Solar cell and photovoltaic module

Abstract

The present application relates to solar cells and photovoltaic modules. The solar cell includes a cell substrate and an electrode structure located on the cell substrate, the electrode structure includes a plurality of current collecting grid lines, at least one first main junction, a plurality of first auxiliary junctions and a first overlap line, the plurality of current collecting grid lines includes a first current collecting grid line and a second current collecting grid line, and forms a first current collecting grid line area and a second current collecting grid line area, the at least one first main junction is located in the first current collecting grid line area and is electrically connected with at least part of the first current collecting grid lines in the first current collecting grid line area, the plurality of first auxiliary junctions are located in the second current collecting grid line area and are electrically connected with the first current collecting grid lines in the second current collecting grid line area, and part of the first current collecting grid lines in the first current collecting grid line area are electrically connected with the at least one first main junction and the at least one first auxiliary junction through the first overlap line. In this way, once the main junction electrical connection fails, the current can still be led out through the auxiliary junction, thereby improving the yield of the solar cell.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of photovoltaic, in particular, to a solar cell and a photovoltaic module. BACKGROUND

[0002] In the electrode structure of the existing solar cell, a current collecting grid line discontinuous region is usually arranged at the end of the solar cell along the interconnection direction, and part of the current collecting grid lines of the same polarity of the current collecting grid line discontinuous region are electrically connected with the bonding part through the lap joint line, so as to effectively collect the current. However, in the process of preparing the solar cell, when the bonding parts of the same polarity are electrically connected through the conductive interconnection such as the solder strip, the bonding parts electrically connected with part of the current collecting grid lines of the current collecting grid line discontinuous region are prone to failure when the cells are interconnected, so that the current of part of the current collecting grid lines of the current collecting grid line discontinuous region cannot be collected, resulting in the loss of output current, and further causing the yield of the solar cell to decrease.

[0003] Therefore, it is necessary to provide an improved solar cell and photovoltaic module to overcome or at least reduce at least part of the shortcomings existing in the prior art. SUMMARY

[0004] To solve the above technical problems, according to a first aspect of the present application, a solar cell is provided, which comprises a cell substrate and an electrode structure, the cell substrate comprises a first end portion and a second end portion arranged oppositely in a first direction, and a third end portion and a fourth end portion arranged oppositely in a second direction, wherein the second direction intersects the first direction; the electrode structure is located on the cell substrate, and the electrode structure comprises a plurality of current collecting grid lines, at least one first main bonding part, a plurality of first auxiliary bonding parts and a first lap joint line; the plurality of current collecting grid lines comprise first current collecting grid lines and second current collecting grid lines of opposite polarity, which all extend in the first direction, at least part of the first current collecting grid lines and at least part of the second current collecting grid lines are alternately distributed in the second direction, the plurality of current collecting grid lines located at the third end portion form a first current collecting grid line region, and the plurality of current collecting grid lines located between the third end portion and the fourth end portion form a second current collecting grid line region; the first main bonding part is located in the first current collecting grid line region and is electrically connected with at least part of the first current collecting grid lines of the first current collecting grid line region; the plurality of first auxiliary bonding parts are located in the second current collecting grid line region, wherein part of the first main bonding parts and part of the first auxiliary bonding parts are at least partially collinear in the second direction, at least one of the first auxiliary bonding parts is electrically connected with one of the first current collecting grid lines of the second current collecting grid line region; part of the first current collecting grid lines of the first current collecting grid line region are electrically connected with the first main bonding part through the first lap joint line, and part of the first current collecting grid lines of the first current collecting grid line region are electrically connected with at least one of the first auxiliary bonding parts through the first lap joint line.

[0005] Optionally, the first current collecting grid line region is a current collecting grid line discontinuous region, and the second current collecting grid line region is a current collecting grid line continuous region.

[0006] Optionally, the first main junction is located at the first end portion and is electrically connected with the first current collecting grid line of the current collecting grid line discontinuous region at the first end portion, the plurality of first auxiliary junctions are located at the first end portion, and the first auxiliary junctions at the first end portion are electrically connected with the first current collecting grid line of the current collecting grid line continuous region at the first end portion, the first lap joint is located at the first end portion, the first current collecting grid line of the current collecting grid line discontinuous region is electrically connected with the first main junction at the first end portion through the first lap joint, and the first current collecting grid line of the current collecting grid line discontinuous region is electrically connected with at least one of the first auxiliary junctions at the first end portion through the first lap joint.

[0007] Optionally, the electrode structure further comprises at least one second main junction, a plurality of second auxiliary junctions, and a second lap joint, the second main junction is located at the current collecting grid line discontinuous region and is electrically connected with at least part of the second current collecting grid line of the current collecting grid line discontinuous region; the plurality of second auxiliary junctions are located at the current collecting grid line continuous region, wherein part of the second main junctions and part of the second auxiliary junctions are at least partially collinear in the second direction, at least one of the second auxiliary junctions is electrically connected with one of the second current collecting grid lines of the current collecting grid line continuous region; part of the second current collecting grid lines of the current collecting grid line discontinuous region are electrically connected with the second main junction through the second lap joint, and part of the second current collecting grid lines of the current collecting grid line discontinuous region are electrically connected with at least one of the second auxiliary junctions through the second lap joint.

[0008] Optionally, the second main junction is located at the second end portion and is electrically connected with the second current collecting grid line of the current collecting grid line discontinuous region at the second end portion, the plurality of second auxiliary junctions are located at the second end portion, and the second auxiliary junctions at the second end portion are electrically connected with the second current collecting grid line of the current collecting grid line continuous region at the second end portion, the second lap joint is located at the second end portion, the second current collecting grid line of the current collecting grid line discontinuous region is electrically connected with the second main junction at the second end portion through the second lap joint, and the second current collecting grid line of the current collecting grid line discontinuous region is electrically connected with at least one of the second auxiliary junctions at the second end portion through the second lap joint.

[0009] Optionally, a distance from an end of the first tap line located at the first end portion away from the third end portion to the first current collecting grid line adjacent to an edge of the third end portion is different from a distance from an end of the second tap line located at the second end portion away from the third end portion to the second current collecting grid line adjacent to the edge of the third end portion.

[0010] Optionally, a projection of the first main junction portion located at the first end portion on a plane perpendicular to the first direction at least partially overlaps with a projection of the second main junction portion located at the second end portion on the plane perpendicular to the first direction.

[0011] Optionally, the plurality of current collecting grid lines located at the fourth end portion form another current collecting grid line discontinuous region, and the electrode structure further comprises a first parallel tap line and at least one first parallel main junction portion located at the another current collecting grid line discontinuous region, wherein the first current collecting grid lines of the another current collecting grid line discontinuous region are electrically connected with the first parallel main junction portion through the first parallel tap line, the first current collecting grid lines of the another current collecting grid line discontinuous region are electrically connected with at least one first auxiliary junction portion through the first parallel tap line, and a distance from an end of the first tap line located at the third end portion away from the third end portion to the first current collecting grid line adjacent to an edge of the third end portion is the same as a distance from an end of the first parallel tap line located at the fourth end portion away from the fourth end portion to the first current collecting grid line adjacent to an edge of the fourth end portion.

[0012] Optionally, in the first direction, a number of discontinuous second current collecting grid lines broken by the first main junction portion located at the first end portion is the same as a number of discontinuous first current collecting grid lines broken by the second main junction portion located at the second end portion, and the discontinuous second current collecting grid lines broken by the first main junction portion and the discontinuous first current collecting grid lines broken by the second main junction portion are alternately distributed along the second direction.

[0013] Optionally, a number of the first auxiliary junction portions electrically connected with the first main junction portion is no more than 3; and / or a number of the second auxiliary junction portions electrically connected with the second main junction portion is no more than 3; and / or a number of the first auxiliary junction portions electrically connected with the first parallel main junction portion is no more than 3.

[0014] Optionally, a distance between the first main junction portion adjacent to the first auxiliary junction portion and the first busbar line adjacent to the third end edge is greater than a distance between the first main junction portion adjacent to the first auxiliary junction portion and the first auxiliary junction portion adjacent to the first main junction portion; and / or a distance between the second main junction portion adjacent to the second auxiliary junction portion and the second busbar line adjacent to the third end edge is greater than a distance between the second main junction portion adjacent to the second auxiliary junction portion and the second auxiliary junction portion adjacent to the second main junction portion; and / or a distance between the first parallel main junction portion adjacent to the first auxiliary junction portion and the first busbar line adjacent to the fourth end edge is greater than a distance between the first parallel main junction portion adjacent to the first auxiliary junction portion and the first auxiliary junction portion adjacent to the first parallel main junction portion.

[0015] Optionally, the first busbar line and / or the second busbar line and / or the first parallel busbar line gradually increases in width in the second direction from the first direction, the first busbar line being widest at a position electrically connected to the first main junction portion, the second busbar line being widest at a position electrically connected to the second main junction portion, the first parallel busbar line being widest at a position electrically connected to the first parallel main junction portion, the first busbar line or the second busbar line or the first parallel busbar line gradually changing in width to different extents from the widest position towards the direction in which the width decreases.

[0016] Optionally, the first busbar line adjacent to the third end edge in the busbar line discontinuous region is continuous.

[0017] Optionally, in the busbar line continuous region, at least one of the second busbar lines adjacent to the first main junction portion has a length smaller than that of the rest of the second busbar lines.

[0018] Optionally, in the busbar line continuous region, at least one of the second busbar lines adjacent to the first main junction portion and having a length smaller than that of the rest of the second busbar lines is electrically connected to the second auxiliary junction portion.

[0019] Optionally, the solar cell further comprises a doped semiconductor layer, the doped semiconductor layer being disposed between the electrode structure and the cell substrate and being electrically connected to the electrode structure.

[0020] According to a second aspect of the present application, there is provided a photovoltaic module comprising at least two of the aforementioned solar cells.

[0021] According to the technical solution of the present application, by using the bridging line to interconnect the corresponding main junction and at least one auxiliary junction, the current collecting grid line at the end of the interconnection direction can be well interconnected with at least one of the corresponding main junction and auxiliary junction with as few broken current collecting grid lines as possible, so that once the main junction fails, the current can also be discharged through the auxiliary junction, which improves the connection reliability and effectively collects the same current in the discontinuous area of the current collecting grid line, improves the current collection efficiency, avoids the loss of output current, and ultimately helps to improve the yield of the solar cell.

[0022] The above and other objects, advantages and features of the present application will become more apparent from the following detailed description of specific embodiments thereof, when taken in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF DRAWINGS

[0023] The features, advantages and example embodiments of the present application will be described below with reference to the accompanying drawings, in which the same reference numerals indicate the same elements, and wherein:

[0024] Figure 1 a plan view of a solar cell according to an embodiment of the present application;

[0025] Figure 2 a partial view of a first main junction and a first auxiliary junction at a first end of a solar cell according to an embodiment of the present application and the electrode structure adjacent thereto;

[0026] Figure 3 a partial view of a second main junction and a second auxiliary junction at a second end of a solar cell according to an embodiment of the present application and the electrode structure adjacent thereto;

[0027] Figure 4 a partial view of a first auxiliary junction and a first parallel main junction at a first end of a solar cell according to an embodiment of the present application and the electrode structure adjacent thereto; and

[0028] Figure 5 a partial view of a second auxiliary junction and a second parallel main junction at a second end of a solar cell according to an embodiment of the present application and the electrode structure adjacent thereto. DETAILED DESCRIPTION

[0029] The exemplary embodiments of the present application will be described in more detail below with reference to the accompanying drawings. The description of the exemplary embodiments is merely exemplary, and is in no way limiting on the present application and its applications or uses. Moreover, the size and proportions of the various components in the drawings are merely illustrative, and do not strictly correspond to actual products.

[0030] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0031] The solar cell and the photovoltaic module provided by the embodiments of the present application will be described in detail below with reference to the drawings.

[0032] The present application provides a solar cell 100. Figure 1 A plan view of the solar cell 100 of an embodiment of the present application. Figure 2 A partial view of the solar cell 100 of an embodiment of the present application, showing the first main junction P1 and the first auxiliary junction P2 at the first end E1 and the electrode structures adjacent thereto, wherein the middle section at the natural breaking line of the solar cell 100 is not shown. Figure 3 A partial view of the solar cell 100 of an embodiment of the present application, showing the second main junction N1 and the second auxiliary junction N2 at the second end E2 and the electrode structures adjacent thereto, wherein the middle section at the natural breaking line of the solar cell 100 is not shown. Figure 4 A partial view of the solar cell 100 of an embodiment of the present application, showing the first auxiliary junction P2 and the first parallel main junction P3 at the first end E1 and the electrode structures adjacent thereto, wherein the middle section at the natural breaking line of the solar cell 100 is not shown. Figure 5 A partial view of the solar cell 100 of an embodiment of the present application, showing the second auxiliary junction N2 and the second parallel main junction N3 at the second end E2 and the electrode structures adjacent thereto, wherein the middle section at the natural breaking line of the solar cell 100 is not shown. It should be noted that the "end" described herein does not refer to the edge of the corresponding component or region, but refers to the region within a distance range from the corresponding edge.

[0033] As Figure 1As shown, the solar cell 100 includes a cell substrate 10 and an electrode region A located on the cell substrate 10, wherein the cell substrate 10 is used to generate current. In this embodiment, the solar cell 100 can be a back-contact solar cell, and the surface where the electrode region A is located is the backlight surface of the cell substrate 10. The cell substrate 10 includes a first end E1 and a second end E2 disposed opposite to each other in a first direction D1, and a third end E3 and a fourth end E4 disposed opposite to each other in a second direction D2, wherein the first direction D1 intersects the second direction D2. Specifically, as shown... Figure 1 As shown, in this embodiment, the first direction D1 is perpendicular to the second direction D2. For ease of description, the direction from the first end E1 to the second end E2 is defined as the positive direction of the first direction D1, and the direction from the fourth end E4 to the third end E3 is defined as the positive direction of the second direction D2.

[0034] like Figures 1 to 5 As shown, the solar cell 100 also includes an electrode structure located on the cell substrate 10, specifically in the region corresponding to electrode region A, for collecting and conducting current generated by the cell substrate 10. The electrode structure includes multiple collector grid lines, at least one first main junction, multiple first auxiliary junctions, and a first bridging line. The multiple collector grid lines include first and second collector grid lines with opposite polarities, both extending in a first direction. At least a portion of the first and second collector grid lines are alternately distributed in a second direction. The multiple collector grid lines located at the third end form a first collector grid line region, and the multiple collector grid lines located between the third and fourth ends form a second collector grid line region. The first main junction is located in the first collector grid line region and is electrically connected to at least a portion of the first collector grid lines in the first collector grid line region. The multiple first auxiliary junctions are located in the second collector grid line region, wherein a portion of the first main junction and a portion of the first auxiliary junctions are at least partially collinear in the second direction, and at least one first auxiliary junction is electrically connected to a first collector grid line in the second collector grid line region. A portion of the first collector grid lines in the first collector grid line area are electrically connected to the first main joint via a first lap joint, and a portion of the first collector grid lines in the first collector grid line area are electrically connected to at least one first auxiliary joint via a first lap joint.

[0035] In the present application, by interconnecting the first main junction with the at least one first auxiliary junction through the first overlap line, the current collecting grid lines at the end of the interconnection direction can be well interconnected with at least one of the first main junction and the first auxiliary junction with as few broken current collecting grid lines as possible, so that once the electrical connection of the first main junction fails, the current can also be discharged through the first auxiliary junction, which not only improves the connection reliability, but also effectively collects the same current in the first current collecting grid line area, improves the current collection efficiency, avoids the loss of output current, and ultimately helps to improve the yield of the solar cell.

[0036] It should be understood that in other embodiments not shown in the application, the first main junction can also be electrically connected with two or more first auxiliary junctions. Optionally, the number of first auxiliary junctions electrically connected with the first main junction is not more than 3, so as to avoid increasing the current transmission path and thus increasing the current collection loss.

[0037] It should be noted that the first current collecting grid line area, the second current collecting grid line area and the third current collecting grid line area to be described later can all be continuous current collecting grid line areas. At this time, the electrical insulation between the first overlap line and the second current collecting grid line can be realized by the insulating material arranged therebetween, and the electrical insulation between the first parallel overlap line and the second current collecting grid line to be described later can be realized by the insulating material arranged therebetween, that is, the second current collecting grid line of the first current collecting grid line area, the second current collecting grid line area and the third current collecting grid line area is still continuous.

[0038] It should be understood that the electrical insulation between the first overlap line, the first parallel overlap line and the second current collecting grid line can also be realized by the disconnection of the second current collecting grid line. Specifically, as shown in Figures 2 to 5 , the first current collecting grid line area can be an intermittent current collecting grid line area, and the second current collecting grid line area can be a continuous current collecting grid line area. The specific structure of the electrode structure of an embodiment of the present application will be described in more detail below. Figures 2 to 5

[0039] As shown in Figure 2 , the electrode structure includes a plurality of current collecting grid lines, the plurality of current collecting grid lines including first current collecting grid lines 211 and second current collecting grid lines 212 which are opposite in polarity and both extend in a first direction D1, at least part of the first current collecting grid lines 211 and at least part of the second current collecting grid lines 212 are alternately distributed in a second direction D2, the plurality of current collecting grid lines at a third end E3 form an intermittent current collecting grid line area, and the plurality of current collecting grid lines between the third end E3 and a fourth end E4 form a continuous current collecting grid line area, wherein the plurality of current collecting grid lines are used to collect the current generated in the cell substrate. Specifically, as shown in Figures 2 to 5 ​As shown, the first current collecting gate lines 211 and the second current collecting gate lines 212 are alternately distributed equidistantly in the second direction D2, where the distance between two adjacent first current collecting gate lines 211 and the distance between two adjacent second current collecting gate lines 212 are both d.

[0040] It should be noted that, in the embodiment, the first current collecting gate lines 211 are all drawn in solid lines, and the second current collecting gate lines 212 are all drawn in dashed lines. The solid lines and the dashed lines are not used to indicate the actual shape and the actual thickness of the first current collecting gate lines 211 and the second current collecting gate lines 212. In addition, the first current collecting gate lines 211 and the second current collecting gate lines 212 are opposite in polarity, which means that the first current collecting gate lines 211 are positive current collecting gate lines, and the second current collecting gate lines 212 are negative current collecting gate lines, or the first current collecting gate lines 211 are negative current collecting gate lines, and the second current collecting gate lines 212 are positive current collecting gate lines. In the current collecting gate line continuous region, most of the first current collecting gate lines 211 and the second current collecting gate lines 212 extend to the edges of the electrode region A at the first end E1 and the second end E2, and neither the first current collecting gate lines 211 nor the second current collecting gate lines 212 are broken by the first auxiliary joint or the second auxiliary joint which will be described later. In the current collecting gate line discontinuous region, the first current collecting gate lines 211 and the second current collecting gate lines 212 are both broken, specifically, the first current collecting gate lines 211 are broken by at least one second main joint which will be described later, and the second current collecting gate lines 212 are broken by at least one first main joint which will be described later.

[0041] The electrode structure further comprises at least one first main joint, which is located in the current collecting gate line discontinuous region and is electrically connected with at least part of the first current collecting gate lines 211 in the current collecting gate line discontinuous region. Specifically, in the current collecting gate line discontinuous region, the first current collecting gate lines 211 are broken by at least one second main joint which will be described later, and the second current collecting gate lines 212 are broken by at least one first main joint which will be described later. Figure 2In the localized area shown, the electrode structure is provided with a first main junction P1, which is the junction closest to the third end E3 among all junctions adjacent to the first end E1. It should be noted that in other embodiments not shown in this application, the portion at the first end E1 of the electrode structure may also be provided with two or more first main junctions P1 to achieve effective current collection. It should be understood that the middle section of the electrode structure not shown in this application may also be provided with a first main junction to achieve effective current collection in the middle section. The first main junction may be directly electrically connected to at least a portion of the first collector grid line 211 in the collector grid line discontinuity region, or electrically connected to at least a portion of the first collector grid line 211 in the collector grid line discontinuity region by means of a first connecting wire, which will be detailed later, thereby converging the current collected by at least a portion of the first collector grid line 211 in the collector grid line discontinuity region to the first main junction. It should be noted that all the collector grid lines electrically connected to the first main junction are the first collector grid lines 211, that is, all the collector grid lines electrically connected to the first main junction are of the same polarity. The first main junction and the first lap wire are spaced a certain distance away from the second collector grid lines 212 of opposite polarity, so there is no connection with the second collector grid lines 212, thus avoiding short circuits.

[0042] The electrode structure also includes a plurality of first auxiliary junctions located in a continuous region of the collector grid lines. A portion of the first main junction and a portion of the first auxiliary junctions are at least partially collinear in the second direction D2. At least one first auxiliary junction is electrically connected to a first collector grid line 211 in the continuous region of the collector grid lines. Specifically, in Figure 2In the illustrated local region, the first auxiliary joint P2 is the joint closest to the first end E1 in the continuous region of the current collecting grid line. The first current collecting grid line 211 in the continuous region is illustrated as continuous region first current collecting grid line 2113, wherein each continuous region first current collecting grid line 2113 is directly electrically connected with one first auxiliary joint P2 at the first end E1. It should be understood that in the middle section of the electrode structure not shown in the present application, each continuous region first current collecting grid line 2113 can also be electrically connected with at least one first auxiliary joint arranged in the middle section to achieve effective collection of current in the middle section. It should be noted that the partial first main joint and the partial first auxiliary joint are at least partially collinear in the second direction D2, which means that the partial first main joint and the partial first auxiliary joint arranged in a column in the second direction D2 can be connected in series by a solder strip extending in the second direction D2, so as to collect the current on the same type of joint. Specifically, in this embodiment, the length of the first main joint in the first direction D1 can be the same as the length of the first auxiliary joint in the first direction D1, so as to facilitate the operation convenience in the soldering process of the solder strip. It should be understood that in other embodiments not shown in the present application, the length of the first main joint in the first direction D1 can also be greater than the length of the first auxiliary joint in the first direction D1. In addition, the length of the first main joint in the second direction D2 is slightly greater than the interval d of the adjacent first current collecting grid line 211 in the second direction D2, and the length of the first auxiliary joint in the second direction D2 is significantly less than half of the interval d. In this way, the layout of the current collecting grid line is more compact, which is conducive to effective collection of current. Optionally, the thickness of the first main joint in the direction perpendicular to the plane in which the first direction D1 and the second direction D2 are located is the same as the thickness of the first auxiliary joint in the direction perpendicular to the plane in which the first direction D1 and the second direction D2 are located, so that the solder strip can be soldered in the same plane in the soldering process of the solder strip, thereby improving the convenience and operability of the soldering process.

[0043] Optionally, the first main joint and the first auxiliary joint can be similar-shaped joints formed by the same process and from the same material.

[0044] As Figures 2 to 5 illustrated, the electrode structure further comprises a first lap wire, and the partial first current collecting grid line 211 in the current collecting grid line discontinuous region is electrically connected with the first main joint through the first lap wire, and the partial first current collecting grid line 211 in the current collecting grid line discontinuous region is electrically connected with at least one first auxiliary joint through the first lap wire. In the present embodiment, the lap wire is used to collect the current collected by the current collecting grid line, and generally extends in the second direction D2. Also, it should be understood that in the middle section of the electrode structure not shown in the present application, the first lap wire can also be arranged to collect the current collected by the first current collecting grid line 211 in the middle section.

[0045] Optionally, the distance between the first main joint adjacent to the first auxiliary joint and the first collector grid line adjacent to the third end edge is greater than the distance between the first main joint adjacent to the first auxiliary joint and the first auxiliary joint adjacent to the first main joint. The width of the first lap wire along the second direction D2 first increases and then decreases along the first direction D1. The degree of width gradient of the first lap wire from its widest point toward the direction of width reduction is different. For example, the width at the two ends along the second direction D2 is approximately the same, and the first lap wire is widest at the position where it is electrically connected to the first main joint.

[0046] exist Figure 2 In the local region shown, the continuous region of the collector grid lines located at the first end E1 is shown as L1. This continuous region of the collector grid lines L1 refers to the region L1 enclosed by a single-dot dashed line and a natural break line. Within the continuous region of the collector grid lines L1 located at the first end E1, a plurality of first auxiliary joints P2 are provided, and most of the first collector grid lines 211 and 212 extend to the edge of the electrode region A at the first end E1. Figure 2 In the local area shown, the collector grid line discontinuity region located at the first end E1 is shown as M1. The collector grid line discontinuity region M1 refers to the area M1 at the first end E1 enclosed by a single-dot dashed line and a natural break line. In the collector grid line discontinuity region M1 located at the first end E1, a first main joint P1 is provided, and the second collector grid line 212 does not extend to the edge of the electrode region A at the first end E1 like the first collector grid line 211. That is to say, there is a discontinuity between the second collector grid line 212 and the edge of the electrode region A at the first end E1.

[0047] like Figure 2As shown, the first main junction P1 is located at the first end E1 and is electrically connected with the first current collecting grid line 211 of the current collecting grid line discontinuous region M1 located at the first end E1, the plurality of first auxiliary junctions P2 are located at the first end E1, and the first auxiliary junction P2 located at the first end E1 is electrically connected with the first current collecting grid line 211 of the current collecting grid line continuous region L1 located at the first end E1, the first lap joint 22 is located at the first end E1, the first current collecting grid line 211 of the current collecting grid line discontinuous region M1 is electrically connected with the first main junction P1 through the first lap joint 22 at the first end E1, and the first current collecting grid line 211 of the current collecting grid line discontinuous region M1 is electrically connected with at least one first auxiliary junction P2 through the first lap joint 22 at the first end E1. It should be noted that in the case where the first lap joint 22 does not electrically connect the first main junction P1 with the first auxiliary junction P2, the first current collecting grid line located at the first end E1 can only be electrically connected with the first main junction through the first lap joint, and once the first main junction fails to be welded, the current close to the first end E1 in the fine grid discontinuous region cannot be collected and led out, thereby the risk of the current being unable to be collected and led out is high, and by using the technical solution of the present application, once the first main junction fails to be electrically connected, the current can still be led out through the first auxiliary junction by means of the first lap joint, thereby the current collection efficiency and yield of the photovoltaic module are significantly improved.

[0048] Specifically, in the local region shown, Figure 2 As shown in the local region, the first main junction P1 is one of all the junctions closest to the third end E3 among the junctions adjacent to the first end E1. It should be noted that in other embodiments not shown in the present application, the electrode structure can also be provided with two or more first main junctions P1 to achieve effective current collection. The first main junction P1 can be directly electrically connected with part of the first current collecting grid line 211 of the current collecting grid line discontinuous region, or be electrically connected with part of the first current collecting grid line 211 of the current collecting grid line discontinuous region by means of the first lap joint 22, thereby the current collected by the first current collecting grid line 211 of the current collecting grid line discontinuous region M1 located at the first end E1 can be collected to the first main junction P1. It should be noted that the current collecting grid lines electrically connected with the first main junction P1 are all the first current collecting grid lines 211, that is, the current collecting grid lines electrically connected with the first main junction P1 are all the same current collecting grid lines, and the first main junction P1 and the first lap joint 22 are both spaced apart from the different second current collecting grid line 212, thereby there is no connection with the second current collecting grid line 212, and short circuit is avoided.

[0049] In the above embodiments, Figure 2In the shown local area, the first auxiliary joint P2 is the joint closest to the first end E1 in the continuous region of collector grid lines L1 at the first end E1. The first collector grid line 211 in the continuous region of collector grid lines L1 at the first end E1 is shown as continuous region first collector grid line 2113, wherein each continuous region first collector grid line 2113 is provided with one first auxiliary joint P2 at the first end E1, and one continuous region first collector grid line 2113 is directly electrically connected with one first auxiliary joint P2.

[0050] In Figure 2 In the shown local area, the first lap line 22 is provided at the edge of the electrode area A at the first end E1 and extends substantially in the second direction D2. In addition, the first collector grid line 211 in the discontinuous region of collector grid lines M1 at the first end E1 is divided into a first lap line collector grid line 2111 and a first main joint collector grid line 2112, wherein the first lap line collector grid line 2111 is directly electrically connected with the first lap line 22 at the edge of the electrode area A at the first end E1, and the first main joint collector grid line 2112 is directly electrically connected with the first main joint P1 at the first end E1.

[0051] In particular, in Figure 2 In the shown local area, the length of the first main joint P1 in the first direction D1 can be the same as the length of the first auxiliary joint P2 in the first direction D1, and the length of the first main joint P1 in the second direction D2 is slightly greater than the pitch d of the adjacent first collector grid line 211 in the second direction D2, and the first main joint collector grid line 2112 is electrically connected with the first main joint P1 at both ends of the first main joint P1 in the second direction D2, so that the current collected by the first main joint collector grid line 2112 can be directly collected to the first main joint P1.

[0052] The first bridging wire 22 can be electrically connected to the first main junction P1 via the first collector grid line 2112a disposed between the first bridging wire 22 and the first main junction P1. Optionally, the first bridging wire 22 can also be electrically connected to the first main junction P1 via the first connecting line 23 disposed between the first bridging wire 22 and the first main junction P1. In this case, the first collector grid line 2112a and the first connecting line 23 are stacked on the plane perpendicular to the first direction D1 and the second direction D2. The width of the first connecting line 23 is greater than the width of the first collector grid line 211a to increase the reliability of current transmission. This arrangement not only allows the current collected by the first bridging wire collector grid line 2111 and the first main junction collector grid line 2112a in the collector grid line discontinuity region M1 at the first end E1 to be directly collected to the first main junction P1, but also helps to reduce the difficulty of bridging the first connecting line 23 and the first main junction P1, and improves the fault tolerance rate in the electrode structure fabrication process. Furthermore, by providing the first connecting line 23, the stress in the edge region of the solar cell is made more uniform, which helps to reduce the probability of solar cell breakage. It should be noted that the wider the first connecting line 23, the lower its resistance when transmitting current, which is more beneficial for current transmission. In this embodiment, there is one first connecting line 23. In other embodiments, the number of first connecting lines 23 is not limited to this.

[0053] In this embodiment, as Figure 2 As shown, in the second direction D2, in the region between the first main joint P1 and the first bridging wire 22, a first main joint current collector wire 2112 is provided on both the upper and lower sides of the first connecting line 23. The first main joint current collector wire 2112 is electrically connected to the first bridging wire 22 at its end immediately adjacent to the first end edge, and electrically connected to the first main joint P1 at its other end. This arrangement increases the reliability of current transmission collected by the first bridging wire 22 and ensures sufficient current collection in the region between the first main joint P1 and the first bridging wire 22.

[0054] Optionally, in some embodiments, the first bridging wire 22 can be integrally formed with the first collector wire 211, which is directly electrically connected to the first bridging wire 22. Integral forming here can mean that the two are printed together. In this case, the first bridging wire 22 and the first collector wire 211 are made of the same material. Integral forming facilitates processing, increases production efficiency, and avoids the problem of processing errors caused by forming the first bridging wire 22 and the first collector wire 211 in stages, which could lead to an inability to form an effective electrical connection between them. This ensures a reliable connection between the first bridging wire 22 and the first collector wire 211, which is directly electrically connected to the first bridging wire 22.

[0055] In addition, in some embodiments, the first bonding wire 22 can also be integrally formed with the first end connecting wire 23. The integral forming method and its beneficial effects are described above and will not be repeated here.

[0056] like Figure 2 As shown, the first main joint P1, which is electrically connected to a portion of the first collector wire 211 in the discontinuity region of the collector wire, is also electrically connected to at least one first auxiliary joint P2 via a first lap wire 22. In this embodiment, the number of first main joints P1 and first auxiliary joints P2 electrically connected to the first lap wire 22 is the same. Specifically, as... Figure 2 As shown, a first main junction P1 is electrically connected to a first auxiliary junction P2 via a first bonding wire 22. This arrangement allows for a good interconnection between the first main junction P1 and the first auxiliary junction P2 with as few interruptions to the collector grid lines as possible between the first and second ends. This improves connection reliability and enables the effective collection of the same-pole current in the collector grid line discontinuity region M1 at the first end E1, increasing current collection efficiency, avoiding output current loss, and ultimately improving the yield of the solar cell. It should be understood that in other embodiments not shown in the application, the first main junction P1 at the first end E1 may also be electrically connected to two or more first auxiliary junctions P2 at the first end E1.

[0057] Furthermore, in this embodiment, both the first collector grid line 211 and the second collector grid line 212 extend in the first direction D1, meaning that neither the first collector grid line 211 nor the second collector grid line 212 has a bending section. This avoids the problem of easy breakage at bending sections during the printing of the collector grid lines, ultimately contributing to improved yield of the solar cell.

[0058] In this embodiment, the electrode structure further includes at least one second main junction, which is located in the collector grid line discontinuity region and electrically connected to at least a portion of the second collector grid line in the collector grid line discontinuity region. Specifically, in Figure 3In the shown local region, the electrode structure is provided with one second main junction N1, which is the junction closest to the third end E3 among all the junctions next to the second end E2. It should be noted that in other embodiments not shown in the present application, the portion at the second end E2 of the electrode structure can also be provided with two or more second main junctions N1 to achieve effective collection of current. It should be understood that in the middle section of the electrode structure not shown in the present application, the second main junction can also be provided to achieve effective collection of current in the middle section. The second main junction N1 can be directly electrically connected with at least part of the second current collecting grid line 212 of the current collecting grid line discontinuous region, or electrically connected with at least part of the second current collecting grid line 212 of the current collecting grid line discontinuous region by means of the second lap joint 24 to be described later, so that the current collected by at least part of the second current collecting grid line 212 of the current collecting grid line discontinuous region can be collected to the second main junction N1. It should be noted that the current collecting grid lines electrically connected with the second main junction N1 are all second current collecting grid lines 212, that is, all the current collecting grid lines electrically connected with the second main junction N1 are homopolar current collecting grid lines, and the second main junction N1 and the second lap joint 24 are both spaced apart from the heteropolar first current collecting grid line 211 by a certain distance, so that there is no connection with the first current collecting grid line 211, avoiding short circuit.

[0059] The electrode structure further comprises a plurality of second auxiliary junctions, which are located in the current collecting grid line continuous region, wherein part of the second main junctions and part of the second auxiliary junctions are at least partially collinear in the second direction, and at least one second auxiliary junction is electrically connected with a second current collecting grid line of the current collecting grid line continuous region. Specifically, in the shown local region embodiment, the second auxiliary junction N2 is the junction next to the second end E2 in the current collecting grid line continuous region. The second current collecting grid lines 212 in the current collecting grid line continuous region are shown as continuous region second current collecting grid lines 2123, wherein each continuous region second current collecting grid line 2123 is directly electrically connected with one second auxiliary junction N2 at the second end E2. It should be understood that in the middle section of the electrode structure not shown in the present application, each continuous region second current collecting grid line 2123 can also be electrically connected with at least one second auxiliary junction provided in the middle section to achieve effective collection of current in the middle section. It should be noted that part of the second main junctions and part of the second auxiliary junctions are at least partially collinear in the second direction D2, which means that part of the second main junctions and part of the second auxiliary junctions arranged in a column in the second direction D2 can be connected in series by a solder strip extending in the second direction D2, so as to collect the current on the homopolar junctions. Figure 3 In the shown local region embodiment, the second auxiliary junction N2 is the junction next to the second end E2 in the current collecting grid line continuous region. The second current collecting grid lines 212 in the current collecting grid line continuous region are shown as continuous region second current collecting grid lines 2123, wherein each continuous region second current collecting grid line 2123 is directly electrically connected with one second auxiliary junction N2 at the second end E2. It should be understood that in the middle section of the electrode structure not shown in the present application, each continuous region second current collecting grid line 2123 can also be electrically connected with at least one second auxiliary junction provided in the middle section to achieve effective collection of current in the middle section. It should be noted that part of the second main junctions and part of the second auxiliary junctions are at least partially collinear in the second direction D2, which means that part of the second main junctions and part of the second auxiliary junctions arranged in a column in the second direction D2 can be connected in series by a solder strip extending in the second direction D2, so as to collect the current on the homopolar junctions.

[0060] In the embodiments of the present application, the shapes and sizes of the second main junctions and the second auxiliary junctions are similar to those of the first main junctions and the first auxiliary junctions, which will not be described here for brevity.

[0061] As shown in Figure 3 , the electrode structure further comprises a second busbar, the second busbar is electrically connected with the second main junction and at least one second auxiliary junction of the second busbar discontinuous region through the second busbar. Similarly, the second busbar is used to collect the current collected by the busbar, and generally extends in the second direction D2. It should be understood that in the middle section of the electrode structure not shown in the present application, the second busbar can also be provided to collect the current collected by the second busbar 212 of the middle section. In the present application, by interconnecting the second main junction and at least one second auxiliary junction through the second busbar, the second main junction and the second auxiliary junction can be well interconnected with as few busbars as possible broken between the first end and the second end, which not only improves the connection reliability, but also enables the same polarity current in the busbar discontinuous region to be effectively collected, improves the current collection efficiency, avoids the loss of output current, and ultimately helps to improve the yield of the solar cell. It should be understood that in other embodiments not shown in the application, the second main junction can also be electrically connected with two or more second auxiliary junctions. Alternatively, the number of second auxiliary junctions electrically connected with the second main junction is not more than 3, so as to avoid increasing the path of current transmission and in turn increasing the loss of current collection.

[0062] In Figure 3 the local area shown, the busbar continuous region at the second end E2 is shown as L2, which refers to the area L2 enclosed by the single-dot chain line and the natural broken line. In the busbar continuous region L2 at the second end E2, a plurality of second auxiliary junctions N2 are provided, and most of the first busbar 211 and the second busbar 212 extend to the edge of the electrode area A at the second end E2; in Figure 3 the local area shown, the busbar discontinuous region at the second end E2 is shown as M2, which refers to the area M2 at the second end E2 enclosed by the single-dot chain line and the natural broken line. In the busbar discontinuous region M2 at the second end E2, one second main junction N1 is provided, and the first busbar 211 does not extend to the edge of the electrode area A at the second end E2 as the second busbar 212 does, that is, there is a discontinuity between the first busbar 211 and the edge of the electrode area A at the second end E2. In this way, a different polarity electrode is provided at both ends of the solar cell along the extension direction of the busbar, and the electrodes at both ends of the solar cell are better corresponding, which not only avoids the individualized design of the solar cell, but also reduces the interconnection difficulty between the solar cells.

[0063] like Figure 3 As shown, the second main joint N1 is located at the second end E2 and is electrically connected to the second collector line 212 located at the collector line discontinuity region M2 at the second end E2. Specifically, in Figure 3 In the illustrated embodiment, the electrode structure has a second main junction N1, which is the junction closest to the third end E3 among all the junctions adjacent to the second end E2. It should be noted that in other embodiments not shown in this application, the electrode structure may also have two or more second main junctions N1 to achieve efficient current collection. The second main junction N1 can be directly electrically connected to a portion of the second collector grid line 212 in the collector grid line discontinuity region, or electrically connected to a portion of the second collector grid line 212 in the collector grid line discontinuity region via a second connecting wire 24, which will be detailed later, thereby converging the current collected by the second collector grid line 212 in the collector grid line discontinuity region M2 located at the second end E2 to the second main junction N1. It should be noted that all the collector grid lines electrically connected to the second main junction N1 are the second collector grid lines 212, that is, all the collector grid lines electrically connected to the second main junction N1 are collector grid lines of the same polarity. The second main junction N1 and the second bridging wire 24 are both spaced a certain distance from the first collector grid line 211 of the opposite polarity, so there is no connection with the first collector grid line 211, thus avoiding short circuits.

[0064] exist Figure 3 In the shown local area, multiple second auxiliary joints N2 are located at the second end E2, and the second auxiliary joints N2 located at the second end E2 are electrically connected to the second collector grid line 212 located in the continuous collector grid line region L2 at the second end E2. Specifically, the second auxiliary joint N2 is a joint immediately adjacent to the second end E2 in the continuous collector grid line region L2 located at the second end E2. The second collector grid line 212 in the continuous collector grid line region L2 located at the second end E2 is shown as a continuous region second collector grid line 2123, wherein each continuous region second collector grid line 2123 has a second auxiliary joint N2 provided at its second end E2, and one continuous region second collector grid line 2123 is directly electrically connected to one second auxiliary joint N2.

[0065] exist Figure 3In the region shown, the second bridging wire 24 is located at the second end E2, and the second collector grid line 212 of the collector grid line discontinuity region M2 is electrically connected to the second main junction N1 at the second end E2 via the second bridging wire 24. Specifically, the second bridging wire 24 is provided at the edge of the electrode region A at the second end E2 and extends generally in the second direction D2. Furthermore, the second collector grid line 212 in the collector grid line discontinuity region M2 located at the second end E2 is divided into a second bridging wire collector grid line 2121 and a second main junction collector grid line 2122. The second bridging wire collector grid line 2121 is directly electrically connected to the second bridging wire 24 at the second end E2, at the edge of the electrode region A, and the second main junction collector grid line 2122 is directly electrically connected to the second main junction N1 at the second end E2.

[0066] The shape and size of the second main joint and the second auxiliary joint are similar to those of the first main joint and the first auxiliary joint, and will not be described again here for the sake of brevity.

[0067] like Figure 3 As shown, in the opposite direction of the first direction D1, the second main junction N1 is electrically connected to only one second main junction collector grid line 2122, so that the current collected by the second main junction collector grid line 2122 can be directly collected to the second main junction N1. The second bridging wire 24 can be electrically connected to the second main junction N1 via the second main junction collector grid line 2122a disposed between the second bridging wire 24 and the second main junction N1. Optionally, the second bridging wire 24 can also be electrically connected to the second main junction N1 via the second connecting wire 25 disposed between the second bridging wire 24 and the second main junction N1. In this manner, the current collected by the second bridging wire collector grid line 2121 and the second main junction collector grid line 2122 in the collector grid line discontinuity zone M2 located at the second end E2 can both be directly collected to the second main junction N1.

[0068] Similarly, the second bonding wire 24 can be integrally formed with the second collector wire 212, which is directly electrically connected to the second bonding wire 24; alternatively, the second bonding wire 24 can also be integrally formed with the second connecting wire 25. The integral forming method and its beneficial effects are described above regarding the first bonding wire 22, and will not be repeated here. Furthermore, the shape and arrangement of the second connecting wire 25 are described above regarding the first connecting wire 23, and will not be repeated here for simplicity.

[0069] The arrangement of the electrode structure at the second end E2 is different from that at the first end E1. At the second end E2, in the area between the second main joint N1 and the second lap line 24, no second collector grid line is provided on the upper and lower sides of the second connecting line 25.

[0070] likeFigure 3 As shown, the second collector grid line 212 of the collector grid line interruption region M2 at the second end portion E2 is electrically connected to at least one second auxiliary junction N2 by a second bridging line 24, that is, the second main junction N1 is also electrically connected to at least one second auxiliary junction N2 by the second bridging line 24. In the present embodiment, the number of second main junctions N1 and second auxiliary junctions N2 electrically connected to the second bridging line 24 is the same. Specifically, as shown, one second main junction N1 is electrically connected to one second auxiliary junction N2 by the second bridging line 24. It should be understood that in other embodiments not shown in the application, one second main junction N1 can also be electrically connected to two or more second auxiliary junctions N2. In this way, the second main junction N1 can form good interconnection with the second auxiliary junction N2 with as few collector grid lines interrupted between the first end portion and the second end portion as possible, which not only improves the connection reliability, but also enables the same polarity current in the collector grid line interruption region M2 at the second end portion E2 to be effectively collected; in addition, it can avoid the second bridging line 24 at the second end portion E2 from interrupting more first collector grid lines 211 to prevent electrical connection with the first collector grid lines 211, thereby achieving effective collection of the opposite polarity current and reducing the dead zone on the solar cell, reducing the loss of solar cell performance. Figure 2 As shown, the second collector grid line 212 of the collector grid line interruption region M2 at the second end portion E2 is electrically connected to at least one second auxiliary junction N2 by a second bridging line 24, that is, the second main junction N1 is also electrically connected to at least one second auxiliary junction N2 by the second bridging line 24. In the present embodiment, the number of second main junctions N1 and second auxiliary junctions N2 electrically connected to the second bridging line 24 is the same. Specifically, as shown, one second main junction N1 is electrically connected to one second auxiliary junction N2 by the second bridging line 24. It should be understood that in other embodiments not shown in the application, one second main junction N1 can also be electrically connected to two or more second auxiliary junctions N2. In this way, the second main junction N1 can form good interconnection with the second auxiliary junction N2 with as few collector grid lines interrupted between the first end portion and the second end portion as possible, which not only improves the connection reliability, but also enables the same polarity current in the collector grid line interruption region M2 at the second end portion E2 to be effectively collected; in addition, it can avoid the second bridging line 24 at the second end portion E2 from interrupting more first collector grid lines 211 to prevent electrical connection with the first collector grid lines 211, thereby achieving effective collection of the opposite polarity current and reducing the dead zone on the solar cell, reducing the loss of solar cell performance.

[0071] Optionally, the distance between the second main junction N1 adjacent to the second auxiliary junction N2 and the second collector grid line 212 adjacent to the third end portion edge is greater than the distance between the second main junction N1 adjacent to the second auxiliary junction N2 and the second auxiliary junction N2 adjacent to the second main junction N1. The width of the second bridging line 24 in the second direction D2 first increases and then decreases in the first direction D1, and the degree of width tapering of the second bridging line 24 from the widest point to the direction of width decrease is different, for example, the width at the two ends in the second direction D2 is substantially the same, and the second bridging line 24 is widest at the position electrically connected to the second main junction N1.

[0072] As described above, it should be understood that in the middle region of the solar cell 100 between the first end portion E1 and the second end portion E2 not shown in the present application, the electrode structure can also include first intermediate main junctions and first intermediate auxiliary junctions, wherein part of the first intermediate main junctions and part of the first main junctions P1 are at least partially collinear in the first direction D1, and part of the first intermediate auxiliary junctions and part of the first auxiliary junctions P2 are at least partially collinear in the first direction D1. The first intermediate main junctions and the first intermediate auxiliary junctions are each electrically connected to part of the first collector grid lines 211 in the middle region, so that the current collected by part of the first collector grid lines 211 in the middle region can be collected to the first intermediate main junctions and the first intermediate auxiliary junctions.

[0073] In addition, the electrode structure can further include a second intermediate main junction portion and a second intermediate auxiliary junction portion, wherein a portion of the second intermediate main junction portion and a portion of the second main junction portion N1 are at least partially collinear in the first direction D1, and a portion of the second intermediate auxiliary junction portion and a portion of the second auxiliary junction portion N2 are at least partially collinear in the first direction D1. The second intermediate main junction portion and the second intermediate auxiliary junction portion are each electrically connected to a portion of the second current collecting grid line 212 in the intermediate region, so that the current collected by the portion of the second current collecting grid line 212 in the intermediate region can be collected to the second intermediate main junction portion and the second intermediate auxiliary junction portion.

[0074] Optionally, the distance from one end of the first overlap line 22 located at the first end portion E1 to the first current collecting grid line 2111 adjacent to the edge of the third end portion is different from the distance from one end of the second overlap line 24 located at the second end portion E2 to the second current collecting grid line 2121 adjacent to the edge of the third end portion E3. In the embodiment of the present application, the distance from one end of the first overlap line 22 located at the first end portion E1 to the first current collecting grid line 2111 adjacent to the edge of the third end portion E3 is longer than the distance from one end of the second overlap line 24 located at the second end portion E2 to the second current collecting grid line 2121 adjacent to the edge of the third end portion E3, and the chamfer size of the first overlap line 22 located at the first end portion E1 adjacent to the edge of the third end portion E3 is longer, so that the current at the chamfer can be fully collected, which is beneficial to reducing the dead zone on the solar cell and reducing the performance loss of the solar cell.

[0075] Optionally, the number of the first main junction portions P1 electrically connected to the first overlap line 22 is equal to the number of the second main junction portions N1 electrically connected to the second overlap line 24, and the number of the first auxiliary junction portions P2 electrically connected to the first overlap line 22 is equal to the number of the second auxiliary junction portions N2 electrically connected to the second overlap line 24.

[0076] Optionally, the number of the first main junction portions P1 and the first auxiliary junction portions P2 electrically connected to the first overlap line 22 located at the first end portion E1 is equal to the number of the second main junction portions N1 and the second auxiliary junction portions N2 electrically connected to the second overlap line 24 located at the second end portion E2. That is, the arrangement of the first current collecting grid line 211 and the second current collecting grid line 212 at the first end portion E1 is asymmetric to the arrangement of the first current collecting grid line 211 and the second current collecting grid line 212 at the second end portion E2.

[0077] Specifically, in the present embodiment, one first main junction P1 is electrically connected with one first auxiliary junction P2 through the first bridging line 22, and one second main junction N1 is electrically connected with one second auxiliary junction N2 through the second bridging line 24. In this way, the broken current collecting grid lines in the current collecting grid line discontinuous region are as few as possible while ensuring the electrical connection between the main junctions and the auxiliary junctions, which realizes the effective collection of the hetero-current and is conducive to reducing the dead zone on the solar cell and further reducing the performance loss of the solar cell.

[0078] Optionally, the projection of the first main junction P1 located at the first end E1 on a plane perpendicular to the first direction D1 at least partially overlaps with the projection of the second main junction N1 located at the second end E2 on a plane perpendicular to the first direction D1. In this way, the uniform collection of current is facilitated, the mismatch of the current collected by the main junctions of different polarities is avoided, the interconnection difficulty of the battery is reduced, the fault tolerance rate in the electrode structure preparation process is improved, and the production efficiency is high.

[0079] Further, the number of the first main junctions located at the first end E1 is the same as the number of the second main junctions located at the second end E2, and the number of the first auxiliary junctions located at the first end E1 is the same as the number of the second auxiliary junctions located at the second end E2. In this way, the current collecting grid lines between the first end and the second end can be broken as few as possible, thereby avoiding the formation of a dead zone on the solar cell and improving the output efficiency of the current.

[0080] In addition, in the first direction D1, the number of the discontinuous second current collecting grid lines 212 broken by the first main junction P1 located at the first end E1 is the same as the number of the discontinuous first current collecting grid lines 211 broken by the second main junction N1 located at the second end E2, and the discontinuous second current collecting grid lines 212 broken by the first main junction P1 and the discontinuous first current collecting grid lines 211 broken by the second main junction N1 are alternately distributed along the second direction D2. As shown in Figure 2 and Figure 3 The discontinuous second current collecting grid lines 212a broken by the first main junction P1 and the discontinuous first current collecting grid lines 211a broken by the second main junction N1 are not symmetrically arranged, specifically, the number of the discontinuous second current collecting grid lines 212 broken by the first main junction P1 is two, and the two second current collecting grid lines 212 are marked with reference numerals 212a, and the number of the discontinuous first current collecting grid lines 211 broken by the second main junction N1 is two, and the two first current collecting grid lines 211 are marked with reference numerals 211a, and the two first current collecting grid lines 211a are collinear with the two first main junction current collecting grid lines 2112 shown in Figure 2 In addition, the two second current collecting grid lines 212a are collinear with the two second main junction current collecting grid lines 2122 shown in Figure 3The second main junction busbar collector grid line 2122 and the second overlap line busbar collector grid line 2121 adjacent to the second main junction busbar collector grid line 2122 in the second direction D2 are collinear.

[0081] As shown in FIG. 1, the first overlap line 22 extends in the second direction D2 by a distance greater than the second overlap line 24 extends in the second direction D2. Figures 1 to 3 As shown in FIG. 1, the first overlap line 22 extends in the second direction D2 by a distance greater than the second overlap line 24 extends in the second direction D2. Figure 2 As shown in FIG. 1, the first overlap line 22 extends in the second direction D2 by a distance greater than the second overlap line 24 extends in the second direction D2. Figure 3 As shown in FIG. 1, the first overlap line 22 extends in the second direction D2 by a distance greater than the second overlap line 24 extends in the second direction D2. As such, in the first direction D1, not only is the layout of the busbar collector grid lines simplified, making the appearance of the electrode structure aesthetically pleasing, but also the electrical interconnection difficulty of the solar cell module is reduced, facilitating standardized operation in the soldering process and improving the possibility of realizing automatic production of the solar cell module. It should be noted that in other embodiments, the number of intermittent second busbar collector grid lines 212 adjacent to the first main junction P1 and the number of intermittent first busbar collector grid lines 211 adjacent to the second main junction N1 are not limited to the above.

[0082] Optionally, the projection of the first intermediate main junction in the plane perpendicular to the first direction D1, the projection of the second intermediate main junction in the plane perpendicular to the first direction D1, the projection of the first main junction P1 in the plane perpendicular to the first direction D1, and the projection of the second main junction N1 in the plane perpendicular to the first direction D1 are completely overlapped.

[0083] As shown in FIG. 1, the first overlap line 22 extends in the second direction D2 by a distance greater than the second overlap line 24 extends in the second direction D2. Figure 4As shown, multiple collector grid lines located at the fourth end E4 form a third collector grid line region. In this embodiment, the third collector grid line region is another collector grid line discontinuity region. The electrode structure also includes a first parallel connection line and at least one first parallel main joint located in the other collector grid line discontinuity region. A portion of the first collector grid lines 211 in the other collector grid line discontinuity region is electrically connected to the first parallel main joint via the first parallel connection line. A portion of the first collector grid lines 211 in the other collector grid line discontinuity region is electrically connected to at least one first auxiliary joint via the first parallel connection line. The distance between the end of the first connection line located at the third end E3 and the first collector grid line 211 adjacent to the edge of the third end is the same as the distance between the end of the first parallel connection line located at the fourth end E4 and the first collector grid line 211 adjacent to the edge of the fourth end. Optionally, the number of interrupted second collector grid lines interrupted by the first main joint at the third end E3 is the same as the number of interrupted second collector grid lines interrupted by the first parallel main joint at the fourth end E4. In other words, the electrode patterns near the first main joint at the third end E3 and near the first parallel main joint at the fourth end E4 are arranged approximately symmetrically. This arrangement facilitates standardized operation during the welding process.

[0084] Preferably, the electrode patterns at the third end E3 and the electrode patterns at the fourth end E4 are symmetrically designed, and the polarity of the first main joint at the third end E3 and the polarity of the first parallel main joint at the fourth end E4 are also the same. By setting it in this way, current mismatch at the third end E3 and the fourth end E4 of the photovoltaic module 1 can be avoided, and the welding difficulty of the joint can be reduced.

[0085] like Figure 4 As shown, at the first end E1, the electrode structure further includes a first parallel connection wire 26 and at least one first parallel main junction P3 located in another collector grid line discontinuity region. A portion of the first collector grid line 211 in the other collector grid line discontinuity region is electrically connected to the first parallel main junction P3 via the first parallel connection wire 26. A portion of the first collector grid line 211 in the other collector grid line discontinuity region is electrically connected to at least one first auxiliary junction P2 via the first parallel connection wire 26. The distance between the end of the first connection wire 22 located at the third end E3 and the first collector grid line 211 adjacent to the edge of the third end is the same as the distance between the end of the first parallel connection wire 26 located at the fourth end E4 and the first collector grid line 211 adjacent to the edge of the fourth end. Optionally, the number of first auxiliary junctions electrically connected to the first parallel main junctions does not exceed three to avoid increasing the current transmission path and thus increasing current collection losses.

[0086] In particular, in Figure 4 In the illustrated embodiment, the electrode structure is provided with one first parallel main junction P3, which is the junction closest to the fourth end E4 among all the junctions adjacent to the first end E1. It should be noted that in other embodiments not shown in the present application, the electrode structure can also be provided with two or more first parallel main junctions P3 to achieve effective current collection. The first parallel main junction P3 can be directly electrically connected to the portion of the first collector grid line 211 of the other collector grid line discontinuity S1 located at the first end E1, or electrically connected to the portion of the first collector grid line 211 of the other collector grid line discontinuity S1 located at the first end E1 by means of the first parallel lap line 26 to be described later, so that the current collected by the first collector grid line 211 of the other collector grid line discontinuity S1 located at the first end E1 can be collected to the first parallel main junction P3. It should be noted that the collector grid lines electrically connected to the first parallel main junction P3 are all first collector grid lines 211, i.e. the collector grid lines electrically connected to the first parallel main junction P3 are all homopolar collector grid lines, and the first parallel main junction P3 and the first parallel lap line 26 are both spaced apart from the heteropolar second collector grid line 212 by a certain distance, so that there is no connection with the second collector grid line 212, avoiding short circuit.

[0087] The first parallel lap line 26 is provided at the edge of the electrode area A at the first end E1 and extends generally in the second direction D2. Similar to the first lap line 22, the first parallel lap line 26 can be electrically connected to the first parallel main junction P3 through the first collector grid line 211 provided between the first parallel lap line 26 and the first parallel main junction P3. Alternatively, the first parallel lap line 26 can also be electrically connected to the first parallel main junction P3 via the first parallel connection line 25 provided between the first parallel lap line 26 and the first parallel main junction P3, wherein the width of the first parallel connection line 25 is greater than the width of the first collector grid line 211 to increase the reliability of current transmission. In addition, in the present embodiment, the distance of the first lap line 22 extending in the second direction D2 and the distance of the first parallel lap line 26 extending in the second direction D2 are both 7d. In this way, it is beneficial to the standardized operation in the welding process of welding the solar cells to form a cell string.

[0088] Optionally, the distance between the first parallel main joint P3 adjacent to the first auxiliary joint P2 and the first collector grid line 211 adjacent to the fourth end edge is greater than the distance between the first parallel main joint P3 adjacent to the first auxiliary joint P2 and the first auxiliary joint P3 adjacent to the first auxiliary joint P2. The width of the first parallel lap wire 26 along the second direction D2 first increases and then decreases along the first direction D1. The degree of width gradient of the first parallel lap wire from its widest point toward the direction of width reduction is different. For example, the width at the two ends along the second direction D2 is approximately the same, and the first parallel lap wire 26 is widest at the position where it is electrically connected to the first parallel main joint P3.

[0089] Furthermore, in the second direction D2, the third end E3 and the fourth end E4 of the electrode structure are provided with electrodes of the same polarity. On the one hand, from the perspective of the physical structure of the electrodes, the area of ​​the emitter can be increased. More emitter area means that more current can be carried. On the other hand, it can enhance the tunneling passivation effect, effectively reduce the energy loss of current during tunneling, and improve the transmission efficiency of the solar cell.

[0090] like Figure 5 As shown, the electrode structure also includes a second parallel main junction N3, which is the junction closest to the fourth end E4 among all the junctions adjacent to the second end E2. It should be noted that in other embodiments not shown in this application, the electrode structure may also include two or more second parallel main junctions N3 to achieve efficient current collection. The second parallel main junction N3 can be directly electrically connected to a portion of the second collector grid line 212 located in another collector grid line discontinuity region S2 at the second end E2, or electrically connected to a portion of the second collector grid line 212 located in another collector grid line discontinuity region S2 at the second end E2 via a second parallel connection wire 27, which will be detailed later. This allows the current collected by the second collector grid line 212 in the other collector grid line discontinuity region S2 at the second end E2 to be collected into the second parallel main junction N3. It should be noted that all collector wires electrically connected to the second parallel main junction N3 are second collector wires 212, meaning all collector wires electrically connected to the second parallel main junction N3 are of the same polarity. Both the second parallel main junction N3 and the second parallel contact line 27 are spaced a certain distance from the dissimilar first collector wire 211, thus preventing connection with the first collector wire 211 and avoiding short circuits. Similarly, the second parallel main junction can be electrically connected to two or more second auxiliary junctions. Optionally, the number of second auxiliary junctions electrically connected to the second parallel main junction does not exceed three to avoid increasing the current transmission path and thus increasing current collection losses.

[0091] The second parallel connecting line 27 is arranged at the edge of the electrode region A at the second end E2 and extends generally in the second direction D2. Similar to the second connecting line 24, the second parallel connecting line 27 can be electrically connected to the second parallel main junction N3 through the second current collecting grid line 212 arranged between the second parallel connecting line 27 and the second parallel main junction N3. Alternatively, the second parallel connecting line 27 can also be electrically connected to the second parallel main junction N3 via the second parallel connecting line 28 arranged between the second parallel connecting line 27 and the second parallel main junction N3, wherein the width of the second parallel connecting line 27 is greater than the width of the second current collecting grid line 212 to increase the reliability of current transmission. In addition, in the present embodiment, the distance of the second connecting line 24 extending in the second direction D2 and the distance of the second parallel connecting line 27 extending in the second direction D2 are both 6d. In this way, it is beneficial to the standardized operation in the welding process of the solar cells to form the cell string.

[0092] In addition, similar to the arrangement of the discontinuous first current collecting grid line and the discontinuous second current collecting grid line in the current collecting grid line discontinuous region at the third end E3, the number of discontinuous second current collecting grid lines interrupted by the first parallel main junction and the number of discontinuous first current collecting grid lines interrupted by the second parallel main junction are the same, and the discontinuous second current collecting grid lines interrupted by the first parallel main junction and the discontinuous first current collecting grid lines interrupted by the second parallel main junction are alternately distributed along the second direction. The specific arrangement will be described in the foregoing description of the arrangement of the discontinuous first current collecting grid line and the discontinuous second current collecting grid line in the current collecting grid line discontinuous region at the third end E3, which will not be described herein for brevity. That is, the electrode structures at the third end E3 and the fourth end E4 are arranged in a substantially symmetrical manner to facilitate the standardized operation in the welding process.

[0093] Alternatively, the distance between the second parallel main junction N3 adjacent to the second auxiliary junction N2 and the second current collecting grid line 212 adjacent to the fourth end edge is greater than the distance between the second parallel main junction N3 adjacent to the second auxiliary junction N2 and the second auxiliary junction N2 adjacent to the second parallel main junction N3. The width of the second parallel connecting line 27 in the second direction D2 on the first direction D1 first increases and then decreases, and the degree of width tapering of the second parallel connecting line 27 from the widest point towards the direction of width decrease is different. For example, the width at the two ends in the second direction D2 is substantially the same, and the second parallel connecting line 27 is the widest at the position electrically connected to the second parallel main junction N3.

[0094] Alternatively, the current collecting grid line adjacent to the third end edge in the current collecting grid line discontinuous region is continuous. Specifically, in the present embodiment, as shown in FIG. 6, the discontinuous second current collecting grid line adjacent to the third end edge in the current collecting grid line discontinuous region is continuous. Figure 2 and Figure 4As shown, the collector grid line immediately adjacent to the third end edge in the collector grid line discontinuous region is the first collector grid line 211, which is not broken in the first direction D1. In this way, the collector grid line can be broken as little as possible, thereby avoiding the formation of dead zones on the solar cell, while the current at the cell base edge can also be fully collected, improving the current output efficiency. It should be understood that the collector grid line immediately adjacent to the fourth end edge in the collector grid line discontinuous region at the fourth end E4 can also be arranged to be continuous.

[0095] Optionally, in the collector grid line continuous region, the length of at least one second collector grid line 212 adjacent to the first main junction is less than the length of the remaining second collector grid lines. Specifically, in the local region shown, the number of discontinuous second collector grid lines 212 broken by the first main junction P1 in the first direction D1 is one, and there is also one discontinuous second collector grid line broken by the first parallel main junction P3 at the corresponding position of the fourth end, which is marked with the reference numeral 212b, and the length of this second collector grid line 212b is less than the length of the remaining second collector grid lines 212 in the collector grid line continuous region. In this way, the number of broken second collector grid lines in the collector grid line discontinuous region is as small as possible while ensuring that the first main junction and the first auxiliary junction are electrically connected, achieving effective collection of the hetero-current, which is conducive to reducing the dead zones on the solar cell and reducing the performance loss of the solar cell. Figure 2

[0096] Optionally, in the collector grid line continuous region, the at least one second collector grid line 212b adjacent to the first main junction and having a length less than the length of the remaining second grid lines is electrically connected to the second auxiliary junction. That is, there is an isolation region between the corresponding doped semiconductor layers between the first main junction and the first auxiliary junction, and there is no isolation region between the corresponding doped semiconductor layers between the second main junction and the second auxiliary junction, and the isolation region is used to isolate the two doped semiconductor layers with opposite polarities. In this way, the first main junction P1 and the first auxiliary junction P2 can be well interconnected while breaking the number of collector grid lines between the first end and the second end as little as possible.

[0097] Optionally, the solar cell 100 can further include a doped semiconductor layer arranged between the electrode structure and the cell base 10 and electrically connected to the electrode structure. Specifically, the doped semiconductor layer can be arranged on or in the cell base 10, and at least the first collector grid line 211 and the second collector grid line 212 are electrically connected to the doped semiconductor layer.

[0098] ​Optionally, the area where the projection of the electrode structure on the battery substrate 10 is located is provided with a doped semiconductor layer. In this way, the tunneling passivation area can be increased, while avoiding the short circuit problem caused by electrode burning.

[0099] The embodiments of the present application also provide a photovoltaic module. The photovoltaic module includes at least two solar cells 100 described above. The at least two solar cells 100 in the photovoltaic module can be connected in series and / or parallel by conductive interconnections (such as solder strips) to form a cell string.

[0100] In the description of the present specification, the description of the terms "one embodiment", "some embodiments", "one example", "some examples", or "preferred embodiments" and the like means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0101] The embodiments of the present application are described in detail above. However, aspects of the present application are not limited to the above-described embodiments. Various modifications and alternatives can be applied to the above-described embodiments without departing from the scope of the present application.

Claims

1. A solar cell, characterized in that, include: A battery substrate, the battery substrate including a first end and a second end disposed opposite to each other in a first direction, and a third end and a fourth end disposed opposite to each other in a second direction, wherein the second direction intersects the first direction; and An electrode structure, located on the battery substrate, includes: Multiple collector grid lines, including a first collector grid line and a second collector grid line with opposite polarities extending in a first direction, at least a portion of the first collector grid line and at least a portion of the second collector grid line are alternately distributed in the second direction, the multiple collector grid lines located at the third end form a first collector grid line region, and the multiple collector grid lines located between the third end and the fourth end form a second collector grid line region; At least one first main junction, the first main junction being located in the first collector grid region and electrically connected to at least a portion of the first collector grid in the first collector grid region; A plurality of first auxiliary joints are located in the second collector grid region, wherein a portion of the first main joints and a portion of the first auxiliary joints are at least partially collinear in the second direction, and at least one first auxiliary joint is electrically connected to a first collector grid line in the second collector grid region; and A first connection wire is used to electrically connect a portion of the first collector grid line in the first collector grid line area to the first main joint, and a portion of the first collector grid line in the first collector grid line area is electrically connected to at least one first auxiliary joint through the first connection wire, wherein the number of first auxiliary joints electrically connected to the first main joint does not exceed three.

2. The solar cell according to claim 1, characterized in that, The first collector grid region is a collector grid discontinuity region, and the second collector grid region is a collector grid continuity region.

3. The solar cell according to claim 2, characterized in that, The first main joint is located at the first end and is electrically connected to the first collector grid line in the collector grid line discontinuity region located at the first end. The plurality of first auxiliary joints are located at the first end, and the first auxiliary joints located at the first end are electrically connected to the first collector grid line in the collector grid line continuity region located at the first end. The first lap joint is located at the first end, and the first collector grid line in the collector grid line discontinuity region is electrically connected to the first main joint at the first end via the first lap joint. The first collector grid line in the collector grid line discontinuity region is electrically connected to at least one of the first auxiliary joints at the first end via the first lap joint.

4. The solar cell according to claim 3, characterized in that, The electrode structure further includes: At least one second main junction is located in the collector grid line discontinuity region and is electrically connected to at least a portion of the second collector grid line in the collector grid line discontinuity region. A plurality of second auxiliary joints are located in the continuous region of the collector grid lines, wherein a portion of the second main joints and a portion of the second auxiliary joints are at least partially collinear in the second direction, and at least one second auxiliary joint is electrically connected to a second collector grid line in the continuous region of the collector grid lines; and The second connection wire is used to electrically connect a portion of the second collector grid line in the discontinuity zone to the second main joint, and the second collector grid line in the discontinuity zone is also electrically connected to at least one second auxiliary joint via the second connection wire.

5. The solar cell according to claim 4, characterized in that, The second main joint is located at the second end and is electrically connected to the second collector grid line in the collector grid line discontinuity region located at the second end. The plurality of second auxiliary joints are located at the second end, and the second auxiliary joints located at the second end are electrically connected to the second collector grid line in the collector grid line continuity region located at the second end. The second lap wire is located at the second end. The second collector grid line in the collector grid line discontinuity region is electrically connected to the second main joint at the second end via the second lap wire, and the second collector grid line in the collector grid line discontinuity region is electrically connected to at least one second auxiliary joint at the second end via the second lap wire.

6. The solar cell according to claim 5, characterized in that, The distance between the end of the first lap wire located at the first end and the first collector grid line adjacent to the edge of the third end is different from the distance between the end of the second lap wire located at the second end and the second collector grid line adjacent to the edge of the third end.

7. The solar cell according to claim 5, characterized in that, The projection of the first main joint located at the first end on a plane perpendicular to the first direction at least partially overlaps with the projection of the second main joint located at the second end on the same plane perpendicular to the first direction.

8. The solar cell according to claim 5, characterized in that, The plurality of collector grid lines located at the fourth end form another collector grid line discontinuity region. The electrode structure further includes a first parallel lap wire and at least one first parallel main joint located in the other collector grid line discontinuity region. A portion of the first collector grid lines in the other collector grid line discontinuity region are electrically connected to the first parallel main joint via the first parallel lap wire. A portion of the first collector grid lines in the other collector grid line discontinuity region are electrically connected to at least one first auxiliary joint via the first parallel lap wire. The distance between the end of the first lap wire located at the third end and the first collector grid line adjacent to the edge of the third end is the same as the distance between the end of the first parallel lap wire located at the fourth end and the first collector grid line adjacent to the edge of the fourth end.

9. The solar cell according to claim 5, characterized in that, In the first direction, the number of interrupted second collector grid lines interrupted by the first main joint located at the first end is the same as the number of interrupted first collector grid lines interrupted by the second main joint located at the second end, and the interrupted second collector grid lines interrupted by the first main joint and the interrupted first collector grid lines interrupted by the second main joint are alternately distributed along the second direction.

10. The solar cell according to claim 8, characterized in that, The number of second auxiliary joints electrically connected to the second main joint is no more than three; and / or the number of first auxiliary joints electrically connected to the first parallel main joint is no more than three.

11. The solar cell according to claim 8, characterized in that, The distance between the first main joint adjacent to the first auxiliary joint and the first collector grid line adjacent to the third end edge is greater than the distance between the first main joint adjacent to the first auxiliary joint and the first auxiliary joint adjacent to the first main joint; and / or The distance between the second main joint adjacent to the second auxiliary joint and the second collector grid line adjacent to the third end edge is greater than the distance between the second main joint adjacent to the second auxiliary joint and the second auxiliary joint adjacent to the second main joint; and / or The distance between the first parallel main joint adjacent to the first auxiliary joint and the first collector grid line adjacent to the fourth end edge is greater than the distance between the first parallel main joint adjacent to the first auxiliary joint and the first auxiliary joint adjacent to the first parallel main joint.

12. The solar cell according to claim 11, characterized in that, The width of the first lap joint, and / or the second lap joint, and / or the first parallel lap joint increases and then decreases along the second direction in the first direction. The first lap joint is widest at the position where it is electrically connected to the first main joint, the second lap joint is widest at the position where it is electrically connected to the second main joint, and the first parallel lap joint is widest at the position where it is electrically connected to the first parallel main joint. The degree of width gradient of the first lap joint, the second lap joint, or the first parallel lap joint from its widest point toward the direction of width reduction is different.

13. The solar cell according to any one of claims 2 to 12, characterized in that, The first collector grid line immediately adjacent to the third end edge in the discontinuity region of the collector grid line is continuous.

14. The solar cell according to claim 2 or 3, characterized in that, In the continuous region of the collector grid lines, the length of at least one of the second collector grid lines adjacent to the first main junction is less than the length of the remaining second collector grid lines.

15. The solar cell according to any one of claims 4 to 12, characterized in that, In the continuous region of the collector grid lines, the length of at least one of the second collector grid lines adjacent to the first main junction is less than the length of the remaining second collector grid lines.

16. The solar cell according to any one of claims 15, characterized in that, In the continuous region of the collector grid lines, at least one second collector grid line whose length is less than the other second collector grid lines and which is adjacent to the first main junction is electrically connected to the second auxiliary junction.

17. The solar cell according to any one of claims 1 to 12, characterized in that, The solar cell further includes a doped semiconductor layer disposed between the electrode structure and the cell substrate, and electrically connected to the electrode structure.

18. A photovoltaic module, characterized in that, It includes at least two solar cells as described in any one of claims 1 to 17.

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