Large-area battery sheet, solar cell sheet, shingled assembly, and manufacturing method

Abstract

The present application relates to a kind of battery piece big piece, solar cell piece, shingle assembly and manufacturing method. The top surface of each unit interface portion of battery piece big piece is divided into cutting zone, top surface bonding zone and top surface conductive contact zone. The cutting zone is configured so that the battery piece big piece can be cut along it;The top surface bonding zone is alternately arranged with the top surface conductive contact zone, and the cutting zone and top surface conductive contact zone form a lap edge of the battery piece, and the top surface conductive contact zone after the splitting of the battery piece big piece can be directly contacted with the bottom surface of another solar cell piece to realize conductive connection. The battery piece big piece provided by the present application can facilitate splitting operation, and the battery piece single piece is provided with special bonding zone and conductive contact zone, and such arrangement can optimize the production process and use performance of solar cell piece.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of energy, in particular to a large piece of battery piece, solar cell piece, shingle assembly and manufacturing method. BACKGROUND

[0002] With the accelerated consumption of global conventional fossil energy such as coal, oil and natural gas, the ecological environment is deteriorating, and in particular, the increasingly severe global climate change caused by greenhouse gas emissions has seriously threatened the sustainable development of human society. Countries around the world have formulated their own energy development strategies to cope with the finiteness of conventional fossil energy resources and the environmental problems caused by their development and utilization. Solar energy has become one of the most important renewable energy sources due to its reliability, safety, universality, long service life, environmental protection and resource adequacy, and is expected to become the main pillar of future global power supply.

[0003] In the new round of energy revolution, China's photovoltaic industry has grown into a strategic emerging industry with international competitive advantage. However, the development of photovoltaic industry still faces many problems and challenges. Conversion efficiency and reliability are the biggest technical obstacles to the development of photovoltaic industry, and cost control and scale also form economic constraints. As the core component of photovoltaic power generation, improving the conversion efficiency of photovoltaic modules to develop high-efficiency modules is an inevitable trend. At present, various high-efficiency modules such as shingle, half-piece, multi-main grid and double-sided module have appeared in the market. With the increasingly wide application of photovoltaic modules in various places and regions, the reliability requirements are becoming higher and higher, especially in some areas where severe or extreme weather occurs, high-efficiency and high-reliability photovoltaic modules are needed.

[0004] Under the background of vigorously promoting and using solar green energy, shingle assembly uses the electrical principle of small current and low loss (the power loss of photovoltaic module is proportional to the square of the working current) to greatly reduce the power loss of the module. Secondly, it makes full use of the space between the cells in the module to generate electricity, and the energy density per unit area is high. In addition, a conductive adhesive with elastomer properties is used instead of the conventional photovoltaic metal ribbon, and the current loop of the conductive adhesive is much smaller than the welding band, so that the shingle assembly becomes a high-efficiency module, and the outdoor application reliability is better than that of the conventional photovoltaic module. Because the shingle assembly avoids the stress damage of the metal welding band to the battery and the interconnection position of the battery and other busbar areas. Especially in the dynamic (wind, snow and other natural loads) environment of high and low temperature alternation, the failure probability of the conventional module interconnected and packaged by metal welding band is much higher than that of the shingle module packaged by the elastomer conductive adhesive interconnected and cut silicon cell small pieces.

[0005] The mainstream process of the current shingled assembly uses conductive adhesive to interconnect the cut battery pieces. The conductive adhesive is mainly composed of a conductive phase and a bonding phase. The conductive phase is mainly composed of noble metals, such as pure silver particles or silver-coated copper, silver-coated nickel, silver-coated glass particles, and is used to conduct electricity between solar cell pieces. The particle shape and distribution are based on the optimal electrical conduction. At present, more D50<10um flaky or spherical silver powder is used. The bonding phase is mainly composed of high molecular resin polymers with weather resistance. Acrylic resin, silicone resin, epoxy resin, polyurethane, etc. are usually selected according to the bonding strength and weather stability. In order to make the conductive adhesive bonding achieve low contact resistance and low volume resistivity, high bonding and long-term excellent weathering properties, the conductive adhesive manufacturer will complete the design of the conductive phase and the bonding phase, so as to ensure the stability of the performance of the shingled assembly in the initial stage of environmental erosion test and long-term outdoor actual application.

[0006] However, for the battery assembly connected by conductive adhesive, after being packaged, it is subjected to environmental erosion during outdoor actual use, such as thermal expansion and contraction caused by high and low temperature alternation, which causes relative displacement between the conductive adhesives. The most serious problem is that it causes current virtual connection or even open circuit. The main reason is that the connection ability between the materials after combination is weak. The weak connection ability mainly shows that the conductive adhesive operation in the process needs a process operation window. In the actual production process, this window is relatively narrow and is easily affected by environmental factors, such as the temperature and humidity of the working place, the length of time of the conductive adhesive in the air after coating, etc. which can cause the conductive adhesive to lose activity. At the same time, the adhesive itself has the characteristics of uneven application, which can cause great hidden troubles to the reliability of the product. Secondly, the conductive adhesive is mainly composed of high molecular resin and a large amount of noble metal powder, which is high in cost and damages the ecological environment to a certain extent (the production and processing of noble metals pollute the environment). In addition, the conductive adhesive belongs to paste, which has a certain flowability during the application or lamination process, and is very easy to overflow and cause short circuit of the positive and negative electrodes of the shingled interconnected battery string.

[0007] That is to say, for most shingled assemblies made by conductive adhesive bonding, there are problems such as weak mutual connection strength, high environmental requirements for the process, easy overflow and short circuit in the process, high use cost, and low production efficiency.

[0008] In addition, in order to realize the conductive connection of each solar cell piece, an electrode is usually arranged on the surface of the solar cell piece, and the electrode is made of expensive metal, so the solar cell piece usually has a high cost.

[0009] In the manufacturing of solar cells, there is also no large piece of battery piece that can form the above-mentioned solar cell piece and is easy to crack the piece.

[0010] Therefore, it is necessary to provide a battery wafer, a solar cell wafer, a shingle assembly and a manufacturing method to at least partially solve the above problems. SUMMARY

[0011] The present application aims to provide a battery wafer, a solar cell wafer, a shingle assembly and a manufacturing method. The battery wafer provided by the present application can facilitate wafer splitting operation, and the battery wafer is provided with a conductive contact area for realizing conductive connection of the solar cell wafer after wafer splitting and a bonding area for applying adhesive, which can optimize the production process and use performance of the solar cell wafer.

[0012] Further, the solar cell wafers formed by wafer splitting can realize conductive connection through direct contact of the main grid lines and the auxiliary grid lines, so that the adhesive without conductive property can also be used for fixing, which at least has the following advantages:

[0013] I. The main grid lines are arranged only on the top surface or the bottom surface of the solar cell wafer, compared with the scheme of arranging the main grid lines on the top surface and the bottom surface at the same time, the present application can also reduce the amount of silver paste to reduce the cost;

[0014] II. The adhesive can not have conductive property, so that the factors such as environmental erosion, high-low temperature alternation, thermal expansion and cold contraction which are easy to damage the conductive adhesive will not affect the shingle assembly of the present application, and the shingle assembly is not easy to appear virtual connection and open circuit of current, and the problems such as open circuit of positive and negative poles of the battery string caused by overflow of the conductive adhesive will not occur.

[0015] According to one aspect of the present application, a battery wafer is provided for splitting to form a plurality of solar cell wafers, the plurality of solar cell wafers can be arranged in a shingle manner to form a battery string,

[0016] The battery wafer includes a base wafer, the top surface and the bottom surface of the base wafer are provided with auxiliary grid lines, and the top surface or the bottom surface of the base wafer is provided with a main grid line crossing the auxiliary grid lines, the battery wafer is divided into a plurality of units arranged along a first direction, any two adjacent units are a first unit and a second unit, when the battery wafer is split, the first unit forms a first solar cell wafer, and the second unit forms a second solar cell wafer,

[0017] The top surface of the interface part between the first unit and the second unit is divided into:

[0018] a cutting area extending along a direction perpendicular to the first direction, the cutting area is configured to enable the battery wafer to be cut along the cutting area; and

[0019] a top surface bonding region and a top surface conductive contact region disposed on one side of the cutting region, and the top surface bonding region and the top surface conductive contact region are alternately disposed in a direction perpendicular to the first direction, the cutting region and the top surface conductive contact region forming a top surface of one of the lapped edges of the second solar cell piece,

[0020] wherein the top surface bonding region and the top surface conductive contact region are configured to be capable of applying a bonding agent on the top surface bonding region to mutually fix a bottom surface of a solar cell piece adjacent thereto when the second solar cell piece is located in a solar cell string, and the top surface conductive contact region is capable of facing a corresponding region on a bottom surface of another solar cell piece formed by the solar cell piece large piece to realize the tile connection of the two solar cell pieces, and the solar cell piece large piece is configured such that the one of the top surface conductive contact region and the corresponding region is provided with the auxiliary busbar, and the other is provided with the main busbar, and the auxiliary busbar and the main busbar directly contact to realize the conductive connection of the two solar cell pieces.

[0021] In an embodiment, the base piece includes a center layer and a light-transmissive conductive film formed on a top surface and a bottom surface of the center layer.

[0022] In an embodiment, the main busbar is disposed on a top surface of the solar cell piece large piece, and the main busbar includes a plurality of groups, one group is disposed at an edge of each of the units, and each group of main busbars includes a plurality of segment structures disposed intermittently, and each segment of the main busbar is disposed in one-to-one correspondence in each of the top surface conductive contact regions.

[0023] In an embodiment, a bottom surface bonding region and a bottom surface conductive contact region are further disposed on a bottom surface of the junction portion of the first unit and the second unit, the bottom surface bonding region and the bottom surface conductive contact region are located on the other side of the cutting region in the first direction, and the bottom surface bonding region and the bottom surface conductive contact region are alternately disposed in a direction perpendicular to the first direction, and the bottom surface conductive contact region forms the corresponding region.

[0024] In an embodiment, the main busbar is disposed on a bottom surface of the solar cell piece large piece, and the main busbar includes a plurality of groups, one group is disposed at an edge of each of the units, and each group of main busbars includes a plurality of segment structures disposed intermittently, and each segment of the main busbar is disposed in one-to-one correspondence in each of the bottom surface conductive contact regions,

[0025] and the auxiliary busbar is disposed in the top surface conductive contact region of the solar cell piece large piece.

[0026] In an embodiment, the light-transmissive conductive film extends over the entire top surface and bottom surface of the center layer.

[0027] In an embodiment, the light-transmissive conductive film is absent at the top surface bonding region and the bottom surface bonding region.

[0028] In an embodiment, the top surface of the junction between a pair of the first unit and the second unit at the foremost end of the base piece of the solar cell piece is further provided with another set of top surface bonding region and top surface conductive contact region, which is located on the other side of the cutting region and forms the top surface of a lap edge of the first solar cell piece.

[0029] In an embodiment, the center layer comprises a silicon wafer, a top side intrinsic amorphous silicon thin film provided on the top surface of the silicon wafer, a P-type amorphous silicon thin film provided on the top surface of the top side intrinsic amorphous silicon thin film, a bottom side intrinsic amorphous silicon thin film provided on the bottom surface of the silicon wafer, and an N-type amorphous silicon thin film provided on the bottom surface of the bottom side intrinsic amorphous silicon thin film.

[0030] The second aspect of the present application provides a solar cell piece, which is split from the base piece according to any one of the above-mentioned solutions.

[0031] In an embodiment, the base piece of the solar cell piece comprises a center layer and a light-transmissive conductive film, which extends over the entire top surface and bottom surface of the center layer, and the light-transmissive conductive film has the same thickness everywhere, so that when a bonding agent is applied on the top surface bonding region, the bonding agent protrudes from the light-transmissive conductive film, thereby when the solar cell piece is connected with another solar cell piece, the light-transmissive conductive films on the surfaces of the two solar cell pieces opposite to each other are spaced apart by the bonding agent at the bonding agent.

[0032] In an embodiment, the base piece of the solar cell piece comprises a center layer and a light-transmissive conductive film on the top surface and bottom surface of the center layer, and the light-transmissive conductive film has a notch at the top surface bonding region, so that when a bonding agent is applied on the solar cell piece, the bonding agent is located in the notch and does not protrude from the light-transmissive conductive film.

[0033] In an embodiment, the top surface of the lap edge of the solar cell piece in contact with another solar cell piece is provided with top surface bonding regions and top surface conductive contact regions extending along the lap edge and arranged alternately, and the top surface conductive contact regions are provided with main grid lines.

[0034] In one embodiment, the bottom surface of the overlapping edge of the solar cell piece in contact with another solar cell piece is provided with bottom surface adhesive areas and bottom surface conductive contact areas extending along the overlapping edge and arranged alternately, and the bottom surface conductive contact areas are provided with main grid lines.

[0035] According to a third aspect of the present application, a shingled assembly is provided, comprising a cell string, characterized in that the cell string is formed by a plurality of solar cell pieces according to any one of the above solutions connected in shingled manner in sequence, each of the solar cell pieces is fixed to each other by an adhesive, and the top surface and the bottom surface of each of the solar cell pieces are provided with a secondary grid line, the top surface or the bottom surface is provided with a main grid line, and the main grid line of one of two adjacent solar cell pieces can be in direct contact with the secondary grid line of the other of the two solar cell pieces to realize conductive connection between the two adjacent solar cell pieces.

[0036] In one embodiment, the adhesive is a non-conductive adhesive.

[0037] In one embodiment, the adhesive is a point structure adhesive made of acrylic resin, silicone resin, epoxy resin or polyurethane.

[0038] In one embodiment, the adhesive is a point structure adhesive comprising a curing agent, a cross-linking agent, a coupling agent or a rubber ball.

[0039] According to a fourth aspect of the present application, a manufacturing method for manufacturing a shingled assembly is provided, the method comprising the following steps:

[0040] manufacturing a cell piece wafer according to any one of the above solutions, and the cell piece wafer has a secondary grid line;

[0041] cutting along each of the cutting areas of the cell piece wafer, so that the cell piece wafer is cracked into a plurality of solar cell pieces;

[0042] connecting a plurality of the solar cell pieces in shingled manner by an adhesive without conductive properties, so that the main grid line of one of two adjacent solar cell pieces is in direct contact with the secondary grid line of the other to realize conductive connection.

[0043] In one embodiment, the method further comprises the step of applying the adhesive to the solar cell piece in one of the following ways: spraying, dripping, rolling, printing, and brushing.

[0044] In one embodiment, the method of manufacturing a cell piece wafer does not include the step of providing a main grid line.

[0045] According to the present application, a cell sheet for manufacturing solar cell sheets can be provided, a connection area of each unit of the cell sheet is formed with a cutting area, a top surface bonding area and a top surface conductive contact area, the cutting area can facilitate the splitting of the cell sheet, the top surface bonding area and the top surface conductive contact area are formed as a lap edge of a solar cell sheet, wherein the solar cell sheets formed after the splitting of the cell sheet can be arranged in a cell string in a shingle manner, and in the cell string, the top surface conductive contact area of one of any two adjacent solar cell sheets can be in contact with the other solar cell sheet, so as to realize the contact of the main grid line of one of the two solar cell sheets with the auxiliary grid line of the other solar cell sheet to realize the conductive connection; the bonding agent for bonding the adjacent solar cell sheets together can be applied to the top surface bonding area.

[0046] Such arrangement can facilitate the splitting of the cell sheet, and the direct contact of the main grid line and the auxiliary grid line between the solar cell sheets formed after the splitting can realize the conductive connection, so that the bonding agent without conductive property can also be used for fixing, which at least has the following advantages:

[0047] I. The main grid line is arranged only on the top surface or the bottom surface of the solar cell sheet, compared with the scheme that the main grid line is arranged on the top surface and the bottom surface at the same time, the present application can also reduce the amount of silver paste to reduce the cost;

[0048] II. The bonding agent can not have conductive property, so that the factors such as environmental erosion, high-low temperature alternation, thermal expansion and cold contraction which are easy to damage the conductive glue will not affect the shingle assembly of the present application, the shingle assembly is not easy to appear current virtual connection and open circuit, and the problems such as the open circuit of the positive and negative poles of the cell string caused by the overflow of the conductive glue will not occur. BRIEF DESCRIPTION OF DRAWINGS

[0049] For better understanding of the above and other objects, features, advantages and functions of the present application, reference can be made to the preferred embodiments shown in the accompanying drawings. The same reference signs in the drawings refer to the same parts. It should be understood by those skilled in the art that the drawings are intended to illustrate the preferred embodiments of the present application schematically, and have no limiting effect on the scope of the present application, and the various parts in the drawings are not drawn to scale.

[0050] Figure 1 A top surface schematic view of a cell sheet according to the first embodiment of the present application is shown;

[0051] Figure 2 A partial enlarged view of part A in Figure 1 ;

[0052] Figure 3 A partial enlarged view of part B in Figure 1 ;

[0053] Figure 4 a schematic view of a top surface of a single solar cell piece formed by splitting the solar cell piece of the large piece of the solar cell piece in

[0054] Figure 5 a partial enlarged view of the C part in Figure 4

[0055] Figure 6A Figure 6B a schematic view of a top surface and a schematic view of a bottom surface of a single solar cell piece formed by splitting the solar cell piece of the large piece of the solar cell piece in Figure 1

[0056] Figure 7 a schematic view of a top surface of two solar cell pieces shown in Figures 6A-6B

[0057] Figure 8 Figure 7

[0058] Figure 9A Figure 9B a schematic view of a top surface and a schematic view of a bottom surface of a solar cell piece according to the second embodiment of the present application

[0059] Figure 10 a schematic view of a top surface of two solar cell pieces shown in Figures 9A-9B

[0060] Figure 11 a sectional view taken along the line B-B in Figure 10 DETAILED DESCRIPTION

[0061] Reference will now be made in detail to the preferred embodiments of the present application, examples of which are illustrated in the accompanying drawings. The preferred embodiments described herein are merely exemplary and not limiting, as the present application can be applied to other ways as well, which would be apparent to those skilled in the art, based on the preferred embodiments described herein, and which would fall within the scope of the present application.

[0062] The present application provides a large piece of solar cell piece, a solar cell piece, a tile assembly and a manufacturing method. The large piece of solar cell piece is used for manufacturing a solar cell piece, for example, for manufacturing a heterojunction solar cell piece, a PERC solar cell piece and a topcon solar cell piece. Correspondingly, the solar cell piece provided by the present application can be a heterojunction solar cell piece, a PERC solar cell piece or a topcon solar cell piece.

[0063] Figures 1 to 11 ​​​​​​​​​Several preferred embodiments of the inventive cell sheet and solar cell sheet are shown. In the present embodiment, the cell sheet is a cell sheet for manufacturing a heterojunction solar cell sheet, and the solar cell sheet in the present embodiment is a heterojunction solar cell sheet.

[0064] Figures 1-8 A first embodiment according to the present application is shown. Figure 1 The cell sheet 100 in the present embodiment is shown, which can be split to form a plurality of solar cell sheets. The cell sheet 100 includes a base sheet 11, which includes a center layer and a light-transmissive conductive film 13 disposed on the top and bottom surfaces of the center layer. The center layer, for example, further includes a silicon sheet, a top-side intrinsic amorphous silicon thin film disposed on the top surface of the silicon sheet, a P-type amorphous silicon thin film disposed on the top surface of the top-side intrinsic amorphous silicon thin film, a bottom-side intrinsic amorphous silicon thin film disposed on the bottom surface of the silicon sheet, and an N-type amorphous silicon thin film disposed on the bottom surface of the bottom-side intrinsic amorphous silicon thin film.

[0065] The top and bottom surfaces of the cell sheet 100 further include sub-grid lines 12, and the top or bottom surface of the cell sheet includes a main grid line that spans the sub-grid lines 12, and the two solar cell sheets formed by splitting the cell sheet 100 can be connected in a shingle manner and electrically connected by direct contact of the main grid line and the sub-grid lines 12. In the present embodiment, the main grid line is disposed on the bottom surface of the cell sheet 100 (as shown in the bottom surface conductive contact region 23a), and no main grid line is disposed on the top surface of the cell sheet 100. Figure 5 The top and bottom surfaces of the cell sheet 100 further include sub-grid lines 12, and the top or bottom surface of the cell sheet includes a main grid line that spans the sub-grid lines 12, and the two solar cell sheets formed by splitting the cell sheet 100 can be connected in a shingle manner and electrically connected by direct contact of the main grid line and the sub-grid lines 12. In the present embodiment, the main grid line is disposed on the bottom surface of the cell sheet 100 (as shown in the bottom surface conductive contact region 23a), and no main grid line is disposed on the top surface of the cell sheet 100.

[0066] Referring to Figure 2 , the cell sheet 100 is divided into a plurality of units 1 arranged in a straight line direction, and any two adjacent units 1 are a first unit 1a and a second unit 1b, wherein the first unit 1a forms a first cell sheet, and the second unit 1b forms a second cell sheet.

[0067] Continuing to refer to Figure 2 , the top surface of the interface portion 2 between the first unit 1a and the second unit 1b is divided into a cutting region 21, a top surface bonding region 22, and a top surface conductive contact region 23. The cutting region 21 extends in a direction perpendicular to the arrangement direction of the solar cell sheet, and the cell sheet 100 can be split along the cutting region 21. After splitting, the top surface bonding region 22 and the top surface conductive contact region 23 can form the lap edges of the second cell sheet, and the top surface bonding region 22 and the top surface conductive contact region 23 are disposed on one side of the cutting region 21 and are alternately disposed in a direction parallel to the cutting region 21 on the cell sheet 100.

[0068] When the solar cell wafer 100 is split, the second solar cell wafer can be arranged in a shingled manner with another solar cell wafer (for example, the first solar cell wafer), and the bottom surface of the other solar cell wafer can be in direct contact with the top surface conductive contact area 23 of the second solar cell wafer to achieve conductive connection, and the adhesive 9 for fixing the two solar cell wafers can be applied on the top surface bonding area 22.

[0069] The structure of the bottom surface of the solar cell wafer 100 is shown in Figure 4 and Figure 5 . Referring to Figure 4 and Figure 5 , on the solar cell wafer 100, the bottom surface of the junction portion 2 of the first unit 1a and the second unit 1b is also provided with a bottom surface bonding area 22a and a bottom surface conductive contact area 23a. The bottom surface bonding area 22a and the bottom surface conductive contact area 23a are located on one side of the cutting area 21, and the bottom surface bonding area 22a and the bottom surface conductive contact area 23a are arranged alternately in a direction parallel to the cutting area 21. The bottom surface conductive contact area 23a and the bottom surface bonding area 22a together constitute a lap edge of the first solar cell wafer. The bottom surface conductive contact area 23a is provided with a main grid line, and as can be seen from the figure, the width of the main grid line is greater than the width of the auxiliary grid line 12.

[0070] Preferably, the main grid line includes multiple groups, each group of main grid lines corresponding to each unit of the solar cell wafer, and each group of main grid lines includes multiple segments, each segment of main grid line being arranged in each bottom surface conductive contact area 23a in a one-to-one correspondence.

[0071] As can be seen from Figure 2 and Figure 5 , the solar cell wafer 100 is configured such that the top surface conductive contact area 23 of the lap edge of the top surface of the first solar cell wafer formed by the first unit 1a is provided with an auxiliary grid line 12, and the top surface conductive contact area 23a of the lap edge of the bottom surface is provided with a main grid line, so that when two solar cell wafers are arranged in a shingled manner, the top surface conductive contact area 23 and the bottom surface conductive contact area 23a of the two solar cell wafers facing each other are in contact with each other, at this time, the auxiliary grid line 12 in the top surface conductive contact area 23 of the solar cell wafer on the bottom side (for example, the second solar cell wafer formed by the second unit 1b) can be in direct contact with the main grid line of the solar cell wafer on the top side (for example, the first solar cell wafer formed by the first unit 1a) to achieve conductive connection.

[0072] It should be noted that the "first unit" and "second unit", "first solar cell wafer" and "second solar cell wafer" mentioned herein are relative descriptions rather than absolute descriptions, for example, the "first unit" in a pair of adjacent units can also be the "second unit" in another pair of adjacent units.

[0073] Turning now to Figure 1 and Figure 3 It can be seen that the pair of first cell 1a and second cell 1b at the foremost end of the battery sheet large piece 100 also comprises another set of top surface bonding area 22 and top surface conductive contact area 23, that is to say, there is a set of top surface bonding area 22 and top surface conductive contact area 23 on both sides of the cutting area 21. The two sets of top surface bonding area 22 and top surface conductive contact area 23 are respectively formed as the top surface of the lap joint edges of the first battery sheet and the second battery sheet.

[0074] Figure 6A and Figure 6B The schematic diagram of the top surface and the bottom surface of a single solar battery sheet composed of a single cell 1 after the battery sheet large piece 100 is split in the present embodiment is shown. It can be seen that there are top surface bonding area 22 and top surface conductive contact area 23 alternately arranged at the edge for lap joint with another solar battery sheet on the top surface of the solar battery sheet, and the top surface conductive contact area 23 has the sub-grid line 12 therein without the main grid line; there are bottom surface bonding area 22a and bottom surface conductive contact area 23a alternately arranged at the edge for lap joint with another solar battery sheet on the bottom surface of the solar battery sheet, and the bottom surface conductive contact area 23a is provided with the main grid line.

[0075] Figure 7 and Figure 8 The structure after two solar battery sheets composed of the above-mentioned first cell 1a and second cell 1b are connected in a shingle manner is shown. It can be seen that the solar battery sheets composed of the first cell 1a and the second cell 1b each comprise a center layer and a light-transmitting conductive film 313 provided on the surface of the center layer.

[0076] When the two solar battery sheets are connected in a shingle manner, in the area where the two are in contact with each other, the direct contact of the sub-grid line 12 (located in the top surface conductive contact area 23) of the top surface of the solar battery sheet composed of the second cell 1b and the main grid line 14 (located in the bottom surface conductive contact area 23a) of the bottom surface of the solar battery sheet composed of the first cell 1a realizes the conductive connection. And since the main grid line is filled in the bottom surface conductive contact area, and the bottom surface conductive contact area is discontinuously arranged in its extension direction, thus in the cross-sectional view shown in Figure 7 the main grid line 14 is also discontinuously arranged, and between each segment of the main grid line 14 is the adhesive 9 applied on the bonding area.

[0077] In the present embodiment, the solar cell pieces produced by splitting the solar cell wafer 100 are arranged in a shingle manner, and the direct contact between the main busbar 14 and the sub busbar 12 realizes the conductive connection, so that the solar cell wafer 100 can reduce the amount of silver paste used to form the main busbar (compared with the scheme of arranging the main busbar on both the top surface and the bottom surface), which can reduce the cost and reduce the weight of the solar cell wafer.

[0078] Figures 9A to 11 The solar cell piece in the second embodiment according to the present application is shown, which is also produced by splitting the solar cell wafer (not shown). The structure of each component in the present embodiment is similar to the previous embodiment, so the same or similar parts of the previous embodiment will not be described again.

[0079] Reference Figure 9A The top surface of the solar cell piece 3 is provided with top surface conductive contact areas 33 and top surface adhesive areas 32 arranged alternately along the lap edge thereof, and the main busbar is formed in the top surface conductive contact area. Reference Figure 9B The bottom surface of the solar cell piece 3 is provided with bottom surface conductive contact areas 33a and bottom surface adhesive areas 32a arranged alternately along the lap edge thereof, and the sub busbar is arranged in the bottom surface conductive contact area 33a without the main busbar.

[0080] The state after two such solar cell pieces are connected in a shingle manner is shown in Figure 10 and Figure 11 For the convenience of description, Figures 10-11 the two heterojunction solar cell pieces in are respectively referred to as the first solar cell piece 3a and the second solar cell piece 3b.

[0081] The first solar cell piece 3a includes a substrate piece and a light-transmitting conductive film 313 on the bottom surface of the substrate piece, and the bottom surface of the first solar cell piece 3a is provided with the sub busbar 312 (specifically arranged in the bottom surface conductive contact area). The second solar cell piece 3b includes a substrate piece and a light-transmitting conductive film 313 on the top surface of the substrate piece, and the top surface of the second solar cell piece 3b is provided with the main busbar 314 (specifically arranged in the top surface conductive contact area). The direct contact between the sub busbar 312 and the main busbar 314 realizes the conductive connection between the first solar cell piece 3a and the second solar cell piece 3b. And since the main busbar 314 is filled in the top surface conductive contact area, and the top surface conductive contact area is arranged discontinuously in the extension direction thereof, in the cross-sectional view shown in Figure 11 , the main busbar 314 is also arranged discontinuously, and the adhesive 9 applied on the adhesive area is between each segment of the main busbar 314.

[0082] In addition to the above, each component can have other preferred arrangements in the above two embodiments.

[0083] For example, the adhesive is preferably a non-conductive adhesive. The adhesive material is selected taking into account various factors, such as the influence on electrical connectivity, mechanical strength, influence on product reliability, as well as application compatibility, cost, and the like. Preferably, a liquid or highly flowable non-conductive material is selected to facilitate penetration into the overlap gap between adjacent solar cell pieces. The adhesive material can be made of, for example, an acrylic resin, a silicone resin, an epoxy resin, or a polyurethane, and a curing agent, a cross-linking agent, a coupling agent, or a rubber ball, or the like, can be added to the adhesive material to form a certain thickness.

[0084] Since the adhesive is non-conductive, factors such as environmental erosion, high-low temperature alternation, thermal expansion and contraction, and the like, which can easily damage conductive adhesive, do not affect the shingled assembly and the solar cell pieces of the present application, and the shingled assembly and the solar cell pieces are less likely to have a virtual connection and a circuit break, and the requirement for the coating precision of the adhesive is reduced. Moreover, since the conductive adhesive does not have to be provided, problems such as a positive and negative electrode circuit break of the cell string caused by overflow of the conductive adhesive do not occur. In addition, since the conductivity of the adhesive is not required, the production cost of the shingled assembly is reduced.

[0085] The adhesive can also have various forms of arrangement. For example, the adhesive can be in a dot shape, and a plurality of adhesives are arranged intermittently on the overlap edges of each pair of adjacent solar cell pieces; or the adhesive can be in a strip shape and extend along the overlap edges of each pair of adjacent solar cell pieces; or the adhesive can be applied on the top surface of a plurality of solar cell pieces so that the adhesive spans a plurality of solar cell pieces, in which case the adhesive is preferably a plurality of adhesives and the plurality of adhesives are arranged parallel to each other on the top surface of the cell string; or a plurality of adhesives can be applied on the top surface and / or the bottom surface of the solar cell pieces, and the adhesives can be arranged non-parallel to each other.

[0086] Preferably, the adhesive can also be applied on each solar cell piece before the solar cell pieces are interconnected with each other.

[0087] For example, the light-transmissive conductive film can be arranged to extend over the top surface and the bottom surface of the entire base piece, and the light-transmissive conductive film has a uniform thickness everywhere before the solar cell pieces are interconnected with each other. In this way, for example, for the light-transmissive conductive film on the top surface of the center layer, the adhesive protrudes upward from the light-transmissive conductive film after the adhesive is applied on the light-transmissive conductive film at the top surface bonding region; and for the light-transmissive conductive film on the bottom surface of the center layer, the adhesive protrudes downward from the light-transmissive conductive film after the adhesive is applied on the light-transmissive conductive film at the bottom surface bonding region.

[0088] In this way, when two solar cell pieces are connected in a shingle manner, the light-transmissive conductive films on the surfaces opposite to each other are bent at the adhesive due to extrusion of the adhesive, so that the light-transmissive conductive films of the two are spaced apart at positions close to the adhesive. This arrangement is simple and does not require additional processing of the light-transmissive conductive films, thus being high in production efficiency and low in cost.

[0089] Alternatively, the light-transmissive conductive film is provided with a notch at a position where the adhesive is arranged to at least partially accommodate the adhesive, so that when two solar cell pieces are connected in a shingle manner, the light-transmissive conductive films of the two are in close contact, and the contact surface is free from bending and the like. This arrangement avoids problems caused by extrusion and deformation of the light-transmissive conductive film, and stable accommodation of the adhesive in the notch avoids problems such as detachment and failure of the adhesive.

[0090] Preferably, the light-transmissive conductive film of the top side and / or the bottom side of the solar cell piece can be of a multi-layer structure, and the light-transmissivity of each of the light-transmissive conductive films increases in a direction from the central layer outward in a direction perpendicular to the central layer. This arrangement improves the carrier displacement rate, light-transmissivity, and conductivity of the solar cell piece, avoids problems such as low fill factor and low short-circuit current, and enables the solar cell piece to have a high photoelectric conversion rate.

[0091] The present application also provides a preferred example of a method of manufacturing the shingle assembly as described above. The manufacturing method comprises the following steps: manufacturing the cell piece large piece as described in the above embodiments; cutting along each of the cutting regions of the cell piece large piece, so that the cell piece large piece is split into a plurality of solar cell pieces; and connecting the plurality of solar cell pieces in a shingle manner by the adhesive without conductive properties, so that the main grid lines of one of the two adjacent solar cell pieces and the sub grid lines of the other are in direct contact to achieve conductive connection.

[0092] In this way, when two solar cell pieces are connected in a shingle manner, the light-transmissive conductive films on the surfaces opposite to each other are bent at the adhesive due to extrusion of the adhesive, so that the light-transmissive conductive films of the two are spaced apart at positions close to the adhesive. This arrangement is simple and does not require additional processing of the light-transmissive conductive films, thus being high in production efficiency and low in cost.

[0093] Preferably, the method further comprises the following step between the step of applying the adhesive to the first solar cell piece and the step of connecting the first solar cell piece and the second solar cell piece to each other: applying the adhesive to the light-transmissive conductive film of the bottom surface bonding region of the second solar cell piece.

[0094] Alternatively, the individual solar cell pieces can be arranged in a shingle manner and then the adhesive is applied thereon. Such a manner can be implemented in several different ways.

[0095] The step of applying the adhesive can include discontinuously applying the adhesive along the overlapping edges of each pair of adjacent solar cell pieces so that the adhesive is formed into a plurality of dot-like structures spaced along the overlapping edges.

[0096] Alternatively, the step of applying the adhesive can include continuously applying the adhesive along the overlapping edges of each pair of adjacent solar cell pieces so that the adhesive is formed into a strip-like structure extending along the overlapping edges.

[0097] Alternatively, the step of applying the adhesive can include continuously applying the adhesive along the arrangement direction of the individual solar cell pieces so that the adhesive spans the plurality of solar cell pieces.

[0098] Preferably, the above-mentioned ways of applying the adhesive can be implemented by spraying, dropping, rolling, printing, and brushing.

[0099] Also preferably, the adhesive can be applied by using a screen having a plurality of openings, and the method of applying the adhesive includes the steps of positioning the screen on the top surface of the individual arranged solar cell pieces and coating the adhesive on the screen so that the adhesive is printed on the desired locations through the openings.

[0100] As mentioned above, since the center layer of the solar cell piece also has a multi-layer structure, the method of manufacturing the large solar cell piece includes the steps of providing a silicon wafer, providing a top-side intrinsic amorphous silicon thin film on the top surface of the silicon wafer and a bottom-side intrinsic amorphous silicon thin film on the bottom surface of the silicon wafer, providing a light-transmitting conductive film on the top surface of the top-side intrinsic amorphous silicon thin film and on the bottom surface of the bottom-side intrinsic amorphous silicon thin film, and providing a sub-grid line on the light-transmitting conductive film. Preferably, the method of manufacturing the large solar cell piece does not include the step of providing a main grid line.

[0101] The large solar cell piece provided by the present application can be conveniently split into solar cell pieces, and the large solar cell piece is provided with a conductive contact area for conductive connection of the solar cell pieces and an adhesive area for applying the adhesive, which can optimize the production process and use performance of the solar cell pieces.

[0102] Further, the solar cell pieces formed by splitting can be conductively connected by direct contact of the main grid line and the sub-grid line, so that the adhesive without conductive property can also be used for fixation, which at least has the following advantages:

[0103] One, the main grid line can be reduced, thereby saving silver paste and reducing cost;

[0104] Two, the binder can not be conductive, so that environmental erosion, high and low temperature alternation, thermal expansion and contraction and other factors that easily damage the conductive adhesive will not affect the shingle assembly of the application, and the shingle assembly is not easy to appear current virtual connection and open circuit. The problem of positive and negative open circuit of battery string caused by conductive adhesive overflow will not occur.

[0105] The above description of various embodiments of the application is provided to one of ordinary skill in the relevant art for descriptive purposes. It is not intended to exclude or limit the application to a single disclosed embodiment. As described above, one of ordinary skill in the art of the above teachings will understand various alternatives and modifications to the application. Therefore, although some alternative embodiments are specifically described, one of ordinary skill in the art will understand or relatively easily develop other embodiments. The application is intended to include all alternatives, modifications and variations of the application described herein, and other embodiments falling within the spirit and scope of the above-described application.

[0106] Reference signs:

[0107] Large battery sheet 100

[0108] Unit 1

[0109] First unit 1a

[0110] Second unit 1b

[0111] First battery sheet 3a

[0112] Second battery sheet 3b

[0113] Interface 2

[0114] Cutting zone 21

[0115] Top surface bonding area 22, 32

[0116] Top surface conductive contact area 23, 33

[0117] Substrate sheet 11

[0118] Sub-grid line 12

[0119] Bottom surface bonding area 22a, 32a

[0120] Bottom surface conductive contact area 23a, 33a

[0121] Light-transmitting conductive film 13, 313

[0122] Binder 9

[0123] Main grid line 14.

Claims

1. A large solar cell sheet, used for splitting to form multiple solar cells, wherein the multiple solar cells can be arranged in a shingled manner to form a cell string. in, The large solar cell includes a substrate sheet. Sub-grid lines are disposed on the top and bottom surfaces of the substrate sheet, and main grid lines spanning the sub-grid lines are disposed on the top or bottom surface of the substrate sheet. The large solar cell is divided into multiple units arranged along a first direction. Any two adjacent units are designated as a first unit and a second unit. After the large solar cell is split into smaller cells, the first unit forms a first solar cell, and the second unit forms a second solar cell. The feature is that the top surface of the boundary portion between the first unit and the second unit is divided into: A cutting region extending in a direction perpendicular to the first direction, the cutting region being configured to allow the large battery cell to be cut along it; and The top surface bonding area and the top surface conductive contact area are disposed on one side of the cutting area, and the top surface bonding area and the top surface conductive contact area are alternately arranged in a direction perpendicular to the first direction. The cutting area and the top surface conductive contact area form the top surface of an overlapping edge of the second battery cell. The top surface bonding area and the top surface conductive contact area are configured such that when the second solar cell is located in the solar cell string, an adhesive can be applied to the top surface bonding area to fix it to the bottom surface of the adjacent solar cell. The top surface conductive contact area can face the corresponding area on the bottom surface of another solar cell formed by splitting the solar cell into large sheets, thereby realizing the shingled connection of the two solar cells. Furthermore, the large solar cell is configured such that: one of the top surface conductive contact area and the corresponding area is provided with the sub-grid line, and the other is provided with the main grid line. The sub-grid line and the main grid line are in direct contact to realize the conductive connection of the two solar cells.

2. The large battery cell according to claim 1, characterized in that, The substrate sheet includes a central layer and light-transmitting conductive films formed on the top and bottom surfaces of the central layer.

3. The large battery cell according to claim 1, characterized in that, The main grid lines are disposed on the top surface of the large battery cell, and the main grid lines include multiple sets, with one set disposed at the edge of each unit. Each set of main grid lines includes multiple discontinuously arranged segments, and each segment of the main grid line is disposed in a corresponding conductive contact area on the top surface.

4. The large battery cell according to claim 2, characterized in that, A bottom surface bonding area and a bottom surface conductive contact area are further provided on the bottom surface of the junction of the first unit and the second unit. The bottom surface bonding area and the bottom surface conductive contact area are located on the other side of the cutting area in the first direction, and the bottom surface bonding area and the bottom surface conductive contact area are alternately arranged in a direction perpendicular to the first direction. The bottom surface conductive contact area forms the corresponding area.

5. The large battery cell according to claim 4, characterized in that, The main grid lines are disposed on the bottom surface of the large solar cell, and the main grid lines include multiple sets, with one set disposed at the edge of each cell. Each set of main grid lines includes multiple discontinuous segments, and each segment of the main grid line is disposed one-to-one in the conductive contact area of ​​the bottom surface. Furthermore, a sub-grid line is provided in the conductive contact area on the top surface of the large battery cell.

6. The large battery cell according to claim 2, characterized in that, The light-transmitting conductive film extends across the entire top and bottom surfaces of the central layer.

7. The large battery cell according to claim 4, characterized in that, The transparent conductive film is not present in the top surface bonding area and the bottom surface bonding area.

8. The large battery cell according to claim 1, characterized in that, The top surface of the junction between the first unit and the second unit at the foremost front end of the large battery cell is further provided with another set of top surface bonding areas and top surface conductive contact areas. The other set of top surface bonding areas and top surface conductive contact areas are located on the other side of the cutting area, and the other set of top surface bonding areas and top surface conductive contact areas form the top surface of an overlapping edge of the first battery cell.

9. The large battery cell according to claim 2, characterized in that, The central layer includes a silicon wafer, a top-side intrinsic amorphous silicon film disposed on the top surface of the silicon wafer, a P-type amorphous silicon film disposed on the top surface of the top-side intrinsic amorphous silicon film, a bottom-side intrinsic amorphous silicon film disposed on the bottom surface of the silicon wafer, and an N-type amorphous silicon film disposed on the bottom surface of the bottom-side intrinsic amorphous silicon film.

10. A solar cell, said solar cell being formed by splitting a large solar cell sheet according to any one of claims 1-9.

11. The solar cell according to claim 10, characterized in that, The substrate of the solar cell includes a central layer and a light-transmitting conductive film. The light-transmitting conductive film extends across the entire top and bottom surfaces of the central layer and has the same thickness everywhere, such that when an adhesive is applied to the bonding area on the top surface, the adhesive protrudes beyond the light-transmitting conductive film. This allows the light-transmitting conductive film on the opposing surfaces of the two solar cells to be separated by the adhesive at the adhesive when the solar cell is connected to another solar cell.

12. The solar cell according to claim 10, characterized in that, The substrate of the solar cell includes a central layer consisting of a light-transmitting and conductive film located on the top and bottom surfaces of the central layer. The light-transmitting and conductive film has a notch in the bonding area on the top surface. When an adhesive is applied to the solar cell, the adhesive is located within the notch and does not protrude from the light-transmitting and conductive film.

13. The solar cell according to claim 10, characterized in that, The top surface of the overlapping edge of the solar cell that contacts another solar cell is provided with a top surface bonding area and a top surface conductive contact area that extend along the overlapping edge and are alternately arranged, and the main grid line is provided in the top surface conductive contact area.

14. The solar cell according to claim 10, characterized in that, The bottom surface of the overlapping edge of the solar cell that contacts another solar cell is provided with a bottom surface bonding area and a bottom surface conductive contact area that extend along the overlapping edge and are alternately arranged, and the bottom surface conductive contact area is provided with a main grid line.

15. A shingled module comprising a battery string, characterized in that, The battery string is formed by sequentially connecting multiple solar cells according to any one of claims 10-14 in a shingled manner. Each solar cell is fixed to each other by an adhesive. Sub-grid lines are provided on the top and bottom surfaces of the solar cells, and main grid lines are provided on the top or bottom surface. The main grid line of one of two adjacent solar cells can directly contact the sub-grid line of the other two solar cells to achieve a conductive connection between the two adjacent solar cells.

16. The shingled assembly according to claim 15, characterized in that, The adhesive is a non-conductive adhesive.

17. The shingled assembly according to claim 15, characterized in that, The adhesive is a dot-structure adhesive made of acrylic resin, silicone resin, epoxy resin or polyurethane.

18. The shingled assembly according to claim 15, characterized in that, The adhesive is a dotted structure comprising a curing agent, a crosslinking agent, a coupling agent, or rubber balls.

19. A manufacturing method for manufacturing shingled components, characterized in that, The method includes the following steps: Manufacture a large solar cell sheet according to any one of claims 1-9, wherein the large solar cell sheet has sub-busbars; The large solar cell is cut along each cutting section, thereby splitting the large solar cell into multiple solar cells; Multiple solar cells are connected in a shingled manner using a non-conductive adhesive, so that the main grid line of one of two adjacent solar cells and the sub-grid line of the other are in direct contact to achieve a conductive connection.

20. The manufacturing method according to claim 19, characterized in that, The method further includes the step of applying an adhesive to the solar cell in one of the following ways: spraying, dripping, rolling, printing, or brushing.

21. The manufacturing method according to claim 19, characterized in that, The method for manufacturing large solar cells does not include the step of setting up the main busbars.

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