Composite electrode sheet preform structure, electrode sheet pouching method, and electrode sheet pouching system

Abstract

A composite electrode sheet preform structure, an electrode sheet pouching method, and an electrode sheet pouching system. The composite electrode sheet preform structure comprises: an electrode sheet strip comprising, in the length direction of the composite electrode sheet preform structure, a plurality of connecting portions sequentially arranged at intervals and a main body portion connected between every two adjacent connecting portions; and separator strips provided with a plurality of openings sequentially arranged at intervals in the length direction of the composite electrode sheet preform structure, the plurality of openings being arranged corresponding to the plurality of connecting portions, and the separator strips being respectively arranged on two opposite sides of the electrode sheet strip in the thickness direction of the composite electrode sheet preform structure. The problems in the prior art of complex operations being required in an electrode sheet pouching process, high precision requirements for the manufacturing process, and misalignment being prone to occurring are solved.

Description

Composite electrode prefabricated structure, electrode bag making method and electrode bag making system

[0001] This application claims priority to the patent application submitted to the State Intellectual Property Office of China on November 22, 2023, with application number 2023115686215 and invention name "Composite electrode prefabricated structure, electrode bag making method and electrode bag making system". Technical Field

[0002] The present application relates to the field of battery technology, and in particular to a composite electrode prefabricated structure, an electrode bag making method, and an electrode bag making system. Background Art

[0003] With the rapid development of the new energy vehicle industry, lithium-ion batteries, the powerhouses of electric vehicles, have become a hot topic of research. Due to their high voltage, high specific energy, excellent cycle performance, and clean, pollution-free design, lithium-ion batteries are widely used in electric vehicles. The production speed of lithium-ion batteries is a key indicator during battery production.

[0004] The manufacturing method of lithium-ion batteries includes lamination and winding. Lamination methods include Z-stack and electrode bag lamination. However, in the existing electrode bag lamination methods, the electrode bag making process usually requires first cutting the electrode strip into individual electrode pieces, then positioning the electrode pieces one by one on the diaphragm strip at a certain distance, and then bagging and cutting. The process of positioning the electrode pieces one by one is cumbersome, requires high precision, and is prone to misalignment.

[0005] Summary of the Invention

[0006] The main purpose of this application is to provide a composite electrode prefabricated structure, an electrode bag making method and an electrode bag making system to solve the problems in the prior art that the bag making process is cumbersome, has high precision requirements for the bag making process, and is prone to misalignment during the bag making process.

[0007] In order to achieve the above-mentioned purpose, according to one aspect of the present application, a composite pole piece prefabricated structure is provided, comprising: a pole piece strip, along the length direction of the composite pole piece prefabricated structure, the pole piece strip comprises a plurality of connecting portions arranged in sequence and spaced apart and a main body portion connected between two adjacent connecting portions; a diaphragm strip, along the length direction of the composite pole piece prefabricated structure, the diaphragm strip is provided with a plurality of notches in sequence and spaced apart, and the plurality of notches are arranged corresponding to the plurality of connecting portions; along the thickness direction of the composite pole piece prefabricated structure, diaphragm strips are respectively provided on opposite sides of the pole piece strip.

[0008] In one achievable manner, along the width direction of the composite electrode prefabricated structure, two diaphragm strips are connected at both sides and a sealing portion is formed at the connection on each side, and a channel for electrolyte to pass through is provided on the sealing portion.

[0009] In one achievable manner, a plurality of channels are provided on the line sealing portion, and the plurality of channels of the line sealing portion are sequentially spaced apart along the length direction.

[0010] In one practicable manner, the connecting portion is used to form a tab.

[0011] In one achievable manner, the pole piece strip further includes a pole ear portion connected to the main body portion, and along the width direction of the composite pole piece prefabricated structure, the pole ear portion is located on one side of the main body portion.

[0012] In one achievable manner, along the width direction of the composite pole piece prefabricated structure, the width of the connecting portion is less than or equal to the width of the notch.

[0013] According to another aspect of the present application, a method for making a pole piece bag is provided, comprising: step S1, a pole piece strip pretreatment step: cutting the pole piece strip to form a plurality of connection parts and a main body connected between two adjacent connection parts in the length direction of the composite pole piece prefabricated structure; step S2, a diaphragm strip pretreatment step: cutting a plurality of notches arranged in sequence along the length direction of the composite pole piece prefabricated structure on the diaphragm strip, so that the part of the diaphragm strip between two adjacent notches forms a bag body; step S3, an alignment step: in the thickness direction of the composite pole piece prefabricated structure, respectively arranging two diaphragm strips on both sides of the pole piece strip, and arranging the plurality of notches of each diaphragm strip corresponding to the plurality of connection parts of the pole piece strip.

[0014] In one achievable method, step S4 is further included, a bag sealing step: in the width direction of the composite pole piece prefabricated structure, the two diaphragm strips are at least partially connected on both sides of the pole piece strip, and the portion of the diaphragm strip located outside the gap is removed.

[0015] In one achievable manner, in step S4 , a sealing portion is formed at the connection between the two diaphragm strips, and a channel for allowing electrolyte to pass through is provided on the sealing portion.

[0016] In one feasible embodiment, when the connecting portion is used to form a pole ear, after step S4, the pole piece bag making method further includes step S5, a splitting step: cutting at one of the two ends of the connecting portion along the length direction of the composite pole piece prefabricated structure to split out the pole piece bag; or, when at least one side of the main body portion is connected to the pole ear portion along the width direction of the composite pole piece prefabricated structure, after step S4, the pole piece bag making method further includes step S6, a splitting step: cutting at both ends of the connecting portion along the length direction of the composite pole piece prefabricated structure to split out the pole piece bag.

[0017] In one achievable manner, after step S4, the electrode bag making method further includes: a step of connecting two diaphragm strips on both sides of the main body in the length direction of the composite electrode prefabricated structure.

[0018] In one practicable manner, when a pole ear portion is provided on one side of the main body portion along the width direction of the composite pole piece prefabricated structure, in step S4 , the connection position avoids the pole ear portion.

[0019] According to another aspect of the present application, a pole piece bag making system is provided, comprising: pole piece cutting equipment for completing the pole piece strip pretreatment step; diaphragm cutting equipment for completing the diaphragm strip pretreatment step; and alignment equipment for completing the alignment step.

[0020] The technical solution of the present application is different from the prior art in that the electrode pieces are cut into electrode pieces one by one, and the electrode pieces are positioned one by one on the diaphragm tape at a certain interval and then sealed and cut, resulting in a complicated bag-making process, high requirements on the precision of the manufacturing process, and easy misalignment. In this embodiment, the electrode tape and the diaphragm tape are pre-processed, multiple connecting parts are provided on the electrode tape, and multiple notches are provided at corresponding positions of the diaphragm tape. When the diaphragm tapes are respectively provided on opposite sides in the thickness direction of the electrode tape, the main body and the bag body between the two adjacent notches can be aligned through the corresponding connecting parts and notches. In this way, it is convenient to pre-seal the pre-processed electrode tape with the pre-processed diaphragm tape and then cut it to form a electrode bag, thereby simplifying the production process, reducing the requirements on the precision of the manufacturing process, avoiding the problem of easy misalignment, and thus helping to improve production efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The drawings that constitute part of this application are used to provide a further understanding of this application. The illustrative embodiments of this application and their descriptions are used to explain this application and do not constitute an improper limitation on this application. In the drawings:

[0022] FIG1 shows a schematic structural diagram of a pole piece strip and a diaphragm strip in one embodiment of a composite pole piece prefabricated structure of the present application;

[0023] 2 to 6 are schematic structural diagrams showing a process of making a bag using the electrode strip and diaphragm strip of FIG. 1 ;

[0024] FIG7 shows a schematic structural diagram of a pole piece bag made of the pole piece strip and diaphragm strip of FIG1 ;

[0025] FIG8 shows a schematic structural diagram of a pole piece strip and a diaphragm strip of another embodiment of a composite pole piece prefabricated structure of the present application;

[0026] 9 to 13 are schematic structural diagrams showing a process of bagging using the electrode strip and diaphragm strip of FIG. 8 ;

[0027] FIG14 shows a schematic structural diagram of a pole piece bag made of the pole piece strip and diaphragm strip of FIG8 ;

[0028] FIG15 is a schematic flow chart showing an embodiment of a method for making a bag of an electrode according to the present application;

[0029] FIG16 shows a schematic structural diagram of an embodiment of a bag making system of the present application;

[0030] FIG17 shows a front view of the bag making system of FIG16; and

[0031] FIG18 shows a schematic structural diagram of the stacking process of the battery cell of the present application.

[0032] Among them, the above-mentioned drawings include the following figure marks: 1. Pole piece strip; 11. Connecting part; 12. Main body; 13. Pole ear; 2. Diaphragm strip; 21. Notch; 22. Bag body; 9. Sealing part; 91. Channel; 3. Pole piece bag; 4. Pole piece roll; 5. Diaphragm roll; 6. Bag sealing equipment; 61. First bag sealing device; 62. Second bag sealing device; 7. Cutting equipment; 8. Positive electrode. DETAILED DESCRIPTION

[0033] It should be noted that, in the absence of conflict, the embodiments and features of the embodiments in this application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0034] As shown in Figures 1 to 17, the present application provides a composite electrode prefabricated structure, including: a electrode strip 1, along the length direction L of the composite electrode prefabricated structure, the electrode strip 1 includes a plurality of connecting portions 11 arranged in sequence and spaced apart and a main body 12 connected between two adjacent connecting portions 11; a diaphragm strip 2, along the length direction L of the composite electrode prefabricated structure, a plurality of notches 21 are arranged on the diaphragm strip 2 in sequence and spaced apart, and the plurality of notches 21 are arranged corresponding to the plurality of connecting portions 11; along the thickness direction of the composite electrode prefabricated structure, diaphragm strips 2 are respectively provided on opposite sides of the electrode strip 1.

[0035] In the above technical solution, compared with the prior art in which the electrode sheets are cut into electrode units one by one, and the electrode units are positioned one by one on the diaphragm tape at a certain interval and then sealed and cut, resulting in a complicated bag making process, high precision requirements for the manufacturing process, and easy misalignment problems, in this embodiment, by pre-treating the electrode tape 1 and the diaphragm tape 2, a plurality of connecting parts 11 are provided on the electrode tape 1, and a plurality of notches 21 are provided at corresponding positions of the diaphragm tape 2. When the diaphragm tapes 2 are respectively provided on opposite sides in the thickness direction of the electrode tape 1, the main body 12 and the bag body 22 between the two adjacent notches 21 can be aligned through the corresponding connecting parts 11 and the notches 21. In this way, it is convenient to pre-seal the pre-treated electrode tape 1 with the pre-treated diaphragm tape 2 and then cut to form the electrode bag 3, thereby simplifying the production process, reducing the precision requirements for the manufacturing process, avoiding the problem of easy misalignment, and thus helping to improve production efficiency.

[0036] It should be noted that, as shown in Figures 1 to 3, in the embodiments of the present application, pre-sealing refers to the process of connecting two diaphragm strips 2 on both sides along the width direction w of the composite electrode prefabricated structure and forming a sealing portion 9 at the connection on each side.

[0037] It should be noted that, as shown in FIG. 1 and FIG. 2 , in the embodiment of the present application, in the width direction w, the width w11 of the connecting portion 11 is smaller than the width of the main body portion 12 .

[0038] As shown in Figures 1 to 3, in an embodiment of the present application, along the width direction w of the composite electrode prefabricated structure, two diaphragm strips 2 are connected on both sides and a sealing portion 9 is formed at the connection on each side, and a channel 91 for electrolyte to pass through is provided on the sealing portion 9.

[0039] In the above technical solution, in the width direction w, by providing sealing parts 9 on both sides of the two diaphragm strips 2, the two diaphragm strips 2 located on both sides of the electrode strip 1 along the thickness direction of the composite electrode prefabricated structure can be connected, thereby preventing the main body 12 in the two diaphragm strips 2 from moving relative to the diaphragm strip 2 in the width direction w and detaching from the diaphragm strip 2, that is, preventing the electrode strip 1 from moving relative to the diaphragm strip 2 in the width direction w.

[0040] Furthermore, by providing a channel 91 on the sealing portion 9, electrolyte can pass through, thereby accelerating the speed of electrolyte infiltration.

[0041] As shown in FIG3 , in the embodiment of the present application, a plurality of channels 91 are provided on the line sealing portion 9 , and the plurality of channels 91 of the line sealing portion 9 are sequentially spaced apart along the length direction L.

[0042] Through the above arrangement, the electrolyte infiltration speed can be further improved.

[0043] As an embodiment, in the examples of the present application, in the length direction L of the composite electrode prefabricated structure, the total length of the multiple channels 91 provided on the sealing portion 9 accounts for 1 / 3 to 1 / 2 of the total length of the sealing portion 9. This avoids the total length of the multiple channels 91 provided on the sealing portion 9 accounting for too large a proportion of the total length of the sealing portion 9, thereby preventing poor heat-sealed connection stability, and avoids the total length of the multiple channels 91 provided on the sealing portion 9 accounting for too small a proportion of the total length of the sealing portion 9, thereby affecting the infiltration efficiency.

[0044] As shown in Figures 1 to 7, in the embodiment of the present application, the connecting portion 11 is used to form a tab. The simple structure simplifies the production process and helps reduce the amount of electrode strip 1 that needs to be cut during the manufacturing process, thereby saving costs.

[0045] As an implementation manner, in the embodiment of the present application, the electrode strip 1 is cut to form a main body portion 12 and a connecting portion 11 , and the connecting portion 11 forms a pole lug.

[0046] As shown in Figures 8 to 14, in another embodiment, the pole piece strip 1 further includes a pole ear portion 13 connected to the main body portion 12. Along the width direction w of the composite pole piece prefabricated structure, the pole ear portion 13 is located on one side of the main body portion 12. The above structure is simple, thereby simplifying the production process.

[0047] As an implementation manner, in the embodiment of the present application, the main body portion 12 , the connecting portion 11 and the pole lug portion 13 are formed by cutting the pole piece strip 1 .

[0048] As an implementation mode, in the embodiment of the present application, along the width direction w, the pole ear portion 13 protrudes from the diaphragm strip 2. In this way, the welding connection of the pole ear portion 13 is facilitated when the battery cell is stacked.

[0049] As an implementation manner, in the embodiment of the present application, there are multiple pole ear portions 13 , and the multiple pole ear portions 13 are arranged corresponding to the multiple main body portions 12 .

[0050] Alternatively, the tab portion 13 is connected to the end portion of the main body portion 12 along the width direction w.

[0051] It should be noted that, in the embodiment of the present application, along the width direction w, the pole lug portion 13 extends to the outside of the diaphragm strip 2 , and the sealing line portion 9 does not cover the pole lug portion 13 .

[0052] As shown in FIG2 , in the embodiment of the present application, along the width direction w of the composite electrode prefabricated structure, the width w11 of the connecting portion 11 is less than or equal to the width w21 of the notch 21. This prevents damage to the connecting portion 11 when removing the portion of the diaphragm strip 2 outside the notch 21 along the width direction w.

[0053] As an implementation manner, in the embodiment of the present application, there is a gap between the edge of the connecting portion 11 and the edge of the notch 21 along the width direction w.

[0054] As shown in Figures 1 to 15, the present application provides a method for making electrode bags, including: step S1, a electrode strip pretreatment step: cutting the electrode strip 1 to form a plurality of connecting portions 11 and a main body portion 12 connected between two adjacent connecting portions 11 in the length direction L of the composite electrode prefabricated structure; step S2, a diaphragm strip pretreatment step: cutting a plurality of notches 21 on the diaphragm strip 2 that are arranged in sequence along the length direction L of the composite electrode prefabricated structure, so that the part of the diaphragm strip 2 between two adjacent notches 21 forms a bag body 22; step S3, an alignment step: in the thickness direction of the composite electrode prefabricated structure, respectively arrange the two diaphragm strips 2 on both sides of the electrode strip 1, and arrange the multiple notches 21 of each diaphragm strip 2 corresponding to the multiple connecting portions 11 of the electrode strip 1.

[0055] In the above technical solution, compared with the prior art in which the electrode sheets are cut into electrode units one by one, and the electrode units are positioned one by one on the diaphragm tape at a certain interval and then sealed and cut, resulting in a complicated bag making process, high precision requirements for the manufacturing process, and easy misalignment problems, in this embodiment, by pre-treating the electrode tape 1 and the diaphragm tape 2, a plurality of connecting parts 11 are provided on the electrode tape 1, and a plurality of notches 21 are provided at corresponding positions of the diaphragm tape 2. When the diaphragm tapes 2 are respectively provided on opposite sides in the thickness direction of the electrode tape 1, the main body 12 and the bag body 22 between the two adjacent notches 21 can be aligned through the corresponding connecting parts 11 and the notches 21. In this way, it is convenient to pre-seal the pre-treated electrode tape 1 with the pre-treated diaphragm tape 2 and then cut to form the electrode bag 3, thereby simplifying the production process, reducing the precision requirements for the manufacturing process, avoiding the problem of easy misalignment, and thus helping to improve production efficiency.

[0056] It should be noted that in the embodiments of the present application, there is no order for step S1 and step S2. Step S1 can be performed first, and then step S2; or step S2 can be performed first, and then step S1; or they can be performed in parallel.

[0057] As shown in Figures 1 to 5, in the embodiment of the present application, after step S3, the electrode bag making method further includes: step S4, a bag sealing step: in the width direction w of the composite electrode prefabricated structure, two diaphragm strips 2 are at least partially connected on both sides of the electrode strip 1, and the portion of the diaphragm strip 2 located outside the notch 21 (such as the area covered by the oblique lines in Figure 4) is removed. In this way, the bag body portions 22 adjacent and connected along the length direction L can be separated, and the main body portion 12 can be sealed between the two bag body portions 22 located on both sides of the main body portion 12 along the thickness direction.

[0058] As an implementation manner, in the embodiment of the present application, the method of connecting the two diaphragm strips 2 in step S4 includes but is not limited to hot melt connection, ultrasonic connection or high frequency connection.

[0059] As an implementation manner, in an embodiment of the present application, in step S4, a portion of the diaphragm tape 2 located outside the notch 21 along the width direction w is removed by a hot melt knife.

[0060] As shown in Figures 1 to 3, in an embodiment of the present application, in step S4, along the width direction w of the composite electrode prefabricated structure, the two diaphragm strips 2 form sealing portions 9 at the connections on both sides, and each connection is intermittently connected to form a channel 91 for the electrolyte to pass through.

[0061] In the above technical solution, by providing a channel 91 on the sealing portion 9, electrolyte can pass through, thereby accelerating the speed of electrolyte infiltration.

[0062] As an implementation mode, in an embodiment of the present application, in the width direction w, two diaphragm belts 2 are connected at both ends by a gear hobbing head, and a channel 91 exists in the sealing portion 9 formed by the gear hobbing head.

[0063] As shown in Figures 5 to 7, in the embodiment of the present application, when the connecting portion 11 is used to form a pole lug, after step S4, the pole piece bag making method further includes step S5, a segmentation step: cutting along the length direction L of the composite pole piece prefabricated structure at one of the two ends of the connecting portion 11 to separate the pole piece bag 3. In this way, less foil material can be wasted on the pole piece strip 1 due to being cut off, so as to improve the material utilization rate of the pole piece strip 1 and achieve the purpose of fully utilizing the material of the pole piece strip 1. As an embodiment, in the embodiment of the present application, in the length direction L, the end of the connecting portion 11 is cut by laser.

[0064] As an implementation manner, in an embodiment of the present application, the connecting portion 11 is a tab, and in step S4 , only one end of the connecting portion 11 is cut off in the length direction L.

[0065] As shown in Figures 8 to 14, in another embodiment, when the main body 12 is connected to the pole ear 13 on at least one side along the width direction w of the composite pole piece prefabricated structure, after step S4, the pole piece bag making method further includes step S6, a segmentation step: along the length direction L of the composite pole piece prefabricated structure, both ends of the connecting portion 11 are cut off to separate the pole piece bags 3. The above structure is simple and easy to process.

[0066] As an implementation manner, in the embodiment of the present application, the end portion of the connecting portion 11 in the length direction L is cut by laser.

[0067] As shown in Figures 7 and 14 , in the embodiment of the present application, while the portion of the diaphragm strip 2 outside the notch 21 along the width direction w is being cut away by a hot melt knife in step S4, the two bag portions 22 located on either side of the main body 12 in the thickness direction are connected at the hot melt location. This allows the connection to be completed simultaneously with the cutting, thereby simplifying the production process.

[0068] In the above technical solution, by connecting the two bag bodies 22 located on both sides of the main body 12 in the thickness direction at the hot melt point, the main body 12 can be prevented from moving relative to the bag body 22 in the length direction L and separating from the corresponding bag body 22.

[0069] As shown in FIG10 and FIG14 , in another embodiment, when a pole ear portion 13 is provided on one side of the main body portion 12 along the width direction w of the composite pole piece prefabricated structure, in step S4 , the connection position avoids the pole ear portion 13 .

[0070] In the above technical solution, the position where the diaphragm strip 2 is connected avoids the pole ear portion 13 , thereby preventing the pole ear portion 13 from being damaged.

[0071] The present application provides a system for making electrode bags, including: an electrode cutting device (not shown) for completing the electrode tape pretreatment step; a diaphragm cutting device (not shown) for completing the diaphragm tape pretreatment step; and an alignment device (not shown) for completing the alignment step. Under this system, the unrolled electrode tape 1 and the diaphragm tape 2 that have not been pretreated are directly subjected to the subsequent alignment step after pretreatment. By pretreating the electrode tape 1 and the diaphragm tape 2, a plurality of connecting portions 11 are provided on the electrode tape 1, and a plurality of notches 21 are correspondingly provided on the diaphragm tape 2. When the diaphragm tapes 2 are respectively provided on opposite sides of the thickness direction of the electrode tape 1, the main body 12 and the bag body 22 between the two adjacent notches 21 can be aligned through the corresponding connecting portions 11 and the notches 21.

[0072] Alternatively, as another embodiment, as shown in Figures 16 and 17, the present application provides a pole piece bag making system, comprising: a pole piece roll 4 that has been pre-processed by a pole piece cutting device, for unwinding the pole piece tape 1 that has been pre-processed; a diaphragm roll 5 that has been pre-processed by a diaphragm cutting device, for unwinding the diaphragm tape 2 that has been pre-processed; and an alignment device (not shown) for aligning the pole piece tape 1 unwound from the pole piece roll 4 and the two diaphragm tapes 2 unwound from the diaphragm roll 5. Under this system, the equipment for pre-processing the pole piece tape 1 and the diaphragm tape 2 can be separated from other equipment, and the pole piece tape pre-processing step and the diaphragm tape pre-processing step can be completed in advance and then rewound for use.

[0073] As an embodiment, the alignment device may include a visual inspection device of the prior art, and / or the alignment device may include a clamping and positioning device of the prior art.

[0074] As an embodiment, as shown in Figures 16 and 17, the system also includes a bag sealing device 6, which is arranged downstream of the positioning device. The bag sealing device 6 is used to connect the two ends of the two diaphragm strips 2 in the width direction w of the composite pole piece prefabricated structure in the bag sealing step, and to remove the portion of the diaphragm strips 2 located outside the notch 21 in the width direction w of the composite pole piece prefabricated structure.

[0075] As an embodiment, as shown in FIG. 16 and FIG. 17 , the system further includes a cutting device 7 , which is disposed downstream of the bag sealing device 6 and is used to cut off the connecting portion 11 on the electrode roll 4 .

[0076] In the above technical solution, as shown in Figures 1 to 17, the electrode tape 1 and the diaphragm tape 2 are first pre-processed, that is, a plurality of connecting parts 11 and a main body 12 connected between adjacent connecting parts 11 are sequentially arranged on the electrode tape 1, and a plurality of notches 21 and a bag body 22 between two adjacent notches 21 are sequentially arranged on the diaphragm tape 2. Then, the main body 12 on the electrode tape 1 and the bag body 22 on the diaphragm tape 2 are aligned; pre-sealing is performed by the bag sealing device 6, and finally cutting is performed by the cutting device 7 to form the electrode bag 3. In this way, the production process can be simplified, the precision requirements for the manufacturing process can be reduced, the problem of easy dislocation can be avoided, and production efficiency can be improved.

[0077] As an embodiment, in the present application, the bag sealing device 6 includes a first bag sealing device 61 and a second bag sealing device 62, with the first bag sealing device 61 located upstream of the second bag sealing device 62. Thus, the first bag sealing device 61 can connect the two membrane strips 2 to form the sealing portion 9 and the channel 91; the second bag sealing device 62 can remove the portion of the membrane strip 2 located outside the notch 21 along the width direction w and connect the two membrane strips 2 at this location.

[0078] As an implementation mode, in the embodiment of the present application, the first bag sealing device 61 is a gear hobbing head, which connects the two diaphragm belts 2, and the sealing line portion 9 formed by the gear hobbing head has a channel 91.

[0079] Furthermore, by providing a channel 91 on the sealing portion 9, electrolyte can pass through, thereby accelerating the speed of electrolyte infiltration.

[0080] As an implementation manner, in the embodiment of the present application, the connection method of the first bag sealing device 61 connecting the two diaphragm belts 2 includes but is not limited to hot melt connection, ultrasonic connection or high frequency connection.

[0081] As an implementation manner, in the embodiment of the present application, the second bag sealing device 62 is a hot melt knife.

[0082] As an implementation manner, in the embodiment of the present application, the segmentation device 7 is a laser cutting device.

[0083] As shown in Figures 1 and 18, an embodiment of the present application provides a battery cell comprising the aforementioned electrode bag 3 and positive electrode sheet 8. There are multiple electrode bags 3 and multiple positive electrode sheets 8. A positive electrode sheet 8 is provided between two adjacent electrode bags 3, and the electrode strip 1 used to form the electrode bags 3 is a negative electrode strip.

[0084] From the above description, it can be seen that the above-mentioned embodiments of the present application achieve the following technical effects: compared with the prior art in which the electrode pieces are cut into electrode pieces one by one, and the electrode pieces are positioned one by one on the diaphragm tape at a certain interval and then sealed and cut, resulting in a complicated bag-making process, high requirements on the precision of the manufacturing process, and easy misalignment problems, in this embodiment, by pre-treating the electrode tape and the diaphragm tape, a plurality of connecting parts are provided on the electrode tape, and a plurality of notches are provided at corresponding positions of the diaphragm tape. When the diaphragm tapes are respectively provided on opposite sides in the thickness direction of the electrode tape, the main body and the bag body between the two adjacent notches can be aligned through the corresponding connecting parts and notches. In this way, it is convenient to pre-seal the pre-treated electrode tape with the pre-treated diaphragm tape and then cut to form an electrode bag, thereby simplifying the production process, reducing the requirements on the precision of the manufacturing process, avoiding the problem of easy misalignment, and thus helping to improve production efficiency.

[0085] The foregoing is merely an embodiment of the present application and is not intended to limit the present application. Various modifications and variations are possible for those skilled in the art. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present application shall be included within the scope of protection of the present application.

Claims

1. A prefabricated structure of a composite electrode sheet, characterized in that, it includes: An electrode sheet strip (1), along the length direction (L) of the prefabricated structure of the composite electrode sheet, the electrode sheet strip (1) includes a plurality of connecting parts (11) arranged at intervals in sequence and a main body part (12) connected between two adjacent connecting parts (11); A separator strip (2), along the length direction (L) of the prefabricated structure of the composite electrode sheet, a plurality of notches (21) are arranged at intervals in sequence on the separator strip (2), and the plurality of notches (21) are arranged corresponding to the plurality of connecting parts (11); Along the thickness direction of the prefabricated structure of the composite electrode sheet, the separator strips (2) are respectively arranged on the opposite sides of the electrode sheet strip (1).

2. The prefabricated structure of the composite electrode sheet according to claim 1, characterized in that, Along the width direction (W) of the prefabricated structure of the composite electrode sheet, the two separator strips (2) are connected on both sides and a sealing line part (9) is formed at each connection on each side, and a channel (91) for the electrolyte to pass through is provided on the sealing line part (9).

3. The prefabricated structure of the composite electrode sheet according to claim 2, characterized in that, A plurality of the channels (91) are provided on the sealing line part (9), and the plurality of channels (91) on the sealing line part (9) are arranged at intervals in sequence along the length direction (L).

4. The prefabricated structure of the composite electrode sheet according to any one of claims 1 to 3, characterized in that, The connecting part (11) is used to form a tab.

5. The prefabricated structure of the composite electrode sheet according to any one of claims 1 to 3, characterized in that, The electrode sheet strip (1) further includes an electrode tab part (13) connected to the main body part (12), and along the width direction (W) of the prefabricated structure of the composite electrode sheet, the electrode tab part (13) is located on one side of the main body part (12).

6. The prefabricated structure of the composite electrode sheet according to any one of claims 1 to 3, characterized in that, Along the width direction (W) of the prefabricated structure of the composite electrode sheet, the width (W11) of the connecting part (11) is less than or equal to the width (W21) of the notch (21).

7. A method for manufacturing an electrode sheet bag, characterized in that, The prefabricated structure of the composite electrode sheet according to any one of claims 1 to 6 is made by the method for manufacturing an electrode sheet bag, and the method for manufacturing an electrode sheet bag includes: Step S1, an electrode sheet strip pretreatment step: cutting the electrode sheet strip (1) to form a plurality of connecting parts (11) and a main body part (12) connected between two adjacent connecting parts (11) in the length direction (L) of the prefabricated structure of the composite electrode sheet; Step S2, a separator strip pretreatment step: cutting a plurality of notches (21) arranged at intervals in sequence along the length direction (L) on the separator strip (2), so that a part of the separator strip (2) between two adjacent notches (21) forms a bag body part (22); Step S3, alignment step: In the thickness direction of the composite electrode sheet prefabricated structure, the two separator tapes (2) are respectively arranged on both sides of the electrode sheet tape (1), and a plurality of the notches (21) of each separator tape (2) are correspondingly arranged with a plurality of the connecting parts (11) of the electrode sheet tape (1).

8. The method for manufacturing an electrode sheet bag according to claim 7, wherein, after the step S3, the method for manufacturing an electrode sheet bag further includes: Step S4, bag sealing step: In the width direction (W) of the composite electrode sheet prefabricated structure, the two separator tapes (2) are connected on both sides of the electrode sheet tape (1), and the parts of the separator tapes (2) located outside the notches (21) are removed.

9. The method for manufacturing an electrode sheet bag according to claim 8, wherein, in the step S4, a sealing line part (9) is formed at the connection of the two separator tapes (2), and a channel (91) for allowing electrolyte to pass through is provided on the sealing line part (9).

10. The method for manufacturing an electrode sheet bag according to claim 8, wherein, when the connecting part (11) is used to form an electrode tab, after the step S4, the method for manufacturing an electrode sheet bag further includes step S5, cutting step: Along the length direction (L) of the composite electrode sheet prefabricated structure, cutting is performed at one of the two ends of the connecting part (11) to divide an electrode sheet bag (3); or, when at least one side of the main body part (12) is connected with an electrode tab part (13) along the width direction (W) of the composite electrode sheet prefabricated structure, after the step S4, the method for manufacturing an electrode sheet bag further includes step S6, cutting step: Along the length direction (L) of the composite electrode sheet prefabricated structure, cutting is performed at both ends of the connecting part (11) to divide an electrode sheet bag (3).

11. The method for manufacturing an electrode sheet bag according to claim 8, wherein, after the step S4, the method for manufacturing an electrode sheet bag further includes: In the length direction (L) of the composite electrode sheet prefabricated structure, connecting the two separator tapes (2) on both sides of the main body part (12).

12. The method for manufacturing an electrode sheet bag according to claim 8, wherein, when an electrode tab part (13) is provided on one side of the main body part (12) along the width direction (W) of the composite electrode sheet prefabricated structure, in the step S4, the connection position avoids the electrode tab part (13).

13. An electrode sheet bag manufacturing system, wherein, using the method for manufacturing an electrode sheet bag according to any one of claims 7 to 12 for bag manufacturing, the electrode sheet bag manufacturing system includes: An electrode sheet cutting device for completing the pre-treatment step of the electrode sheet tape; A separator cutting device for completing the pre-treatment step of the separator tape; An alignment device for completing the alignment step.

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