Battery piece, battery string and photovoltaic module

Abstract

The invention discloses a battery piece, a battery string and a photovoltaic module, and relates to the technical field of solar battery manufacturing, and the battery piece specifically comprises a battery piece main body, and a metal fine grid and an encrypted fine grid which are arranged at one side of the back surface of the battery piece main body; wherein the metal fine grids extend along the first direction of the battery piece main body; and the encrypted fine grids are parallel to the metal fine grids and are arranged around part of or all the metal fine grids. According to the battery piece, the encrypted fine grids are arranged on one side of the back surface of the battery piece main body, so that the encrypted arrangement can be carried out on the partial region without the metal fine grids under the condition that the light receiving area of the battery piece is not influenced, and higher current leading-out efficiency is realized.

Description

Technical Field

[0001] The present invention relates to the technical field of solar cell manufacturing, and in particular, to a battery cell, a battery string, and a photovoltaic module. Background Art

[0002] For the existing main-gridless battery cells, a plurality of metal fine grids are usually uniformly arranged on at least one side of the battery cell to achieve the extraction of current in the battery cell. Since the fine grids arranged on the front side of the battery cell will block part of the sunlight, and for the convenience of batch process production, in the prior art, the number of metal fine grids arranged and the interval between adjacent metal fine grids are relatively fixed, and the current extraction efficiency that can be achieved is also relatively fixed. Summary of the Invention

[0003] In view of this, embodiments of the present invention provide a battery cell, a battery string, and a photovoltaic module. By arranging encrypted fine grids on the back side of the battery cell body, it is possible to perform encrypted setting in some areas where no metal fine grids are provided without affecting the light-receiving area of the battery cell, thereby achieving a higher current extraction efficiency.

[0004] To solve the above technical problems, the present invention provides the following technical solutions:

[0005] In a first aspect, the present invention provides a battery cell, including: a battery cell body, a metal fine grid, and an encrypted fine grid arranged on the back side of the battery cell body; wherein, the metal fine grid extends along a first direction of the battery cell body; the encrypted fine grid is parallel to the metal fine grid and is arranged around part or all of the metal fine grids.

[0006] Optionally, the encrypted fine grids are arranged at intervals along the first direction; or, for the structure in which the encrypted fine grids are arranged around part of the metal fine grids, the encrypted fine grids penetrate through the battery cell body along the first direction.

[0007] Optionally, the encrypted fine grids are arranged in the edge area of the battery cell body along a second direction, and the second direction is perpendicular to the first direction.

[0008] In a second aspect, the present invention provides a battery string, including: a plurality of connected battery cells and a first solder tape; wherein, at least one of the plurality of battery cells is a first battery cell, and the first battery cell is any one of the battery cells provided above;

[0009] The first battery cell is at least arranged at a position where the battery string is connected to a bus bar;

[0010] The first solder strip is connected to a plurality of metal fine grids and encrypted fine grids with the same polarity on the second side of the first solar cell, and is connected to the bus bar. The second direction is perpendicular to the first direction in which the metal fine grid extends.

[0011] In a third aspect, the present invention provides a photovoltaic module, including: a bus bar and any one of the above-provided battery strings; wherein, the bus bar extends along a first direction, and the bus bar is connected to the first solder strip included in the battery string; when the second solder strip is included in the battery string, electrical isolation is provided between the bus bar and the second solder strip (300).

[0012] The technical solution of the first aspect of the above invention has the following advantages or beneficial effects: By providing encrypted fine grids on one side of the back of the solar cell body, it is possible to encrypt the fine grids in some areas where the metal fine grids are not provided without affecting the light-receiving area of the solar cell, achieving higher current extraction efficiency. Description of the Drawings

[0013] The drawings are used to better understand the present invention and do not constitute an improper limitation to the present invention. Among them:

[0014] Figure 1 is a schematic diagram of the first structure of the solar cell according to an embodiment of the present invention;

[0015] Figure 2 is a schematic diagram of the second structure of the solar cell according to an embodiment of the present invention;

[0016] Figure 3 is a schematic diagram of the third structure of the solar cell according to an embodiment of the present invention;

[0017] Figure 4 is a schematic diagram of the first structure of the battery string according to an embodiment of the present invention;

[0018] Figure 5 is a schematic diagram of the second structure of the battery string according to an embodiment of the present invention;

[0019] Figure 6 is a schematic diagram of the structure of the battery string and the bus bar in the photovoltaic module according to an embodiment of the present invention;

[0020] Figure 7 is a schematic diagram of the structure of the position where the bus bar is arranged according to an embodiment of the present invention;

[0021] Figure 8 is a schematic diagram of the position where the insulating gasket is arranged according to an embodiment of the present invention;

[0022] Figure 9 is a schematic cross-sectional structure diagram of the battery string and the bus bar provided with the support gasket according to an embodiment of the present invention;

[0023] Figure 10 is a bottom view of a battery string provided with a support cushion strip according to an embodiment of the present invention;

[0024] Figure 11 is a bottom view of a support cushion strip and an insulating cushion strip being an integral structure according to an embodiment of the present invention;

[0025] Figure 12 is a schematic structural view of a welding head for welding a bus bar according to an embodiment of the present invention.

[0026] The reference signs are as follows:

[0027] 1 - battery cell body; 2 - metal fine grid; 3 - encrypted fine grid; 4 - bus bar; 5 - insulating cushion strip; 6 - support cushion strip; 7 - welding head; 71 - first welding part; 72 - second welding part;

[0028] 100 - first battery cell; 200 - first welding tape; 300 - second welding tape; 400 - second battery cell. Detailed implementation manners

[0029] For the convenience and clear description of the technical solution of the present invention, the following makes an illustration of the exemplary embodiments of the present invention in conjunction with the accompanying drawings. Various details of the embodiments of the present invention are included therein to facilitate understanding, and they should be considered merely exemplary. Therefore, those of ordinary skill in the art should recognize that various changes and modifications can be made to the embodiments described herein without departing from the scope and spirit of the present invention. Similarly, for the sake of clarity and conciseness, the description of well - known functions and structures is omitted below.

[0030] Figures 1 to 3 shows a schematic structural view of a battery cell provided in the first aspect of the embodiment of the present invention. As Figures 1 to 3 shown, the battery cell provided by the present invention includes: a battery cell body 1, a metal fine grid 2 disposed on one side of the back surface of the battery cell body 1, and an encrypted fine grid 3; wherein, the metal fine grid 2 extends along a first direction of the battery cell body 1; the encrypted fine grid 3 is parallel to the metal fine grid 2 and is disposed around part or all of the metal fine grid 2.

[0031] Among them, Figures 1 to 3 is a schematic structural view of a battery cell applied in a battery string. Therefore, in Figures 1 to 3 the positions of the first welding tape 200 and the second welding tape 300 are included, and the specific description will be given in the subsequent description of the battery string.

[0032] By arranging the encrypted fine grid 3 around part or all of the metal fine grid 2 on the back side of the battery cell body 1, the export efficiency of the current of the battery cell can be increased in the area where the encrypted fine grid 3 is arranged, and subsequently, by connecting the welding tape to the encrypted fine grid 3, the path length of current transmission can be reduced, thereby improving the overall current collection efficiency. It should be noted that in the embodiments of the present invention, it is preferably to arrange the encrypted fine grid 3 parallel to the metal fine grid 2, which can ensure that the welding tape can be connected to the encrypted fine grid 3 while being connected to the metal fine grid 2 in the subsequent process, and the situation where the encrypted fine grid 3 is parallel to the setting direction of the welding tape will not occur. However, in the actual application process, as long as it can be ensured that the encrypted fine grid 3 can be connected to the welding tape subsequently, the encrypted fine grid 3 can also be extended in other directions.

[0033] It can be understood that if the encrypted fine grid 3 is arranged on the front surface side of the battery cell body 1, it may block the sunlight and affect the power generation efficiency of the solar cell. Therefore, in the embodiments of the present invention, it is preferably to arrange the encrypted fine grid 3 on the side of the battery cell body 1 facing away from the sunlight (i.e., the back side of the battery cell body 1).

[0034] The following takes Figures 1 to 3 as an example to schematically illustrate various possible structures of the battery cell provided by the embodiments of the present invention:

[0035] In an alternative embodiment of the present invention, the encrypted fine grids 3 are arranged at intervals in the first direction. As Figure 1 shown, it shows the specific structure in which the encrypted fine grid 3 is arranged around part of the metal fine grid 2 and is arranged at intervals in the first direction. In this structure, the encrypted fine grid 3 can be arranged around part of the metal fine grid 2 or around all of the metal fine grid 2. When a plurality of encrypted fine grids 3 arranged at intervals horizontally are arranged around the same metal fine grid 2, a plurality of encrypted fine grids 3 need to export current through the welding tapes arranged at intervals.

[0036] In another alternative embodiment of the present invention, the encrypted fine grids 3 are arranged at intervals in the second direction perpendicular to the first direction. As Figure 2 shown, in this structure, the encrypted fine grid 3 can also be selected to be arranged around part of the metal fine grid 2 or all of the metal fine grid 2, but a plurality of encrypted fine grids 3 are arranged around different metal fine grids 2, and a plurality of encrypted fine grids 3 arranged at intervals in the second direction can be connected to the same welding tape to achieve current export. Among them, Figure 2 the setting of the encrypted fine grid 3 at the edge in the first direction is only an optional setting position, and it can also be set at other positions in the first direction. In addition, it can also be combined with Figure 1 and arranged at intervals in both the first direction and the second direction.

[0037] In another alternative embodiment of the present invention, for the structure in which the encrypted fine grid 3 is disposed around a part of the metal fine grid 2, the encrypted fine grid 3 penetrates through the battery chip body 1 along the first direction. As Figure 3 shown, when the encrypted fine grid 3 penetrates through the battery chip body 1, it can be equivalent to increasing the number of metal fine grids 2 at some positions. This setting method ensures that the solder tape set at any position can achieve good contact with the encrypted fine grid 3.

[0038] In a further alternative embodiment, as Figure 1 and Figure 3 shown, the encrypted fine grid 3 is located in the edge region of the battery chip body 1 in the second direction perpendicular to the first direction. This is because when the battery chip is applied to a photovoltaic module, a bus bar 4 is usually provided on the battery chips at both ends of the battery string to export the current of the entire battery string by means of the bus bar 4. Since the bus bar 4 itself is relatively wide, it will partially block the back surface of the battery chip body 1. If the shielding area of the encrypted fine grid 3 is additionally increased, it will have a greater impact on the performance of the solar cell. Therefore, in the embodiment of the present invention, the encrypted fine grid 3 is arranged in the edge region of the battery chip body 1 in the second direction. When forming the battery string, by arranging the encrypted fine grid 3 at the edge of the battery string, the setting position of the bus bar 4 just covers the encrypted fine grid 3, that is, the bus bar 4 and the encrypted fine grid 3 will not cause repeated shielding problems. Among them, the setting position of the bus bar 4 and the specific structure of the battery string will be specifically described later.

[0039] In summary, it can be seen that the battery chip provided by the embodiment of the present invention can perform encrypted setting in some areas where the metal fine grid is not provided without affecting the light-receiving area of the front surface of the battery chip, and achieve higher current export efficiency by arranging the encrypted fine grid on one side of the back surface of the battery chip body.

[0040] According to the second aspect of the present invention, a battery string is further provided. As Figure 4 and Figure 5 shown, it includes: a plurality of connected battery chips and a first solder tape 200; wherein, at least one first battery chip 100 is included in the plurality of battery chips, and the first battery chip 100 is any one of the battery chips provided above; the first battery chip 100 is at least arranged at the position where the battery string is connected to the bus bar 4; the first solder tape 200 is connected to a plurality of metal fine grids 2 and encrypted fine grids 3 with the same polarity on the second direction of the first battery chip 100 and is connected to the bus bar 4, and the second direction is perpendicular to the first direction in which the metal fine grids 2 extend.

[0041] Among them, Figure 4 shows a schematic structural diagram of the first battery chip 100 located at the end of the battery string. Since the bus bar 4 will block the encrypted fine grid 3 after being set, therefore in Figure 4The position of the bus bar 4 is indicated by a dotted line in the figure to clearly show the positional relationship between the dense fine grid 3 and the bus bar 4. Figure 5 A schematic structural view showing the first cell 100 located at the middle position of the cell string is shown. By Figure 4 and Figure 5 It can be seen that the first solder tape 200 of the embodiment of the present invention realizes the export of the current in both the dense fine grid 3 and the metal fine grid 2 together, greatly improving the current export efficiency.

[0042] It can be understood that Figure 4 and Figure 5 are only a schematic illustration of the cell string structure. The cell string provided by the embodiment of the present invention can also be entirely composed of the first cells 100 or composed of the first cells 100 arranged at intervals in part in series. In the actual application process, there is no need to set too many first cells 100 in the cell string, and only the first cells 100 need to be set at the connection positions of the back bus bar 4. This is because, after the bus bar 4 is welded on the back of the cell string (back welding of the bus bar 4) and cooled, due to the relatively large cross-sectional area of the bus bar 4 itself, a relatively large shrinkage tensile force will be generated. If there are too many welding sites, it may cause excessive stress on some welding sites, leading to the problem of cell cracking and distortion. Therefore, in the embodiment of the present invention, by setting the first cells 100 at the connection with the bus bar 4 and arranging the dense fine grid 3 in part of the area of the first cells 100, the number of solder tapes connected to the bus bar 4 is reduced, the current efficiency exported by the bus bar 4 is ensured, and at the same time, the risk of cell cracking caused by shrinkage stress during the back welding of the bus bar 4 can be effectively reduced.

[0043] In an optional embodiment, as Figure 4 and Figure 5 shown, among the multiple cells, there are also included: at least one second cell 400 without the dense fine grid 3 provided; the first cell 100 is connected in series with the adjacent second cell 400. That is to say, in the embodiment of the present invention, it is not necessary for the cell string to be entirely composed of the first cells 100, and the first cells 100 and the second cells 400 can be combined and arranged. Since the bus bar 4 is connected to the first cells 100, this combined arrangement method can also reduce the number of solder tapes connecting the bus bar 4 and the cells, thereby reducing the risk of cell cracking during the back welding of the bus bar 4.

[0044] Regarding the set number of the first solder tapes 200, it can correspond to the number of the encrypted fine grids 3 spaced in the first direction. This is because in order to improve the welding yield between the bus bar 4 and the solder tapes, only some of the first solder tapes 200 are provided in the embodiments of the present invention. However, this will lead to a reduction in current efficiency. Therefore, in order to ensure the current efficiency of the first solder tapes 200 transmitted to the bus bar 4, the embodiments of the present invention further utilize the encrypted fine grids 3 to improve the current extraction efficiency. That is to say, the first solder tapes 200 in the embodiments of the present invention cooperate with the encrypted fine grids 3, and the set number of the first solder tapes 200 can be appropriately reduced on the basis of the number of solder tapes in the prior art, that is, the encrypted fine grids 3 can extract the current required by the unconnected solder tapes, so as to ensure the current extraction efficiency.

[0045] However, since the number of existing solder tapes is relatively fixed and for the unity of the process flow, the welding positions and the number of welded solder tapes cannot be changed during the preparation of the battery string. Therefore, in an alternative embodiment, as Figure 4 and Figure 5 shown, for the structure in which the encrypted fine grids 3 of the first solar cell are arranged at intervals in the first direction, the battery string further includes: a second solder tape 300; the second solder tape 300 is arranged between two adjacent encrypted fine grids 3 in the first direction; and the second solder tape 300 is connected to a plurality of metal fine grids 2 with the same polarity in the second direction, and the metal fine grids 2 connected by the second solder tape 300 have the same polarity as the metal fine grids 2 connected by the first solder tape 200. That is to say, the embodiments of the present invention retain the same number of solder tapes as in the prior art, but only use the first solder tapes 200 connected to the encrypted fine grids 3 to be connected to the bus bar 4, and the second solder tapes 300 not connected to the encrypted fine grids 3 do not need to be connected to the bus bar 4. From Figure 4 and Figure 5 it can be seen that the difference between the first solder tape 200 and the second solder tape 300 lies in whether they are connected to the encrypted fine grids 3. That is to say, the first solder tape 200 synchronously extracts the current in the encrypted fine grids 3 and the metal fine grids 2, while the second solder tape 300 only extracts the current in the metal fine grids 2. Through the above settings, on the basis of retaining the number of solder tapes in the prior art, only some of the solder tapes can be used to realize the connection between the encrypted fine grids 3 and the bus bar 4, thereby improving the current extraction efficiency.

[0046] In an alternative embodiment, the first solder tape 200 and the second solder tape 300 can be solder tapes of the same material and the same specification. The "first" and "second" in the embodiments of the present invention only represent the difference in the set positions, and do not represent the difference in the structure of the solder tapes themselves. Both the first solder tape 200 and the second solder tape 300 can adopt the common solder tape structures in the market, and the diameters, thicknesses, etc. of the first solder tape 200 and the second solder tape 300 can be the same.

[0047] In summary, the battery string provided by the embodiment of the present invention can reduce the number of connections between the solder tapes and the bus bar by setting at least one first battery cell 100 including the encrypted fine grid 3, and using the encrypted fine grid 3 in the first battery cell 100 to improve the current extraction efficiency, thereby reducing the risk of cracking of the battery cells.

[0048] According to the third aspect of the present invention, a photovoltaic module is further provided, as Figure 1 and Figure 6 shown, including: a bus bar 4 and any one of the battery strings provided above; wherein, the bus bar 4 extends along a first direction, and the bus bar 4 is connected to the first solder tape 200 included in the battery string. It can be seen from Figure 6 that the bus bar 4 in the embodiment of the present invention is not connected to all the solder tapes with the same polarity, but is selectively connected to a part of the first solder tapes 200 connected to the encrypted fine grid 3, thereby reducing the number of connections between the bus bar 4 and the solder tapes, and further reducing the defective soldering rate of the back soldering of the bus bar 4 (such as false soldering, cracking, etc.). Among them, Figure 6 the encrypted fine grid 3 marked only distinguishes the difference between the first solder tape 200 and the second solder tape 300, that is, the first solder tape 200 is connected to the encrypted fine grid 3, which does not represent the actual thickness or length of the encrypted fine grid 3. In the actual manufacturing process, both the encrypted fine grid 3 and the metal fine grid 2 are disposed on the back surface of the battery cell.

[0049] In an optional embodiment, the bus bar 4 covers part or all of the encrypted fine grids 3 in the first battery cell 100. Exemplarily, as Figure 7 shown, the bus bar 4 has the same extension direction as the encrypted fine grid 3 and the metal fine grid 2, and covers all the encrypted fine grids 3, and is used to extract the current in one or more battery strings. By covering the encrypted fine grids 3 in the first battery cell 100 with the bus bar 4, the light shielding caused by the encrypted fine grids 3 and the bus bar 4 to the back surface of the battery cell can be minimized as much as possible, and at the same time, it is convenient to extract the current in the encrypted fine grids 3. When the encrypted fine grids 3 are arranged at intervals along a second direction as Figure 2 shown, the setting position of the bus bar 4 can only cover one of the encrypted fine grids 3, that is, cover part of the encrypted fine grids 3.

[0050] Similarly, taking Figure 7 as an example, in a further optional embodiment, when the battery string includes a second solder tape 300, the bus bar 4 is electrically isolated from the second solder tape 300. As described above, in the embodiment of the present invention, only the first solder tape 200 is connected to the bus bar 4. By reducing the welding sites, the risk of false soldering and welding cracking caused by welding is effectively reduced. Therefore, at the position where the second solder tape 300 is arranged, it is necessary to ensure that the second solder tape 300 is not electrically connected to the bus bar 4.

[0051] For the electrical isolation method, in an alternative embodiment, as Figure 7 and Figure 8 shown, the photovoltaic module provided by the present invention further includes: an insulating gasket 5 disposed between the second solder strip 300 and the bus bar 4. Specifically, Figure 7 shows the installation position of the insulating gasket 5 from a bottom view angle, Figure 8 shows the installation position of the insulating gasket 5 in a sectional structure. From Figure 7 and Figure 8 it can be seen that in the embodiment of the present invention, by providing the insulating gasket 5 covering the second solder strip 300, the bus bar 4 is only electrically connected to the first solder strip 200 and is electrically isolated from the second solder strip 300. It can be understood that since the bus bar 4 has a certain width, in order to ensure that the second solder strip 300 will not be electrically connected to the edge in the width direction of the bus bar 4, in a further alternative embodiment, the length of the insulating gasket 5 in the second direction is greater than the width of the bus bar 4 in the second direction, and the width of the insulating gasket 5 is greater than or equal to four times the diameter of the second solder strip 300. That is to say, the two ends of the insulating gasket 5 extending along the second direction are exposed outside the bus bar 4 from a bottom view angle, thus ensuring the electrical isolation between the bus bar 4 and the second solder strip 300.

[0052] Furthermore, in order to solve the shrinkage problem caused by the welding and cooling of the bus bar 4, on the basis of reducing the number of the first solder strips 200 welded to the bus bar 4, the embodiment of the present invention further improves the structure of the bus bar 4. That is, in an alternative embodiment, as Figure 8 shown, the area of the bus bar 4 corresponding to the second solder strip 300 is a bending structure, and the bending direction of the bending structure is away from the second solder strip 300. On the one hand, after the insulating gasket 5 is provided, due to the certain thickness of the insulating gasket 5 itself, it is necessary to bend and leave a long length for the bus bar 4; on the other hand, the length left by the bending structure can cope with the shrinkage problem of the bus bar 4 after welding and cooling, providing a margin for the shrinkage of the bus bar 4 during the welding and cooling process, thereby reducing the influence on the welding sites of the first solder strips 200. In an alternative embodiment, the arc length of the bending structure is 1 / 3 to 3 / 4 of the distance between two adjacent first solder strips 200, such as 1 / 3, 2 / 3, 3 / 4, etc.

[0053] In the actual application process, the bus bar 4 usually has a certain flexibility. During the welding process with the first solder strip 200, some areas may be bent into the gap between the adjacent first solder strip 200 and the second solder strip 300 under the action of gravity, resulting in waste of the bus bar 4 material. At the same time, since the insulating gasket 5 is provided between the second solder strip 300 and the bus bar 4, the thickness at the insulating gasket 5 is thicker, which may cause a problem of concentrated stress during the lamination process. Therefore, in an alternative embodiment of the present invention, asFigure 9 and Figure 10 As shown in Figure 10 , the photovoltaic module provided by the present invention further includes: a support strip 6 disposed between every two adjacent first solder tapes 200 and second solder tapes 300. Among them, Figure 9 FIG. Figure 9 is a schematic cross-sectional structure diagram of a photovoltaic module provided with a support strip, Figure 10 FIG. Figure 10 is a bottom view of a photovoltaic module provided with a support strip. From Figure 9 and Figure 10 it can be seen that by providing the support strip 6 in the embodiment of the present invention, the stress on each area below the bus bar 4 during lamination can be made more uniform, effectively avoiding the possible crack problem during the lamination process.

[0054] In an optional embodiment, the thickness of the support strip 6 is the same as the thickness of the first solder tape 200. When the thicknesses of the first solder tape 200 and the second solder tape 300 are the same, since an insulating strip 5 is provided outside the second solder tape 300, the thickness corresponding to the second solder tape 300 is thicker. Therefore, the thickness of the support strip 6 needs to be set at least the same as the thickness of the first solder tape 200 to effectively disperse the stress during the lamination process. If the thickness of the support strip 6 is set too thin, it cannot achieve an effective protection effect. In another optional embodiment, the thickness of the support strip 6 is the same as the sum of the thicknesses of the second solder tape 300 and the insulating strip 5. It can be understood that during the welding process of the bus bar 4, a certain downward pressure will be generated, and welding is performed while ensuring contact with the first solder tape 200. Therefore, even if the thickness of the support strip 6 is the same as the sum of the thicknesses of the second solder tape 300 and the insulating strip 5, due to the existence of the welding pressure, the welding effect between the bus bar 4 and the first solder tape 200 will not be affected during the actual welding process.

[0055] In a further optional embodiment, as Figure 11 shown, for the case where the thickness of the support strip 6 is the same as the sum of the thicknesses of the second solder tape 300 and the insulating strip 5, the support strip 6 and the insulating strip 5 are of an integral structure. As Figure 11 shown, when the support strip 6 and the insulating strip 5 are of an integral structure, they can form a serrated insulating structure, and a certain welding space is left at the position where it is welded to the first solder tape 200 to facilitate the welding of the bus bar 4 and the first solder tape 200.

[0056] Among them, the material of the support strip 6 can be the same as the material of the insulating strip 5. For example, it is composed of PET (polyethylene terephthalate) as the base material and EVA (ethylene-vinyl acetate copolymer), or it can be other insulating materials with a certain hardness.

[0057] For the width of the support spacer 6, in an alternative embodiment, the width of the support spacer 6 is 2 / 3 to 1 times the distance between the adjacent first solder strip 200 and the second solder strip 300. That is to say, the width of the support spacer 6 should be at least 2 / 3 of the distance between the first solder strip 200 and the second solder strip 300 to provide sufficient support. If the width is too narrow, effective support cannot be achieved.

[0058] In a further alternative embodiment, in order to facilitate the welding of the bus bar 4, the photovoltaic module provided by the embodiment of the present invention may use Figure 12 the welding head 7 with grooves shown in the figure for welding. Specifically, the welding head 7 includes alternately arranged first welding parts 71 and second welding parts 72. Among them, the position of the first welding part 71 corresponds to that of the first solder strip 200, the position of the second welding part 72 corresponds to that of the second solder strip 300, and the first welding part 71 and the second welding part 72 are staggeredly arranged. By protruding the first welding part 71, good contact with the first solder strip 200 can be achieved, thereby completing the welding between the first solder strip 200 and the bus bar 4. At the same time, by recessing the second welding part 72, sufficient space can be left for the second solder strip 300, the insulating spacer 5 located above the second solder strip 300, and the bus bar 4, and it can play a role in restricting the bending structure of the bus bar 4, avoiding the displacement of the bus bar 4 during the welding process, thereby affecting the welding effect.

[0059] In summary, for the photovoltaic module provided by the embodiment of the present invention, by connecting the bus bar 4 with the first solder strip 200 included in the battery string, the connection number of the bus bar 4 and the solder strip can be effectively reduced, and the current extraction efficiency is improved by using the dense fine grid 3 connected by the first solder strip 200. At the same time, by arranging the insulating spacer 5 between the bus bar 4 and the second solder strip 300 and setting the area of the bus bar 4 corresponding to the insulating spacer 5 as a bending structure, the influence of the shrinkage force of the bus bar 4 after welding and cooling on the welding site can be minimized, and the probability of de-welding is reduced.

[0060] The embodiment of the present invention also provides the following technical solutions:

[0061] Technical solution 1. A battery cell, characterized by comprising:

[0062] a battery cell body 1, a metal fine grid 2 provided on one side of the back of the battery cell body 1, and a dense fine grid 3; wherein,

[0063] the metal fine grid 2 extends along the first direction of the battery cell body 1;

[0064] the dense fine grid 3 is parallel to the metal fine grid 2 and is arranged around part or all of the metal fine grid 2.

[0065] Technical solution 2. The solar cell according to technical solution 1, characterized in that

[0066] the encrypted fine grids 3 are arranged at intervals along the first direction;

[0067] Or,

[0068] For the structure in which the encrypted fine grids 3 surround part of the metal fine grids 2, the encrypted fine grids 3 penetrate through the main body 1 of the solar cell along the first direction.

[0069] Technical solution 3. The solar cell according to technical solution 1 or 2, characterized in that

[0070] the encrypted fine grids 3 are arranged along the second direction in the edge area of the main body 1 of the solar cell, and the second direction is perpendicular to the first direction.

[0071] Technical solution 4. A battery string, characterized in that it includes: a plurality of connected solar cells and a first solder tape 200; wherein,

[0072] at least one first solar cell 100 is included in the plurality of solar cells, and the first solar cell 100 is any one of the solar cells provided by technical solutions 1 to 3;

[0073] the first solar cell 100 is at least arranged at the position where the battery string is connected to the bus bar 4;

[0074] the first solder tape 200 connects a plurality of metal fine grids 2 and encrypted fine grids 3 with the same polarity in the second direction of the first solar cell 100, and is connected to the bus bar 4, and the second direction is perpendicular to the first direction in which the metal fine grids 2 extend.

[0075] Technical solution 5. The battery string according to technical solution 4, characterized in that for the structure in which the encrypted fine grids 3 of the first solar cell 100 are arranged at intervals along the first direction,

[0076] the battery string further includes: a second solder tape 300;

[0077] the second solder tape 300 is arranged between two adjacent encrypted fine grids 3 in the first direction;

[0078] the second solder tape 300 connects a plurality of metal fine grids 2 with the same polarity in the second direction, and the metal fine grids 2 connected by the second solder tape 300 have the same polarity as the metal fine grids 2 connected by the first solder tape 200.

[0079] Technical solution 6. The battery string according to technical solution 4, characterized in that at least one second solar cell 400 without the encrypted fine grids 3 is further included in the plurality of solar cells;

[0080] The first cell 100 is connected in series with the adjacent second cell 400.

[0081] Technical solution 7. A photovoltaic module, characterized in that it comprises: a bus bar 4 and any one of the cell strings provided in Technical solutions 4 to 6; wherein,

[0082] The bus bar 4 extends along a first direction, and the bus bar 4 is connected to the first solder strip 200 included in the cell string;

[0083] When the cell string includes the second solder strip 300, the bus bar 4 is electrically isolated from the second solder strip 300.

[0084] Technical solution 8. The photovoltaic module according to Technical solution 7, characterized in that

[0085] The bus bar 4 covers some or all of the encrypted fine grids 3 in the first cell 100.

[0086] Technical solution 9. The photovoltaic module according to Technical solution 7, characterized in that

[0087] The photovoltaic module further comprises: an insulating gasket strip 5 disposed between the second solder strip 300 and the bus bar 4.

[0088] Technical solution 10. The photovoltaic module according to Technical solution 9, characterized in that

[0089] The area of the bus bar 4 corresponding to the second solder strip 300 is a bent structure, and the bending direction of the bent structure is away from the second solder strip 300.

[0090] Technical solution 11. The photovoltaic module according to Technical solution 10, characterized in that

[0091] The arc length of the bent structure is 1 / 3 to 3 / 4 of the distance between two adjacent first solder strips 200.

[0092] Technical solution 12. The photovoltaic module according to any one of Technical solutions 8 to 11, characterized in that

[0093] The photovoltaic module further comprises: a support gasket strip 6 disposed between each adjacent first solder strip 200 and second solder strip 300.

[0094] Technical solution 13. The photovoltaic module according to Technical solution 12, characterized in that

[0095] The thickness of the support gasket strip 6 is the same as the thickness of the first solder strip 200;

[0096] and / or

[0097] The thickness of the support cushion strip 6 is the same as the sum of the thicknesses of the second solder strip 300 and the insulating cushion strip 5.

[0098] Technical solution 14. The photovoltaic module according to technical solution 13, characterized in that, for the case where the thickness of the support cushion strip 6 is the same as the sum of the thicknesses of the second solder strip 300 and the insulating cushion strip 5,

[0099] The support cushion strip 6 and the insulating cushion strip 5 are of an integral structure.

[0100] Technical solution 15. The photovoltaic module according to technical solution 12, characterized in that,

[0101] The width of the support cushion strip 6 is 2 / 3 to 1 of the distance between the adjacent first solder strip 200 and the second solder strip 300.

[0102] 16. The photovoltaic module according to claim 9, characterized in that,

[0103] The length of the insulating cushion strip (5) in the second direction is greater than the width of the bus bar (4) in the second direction;

[0104] and / or

[0105] The width of the insulating cushion strip (5) is greater than or equal to four times the diameter of the second solder strip (200).

[0106] The introduction provided in the above steps is only used to help understand the structure, method and core idea of the present invention. For those of ordinary skill in the art of this technology, without departing from the principle of the present invention, several improvements and modifications can be made to the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

Claims

1. A battery cell, characterized in that, Comprising: A cell body (1), a metal fine grid (2) disposed on one side of the back of the cell body (1), and an encrypted fine grid (3); wherein, The metal fine grid (2) is disposed extending along a first direction of the cell body (1); The encrypted fine grid (3) is parallel to the metal fine grid (2) and is disposed surrounding part or all of the metal fine grid (2).

2. The cell according to claim 1, characterized in that The encrypted fine grids (3) are disposed at intervals along the first direction; Or, For the structure in which the encrypted fine grid (3) surrounds part of the metal fine grid (2), the encrypted fine grid (3) is disposed penetrating the cell body (1) along the first direction.

3. The cell according to claim 1 or 2, characterized in that The encrypted fine grid (3) is disposed in an edge region of the cell body (1) along a second direction, and the second direction is perpendicular to the first direction.

4. A battery string, characterized in that, Comprising: A plurality of connected cells and a first solder ribbon (200); wherein, At least one first cell (100) is included in the plurality of cells, and the first cell (100) is any one of the cells provided in claims 1 to 3; The first cell (100) is disposed at least at a position where the cell string is connected to the bus bar (4); The first solder ribbon (200) connects a plurality of metal fine grids (2) and encrypted fine grids (3) having the same polarity on the first cell (100) in a second direction, and is connected to the bus bar (4), and the second direction is perpendicular to the first direction in which the metal fine grid (2) extends.

5. The battery string according to claim 4, wherein For the structure in which the encrypted fine grids (3) of the first cell (100) are arranged at intervals along the first direction, The cell string further includes: a second solder ribbon (300); The second solder ribbon (300) is disposed between two adjacent encrypted fine grids (3) in the first direction; The second solder ribbon (300) connects a plurality of metal fine grids (2) having the same polarity in the second direction, and the metal fine grids (2) connected by the second solder ribbon (300) have the same polarity as the metal fine grids (2) connected by the first solder ribbon (200).

6. The battery string according to claim 4, wherein At least one second cell (400) without the encrypted fine grid (3) is further included in the plurality of cells; The first cell (100) is connected in series with the adjacent second cell (400).

7. A photovoltaic module, characterized in that, Comprising: A bus bar (4) and any one of the cell strings provided in claims 4 to 6; wherein, The bus bar (4) is disposed extending along a first direction, and the bus bar (4) is connected to the first solder ribbon (200) included in the cell string; When the cell string includes the second solder ribbon (300), electrical isolation is provided between the bus bar (4) and the second solder ribbon (300).

8. The photovoltaic module according to claim 7, characterized in that The bus bar (4) covers part or all of the encrypted fine grids (3) in the first cell (100).

9. The photovoltaic module according to claim 7, characterized in that The photovoltaic module further includes: an insulating gasket (5) disposed between the second solder strip (300) and the bus bar (4).

10. The photovoltaic module according to claim 9, wherein the region of the bus bar (4) corresponding to the second solder strip (300) is a bent structure, and the bending direction of the bent structure is away from the second solder strip (300).

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