A solder ribbon-free flip chip assembly

Abstract

This application relates to a shingled module without solder strip folding, belonging to the technical field of photovoltaic modules. It includes at least one cell string, each cell string comprising multiple cells arranged in a shingled manner. Both the front and back sides of each cell have main grids and several sub-grids perpendicular to the main grids. An insulating strip is provided on the back side of the cell string, and a busbar is provided on the side of the insulating strip away from the cells. Busbar structures are provided at the sub-grids on the back of the cells at both ends of the cell string. These busbar structures form a surface contact conductive connection with the sub-grids on the back of the cells at both ends of the cell string, collecting and conducting current to the busbars. The busbar structure of this application can convert the output electrode located at one end of the front side of the shingled cell string to the back side, thereby realizing a back-side busbar process while maintaining the consistency of the busbar structures at both ends of the shingled module, achieving unified busbar process parameters, improving process versatility, and facilitating automated processing.

Description

Technical Field

[0001] This application relates to the technical field of photovoltaic modules, and in particular to a shingled module without solder strip folding. Background Technology

[0002] The solar cells used in shingled modules typically have a front and a back side with opposite polarities. The edge areas of both the front and back sides of the solar cells are provided with main grids, and the front and back surfaces of the solar cells are provided with several sub-grids perpendicular to the main grids. The sub-grids are electrically connected to the main grids. Any two adjacent solar cells are electrically connected in series by overlapping the front main grid of one solar cell with the back main grid of another solar cell, forming a shingled solar cell string with one end of the output electrode on the front and the other end of the output electrode on the back.

[0003] To achieve a unified arrangement of positive and negative busbars on the back side, a punched welding strip reverse folding busbar process is generally used: (Refer to...) Figure 1 and Figure 2 The perforated welding strips 3 are located at the beginning and end of the battery string 1, respectively. One end of the perforated welding strip 3 is welded to the main grid of the battery cell 2 at the beginning and end of the battery string 1. The other end of the perforated welding strip 3 is bent along the edge of the beginning and end to the back of the battery cell 2 and then welded to the two busbars 5 on the back. In order to prevent short circuits, an insulating strip 4 needs to be placed between the back of the battery cell 2 and the busbars 5 beforehand. However, this process has the following defects: The positioning accuracy requirement is extremely high. The bending positions of the insulating strip 4 and the punched welding strip 3 must be precisely aligned with the edge of the battery cell 2. Even a slight deviation will cause a short circuit or poor contact. The automation adaptation is difficult. The reverse bending angle and stroke of the punched welding strip 3 welded on both sides of the battery string 1 are different, requiring two sets of differentiated bending and positioning programs, resulting in poor process versatility. The process is highly complex, involving multiple steps such as welding on both sides, bending, and laying insulating strips. Not only is it inefficient, but the mechanical stress generated by bending can also easily cause the battery cell 2 to crack, affecting the product yield and reliability.

[0004] To address the shortcomings of the aforementioned punched strip welding process, Chinese Patent CN112420862A discloses a shingled module and its manufacturing method, comprising: at least one battery string, each battery string including a connecting piece at its end, the bottom surface of the connecting piece having a first conductive structure and a second conductive structure, the first conductive structure being in conductive contact with the positive electrode of the solar cell adjacent to the connecting piece, and the second conductive structure being in conductive contact with a second busbar. The first busbar is in conductive contact with the conductive structure on the bottom surface of the solar cell at the beginning of each battery string. This technology abandons the reverse folding of the welding strip, and by adding an independent connecting piece at the end of the battery string, the current from the front output electrode of the battery string is guided to the back side using the conductive structure on the bottom surface of the connecting piece, and then connected to the busbar, thereby achieving full back-side busing.

[0005] Regarding the prior art described above, the inventor believes that it has the following drawbacks: The complexity of the process has not decreased but increased. It requires the development of additional processes for the preparation of connecting pieces and matching conductive structures. It also requires the addition of steps such as feeding, positioning, and connecting the connecting pieces to the battery string in the production line, resulting in poor compatibility with the existing production line. Automation efficiency is still constrained. The first end of the battery string is directly connected to the busbar using the conductive structure of the battery cell, while the last end is connected through a connecting piece. The busbar structures at the beginning and end are not uniform, requiring the debugging of two sets of process parameters, resulting in high production change costs. There are reliability risks. The connecting piece and the battery string are spliced ​​as independent components. Even if the connecting piece is made of silicon wafer, there are still differences in the matching of thermal expansion coefficients at the splicing point. During lamination and outdoor high and low temperature cycling, problems such as loosening of the joint and delamination may occur. Summary of the Invention

[0006] To address the above issues, this application provides a shingled assembly without solder strip folding.

[0007] The shingled module without solder strip folding provided in this application adopts the following technical solution: A shingled module without solder strip folding includes at least one battery string, each battery string including multiple cells arranged in a shingled manner, each cell having a front and a back with opposite polarities, a main grid being provided on the edge region of both the front and back of the cell, and a plurality of sub-grids perpendicular to the main grid being provided on both the front and back surfaces of the cell, the sub-grids being electrically connected to the main grid; any two adjacent cells are electrically connected in series by overlapping the main grid on the front of one cell with the main grid on the back of the other cell, characterized in that: an insulating strip is provided on the back of the battery string, a busbar is provided on the side of the insulating strip away from the cell, and a bus structure is provided at the sub-grid on the back of the cells at both ends of the battery string, the bus structure forming a surface contact conductive connection with the sub-grid on the back of the cells at both ends of the battery string, and collecting and conducting the current to the busbar.

[0008] By adopting the above technical solution, the busbar structure forms a surface contact conductive connection with the back sub-busbar and collects and conducts the current to the busbar. This can convert the front output electrode of the battery string to the back to achieve full back-side busbar, completely eliminating the punching and bending process, eliminating the mechanical stress of the welding strip bending and the high-precision positioning requirements, and avoiding microcracks and cell breakage. At the same time, the busbar structures at the beginning and end of the battery string are completely consistent, the busbar process parameters are unified, and the process is standardized, which can greatly improve the adaptability of automated processing and the yield of module production.

[0009] Preferably, the busbar structure includes a conductive sheet that is conductive on both sides. The conductive sheet can be attached to and electrically connected to part or all of the back sub-grid of the battery cells at both ends of the battery string. The conductive sheet collects and conducts the current to the busbar.

[0010] By adopting the above technical solution, the conductive sheet forms a surface contact conductive connection with the back of the battery cell and the busbar, which can effectively reduce contact resistance and current transmission loss, improve the assembly alignment tolerance, and make the conductive sheet layout flexible and easy to automate.

[0011] Preferably, the conductive sheet is arranged on the side of the busbar away from the insulating strip, and the conductive sheet is in direct contact with the surface of the busbar for conductive connection. The busbar is a single-sided conductive tape or a double-sided conductive tape. The single-sided conductive tape includes a metal substrate and a pressure-sensitive adhesive layer, and the double-sided conductive tape includes a metal substrate and a voltage-sensitive adhesive layer.

[0012] By adopting the above technical solution, the conductive sheet is arranged on the side of the busbar away from the insulating strip, and the conductive sheet can be directly exposed for operation, making the installation operation simple.

[0013] Preferably, the insulating strip and the busbar are prefabricated integrated composite membrane materials.

[0014] By adopting the above technical solutions, integrated composite membrane materials can eliminate assembly alignment deviations, simplify processing procedures, and adapt to the automated processing rhythm of mass production.

[0015] Preferably, the conductive sheet is arranged between the insulating strip and the busbar, and the conductive sheet is in surface contact with the busbar for conductive connection.

[0016] By adopting the above technical solution, and by sandwiching the conductive sheet between the insulating strip and the busbar, the loosening of the contact between the conductive sheet and the busbar can be effectively suppressed, ensuring the long-term stability of the electrical connection.

[0017] Preferably, the end of the busbar extends into the direction of the beginning and end of the battery cell, and the conductive sheet is arranged between the battery cell and the extension section, and the conductive sheet is in direct contact with the surface of the extension section for conductive connection.

[0018] By adopting the above technical solution, the busbar extends relative to the insulating strip and is directly connected to the conductive sheet through the extension section of the busbar, without the need to add intermediate connecting parts, which simplifies the structure and material types.

[0019] Preferably, the busbar structure further includes a conductive connecting piece, which is used to connect the busbar to the conductive piece.

[0020] By adopting the above technical solution, the busbar and the conductive sheet are electrically connected by the conductive connecting piece, which can overcome the width limitation of the busbar and enable the conductive sheet to be electrically connected to part or all of the sub-grid on the back of the end cell, adapting to shingled cell strings with different currents.

[0021] Preferably, the busbar is conductive on both sides, and the bus structure is an extension of the busbar extending towards both ends of the battery string. The extension is directly electrically connected to the sub-grid on the back of the battery cells at both ends of the battery string.

[0022] By adopting the above technical solution, the extension section is directly connected to the secondary grid on the back of the battery cells at both ends of the battery string. The structure is simple and suitable for single-cell string shingled module products with low current requirements.

[0023] Preferably, the conductive sheet is a double-sided conductive tape, which includes a metal substrate and a voltage-sensitive adhesive layer. The metal substrate is one of copper foil, aluminum foil, nickel foil, tin foil, silver foil, alloy foil, or copper-tin composite foil or aluminum-polymer composite film.

[0024] Preferably, the conductive connecting piece is a double-sided conductive tape, which includes a metal substrate and a voltage-sensitive adhesive layer. The metal substrate is one of copper foil, aluminum foil, nickel foil, tin foil, silver foil, alloy foil, or copper-tin composite foil or aluminum-polymer composite film.

[0025] Preferably, the shingled assembly includes multiple parallel battery strings, and the output polarity of any adjacent battery strings at the same end is the same; the bus structure includes a continuous conductive sheet that is conductive on both sides, and the continuous conductive sheet is attached to and electrically connected to the back sub-grids of the battery cells at both ends of all battery strings along a direction perpendicular to the length of the battery string, thereby realizing the parallel connection of all battery strings.

[0026] Preferably, the shingled assembly includes multiple parallel battery strings, and the output polarities at the same end of any adjacent battery strings are opposite; the bus structure includes several conductive sheets that are conductive on both sides, and each conductive sheet is attached to and electrically connected to the back sub-gates of the battery cells at both ends of adjacent battery strings along a direction perpendicular to the length of the battery string, thereby realizing the series connection of all battery strings.

[0027] In summary, this application includes at least one of the following beneficial technical effects: 1. By setting a busbar structure at the back sub-busbar of the cells at both ends of each cell string, the busbar structure forms a surface contact conductive connection with the back sub-busbar and collects and conducts the current to the busbar. This allows the output electrode of the cell string to be converted to the back, achieving full back-side busbar operation. This completely eliminates the need for punching and bending processes, removes the mechanical stress of solder strip bending and the high-precision positioning requirements, and avoids cell microcracks. At the same time, the busbar structures at both ends of the cell string are completely identical, and the busbar process parameters are unified and the process is standardized, which can significantly improve the adaptability of automated processing and the yield of module production.

[0028] 2. By setting conductive sheets on the back of the battery cells at both ends of the battery string, the conductive sheets form a surface contact conductive connection with the back of the battery cells and the busbar, which can effectively reduce contact resistance and current transmission loss, improve the assembly alignment tolerance, and make the conductive sheet layout flexible and easy to automate.

[0029] 3. By using the extension section of the busbar itself as the busbar structure, a high degree of integration and simplification of the structure is achieved. While maintaining the complete consistency of the busbar structure at the beginning and end of the battery string, the number of contact interfaces can be reduced to the greatest extent, the contact resistance can be reduced and the stability of current transmission can be improved. It is particularly suitable for the busbar of low-power single-string shingled modules. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the structure used in the prior art to illustrate the punched weld strip.

[0031] Figure 2 This is a schematic diagram used in existing technology to illustrate the connection relationship between the perforated welding strip, the busbar, and the battery cell.

[0032] Figure 3 This is a schematic diagram of the busbar structure, including conductive sheets, used in Embodiment 1 of this application.

[0033] Figure 4 This is a schematic diagram illustrating the structure of the busbar structure, including the conductive sheet, in Embodiment 1 of this application.

[0034] Figure 5 yes Figure 3 A schematic diagram of the structure after the area of ​​one end electrode of the battery string that is not covered by the conductive sheet is removed.

[0035] Figure 6 This is a schematic diagram of the structure in Embodiment 1 of this application, illustrating the conductive sheet sandwiched between the insulating strip and the busbar.

[0036] Figure 7 This is a schematic diagram of the structure in Embodiment 1 of this application, illustrating that the conductive sheet is located between the battery cell and the busbar.

[0037] Figure 8 This is a schematic diagram of Embodiment 2 of this application, illustrating the structure of the busbar structure including the conductive connecting piece.

[0038] Figure 9 This is a schematic diagram illustrating the structure of the busbar structure, including the conductive connecting piece, in Embodiment 2 of this application.

[0039] Figure 10 This is a schematic diagram illustrating the structure of the busbar structure, including the conductive connecting piece, in Embodiment 2 of this application.

[0040] Figure 11 This is a schematic diagram of the structure in Embodiment 3 of this application, which illustrates that the busbar structure is an extension of the busbar strip.

[0041] Figure 12 This is a schematic diagram illustrating the connection relationship of conductive sheets after all multiple shingled battery strings are connected in parallel, as shown in Embodiment 4 of this application.

[0042] Figure 13 This is a schematic diagram illustrating the connection relationship of conductive sheets after all multiple shingled battery strings are connected in series, as shown in Embodiment 4 of this application.

[0043] Explanation of reference numerals in the attached diagram: 1. Battery string; 2. Battery cell; 3. Perforated welding strip; 4. Insulating strip; 5. Busbar; 6. Conductive sheet; 7. Conductive connecting piece. Detailed Implementation

[0044] The following is in conjunction with the appendix Figure 3-13 This application will be described in further detail.

[0045] Reference Figures 3-11This embodiment provides a shingled assembly without solder strip folding, including at least one battery string 1. Each battery string 1 includes multiple battery cells 2 arranged in a shingled manner. Each battery cell 2 has a front and a back with opposite polarities. A main grid is provided on the edge area of ​​the front and back of each battery cell 2. Several sub-grids perpendicular to the main grid are provided on the front and back surfaces of the battery cell 2. The sub-grids are electrically connected to the main grid.

[0046] Any two adjacent battery cells 2 are connected in series through the front main grid of one battery cell 2 and the back main grid of the other battery cell 2, so that the battery string 1 forms an electrical structure with one end of the output electrode on the front and the other end of the output electrode on the back. An insulating strip 4 is provided on the back of the battery string 1. A busbar 5 is provided on the side of the insulating strip 4 away from the battery cell 2. The width of the busbar 5 is smaller than the width of the insulating strip 4. The insulating strip 4 is used to achieve insulation between the busbar 5 and the battery cell 2.

[0047] The key to this embodiment is that a busbar structure is provided on the back sub-grid of the battery cell 2 at both ends of each battery string 1. The busbar structure is in contact with the back sub-grid of the battery cell 2 at both ends of the battery string 1 and is conductively connected. The busbar structure is used to collect the current of the corresponding battery string 1 and conduct it to the busbar 5.

[0048] By arranging the busbar structure, the output electrode of battery string 1 on the front is turned to the back, and a new output electrode is set at one end of the output electrode of battery string 1 on the back, so that the output electrodes at both ends of battery string 1 are on the back, and the area of ​​the output electrodes is increased. On the one hand, the busbar structure and the output electrode of battery cell 2 adopt a surface contact fit, eliminating the need for traditional punching, bending and high-precision welding positioning, resulting in a higher assembly fault tolerance rate and no mechanical stress damage to the battery cells caused by bending, which can effectively avoid microcracks and cracks in the battery cells. On the other hand, the busbar structure at both ends of each battery string 1 adopts a busbar structure with completely consistent structure, connection form and contact position, ensuring stable current collection and conduction. The busbar process parameters are unified and the process is standardized, which can significantly improve the adaptability of automated processing and the yield of module production.

[0049] Reference Figures 3-11 For cases where shingled modules consist of only a single battery string, this application further provides several alternative implementations of the bus structure: Example

[0050] Reference Figure 3The busbar structure includes a conductive sheet 6, which has a first conductive surface and a second conductive surface arranged opposite to each other. The conductive sheet 6 can be surface-mounted and electrically connected to part or all of the back sub-grids of the battery cells 2 at both ends of the battery string 1. The first conductive surface of the conductive sheet 6 is in conductive contact with part or all of the back sub-grids of the battery cells 2 at both ends of each battery string 1, and the conductive sheet 6 collects and conducts the current to the busbar 5. The conductive sheet 6, with its independent sheet structure, is surface-mounted and electrically connected to part or all of the back sub-grids of the battery cells 2 at both ends of the battery string 1, resulting in higher assembly alignment tolerance, more uniform current collection, and stronger connection stability.

[0051] Furthermore, the conductive sheet 6 can be made of double-sided conductive tape, which includes a metal substrate and a voltage-sensitive adhesive layer coated on the surface of the metal substrate. The voltage-sensitive adhesive layer has both adhesive and conductive properties, and can achieve mechanical fixation and electrical connection simultaneously through bonding, without welding or bending. This completely eliminates the mechanical stress and high-precision positioning requirements caused by the refraction of the solder strip, significantly reducing the risk of microcracks and cracks in the solar cell. At the same time, the surface contact conductive connection can increase the conductive contact area, reduce contact resistance, improve the stability of current transmission and the reliability of shingled modules, and is suitable for thin-film solar cells and high-speed automated production lines.

[0052] Based on this, refer to Figures 3-7 This embodiment further provides several optional implementations of the conductive sheet 6: In the first alternative implementation, refer to Figure 3 , Figure 4 The conductive sheet 6 is partially or completely attached to and electrically connected to the back sub-grids of the battery cells 2 at both ends of the battery string 1. The first conductive surface of the conductive sheet 6 is in contact with and electrically connected to the back sub-grid surface of the battery cells 2 at both ends of the battery string 1. Simultaneously, the first conductive surface of the conductive sheet 6 is also in contact with and electrically connected to the side of the busbar 5 away from the insulating strip 4. By arranging the conductive sheet 6 on the side of the busbar 5 away from the insulating strip 4, the conductive sheet 6 can be directly exposed for easy installation. The direct contact and electrical connection between the conductive sheet 6 and the side of the busbar 5 shortens the current transmission path.

[0053] Furthermore, the busbar 5 has a single-sided conductive structure. Preferably, the busbar 5 can be a single-sided conductive tape, which includes a metal substrate and a pressure-sensitive adhesive layer coated on the surface of the metal substrate. Through the adhesiveness of the pressure-sensitive adhesive layer, the busbar 5 can be firmly attached to the side of the insulating strip 4 away from the battery cell 2. Meanwhile, the metal substrate is a metal foil such as copper foil, aluminum foil, nickel foil, tin foil, silver foil or its alloy foil, or a composite metal foil such as copper-tin composite foil or aluminum-polymer composite film.

[0054] Alternatively, the busbar 5 may have a double-sided conductive structure. Preferably, the busbar 5 may be a double-sided conductive tape, the structure of which and its beneficial effects will not be described in detail here.

[0055] Furthermore, to adapt to mass automated production, the insulating strip 4 and the busbar 5 can be prefabricated as an integrated composite film. The composite film ensures the relative positional accuracy of the insulating strip 4 and the busbar 5, and can be assembled as a whole in the lamination process, eliminating assembly misalignment deviations and avoiding short circuit problems caused by improper alignment. This simplifies the processing steps and improves production efficiency.

[0056] Furthermore, referring to Figure 5 For the end cell 2 of the battery string 1 with the output electrode located at the front end, since its function is to extend and turn the front main grid of the adjacent cell 2 that overlaps with the back main grid of the end cell 2, the end cell 2 itself does not generate power. Therefore, the area on the end cell 2 that is not connected to the conductive sheet 6 can be selectively cut off along the length of the battery string 1 in subsequent processes to save space in the photovoltaic module.

[0057] In the second alternative implementation, refer to Figure 6 The conductive sheet 6 can be placed between the insulating strip 4 and the busbar 5. Specifically, the conductive sheet 6 can be attached to and electrically connected to part or all of the back sub-grid of the battery cells 2 at both ends of the battery string 1. The first conductive surface of the conductive sheet 6 is in contact with and electrically connected to the back sub-grid of the battery cells 2 at both ends of the battery string 1, and the first conductive surface of the conductive sheet 6 is also arranged on the side of the insulating strip 4 away from the battery cells 2. At the same time, the second conductive surface of the conductive sheet 6 is in contact with and electrically connected to the side of the busbar 5 close to the insulating strip 4. By sandwiching the conductive sheet between the insulating strip 4 and the busbar 5, the conductive sheet 6 and the busbar 5 always maintain a tight fit, and the electrical connection stability between the conductive sheet 6 and the busbar 5 can be further improved.

[0058] At this time, the busbar 5 has a double-sided conductive structure. Preferably, the busbar 5 is a double-sided conductive tape, which allows the busbar 5 to be firmly attached to the side of the insulating strip 4 away from the battery cell 2, and to form a stable and reliable surface contact electrical connection with the second conductive surface of the conductive sheet 6.

[0059] In the third alternative implementation, refer to Figure 7The extension section of the busbar 5 extends towards the beginning and end of the battery cell 2. The conductive sheet 6 can be attached to and electrically connected to part or all of the back sub-grid of the battery cell 2 at both ends of the battery string 1. The conductive sheet 6 is arranged between the back of the battery cell 2 and the busbar 5. The first conductive surface of the conductive sheet 6 is in contact with the back sub-grid surface of the battery cell 2 at both ends of the battery string 1, and the second conductive surface of the conductive sheet 6 is electrically connected to the side of the extension section of the busbar 5 near the back of the battery cell 2. By directly attaching the conductive sheet 6 between the back of the battery cell 2 and the insulating strip 4, the current transmission path can be shortened and the current transmission loss can be further reduced because the conductive sheet 6 is directly connected to the back sub-grid of the battery cell 2 and the extension section of the busbar 5. Example

[0060] Reference Figures 8-11 The busbar structure also includes a conductive connecting piece 7, which connects the busbar 5 and the conductive sheet 6. By electrically connecting the busbar 5 and the conductive sheet 6 via the conductive connecting piece 7, the width limitation of the busbar 5 can be overcome, allowing the conductive sheet 6 to be electrically connected to part or all of the sub-grid on the back of the end cell 2, adapting to shingled modules with different current requirements. Specifically, the conductive connecting piece 7 can be made of double-sided conductive tape; its structure and beneficial effects will not be elaborated here.

[0061] Based on this, this embodiment further provides several optional implementations of the conductive connector 7: In the first alternative implementation, refer to Figure 8 The conductive sheet 6 can be attached to and electrically connected to part or all of the back sub-grids of the battery cells 2 at both ends of the battery string 1. The first conductive surface of the conductive sheet 6 is in contact with the back sub-grid surface of the battery cells 2 at both ends of the battery string 1, and the second conductive surface of the conductive sheet 6 is in contact with one end face of the conductive connecting sheet 7. The conductive connecting sheet 7 is located on the side of the busbar 5 away from the insulating strip 4, and the side of the conductive connecting sheet 7 closest to the busbar 5 forms a surface contact electrical connection with the busbar 5. By arranging the conductive connecting sheet 7 on the side of the busbar 5 away from the insulating strip 4, the conductive connecting sheet 7 can be directly exposed for easy installation.

[0062] Specifically, the busbar 5 has a single-sided conductive structure or a double-sided conductive structure. Preferably, the busbar 5 is a single-sided conductive tape or a double-sided conductive tape.

[0063] Furthermore, the insulating strip 4 and the busbar 5 can be prefabricated as an integrated composite film material, which can be used as a whole in the busbar processing to adapt to mass automated production and improve production efficiency.

[0064] In the second alternative implementation, refer to Figure 9The conductive sheet 6 can be attached to and electrically connected to part or all of the back sub-grid of the battery cells 2 at both ends of the battery string 1. The first conductive surface of the conductive sheet 6 is in contact with and electrically connected to the back sub-grid of the battery cells 2 at both ends of the battery string 1. The first conductive surface of the conductive sheet 6 is also electrically connected to one end of the conductive connecting sheet 7. The other end of the conductive connecting sheet 7 is located between the busbar 5 and the insulating strip 4, and the side of the conductive connecting sheet 7 away from the insulating strip 4 is in contact with and electrically connected to the side of the busbar 5 close to the insulating strip 4. By clamping the conductive connecting sheet 7 between the busbar 5 and the insulating strip 4, the electrical connection stability between the conductive connecting sheet 7 and the busbar 5 can be enhanced because the conductive connecting sheet 7 is clamped and limited by the two-layer structure.

[0065] Specifically, busbar 5 has a double-sided conductive structure. Preferably, busbar 5 is a double-sided conductive tape.

[0066] In the third alternative implementation, refer to Figure 10 The conductive sheet 6 can be attached to and electrically connected to part or all of the back sub-grid of the battery cells 2 at both ends of the battery string 1. The first conductive surface of the conductive sheet 6 is in contact with and electrically connected to the back sub-grid of the battery cells 2 at both ends of the battery string 1. The first conductive surface of the conductive sheet 6 is also electrically connected to one end of the conductive connecting sheet 7. The other end of the conductive connecting sheet 7 is located on the side of the busbar 5 away from the insulating strip 4, and the side of the conductive connecting sheet 7 close to the battery cell 2 is in contact with and electrically connected to the side of the busbar 5 away from the insulating strip 4.

[0067] Specifically, the busbar 5 has a single-sided conductive structure or a double-sided conductive structure. Preferably, the busbar 5 is a single-sided conductive tape or a double-sided conductive tape.

[0068] Furthermore, the insulating strip 4 and the busbar 5 can be prefabricated as an integrated composite film material, which can be used as a whole in the busbar processing to adapt to mass automated production and improve production efficiency. Example

[0069] Reference Figure 11 The busbar structure is an extension section formed by the end of the busbar 5 extending along the direction of the beginning and end of the battery string 1. The extension section directly forms a large-area surface contact conductive connection with the back sub-grid of the battery cell 2 at both ends of the battery string 1, thereby directly conducting the current collected on the end battery cell 2 to the busbar 5.

[0070] The busbar 5 has a double-sided conductive structure. Specifically, both the side of the busbar 5 that contacts the insulating strip and the side of the busbar 5 that is away from the insulating strip are conductive. Preferably, the busbar 5 can be made of the aforementioned double-sided conductive tape.

[0071] By extending the busbar 5 itself as the busbar structure, a high degree of integration and simplification of the structure is achieved. While maintaining the complete consistency of the busbar structure at the beginning and end of the battery string 1, the number of contact interfaces can be reduced to the greatest extent, the contact resistance can be reduced and the stability of current transmission can be improved. It is the preferred busbar solution with the simplest structure and the fewest processes for single-cell string shingled modules. Example

[0072] Reference Figures 12-13 For shingled modules containing multiple battery strings, this embodiment further provides several optional implementations of the bus structure: In the first alternative implementation, refer to Figure 12 To further reduce the number of conductive sheets 6 used and simplify the process, when multiple battery strings 1 are connected in parallel, the independent conductive sheets 6 that were originally attached to the back of the battery cells 2 at both ends of each battery string 1 can be merged into one continuous conductive sheet 6 at the beginning and end of each battery string. The continuous conductive sheet 6 is attached to the back of the battery cells at the end of all battery strings 1 along the direction perpendicular to the length of the battery string and electrically connected to the sub-grid on the back of the battery cells at the end of all battery strings 1. The current busing at the beginning and end of all battery strings 1 is completed at one time, which greatly simplifies the back busing process of multi-string parallel shingled modules.

[0073] Specifically, a shingled module without solder strip folding includes multiple battery strings 1 arranged in parallel, with the same output polarity at the same end of any adjacent battery strings 1; each battery string 1 includes multiple battery cells 2 arranged in a shingled manner, each battery cell 2 having a front and a back side with opposite polarities, a main grid is provided on the edge area of ​​the front and back sides of each battery cell 2, and several sub-grids perpendicular to the main grid are provided on the front and back surfaces of the battery cell 2, with the sub-grids electrically connected to the main grid; any two adjacent battery cells 2 are connected in series through the front main grid of one and the back main grid of the other, so that the battery string 1 forms an electrical structure with the output electrode at one end on the front and the output electrode at the other end on the back.

[0074] An insulating strip 4 is provided on the back of multiple battery strings 1. A busbar 5 is provided on the side of the insulating strip 4 away from the battery cell 2. A busbar structure is provided at the back sub-grid of the battery cell 2 at both ends of the multiple battery strings 1. The busbar structure includes a continuous conductive sheet 6 with double-sided conductivity. The continuous conductive sheet 6 is surface-mounted and electrically connected to the back sub-grid of the battery cell 2 at both ends of all battery strings 1 along a direction perpendicular to the length of the battery string 1, realizing the parallel connection of all battery strings 1. By using the continuous conductive sheet 6 to realize the parallel connection of multiple battery strings 1, the busbar layout on the back of the shingled module is simplified. At the same time, the surface contact conductive connection can ensure the stability and reliability of the uniform current collection of each battery string 1.

[0075] In the second alternative implementation, refer to Figure 13To further simplify the process of attaching the conductive sheet 6, when multiple battery strings 1 are connected in series, the method of attaching the conductive sheet 6 independently to the end of each battery string 1 can be eliminated. Instead, a conductive sheet 6 can be attached between the opposite electrode ends of adjacent battery strings 1 to achieve series conduction between adjacent battery strings 1.

[0076] Specifically, multiple battery strings 1 are arranged in parallel, with the polarities of any adjacent battery strings 1 being opposite at the same end; each battery string 1 includes multiple battery cells 2 arranged in a shingled manner, each battery cell 2 having a front and a back side with opposite polarities, and a main grid is provided on the edge area of ​​the front and back sides of each battery cell 2, and several sub-grids perpendicular to the main grid are provided on the front and back surfaces of the battery cell 2, with the sub-grids electrically connected to the main grid; any two adjacent battery cells 2 are connected in series through the front main grid of one and the back main grid of the other, so that the battery string 1 forms an electrical structure with the output electrode at one end on the front and the output electrode at the other end on the back.

[0077] An insulating strip 4 is provided on the back of multiple battery strings 1. A busbar 5 is provided on the side of the insulating strip 4 away from the battery cell 2. A busbar structure is provided at the secondary grid on the back of the battery cell 2 at both ends of the multiple battery strings 1. The busbar structure includes several conductive sheets 6 that are conductive on both sides. The conductive sheets 6 are attached to each other and electrically connected to the secondary grid on the back of the battery cell 2 at both ends of adjacent battery strings 1 along a direction perpendicular to the length of the battery string, realizing the series connection of all battery strings 1. Specifically, the conductive sheet 6 connects the positive terminal of the first end of the battery string 1 to the negative terminal of the first end of the adjacent battery string 1. The current flows out from the tail end of the previous battery string 1, flows through the conductive sheet 6 into the first end of the next battery string 1, and so on.

[0078] In addition to the above-mentioned implementation scenarios where all battery strings 1 are connected in series or in parallel, the present invention is also applicable to shingled assemblies that are connected in series first and then in parallel or in parallel first and then in series, flexibly realizing the series and parallel combinations between battery strings 1.

[0079] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A shingled module without solder strip folding, comprising at least one battery string, each battery string comprising a plurality of cells arranged in a shingled manner, each cell having a front and a back side with opposite polarities, a main grid being disposed on the edge region of both the front and back sides of the cell, and a plurality of sub-grids perpendicular to the main grid being disposed on both the front and back surfaces of the cell, the sub-grids being electrically connected to the main grid; any two adjacent cells are electrically connected in series by overlapping the front main grid of one cell with the back main grid of the other cell, characterized in that: An insulating strip is provided on the back of the battery string, and a busbar is provided on the side of the insulating strip away from the battery cell. A busbar structure is provided on the back of the battery cells at both ends of the battery string at the sub-grid. The busbar structure forms a surface contact conductive connection with the sub-grid on the back of the battery cells at both ends of the battery string, and collects and conducts the current to the busbar.

2. The shingled assembly without solder strip folding according to claim 1, characterized in that: The busbar structure includes a conductive sheet that is conductive on both sides. The conductive sheet can be attached to and electrically connected to part or all of the back sub-grid of the battery cells at both ends of the battery string. The conductive sheet collects and conducts the current to the busbar.

3. A shingled assembly without solder strip folding according to claim 2, characterized in that: The conductive sheet is arranged on the side of the busbar away from the insulating strip, and the conductive sheet is in direct contact with the surface of the busbar for conductive connection. The busbar is a single-sided conductive tape or a double-sided conductive tape. The single-sided conductive tape includes a metal substrate and a pressure-sensitive adhesive layer, and the double-sided conductive tape includes a metal substrate and a voltage-sensitive adhesive layer.

4. A shingled assembly without solder strip folding according to claim 3, characterized in that: The insulating strip and the busbar are prefabricated integrated composite membrane materials.

5. A shingled assembly without solder strip folding according to claim 2, characterized in that: The conductive sheet is arranged between the insulating strip and the busbar, and the conductive sheet is in surface contact with the busbar for conductive connection.

6. A shingled assembly without solder strip folding according to claim 2, characterized in that: The end of the busbar extends into the beginning and end of the battery cell, and the conductive sheet is arranged between the battery cell and the extension section, and the conductive sheet is in direct contact with the surface of the extension section for conductive connection.

7. A shingled assembly without solder strip folding according to claim 2, characterized in that: The busbar structure also includes a conductive connecting piece, which is used to connect the busbar to the conductive piece.

8. A shingled module without solder strip folding according to claim 1, characterized in that: The busbar is conductive on both sides, and the bus structure is an extension of the busbar extending towards both ends of the battery string. The extension is directly electrically connected to the sub-grid on the back of the battery cells at both ends of the battery string.

9. The shingled assembly without solder strip folding according to any one of claims 2-7, characterized in that: The conductive sheet is a double-sided conductive tape, which includes a metal substrate and a voltage-sensitive adhesive layer. The metal substrate is one of copper foil, aluminum foil, nickel foil, tin foil, silver foil, alloy foil, or copper-tin composite foil or aluminum-polymer composite film.

10. A shingled assembly without solder strip folding according to claim 7, characterized in that: The conductive connector is a double-sided conductive tape, which includes a metal substrate and a voltage-sensitive adhesive layer. The metal substrate is one of copper foil, aluminum foil, nickel foil, tin foil, silver foil, alloy foil, or copper-tin composite foil or aluminum-polymer composite film.

11. A shingled assembly without solder strip folding according to claim 1, characterized in that: The shingled assembly includes multiple parallel battery strings, and the output polarity of any adjacent battery strings at the same end is the same. A busbar structure is provided at the back sub-grid of the battery cells at both ends of the multiple battery strings. The busbar structure includes a continuous conductive sheet that is conductive on both sides. The continuous conductive sheet is attached to and electrically connected to the back sub-grid of the battery cells at both ends of all battery strings along a direction perpendicular to the length of the battery string, so as to realize the parallel connection of all battery strings.

12. A shingled assembly without solder strip folding according to claim 1, characterized in that: The shingled assembly includes multiple parallel battery strings, and the output polarity of any adjacent battery strings at the same end is opposite. Each of the battery cells at both ends of the battery strings has a busbar structure on its back side. The busbar structure includes several conductive sheets that are conductive on both sides. Each conductive sheet is attached to and electrically connected to the back side side sub-grids of the battery cells at both ends of the adjacent battery strings along a direction perpendicular to the length of the battery string, thereby realizing the series connection of all battery strings.

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