CN116525694A - Back contact solar cell without main grid, cell assembly and preparation method thereof - Google Patents

Abstract

The invention discloses a back-contact busbar-free solar cell, a battery component and a preparation method thereof. The solar cell includes: an n+ doped layer and a p+ doped layer, and the n+ doped layer and the p+ doped layer are in the solar cell Arranged alternately on the chip; positive electrode grid lines, the positive electrode grid lines are electrically connected to the p+ doped layer; negative electrode grid lines, the negative electrode grid lines are electrically connected to the n+ doped layer, and the two ends of the negative electrode grid lines are connected to the positive electrode grid lines The two ends of the negative electrode grid line are not aligned, the end of the negative electrode grid line protruding relative to the positive electrode grid line has a negative electrode grid line connection end, and the end of the positive electrode grid line protruding relative to the negative electrode grid line has a positive electrode grid line connection end; wherein, The negative electrode grid wire connection end and/or the positive electrode grid wire connection end are figures formed by a plurality of line segments and/or at least one arc. Therefore, it is not only beneficial to improve the mechanical properties of the connection between the connecting end of the grid wire and the conductive element, but also prevents grid breakage at the connecting end of the thin grid wire, and enhances the confluence effect of the conductive element.

Description

Back-contact busbar-free solar cell, cell module and preparation method thereof

technical field

The invention belongs to the technical field of solar cells, and in particular relates to a back-contact non-busbar solar cell, a cell component and a preparation method thereof.

Background technique

Solar cells are photoelectric devices that convert light energy into electrical energy. High power generation efficiency, long-term reliability and reduced production costs have been leading the development of the photovoltaic industry. Due to traditional solar cells, the grid line of the solar cell is placed On the light-receiving surface and the backlight surface, due to the shading of the light-receiving surface grid lines, part of the optical loss will be caused, which will affect the photoelectric conversion efficiency of the solar cell. The positive and negative grid lines of the back-contact solar cell are located on the back of the battery, which can effectively improve the absorption of sunlight by the solar cell. However, the grid line pattern on the current back-contact solar cell without main grid has the following problems in the specific implementation process: (1) Because the area of the connection end of the thin grid wire is too small, the mechanical properties of the connection end of the grid wire and the conductive part are poor, which will affect the confluence effect of the conductive part; (2) There is an adhesive film on the conductive tape. The film is used to realize the connection between the fine grid lines and the conductive metal on the conductive tape. In the process of connecting the fine grid lines to the conductive tape, the fine grid lines need to pass through the film layer on the conductive tape and the conductive metal on the conductive tape. Connection, the adhesive film layer will increase the economic cost, and in the subsequent hot pressing process, the adhesive film may melt, resulting in leakage short circuit of the back contact solar cell.

Contents of the invention

The present invention aims to solve one of the technical problems in the related art at least to a certain extent. Therefore, the object of the present invention is to provide a back contact busbarless solar cell, a cell module and a preparation method thereof. Therefore, it is not only beneficial to improve the mechanical properties of the connection between the connecting end of the grid wire and the conductive element, but also prevents grid breakage at the connecting end of the thin grid wire, and enhances the confluence effect of the conductive element.

In the first aspect of the present invention, the present invention provides a back-contact busbarless solar cell. In an embodiment of the present invention, the back contact busbar-free solar battery sheet includes: n+ doped layers and p+ doped layers, the n+ doped layers and the p+ doped layers are alternately arranged on the solar battery sheet; An electrode grid line, the positive electrode grid line is located on one side of the p+ doped layer, and is electrically connected to the p+ doped layer; a negative electrode grid line, the negative electrode grid line is located on the n+ doped layer and is electrically connected to the n+ doped layer, the two ends of the negative electrode grid line are not aligned with the two ends of the positive electrode grid line, and the negative electrode grid line is opposite to the positive electrode grid line The protruding end of the wire has a negative electrode grid line connection end, and a plurality of the negative electrode grid line connection ends are located on the same side of the negative electrode grid line, and the protruding end of the positive electrode grid line is opposite to the negative electrode grid line It has a positive electrode grid line connection end, and a plurality of the positive electrode grid line connection ends are located on the same side of the positive electrode grid line; wherein, the negative electrode grid line connection end is composed of a plurality of line segments and/or at least one arc A graph composed of lines; and/or, the connecting end of the positive electrode grid wire is a graph composed of multiple line segments and/or at least one arc.

According to the back contact busbar-free solar cell sheet of the embodiment of the present invention, compared with the traditional fine grid line connection end, the negative electrode grid line connection end and/or the positive electrode grid line connection end of the present invention have the following advantages: first , the area of the negative electrode grid wire connection end and/or the positive electrode grid wire connection end is increased, so that the mechanical properties of the negative electrode grid wire connection end and/or the positive electrode grid wire connection end and the conductive member that conducts the current are significantly increased; the second , which can effectively solve the problem of broken grid at the connecting end of the thin grid wire; thirdly, it is beneficial to enhance the converging effect of the conductive parts that conduct current. As a result, it is not only beneficial to improve the mechanical performance of the connection between the connecting end of the grid wire and the conductive element, but also prevents grid breakage at the connecting end of the thin grid wire, and enhances the confluence effect of the conductive element.

In addition, the back contact busbarless solar cells according to the above embodiments of the present invention may also have the following additional technical features:

In some embodiments of the present invention, the negative electrode grid wire connection end is a closed figure surrounded by a plurality of line segments and/or at least one arc.

In some embodiments of the present invention, the positive electrode grid wire connection end is a closed figure surrounded by a plurality of line segments and/or at least one arc.

In some embodiments of the present invention, the shape of the connecting end of the negative electrode grid wire and the shape of the connecting end of the positive electrode grid wire include at least one of triangle, circle, square and hexagon.

In some embodiments of the present invention, the negative electrode grid line connection end and/or the positive electrode grid line connection end further include at least one line segment arranged in a closed pattern.

In some embodiments of the present invention, the area of the orthographic projection of the negative electrode grid line connection end on the n+ doped layer is 0.02 square millimeters to 3 square millimeters.

In some embodiments of the present invention, the area of the orthographic projection of the positive electrode grid line connection end on the p+ doped layer is 0.05 square millimeters to 5 square millimeters.

In some embodiments of the present invention, the width of the negative electrode grid line is 10 microns-100 microns.

In some embodiments of the present invention, the width of the positive electrode grid line is 20 microns-200 microns.

In the second aspect of the present invention, the present invention provides a back-contact busbarless solar cell assembly. In an embodiment of the present invention, the solar cell module includes: a plurality of back contact solar cells without busbar described in the above embodiments; a conductive member, the conductive member is connected with the back contact solar cell without busbar The negative electrode grid wire connection end and the positive electrode grid wire connection end are electrically connected, so as to electrically connect a plurality of solar cells together.

According to the back contact busbar-free solar cell assembly of the embodiment of the present invention, by setting the conductive member to electrically connect the negative electrode grid line connection end and the positive electrode grid line connection end, the electrical connection of multiple solar cells can be realized; The area of the electrode grid wire connection end and/or the positive electrode grid wire connection end can increase the connection area of the negative electrode grid wire connection end and/or the positive electrode grid wire connection end and the conductive member for electrical connection, significantly improving the mechanical properties, This is beneficial to the interconnection effect between the grid line and the conductive member; when a partial area of the grid line connection end is broken, the area of the grid line connection end that is connected to the grid line and is not broken can still be connected to the conductive member, thereby improving the current. The safety of transmission; compared with the traditional thin grid wire connection end, the grid wire connection end of the present invention has a better confluence effect.

In addition, the back contact busbarless solar cell module according to the above-mentioned embodiments of the present invention may also have the following additional technical features:

In some embodiments of the present invention, the conductive member is metal foil plating or solder strip.

In some embodiments of the present invention, the conductive member includes a first conductive part and a second conductive part, and the first conductive part is used to connect the negative electrode grid wire connection ends of a plurality of solar cells, The second conductive part is used to connect the positive electrode grid wire connection terminals of the plurality of solar cells.

In some embodiments of the present invention, a plurality of back contact solar cells without busbar are arranged in multiple rows, and in two adjacent rows of back contact solar cells without busbar, one row of back contact solar cells without busbar The positive electrode grid wire end of another row of back contact non-busbar solar cells is close to the negative electrode grid wire end; The back-contact solar cells without busbar of each row in the cells are electrically connected together through one of the third conductive parts; The negative electrode grid terminal is electrically connected through the third conductive part.

In the third aspect of the present invention, the present invention proposes a method for preparing the back contact busbar-free solar cell module described in the above embodiments, the method includes: providing a patterned metal foil, the patterned metal foil The foil is pasted on the preset position of the first adhesive film; the first adhesive film pasted with the metal foil is pasted on the back plate; a plurality of back-contact busbar-free solar energy as described in the above-mentioned embodiment The cells are laid out and welded on the back plate with the metal foil attached; wherein, a plurality of the back contact busbarless solar cells are electrically connected together through the metal foil; A second adhesive film and glass are formed on the grid solar cells and laminated.

According to the method for preparing a back-contact busbar-free solar cell module according to the embodiment of the present invention, in the prior art, the metal foil is generally connected to the back sheet through the first adhesive film, and then the metal foil is patterned, and finally the waste is removed. After the patterned metal foil is obtained, the present invention pre-patterns the metal foil, and then, in the process of preparing the solar cell module, passes the patterned metal foil through the first adhesive film and the back plate. Therefore, by removing the waste in advance, there is no need to remove the waste in the process of preparing the solar cell module, which can reduce the process of preparing the back-contact busbar-free solar cell module, and can effectively avoid problems such as leakage and short circuit.

In addition, the method for preparing a back-contact busbar-free solar cell module according to the above-mentioned embodiments of the present invention may also have the following additional technical features:

In some embodiments of the present invention, before providing the patterned metal foil, the method further includes: pasting the metal foil on the carrier film through the first adhesive film; patterning the metal foil, removing the waste Forming a patterned metal foil; before sticking the first adhesive film pasted with the metal foil on the backplane, the method further includes: removing the carrying film.

Additional aspects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention.

Description of drawings

The above and/or additional aspects and advantages of the present invention will become apparent and understandable from the description of the embodiments in conjunction with the following drawings, wherein:

Fig. 1 is a schematic structural view of a plurality of back contact solar cells without busbars according to an embodiment of the present invention;

Fig. 2 is a schematic structural view of a single back-contact busbar-free solar cell according to an embodiment of the present invention;

Fig. 3 is a schematic structural view of a back contact busbarless solar cell module according to an embodiment of the present invention;

Fig. 4 is a schematic structural view of a back contact solar cell assembly without a busbar according to another embodiment of the present invention;

Fig. 5 is a schematic structural view of an encapsulated back contact busbarless solar cell module according to an embodiment of the present invention;

Fig. 6 is a schematic structural view of the prepared first intermediate piece according to an embodiment of the present invention.

Reference signs:

100-solar battery sheet; 110-positive electrode grid wire; 111-positive electrode grid wire connection end; 112-cross grid wire; 120-negative electrode grid wire; 121-negative electrode grid wire connection end; 200-conductive member; 210 -first conductive part; 220-second conductive part; 230-third conductive part; 300-first adhesive film; 400-back plate; 500-glass plate; 600-second adhesive film; 700-first intermediate .

Detailed ways

Embodiments of the present invention are described in detail below, examples of which are shown in the drawings, wherein the same or similar reference numerals designate the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the figures are exemplary and are intended to explain the present invention and should not be construed as limiting the present invention.

In describing the present invention, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", " Rear", "Left", "Right", "Vertical", "Horizontal", "Top", "Bottom", "Inner", "Outer", "Axial", "Radial", "Circumferential" The orientation or positional relationship indicated by etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the referred elements must have a specific orientation or be configured in a specific orientation. and operation, and therefore should not be construed as limiting the invention.

In addition, the terms "first" and "second" are used for descriptive purposes only, and cannot be interpreted as indicating or implying relative importance or implicitly specifying the quantity of indicated technical features. Thus, the features defined as "first" and "second" may explicitly or implicitly include at least one of these features. In the description of the present invention, "plurality" means at least two, such as two, three, etc., unless otherwise specifically defined.

In the present invention, terms such as "installation", "connection", "connection" and "fixation" should be interpreted in a broad sense unless otherwise clearly specified and limited, for example, it may be a fixed connection or a detachable connection, or integrated; it may be mechanically connected or electrically connected; it may be directly connected or indirectly connected through an intermediary, and it may be the internal communication of two components or the interaction relationship between two components, unless otherwise specified limited. Those of ordinary skill in the art can understand the specific meanings of the above terms in the present invention according to specific situations.

In the present invention, unless otherwise clearly specified and limited, the first feature may be in direct contact with the first feature or the first and second feature may be in direct contact with the second feature through an intermediary. touch. Moreover, "above", "above" and "above" the first feature on the second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. "Below", "beneath" and "beneath" the first feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is less horizontally than the second feature.

In one aspect of the present invention, the present invention provides a back contact busbarless solar cell 100 . In an embodiment of the present invention, with reference to accompanying drawings 1 and 2, the solar battery sheet 100 includes: n+ doped layers and p+ doped layers, and the above n+ doped layers and the above p+ doped layers are alternately arranged on the solar battery sheet 100 ; The positive electrode grid line 110, the above-mentioned positive electrode grid line 110 is located on one side of the above-mentioned p+ doped layer, and is electrically connected with the above-mentioned p+ doped layer; the negative electrode grid line 120, the above-mentioned negative electrode grid line 120 is located on the above-mentioned n+ doped layer layer, and is electrically connected to the above-mentioned n+ doped layer, the two ends of the above-mentioned negative electrode grid line 120 are not aligned with the two ends of the above-mentioned positive electrode grid line 110, and the above-mentioned negative electrode grid line 120 is opposite to the above-mentioned positive electrode grid line One protruding end of 110 has a negative electrode grid line connection end 121, and a plurality of the above-mentioned negative electrode grid line connection ends 121 are located on the same side of the above-mentioned negative electrode grid line 120, and the above-mentioned positive electrode grid line 110 protrudes relative to the above-mentioned negative electrode grid line 120 One end has a positive electrode grid line connection end 111; a plurality of above-mentioned positive electrode grid line connection ends 111 are located on the same side of the above-mentioned positive electrode grid line 110; wherein, the above-mentioned negative electrode grid line connection end 121 is composed of a plurality of line segments and/or at least A figure formed by an arc; and/or, the positive electrode grid wire connection end 111 is a figure formed by a plurality of line segments and/or at least one arc.

According to the back contact busbar-free solar cell 100 of the embodiment of the present invention, compared with the traditional thin grid line connection end, the negative electrode grid line connection end 121 and/or the positive electrode grid line connection end 111 of the present invention have the following advantages First, the area of the negative electrode grid line connection end 121 and/or the positive electrode grid line connection end 111 increases, so that the negative electrode grid line connection end 121 and/or the positive electrode grid line connection end 111 are connected to the conductive member 200 of the conduction current The mechanical properties of the connection are significantly increased; secondly, it can effectively solve the problem of grid breakage at the connection end of the thin grid wire; thirdly, it is beneficial to enhance the confluence effect of the conductive parts that conduct current. As a result, it is not only beneficial to improve the mechanical performance of the connection between the connecting end of the grid wire and the conductive element, but also prevents grid breakage at the connecting end of the thin grid wire, and enhances the confluence effect of the conductive element.

Further, the back contact busbar-free solar battery sheet 100 of the present invention also has the following advantages: (1) only auxiliary grid lines are set on the solar battery sheet 100, and the main grid lines are removed, thereby saving the efficiency brought by the busbar lines; loss, process complexity and cost; (2) the use of positive and negative grid lines with asymmetrical ends can effectively avoid the insulation problem between the opposite polarity grid lines.

In an embodiment of the present invention, the n+ doped layer and the p+ doped layer are formed in such a way that the substrate in the solar cell 100 can be directly doped, or they can be formed on the substrate in the solar cell 100 Formed alone.

In some embodiments of the present invention, the above-mentioned back contact busbar-free solar cell 100 further includes: an insulating layer, and the above-mentioned negative electrode grid line 120 and the above-mentioned positive electrode grid line 110 pass through the insulating layer and the n+ doped layer, p+ The doped layer is electrically connected in order to increase the safety of the current conduction process.

According to a specific embodiment of the present invention, the shape of the negative electrode grid line connection end 121 and/or the positive electrode grid line connection end 111 (referred to as the grid line connection end for short) can be a closed figure or an unclosed figure. When the connecting end of the grid line is a closed figure, the connecting end of the grid line can be a closed figure surrounded by multiple line segments and/or at least one arc, and the middle of the closed figure is empty and not filled with metal materials; the grid line The connection end can also be a closed figure whose boundary is surrounded by a plurality of line segments and/or at least one arc, and the middle of the closed figure is filled with the same metal material as the above line segments and arcs. Preferably, the gate wire connection end is a closed figure surrounded by a plurality of line segments and/or at least one arc, and the middle of the closed figure is empty and not filled with metal material.

In the embodiment of the present invention, the shapes of the above-mentioned negative electrode grid line connection end 121 and the above-mentioned positive electrode grid line connection end 111 are not particularly limited. As a preferred solution, the above-mentioned negative electrode grid line connection end 121 and the above-mentioned positive electrode The shape of the electrode grid wire connection end 111 may include at least one of a triangular shape, a circular shape, a square shape and a hexagonal shape.

According to yet another specific embodiment of the present invention, with reference to accompanying drawing 2, above-mentioned negative electrode grid line connecting end 121 and/or above-mentioned positive electrode grid line connecting end 111 also include at least one line segment arranged in the closed figure, thus, through Setting at least one line segment can set up an interconnection bridge in the grid line connection end with a closed pattern, which can effectively prevent grid breakage and missing printing during the screen printing process, resulting in unsmooth grid line confluence, and can prevent the conductive paste from being unobstructed. When the area fails, use at least one line segment in the closed figure to replace the conductive paste for conduction. Preferably, the above-mentioned negative electrode grid line connection end 121 and/or the inside of the above-mentioned positive electrode grid line connection end 111 is provided with a cross grid line 112, and the above-mentioned cross grid line 112 and the corresponding grid line connection end are in the same plane, and the cross grid line The wires 112 communicate with the corresponding gate wire connection terminals.

In the embodiment of the present invention, the shape of the cross grid lines 112 is not particularly limited, and can be selected according to actual conditions in the field. As a preferred shape, the cross grid lines 112 can be T-shaped or cross-shaped.

According to another specific embodiment of the present invention, with reference to accompanying drawings 1-4, the area of the positive projection of the above-mentioned negative electrode grid line connection end 121 on the above-mentioned n+ doped layer is 0.02 square millimeters to 3 square millimeters, thus, by The area of the orthographic projection of the above-mentioned negative electrode grid line connection end 121 on the above-mentioned n+ doped layer is controlled within the above-mentioned range, which avoids the small connection stress between the negative electrode grid line connection end 121 and the conductive member 200 due to the small area of the orthographic projection , avoiding the increase in material consumption required for printing the negative electrode grid line connection end 121 due to an excessively large orthographic projection area, and increasing production costs.

According to another specific embodiment of the present invention, with reference to accompanying drawings 1-4, the area of the orthographic projection of the above-mentioned positive electrode grid line connection end 111 on the above-mentioned p+ doped layer is 0.05 square millimeters to 5 square millimeters, thus, by The area of the orthographic projection of the positive electrode grid line connection end 111 on the p+ doped layer is controlled within the above range, which avoids the small connection stress between the positive electrode grid line connection end 111 and the conductive member 200 due to the small area of the orthographic projection , and avoid the increase of material consumption required for printing the positive electrode grid line connection end 111 due to the excessively large orthographic projection area, which increases the production cost.

It should be explained that the area of the positive projection of the above-mentioned negative electrode grid line connection end on the above-mentioned n+ doped layer and the area of the positive projection of the above-mentioned positive electrode grid line connection end on the above-mentioned p+ doped layer are different because: the negative electrode grid The material of the wire is generally silver, the material of the positive electrode grid line is generally aluminum or silver-aluminum mixed metal, and the conductivity of the negative electrode grid line is generally greater than that of the positive electrode grid line. The area of the orthographic projection of the impurity layer is generally larger than the area of the orthographic projection of the connection end of the positive electrode grid line on the p+ doped layer.

According to yet another specific embodiment of the present invention, with reference to accompanying drawings 1-4, the above-mentioned negative electrode grid line 120 is elongated, and the width of the above-mentioned negative electrode grid line 120 is 10 microns-100 microns, thus, the above-mentioned negative electrode The width of the grid lines 120 is controlled within the above range, which can ensure good electrical conductivity of the negative electrode grid lines 120, and avoid the excessive width of the negative electrode grid lines 120, resulting in the material consumption required for printing the negative electrode grid lines 120. is too big.

According to yet another specific embodiment of the present invention, with reference to accompanying drawings 1-4, the above-mentioned positive electrode grid line 110 is elongated, and the width of the above-mentioned positive electrode grid line 110 is 10 microns-100 microns, thus, the above-mentioned positive electrode The width of the grid lines 110 is controlled within the above range, which can ensure good electrical conductivity of the positive electrode grid lines 110 and avoid the excessive width of the positive electrode grid lines 110, resulting in the material consumption required for printing the positive electrode grid lines 110. is too big. Here, the reason why the width of the negative electrode grid line 120 is different from the width of the positive electrode grid line 110 is the same as the reason why the electrical connection area is different.

According to another specific embodiment of the present invention, with reference to accompanying drawings 1-4, the above-mentioned n+ doped layer is parallel to the above-mentioned p+ doped layer, thus, it is beneficial to realize as many n+ doped layers and p+ doped layers as possible Arrangement is performed on the solar battery sheet 100 .

According to yet another specific embodiment of the present invention, with reference to accompanying drawings 1-4, above-mentioned negative electrode grid line 120 and above-mentioned positive electrode grid line 110 are parallel, thus, help to realize as many negative electrode grid lines 120 and positive electrode grid line as possible. The grid lines 110 are arranged on the solar cells 100 .

For the convenience of understanding, the method for preparing the above-mentioned back-contact busbar-free solar cell 100 is described in detail below, and the method includes the following steps:

(1) forming alternately arranged p+ doped layers and n+ doped layers on the solar cell 100;

(2) form negative electrode grid line 120 on one side of n+ doped layer, form positive electrode grid line 110 on one side of p+ doped layer, make the two ends of above-mentioned negative electrode grid line 120 and above-mentioned positive electrode grid line 110 The two ends of the above-mentioned negative electrode grid lines are not aligned, and a plurality of the above-mentioned negative electrode grid line connection ends 121 are located on the same side of the above-mentioned negative electrode grid line 120. terminal 111, a plurality of above-mentioned positive electrode grid line connection ends 111 are located on the same side of the above-mentioned positive electrode grid line 110; Graphics made of line segments and/or at least one arc.

According to another specific embodiment of the present invention, the upper surface of the p+ doped layer in the above step (1) can be provided with a positive electrode contact point, thereby realizing the electrical connection between the upper surface of the p+ doped layer and the positive electrode grid line 110; the above step (1) ) can be provided with a negative electrode contact point on the upper surface of the n+ doped layer, so as to realize the electrical connection between the upper surface of the n+ doped layer and the negative electrode grid line 120.

In an embodiment of the present invention, the method of arranging the negative electrode grid lines 120 on the n+ doped layer and the positive electrode grid lines 110 on the p+ doped layer includes but is not limited to at least one of printing, electroplating and laser transfer printing. kind.

In the second aspect of the present invention, the present invention provides a back-contact busbarless solar cell assembly. In an embodiment of the present invention, with reference to accompanying drawings 3 and 4, the above-mentioned solar cell assembly includes: a plurality of back-contact busbarless solar cells 100 described in the above-mentioned embodiments; Contact the negative electrode grid line connection end 121 and the positive electrode grid line connection end 111 in the busbarless solar battery sheet 100 to be electrically connected, so as to electrically connect a plurality of the solar battery sheets 100 mentioned above.

According to the back contact busbar-free solar cell assembly of the embodiment of the present invention, by setting the conductive member 200 to electrically connect the negative electrode grid line connection end 121 and the positive electrode grid line connection end 111 in the solar battery sheet 100, multiple solar energy can be realized. The electrical connection of the battery sheet 100; by increasing the area of the negative electrode grid line connection end 121 and/or the positive electrode grid line connection end 111, the connection between the negative electrode grid line connection end 121 and/or the positive electrode grid line connection end 111 and the positive electrode grid line connection end 111 can be increased. The connection area of the conductive member 200 for electrical connection significantly improves the mechanical properties, thereby facilitating the interconnection effect of the grid line and the conductive member 200; when a part of the grid line connection end is broken, the unbroken area connected to the grid line The area of the connecting end of the grid wire can still be connected with the conductive member 200, thereby improving the safety of current transmission; compared with the traditional thin grid wire connecting end, the grid wire connecting end of the present invention has a better confluence effect.

According to a specific embodiment of the present invention, the above-mentioned conductive member 200 is a metal foil coating or a welding strip, and the above-mentioned conductive member 200 is welded to the above-mentioned negative electrode grid line connection end 121 and the positive electrode grid line connection end 111 to realize multiple battery slices in series or in parallel.

Further, the present invention directly welds the conductive member 200 to the negative electrode grid line connection end 121 and/or the positive electrode grid line connection end 111, and replaces the adhesive film connection with a welded connection, which can solve the problem of back contact with solar energy caused by the melting of the adhesive film. Battery leakage, short circuit and other problems. Specifically, when the conductive member 200 is connected to the connection end of the grid wire of the solar cell 100 through an adhesive film, the adhesive film may be heated and melted during the subsequent lamination process, and the conductive member 200 and the grid wire of the solar cell 100 As a result, the connection position of the connection end may be shifted, causing leakage and short circuit of the solar cell module. Soldering connection instead of film connection can avoid problems such as leakage and short circuit of the solar cell module. Thus, it is beneficial to further improve the mechanical properties of the connection between the connecting end of the grid wire and the conductive member 200, prevent grid breakage at the connecting end of the thin grid wire, enhance the confluence effect of the conductive member 200, and solve the problem of back contact with solar energy due to the melting of the adhesive film. The problem of battery leakage and short circuit.

According to yet another specific embodiment of the present invention, with reference to FIGS. 3-5 , the conductive member 200 is a metal foil coating or a solder strip, preferably a metal foil coating. Thus, the conductive member 200 can be connected to the connecting end of the grid wire by welding, thereby further avoiding the leakage and short circuit of the solar battery module caused by the melting of the adhesive film when the conductive member 200 is connected to the connecting end of the grid wire. And other issues.

In the embodiment of the present invention, the type of the above-mentioned metal foil coating is not particularly limited, and the field can be selected according to the actual situation. As a preferred solution, the above-mentioned metal foil coating includes aluminum foil tin plating, aluminum foil copper plating and aluminum foil plating At least one of the nickels is preferably tin-plated on the aluminum foil, thereby further facilitating the welding of the conductive member and the metal foil plating, and saving the cost of the conductive member.

According to yet another specific embodiment of the present invention, the solder strip is a copper strip wrapped by the metal coating, and the material of the metal coating includes at least one of tin, tin-lead alloy, tin-bismuth alloy, and tin-lead-silver alloy.

According to yet another specific embodiment of the present invention, referring to FIG. 3 , the above-mentioned conductive member 200 includes a first conductive part 210 and a second conductive part 220, and the above-mentioned first conductive part 210 is used to connect the above-mentioned solar cells 100 of the plurality of solar cells 100. Negative electrode grid wire connection end 121, the above-mentioned second conductive part 220 is used to connect the above-mentioned positive electrode grid wire connection end 111 of a plurality of above-mentioned solar cells 100, thus, the first conductive part 210 and the second conductive part 220 realize Parallel use of multiple solar cells 100 .

Specifically, the negative electrode grid wire connection ends 121 of two adjacent rows of battery sheets 100 are close to each other, and/or, the positive electrode grid wire connection ends 111 of two adjacent rows of solar cell sheets 100 are close to each other, through the first conductive part 210 Connect the negative electrode grid line connection ends 121 of two adjacent rows of solar cell sheets 100, and connect the positive electrode grid line connection ends 111 of two adjacent rows of solar cell sheets 100 through the second conductive part 220, thus, the first conductive part 210 and The second conductive portion 220 realizes the parallel use of multiple solar cell sheets 100 . For example, as shown in accompanying drawing 2, when using the conductive member 200 to carry out parallel use of a plurality of solar cells 100, the shape of the conductive member 200 is interdigitated, and the width of the above-mentioned interdigitated figure is 0.8cm-1.2cm, thus , which is beneficial to improve the confluence effect of the conductive member 200 . Preferably, the above-mentioned conductive member 200 is a metal foil coating.

According to yet another specific embodiment of the present invention, referring to FIG. 4 , a plurality of the above-mentioned back-contact busbar-free solar cells 100 are arranged in multiple rows, and among two adjacent rows of back-contact busbar-free solar cells 100 , one row The positive electrode grid end 111 contacting the non-busbar solar cell is close to the negative electrode grid end 121 of another row of back contacting the non-busbar solar cell; the above-mentioned conductive member 200 includes a plurality of third conductive parts 230 located at the most Each row of the back contact non-busbar solar cells 100 in the outer two rows of back contact non-busbar solar cells 100 is electrically connected together through one of the above-mentioned third conductive parts 230; the other two adjacent rows of back contact without busbar The positive electrode grid terminal 111 and the negative electrode grid terminal 121 of the solar cell 100 are electrically connected through the third conductive portion 230 . Thus, the use of multiple rows of solar cells 100 in series is realized through the conductive member 200 .

According to yet another specific embodiment of the present invention, the above-mentioned back-contact solar cell 100 without busbar may be a whole solar cell 100 , or may be a laser-cut half cell or a small cell.

In an embodiment of the present invention, referring to FIG. 5 , the back contact busbarless solar cell module includes: a back sheet 400 , a first adhesive film 300 , a conductive member 200 , and a plurality of solar cells described in the above embodiments are sequentially stacked. The battery sheet 100 , the second adhesive film 600 and the glass plate 500 . Wherein, the back plate 400 is connected to the conductive member 200 through the first adhesive film 300 , and the glass plate 500 is connected to the solar cell 100 through the second adhesive film 600 .

In a third aspect of the present invention, the present invention proposes a method for preparing the above-mentioned back-contact busbar-free solar cell module in the above-mentioned embodiment. Referring to accompanying drawings 5 and 6, the method includes:

S100: Provide patterned metal foil

In this step, a patterned metal foil is provided, and the patterned metal foil is pasted on a predetermined position of the first adhesive film 300 . The metal foil can be patterned according to the connection method of the battery slices 100 in the battery assembly, so that the patterned metal foil electrically connects a plurality of the above-mentioned solar battery slices 100 together. For example, a large piece of metal foil is patterned into the interdigitated shape shown in Figure 2, so that a plurality of the above-mentioned solar cells 100 are connected in parallel; or a large piece of metal foil is patterned into a plurality of Smaller strips are used to connect multiple rows of the above-mentioned solar cells 100 in series.

In some embodiments of the present invention, before providing the above-mentioned patterned metal foil, with reference to accompanying drawing 6, the above-mentioned method also includes: the metal foil is pasted on the carrier film through the first adhesive film 300 (for example, the carrier film can be a release film ) on the above-mentioned metal foil, patterning the above-mentioned metal foil, and forming a patterned metal foil after removing the waste; before pasting the above-mentioned first adhesive film 300 with the above-mentioned metal foil on the above-mentioned back plate 400, the above-mentioned method also includes: removing the above-mentioned carrier film. In the present invention, the metal foil is pasted on the carrier film through the first adhesive film 300; the above-mentioned metal foil is patterned, and the patterned metal foil is formed after removing the waste, and then the above-mentioned carrier film is removed to obtain the patterned metal foil, thus, for example During the preparation process of solar cell modules, the patterned metal foil is pasted on the carrier film through the first adhesive film 300 to form a semi-finished product, and the operator can directly wind the above semi-finished product into a roll. There is no need to remove waste during the assembly process, which can reduce the process of preparing the back contact solar cell assembly without busbar, and can effectively avoid problems such as leakage and short circuit.

In the embodiment of the present invention, the method for patterning the above-mentioned metal foil is not particularly limited, and can be selected according to the actual situation in the field. As a preferred solution, the method for patterning the metal foil includes laser Processing, die-cutting or chemical etching, thereby, facilitates the patterned metal foil to electrically connect a plurality of the above-mentioned solar cells 100 together.

According to a specific embodiment of the present invention, with reference to accompanying drawings 3 and 6, the above-mentioned patterned metal foil is in the shape of a strip, and the width of the above-mentioned patterned metal foil is 0.5cm-5cm, thus, both The current collecting effect of the metal foil can be well realized, and the patterned metal foil can be well electrically connected to the connecting end of the gate line.

S200: Paste the first adhesive film with metal foil on the back plate

In this step, referring to FIG. 5 , the first adhesive film 300 pasted with the metal foil is pasted on the backplane 400 to form the first intermediate piece 700 .

S300: Arranging and laminating the first intermediate piece, multiple solar cells, the second adhesive film and glass

In this step, with reference to FIG. 5 , a plurality of back-contact busbar-free solar cells 100 described in the above-mentioned embodiments are laid out and welded on the first intermediate member 700; wherein, a plurality of back-contact busbar-free solar cells The sheets 100 are electrically connected together through metal foil; the second adhesive film and glass are sequentially formed on the back contact solar cell sheet 100 without busbar, and laminated, thereby obtaining the back contact solar cell module without busbar.

According to the method for preparing a back-contact busbar-free solar cell module according to the embodiment of the present invention, in the prior art, the metal foil is generally connected to the back sheet 400 through the first adhesive film 300, and then the metal foil is patterned, and finally After the waste is removed, the patterned metal foil is obtained. In the present invention, the metal foil is patterned in advance, and then, in the process of preparing the solar cell module, the patterned metal foil is passed through the first adhesive film 300 and The backsheet 400 is connected to each other. Therefore, by removing the waste in advance, there is no need to remove the waste during the preparation of the solar cell module, which can reduce the process of preparing the back contact busbar-free solar cell module, and can effectively avoid problems such as leakage and short circuit.

When the conductive member 200 is a soldering strip, referring to accompanying drawing 6, first use the conductive member 200 (soldering ribbon) to connect a plurality of solar cells 100 in parallel or in series to form a second intermediate member; then follow the sequence from bottom to top The back sheet 400, the first adhesive film 300, the second intermediate piece, the second adhesive film 600, and the glass plate 500 are arranged, and then laminated to obtain the above-mentioned back contact busbarless solar cell module.

In the description of this specification, descriptions referring to the terms "one embodiment", "some embodiments", "example", "specific examples", or "some examples" mean that specific features described in connection with the embodiment or example , structure, material or characteristic is included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms are not necessarily directed to the same embodiment or example. Furthermore, the described specific features, structures, materials or characteristics may be combined in any suitable manner in any one or more embodiments or examples. In addition, those skilled in the art can combine and combine different embodiments or examples and features of different embodiments or examples described in this specification without conflicting with each other.

Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limiting the present invention, those skilled in the art can make the above-mentioned The embodiments are subject to changes, modifications, substitutions and variations.

Claims (11)

1. A back-contact busbar-free solar cell, characterized in that it comprises: an n+ doped layer and a p+ doped layer, the n+ doped layer and the p+ doped layer are alternately arranged on the solar cell sheet; a positive electrode grid line, the positive electrode grid line is located on one side of the p+ doped layer and is electrically connected to the p+ doped layer; Negative electrode grid line, the negative electrode grid line is located on one side of the n+ doped layer, and is electrically connected to the n+ doped layer, the two ends of the negative electrode grid line are connected to the positive electrode grid line The two ends are not aligned, the protruding end of the negative electrode grid line relative to the positive electrode grid line has a negative electrode grid line connection end, and a plurality of the negative electrode grid line connection ends are located on the same side of the negative electrode grid line , the protruding end of the positive electrode grid line relative to the negative electrode grid line has a positive electrode grid line connection end; a plurality of the positive electrode grid line connection ends are located on the same side of the positive electrode grid line; Wherein, the connection end of the negative electrode grid line is a figure composed of a plurality of line segments and/or at least one arc; And/or, the positive electrode grid wire connection end is a figure formed by a plurality of line segments and/or at least one arc. 2. The back contact busbarless solar cell according to claim 1, characterized in that, the negative electrode grid line connection end is a closed figure surrounded by a plurality of line segments and/or at least one arc; And/or, the positive electrode grid wire connection end is a closed figure surrounded by a plurality of line segments and/or at least one arc. 3. The back contact busbar-free solar cell according to claim 2, wherein the shape of the connection end of the negative electrode grid line and the shape of the connection end of the positive electrode grid line both include triangle, circle, and square and at least one of the hexagons. 4. The back contact busbar-free solar cell according to claim 2 or 3, characterized in that, the negative electrode grid line connection end and/or the positive electrode grid line connection end are also arranged in a closed pattern at least one line segment of . 5. The back contact busbar-free solar cell according to claim 1, wherein the area of the orthographic projection of the negative electrode grid line connection end on the n+ doped layer is 0.02 square millimeters to 3 square millimeters ; And/or, the area of the orthographic projection of the positive electrode grid line connection end on the p+ doped layer is 0.05 square millimeters to 5 square millimeters; And/or, the width of the negative electrode grid line is 10 microns-100 microns; And/or, the width of the positive electrode grid line is 20 microns-200 microns. 6. A back-contact busbar-free solar cell module, characterized in that it comprises: The back contact solar cell without busbar according to any one of claims 1-5; A conductive member, the conductive member is electrically connected to the negative electrode grid line connection end and the positive electrode grid line connection end of the back contact non-busbar solar battery sheet, so as to electrically connect a plurality of the solar battery sheets together. 7 . The back contact busbarless solar cell module according to claim 6 , wherein the conductive member is a metal foil coating or a solder strip. 8 . 8. The back contact busbarless solar cell module according to claim 6 or 7, wherein the conductive member comprises a first conductive part and a second conductive part, and the first conductive part is used to connect multiple The negative electrode grid line connection end of the solar battery sheet, the second conductive part is used to connect the positive electrode grid line connection ends of a plurality of the solar battery sheets. 9. The back contact non-busbar solar cell module according to claim 6 or 7, characterized in that, a plurality of said back contact non-busbar solar cells are arranged in multiple rows, and two adjacent rows of back contact without busbar In the solar cells, the positive electrode grid end of one row of back-contact solar cells without busbar is close to the negative electrode grid end of another row of back-contact solar cells without busbar; The conductive member includes a plurality of third conductive parts, and the back contact solar cells without busbar in each row of the two outermost rows of back contact solar cells without busbar are electrically connected to each other through one of the third conductive parts. together; the positive electrode grid line end and the negative electrode grid line end of the remaining two adjacent rows of back-contact solar cells without busbar are electrically connected through the third conductive part. 10. A method for preparing a back contact solar cell module without a busbar, characterized in that it comprises: providing a patterned metal foil, the patterned metal foil pasted on the preset position of the first adhesive film; Paste the first adhesive film pasted with the metal foil on the backboard; Typesetting and soldering a plurality of back contact busbarless solar cells as claimed in any one of claims 1 to 5 on the back plate pasted with the metal foil; wherein, a plurality of back contact busbarless solar cells The grid solar cells are electrically connected together through the metal foil; Forming a second adhesive film and glass on the back-contact busbarless solar cells, and laminating them. 11. The preparation method according to claim 10, characterized in that, before providing the patterned metal foil, the method further comprises: Pasting the metal foil on the carrier film through the first adhesive film; patterning the metal foil, and forming a patterned metal foil after removing waste; Before pasting the first adhesive film pasted with the metal foil on the backboard, the method further includes: The carrier film is removed.