Battery piece and photovoltaic module

Abstract

The utility model relates to a battery piece and a photovoltaic module, the battery piece comprises a battery piece main body, a plurality of main grid lines and a plurality of auxiliary grid lines, the battery piece main body is provided with a plurality of grooves arranged in parallel, the grooves penetrate to at least one side edge of the battery piece main body, the plurality of main grid lines are correspondingly accommodated in the plurality of grooves, the thickness of the main grid lines is smaller than the depth of the grooves, and the auxiliary grid lines are arranged in the grooves. The plurality of auxiliary grid lines are vertically connected with the plurality of main grid lines, and partial structures of the auxiliary grid lines extend from the surface of the battery piece main body to the main grid lines along the groove walls of the grooves. According to the battery piece and the photovoltaic module, the protruding height of the welding strip from the surface of the battery piece main body can be reduced due to the arrangement of the groove, so that the thickness of an adhesive film can be reduced under the condition that the lamination requirement is met, and the cost is reduced; moreover, the protruding height of the welding strip from the surface of the battery piece main body is reduced, so that the shielding of the welding strip on the light receiving surface of the battery piece can be reduced, and the power of the photovoltaic module can be improved.

Description

Technical Field

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

[0002] In photovoltaic modules, soldering ribbons are typically welded to the main grid lines of the cell to interconnect the cells. After welding, the ribbons protrude from the surface of the cell. However, the weight and thickness of the adhesive film are required during the packaging of photovoltaic modules. The higher the protrusion of the ribbons, the thicker the film needs to be to prevent hidden cracks in the cell during the lamination process. In addition, when the photovoltaic module is operating, light may shine obliquely on the surface of the cell. In this way, the ribbons protruding from the surface of the cell will cast a shadow on the light-receiving surface of the cell. In other words, the solder joints will block light from reaching the light-receiving surface of the cell, resulting in a decrease in the power of the photovoltaic module. Summary of the Invention

[0003] Based on this, the present application provides a solar cell and a photovoltaic module to solve the technical problem of how to reduce costs and increase power.

[0004] In one aspect, the present application provides a battery cell, comprising:

[0005] A battery cell body, wherein the battery cell body is provided with a plurality of parallel grooves, wherein the grooves extend through at least one side edge of the battery cell body;

[0006] A plurality of busbars, each of the busbars being correspondingly received in a plurality of grooves, wherein a thickness of the busbars is less than a depth of the grooves;

[0007] A plurality of auxiliary grid lines are vertically connected to the plurality of main grid lines, and a portion of the auxiliary grid lines extends from the surface of the battery cell body along the groove wall of the groove to the main grid lines.

[0008] In one embodiment, the depth of the groove is 20 μm to 50 μm.

[0009] In one embodiment, the width of the groove gradually decreases in the depth direction of the groove.

[0010] In one embodiment, the cross-sectional shape of the groove wall of the groove is trapezoidal, triangular or arc-shaped.

[0011] In one embodiment, the cell body includes a silicon wafer, a doping layer, a passivation layer and an anti-reflection layer. A plurality of recessed areas are provided on the front side of the silicon wafer. The doping layer, the passivation layer and the anti-reflection layer are sequentially arranged on the front side of the silicon wafer, and are all recessed at positions corresponding to the recessed areas, so that the groove is formed on the surface of the anti-reflection layer facing away from the passivation layer.

[0012] In one embodiment, the thickness of at least one of the doping layer, the passivation layer and the anti-reflection layer at a position corresponding to the recessed area is the same as the thickness at a position corresponding to the non-recessed area.

[0013] On the other hand, the present application provides a photovoltaic module, comprising a plurality of welding ribbons and a cell as described above, wherein the cell is connected to another cell via a plurality of the welding ribbons, the welding ribbons are embedded in the grooves, and the welding ribbons are welded to the main grid lines.

[0014] In one embodiment, the thickness of the welding strip is greater than the depth of the groove, and a packaging film is provided on the front of the battery cell. The position where the packaging film covers the welding strip is formed with an embedding groove corresponding to the groove. In the thickness direction of the battery cell, part of the structure of the welding strip is located in the groove, and the rest of the structure is located in the embedding groove.

[0015] In one embodiment, a plurality of grooves are provided on the front and back sides of the battery cell body, and the grooves on the front side of the battery cell body are parallel to the grooves on the back side of the battery cell body, each of the grooves is provided with the main grid line, and the main grid line on the front side of the battery cell is connected to the main grid line on the back side of the adjacent battery cell through the welding strip.

[0016] In one embodiment, the cross-section of the welding ribbon is flat or circular.

[0017] The above-mentioned photovoltaic modules and battery cells are provided with a plurality of parallel grooves, and the grooves extend to at least one side edge of the battery cell body, so that the main grid lines can be set by using the grooves, and since the thickness of the main grid lines is less than the depth of the grooves, the main grid lines will not protrude from the surface of the battery cell body, and part of the structure of the secondary grid lines extends from the surface of the battery cell body along the groove walls to the main grid lines, so as not to interfere with the welding strips embedded in the grooves to achieve welding with the main grid lines, and when the welding strips are welded to the main grid lines, the setting of the grooves can reduce the protruding height of the welding strips from the surface of the battery cell body, thereby reducing the thickness of the adhesive film while meeting the lamination requirements to reduce costs; moreover, since the structure of the battery cell of the present application can reduce the protruding height of the welding strips from the surface of the battery cell body, it can also reduce the blocking of the welding strips on the light-receiving surface of the battery cell, so as to help improve the power of the photovoltaic module. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present application or related technologies, the following briefly introduces the drawings required for use in the embodiments or related technical descriptions. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, without paying any creative work, they can also obtain drawings of other embodiments based on these drawings.

[0019] Figure 1 This is a schematic structural diagram of a photovoltaic module according to one embodiment of the present application.

[0020] Figure 2 A photovoltaic module according to an embodiment of the present application Figure 1 Schematic diagram of the cross-sectional structure of line II in.

[0021] Figure 3 This is a schematic structural diagram of a battery cell according to one embodiment of the present application.

[0022] Figure 4 The battery cell edge of one embodiment of the present application Figure 3 Schematic diagram of the cross-sectional structure of line II-II.

[0023] Figure 5 for Figure 3 Schematic side view of a battery cell.

[0024] Figure 6 This is a schematic cross-sectional structural diagram of a photovoltaic assembly according to one embodiment of the present application from another angle.

[0025] Description of reference numerals:

[0026] 100, photovoltaic module; 10, battery cell; 11, battery cell body; 101, groove; 111, silicon wafer; 1111, recessed area; 112, doping layer; 113, passivation layer; 114, anti-reflection layer; 12, main grid line; 13, auxiliary grid line; 20, welding ribbon; 30, encapsulation film; 31, joint groove. DETAILED DESCRIPTION

[0027] To make the above-mentioned objects, features, and advantages of the present application more clearly understood, the specific embodiments of the present application are described in detail below with reference to the accompanying drawings. The following description sets forth many specific details to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways than those described herein, and those skilled in the art can make similar improvements without violating the scope of the present application. Therefore, the present application is not limited to the specific embodiments disclosed below.

[0028] In the description of this application, it should be understood that if the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. appear, the orientation or position relationship indicated by these terms is based on the orientation or position relationship shown in the accompanying drawings, which is only for the convenience of describing this application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on this application.

[0029] In addition, if the terms "first" or "second" appear, these terms are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of technical features indicated. Therefore, a feature specified as "first" or "second" may explicitly or implicitly include at least one of such features. In the description of this application, if the term "plurality" appears, "plurality" means at least two, for example, two, three, etc., unless otherwise specifically defined.

[0030] In this application, unless otherwise specified or limited, the terms "mounted," "connected," "connected," "fixed," etc., should be interpreted broadly. For example, these terms may refer to fixed connections, removable connections, or integration; mechanical connections or electrical connections; direct connections or indirect connections through an intermediary; and internal communication between two components or interaction between two components, unless otherwise specified. Those skilled in the art will understand the specific meanings of these terms in this application based on the specific circumstances.

[0031] In this application, unless otherwise expressly specified or limited, if a first feature is described as being "above" or "below" a second feature, or similar descriptions, this may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. Furthermore, when a first feature is described as being "above," "above," or "above" a second feature, it may mean that the first feature is directly above or diagonally above the second feature, or simply means that the first feature is at a higher level than the second feature. When a first feature is described as being "below," "below," or "below" a second feature, it may mean that the first feature is directly below or diagonally below the second feature, or simply means that the first feature is at a lower level than the second feature.

[0032] It should be noted that if an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be an intermediate element. If an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be an intermediate element. If any, the terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used in this application are for illustrative purposes only and do not represent the only embodiment.

[0033] Combine Figure 1 and Figure 2 As shown, one embodiment of the present application provides a photovoltaic module 100, comprising a cell 10 and a plurality of welding ribbons 20. The cell 10 is connected to another cell 10 via the plurality of welding ribbons 20.

[0034] The cell 10 includes a cell body 11, a plurality of main grid lines 12 and a plurality of auxiliary grid lines 13. The cell body 11 is provided with a plurality of parallel grooves 101, and the grooves 101 extend to at least one side edge of the cell body 11. The plurality of main grid lines 12 are correspondingly accommodated in the plurality of grooves 101, and the thickness of the main grid lines 12 is less than the depth of the grooves 101. The plurality of auxiliary grid lines 13 are vertically connected to the plurality of main grid lines 12, and part of the structure of the auxiliary grid lines 13 extends from the surface of the cell body 11 along the groove wall of the groove 101 to the main grid lines 12. It should be noted that in the photovoltaic module 100, when the cell 10 is connected by a plurality of welding strips 20, the welding strips 20 are embedded in the grooves 101, and the welding strips 20 are welded to the main grid lines 12.

[0035] In the embodiment of the present application, since the battery cell body 11 is provided with a plurality of parallel grooves 101, the main grid lines 12 can be set using the grooves 101, and since the thickness of the main grid lines 12 is less than the depth of the grooves 101, the main grid lines 12 will not protrude from the surface of the battery cell body 11, and part of the structure of the secondary grid lines 13 extends from the surface of the battery cell body 11 along the groove walls of the grooves 101 to the main grid lines 12, so as not to interfere with the welding strips 20 embedded in the grooves 101 to achieve welding with the main grid lines 12, and the grooves 101 pass through at least one side edge of the battery cell body 11, so that the edge of the battery cell 10 will not interfere with the welding strips 20, thereby reducing the risk of the welding strips 20 squeezing the edge of the battery cell 10 and causing the edge of the battery cell 10 to be broken. When the welding ribbon 20 is welded to the main grid line 12, the setting of the groove 101 can reduce the protrusion height of the welding ribbon 20 from the surface of the battery cell body 11. As a result, the thickness of the adhesive film can be reduced while meeting the lamination requirements to reduce costs. Moreover, since the structure of the battery cell 10 of the present application can reduce the protrusion height of the welding ribbon 20 from the surface of the battery cell body 11, it can also reduce the blocking of the light-receiving surface of the battery cell 10 by the welding ribbon 20, which is beneficial to improving the power of the photovoltaic module 100.

[0036] Combine Figure 3 and Figure 4 As shown, in some embodiments, the depth d of the groove 101 is 20 μm to 50 μm. The depth d of the groove 101 can be 20 μm, 25 μm, 30 μm, 35 μm, 40 μm, 45 μm, or 50 μm, without limitation herein. The groove 101 can be formed by etching or laser cutting, and the form of the groove 101 is not limited herein.

[0037] Continue to combine Figure 3 and Figure 4 As shown, the cell body 11 includes a silicon wafer 111, a doped layer 112, a passivation layer 113, and an anti-reflection layer 114. The front surface of the silicon wafer 111 is provided with multiple recessed regions 1111. The doped layer 112, passivation layer 113, and anti-reflection layer 114 are sequentially arranged on the front surface of the silicon wafer 111, and are each recessed at the locations corresponding to the recessed regions 1111, so that a groove 101 is formed on the surface of the anti-reflection layer 114 facing away from the passivation layer 113. It should be noted that recessed regions 1111 are provided on the silicon wafer 111 at locations corresponding to where the grooves 101 are to be formed in the cell 10.

[0038] In some embodiments, during the production of the cell 10, the front (i.e., light-receiving) side of the cell 10 can be etched at locations corresponding to the busbars 12 according to the cell layout design during the texturing stage. Areas other than the busbars 12 can be protected using a mask. This creates corresponding grooves 101 at locations corresponding to the busbars 12. The etching depth can range from 20 μm to 50 μm, depending on the thickness of the cell 10 and the diameter of the solder ribbon 20. For example, the etching depth can be 20 μm, 25 μm, 30 μm, 35 μm, 40 μm, 45 μm, or 50 μm.

[0039] In some embodiments, at least one of the doping layer 112, the passivation layer 113, and the anti-reflection layer 114 has the same thickness at the location corresponding to the recessed area 1111 as at the location corresponding to the non-recessed area. The non-recessed area can be understood as the area other than the recessed area 1111. In this embodiment, since the thickness at the location corresponding to the recessed area 1111 is the same as the thickness at the location corresponding to the non-recessed area, the performance of the structural layers such as the doping layer 112, the passivation layer 113, or the anti-reflection layer 114 is stable in each area.

[0040] It should be noted that in the embodiment of the present application, since a plurality of recessed areas 1111 are provided on the front side of the silicon wafer 111, a structural setting with consistent thickness is maintained when forming the doping layer 112, the passivation layer 113 and the anti-reflection layer 114. This can maintain the corresponding performance of each structural layer while also facilitating the formation of a groove 101 having the same shape as the recessed area 1111 at the position corresponding to the recessed area 1111 of the cell body 11. In this way, the process of setting the recess 101 in the cell 10 of the present application does not increase the complexity of the process, making the cell 10 easy to manufacture.

[0041] In some embodiments, the width of the groove 101 gradually decreases along its depth (i.e., the thickness of the cell body 11). This structural arrangement allows the groove 101 to have a larger opening and a larger bottom, facilitating the placement of the busbars 12 and the soldering ribbons 20. Furthermore, because the busbars 12 are contained within the groove 101, the soldering ribbons 20 have a larger contact area with the cell 10 when embedded therein, facilitating good ohmic contact.

[0042] It should be noted that the shape of the groove 101 can be various. For example, in some embodiments, the cross-sectional shape of the groove wall of the groove 101 is trapezoidal, triangular, or arcuate. The shape of the groove 101 can be specifically set according to the size and shape of the welding ribbon 20 and is not limited here. In some embodiments, the cross-section of the welding ribbon 20 is flat or circular, which is not limited here.

[0043] Combine Figure 5 and Figure 6 As shown, in some embodiments, the thickness of the welding ribbon 20 is greater than the depth of the groove 101, and a packaging film 30 is provided on the front of the battery cell 10. An embedding groove 31 corresponding to the groove 101 is formed at the position where the packaging film 30 covers the welding ribbon 20. In the thickness direction of the battery cell 10, part of the structure of the welding ribbon 20 is located in the groove 101, and the remaining part of the structure is located in the embedding groove 31. In this embodiment, since the groove 101 not only accommodates the main grid line 12, but also part of the structure of the welding ribbon 20 is located in the groove 101, the height of the welding ribbon 20 protruding from the surface of the battery cell body 11 is reduced. Based on this, when the packaging film 30 is used for packaging, the packaging film 30 meets the thickness requirement to ensure that the battery cell 10 does not have hidden cracks during the lamination process. The packaging film 30 accommodates the remaining part of the welding ribbon 20 through the embedding groove 31. In this way, the packaging film 30 reduces the amount of adhesive used by reducing the material of the embedding groove 31, thereby reducing costs.

[0044] In some embodiments, a plurality of grooves 101 are provided on both the front and back sides of the cell body 11. The grooves 101 on the front side of the cell body 11 are parallel to the grooves 101 on the back side of the cell body 11. Each groove 101 is provided with a main grid line 12, and the main grid line 12 on the front side of the cell 10 is connected to the main grid line 12 on the back side of the adjacent cell 10 through the welding ribbon 20. In this embodiment, grooves 101 are provided on both the front and back sides of the cell 10, and then when the welding ribbon 20 is used to connect the cell 10 to the adjacent cell 10, the portion where the welding ribbon 20 is welded to the main grid line 12 on the front side of the cell 10 is embedded in the groove 101 on the front side of the cell 10, and the portion where the welding ribbon 20 is welded to the main grid line 12 on the back side of the cell 10 is embedded in the groove 101 on the back side of the cell 10, thereby achieving the overall thinning of the photovoltaic module 100.

[0045] In some embodiments, on the front side of the battery cell body 11, the distance between any two adjacent main grid lines 12 is the same. The number of main grid lines 12 can be configured according to actual needs. For example, 20 to 30 main grid lines 12 are spaced apart in the extension direction of the auxiliary grid lines 13. In some embodiments, the number of main grid lines 12 can be 20, 23, 25, 26, 27, 29 or 30, and the number of main grid lines 12 is not limited here.

[0046] On the front surface of the battery cell body 11, the distance between any two adjacent secondary grid lines 13 is the same. The number of secondary grid lines 13 is 85-185. The number of secondary grid lines 13 can be 85, 90, 95, 105, 125, 135, 155, 165, or 185 to meet the production requirements of battery cells 10 of corresponding specifications. The number and width of the secondary grid lines 13 are not limited here.

[0047] The technical features of the above embodiments can be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0048] The above embodiments merely illustrate several implementation methods of the present application, and while their descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that a person skilled in the art would be able to make various modifications and improvements without departing from the inventive concept of the present application, all of which fall within the scope of protection of the present application. Therefore, the scope of protection of the present invention shall be determined by the appended claims.

Claims

1. A battery cell (10), characterized in that: The battery cell (10) comprises: A battery cell body (11), the battery cell body (11) being provided with a plurality of parallel grooves (101), the grooves (101) penetrating to at least one side edge of the battery cell body (11); A plurality of main grid lines (12), wherein the plurality of main grid lines (12) are correspondingly accommodated in a plurality of grooves (101), and the thickness of the main grid lines (12) is less than the depth of the grooves (101); A plurality of auxiliary grid lines (13), wherein the plurality of auxiliary grid lines (13) are vertically connected to the plurality of main grid lines (12), and a portion of the structure of the auxiliary grid lines (13) extends from the surface of the battery cell body (11) along the groove wall of the groove (101) to the main grid lines (12).

2. The battery cell (10) according to claim 1, characterized in that: The depth of the groove (101) is 20 μm to 50 μm.

3. The battery cell (10) according to claim 1 or 2, characterized in that: In the depth direction of the groove (101), the width of the groove (101) gradually decreases.

4. The battery cell (10) according to claim 3, characterized in that: The cross-sectional shape of the groove wall of the groove (101) is trapezoidal, triangular or arc-shaped.

5. The battery cell (10) according to claim 1, characterized in that: The cell body (11) comprises a silicon wafer (111), a doping layer (112), a passivation layer (113) and an anti-reflection layer (114); a plurality of recessed areas (1111) are provided on the front side of the silicon wafer (111); the doping layer (112), the passivation layer (113) and the anti-reflection layer (114) are sequentially arranged on the front side of the silicon wafer (111) and are all recessed at positions corresponding to the recessed areas (1111), so that the groove (101) is formed on the surface of the anti-reflection layer (114) on the side facing away from the passivation layer (113).

6. The battery cell (10) according to claim 5, characterized in that: The thickness of at least one of the doping layer (112), the passivation layer (113) and the anti-reflection layer (114) at a position corresponding to the recessed area (1111) is the same as the thickness at a position corresponding to the non-recessed area.

7. A photovoltaic assembly (100), characterized in that: The invention comprises a plurality of welding strips (20) and a cell (10) according to any one of claims 1 to 6, wherein the cell (10) is connected to another cell (10) via the plurality of welding strips (20), the welding strips (20) are embedded in the grooves (101), and the welding strips (20) are welded to the main grid lines (12).

8. The photovoltaic assembly (100) according to claim 7, characterized in that The thickness of the soldering strip (20) is greater than the depth of the groove (101); a packaging film (30) is provided on the front surface of the battery cell (10); an embedding groove (31) corresponding to the groove (101) is formed at a position where the packaging film (30) covers the soldering strip (20); in the thickness direction of the battery cell (10), part of the structure of the soldering strip (20) is located in the groove (101), and the remaining part of the structure is located in the embedding groove (31).

9. The photovoltaic assembly (100) according to claim 7 or 8, characterized in that The front and back sides of the battery cell body (11) are both provided with a plurality of the grooves (101), and the grooves (101) located on the front side of the battery cell body (11) and the grooves (101) located on the back side of the battery cell body (11) are parallel to each other, and each of the grooves (101) is provided with the main grid line (12), and the main grid line (12) on the front side of the battery cell (10) is connected to the main grid line (12) on the back side of the adjacent battery cell (10) through the welding strip (20).

10. The photovoltaic assembly (100) according to claim 7 or 8, characterized in that: The cross section of the welding strip (20) is flat or circular.

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