Packaging method, sealing head and packaging equipment for packaging soft package battery

Abstract

The invention relates to the field of battery manufacturing, and provides a packaging method, a sealing head and packaging equipment for packaging a soft package battery. The packaging equipment comprises two sealing heads, and the two sealing heads clamp the packaging layer of the soft package battery; according to the packaging method, the sealing head heating packaging layer is adopted to package a naked battery cell of the soft package battery, a temperature indicating layer is arranged in a visible area when the sealing head heating packaging layer is used, the temperature indicating layer is made of a reversible thermochromic material, the temperature of the sealing head is judged and the sealing head heating packaging layer is controlled by observing the color change of the temperature indicating layer, and the operation is simple, convenient, efficient and reliable.

Description

Technical Field

[0001] The present invention relates to the field of battery manufacturing, and in particular to a packaging method, a sealing head and a packaging device for soft-pack battery packaging. Background Art

[0002] Soft-pack batteries are a type of battery commonly used in electric vehicles. Soft-pack batteries have the advantages of high energy density and good safety performance, and generally will not explode in the event of thermal failure.

[0003] The battery cell of the soft-pack battery includes a bare battery cell and a packaging layer. The packaging layer is used to package the bare battery cell. The packaging layer generally uses an aluminum-plastic film. The aluminum-plastic film is mainly divided into three parts: the outermost nylon layer, the middle layer is an aluminum layer, and the innermost layer is a polypropylene layer (referred to as the PP layer), which mainly plays a packaging role and insulates the aluminum layer from the electrolyte and the bare battery cell. The packaging process of the soft-pack battery is to set the PP layers of the two aluminum-plastic films face to face, heat the head to a preset temperature, and then apply a certain pressure and time to the area of ​​the aluminum-plastic film to be packaged. The temperature of the head is used to fuse the PP layers of the two aluminum-plastic films to achieve the packaging effect. The temperature, time, and pressure of the head are confirmed through experimental design to ensure the sealing reliability of the package. However, in the actual production operation process, due to the influence of factors such as the stability of the equipment, whether the actual temperature of the head reaches the set temperature needs to be measured before each operation begins. The operation is complicated and affects production efficiency. If the number of inspections is not enough, it may cause the head temperature to be too low during the production process, resulting in production accidents such as false sealing and poor packaging. Summary of the invention

[0004] The technical problem to be solved by the present invention is to overcome the defects of the prior art in soft-pack battery packaging, such as complex operation, low efficiency and poor reliability, and to provide a packaging method, a sealing head and a packaging device for soft-pack battery packaging.

[0005] The present invention solves the above technical problems through the following technical solutions:

[0006] A packaging method for a soft-pack battery, the soft-pack battery comprising a bare cell and a packaging layer, wherein a sealing head is used to heat the packaging layer to package the bare cell,

[0007] A temperature indicating layer is arranged in a visible area when the sealing head heats the packaging layer, and the material of the temperature indicating layer is a reversible thermochromic material.

[0008] In the present solution, the visible area when the head heats the encapsulation layer refers to the part of the head that can be seen when the head heats the encapsulation layer. By setting a temperature-indicating layer in this part of the area, the temperature-indicating layer is visible when the head is working. By setting the material of the temperature-indicating layer to a thermochromic material, in the process of the head heating the encapsulation layer, the temperature of the head can be judged by observing the positive change in the color of the temperature-indicating layer to control the head to heat the encapsulation layer. Furthermore, the thermochromic material of the temperature-indicating layer is set to be reversible. On the one hand, a signal that the temperature of the head has dropped can be obtained by the reverse change in the color of the temperature-indicating layer; on the other hand, it can be reused. By setting a temperature-indicating layer in the visible area and setting the material of the temperature-indicating layer to a reversible thermochromic material, the temperature of the head can be judged by the color change of the temperature-indicating layer to control the head to heat the encapsulation layer. The operation is simple, convenient, efficient and reliable.

[0009] A sealing head for soft-pack battery packaging, the sealing head is used to heat the packaging layer of the soft-pack battery to encapsulate the bare battery cells of the soft-pack battery, a temperature indicating layer is provided in the visible area when the sealing head heats the packaging layer, and the material of the temperature indicating layer is a reversible thermochromic material.

[0010] Preferably, the color change temperature of the temperature indicating layer is between 180°C and 200°C.

[0011] Preferably, the material of the temperature indicating layer is BiVO4;

[0012] Or, the material of the temperature indicating layer is Bi-V-Cr mixed crystal oxide;

[0013] Alternatively, the material of the temperature indicating layer is BiCrO3.

[0014] Preferably, one side of the sealing head in the length direction is used for the packaging layer to extend into, and the other side is provided with the temperature indicating layer.

[0015] Preferably, when the sealing head heats the encapsulation layer, the encapsulation layer is located on one side of the sealing head in the thickness direction, and the temperature indicating layer is provided on the other side of the sealing head in the thickness direction;

[0016] And / or, the temperature indicating layer is provided on at least one side in the width direction of the head.

[0017] Preferably, the temperature indicating layer comprises a first temperature indicating layer and a second temperature indicating layer, and the materials of the first temperature indicating layer and the second temperature indicating layer have different color change temperatures and / or are staggered.

[0018] Preferably, an isolation layer is further provided on the end cover, and the isolation layer is arranged on the outside of the temperature indicating layer. The material of the isolation layer is a transparent material, and the melting point thereof is greater than a preset temperature for heating the end cover.

[0019] Preferably, the thickness of the temperature indicating layer is greater than 1 mm.

[0020] A packaging device for soft-pack battery packaging, the packaging device comprising two rising sealing heads for soft-pack battery packaging, the two sealing heads are used to clamp the packaging layer.

[0021] In this solution, the packaging layer is clamped by two sealing heads to heat the packaging layer, so that the packaging layer is heated evenly and pressed evenly, and the packaging effect is good.

[0022] The positive and progressive effects of the present invention are:

[0023] By setting a temperature-indicating layer in the visible area when the head is heating the packaging layer, the temperature-indicating layer is visible when the head is working. By setting the material of the temperature-indicating layer to a thermochromic material, in the process of the head heating the packaging layer, the temperature of the head can be judged by observing the positive change in the color of the temperature-indicating layer to control the heating of the packaging layer by the head. Furthermore, the thermochromic material of the temperature-indicating layer is set to be reversible. On the one hand, a signal of a drop in the temperature of the head can be obtained by the reverse change in the color of the temperature-indicating layer; on the other hand, it can be reused. By setting the temperature-indicating layer in the visible area and setting the material of the temperature-indicating layer to a reversible thermochromic material, the temperature of the head can be judged by the color change of the temperature-indicating layer, and the heating of the packaging layer by the head can be controlled. The operation is simple, convenient, efficient and reliable. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 A schematic diagram of the exploded structure of a bare battery cell and a packaging layer along the thickness direction provided by an embodiment of the present invention;

[0025] Figure 2 A schematic diagram of the three-dimensional structure of a bare cell encapsulated in a head provided by an embodiment of the present invention;

[0026] Figure 3 A schematic diagram of a top view of a bare cell encapsulated with a head provided in an embodiment of the present invention;

[0027] Figure 4 for Figure 3 Middle AA section view;

[0028] Figure 5 for Figure 4 Enlarged view of part B in the middle.

[0029] Description of reference numerals:

[0030] Battery core 1, bare battery core 11, packaging layer 12;

[0031] Head cover 21, left head cover 211, right head cover 212. DETAILED DESCRIPTION

[0032] The present invention is further described below by way of examples, but the present invention is not limited to the scope of the examples.

[0033] It should be noted that:

[0034] The two sides of the head 21 in the length direction L are the left side and the right side, and the corresponding surfaces are the left side and the right side M4; the two sides of the head 21 in the width direction W are the front side and the rear side, and the corresponding surfaces are the front side M1 and the rear side; the two sides of the head 21 in the thickness direction H are the top side and the bottom side, and the corresponding surfaces are the top surface M5 and the bottom surface;

[0035] The directions representing the viewing angles in this embodiment, such as three-dimensional, top view, front M1, back, left, right M4, top M5, bottom, front side, back side, left side, right side, top side, bottom side, etc., are based on the viewing angles shown in the drawings and are used to indicate relative positions, and are not used to limit the specific arrangement positions of the sealing head 21 and the packaging layer 12;

[0036] The length direction L, the width direction W, and the thickness direction H are not used to limit the size of the head 21; for example, it does not mean that the size in the length direction L is greater than the size in the width direction W;

[0037] Positive color change refers to the color change of the thermometric layer when the temperature changes from low to high; reverse color change refers to the color change of the thermometric layer when the temperature changes from high to low.

[0038] Figure 1-Figure 5 A schematic diagram of a structure provided for an embodiment of the present invention.

[0039] like Figure 1 As shown, the battery cell 1 of the soft pack battery includes a bare battery cell 11 and a packaging layer 12, and the bare battery cell 11 is arranged in the packaging layer 12. Figure 2-Figure 5 As shown, the sealing head 21 of the packaging equipment is used to heat the packaging layer 12 so that the two layers of packaging layers 12 are fused together, so that the bare battery 11 is encapsulated by the packaging layer 12. The relative position of the bare battery 11 and the packaging layer 12 can be seen in Figure 1 . The outermost layer of the encapsulation layer 12 is a nylon layer, the middle layer is a metal layer, and the innermost layer is a resin layer (referred to as PP layer). In this embodiment, the metal layer is specifically an aluminum layer, and the resin layer is specifically a polypropylene layer. In other embodiments, the encapsulation layer can be a nickel plastic film, a copper plastic film, etc., and the corresponding metal layer is a nickel layer, a copper layer, etc. The specific structure of the battery cell 1 and other parts in the soft-pack battery can refer to the prior art.

[0040] like Figure 2-Figure 5As shown, the packaging device includes four heads 21, a pair of left heads 211 located on the left side and a pair of right heads 212 located on the right side in the direction of the figure, the pair of left heads 211 clamp the left side of the packaging layer 12, and the pair of right heads 212 clamp the right side of the packaging layer 12. The heads 21 are arranged in pairs, and the packaging layer 12 is heated by a pair of heads 21 clamping the packaging layer 12, so that the packaging layer 12 can be heated evenly and the pressure is balanced, and the packaging effect is good. The specific structure of the heads 21 in the packaging device and other structures in the packaging device can refer to the existing technology.

[0041] The sealing head 21 is provided with a temperature-indicating layer, and the material of the temperature-indicating layer is a reversible thermochromic material. The temperature-indicating layer is specifically provided in a visible area when the sealing head 21 heats the encapsulation layer 12, that is, the temperature-indicating layer can be seen when the sealing head 21 heats the encapsulation layer 12. By setting the material of the temperature-indicating layer to be a thermochromic material, in the process of the sealing head 21 heating the encapsulation layer 12, in the process of the temperature of the sealing head 21 rising, it is possible to observe the positive color change of the temperature-indicating layer to judge whether the temperature of the sealing head 21 reaches the preset temperature for heating the encapsulation layer 12 to fuse the encapsulation layer 12, so as to control the sealing head 21 to heat the encapsulation layer 12, reduce the number of temperature measurements of the sealing head 21, and make the operation simple, convenient and efficient. Furthermore, the thermochromic material of the temperature-indicating layer is set to be reversible. On the one hand, when the temperature of the head 21 drops, a signal of the temperature drop of the head 21 can be obtained through the reverse change of the color of the temperature-indicating layer, and the head 21 can be heated in time to reach the preset temperature, thereby avoiding false sealing and other poor packaging phenomena caused by low temperature below the preset temperature, thereby improving the reliability of packaging; on the other hand, it can be reused.

[0042] When the sealing head 21 is heated to 180°C-200°C, the heating and encapsulation effect of the encapsulation layer 12 is better. Optionally, in this embodiment, the color change temperature of the temperature indicating layer is 180°C-200°C, so that the signal that the temperature of the sealing head 21 is heated to 180°C-200°C can be obtained through the color change of the temperature indicating layer.

[0043] In this embodiment, the preset temperature of the heat seal of the encapsulation layer 12 is 200°C; the material of the temperature-indicating layer is BiVO4, and the color change temperature of BiVO4 is 200°C. The preset temperature is consistent with the color change temperature, so that the temperature of the head 21 can be judged by the color change of the temperature-indicating layer, and the encapsulation process can be accurately controlled. In the process of heating the head 21, when the actual temperature of the head 21 reaches the preset temperature, that is, after reaching 200°C, the color of the temperature-indicating layer changes positively, from orange to red, and it can be clearly identified whether the temperature of the head 21 reaches the preset temperature of 200°C; when the temperature of the head 21 drops during use and drops below the preset temperature, that is, after dropping below 200°C, the color of the temperature-indicating layer changes reversely, from red to orange. At this time, it is necessary to stop the encapsulation and adjust the temperature compensation and other parameters on the encapsulation equipment to make the actual temperature of the head 21 rise and reach the preset temperature of 200°C again, so as to avoid production accidents such as false sealing caused by low temperatures below the preset temperature.

[0044] In other embodiments, the material of the temperature-indicating layer can be a reversible thermochromic material such as BiVO4, Bi-V-Cr mixed crystal oxide, BiCrO3, etc. When the preset temperature of the heat seal of the encapsulation layer 12 is 180°C, Bi-V-Cr mixed crystal oxide can be used as the material of the temperature-indicating layer, and the color change temperature of Bi-V-Cr mixed crystal oxide is 180°C; when the actual temperature of the end cap 21 rises to the preset temperature of 180°C, the color of the temperature-indicating layer changes positively from yellowish brown to dark brown; when the temperature of the end cap 21 drops below the preset temperature of 180°C, the color of the temperature-indicating layer changes reversely from dark brown to yellowish brown, and the encapsulation needs to be stopped at this time. When BiCrO3 is the material of the temperature-indicating layer, when the actual temperature of the end cap 21 rises to 140°C, the color of the temperature-indicating layer changes positively from green to yellow; when the temperature of the end cap 21 drops below 140°C, the color of the temperature-indicating layer changes reversely from yellow to green.

[0045] Optional, such as Figure 2-Figure 4 As shown, the right side of the left head 211 is used for the packaging layer 12 to extend into, and the left side of the left head 211 is provided with a temperature indicating layer, specifically the first temperature indicating layer; the left side of the right head 212 is used for the packaging layer 12 to extend into, and the right side M4 of the right head 212 is provided with a temperature indicating layer, specifically the first temperature indicating layer; when the head 21 heats the packaging layer 12, the bare cell 11 is located between the left head 211 and the right head 212, and the side of the head 21 in the length direction L away from the bare cell 11 is most convenient for observation, and this side is provided with a temperature indicating layer, which makes it most convenient to observe the color change of the temperature indicating layer.

[0046] Optional, such as Figure 2As shown, the front side M1 of the left head 211 and the right head 212 are both provided with a temperature indicating layer, specifically a second temperature indicating layer. The first temperature indicating layer and the second temperature indicating layer on the left head 211 or the right head 212 are located at different positions of the head 21, and the staggered arrangement allows the color change of the temperature indicating layer to be observed from multiple directions. On the one hand, the accuracy of judging the temperature of the head 21 by the color change of the temperature indicating layer can be improved; on the other hand, the convenience of observation can be improved.

[0047] Specifically, in this embodiment, the temperature indicating layer is set in the area Figure 2 It is shown by shadow in the figure, wherein the temperature indicating layer is covered in the setting area on the left side of the left sealing head 211. Optionally, in other embodiments, the temperature indicating layer can be set in any visible area when the sealing head 21 heats the packaging layer 12.

[0048] In other embodiments, the design point 1 may be included: when the sealing head 21 heats the encapsulation layer 12, the encapsulation layer 12 is located on one side of the thickness direction H of the sealing head 21, and a temperature indicating layer is provided on the other side of the thickness direction H of the sealing head 21; Figure 2 As shown, it corresponds to the top surface M5 of the upper head 21 and the bottom surface of the lower head 21 in this embodiment.

[0049] In other embodiments, the second design point may be included: at least one side of the width direction W of the head 21 is provided with a temperature indicating layer; Figure 2 As shown, it corresponds to the front side M1 and / or the back side of the head 21 in this embodiment.

[0050] In other embodiments, two or either one of the first and second design points may be included simultaneously.

[0051] In other embodiments, the design point 3 may be included: the temperature indicating layer includes a first temperature indicating layer and a second temperature indicating layer, and the first temperature indicating layer and the second temperature indicating layer are staggered; specifically, they may be in different directions or different positions in the same direction. By staggering the first temperature indicating layer and the second temperature indicating layer, it is convenient to observe in multiple positions and improve the convenience of observation.

[0052] In other embodiments, the design point four may be included: the temperature indicating layer includes a first temperature indicating layer and a second temperature indicating layer, and the material color change temperatures of the first temperature indicating layer and the second temperature indicating layer are different. For example, the preset temperature of the package is 200°C, the material of the first temperature indicating layer is Bi-V-Cr mixed crystal oxide, and the material of the second temperature indicating layer is BiVO4; after the temperature of the head 21 rises to 180°C, the color of the first temperature indicating layer changes from yellowish brown to dark brown; after the temperature of the head 21 continues to rise to 200°C, the color of the second temperature indicating layer changes from orange to red. By setting the material color change temperatures of the first temperature indicating layer and the second temperature indicating layer to be different, at least two temperature values ​​during the heating process of the head 21 can be obtained through the color changes of the first temperature indicating layer and the second temperature indicating layer, thereby facilitating the observation of the temperature change process of the head 21 and improving the controllability and safety of the packaging process.

[0053] In other embodiments, two or any one of the three and four design points may be included simultaneously.

[0054] Optionally, in the present embodiment, an isolation layer is further provided on the head 21, and the isolation layer is arranged on the outside of the temperature indicating layer. The material of the isolation layer is a transparent material, and its melting point is greater than the preset temperature at which the head 21 is heated. By arranging the isolation layer to be located on the outside of the temperature indicating layer, the temperature indicating layer is protected and wear of the temperature indicating layer is avoided. By setting the material of the isolation layer to be a transparent material, the isolation layer does not affect the observation of the color change of the temperature indicating layer. By setting the melting point of the isolation layer to be greater than the preset temperature at which the head 21 is heated, the isolation layer is prevented from melting due to heat when the head 21 is working. Specifically, in the present embodiment, the material of the isolation layer is transparent glass with a melting point greater than 200°C.

[0055] The isolation layer can play a role in fixing the temperature-indicating layer on the end cap 21. For example, in this embodiment, the material of the temperature-indicating layer is in powder form, which is fixed on the end cap 21 through the isolation layer after being compacted on the end cap 21. In other embodiments, the material of the temperature-indicating layer can be fixed on the end cap 21 by bonding, fastening with fasteners such as screws, or packaging with transparent materials.

[0056] Optionally, in this embodiment, the thickness of the temperature indicating layer is greater than 1 mm, specifically 2 mm. The thickness of the temperature indicating layer is set to be greater than 1 mm, and the color is obvious, which is convenient for observation. In other embodiments, the thickness of the temperature indicating layer can be flexibly adjusted according to the performance of the material.

[0057] Although the specific embodiments of the present invention are described above, it should be understood by those skilled in the art that this is only for illustration and the protection scope of the present invention is defined by the appended claims. Those skilled in the art may make various changes or modifications to these embodiments without departing from the principles and essence of the present invention, but these changes and modifications all fall within the protection scope of the present invention.

Claims

1. A packaging method for a soft-pack battery, wherein the soft-pack battery comprises a bare cell and a packaging layer, wherein the packaging layer is heated by a sealing head to package the bare cell, wherein: A temperature indicating layer is arranged in a visible area when the sealing head heats the packaging layer, and the material of the temperature indicating layer is a reversible thermochromic material.

2. A sealing head for soft-pack battery packaging, the sealing head is used to heat the packaging layer of the soft-pack battery to seal the bare battery cell of the soft-pack battery, characterized in that: A temperature indicating layer is provided in the visible area when the sealing head heats the packaging layer, and the material of the temperature indicating layer is a reversible thermochromic material.

3. The sealing head for soft pack battery packaging according to claim 2, characterized in that: The color change temperature of the temperature indicating layer is between 180°C and 200°C.

4. The sealing head for soft pack battery packaging according to claim 2, characterized in that: The material of the temperature indicating layer is BiVO4; Or, the material of the temperature indicating layer is Bi-V-Cr mixed crystal oxide; Alternatively, the material of the temperature indicating layer is BiCrO3.

5. The sealing head for soft pack battery packaging according to claim 2, characterized in that: One side of the sealing head in the length direction is used for the packaging layer to extend into, and the other side is provided with the temperature indicating layer.

6. The sealing head for soft pack battery packaging according to claim 5, characterized in that: When the sealing head heats the encapsulation layer, the encapsulation layer is located on one side of the sealing head in the thickness direction, and the temperature indicating layer is provided on the other side of the sealing head in the thickness direction; And / or, the temperature indicating layer is provided on at least one side in the width direction of the head.

7. The sealing head for soft pack battery packaging according to claim 2, characterized in that: The temperature indicating layer comprises a first temperature indicating layer and a second temperature indicating layer, wherein the materials of the first temperature indicating layer and the second temperature indicating layer have different color change temperatures and / or are staggered.

8. The sealing head for soft pack battery packaging according to claim 2, characterized in that: The sealing head is also provided with an isolation layer, which is arranged on the outside of the temperature indicating layer. The material of the isolation layer is a transparent material, and its melting point is greater than the preset temperature of the sealing head heating.

9. The sealing head for soft pack battery packaging according to claim 2, characterized in that: The thickness of the temperature indicating layer is greater than 1 mm.

10. A packaging device for soft pack battery packaging, characterized in that: The packaging device comprises two sealing heads for soft-pack battery packaging as described in any one of claims 2 to 9, and the two sealing heads are used to clamp the packaging layer.

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