Photovoltaic cell without main grid and photovoltaic module
By adopting a main gateless design and fixed structure on the photovoltaic cell, the problems of large amount of silver paste and hidden crack risks during welding are solved, and cost reduction and current collection efficiency are improved.
Patent Information
- Application Number
- CN202420217155.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-01-30
- Publication Date
- 2025-02-18
- Estimated Expiration
- 2034-01-30
AI Technical Summary
Existing photovoltaic cells consume a lot of silver paste when printing main gate lines, which increases costs, and the welding process can easily lead to cracks and fragmentation of the cell, reducing power generation and product qualification rate.
Adopting a main gateless photovoltaic cell design, by setting several thin grid lines and welding tapes on the main body of the solar cell, and using the first and second mounting grooves in the fixed structure, the welding tapes and thin grid lines are fixed to ensure their stable connection. .
It reduces the use of silver paste, reduces the cost of battery cells, improves the current collection efficiency, reduces the risk of hidden cracks, and improves the reliability and pass rate of the product.
Smart Images
Figure CN222509902U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of photovoltaic products, in particular to a main grid-free photovoltaic cell and a photovoltaic module. Background Art
[0002] The power generation substrate of the main body of the crystalline silicon solar cell (abbreviated as crystalline silicon cell) is a silicon wafer. Conventional cells are printed with many fine grid lines to collect the current generated by the silicon wafer after being exposed to light, and conventional cells are also printed with 5-20 main grid lines to collect the current on the fine grid lines. However, the main grid line needs to have a sufficient line width to achieve a good welding with the welding strip by chemical welding using the welding points on it. Therefore, printing the main grid line requires a large amount of silver paste, which will greatly increase the cost investment of the cell; and, in order to ensure the welding effect, during the chemical welding process, the welding strip usually needs to be welded and pressed with the welding points on the main grid line in a molten state. The welding process is likely to cause hidden cracks and fragments in the cell, which will reduce the power generation of the cell and cause a decrease in the product qualification rate of the cell. Therefore, under the urging of the goal of low-cost, high-power-generation cells, in order to reduce the use of silver paste, the main grid-free cell technology came into being.
[0003] A busbar-free cell generally refers to a conventional cell with the busbar removed and the fine grid retained. This type of cell can greatly reduce the use of expensive silver paste because it has no busbar. On the other hand, since there is no busbar on the surface of the cell to block the sunlight, it can also increase the effective illumination area of the cell. In actual operation, if you only rely on the metal connection between the round welding wire (or copper wire) and the fine grid, the connection reliability of the fine grid and the welding wire cannot be met, which can easily cause reliability risks such as poor welding, and then lead to poor current collection effect. Moreover, after welding, since the round welding wire is exposed on the outer surface of the cell, the height of the welding wire connection point of the cell is increased. Therefore, in the subsequent photovoltaic module lamination process, these welding wire connection points are prone to form stress concentration points, which brings a great risk of hidden cracks in the cell. Utility Model Content
[0004] The technical problem to be solved by the utility model is to provide a main grid-free photovoltaic cell and a photovoltaic assembly.
[0005] The utility model is realized by the following technical solutions:
[0006] A main-gridless photovoltaic cell comprises a solar cell body, a plurality of fine grid lines arranged on the solar cell body, and a plurality of welding strips arranged on the solar cell body and interlaced with the fine grid lines. A fixing structure for fixing the fine grid lines is arranged between the solar cell body and the welding strips. The fixing structure comprises a plurality of first mounting grooves uniformly arranged on the solar cell body for accommodating the welding strips. A plurality of second mounting grooves uniformly arranged on the welding strips for clamping the fine grid lines, and the sum of the depth of the first mounting grooves and the depth of the second mounting grooves is greater than the diameter of the welding strips.
[0007] As a further improvement of the present invention, the fine grid lines extend along the first direction and are evenly arranged along the second direction, the welding strips extend along the second direction and are evenly arranged along the first direction, and the first direction is perpendicular to the second direction.
[0008] As a further improvement of the present invention, the first mounting groove is a wire groove opened on the solar cell sheet body and extending along the second direction to match the welding strip.
[0009] As a further improvement of the present invention, the welding strip includes a conductive substrate and a low-temperature alloy layer coated on the surface of the conductive substrate.
[0010] As a further improvement of the present invention, a first welding portion is provided between the welding strip and the solar cell body.
[0011] As a further improvement of the present invention, a second welding portion is provided between the solar cell sheet body and the thin grid lines.
[0012] Based on the same concept, the utility model also proposes: a photovoltaic component, including a photovoltaic front panel, a first packaging film layer 8, a solar cell layer, a second packaging film layer, and a photovoltaic back panel stacked in sequence, characterized in that: the solar cell layer includes a plurality of solar cell body arranged in an array, and the solar cell body is the above-mentioned main grid-free photovoltaic cell.
[0013] Beneficial effects of the utility model:
[0014] 1. The welding strip is arranged in the first mounting groove, and the fine grid line is clamped on the second mounting groove, so that the overall height (thickness) of the busbarless photovoltaic cell is reduced, which can effectively reduce the risk of hidden cracks on the surface of the busbarless cell after subsequent photovoltaic lamination; and the sum of the depth of the first mounting groove and the depth of the second mounting groove is greater than the diameter (width) of the welding strip, so that the fine grid line can be attached to the outer surface of the solar cell body, avoiding the existence of a gap between the fine grid line and the solar cell body, and improving the current collection efficiency.
[0015] 2. The fine grid line is clamped on the second mounting groove, which can increase the contact area between the fine grid line and the welding strip, improve the stability and reliability of the connection, and effectively avoid the problem of poor contact between the welding strip and the fine grid line. After the contact area is increased, the welding strip can more effectively collect the current on the fine grid line, effectively improving the current collection capacity.
[0016] 3. The first mounting groove cooperates with the second mounting groove to fix the welding strip and the fine grid line to prevent them from shifting during installation or lamination, thereby avoiding the breakage of the fine grid line. BRIEF DESCRIPTION OF THE DRAWINGS
[0017] The following is a detailed description of the preferred implementation examples of the present invention with reference to the accompanying drawings to help understand the purpose and advantages of the present invention, wherein:
[0018] Figure 1 This is a schematic diagram of the main structure of a solar cell in an embodiment of the utility model;
[0019] Figure 2 This is a schematic diagram of the welding strip structure in the embodiment of the utility model;
[0020] Figure 3 This is a schematic diagram of the internal structure of the solar cell body in the embodiment of the utility model;
[0021] Figure 4 For the embodiment of the utility model corresponding to Figure 3 A partial enlarged view of the middle part;
[0022] Figure 5 This is a schematic diagram of the internal structure of the welding strip in the embodiment of the utility model;
[0023] Figure 6 It is a schematic diagram of the internal structure when the welding strip and the fine grid line are matched in the embodiment of the utility model.
[0024] Numbers in the figure:
[0025] Solar cell body 1, thin grid lines 2, welding strips 3, first mounting grooves 4, second mounting grooves 5, first welding parts 6, second welding parts 7, first packaging film layer 8, conductive substrate 301, and low-temperature alloy layer 302. DETAILED DESCRIPTION
[0026] The utility model is further described in detail below based on the accompanying drawings and implementation cases.
[0027] The directional terms such as up, down, left, right, front, back, front, back, top, bottom, etc. mentioned or may be mentioned in this specification are defined relative to the structures shown in the drawings. The words "inside" and "outside" refer to the direction toward or away from the geometric center of a specific component, respectively. They are relative concepts, and therefore may change accordingly according to different locations and different usage conditions. Therefore, these or other directional terms should not be interpreted as restrictive terms.
[0028] refer to Figures 1 to 6 , the utility model embodiment discloses:
[0029] A photovoltaic component comprises a photovoltaic front plate, a first packaging film layer 8, a solar cell layer, a second packaging film layer, and a photovoltaic back plate which are stacked in sequence, wherein the solar cell layer comprises a plurality of solar cell main bodies 1 arranged in an array, a plurality of fine grid lines 2 are arranged on the solar cell main bodies 1, a plurality of welding strips 3 interlaced with the fine grid lines 2 are arranged on the solar cell main bodies 1, a fixing structure for fixing the fine grid lines 2 is arranged between the solar cell main bodies 1 and the welding strips 3, the fixing structure comprises a plurality of first mounting grooves 4 uniformly arranged on the solar cell main bodies 1 for accommodating the welding strips 3, a plurality of second mounting grooves 5 uniformly arranged on the welding strips 3 for clamping the fine grid lines 2, the sum of the depths of the first mounting grooves 4 and the second mounting grooves 5 being greater than the diameter of the welding strips 3; the welding strips 3 are arranged in the first mounting grooves 4, and the fine grid lines 2 are clamped in the second mounting grooves 5, thereby reducing the overall height (thickness) of the busbar-free photovoltaic cell, which can effectively reduce the risk of hidden cracks on the surface of the busbar-free cell after subsequent photovoltaic lamination; and the sum of the depth of the first mounting groove 4 and the depth of the second mounting groove 5 is greater than the width of the welding strip 3, so that the fine grid line 2 can be attached to the outer surface of the solar cell body 1, avoiding the existence of a gap between the fine grid line 2 and the solar cell body 1, affecting the current collection efficiency; the fine grid line 2 is clamped on the second mounting groove 5, which can increase the contact area between the fine grid line 2 and the welding strip 3, improve the stability and reliability of the connection, and effectively avoid the problem of poor contact between the welding strip 3 and the fine grid line 2, and after the contact area is increased, the welding strip 3 can more effectively collect the current on the fine grid line 2, effectively improving the current collection capacity; the first mounting groove 4 cooperates with the second mounting groove 5 to fix the welding strip 3 and the fine grid line 2, prevent them from shifting during installation or lamination, and thus avoid the breakage of the fine grid line 2.
[0030] In this embodiment, the first packaging film layer 8 is a PO film or an EVA film.
[0031] The fine grid lines 2 extend along the first direction and are evenly arranged along the second direction, and the welding strips 3 extend along the second direction and are evenly arranged along the first direction, and the first direction and the second direction are perpendicular to each other; the first installation groove is a wire groove opened on the solar cell body 1 and extends along the second direction to match the welding strip 3; by arranging the two perpendicularly to each other, the arrangement and installation of the welding strip 3 and the fine grid lines 2 are facilitated.
[0032] The soldering strip 3 includes a conductive substrate 301 and a low-temperature alloy layer 302 coated on the surface of the conductive substrate 301, specifically a low-temperature tin-lead-bismuth alloy layer, whose melting point is lower than the lamination temperature and will melt during the lamination process of the photovoltaic module.
[0033] A first welding portion 6 is provided between the welding ribbon 3 and the solar cell body 1. Specifically, the low-temperature alloy layer 302 is melted after lamination and flows into the first mounting groove 4 to contact the solar cell body 1, forming a first welding portion 6 for welding the welding ribbon 3 to the first mounting groove 4.
[0034] A second welding portion 7 is provided between the solar cell sheet body 1 and the fine grid wire 2. Specifically, the low-temperature alloy layer 302 is melted after lamination and overflows from the first mounting groove 4 and contacts the fine grid wire 2, and / or the low-temperature alloy layer 302 is melted after lamination and flows into the second mounting groove 5 and contacts the fine grid wire 2, so as to form a second welding portion 7 for welding the fine grid wire 2 to the welding strip 3; by cooperating with the first welding portion 6 and the second welding portion, the connection strength between the fine grid wire 2 and the welding strip 3 is further improved.
[0035] Finally, it should be noted that the above implementation cases are only used to illustrate the technical solutions of the utility model, rather than to limit it. Although the utility model has been described in detail with reference to the above implementation cases, ordinary technicians in this field should understand that they can still modify the technical solutions recorded in the above implementation cases, or replace some of the technical features therein with equivalents. These modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the implementation cases of the utility model.
Claims
1. A busbar-less photovoltaic cell, comprising a solar cell body (1), a plurality of fine grid lines (2) arranged on the solar cell body (1), and a plurality of welding strips (3) arranged on the solar cell body (1) and interlaced with the fine grid lines (2), wherein a fixing structure for fixing the fine grid lines (2) is arranged between the solar cell body (1) and the welding strips (3), and characterized in that: The fixing structure comprises a plurality of first mounting grooves (4) uniformly formed on the solar cell sheet body (1) for accommodating the welding strip (3), a plurality of second mounting grooves (5) uniformly formed on the welding strip (3) for clamping the thin grid lines (2), and the sum of the depths of the first mounting grooves (4) and the second mounting grooves (5) being greater than the diameter of the welding strip (3).
2. A busbar-free photovoltaic cell according to claim 1, characterized in that: The fine grid lines (2) extend along the first direction and are evenly arranged along the second direction, the welding strips (3) extend along the second direction and are evenly arranged along the first direction, and the first direction and the second direction are perpendicular to each other.
3. A busbar-free photovoltaic cell according to claim 2, characterized in that: The first mounting groove (4) is a wire groove formed on the solar cell sheet body (1) and extending along the second direction to match the welding strip (3).
4. The busbar-free photovoltaic cell according to claim 1, characterized in that: The welding strip (3) comprises a conductive substrate (301) and a low-temperature alloy layer (302) coated on the surface of the conductive substrate (301).
5. A busbar-free photovoltaic cell according to claim 4, characterized in that: A first welding portion (6) is provided between the welding ribbon (3) and the solar cell sheet body (1).
6. A busbar-free photovoltaic cell according to claim 4, characterized in that: A second welding portion (7) is provided between the solar cell sheet body (1) and the thin grid lines (2).
7. A photovoltaic module, comprising a photovoltaic front panel, a first packaging film layer (8), a solar cell layer, a second packaging film layer, and a photovoltaic back panel stacked in sequence, characterized in that The solar cell layer comprises a plurality of solar cell bodies (1) arranged in an array, and the solar cell body (1) is a busbar-free photovoltaic cell as claimed in any one of claims 1 to 6.