the cell size, the larger the spacing between adjacent grooves 402; the smaller the cell size, the smaller the spacing between adjacent grooves 402. In this embodiment, the adjacent grooves 402 are arranged at equal intervals. In other embodiments, the spacing between adjacent grooves may be different.

In this embodiment, the cross-sectional shape of the groove 402 is circular arc in the direction parallel to the arrangement direction of the plurality of battery pieces in the same battery string. In other embodiments, the cross-sectional shape of the groove may also be an inverted trapezoid, a square or an inverted triangle in the direction parallel to the arrangement direction of the plurality of battery pieces in the same battery string.

In this embodiment, the cross-sectional width of the groove 402 is 5mm to 20mm, for example, 6mm, 10mm, 12mm, 15mm, and 18mm, in the direction parallel to the arrangement direction of the plurality of battery pieces in the same battery string, i.e., in the cross-sectional direction perpendicular to the connecting lines.

The adhesive film 401 may further include: a plurality of raised structures (not shown) located on the surface of the recess 402. The shape of the protruding structure can be triangular prism shape or semicircular shape. These raised structures are beneficial to further relieve the pressure on the overlapped area during the lamination stage, and are beneficial to increase the contact area between the adhesive film 401 and the cover plate so as to enhance the packaging strength between the cover plate and the adhesive film 401.

In addition, the adhesive film 401 may further include: the burr structure is positioned on the first surface, and the shape of the burr structure can be triangular prism shape or semicircular shape. The size of burr structure is less than the size of protruding structure, and the setting of this burr structure not only is favorable to increasing the frictional force between range upon range of stage apron and glued membrane 401, and is favorable to alleviating the pressure that non-overlapping area received when the lamination, reduces the risk that non-overlapping area takes place the lobe of a leaf.

The peripheral region II of the adhesive film 401 provided in this embodiment is provided with the grooves 402, and the size and number of the grooves 402 are related to the type of the battery string, the size of the battery piece, and the size of the overlapping region, which are provided in the peripheral region II, and the peripheral region II can be compatible with the whole type of the battery string or the half type of the battery string by adjusting the size and the position of the grooves 402. In the production stage, the adhesive film 01 having the grooves 402 may be manufactured by a calender roll having a convex structure.

During the production of the photovoltaic module, the grooves 402 correspond to the overlapping regions of the cell strings; and there is a gap between the adhesive film 401 and the battery string, and in the laminating stage, the adhesive film 401 is melted by heat to fill the groove 402. In the laminating stage, the pressure applied to the area corresponding to the groove 402 of the adhesive film 401 is eliminated after passing through the groove 402, so that the pressure applied to the overlapping area corresponding to the groove 402 is reduced, and the risk of the overlapping area of hidden cracking and chipping is greatly reduced. That is, in the lamination stage, since the pressure applied to the overlapping region of the peripheral region II is small, the probability of the overlapping region of the peripheral region II being hidden crack or broken is greatly reduced.

Therefore, adopt the glued membrane production photovoltaic module that this embodiment provided, when improving photovoltaic module's subassembly efficiency, be favorable to improving photovoltaic module's yield.

The fifth embodiment of the present invention further provides an adhesive film, which is substantially the same as the adhesive film of the previous embodiment, and the main difference includes that the groove of the fifth embodiment is also located in the central region. The adhesive film provided by the fifth embodiment of the present invention will be described in detail below with reference to the accompanying drawings, and the same or corresponding portions as or to the previous embodiment can be referred to the description of the previous embodiment, which will not be described in detail below. Fig. 8 to 10 are schematic structural views of an adhesive film according to a fifth embodiment of the invention.

Referring to fig. 8, in the present embodiment, the adhesive film 501 is used for encapsulating a cell string in a photovoltaic module, the cell string includes a plurality of cell pieces, and adjacent cell pieces have an overlapping region, the adhesive film 501 has a first surface (not labeled) facing the cell string and a second surface (not labeled) opposite to the first surface, the first surface includes a central region I and a peripheral region II located outside the central region I; the adhesive film 501 includes: at least one groove 502 extending from the first surface to the second surface, the groove 502 being located in the central region I and the peripheral region II, and the position of each groove 502 being opposite to the position of the at least one overlapping region; the volume of the groove 502 opposite to each overlapping area of the peripheral area II is a first volume, the volume of the groove 502 opposite to each overlapping area of the central area I is a second volume, and the first volume is larger than the second volume.

In this embodiment, taking the first surface as a rectangle as an example, the peripheral areas II are respectively located at two opposite sides of the central area I. In other embodiments, the first face may also be square or circular in shape, with a peripheral region surrounding the central region. For a detailed description of the first face, the central region and the peripheral region, reference may be made to the detailed description of the foregoing embodiments.

Adjacent cells have a connecting line in the overlap region and volume refers to the volume of the groove 502 within the facing length of the connecting line. The larger the volume of the groove 502 is, the larger the amount of adhesive film flowing to the groove 502 during the lamination stage is, and the stronger the pressure relief capability of the groove 502 is, the more beneficial the pressure on the overlapping area facing the groove 502 is. In other words, the first volume being greater than the second volume is effectively: in the direction parallel to the arrangement direction of the plurality of battery pieces in the same battery string, i.e. in the section perpendicular to the connecting line, the sectional area of the groove 502 in the peripheral region II is larger than that of the groove 502 in the central region I.

As can be seen from the foregoing, the overlapping region of the peripheral region II is more susceptible to the risk of breakage than the overlapping region of the central region I during the lamination stage. In this embodiment, the grooves 502 are disposed in the peripheral region II and the central region I, and the pressure eliminating capability of the grooves 502 in the peripheral region II is stronger than that of the grooves 502 in the central region I, so that the overlapping region of the peripheral region II can be prevented from being broken, and the overlapping region of the central region I can be prevented from being broken, which is beneficial to further improving the yield of the photovoltaic module produced by using the adhesive film 501.

In this embodiment, the depth h of the groove 502 in the peripheral region II is the same as the depth h of the groove 502 in the central region I.

Fig. 9 is a schematic cross-sectional view of fig. 8 cut along the direction of AA1 and along the BB square. As shown in fig. 9, in one example, the adjacent cells have connecting lines in the overlapping region, and the cross-sectional shape of the groove 502 in the peripheral region II and the cross-sectional shape of the groove 502 in the central region I may be the same in a cross-sectional direction perpendicular to the connecting lines, i.e., in a direction parallel to the arrangement direction of the plurality of cells in the same cell string. The cross-sectional width of the grooves 502 in the peripheral region II is greater than the cross-sectional width of the grooves 502 in the central region I in a cross-sectional direction perpendicular to the connecting line (i.e., in the AA1 direction), i.e., in a direction parallel to the arrangement direction of the plurality of battery pieces in the same battery string.

Specifically, the cross-sectional width of the groove 502 in the central region I is a first width w1, the cross-sectional width of the groove 502 in the peripheral region II is a second width w2, and the difference between the second width w2 and the first width w1 is greater than or equal to 2mm and less than or equal to 5mm, for example, w2-w1 is 2.5mm, 3mm, 4.5mm, or 4 mm. Thus, the difference between the widths of the grooves 502 of the peripheral area II and the grooves 502 of the central area I is moderate, so that the pressure relieving effect of the grooves 102 of the peripheral area II is better than that of the grooves 502 of the central area I; since w2-w1 is less than or equal to 5, the difference is set to take into account the error caused by the shrinkage of the adhesive film 501, and even if the adhesive film 501 shrinks, the width of the groove 502 in the peripheral region II is smaller than the width of the groove 502 in the central region I.

Specifically, in the direction parallel to the arrangement direction of the plurality of battery pieces in the same battery string, the first width w1 is 3mm to 15mm, such as 4mm, 6mm, 10mm, and 12mm, and the second width w2 is 5mm to 20mm, such as 6mm, 10mm, 15mm, and 18 mm.

Fig. 9 is a schematic view of another cross-sectional structure of fig. 8 cut along the AA1 direction and the BB1 direction, below the dashed line. As shown in fig. 9, in another example, in a cross-sectional direction perpendicular to the connection line, that is, in a direction parallel to the arrangement direction of the plurality of battery pieces in the same battery string, the cross-sectional shape of the groove 502 in the peripheral region II may be different from the cross-sectional shape of the groove 502 in the central region I, and the depth h of the groove 502 in the peripheral region II is the same as the depth h of the groove 502 in the central region I, and in a cross-sectional direction parallel to the arrangement direction of the plurality of battery pieces in the same battery string, the cross-sectional width of the groove 502 in the peripheral region II is greater than the cross-sectional width of the groove 502 in the central region I. Specifically, the cross-sectional shape of the groove 502 in the central region I may be an inverted triangle, and the cross-sectional shape of the groove 502 in the peripheral region II may be an arc.

The cross-sectional shape of the groove 502 of the peripheral region II and the cross-sectional shape of the groove 502 of the central region I may be different in a direction parallel to the arrangement direction of the plurality of battery pieces in the same battery string. Thus, even if the cross-sectional widths and/or depths of the grooves 502 of the central region I and the peripheral region II are the same, by arranging the grooves 502 of the central region I and the peripheral region II to have different shapes, it can be ensured that the cross-sectional area of the grooves 502 of the peripheral region II is larger than the cross-sectional area of the grooves 502 of the central region I in the direction parallel to the arrangement direction of the plurality of battery pieces in the same battery string.

It is understood that no matter how the shape, width or depth of the grooves 502 of the peripheral region II and the central region I are set, the volume of the grooves 502 of the peripheral region II may be ensured to be larger than the volume of the grooves 502 of the central region I, or the cross-sectional area of the grooves 502 of the peripheral region II may be ensured to be larger than the cross-sectional area of the grooves 502 of the central region I in the direction parallel to the arrangement direction of the plurality of battery pieces in the same battery string. For example, the cross-sectional width of the groove 502 of the peripheral region II is the same as the cross-sectional width of the groove 502 of the central region I and the depth thereof is the same in the direction parallel to the arrangement of the plurality of battery pieces in the same battery string, and the cross-sectional shape of the groove 502 of the peripheral region II is different from the cross-sectional shape of the groove 502 of the central region I in the direction parallel to the arrangement of the plurality of battery pieces in the same battery string. Or, in the direction parallel to the arrangement direction of the plurality of battery pieces in the same battery string, the cross-sectional width of the groove 502 in the peripheral area II is greater than the cross-sectional width of the groove 502 in the central area I, and the depth of the groove 502 in the peripheral area II is greater than the depth of the groove 502 in the central area I.

In one example, as shown in fig. 8, the same groove 502 spans the peripheral region II and the central region I; in another example, as shown in fig. 10, the grooves 502 located in the peripheral region II are separated from the grooves located in the central region I.

In addition, as shown in fig. 8 or fig. 10, a groove 502 of the same peripheral region II may cross the peripheral region II in the long side direction along the first face. In other embodiments, at least 2 mutually discrete grooves may be provided in the same peripheral region along the long side direction of the first surface, a plurality of mutually discrete grooves may be provided in the central region, and the pitch between adjacent grooves matches the pitch between cell strings constituting the photovoltaic module along the long side direction of the first surface.

In the production stage, the adhesive film 501 having the grooves 502 can be produced by a calender roll having a periodic convex structure.

In the adhesive film 501 provided in this embodiment, the groove 502 is not only located in the peripheral region II but also located in the central region I, and the volume of the groove 502 in the peripheral region II is greater than the volume of the groove 502 in the central region I. Therefore, the pressure on the overlapped area of the central area I and the peripheral area II can be reduced, the adhesive film 501 can be guaranteed to have a good packaging effect, the problem that the packaging effect is poor due to the fact that the amount of the adhesive film 501 is too small is solved, the yield of the photovoltaic module is further improved, and the service life of the photovoltaic module is prolonged.

If the size of the groove in the central area is the same as that of the groove in the peripheral area, the total volume of the grooves of the adhesive film is large, so that the amount of the adhesive film is too small under the condition that the thickness of the adhesive film is not changed, and the problem of poor packaging can occur when the adhesive film is used for packaging, so that the yield and the service life of the photovoltaic module are influenced.

The sixth embodiment of the present invention further provides an adhesive film, which is substantially the same as the foregoing embodiments except that the depth of the groove in the peripheral region is greater than the depth of the groove in the central region. The adhesive film provided in this embodiment will be described in detail below with reference to the accompanying drawings, and the same or corresponding parts as those in the foregoing embodiment can be referred to in the detailed description of the foregoing embodiment, and will not be described in detail below.

Fig. 11 and 12 are schematic structural views of an adhesive film according to a sixth embodiment of the invention.

Referring to fig. 11, fig. 11 is a schematic top view of the adhesive film 601, which includes a first surface and a second surface, and includes a central area I and a peripheral area II; grooves 602 extending from the first surface to the second surface, wherein the grooves 602 are located in the central region I and the peripheral region II, and the position of each groove 602 is opposite to the position of at least one overlapping region; the volume of the recess 602 facing each overlapping area of the peripheral area II is a first volume, the volume of the recess 602 facing each overlapping area of the central area I is a second volume, and the first volume is larger than the second volume.

Specifically, the adhesive film is used for forming a photovoltaic module with a battery string, and adjacent battery pieces in the battery string are provided with connecting lines in an overlapping area, and the extending direction of the connecting lines is perpendicular to the AA1 direction. The cross-sectional area of the grooves 602 in the peripheral region II is larger than that of the grooves 602 in the central region I in a direction perpendicular to the connecting line, i.e., in a direction parallel to the arrangement direction of the plurality of battery pieces in the same battery string.

In this embodiment, in the direction parallel to the arrangement direction of the plurality of battery pieces in the same battery string, the cross-sectional width w of the groove 602 in the peripheral region II is the same as the cross-sectional width w of the groove 602 in the central region I.

In one example, as shown in fig. 12, the cross-sectional structure of fig. 11 along the direction AA1 and the direction BB1 is shown above the dashed line in fig. 12, and the depth of the grooves 602 in the peripheral region II is greater than the depth of the grooves 602 in the central region I. Specifically, the depth of the grooves 602 of the central region I is a first depth h1, the depth of the grooves 602 of the peripheral region II is a second depth h2, and the second depth h2 is greater than the first depth h 1. Wherein, in the direction parallel to the arrangement direction of a plurality of battery pieces in the same battery string, the cross-sectional shape of the groove 602 in the central area I is the same as the cross-sectional shape of the groove 602 in the peripheral area II. In other embodiments, the cross-sectional shape of the groove in the central region may also be different from the cross-sectional shape of the groove in the peripheral region in a direction parallel to the arrangement direction of the plurality of battery pieces in the same battery string.

Fig. 12 is a schematic cross-sectional view taken along the AA1 direction and the BB1 direction in fig. 11, shown below the dashed line. As shown in fig. 12, in another example, the depth h of the grooves 602 in the peripheral region II is the same as the depth h of the grooves 602 in the central region I, and the cross-sectional width w of the grooves 602 in the peripheral region II may also be equal to the cross-sectional width w of the grooves 602 in the central region I in the direction parallel to the arrangement direction of the plurality of battery pieces in the same battery string; the cross-sectional shape of the groove 602 in the peripheral region II may be different from the cross-sectional shape of the groove 602 in the central region I in a direction parallel to the arrangement direction of the plurality of battery pieces in the same battery string. Specifically, the cross-sectional shape of the groove 602 in the central region I may be an inverted triangle, and the cross-sectional shape of the groove 102 in the peripheral region II may be a circular arc.

The seventh embodiment of the present invention further provides an adhesive film, which is substantially the same as the adhesive film of the previous embodiment, except that the extending direction of the groove is the extending direction of the short side of the first surface. The adhesive film provided by the seventh embodiment will be described in detail below with reference to the accompanying drawings, and the same or corresponding parts as those in the foregoing embodiments can be referred to the foregoing embodiments, and will not be described in detail below. Fig. 13 is a schematic structural diagram of an adhesive film according to a seventh embodiment of the invention, which includes a top-view structural diagram and a cross-sectional structural diagram along a CC1 direction.

Referring to fig. 13, in the present embodiment, the adhesive film 701 includes a groove 702 extending from the first surface to the second surface, the first surface includes a central area I and a peripheral area II, the groove 702 is located in the central area I and the peripheral area II, a volume of the groove facing each overlapping area located in the peripheral area is a first volume, a volume of the groove facing each overlapping area located in the central area is a second volume, and the first volume is greater than the second volume.

In this embodiment, the first surface is rectangular, and the extending direction of the same groove 702 is the same as the extending direction of the short side of the first surface.

The overlapping area of adjacent cells of the same cell string is provided with a connecting line, the extending direction of the connecting line is perpendicular to the CC1 direction, namely the extending direction of the connecting line is the same as the extending direction of the short side of the first surface, and the adjacent cells are arranged along the long side of the first surface. Or, the arrangement direction of a plurality of battery pieces in the same battery string is parallel to the CC1 direction.

In this embodiment, in the direction parallel to the arrangement direction of the plurality of battery pieces in the same battery string, the cross-sectional area of the groove 702 in the peripheral region II is larger than the cross-sectional area of the groove 702 in the central region I.

In one example, the depth of the grooves 702 in the central region I is the same as the depth of the grooves 702 in the peripheral region II, and the cross-sectional width of the grooves 702 in the peripheral region II is greater than the cross-sectional width of the grooves 702 in the central region I in a direction parallel to the arrangement direction of the plurality of battery pieces in the same battery string. Specifically, the grooves 702 of the central region I have a first width w1, and the grooves 702 of the peripheral region II have a second width w2, the second width w2 being greater than the first width w 1. The cross-sectional shapes of the grooves 702 in the central region I and the grooves 702 in the peripheral region II may be the same, such as square; the cross-sectional shapes of the grooves 702 in the central region I and the grooves 702 in the peripheral region II may also be different.

In another example, the depth of the groove 702 in the central area I is less than the depth of the groove 702 in the peripheral area II, and the sectional width of the groove 702 in the peripheral area II is equal to the sectional width of the groove 702 in the central area I in the direction parallel to the arrangement direction of the plurality of battery pieces in the same battery string; or, the depth of the groove 702 in the central area I is less than the depth of the groove 702 in the peripheral area II, and the cross-sectional width of the groove 702 in the peripheral area II is less than the cross-sectional width of the groove 702 in the central area I in the direction parallel to the arrangement direction of the plurality of battery pieces in the same battery string.

As shown in fig. 13, the same groove 702 located in the peripheral region II crosses the short side of the first face, and the same groove 702 located in the central region I crosses the short side of the first face. In other embodiments, a plurality of mutually discrete recesses are provided in the direction extending along the short sides of the first face. The number of the grooves extending in the short side direction of the first face can be reasonably set according to the type of the cell string of the photovoltaic module.

An eighth embodiment of the present invention further provides a glue film, different from the previous embodiments, wherein the peripheral areas are respectively located at two opposite sides of the central area, and the peripheral area surrounds the central area in the eighth embodiment. Fig. 14 is a schematic top view of the adhesive film according to the eighth embodiment.

Referring to fig. 14, the adhesive film 801 has a first surface and a second surface, and the first surface has a central area and a peripheral area surrounding the central area, wherein the central area is located inside the dashed line frame a, and the peripheral area is located outside the dashed line frame a; a groove 802 extending from the first face to the second face, the groove 802 being located in the central region and the peripheral region; the volume of the groove opposite to each overlapping area positioned in the peripheral area is a first volume, the volume of the groove opposite to each overlapping area positioned in the central area is a second volume, and the first volume is larger than the second volume.

For the detailed description of the first volume and the second volume, reference may be made to the detailed description of the foregoing embodiments, which are not repeated herein.

In this embodiment, the overlapping region of the cell string has a connecting line, and in a cross-sectional direction perpendicular to the connecting line, i.e. in a direction parallel to the arrangement direction of the plurality of cells in the same cell string, the cross-sectional width of the groove 802 in the peripheral region is greater than the cross-sectional width of the groove 802 in the central region. In other embodiments, the cross-sectional width of the groove in the peripheral region may be equal to the cross-sectional width of the groove in the central region.

Regarding the dimensional relationship between the grooves in the peripheral region and the central region, reference may be made to the description of the foregoing embodiments, as long as the cross-sectional area of the grooves in the peripheral region is larger than that of the central region in the direction parallel to the arrangement direction of the plurality of battery pieces in the same battery string.

In other embodiments, the adhesive film has grooves extending from the first surface to the second surface, the grooves including a plurality of grooves extending in a long side direction of the first surface and a plurality of grooves extending in a short side of the first surface; for a plurality of grooves extending along the same extending direction, the volume of the groove opposite to each overlapping area in the peripheral area is a first volume, the volume of the groove opposite to each overlapping area in the central area is a second volume, and the first volume is larger than the second volume. Specifically, for a plurality of grooves extending in the same extending direction, the overlapping region of the cell string has a connecting line, and the sectional area of the groove in the peripheral region is larger than that of the groove in the central region in a sectional direction perpendicular to the connecting line.

Correspondingly, the embodiment of the invention also provides a photovoltaic module, which comprises the adhesive film of any one of the embodiments.

Fig. 15 is a schematic cross-sectional structure view of a photovoltaic module according to an embodiment of the present invention.

Referring to fig. 15, the photovoltaic module includes: the battery pack comprises a first cover plate 13, a first adhesive film 15, a battery string, a second adhesive film 14 and a second cover plate 11 which are sequentially stacked, wherein at least one of the first adhesive film 15 or the second adhesive film 14 adopts the adhesive film provided by any one of the embodiments, the battery string comprises a plurality of battery pieces 18, the adjacent battery pieces 18 are provided with overlapping regions 17, and the position of each groove 12 is opposite to the position of at least one overlapping region 17.

Photovoltaic module can be single glass photovoltaic module, also can be dual glass photovoltaic module. The battery string may further include: the solder strips located in the overlapping regions 17 are used to electrically connect the adjacent battery cells 17.

One of the first cover plate 13 and the second cover plate 11 is a front plate, and the other is a back plate. In this embodiment, the second cover plate 11 is a back plate, and the first cover plate 13 is a front plate. The first cover plate 13 is a glass cover plate, and the second cover plate 11 is a glass cover plate, a polymer cover plate or a stainless steel cover plate.

In this embodiment, the first adhesive film 15 is the adhesive film of the above embodiment, that is, the first adhesive film 15 has a groove 12; the second adhesive film 14 is the adhesive film in the previous embodiment, the second adhesive film 14 has a groove 12, and the groove 12 in the second adhesive film 14 is opposite to the groove 12 in the first adhesive film 15. That is, the same overlap 17 is directly opposite 2 grooves 12.

The large arrows in fig. 15 indicate the lamination pressure to which the photovoltaic module is subjected during the lamination stage. The grooves 12 may cushion the pressure to which the overlapping region 17 is subjected during the lamination stage, reducing the pressure to which the overlapping region 17 is subjected, thereby reducing the risk of subfissure and fragmentation of the overlapping region 17.

In addition, in the present embodiment, the first adhesive film 15 and the second adhesive film 14 have a central region I and a peripheral region II, and the groove 12 is located in both the central region I and the peripheral region II. For a detailed description of the grooves 12 in the central region I and the peripheral region II, reference is made to the description of the foregoing embodiments, which are not repeated herein.

It should be noted that, in other embodiments, the grooves may be only located in the peripheral region, and the central region is not provided with grooves.

The present invention further provides a photovoltaic module, different from the previous embodiment, in this embodiment, the second adhesive film is the adhesive film, and the second adhesive film has a groove. Fig. 17 is a schematic cross-sectional view of a photovoltaic module according to another embodiment of the present invention.

Referring to fig. 17, the photovoltaic module includes: the battery pack comprises a first cover plate 23, a first adhesive film 25, a battery string, a second adhesive film 24 and a second cover plate 21 which are sequentially stacked, wherein at least one of the first adhesive film or the second adhesive film adopts the adhesive film provided by any one of the above embodiments, the battery string comprises a plurality of battery pieces 28, the adjacent battery pieces 28 are provided with overlapping areas 27, and the position of each groove 22 is opposite to the position of at least one overlapping area 27.

The second adhesive film 24 adopts the adhesive film, and the second adhesive film 24 is provided with a groove 22; during the lamination process of the photovoltaic module, pressure is applied to the surface of the second cover sheet 21 away from the second adhesive film 24. The groove 22 can buffer the pressure applied to the overlapping region 27, thereby improving the yield of the photovoltaic module.

The large arrows in fig. 17 indicate the lamination pressure to which the photovoltaic module is subjected during the lamination stage. In this embodiment, the second adhesive film 24 has a central region I and a peripheral region II, and the groove 22 is located in both the central region I and the peripheral region II.

In other embodiments, the first adhesive film may have a groove, and the second adhesive film does not have a groove; in the laminating stage, after the overlapping region is stressed, the groove below the overlapping region provides a pressure releasing space for the overlapping region, and the pressure of the overlapping region 27 can be relieved to a certain extent, so that the yield of the photovoltaic module is improved.

The present invention further provides a photovoltaic module, which is different from the foregoing embodiments in that in the present embodiment, the first adhesive film and the second adhesive film are the adhesive films, and the grooves in the second adhesive film and the grooves in the first adhesive film are staggered. Fig. 18 is a schematic cross-sectional structure view of a photovoltaic module according to still another embodiment of the present invention.

Referring to fig. 18, the photovoltaic module includes: the first cover plate 33, the first adhesive film 35, the battery string, the second adhesive film 34 and the second cover plate 31 are sequentially stacked, the adhesive films provided by any one of the embodiments are adopted for the first adhesive film 35 and the second adhesive film 34, the grooves 32 are formed in the adhesive films, the battery string comprises a plurality of battery pieces 38, the adjacent battery pieces 38 are provided with overlapping areas 37, and the position of each groove 32 is opposite to the position of at least one overlapping area 37.

In this embodiment, the grooves 32 in the second adhesive film 34 and the grooves 32 in the first adhesive film 35 are staggered. In addition, the adhesive film includes a central region I and a peripheral region II, and the grooves 32 are located in the central region I and the peripheral region II, and one groove or a plurality of grooves may be disposed in the same peripheral region II, for example, one groove 32 may be disposed only in the peripheral region II of the first adhesive film 34, or one groove 32 may be disposed only in the peripheral region II of the second adhesive film 34.

Compared with the previous embodiment, in the case that the thicknesses of the first adhesive film 35 and the second adhesive film 34 are the same, the material contents of the first adhesive film 35 and the second adhesive film 34 are larger in the present embodiment. Therefore, in the embodiment, while the risk of cracking in the overlapping area of the central area I and the peripheral area II is reduced, the packaging effect of the first adhesive film 35 and the second adhesive film 34 is improved.

Correspondingly, the embodiment of the invention also provides a manufacturing method of the photovoltaic module. The manufacturing method of the photovoltaic module comprises the following steps:

referring to fig. 15, a first cover plate 13, a first adhesive film 15, a battery string, a second adhesive film 14, and a second cover plate 11 are sequentially stacked to form a stacked structure, at least one of the first adhesive film 15 or the second adhesive film 14 is the adhesive film provided in any of the foregoing embodiments, the battery string includes a plurality of battery pieces 18, adjacent battery pieces 18 have overlapping regions 17, and a position of each groove 12 is opposite to a position of at least one overlapping region 17.

In this embodiment, the first adhesive film 15 and the second adhesive film 14 are both the aforementioned adhesive films, and the groove 12 in the first adhesive film 15 is disposed opposite to the groove 12 in the second adhesive film 14. The adhesive film includes a central region I and a peripheral region II, and the groove 12 is located in the central region I and the peripheral region II.

The grooves 12 correspond to the positions of the overlapping regions 17 of the battery pieces 18 in the stacking stage, and can play a role in positioning the battery strings.

It is understood that, in other embodiments, as shown in fig. 17, one of the first adhesive film or the second adhesive film adopts the adhesive film of the previous embodiment; alternatively, as shown in fig. 18, one of the first adhesive film and the second adhesive film is the adhesive film of the foregoing embodiment, and the grooves in the first adhesive film and the grooves in the second adhesive film are staggered.

In addition, it should be noted that, in other embodiments, the overlapping regions of the adjacent battery pieces have connecting lines, and the shape and size of the groove in the central region may also be the same as those in the peripheral region in the direction perpendicular to the connecting lines.

With reference to fig. 15 and 16, fig. 16 is a schematic cross-sectional view of a photovoltaic module after lamination processing, and the lamination processing is performed to form a laminated photovoltaic module.

Specifically, air extraction treatment is carried out to remove gas in the laminated structure; entering a laminating stage, wherein before the laminating stage, the laminated structure of the peripheral area II is upwarped relative to the central area I, pressure is applied to the second cover plate 11, the laminated structure is subjected to heat treatment to melt the first adhesive film 15 and the second adhesive film 14, and the grooves 12 are filled to form the adhesive film layer 10; the recesses 12 of the peripheral zone II cushion the pressure to which the overlapping zone is subjected from the second cover plate 11, reducing the pressure to which the overlapping zone is subjected and thus reducing the risk of the overlapping zone 17 breaking. Likewise, the pressure experienced by the overlapping region 17 of the central region I is also reduced.

The manufacturing method of the photovoltaic module provided by the embodiment is beneficial to improving the yield of the manufactured photovoltaic module and improving the reliability of the photovoltaic module.

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.

Claims

1. An adhesive film for encapsulating a cell string in a photovoltaic module, the cell string including a plurality of cells, adjacent ones of the cells having an overlap region, the adhesive film having a first side facing the cell string and a second side opposite to the first side, comprising:

at least one groove extending from said first face to said second face, each said groove being positioned directly opposite at least one said overlap region;

the orthographic projection of the overlapping area on the first surface is a first projection, the orthographic projection of the groove on the first surface is a second projection, and the boundary of the first projection is overlapped with the boundary of the second projection in the arrangement direction of a plurality of battery pieces parallel to the same battery string; or, the boundary of the first projection is located within the boundary of the second projection;

in the arrangement direction parallel to the plurality of battery pieces in the same battery string, the cross section of the groove is in a shape of circular arc, inverted trapezoid, square or inverted triangle.

2. The adhesive film of claim 1, wherein the same groove spans a plurality of the overlapping regions.

3. The adhesive film according to claim 1 or 2, wherein adjacent battery pieces have connecting lines in the overlapping region, and the length direction of the groove is the same as the extending direction of the connecting lines.

4. The adhesive film according to claim 1, wherein the first surface comprises a central region and a peripheral region located outside the central region, the grooves are located in the peripheral region, and each groove is located opposite to at least one of the overlapping regions.

5. The adhesive film of claim 4, wherein the groove is further located in the central region, the volume of the groove opposite to each of the overlapping regions located in the peripheral region is a first volume, the volume of the groove opposite to each of the overlapping regions located in the central region is a second volume, and the first volume is greater than the second volume.

6. The adhesive film according to claim 5, wherein the cross-sectional area of the groove in the peripheral region is larger than the cross-sectional area of the groove in the central region in a direction parallel to the arrangement direction of the plurality of battery pieces in the same battery string.

7. The adhesive film according to claim 5, wherein the depth of the groove of the peripheral region is greater than the depth of the groove of the central region; or, in the direction parallel to the arrangement direction of the plurality of battery pieces in the same battery string, the cross-sectional width of the groove in the peripheral region is greater than the cross-sectional width of the groove in the central region.

8. The adhesive film of claim 5, wherein the same groove spans the central region and the peripheral region; alternatively, the grooves in the peripheral region and the grooves in the central region are separated from each other.

9. The adhesive film of claim 5, wherein the first surface is rectangular, the central region and the peripheral region both span the short side of the first surface, and the peripheral region is disposed on opposite sides of the central region; alternatively, the first face is square or circular in shape, and the peripheral region surrounds the central region.

10. The adhesive film of any one of claims 1-2 and 4-9, wherein the depth of the groove is less than or equal to 1/2 of the thickness of the adhesive film.

11. The adhesive film of any one of claims 1-2 and 4-9, further comprising: and the plurality of convex structures are positioned on the surface of the groove.

12. A photovoltaic module comprising the adhesive film according to any one of claims 1 to 11.

13. A method of manufacturing a photovoltaic module, comprising:

sequentially stacking a first cover plate, a first adhesive film, a battery string, a second adhesive film and a second cover plate, wherein at least one of the first adhesive film or the second adhesive film adopts the adhesive film as defined in any one of claims 1 to 11, the battery string comprises a plurality of battery pieces, adjacent battery pieces are provided with overlapping regions, and the position of each groove is opposite to the position of at least one overlapping region;

and carrying out lamination treatment to form the laminated photovoltaic module.

14. The manufacturing method according to claim 13, wherein the first adhesive film is the adhesive film according to any one of claims 1 to 11, and the first adhesive film has a groove; the adhesive film of any one of claims 1-11 is used as the second adhesive film, the second adhesive film has a groove, and in the stacking process, the groove of the second adhesive film is disposed opposite to the groove of the first adhesive film, or the groove of the second adhesive film and the groove of the first adhesive film are disposed in a staggered manner.

15. The manufacturing method according to claim 13, wherein the second adhesive film is the adhesive film according to any one of claims 1 to 11, and the second adhesive film has a groove; and applying pressure to the surface of the second cover plate far away from the second adhesive film in the laminating process.

16. The manufacturing method according to claim 13, wherein the adhesive film having the grooves is manufactured by a calender roll designed with a convex structure.