CN115763603A

CN115763603A - Photovoltaic module

Info

Publication number: CN115763603A
Application number: CN202211611757.5A
Authority: CN
Inventors: 郝国晖; 郭志球; 黄世亮; 刘大娇
Original assignee: Zhejiang Jinko Solar Co Ltd; Jinko Solar Co Ltd
Current assignee: Zhejiang Jinko Solar Co Ltd; Jinko Solar Co Ltd
Priority date: 2022-12-12
Filing date: 2022-12-12
Publication date: 2023-03-07

Abstract

The embodiment of the application relates to the photovoltaic field, and provides a photovoltaic module, which comprises: a battery piece; the connecting parts are arranged at intervals along a first direction and are positioned on the surface of the cell piece; a plurality of pieces of glue arranged at intervals along the first direction, wherein the glue covers the surfaces of the connecting parts and the surfaces of the battery pieces with partial widths; the packaging layer covers the surface of the glue and the surface of the battery piece; the cover plate is positioned on one side, far away from the battery piece, of the packaging layer. The photovoltaic module provided by the embodiment of the application can at least improve the yield of the photovoltaic module.

Description

Photovoltaic module

Technical Field

The embodiment of the application relates to the photovoltaic field, in particular to a photovoltaic module.

Background

Solar cells are devices that directly convert light energy into electrical energy by the photoelectric or photochemical effect. The single solar cell cannot be directly used for power generation. Several single batteries must be used after being packaged tightly into an assembly through solder strip series and parallel connection. The solar cell module (also called solar panel) is a core part in a solar power generation system and is also the most important part in the solar power generation system. The solar cell module is used for converting solar energy into electric energy, or transmitting the electric energy to a storage battery for storage, or pushing a load to work.

The battery piece is very fragile, and generally, the upper and lower surfaces of the battery assembly need to be provided with an adhesive film and a cover plate for protecting the battery piece. The cover plate is generally made of photovoltaic glass, the photovoltaic glass cannot be directly attached to the battery piece, and the adhesive film is needed to play a role in bonding. The battery piece and the battery piece are connected by a welding strip which is usually used for collecting current, the welding strip in the conventional process needs to be alloyed with a fine grid by welding, the conventional welding strip usually comprises a tin welding layer, the components of the tin welding layer are 60% of tin and 40% of lead, the eutectic point temperature of the tin-lead alloy in a phase diagram is about 183 ℃, namely the melting point of the tin welding layer in the welding strip is 183 ℃, and in the actual welding process, the welding temperature is higher than the melting point of the solder by more than 20 ℃. The battery piece is larger in warping deformation in the welding process, the hidden crack risk after welding is large, and the breakage rate is higher. Especially for PERC (Passivated Emitter and Rear Cell) batteries, the internal stress of the battery is large, and after welding, warping deformation and breakage are more likely to occur, so that the repair rate of components is increased and the yield is reduced. Under the above background, in order to improve the welding quality, a low-temperature weld bead is produced by transportation. However, there are many factors that affect the yield of the device, such as the soldering and the contact resistance between the solder strip and the fine grid.

Disclosure of Invention

The embodiment of the application provides a photovoltaic module, at least, the yield of the photovoltaic module is favorably improved.

According to some embodiments of the present application, there is provided a photovoltaic module comprising: a battery piece; the connecting parts are arranged at intervals along a first direction and are positioned on the surface of the cell piece; a plurality of pieces of glue arranged at intervals along the first direction, wherein the glue covers the surfaces of the connecting parts and the surfaces of the battery pieces with partial widths; the packaging layer covers the surface of the glue and the surface of the battery piece; the cover plate is positioned on one side, far away from the battery piece, of the packaging layer.

In some embodiments, the thickness of the glue is greater than or equal to the height of the connecting member in a direction perpendicular to the surface of the battery piece.

In some embodiments, in the first direction, the width of the contact surface of the glue and the battery piece is larger than the width of the contact surface of the connecting component and the battery piece.

In some embodiments, the glue is proportional to the width of the contact surface of the cell and the distance between adjacent connecting members.

In some embodiments, the ratio of the width of the contact surface of the glue and the battery piece to the maximum width of the connecting component is 1-2.5.

In some embodiments, the melting point of the glue is greater than the melting point of the encapsulation layer.

In some embodiments, the glue is a cured layer.

In some embodiments, further comprising: the battery piece is characterized by comprising a plurality of pre-fixing glues, wherein the pre-fixing glues are distributed at intervals along the extending direction of the connecting parts, the pre-fixing glues are located between the battery piece and the connecting parts, and the pre-fixing glues are covered by the glue.

In some embodiments, the width of the pre-anchoring glue is greater than the width of the connecting part in the first direction, the pre-anchoring glue surrounding the connecting part for a portion of the height.

In some embodiments, along the first direction, the width of the contact surface of the pre-fixing glue and the cell is smaller than or equal to the width of the contact surface of the glue and the cell.

In some embodiments, the material of the pre-fixing glue is the same as the material of the glue.

The technical scheme provided by the embodiment of the application has at least the following advantages:

in the photovoltaic module that this application embodiment provided, through forming one deck glue on adapting unit surface, glue covers adapting unit's surface, when stopping lamination, the encapsulating layer of fuse state flows between adapting unit and the battery piece, and then causes the electric connection problem between battery piece and the adapting unit, and improve the subassembly weldability, the pulling force of solder strip direction has been improved, the subassembly welding quality has been improved, reduce the subassembly rosin joint scheduling problem, improve subassembly product quality, reduce the abnormality such as reprocessing in the subassembly processing procedure, the subassembly productivity has been improved greatly. In addition, glue compares with glued membrane and sticky tape, and the mobility and the adhesion of liquid glue are stronger, can all discharge the air between grid line structure, adapting unit and the glue as far as, so, can prevent follow-up because the mechanical strength that the clearance leads to is poor in the monomer solar photovoltaic cell, easy fracture and moisture in the air and corrosive gas can gradually oxidize and corrosion grid line structure, influence the condition such as performance of grid line structure. The characteristic of glue itself is favorable to improving photovoltaic module's yield. The use of glue can prevent that the gas that encapsulates between sticky tape and battery that leads to when using the sticky tape from being heated the inflation and leading to the sticky tape to break away from when the lamination for the glued membrane that melts gets into and leads to the insulation problem.

Drawings

One or more embodiments are illustrated by the accompanying drawings in the drawings, which correspond to the figures in the drawings, and the illustrations are not to be construed as limiting the embodiments, unless otherwise specified, and the drawings are not to scale; in order to more clearly illustrate the embodiments of the present application or technical solutions in the conventional technologies, the drawings required in the embodiments will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative efforts.

Fig. 1 is a schematic view of a first structure of a photovoltaic module according to an embodiment of the present disclosure;

FIG. 2 is a view of the photovoltaic module shown in FIG. 1 along a ₁ -a ₂ A schematic cross-sectional structure of a cross-section;

FIG. 3 is a view of the photovoltaic module shown in FIG. 1 along b ₁ -b ₂ A schematic cross-sectional structure of the cross-section;

FIG. 4 is a view of the photovoltaic module shown in FIG. 1 along the line c ₁ -c ₂ A schematic cross-sectional structure of a cross-section;

fig. 5 is a second structural schematic diagram of a photovoltaic module according to an embodiment of the present disclosure;

FIG. 6 is a view of the photovoltaic module shown in FIG. 5 along b ₁ -b ₂ A schematic cross-sectional structure of a cross-section;

FIG. 7 is a schematic diagram of a connecting member according to an embodiment of the present disclosure;

fig. 8 is a laminated photovoltaic module along a according to an embodiment of the present application ₁ -a ₂ A schematic cross-sectional structure of a cross-section.

Detailed Description

As can be seen from the background art, the yield of the current photovoltaic devices is not good enough.

Analysis finds that one reason for poor yield of the photovoltaic module is that sunlight enters the cell from the front side of the cell, a metal electrode on the front side can shield a part of silicon wafer, and the part of light energy irradiated on the electrode cannot be converted into electric energy, and from this viewpoint, it is desirable that the grid line is made as thin as possible. And the responsibility of the grid line lies in conducting current, and from the angle of resistivity analysis, the thinner the grid line, the smaller the conducting cross-sectional area, and the larger the resistance loss. Therefore, the main grid and the auxiliary grid are designed to balance between shading and conducting, and the solder strip which is subsequently electrically contacted with the grid line also needs to balance between shading and conducting. In addition, alloying of the solder ribbon with the grid lines is conventionally achieved by radiating heat from the top of the solder ribbon toward the cell chip at a temperature 20 ℃ higher than the solder ribbon temperature, so that the high melting temperature of the solder ribbon requires a higher reflow temperature during soldering, which makes the cell chip susceptible to thermal warping. Thermal warping of the cell sheet may compromise the integrity of the welds formed, thereby affecting their performance. Thermal warping of the battery cell may also lead to various soldering defects, such as breakage of the battery cell, pillow effect, cold solder, and the like.

Further, when the connecting member uses a low melting point metal as a solder and the alloying of the gate line structure with the connecting member is achieved using a lamination process, for example, in an assembly lamination process, the pressure and temperature of a laminator help the low melting point metal bond with the gate line structure. However, in the process of welding the low melting point metal and the grid line structure, the situation of battery sheet fragmentation or insufficient welding and the like is usually caused by the fact that the welding strip is deviated due to the pushing of the molten glue film or the glue film overflows to the space between the welding strip and the thin grid, and the performance of the battery is affected.

The embodiment of the application provides a photovoltaic module, through forming one deck glue on adapting unit surface, glue covers adapting unit's surface, the encapsulating layer of fuse state flows between adapting unit and the battery piece when stopping lamination processing, and then causes the electric connection problem between battery piece and the adapting unit, and improve the subassembly weldability, the pulling force of solder strip direction has been improved, the subassembly welding quality has been improved, reduce the problem such as subassembly rosin joint, improve subassembly product quality, reduce abnormalities such as reprocessing in the subassembly processing procedure, the subassembly productivity has been improved greatly. In addition, glue compares with glued membrane and sticky tape, and the mobility and the adhesion of liquid glue are stronger, can all discharge the air between grid line structure, adapting unit and the glue as far as, so, can prevent follow-up because the mechanical strength that the clearance leads to is poor in the monomer solar photovoltaic cell, easy fracture and moisture in the air and corrosive gas can gradually oxidize and corrosion grid line structure, influence the condition such as performance of grid line structure. The characteristic of glue itself is favorable to improving photovoltaic module's yield. The use of glue can prevent that the gas that encapsulates between sticky tape and battery that leads to when using the sticky tape from being heated the inflation and leading to the sticky tape to break away from when the lamination for the glued membrane that melts gets into and leads to the insulation problem.

Embodiments of the present application will be described in detail below with reference to the accompanying drawings. However, it will be appreciated by those of ordinary skill in the art that in the various embodiments of the present application, numerous technical details are set forth in order to provide a better understanding of the present application. However, the technical solutions claimed in the present application can be implemented without these technical details and various changes and modifications based on the following embodiments.

Fig. 1 is a schematic view of a first structure of a photovoltaic module according to an embodiment of the present disclosure; FIG. 2 is a view of the photovoltaic module shown in FIG. 1 along a ₁ -a ₂ A schematic cross-sectional structure of the cross-section; FIG. 3 is a view of the photovoltaic module shown in FIG. 1 along b ₁ -b ₂ A schematic cross-sectional structure of the cross-section;

FIG. 4 is a view of the photovoltaic module shown in FIG. 1 along c ₁ -c ₂ A schematic cross-sectional structure of a cross-section; fig. 5 is a schematic view of a second structure of a photovoltaic module according to an embodiment of the present disclosure; FIG. 6 is a view of the photovoltaic module shown in FIG. 5 along the line b ₁ -b ₂ A schematic cross-sectional structure of a cross-section; FIG. 7 is a schematic structural diagram of a connecting member according to an embodiment of the present disclosure; fig. 8 is a laminated photovoltaic module along a according to an embodiment of the present application ₁ -a ₂ A cross-sectional structure of the cross-section.

In fig. 1 and 5, the encapsulation layer and the cover plate of the photovoltaic module are not shown, or the encapsulation layer and the cover plate are in a perspective state, so as to show and explain the position and the connection relationship between the battery piece and the connection component. The cross-sectional views of fig. 2 to 4, 6 and 8 only show the film structures on one side of the battery cell, and the film structures on the other side of the battery cell may be the same as or different from the film structures on the corresponding one side of the battery cell. Fig. 2 to 4 and 6 are schematic structural views showing that the lamination process is not performed and the connecting member and the gate line structure are not alloyed, and fig. 8 is a schematic structural view showing that the photovoltaic module is formed after the lamination process.

Referring to fig. 1-8, in accordance with some embodiments of the present application, there is provided a photovoltaic assembly, comprising: a battery piece 10; a plurality of connecting members 11 arranged at intervals along the first direction Y, the connecting members 11 being located on the surface of the cell sheet 10; a plurality of glues 12 arranged at intervals along the first direction Y, wherein the glues 12 cover the surface of the connecting component 11 and the surface of the cell 10 with partial width; the packaging layer 13, wherein the packaging layer 13 covers the surface of the glue 12 and the surface of the battery piece 10; and the cover plate 14 is positioned on one side of the packaging layer 13 far away from the battery piece 10.

In some embodiments, the cell 10 includes, but is not limited to, any one of a PERC cell, a PERT cell (Passivated Emitter and real Rear-diffused cell), a TOPCon cell (Tunnel Oxide Passivated Contact cell), a HIT/HJT cell (Heterojunction cell). In some embodiments, the cell sheet 10 may be a single crystalline silicon solar cell, a polycrystalline silicon solar cell, an amorphous silicon solar cell, or a multi-compound solar cell, which may be a cadmium sulfide solar cell, a gallium arsenide solar cell, a copper indium selenide solar cell, or a perovskite solar cell. If the front surface of the battery piece 10 has a first electrode, and the opposite back surface of the front surface has a second electrode, and the first electrode and the second electrode have different polarities, the film structures on one side of the battery piece 10 are the same as those on the other side of the battery piece 10 in the cross-sectional view shown in the figure.

In some embodiments, the battery piece 10 is an all-back-contact crystalline silicon solar cell (IBC), where the IBC is a back-junction back-contact solar cell structure in which positive and negative metal electrodes are arranged on a back surface of the battery in an interdigital manner, and a PN junction and the electrodes of the IBC are located on the back surface of the battery, that is, the electrodes of an emitter region and a base region of the battery are located on the back surface, and the front surface is not blocked by grid lines, so that the photoelectric conversion performance of the battery can be improved, and then each film layer structure on one side of the battery piece 10 in the cross-sectional view shown in the drawing is different from each film layer structure on the other side of the battery piece 10, and each film layer structure of the battery piece 10 includes an encapsulation layer 13 and a cover plate 14.

In some embodiments, the first surface of the cell sheet 10 has a first electrode, which is one of a positive electrode or a negative electrode, and the side opposite to the first surface has a second electrode, which is the other of the positive electrode or the negative electrode. The connection member 11 connects the first electrode of any one of the battery cells 10 and the second electrode of the adjacent battery cell 10.

The battery sheet 10 is a full-sheet battery or a sliced battery. The sliced battery refers to a battery piece formed by a complete whole battery through a cutting process. The cutting process comprises the following steps: a laser grooving + cutting (LSC) process and a thermal stress cell separation (TMC) process. In some embodiments, the sliced cell is a half cell, which can also be understood as a sliced half cell or a bipartite cell. The function of the half-cut cell assembly is to improve the generated power by reducing the resistive loss. According to ohm's law, the interconnection electrical loss of the solar cell is proportional to the square of the current magnitude. After the battery is cut into two halves, the current is also reduced by half, and the electric loss is also reduced to one fourth of the loss of the full-size battery. The increase in the number of cells also correspondingly increases the number of cell gaps, which contribute to the increase in short circuit current through reflection by the back plate of the assembly. In addition, the width of the battery solder strip can be optimized by cutting the half-cell assembly, and the optimization balance between increasing the width of the solder strip to reduce the electric loss and reducing the width of the solder strip to reduce the shading loss is required conventionally. Cut half battery pack and reduced the battery loss, then the width of welding the area can set up thin in order to reduce the shading loss, is favorable to promoting battery efficiency and electricity generation consumption. In some embodiments, the sliced battery can be a three-slice battery, a 4-slice battery, or an 8-slice battery, etc.

In some embodiments, the photovoltaic module includes at least two battery pieces, at least two battery pieces 10 are connected in series or in parallel by a connecting member 11 to form a battery string group, and a battery gap is formed between adjacent battery pieces 10 to achieve electrical insulation between different battery pieces 10.

In some embodiments, the grid line structure 101 is used to collect the photo-generated current in the solar cell sheet and lead the photo-generated current to the outside of the cell sheet 10. The battery piece comprises a main grid line and an auxiliary grid line, the auxiliary grid line intersects with the extending direction of the main grid line, the auxiliary grid line is used for collecting current of the substrate, and the main grid line is used for collecting the current of the auxiliary grid line and transmitting the current to the welding strip. In some embodiments, the gate line structure 101 is an auxiliary gate line, which may also be referred to as an auxiliary gate line, the auxiliary gate line is used for guiding current, and the battery piece 10 is designed without a main gate, so as to shorten a carrier transport path and reduce series resistance, thereby increasing a front light receiving area, improving component power, facilitating improvement of short-circuit current, and reducing the usage amount of gate line printing silver paste to reduce production cost.

In some embodiments, the connecting member 11 is a solder strip, which is used for connecting the cell pieces 10 to each other and collecting current to be transmitted to an element outside the photovoltaic module. The solder strips comprise confluence solder strips and interconnection solder strips, the confluence solder strips are used for connecting the photovoltaic cell strings and the junction boxes, and the interconnection solder strips are used for connecting the cell pieces 10 and the cell pieces 10.

In some embodiments, referring to fig. 7, fig. 7 is an initial state in which the connection member 11 is not subjected to the welding process or the laminating process. The connecting member 11 includes a body portion 111 and a coating layer 112 covering a surface of the body portion 111.

In some embodiments, the main body 111 is a conductive layer with certain strength and good conductivity, and the conductive layer functions as a main conductive transmission layer of the connecting member 11, so that the lower the resistivity of the main body 111, the smaller the electrical loss of the connecting member 11, and the better the battery efficiency and the generated power.

In some embodiments, the material of the body portion 111 is a conductive material with better conductivity, such as copper, nickel, gold, silver, or an alloy material with low resistivity. When the resistivity of the body part 111 is less than 1 × 10 ^-7 Ω · m, or a conductivity of 1 × 10 or more ⁷ At S/m, the electrical loss of the body portion 111 is small, and the cell efficiency and the generated power are large. Resistivity (Resistivity) is a physical quantity that represents resistance characteristics of various substances and reflects a property of a substance that inhibits an electric current. Conductivity (conductivity) is a parameter used to describe the ease of charge flow in a material. In some embodiments, the material of the body portion 111 is a copper layer, which has a low resistivity (1.75 × 10) ^-8 Ω · m) and the cost of copper is lower than that of gold and silver. And the chemical stability of copper is high, the strength of copper is moderate, and the copper can not be deformed in welding treatment during welding and laminating treatment during packaging, so that the shielding area of the connecting part 11 is smaller.

In some embodiments, the coating layer 112 may be plated on the surface of the body portion 111 or coated on the surface of the body portion 111, and specifically, the coating source material of the coating layer 112 may be uniformly coated around the body portion 111 according to a certain composition ratio and thickness by using a special process such as electroplating, vacuum deposition, spraying, or hot dip coating. The coating 112 mainly functions to allow the connecting member 11 to satisfy solderability, and firmly welds the connecting member 11 to the grid line structure 101 of the battery piece 10, thereby achieving good current guiding.

In some embodiments, the material of the coating layer 112 is a metal material or an alloy material having a lower melting point than the body portion 111, such as a tin alloy, which may include a tin-zinc alloy, a tin-bismuth alloy, or a tin-indium alloy. The tin is used as a welding material for welding, has low melting point, has better affinity with metals such as copper and the like, and has better welding fastness. Lead in the tin-lead alloy can reduce the melting point of the welding strip, tin and lead can form an eutectic point with the melting point of 183 ℃, and the tin-lead alloy has good welding performance and use performance. The use of bismuth can lower the melting temperature and reduce the surface tension by replacing lead with other metal elements or adding other elements, such as bismuth, to the tin-lead alloy. The melting point of the tin-bismuth alloy can be reduced to 139 ℃, and the requirement of low-temperature welding is met.

In some embodiments, a fluxing agent is included in coating 112, which refers to a chemical that aids and facilitates the soldering process while providing protection against oxidation reactions during the soldering process. The flux includes an inorganic flux, an organic flux, and a resin flux. It will be appreciated that the melting point of the flux is lower than the melting point of the coating 112 and increases the fluidity of the coating 112 in the molten state to allow good alloying of the coating 112 with the gridline structure 101.

In some embodiments, the cross-sectional shape of the connecting part 11 along the section in the first direction Y is circular, the circular solder ribbon is free from orientation problems and alignment problems, and the circular solder ribbon is easier to mass produce. In some embodiments, the cross-sectional shape of the connecting component 11 may be a triangle or any other shape to increase the contact area between the solder strip and the grid line structure and reduce the problem of alignment offset between the connecting component 11 and the grid line structure.

In some embodiments, the surface of the connecting member 11 away from the battery skin has a light reflecting layer, and the light reflecting layer is located on the outer side surface of the coating layer 112 away from the body portion 111 and the battery piece 10. The light reflection layer serves to improve electrical loss due to the shielding area of the connection member 11 with respect to the battery cell 10. In some embodiments, the outer surface of the coating 112 has a light reflecting groove, which is a recessed groove or trench from the coating 112 toward the body portion 111, and sunlight is reflected onto the cell 10 through the sidewall of the light reflecting groove, so as to improve the utilization rate of sunlight.

In some embodiments, the glue 12 refers to a substance that is capable of bonding two or more materials together in a liquid state and that has sufficient bonding strength after curing in a certain manner. Therefore, the glue is mostly present in water or other liquid solvents. The liquid glue has strong fluidity and adhesiveness, and can completely discharge the air among the gate line structure 101, the connecting part 11 and the glue 12 as much as possible, so that the conditions that the mechanical strength is poor, the breakage is easy, the moisture and corrosive gas in the air can be gradually oxidized and corrode the gate line structure 101 to influence the performance of the gate line structure 101 and the like due to the fact that gaps are formed in the single solar photovoltaic cell in the follow-up process can be prevented. The characteristic of glue itself is favorable to improving photovoltaic module's yield.

It is understood that the glue 12 is not equivalent to an adhesive tape or an adhesive film, and the adhesive tape refers to a new material compounded by coating an adhesive on a substrate, so that the sealing property and the toughness of the adhesive tape itself cannot discharge air among the grid line structure 101, the connecting component and the adhesive tape, and gaps exist among the grid line structure 101, the connecting component and the adhesive tape, and the risk of damage to the battery cell exists in the subsequent lamination process or other operations. The glue film refers to a film layer which has a certain cross-linking degree and is sticky and is formed by mutually combining epoxy micromolecules, olefine acid micromolecules or other active micromolecules through a high molecular reaction, the fluidity of the glue film is not enough to exhaust gas, the melting point of the glue film is possibly smaller than that of an encapsulation layer of a subsequent encapsulation process, and the glue 12 provided by the embodiment of the application can exhaust air and simultaneously prevent the molten encapsulation layer from entering a grid line structure and a connecting part.

In some embodiments, the glue 12 is formed after the connection components are arranged on the cell pieces, so that the glue 12 has a smaller probability of being immersed between the grid line structure and the connection components, thereby reducing the separation of the connection components and the grid line structure caused by insufficient connection component cold solder and welding stress, and facilitating the improvement of the yield of the photovoltaic module. In some embodiments, the glue 12 is formed by coating glue on the surface of the connecting part in a part of the length, then curing the glue, coating glue on the surface of the connecting part in another part of the length again, and then curing the glue to fix the connecting part.

In some embodiments, the glue 12 is a cured layer, and the fluidity of the glue in the cured layer is lower than that of the glue in the non-cured layer, so that the glue can be prevented from flowing to the connecting part and between the grid line structures, and the grid line structures are electrically insulated from the connecting part. The adhesiveness of the glue presenting the cured layer is stronger than that of the glue presenting the uncured layer, and the connection part can be more adhered to the surface of the battery piece to prevent the connection part from deviating. The compactness of the glue presenting the cured layer is stronger than that of the glue of the uncured layer, so that a good isolation effect can be achieved, the packaging layer in an isolated molten state enters between the connecting part and the grid line structure, and meanwhile, the water vapor in subsequent isolated air corrodes the grid line structure and the battery piece, so that the yield of the photovoltaic module is influenced.

In some embodiments, the viscosity value of glue 12 before curing is in the range of 8000 to 20000mPa s at a temperature of 25 ℃. The viscosity range of the glue 12 is used to ensure that the glue has certain fluidity and poor compactness before curing, and air can be discharged to prevent the subsequent air from ejecting the cured glue due to heat so that the molten glue film flows between the connecting component and the grid line structure. The viscosity of the glue 12 can be increased to 10000-3000 mPas after curing, so that the connecting part 11 and the surface of the battery piece 10 have enough connecting force, and the connecting part 1 is protected from glue film penetration during lamination and water vapor erosion of the assembly in long-term use.

In some embodiments, the type of glue 12 includes an acrylate glue, a polymer glue, a hot melt glue, or a polymer adhesive. The type or curing mode of the glue can be adjusted according to the actual requirements of the photovoltaic module, for example, the glue 12 can be low-temperature glue, so that the curing temperature of the glue is low, the thermal stress degree of the cell 10 is reduced, and the problems of thermal warping and the like caused by high thermal stress of the cell are avoided.

In some embodiments, the thickness of the glue 12 is greater than or equal to the height of the connecting member 11 in the direction Z perpendicular to the surface of the cell. When the thickness of the glue 12 is greater than or equal to the height of the connecting part 11, the glue 12 can completely cover the connecting part 11 to realize the function of fixing the connecting part 12, so as to prevent the connecting part 11 from being pushed and shifted in the preparation process before alloying, and further prevent the situations of insufficient soldering, missing soldering and the like between the battery piece 10 and the connecting part 11; the second aspect is a barrier film layer as the connecting member 11, which is used to prevent the molten adhesive film of the connecting member 11 from flowing between the cell sheet 10 and the connecting member 11 and further between the grid line structure 101 and the connecting member 11 during the lamination process, thereby affecting the alloying of the grid line structure 101 and the connecting member 11, and even affecting the cell efficiency and the generated power. In addition, the glue can also reduce the probability that the connecting part pierces through the packaging layer, and is favorable for improving the probability of the packaging layer.

In some embodiments, the width of the contact surface of the glue 12 with the cell piece 10 is greater than the width of the contact surface of the connecting member 11 with the cell piece 10 along the first direction Y. The glue 12 flows from the top surface of the connecting member 11 to the surface of the cell piece 10, and due to the self-gravity of the glue 12, the width of the contact surface of the glue 12 and the cell piece 10 is larger than that of the contact surface of the connecting member 11 and the cell piece 10. When the width of the contact surface between the glue 12 and the battery piece 10 meets the above conditions, the glue 12 can well protect the space between the connecting part 12 and the grid line structure 101, on one hand, air between the connecting part 11 and the grid line structure 101 can be exhausted, on the other hand, the packaging layer 13 cannot exist between the connecting part 11 and the grid line structure 101, the contact surface between the connecting part 11 and the grid line structure 101 is large, the welding tension is large, and the yield of the battery is favorably improved.

In some embodiments, the width of the contact surface of the glue 12 and the cell sheet 10 is proportional to the distance between the adjacent connecting members 11. When the distance between the connecting parts 11 is large, the width of the contact surface between the glue 12 and the battery piece 10 is large, the content, thickness and thickness of the glue are large, due to the curing thickness, the curing degree of the glue 12 close to one side of the connecting part 11 is low, namely, the fluidity and compactness are small, alloying is performed between the connecting part 11 and the grid line structure 101 in the subsequent lamination treatment, the area of an alloy layer between the connecting part 11 and the grid line structure 101 is large, so that the contact area between the connecting part 11 and the grid line structure 101 is large, the contact resistance is reduced, and the improvement of the battery efficiency is facilitated. In addition, the glue 12 covering the adjacent connecting parts 11 is discontinuous, so that the shielding area is reduced and the using amount of the glue is reduced; secondly, the fluidity and the sealing performance of the glue 12 are inferior to those of the glue film, and when the glue film covers the surface of the cell, the air gap in the photovoltaic module is less and the sealing performance is better.

In some embodiments, along the first direction Y, the width of the contact surface between the glue 12 and the battery piece 10 is smaller than the maximum width of the connecting component 11, so that the amount of the glue used is reduced, the shielding area of the glue is also reduced, and the improvement of the battery efficiency is facilitated.

In some embodiments, along the first direction Y, the width of the contact surface between the glue 12 and the battery piece 10 is greater than the maximum width of the connection part 11, the greater the content and the greater the thickness of the glue 12 are, the larger the area of the alloy layer between the connection part 11 and the grid line structure 101 is, so that the contact area between the connection part 11 and the grid line structure 101 is larger, the contact resistance is reduced, and the improvement of the battery efficiency is facilitated.

In some embodiments, the ratio of the width of the contact surface of the glue 12 and the battery piece 10 to the maximum width of the connecting member 11 is 1-2.5. The ratio of the width of the contact surface of the glue 12 and the battery piece 10 to the maximum width of the connecting part 11 is 1.5-2.5, 1.5-2, 1.23-2.5, 1.8-2.5, 2-2.5, 1.3-2 or 1.79-2.3. The ratio may be 1, 1.38, 1.69, 2.01, 2.28, or 2.46, and the ratio is within the above range, the larger the area of the alloy layer between the connection part 11 and the gate line structure 101 is, so that the contact area between the connection part 11 and the gate line structure 101 is larger, the contact resistance is reduced, and the improvement of the battery efficiency is facilitated; meanwhile, the glue 12 covering the adjacent connecting parts 11 is discontinuous, so that the shielding area is reduced and the using amount of the glue is reduced; and secondly, the flowability and the sealing property of the glue are inferior to those of the glue film, when the glue film covers the surface of the cell, the air gap in the photovoltaic module is less, and the sealing property is better.

In some embodiments, the length of the glue 12 is greater than or equal to the length of the connection component 11 along the second direction X, and since the encapsulation layer 13 covers the surfaces of all the battery pieces 10, it can be known that the encapsulation layer 13 also covers the battery gap, and the connection component 11 is also located in the battery gap so as to connect the adjacent battery pieces 10 in series or in parallel, when the length of the glue 12 is greater than or equal to the length of the connection component 11, the molten glue film will not penetrate between the grid line structure 101 and the connection component 11 through the battery gap or the edge of the battery piece 10, thereby improving the yield of the battery.

In some embodiments, the glue 12 located in the cell gap may wrap the surface of the connection component 11 to achieve an omni-directional alloying of the grid line structure 101 and the connection component 11. In some embodiments, the glue 12 has a reflective layer or a reflective groove on the side away from the connecting part 11 to improve the utilization of the incident light.

In some embodiments, the encapsulant layer 13 includes a first encapsulant layer covering one of the front or back of the battery sheet 10 and a second encapsulant layer covering the other of the front or back of the battery sheet 10, and specifically, at least one of the first encapsulant layer or the second encapsulant layer may be an organic encapsulant film such as an ethylene-vinyl acetate copolymer (EVA) film, a polyethylene octene co-elastomer (POE) film, or a polyvinyl butyral (PVB) film.

In some embodiments, the melting point of the encapsulation layer 13 is lower than the lamination temperature during the lamination process, and the encapsulation layer 13 is a film layer formed by the adhesive film that is in a molten state at the temperature of the laminator and then the small molecules in the adhesive film are promoted to combine with each other to form cross-linked macromolecules due to the initiator in the encapsulation layer 13.

In some embodiments, the melting point of the encapsulation layer 13 and the melting point of the connection component 11 may be set according to actual requirements. When the melting point of the encapsulation layer 13 is greater than that of the connection component 11, the connection component 11 may be alloyed before the encapsulation layer 13 assumes a molten state, so that the molten film may be effectively prevented from immersing into the grid line structure 101 and the connection component 11 and pushing the connection component 11 to cause deviation. When the melting point of the encapsulation layer 13 is less than the melting point of the connecting member 11, the lamination temperature can be set to be lower, so that the thermal stress on the battery piece is improved, and the yield of the photovoltaic module is improved.

In some embodiments, the melting point of the glue 12 is greater than that of the encapsulation layer 13, and when the encapsulation layer 13 is in a molten state, the glue 12 still maintains a good shape, so as to effectively prevent the molten glue film from infiltrating into the grid line structure 101 and the connection component 11 and push the connection component 11 to cause a deviation.

In some embodiments, the cover plate 14 may be a glass cover plate, a plastic cover plate, or the like having a light-transmitting function. Specifically, the surface of the cover plate 14 facing the encapsulation layer 13 may be a concave-convex surface, thereby increasing the utilization rate of incident light. The cover plate 14 includes a first cover plate opposite to the first encapsulation layer and a second cover plate opposite to the second encapsulation layer.

In some embodiments, referring to fig. 5 and 6, further comprising: a plurality of pre-fixing glues 105, wherein the pre-fixing glues 105 are arranged at intervals along the extending direction (the second direction X) of the connecting part 11, the pre-fixing glues 105 are located between the cell pieces 10 and the connecting part 11, and the glue 12 covers the pre-fixing glues 105. The pre-fixing glue 105 is positioning glue, positions of the connecting parts 11 are positioned through the glue, the position relation between the connecting parts 11 and the grid line structure 101 is accurately positioned, and good contact between the connecting parts 11 and the battery is achieved through subsequent welding treatment or laminating treatment, so that the efficiency of the battery is maximized. In addition, by the positioning glue, the lengths of the grid line structures 101 between the adjacent connecting parts 11 are close, so that the transmission paths of the current collected by the battery pieces 10 are uniform, and the transmission loss of the paths is reduced.

In some embodiments, the width of the pre-fixing glue 105 is greater than the width of the connecting part 11 along the first direction Y, the pre-fixing glue 105 surrounding the connecting part 11 partially at its height. Thus, the thickness of the pre-fixing glue 105 can tightly position the connection member 11 on the battery sheet 10, preventing the connection member 11 from being displaced in a subsequent operation.

In some embodiments, along the first direction Y, the width of the contact surface of the pre-fixing glue 105 and the cell piece 10 is smaller than or equal to the width of the contact surface of the glue 12 and the cell piece 10, so as to reduce the shielding area of the pre-fixing glue 105.

In some embodiments, the material of the pre-fixing glue 105 is the same as the material of the glue 12, so that there is no interface state between the film layers between the pre-fixing glue 105 and the glue 12, there may be no gap between the glue and the pre-fixing glue, and the strength is strong. In some embodiments, the pre-fixing glue is of a different material than the glue.

In some embodiments, the second direction X and the first direction Y may be perpendicular to each other, or have an included angle smaller than 90 degrees, for example, 60 degrees, 45 degrees, 30 degrees, etc., and the second direction X and the first direction Y are not the same direction. For convenience of description and understanding, the second direction X and the first direction Y are perpendicular to each other as an example for description, and in a specific application, the setting of the included angle between the second direction X and the first direction Y may be adjusted according to actual needs and an application scenario, which is not limited in the embodiment of the present application.

The embodiment of the application provides a photovoltaic module, through forming one deck glue 12 on adapting unit 11 surface, glue 12 covers adapting unit 11's surface, when stopping lamination, fusing state's encapsulation layer 13 flows between adapting unit 11 and battery piece 10, and then causes the insulation of battery piece 10 and adapting unit 11, and improve the subassembly solderability, the pulling force of solder strip direction has been improved, the subassembly welding quality has been improved, reduce the problem such as subassembly rosin joint, improve subassembly product quality, reduce abnormalities such as reprocessing in the subassembly processing procedure, the subassembly productivity has been improved greatly. In addition, compared with the adhesive film and the adhesive tape, the liquid adhesive has stronger fluidity and adhesiveness, and can completely discharge the air among the grid line structure 101, the connecting part 11 and the adhesive 12 as much as possible, so that the conditions that the mechanical strength is poor, the breakage is easy, the water and corrosive gas in the air can be gradually oxidized and corrode the grid line structure, and the performance of the grid line structure 101 is influenced due to the fact that gaps are formed in the single solar photovoltaic cell in the follow-up process can be prevented. The characteristics of the glue 12 are beneficial to improving the yield of the photovoltaic module. The use of glue can prevent that the gas that encapsulates between sticky tape and battery that leads to when using the sticky tape from being heated the inflation and leading to the sticky tape to break away from when the lamination for the glued membrane that melts gets into and leads to the insulation problem.

Correspondingly, another aspect of the embodiments of the present application provides a method for preparing a photovoltaic module, which is used to prepare the photovoltaic module provided in the above embodiments, and the same or similar elements as those in the above embodiments are not repeated here.

Referring to fig. 8, a battery piece 10 is provided, and the surface of the battery piece 10 is provided with a grid line structure 101 extending along a first direction Y.

In some embodiments, the pre-fixing glue 105 arranged at intervals is disposed on the surface of the cell 10, the pre-fixing glue 105 is located between the adjacent grid line structures 101, and the pre-fixing glue 105 may be arranged at intervals along the arrangement direction X of the cell; or alternatively, the cells may be arranged in a staggered manner along the arrangement direction X of the cells, that is, the first pre-fixing glue 105 is located between the first grid line structure 101 and the second grid line structure 101, the second pre-fixing glue 105 is located between the second grid line structure 101 and the third grid line structure 101, the third pre-fixing glue 105 is located between the first grid line structure 101 and the second grid line structure 101, and so on.

In some embodiments, pre-fixing glue 105 may not be provided.

In some embodiments, the connecting member 11 shown in fig. 1 is laid on the surface of the battery piece 10, and the surface of the connecting member 11 is covered with glue 12, and the length of the glue 12 in the first direction Y is greater than 2/3 of the outer circumference of the coating 112, so as to form a more complete wrapping property. Further, the length of the glue 12 is greater than the outer circumference of the coating 112, and both ends of the glue 12 are located on the surface of the battery cell 10, so that the coating 112 partially contacting the grid line structure 101 is converted into the first portion 121 in the subsequent lamination, and the coating 112 wrapped by the glue 12 is converted into the second portion 122. Due to the temperature transfer and the sealing property of the glue 12, the thickness of the second portion 122 appears to be thicker the farther away from the surface of the cell piece 10. The second portion 122 may act as a partial thickness barrier that may be used to prevent the body portion 111 from piercing the encapsulation layer 13; the packaging layer 13 outside the connecting component 11 can be arranged to be thin, so that the effect of a low-gram-weight adhesive film is achieved, and the cost is reduced. In addition, if the second portion 122 is not melted, the shielding area of the connecting member 11 on the battery sheet 10 is also reduced accordingly, and on the one hand, the thickness of the second portion 122 may be thinner than the thickness of the first portion 121 at the initial stage of providing the connecting member 11, so that the cost can be reduced; in the second aspect, the shadow shielding area caused by the connecting member 11 is small, so that the optical loss of the cell piece 10 is reduced, and the cell efficiency is improved.

In some embodiments, the first portion 121 and the second portion 122 are continuous films, the coating 112 of the customized partial region and the coating 112 on the surface of the battery piece 10 are the first portion 121, and the rest of the coating 112 is the second portion 122. In some embodiments, there is a discontinuity between first portion 121 and second portion 122, i.e., during welding of coating 112, a portion of coating 112 melts to form first portion 111, a portion of coating 112 remains to form second portion 122 due to the action of glue 12, and there is a break between first portion 121 and second portion 122.

In some embodiments, the ratio of the second portions 122 is greater than that of the first portions 121, and the ratio of the unmelted second portions 122 is greater than that of the melted first portions 121, so that the temperature during the lamination process can be reduced, and the series of problems such as thermal warping of the battery sheet 10 caused by high temperature can be avoided. Compared with the case that the proportion of the second portion 122 is smaller than that of the first portion 121 or the proportion of the second portion 122 is equal to that of the first portion 121, the shielding area formed by alloying the connecting member 11 with the grid line structure is smaller, and the electrical loss of the photovoltaic module is also smaller.

In some embodiments, the ratio of the first portion 121 is 1/4 to 2/3 times the ratio of the second portion 122 in a cross-sectional view perpendicular to the extending direction of the connecting member 11. The occupation range of the first portion 121 and the second portion 122 is larger, when the first portion 121 is arranged, the contact surface between the connecting component 11 and the gate line structure is larger, the contact area between the connecting component 11 and the gate line structure is larger, the contact resistance is lower, the range of current collected by the connecting component 11 is larger, and the generated power is favorably improved. When the first portion 121 is arranged to be small, the shielding area of the connecting member 11 is small, the electrical loss is small, and the temperature of the lamination process is low, so that the degree of the thermal stress on the battery piece 10 is also low, thereby being beneficial to improving the yield of the photovoltaic module.

In some embodiments, the area with pre-fixing glue 105 is uv-fixed to increase the adhesion of pre-fixing glue 105.

In some embodiments, an adhesive film is provided, and the adhesive film is laid on the surface of the battery piece 10 and covers the surfaces of the battery piece 10, the connecting part 11 and the glue 12; providing a cover plate 14, wherein the cover plate 14 is positioned on the surface of the adhesive film far away from the battery piece 10; a lamination process is performed and the coating 112 is transformed into a first portion 121 and a second portion 122.

Although the present application has been described with reference to preferred embodiments, it is not intended to limit the scope of the claims, and many possible variations and modifications may be made by one skilled in the art without departing from the spirit of the application. Furthermore, the embodiments described herein and the drawings shown are merely illustrative and not intended to be the full scope of the claims.

It will be understood by those of ordinary skill in the art that the foregoing embodiments are specific examples for carrying out the present application, and that various changes in form and details may be made therein without departing from the spirit and scope of the present application in practice. Various changes and modifications may be effected by one skilled in the art without departing from the spirit and scope of the application, and the scope of protection is defined by the claims.

Claims

1. A photovoltaic module, comprising:

a battery piece;

the connecting parts are arranged at intervals along a first direction and are positioned on the surface of the cell piece;

a plurality of pieces of glue arranged at intervals along the first direction, wherein the glue covers the surfaces of the connecting parts and the surfaces of the battery pieces with partial widths;

the packaging layer covers the surface of the glue and the surface of the battery piece;

the cover plate is positioned on one side, far away from the battery piece, of the packaging layer.

2. The assembly according to claim 1, wherein the glue has a thickness greater than or equal to the height of the connecting member in a direction perpendicular to the surface of the cell sheet.

3. The photovoltaic module of claim 1, wherein in the first direction, a width of a contact surface of the glue with the cell is larger than a width of a contact surface of the connecting member with the cell.

4. The assembly according to claim 3, wherein the glue is proportional to the width of the contact surface of the cell sheet and the distance between adjacent connecting members.

5. The photovoltaic module according to claim 3, wherein the ratio of the width of the contact surface of the glue and the cell sheet to the maximum width of the connecting member is 1-2.5.

6. The photovoltaic module of claim 1, wherein the glue has a melting point greater than a melting point of the encapsulant layer.

7. Photovoltaic module according to claim 1 or 6, characterized in that the glue is a cured layer.

8. The photovoltaic module of claim 1, further comprising: the battery piece is characterized by comprising a plurality of pre-fixing glues, wherein the pre-fixing glues are distributed at intervals along the extending direction of the connecting parts, the pre-fixing glues are located between the battery piece and the connecting parts, and the glue covers the pre-fixing glues.

9. The photovoltaic module of claim 8, wherein the width of the pre-tacking glue is greater than the width of the connecting member in the first direction, the pre-tacking glue surrounding a portion of the height of the connecting member.

10. The assembly according to claim 8, wherein in the first direction, the width of the contact surface of the pre-fixing glue and the cell piece is smaller than or equal to the width of the contact surface of the glue and the cell piece.

11. The photovoltaic module of claim 8, wherein the pre-fixing glue is the same material as the glue.