Solar cell and photovoltaic module

Abstract

The utility model provides a solar cell and a photovoltaic assembly. The solar cell comprises a silicon substrate; the plurality of collector electrodes are arranged on one surface of the silicon substrate, are alternately arranged at intervals with different polarities in a first direction, and extend along a second direction vertical to the first direction; wherein each current collection electrode is provided with a first disconnection part, and the first length of the first disconnection part in the second direction is 0.6 mm-3 mm.

Description

Technical Field

[0001] At least one embodiment of this utility model relates to the field of solar cell technology, and more particularly to a solar cell and a photovoltaic module. Background Technology

[0002] Solar power generation is a technology that uses the photovoltaic effect of semiconductors to directly convert light energy into electrical energy. Its core unit is the photovoltaic module. During the production of photovoltaic modules, multiple cells are electrically connected by several solder ribbons. The solder ribbons are electrically connected to the same-polarity sub-buses (collector electrodes) on the cells and electrically isolated from the opposite-polarity sub-buses; otherwise, the solder ribbons would conduct with the opposite-polarity sub-buses, causing a short circuit. To electrically isolate the opposite-polarity sub-buses from the solder ribbons, an electrically insulating adhesive (usually green adhesive) is printed on the portion of the opposite-polarity sub-buses near the solder ribbons.

[0003] However, printing green adhesive can cause the sub-busbar pads to rise. This green adhesive can cause stress damage due to the difference in the coefficient of thermal expansion between the green adhesive and the silicon wafer. On the other hand, it also increases the risk of microcracks and fragmentation of photovoltaic modules during welding. Utility Model Content

[0004] In view of this, in order to at least partially solve the aforementioned technical problems, the present invention provides a solar cell and a photovoltaic module.

[0005] To achieve the above objectives, the technical solution of this utility model is as follows:

[0006] According to one aspect of the present invention, a solar cell is provided, comprising:

[0007] Silicon substrate;

[0008] Multiple current collector electrodes are disposed on a surface of a silicon substrate, and are arranged alternately with different polarities in a first direction, and extend along a second direction perpendicular to the first direction;

[0009] Each current collector electrode has a first disconnection portion, and the first length of the first disconnection portion along the second direction is 0.6 mm to 3 mm.

[0010] In some embodiments, the solar cell further includes: a plurality of first bus electrodes disposed on the aforementioned surface, arranged alternately at different polarities in a second direction and extending along a first direction, each first bus electrode being electrically connected to a current collector electrode having the same polarity and electrically isolated from current collector electrodes having different polarities; wherein each first bus electrode passes through a first disconnection portion of a current collector electrode having different polarities and is electrically connected to a current collector electrode having the same polarity, and the ratio of the first length of the first disconnection portion along the second direction to the width of the first bus electrode along the second direction is 1-150.

[0011] In some embodiments, the solar cell further includes: at least two junctions disposed on the surface, spaced apart along a first direction, and electrically connected to a first bus electrode of the same polarity; wherein a current collector electrode of opposite polarity to the junction has a second disconnection in a second direction, the junction passes through the second disconnection and is electrically connected to the first bus electrode of the same polarity as the junction, and the second length of the second disconnection along the second direction is 0.6 mm to 3 mm.

[0012] In some embodiments, the aforementioned surface of the silicon substrate has two opposing first sides extending along a first direction and two opposing second sides extending along a second direction;

[0013] Solar cells also include:

[0014] The second bus electrode extends along the first direction and is located between the first side and the first bus electrode located at the edge, and the polarity of the second bus electrode is opposite to that of the first bus electrode located at the edge.

[0015] The third bus electrode extends along the second direction and is close to the second side.

[0016] The second bus electrode is electrically connected to the adjacent first bus electrode of the same polarity via the third bus electrode.

[0017] In some embodiments, the ratio of the width of the second bus electrode along the second direction to the width of the third bus electrode along the first direction is 1 to 2.

[0018] In some embodiments, the width of the third bus electrode along the first direction is 0.1 mm to 0.6 mm.

[0019] In some embodiments, the collector electrode includes a first collector electrode and a second collector electrode, one of which is located in the N-type region, and the other is located in the P-type region.

[0020] The second bus electrode includes a first type of second bus electrode and a second type of second bus electrode. The first type of second bus electrode is electrically connected to the collector electrode located in the P-type region, and the second type of second bus electrode is electrically connected to the collector electrode located in the N-type region.

[0021] The ratio of the width of the first type second bus electrode along the second direction to the width of the second type second bus electrode along the second direction is 0.33-60.

[0022] In some embodiments, the width of the first type second bus electrode along the second direction is 0.1 mm to 0.6 mm, and the width of the second type second bus electrode along the second direction is 0.01 mm to 0.3 mm.

[0023] In some embodiments, the silicon substrate further includes at least one chamfer connecting adjacent first and second sides, and the solar cell further includes an electrical connection line located at the chamfer location, the electrical connection line being configured to electrically connect a second bus electrode and a third bus electrode.

[0024] In some embodiments, the electrical connection wire is rectangular in shape, with a length of 0.5mm to 1.5mm and a width of 0.1mm to 0.6mm.

[0025] In some embodiments, the shape of the electrical connection wire is a trapezoid with a cross-section that gradually increases from the end near the chamfer to the end away from the chamfer, the length of the first base of the trapezoid is 0.015mm to 0.3mm, and the length of the second base of the trapezoid is 0.01mm to 0.3mm.

[0026] In some embodiments, the electrical connection wire is an arc with a radial width of 0.01 mm to 0.6 mm.

[0027] In some embodiments, the solar cell further includes:

[0028] At least one fourth bus electrode extends along a second direction and is located between two second sides. The fourth bus electrode is electrically connected to a second bus electrode of the same polarity and a first bus electrode of the same polarity, and is electrically isolated from a first bus electrode of a different polarity.

[0029] The first bus electrode, which has the opposite polarity to the fourth bus electrode, has a third disconnection portion, and the fourth bus electrode passes through the third disconnection portion to be electrically connected to the first bus electrode, which has the same polarity.

[0030] In some embodiments, the fourth bus electrode includes a first type fourth bus electrode and a second type fourth bus electrode, wherein one of the first type fourth bus electrode and the second type fourth bus electrode is located in the N-type region, and the other of the first type fourth bus electrode and the second type fourth bus electrode is located in the P-type region.

[0031] The width of the fourth bus electrode located in the P-type region along the first direction is 0.1mm to 0.6mm, and the width of the fourth bus electrode located in the N-type region along the first direction is 0.01mm to 0.3mm.

[0032] In some embodiments, the length of the third disconnection portion along the first direction is less than the distance along the first direction between two adjacent collector electrodes having opposite polarities to the fourth bus electrode.

[0033] According to another embodiment of the present invention, a photovoltaic module is provided, including the solar cell described above.

[0034] According to the solar cell provided in the above embodiments of the present invention, by increasing the first length of the first disconnection portion along the second direction, the risk of short circuit between the solder ribbon and the opposite current collector electrode can be reduced during the process of electrically connecting multiple cells using solder ribbon.

[0035] According to the above embodiments of the present invention, the solar cell can improve the contact performance between the solder ribbon and the joint and the first bus electrode by reducing the amount of electrical insulating adhesive or eliminating the need to cover the current collector electrode with electrical insulating adhesive, and by allowing direct contact between the solder ribbon and the joint and the first bus electrode between two adjacent joints. Furthermore, by reducing the amount of electrical insulating adhesive or eliminating the need to use electrical insulating adhesive, the manufacturing process of the photovoltaic module can be simplified, and the risk of microcracks in the photovoltaic module can be reduced. Attached Figure Description

[0036] To more clearly illustrate the technical solutions of the embodiments of this utility model, the accompanying drawings of the embodiments will be briefly introduced below. Obviously, the drawings described below only involve some embodiments of this utility model, and are not intended to limit this utility model.

[0037] Figure 1 A partial top view of a solar cell provided in an embodiment of this utility model;

[0038] Figure 2 Another partial top view of the solar cell provided in an embodiment of this utility model;

[0039] Figure 3 Another partial top view schematic diagram of the solar cell provided in an embodiment of the present utility model;

[0040] Figure 4 A partial top view of a solar cell provided in another embodiment of the present invention;

[0041] Figure 5 This is another partial top view of a solar cell provided in another embodiment of the present invention;

[0042] Figure 6 A partial top view of a solar cell provided in another embodiment of the present invention;

[0043] Figure 7 Another partial top view of a solar cell provided in yet another embodiment of the present invention;

[0044] Figure 8 This is a partial top view schematic diagram of a solar cell in related technologies; and

[0045] Figure 9 This is a partial top view of a solar cell provided in an embodiment of the present invention.

[0046] Explanation of reference numerals in the attached figures:

[0047] 1-Collector;

[0048] 11-First collector electrode;

[0049] 12 - Second collector electrode;

[0050] 2-First bus electrode;

[0051] 21-First type first bus electrode;

[0052] 22-Second type first bus electrode;

[0053] 3-Joint;

[0054] 31-First joint;

[0055] 32 - Second joint;

[0056] 4-First side;

[0057] 5-Second side;

[0058] 6-Second bus electrode;

[0059] 61-Type 1 Second Bus Electrode;

[0060] 62-Second type, second bus electrode;

[0061] 7-Third bus electrode;

[0062] 71-Type 1 Third Bus Electrode;

[0063] 72-Second type third bus electrode;

[0064] 8-Fourth bus electrode;

[0065] 81-Type 1 Fourth Bus Electrode;

[0066] 82-Type II, Fourth Bus Electrode;

[0067] 9-Electrical connection wire;

[0068] 91-First electrical connection line;

[0069] 92-Second electrical connection wire;

[0070] 10-Electrically insulating adhesive. Detailed Implementation

[0071] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to specific embodiments and accompanying drawings.

[0072] In the following detailed description, numerous specific details are set forth for ease of explanation to provide a comprehensive understanding of the embodiments of the present invention. However, it will be apparent that one or more embodiments may be practiced without these specific details. Furthermore, descriptions of well-known structures and techniques are omitted in the following description to avoid unnecessarily obscuring the concepts of the present invention.

[0073] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of the invention. The term "comprising" as used herein indicates the presence of features, steps, or operations, but does not exclude the presence or addition of one or more other features.

[0074] When using expressions such as "at least one of A, B, and C," the expression should generally be interpreted in accordance with the meaning commonly understood by a person skilled in the art (e.g., "a system having at least one of A, B, and C" should include, but is not limited to, systems having A alone, having B alone, having C alone, having A and B, having A and C, having B and C, and / or having A, B, and C, etc.). When using expressions such as "at least one of A, B, or C," the expression should generally be interpreted in accordance with the meaning commonly understood by a person skilled in the art (e.g., "a system having at least one of A, B, or C" should include, but is not limited to, systems having A alone, having B alone, having C alone, having A and B, having A and C, having B and C, and / or having A, B, and C, etc.).

[0075] In this invention, the relative position between two components (e.g., a membrane or region), referred to as "above," "on," or "above," can mean that the two components are in direct contact or that they are not in direct contact. Similarly, the relative position between two components, referred to as "below," "under," or "below," can mean that the two components are in direct contact or that they are not in direct contact. For example, when one component (e.g., a membrane or region) is referred to as "on another component," it can be directly on the other component, or there may be other components between them. On the other hand, when a component is referred to as "directly on another component," there are no components between them. Furthermore, when one component is referred to as "on another component," the two have a vertical relationship in the planar view, and this component can be above or below the other component, thus this vertical relationship depends on the orientation of the device.

[0076] To electrically isolate the heterogeneous sub-gate from the solder strip, an electrically insulating adhesive (usually green adhesive) is typically printed on the portion of the heterogeneous sub-gate near the solder strip.

[0077] Printing green adhesive can cause the sub-gate pad to rise by 0.01-0.06mm. This green adhesive can cause stress damage due to the difference in expansion coefficient between the green adhesive and the silicon wafer. On the other hand, it also increases the risk of microcracks and fragmentation of photovoltaic modules during welding.

[0078] In view of this, the present invention provides a solar cell and a photovoltaic module to solve the technical problems existing in the manufacturing process of photovoltaic modules, such as the difficulty in manufacturing control and the risk of microcracks and fragmentation in the manufactured photovoltaic modules.

[0079] According to an exemplary embodiment of the present invention, the present invention provides a solar cell, comprising:

[0080] Silicon substrate;

[0081] Multiple current collector electrodes are disposed on a surface of a silicon substrate, and are arranged alternately with different polarities in a first direction, and extend along a second direction perpendicular to the first direction;

[0082] Each current collector electrode has a first disconnection portion, and the first length of the first disconnection portion along the second direction is 0.6 mm to 3 mm.

[0083] In some embodiments, the first length of the first break portion along the second direction is 0.6mm to 3mm, for example, it can be 0.6mm, 1.0mm, 2.0mm, 2.5mm, or 3.0mm, but is not limited to the values ​​mentioned.

[0084] According to embodiments of the present invention, the solar cell is, for example, a back-contact solar cell. The back-contact solar cell includes, but is not limited to, tunneling oxide passivated contact back contact (TBC), all back contact (ABC), heterojunction back contact (HBC), polycrystalline silicon on oxide interdigitated back contact (POLO-IBC), dopant-free heterojunction interdigitated back contact (DFHJ-IBC), and any one of the following: a hybrid BC formed by the mutual hybridization of different passivation contact structures.

[0085] According to an embodiment of this invention, the aforementioned surface of the silicon substrate is the back surface of a back-contact solar cell. Different doped regions on the back surface of the back-contact solar cell are alternately distributed, i.e., the back surface includes a first polarity carrier collection region and a second polarity carrier collection region with opposite polarity to the first polarity carrier collection region, alternately distributed along a first direction; correspondingly, collector electrodes (also called sub-gates) arranged on different doped regions are also alternately distributed and have different conductivity types.

[0086] According to embodiments of this invention, the silicon substrate can be N-type or P-type.

[0087] According to an embodiment of the present invention, one of the first polar carrier collection region and the second polar carrier collection region is N-type, and the other of the first polar carrier collection region and the second polar carrier collection region is P-type; for example, the first polar carrier collection region is N-type and the second polar carrier collection region is P-type; or, the first polar carrier collection region is P-type and the second polar carrier collection region is N-type.

[0088] In an embodiment of this utility model, the current collector 1 includes a first current collector 11 and a second current collector 12 with the opposite polarity to the first current collector 11. The first current collector 11 and the second current collector 12 are alternately arranged along a first direction and extend along a second direction perpendicular to the first direction.

[0089] The first collector electrode 11 is located in the first polarity carrier collection region, and the second collector electrode 12 is located in the second polarity carrier collection region. That is, one of the first collector electrode 11 and the second collector electrode 12 is located in the N-type region, and the other of the first collector electrode 11 and the second collector electrode 12 is located in the P-type region. The ratio of the width of the collector electrode located in the P-type region along the first direction to the width of the collector electrode located in the N-type region along the first direction is 1-10.

[0090] In some embodiments, the width of the collector electrode located in the P-type region along the first direction is 0.01 mm to 0.6 mm, for example, 0.01 mm, 0.03 mm, 0.06 mm, 0.09 mm, 0.1 mm, 0.2 mm, 0.4 mm, 0.5 mm, or 0.6 mm, but is not limited to the values ​​listed.

[0091] In some embodiments, the width of the collector electrode located in the N-type region along the first direction is 0.01 mm to 0.05 mm, for example, 0.01 mm, 0.02 mm, 0.03 mm, 0.04 mm, or 0.05 mm, but is not limited to the values ​​listed.

[0092] According to an embodiment of the present invention, by increasing the first length of the first disconnection portion along the second direction, the risk of short circuit between the solder ribbon and the opposite current collector electrode can be reduced during the process of electrically connecting multiple battery cells using solder ribbon.

[0093] In some embodiments, the solar cell has a main grid structure. That is, in order to collect the current collected by the current collector electrode (also known as the sub-grid), some back contact cells will also have a busbar (also known as the main grid) that intersects with the current collector electrode. In addition to being connected to the sub-grid of the same polarity, the main grid also needs to cross the sub-grid of different polarities. Therefore, the main grid needs to be electrically isolated from the sub-grid of different polarities.

[0094] Figure 1 This is a partial top view of a solar cell provided in an embodiment of the present invention.

[0095] In some embodiments, reference Figure 1 As shown, the solar cell also includes: a plurality of first bus electrodes 2 disposed on the aforementioned surface of the silicon substrate, arranged alternately at different polarities in a second direction and extending along a first direction, each first bus electrode 2 being electrically connected to a current collector 1 having the same polarity and electrically isolated from a current collector 1 having different polarities.

[0096] Each first bus electrode 2 passes through a first disconnection portion of a current collector 1 with different polarities and is electrically connected to a current collector 1 with the same polarity. The ratio of the first length of the first disconnection portion along the second direction to the width of the first bus electrode 2 along the second direction is any value between 1 and 150.

[0097] In some embodiments, the ratio of the first length of the first disconnection portion along the second direction to the width of the first bus electrode 2 along the second direction is, for example, 1, 10, 20, 50, 100, or 150, but is not limited to the values ​​listed.

[0098] In an embodiment of this utility model, the first bus electrode 2 includes a first type first bus electrode 21 and a second type bus electrode 22 with the opposite polarity to the first type first bus electrode 21. The first type first bus electrode 21 and the second type bus electrode 22 are alternately arranged along the second direction and extend along the first direction.

[0099] According to an embodiment of the present invention, the first collector electrode 11 is located in the first polarity carrier collection region and is adapted to collect the current in the first polarity carrier collection region. The second collector electrode 12 is located in the second polarity carrier collection region and is adapted to collect the current in the second polarity carrier collection region. The first bus electrode (main gate) is electrically connected to the collector electrode (secondary gate) of the same polarity to collect the current collected by the collector electrode (secondary gate) of the same polarity.

[0100] The first type of first bus electrode 21 passes through the second collector electrode 12 with opposite polarity and is electrically connected to the first collector electrode 11 with the same polarity, and the second type of first bus electrode 22 passes through the first collector electrode 11 with opposite polarity and is electrically connected to the second collector electrode 12 with the same polarity.

[0101] In an embodiment of this utility model, the first collector electrode 11 is discontinuous in the second direction and forms a first break portion. The second type first bus electrode 22 passes through the first break portion of the first collector electrode 11 and is electrically connected to the second collector electrode 12. The ratio of the first length of the first break portion along the second direction (i.e., the break spacing of the heterogeneous sub-gate through which the main gate passes) to the width of the second type first bus electrode 22 along the second direction is 1-150.

[0102] In an embodiment of the present invention, the second collector electrode 12 is discontinuous in the second direction and forms a first break portion at a discontinuous position. The first type first bus electrode 21 passes through the first break portion of the second collector electrode 12 and is electrically connected to the first collector electrode 11. The ratio of the first length of the first break portion along the second direction to the width of the first type first bus electrode 21 along the second direction is 1-150.

[0103] In some embodiments, reference Figure 1 As shown, the solar cell further includes: at least two junction portions 3, disposed on the aforementioned surface of the silicon substrate, spaced apart along a first direction, and electrically connected to a first bus electrode 2 of the same polarity;

[0104] The current collector 1, which has a polarity opposite to that of the junction 3, has a second disconnection in the second direction. The junction 3 passes through the second disconnection and is electrically connected to the first bus electrode 2, which has the same polarity as the junction 3. The second length of the second disconnection in the second direction is 0.6 mm to 3 mm.

[0105] According to an embodiment of the present invention, by increasing the first length of the first disconnection portion along the second direction, the risk of a short circuit between the first bus electrode and the opposite current collector electrode can be reduced, as well as the risk of a short circuit between the solder ribbon and the opposite current collector electrode during the soldering process of the solar cell using solder ribbon.

[0106] According to embodiments of this utility model, by reducing or eliminating the need for electrical insulating adhesive (usually green adhesive) to electrically insulate the end of the first disconnected portion of the heterogeneous current collector electrode, the solder ribbon directly contacts the joint (e.g., solder pad) and the first bus electrode between two adjacent joints, thereby increasing the contact performance between the solder ribbon and the joint and the first bus electrode; and by reducing or eliminating the need for electrical insulating adhesive, the manufacturing process of photovoltaic modules can be simplified, and the risk of microcracks in photovoltaic modules can be reduced.

[0107] It should be noted that if the first length of the first disconnection part along the second direction is too large, it will be more difficult to collect charge carriers near the first busbar electrode region. The first length is set to 0.6~3mm. This setting maximizes the collection of charge carriers near the area near the solder strip while achieving electrical isolation between the solder strip and the opposite-shaped collector electrode (sub-gate).

[0108] The current collector electrode, the first bus electrode, and the junction located in the P-type region are formed by printing with aluminum paste, silver-aluminum paste, silver paste, copper-clad silver paste, or copper paste; the current collector electrode, the first bus electrode, and the junction located in the N-type region are formed by printing with silver paste, copper-clad silver paste, or copper paste.

[0109] Figure 2 This is another partial top view of a solar cell provided in an embodiment of the present invention.

[0110] Figure 3 This is another partial top view of the solar cell provided in an embodiment of the present invention.

[0111] In some embodiments, reference Figure 2 , Figure 3 As shown, the aforementioned surface of the silicon substrate has two opposing first sides 4 extending along a first direction and two opposing second sides 5 extending along a second direction.

[0112] According to an embodiment of the present invention, the first bus electrode 2 is located near the first side 4, suitable for collecting charge carriers near the first side 4, and transmitting the collected current to the adjacent joint 3 through an electrical connection line. In this embodiment, solder strips are welded to at least two joints 3 distributed along the first direction, and this implementation inevitably requires printing electrical insulating adhesive (usually green adhesive) on the joints 3.

[0113] Figure 4 This is a partial top view of a solar cell provided in another embodiment of the present invention.

[0114] Figure 5 This is another partial top view of a solar cell provided in another embodiment of the present invention.

[0115] According to an embodiment of the present invention, referring to Figure 4 , Figure 5 As shown, the aforementioned surface of the silicon substrate has two opposing first sides 4 extending along a first direction and two opposing second sides 5 extending along a second direction.

[0116] refer to Figure 4 , Figure 5As shown, the aforementioned solar cell further includes: a second bus electrode 6, extending along a first direction and located between the first side 4 and the first bus electrode 2 located at the edge, wherein the polarity of the second bus electrode 6 is opposite to that of the first bus electrode 2 located at the edge; and a third bus electrode 7, extending along a second direction and close to the second side 5, located between the second side 5 and the outermost collector electrode 1, wherein the second bus electrode 6 is electrically connected to the adjacent first bus electrode 2 of the same polarity through the third bus electrode 7.

[0117] According to an embodiment of the present invention, the second bus electrode 6 is adapted to collect current located near the first side 4 of the silicon substrate and transmit the collected current to the adjacent first bus electrode 2 of the same polarity.

[0118] In some embodiments, the ratio of the width of the second bus electrode 6 along the second direction to the width of the third bus electrode 7 along the first direction is 1 to 2. Since the length of the second bus electrode 6 is greater than the length of the third bus electrode 7, setting the width of the second bus electrode 6 to be slightly larger can reduce the risk of the second bus electrode 6 breaking to some extent.

[0119] In some embodiments, the width of the third bus electrode 7 along the first direction is 0.1mm to 0.6mm. This configuration can effectively transmit the current collected by the second bus electrode 6. The width of the third bus electrode 7 can be, for example, 0.1mm, 0.2mm, 0.3mm, 0.5mm, or 0.6mm, but is not limited to these values. If the width of the third bus electrode 7 along the first direction is too small, the third bus electrode 7 will have difficulty effectively collecting current. If the width of the third bus electrode 7 along the first direction is too large, there is a risk of current imbalance.

[0120] According to an embodiment of the present invention, by setting the second bus electrode 6 and the third bus electrode 7, the current located near the edge of the silicon substrate can be effectively collected, and there is no need to print electrical insulating adhesive (usually green adhesive) at the edge of the silicon substrate.

[0121] In some embodiments, the second bus electrode 6 includes a first type second bus electrode 61 and a second type second bus electrode 62, wherein the first type second bus electrode 61 is electrically connected to the collector electrode located in the P-type region, and the second type second bus electrode 62 is electrically connected to the collector electrode located in the N-type region.

[0122] The ratio of the width of the first type second bus electrode 61 along the second direction to the width of the second type second bus electrode 62 along the second direction is 1 to 5. Since the contact performance of the P region is slightly weaker than that of the N region, setting the bus electrode of the P region wider can increase the contact area between the electrode and the P region, thus balancing the difference in contact performance between the P region and the N region.

[0123] In some embodiments, the width of the first type second bus electrode 61 along the second direction is 0.1mm to 0.6mm, for example, it can be 0.1mm, 0.2mm, 0.3mm, 0.5mm, or 0.6mm, but is not limited to the values ​​mentioned above.

[0124] In some embodiments, the width of the second type second bus electrode 62 along the second direction is 0.01mm to 0.3mm, for example, it can be 0.01mm, 0.05mm, 0.1mm, 0.2mm, or 0.3mm, but is not limited to the values ​​mentioned above.

[0125] In some embodiments, the first bus electrode and the second bus electrode may be a junction and an end wire connected to the junction, with the end wire connected to the side of the junction near the edge of the battery cell along a first direction.

[0126] In some embodiments, the silicon substrate further includes at least one chamfer connecting adjacent first and second sides, and the solar cell further includes an electrical connection line 9 located at the chamfer position, the electrical connection line 9 being configured to electrically connect a second bus electrode 6 and a third bus electrode 7.

[0127] In some embodiments, the electrical connection wire 9 can be rectangular, with a length of 0.5~1.5mm and a width of 0.1~0.6mm.

[0128] In some embodiments, the electrical connection wire 9 is a trapezoid with a cross-section that gradually increases from the end near the chamfer to the end away from the chamfer, the length of the first base of the trapezoid is 0.015mm to 0.3mm, and the length of the second base of the trapezoid is 0.01mm to 0.3mm.

[0129] In some embodiments, the chamfer can be, for example, an arc shape, and the electrical connection line 9 can be an arc with the same center as the silicon wafer chamfer, with a radial width of 0.01mm to 0.6mm, for example, 0.01mm, 0.1mm, 0.2mm, 0.5mm, or 0.6mm, but not limited to the values ​​mentioned.

[0130] Figure 6 This is a partial top view of a solar cell provided in another embodiment of the present invention.

[0131] Figure 7 This is another partial top view of a solar cell provided in yet another embodiment of the present invention.

[0132] In some embodiments, the solar cell further includes: at least one fourth bus electrode 8 extending along a second direction and located between two second sides, the fourth bus electrode 8 being electrically connected to a second bus electrode 6 of the same polarity and a first bus electrode 2 of the same polarity, and electrically isolated from a first bus electrode 2 of a different polarity; wherein the first bus electrode 2 having a polarity opposite to that of the fourth bus electrode 8 has a third disconnection portion, and the fourth bus electrode 8 passes through the third disconnection portion to be electrically connected to the first bus electrode 2 having the same polarity.

[0133] According to an embodiment of the present invention, the fourth bus electrode can transmit the current collected by the second bus electrode to the adjacent first bus electrode of the same polarity. Since the collection capacity of the third bus electrode is limited, by setting at least one fourth bus electrode, the current transmitted by the third bus electrode can be dispersed, avoiding the risk of component overheating due to current imbalance caused by the excessive current of the third bus electrode, which would reduce the component life.

[0134] In some embodiments, the fourth bus electrode 8 includes a first type fourth bus electrode 81 and a second type fourth bus electrode 82, wherein one of the first type fourth bus electrode 81 and the second type fourth bus electrode 82 is located in the N-type region, and the other of the first type fourth bus electrode 81 and the second type fourth bus electrode 82 is located in the P-type region.

[0135] The width of the fourth bus electrode located in the P-type region along the first direction is 0.01-0.08 mm, and the width of the fourth bus electrode located in the N-type region along the first direction is 0.01-0.08 mm, for example, it can be 0.01 mm, 0.02 mm, 0.03 mm, 0.06 mm, or 0.08 mm, but is not limited to the values ​​mentioned.

[0136] According to an embodiment of the present invention, referring to Figure 6 As shown, the first type fourth bus electrode 81 has the same electrical properties as the first type first bus electrode 21. The second type first bus electrode 22 is discontinuous in the first direction and forms a third break at a discontinuous position. The first type fourth bus electrode 81 passes through the third break of the second type first bus electrode 22 and is electrically connected to the first type first bus electrode 21.

[0137] According to an embodiment of the present invention, referring to Figure 7 As shown, the second type fourth bus electrode 82 has the same electrical properties as the second type first bus electrode 22. The first type first bus electrode 21 is discontinuous in the first direction and forms a third break at a discontinuous position. The second type fourth bus electrode 82 passes through the third break of the first type first bus electrode 21 and is electrically connected to the second type first bus electrode 22.

[0138] In some embodiments, the length of the third disconnection portion along the first direction is less than the distance along the first direction between two adjacent collector electrodes 1 that have opposite polarities to the fourth bus electrode 8.

[0139] According to an embodiment of the present invention, the length of the third break portion along the first direction is 0.01mm to 1.5mm, for example, 0.01mm, 0.1mm, 0.5mm, 1.0mm, 1.5mm, but is not limited to the values ​​mentioned.

[0140] According to an embodiment of the present invention, the number of fourth bus electrodes 8 can be set as needed, and the number of fourth bus electrodes 8 can be one or more.

[0141] In some embodiments, the solar cell has a gridless (OBB) structure, meaning it only has current collector electrodes (also called sub-grids) with junctions on them, but no current collector electrodes (also called main grids) to collect current from the current collector electrodes. Alternatively, a portion of the first current collector electrode may be located near the edge of the cell. During the electrical connection of multiple solar cells to form a photovoltaic module, current is collected directly from the current collector electrodes using solder ribbons (typically extending in a direction perpendicular to the direction of the current collector electrodes). By shortening or even eliminating the current collector electrodes, not only is the use of electrode paste reduced, but the shading of the grid lines on the cell surface is also reduced, improving the utilization rate of light illuminating the cell surface.

[0142] Figure 8 This is a partial top view of a solar cell in related technologies.

[0143] refer to Figure 8 As shown, a solder ribbon (not shown) is used to directly collect the current from the current collector electrode. The solder ribbon is electrically connected to the current collector electrode of the same polarity and electrically isolated from the current collector electrode of the opposite polarity. Therefore, it is necessary to print an electrically insulating adhesive 10 (usually green adhesive) on the current collector electrode with the opposite polarity to the solder ribbon to electrically isolate the solder ribbon from the current collector electrode of the opposite polarity. Furthermore, conductive adhesive (usually gray adhesive) is printed on the joint 3 to enhance the welding effect between the solder ribbon and the joint 3.

[0144] In the process of electrically connecting multiple solar cells to form a photovoltaic module, printing electrical insulating adhesive and / or conductive adhesive will increase the process cost, and the shrinkage of electrical insulating adhesive and / or conductive adhesive will generate stress, leading to the risk of fragmentation and microcracks.

[0145] Figure 9 This is a partial top view of a solar cell provided in an embodiment of the present invention.

[0146] refer to Figure 9As shown, multiple current collectors 1 are arranged alternately with different polarities in a first direction and extend along a second direction perpendicular to the first direction. Each current collector 1 includes a first current collector 11 and a second current collector 12. The junction 3 includes a first junction 31 located on the first current collector 11 and a second junction 32 located on the second current collector 12. Each current collector 1 has a discontinuous first break along the second direction, with a first length of 0.3 mm to 3 mm along the second direction. A solder strip passes through the first break of the opposite-polarity current collector and electrically connects to the current collector and junction of the same polarity.

[0147] It should be noted that the joint 3 can be provided with joints of the same size along the first direction as shown in the figure, or joints 3 of different sizes can be provided according to the welding process requirements and cost considerations. The distribution pattern of joints 3 of different sizes can be that, in the first direction, the size of the joint 3 gradually decreases from the edge of the battery cell towards the middle.

[0148] In some embodiments, the first length is preferably 0.5mm to 1mm. It should be noted that the larger the first length, the better the electrical isolation effect between the solder strip and the dissimilar current collector electrode, but if the first length is too large, the current collection effect will be poor. The first length is preferably 0.5mm to 1mm, so that electrical isolation between the solder strip and the dissimilar current collector electrode can be achieved while ensuring the electrode collection efficiency.

[0149] According to embodiments of this invention, by forming a first disconnection, electrical isolation between the solder ribbon and the dissimilar current collector electrode can be achieved without forming an electrically insulating adhesive on the current collector electrode. Furthermore, eliminating the electrically insulating adhesive avoids the height difference caused by its presence, allowing the solder ribbon to directly contact the electrode, thus eliminating the need for additional conductive adhesive printing. This simplifies the manufacturing process of photovoltaic modules, reduces process costs, and lowers the risk of fragmentation and microcracks caused by the use of electrically insulating and / or conductive adhesives.

[0150] According to another embodiment of the present invention, a photovoltaic module is provided, including the solar cell described above.

[0151] The use of ordinal numbers such as "first," "second," "third," etc., in the specification and claims to modify the corresponding elements does not imply that the element has any ordinal number, nor does it represent the order of one element with another element, or the order of manufacturing methods. The use of these ordinal numbers is only to enable a named element to be clearly distinguished from another element with the same name.

[0152] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of this utility model. It should be understood that the above description is only a specific embodiment of this utility model and is not intended to limit this utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A solar cell, characterized in that, include: Silicon substrate; Multiple current collector electrodes (1) are disposed on one surface of the silicon substrate, and are arranged alternately with different polarities in a first direction, and extend along a second direction perpendicular to the first direction; Each of the current collector electrodes (1) has a first break portion, and the first break portion has a first length of 0.6 mm to 3 mm along the second direction.

2. The solar cell according to claim 1, characterized in that, Also includes: Multiple first bus electrodes (2) are disposed on the surface, arranged alternately with different polarities in the second direction, and extending along the first direction. Each first bus electrode (2) is electrically connected to a collector electrode (1) with the same polarity and electrically isolated from a collector electrode (1) with different polarities. Each of the first busbars (2) passes through a first disconnection of a current collector (1) with different polarities and is electrically connected to a current collector (1) with the same polarity. The ratio of the first length of the first disconnection along the second direction to the width of the first busbar (2) along the second direction is 1-150.

3. The solar cell according to claim 2, characterized in that, Also includes: At least two joints (3) are disposed on the surface, spaced apart along the first direction, and electrically connected to a first bus electrode (2) of the same polarity; The current collector (1) with the opposite polarity to the junction (3) has a second disconnection in the second direction. The junction (3) passes through the second disconnection and is electrically connected to the first bus electrode (2) with the same polarity as the junction (3). The second length of the second disconnection in the second direction is 0.6 mm to 3 mm.

4. The solar cell according to any one of claims 2-3, characterized in that, The surface of the silicon substrate has two opposing first sides (4) extending along the first direction and two opposing second sides (5) extending along the second direction. The solar cell also includes: The second bus electrode (6) extends along the first direction and is located between the first side and the first bus electrode (2) located at the edge, the polarity of the second bus electrode (6) being opposite to that of the first bus electrode (2) located at the edge; The third bus electrode (7) extends along the second direction and is close to the second side. The second bus electrode (6) is electrically connected to the adjacent first bus electrode (2) of the same polarity through the third bus electrode (7).

5. The solar cell according to claim 4, characterized in that, The ratio of the width of the second bus electrode (6) along the second direction to the width of the third bus electrode (7) along the first direction is 1 to 2.

6. The solar cell according to claim 4, characterized in that, The width of the third bus electrode (7) along the first direction is 0.1 mm to 0.6 mm.

7. The solar cell according to claim 4, characterized in that, The current collector (1) includes a first current collector (11) and a second current collector (12), one of the first current collector (11) and the second current collector (12) being located in the N-type region, and the other of the first current collector (11) and the second current collector (12) being located in the P-type region. The second bus electrode (6) includes a first type second bus electrode (61) and a second type second bus electrode (62). The first type second bus electrode (61) is electrically connected to the collector electrode located in the P-type region, and the second type second bus electrode (62) is electrically connected to the collector electrode located in the N-type region. The ratio of the width of the first type second bus electrode (61) along the second direction to the width of the second type second bus electrode (62) along the second direction is 0.33-60.

8. The solar cell according to claim 7, characterized in that, The width of the first type of second bus electrode (61) along the second direction is 0.1 mm to 0.6 mm. The width of the second type of second bus electrode (62) along the second direction is 0.01 mm to 0.3 mm.

9. The solar cell according to claim 4, characterized in that, The silicon substrate also includes at least one chamfer connecting adjacent first and second sides. The solar cell also includes: Electrical connection line (9), located at the chamfered position, is configured to electrically connect the second bus electrode (6) and the third bus electrode (7).

10. The solar cell according to claim 9, characterized in that, The electrical connection wire (9) is rectangular in shape, with a length of 0.5mm to 1.5mm and a width of 0.1mm to 0.6mm.

11. The solar cell according to claim 9, characterized in that, The electrical connection wire (9) is a trapezoid with a cross-section that gradually increases from the end near the chamfer to the end away from the chamfer. The length of the first base of the trapezoid is 0.015mm~0.3mm, and the length of the second base is 0.01mm~0.3mm.

12. The solar cell according to claim 9, characterized in that, The electrical connection line (9) is an arc, and the width along the radial direction of the arc is 0.01mm~0.6mm.

13. The solar cell according to claim 4, characterized in that, Also includes: At least one fourth bus electrode (8) extends along the second direction and is located between two second sides. The fourth bus electrode (8) is electrically connected to the second bus electrode (6) of the same polarity and the first bus electrode (2) of the same polarity, and is electrically isolated from the first bus electrode (2) of different polarity. The first bus electrode (2), which has the opposite polarity to the fourth bus electrode (8), has a third disconnection portion, through which the fourth bus electrode (8) is electrically connected to the first bus electrode (2), which has the same polarity.

14. The solar cell according to claim 13, characterized in that, The fourth bus electrode (8) includes a first type fourth bus electrode (81) and a second type fourth bus electrode (82), wherein one of the first type fourth bus electrode (81) and the second type fourth bus electrode (82) is located in the N-type region, and the other of the first type fourth bus electrode (81) and the second type fourth bus electrode (82) is located in the P-type region; The width of the fourth bus electrode located in the P-type region along the first direction is 0.1 mm to 0.6 mm, and the width of the fourth bus electrode located in the N-type region along the first direction is 0.01 mm to 0.3 mm.

15. The solar cell according to claim 13, characterized in that, The length of the third disconnection along the first direction is less than the distance between two adjacent collector electrodes (1) with opposite polarity to the fourth bus electrode (8) along the first direction.

16. A photovoltaic module, characterized in that, Includes the solar cell as described in any one of claims 1 to 15.

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