Solar cell, cell string and photovoltaic module

Abstract

The utility model provides a solar cell, a cell string and a photovoltaic assembly. The solar cell comprises a cell body having a first edge and a second edge which are intersected; the plurality of first electrodes are arranged on the first surface of the battery body, extend in the direction parallel to the first side and are arranged at intervals in the direction perpendicular to the first side; the bus bar is arranged at the position, close to the second edge, of the first surface and intersects with at least one part of the first electrodes. Wherein the first electrode intersected with the bus bar is provided with an extension part which passes through the bus bar and extends towards the second side. The cell string comprises a plurality of solar cells; and the interconnection strip is electrically connected with the at least two solar cells, and the projection of the interconnection strip on the solar cells is not overlapped with the bus bar. The photovoltaic module comprises at least one battery string.

Description

Technical Field

[0001] At least one embodiment of the utility model relates to the field of photovoltaic technology, and in particular to a solar cell, a battery string and a photovoltaic module. Background Art

[0002] In order to maintain a large light-receiving area of ​​the solar cell body, the current design mostly sets the electrodes (such as auxiliary grids) on the light-receiving surface of the cell body to be thinner and denser. This is beneficial to reduce the blocking of light by the electrodes and the resistance loss of the electrodes, but thinner electrodes are also prone to causing grid breakage.

[0003] Since the broken gate portion between the broken gate position of the electrode and the end close to the cell cannot collect the current in the corresponding area of ​​the cell body, the photoelectric conversion efficiency of the solar cell is reduced. To this end, a busbar connected to the electrode (such as a secondary grid) can be set at the edge of the cell body to collect and output the current collected by the broken gate portion through other electrodes, so as to enhance the current collection effect on the edge of the cell.

[0004] Due to the limitations of the manufacturing process and process accuracy of the electrode, the end of the electrode close to the edge of the battery cell is prone to deformation. In order to connect the bus bar to each electrode, the bus bar must be sufficiently far away from the edge of the battery cell. However, this will make it difficult to collect the current in the area between the bus bar and the edge of the battery cell.

[0005] Therefore, how to collect the edge current of the battery cell has become a technical problem that needs to be solved urgently. Utility Model Content

[0006] To solve at least one of the above and other technical problems in the prior art, the utility model provides a solar cell, a cell string and a photovoltaic module, which can collect current at the edge of the cell and improve the reliability of the connection between the first electrode and the busbar.

[0007] An embodiment of the utility model provides a solar cell sheet, comprising: a battery body, having a first side and a second side that are orthogonal to each other; a plurality of first electrodes, which are arranged on the first surface of the battery body, extend in a direction parallel to the first side, and are arranged at intervals in an extension direction perpendicular to the first side; and a bus bar, which is arranged on the first surface at a position close to the second side and intersects with at least a portion of the first electrode; wherein the first electrode intersecting with the bus bar has an extension portion that passes through the bus bar and extends toward the second side.

[0008] According to an embodiment of the present invention, at least a portion of the extending portion has a different length from the other extending portions.

[0009] According to an embodiment of the present invention, the length of the extension portion is configured to be greater than or equal to 0.2 mm and less than or equal to half of the distance between the bus bar and the second side.

[0010] According to an embodiment of the present invention, the bus bar extends in a direction parallel to the second side, and in a portion where the bus bar intersects with the first electrode, the bus bar covers the first electrode.

[0011] According to an embodiment of the present invention, at the intersection of the bus bar and the first electrode, protruding portions protruding upward are formed on both sides of the width of the bus bar, and recessed portions concave downward are formed between the protruding portions.

[0012] According to an embodiment of the present invention, the width of the first electrode is smaller than the width of the bus bar.

[0013] According to an embodiment of the present invention, the aspect ratio of the first electrode is greater than the aspect ratio of the bus bar.

[0014] According to an embodiment of the utility model, the solar cell further comprises a second electrode extending in a direction perpendicular to the first side, and the second electrode is connected to the first electrode of the same polarity.

[0015] According to an embodiment of the present invention, the bus bar intersects with each of the first electrodes.

[0016] According to an embodiment of the present invention, the first surface is the backlight surface of the solar cell.

[0017] According to an embodiment of the present invention, the busbar intersects with the first electrode of the first polarity and is electrically isolated from the first electrode of the second polarity.

[0018] According to an embodiment of the utility model, it further comprises a joint portion close to the bus bar, and a connecting portion is provided between the joint portion and the bus bar.

[0019] According to an embodiment of the utility model, the second surface of the battery body has a third electrode parallel to the first edge, the width of the third electrode is greater than the width of the first electrode, the first surface is the light-receiving surface of the solar cell, and the second surface is the backlight surface of the solar cell.

[0020] According to an embodiment of the present invention, an aspect ratio of the third electrode is smaller than an aspect ratio of the first electrode.

[0021] An embodiment of the utility model further provides a battery string, comprising: a plurality of solar cells; and at least one interconnection bar electrically connecting at least two of the solar cells and having a projection on the cell that does not overlap with the busbar.

[0022] An embodiment of the utility model further provides a photovoltaic assembly, comprising at least one battery string.

[0023] According to the solar cell, battery string and photovoltaic module provided by the utility model, the extension portion of the first electrode passing through the busbar extends toward the edge of the battery body, and is suitable for collecting the current in the area between the edge of the battery body and the busbar, so as to improve the current collection rate of the edge of the battery body. Since the busbar is no longer limited to the end connected to the first electrode, the reliability of the connection is also improved. In addition, in the case of a broken busbar in the first electrode, the current collected by the extension portion and the portion of the first electrode located on the other side of the busbar are respectively collected by the two sides of the busbar, which is also conducive to preventing current concentration. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 is a schematic diagram of a solar cell according to an exemplary embodiment of the present invention from a formal perspective, showing a solar cell with a heterojunction cell structure;

[0025] Figure 2 yes Figure 1 A partial enlarged view of portion C of the exemplary embodiment shown;

[0026] Figure 3 yes Figure 1 A partial enlarged view of the connection portion between the busbar and the first electrode of the exemplary embodiment shown;

[0027] Figure 4 yes Figure 3 A partial cross-sectional view of the exemplary embodiment shown in A1-A2 perspective;

[0028] Figure 5 yes Figure 3 A partial cross-sectional view of the exemplary embodiment shown at perspective B1-B2; and

[0029] Figure 6 It is a schematic diagram of a solar cell according to another exemplary embodiment of the present invention from a formal perspective, showing a solar cell with a back contact cell structure.

[0030] In the drawings, the meanings of the reference numerals are as follows:

[0031] 1. Battery body;

[0032] 2. a first electrode;

[0033] 21. Extension;

[0034] 22. a first electrode of a first polarity;

[0035] 23. a second polarity first electrode;

[0036] 3. Harpoon unit;

[0037] 4. A second electrode;

[0038] 5. Joint;

[0039] 6. Busbar;

[0040] 61. protrusion;

[0041] 62, recessed part;

[0042] 7. Interconnection strips; and

[0043] 8. Connection part. DETAILED DESCRIPTION

[0044] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with specific embodiments and with reference to the accompanying drawings.

[0045] The terms used herein are only for describing specific embodiments and are not intended to limit the present invention. The terms "include", "comprises", etc. used herein indicate the existence of the features, steps, operations and / or components, but do not exclude the existence or addition of one or more other features, steps, operations or components.

[0046] All terms used herein, including technical and scientific terms, have the meanings commonly understood by those skilled in the art, unless otherwise defined. It should be noted that the terms used herein should be interpreted as having a meaning consistent with the context of this specification, and should not be interpreted in an idealized or overly rigid manner.

[0047] When using expressions such as "at least one of A, B, and C, etc.", it should generally be interpreted as the meaning of the expression generally understood by those skilled in the art. For example, "a system having at least one of A, B, and C" should include but not be limited to a system having A alone, B alone, C alone, A and B, A and C, B and C, and / or A, B, C, etc. When using expressions such as "at least one of A, B, or C, etc.", it should generally be interpreted as the meaning of the expression generally understood by those skilled in the art. For example, "a system having at least one of A, B, or C" should include but not be limited to a system having A alone, B alone, C alone, A and B, A and C, B and C, and / or A, B, C, etc.

[0048] The electrodes of solar cells (such as the main grid and the auxiliary grid) are often printed on the battery body. The more commonly used printing processes include but are not limited to screen printing and laser transfer printing (LT). Among them, screen printing is based on a designed screen (such as a screen with mesh knots or a screen without mesh knots), and the slurry (such as silver) is leaked through the mesh holes set on the screen to print on the battery body to form the required electrode pattern on the battery body; laser transfer is to pre-fill the slurry into the forming groove (such as a trapezoidal groove) of the transfer film designed with the electrode pattern, and then transplant the transfer film to the surface of the battery body. The laser output by the laser transfer machine separates the slurry from the forming groove so that the electrode is attached to the surface of the battery body.

[0049] Both screen printing and laser transfer technologies can cause problems such as edge breakage and low edge current collection efficiency. Therefore, how to provide a current collection method between the busbar and the edge of the solar cell and improve the reliability of the connection between the first electrode and the busbar to reduce the occurrence of breakage and electroluminescent black edges in solar cells has become a technical problem that needs to be solved urgently.

[0050] Figure 1 It is a schematic diagram of a solar cell according to an exemplary embodiment of the present invention from a formal perspective, showing a solar cell with a heterojunction cell structure. Figure 2 yes Figure 1 A partial enlarged view of portion C of the exemplary embodiment shown.

[0051] According to the solar cell provided by the utility model, Figure 1 and Figure 2 As shown, the battery body 1 includes a battery body 1, a plurality of first electrodes 2 and a busbar 6. The battery body 1 has a first side and a second side intersecting each other. In certain specific cases, the first side and the second side may intersect each other at an angle of 120-150 degrees, for example, 145 degrees. However, preferably, the first side (such as Figure 1 left and right as shown) and a second side (as shown Figure 1 The first side and the second side are perpendicular to each other, and the following description takes the perpendicular intersection as an example. A plurality of first electrodes 2 are arranged on the first surface of the battery body 1 (ie, Figure 1The first electrode 2 is a first electrode 2 having a first side and a second side. The first electrode 2 is a first electrode 2 having a first side and a second side. The first electrode 2 is a first electrode 2 having a first side and a second side. The first electrode 2 has ...

[0052] In an illustrative embodiment, Figure 1 and Figure 2 As shown, the battery body 1 (as Figure 1 The portion surrounded by the dashed line shown in FIG. 1 is configured as a substantially rectangular structure (which may have chamfered corners) including a first direction (such as Figure 1 The first side (as shown in the up and down direction) extending Figure 1 left and right as shown) and along the second direction (as shown Figure 1 The second side (as shown in the left and right directions) extending Figure 1 In detail, the surface of the battery body 1 (such as Figure 1 A plurality of first electrodes 2 are arranged on the surface facing away from the paper as shown in FIG. 1 , and each first electrode 2 is arranged at equal intervals along the second direction. Further, two bus bars 6 are arranged on the same side surface of the battery body 1 as the surface facing away from the paper as shown in FIG. Figure 1 The first electrode 2 is provided at two ends of the battery body in the longitudinal direction (ie, the first direction) to be connected and electrically connected to the first electrode 2. It should be understood that the embodiments of the present utility model are not limited thereto.

[0053] For example, the busbar 6 may be a line segment structure, the length of which is less than 1 / 4 of the length of the second side, and may be disposed at only one end of the battery body (ie, Figure 1 upper or lower end as shown).

[0054] In an illustrative embodiment, Figure 1 and Figure 2 As shown, the first electrode 2 and the bus bar 6 are arranged in a "cross shape". In detail, the extension portion 21 of the first electrode 2 extends toward the second side in a direction substantially perpendicular to the bus bar 6 and forms a gap with the second side.

[0055] In such an embodiment, the extension portion 21 of the first electrode 2 protruding from the bus bar 6 is suitable for collecting the current between the edge of the battery body 1 and the bus bar 6, which is beneficial to improving the collection efficiency of the edge current of the solar cell. In addition, since the bus bar 6 is no longer limited to the end connected to the first electrode 2, the location of the bus bar 6 can be closer to the middle of the battery body 1, which is beneficial to improving the reliability of the connection between the bus bar 6 and the first electrode 2, and can more effectively reduce the occurrence of bus bar breakage. Furthermore, in the event of a bus bar breakage, the current collected by the extension portion 21 of the first electrode 2 and the current collected by the portion of the first electrode 2 located on the other side of the bus bar 6 are respectively collected by the two sides of the bus bar 6, which can also prevent the current passing through the bus bar 6 from being too concentrated.

[0056] According to the embodiments of the present utility model, Figure 1 and Figure 2 As shown, the solar cell further includes a second electrode 4 extending in a direction perpendicular to the first side, and the second electrode 4 is connected to the first electrode 2 of the same polarity. The second electrode 4 can also be called a main grid, etc., which is used to collect the current collected by the first electrode 2 (i.e., the auxiliary grid). In an exemplary embodiment, as Figure 1 and Figure 2 As shown, the solar cell is also provided with a plurality of joints 5 (ie pads). Further, the second electrode 4 (ie main grid) is arranged along the second direction (eg Figure 1 The left and right directions as shown) are arranged to connect adjacent joining portions 5 (ie, pads).

[0057] In such an embodiment, the second electrode 4 (ie, the main grid) is suitable for collecting the current collected by the first electrode 2 and connected to other solar cells via the joint 5. It should be understood that the embodiments of the present utility model are not limited thereto.

[0058] For example, the second electrode 4 may be omitted, and the current is collected only through the interconnection bar 7. That is, a solar cell without a busbar is formed.

[0059] According to the embodiments of the present utility model, Figure 1 and Figure 2 As shown, the busbar 6 intersects each first electrode 2 .

[0060] In an illustrative embodiment, Figure 1 and Figure 2 As shown, the solar cell includes but is not limited to being configured with 18 second electrodes 4 (i.e., main grids). In detail, each second electrode 4 (i.e., main grid) includes but is not limited to being configured with five joints 5. Furthermore, each second electrode 4 (i.e., main grid) is also configured with harpoon portions 3 at both ends.

[0061] In an illustrative embodiment, Figure 1 and Figure 2 As shown, the harpoon portion 3 and the two ends of the second electrode 4 (such as Figure 1 In detail, the harpoon portion 3 includes but is not limited to a rectangular structure configured with an opening on one side.

[0062] In such an embodiment, the harpoon portion 3 is suitable for collecting the second direction (such as Figure 1 The edge current of the edge (in the up and down directions shown).

[0063] According to the embodiments of the present utility model, Figure 2 As shown, at least a portion of the extensions 21 have different lengths from the other extensions 21 .

[0064] According to the embodiments of the present utility model, Figure 2 As shown, the length of the extension portion 21 is configured to be greater than or equal to 0.2 mm and less than or equal to one half of the distance between the bus bar 6 and the second side.

[0065] The extensions 21 of different first electrodes 2 may have length differences or shape differences due to the accuracy of the printing process and the equipment configured for the printing process (including but not limited to the screen or transfer film), wherein the shape difference is not limited to the first electrode 2 along the first direction (such as Figure 2 The spacing between the two ends (in the left and right directions shown) changes.

[0066] On this basis, in an illustrative embodiment, as Figure 2 As shown, the busbar 6 protrudes (as shown Figure 2 The extension 21 (shown as protruding to the left) can be configured to have different lengths (such as Figure 2 L1 shown). Further, the busbar 6 is arranged at a position that can be connected to each first electrode 2 having the same polarity.

[0067] In an illustrative embodiment, Figure 2As shown, the position of the busbar 6 relative to the first electrode 2 determines the length of the extension 21, and for this purpose, the length of the extension 21 can be set by designing the length of the extension 21. In detail, the length of the extension 21 (i.e., L1) includes but is not limited to being configured to be greater than or equal to 0.2 mm (i.e., L1 ≥ 0.2 mm). In this way, the extension 21 protruding from the busbar 6 is closer to the edge of the battery body 1 (i.e., the second side), and for this reason, it is beneficial to collect the current at the edge of the battery body 1. Further, the length of the extension 21 (i.e., L1) is also configured to be less than half of the spacing (i.e., L2) between the busbar 6 and the second side (i.e., L1 ≤ L2 / 2). In this way, the extension 21 can be kept at a sufficient distance from the edge of the battery body 1 (i.e., the second side) to prevent the extension 21 from extending from the edge of the battery body 1 and being mistakenly connected to other battery cells. It should be understood that the embodiments of the utility model are not limited to this.

[0068] For example, the length of the extension portion 21 (ie, L1 ) may be set to other values ​​(eg, empirical values ​​or calculated values).

[0069] Figure 3 yes Figure 1 A partial enlarged view of the connecting portion between the bus bar and the first electrode of the exemplary embodiment shown. Figure 4 yes Figure 3 A partial cross-sectional view of the exemplary embodiment shown along the A1 - A2 perspective. Figure 5 yes Figure 3 A partial cross-sectional view of the exemplary embodiment shown in FIG. 1 from perspective B1 - B2 .

[0070] According to the embodiments of the present utility model, Figure 3 As Figure 5 As shown, the busbar 6 extends in a direction parallel to the second side, and in the portion where the busbar 6 intersects with the first electrode 2 , the busbar 6 covers the first electrode 2 .

[0071] According to the embodiments of the present utility model, Figures 3 to 5 As shown, at the intersection of the bus bar 6 and the first electrode 2 , protruding portions 61 protruding upward are formed on both sides of the width of the bus bar 6 , and recessed portions 62 concave downward are formed between the protruding portions 61 .

[0072] In an illustrative embodiment, Figure 3 As shown, the first electrode 2 is arranged along a first direction (such as Figure 3 The busbar 6 is along the second direction (as shown in the left and right direction). Figure 3 In detail, the portion where the busbar 6 is joined to the first electrode 2 (i.e., Figure 3 The overlapped portion shown in FIG. 1 is formed on the first electrode 2. Further, the width of the joined portion is Figure 3The left and right sides shown in the figure) form a protrusion 61 (i.e. Figure 3 The arc-shaped area defined by the dotted line shown in FIG. 1 ) and a recessed portion 62 is formed between the two protruding portions 61 (i.e., as shown in FIG. 1 ). Figure 3 The elliptical region enclosed by the dotted line shown in FIG. 1 ). The thickness of the protrusion 61 includes but is not limited to being configured to be 5 to 20 microns.

[0073] In such an embodiment, the protrusion 61 and the recess 62 of the bus bar 6 make it Figure 4 and Figure 5 The upper and lower directions shown in FIG. 1 are similar to form a peak structure and a valley structure. Based on the same material of the busbar 6, the cross-sectional area of ​​the protrusion 61 (eg Figure 5 The cross-sectional area shown in FIG. 1 is larger than that of the concave portion 62. Therefore, the resistance value of the protrusion 61 is lower than that of the concave portion 62. Figure 3 The current collected on the left side (i.e., the extension portion 21) and the right side) as shown can be roughly gathered along the corresponding protrusions 61 (i.e., the current collected from the left side is gathered along the protrusion on the left, and the current collected from the right side is gathered along the protrusion on the right) to avoid current concentration.

[0074] According to the embodiments of the present utility model, Figure 4 and Figure 5 As shown, the width of the first electrode 2 is smaller than the width of the bus bar 6. Preferably, the width of the first electrode 2 is 20-40 microns, and the width of the bus bar 6 is 30-60 microns.

[0075] According to the embodiments of the present utility model, Figure 4 and Figure 5 As shown, the aspect ratio of the first electrode 2 is greater than that of the bus bar 6. Preferably, the aspect ratio of the first electrode 2 is greater than or equal to 0.8, while the aspect ratio of the bus bar 6 is less than or equal to 1.

[0076] In an illustrative embodiment, Figure 4 and Figure 5 As shown, the width of the first electrode 2 (eg Figure 4 The distance from the left end to the right end of the first electrode 2 shown in FIG. 1 is configured to be smaller than the width of the bus bar 6 (eg, Figure 5 Further, the aspect ratio (ie, thickness-to-width ratio or height-to-width ratio, i.e., Figure 4 and Figure 5 The ratio of the thickness to the width of the electrode shown in the figure is also configured to be greater than the aspect ratio of the busbar 6. The thickness of the busbar 6 can be configured to be consistent with the thickness of the first electrode 2, or thicker than or less than the first electrode 2. The aspect ratio should be comprehensively designed based on the resistance of the electrode, the current collection effect, the shielding effect and other arbitrary design indicators.

[0077] In such an embodiment, the width of the first electrode 2 is configured to be smaller than the width of the busbar 6, so that the shielding effect of the first electrode 2 is small, which is conducive to making the solar cell have a higher photoelectric conversion efficiency. On the basis that the width of the busbar 6 is smaller than the first electrode 2, it is configured to have a larger aspect ratio, so that the busbar 6 has a smaller resistance, which is conducive to collecting current.

[0078] According to an embodiment of the utility model, not shown in the figure, the second surface of the battery body 1 has a third electrode parallel to the first side, the width of the third electrode is greater than the width of the first electrode 2, the first surface is the light-receiving surface of the solar cell, and the second surface is the backlight surface of the solar cell.

[0079] According to an embodiment of the present utility model, which is not shown in the figure, the aspect ratio of the third electrode is smaller than the aspect ratio of the first electrode 2 .

[0080] In an illustrative embodiment, Figures 1 to 5 As shown, the battery body 1 has a first surface (i.e., Figure 1 The first surface is used as the light-receiving surface of the solar cell, and the second surface is used as the backlight surface of the solar cell. In detail, the first electrode 2 is arranged on the first surface, and the third electrode is arranged on the second surface. Similar to the first electrode 2, the third electrode can also be called a fine grid, a collector grid line, a secondary grid, etc., which is used to extract the majority carriers of the doped region of the backlight surface of the solar cell.

[0081] In an illustrative embodiment, the width of the third electrode is configured to be greater than the width of the first electrode 2, and the aspect ratio of the third electrode is less than the aspect ratio of the first electrode 2, that is, in the cross section along the width direction of the third electrode and the first electrode 2, the third electrode has a larger cross-sectional area. Among them, the first electrode 2 includes but is not limited to being printed by laser transfer technology, and the third electrode includes but is not limited to being printed by screen printing technology. In this way, it is beneficial to save the cost of the electrode printing process. It should be understood that the embodiments of the utility model are not limited to this.

[0082] For example, the first electrode 2 may also be printed by screen printing technology.

[0083] For another example, the third electrode may also be printed using laser transfer technology.

[0084] In an exemplary embodiment, a bus bar 6 may also be provided near the second edge of the second surface. In detail, the third electrode intersects with the bus bar and may be provided with an extension protruding from the bus bar similar to the first electrode 2 .

[0085] In a preferred embodiment, the width of the third electrode includes but is not limited to being configured to be greater than or equal to 35 micrometers, and the aspect ratio is configured to be less than or equal to 1.

[0086] In such an embodiment, the first electrode 2 is disposed on the light-receiving surface of the solar cell, the third electrode is disposed on the backlight surface of the solar cell, and the width of the third electrode is greater than the first electrode 2. The first electrode 2 with a smaller width can reduce the shielding of the electrode on the light-receiving surface, while the third electrode with a larger width can more effectively collect carriers in the PN junction region located on the backlight surface.

[0087] Figure 6 It is a schematic diagram of a solar cell according to another exemplary embodiment of the present invention from a formal perspective, showing a solar cell with a back contact cell structure.

[0088] According to the embodiments of the present utility model, Figure 6 As shown, the first surface is the backlight surface of the solar cell.

[0089] According to the embodiments of the present utility model, Figure 6 As shown, the busbar 6 intersects with the first electrode 2 of the first polarity and is electrically isolated from the first electrode 2 of the second polarity.

[0090] In an illustrative embodiment, Figure 6 As shown, the first electrode 2, the second electrode 4 (i.e., the main grid) and the busbar 6 are all arranged on the back side of the battery body 1, i.e., a back contact battery structure is formed. In detail, the first electrode 2 has a first polarity (e.g., a positive pole) that is the same as the second electrode 4 or a second polarity (e.g., a negative pole) that is different from the second electrode 4, and the first polarity first electrode 22 and the second polarity first electrode 23 are connected along the second direction (e.g., Figure 6 Furthermore, the first polarity first electrode 22 and the second polarity first electrode 23 are arranged alternately and spaced along the second direction (as shown in the upper and lower directions). Figure 6 The left and right directions shown in the figure are discontinuous and the discontinuous positions are formed as disconnected portions to accommodate the passage of the second electrode 4 of the opposite polarity. The busbar 6 includes but is not limited to a configuration such as Figure 6 The two ends shown have a bent structure.

[0091] According to the embodiments of the present utility model, Figure 6 As shown, the solar cell further comprises a joint portion 5 close to the bus bar 6 , and a connecting portion 8 is provided between the joint portion 5 and the bus bar 6 .

[0092] In an illustrative embodiment, Figure 6As shown, the joint part (i.e., pad) 5 includes a plurality of first joint parts (i.e., pads) disposed in the middle of the battery body 1, and a plurality of second joint parts (i.e., pads) disposed at the edge of the battery body 1. Figure 6 A second electrode 4 is disposed between the first bonding portions (i.e., pads) arranged in the upper and lower directions as shown in FIG. Figure 6 The second bonding portion (ie, pad) arranged in the vertical direction (as shown in FIG. 1 ) and the busbar 6 are connected by a current flowing along the first direction (as shown in FIG. 1 ). Figure 6 The connecting portion 8 is connected to a connecting portion 8 extending in the left and right directions as shown. The connecting portion 8 includes but is not limited to being configured as a rectangular structure.

[0093] In such an embodiment, the first joint portion (i.e., pad) located in the middle of the battery body 1 is connected through the second electrode 4 (i.e., main grid) to collect the current collected by the first electrode 2. However, the second joint portion (i.e., pad) is close to the edge of the battery body 1 (the strength of this portion is relatively low), and is susceptible to stress and cracking, and is not suitable for configuring the second electrode 4 (i.e., main grid). Therefore, the connection portion 8 can be configured to further collect the current collected by the busbar 6.

[0094] Similar to the above-mentioned heterojunction battery structure, the second electrode 4 can also be omitted in the solar cell of the back contact battery structure to form a battery structure without a main grid.

[0095] Based on the same inventive concept as the solar cell, the utility model also provides a battery string and a photovoltaic module.

[0096] According to an embodiment of the present invention, the battery string includes a plurality of solar cells and at least one interconnection bar 7 (ie, welding strip). The interconnection bar 7 connects at least two solar cells and its projection on the solar cell does not overlap with the busbar 6.

[0097] According to an embodiment of the present invention, a photovoltaic assembly includes at least one battery string.

[0098] It should also be noted that the directional terms mentioned in the embodiments, such as "upper", "lower", "front", "back", "left", "right", etc., are only for reference to the drawings and are not intended to limit the scope of protection of the present invention. Throughout the drawings, the same elements are represented by the same or similar reference numerals. Conventional structures or constructions will be omitted when they may cause confusion in the understanding of the present invention.

[0099] The embodiments of the present invention are described above. However, these embodiments are for illustrative purposes only and are not intended to limit the scope of the present invention. Although the embodiments are described above separately, this does not mean that the measures in the various embodiments cannot be used in combination to advantage. The scope of the present invention is defined by the attached claims and their equivalents. Without departing from the scope of the present invention, a person skilled in the art may make a variety of substitutions and modifications, which should all fall within the scope of the present invention.

Claims

1. A solar cell, characterized in that: include: A battery body (1) having a first side and a second side intersecting each other; A plurality of first electrodes (2) are arranged on a first surface of the battery body (1), extending in a direction parallel to the first side, and arranged at intervals in a direction perpendicular to the first side; as well as A busbar (6) is arranged on the first surface at a position close to the second edge and intersects with at least a portion of the first electrode (2); The first electrode (2) intersecting the bus bar (6) has an extension portion (21) passing through the bus bar (6) and extending toward the second side.

2. The solar cell according to claim 1, characterized in that: At least a portion of the extension portions (21) has a different length from the other extension portions (21).

3. The solar cell according to claim 1, characterized in that: The length of the extension portion (21) is configured to be greater than or equal to 0.2 mm and less than or equal to one half of the distance between the busbar (6) and the second side.

4. The solar cell according to claim 1, characterized in that: The busbar (6) extends in a direction parallel to the second side, and at a portion where the busbar (6) intersects with the first electrode (2), the busbar (6) covers the first electrode (2).

5. The solar cell according to claim 4, characterized in that: At the intersection of the busbar (6) and the first electrode (2), protruding portions (61) protruding upward are formed on both sides of the width of the busbar (6), and recessed portions (62) are formed between the protruding portions (61).

6. The solar cell according to claim 1, characterized in that: The width of the first electrode (2) is smaller than the width of the busbar (6).

7. The solar cell according to claim 1, characterized in that: The aspect ratio of the first electrode (2) is greater than the aspect ratio of the bus bar (6).

8. The solar cell according to claim 1, characterized in that: It also comprises a second electrode (4) extending in a direction perpendicular to the first side, wherein the second electrode (4) is connected to the first electrode (2) of the same polarity.

9. The solar cell according to any one of claims 1 to 8, characterized in that: The busbar (6) intersects each of the first electrodes (2).

10. The solar cell according to any one of claims 1 to 8, characterized in that: The first surface is the backlight surface of the solar cell.

11. The solar cell according to claim 10, characterized in that: The busbar (6) intersects with the first electrode (2) of the first polarity and is electrically isolated from the first electrode (2) of the second polarity.

12. The solar cell according to claim 10, characterized in that: It also comprises a joint portion (5) close to the busbar (6), and a connecting portion (8) is provided between the joint portion (5) and the busbar (6).

13. The solar cell according to claim 1, characterized in that: The second surface of the battery body (1) has a third electrode parallel to the first edge, the width of the third electrode is greater than the width of the first electrode (2), the first surface is the light-receiving surface of the solar cell, and the second surface is the backlight surface of the solar cell.

14. The solar cell according to claim 13, characterized in that: The aspect ratio of the third electrode is smaller than the aspect ratio of the first electrode (2).

15. A battery string, characterized in that: include: A plurality of solar cells as claimed in any one of claims 1 to 14; as well as At least one interconnection bar (7) electrically connects at least two of the solar cells and its projection on the cell does not overlap with the busbar (6).

16. A photovoltaic module, characterized in that: Comprising at least one battery string as claimed in claim 15.

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