Solar cell module

Abstract

The utility model discloses a solar cell module, and relates to the technical field of solar cells, the solar cell module comprises a plurality of cell sheets, the plurality of cell sheets are arranged in a multi-row and multi-column array, each cell sheet comprises a first surface and a second surface which are oppositely arranged, and the first surface of each cell sheet is provided with a plurality of first grooves which are arranged in parallel at intervals; a plurality of second grooves which are arranged in parallel at intervals are formed in the second surface; the parallel directions of the first groove and the second groove are consistent; conductive layers are respectively arranged in the plurality of grooves, and cover the groove surfaces of the corresponding grooves; a welding strip is arranged between adjacent battery pieces in the solar battery assembly, and the adjacent battery pieces are electrically connected through the welding strip. The welding strips are embedded in the grooves and attached to the conductive layers in the corresponding grooves. According to the solar cell module, the power generation efficiency of the solar cell module can be further improved while the connection reliability between the cell pieces is ensured.

Description

Technical Field

[0001] The utility model relates to the technical field of solar cells, in particular to a solar cell assembly. Background Art

[0002] In related technologies, solar cell modules are typically connected in series or parallel to meet user requirements for performance parameters such as voltage and current. Using solder tape to achieve series and parallel connection between cells is a common and important technical approach in this field.

[0003] The morphology of the welding ribbon and the welding method have an impact on the performance parameters of the solar cell module, such as the power generation efficiency and reliability. For example, when a welding ribbon with a narrower cross-section (such as a round welding ribbon) is used to connect the battery cell, a linear connection is formed between the welding ribbon and the battery cell, which is prone to cold welding, limiting the current collection capacity, and thus reducing the power generation efficiency of the battery cell. When a welding ribbon with a wider cross-section (such as a flat welding ribbon) is used to connect the battery cell, although a more reliable surface connection can be formed between the welding ribbon and the battery cell, the wider welding ribbon will increase the blocking area of the battery cell, which will also reduce the power generation efficiency of the battery cell.

[0004] Therefore, it is necessary to make further technical improvements to the structure of solar cell modules. Utility Model Content

[0005] The present invention aims to solve one of the technical problems in the related art to a certain extent. To this end, the present invention provides a solar cell assembly that further improves the power generation efficiency of the solar cell assembly while ensuring the reliability of the connection between the cells.

[0006] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0007] A solar cell assembly includes a plurality of cells arranged in a multi-row and multi-column array, wherein the cell includes a first surface and a second surface disposed opposite to each other.

[0008] The first surface of the battery cell is provided with a plurality of first grooves arranged in parallel and spaced apart;

[0009] The second surface of the battery cell is provided with a plurality of second grooves arranged in parallel and spaced apart; the parallel directions of the first grooves and the second grooves are consistent; wherein,

[0010] A conductive layer is provided in each of the first groove and the second groove, and the conductive layer covers the groove surface of the corresponding first groove and the second groove;

[0011] A welding ribbon is provided between adjacent battery cells in the solar cell assembly, and adjacent battery cells are electrically connected through the welding ribbon; one end of the welding ribbon is embedded in the first groove of one of the adjacent battery cells; the other end of the welding ribbon is embedded in the second groove of the other adjacent battery cell; the welding ribbon is bonded to the corresponding conductive layer.

[0012] In the above scheme, after the first groove and the second groove for welding with the welding ribbon are set on the battery cell, since each groove (such as the first groove and the second groove) has a concave surface, the area of the concave surface is larger than the contour area of the notch, which is equivalent to changing the original two-dimensional plane where the battery cell surface contacts the welding ribbon into a three-dimensional concave surface. While maintaining a smaller blocking area of the welding ribbon on the battery cell, the contact surface area between the welding ribbon and the battery cell is increased, thereby reducing defects such as cold soldering, increasing the welding force between the welding ribbon and the battery cell, and improving the current collection capability, thereby improving the power generation efficiency.

[0013] Moreover, each groove (such as the first groove and the second groove) can accommodate part of the welding ribbon, so that only part of the welding ribbon is exposed on the surface of the battery cell. That is, compared with the solution in the related art of setting the welding ribbon entirely on the surface of the battery cell, this solution can effectively reduce the protrusion height of the welding ribbon on the surface of the battery cell. In this way, when sunlight is obliquely irradiated on the surface of the battery cell, the welding ribbon with a lower protrusion height reduces the obstruction of sunlight, thereby further improving the power generation efficiency.

[0014] Optionally, in each of the battery cells, the plurality of first grooves on the first surface and the plurality of second grooves on the second surface are staggered.

[0015] Optionally, in each of the battery cells, orthographic projections of the plurality of first grooves located on the first surface on the second surface are separated from or partially overlapped with orthographic projections of the plurality of second grooves located on the second surface on the second surface.

[0016] Optionally, in each of the battery cells, a minimum distance between a first groove located on the first surface of the battery cell and a second groove located on the second surface of the battery cell in a direction perpendicular to the thickness of the battery cell is at least 30% of the thickness of the battery cell.

[0017] Optionally, the depth of the first groove and / or the second groove is 30%-70% of the thickness of the battery cell; correspondingly, the thickness of the conductive layer includes: 5μm-50μm.

[0018] Optionally, the width of the first groove and / or the second groove is 100 μm-300 μm.

[0019] Optionally, the height of the exposed portion of the soldering ribbon relative to the surface of the battery cell is less than or equal to half of the total height of the soldering ribbon.

[0020] Optionally, the battery cell includes:

[0021] a silicon substrate having a first initial surface and a second initial surface opposite to each other;

[0022] A first functional layer is located on the first initial surface side of the silicon substrate; and

[0023] The second functional layer is located on the second initial surface side of the silicon substrate; wherein,

[0024] A first initial groove is formed on the first initial surface of the silicon substrate; a portion of the first functional layer conformally covering the first initial groove is formed as the first groove;

[0025] A second initial groove is formed on the second initial surface of the silicon substrate; and a portion of the second functional layer conformally covering the second initial groove is formed as the second groove.

[0026] Optionally, the battery cell includes:

[0027] a silicon substrate having a first initial surface and a second initial surface opposite to each other;

[0028] A first functional layer is located on the first initial surface side of the silicon substrate; and

[0029] The second functional layer is located on the second initial surface side of the silicon substrate; wherein,

[0030] The first groove is formed on the first functional layer and at least partially penetrates the first functional layer;

[0031] The second groove is formed on the second functional layer and at least partially penetrates the second functional layer.

[0032] Optionally, the conductive layer includes at least one of a conductive adhesive layer, a silver paste layer, a copper paste layer, and a tin paste layer.

[0033] These features and advantages of the present invention will be detailed in the following detailed description and accompanying drawings. The preferred embodiments or means of the present invention will be fully illustrated in conjunction with the accompanying drawings, but are not intended to limit the technical solutions of the present invention. Furthermore, although multiple features, elements, and components may be present and are labeled with different symbols or numbers for convenience, they all represent components with the same or similar structure or function. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] The present invention will be further described below with reference to the accompanying drawings:

[0035] Figure 1This is a schematic structural diagram of a solar cell assembly provided in some embodiments of the present application;

[0036] Figure 2 This is a schematic structural diagram of a battery cell provided in some embodiments of the present application;

[0037] Figure 3 for Figure 2 A schematic cross-sectional view of a battery cell along the AA direction is shown;

[0038] Figure 4 A schematic diagram of the film layer structure of a battery cell provided in some embodiments of the present application;

[0039] Figure 5 A schematic diagram of the film layer structure of another battery cell provided in some embodiments of the present application;

[0040] Figure 6 for Figure 5 Enlarged view of point A in the middle.

[0041] Figure 7 This is a schematic structural diagram of a battery cell and solder ribbon assembly provided in some embodiments of the present application.

[0042] Reference numerals:

[0043] 100 - cell; 110 - silicon substrate; 120 - functional layer; 121 - first functional layer; 122 - second functional layer; 130 - groove; 131 - first groove; 132 - second groove; 140 - conductive layer; 200 - gate line; 210 - soldering strip. DETAILED DESCRIPTION

[0044] The following describes in detail embodiments of the present invention, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described in the embodiments are intended to explain the present invention and are not to be construed as limiting the present invention.

[0045] References in this specification to "one embodiment," "an example," or "an example" mean that a particular feature, structure, or characteristic described in connection with the embodiment itself can be included in at least one embodiment disclosed herein. The appearance of the phrase "in one embodiment" in various places in the specification does not necessarily refer to the same embodiment.

[0046] The morphology of the welding ribbon and the welding method have an impact on the performance parameters of the solar cell module, such as the power generation efficiency and reliability. For example, when a welding ribbon with a narrower cross-section (such as a round welding ribbon) is used to connect the battery cell, a linear connection is formed between the welding ribbon and the battery cell, which is prone to cold welding, limiting the current collection capacity, and thus reducing the power generation efficiency of the battery cell. When a welding ribbon with a wider cross-section (such as a flat welding ribbon) is used to connect the battery cell, although a more reliable surface connection can be formed between the welding ribbon and the battery cell, the wider welding ribbon will increase the blocking area of the battery cell, which will also reduce the power generation efficiency of the battery cell.

[0047] Example:

[0048] See also Figure 1 This embodiment provides a solar cell assembly comprising a plurality of cells 100 arranged in a multi-row and multi-column array. The drawings of this application illustrate the arrangement of the cells 100 in three rows and two columns. It should be understood that the aforementioned number of rows and / or columns is for illustrative purposes only and does not constitute a limitation on the technical solutions of this application.

[0049] See also Figure 2 The cell 100 has a first surface and a second surface opposite to each other, namely, a front surface (e.g., a light incident surface) and a back surface (e.g., a light-receiving surface) of the cell 100. The first surface of the cell 100 is provided with a plurality of first grooves 131 arranged in parallel and spaced apart, and the second surface of the cell 100 is provided with a plurality of second grooves 131 arranged in parallel and spaced apart; the first grooves 131 and the second grooves 132 are arranged in the same parallel direction;

[0050] A conductive layer 140 is disposed in each of the first groove 131 and the second groove 132 . The conductive layer 140 covers the corresponding groove surfaces of the first groove 131 and the second groove 132 .

[0051] Correspondingly, welding ribbons 210 are provided between adjacent cells 100 in the solar cell assembly, electrically connecting the adjacent cells 100 via the plurality of welding ribbons 210. One end of the welding ribbon 210 is embedded in the first groove 131 of one of the adjacent cells 100; the other end of the welding ribbon 210 is embedded in the second groove 132 of the other adjacent cell 100. The welding ribbon 210 is bonded to the corresponding conductive layer 140, and the two are fixed and electrically connected by welding at the bonding surface. Multiple cells 100 can be connected in series or in parallel as needed, without limitation.

[0052] In some embodiments, the battery cell 100 is generally configured as a square or rectangle, and in other embodiments, it can also be configured as a triangle, a regular hexagon, a trapezoid or a fan, etc. The front and back of the battery cell 100 are respectively located on both sides of the thickness direction of the battery cell 100, and the thickness direction is the z-axis direction in the figure. The front and back of the battery cell 100 are parallel to the plane formed by the x and y axes. Both the front and back of the battery cell 100 can be used to receive light and generate electricity. This application does not impose any restrictions on this. When in use, the side that receives sunlight is generally used as the front (i.e., the light-entering side), and the back of the battery cell (i.e., the backlight side) can receive sunlight diffusely reflected by the environment, and its power generation efficiency is usually lower than that of the front.

[0053] In some embodiments, the type of the cell 100 includes: a PERC cell, a TOPCon cell, a BC cell, an HJT cell or a stacked cell, which is not limited in this application.

[0054] Please continue reading Figure 2 In one embodiment, the plurality of first grooves 131 located on the first surface of the battery cell 100 and the plurality of second grooves 131 located on the second surface extend in both directions along a first direction (e.g., the Y direction) and connect to the edge of the battery cell 100. The plurality of first grooves 131 located on the first surface of the battery cell 100 and the plurality of second grooves 131 located on the second surface are arranged in parallel and spaced apart along a second direction (e.g., the X direction), and may be arranged at equal or uneven intervals. The first direction (e.g., the Y direction) intersects with the second direction (e.g., the X direction), and preferably, the first direction (e.g., the Y direction) and the second direction (e.g., the X direction) are perpendicular to each other.

[0055] In some embodiments, the first direction (e.g., Y direction) is the width direction of the battery cell 100, and the second direction (e.g., X direction) is the length direction of the battery cell 100; alternatively, the first direction (e.g., Y direction) is the length direction of the battery cell 100, and the second direction (e.g., X direction) is the width direction of the battery cell 100. This application does not limit this.

[0056] For example, in this embodiment, the first direction (e.g., the Y direction) is the width direction of the battery cell 100, and the second direction is the length direction of the battery cell 100, wherein a plurality of first grooves 131 and second grooves 132 are arranged in parallel along the length direction (i.e., the X direction) in an equidistant manner on the front and back sides of the battery cell 100, i.e., the spacing between two adjacent first grooves 130 and / or second grooves 132 on the front or back sides of the battery cell 100 is the same. Through such an arrangement, the first grooves 130 and / or the second grooves 132 can be relatively evenly distributed on the surface (i.e., the front and back sides) of the battery cell 100, so as to avoid stress concentration on the surface of the battery cell 100, thereby causing abnormal rupture of the battery cell 100. In addition, this relatively regular groove arrangement also facilitates large-scale production and manufacturing, reducing production costs.

[0057] See also Figure 3 In one embodiment, on each battery cell 100, the plurality of first grooves 131 located on the front surface of the battery cell 100 and the plurality of second grooves 132 located on the back surface of the battery cell 100 are staggered. For example, on the same battery cell 100, the orthographic projections of the plurality of first grooves 131 located on the first surface on the second surface (e.g., the XY plane) and the orthographic projections of the plurality of second grooves 132 located on the second surface on the second surface are separated from or partially overlapped.

[0058] In the above embodiment, the first groove 131 on the front side of the battery cell 100 and the second groove 132 on the back side are offset by a small distance on the orthographic projection plane, thereby preventing the first groove 131 on the front side of the battery cell 100 and the second groove 132 on the back side from facing each other in the thickness direction. It can be understood that since the battery cell 100 has a certain thickness, after the first groove 131 is provided on the front side of the battery cell 100 and the second groove 132 is provided on the back side, the thickness of the battery cell 100 at the bottom of the first groove 131 and the second groove 132 is equivalently reduced. If the first groove 131 on the front side of the battery cell 100 and the second groove 132 on the back side are provided to face each other in the thickness direction, the equivalent thickness of the battery cell 100 at the grooves will be further reduced, resulting in stress concentration in the groove area of the battery cell 100, and even the risk of rupture. In this embodiment, by staggering the first groove 131 and the second groove 132 on the front and back sides, the first groove 131 on the front side of the battery cell 100 and the second groove 132 on the back side are avoided from facing each other in the thickness direction, that is, the strength can be maintained without increasing the thickness of the battery cell 100.

[0059] For example, the cross-sectional shape of the first groove 131 and / or the second groove 132 in the thickness plane of the cell 100 (e.g., the XZ plane) is semicircular, arcuate, triangular, trapezoidal, or similar, or a shape approximating a portion of a parabola, hyperbola, or other curved line segment, preferably a semicircular or arcuate shape, to best match the cross-sectional profile of the circular solder ribbon. It is understood that, in the thickness direction, the depth of the first groove 131 and / or the second groove 132 is shallower at the notches on either side, and the depth increases toward the center, i.e., the bottom, of the groove. However, it should be noted that the maximum depth of the first groove 131 and / or the second groove 132 is between 30% and 70% of the thickness of the cell 100. This ensures that the minimum distance between the first groove 131 on the front of the cell 100 and the second groove 132 on the back of the cell 100, after they are offset, is at least 30% of the thickness of the cell 100, ensuring that the cell 100 maintains sufficient thickness to maintain overall strength.

[0060] For example, the maximum depth of the first groove 131 is 30%, 40%, 50%, 60% or 70% of the thickness of the battery cell 100 .

[0061] For example, the maximum depth of the second groove 132 is 30%, 40%, 50%, 60% or 70% of the thickness of the battery cell 100 .

[0062] For example, the minimum distance between the first groove 131 on the first surface of the battery cell 100 and the second groove 132 on the second surface of the battery cell 100 in the direction perpendicular to the thickness of the battery cell 100 is 30%, 40%, 50% or 60% of the thickness of the battery cell 100.

[0063] In some embodiments, the conductive layer 140 is made of at least one of a conductive adhesive, silver paste, copper paste, and tin paste. Specifically, the conductive layer 140 on the inner wall of the groove 130 can be formed by applying a conductive adhesive and then photocuring it; it can also be formed by applying one or more layers of silver paste, copper paste, or tin paste. For example, the conductive layer 140 can be applied by electroplating, evaporation, thin film deposition, inkjet printing, screen printing, or slit coating.

[0064] Illustratively, the thickness of the conductive layer 140 is 5 μm-50 μm, such as 5 μm, 10 μm, 20 μm, 30 μm, 40 μm or 50 μm.

[0065] The thickness of the conductive layer 140 can be adjusted according to the cross-sectional shape of the groove 130, the cross-sectional shape of the soldering ribbon 210, the cost of the soldering ribbon 210, and the soldering process, and this application does not impose any restrictions on this. It should be noted that the cross-sectional shape of the soldering ribbon 210 can be circular, oblate, triangular, rectangular, polygonal, etc.

[0066] It is worth noting that, when the cell 100 is in use, the amount of electricity generated by direct sunlight on the front side is greater than the amount of electricity generated by ambient light on the back side. Based on this, those skilled in the art can, based on the usage characteristics of the front and back sides, form the conductive layer 140 located in the first groove 131 on the front side (i.e., the first surface) by coating it with a conductive silver paste to improve conductivity, and the conductive layer 140 located in the second groove 132 on the back side (i.e., the second surface) by curing a conductive adhesive or electroplating a silver paste layer, a copper paste layer, or a tin paste layer. In this way, the amount of paste used in the second groove 132 on the back side (i.e., the second surface) can be reduced, thereby reducing production costs.

[0067] In addition, in this embodiment, a conductive layer 140 is provided to connect the battery cell 100 and the welding strip 210. The presence of the conductive layer 140 can fill the surface defects such as fine cracks and pits generated on the surface of the first groove 131 and / or the second groove 132 during the processing, and bury burrs, protrusions and other defects, so that the surface flatness of the groove wall of the first groove 131 and / or the second groove 132 is improved, so that it can fully fit the surface shape of the welding strip 210, so that it forms a substantial welding part after welding with the welding strip 210, reducing the occurrence of cold welding, and improving the welding force of the welding strip 210 and the current collection efficiency.

[0068] Moreover, in this embodiment, after the first groove 131 and / or the second groove 132 for welding with the welding ribbon 210 are provided on the battery cell 100, since the first groove 131 and / or the second groove 132 have a concave surface, the area of the concave surface is larger than the contour area of the notch, which is equivalent to changing the original two-dimensional plane where the surface of the battery cell 100 contacts the welding ribbon 210 into a three-dimensional concave surface. While maintaining a small shielding area of the welding ribbon 210 on the battery cell 100, the contact surface area between the battery cell 100 and the welding ribbon 210 is increased, thereby further improving the contact area. The first groove 131 and / or the second groove 132 can accommodate part of the welding ribbon 210, so that only part of the welding ribbon 210 is exposed on the surface of the battery cell 100. That is, compared with the solution in the prior art in which the welding ribbon 210 is entirely set on the surface of the battery cell 100, this solution can effectively reduce the protrusion height of the welding ribbon 210 on the surface of the battery cell 100. When sunlight is obliquely irradiated to the surface of the battery cell 100, the welding ribbon 210 with a lower height reduces the obstruction of sunlight, thereby further improving the power generation efficiency of the battery cell 100.

[0069] See also Figure 4In some embodiments, the first groove 131 and / or the second groove 132 are formed by processing on the surface of the finished cell 100, such as by removing part of the structure on the surface of the finished cell 100 using an etching process. For example, the finished cell 100 includes a silicon substrate 110 and a first functional layer 121 located on the first initial surface of the silicon substrate 110 and a second functional layer 122 located on the second initial surface, that is, the first functional layer 121 located on the first initial surface of the silicon substrate 110 and the second functional layer 122 located on the second initial surface of the silicon substrate. Depending on the type of cell 100, the silicon substrate 110 is a silicon substrate, and the first functional layer 121 / the second functional layer 122 can be various functional film layers provided on the surface of the silicon substrate, such as an ITO layer, a passivation film, a polysilicon film, an anti-reflection film, etc.

[0070] For example, when the cell 100 is an HJT cell, the first functional layer 121 may include a composite film layer stacked sequentially by an intrinsic silicon passivation layer, an n-type doped amorphous silicon layer, and a transparent conductive layer; and the second functional layer 122 may include a composite film layer stacked sequentially by an intrinsic silicon passivation layer, a p-type doped amorphous silicon layer, and a transparent conductive layer. Alternatively, the first functional layer 121 may include a composite film layer stacked sequentially by an intrinsic silicon passivation layer, a p-type doped amorphous silicon layer, and a transparent conductive layer; and the second functional layer 122 may include a composite film layer stacked sequentially by an intrinsic silicon passivation layer, an n-type doped amorphous silicon layer, and a transparent conductive layer.

[0071] In the above embodiments, the first groove 131 and / or the second groove 132 are formed by machining the finished cell 100. This machining method requires minimal changes to the existing manufacturing process for producing the cell 100 and is easy to implement. However, regardless of whether the depth of the first groove 131 and / or the second groove 132 is thicker or thinner than the functional layer 120, this method may damage the functional layer 120 to a certain extent. In other words, the machining of the groove may penetrate at least part of the film layer of the functional layer, or completely penetrate all of the film layers, thereby reducing the power generation performance of the cell 100.

[0072] See also Figure 5 and Figure 6 In other embodiments, a first initial groove is first processed on the silicon substrate, that is, on the first initial surface of the original silicon wafer, and a second initial groove is processed on the second initial surface of the original silicon wafer; then, a conventional battery process is performed based on the silicon wafer that has undergone the groove processing process, so that the first functional layer 121 formed later conformally covers the part of the first initial groove to form the first groove 131; the second functional layer 122 conformally covers the part of the second initial groove to form the second groove 132; in this way, damage to the functional layer 120 can be avoided, thereby reducing the impact of the first groove 131 and / or the second groove 132 on the power generation performance of the battery cell 100.

[0073] The width of the first groove 131 and / or the second groove 132 can be flexibly set between 100 μm and 300 μm according to the actual process conditions of the cell 100, and this application does not impose any restrictions on this. For example, when a certain number of auxiliary (fine) grids are provided on the cell 100, the width of the first groove 131 and / or the second groove 132 can be adjusted according to the number of auxiliary (fine) grids, so that they can function as main grids during welding.

[0074] For example, the width of the first groove 131 is 100 μm, 130 μm, 150 μm, 180 μm, 200 μm, 240 μm, 260 μm, 280 μm or 300 μm.

[0075] For example, the width of the second groove 132 is 100 μm, 130 μm, 150 μm, 180 μm, 200 μm, 240 μm, 260 μm, 280 μm, or 300 μm.

[0076] See also Figure 7 In one embodiment, a solar cell assembly comprises a cell 100 and a soldering ribbon 210. The cell 100 is provided with a plurality of grid lines 200 formed by the soldering ribbon 210 and the conductive layer 140. This not only replaces the existing main grid lines on the cell surface, but also allows the conventional secondary grid lines to be omitted by providing a sufficiently dense arrangement of grooves 130 and soldering ribbons 210. Although the number of soldering ribbons 210 increases, the reduced number of secondary grid lines reduces the total silver paste used in the cell 100 compared to the prior art, thereby reducing costs.

[0077] In one embodiment, with the surface of the cell 100 as the boundary, a portion of the soldering ribbon 210 is exposed from the cell 100 surface, while a portion of the soldering ribbon 210 is embedded in the first groove 131 and / or the second groove 132. Furthermore, the volume of the soldering ribbon 210 exposed from the cell 100 surface is smaller than the volume of the soldering ribbon 210 embedded in the first groove 131 and / or the second groove 132. This arrangement allows a majority of the soldering ribbon 210 to bond with the groove 130 of the cell 100, improving the connection strength between the two. Furthermore, the exposed portion of the soldering ribbon 210 is reduced, which is equivalent to reducing the height of the soldering ribbon 210 protruding from the cell 100 surface.

[0078] In a specific implementation, a first groove 131 and / or a second groove 132 with a semicircular cross-section can be used, and the welding ribbon 210 can be a circular cross-section welding ribbon. The diameter of the first groove 131 and / or the second groove 132 is slightly larger than the diameter of the welding ribbon 210. When the welding ribbon 210 is placed in the first groove 131 and / or the second groove 132, the height of the welding ribbon 210 exposed on the surface of the solar cell is less than or equal to half of the total height of the welding ribbon 210. After the welding ribbon 210 is welded to the conductive layer 140 in the first groove 131 and / or the second groove 132, most of the welding ribbon 210 is located below the surface notch of the solar cell 100. After the metallization welding, the welding ribbon 210 and the conductive layer 140 partially melt and solidify into one, so that most of the welding ribbon 210 is located in the first groove 131 and / or the second groove 132.

[0079] For example, the welding process between the welding ribbon 210 and the conductive layer 140 includes: laser-assisted welding or high-temperature sintering and curing.

[0080] The above are only specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Those skilled in the art should understand that the present invention includes but is not limited to the contents described in the drawings and the above specific embodiments. Any modifications that do not deviate from the functional and structural principles of the present invention are included within the scope of the claims.

Claims

1. A solar cell assembly comprising a plurality of cells arranged in a multi-row and multi-column array, wherein the cells comprise a first surface and a second surface disposed opposite to each other, characterized in that: The first surface of the battery cell is provided with a plurality of first grooves arranged in parallel and spaced apart; The second surface of the battery cell is provided with a plurality of second grooves arranged in parallel and spaced apart; the parallel directions of the first grooves and the second grooves are consistent; wherein, A conductive layer is provided in each of the first groove and the second groove, and the conductive layer covers the groove surface of the corresponding first groove and the second groove; A welding ribbon is provided between adjacent battery cells in the solar cell assembly, and adjacent battery cells are electrically connected through the welding ribbon; one end of the welding ribbon is embedded in the first groove of one of the adjacent battery cells; the other end of the welding ribbon is embedded in the second groove of the other adjacent battery cell; the welding ribbon is bonded to the corresponding conductive layer.

2. The solar cell assembly according to claim 1, wherein In each of the battery cells, the plurality of first grooves on the first surface and the plurality of second grooves on the second surface are staggered.

3. The solar cell assembly according to claim 2, wherein: In each of the battery cells, orthographic projections of the plurality of first grooves on the first surface on the second surface are separated from or partially overlapped with orthographic projections of the plurality of second grooves on the second surface on the second surface.

4. The solar cell assembly according to any one of claims 1 to 3, characterized in that: In each of the battery cells, a minimum distance between the first groove on the first surface of the battery cell and the second groove on the second surface of the battery cell in a direction perpendicular to the thickness of the battery cell is at least 30% of the thickness of the battery cell.

5. The solar cell assembly according to any one of claims 1 to 3, characterized in that: The depth of the first groove and / or the second groove is 30%-70% of the thickness of the battery cell; correspondingly, The thickness of the conductive layer is 5 μm-50 μm.

6. The solar cell assembly according to any one of claims 1 to 3, characterized in that: The width of the first groove and / or the second groove ranges from 100 μm to 300 μm.

7. The solar cell assembly according to any one of claims 1 to 3, characterized in that: The height of the exposed portion of the soldering ribbon relative to the surface of the solar cell is less than or equal to half of the total height of the soldering ribbon.

8. The solar cell assembly according to any one of claims 1 to 3, characterized in that: The battery cell includes: a silicon substrate having a first initial surface and a second initial surface opposite to each other; A first functional layer is located on the first initial surface side of the silicon substrate; and The second functional layer is located on the second initial surface side of the silicon substrate; wherein, A first initial groove is formed on the first initial surface of the silicon substrate; a portion of the first functional layer conformally covering the first initial groove is formed as the first groove; A second initial groove is formed on the second initial surface of the silicon substrate; and a portion of the second functional layer conformally covering the second initial groove is formed as the second groove.

9. The solar cell assembly according to any one of claims 1 to 3, characterized in that: The battery cell includes: a silicon substrate having a first initial surface and a second initial surface opposite to each other; A first functional layer is located on the first initial surface side of the silicon substrate; and The second functional layer is located on the second initial surface side of the silicon substrate; wherein, The first groove is formed on the first functional layer and at least partially penetrates the first functional layer; The second groove is formed on the second functional layer and at least partially penetrates the second functional layer.

10. The solar cell assembly according to any one of claims 1 to 3, characterized in that: The conductive layer includes at least one of a conductive adhesive layer, a silver paste layer, a copper paste layer, and a tin paste layer.

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