Back-contact photovoltaic module and system

Abstract

Disclosed are a back-contact photovoltaic module and system. The back-contact photovoltaic module comprises: a cell string (10A, 10B) comprising solar cells connected in series, the solar cells comprising a first solar cell (11) and a second solar cell (12) arranged in a first direction, and the first solar cell being located at an end of the cell string; a first insulating strip (21) located at the end of the second solar cell close to the first solar cell; a first busbar (31) located on the side of the first insulating strip facing away from the second solar cell, the first insulating strip and the first busbar both extending in a second direction, and the first direction intersecting the second direction; and a first solder strip (41) configured to electrically connect the first busbar and the first solar cell, where an extension section (311) is provided at the end of the first busbar close to the first solar cell, the extension section extends beyond an edge of the first insulating strip in the first direction and is electrically connected to the first solder strip, and a connection end (312) is formed at the joint between the extension section and the first solder strip.

Description

Back contact photovoltaic module and system

[0001] The present disclosure claims priority to the Chinese patent application No. 202411276578X, filed on September 11, 2024, and entitled "Back contact cell module and photovoltaic system", the entire content of which is incorporated herein by reference. TECHNICAL FIELD

[0002] The present disclosure relates to the technical field of back contact cells, and in particular to a back contact photovoltaic module and system. BACKGROUND

[0003] In the existing back contact cell module, the series connection bus bar between adjacent series connection cell strings is usually placed at the edge of the cell module, and the parallel connection bus bar between adjacent parallel connection cell strings is usually placed in the reserved spacing area between two parallel connection cell strings, which results in that a certain space needs to be reserved at the edge of the cell module for placing the series connection bus bar, and a certain space also needs to be reserved between two parallel connection cell strings for placing the parallel connection bus bar. On the one hand, the effective light receiving area of the cell module is reduced, which affects the conversion efficiency of the module, and on the other hand, the appearance of the cell piece is affected.

[0004] In some products, the bus bar is installed at the middle position of the back surface of the cell piece, and an insulating strip is arranged between the bus bar and the cell piece. Although this arrangement can hide the bus bar, the insulating strip needs to be punched or the bus bar needs to be replaced by an insulating block arranged at intervals, so that the bus bar can contact the same polarity solder strip on the cell piece and be insulated from the reverse polarity solder strip on the cell piece. This arrangement requires high precision of punching of the insulating strip and precision of arrangement position of the insulating block, and is difficult to produce, and is prone to short circuit due to position deviation of the insulating strip during punching or position deviation of the insulating block during lamination. SUMMARY

[0005] The present disclosure aims to provide a back contact photovoltaic module and system in view of the existing technical situation.

[0006] The present disclosure can increase the effective light receiving area of the cell module, improve the conversion efficiency of the module, and the area of the bus bar observed from the light receiving side is smaller, or even completely hidden, which is more beautiful. At the same time, the production difficulty can be effectively reduced, the risk of cell piece hidden cracking and fragmentation can be reduced, and the reliability can be improved.

[0007] To achieve the above-mentioned purpose, the present disclosure adopts the following technical solutions:

[0008] Firstly, the present disclosure provides a back contact cell module, comprising:

[0009] A battery string comprising battery pieces connected in series, the battery pieces comprising first battery pieces and second battery pieces arranged along a first direction, the first battery pieces being located at end portions of the battery string,

[0010] A first insulating strip located at one end of the second battery piece close to the first battery piece,

[0011] A first busbar located at a side of the first insulating strip away from the second battery piece,

[0012] The first insulating strip and the first busbar are both arranged along a second direction, the first direction intersecting the second direction,

[0013] A first solder strip for electrically connecting the first busbar and the first battery piece,

[0014] The first busbar has an extension segment at one end close to the first battery piece, the extension segment extending beyond an edge of the first insulating strip in the first direction and electrically connected with the first solder strip, the connection between the extension segment and the first solder strip forming a connection end.

[0015] In some embodiments, the first busbar comprises a main body, a projection of the main body in a thickness direction of the second battery piece falling within a projection of the first insulating strip,

[0016] A relative height distance from the connection end to the first battery piece is less than a relative height distance from a side of the main body away from the first insulating strip to the first battery piece.

[0017] In some embodiments, the main body and the extension segment are both in a strip shape extending along the second direction.

[0018] In some embodiments, the extension segment comprises extension sub-segments arranged in the second direction at one end of the main body close to the first battery piece.

[0019] In some embodiments, the first insulating strip at least partially extends beyond an edge of the second battery piece at one end close to the first battery piece.

[0020] In some embodiments, the connection end is at least partially located beyond an edge of the second battery piece at one end close to the first battery piece, a projection of the connection end in a thickness direction of the second battery piece at least partially overlapping a projection of the first battery piece.

[0021] In some embodiments, the first battery pieces and the second battery pieces are located on the same plane,

[0022] In the first direction, the relative distance from the end of the second cell tab close to the first cell tab to the connection end is greater than the spacing between the second cell tab and the first cell tab.

[0023] In some embodiments, in the first direction, the relative distance from the end of the second cell tab close to the first cell tab to the connection end is l 11 <L1<l 12 ,

[0024] wherein L1 is the relative distance from the end of the second cell tab close to the first cell tab to the connection end in the first direction, l 11 is the spacing between the second cell tab and the first cell tab, l 12 is the relative distance from the end of the second cell tab close to the first cell tab to the first soldering point, the first soldering point being located at the end of the first cell tab close to the second cell tab, and the first soldering point being connected to the first soldering ribbon.

[0025] In some embodiments, the first cell tab and the second cell tab close to the end of the first cell tab are at least partially laminated.

[0026] In some embodiments, in the first direction, the relative distance from the end of the first cell tab close to the second cell tab to the connection end is l 21 <L2<l 21 +l 22 ,

[0027] wherein L2 is the relative distance from the end of the first cell tab close to the second cell tab to the connection end in the first direction, l 21 is the width of the laminated region of the first cell tab and the second cell tab, l 22 is the relative distance from the end of the second cell tab close to the first cell tab to the first soldering point, the first soldering point being located at the end of the first cell tab close to the second cell tab, and the first soldering point being connected to the first soldering ribbon.

[0028] In some embodiments, the battery assembly comprises at least one series cell string group, each of the series cell string group comprising two of the cell strings arranged along a second direction and connected in series with each other,

[0029] and in the same series cell string group, the same first bus bar extends from the second cell tab in one of the cell strings to the second cell tab of another of the cell strings.

[0030] In some embodiments, each of the battery strings is provided with a fourth battery piece away from one end of the first battery piece, and the fourth battery piece is provided with a third battery piece close to one end of the first battery piece,

[0031] The battery assembly comprises parallel battery string groups, and each of the parallel battery string groups comprises at least two battery strings arranged in a first direction and connected in parallel with each other, and the fourth battery pieces of the two battery strings connected in parallel with each other are arranged adjacent to each other in the first direction,

[0032] The battery assembly further comprises:

[0033] A second insulating strip is located at the edge of the third battery piece in one of the battery strings, and the second insulating strip is located at one end of the third battery piece close to the fourth battery piece,

[0034] An intermediate bus bar is used to connect in parallel two battery strings arranged adjacent to each other in the first direction, and the intermediate bus bar is located at the side of the second insulating strip away from the third battery piece,

[0035] The second insulating strip and the intermediate bus bar are both arranged in extension in a second direction,

[0036] A second solder strip is used to electrically connect the intermediate bus bar, the fourth battery piece in the battery string, and the fourth battery piece in another battery string adjacent to the battery string in the first direction.

[0037] In some embodiments, the intermediate bus bar is provided with an extension section at one end close to the fourth battery piece, the extension section extends to the outside of the edge of the second insulating strip in the first direction, and is electrically connected with the second solder strip, and the connection between the extension section and the second solder strip forms a joint end.

[0038] Secondly, the disclosure provides a back contact battery assembly, comprising:

[0039] Parallel battery string groups, and each of the parallel battery string groups comprises at least two battery strings arranged in a first direction and connected in parallel with each other, and each of the battery strings comprises battery pieces connected in series with each other, and the battery pieces comprise third battery pieces and fourth battery pieces arranged in the first direction, and the fourth battery pieces are located at the end of the battery strings, and the fourth battery pieces of the two battery strings connected in parallel with each other are arranged adjacent to each other in the first direction,

[0040] A second insulating strip is located at the edge of the third battery piece in one of the battery strings, and the second insulating strip is located at one end of the third battery piece close to the fourth battery piece,

[0041] an intermediate busbar for connecting two battery strings arranged adjacent to each other in the first direction in parallel, the intermediate busbar being located on the side of the second insulation strip facing away from the third battery sheet,

[0042] the second insulation strip and the intermediate busbar are arranged extending in the second direction,

[0043] a second solder strip for electrically connecting the intermediate busbar, the fourth battery sheet in the battery string where the intermediate busbar is located, and the fourth battery sheet in another battery string adjacent to the battery string in the first direction,

[0044] the intermediate busbar is provided with an extension section at one end close to the fourth battery sheet, the extension section extending beyond the edge of the second insulation strip in the first direction and being electrically connected with the second solder strip, and the connection between the extension section and the second solder strip forms a joint end.

[0045] In some embodiments, the intermediate busbar is provided with a main body, and in the thickness direction of the third battery sheet, the orthographic projection of the main body falls within the orthographic projection of the second insulation strip,

[0046] the relative height distance from the joint end to the fourth battery sheet is less than the relative height distance from the side of the main body facing away from the second insulation strip to the fourth battery sheet.

[0047] In some embodiments, the main body and the extension section are both in the form of a long strip structure extending in the second direction, or

[0048] the extension section comprises an extension subsection arranged at one end of the main body close to the fourth battery sheet in the second direction, and the extension subsection is in the form of a long strip structure extending in the first direction.

[0049] In some embodiments, in the thickness direction of the third battery sheet, the second insulation strip extends at least partially beyond the edge of the third battery sheet close to the fourth battery sheet.

[0050] In some embodiments, in the battery string provided with the intermediate busbar, in the thickness direction of the third battery sheet, the orthographic projection of the joint end at least partially coincides with the orthographic projection of the fourth battery sheet.

[0051] In some embodiments, in the same battery string, the fourth battery sheet and the third battery sheet are located on the same plane,

[0052] In the battery string provided with the intermediate busbar, in the first direction, the relative distance from the end of the third cell tab close to the fourth cell tab to the joint end is greater than the interval between the third cell tab and the fourth cell tab.

[0053] In some embodiments, in the battery string provided with the intermediate busbar, in the first direction, the relative distance from the end of the third cell tab close to the fourth cell tab to the joint end is: 31 <L3<l 32 ,

[0054] In some embodiments, in the battery string provided with the intermediate busbar, in the first direction, the relative distance from the end of the third cell tab close to the fourth cell tab to the joint end is: 31 l 32 is the relative distance from the edge of the end of the third cell tab close to the fourth cell tab to a second soldering point in the battery string provided with the intermediate busbar, the second soldering point is located on the fourth cell tab in the battery string provided with the intermediate busbar and is located at the end of the fourth cell tab close to the third cell tab, and the second soldering point is connected with the second soldering band.

[0055] In some embodiments, the end of the third cell tab close to the fourth cell tab is at least partially laminated with the fourth cell tab.

[0056] In some embodiments, in the battery string provided with the intermediate busbar, in the first direction, the relative distance from the end of the fourth cell tab close to the third cell tab to the joint end is: 41 <L4<l 41 +l 42 ,

[0057] In some embodiments, in the battery string provided with the intermediate busbar, in the first direction, the relative distance from the end of the fourth cell tab close to the third cell tab to the joint end is: 41 l 42 is the relative distance from the edge of the end of the third cell tab close to the fourth cell tab to a second soldering point in the battery string provided with the intermediate busbar, the second soldering point is located on the fourth cell tab in the battery string provided with the intermediate busbar and is located at the end of the fourth cell tab close to the third cell tab, and the second soldering point is connected with the second soldering band.

[0058] Further, the present disclosure provides a photovoltaic system comprising the back contact cell module as described above.

[0059] The present disclosure has the following beneficial effects:

[0060] 1) The end busbar built-in structure of the present disclosure can increase the effective light-receiving area of the cell module, improve the conversion efficiency of the module, avoid the exposure of the first busbar, and make the overall appearance of the cell module better. On the other hand, it can ensure that the first solder strip can fully match and weld with the effective welding position of the first cell piece, avoid the installation of the first busbar causing insufficient welding of the first solder strip and the first cell piece, and affect the current collection. When assembling, only the first insulating strip needs to be placed at one end of the second cell piece close to the first cell piece, effectively reducing the production precision requirement and production difficulty. Further, the end busbar built-in structure of the present disclosure can be applied to back contact cell modules with and without main grids, and has stronger universality. The built-in end busbar and the overhanging setting of the extension section make the relative height distance of the connection between the end busbar and the first solder strip smaller, thereby making the stress smaller when the end busbar built-in structure is laminated, reducing the risk of cell piece cracking and fragmentation, and making the reliability of the back contact cell module better.

[0061] 2) The middle busbar built-in structure of the present disclosure can increase the effective light-receiving area of the cell module, improve the conversion efficiency of the module, avoid the exposure of the middle busbar, and make the overall appearance of the cell module better. On the other hand, it can ensure that the second solder strip can fully match and weld with the effective welding position of the fourth cell piece, avoid the installation of the middle busbar causing insufficient welding of the second solder strip and the fourth cell piece, and affect the current collection. When assembling, only the second insulating strip needs to be placed at one end of the third cell piece close to the fourth cell piece, effectively reducing the production precision requirement and production difficulty. Further, the middle busbar built-in structure of the present disclosure can be applied to back contact cell modules with and without main grids, and has stronger universality. The built-in middle busbar and the overhanging setting of the extension section make the relative height distance of the connection between the middle busbar and the second solder strip smaller, thereby making the stress smaller when the middle busbar built-in structure is laminated, reducing the risk of cell piece cracking and fragmentation, and making the reliability of the back contact cell module better. BRIEF DESCRIPTION OF DRAWINGS

[0062] FIG. 1 is a structural schematic diagram of a series cell string group (adjacent cell pieces are in the same plane, and the extension section is a long strip structure) according to Embodiment 1 of the present disclosure.

[0063] FIG. 2 is a structural schematic diagram of a cell string according to Embodiment 1 of the present disclosure.

[0064] FIG. 3 is a structural schematic diagram of a series cell string group (adjacent cell pieces are in the same plane, and the extension section includes an extension subsection) according to Embodiment 1 of the present disclosure.

[0065] Figure 4 is a cross-sectional view of an end busbar built-in structure of Embodiment 1 of the present disclosure.

[0066] Figure 5 is a structural schematic diagram of a first busbar (extending segment including an extending subsection) of Embodiment 1 of the present disclosure.

[0067] Figure 6 is a structural schematic diagram of a back contact cell assembly of Embodiment 1 of the present disclosure.

[0068] Figure 7 is a structural schematic diagram of a parallel cell string group (adjacent cell pieces in the same plane) of Embodiment 1 of the present disclosure.

[0069] Figure 8 is a structural schematic diagram of a series cell string group (adjacent cell pieces exist in a stack) of Embodiment 2 of the present disclosure.

[0070] Figure 9 is a cross-sectional view of one embodiment of an end busbar built-in structure of Embodiment 2 of the present disclosure.

[0071] Figure 10 is a cross-sectional view of another embodiment of an end busbar built-in structure of Embodiment 2 of the present disclosure.

[0072] Figure 11 is a structural schematic diagram of a parallel cell string group (adjacent cell pieces in the same plane) of Embodiment 3 of the present disclosure.

[0073] Figure 12 is a structural schematic diagram of a middle busbar (extending segment including an extending subsection) of Embodiment 3 of the present disclosure.

[0074] Figure 13 is a cross-sectional view of an end busbar built-in structure of Embodiment 3 of the present disclosure.

[0075] Figure 14 is a structural schematic diagram of a parallel cell string group (adjacent cell pieces exist in a stack) of Embodiment 4 of the present disclosure.

[0076] Figure 15 is a cross-sectional view of one embodiment of a middle busbar built-in structure of Embodiment 4 of the present disclosure.

[0077] Figure 16 is a cross-sectional view of another embodiment of a middle busbar built-in structure of Embodiment 4 of the present disclosure. DETAILED DESCRIPTION

[0078] In order to make the purpose, technical scheme and advantages of the present disclosure clearer, the present disclosure is further described in detail below in combination with the drawings and embodiments. The examples of the embodiments are shown in the drawings, wherein the same or similar reference signs represent the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the drawings are exemplary and are only used to explain the present disclosure, and cannot be understood as a limitation on the present disclosure. In addition, it should be understood that the specific embodiments described herein are only used to explain the present disclosure and do not limit the present disclosure.

[0079] In the description of the present disclosure, the terms "first", "second", "third", "fourth" and the like are only for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined with "first", "second", "third", "fourth" and the like can explicitly or implicitly include one or more of the features. In the description of the present disclosure, the meaning of "a plurality of" is two or more, unless otherwise explicitly specified.

[0080] 1) The end busbar built-in structure of the present disclosure can increase the effective light receiving area of the battery assembly, improve the conversion efficiency of the assembly, avoid the exposure of the first busbar, and make the overall appearance of the battery assembly better. On the other hand, it can ensure that the first solder strip can fully match and weld with the effective welding position of the first battery piece, avoid the installation of the first busbar from affecting the welding of the first solder strip and the first battery piece, and reduce the production precision requirement and production difficulty. In addition, the end busbar built-in structure of the present disclosure can be applied to both main grid back contact battery assemblies and non-main grid back contact battery assemblies, and has stronger universality. The built-in end busbar and the overhanging extension section make the relative height distance of the connection between the end busbar and the first solder strip smaller, so that the stress of the end busbar built-in structure is smaller when laminating, which can reduce the risk of hidden cracks and fragments of the battery piece, and the reliability of the back contact battery assembly is good.

[0081] 2) The middle busbar built-in structure of the present disclosure can increase the effective light receiving area of the battery assembly, improve the conversion efficiency of the assembly, avoid the exposure of the middle busbar, and make the overall appearance of the battery assembly better. On the other hand, it can ensure that the second solder strip can fully match and weld with the effective welding position of the fourth battery piece, avoid the installation of the middle busbar from affecting the welding of the second solder strip and the fourth battery piece, and reduce the production precision requirement and production difficulty. In addition, the middle busbar built-in structure of the present disclosure can be applied to both main grid back contact battery assemblies and non-main grid back contact battery assemblies, and has stronger universality. The built-in middle busbar and the overhanging extension section make the relative height distance of the connection between the middle busbar and the second solder strip smaller, so that the stress of the middle busbar built-in structure is smaller when laminating, which can reduce the risk of hidden cracks and fragments of the battery piece, and the reliability of the back contact battery assembly is good.

[0082] Embodiment 1

[0083] Referring to FIGS. 1, 2 and 4, the present embodiment discloses a back contact battery assembly, comprising:

[0084] The battery string comprises battery pieces connected in series, and the battery pieces comprise first battery pieces 11 and second battery pieces 12 arranged along a first direction, the first battery pieces 11 are located at the end of the battery string,

[0085] The first insulating strip 21 is located at one end of the second battery piece 12 close to the first battery piece 11,

[0086] The first bus bar 31 is located at a side of the first insulating strip 21 away from the second battery piece 12 (i.e., the back of the first insulating strip 21, and vice versa, the side of the first insulating strip 21 facing the second battery piece 12 is the front of the first insulating strip 21),

[0087] The first insulating strip 21 and the first bus bar 31 are both arranged along a second direction, and the first direction intersects the second direction,

[0088] The first solder strip 41 is used to electrically connect the first bus bar 31 and the first battery piece 11,

[0089] The first bus bar 31 has an extension segment 311 at one end close to the first battery piece 11, the extension segment 311 extends to the edge of the first insulating strip 21 in the first direction and is electrically connected with the first solder strip 41, and the connection between the extension segment 311 and the first solder strip 41 forms a connection end 312, wherein the electrical connection mode can be welding, bonding through conductive glue, etc., but is not limited thereto.

[0090] It can be understood that in the battery string, the battery string can comprise two battery pieces connected in series, three battery pieces connected in series, or more battery pieces connected in series, and the number of battery pieces to be connected in series can be determined according to actual use.

[0091] In the embodiment, the first bus bar 31 is an end bus bar, and the first battery piece 11 is located at the end of the battery string, for the convenience of description, in the embodiment, the end where the first battery piece 11 is located is recorded as the tail end of the battery string, that is, in the first direction, the first battery piece 11 is the last battery piece of the battery string, and the second battery piece 12 is the second last battery piece of the battery string, it can be understood that the end where the first battery piece 11 is located can also be recorded as the head end of the battery string, which is not described herein.

[0092] Optionally, in the same battery string, the adjacent battery pieces can be connected in series through solder strips, conductive glue, etc.

[0093] In an embodiment, the adjacent battery pieces are connected by the series welding ribbons 51, specifically, the series welding ribbons 51 include first series welding ribbons 511 and second series welding ribbons 512, in the first direction, the first series welding ribbons 511 and the second series welding ribbons 512 are arranged alternately, in the second direction, the first series welding ribbons 511 and the second series welding ribbons 512 are arranged alternately, in one battery string, the Nth battery piece, the N+1th battery piece and the N+2th battery piece are arranged in the first direction in sequence (N is a positive integer greater than 1), wherein the positive electrode welding point of the Nth battery piece and the negative electrode welding point of the N+1th battery piece are connected in series by a plurality of first series welding ribbons 511, and the positive electrode welding point of the N+1th battery piece and the negative electrode welding point of the N+2th battery piece are connected in series by a plurality of second series welding ribbons 512.

[0094] In assembly, the battery pieces in the battery string are connected in series, the first insulating strip 21 is arranged at one end of the second battery piece 12 close to the first battery piece 11, the first bus bar 31 is arranged at the back of the first insulating strip 21, the main body of the first welding ribbon 41 is electrically connected with the effective welding position of the first battery piece 11, and one end of the first welding ribbon 41 close to the second battery piece 12 is electrically connected with the first bus bar 31, so that the first bus bar 31 can lead out the current of the battery string.

[0095] Firstly, in the present disclosure, the first bus bar 31 is located on the second battery piece 12, and the first bus bar 31 is separated from the second battery piece 12 by the first insulating strip 21, on the one hand, the edge of the battery assembly does not need to reserve space for placing the bus bar, and the battery assembly can reserve more space for installing the battery piece, so that the effective light receiving area of the battery assembly is larger, and the conversion efficiency of the assembly is higher, on the other hand, from the direction of the light receiving surface (or called "front surface") of the battery piece, the first insulating strip 21 can shield the first bus bar 31, avoiding the first bus bar 31 from being exposed, and the overall appearance of the battery assembly is better.

[0096] Secondly, compared with arranging the bus bar at the middle position of the back of the battery piece, the first bus bar 31 of the present disclosure is arranged at one end of the second battery piece 12 close to the first battery piece 11, and the first welding ribbon 41 can fully match and weld with the effective welding position of the first battery piece 11, avoiding that the installation of the first bus bar 31 affects the current collection due to insufficient welding of the first welding ribbon 41 with the first battery piece 11, at the same time, after the first welding ribbon 41 is welded with the first battery piece 11, it can be directly connected with the first bus bar 31, without the need of opening holes in the insulating strip or replacing it with an insulating block arranged at intervals, and only one whole first insulating strip 21 needs to be placed at one end of the second battery piece 12 close to the first battery piece 11 in assembly, effectively reducing the production precision requirement and production difficulty, and avoiding short circuit caused by position deviation when the insulating strip is opened or position deviation when the insulating block is laminated, and increasing the product yield.

[0097] Furthermore, when the busbar is arranged at the outer edge of the last cell tab of the cell string, i.e. the end of the first cell tab 11 away from the second cell tab 12, since the outer edge of the last cell tab of the cell string is close to the edge of the battery module, the stress at this position is large during lamination, and it is easy to produce fragments and other defects, at the same time, the installation of the busbar will affect the welding between the first welding band 41 and the first cell tab 11, the first welding band 41 cannot be welded with the first cell tab 11 at the position covered by the busbar, resulting in insufficient welding between the first welding band 41 and the first cell tab 11, poor current collection, and this situation is particularly serious when the battery module is a back contact battery module without main grid.

[0098] In contrast, the end busbar built-in structure of the present disclosure can be applied to back contact battery modules with main grid and back contact battery modules without main grid, and has stronger universality. On the one hand, the end of the second cell tab 12 close to the first cell tab 11 has smaller stress than the outer edge of the last cell tab of the cell string during lamination, and on the other hand, when the connection between the busbar and the welding band is located directly above the insulating strip, the relative height distance from the connection between the busbar and the welding band to the first cell tab 11 is relatively large, and it is easy to produce fragments and cracks. Therefore, the first busbar 31 of the present disclosure is provided with an extension segment 311 extending out of the first insulating strip 21, and the extension segment 311 can hang down after extending to the first insulating strip 21, so that the relative height distance from the connection (connection end 312) between the first busbar 31 and the first welding band 41 to the first cell tab 11 is reduced, thereby further reducing the risk of cell tab cracking and fragmenting and improving the reliability of the back contact battery module.

[0099] In some embodiments, referring to FIGS. 1, 2 and 4, the first busbar 31 includes a main body 313, and in the thickness direction of the second cell tab 12, the orthographic projection of the main body 313 is located within the orthographic projection of the first insulating strip 21,

[0100] The relative height distance from the connection end 312 to the first cell tab 11 is smaller than the relative height distance from the side of the main body 313 away from the first insulating strip 21 to the first cell tab 11.

[0101] It should be noted that the relative height distance in the present disclosure refers to the distance between two structures in the thickness direction of the second cell tab.

[0102] After the extension segment 311 extends to the first insulating strip 21, the extension segment 311 can be hung down, so that the relative height distance from the connecting end 312 to the first cell sheet 11 is smaller than the relative height distance from the side of the main body 313 facing away from the first insulating strip 21 to the first cell sheet 11, and the relative height distance from the connecting position (the connecting end 312) of the first bus bar 31 and the first solder strip 41 to the first cell sheet 11 is reduced, thereby further reducing the risk of cell sheet cracking and fragmentation and improving the reliability of the back contact type battery assembly.

[0103] In the first embodiment, as shown in FIG. 1 and FIG. 2, the main body 313 and the extension segment 311 are both in a long strip structure extending in the second direction. At this time, the first bus bar 31 can be made in a long strip rectangular structure as a whole, and the first bus bar 31 does not need to be cut or spliced, and only needs to ensure the insulation between the first bus bar 31 and the male solder strip / male grid line on the first cell sheet 11, and the production process is simpler.

[0104] In the second embodiment, as shown in FIG. 3 to FIG. 5, the extension segment 311 includes extension segments 314 which are arranged in the second direction and are spaced apart from each other at one end of the main body 313 close to the first cell sheet 11. Compared with the above-mentioned long strip type extension segment 311, on the one hand, the extension segments 314 are easier to hang down, and the connecting end 312 can achieve a smaller relative height distance at a position closer to the main body 313 of the first bus bar 31, and on the other hand, the extension segments 314 can be arranged corresponding to the first solder strip 41 and are staggered and spaced apart from the male solder strip / male grid line on the first cell sheet 11, thereby reducing the risk of short circuit and increasing the reliability of the battery assembly.

[0105] Further, as shown in FIG. 5, the width w1 of each extension segment 314 in the second direction is 1mm≤w1≤5mm, so that each extension segment 314 can be staggered and spaced apart from the male solder strip / male grid line on the first cell sheet 11.

[0106] Further, as shown in FIG. 3, the number of the extension segments 314 corresponds to the number of the first solder strip 41, and the spacing between adjacent extension segments 314 corresponds to the spacing between adjacent first solder strips 41, so as to facilitate one-to-one connection of the extension segments 314 and the first solder strip 41.

[0107] In the first embodiment, in the thickness direction of the second cell sheet 12, the orthographic projection of the first insulating strip 21 is located on the second cell sheet 12, and at this time, the first insulating strip 21 can insulate and separate the first bus bar 31 from the solder strip on the second cell sheet 12.

[0108] In the second embodiment, referring to FIG. 4, the first insulating strip 21 extends at least partially beyond the edge of the second cell 12 close to the first cell 11, at this time, the first insulating strip 21 can not only ensure that the first bus bar 31 is insulated from the welding strip on the second cell 12, but also ensure that the first welding strip 41 is insulated from the welding strip on the second cell 12, thereby avoiding short circuit and improving the reliability of the battery assembly.

[0109] It can be understood that when the first cell 11 and the second cell 12 are arranged in the same plane, the part of the first insulating strip 21 extending beyond the edge of the second cell 12 can be less than, equal to, or greater than the cell spacing of the two cells. In some embodiments, the part of the first insulating strip 21 extending beyond the edge of the second cell 12 is greater than the cell spacing of the two cells, so as to avoid the short circuit caused by the contact between the first bus bar 31 and the female welding strip / female grid line on the first cell 11, reduce the risk of short circuit caused by conductive foreign matter such as tin slag in the preparation process, and improve the reliability of the battery assembly.

[0110] In some embodiments, referring to FIG. 4, in the thickness direction of the second cell 12, the orthographic projection of the connecting end 312 at least partially overlaps the orthographic projection of the first cell 11, that is, the orthographic projection of the connecting end 312 can partially overlap the orthographic projection of the first cell 11, or the orthographic projection of the connecting end 312 can completely fall within the orthographic projection of the first cell 11.

[0111] On the one hand, the connecting end 312 is away from the second cell 12, and the first welding strip 41 can be connected to the connecting end 312 at a position away from the second cell 12, thereby avoiding the short circuit caused by the contact between the first welding strip 41 and the female welding strip / female grid line of the second cell 12. On the other hand, the connecting end 312 can be located at a lower position, reducing the risk of fragmentation and further improving the reliability of the battery assembly.

[0112] In some embodiments, referring to FIG. 1 and FIG. 4, the first cell 11 and the second cell 12 are located in the same plane,

[0113] In the first direction, the relative distance from the end of the second cell 12 close to the first cell 11 to the connecting end 312 is greater than the spacing between the second cell 12 and the first cell 11.

[0114] It should be noted that the width distance in the present disclosure actually refers to the distance between two structures.

[0115] Thus, the hanging connecting end 312 is away from the second cell piece 12, the first solder strip 41 can be connected to the connecting end 312 at a position away from the second cell piece 12, thereby avoiding the short circuit caused by the contact between the first solder strip 41 and the female solder strip / female grid line on the second cell piece 12, meanwhile, the connecting end 312 can be located at a lower position, reducing the risk of fragmentation and cracking, further improving the reliability of the battery assembly, in addition, it can also cooperate with the first insulating strip 21 to cover the edge of the first cell piece 11 (i.e. the first insulating strip 21 at least partially extends to the edge of the second cell piece 12 near one end of the first cell piece 11, and the part of the first insulating strip 21 extending to the edge of the second cell piece 12 is greater than the inter-cell distance of the two cell pieces), to avoid the short circuit caused by the contact between the first bus bar 31 and the female solder strip / female grid line on the first cell piece 11, and the reliability of the battery assembly is better.

[0116] In some embodiments, as shown in FIG. 1 and FIG. 4, in the first direction, the relative distance from the one end of the second cell piece 12 close to the first cell piece 11 to the connecting end 312 is: l 11 <L1<l 12 ,

[0117] In the formula, L1 is the relative distance from the one end of the second cell piece 12 close to the first cell piece 11 to the connecting end 312 in the first direction, l 11 is the inter-cell distance between the second cell piece 12 and the first cell piece 11, l 12 is the relative distance from the one end of the second cell piece 12 close to the first cell piece 11 to the first solder point 61, and the first solder point 61 is located at the one end of the first cell piece 11 close to the second cell piece 12, and the first solder point 61 is connected to the first solder strip 41.

[0118] It can be understood that the first solder point 61 is located at the edge of the first cell piece 11 closest to the second cell piece 12, by controlling L1 greater than l 11 and less than l 12 , the connecting end 312 can be kept at a relatively far distance away from the second cell piece 12 while ensuring that it does not exceed the effective soldering position of the first cell piece 11, thereby effectively reducing the relative height of the connecting end 312, the first solder strip 41 can be connected to the connecting end 312 at a position away from the second cell piece 12, and sufficient contact and soldering between the first solder strip 41 and the first cell piece 11 can be ensured, thereby reducing the risk of fragmentation and cracking while avoiding short circuit, so that the battery assembly can maintain high reliability.

[0119] In some embodiments, as shown in FIG. 1 and FIG. 4, more preferably, in the first direction, the relative distance from the one end of the second cell piece 12 close to the first cell piece 11 to the connecting end 312 is: l 11 <L1<l12 ,

[0120] In the formula, L1 is the relative distance from the end of the second battery piece 12 close to the first battery piece 11 to the connecting end 312 in the first direction, l 11 is the interval between the second battery piece 12 and the first battery piece 11, l 12 is the relative distance from the end of the second battery piece 12 close to the first battery piece 11 to the first soldering point 61, and the first soldering point 61 is located at the end of the first battery piece 11 close to the second battery piece 12, and the first soldering point 61 is connected with the first soldering band 41.

[0121] By controlling L1 to be greater than l 11 and less than l 12 In this range, the reliability of the battery assembly is better.

[0122] In some embodiments, referring to FIG. 1 and FIG. 6, the battery assembly comprises at least one series battery string group 100, each series battery string group 100 comprises two battery strings arranged along the second direction and connected in series with each other,

[0123] and in the same series battery string group 100, the same first bus bar 31 extends from the second battery piece 12 in one battery string to the second battery piece 12 of another battery string.

[0124] Further, the first soldering band 41 comprises a first positive soldering band 411 and a first negative soldering band 412, the same first bus bar 31 is electrically connected with the first positive soldering band 411 in one battery string and electrically connected with the first negative soldering band 412 in another battery string, so as to form series connection between adjacent battery strings.

[0125] For example, the same series battery string group 100 comprises a first battery string 10A and a second battery string 10B, the first soldering band 41 comprises a first positive soldering band 411 and a first negative soldering band 412, in the same series battery string group 100, the same first bus bar 31 extends from the second battery piece 12 in the first battery string 10A to the second battery piece 12 of the second battery string 10B, and in the first battery string 10A, the first bus bar 31 is electrically connected with the first positive soldering band 411 on the first battery piece 11, and in the second battery string 10B, the first bus bar 31 is electrically connected with the first negative soldering band 412 on the first battery piece 11.

[0126] In one embodiment, the battery assembly comprises a parallel battery string group 200, the same parallel battery string group 200 comprises at least two battery strings arranged in the first direction and arranged in parallel with each other, and a spacing area is arranged between the two battery strings arranged in parallel with each other, and the spacing area is provided with an intermediate busbar 32, and the intermediate busbar 32 is used to connect the two battery strings arranged adjacent in the first direction in parallel, that is, the end busbar built-in structure of the present disclosure can cooperate with the conventional intermediate busbar 32 mounting structure.

[0127] In another more preferred embodiment, as shown in FIGS. 6 and 7, each battery string is provided with a fourth cell tab 14 away from one end of the first cell tab 11, and the fourth cell tab 14 is provided with a third cell tab 13 close to one end of the first cell tab 11,

[0128] The battery assembly comprises a parallel battery string group 200, the same parallel battery string group 200 comprises at least two battery strings arranged in the first direction and arranged in parallel with each other, and the fourth cell tab 14 in the two battery strings arranged in parallel with each other is arranged adjacent in the first direction,

[0129] The battery assembly further comprises:

[0130] A second insulating strip 22 is located at the edge of the third cell tab 13 in a battery string, and the second insulating strip 22 is located at one end of the third cell tab 13 close to the fourth cell tab 14,

[0131] An intermediate busbar 32 is used to connect the two battery strings arranged adjacent in the first direction in parallel, and the intermediate busbar 32 is located on the side of the second insulating strip 22 away from the third cell tab 13,

[0132] The second insulating strip 22 and the intermediate busbar 32 are both arranged in the second direction,

[0133] A second welding strip 42 is used to electrically connect the intermediate busbar 32, the fourth cell tab 14 in the battery string, and the fourth cell tab 14 in another battery string adjacent to the battery string in the first direction.

[0134] For example, for the sake of illustration, the third battery string 20A and the fourth battery string 20B in the same parallel battery string group 200 are taken as an example, wherein the third battery string 20A is the battery string where the intermediate busbar 32 is located:

[0135] The third cell tab 13 in the third battery string 20A is denoted as the third cell tab 13A, and the fourth cell tab 14 is denoted as the fourth cell tab 14A. The third cell tab 13 in the fourth battery string 20B is denoted as the third cell tab 13B, and the fourth cell tab 14 is denoted as the fourth cell tab 14B. The third battery string 20A and the fourth battery string 20B are arranged in the first direction, and the fourth cell tab 14A and the fourth cell tab 14B are arranged adjacent in the first direction,

[0136] The battery assembly further comprises:

[0137] a second insulating strip 22 located at an edge of the third cell tab 13A in the third cell string 20A, and the second insulating strip 22 is located at one end of the third cell tab 13A close to the fourth cell tab 14A,

[0138] a middle busbar 32 for connecting the third cell string 20A and the fourth cell string 20B in parallel, and the middle busbar 32 is located at a side of the second insulating strip 22 away from the third cell tab 13,

[0139] The second insulating strip 22 and the middle busbar 32 are both arranged in extension along the second direction,

[0140] A second welding strip 42 is used to electrically connect the middle busbar 32, the fourth cell tab 14A and the fourth cell tab 14B, that is, the same second welding strip 42 extends from the fourth cell tab 14B to the fourth cell tab 14A and the center busbar in sequence.

[0141] Further, the second welding strip 42 comprises a second positive electrode welding strip 421 and a second negative electrode welding strip 422, and the fourth cell tab 14A, the fourth cell tab 14B and the center busbar are electrically connected by the second positive electrode welding strip 421 or the second negative electrode welding strip 422.

[0142] On the one hand, the middle busbar built-in structure of the present disclosure can increase the effective light receiving area of the battery assembly, improve the conversion efficiency of the assembly, avoid the exposure of the middle busbar 32, and the overall appearance of the battery assembly is better; on the other hand, it can ensure that the second welding strip 42 can fully match and weld with the effective welding position of the fourth cell tab 14, avoid the installation of the middle busbar 32 to cause insufficient welding of the second welding strip 42 and the fourth cell tab 14, and affect the current collection, and only need to place the first insulating strip 21 at one end of the third cell tab 13 close to the fourth cell tab 14 during assembly, effectively reducing the production precision requirement and production difficulty; further, the middle busbar built-in structure of the present disclosure can be applied to the main grid back contact battery assembly and the main grid back contact battery assembly, and the universality is stronger, the stress is smaller when laminating the middle busbar built-in structure, the risk of cell tab hidden crack and fragment can be reduced, and the reliability of the back contact battery assembly is good.

[0143] The end busbar built-in structure of the present disclosure cooperates with the middle busbar built-in structure of the present disclosure, can increase the effective light receiving area of the battery assembly, improve the conversion efficiency of the assembly, and the overall appearance and reliability of the battery assembly are better, effectively reducing the production precision requirement and production difficulty, and improving the production efficiency.

[0144] In some embodiments, referring to FIG. 7, the middle busbar 32 is provided with an extension segment 321 near one end of the fourth cell piece 14, the extension segment 321 extends to the outside of the edge of the second insulating strip 22 in the first direction and is electrically connected with the second solder strip 42, and the connection between the extension segment 321 and the second solder strip 42 forms a joint end 322.

[0145] The built-in structure of the middle busbar of the present disclosure can be applied to both the back contact cell module with main grid and the back contact cell module without main grid, and has stronger universality. On one hand, the stress of the third cell piece 13 near one end of the fourth cell piece 14 is smaller than the outer edge of the last cell piece of the cell string during lamination, and on the other hand, when the connection between the busbar and the solder strip is located directly above the insulating strip, the relative height distance from the connection between the busbar and the solder strip to the first cell piece 11 is relatively large, which is easy to cause fragmentation and cracking. Therefore, the middle busbar 32 of the present disclosure is provided with an extension segment 321 extending to the outside of the second insulating strip 22, and after extending to the second insulating strip 22, the extension segment 321 can fall down, so that the relative height distance from the connection (joint end 322) between the middle busbar 32 and the second solder strip 42 to the third cell piece 13 is reduced, thereby further reducing the risk of cell piece cracking and fragmentation and improving the reliability of the back contact cell module.

[0146] Further, the present disclosure provides a photovoltaic system comprising the back contact cell module described above.

[0147] Embodiment 2

[0148] The difference between this embodiment and embodiment 1 is that, referring to FIGS. 8 to 10, the first cell piece 11 and the second cell piece 12 are at least partially laminated near one end of the first cell piece 11, that is, stacked together

[0149] That is, the first cell piece 11 and the second cell piece 12 are arranged in a laminated manner, and there is no gap between the two cells.

[0150] In one embodiment, referring to FIG. 9, the side of the second cell piece 12 facing the first insulating strip 21 is at least partially laminated with the first cell piece 11.

[0151] In another embodiment, referring to FIG. 10, the side of the second cell piece 12 away from the first insulating strip 21 is at least partially laminated with the first cell piece 11.

[0152] In the first embodiment, in the thickness direction of the second cell piece 12, the orthographic projection of the first insulating strip 21 falls on the second cell piece 12, at this time, the first insulating strip 21 can insulate and separate the first busbar 31 and the solder strip on the second cell piece 12.

[0153] In the second embodiment, the first insulating strip 21 extends at least partially beyond the edge of the second cell tab 12 near the end of the first cell tab 11, and in this case, the first insulating strip 21 can not only ensure that the first bus bar 31 is insulated from the solder strip on the second cell tab 12, but also ensure that the first solder strip 41 is insulated from the solder strip on the second cell tab 12, thereby avoiding short circuit and improving the reliability of the battery assembly.

[0154] When the first cell tab 11 and the second cell tab 12 at least partially overlap, i.e., the first cell tab 11 and the second cell tab 12 are arranged in a stacked manner, the portion of the first insulating strip 21 extending beyond the edge of the second cell tab 12 can be less than, equal to, or greater than the width of the stacked region of the two cell tabs, and preferably the portion of the first insulating strip 21 extending beyond the edge of the second cell tab 12 is greater than the width of the stacked region of the two cell tabs, so as to avoid the first bus bar 31 contacting the female solder strip / female grid line on the first cell tab 11 and causing short circuit, thereby improving the reliability of the battery assembly.

[0155] In some embodiments, as shown in FIGS. 9 and 10, in the first direction, the relative distance between the first cell tab 11 near the end of the second cell tab 12 and the connecting end 312 is: l 21 <L2<l 21 +l 22 ,

[0156] wherein L2 is the relative distance between the first cell tab 11 near the end of the second cell tab 12 and the connecting end 312 in the first direction, l 21 is the width of the stacked region of the first cell tab 11 and the second cell tab 12, l 22 is the relative distance between the end of the second cell tab 12 near the first cell tab 11 and the first solder point 61, and the first solder point 61 is located at the end of the first cell tab 11 near the second cell tab 12, and the first solder point 61 is connected to the first solder strip 41.

[0157] It can be understood that the first solder point 61 is located at the effective soldering position of the first cell tab 11 closest to the edge of the second cell tab 12, and by controlling L2 to be greater than or equal to l 21 and less than l 22 , the connecting end 312 can be kept at a relatively far distance from the second cell tab 12 while ensuring that it does not exceed the effective soldering position of the first cell tab 11, thereby effectively reducing the relative height of the connecting end 312, the first solder strip 41 can be connected to the connecting end 312 at a certain distance from the second cell tab 12, and sufficient contact and soldering between the first solder strip 41 and the first cell tab 11 can be ensured, thereby reducing the risk of fragmentation and cracking while avoiding short circuit, so that the battery assembly can maintain high reliability.

[0158] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the structure and implementation principle of the back contact battery described above can refer to the corresponding structure and implementation principle in the foregoing embodiment 1, which will not be described here.

[0159] Embodiment 3

[0160] Referring to FIG. 11 and FIG. 13, the embodiment discloses a back contact battery assembly, comprising:

[0161] The parallel battery string group 200 comprises at least two battery strings arranged along the first direction and connected in parallel with each other, each battery string comprising battery pieces connected in series with each other, the battery pieces comprising the third battery piece 13 and the fourth battery piece 14 arranged along the first direction, the fourth battery piece 14 being located at an end of the battery string, and the fourth battery pieces 14 in the two battery strings connected in parallel with each other being arranged adjacent to each other in the first direction,

[0162] The second insulation strip 22 is located at an edge of the third battery piece 13 in a battery string, and the second insulation strip 22 is located at one end of the third battery piece 13 close to the fourth battery piece 14,

[0163] The intermediate busbar 32 is used for connecting in parallel two battery strings arranged adjacent to each other in the first direction, and the intermediate busbar 32 is located at a side of the second insulation strip 22 away from the third battery piece 13,

[0164] The second insulation strip 22 and the intermediate busbar 32 are both arranged extending along the second direction,

[0165] The second solder strip 42 is used for electrically connecting the intermediate busbar 32, the fourth battery piece 14 in the battery string where the intermediate busbar 32 is located, and the fourth battery piece 14 in another battery string adjacent to the battery string in the first direction,

[0166] The intermediate busbar 32 is provided with an extension segment 321 at one end close to the fourth battery piece 14, the extension segment 321 extends to the outside of the edge of the second insulation strip 22 in the first direction, and is electrically connected with the second solder strip 42, and the connection between the extension segment 321 and the second solder strip 42 forms a joint end 322.

[0167] For example, for the convenience of description, the third battery string 20A and the fourth battery string 20B connected in parallel with each other in the same parallel battery string group 200 are taken as an example, wherein the third battery string 20A is the battery string where the intermediate busbar 32 is located:

[0168] The third cell tab 13 in the third cell string 20A is referred to as third cell tab 13A, the fourth cell tab 14 is referred to as fourth cell tab 14A, the third cell tab 13 in the fourth cell string 20B is referred to as third cell tab 13B, the fourth cell tab 14 is referred to as fourth cell tab 14B, the third cell string 20A and the fourth cell string 20B are arranged along a first direction, and the fourth cell tab 14A and the fourth cell tab 14B are arranged adjacent to each other along the first direction,

[0169] The battery assembly further comprises:

[0170] A second insulation strip 22 is arranged at an edge of the third cell tab 13A in the third cell string 20A, and the second insulation strip 22 is arranged at one end of the third cell tab 13A close to the fourth cell tab 14A,

[0171] An intermediate busbar 32 is arranged in parallel to the third cell string 20A and the fourth cell string 20B, and the intermediate busbar 32 is arranged at a side of the second insulation strip 22 away from the third cell tab 13,

[0172] The second insulation strip 22 and the intermediate busbar 32 are arranged along a second direction,

[0173] A second solder strip 42 is arranged to electrically connect the intermediate busbar 32, the fourth cell tab 14A and the fourth cell tab 14B, that is, the same second solder strip 42 extends from the fourth cell tab 14B to the fourth cell tab 14A and the intermediate busbar 32 in sequence,

[0174] The intermediate busbar 32 is provided with an extension segment 321 at one end close to the fourth cell tab 14A, the extension segment 321 extends to an edge of the second insulation strip 22 outside in the first direction, and is electrically connected with the second solder strip 42, and the connection between the extension segment 321 and the second solder strip 42 forms a joint end 322.

[0175] During assembly, each cell tab in the cell string is connected in series with each other, the second insulation strip 22 is arranged at one end of the third cell tab 13A close to the fourth cell tab 14A, the intermediate busbar 32 is arranged at a back of the second insulation strip 22, the main body of the second solder strip 42 is electrically connected with an effective welding position of the fourth cell tab 14A and an effective welding position of the fourth cell tab 14B respectively, and one end of the second solder strip 42 close to the third cell tab 13A is electrically connected with the intermediate busbar 32, so that the intermediate busbar 32 can be connected in parallel to the third cell string 20A and the fourth cell string 20B.

[0176] Firstly, in the present disclosure, the intermediate busbar 32 is located on the third cell piece 13A, and the intermediate busbar 32 is separated from the third cell piece 13A by the second insulating strip 22. On the one hand, the edge of the battery assembly does not need to reserve space for placing the busbar, and the battery assembly can reserve more space for installing the cell piece, so that the effective light receiving area of the battery assembly is larger, and the conversion efficiency of the assembly is higher. On the other hand, from the direction of the light receiving surface (or "front surface") of the cell piece, the second insulating strip 22 can shield the intermediate busbar 32 to avoid the exposure of the intermediate busbar 32, and the overall appearance of the battery assembly is better.

[0177] Secondly, compared with the intermediate position of the busbar arranged on the back surface of the cell piece, the intermediate busbar 32 of the present disclosure is arranged at one end of the third cell piece 13A close to the fourth cell piece 14A. The second solder strip 42 extends to the fourth cell piece 14A after being connected to the effective welding position of the fourth cell piece 14B, and can fully fit and weld with the effective welding position of the fourth cell piece 14A. The installation of the intermediate busbar 32 avoids the insufficient welding of the second solder strip 42 with the fourth cell piece 14A, which affects the current collection. At the same time, after the second solder strip 42 is welded with the fourth cell piece 14A and the fourth cell piece 14B, it can be directly connected with the intermediate busbar 32 without the need of opening holes in the insulating strip or replacing it with an insulating block arranged at intervals. When assembling, only the second insulating strip 22 needs to be placed at one end of the third cell piece 13A close to the fourth cell piece 14A, which effectively reduces the production precision requirement and production difficulty, avoids short circuit caused by position deviation when the insulating strip is opened or position deviation when the insulating block is laminated, and increases the product yield.

[0178] Furthermore, when the busbar is arranged at the outer edge of the last cell piece of the battery string, that is, at one end of the fourth cell piece 14A away from the third cell piece 13A, since the stress at the outer edge of the last cell piece of the battery string is large during lamination, it is easy to produce fragments and other defects. At the same time, the installation of the busbar will affect the welding between the second solder strip 42 and the fourth cell piece 14A. The second solder strip 42 cannot be welded with the fourth cell piece 14A at the position covered by the busbar, resulting in insufficient welding between the second solder strip 42 and the fourth cell piece 14A, poor current collection, and especially serious when the battery assembly is a main grid back contact battery assembly.

[0179] In contrast, the intermediate busbar built-in structure of the present disclosure can be applied to both the back contact cell assembly with a main grid and the back contact cell assembly without a main grid, and has stronger versatility. On the one hand, the stress of the one end of the third cell piece 13A close to the fourth cell piece 14A compared to the outer edge of the last cell piece of the cell string is smaller during lamination. On the other hand, when the connection between the busbar and the solder strip is located directly above the insulating strip, the relative height distance from the connection between the busbar and the solder strip to the fourth cell piece 14 is relatively large, and it is easy to break and crack. Therefore, the intermediate busbar 32 of the present disclosure is provided with an extension segment 311 extending out of the second insulating strip 22. After extending to the second insulating strip 22, the extension segment 311 can be hung down, so that the relative height distance from the connection (connection end 312) between the intermediate busbar 32 and the second solder strip 42 to the fourth cell piece 14A is small, thereby further reducing the risk of cell cracking and breaking and improving the reliability of the back contact cell assembly.

[0180] Further, the second solder strip 42 includes a second positive solder strip 421 and a second negative solder strip 422, and the fourth cell piece 14A, the fourth cell piece 14B and the center busbar are electrically connected by the second positive solder strip 421 or the second negative solder strip 422.

[0181] In some embodiments, referring to FIG. 13, the intermediate busbar 32 is provided with a main body 323, and in the thickness direction of the third cell piece 13, the orthographic projection of the main body 323 falls within the orthographic projection of the second insulating strip 22,

[0182] The relative height distance from the joint end 322 to the fourth cell piece 14 is smaller than the relative height distance from the side of the main body 323 away from the second insulating strip 22 to the fourth cell piece 14.

[0183] After extending to the second insulating strip 22, the extension segment 321 can be hung down, so that the relative height distance from the joint end 322 to the fourth cell piece 14A is smaller than the relative height distance from the side of the main body 323 away from the second insulating strip 22 to the fourth cell piece 14A, and the relative height distance from the connection (joint end 322) between the intermediate busbar 32 and the second solder strip 42 to the fourth cell piece 14A is small, thereby further reducing the risk of cell cracking and breaking and improving the reliability of the back contact cell assembly.

[0184] In the first embodiment, referring to FIG. 11, the main body 323 and the extension segment 321 both have a long strip structure extending in the second direction.

[0185] At this time, the intermediate busbar 32 can be made into a long strip rectangular structure as a whole, and the intermediate busbar 32 does not need to be cut or spliced, and only needs to ensure the insulation between the intermediate busbar 32 and the heterogeneous solder strip / heterogeneous grid line on the fourth cell piece 14A, and the production process is simpler.

[0186] In the second embodiment, referring to FIG. 12, the extension section 321 comprises extension subsections 324, which are arranged in the second direction at one end of the main body 323 close to the fourth cell tab 14, and the extension subsections 324 are long strip structures extending in the first direction.

[0187] The extension section 321 is made of the extension subsections 324 arranged at intervals, compared with the long strip integral extension section 321 described above, on the one hand, the extension subsections 324 are more prone to fall, and the joint end 322 can achieve a smaller relative height distance at a position closer to the main body 323 of the middle busbar 32, on the other hand, the extension subsections 324 can be arranged corresponding to the second solder strip 42, and are staggered and spaced apart from the heterogeneous solder strip / heterogeneous grid line on the fourth cell tab 14A, reducing the risk of short circuit and increasing the reliability of the battery assembly.

[0188] Further, the width w2 of each extension subsection 324 in the second direction is 1mm≤w2≤5mm, so that each extension subsection 324 can be staggered and spaced apart from the heterogeneous solder strip / heterogeneous grid line on the fourth cell tab 14A.

[0189] Further, the number of extension subsections 324 corresponds to the number of second solder strips 42, and the distance between adjacent extension subsections 324 corresponds to the distance between adjacent second solder strips 42, so as to facilitate one-to-one connection of the extension subsections 324 and the second solder strips 42.

[0190] In the first embodiment, in the thickness direction of the third cell tab 13, the orthographic projection of the second insulating strip 22 falls on the third cell tab 13, at this time, the second insulating strip 22 can insulate and separate the middle busbar 32 from the solder strip on the third cell tab 13.

[0191] In the second embodiment, the second insulating strip 22 at least partially extends to the edge outside the end of the third cell tab 13 close to the fourth cell tab 14, at this time, the second insulating strip 22 can not only ensure that the middle busbar 32 is insulated and separated from the solder strip on the fourth cell tab 14, but also ensure that the second solder strip 42 is insulated and separated from the solder strip on the third cell tab 13, avoiding short circuit, and the reliability of the battery assembly is better.

[0192] It can be understood that when the third cell tab 13 and the fourth cell tab 14 are arranged in the same plane, the part of the second insulating strip 22 extending outside the edge of the third cell tab 13 can be less than, equal to, or greater than the tab spacing of the two cell tabs, preferably the part of the second insulating strip 22 extending outside the edge of the third cell tab 13 is greater than the tab spacing of the two cell tabs, so as to avoid the middle busbar 32 contacting the heterogeneous solder strip / heterogeneous grid line on the fourth cell tab 14 to cause short circuit, and the reliability of the battery assembly is better.

[0193] In some embodiments, referring to FIG. 13, in the battery string provided with the intermediate busbar 32, in the thickness direction of the third cell tab 13, the orthographic projection of the joint end 322 at least partially overlaps the orthographic projection of the fourth cell tab 14, i.e., in the third battery string 20A, in the thickness direction of the third cell tab 13A, the orthographic projection of the joint end 322 at least partially overlaps the orthographic projection of the fourth cell tab 14A.

[0194] It can be understood that the orthographic projection of the joint end 322 and the orthographic projection of the fourth cell tab 14A can partially overlap, or the orthographic projection of the joint end 322 can completely fall within the orthographic projection of the fourth cell tab 14A.

[0195] On the one hand, the joint end 322 is away from the third cell tab 13A, and the second solder strip 42 can be connected to the joint end 322 at a position away from the third cell tab 13A, thereby avoiding short circuit caused by the contact between the second solder strip 42 and the heterogeneous solder strip / heterogeneous grid line of the third cell tab 13A, and on the other hand, the joint end 322 can be located at a lower position, reducing the risk of fragmentation and cracking, and further improving the reliability of the battery assembly.

[0196] In some embodiments, referring to FIG. 13, in the same battery string, the fourth cell tab 14 and the third cell tab 13 are located on the same plane,

[0197] In the battery string provided with the intermediate busbar 32, in the first direction, the relative distance from the third cell tab 13 to the joint end 322 at the end close to the fourth cell tab 14 is greater than the interval between the third cell tab 13 and the fourth cell tab 14.

[0198] Thus, the joint end 322 is away from the third cell tab 13A, and the second solder strip 42 can be connected to the joint end 322 at a position away from the third cell tab 13A, thereby avoiding short circuit caused by the contact between the second solder strip 42 and the heterogeneous solder strip / heterogeneous grid line of the third cell tab 13A, and on the other hand, the joint end 322 can be located at a lower position, reducing the risk of fragmentation and cracking, and further improving the reliability of the battery assembly. In addition, the second insulating strip 22 can be arranged to cover the edge of the fourth cell tab 14A (i.e., the second insulating strip 22 at least partially extends to the edge of the third cell tab 13A at the end close to the fourth cell tab 14A, and the portion of the second insulating strip 22 extending to the edge of the third cell tab 13A is greater than the interval between the two cell tabs), to avoid short circuit caused by the contact between the intermediate busbar 32 and the heterogeneous solder strip / heterogeneous grid line on the fourth cell tab 14A, and the reliability of the battery assembly is better.

[0199] In some embodiments, referring to FIG. 13, in the battery string provided with the intermediate busbar 32, in the first direction, the relative distance from the third cell tab 13 to the joint end 322 at the end close to the fourth cell tab 14 is:31 L3 32 ,

[0200] In the formula, L3 is the relative distance from the edge of the third cell tab 13 (the third cell tab 13A) close to the fourth cell tab 14 (the fourth cell tab 14A) to the joint end 322 in the battery string provided with the intermediate busbar 32 in the first direction, l 31 is the spacing between the third cell tab 13 (the third cell tab 13A) and the fourth cell tab 14 (the fourth cell tab 14A) in the battery string provided with the intermediate busbar 32, l 32 is the relative distance from the edge of the third cell tab 13 (the third cell tab 13A) close to the fourth cell tab 14 (the fourth cell tab 14A) to the second soldering point 62 in the battery string provided with the intermediate busbar 32, the second soldering point 62 is located on the fourth cell tab 14 (the fourth cell tab 14A) in the battery string provided with the intermediate busbar 32 and is located close to the third cell tab 13 (the third cell tab 13A), and the second soldering point 62 is connected with the second soldering strip 42.

[0201] It can be understood that the second soldering point 62 is located at the edge of the effective soldering position of the fourth cell tab 14A closest to the third cell tab 13A, by controlling L2 to be greater than or equal to l 21 and less than l 22 , so that the joint end 322 can keep a relatively far distance from the third cell tab 13A while ensuring that it does not exceed the effective soldering position of the fourth cell tab 14A, thereby effectively reducing the relative height of the joint end 322, the second soldering strip 42 can be connected to the joint end 322 at a distance from the third cell tab 13A, and sufficient contact and soldering between the second soldering strip 42 and the fourth cell tab 14A can be ensured, thereby reducing the risk of debris and cracks while avoiding short circuits, so that the battery assembly can maintain high reliability.

[0202] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the structure and implementation principle of the back contact battery described above can refer to the corresponding structure and implementation principle in the foregoing embodiment 1, which will not be described here.

[0203] Embodiment 4

[0204] The difference between this embodiment and embodiment 3 is that, as shown in FIGS. 14-16, the fourth cell tab 14 is at least partially laminated with the third cell tab 13 close to one end of the fourth cell tab 14.

[0205] That is, the third cell tab 13A and the fourth cell tab 14A are arranged in a laminated manner, and there is no gap between the two cells.

[0206] In one embodiment, referring to FIG. 15, the third cell tab 13A is at least partially laminated with the fourth cell tab 14A on a side facing the first insulating strip 21.

[0207] In another embodiment, referring to FIG. 16, the third cell tab 13A is at least partially laminated with the fourth cell tab 14A on a side facing away from the second insulating strip 22.

[0208] In the first embodiment, in the thickness direction of the third cell tab 13A, the orthographic projection of the second insulating strip 22 falls on the third cell tab 13A, at this time, the second insulating strip 22 can insulate and separate the intermediate busbar 32 and the solder strip on the third cell tab 13A.

[0209] In the second embodiment, the second insulating strip 22 at least partially extends to the edge of the third cell tab 13A close to the end of the fourth cell tab 14A, at this time, the second insulating strip 22 can not only ensure that the intermediate busbar 32 and the solder strip on the third cell tab 13A are insulated and separated, but also ensure that the first solder strip 41 and the solder strip on the third cell tab 13A are insulated and separated, avoiding short circuit, and the reliability of the battery assembly is better.

[0210] When the fourth cell tab 14A and the third cell tab 13A are at least partially overlapped, that is, the fourth cell tab 14A and the third cell tab 13A are laminated, the part of the second insulating strip 22 extending to the edge of the third cell tab 13A can be less than, equal to, or greater than the width of the lamination area of the two cell tabs, preferably the part of the second insulating strip 22 extending to the edge of the third cell tab 13A is greater than the width of the lamination area of the two cell tabs, to avoid the contact between the intermediate busbar 32 and the heterogeneous solder strip / heterogeneous grid line on the fourth cell tab 14A causing short circuit, and the reliability of the battery assembly is better.

[0211] In some embodiments, referring to FIG. 15 and FIG. 16, in the battery string provided with the intermediate busbar 32, in the first direction, the relative distance from the end of the third cell tab 13 close to the fourth cell tab 14 to the junction end 322 is: 41 <L4<l 41 +l 42 ,

[0212] In the formula, L4 is the relative distance from the end of the fourth cell tab 14 (the fourth cell tab 14A) close to the third cell tab 13 (the third cell tab 13A) to the junction end 322 in the battery string provided with the intermediate busbar 32, l 41 is the width of the lamination area of the third cell tab 13 (the third cell tab 13A) and the fourth cell tab 14 (the fourth cell tab 14A) in the battery string provided with the intermediate busbar 32, l 42The relative distance from the edge of the third cell sheet 13 (the third cell sheet 13A) to the second welding spot 62 near the end of the fourth cell sheet 14 (the fourth cell sheet 14A) close to the third cell sheet 13 (the third cell sheet 13A) in the battery string provided with the intermediate busbar 32 is connected with the second welding strip 42.

[0213] It can be understood that the second welding spot 62 is located at the edge of the effective welding position of the fourth cell sheet 14 (the fourth cell sheet 14A) closest to the third cell sheet 13 (the third cell sheet 13A), and by controlling L2 to be greater than or equal to l 21 and less than l 22 , so that the connecting end 312 can be kept away from the third cell sheet 13 (the third cell sheet 13A) at a relatively far distance while ensuring that it does not exceed the effective welding position of the fourth cell sheet 14 (the fourth cell sheet 14A), thereby effectively reducing the relative height of the connecting end 312, the second welding strip 42 can be connected to the connecting end 312 at a distance from the third cell sheet 13 (the third cell sheet 13A), and sufficient contact and welding between the second welding strip 42 and the fourth cell sheet 14 (the fourth cell sheet 14A) can be ensured, thereby reducing the risk of debris and cracks while avoiding short circuits, so that the battery assembly can maintain high reliability.

[0214] It can be clearly understood by those skilled in the art that, for the convenience and brevity of description, the structure and implementation principle of the back contact battery described above can refer to the corresponding structure and implementation principle in the foregoing embodiment 1 and embodiment 3, which will not be described here.

[0215] In the description of the present specification, the description of the terms "some embodiments", "exemplary embodiments", "examples", "specific examples", or "some examples" and the like means that the specific features, structures, materials or characteristics described in connection with the embodiments or examples are included in at least one embodiment or example of the present disclosure. In the present specification, the exemplary description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0216] The above merely describes the preferred embodiments of the present disclosure and is not intended to limit the present disclosure in any form. Although the present disclosure has been disclosed as the above preferred embodiments, it is not intended to limit the present disclosure. Any person skilled in the art can make some changes or modifications to the above-mentioned technical content as equivalent embodiments with slight changes or modifications within the scope of the technical solutions of the present disclosure without departing from the technical solutions of the present disclosure. Any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present disclosure are still within the scope of the present disclosure.

Claims

1. A back contact cell assembly, characterized by, The battery assembly comprises: a battery string comprising battery pieces in series, the battery pieces comprising first battery pieces and second battery pieces arranged along a first direction, the first battery pieces being located at the end of the battery string, a first insulating strip located at one end of the second battery piece close to the first battery piece, a first busbar located at one side of the first insulating strip away from the second battery piece, the first insulating strip and the first busbar are both arranged along a second direction, the first direction and the second direction intersecting, a first solder strip for electrically connecting the first busbar and the first battery piece, the first busbar has an extension segment at one end close to the first battery piece, the extension segment extends to the edge of the first insulating strip in the first direction and is electrically connected with the first solder strip, and the connection between the extension segment and the first solder strip forms a connection end.

2. A back contact solar cell assembly according to claim 1, wherein, The first busbar comprises a main body, and in the thickness direction of the second battery piece, the orthogonal projection of the main body is located within the orthogonal projection of the first insulating strip, The relative height distance from the connection end to the first battery piece is less than the relative height distance from one side of the main body away from the first insulating strip to the first battery piece.

3. A back contact solar cell assembly according to claim 2, wherein, The main body and the extension segment are both long strip structures extending along the second direction.

4. A back contact solar cell assembly according to claim 2, wherein, The extension segment comprises extension sub-segments, which are arranged at one end of the main body close to the first battery piece along the second direction.

5. A back contact solar cell assembly according to claim 1, wherein, At least part of the first insulating strip extends to the edge of the second battery piece at one end close to the first battery piece.

6. A back contact solar cell assembly according to claim 1, wherein, At least part of the connection end is located outside the edge of the second battery piece at one end close to the first battery piece, and in the thickness direction of the second battery piece, the orthogonal projection of the connection end at least partially overlaps with the orthogonal projection of the first battery piece.

7. A back contact solar cell assembly according to claim 6, wherein, The first battery piece and the second battery piece are located on the same plane, In the first direction, the distance from one end of the second battery piece close to the first battery piece to the connection end is greater than the spacing between the second battery piece and the first battery piece.

8. A back contact solar cell assembly according to claim 6, wherein, In the first direction, the distance from the end of the second battery piece close to the first battery piece to the connecting end is: l 11 <L1 < l 12 , wherein L1 is the distance from the end of the second cell tab close to the first cell tab to the connection end in the first direction, l 11 is the spacing between the second cell tab and the first cell tab, l 12 is the distance from the end of the second cell tab close to the first cell tab to the first solder point, the first solder point being located at the end of the first cell tab close to the second cell tab, and the first solder point being connected to the first solder band.

9. A back contact solar cell assembly according to claim 6, wherein, The second battery piece is at least partially laminated with the first battery piece at one end close to the first battery piece.

10. A back contact solar cell assembly according to claim 9, wherein, In the first direction, the distance from the end of the first battery piece close to the second battery piece to the connecting end is: l 21 <L2 < l 21 + l 22 , wherein L2 is a distance from an end of the first cell tab close to the second cell tab to the connection end in the first direction, l 21 is a width of a laminated region of the first cell tab and the second cell tab, l 22 is a distance from an end of the second cell tab close to the first cell tab to a first soldering point, the first soldering point is located at an end of the first cell tab close to the second cell tab, and the first soldering point is connected with the first soldering band.

11. A back contact solar cell assembly according to claim 1, wherein, The battery assembly comprises at least one series battery string group, each series battery string group comprising two battery strings arranged along the second direction and in series, and in the same series battery string group, the same first busbar extends from the second battery piece in one battery string to the second battery piece of another battery string.

12. A back contact solar cell assembly according to claim 1, wherein, Each battery string is provided with a fourth battery piece at one end away from the first battery piece, and a third battery piece at one end of the fourth battery piece close to the first battery piece, The battery assembly comprises a parallel battery string group, the same parallel battery string group comprising at least two battery strings arranged along the first direction and in parallel, and the fourth battery pieces in the two battery strings arranged in parallel are arranged adjacent in the first direction, The battery assembly further comprises: A second insulation strip is located at an edge of the third cell tab in one of the battery strings, and the second insulation strip is located at one end of the third cell tab close to the fourth cell tab, An intermediate busbar is used to parallel two of the battery strings arranged adjacent to each other in the first direction, and the intermediate busbar is located at a side of the second insulation strip away from the third cell tab, The second insulation strip and the intermediate busbar are both arranged in extension along the second direction, A second welding strip is used to electrically connect the intermediate busbar, the fourth cell tab in the battery string where the intermediate busbar is located, and the fourth cell tab in another battery string adjacent to the battery string in the first direction.

13. A back contact solar cell assembly according to claim 12, wherein, The intermediate busbar is provided with an extension section at one end close to the fourth cell tab, the extension section extends to outside of an edge of the second insulation strip in the first direction, and is electrically connected with the second welding strip, and a joint end is formed at a connection position of the extension section and the second welding strip.

14. A back contact solar cell module, characterized by, Comprise: Parallel battery string groups, the same parallel battery string group comprises at least two battery strings arranged in a first direction and parallel to each other, each of the battery strings comprises cell tabs in series with each other, the cell tabs comprise third cell tabs and fourth cell tabs arranged in the first direction, the fourth cell tabs are located at end portions of the battery strings, and the fourth cell tabs in the two battery strings parallel to each other are arranged adjacent to each other in the first direction, A second insulation strip is located at an edge of the third cell tab in one of the battery strings, and the second insulation strip is located at one end of the third cell tab close to the fourth cell tab, An intermediate busbar is used to parallel two of the battery strings arranged adjacent to each other in the first direction, and the intermediate busbar is located at a side of the second insulation strip away from the third cell tab, The second insulation strip and the intermediate busbar are both arranged in extension along the second direction, A second welding strip is used to electrically connect the intermediate busbar, the fourth cell tab in the battery string where the intermediate busbar is located, and the fourth cell tab in another battery string adjacent to the battery string in the first direction, The intermediate busbar is provided with an extension section at one end close to the fourth cell tab, the extension section extends to outside of an edge of the second insulation strip in the first direction, and is electrically connected with the second welding strip, and a joint end is formed at a connection position of the extension section and the second welding strip.

15. A back contact solar cell assembly according to claim 14, wherein, The intermediate busbar comprises a main body, and a projection of the main body in a thickness direction of the third cell tab is located within a projection of the second insulation strip, A relative height distance from the joint end to the fourth cell tab is less than a relative height distance from a side of the main body away from the second insulation strip to the fourth cell tab.

16. A back contact solar cell assembly according to claim 15, wherein, The main body and the extension section are both long strip structures extending along the second direction, or The extension section comprises extension subsections arranged in the second direction at one end of the main body close to the fourth cell tab, and the extension subsections are long strip structures extending along the first direction.

17. A back contact solar cell assembly according to claim 14, wherein, At least part of the second insulating strip extends outside an edge of the third cell piece near an end of the fourth cell piece.

18. A back contact solar cell assembly according to claim 14, wherein, In the battery string provided with the intermediate bus bar, in a thickness direction of the third cell piece, a projection of the joint end and a projection of the fourth cell piece at least partially overlap.

19. A back contact solar cell assembly according to claim 18, wherein, In the same battery string, the fourth cell piece and the third cell piece are located on the same plane, In the battery string provided with the intermediate bus bar, in the first direction, a distance from an end of the third cell piece near the fourth cell piece to the joint end is greater than a spacing between the third cell piece and the fourth cell piece.

20. A back contact solar cell assembly according to claim 18, wherein, In the battery string provided with the intermediate busbar, in the first direction, the distance from the third cell tab to the junction end close to the fourth cell tab is: l 31 <L3 < l 32 , wherein L3 is a distance from an edge of the third cell tab near the fourth cell tab in the first direction to the junction end in the battery string with the intermediate busbar, l 31 is a distance between the third cell tab and the fourth cell tab in the battery string with the intermediate busbar, l 32 is a distance from an edge of the third cell tab near the fourth cell tab to a second soldering point on the fourth cell tab in the battery string with the intermediate busbar, and the second soldering point is near the third cell tab and connected to the second busbar.

21. A back contact solar cell assembly according to claim 18, wherein, The end of the third cell piece near the fourth cell piece and the fourth cell piece are at least partially laminated.

22. A back contact solar cell assembly according to claim 21, wherein, In the battery string provided with the intermediate busbar, in the first direction, the distance from the fourth cell tab to the junction end close to one end of the third cell tab is: l 41 <L4<l 41 +l 42 , In the formula, L4 is a distance from an edge of the third cell tab near an end of the fourth cell tab to a second welding point in the battery string provided with the intermediate bus bar, the second welding point being located at an end of the fourth cell tab near the third cell tab and the second welding point being connected to the second welding band. 41 In the formula, L4 is a distance from an edge of the third cell tab near an end of the fourth cell tab to a second welding point in the battery string provided with the intermediate bus bar, the second welding point being located at an end of the fourth cell tab near the third cell tab and the second welding point being connected to the second welding band. 42 In the formula, L4 is a distance from an edge of the third cell tab near an end of the fourth cell tab to a second welding point in the battery string provided with the intermediate bus bar, the second welding point being located at an end of the fourth cell tab near the third cell tab and the second welding point being connected to the second welding band.

23. A photovoltaic system characterized by, A back contact cell module comprising a back contact cell module according to any one of claims 1 to 22.

Images