CN111739966B - Cover plate and photovoltaic module - Google Patents

Abstract

The embodiment of the invention provides a cover plate and a photovoltaic module, wherein the cover plate is used for forming the photovoltaic module with a battery string, the battery string comprises a plurality of battery pieces, adjacent battery pieces are provided with overlapping areas, the photovoltaic cover plate is provided with a first surface facing the battery string and a second surface opposite to the first surface, and the first surface comprises a central area and a peripheral area positioned outside the central area, and the photovoltaic module is characterized by comprising: at least one groove extending from the first face to the second face, the grooves being located in the peripheral region, and each groove being located opposite to at least one of the overlapping regions. The embodiment of the invention improves the assembly efficiency of the photovoltaic assembly and is beneficial to improving the yield of the photovoltaic assembly.

Description

Cover plate and photovoltaic module

Technical Field

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

Background

With the remarkable problems of energy shortage, global temperature rise, and environmental deterioration, solar energy is receiving increasing 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 on the light energy. Specifically, the high assembly efficiency is beneficial to reducing the cost in the manufacturing process of the photovoltaic assembly and reducing the occupied area required in the operation stage of the power station; in addition, under the condition that the component power of the photovoltaic component is the same, the higher the component efficiency is, the lower the size of the photovoltaic component is, and the lower the weight of the corresponding photovoltaic component is.

However, the efficiency of the photovoltaic module is improved, and the yield of the photovoltaic module is lowered.

Disclosure of Invention

The technical problem solved by the embodiment of the invention is to provide a cover plate and a photovoltaic module, and the problem of low yield of the photovoltaic module is solved.

To solve the above-mentioned problems, an embodiment of the present invention provides a cover plate for forming a photovoltaic module with a cell string, the cell string including a plurality of cells, and adjacent cells having an overlapping region, the photovoltaic cover plate having a first face facing the cell string and a second face opposite to the first face, the first face including a central region and a peripheral region located outside the central region, including: at least one groove extending from the first face to the second face, the grooves being located in the peripheral region, and each groove being located opposite to at least one of the overlapping regions.

In addition, the groove is also located in the central area, wherein the volume of the groove opposite to each overlapping area located in the peripheral area is a first volume, the volume of the groove opposite to each overlapping area located 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 of the peripheral region is larger than the cross-sectional area of the groove of the central region.

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

In addition, the cross-sectional shape of the groove of the peripheral region is different from the cross-sectional shape of the groove of the central region in the direction parallel to the arrangement direction of the plurality of battery cells in the same battery string.

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

In addition, the first surface is rectangular in shape, the central area and the peripheral area both cross the short side of the first surface, and the peripheral areas are respectively positioned on two opposite sides of the central area; or 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 cover plate.

In addition, the cover plate includes a glass cover plate, a polymer cover plate, or a stainless steel cover plate.

In addition, 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 comprises a circular arc shape, an inverted trapezoid shape, a square shape or an inverted triangle shape.

In addition, the method further comprises the steps of: a plurality of raised structures located on the surface of the recess.

Correspondingly, the embodiment of the invention also provides a photovoltaic module, which comprises: the cover plate; the battery string comprises a plurality of battery pieces, wherein 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; the adhesive film is positioned between the cover plate and the battery string and also positioned in the groove.

In addition, the apron is the backplate, photovoltaic module still includes: the transparent front plate is positioned at one side of the battery string away from the back plate; or the cover plate is a transparent front plate, and the photovoltaic module further comprises: and the backboard is positioned at one side of the battery string away from the transparent front board.

In addition, the cover plate includes: the back plate and the transparent front plate are respectively positioned at two opposite sides of the battery string, and each overlapping area is opposite to the grooves in the back plate and/or the grooves in the transparent front plate.

In addition, the grooves in the back plate are opposite to the grooves in the transparent front plate; or the positions of the grooves in the back plate and the grooves in the transparent front plate are staggered. Compared with the prior art, the technical scheme provided by the embodiment of the invention has the following advantages:

The embodiment of the invention provides a cover plate with excellent structural performance, which is provided with a first surface and a second surface which are opposite, wherein the first surface is provided with a central area and a peripheral area; at least one groove extending from the first face to the second face, the grooves being located in the peripheral region, and each groove being located opposite to the at least one overlapping region. In the laminating stage of adopting this apron preparation photovoltaic module, the recess can cushion the lamination pressure that the battery piece overlap region received, plays the effect that reduces the hidden crack in overlap region and broken piece risk to be favorable to improving photovoltaic module's module efficiency, improve photovoltaic module's yield.

In addition, the groove is also located in the central area, the volume of the groove opposite to each overlapping area located in the peripheral area is a first volume, the volume of the groove opposite to each overlapping area located in the central area is a second volume, and the first volume is larger than the second volume. Therefore, hidden cracking or fragmentation of the overlapping area of the central area and the peripheral area can be avoided at the same time, and the cover plate with the groove still has enough strength due to the fact that the groove of the central area is relatively smaller, so that the cover plate is prevented from being broken during manufacturing of the photovoltaic module or using of the photovoltaic module, the yield of the photovoltaic module is further improved, and the service life of the photovoltaic module is prolonged.

Correspondingly, the photovoltaic module provided by the embodiment of the invention comprises the cover plate, and the cover plate is internally provided with the groove, so that the contact area between the cover plate and the adhesive film is increased, the adhesion between the cover plate and the adhesive film is improved, and the reliability of the photovoltaic module is improved.

Drawings

One or more embodiments are illustrated by way of example and not limitation in the figures of the accompanying drawings, which are not to be construed as limiting the embodiments unless specifically indicated otherwise.

Fig. 1 is a schematic structural view of a cover plate according to a first embodiment of the present invention;

Fig. 2 to 8 are schematic structural views of a cover plate according to a second embodiment of the present invention;

fig. 9 to 11 are schematic structural views of a cover plate according to a third embodiment of the present invention;

Fig. 12 to 14 are schematic structural views of a cover plate according to a fourth embodiment of the present invention;

Fig. 15 is a schematic top view of a cover plate according to a fifth embodiment;

fig. 16 is a schematic top view of a cover plate according to a sixth embodiment;

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

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

Fig. 19 is a schematic cross-sectional view of a photovoltaic module according to another embodiment of the present invention.

Detailed Description

As known from the background art, the prior art has the problem that the yield of the photovoltaic module becomes low while improving the module efficiency of the photovoltaic module.

In order to improve the assembly efficiency of the photovoltaic assembly, stitch welding technology can be used to eliminate the gaps between the battery pieces, that is, in the battery string of the photovoltaic assembly, an overlapping area is formed between adjacent battery pieces, and in the overlapping area, there is not only overlapping between the adjacent battery pieces, but also a welding strip for electrically connecting the adjacent battery pieces. In the production process of the photovoltaic module, under the action of lamination pressure, the overlapped areas have higher hidden cracking or fragmentation risks than other areas, so that the yield of the manufactured photovoltaic module is affected. The inventor of the present application has found that a photovoltaic module has a central region and a peripheral region located outside the central region, and that the risk of occurrence of hidden cracks or fragments in an overlapping region located at the peripheral region is higher than in an overlapping region at the peripheral region.

Further analysis found that the causes of this problem included: the manufacturing steps of the photovoltaic module comprise a lamination stage and a lamination stage; in the laminating stage, the back plate, the lower adhesive film, the battery string, the upper adhesive film and the front plate are laminated in sequence to form a laminated structure; in the lamination stage, firstly, pumping treatment is carried out to pump gas among layers of the laminated structure, and pressurizing treatment is carried out after the pumping treatment; the peripheral area is tilted upward during or after the air extraction process, and the laminated structure is subjected to a heating process during or after the air extraction process, which also increases the degree of tilt of the peripheral area to some extent. To eliminate the upwarp 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 risk of hidden cracking or chipping of the overlapped zone of the peripheral zone; or to eliminate the upwarp of the peripheral zone, even if the pressure applied to the peripheral zone is the same as the pressure applied to the central zone during the lamination stage, the deformation of the back plate and the front plate of the peripheral zone under pressure is greater than that of the back plate and the front plate of the central zone during the lamination stage, which also results in the risk of hidden cracking or chipping of the overlapped zone of the peripheral zone more easily than that of the central zone.

In order to solve the problems, the embodiment of the application provides a cover plate, wherein a groove is arranged in the peripheral area of the cover plate, so that the pressure applied to the overlapping area of the peripheral area is buffered, the risk of hidden cracking or chipping of the overlapping area in the manufacturing process of the photovoltaic module is avoided, and the yield of the photovoltaic module manufactured by using the cover plate is improved. For the purpose of making the objects, technical solutions and advantages of the embodiments of the present application more apparent, the embodiments of the present application will be described in detail below with reference to the accompanying drawings. However, it will be understood by those of ordinary skill in the art that in various embodiments of the present application, numerous specific details are set forth in order to provide a thorough understanding of the present application. The claimed application may be practiced without these specific details and with various changes and modifications based on the following embodiments.

Fig. 1 is a schematic structural diagram of a cover plate according to a first embodiment of the present invention, including a schematic top view and a schematic cross-sectional view along aa 1.

Referring to fig. 1, in the present embodiment, a cover plate 01 is used to form a photovoltaic module with a cell string, where the cell string includes a plurality of cells, and adjacent cells have overlapping areas, the cover plate has a first face Front facing the cell string and a second face Back opposite to the first face, and the first face includes a central area I and a peripheral area II located outside the central area I; the cover plate includes: at least one groove 02 extending from the first face Front to the second face Back, the grooves 02 being located in the peripheral zone II, and each groove 02 being located opposite to the location of at least one overlapping zone.

The cover plate provided in this embodiment will be described in detail with reference to the accompanying drawings.

In one example, the cover 01 is a front plate of a photovoltaic module, and accordingly, the cover 01 may be a glass cover. In another example, the cover 01 is a back sheet of a photovoltaic module, and accordingly, the cover 01 may be a glass cover, a polymer cover, or a stainless steel cover. In yet another example, the cover plate 01 may be a front plate as well as a back plate of a photovoltaic module.

The peripheral zone II may be located on opposite sides of the central zone I; or the peripheral zone II may surround the central zone I.

The width of the peripheral zone II may be at least across the width of 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 area II can be 1/N of the width of a single battery string, and N is larger than 1; thus, the peripheral region II faces 1/N of the cell strings when the photovoltaic module is constructed. Or the width of the peripheral area II can be the width of N battery strings and 1/N width of a single battery string, and 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 the width in the direction perpendicular to the arrangement direction of the plurality of battery pieces in the same battery string.

It will be appreciated 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 with a larger area is prone to the problem of upwarp, and the width of the peripheral area II is larger; when the size of the first face Front is smaller, the area of the region where the warpage problem occurs is smaller, and the width of the peripheral region II is larger.

It should be 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 present embodiment, the first face Front is rectangular, the central area I and the peripheral area II are both arranged across the short side of the first face Front and along the long side of the first face Front, and the peripheral areas II are respectively located on opposite sides of the central area I. In other embodiments, the first face is rectangular or circular in shape, with the peripheral region surrounding the central region.

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

It is understood that, in other embodiments, the shape of the first surface may be triangular, trapezoidal, regular polygonal, or irregular, and the area where upwarp is likely to occur may be reasonably expected according to the shape of the first surface, and the corresponding area where upwarp is likely to occur is a peripheral area. For example, the first surface is triangular in shape, and the peripheral regions are located in the areas where the three corners of the first surface are located, and the first surface has a central region and three peripheral regions.

Because the peripheral area II is provided with the groove 02, in the lamination process of manufacturing the photovoltaic module by utilizing the cover plate 01, the lamination pressure born by the cover plate 01 in the area corresponding to the groove 02 is transmitted to the overlapped area after passing through the groove 02, so that the pressure born by the overlapped area opposite to the groove 02 is reduced or eliminated, the risk of hidden cracking or breaking of the overlapped area of the peripheral area II is greatly reduced, and the yield of the photovoltaic module is improved; in addition, in the lamination stage, the adhesive film at the groove 02 is heated and melted, the groove 02 is filled, and the flowable area of the adhesive film is increased, so that the pressure applied to the overlapped 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 02 is the same as the extending direction of a connecting line of the adjacent battery pieces of the same battery string in the overlapping area; or, the extending direction of the same groove 02 is the same as the arrangement direction of a 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 battery strings. In this embodiment, the same groove 02 extends along a transverse direction, different grooves 02 are arranged at intervals in a longitudinal direction, the transverse direction refers to a long side direction of the first surface, and the longitudinal direction refers to a short side direction of the first surface; correspondingly, when the photovoltaic module is formed, the arrangement of the battery pieces on the peripheral area II is that each battery piece in the same battery string is longitudinally arranged, and the extending direction of the connecting line of the overlapping area in the same battery string is transversely extended. In other embodiments, the same groove may extend longitudinally, with different grooves being laterally spaced apart; correspondingly, when the photovoltaic module is formed, the arrangement of the battery pieces on the peripheral area is that each battery piece in the same battery string is transversely arranged, and the extending direction of the connecting line of the overlapping area in the same battery string is longitudinally extending. In yet another embodiment, the grooves include a first groove extending in a lateral direction and a second groove extending in a longitudinal direction, and the respective battery strings include: a first battery string with each battery piece arranged along the longitudinal direction and a second battery string with each battery piece arranged along the transverse direction.

In addition, in this embodiment, in the extending direction of the connecting lines of the adjacent battery pieces in the overlapping area along the same battery string, that is, in the direction perpendicular to the arrangement direction of the plurality of battery pieces in the same battery string, the same peripheral area II has a groove 02, and the groove 02 may be opposite to one overlapping area of one battery string, or may be opposite to the overlapping area of at least 2 battery strings, that is, the cover plate 01 may be suitable for a gapless layout between battery strings or a gapless layout between battery strings. In other embodiments, the same peripheral region may also have at least 2 grooves in the extending direction of the connecting lines of the adjacent battery pieces in the overlapping region along the same battery string, and the spacing between the adjacent grooves is the same as the spacing between the adjacent battery strings, that is, the cover plate may be suitable for the inter-battery string gap layout.

The positions of the grooves 02 are opposite to the positions of the overlapped areas, and the distance between the adjacent grooves 02 is matched with the size of the battery piece. Specifically, the larger the cell size is, the larger the distance between adjacent grooves 02 is; the smaller the cell size, the smaller the pitch of adjacent grooves 02. In this embodiment, adjacent grooves 02 are arranged at equal intervals. In other embodiments, the spacing of adjacent grooves may also vary. Wherein, the size of the battery piece can be 150mm-250mm.

In this embodiment, the width of the cross section of the groove 02 is 5mm to 20mm, for example, 6mm, 10mm, 12mm, 15mm, 18mm, in the direction parallel to the arrangement direction of the plurality of battery pieces in the same battery string, i.e., in the direction perpendicular to the cross section of the connecting line.

In this embodiment, the cross-sectional shape of the groove 02 is circular arc in the direction parallel to the arrangement direction of the plurality of battery pieces in the same battery string, i.e., the cross-sectional direction perpendicular to the connecting line. In other embodiments, the cross-sectional shape of the groove may be inverted trapezoid, square or inverted triangle in a direction parallel to the arrangement direction of the plurality of battery cells in the same battery string.

In the direction parallel to the arrangement direction of the adjacent battery pieces of the same battery string, the width of the groove 02 is larger than or equal to the width of the overlapping area, so that the pressure born by each area of the overlapping area is further ensured to be smaller, and the risk of cracking or breaking the overlapping area is further reduced. Specifically, the orthographic projection of the overlapping area on the first surface is a first projection, the orthographic projection of the groove 02 on the first surface is a second projection, and in the direction parallel to the arrangement direction of the plurality of battery pieces in 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 02 is less than or equal to 1/2 of the thickness of the cover plate 01. In this way, the depth of the groove 02 occupies a moderate proportion of the thickness of the cover plate 01, so that the cover plate 01 in the area where the groove 02 is located still has good strength, thereby preventing the cover plate 01 from being broken. The depth of the groove 02 may also be greater than 1/6 of the thickness of the cover plate 01, for example, the depth of the groove 02 is 1/3, 1/4 or 1/5 of the thickness of the cover plate 01, so that the groove 02 has a large enough volume while ensuring the strength of the cover plate 01, and the pressure relieving or eliminating capability of the groove 02 is improved.

In this embodiment, the cover plate 01 may further include: a plurality of raised structures (not shown) located on the surface of the recess 02. The shape of the protruding structure can be triangular prism shape or semicircle shape, etc. These raised structures are advantageous for further relieving the pressure applied to the overlapping area in the lamination stage and for increasing the contact area between the cover plate 01 and the adhesive film so as to enhance the packaging strength between the cover plate 01 and the adhesive film.

In addition, the cover plate 01 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 semicircle shape. The size of the burr structure is smaller than that of the protruding structure, and the arrangement of the burr structure is not only beneficial to increasing friction force between the cover plate 01 and the adhesive film in the lamination stage, but also beneficial to relieving pressure born by the non-overlapping area during lamination and reducing risk of cracking of the non-overlapping area.

The peripheral area II of the cover plate 01 provided in this embodiment is provided with grooves 02, and the size and number of the grooves 02 are related to the layout of the battery strings provided in the peripheral area II, the size of the battery sheets, and the size of the overlapping area, and by adjusting the size and position of the grooves 02, the peripheral area II can be compatible with the whole layout of the battery strings or the half layout of the battery strings.

In the production phase, the cover plate 01 with the grooves 02 can be produced by means of calender rolls with a convex structure.

In the production process of the photovoltaic module, the grooves 02 correspond to the overlapping areas of the battery strings; and a glue film is arranged between the cover plate 01 and the battery string, and in the lamination stage, the glue film corresponding to the groove 02 is heated to melt and fill the groove 02. In the lamination stage, the pressure applied to the region corresponding to the groove 02 of the cover plate 01 is eliminated after passing through the groove 02, so that the pressure applied to the overlapped region corresponding to the groove 02 is reduced, and the risk of hidden cracking and chipping of the overlapped region is greatly reduced. That is, even if the cover plate 01 of the peripheral region II receives a larger pressure than the cover plate 01 of the central region I or the cover plate 01 of the peripheral region II deforms to a larger extent than the cover plate 01 of the central region in the lamination stage, the overlap region of the peripheral region II receives a smaller pressure, and thus the probability of occurrence of hidden cracks or fragments of the overlap region of the peripheral region II is greatly reduced.

Therefore, the cover plate provided by the embodiment is adopted to produce the photovoltaic module, so that the module efficiency of the photovoltaic module is improved, and the yield of the photovoltaic module is improved.

The second embodiment of the present invention also provides a cover plate which is substantially identical to the previous embodiment, the main differences including that the recess is also located in the central region in the second embodiment. The cover plate according to the second embodiment of the present invention will be described in detail with reference to the drawings, and the same or corresponding parts as those of the previous embodiment will be referred to for description of the previous embodiment, and will not be repeated. Fig. 2 to 8 are schematic structural diagrams of a cover plate according to a second embodiment of the present invention.

Referring to fig. 2, fig. 2 is a schematic top view of a cover plate, in this embodiment, the cover plate 101 is used to form a photovoltaic module with a cell string, the cell string includes a plurality of cells, and adjacent cells have overlapping areas, the cover plate 101 has a first face (not labeled) facing the cell string and a second face (not labeled) opposite to the first face, the first face includes a central area I and a peripheral area II located outside the central area I; the cover plate 101 includes: at least one groove 102 extending from the first face to the second face, the groove 102 being located in a central region I and a peripheral region II, and each groove 102 being located opposite to the location of at least one overlapping region; the volume of the groove 102 opposite to each overlapping area of the peripheral area II is a first volume, the volume of the groove 102 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 plane 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 the peripheral region surrounding the central region. For a detailed description of the first face, the central zone and the peripheral zone, reference may be made to the detailed description of the foregoing embodiments.

Adjacent cells have a connecting line in the overlap region, with volume referring to the volume of the recess 102 within the facing length of the connecting line. The larger the volume of the groove 102, the larger the amount of adhesive film flowing to the groove 102 during the lamination stage, and the greater the ability of the groove 102 to relieve pressure, the more advantageous the pressure experienced by the overlapping area directly opposite the groove 102. In other words, the first volume is greater than the second volume by actually: the cross-sectional area of the groove 102 of the peripheral region II is larger than the cross-sectional area of the groove 102 of the central region I in a direction parallel to the arrangement direction of the plurality of battery cells in the same battery string, i.e., in a cross-section perpendicular to the connecting line.

As can be seen from the foregoing, the overlapping areas of the peripheral areas II are more prone to cracking during the lamination stage than the overlapping areas of the central areas I. In this embodiment, the grooves 102 are disposed in both the peripheral area II and the central area I, and the ability of the grooves 102 of the peripheral area II to eliminate pressure is stronger than that of the grooves 102 of the central area I, so that the overlapping area of the peripheral area II is prevented from being broken, and the overlapping area of the central area I is prevented from being broken, which is beneficial to further improving the yield of the photovoltaic module produced by using the cover plate 101.

In this embodiment, the depth h of the groove 102 in the peripheral region II is the same as the depth h of the groove 102 in the central region I.

Fig. 3 is a schematic cross-sectional view of the square cut along AA1 and BB in fig. 2. As shown in fig. 3, in one example, adjacent cells have connecting lines in the overlapping region, and the cross-sectional shape of the groove 102 of the peripheral region II and the cross-sectional shape of the groove 102 of the central region I may be the same in the cross-sectional direction perpendicular to the connecting lines, i.e., in the direction parallel to the arrangement of the plurality of cells in the same cell string. The cross-sectional width of the groove 102 in the peripheral region II is greater than the cross-sectional width of the groove 102 in the central region I in the cross-sectional direction perpendicular to the connecting line (i.e., AA1 direction).

Specifically, the cross-sectional width of the groove 102 in the central region I is a first width w1, the cross-sectional width of the groove 102 in the peripheral region II is a second width w2, and the difference between the second width w2 and the first width w1 is 2mm or more and 5mm or less, for example, w2-w1 is 2.5mm, 3mm, 4.5mm or 4mm. In this way, the difference between the width of the groove 102 in the peripheral area II and the width of the groove 102 in the central area I are moderate, so that the effect of relieving the pressure of the groove 102 in the peripheral area II is better than that of the groove 102 in the central area I, the excessive volume of the groove 102 in the peripheral area II is avoided, and the cover plate 101 is ensured to have good effects of supporting the battery piece and protecting the battery piece.

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

As shown in fig. 4, the cross-sectional shape of the groove 102 may be circular arc, inverted trapezoid, square or inverted triangle in a direction parallel to the arrangement direction of the plurality of battery cells in the same battery string.

As shown in fig. 5, the cover plate 101 may further include: a plurality of raised structures 112 located on the surface of the recess 102; a burr formation 113 on the first side. For the bump structure 112 and the burr structure 113, reference should be made to the detailed description of the foregoing embodiments, and the detailed description thereof is omitted.

Fig. 6 is a schematic view of another cross-sectional structure of fig. 2 along the AA1 direction and the BB1 direction. As shown in fig. 6, in another example, the cross-sectional shape of the groove 102 of the peripheral area II and the cross-sectional shape of the groove 102 of the central area I may be different in parallel to the arrangement direction of the plurality of battery cells in the same battery string, and the depth h of the groove 102 of the peripheral area II and the depth h of the groove 102 of the central area I are the same, and the cross-sectional width of the groove 102 of the peripheral area II is larger than the cross-sectional width of the groove 102 of the central area I in parallel to the arrangement direction of the plurality of battery cells in the same battery string. Specifically, the cross-sectional shape of the groove 102 of the central region I may be an inverted triangle, and the cross-sectional shape of the groove 102 of the peripheral region II may be a circular arc.

It will be appreciated that, regardless of the shape, width or depth of the grooves 102 in the peripheral region II and the central region I, it is only necessary to ensure that the volume of the grooves 102 in the peripheral region II is larger than the volume of the grooves 102 in the central region I, or that the cross-sectional area of the grooves 102 in the peripheral region II is larger than the cross-sectional area of the grooves 102 in the central region I. For example, the cross-sectional width of the groove 102 of the peripheral region II is the same as the cross-sectional width of the groove 102 of the central region I and the depth thereof is the same in parallel to the arrangement direction of the plurality of battery cells in the same battery string, and the cross-sectional shape of the groove 102 of the peripheral region II is different from the cross-sectional shape of the groove 102 of the central region I in parallel to the arrangement direction of the plurality of battery cells in the same battery string. Or in a direction parallel to the arrangement direction of a plurality of battery cells in the same battery string, the cross-sectional width of the groove 102 of the peripheral area II is larger than the cross-sectional width of the groove 102 of the central area I, and the depth of the groove 102 of the peripheral area II is larger than the depth of the groove 102 of the central area I.

In one example, as shown in FIG. 2, the same groove 102 spans the peripheral zone II and the central zone I; in another example, as shown in fig. 7, the grooves 102 in the peripheral region II and the grooves in the central region I are separated from each other, so that the mechanical strength of the cover plate 101 is improved, and the yield and reliability of the photovoltaic module are further improved, compared to the case where the grooves in the peripheral region and the grooves in the central region are communicated.

In addition, as shown in fig. 2 or 7, a groove 102 of the same peripheral area II may cross the peripheral area II in the longitudinal direction along the first face.

In another example, as shown in fig. 8, the same peripheral region II may also be provided with at least 2 mutually separated grooves 102 in the long-side direction along the first face, the central region I is provided with a plurality of mutually separated grooves 102, and the pitch of adjacent grooves 102 matches the pitch of the cell strings constituting the photovoltaic module in the long-side direction along the first face. Because the plurality of grooves 102 are mutually separated, different grooves 102 positioned in the peripheral area II or the central area I can be provided with different sizes, so that the matching of battery strings with different sizes is facilitated, and the structural flexibility of the photovoltaic module is improved. In addition, compared with the scheme that adjacent grooves are communicated, the cover plate 101 is made of the material between the adjacent grooves 102 along the extending direction of the connecting line, so that the mechanical strength of the cover plate 101 can be enhanced under the condition that the thickness of the cover plate 101 is unchanged, and the yield and the reliability of the photovoltaic module are further improved.

In the production phase, the cover plate 101 with the grooves 102 can be manufactured by means of calender rolls having a periodically protruding structure.

The cover plate 101 provided in this embodiment has the grooves 102 located not only in the peripheral area II but also in the central area I, and the volume of the grooves 102 in the peripheral area II is larger than the volume of the grooves 102 in the central area I. In this way, the pressure applied to the overlapping area of the central area I and the peripheral area II can be reduced, the cover plate 101 can be ensured to have enough strength, and the risk of fragments of the cover plate 101 is avoided, so that 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 in the cover plate is large, so that the strength of the cover plate is low, and when the cover plate is adopted for lamination, the problem of cover plate breakage easily occurs, and the yield of the photovoltaic module is affected; and in the use process of the photovoltaic module, the problem of cover plate cracking is easy to occur, and the service life of the photovoltaic module is influenced.

The third embodiment of the present invention further provides a cover plate, and the cover plate provided in this embodiment will be described in detail with reference to the drawings, and the same or corresponding parts as those of the foregoing embodiment may be referred to the detailed description of the foregoing embodiment, and will not be described in detail.

Fig. 9 to 11 are schematic structural views of a cover plate according to a third embodiment of the present invention.

Referring to fig. 9 to 11, fig. 9 is a schematic top view of a cover plate, wherein the cover plate 201 includes a first surface and a second surface, and includes a central region I and a peripheral region II; grooves 202 extending from the first surface to the second surface, wherein the grooves 202 are positioned in a central area I and a peripheral area II, and each groove 202 is opposite to at least one overlapping area; the volume of the groove 202 opposite to each overlapping area of the peripheral area II is a first volume, the volume of the groove 202 opposite to each overlapping area of the central area I is a second volume, and the first volume is larger than the second volume.

Specifically, the cover plate 201 is used to form a photovoltaic module with the cell string, and adjacent cells in the cell string have connecting lines in the overlapping region, and the extending direction of the connecting lines is perpendicular to the AA1 direction. The cross-sectional area of the groove 202 of the peripheral region II is larger than the cross-sectional area of the groove 202 of the central region I in a direction perpendicular to the connecting line, i.e., in a direction parallel to the arrangement of the plurality of battery cells in the same battery string.

In this embodiment, the cross-sectional width w of the groove 202 in the peripheral area II is the same as the cross-sectional width w of the groove 202 in the central area I in the direction parallel to the arrangement direction of the plurality of battery cells in the same battery string.

In one example, as shown in fig. 10, fig. 10 is a schematic cross-sectional structure along the AA1 direction and the BB1 direction in fig. 9, where the depth of the groove 202 in the peripheral region II is greater than the depth of the groove 202 in the central region I. Specifically, the depth of the groove 202 in the central region I is a first depth h1, the depth of the groove 202 in the peripheral region II is a second depth h2, and the second depth h2 is greater than the first depth h1. Wherein, 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 202 of the central area I is the same as the cross-sectional shape of the groove 202 of the peripheral area II.

In other embodiments, the cross-sectional shape of the grooves of the central region may also be different from the cross-sectional shape of the grooves of the peripheral region in a direction parallel to the arrangement direction of the plurality of battery cells in the same battery string. In this way, even if the cross-sectional widths and/or depths of the grooves of the central region and the peripheral region are the same, by providing the grooves of the central region and the peripheral region with different shapes, it is possible to ensure that the cross-sectional area of the grooves of the peripheral region is larger than the cross-sectional area of the grooves of the central region in the direction parallel to the arrangement direction of the plurality of battery pieces in the same battery string.

Fig. 11 is a schematic view showing a further cross-sectional structure of fig. 9 along the AA1 direction and the BB1 direction. As shown in fig. 11, in still another example, the depth h of the groove 202 of the peripheral area II is the same as the depth h of the groove 202 of the central area I, and the cross-sectional width w of the groove 202 of the peripheral area II may also be equal to the cross-sectional width w of the groove 202 of the central area I in a direction parallel to the arrangement direction of the plurality of battery pieces in the same battery string; wherein the cross-sectional shape of the groove 202 of the peripheral region II may be different from the cross-sectional shape of the groove 202 of the central region I in a direction parallel to the arrangement direction of the plurality of battery cells in the same battery string. Specifically, the cross-sectional shape of the groove 202 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 fourth embodiment of the present invention also provides a cover plate, which is substantially the same as the cover plate of the previous embodiment, and is mainly different in that the extending direction of the groove is the extending direction of the short side of the first surface. The cover plate provided in the fourth embodiment will be described in detail with reference to the drawings, and the same or corresponding parts as those in the previous embodiments may be referred to, and detailed description thereof will not be repeated.

Fig. 12 to 14 are schematic structural diagrams of a cover plate according to a fourth embodiment of the present invention, fig. 12 is a schematic structural diagram in a top view, fig. 13 is a schematic structural diagram in a cross section along the direction CC1 in fig. 12, and fig. 14 is a schematic structural diagram in another top view.

Referring to fig. 12 and 13, in the present embodiment, the cover 301 includes a groove 302 extending from a first surface toward a second surface, the first surface includes a central area I and a peripheral area II, the groove 302 is located in the central area I and the peripheral area II, a volume of the groove opposite to each overlapping area located in the peripheral area is a first volume, a volume of the groove opposite to 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 302 is the same as the extending direction of the short side of the first surface.

The overlapping area of the adjacent battery pieces of the same battery 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 battery pieces are distributed along the long side of the first surface. The extending direction of the connecting wire is perpendicular to the arrangement direction of a plurality of battery pieces in the same battery string.

In this embodiment, the cross-sectional area of the groove 302 in the peripheral area II is larger than the cross-sectional area of the groove 302 in the central area I in the direction parallel to the arrangement direction of the plurality of battery cells in the same battery string.

In one example, the depth of the groove 302 in the central region I is the same as the depth of the groove 302 in the peripheral region II, and the cross-sectional width of the groove 302 in the peripheral region II is greater than the cross-sectional width of the groove 302 in the central region I in a direction parallel to the arrangement of the plurality of battery cells in the same battery string. Specifically, the grooves 302 of the central region I have a first width W1, and the grooves 302 of the peripheral region II have a second width W2, the second width W2 being greater than the first width W1. The cross-sectional shapes of the grooves 302 in the central area I and the grooves 302 in the peripheral area II may be the same, for example, square; the cross-sectional shapes of the grooves 302 in the central region I and the grooves 302 in the peripheral region II may also be different.

In another example, the depth of the groove 302 in the central region I is smaller than the depth of the groove 302 in the peripheral region II, and the cross-sectional width of the groove 302 in the peripheral region II is equal to the cross-sectional width of the groove 302 in the central region I in a direction parallel to the arrangement direction of the plurality of battery pieces in the same battery string; or the depth of the groove 302 in the central region I is smaller than that of the groove 302 in the peripheral region II, and the cross-sectional width of the groove 302 in the peripheral region II is smaller than that of the groove 302 in the central region I in the direction parallel to the arrangement direction of the plurality of battery pieces in the same battery string.

As shown in fig. 12, the same groove 302 in the peripheral region II spans the short side of the first face, and the same groove 302 in the central region I spans the short side of the first face. In other embodiments, as shown in fig. 14, a plurality of mutually separated grooves 302 are provided in the direction extending along the short side of the first face. The number of grooves extending in the short side direction along the first face can be set reasonably according to the layout of the battery strings of the photovoltaic module.

The fifth embodiment of the present invention also provides a cover plate, which is substantially the same as the previous embodiments, with the main difference that the peripheral area surrounds the central area. Fig. 15 is a schematic top view of a cover plate according to a fifth embodiment.

Referring to fig. 15, the cover plate 401 has a first face and a second face, and the first face has a central area and a peripheral area surrounding the central area, wherein the central area is located inside the dashed frame a, and the peripheral area is located outside the dashed frame a; a groove 402 extending from the first face to the second face, the groove 402 being located in the central region and the peripheral region; 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.

The detailed descriptions of the first and second volumes may refer to the detailed descriptions of the foregoing embodiments, and are not repeated herein.

In this embodiment, the overlapping area of the battery strings has a connecting line, and the cross-sectional width of the groove 402 in the peripheral area is larger than the cross-sectional width of the groove 402 in the central area in the cross-sectional direction perpendicular to the connecting line, i.e., 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 width of the grooves 4 of the peripheral zone may also be equal to the cross-sectional width of the grooves of the central zone.

Regarding the dimensional relationship of the grooves of the peripheral region and the central region, reference may be made to the description of the foregoing embodiments as long as it is satisfied that the cross-sectional area of the grooves of the peripheral region is larger than the cross-sectional area of the central region in the cross-sectional direction perpendicular to the connecting line.

The sixth embodiment of the present invention also provides a cover plate, substantially identical to the previous embodiments, with the main differences comprising grooves in the cover plate including both grooves extending in the transverse direction and grooves extending in the longitudinal direction. Fig. 16 is a schematic top view of a cover plate according to a sixth embodiment. The cover plate provided in this embodiment will be described below with reference to the drawings, and reference will be made to the detailed description of the previous embodiment for the same or corresponding parts of the previous embodiment.

Referring to fig. 16, the cover plate 501 includes a central region I and a peripheral region II, and the cover plate 501 has grooves 502 extending from the first face toward the second face, the grooves 502 including a plurality of grooves 502 extending in a long side direction of the first face, and a plurality of grooves 502 extending in a short side direction of the first face.

For the plurality of grooves 502 extending along the same extending direction, the volume of the groove 502 opposite to each overlapping area in the peripheral area II is a first volume, the volume of the groove 502 opposite to each overlapping area in the central area I is a second volume, and the first volume is larger than the second volume. Specifically, for a plurality of grooves 502 extending in the same extending direction, the overlapping region of the battery string has a connecting line, and the cross-sectional area of the groove 502 of the peripheral region II is larger than the cross-sectional area of the groove 502 of the central region I in the cross-sectional direction perpendicular to the connecting line.

The cover plate 501 provided in this embodiment can form a photovoltaic module with the battery strings of the battery pieces arranged transversely and the battery strings of the battery pieces arranged longitudinally, and can also avoid the occurrence of hidden cracks or broken pieces in the overlapping area of the central area I and the peripheral area II.

Correspondingly, the embodiment of the invention also provides a photovoltaic module, which comprises the cover plate of any embodiment; the battery string comprises a plurality of battery pieces, wherein 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; the adhesive film is positioned between the cover plate and the battery string and is also positioned in the groove. The photovoltaic module can be a single glass module or a double glass module.

Fig. 17 is a schematic cross-sectional structure of a photovoltaic module according to an embodiment of the present invention, wherein an upper diagram in fig. 17 is a schematic cross-sectional structure of the photovoltaic module after a lamination stage, and a lower diagram in fig. 17 is a schematic cross-sectional structure of the photovoltaic module after a lamination stage, and a large arrow indicates a pressure direction in the lamination stage.

Referring to fig. 17, the cover plate includes a back plate 11 and a transparent front plate 13, the cover plate includes a central region I and a peripheral region II located outside the central region I, and the back plate 11 and the transparent front plate 13 are respectively located at opposite sides of a battery string, the battery string includes a plurality of battery pieces 18, and adjacent battery pieces 18 have overlapping regions 17; each overlap region 17 of the peripheral region I is directly opposite to the position of the groove 12 in the back plate 11 and the groove 12 in the transparent front plate 13.

A solder strip may be provided in the overlap region 17, by means of which an electrical connection between adjacent battery cells 18 is achieved.

In this embodiment, the central zone I is also provided with grooves 12. It will be appreciated that in other embodiments, the central region is also not provided with grooves.

In this embodiment, the grooves 12 in the back plate 11 are aligned with the grooves 12 in the transparent front plate 13, so that each overlapping region 17 corresponds to 2 groove positions.

The photovoltaic module may be a single glass module, the corresponding transparent front plate 13 may be a glass cover plate, and the back plate 11 may be a polymer cover plate or a stainless steel cover plate. The photovoltaic module may also be a double-glass module, and the transparent front plate 13 and the back plate 11 are glass cover plates correspondingly.

The photovoltaic module further comprises: the adhesive film 10, the adhesive film 10 is located between the back plate 11, the battery string and the transparent front plate 13, and also fills the groove 12. The adhesive film 10 can be filled in the groove 12, and the adhesive film 10 can also be positioned in a partial area of the groove 12.

Effects of the present embodiment will be described below in conjunction with a manufacturing process of a photovoltaic module: in the lamination stage, the transparent front plate 13, the first adhesive film 15, the battery string, the second adhesive film 14 and the back plate 11 are laminated in sequence to form a laminated structure; performing air extraction treatment to remove gas in the laminated structure; entering a lamination stage, wherein before the lamination stage, the lamination structure of the peripheral region II is tilted upwards relative to the central region I, pressure is applied to the back plate 11, and the lamination structure is subjected to heat treatment to enable the first adhesive film 15 and the second adhesive film 14 to be melted, and the grooves 12 are filled to form the adhesive film 10; the grooves 12 of the peripheral zone II can cushion the pressure from the back plate 11 to which the overlap zone is subjected, reducing the pressure to which the overlap zone is subjected and thus reducing the risk of rupture of the overlap zone 17. In addition, the melted adhesive film fills the groove 12 in the transparent front plate 13, which is favorable for further reducing the pressure applied to the overlapped area and further reducing the risk of hidden cracking and chipping of the overlapped area of the peripheral area II. Likewise, the pressure experienced by the overlap of the central region I is reduced.

Compared with the scheme that the groove volume of the central area is the same as that of the peripheral area, the groove 12 of the central area I has smaller volume than that of the groove 12 of the peripheral area II, so that the cover plate is favorable for ensuring stronger strength, and the cover plate is favorable for avoiding damage to the cover plate while preventing fragments of the overlapping areas of the peripheral area II and the central area I. In addition, the cover plate, namely the back plate 11 and the transparent front plate 13 have stronger strength, so that the cover plate can be ensured to have higher strength in the use process of the photovoltaic module, and the service life of the photovoltaic module is prolonged.

In addition, the contact area between the cover plate (the back plate 11 and the transparent front plate 13) and the adhesive film 10 is increased, so that the adhesion between the cover plate and the adhesive film 10 is improved, and the reliability of the photovoltaic module is improved.

In still another embodiment of the present invention, a photovoltaic module is provided, which is substantially the same as the photovoltaic module provided in the foregoing embodiment, and the main differences include: the cover plate is one of a back plate and a transparent front plate. The photovoltaic module provided in this embodiment will be described in detail below with reference to the accompanying drawings.

Fig. 18 is a schematic cross-sectional structure of a photovoltaic module according to another embodiment of the present invention, wherein the upper graph in fig. 18 is a schematic cross-sectional structure of the photovoltaic module through a lamination stage, and the lower graph in fig. 18 is a schematic cross-sectional structure of the photovoltaic module through a lamination stage.

Referring to fig. 18, the photovoltaic module includes: the cover plate is a back plate 21, the back plate 21 comprises a central area I and a peripheral area II, and the peripheral area II of the back plate 21 is provided with a groove 22; a battery string comprising a plurality of battery cells 18, and adjacent battery cells 28 having overlapping regions 27, each overlapping region 27 of peripheral region I and recess 22 in back plate 21; a transparent front plate 23 located at a side of the battery string away from the back plate 21; the glue film 20 is positioned between the back plate 21 and the transparent front plate 23, and also fills the groove 22.

The photovoltaic module may be a single-glass module or a double-glass module.

In other embodiments, the cover plate may also be a transparent front plate, the groove is located in the transparent front plate, and the photovoltaic module further includes: and the backboard is positioned at one side of the battery string away from the transparent front board.

In the lamination stage, the transparent front plate 23, the first adhesive film 25, the battery string, the second adhesive film 24, and the back plate 21 are laminated in this order to form a laminated structure.

In this embodiment, the groove 22 is only located in the transparent front plate or the back plate, and the overall strength of the photovoltaic module is further improved while reducing the pressure applied to the overlapping area of the peripheral area II and the central area I. Therefore, the manufacturing yield of the photovoltaic module is improved, and the service life of the photovoltaic module is prolonged. In another embodiment of the present invention, a photovoltaic module is further provided, and fig. 19 is a schematic cross-sectional structure of the photovoltaic module provided in another embodiment of the present invention, in which fig. 19 is a schematic cross-sectional structure of the photovoltaic module passing through a lamination stage, and in which fig. 19 is a schematic cross-sectional structure of the photovoltaic module passing through a lamination stage.

Referring to fig. 19, the photovoltaic module includes: the cover plate comprises a back plate 31 and a transparent front plate 33, the back plate 31 and the transparent front plate 33 are respectively positioned on two opposite sides of the battery string, each battery piece comprises a plurality of battery pieces 38, and an overlapping area 37 is arranged between every two adjacent battery pieces 38; and each overlapping region 37 is directly opposite to the position of the groove 32 in the back plate 31 or the groove 32 in the transparent front plate 33; the glue film 30 is located between the back plate 31 and the transparent front plate 33, and also fills the groove 32.

The photovoltaic module can be a single glass module or a double glass module.

In this embodiment, the positions of the grooves 32 in the back plate 31 and the grooves 32 in the transparent front plate 33 are staggered so that each overlapping region 37 is just opposite to one groove 32. In one example, the transparent front plate 33 and the back plate 31 of the peripheral area II each have at least one recess 32 therein; in another example, one of the transparent front plate 33 or the back plate 31 of the peripheral region II has a groove 32, and the other is not provided with a groove.

In the lamination stage, the transparent front plate 33, the first adhesive film 35, the battery string, the second adhesive film 34, and the back plate 31 are laminated in order to form a laminated structure; in the lamination stage, the grooves 32 of the peripheral zone II and the central zone I have the effect of eliminating the pressure, and the grooves 32 of the peripheral zone II have a stronger capacity to eliminate the pressure than the grooves 32 of the central zone I, so that the risk of hidden cracking or chipping of the central zone I with the overlapping zone 37 of the peripheral zone II can be avoided.

In addition, since each overlapping area 37 is opposite to one groove 32, the number of grooves 32 in the back plate 31 and the transparent front plate 33 is reduced, which is beneficial to improving the strength of the back plate 31 and the transparent front plate 33, thereby further improving the service life of the photovoltaic module.

It will be understood by those of ordinary skill in the art that the foregoing embodiments are specific examples of 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. Various changes and modifications may be made by one skilled in the art without departing from the spirit and scope of the invention, and the scope of the invention is therefore intended to be limited only by the appended claims.

Claims (11)

1. A photovoltaic module, comprising:

The battery string comprises a plurality of battery pieces, and adjacent battery pieces are provided with overlapping areas;

The cover plate is used for forming the photovoltaic module with the battery string and is provided with a first surface facing the battery string and a second surface opposite to the first surface, and the first surface comprises a central area and a peripheral area positioned outside the central area;

The cover plate comprises at least one groove extending from the first face to the second face, the grooves are positioned in the peripheral area, and each groove is opposite to at least one overlapping area; the grooves are also positioned in the central area, wherein the volume of the grooves which are opposite to each overlapping area positioned in the peripheral area is a first volume, the volume of the grooves which are opposite to each overlapping area positioned in the central area is a second volume, and the first volume is larger than the second volume;

wherein, the apron includes: the back plate and the transparent front plate are respectively positioned at two opposite sides of the battery string, and the positions of the grooves in the back plate and the grooves in the transparent front plate are staggered;

the adhesive film is positioned between the cover plate and the battery string and also positioned in the groove.

2. The photovoltaic module of claim 1, wherein each of the overlap regions is directly opposite the groove in the backsheet or the groove in the transparent front sheet.

3. The photovoltaic module of claim 1, wherein the grooves of the peripheral region have a cross-sectional area greater than a cross-sectional area of the grooves of the central region in a direction parallel to the arrangement of the plurality of the cells in the same cell string.

4. The photovoltaic module of claim 1, wherein the depth of the grooves of the peripheral region is greater than the depth of the grooves of the central region; or in a direction parallel to the arrangement direction of a plurality of battery pieces in the same battery string, the cross-sectional width of the groove of the peripheral region is larger than the cross-sectional width of the groove of the central region.

5. The photovoltaic module according to claim 1 or 3, wherein a cross-sectional shape of the groove of the peripheral region is different from a cross-sectional shape of the groove of the central region in a direction parallel to an arrangement direction of the plurality of the cells in the same cell string.

6. The photovoltaic module of claim 1, wherein the grooves in the peripheral region are discrete from the grooves in the central region.

7. The photovoltaic module of claim 1, wherein the first face is rectangular in shape, the central region and the peripheral region each span across a short side of the first face, and the peripheral regions are located on opposite sides of the central region, respectively; or the first face is square or circular in shape, and the peripheral region surrounds the central region.

8. The photovoltaic module of any of claims 1-4, 6, or 7, wherein the depth of the groove is less than or equal to 1/2 of the thickness of the cover plate.

9. The photovoltaic module of any of claims 1-4, 6, or 7, wherein the cover plate comprises a glass cover plate, a polymer cover plate, or a stainless steel cover plate.

10. The photovoltaic module of any of claims 1-4, 6, or 7, wherein the cross-sectional shape of the groove comprises a circular arc shape, an inverted trapezoid shape, a square shape, or an inverted triangle shape in a direction parallel to the arrangement of the plurality of cells in the same cell string.

11. The photovoltaic module of any one of claims 1-4, 6, or 7, further comprising: a plurality of raised structures located on the surface of the recess.