Main-grid-free film-coated photovoltaic module

Abstract

The utility model discloses a main-grid-free film-coated photovoltaic module. A film-coated battery string group comprises a plurality of main-grid-free battery pieces, a welding strip and a bearing film, the plurality of main-grid-free battery pieces are arranged on the same layer at intervals in series; the welding strip crosses two adjacent battery pieces, one side of the welding strip is connected to the front side of one battery piece, the other side of the welding strip is connected to the back side of the other adjacent battery piece, and the two welding strips in the front-back direction in the series connection direction of the battery pieces can be in lap joint in parallel; a bus bar is arranged at the end part of the film-coated battery string group; and the two bearing films are pressed on the two opposite sides of the battery piece through low-temperature heating. According to the utility model, series welding is replaced by a low-temperature heating film coating mode, so that 30%-40% of silver consumption at a battery end can be reduced by canceling a main grid line of a battery piece; the stress-free connection of the low-temperature bearing film is more suitable for the development of flaking, and the battery cost is greatly reduced through less silicon and less silver.

Description

Technical Field

[0001] The utility model relates to the technical field of photovoltaic component manufacturing, in particular to a main grid-free film-coated photovoltaic component. Background Art

[0002] In the current mainstream photovoltaic module manufacturing process, the welding process usually uses a high temperature of 200°C to weld the welding ribbon and the main grid on the surface of the battery cell into a battery string, and in the lamination process, multiple battery strings are arranged and welded in series using bus bars to form a battery pack. Problems such as over-welding, broken grids, and broken pieces caused by high-temperature welding have become a normal defect type in the module process.

[0003] In the context of continuous cost reduction and efficiency improvement in photovoltaics, it has become an industry consensus to reduce the use of silicon and silver in solar cells. Among them, heterojunction modules are gradually losing their competitiveness in industry promotion due to the high cost of silver paste for solar cells and the technical difficulties of low-temperature welding at the module end. It is urgent to reduce the silver consumption of heterojunction solar cells.

[0004] The existing photovoltaic module manufacturing technology has the following problems:

[0005] 1. Under the high-temperature series soldering process, over-soldering / broken grid / cold soldering problems are very likely to occur, affecting component power and product yield.

[0006] 2. The design of photovoltaic modules tends to develop with small pitch or even negative pitch, and the problem of process fragmentation is difficult to overcome.

[0007] 3. Low-temperature silver paste is used on the front and back of heterojunction batteries. The low-temperature silver paste has a high unit price and is used in large quantities, resulting in higher battery costs and limiting the promotion of heterojunction technology.

[0008] 4. Welding requires the use of flux, and the machine requires frequent maintenance during the production process, which affects the increase in production capacity.

[0009] 5. Crystallized foreign matter in the flux adversely affects product yield, and the volatilized gases during the welding process are harmful to the human body and the environment.

[0010] The utility model provides a novel photovoltaic component which avoids the traditional string welding process and solves the above problems. Utility Model Content

[0011] The utility model aims to solve at least one of the technical problems existing in the prior art. To this end, the utility model proposes a main grid-free film-coated photovoltaic module.

[0012] The technical solution adopted by an embodiment of the utility model to solve the technical problem is: a main grid-free film-coated photovoltaic module, comprising a front lamination group, a film-coated battery string group and a back lamination group stacked in sequence;

[0013] The film-covered battery string group comprises a plurality of busbar-free battery cells, welding strips and a carrier film; the plurality of busbar-free battery cells are arranged in series at intervals on the same layer; the welding strip crosses over two adjacent battery cells, one side of the welding strip is connected to the front side of the battery cell, and the other side of the welding strip is connected to the back side of another adjacent battery cell, and the two welding strips in front and behind along the battery cell series connection direction can be overlapped in parallel with each other;

[0014] The battery sheets are provided with a plurality of welding strips at intervals along the side-by-side direction; a bus bar is provided at the end of the film-coated battery string group, and the bus bar is electrically connected to the plurality of welding strips at the end of the film-coated battery string group;

[0015] Two carrier films are provided, which are heated at low temperature and pressed on opposite sides of the battery sheet.

[0016] Optionally, the thickness of the carrier film is in the range of 0.1 mm to 0.15 mm.

[0017] Optionally, the welding strip and the bus bar are tin-clad copper structural alloy conductive metals.

[0018] Optionally, the aperture of the welding strip is in the range of 0.18 mm to 0.22 mm; the thickness of the bus bar is in the range of 0.24 mm to 0.35 mm.

[0019] Optionally, the low-temperature heating temperature of the carrier film is less than or equal to 150°C.

[0020] Optionally, the front lamination group includes a front adhesive film and coated glass;

[0021] The back side lamination group includes a back side adhesive film and a glazed glass; or the back side lamination group includes a back side adhesive film or a back plate.

[0022] Optionally, the front adhesive film and the back adhesive film are EVA / POE / EVA three-layer co-extruded adhesive films.

[0023] Optionally, the battery cell may be a HJT battery cell or a TOPcon battery cell.

[0024] Beneficial effects of the utility model: The film-coated battery string group includes multiple main grid-free battery cells, welding strips and carrier films, which are positioned and stacked in sequence according to the carrier film-welding strip-battery cell-welding strip-carrying film structure, wherein one side of the welding strip is connected to the back of the battery cell, and the other side is connected to the front of the adjacent battery cell, and this is repeated, and a pressure mesh is used to fix the welding strip to transmit the low-temperature heating carrier film to form a circuit-connected film-coated battery string group. Multiple film-coated battery strings are arranged into a battery cell array, and are welded in series using bus bars to form a film-coated battery group. A front lamination group of adhesive film and coated glass is provided on the front of the battery group, and a back lamination group of adhesive film and glazed glass or back panel is provided on the back of the battery group. The utility model has the following advantages:

[0025] 1. The low-temperature heating coating method is used to replace the string welding, which can eliminate the main grid line of the battery cell to reduce the silver consumption of the battery end by 30%-40%; the stress-free connection of the low-temperature bearing film is more suitable for the development of thin sheets, and the battery cost can be greatly reduced by reducing silicon and silver.

[0026] 2. The component end is fixed with solder strips by bonding with the battery cell through low-temperature coating, which is stress-free connection, more suitable for thinning and has lower cell loss in the process.

[0027] 3. Use more solder strips with finer specifications to better meet the development needs of small pitch and high conversion efficiency.

[0028] 4. The low-temperature carrier films are independent of each other and connected without stress. There are no problems of over-soldering, broken grid, or biased welding in the process, which improves the component power and product yield.

[0029] 5. In the future, the combination of thin sheets and finer solder strip specifications will provide greater room for cost reduction in laminated packaging materials and enhance product competitiveness.

[0030] 6. No flux required, green and environmentally friendly.

[0031] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and understandable, preferred embodiments are given below and described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0033] Figure 1 This is a schematic diagram of the structure of a partially coated battery string group of the utility model;

[0034] Figure 2 This is a schematic diagram of the cross-sectional structure of a partially coated battery string group of the utility model;

[0035] Figure 3 It is a schematic diagram of the structure of the arrangement state of the carrier film of the partial film-covered battery string group of the utility model before low-temperature heating and pressing;

[0036] Figure 4 It is a schematic diagram of the laminated packaging structure of the main grid-free film-covered component of the utility model.

[0037] Description of main component symbols:

[0038] 10. Film-coated battery string group; 11. Battery cell; 12. Solder ribbon; 13. Carrier film; 20. Bus bar; 30. Front lamination group; 31. Front adhesive film; 32. Coated glass; 40. Back lamination group; 41. Back adhesive film; 42. Glazed glass; 43. Back panel. DETAILED DESCRIPTION

[0039] This section will describe in detail the specific embodiments of the utility model. The preferred embodiments of the utility model are shown in the accompanying drawings. The purpose of the accompanying drawings is to supplement the description of the text part of the specification with graphics, so that people can intuitively and vividly understand each technical feature and the overall technical solution of the utility model, but it cannot be understood as a limitation on the protection scope of the utility model.

[0040] In the description of the present utility model, the meaning of "more than" is more than two, "greater than", "less than", "exceed" etc. are understood to exclude the number itself, and "above", "below", "within" etc. are understood to include the number itself. If there is a description of "first" or "second", it is only used for the purpose of distinguishing technical features, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

[0041] In the description of the present invention, it should be understood that descriptions involving orientation, such as up, down, front, back, left, right, etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do 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 the present invention.

[0042] In the present invention, unless otherwise clearly defined, the words "set", "install", "connect" and the like should be understood in a broad sense, for example, they can be directly connected or indirectly connected through an intermediate medium; they can be fixedly connected or detachably connected or integrally formed; they can be mechanically connected; they can be the internal connection of two elements or the interaction relationship between two elements. Those skilled in the art can reasonably determine the specific meanings of the above words in the present invention in combination with the specific content of the technical solution.

[0043] Example

[0044] Reference Figures 1 to 4 The utility model provides a busbar-free film-coated photovoltaic module, comprising a front lamination group 30, a film-coated battery string group 10 and a back lamination group 40 stacked in sequence;

[0045] The film-covered battery string group 10 includes a plurality of busbar-free battery cells 11, a welding ribbon 12 and a carrier film 13; the plurality of busbar-free battery cells 11 are arranged in series at intervals on the same layer; the welding ribbon 12 spans over two adjacent battery cells 11, one side of the welding ribbon 12 is connected to the front side of the battery cell 11, and the other side of the welding ribbon 12 is connected to the back side of another adjacent battery cell 11, and the two welding ribbons 12 in front and behind along the series connection direction of the battery cells 11 can be overlapped in parallel with each other;

[0046] The battery sheet 11 is provided with a plurality of welding strips 12 at intervals along the side-by-side direction; a bus bar 20 is provided at the end of the film-coated battery string group 10, and the bus bar 20 is electrically connected to the plurality of welding strips 12 at the end of the film-coated battery string group 10;

[0047] Two carrier films 13 are provided, which are heated at a low temperature and pressed on opposite sides of the battery cell 11 .

[0048] In the present utility model, the film-coated battery string group 10 includes a plurality of main grid-free battery cells 11, welding strips 12 and carrier films 13, which are positioned and stacked in sequence according to the structure of carrier film 13-welding strip 12-battery cell 11-welding strip 12-carrier film 13, wherein one side of the welding strip 12 is connected to the back of the battery cell 11, and the other side is connected to the front of the adjacent battery cell 11, and this is repeated, and the welding strip 12 is fixed by a pressing net to transmit the low-temperature heating carrier film 13 to form a circuit-connected film-coated battery string group 10. A plurality of film-coated battery string groups 10 are arranged into an array of battery cells 11, and are welded in series using bus bars 20 to form a film-coated battery group. A front lamination group 30 of adhesive film and coated glass 32 is provided on the front of the battery group, and a back lamination group 40 of adhesive film and glazed glass 42 or back plate 43 is provided on the back of the battery group. The utility model has the following advantages:

[0049] 1. The low-temperature heating coating method is used to replace the string welding, and the main grid line of the battery cell 11 can be eliminated to reduce the silver consumption of the battery end by 30%-40%; the stress-free connection of the low-temperature bearing film 13 is more suitable for the development of thin sheets, and the battery cost can be greatly reduced by reducing silicon and silver.

[0050] 2. The component end is bonded to the battery cell 11 through a low-temperature coating to fix the welding ribbon 12, which is a stress-free connection, more suitable for thinning, and has lower loss in the process of battery cell 11.

[0051] 3. Use of finer specifications and more number of solder strips 12 is more suitable for the development needs of small pitch and high conversion efficiency.

[0052] 4. The low-temperature bearing films 13 are independent of each other and connected without stress. There are no problems of over-welding, broken grid and biased welding in the process, which improves the component power and product yield.

[0053] 5. In the future, the combination of thin sheets and thinner solder strips with specifications of 12 will provide greater room for cost reduction in laminated packaging materials and enhance product competitiveness.

[0054] 6. No flux required, green and environmentally friendly.

[0055] The utility model has a main grid-free battery cell 11, and the main grid lines of the battery cell 11 are eliminated in the screen design. A small number of grid lines are reserved at the main grid position for positioning the welding strip 12. The auxiliary grid at the welding strip 12 position is thickened to increase the contact area between the welding strip 12 and the battery cell 11. This design can reduce the silver consumption of the battery cell 11 by 30%-40%.

[0056] In this embodiment, the thickness of the carrier film 13 is in the range of 0.1 mm to 0.15 mm. It has good adhesion and unique low flow characteristics, ensuring that the soldering ribbon 12 is in close contact with the battery cell 11 during the lamination process, thus avoiding the problem of local EL darkening of the battery due to the packaging film flowing between the soldering ribbon 12 and the battery surface during the lamination process.

[0057] In this embodiment, the soldering ribbon 12 and the bus bar 20 are made of tin-clad copper structural alloy conductive metal.

[0058] Specifically, the aperture of the welding strip 12 is between 0.18mm and 0.22mm; the thickness of the busbar 20 is between 0.24mm and 0.35mm. The design value of the width of the busbar 20 is preferably between 4mm and 8mm. The melting point of the alloy conductive metal is 140-150℃, and the thinner battery is more suitable for the thin-sheet technology; the denser arrangement of the welding strip 12 effectively improves the efficiency of the component.

[0059] Corresponding to the melting point of the tin-clad copper structural alloy conductive metal, the low-temperature heating temperature of the carrier film 13 is less than or equal to 150° C. At this time, during the hot pressing process of the carrier film 13, there is no stress connection, and the welding ribbon 12 can be hot-melted to effectively solve the problems of over-welding, broken grid, and cold welding, and can effectively reduce the risk of welding fragments and improve the efficiency and yield of components.

[0060] In this embodiment, the front lamination group 30 includes a front adhesive film 31 and a coated glass 32 ; the back lamination group 40 includes a back adhesive film 41 and a glazed glass 42 ; or the back lamination group 40 includes a back adhesive film 41 or a back plate 43 .

[0061] Specifically, the front adhesive film 31 and the back adhesive film 41 may use, but are not limited to, an EVA / POE / EVA three-layer co-extruded adhesive film having a function of converting ultraviolet light into blue light, which can give the component a higher initial power.

[0062] In the present invention, the battery cell 11 may be a HJT battery cell 11 or a TOPcon battery cell 11 .

[0063] Specifically, the example of 182-144 half-cell double-glass heterojunction busbar-free coated component is used as an embodiment for explanation: it includes multiple busbar-free battery cells 11, upper and lower layers of carrier films 13 for fixing welding strips 12, welding strips 12 for collecting current and bus bars 20 and other components to form a coated battery pack.

[0064] The material stacking order is as follows: the coated glass 32, the light transfer adhesive film, the film-covered battery pack, the high-transmittance adhesive film, and the glazed grid glass are stacked in sequence to form a main grid-free film-covered photovoltaic module of the 144 half-cell format.

[0065] The size is 182mm*91mm, the front side sub-grid is 47 grids, a small amount of grid lines are reserved at the main grid position for positioning the welding strip 12, and the sub-grid is appropriately thickened at an interval of 8.61mm to increase the contact area between the welding strip 12 and the battery cell 11. This design can reduce the silver consumption of the battery cell 11 by 30%-40%.

[0066] The thickness of the carrier film 13 is between 0.1mm and 0.15mm, and it is an EVA / EPE structure with good adhesion and unique low flow characteristics, which ensures that the soldering ribbon 12 and the battery cell 11 are in close contact during the lamination process, thus avoiding the problem of local EL darkening of the battery due to the packaging film flowing between the soldering ribbon 12 and the battery surface during the lamination process.

[0067] The welding ribbon 12 and the bus bar 20 are tin-clad copper structural alloy conductive metals. The diameter of the welding ribbon 12 is 0.18-0.22mm. The number of welding ribbons 12 is 9-30 according to the screen design of the battery cell 11. The melting point of the alloy conductive metal is 140-150℃. The thinner specification battery is more suitable for thin-film technology; the denser arrangement of the welding ribbons 12 effectively improves the efficiency of the component.

[0068] Among them, the coated glass 32 / glazed grid glass has a reflective layer, which can increase the light absorption utilization rate of the component.

[0069] Specifically, the coated battery pack adopts stress-free flexible connection and heats the carrier film 13 at 150°C or less. Before low-temperature heating, a 4 to 6 mm coating space gap is retained between the carrier film 13 and the end of the battery cell 11 to ensure overlapping contact of adjacent welding strips 12. The carrier film 13 shrinks due to heat and is bonded to the battery cell 11, so that the welding is in close contact with the battery, which solves the problems of over-welding, broken grid, and cold welding, and can effectively reduce the risk of welding fragments and improve component efficiency and yield.

[0070] Of course, the present invention is not limited to the above-mentioned embodiments, and technicians familiar with the field may make equivalent modifications or substitutions without violating the spirit of the present invention. These equivalent modifications and substitutions are all included in the scope defined by the claims of this application.

Claims

1. A busbar-free film-coated photovoltaic module, characterized in that: It comprises a front lamination group (30), a film-coated battery string group (10) and a back lamination group (40) stacked in sequence; The film-coated battery string group (10) comprises a plurality of main-grid-free battery cells (11), welding strips (12) and a carrier film (13); the plurality of battery cells (11) are arranged in series at intervals on the same layer; the welding strip (12) spans over two adjacent battery cells (11), one side of the welding strip (12) is connected to the front side of the battery cell (11), and the other side of the welding strip (12) is connected to the back side of another adjacent battery cell (11); the two welding strips (12) in front and behind along the series connection direction of the battery cells (11) can overlap each other in parallel; The battery sheet (11) is provided with a plurality of welding strips (12) at intervals along a side-by-side direction; a bus bar (20) is provided at the end of the film-coated battery string group (10), and the bus bar (20) is electrically connected to the plurality of welding strips (12) at the end of the film-coated battery string group (10); Two carrier films (13) are provided, which are heated at a low temperature and pressed onto opposite sides of the battery cell (11).

2. The busbar-free film-coated photovoltaic module according to claim 1, characterized in that: The thickness of the carrier film (13) is in the range of 0.1 mm to 0.15 mm.

3. The busbar-free film-coated photovoltaic module according to claim 1, characterized in that: The welding strip (12) and the bus bar (20) are made of tin-clad copper structural alloy conductive metal.

4. The busbar-free film-coated photovoltaic module according to claim 3, characterized in that: The aperture of the welding strip (12) is between 0.18 mm and 0.22 mm; the thickness of the bus bar (20) is between 0.24 mm and 0.35 mm.

5. The busbar-free film-coated photovoltaic module according to claim 1, characterized in that: The low-temperature heating temperature of the carrier film (13) is less than or equal to 150°C.

6. The busbar-free film-coated photovoltaic module according to claim 1, characterized in that: The front lamination group (30) comprises a front adhesive film (31) and coated glass (32); The back side lamination group (40) comprises a back side adhesive film (41) and a glazed glass (42); or the back side lamination group (40) comprises a back side adhesive film (41) or a back plate (43).

7. The busbar-free film-coated photovoltaic module according to claim 6, characterized in that: The front adhesive film (31) and the back adhesive film (41) are EVA / POE / EVA three-layer co-extruded adhesive films.

8. The busbar-free film-coated photovoltaic module according to claim 1, characterized in that: The battery cell (11) may be a HJT battery cell or a TOPcon battery cell.

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