Battery packaging structure

Abstract

The utility model discloses a packaging structure of a battery, and belongs to the technical field of battery packaging. The battery cell comprises a battery cell body and a tab, the tab is formed by overlapping multiple layers of foils and is connected through ultrasonic pre-welding to form an ultrasonic pre-welding area, and one end, connected with the battery cell body, of the tab is subjected to laser thermal fusion to form a laser thermal fusion area; the aluminum plastic film extends to the outer side of the laser heat fusion area; and the tab heat sealing adhesive is filled between the aluminum plastic film and the laser heat fusion region and forms a tab top sealing part through hot-pressing fusion. According to the packaging structure, the design of an outer tab is omitted, a space does not need to be reserved for welding of the inner tab and the outer tab before packaging, a battery cell body with a larger size can be accommodated under the condition of the same finished product size, and the volume energy density of a single battery cell is improved.

Description

Technical Field

[0001] This utility model belongs to the field of battery packaging technology, and specifically relates to a battery packaging structure. Background Technology

[0002] In the battery field, especially in the design and manufacturing of pouch batteries, encapsulation technology is one of the key aspects to ensure battery performance and safety. Traditional pouch cell encapsulation designs typically involve welding the inner tabs (the part directly connected to the positive and negative electrode materials inside the cell) together with the outer tabs (the part used for external circuit connections), and then encapsulating the PP layer of the outer tab position with an aluminum-plastic composite film through thermo-pressing fusion.

[0003] While this packaging method can achieve cell packaging, in order to ensure sufficient welding space between the inner and outer tabs, a certain amount of space must be reserved in the cell design for welding with the outer tabs. However, this space does not contribute to the actual capacity of the cell, thus limiting the volumetric energy density of a single cell. Summary of the Invention

[0004] This utility model addresses the aforementioned problems in the existing technology by proposing a battery packaging structure that eliminates the need for pre-reserved space for welding external tabs and can accommodate larger battery cell bodies within the same size.

[0005] This utility model can be achieved through the following technical solutions:

[0006] A battery packaging structure, comprising:

[0007] Battery cell body,

[0008] The electrode tab is made of multiple layers of foil and is connected by ultrasonic pre-welding to form an ultrasonic pre-welding area. The end of the electrode tab connected to the battery cell body is laser-thermally fused to form a laser-thermally fused area.

[0009] An aluminum-plastic film extending to the outer side of the laser thermal fusion zone;

[0010] The electrode heat-sealing adhesive is filled between the aluminum-plastic film and the laser heat-fusion zone and formed into the electrode top seal by hot-pressing fusion.

[0011] As a further improvement of this utility model, the laser thermal fusion zone covers the ultrasonic pre-welding zone.

[0012] As a further improvement of this utility model, the ultrasonic pre-welding area extends 2-4 cm beyond the top seal of the electrode tab.

[0013] As a further improvement of this utility model, the fusion width of the laser thermal fusion zone is 3-6mm.

[0014] As a further improvement of this utility model, the ultrasonic pre-welding zone is formed by one or more ultrasonic pre-welding processes.

[0015] As a further improvement of this utility model, the laser thermal fusion zone is formed by one or more laser welding processes.

[0016] As a further improvement of this utility model, the width of the electrode heat sealant is greater than the fusion width of the laser heat fusion zone, wherein the electrode heat sealant extends 1-3 mm beyond the fusion width of the laser heat fusion zone on one side along its own width direction.

[0017] As a further improvement of this utility model, the length of the electrode heat sealant is greater than the width of the electrode, wherein the electrode heat sealant extends 2-4 mm beyond the width of the electrode along its own length direction.

[0018] As a further improvement of this utility model, the end face of the electrode heat sealant on the side opposite to the battery cell body extends 1-4mm beyond the end face of the corresponding side of the aluminum-plastic film.

[0019] The end face of the electrode heat sealant facing the cell body extends 1-3mm beyond the end face of the corresponding side of the electrode top seal.

[0020] As a further improvement of this utility model, the heat-sealing adhesive for the electrode tabs and the inner adhesive layer of the aluminum-plastic film are made of PP material or other corrosion-resistant heat-sealing adhesive materials for the electrode tabs.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] 1. After stacking, the tabs are first ultrasonically pre-welded, and then laser welding is performed in the pre-welded area to thermally fuse the multiple tabs together. Finally, tab heat-sealing adhesive is added to both sides of the laser heat-fusion area of ​​the tabs and then heat-pressed with the inner adhesive layer of the aluminum-plastic film. This encapsulation structure ensures the stability and reliability of the internal structure of the tabs and does not need to rely on external tabs to maintain electrical connection. Because the design of external tabs is eliminated, there is no need to reserve space for welding of internal and external tabs before encapsulation. Under the same finished product size conditions, a larger size cell body can be accommodated, thereby improving the volumetric energy density of a single cell.

[0023] 2. Heat-sealing adhesive is applied to both sides of the laser heat fusion zone to further enhance the sealing effect between the electrode tabs and the inner adhesive layer of the aluminum-plastic film, prevent electrolyte leakage and the influence of other external factors, and improve the overall packaging quality.

[0024] 3. The welding process of inner and outer tabs has been eliminated, simplifying the manufacturing process and reducing potential quality risks;

[0025] 4. The tabs have a preset pre-welding width, ensuring that after the battery is packaged, the tabs have a 2-4cm ultrasonic pre-welding area extending outward to maintain the rigidity and stability of the exposed tabs on the top seal, reduce the risk of deformation of the tabs under external stress, and improve their bending resistance. Especially during battery installation and use, it can effectively prevent damage to the tabs caused by physical impact or vibration.

[0026] 5. The tab heat sealant and inner adhesive layer are made of PP material or other corrosion-resistant tab heat sealant material. This material has excellent heat sealing performance and can be tightly bonded to the cell body and tabs during the encapsulation process, effectively preventing electrolyte leakage and other external factors from affecting the inside of the battery. It also has good chemical inertness and can resist the corrosion of electrolyte and other chemicals inside the battery. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the battery packaging structure of this utility model;

[0028] Figure 2 This is the utility model Figure 1 A magnified view of a section at point A in the middle;

[0029] Figure 3 This is a schematic diagram of the electrode laser thermal fusion structure of this utility model;

[0030] Figure 4 This is a schematic diagram of the structure of the electrode heat sealant and the electrode tab bonding of this utility model;

[0031] Figure 5 This is a partial enlarged view of the tab packaging structure of this utility model.

[0032] In the diagram, 100 is the battery cell body; 110 is the electrode tab; 120 is the ultrasonic pre-welding area; 130 is the laser heat fusion area; 140 is the aluminum-plastic film; 150 is the inner adhesive layer; and 160 is the electrode tab heat sealant. Detailed Implementation

[0033] The following are specific embodiments of the present invention, which are described in conjunction with the accompanying drawings. The technical methods of the present invention will be further described, but the present invention is not limited to these embodiments.

[0034] like Figure 1-5 As shown, this utility model provides a battery packaging structure, including:

[0035] Battery cell body 100;

[0036] The tab 110 is formed by multiple layers of foil and is connected by ultrasonic pre-welding to form an ultrasonic pre-welding area 120. The end of the tab 110 connected to the battery cell body 100 is a laser thermal fusion area 130 formed by laser thermal fusion.

[0037] The aluminum-plastic film 140 covers the outside of the cell body 100, and the inner adhesive layer 150 of the aluminum-plastic film extends to the outside of the laser heat fusion area 130. In the battery packaging, the inner adhesive layer 150 of the aluminum-plastic film 140 is mainly responsible for heat sealing performance. After heating, it can soften and fuse with the tab 110 to form a tight seal, prevent electrolyte leakage, and prevent external air and moisture from entering the battery, ensuring the stability and safety of the internal chemical reaction of the battery.

[0038] The electrode heat-sealing adhesive is filled between the aluminum-plastic film 140 and the laser heat-fusion area 130 and formed into an electrode encapsulation part by hot-pressing fusion.

[0039] Specifically, the battery packaging process is as follows:

[0040] 1. Ultrasonic pre-welding

[0041] Ultrasonic pre-welding zone 120: Ultrasonic pre-welding is performed on the multi-layer tabs 110 formed after lamination / winding. The ultrasonic pre-welding zone 120 should cover the entire tab 110 area to ensure tight adhesion between the layers of tabs 110, enhancing mechanical strength and electrical contact. Ultrasonic welding technology can form a stable bond between metal foils without the use of additional materials, greatly enhancing the overall mechanical strength of the tabs and reducing the possibility of delamination or detachment during use.

[0042] 2. Laser welding

[0043] Laser thermal fusion zone 130 creation: Based on ultrasonic pre-welding, laser welding is performed on the tab 110 on the side close to the cell body 100 to form laser thermal fusion zone 130 (i.e., laser thermal fusion zone 130 covers ultrasonic pre-welding zone 120). Laser welding can accurately thermally fuse multiple layers of foil together, while avoiding the thermal damage that may be caused by traditional welding.

[0044] In addition, the high-precision laser welding process ensures the uniformity and reliability of the welding area, avoids unnecessary heat diffusion to non-welded areas, thereby reducing the impact on other parts of the battery cell, especially preventing material damage or performance degradation caused by overheating.

[0045] 3. Application of heat sealant 160 for tabs: Heat sealant 160 for tabs is applied to both sides of the laser heat fusion zone 130. This heat sealant 160 is used to enhance the sealing effect between the tabs 110 and the inner adhesive layer 150 of the aluminum-plastic film 140.

[0046] 4. Aluminum-plastic film 140 encapsulation: The cell body 100 and its tabs 110 are completely wrapped with an aluminum-plastic film 140 with an inner adhesive layer 150. The aluminum-plastic film 140 not only provides physical protection, but also participates in the subsequent hot-pressing fusion process.

[0047] 5. Hot-pressing fusion: The inner adhesive layer 150 of the aluminum-plastic film 140 and the heat-sealing adhesive 160 on the tab 110 work together using a hot-pressing device to achieve a firm bond between the tab 110 and the aluminum-plastic film 140. This process ensures the sealing and stability of the encapsulation structure.

[0048] In addition, the metal foil layer in the aluminum-plastic film 140 has certain thermal conductivity, which helps to distribute heat evenly and avoid local overheating. Especially under high current charging and discharging conditions, it can effectively improve the thermal management performance of the battery, extend its service life, and reduce the safety hazards caused by local overheating.

[0049] It should be noted that the traditional soft-pack battery cell packaging design usually involves welding the inner tab (the part directly connected to the positive and negative electrode materials inside the battery cell) and the outer tab (the part used for external circuit connection) together, and then encapsulating the PP layer of the outer tab position with the aluminum-plastic composite film by hot pressing fusion.

[0050] While this traditional packaging method can achieve cell packaging, in order to ensure sufficient welding space between the inner and outer tabs, a certain amount of space must be reserved in the cell design for welding with the outer tabs. However, this space does not contribute to the actual capacity of the cell, thus limiting the volumetric energy density of a single cell.

[0051] In this embodiment, ultrasonic welding technology enables the multi-layer tabs 110 to be tightly bonded and formed into a solid whole. Ultrasonic pre-welding not only enhances the mechanical connection between the tabs 110, but also ensures good electrical contact, enabling the tabs 110 to achieve reliable current transmission without additional external connectors.

[0052] Based on ultrasonic pre-welding, a high-precision laser welding process is further adopted to form a solid laser thermal fusion zone 130 in the key part of the tab 110. Laser welding can accurately and firmly bond multiple layers of foil, avoiding the thermal damage or deformation problems that may occur in the traditional welding process.

[0053] This combination of ultrasonic pre-welding and laser thermal fusion technology ensures the stability and reliability of the internal structure of the tab 110, thus eliminating the need to rely on the external tab 110 to maintain electrical connection. Because the external tab design is eliminated, there is no need to reserve space for welding the internal and external tabs before packaging. Under the same finished product size conditions, a larger cell body 100 can be accommodated, thereby improving the volumetric energy density of the single cell.

[0054] In addition, the application of the tab heat sealant 160 forms an additional sealing layer between the laser heat fusion zone 130 and the inner adhesive layer 150 of the aluminum-plastic film 140, effectively preventing electrolyte leakage and the influence of other external factors (such as moisture and dust) on the battery's interior. This not only improves the overall sealing performance of the encapsulation structure but also enhances the battery's environmental adaptability and long-term stability.

[0055] Furthermore, the heat-sealing adhesive 160 for the tabs serves as an intermediate medium, adhering tightly to the laser heat-fusion zone 130 and the inner adhesive layer 150 during the hot-pressing process, further strengthening the mechanical connection between the tabs 110 and the aluminum-plastic film 140. This reinforcement significantly improves the physical strength and durability of the entire encapsulation structure, reducing the risk of encapsulation failure due to external impacts or vibrations.

[0056] Preferably, the ultrasonic pre-welding area 120 extends 2-4 cm beyond the top seal of the tab. In other words, the tab 110 has a preset ultrasonic pre-welding width, ensuring that after the battery is encapsulated, the tab 110 has at least a 2-4 cm ultrasonic pre-welding area 120 extending outward to maintain the rigidity and stability of the exposed tab 110 under the top seal, reducing the risk of deformation of the tab 110 under external stress, and improving its bending resistance. Especially during battery installation and use, it can effectively prevent damage to the tab 110 caused by physical impact or vibration, ensuring long-term reliability.

[0057] In addition, the tab 110 can be processed by one or more ultrasonic pre-welding processes to form an ultrasonic pre-welding area. For batteries of different specifications or special application scenarios, the most suitable pre-welding scheme can be selected to meet diverse needs.

[0058] Preferably, the width of the laser thermal fusion zone 130 is 3-6mm, which realizes precise control of the welding area and optimization of welding strength. Similarly, the laser welding width is usually set to 3-6mm, and one or more welding passes can be used according to actual needs to ensure welding quality and reliability.

[0059] In addition, the aluminum-plastic film 140 wraps around the cell body 100, providing physical protection for the cell body 100 from external environmental influences such as physical impact, moisture, and dust. This enhances the overall durability and reliability of the battery, extends its service life, and the aluminum-plastic film 140 has excellent sealing performance. In particular, its inner adhesive layer 150 can tightly bond with the tab heat-sealing adhesive 160 on the tab 110 during the hot-pressing fusion process, forming a completely sealed environment. This not only prevents electrolyte leakage but also prevents external air and moisture from entering the battery, ensuring the stability and safety of the internal chemical reactions.

[0060] Preferred, such as Figure 4 As shown, the width of the tab heat sealant 160 is greater than the fusion width of the laser thermal fusion zone 130. Specifically, the tab heat sealant 160 extends 1-3 mm beyond the fusion width of the laser thermal fusion zone 130 along its own width direction.

[0061] Preferred, such as Figure 4 As shown, the length of the electrode heat sealant 160 is greater than the width of the electrode 110, wherein the electrode heat sealant 160 extends 2-4 mm beyond the width of the electrode 110 along its own length direction.

[0062] By controlling the size range of the tab heat sealant 160, it can be ensured that the outer edge of the top sealing aluminum-plastic film 140 does not pose a short circuit risk with the tab 110, while ensuring reliable encapsulation effect and encapsulation strength, and improving encapsulation quality.

[0063] Preferred, such as Figure 5 As shown, the end face of the tab heat sealant 160 on the side away from the cell body 100 extends 1-4mm beyond the end face of the corresponding side of the aluminum-plastic film 140. Here, the end face of the tab heat sealant 160 on the side away from the cell body 100 refers to the end face of the tab heat sealant 160 on the side away from the cell body 100 along the axis of the tab 110, which is the outer end face of the tab heat sealant 160.

[0064] This design can form an additional protective layer outside the aluminum-plastic film, increasing physical protection and reducing the impact of the external environment on internal components, such as moisture and dust. It can also effectively disperse the mechanical stress applied to the edge of the package from the outside, reducing the risk of seal failure due to edge damage.

[0065] In addition, such as Figure 5 As shown, the end face of the tab heat sealant 160 facing the cell body 100 extends 1-3mm beyond the end face of the corresponding side of the tab top seal. Here, the end face of the tab heat sealant 160 facing the cell body 100 refers to the end face of the tab heat sealant 160 close to the cell body 100 along the axis of the tab 110, which is the inner end face of the tab heat sealant.

[0066] This design provides more robust support for the top sealing area. This over-design allows for better filling and sealing of any possible gaps during the hot-pressing process, further improving the integrity and tightness of the packaging structure.

[0067] Preferably, the tab heat sealant 160 and the inner adhesive layer 150 are made of PP material or other corrosion-resistant tab heat sealant 160 material. This material has excellent heat sealing performance and can be tightly bonded to the cell body 100 and the tab 110 during the encapsulation process, effectively preventing electrolyte leakage and other external factors from affecting the inside of the battery. It also has good chemical inertness and can resist the corrosion of electrolyte and other chemicals inside the battery.

[0068] The technical means disclosed in this utility model are not limited to those described above, but also include technical solutions composed of any combination of the above technical features. The above are specific embodiments of this utility model. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principle of this utility model, and these improvements and modifications are also considered within the scope of protection of this utility model.

[0069] It should be noted that all directional indicators (such as up, down, left, right, front, back, etc.) in this utility model embodiment are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicator will also change accordingly.

[0070] Furthermore, in this utility model, descriptions involving "", "a", "one", etc., are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "" or "a" may explicitly or implicitly include at least one of that feature. In the description of this utility model, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0071] In this utility model, unless otherwise explicitly specified and limited, the terms "connection," "fixing," etc., should be interpreted broadly. For example, "fixing" can mean a fixed connection, a detachable connection, or an integral part; it can mean a mechanical connection or an electrical connection; it can mean a direct connection or an indirect connection through an intermediate medium; it can mean the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0072] Furthermore, the technical solutions of the various embodiments of this utility model can be combined with each other, but only if they are based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by this utility model.

Claims

1. A battery packaging structure, characterized in that, include: Battery cell body, The electrode tab is made of multiple layers of foil and is connected by ultrasonic pre-welding to form an ultrasonic pre-welding area. The end of the electrode tab connected to the battery cell body is laser-thermally fused to form a laser-thermally fused area. An aluminum-plastic film extending to the outer side of the laser thermal fusion zone; The electrode heat-sealing adhesive is filled between the aluminum-plastic film and the laser heat-fusion zone and formed into the electrode top seal by hot-pressing fusion.

2. The battery packaging structure according to claim 1, characterized in that, The laser thermal fusion zone covers the ultrasonic pre-welding zone.

3. The battery packaging structure according to claim 1, characterized in that, The ultrasonic pre-welding area extends 2-4 cm beyond the top seal of the electrode tab.

4. The battery packaging structure according to claim 1, characterized in that, The fusion width of the laser thermal fusion zone is 3-6 mm.

5. A battery packaging structure according to claim 1, characterized in that, The ultrasonic pre-welding zone is formed by one or more ultrasonic pre-welding processes.

6. A battery packaging structure according to claim 1, characterized in that, The laser thermal fusion zone is formed by one or more laser welding processes.

7. A battery packaging structure according to claim 1, characterized in that, The width of the electrode heat sealant is greater than the fusion width of the laser heat fusion zone, wherein the electrode heat sealant extends 1-3 mm beyond the fusion width of the laser heat fusion zone on one side along its own width direction.

8. A battery packaging structure according to claim 1, characterized in that, The length of the heat-sealing adhesive for the electrode tab is greater than the width of the electrode tab, wherein the heat-sealing adhesive for the electrode tab extends 2-4 mm beyond the width of the electrode tab on one side along its own length direction.

9. A battery packaging structure according to claim 1, characterized in that, The end face of the electrode heat sealant on the side opposite to the battery cell body extends 1-4mm beyond the end face of the corresponding side of the aluminum-plastic film. The end face of the electrode heat sealant facing the cell body extends 1-3mm beyond the end face of the corresponding side of the electrode top seal.

10. A battery packaging structure according to claim 1, characterized in that, The heat-sealing adhesive for the electrode tabs and the inner adhesive layer of the aluminum-plastic film are made of PP material or other corrosion-resistant heat-sealing adhesive materials for the electrode tabs.

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