Preparation method of main-grid-free battery string, main-grid-free battery string and photovoltaic module

Abstract

The embodiment of the invention provides a main-grid-free battery string preparation method, a main-grid-free battery string and a photovoltaic module, and relates to the technical field of solar cells. The preparation method of the main-grid-free battery string comprises the following steps: preparing a first packaging adhesive membrane and a second packaging adhesive membrane; preparing conductive grid lines on the surfaces of the first packaging adhesive membrane and the second packaging adhesive membrane; preparing a battery piece; the first packaging adhesive membrane and the second packaging adhesive membrane are attached to the surface of the battery piece, and the conductive grid lines of the first packaging adhesive membrane and the second packaging adhesive membrane make contact with the battery piece to form a battery string; and the first packaging adhesive membranes of the adjacent battery strings are communicated. The conductive grid lines are prepared on the first packaging adhesive membrane and the second packaging adhesive membrane, welding points do not need to be prefabricated on the battery piece, the battery string can be prepared without welding, the process difficulty is reduced, and the production cost is saved.

Description

Technical Field

[0001] The present invention relates to the technical field of solar cells, and in particular to a method for preparing a busbar-free battery string, a busbar-free battery string and a photovoltaic module. Background Art

[0002] As one of the main components of solar cells, the performance and production efficiency of crystalline silicon cells have always been a hot topic of research. In the traditional packaging process of crystalline silicon cells, the preparation of conductive grid lines is a key link. Conductive grid lines are not only used to collect current generated by photogenerated carriers, but also play a key role in connecting the cell to the external circuit. At present, conventional conductive grid lines are usually applied to the surface of crystalline silicon cells through screen printing technology, which requires precise control of the distribution of materials during the printing process to ensure conductive performance and packaging stability. Screen printing is a common method for preparing conductive layers. Conductive ink is printed on crystalline silicon cells through a specific screen to form continuous or disconnected conductive lines. This technology can flexibly adjust the width, spacing and pattern shape of the conductive lines to meet the needs of different battery designs.

[0003] In the existing technology, although screen printing technology has shown a certain flexibility and adaptability in the preparation of conductive grid lines of crystalline silicon solar cells, it still faces technical challenges in printing accuracy, welding point prefabrication, and conductive tape and dispensing application in actual application. These factors jointly affect the manufacturing cost, production efficiency and quality of the final product of the solar cell. Therefore, continuous research and technological innovation are essential to optimize this process, improve the efficiency of photovoltaic cells and reduce costs. Summary of the invention

[0004] The present invention provides a method for preparing a busbar-free battery string, a busbar-free battery string and a photovoltaic module, which can simplify the preparation process of the battery string and reduce production costs.

[0005] The present invention can be implemented like this: An embodiment of the present invention provides a method for preparing a busbar-free battery string, which comprises: Prepare a first packaging adhesive film sheet and a second packaging adhesive film sheet; Prepare conductive gate lines on the surfaces of the first packaging film sheet and the second packaging film sheet; preparing battery cells; The first packaging film sheet and the second packaging film sheet are respectively attached to the surface of the battery sheet, and the conductive grid lines of the first packaging film sheet and the second packaging film sheet are in contact with the battery sheet to form a battery string; The first packaging adhesive films of adjacent battery strings are connected.

[0006] Optionally, the number of the battery cells is N, and the N battery cells are sequentially spaced along a straight line, and the step of laminating the first encapsulation film sheet and the second encapsulation film sheet to the surfaces of the battery cells respectively, and the conductive grid lines of the first encapsulation film sheet and the second encapsulation film sheet are in contact with the battery cells to form a battery string includes: The first packaging film is attached to the back of the battery cell at the end position, and the conductive grid lines on the first packaging film are in contact with the back of the battery cell; then the second packaging film is attached to the front of the battery cell at the end position, and the conductive grid lines on the second packaging film are in contact with the front of the battery cell; Then, the second encapsulating adhesive film is attached to the back of the battery cell adjacent to the battery cell at the end position, and the attached second encapsulating adhesive film is connected to the second encapsulating adhesive film on the front of the battery cell at the end position; then, the second encapsulating adhesive film is attached to the front of the battery cell, and then the surface of the next battery cell is attached according to the same step; The second packaging film is attached to the back of the last battery cell, and the second packaging film is connected to the second packaging film on the front of the adjacent battery cell, and then the first packaging film is attached to the front of the last battery cell to form a battery string.

[0007] Optionally, the step of preparing conductive gate lines on the surfaces of the first packaging film sheet and the second packaging film sheet includes: A connection line and a first connection point are respectively prepared on two opposite edges on the same side of the first packaging film, wherein both the connection line and the first connection point are connected to the conductive gate line; Second connection points are prepared on two opposite edges on the same side of the second packaging film, and both ends of the conductive gate line are connected to the second connection points.

[0008] Optionally, the step of laminating the first encapsulation film sheet and the second encapsulation film sheet to the surface of the battery cell respectively, wherein the conductive grid lines of the first encapsulation film sheet and the second encapsulation film sheet are in contact with the battery cell to form a battery string further includes: When the second packaging film sheet is attached to the battery cell, the second connection point at one end of the second packaging film sheet is exposed to the battery cell, the second connection point at the other end of the second packaging film sheet is connected to the battery cell, and the second connection points exposed on two adjacent battery cells are connected to each other; When the first packaging film sheet and the battery cell are attached to each other, the connection line of the first packaging film sheet is exposed from the battery cell, and the first connection point is connected to the battery cell.

[0009] Optionally, the step of connecting the first packaging adhesive films of adjacent battery strings comprises: The connecting lines of the first packaging film sheets of two adjacent battery strings are connected.

[0010] Optionally, the step of preparing the first packaging adhesive film sheet and the second packaging adhesive film sheet includes: A first packaging adhesive film sheet and a second packaging adhesive film sheet with a thickness of 0.5 nm-1 nm are prepared.

[0011] Optionally, the step of preparing the first packaging adhesive film sheet and the second packaging adhesive film sheet further includes: The horizontal distance between the first packaging film sheet and the second packaging film sheet is 1 mm-5 mm.

[0012] Optionally, the step of preparing the first packaging adhesive film sheet and the second packaging adhesive film sheet further includes: The first packaging adhesive film sheet and the second packaging adhesive film sheet are prepared by using EVA, EPE and POE materials.

[0013] Optionally, the step of preparing conductive gate lines on the surfaces of the first packaging film sheet and the second packaging film sheet includes: A plurality of conductive gate lines are prepared on the surface of the first packaging film and the second packaging film. The plurality of conductive gate lines are sequentially spaced apart along the width direction of the first packaging film and the second packaging film, and the spacing between two adjacent conductive gate lines is 0.8nm-1nm.

[0014] Optionally, the step of preparing conductive gate lines on the surfaces of the first packaging film and the second packaging film further includes: The manufactured conductive grid lines are dried and solidified, the drying temperature is no greater than two-thirds of the melting point of the adhesive film, and the drying time is 20s-140s.

[0015] The present invention also provides a busbar-free battery string, which is prepared using the busbar-free battery string preparation method.

[0016] The present invention also provides a photovoltaic module, comprising a main grid-free battery string.

[0017] The beneficial effects of the method for preparing a busbar-free battery string, the busbar-free battery string and the photovoltaic module of the present invention include, for example: The method for preparing a busbar-free battery string includes preparing a first packaging film sheet and a second packaging film sheet; preparing conductive grid lines on the surfaces of the first packaging film sheet and the second packaging film sheet; preparing battery cells; laminating the first packaging film sheet and the second packaging film sheet to the surfaces of the battery cells respectively, and the conductive grid lines of the first packaging film sheet and the second packaging film sheet are in contact with the battery cells to form a battery string; the first packaging film sheets of adjacent battery strings are connected. When in use, the conductive grid lines are prepared on the first packaging film sheet and the second packaging film sheet, and then the first packaging film sheet and the second packaging film sheet and the battery cells are assembled to form a battery string. Compared with the preparation method in the prior art, the method for preparing a busbar-free battery string prepares the conductive grid lines on the first packaging film sheet and the second packaging film sheet, and no longer needs to prefabricate welding points on the battery cells. The battery string can be made without welding, which reduces the process difficulty and saves production costs.

[0018] The busbar-free battery string is prepared by using the busbar-free battery string preparation method, and the busbar-free battery string has the same beneficial effects as above.

[0019] The photovoltaic module comprises a main grid-free battery string and has the same beneficial effects as above. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0021] Figure 1 A flow chart of a method for preparing a busbar-free battery string provided in this embodiment; Figure 2 A schematic diagram of the structure of a first packaging film provided in this embodiment; Figure 3 A schematic diagram of the structure of a second packaging film provided in this embodiment; Figure 4 A schematic diagram of the structure of a busbar-free battery string provided in this embodiment.

[0022] Icons: 10 - first packaging film; 20 - second packaging film; 30 - conductive grid line; 40 - battery cell; 50 - connection line; 60 - first connection point; 70 - second connection point. DETAILED DESCRIPTION

[0023] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0024] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0025] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0026] In the description of the present invention, it should be noted that if the terms "upper", "lower", "inside", "outside", etc. appear to indicate an orientation or position relationship, they are based on the orientation or position relationship shown in the accompanying drawings, or are the orientation or position relationship in which the product of the invention is usually placed when used. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0027] In addition, the terms “first”, “second”, etc., if used, are merely used to distinguish between the descriptions and should not be understood as indicating or implying relative importance.

[0028] It should be noted that, in the absence of conflict, the features in the embodiments of the present invention may be combined with each other.

[0029] In the field of modern photovoltaic technology, crystalline silicon cells are one of the main components of solar cells, and the improvement of their performance and production efficiency has always been a hot topic of research. In the traditional packaging process of crystalline silicon cells, the preparation of conductive grid lines is a key link. Conductive grid lines are not only used to collect the current generated by photogenerated carriers, but also play a key role in connecting the cell to the external circuit. At present, conventional conductive grid lines are usually applied to the surface of crystalline silicon cells through screen printing technology, which requires precise control of the distribution of materials during the printing process to ensure conductive performance and packaging stability.

[0030] Screen printing is a common method for preparing the conductive layer. It forms a continuous or disconnected conductive line by printing the conductive ink on the crystalline silicon cell through a specific screen. This technology can flexibly adjust the width, spacing and pattern shape of the conductive line to meet the needs of different battery designs. However, there are some inherent limitations of screen printing, including: Printing accuracy: Screen printing depends on the resolution of the screen and the technical level of the operator, which makes it difficult to ensure the uniformity and consistency of the conductive line, affecting the overall performance and manufacturing cost of the battery. Prefabrication of welding points: In order to ensure the conductive performance and reliability, the conductive line after screen printing often needs to prefabricate welding points at key locations (such as the intersection of the grid lines). This process increases the process complexity and manufacturing time, and also puts higher requirements on the subsequent welding process. Conductive tape and dispensing application: In order to enhance the mechanical strength of the conductive line and the reliability of the electrical connection, it is often necessary to use additional conductive tape for reinforcement, and fix the connection between the conductive tape and the cell by dispensing technology. Although this method improves the stability of the circuit, it increases the material cost and process steps, which has a certain impact on the overall production efficiency.

[0031] In summary, although screen printing technology has shown a certain degree of flexibility and adaptability in the preparation of conductive grid lines for crystalline silicon solar cells, it still faces technical challenges in printing accuracy, solder joint prefabrication, and the application of conductive tape and dispensing in practical applications. These factors jointly affect the manufacturing cost, production efficiency and quality of the final product of the solar cell. Therefore, continuous research and technological innovation are essential to optimize this process, improve the efficiency of photovoltaic cells and reduce costs.

[0032] Please refer to Figure 1-Figure 4 The present embodiment provides a method for preparing a busbar-free battery string, a busbar-free battery string and a photovoltaic module, which can effectively improve the above-mentioned technical problems, simplify the preparation process of the battery string and reduce the production cost.

[0033] The method for preparing a busbar-free battery string comprises: S1: preparing a first packaging film sheet 10 and a second packaging film sheet 20 .

[0034] Specifically, prepare ultra-thin front and back packaging films, cut the packaging films into rectangular strips according to specified sizes for later use, adjust the length of the cut rectangular films according to the width of the assembly, and adjust the width of the rectangular films according to the width of the battery cell 40 .

[0035] In this embodiment, a first encapsulating film sheet 10 and a second encapsulating film sheet 20 with a thickness of 0.5 nm-1 nm are prepared. Specifically, the thickness of the first encapsulating film sheet 10 and the second encapsulating film sheet 20 is 0.5 nm. In other embodiments, the thickness of the first encapsulating film sheet 10 and the second encapsulating film sheet 20 can also be 0.6 nm, 0.8 nm or 1 nm, etc., which is not specifically limited here.

[0036] In this embodiment, the spacing between the first encapsulation film sheet 10 and the second encapsulation film sheet 20 in the horizontal direction is 1 mm-5 mm. Specifically, the spacing between the first encapsulation film sheet 10 and the second encapsulation film sheet 20 in the horizontal direction is 1 nm. In other embodiments, the spacing between the first encapsulation film sheet 10 and the second encapsulation film sheet 20 in the horizontal direction is 2 nm, 3 nm or 5 nm, etc., which is not specifically limited here.

[0037] In this embodiment, the first packaging film sheet 10 and the second packaging film sheet 20 are prepared by using materials such as EVA, EPE, and POE.

[0038] S2: preparing conductive gate lines 30 on the surfaces of the first packaging film sheet 10 and the second packaging film sheet 20 .

[0039] Specifically, a plurality of conductive gate lines 30 are prepared on the surface of the first packaging film 10 and the second packaging film 20. The plurality of conductive gate lines 30 are sequentially spaced apart along the width direction of the first packaging film 10 and the second packaging film 20, and the spacing between two adjacent conductive gate lines 30 is 0.8nm-1nm.

[0040] In this embodiment, the spacing between two adjacent conductive gate lines 30 is 0.8 nm. Setting the spacing between two adjacent conductive gate lines 30 to 0.8 nm can effectively increase the light receiving area of ​​the cell 40 while ensuring conductivity. In other embodiments, the spacing between two adjacent conductive gate lines 30 is 0.85 nm, 0.9 nm, or 1 nm, etc., which is not specifically limited here.

[0041] Specifically, the conductive gate lines 30 are arranged along the width direction of the first packaging film sheet 10 and the second packaging film sheet 20 , and a plurality of conductive gate lines 30 are arranged in sequence and at intervals along the length direction of the first packaging film sheet 10 and the second packaging film sheet 20 .

[0042] In this embodiment, the conductive grid lines 30 are prepared on the surfaces of the first encapsulating film sheet 10 and the second encapsulating film sheet 20 by screen printing. A printing screen is made according to the designed OBB busbar-free pattern, and pure copper paste is printed on the ultra-thin film to form the conductive grid lines 30, so as to make ultra-thin conductive film sheets, namely the first encapsulating film sheet 10 and the second encapsulating film sheet 20.

[0043] In other embodiments, other pastes may be used for printing, including but not limited to silver paste, tin paste, etc., which are not specifically limited here.

[0044] It should be noted that the manufactured conductive grid lines 30 are dried and solidified at a temperature not greater than two-thirds of the melting point of the adhesive film, and the drying time is 20s-140s. Specifically, the drying time in this embodiment is 40s.

[0045] In other embodiments, the drying time of the conductive grid lines 30 may be 20 s, 60 s, 100 s or 10 4 s, etc., which is not specifically limited here.

[0046] It is also necessary to explain that please refer to Figure 2-Figure 3 In step S2, a connecting line 50 and a first connecting point 60 are respectively prepared on two opposite edges on the same side of the first packaging film 10, and the connecting line 50 and the first connecting point 60 are both connected to the conductive gate line 30; a second connecting point 70 is prepared on two opposite edges on the same side of the second packaging film 20, and both ends of the conductive gate line 30 are connected to the second connecting point 70.

[0047] Specifically, the connection line 50 is arranged along the length direction of the first packaging film 10 , and the connection line 50 is connected to the same end of all the conductive gate lines 30 at the same time, and the end of each conductive gate line 30 away from the connection line 50 is connected to the first connection point 60 .

[0048] On the second packaging film 20 , both ends of each conductive gate line 30 are connected to a second connection point 70 .

[0049] It should be noted that, in the present embodiment, the conductive gate line 30 , the connecting line 50 , the first connecting point 60 and the second connecting point 70 are all integrally formed by screen printing.

[0050] S3: preparing the battery cell 40 .

[0051] Specifically, a crystalline silicon cell 40 without a main grid is prepared.

[0052] S4: The first packaging film sheet 10 and the second packaging film sheet 20 are respectively attached to the surface of the battery cell 40 , and the conductive grid lines 30 of the first packaging film sheet 10 and the second packaging film sheet 20 are in contact with the battery cell 40 to form a battery string.

[0053] Specifically, the number of battery cells 40 is N, and the N battery cells 40 are arranged in sequence along a straight line. In this embodiment, the number of battery cells 40 is three, and the three battery cells 40 are arranged in sequence. In other embodiments, the number of battery cells 40 can be increased or decreased, which is not specifically limited here.

[0054] In step S4, a first encapsulating film sheet 10 is attached to the back of the battery cell 40 at the end position, and the conductive grid lines 30 on the first encapsulating film sheet 10 are in contact with the back of the battery cell 40; then a second encapsulating film sheet 20 is attached to the front of the battery cell 40 at the end position, and the conductive grid lines 30 on the second encapsulating film sheet 20 are in contact with the front of the battery cell 40; Next, a second encapsulating film sheet 20 is attached to the back of the battery cell 40 adjacent to the battery cell 40 at the end position, and the attached second encapsulating film sheet 20 is connected to the second encapsulating film sheet 20 on the front of the battery cell 40 at the end position; then, the second encapsulating film sheet 20 is attached to the front of the battery cell 40, and then the surface of the next battery cell 40 is attached according to the same steps; The second packaging film 20 is attached to the back of the last battery cell 40, and the second packaging film 20 is connected to the second packaging film 20 on the front of the adjacent battery cell 40, and then the first packaging film 10 is attached to the front of the last battery cell 40 to form a battery string.

[0055] Among them, when the second packaging film 20 and the battery cell 40 are attached to each other, the second connection point 70 at one end of the second packaging film 20 is exposed to the battery cell 40, the second connection point 70 at the other end of the second packaging film 20 is connected to the battery cell 40, and the second connection points 70 exposed on two adjacent battery cells 40 are connected to each other; when the first packaging film 10 and the battery cell 40 are attached to each other, the connection line 50 of the first packaging film 10 is exposed to the battery cell 40, and the first connection point 60 is connected to the battery cell 40.

[0056] It should be noted that after the multiple battery cells 40 are arranged in sequence, the second encapsulation film sheets 20 are stacked on both side surfaces of the battery cells 40 that are not located at both ends, so that the conductive grid lines 30 on the second encapsulation film sheets 20 are in contact with both side surfaces of the battery cells 40, and all the second connection points 70 on one end of the second encapsulation film sheets 20 are connected to the surface of the battery cells 40, and all the second connection points 70 on the other side of the second encapsulation film sheets 20 are all exposed to the outside of the battery cells 40. Among them, the directions of the exposed second connection points 70 on the two second encapsulation film sheets 20 located on the two side surfaces of the same battery cell 40 are opposite.

[0057] The first packaging film sheet 10 and the second packaging film sheet 20 are respectively stacked on the two side surfaces of the battery cell 40 at the end position, and the conductive grid lines 30 on the first packaging film sheet 10 and the second packaging film sheet 20 are in contact with the two side surfaces of the battery cell 40. The first connection point 60 of the first packaging film sheet 10 is connected to the surface of the battery cell 40, and the connection line 50 of the first packaging film sheet 10 is exposed to the outside of the battery cell 40, which is used to connect the connection line 50 on the battery cell 40 at the end of the adjacent battery string, so as to form a whole; the second connection point 70 at one end of the second packaging film sheet 20 is connected to the surface of the battery cell 40, and the second connection point 70 at the other end of the second packaging film sheet 20 is exposed to the outside of the battery cell 40, and the exposed second connection point 70 is connected to the second connection point 70 exposed on the adjacent battery cell 40, so that multiple battery cells 40 are connected to form a whole. Among them, the connection line 50 and the exposed second connection point 70 on the two side surfaces of the battery cell 40 at the end position are in opposite directions.

[0058] It can be understood that since the N battery cells 40 are arranged in a straight line, when connecting the N battery cells 40, the connection can be performed sequentially from right to left according to step S4, such as Figure 4 As shown; the connections can also be performed from left to right in sequence according to step S4.

[0059] S5: The first packaging film sheets 10 of adjacent battery strings are connected.

[0060] Specifically, the connection lines 50 of the first packaging film sheets 10 of two adjacent battery strings are connected.

[0061] In this embodiment, the connecting wire 50 of the first packaging film sheet 10 on the battery cell 40 at the end is exposed outside the battery cell 40, and the connecting wire 50 can contact the connecting wire 50 of the first packaging film sheet 10 on the battery cell 40 at the end of the adjacent battery string, thereby connecting to form a whole.

[0062] S6: Packaging battery strings.

[0063] The present embodiment also provides a photovoltaic module, including a busbarless battery string, the busbarless battery string including a plurality of battery cells 40, a plurality of first encapsulation glue films 10, and a plurality of second encapsulation glue films 20. The busbarless battery string preparation method can be used for preparation. The conductive grid line 30 can be prepared on the first encapsulation glue film 10 and the second encapsulation glue film 20, without welding to form a busbarless battery string, without conductive tape, and without using a string welding machine to form the battery into a battery string by using a conductive tape, and without using a glue dispenser, thereby reducing material costs and equipment costs and simplifying process steps.

[0064] In summary, the embodiments of the present invention provide a method for preparing a busbar-free battery string, a busbar-free battery string and a photovoltaic module. The method for preparing a busbar-free battery string includes preparing a first packaging film sheet 10 and a second packaging film sheet 20; preparing a conductive grid line 30 on the surface of the first packaging film sheet 10 and the second packaging film sheet 20; preparing a battery cell 40; laminating the first packaging film sheet 10 and the second packaging film sheet 20 to the surface of the battery cell 40 respectively, and the conductive grid lines 30 of the first packaging film sheet 10 and the second packaging film sheet 20 are in contact with the battery cell 40 to form a battery string; the first packaging film sheets 10 of adjacent battery strings are connected. When in use, the conductive grid line 30 is prepared on the first packaging film sheet 10 and the second packaging film sheet 20, and then the first packaging film sheet 10 and the second packaging film sheet 20 and the battery cell 40 are assembled to form a battery string. Compared with the preparation method in the prior art, the main grid-free battery string preparation method prepares the conductive grid line 30 on the first packaging film sheet 10 and the second packaging film sheet 20, and no longer needs to prefabricate welding points on the battery cell 40. The battery string can be made without welding, which reduces the process difficulty and saves production costs.

[0065] The above are only specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims

1. A method for preparing a busbar-free battery string, characterized in that: include: Preparing a first packaging adhesive film sheet (10) and a second packaging adhesive film sheet (20); Conductive gate lines (30) are prepared on the surfaces of the first packaging adhesive film sheet (10) and the second packaging adhesive film sheet (20); Preparing a battery cell (40); The first encapsulating adhesive film sheet (10) and the second encapsulating adhesive film sheet (20) are respectively bonded to the surface of the battery cell (40), and the conductive grid lines (30) of the first encapsulating adhesive film sheet (10) and the second encapsulating adhesive film sheet (20) are both in contact with the battery cell (40), so as to form a battery string; The first packaging adhesive films (10) of adjacent battery strings are connected.

2. The method for preparing a busbar-free battery string according to claim 1, characterized in that: The number of the battery cells (40) is N, and the N battery cells (40) are arranged in sequence at intervals along a straight line. The steps of laminating the first encapsulating adhesive film sheet (10) and the second encapsulating adhesive film sheet (20) to the surfaces of the battery cells (40) respectively, and making the conductive grid lines (30) of the first encapsulating adhesive film sheet (10) and the second encapsulating adhesive film sheet (20) contact the battery cells (40) to form a battery string include: The first packaging adhesive film (10) is attached to the back side of the battery cell (40) located at the end position, and the conductive grid lines (30) on the first packaging adhesive film (10) are in contact with the back side of the battery cell (40); then, the second packaging adhesive film (20) is attached to the front side of the battery cell (40) located at the end position, and the conductive grid lines (30) on the second packaging adhesive film (20) are in contact with the front side of the battery cell (40); Then, the second encapsulating adhesive film (20) is affixed to the back of the battery cell (40) adjacent to the battery cell (40) at the end position, and the affixed second encapsulating adhesive film (20) is connected to the second encapsulating adhesive film (20) at the front of the battery cell at the end position; then, the second encapsulating adhesive film (20) is affixed to the front of the battery cell (40), and then the surface of the next battery cell (40) is affixed according to the same steps; The second encapsulating adhesive film (20) is adhered to the back side of the last battery cell (40), and the second encapsulating adhesive film (20) is connected to the second encapsulating adhesive film (20) on the front side of an adjacent battery cell (40), and then the first encapsulating adhesive film (10) is adhered to the front side of the last battery cell (40), thereby forming a battery string.

3. The method for preparing a busbar-free battery string according to claim 2, characterized in that: The step of preparing the conductive gate lines (30) on the surfaces of the first packaging adhesive film sheet (10) and the second packaging adhesive film sheet (20) comprises: A connecting line (50) and a first connecting point (60) are respectively prepared on two opposite edges on the same side of the first packaging film (10), and the connecting line (50) and the first connecting point (60) are both connected to the conductive gate line (30); Second connection points (70) are prepared on two opposite edges on the same side of the second packaging film (20), and both ends of the conductive grid line (30) are connected to the second connection points (70).

4. The method for preparing a busbar-free battery string according to claim 3, characterized in that: The step of laminating the first encapsulating adhesive film sheet (10) and the second encapsulating adhesive film sheet (20) to the surface of the battery cell (40) respectively, wherein the conductive grid lines (30) of the first encapsulating adhesive film sheet (10) and the second encapsulating adhesive film sheet (20) are in contact with the battery cell (40) to form a battery string further comprises: When the second packaging film (20) and the battery cell (40) are attached to each other, the second connection point (70) at one end of the second packaging film (20) is exposed on the battery cell (40), the second connection point (70) at the other end of the second packaging film (20) is connected to the battery cell (40), and the exposed second connection points (70) on two adjacent battery cells (40) are connected to each other; When the first packaging adhesive film (10) and the battery cell (40) are attached to each other, the connection line (50) of the first packaging adhesive film (10) is exposed from the battery cell (40), and the first connection point (60) is connected to the battery cell (40).

5. The method for preparing a busbar-free battery string according to claim 3, characterized in that: The step of connecting the first packaging film sheets (10) of adjacent battery strings comprises: The connecting lines (50) of the first packaging film sheets (10) of two adjacent battery strings are connected.

6. The method for preparing a busbar-free battery string according to claim 1, characterized in that: The steps of preparing the first packaging adhesive film sheet (10) and the second packaging adhesive film sheet (20) include: A first packaging adhesive film sheet (10) and a second packaging adhesive film sheet (20) having a thickness of 0.5 nm-1 nm are prepared.

7. The method for preparing a busbar-free battery string according to claim 6, characterized in that: The step of preparing the first packaging adhesive film sheet (10) and the second packaging adhesive film sheet (20) further comprises: The distance between the first packaging adhesive film sheet (10) and the second packaging adhesive film sheet (20) in the horizontal direction is 1 mm to 5 mm.

8. The method for preparing a busbar-free battery string according to claim 1, characterized in that: The step of preparing the first packaging adhesive film sheet (10) and the second packaging adhesive film sheet (20) further comprises: The first packaging adhesive film sheet (10) and the second packaging adhesive film sheet (20) are prepared using EVA, EPE, and POE materials.

9. The method for preparing a busbar-free battery string according to claim 1, characterized in that: The step of preparing conductive gate lines (30) on the surfaces of the first packaging adhesive film sheet (10) and the second packaging adhesive film sheet (20) comprises: A plurality of conductive gate lines (30) are prepared on the surfaces of the first encapsulating adhesive film sheet (10) and the second encapsulating adhesive film sheet (20), and the plurality of conductive gate lines (30) are sequentially arranged at intervals along the width direction of the first encapsulating adhesive film sheet (10) and the second encapsulating adhesive film sheet (20), and the spacing between two adjacent conductive gate lines (30) is 0.8 nm-1 nm.

10. The method for preparing a busbar-free battery string according to claim 9, characterized in that: The step of preparing conductive gate lines (30) on the surfaces of the first packaging adhesive film (10) and the second packaging adhesive film (20) further comprises: The manufactured conductive grid lines (30) are dried and solidified, the drying temperature is no greater than two-thirds of the melting point of the adhesive film, and the drying time is 20s-140s.

11. A busbar-less battery string, characterized in that: The battery is prepared by the method for preparing a busbar-free battery string according to any one of claims 1 to 10.

12. A photovoltaic module, characterized in that: Including the busbar-free battery string as described in claim 11.

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