Back contact battery piece

Abstract

The utility model provides a back contact battery piece, a first pole region comprises a first bus grid line and a plurality of first grid line groups arranged at intervals along a first direction, and each first grid line group comprises a plurality of first fine grid lines arranged at intervals along a second direction and a first main grid line connected with the plurality of first fine grid lines; the second pole region comprises a plurality of second grid line groups which are arranged along the second bus grid line and along the first direction at intervals; each second grid line group comprises a plurality of second thin grid lines which are arranged along the second direction at intervals and a second main grid line which is connected with the second thin grid lines; the first main grid lines in at least two adjacent first grid line groups are connected through the first bus grid lines, and / or the second main grid lines in at least two adjacent second grid line groups are connected through the second bus grid lines. The current collection effect of a poor contact area can be improved, and the photoelectric conversion efficiency of the back contact battery piece is improved.

Description

Technical Field

[0001] The application relates to the technical field of solar cells, and in particular to a back-contact solar cell. Background Art

[0002] In the existing back-contact battery design, current can be collected through the main grid line. However, during the preparation process of the back-contact battery, due to the large overall area of ​​the back-contact battery, poor contact is prone to occur, resulting in poor current transmission performance, affecting the collection of current by the main grid line, and then affecting the current and fill factor of the back-contact battery, resulting in low photoelectric conversion efficiency. Utility Model Content

[0003] In view of the above problems, embodiments of the present application are proposed to provide a back-contact solar cell that overcomes the above problems or at least partially solves the above problems.

[0004] In order to solve the above problems, the embodiment of the present application discloses a back-contact solar cell, which includes a silicon wafer substrate and an electrode pattern arranged on the back side of the silicon wafer substrate, wherein the electrode pattern includes a first polar region and a second polar region with opposite polarities; wherein,

[0005] The first polar region includes a first bus grid line and a plurality of first grid line groups spaced apart along a first direction, the first grid line group includes a plurality of first fine grid lines spaced apart along a second direction and a first main grid line connecting the plurality of first fine grid lines; the second polar region includes a plurality of second bus grid lines spaced apart along a second bus grid line and a plurality of second fine grid lines spaced apart along the first direction, the second grid line group includes a plurality of second fine grid lines spaced apart along the second direction and a second main grid line connecting the plurality of second fine grid lines;

[0006] At least two adjacent first bus bars in the first bus bar group are connected via the first bus bar line, and / or at least two adjacent second bus bars in the second bus bar group are connected via the second bus bar line;

[0007] In which, the first gate line group and the second gate line group are alternately arranged along the first direction, the first fine gate line and the second fine gate line are alternately arranged at intervals, the first bus gate line is insulated and connected to the second main gate line, the second bus gate line is insulated and connected to the first main gate line, the first fine gate line, the second fine gate line, the first bus gate line, and the second bus gate line all extend along the first direction, the first main gate line and the second main gate line all extend along the second direction, and the first direction is different from the second direction.

[0008] The embodiments of the present application include the following advantages:

[0009] In an embodiment of the present application, the first main grid lines in at least two adjacent first grid line groups are connected by the first bus grid line, so that the first fine grid lines in at least two adjacent first grid line groups can be connected. In this way, the first grid line group can not only collect current through the first main grid lines it contains, but also collect current through the first main grid lines in the first grid line group adjacent to it, so as to ensure the current collection effect of the first grid line group, and improve the current collection effect of the first polar region. Similarly, the second main grid lines in at least two adjacent second grid line groups are connected by the second bus grid line, so that the second fine grid lines in at least two adjacent second grid line groups can be connected, and improve the current collection effect of the second polar region. In an embodiment of the present application, by improving the current collection effect of the electrode pattern, the current and FF of the back contact cell can be increased, thereby improving the photoelectric conversion efficiency of the back contact cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 It is one of the graphic diagrams of an electrode pattern applied for;

[0011] Figure 2 This is the second graphic diagram of an electrode pattern applied for;

[0012] Figure 3 This is the third graphic diagram of an electrode pattern applied for;

[0013] Figure 4 This is the fourth graphic diagram of an electrode pattern applied for;

[0014] Figure 5 This is the fifth graphic diagram of an electrode pattern applied for;

[0015] Figure 6 This is the sixth graphic diagram of an electrode pattern applied for;

[0016] Figure 7 The invention relates to a silicon wafer substrate having a rectangular structure with chamfered corners;

[0017] Figure 8 The invention relates to a silicon wafer substrate having a square structure with chamfered corners;

[0018] Figure 9 It is a silicon wafer substrate with a rectangular structure applied for;

[0019] Figure 10 It is a square structure silicon wafer substrate applied for;

[0020] Figure 11 This is an application for a layout diagram of a back-contact battery cell.

[0021] Reference numerals:

[0022] 100, back contact cell; 1, silicon wafer substrate; 2, electrode pattern; 3, first polar region; 31, first busbar; 32, first gridline group; 33, first fine gridline; 34, first main gridline; 341, first sub-busbar; 41, first guide gridline group; 42, second guide gridline group; 43, third guide gridline group; 44, fourth guide gridline group; 45, fifth guide gridline group; 46, first Six guide grid line groups; 5, second polar region; 51, second bus grid line; 52, second grid line group; 53, second fine grid line; 54, second main grid line; 541, second sub-main grid line; 61, first pass grid line group; 62, second pass grid line group; 63, third pass grid line group; 64, fourth pass grid line group; 65, fifth pass grid line group; 66, sixth pass grid line group; 67, seventh pass grid line group. DETAILED DESCRIPTION

[0023] In order to make the above-mentioned purposes, features and advantages of the application more obvious and easy to understand, the application is further described in detail below with reference to the accompanying drawings and specific implementation methods.

[0024] The terms "first" and "second" in the specification and claims of this application may explicitly or implicitly refer to one or more of the features. In the description of the application, unless otherwise specified, "plurality" means two or more. Furthermore, "and / or" in the specification and claims refers to at least one of the connected items, and the character " / " generally indicates an "or" relationship between the connected items.

[0025] In the description of the application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like, indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are only for the convenience of describing the application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the application.

[0026] In the description of the application, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood broadly. For example, they can refer to fixed, detachable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediary; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the application based on the specific circumstances.

[0027] The present application discloses a back-contact cell 100, which comprises a silicon wafer substrate 1 and an electrode pattern 2 disposed on the back side of the silicon wafer substrate 1, wherein the electrode pattern 2 comprises a first polar region 3 and a second polar region 5 with opposite polarities; Figure 1 As shown, the first polar region 3 includes a first busbar line 31 and a plurality of first grid line groups 32 spaced apart along a first direction. The first grid line group 32 includes a plurality of first fine grid lines 33 spaced apart along a second direction and a first main grid line 34 connecting the plurality of first fine grid lines 33, that is, the first main grid line 34 is connected to a plurality of first main grid lines 34 of the same polarity.

[0028] The second polar region 5 includes a second bus grid line 51 and a plurality of second grid line groups 52 spaced apart along the first direction. The second grid line group 52 includes a plurality of second fine grid lines 53 spaced apart along the second direction and a second main grid line 54 connecting the plurality of second fine grid lines 53, that is, the second main grid line 54 is connected to a plurality of second fine grid lines 53 of the same polarity.

[0029] The first main grid lines 34 in at least two adjacent first grid line groups 32 are connected by the first bus grid line 31, and / or the second main grid lines 54 in at least two adjacent second grid line groups 52 are connected by the second bus grid line 51; wherein, the first grid line group 32 and the second grid line group 52 are alternately arranged along the first direction; the polarities of the first fine grid lines 33 and the second fine grid lines 53 are opposite, the first fine grid lines 33 and the second fine grid lines 53 are alternately arranged, the first bus grid line 31 is insulated from the second main grid line 54 of non-polarity, the second bus grid line 51 is insulated from the first main grid line 34 of non-polarity, the first fine grid line 33, the second fine grid line 53, the first bus grid line 31, and the second bus grid line 51 all extend along the first direction, the first main grid line 34 and the second main grid line 54 all extend along the second direction, and the first direction is different from the second direction.

[0030] In the embodiment of the present application, the first main grid lines 34 in at least two adjacent first grid line groups 32 are connected by the first bus grid line 31, so that the first fine grid lines 33 in at least two adjacent first grid line groups 32 can be connected. In this way, the first grid line group 32 can not only collect current through the first main grid lines 34 it contains, but also collect current through the first main grid lines 34 in the first grid line group 32 adjacent to it, so as to ensure the collection of current by the first grid line group 32, and improve the current collection effect of the first polar region 3. Similarly, the second main grid lines 54 in at least two adjacent second grid line groups 52 are connected by the second bus grid line 51, so that the second fine grid lines 53 in at least two adjacent second grid line groups 52 can be connected, and improve the current collection effect of the second polar region 5. In the embodiment of the present application, by improving the current collection effect of the electrode pattern 2, the current and fill factor (FF) of the back contact cell can be improved, thereby improving the photoelectric conversion efficiency of the back contact cell.

[0031] Specifically, a back contact cell (BC cell) is a solar cell technology whose core feature is to move the PN junction and metal contact of the cell to the back of the cell, so that there is no electrode blocking the front, thereby maximizing the use of incident light and improving the light absorption efficiency and the conversion efficiency of the cell. The back contact cell described in the embodiment of the present application is used to prepare the back contact cell. The back contact cell 100 includes a silicon wafer substrate 1 and an electrode pattern 2 arranged on the back of the silicon wafer substrate 1, and the back of the silicon wafer substrate 1 is the backlight side. The electrode pattern 2 includes a first polar region 3 and a second polar region 5. The first polar region 3 and the second polar region 5 are two regions with different polarities and are respectively arranged in the P region and N region of the back contact cell 100. Among them, the silicon wafer substrate 1 can be an N-type silicon wafer, or it can also be a P-type silicon wafer.

[0032] Optionally, the back-contact cell 100 may further include a passivation layer, which may be arranged on the back side of the silicon wafer substrate 1, and the electrode pattern 2 may also be arranged on the side of the passivation layer away from the silicon wafer substrate 1; or, the electrode pattern 2 may pass through the passivation layer to be connected to the silicon wafer substrate 1, and the electrode pattern 2 may be arranged on the same layer as the passivation layer. In this case, a graphic structure identical to the electrode pattern 2 may be arranged on the passivation layer, and the electrode pattern 2 is disposed within the graphic structure of the passivation layer.

[0033] Specifically, the passivation layer protects the back-contact cell 100 from airborne contaminants while also improving the luminous efficiency of sunlight. The passivation layer prevents premature recombination of electrons and electron holes within the silicon, allowing these charged particles to exit the solar cell and complete its "power generation" function. The passivation layer can be made of materials such as aluminum oxide or silicon carbide.

[0034] Specifically, the electrode pattern 2 may extend along the first direction S1 and the second direction S2. Figure 1 As shown, the first direction S1 may be the length direction of the electrode pattern 2 , and the second direction S2 may be the width direction of the electrode pattern 2 . The first direction S1 is different from the second direction S2 .

[0035] Specifically, the first polar region 3 includes a plurality of first grid line groups 32 spaced apart along the first direction, and the second polar region 5 includes a plurality of second grid line groups 52 spaced apart along the first direction. The second grid line groups 52 and the first grid line groups 32 can be alternately arranged along the first direction. Further, the first grid line group 32 includes a plurality of first fine grid lines 33 spaced apart along the second direction, and the second grid line group 52 includes a plurality of second fine grid lines 53 spaced apart along the second direction. The first fine grid lines 33 and the second fine grid lines 53 can be spaced apart and staggered along the second direction, as shown in FIG. Figure 1 As shown, the first fine gate lines 33 and the second fine gate lines 53 in the electrode pattern 2 are arranged in an array, and the first fine gate lines 33 and the second fine gate lines 53 are arranged in a finger-like cross-arrangement.

[0036] Specifically, in the first polar region 3, the first fine grid lines 33, the first bus grid lines 34, and the first bus grid lines 31 have the same polarity and can be connected to each other to transmit carriers in the first polar region 3. In the second polar region 5, the second fine grid lines 53, the second bus grid lines 54, and the second bus grid lines 51 have the same polarity and can be connected to each other to transmit carriers in the second polar region 5. The first fine grid lines 33 and the second fine grid lines 53 are spaced apart from each other, and the first bus grid lines 31 and the second bus grid lines 54 are insulated from each other, while the second bus grid lines 51 and the first bus grid lines 34 are insulated from each other to avoid short circuits.

[0037] Specifically, the first busbar line 31 and the second busbar line 54 can be separated by an insulating member or spaced apart to achieve insulation isolation between them. Similarly, the second busbar line 51 and the first busbar line 34 can be separated by an insulating member or spaced apart.

[0038] Specifically, the first fine gate line 33, the second fine gate line 53, the first bus gate line 31, and the second bus gate line 51 all extend along the first direction. Figure 1 and Figure 2 As shown, the first fine grid line 33, the second fine grid line 53, the first bus grid line 31, and the second bus grid line 51 are arranged in parallel. The first main grid line 34 and the second main grid line 54 are both extended along the second direction. Figure 1 and Figure 2 As shown, the first bus bar 34 and the second bus bar 54 are arranged in parallel.

[0039] Specifically, the plurality of first fine grid lines 33 in the first grid line group 32 can be connected by a first main grid line 34. The first main grid line 34 can be a whole-line type, that is, the plurality of first fine grid lines 33 in the first grid line group 32 are connected as a whole by a whole first main grid line 34. Alternatively, the first main grid line 34 can be a segmented type, that is, the plurality of first fine grid lines 33 in the first grid line group 32 can be connected into multiple parts by the first main grid line 34. Similarly, the plurality of second fine grid lines 53 in the second grid line group 52 can be connected by a second main grid line 54. The second main grid line 54 can be a whole-line type or a segmented type.

[0040] Specifically, the first main grid line 34 can be used to collect current in the first grid line group 32, and the second main grid line 54 can be used to collect current in the second grid line group 52. The better the current collection effect, the higher the current and fill factor of the battery, and the higher the photoelectric conversion efficiency of the battery.

[0041] Specifically, in the first polar region 3, at least two first busbars 34 of the same polarity are connected by the first busbar 31, so that at least two adjacent first busbar groups 32 are connected. In this way, the first busbar group 32 can not only collect current through the first busbars 34 it contains, but also collect current through the first busbars 34 in the first busbar group 32 connected to it, so as to ensure the current collection effect of the first busbar group 32, and improve the overall current collection effect of the first polar region 3. For example, Figure 1 As shown, in the first polar region 3, multiple first busbars 31 cooperate, and the first main busbars 34 on the left and right sides can connect all the first fine busbars 33 of the same polarity. In this way, the first main busbars 34 on the left and right sides can fully collect the current on the left and right sides and the middle area of ​​the back contact battery cell 100.

[0042] Similarly, in the second polar region 5 , at least two adjacent second gate line groups 52 are connected by the second bus gate line 51 , so that at least two adjacent second gate line groups 52 are connected, which can improve the overall current collection effect of the second polar region 5 .

[0043] Alternatively, as Figure 1As shown, the first grid line group 32 located on the non-edge side of the electrode pattern 2 is the first guide grid line group 41, and the second grid line group 52 located on the non-edge side of the electrode pattern 2 is the first pass grid line group 61; the first main grid line 34 in the first guide grid line group 41 includes at least two sections of first sub-main grid lines 341, and the first sub-main grid lines 341 in the electrode pattern 2 are arrayed along the first direction and the second direction, respectively, and the first sub-main grid lines 341 arranged along the first direction are connected by a first bus grid line 31; the second main grid line 54 in the first pass grid line group 61 includes at least two sections of second sub-main grid lines 541, and the second sub-main grid lines 541 in the electrode pattern 2 are arrayed along the first direction and the second direction, respectively, and the second sub-main grid lines 541 arranged along the first direction are connected by a second bus grid line 51.

[0044] In an embodiment of the present application, the first sub-bus grid lines 341 arranged along the first direction are connected by a first bus grid line 31, so that more first sub-bus grid lines 341 can be connected. In this way, the first fine grid lines 33 in multiple different areas can be connected, so that each section of the first sub-bus grid line 341 can collect current for multiple different areas, which can improve the effect of the first grid line group 32 on current collection. Similarly, the second sub-bus grid lines 541 arranged along the first direction are connected by a second bus grid line 51, which can improve the effect of the second grid line group 52 on current collection.

[0045] Specifically, in an electrode pattern 2, the first bus bar line 31 and the second bus bar line 51 are of a whole-bar type, that is, the first bus bar line 31 can be connected to all the first sub-bus bar lines 341 arranged in a row along the first direction, and the second bus bar line 51 can be connected to all the second sub-bus bar lines 541 arranged in a row along the first direction.

[0046] Specifically, if Figure 1 and Figure 2 As shown, along the second direction, the first main grid line 34 includes at least two sections of first sub-main grid lines 341. The first sub-main grid line 341 is connected to multiple first fine grid lines 33 and collects the current of this part. In this way, the current collected by the first sub-main grid line 341 can be directly transmitted to the first main grid line 34 on the edge side for collection, which can reduce the current loss during the transmission process and help improve the overall current collection effect of the first polar region 3.

[0047] Specifically, during the subsequent assembly of the back-contact cell 100, two adjacent first sub-busbars 341 along the second direction in the same non-edge first busbar group 32 can be connected by a soldering tape. Of course, in other cases, the non-edge first busbars 34 can also be made into a single piece, and insulation treatment is performed at the intersection of the first busbars 34 and the second busbars 51.

[0048] Similarly, the second main grid line 54 is composed of at least two sections of second sub-main grid lines 541, which can also reduce the current loss during the transmission process and help improve the overall current collection effect of the second polar region 5. In the second grid line group 52 on the same non-edge side, the two adjacent sections of the second sub-main grid lines 541 along the second direction can be connected by a welding strip. In other cases, the second main grid line 54 on the non-edge side can also be made into a whole root type, and the intersection of the second main grid line 54 and the first busbar 31 is insulated due to different polarities.

[0049] Optionally, the number of first bus bars 31 and second bus bars 51 is the same, and the first bus bars 31 and second bus bars 51 are alternately arranged along the first direction, which can improve the uniformity and regularity of the arrangement of the electrode pattern 2 and reduce the difficulty of preparing the electrode pattern 2.

[0050] In some embodiments, as Figure 1 As shown, the first grid line group 32 located at one side edge of the electrode pattern 2 is the second guide grid line group 42, and the first main grid line 34 in the second guide grid line group 42 is connected to all the first bus grid lines 31; the second grid line group 52 located at the other side edge of the electrode pattern 2 is the second pass grid line group 62, and the second main grid line 54 in the second pass grid line group 62 is connected to all the second bus grid lines 51.

[0051] In the embodiment of the present application, the first busbars 34 in the second current guide grid line group 42 are connected to all the first busbars 31, so that all the first sub-busbars 341 in the first polar region 3 are connected to the edge first busbars 34, so that the first polar region 3 is fully connected, which can improve the current collection effect of the first polar region 3. Similarly, the second busbars 54 in the second current pass grid line group 62 are connected to all the second busbars 51, so that the second polar region 5 is fully connected, which can improve the current collection effect of the second polar region 5.

[0052] In the embodiments of this application, Figure 1 As shown, in an electrode pattern 2, the left edge is the first main grid line 34 of the second guide grid line group 42, that is, the first main grid line 34 on the edge side is a whole type, and the first main grid line 34 on the non-edge side is a segmented type, that is, the first main grid line 34 of the first polar region 3 has both whole and segmented types; the right edge is the second main grid line 54 of the second flow grid line group 62, that is, the second main grid line 54 on the edge side is a whole type, and the second main grid line 54 on the non-edge side is a segmented type, that is, the second main grid line 54 of the second polar region 5 has both whole and segmented types.

[0053] In the embodiment of the present application, the first main grid line 34 on the non-edge side is divided into at least two sections of first sub-main grid lines 341 in the vertical direction, and the first sub-main grid lines 341 arranged in a row in the horizontal direction are connected by a first bus grid line 31. The first main grid line 34 on the edge side is a whole root type and is connected to all the first bus grid lines 31, so that the first grid line groups 32 of the first polar region 3 are all connected.

[0054] Specifically, the second main grid line 54 on the non-edge side is divided into at least two sections of second sub-main grid lines 541 in the vertical direction, and the second sub-main grid lines 541 arranged in a row in the horizontal direction are connected by a second bus grid line 51. The second main grid line 54 on the edge side is a whole root type and is connected to all the second bus grid lines 51, so that the second grid line groups 52 of the second polar region 5 are all connected.

[0055] Among them, such as Figure 1 As shown, the total number of first busbars 34 and the total number of second busbars 54 can be the same. In other cases, the number of first busbars 34 and the number of second busbars 54 can also be different. The number of first busbars 34 and the number of second busbars 54 can be designed according to different back contact cell 100 sizes and component layouts.

[0056] In some embodiments, the first grid line groups 32 located on both side edges of the electrode pattern 2 are all third guide grid line groups 43; the first main grid lines 34 in the third guide grid line group 43 are connected to all the first bus grid lines 31, so that all the first sub-main grid lines 341 in the first polar region 3 are connected to the first main grid lines 34 at the edge, so that the first polar region 3 is completely connected, which can improve the current collection effect of the first polar region 3.

[0057] Specifically, if Figure 2 As shown, one second bus bar line 51 connects the second sub-bus bars 541 arranged in a row along the first direction into a module, and the second polar region 5 can form a plurality of connected modules.

[0058] In the embodiment of the present application, the first busbar group 32, i.e., the third guide busbar group 43, is located on both sides of the electrode pattern 2. This allows the first busbars 34 in the first polar region 3 to be either whole or segmented, and the second busbars 54 in the second polar region 5 to be all segmented. The total number of second sub-busbars 541 can be greater than the total number of first sub-busbars 341, and the specific difference is not limited.

[0059] Optionally, the electrode pattern 2 includes a plurality of first units spaced apart along a first direction, and a second unit is arranged between each two adjacent first units, so that the electrode pattern 2 can include repeated structural units, which can improve the structural regularity of the electrode pattern 2 and reduce the difficulty of preparing the electrode pattern 2.

[0060] Furthermore, the first unit includes a first grid line group 32, and the first main grid lines 34 in the first unit are connected to all of its first fine grid lines 33; at least one first bus grid line 31 is connected to all of the first main grid lines 34 in the first unit, so as to facilitate the connection between more first main grid lines 34 with the same polarity.

[0061] The second unit includes at least two second gate line groups 52 and a first gate line group 32 disposed between every two second gate line groups 52 .

[0062] Alternatively, as Figure 3 and Figure 4 As shown, the second unit includes two second gate line groups 52, the two second gate line groups 52 are respectively a third pass gate line group 63 and a fourth pass gate line group 64, and the first gate line group 32 arranged between the third pass gate line group 63 and the fourth pass gate line group 64 is a fourth guide gate line group 44; the first main gate line 34 in the fourth guide gate line group 44 includes at least two sections of first sub-main gate lines 341, and each section of the first sub-main gate line 341 is connected to the first main gate line 34 in the first unit adjacent to it through a first bus bar 31; the second main gate line 54 in the third pass gate line group 63 includes at least two sections of second sub-main gate lines 541, and each section of the second sub-main gate line 541 is connected to the second main gate line 54 in the fourth pass gate line group 64 through a second bus bar 51.

[0063] In the embodiment of the present application, each section of the first sub-busbar 341 is connected to the first busbar 34 in at least one adjacent first unit via a first busbar 31, so that the first sub-busbar 341 and the first busbar 34 of the same polarity can collect current in the same area, thereby ensuring the overall current collection effect of the first polar region 3. Similarly, each section of the second sub-busbar 541 is connected to the second busbar 54 in the fourth pass-gate group 64 via a second busbar 51, thereby ensuring the overall current collection effect of the second polar region 5.

[0064] Specifically, the first main grid line 34 in the fourth guide grid line group 44 is segmented, and in the subsequent process of assembling the back contact battery cell 100, the two adjacent first sub-main grid lines 341 along the second direction can be connected by a welding strip. In other cases, the first main grid line 34 in the fourth guide grid line group 44 can also be a whole-root type, and an insulation treatment can be performed at the position where the first main grid line 34 and the second bus grid line 51 intersect. Similarly, the second main grid line 54 in the third through-current grid line group 63 can be segmented or whole-root. Similarly, the second main grid line 54 in the third through-current grid line group 63 can be segmented or whole-root.

[0065] like Figure 3 and Figure 4 As shown, the second bus bars 51 located at the non-edge side of the electrode pattern 2 are arranged in an array along the first direction and the second direction respectively.

[0066] In some embodiments, as Figure 3 As shown, the third pass gate line group 63 and the fourth pass gate line group 64 are symmetrically arranged on both sides of the fourth guide gate line group 44; each section of the first sub-busbar line 341 is connected to the first busbar lines 34 in the two adjacent first units through a first busbar line 31.

[0067] In the embodiment of the present application, each section of the first sub-busbar line 341 is connected to the first busbar lines 34 in the two adjacent first units through a first busbar line 31, which facilitates the rational layout of the first polar region 3, so that more first busbar groups 32 in the first polar region 3 can be connected, thereby ensuring the current collection capability of the first polar region 3.

[0068] like Figure 3 As shown, the second main grid lines 54 in the third current flow grid line group 63 and the fourth current flow grid line group 64 are segmented, and the first main grid lines 34 in the fourth current guide grid line group 44 are segmented. In the entire electrode pattern 2, the second main grid lines 54 in the second polar region 5 are all segmented, and the first main grid lines 34 in the first polar region 3 are both whole and segmented.

[0069] like Figure 3 As shown, the first bus grid line 31 located on the edge side of the electrode pattern 2 is connected to the first main grid line 34 in all the first grid line groups 32 or the first sub-main grid line 341 located on the edge side, so that the first grid line group 32 of the entire first polar region 3 is connected as an electrical connection module, that is, the first fine grid lines 33 in the first polar region 3 can all be connected, which can ensure the current collection effect of the first polar region 3.

[0070] Specifically, the third pass gate line group 63 and the fourth pass gate line group 64 are symmetrically arranged on both sides of the fourth guide gate line group 44. Figure 3 As shown, the second thin gate lines 53 in each second unit are connected into a plurality of independent modules. Further, in the entire electrode pattern 2, the second thin gate lines 53 in the second polar region 5 can be connected into a plurality of independent electrical connection modules.

[0071] Furthermore, the second bus grid line 51 located on the edge side of the electrode pattern 2 is connected to the second main grid lines 54 in all the second grid line groups 52 or the second sub-main grid lines 541 located on the edge side, so that the second bus grid line 51 on the edge side can be connected to more second main grid lines 54, which facilitates the connection of more second fine grid lines 53 in the second polar region 5.

[0072] Alternatively, as Figure 4As shown, the second busbars 54 in the fourth pass-gate group 64 are connected to all of their second fine gate lines 53 ; each section of the first sub-busbars 341 is connected to the first busbar 34 in an adjacent first unit through a first busbar 31 .

[0073] In an embodiment of the present application, the second main gate line 54 in the fourth pass gate line group 64 is connected to all of its second fine gate lines 53, so that the second fine gate lines 53 in the fourth pass gate line group 64 and the third pass gate line group 63 can all be connected, so that the second fine gate lines 53 in each second unit can all be connected.

[0074] Specifically, if Figure 4 As shown, the first bus bars 31 located at the non-edge side of the electrode pattern 2 are arranged in an array along the first direction and the second direction respectively.

[0075] Furthermore, the first busbar lines 31 at the edge of the electrode pattern 2 are connected to the first main grid lines 34 in all first grid line groups 32 or the first sub-main grid lines 341 at the edge, so that all the first fine grid lines 33 in the first polar region 3 can be connected.

[0076] Furthermore, the second busbar lines 51 at the edge of the electrode pattern 2 are connected to the second main grid lines 54 in all the second grid line groups 52 or the second sub-main grid lines 541 at the edge, so that all the second fine grid lines 53 in the second polar region 5 can be connected.

[0077] In some other embodiments of the application, Figure 5 As shown, the second unit includes three adjacent second grid line groups 52, the three second grid line groups 52 are respectively a fifth flow grid line group 65, a sixth flow grid line group 66 and a seventh flow grid line group 67, the first grid line group 32 arranged between the fifth flow grid line group 65 and the sixth flow grid line group 66 is the fifth guide grid line group 45, the first grid line group 32 arranged between the sixth flow grid line group 66 and the seventh flow grid line group 67 is the sixth guide grid line group 46; the second main grid line 54 of the sixth flow grid line group 66 is connected to all the second fine grid lines 53 thereof; the second main grid line 54 of the fifth flow grid line group 65 includes at least two sections of second The sub-busbar line 541, each section of the second sub-busbar line 541 is connected to the second busbar line 54 of the sixth pass-through gate line group 66 through a second busbar line 51; the fifth pass-through gate line group 65 and the seventh pass-through gate line group 67 are symmetrically arranged on both sides of the sixth pass-through gate line group 66; the first busbar line 34 of the fifth guide gate line group 45 includes at least two sections of the first sub-busbar line 341, and each section of the first sub-busbar line 341 is connected to the first busbar line 34 in the first unit adjacent to it through a first busbar line 31; the fifth guide gate line group 45 and the sixth guide gate line group 46 are symmetrically arranged on both sides of the sixth pass-through gate line group 66.

[0078] In the embodiment of the present application, each section of the first sub-busbar 341 is connected to the first busbar 34 in the adjacent first unit via a first busbar 31, so that the fifth guide grid line group 45 and the first fine grid lines 33 in the adjacent first unit are all connected. Each section of the second sub-busbar 541 is connected to the second busbar 54 of the sixth pass grid line group 66 via a second busbar 51, and the second busbar 54 of the sixth pass grid line group 66 is connected to all of its second fine grid lines 53, so that the fifth pass grid line group 65 and the second fine grid lines 53 in the sixth pass grid line group 66 are all connected.

[0079] Specifically, if Figure 5 As shown, the first bus bars 31 located on the non-edge side of the electrode pattern 2 are arrayed along the first direction and the second direction, and the second bus bars 51 located on the non-edge side of the electrode pattern 2 are arrayed along the first direction and the second direction.

[0080] Specifically, the second main gate line 54 of the sixth pass gate line group 66 is connected to all of its second fine gate lines 53, and the second main gate line 54 of the fifth pass gate line group 65 includes at least two sections of second sub-main gate lines 541, and each section of the second sub-main gate line 541 is connected to the second main gate line 54 of the sixth pass gate line group 66 through a second bus gate line 51, so that the second fine gate lines 53 in the fifth pass gate line group 65 and the sixth pass gate line group 66 can be connected.

[0081] Furthermore, the fifth pass gate line group 65 and the seventh pass gate line group 67 are symmetrically arranged on both sides of the sixth pass gate line group 66, and the second sub-main gate line 541 in the seventh pass gate line group 67 is connected to the second main gate line 54 of the sixth pass gate line group 66 through the second bus gate line 51, so that the second fine gate lines 53 of the second unit are all connected.

[0082] Furthermore, when all the second fine gate lines 53 of the second unit are connected, the second bus gate line 51 located on the edge side of the electrode pattern 2 is connected to the second fine gate lines 53 in all the second gate line groups 52 or the second sub-main gate line 541 located on the edge side, so that all the second fine gate lines 53 in the entire second polar region 5 are connected.

[0083] Specifically, the fifth guide gate line group 45 and the sixth guide gate line group 46 are symmetrically arranged on both sides of the sixth pass gate line group 66, the first sub-bus gate line 341 in the fifth guide gate line group 45 is connected to the first bus gate line 34 in the first unit adjacent to it, the first sub-bus gate line 341 in the sixth guide gate line group 46 is connected to the first bus gate line 34 in the first unit adjacent to it, and the first bus gate line 31 located on the edge side of the electrode pattern 2 is connected to the first bus gate lines 34 in all the first gate line groups 32 or the first sub-bus gate line 341 located on the edge side, so that the first fine gate lines 33 in the entire first polar region 3 are all connected.

[0084] Optionally, the first main grid line 34 in the first grid line group 32 is connected to all of its first fine grid lines 33, and the second main grid line 54 in the second grid line group 52 includes at least two sections of second sub-main grid lines 541; a first bus grid line 31 is arranged between two adjacent sections of the second sub-main grid lines 541 along the second direction, and the first bus grid line 31 is connected to all of the first main grid lines 34 in the first grid line group 32.

[0085] In the embodiment of the present application, the first main grid lines 34 in the first grid line group 32 are connected to all the first fine grid lines 33 thereof, and the first bus grid line 31 is connected to all the first main grid lines 34 in the first grid line group 32, so that all the first fine grid lines 33 in the first polar region 3 are connected.

[0086] Specifically, if Figure 6 As shown, a situation in which the second polar region 5 is surrounded by the first polar region 3 is schematically illustrated.

[0087] In the embodiment of the present application, the specific number of the first gate line group 32 and the second gate line group 52 is related to the size of the silicon wafer substrate 1 and the size of the first fine gate lines 33 and the second fine gate lines 53 and is not specifically limited.

[0088] In the first grid line group 32, the first fine grid line 33, the first main grid line 34, and the first bus grid line 31 have a certain carrier collection range, and the carrier collection range of the first fine grid line 33, the first main grid line 34, and the first bus grid line 31 is related to the size of each grid line. The number of the first fine grid line 33, the first main grid line 34, and the first bus grid line 31 can be designed according to the size of the P region or the N region, as well as the size of each grid line, without specific limitation. Similarly, the number of the second fine grid line 53, the second main grid line 54, and the second bus grid line 51 can be designed according to the size of the N region or the P region, as well as the size of each grid line, without specific limitation.

[0089] Specifically, if Figures 7 to 10 As shown, the shape of the silicon wafer substrate 1 can be a rectangle or a rectangle.

[0090] In the layout of the battery assembly, the number of back-contact battery cells 100 is not limited, and two adjacent back-contact battery cells 100 are symmetrically arranged along the first direction or the second direction; or, two adjacent back-contact battery cells 100 are arranged side by side along the first direction; or, two adjacent back-contact battery cells 100 are arranged side by side along the second direction, which can improve the convenience of the layout of the back-contact battery cells 100 and improve the convenience and reliability of the preparation of the back-contact battery cells.

[0091] Specifically, if Figure 11 As shown, the upper and lower back contact battery cells 100 on the left are arranged side by side along the second direction; the left and right back contact battery cells 100 on the upper side are arranged side by side along the first direction; and the upper and lower back contact battery cells 100 on the right side are arranged symmetrically along the second direction.

[0092] The back contact cell described in the embodiments of the present application has at least the following advantages:

[0093] In an embodiment of the present application, the first main grid lines in at least two adjacent first grid line groups are connected by a first bus grid line, so that the first fine grid lines in at least two adjacent first grid line groups can be connected. In this way, the first grid line group can not only collect current through the first main grid lines it contains, but also collect current through the first main grid lines in the first grid line group adjacent to it, so as to ensure the current collection effect of the first grid line group, and improve the current collection effect of the first polar region. Similarly, the second main grid lines in at least two adjacent second grid line groups are connected by a second bus grid line, so that the second fine grid lines in at least two adjacent second grid line groups can be connected, and improve the current collection effect of the second polar region. In an embodiment of the present application, by improving the current collection effect of the electrode pattern, the current and FF of the back contact cell can be increased, thereby improving the photoelectric conversion efficiency of the back contact cell.

[0094] Although preferred embodiments of the present invention have been described, those skilled in the art may make additional changes and modifications to these embodiments once they become aware of the basic inventive concepts. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the embodiments of the present invention.

[0095] Finally, it should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or terminal device that includes a series of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, method, article, or terminal device. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of additional identical elements in the process, method, article, or terminal device that includes the element.

[0096] The above is a detailed introduction to a back-contact battery cell provided by the application. Specific examples are used herein to illustrate the principles and implementation methods of the application. The description of the above embodiments is only used to help understand the method of the application and its core idea. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of the application. In summary, the content of this specification should not be understood as a limitation on the application.

Claims

1. A back contact battery cell, characterized in that: The back contact cell (100) comprises a silicon wafer substrate (1) and an electrode pattern (2) arranged on the back side of the silicon wafer substrate (1), wherein the electrode pattern (2) comprises a first polar region (3) and a second polar region (5) with opposite polarities; wherein: The first polar region (3) comprises a first bus grid line (31) and a plurality of first grid line groups (32) arranged at intervals along a first direction, the first grid line group (32) comprising a plurality of first fine grid lines (33) arranged at intervals along a second direction and a first main grid line (34) connecting the plurality of first fine grid lines (33); the second polar region (5) comprises a plurality of second bus grid lines (51) and a plurality of second grid line groups (52) arranged at intervals along the first direction, the second grid line group (52) comprising a plurality of second fine grid lines (53) arranged at intervals along the second direction and a second main grid line (54) connecting the plurality of second fine grid lines (53); At least two adjacent first bus bars (34) in the first bus bar group (32) are connected via the first bus bar (31), and / or at least two adjacent second bus bars (54) in the second bus bar group (52) are connected via the second bus bar (51); The first grid line group (32) and the second grid line group (52) are alternately arranged along the first direction, the first fine grid lines (33) and the second fine grid lines (53) are alternately arranged, the first bus grid lines (31) are insulated and connected to the second main grid lines (54), the second bus grid lines (51) are insulated and connected to the first main grid lines (34), the first fine grid lines (33), the second fine grid lines (53), the first bus grid lines (31), and the second bus grid lines (51) all extend along the first direction, the first main grid lines (34) and the second main grid lines (54) all extend along the second direction, and the first direction is different from the second direction.

2. The back contact cell according to claim 1, characterized in that: The first gate line group (32) located on the non-edge side of the electrode pattern (2) is a first current guiding gate line group (41), and the second gate line group (52) located on the non-edge side of the electrode pattern (2) is a first current passing gate line group (61); The first busbar (34) in the first guide grid line group (41) comprises at least two sections of first sub-busbars (341); the first sub-busbars (341) in the electrode pattern (2) are arranged in an array along a first direction and a second direction respectively; the first sub-busbars (341) arranged along the first direction are connected via one of the first busbars (31); The second busbars (54) in the first busbar group (61) include at least two sections of second sub-busbars (541); the second sub-busbars (541) in the electrode pattern (2) are arranged in an array along a first direction and a second direction respectively; the second sub-busbars (541) arranged along the first direction are connected via one of the second busbars (51).

3. The back contact cell according to claim 2, characterized in that: The first grid line group (32) located at one side edge of the electrode pattern (2) is a second current guiding grid line group (42), and the first main grid line (34) in the second current guiding grid line group (42) is connected to all the first bus grid lines (31); The second grid line group (52) located at the other side edge of the electrode pattern (2) is a second current-passing grid line group (62), and the second main grid lines (54) in the second current-passing grid line group (62) are connected to all the second bus grid lines (51).

4. The back contact cell according to claim 2, characterized in that: The first grid line group (32) located at the two side edges of the electrode pattern (2) is a third current guide grid line group (43); The first main grid lines (34) in the third guide grid line group (43) are connected to all the first bus grid lines (31).

5. The back contact cell according to claim 1, characterized in that: The electrode pattern (2) comprises a plurality of first units arranged at intervals along a first direction, a second unit is arranged between every two adjacent first units, the first unit comprises a first grid line group (32), and a first main grid line (34) in the first unit is connected to all of its first fine grid lines (33); At least one of the first busbars (31) is connected to the first busbars (34) in all the first units; The second unit comprises at least two second gate line groups (52) and a first gate line group (32) arranged between every two second gate line groups (52).

6. The back contact cell according to claim 5, characterized in that: The second unit comprises two second gate line groups (52), the two second gate line groups (52) are respectively a third flow gate line group (63) and a fourth flow gate line group (64), and the first gate line group (32) arranged between the third flow gate line group (63) and the fourth flow gate line group (64) is a fourth flow guide gate line group (44); The first busbar (34) in the fourth busbar group (44) comprises at least two sections of first sub-busbars (341), each section of the first sub-busbar (341) being connected via one of the first busbars (31) and at least one first busbar (34) in the first unit adjacent thereto; The second busbar (54) in the third pass-through busbar group (63) comprises at least two sections of second sub-busbars (541), and each section of the second sub-busbars (541) is connected to the second busbar (54) in the fourth pass-through busbar group (64) via one of the second busbars (51).

7. The back contact cell according to claim 6, characterized in that: The third flow-through gate line group (63) and the fourth flow-through gate line group (64) are symmetrically arranged on both sides of the fourth flow-through gate line group (44); Each section of the first sub-busbar line (341) is connected to the first busbar lines (34) in two adjacent first units via one of the first busbar lines (31).

8. The back contact cell according to claim 6, characterized in that: The second main grid lines (54) in the fourth current-passing grid line group (64) are connected to all of the second fine grid lines (53); Each section of the first sub-busbar line (341) is connected via a first busbar line (31) and a first busbar line (34) in a first unit adjacent thereto.

9. The back contact cell according to claim 5, characterized in that: The second unit comprises three adjacent second gate line groups (52), the three second gate line groups (52) being respectively a fifth flow gate line group (65), a sixth flow gate line group (66), and a seventh flow gate line group (67); the first gate line group (32) arranged between the fifth flow gate line group (65) and the sixth flow gate line group (66) is a fifth flow guiding gate line group (45), and the first gate line group (32) arranged between the sixth flow gate line group (66) and the seventh flow gate line group (67) is a sixth flow guiding gate line group (46); The second main grid lines (54) of the sixth current-passing grid line group (66) are connected to all of its second fine grid lines (53); The second busbar (54) of the fifth pass-gate line group (65) comprises at least two sections of second sub-busbars (541), each section of the second sub-busbars (541) being connected to the second busbar (54) of the sixth pass-gate line group (66) via one second busbar (51); the fifth pass-gate line group (65) and the seventh pass-gate line group (67) are symmetrically arranged on both sides of the sixth pass-gate line group (66); The first main grid line (34) of the fifth guide grid line group (45) comprises at least two sections of first sub-main grid lines (341), each section of the first sub-main grid line (341) being connected to the first main grid line (34) of the first unit adjacent thereto via one of the first bus grid lines (31); the fifth guide grid line group (45) and the sixth guide grid line group (46) are symmetrically arranged on both sides of the sixth pass grid line group (66).

10. The back contact cell according to claim 1, characterized in that: The first main grid line (34) in the first grid line group (32) connects all the first fine grid lines (33), and the second main grid line (54) in the second grid line group (52) includes at least two sections of second sub-main grid lines (541); A first busbar line (31) is arranged between two adjacent segments of the second sub-busbar lines (541) along the second direction, and the first busbar line (31) is connected to all the first busbar lines (34) in the first busbar line group (32).

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