Punched aluminum-plastic composite film structure suitable for high-rate lithium battery

Abstract

The utility model relates to the technical field of lithium batteries, in particular to an aluminum-plastic composite film post-punching structure suitable for a high-magnification lithium battery, which comprises a punching structure main body, the punching structure main body is provided with two concave bag bodies which are mutually sealed and covered, and each concave bag body is sequentially provided with a protective layer, a barrier layer and a heat sealing layer from the inner side to the outer side. The opening edge of each concave bag body extends outwards to form a heat sealing edge with three sections of lengths, the two concave bag bodies are mutually sealed and covered through the heat sealing edges, and the overall sealing effect is greatly improved through the three sections of heat sealing edges which are subjected to heat sealing treatment in different modes; the first section of heat sealing edge is preliminarily fixed, and the second section of nitrile rubber heat sealing layer can effectively fill tiny gaps possibly generated during heat sealing due to good flexibility and sealing performance, so that external water vapor, oxygen and the like are prevented from invading; and the third section of polyimide modified heat sealing layer has excellent high temperature resistance and chemical corrosion resistance, so that the sealing reliability is further enhanced.

Description

Technical Field

[0001] This utility model relates to the field of lithium battery technology, and in particular to a post-punching structure of an aluminum-plastic composite film suitable for high-rate lithium batteries. Background Technology

[0002] In today's era of rapid development in lithium battery technology, high-rate lithium batteries, with their ability to charge and discharge quickly, have been widely used in new energy vehicles, power tools, and 5G base station energy storage. Aluminum-plastic composite film, as a key packaging material for high-rate lithium battery cells, directly affects the overall performance of the battery. However, current applications of aluminum-plastic composite film after stamping reveal many problems that urgently need to be addressed, especially under the harsh conditions of high-rate charging and discharging.

[0003] On the one hand, the sealing performance is inadequate. Existing sealing methods are mostly simple heat-sealing processes, and the heat-sealing parameters are difficult to control precisely, often resulting in insufficient heat sealing and gaps at the sealing edges. During high-rate charging and discharging, the internal chemical reactions of the battery are intense, and the temperature rises rapidly. External moisture and oxygen can more easily penetrate the battery under the influence of thermal expansion and contraction and pressure differences, interfering with the chemical reactions of the cell, accelerating the degradation of battery performance, and seriously affecting the cycle life and stability of high-rate lithium batteries.

[0004] On the other hand, the tab connection is unreliable. Due to the lack of effective reinforcement and protection measures at the connection point between the tab and the aluminum-plastic composite film, frequent high-current surges during high-rate charge-discharge cycles cause severe overheating at the connection point, easily leading to loose connections and cracked solder joints. This not only results in unstable current transmission, failing to meet the stable high-current output requirements of high-rate charge-discharge cycles, but may also cause electrolyte leakage, significantly threatening battery safety and lifespan.

[0005] Furthermore, the overall structural strength of the aluminum-plastic composite film after stamping is relatively low. In high-rate lithium battery applications, batteries often face complex mechanical environments such as vibration and compression. The aluminum-plastic composite film is prone to deformation and damage, failing to provide reliable protection for the battery cell and greatly limiting the application expansion of high-rate lithium batteries in complex environments. Utility Model Content

[0006] To overcome the shortcomings mentioned above, this utility model aims to provide a technical solution that can solve the above problems.

[0007] A stamped structure for an aluminum-plastic composite film suitable for high-rate lithium batteries includes a stamped structure body with two mutually sealing concave bodies. Each concave body has a protective layer, a barrier layer, and a heat-sealing layer sequentially from the inner side to the outer side. Three heat-sealing edges extend outward from the opening edge of each concave body. The two concave bodies are mutually sealed through these heat-sealing edges. The first heat-sealing edge is heat-sealed using the heat-sealing layer. The second heat-sealing edge has a layer of nitrile rubber heat-sealing layer bonded to it and is heat-sealed using the nitrile rubber heat-sealing layer. The third heat-sealing edge has a layer of polyimide-modified heat-sealing layer bonded to it and is heat-sealed using the polyimide-modified heat-sealing layer.

[0008] Preferably, the concave body is a rectangular structure, with one side of the two concave bodies integrally joined together, and the other three sides of the two concave bodies are heat-sealed together by heat-sealing edges, and a tab fixing part is provided on the heat-sealing edge corresponding to one side of the concave body.

[0009] Preferably, the width of the nitrile rubber heat-sealing layer on the heat-sealing edge is 0.3mm-0.5mm.

[0010] Preferably, the width of the polyimide-modified heat-sealing layer on the heat-sealing edge is 0.2mm-0.3mm.

[0011] Preferably, the protective layer is made of polyester or nylon, the barrier layer is made of aluminum foil, and the heat-sealing layer is made of polyethylene or cast polypropylene. A first adhesive layer is provided between the protective layer and the barrier layer, and a second adhesive layer is provided between the barrier layer and the heat-sealing layer.

[0012] Preferably, a nickel alloy reinforcing sheet is provided on both concave bodies at the position of the electrode tab fixing part, and the nickel alloy reinforcing sheet is heat-sealed to the heat-sealing edge.

[0013] Compared with the prior art, the beneficial effects of this utility model are:

[0014] In terms of sealing performance, the three heat-sealed edges treated with different methods greatly improve the overall sealing effect. The first heat-sealed edge provides initial fixation, while the second nitrile rubber heat-sealing layer, due to its good flexibility and sealing performance, effectively fills any tiny gaps that may arise during heat sealing, preventing the intrusion of external moisture and oxygen. The third polyimide-modified heat-sealing layer has excellent high-temperature resistance and chemical corrosion resistance, further enhancing the reliability of the seal and significantly improving the cycle life and stability of the lithium battery during high-rate charge and discharge. Regarding the tab connection, the enhanced sealing of the heat-sealed edges reduces external... The interference of various factors on the electrode connection reduces the risk of loose connections and cracked welds, ensuring stable transmission of high current and meeting the current output requirements of high-rate charging and discharging. At the same time, it reduces the possibility of electrolyte leakage, improving battery safety and lifespan. From the perspective of overall structural strength, this stamped structure, in the face of complex mechanical environments such as vibration and extrusion, reduces the probability of deformation and damage to the aluminum-plastic composite film due to its multi-layer structure design and reliable sealing method, providing more reliable protection for the battery cell and effectively expanding the application scenarios of high-rate lithium batteries in complex environments.

[0015] Additional aspects and advantages of this invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the structure of this utility model;

[0018] Figure 2 This is an exploded structural diagram of the present invention;

[0019] Figure 3 This is a schematic diagram of the cross-sectional structure of the present invention after heat sealing;

[0020] Figure 4 This is a utility model Figure 3 A schematic diagram of the structure at point A in the middle.

[0021] The reference numerals and names in the figure are as follows:

[0022] The concave body 10, protective layer 11, barrier layer 12, heat-sealing layer 13, heat-sealing edge 14, nitrile rubber heat-sealing layer 15, polyimide modified heat-sealing layer 16, first adhesive layer 17, second adhesive layer 18, and nickel alloy reinforcing sheet 19. Detailed Implementation

[0023] The technical solutions in the embodiments of this utility model will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0024] Please see Figure 1-4 In this embodiment of the present invention, an aluminum-plastic composite film die-cutting structure suitable for high-rate lithium batteries includes a die-cutting structure body. The die-cutting structure body has two mutually sealing concave bodies 10. The concave bodies 10 have a protective layer 11, a barrier layer 12, and a heat-sealing layer 13 sequentially from the inner side to the outer side. Three heat-sealing edges 14 extend outward from the opening edge of the concave bodies 10. The two concave bodies 10 are mutually sealed by the heat-sealing edges 14. The first heat-sealing edge 14 is heat-sealed by the heat-sealing layer 13. A layer of nitrile rubber heat-sealing layer 15 is attached to the second heat-sealing edge 14 and heat-sealed by the nitrile rubber heat-sealing layer 15. A layer of polyimide modified heat-sealing layer 16 is attached to the third heat-sealing edge 14 and heat-sealed by the polyimide modified heat-sealing layer 16.

[0025] When using the above-mentioned aluminum-plastic composite film stamping structure to assemble lithium batteries, first prepare the necessary components of the lithium battery, such as the battery cell; place the battery cell in one of the recesses 10 of the main body of the stamping structure, and pre-treat the battery cell's tabs to ensure a reliable connection with the stamping structure later; then, align the other recess 10 with the recess 10 containing the battery cell, so that the opening edges of the two recesses 10 are aligned; using a heat-sealing process, heat-seal the first section of the heat-sealed edge 14 using its own heat-sealing layer 13 to initially fix the connection between the two recesses 10; then, heat-seal the second section of the heat-sealed edge 14 using the bonded nitrile rubber heat-sealing layer 15 to further enhance the sealing effect; finally, heat-seal the third section of the heat-sealed edge 14 using the polyimide modified heat-sealing layer 16, thereby achieving a complete seal between the two recesses 10, tightly encapsulating the battery cell inside, and completing the assembly of the lithium battery.

[0026] Through this setup, the three heat-sealed edges 14, treated with different heat-sealing methods, significantly improve the overall sealing performance. The first heat-sealed edge 14 provides initial fixation, while the second nitrile rubber heat-sealing layer 15, due to its excellent flexibility and sealing performance, effectively fills any tiny gaps that may arise during heat sealing, preventing the intrusion of external moisture and oxygen. The third polyimide-modified heat-sealing layer 16 possesses excellent high-temperature resistance and chemical corrosion resistance, further enhancing the reliability of the seal and significantly improving the cycle life and stability of the lithium battery during high-rate charge and discharge. Regarding the tab connection, the sealing effect of the heat-sealed edge 14... Enhanced design reduces interference from external factors at the electrode connection points, lowering the risk of loose connections and weld cracking, ensuring stable high-current transmission, meeting the current output requirements of high-rate charging and discharging, and reducing the possibility of electrolyte leakage, thus improving battery safety and lifespan. From the perspective of overall structural strength, this stamped structure, in the face of complex mechanical environments such as vibration and extrusion, reduces the probability of deformation and damage to the aluminum-plastic composite film due to its multi-layer structure design and reliable sealing method, providing more reliable protection for the battery cell and significantly expanding the application scenarios of high-rate lithium batteries in complex environments.

[0027] Please see Figure 1-2 Based on the above technical solution, it is further proposed that the concave body 10 is a rectangular structure, with one side of the two concave bodies 10 integrally joined. This integral joining enhances the stability of the connection between the two concave bodies 10, reduces the number of heat-sealed areas, lowers the risk of seal failure, and further improves the overall sealing performance. The other three sides of the two concave bodies 10 are heat-sealed together through heat-sealing edges 14, and a tab fixing part is provided on the heat-sealing edge 14 corresponding to one side of the concave body 10. A nickel alloy reinforcing sheet 19 is provided at the position of the tab fixing part on each of the two concave bodies 10, and the nickel alloy reinforcing sheet 19 is heat-sealed with the heat-sealing edge 14. The nickel alloy has high strength and good conductivity. On the one hand, the reinforcing sheet can enhance the structural strength of the tab fixing part and reduce deformation caused by vibration, extrusion, etc., thereby ensuring the reliability of the connection between the tab and the stamped structure and reducing the risk of loose connection and cracking of welding point. On the other hand, its good conductivity helps to improve the current conduction efficiency at the tab and meet the requirements of high-rate charging and discharging for stable output of large current. At the same time, the heat-sealing connection between the reinforcing sheet and the heat-sealing edge 14 further enhances the sealing performance of this part, prevents electrolyte leakage, and comprehensively improves the safety, service life and adaptability of lithium battery in complex environments.

[0028] Please see Figure 3-4Based on the above technical solution, it is further proposed that the width of the nitrile rubber heat-sealing layer 15 on the heat-sealing edge 14 is 0.3mm-0.5mm; the width of the polyimide modified heat-sealing layer 16 on the heat-sealing edge 14 is 0.2mm-0.3mm; to ensure synergy with other heat-sealing layers 13, achieve efficient sealing, and effectively prevent external impurities from entering the battery; the protective layer 11 is made of polyester or nylon material, and the protective layer 11 made of polyester or nylon material has excellent mechanical strength and wear resistance, which can effectively resist external friction and impact and protect the internal structure; the barrier layer 12 is made of aluminum foil. In terms of material composition, the aluminum foil barrier layer 12, with its excellent barrier properties, greatly blocks the penetration of water vapor, oxygen, etc., ensuring the stability of the battery's internal environment; the heat-sealing layer 13 is made of polyethylene or cast polypropylene material, which has good heat-sealing performance and is easy to achieve reliable heat-sealing connection; a first adhesive layer 17 is provided between the protective layer 11 and the barrier layer 12, and a second adhesive layer 18 is provided between the barrier layer 12 and the heat-sealing layer 13; making the entire aluminum-plastic composite film structure compact and stable, improving the overall structural strength and deformation resistance.

[0029] It will be apparent to those skilled in the art that this invention is not limited to the details of the exemplary embodiments described above, and that it can be implemented in other specific forms without departing from the spirit or essential characteristics of this invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of this invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within this invention.

Claims

1. A stamped structure for an aluminum-plastic composite film suitable for high-rate lithium batteries, comprising a stamped structure body, the stamped structure body having two mutually sealing concave bodies (10), the concave bodies (10) having a protective layer (11), a barrier layer (12), and a heat-sealing layer (13) sequentially from the inner side to the outer side, characterized in that, Three heat-sealing edges (14) extend outward from the opening edge of the concave body (10). The two concave bodies (10) are sealed together by the heat-sealing edges (14). The first heat-sealing edge (14) is heat-sealed by a heat-sealing layer (13). A layer of nitrile rubber heat-sealing layer (15) is attached to the second heat-sealing edge (14). The second heat-sealing edge (14) is heat-sealed by the nitrile rubber heat-sealing layer (15). A layer of polyimide modified heat-sealing layer (16) is attached to the third heat-sealing edge (14). The third heat-sealing edge (14) is heat-sealed by the polyimide modified heat-sealing layer (16).

2. The post-punching structure of an aluminum-plastic composite film suitable for high-rate lithium batteries according to claim 1, characterized in that, The concave body (10) is a rectangular structure. One side of the two concave bodies (10) are integrally joined together, and the other three sides of the two concave bodies (10) are heat-sealed together by heat-sealing edge (14). A tab fixing part is provided on the heat-sealing edge (14) corresponding to one side of the concave body (10).

3. The post-punching structure of an aluminum-plastic composite film suitable for high-rate lithium batteries according to claim 1, characterized in that, The width of the nitrile rubber heat-sealing layer (15) on the heat-sealing edge (14) is 0.3mm-0.5mm.

4. The post-punching structure of an aluminum-plastic composite film suitable for high-rate lithium batteries according to claim 1, characterized in that, The width of the polyimide modified heat-sealing layer (16) on the heat-sealing edge (14) is 0.2mm-0.3mm.

5. The post-punching structure of an aluminum-plastic composite film suitable for high-rate lithium batteries according to claim 1, characterized in that, The protective layer (11) is made of polyester or nylon, the barrier layer (12) is made of aluminum foil, and the heat-sealing layer (13) is made of polyethylene or cast polypropylene. A first adhesive layer (17) is provided between the protective layer (11) and the barrier layer (12), and a second adhesive layer (18) is provided between the barrier layer (12) and the heat-sealing layer (13).

6. The post-punching structure of an aluminum-plastic composite film suitable for high-rate lithium batteries according to claim 2, characterized in that, Nickel alloy reinforcing plates (19) are provided at the positions of the electrode fixing parts on the two concave bodies (10), and the nickel alloy reinforcing plates (19) are heat-sealed to the heat-sealing edge (14).

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