Sealing head structure, top sealing mechanism and sealing device

Abstract

The utility model relates to the technical field of batteries, and provides a sealing head structure, a top sealing mechanism and a sealing device. The sealing head structure is used for hot-pressing the aluminum-plastic film bag. A hot-pressing face extending in the length direction of the end socket is arranged on one side of the end socket, at least partial area of the hot-pressing face is an arc-shaped section in the width direction of the hot-pressing face, the arc-shaped section comprises at least two arc-shaped faces which are sequentially connected, and each arc-shaped face is inwards concaved in the hot-pressing face, or each arc-shaped face is outwards protruded out of the hot-pressing face. Therefore, in the hot pressing process, a sealing area with a continuous cambered surface can be formed. Compared with a plane sealing area formed by a flat sealing head, the sealing area with the continuous cambered surface can achieve the same sealing effect as the plane sealing area under the condition of smaller width. Therefore, the width of the sealing head can be reduced, the width of the sealing area is reduced, the width of the roll core is increased, and the energy density of the cell is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of batteries, in particular to a sealing head structure, a top sealing mechanism and a sealing device. Background Art

[0002] In the related art, in the top sealing process of soft-pack lithium batteries, a flat seal is usually used to heat-press the aluminum-plastic film bag to achieve sealing. In order to ensure the sealing performance and prevent water vapor from entering, the width of the flat seal is usually greater than 1.5 mm, resulting in the width of the sealing area also greater than 1.5 mm. As a result, the sealing area occupies too much space, resulting in a reduction in the size of the core and a reduction in energy density. Utility Model Content

[0003] The embodiments of the utility model provide a head sealing structure, a top sealing mechanism and a sealing device, which can improve the technical problem of a large sealing area width.

[0004] In a first aspect, an embodiment of the utility model provides a sealing head structure for hot pressing aluminum-plastic film bags, comprising:

[0005] A head, one side of which has a hot pressing surface extending along its length direction, and along the width direction of the hot pressing surface, at least a portion of the hot pressing surface is an arc segment, and the arc segment includes at least two arc surfaces connected in sequence, wherein each of the arc surfaces is concave inwardly of the hot pressing surface, or each of the arc surfaces is convex inwardly of the hot pressing surface.

[0006] In one embodiment, the width of the head is D, which satisfies: 0.5 mm ≤ D ≤ 1.0 mm.

[0007] In one embodiment, along the width direction of the hot pressing surface, the entire area of ​​the hot pressing surface is an arc segment, and every two adjacent arc segments are connected by a straight segment.

[0008] In one embodiment, the arc length and the corresponding central angle of each arc surface are the same.

[0009] In one embodiment, along the width direction of the hot pressing surface, the hot pressing surface includes at least two arc segments arranged at intervals.

[0010] In one embodiment, for the arc surfaces in the same arc segment, the arc lengths and corresponding center angles of the arc surfaces are the same, and for the arc surfaces in different arc segments, at least one of the arc lengths and corresponding center angles of the arc surfaces is different.

[0011] In one embodiment, each of the arc surfaces is concave inwardly of the hot pressing surface, the concave depth of the arc surface is H1, the thickness of the roll core in the aluminum-plastic film bag is H2, and the relationship H1≤H2 is satisfied.

[0012] In one embodiment, each of the arc surfaces is convex to the hot pressing surface, the convex height of the arc surface is H3, the thickness of the roll core in the aluminum-plastic film bag is H2, and the following is satisfied: H3≤H2.

[0013] In a second aspect, an embodiment of the utility model provides a top sealing mechanism, comprising an upper sealing head and a lower sealing head, wherein at least one of the upper sealing head and the lower sealing head adopts the aforementioned sealing head structure.

[0014] In a third aspect, an embodiment of the present utility model provides a sealing device, comprising the top sealing mechanism as described above.

[0015] Beneficial effects of the embodiments of the utility model:

[0016] In an embodiment of the utility model, by setting at least part of the hot pressing surface as an arc segment, the arc segment includes at least two arc surfaces connected in sequence, and a sealing area with a continuous arc surface can be formed during the hot pressing process. Compared with the planar sealing area formed by the flat head, the sealing area with a continuous arc surface can achieve the same sealing effect as the planar sealing area with a smaller width. In this way, the width of the head can be reduced, the width of the sealing area can be reduced, and the width of the core can be increased, thereby improving the energy density of the battery cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0018] Figure 1 It is a three-dimensional schematic diagram of a top sealing mechanism provided in an embodiment of the utility model;

[0019] Figure 2 This is one of the side views of the head provided in the embodiment of the utility model;

[0020] Figure 3 This is the second side view of the head provided in the embodiment of the utility model;

[0021] Figure 4 This is the third side view of the end cap provided in the embodiment of the utility model;

[0022] Figure 5 This is the fourth side view of the head provided in the embodiment of the utility model;

[0023] Figure 6 This is a fifth side view of the end cap provided in the embodiment of the utility model;

[0024] Figure 7 This is the sixth side view of the head provided in the embodiment of the utility model.

[0025] Reference numerals:

[0026] 10-head, 20-hot pressing surface, 30-arc section, 40-arc surface, 50-straight section. DETAILED DESCRIPTION

[0027] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, rather than all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the utility model. In addition, it should be understood that the specific implementation methods described herein are only used to illustrate and explain the utility model, and are not used to limit the utility model. In the utility model, unless otherwise stated, the directional words used, such as "upper" and "lower", generally refer to the upper and lower parts of the device in actual use or working state, specifically the drawing direction in the accompanying drawings; while "inside" and "outside" refer to the outline of the device.

[0028] Specifically, Figures 1 to 7 As shown, an embodiment of the present application provides a head structure. The head structure is used for hot pressing aluminum-plastic film bags. The head structure includes a head 10. One side of the head 10 has a hot pressing surface 20 extending along its length direction, and along the width direction of the hot pressing surface 20, at least a part of the hot pressing surface 20 is an arc segment 30, and the arc segment 30 includes at least two arc surfaces 40 connected in sequence, wherein each arc surface 40 is concave in the hot pressing surface 20, or each arc surface 40 is convex in the hot pressing surface 20.

[0029] In this embodiment, by setting at least part of the hot pressing surface 20 as an arc segment 30, the arc segment 30 includes at least two arc surfaces 40 connected in sequence, and a sealing area with a continuous arc surface 40 can be formed during the hot pressing process. Compared with the planar sealing area formed by the flat head, the sealing area of ​​the continuous arc surface 40 can achieve the same sealing effect as the planar sealing area with a smaller width. In this way, the width of the head 10 can be reduced, the width of the sealing area can be reduced, and the width of the core can be increased, thereby improving the energy density of the battery cell.

[0030] Among them, the hot pressing surface 20 extends along the length direction of the end cap 10, so that the hot pressing surface 20 can cover the entire area of ​​the bag opening of the aluminum-plastic film bag. The width direction of the hot pressing surface 20 is the width of the sealing area formed after hot pressing. The width of the sealing area determines the length of the sealing path. In the embodiment of the present application, the end cap 10 can form a sealing area with a continuous arc surface 40 on the aluminum-plastic film bag. Since the length of the curve between two points must be greater than the length of the straight line, the actual sealing path of the end cap 10 in the present application will be much greater than the width of the end cap 10. In this way, it can be ensured that the sealing area has a sealing path of sufficient depth to prevent water vapor from entering the aluminum-plastic film bag and causing bloating and leakage of the battery cell.

[0031] It is understandable that after the end cap 10 hot presses the aluminum-plastic film bag to seal the aluminum-plastic film bag, the shape of the formed sealing area will be the same as the shape of the hot pressing surface 20. As a result, at least part of the sealing area will also be in the shape of a continuous arc surface 40. Compared with the horizontal surface sealing area formed by the flat end cap, the sealing area that is at least partly a continuous arc surface 40 can have a certain distribution in the height direction, thereby lengthening the sealing distance, so that a narrower sealing area can also achieve the same sealing effect. As a result, the width of the end cap 10 can be reduced. For the same model of battery cells, reducing the width of the end cap 10 can reduce the width of the sealing area, and the size of the core can be designed to be larger, thereby improving the energy density of the battery cell.

[0032] like Figure 4 and Figure 7 As shown, only a portion of the hot pressing surface 20 may be an arc segment 30, and this portion of the arc segment 30 can also increase the sealing path of the aluminum-plastic film bag during the hot pressing and sealing process. Figure 3 and Figure 6 As shown, the hot pressing surface 20 may have two arc sections 30, which can increase the sealing path of the aluminum-plastic film bag during the hot pressing and sealing process. Figure 2 and Figure 5 As shown, the entire area of ​​the hot pressing surface 20 is the arc segment 30. During the hot pressing sealing process, the arc segment 30 that runs through the width direction of the hot pressing surface 20 can greatly extend the sealing path of the aluminum-plastic film bag.

[0033] Since each arc surface 40 is concave inwardly or convexly inwardly of the hot pressing surface 20, the arc segment 30 formed is non-S-shaped. It is understandable that the "S"-shaped arc segment 30 will have crests and troughs, and the height difference between the crests and the troughs is large, which easily leads to excessive deformation of the sealing area and causes the aluminum-plastic film to break, resulting in sealing failure. The non-S-shaped arc segment 30 formed in the embodiment of the present application can only have concave troughs or convex crests to control the deformation degree of the sealing area within a suitable range, thereby preventing the aluminum-plastic film from breaking and causing sealing failure.

[0034] The continuous arc surface 40 structure formed in the embodiment of the present application is also non-zigzag. It is understandable that the sawtooth shape will also have a highest point similar to a crest and a lowest point similar to a trough, and its bend is directly bent at an angle. Based on the height difference and the bending method, it is easy to cause the deformation degree of the sealing area to be too large, causing the aluminum-plastic film to break, resulting in sealing failure. The non-"S"-shaped arc segment 30 formed in the embodiment of the present application can only have an inwardly concave trough or an outwardly convex crest to control the deformation degree of the sealing area within a suitable range, thereby preventing the aluminum-plastic film from breaking and causing sealing failure.

[0035] like Figures 2 to 4 As shown, in some embodiments, each arc surface 40 is convex from the hot pressing surface 20, and two adjacent arc surfaces 40 are connected at one end close to each other.

[0036] like Figures 5 to 7 As shown, in some embodiments, each arc surface 40 is concave inwardly of the hot pressing surface 20 , and two adjacent arc surfaces 40 are connected at one end close to each other.

[0037] Among them, the head structure is particularly suitable for the top sealing process of aluminum-plastic film bags. Based on the top sealing of aluminum-plastic film bags, the head 10 is usually set to two, namely an upper head and a lower head. The hot pressing surface 20 of the upper head and the hot pressing surface 20 of the lower head are arranged opposite to each other. When the arc segment 30 of the hot pressing surface 20 in the upper head is an inwardly concave arc surface 40, the arc segment 30 of the hot pressing surface 20 in the lower head is an outwardly convex arc surface 40, and the inwardly concave arc surface 40 is matched with the outwardly convex arc surface 40. When the arc segment 30 of the hot pressing surface 20 in the upper head is an outwardly convex arc surface 40, the arc segment 30 of the hot pressing surface 20 in the lower head is an inwardly concave arc surface 40, and the inwardly concave arc surface 40 is matched with the outwardly convex arc surface 40. As a result, the hot pressing surface 20 of the upper sealing head and the hot pressing surface 20 of the lower sealing head can be butted against each other during the hot pressing sealing process, thereby achieving hot pressing sealing of the aluminum-plastic film bag.

[0038] like Figure 2 and Figure 5 As shown, the width of the end cap 10 is D, which satisfies: 0.5 mm ≤ D ≤ 1.0 mm.

[0039] When a flat head is used for hot pressing sealing in the related art, the width of the flat head needs to be designed to be at least 1.5 mm. The sealing width in the embodiment of the present application can be designed to be between 0.5 mm and 1.0 mm, which can greatly reduce the width of the head 10, reduce the width of the sealing area, and increase the width of the core, thereby improving the energy density of the battery cell.

[0040] For example, the width D of the sealing head 10 can be set to 0.5 mm, 0.7 mm, 0.8 mm, 1.0 mm, or any value therebetween.

[0041] It is understandable that if the width of the seal 10 is too small, less than 0.5 mm, the length of the sealing path may be insufficient, making it difficult for the aluminum-plastic film bag to meet the sealing requirements, causing water vapor to enter the aluminum-plastic film bag and cause the battery cell to swell and leak. If the width of the seal 10 is too large, greater than 1.0 mm, the width of the sealing area will be larger, and the sealing area will also occupy a larger space, affecting the width design of the winding core, resulting in an insignificant increase in the energy density of the battery cell.

[0042] Please continue reading Figure 2 and Figure 5 In some embodiments, along the width direction of the hot pressing surface 20 , the entire area of ​​the hot pressing surface 20 is an arc segment 30 .

[0043] It can be understood that the arc segment 30 runs through the width direction of the hot pressing surface 20, so that the entire sealing area is a continuous arc surface 40 structure. Therefore, each part of the sealing area can be fully utilized to extend the sealing path, ensure the sealing effect of the aluminum-plastic film bag, and prevent water vapor from entering the aluminum-plastic film bag and causing the battery core to swell and leak.

[0044] like Figure 2 As shown, along the width direction of the hot pressing surface 20 , the entire area of ​​the hot pressing surface 20 is the convex arc surface 40 connected in sequence.

[0045] like Figure 5 As shown, along the width direction of the hot pressing surface 20 , the entire area of ​​the hot pressing surface 20 is the concave arc surface 40 connected in sequence.

[0046] In some embodiments, the arc length and the corresponding central angle of each arc surface 40 are the same. Then, the shape of each arc surface 40 is the same, thereby facilitating the manufacture of the end cap 10. It can be understood that the shape of each arc surface 40 is the same, which can facilitate the mold design, mold opening, and demolding of the end cap 10.

[0047] To ensure the curvature of the arc surface 40 , the value range of the central angle α corresponding to the arc surface 40 is: 172°≤α≤180°.

[0048] In some embodiments, each arc surface 40 is convex from the hot pressing surface 20 , and the central angle of each arc surface 40 is 180°, and the arc length of each arc surface 40 is 0.1 mm.

[0049] In some embodiments, each arc surface 40 is concave inwardly of the hot pressing surface 20 , and the central angle of each arc surface 40 is 180°, and the arc length of each arc surface 40 is 0.1 mm.

[0050] In some embodiments, each arc surface 40 is convex from the hot pressing surface 20 , and the central angle of each arc surface 40 is 172°, and the arc length of each arc surface 40 is 0.08 mm.

[0051] In some embodiments, each arc surface 40 is concave inwardly of the hot pressing surface 20 , and the central angle of each arc surface 40 is 172°, and the arc length of each arc surface 40 is 0.08 mm.

[0052] like Figure 3 and Figure 6 As shown, in some embodiments, along the width direction of the hot pressing surface 20 , the hot pressing surface 20 includes at least two arc segments 30 disposed at intervals, and each two adjacent arc segments 30 are connected by a straight segment 50 .

[0053] By providing a plurality of arc segments 30, the sealing path can be fully extended. This ensures that the sealing area has a sealing path of sufficient depth to prevent water vapor from entering the aluminum-plastic film bag and causing the battery core to swell and leak. The straight segment 50 connects two adjacent arc segments 30 to prevent the hot pressing surface 20 from forming an "S"-shaped structure, which causes the sealing area to deform too much and cause the aluminum-plastic film to break, resulting in sealing failure.

[0054] like Figure 3 As shown, along the width direction of the hot pressing surface 20 , the hot pressing surface 20 includes two arc segments 30 disposed at intervals, and each arc segment 30 includes at least two arc surfaces 40 that are connected in sequence and protrude from the hot pressing surface 20 .

[0055] like Figure 6 As shown, along the width direction of the hot pressing surface 20 , the hot pressing surface 20 includes two arc segments 30 disposed at intervals, and each arc segment 30 includes at least two arc surfaces 40 connected in sequence and concave in the hot pressing surface 20 .

[0056] In some embodiments, for the arc surfaces 40 in the same arc segment 30, the arc length and the corresponding central angle of the arc surface 40 are the same, and for the arc surfaces 40 in different arc segments 30, at least one of the arc length and the corresponding central angle of the arc surface 40 is different.

[0057] It can be understood that the shapes of the arc surfaces 40 in the same arc segment 30 are the same, and the arc surfaces 40 in different arc segments 30 may have the same arc length but different corresponding center angles. Alternatively, the arc surfaces 40 in different arc segments 30 may have different arc lengths but the same corresponding center angles. The arc lengths and corresponding center angles of the arc surfaces 40 in different arc segments 30 are different.

[0058] Based on the above design, the parameters of the arc surface 40 can be reasonably designed according to different arc segments 30 to ensure the sealing effect of the sealing head 10 on the aluminum-plastic film bag after hot pressing.

[0059] In some embodiments, the central angles of the arc surfaces 40 located in different arc segments 30 are 180°, 175° and 172° respectively, and the arc lengths of the arc surfaces 40 located in different arc segments 30 are all 0.1 mm.

[0060] In some embodiments, the central angles of the arc surfaces 40 in different arc segments 30 are all 180°, and the arc lengths of the arc surfaces 40 in different arc segments 30 are 0.1 mm, 0.08 mm, and 0.07 mm, respectively.

[0061] In some embodiments, the central angles of the arc surfaces 40 in different arc segments 30 are 180°, 175° and 172°, respectively, and the arc lengths of the arc surfaces 40 in different arc segments 30 are 0.1 mm, 0.08 mm and 0.07 mm, respectively.

[0062] In some embodiments, each arc surface 40 is concave inwardly of the hot pressing surface 20 , the concave depth of the arc surface 40 is H1 , the thickness of the roll core in the aluminum-plastic film bag is H2 , and the following is satisfied: H1 ≤ H2 .

[0063] Since the depth of the concave surface 40 is less than or equal to the thickness of the core roll in the aluminum-plastic film bag, the height of the sealed area formed after the aluminum-plastic film bag is hot-pressed and sealed will be less than or equal to the thickness of the core roll to prevent the sealed area from being too high and affecting the packaging of the core roll.

[0064] It is understandable that since the thickness of the packaging shell is designed based on the thickness of the core in the packaging process, if the recessed depth H1 of the arc surface 40 is greater than the thickness H2 of the core, the height of the sealing area will be greater than the height of the core. At this time, the sealing area will not be able to enter the shell, thereby affecting the continuation of subsequent processes.

[0065] In the embodiment of the present application, it is preferred that the concave depth H1 of the arc surface 40 is less than the thickness H2 of the winding core. When assembling into the shell, one side of the sealing area can be inserted into the packaging shell first, which is conducive to the rapid assembly of the winding core.

[0066] In some embodiments, each arc surface 40 is convex from the hot pressing surface 20 , the convex height of the arc surface 40 is H3 , the thickness of the roll core in the aluminum-plastic film bag is H2 , and the following is satisfied: H3≤H2.

[0067] Since the convex height of the arc surface 40 is less than or equal to the thickness of the core roll in the aluminum-plastic film bag, after the aluminum-plastic film bag is hot-pressed and sealed, the height of the sealed area formed will be less than or equal to the thickness of the core roll to prevent the sealed area from being too high and affecting the packaging of the core roll.

[0068] It is understandable that since the thickness of the packaging shell is designed based on the thickness of the core in the packaging process, if the convex height H3 of the arc surface 40 is greater than the thickness H2 of the core, the height of the sealing area will be greater than the height of the core. At this time, the sealing area will not be able to enter the shell, thereby affecting the continuation of subsequent processes.

[0069] In the embodiment of the present application, it is preferred that the convex height H3 of the arc surface 40 is less than the thickness H2 of the winding core. When assembling into the shell, one side of the sealing area can be inserted into the packaging shell first, which is conducive to the rapid assembly of the winding core.

[0070] On the other hand, the embodiment of the present application further provides a top sealing mechanism, including an upper sealing head and a lower sealing head, wherein at least one of the upper sealing head and the lower sealing head adopts the aforementioned sealing head structure.

[0071] In this embodiment, by setting at least part of the hot pressing surface 20 as an arc segment 30, the arc segment 30 includes at least two arc surfaces 40 connected in sequence, and a sealing area with a continuous arc surface 40 can be formed during the hot pressing process. Compared with the planar sealing area formed by the flat head, the sealing area of ​​the continuous arc surface 40 can achieve the same sealing effect as the planar sealing area with a smaller width. In this way, the width of the head 10 can be reduced, the width of the sealing area can be reduced, and the width of the core can be increased, thereby improving the energy density of the battery cell.

[0072] Among them, when the top sealing mechanism is used to perform hot-pressing sealing on the aluminum-plastic film bag, the hot-pressing surface 20 of the upper head and the hot-pressing surface 20 of the lower head are arranged opposite to each other. When the arc segment 30 of the hot-pressing surface 20 in the upper head is an inwardly concave arc surface 40, the arc segment 30 of the hot-pressing surface 20 in the lower head is an outwardly convex arc surface 40, and the inwardly concave arc surface 40 matches the outwardly convex arc surface 40. When the arc segment 30 of the hot-pressing surface 20 in the upper head is an outwardly convex arc surface 40, the arc segment 30 of the hot-pressing surface 20 in the lower head is an inwardly concave arc surface 40, and the inwardly concave arc surface 40 matches the outwardly convex arc surface 40. As a result, the hot-pressing surface 20 of the upper head and the hot-pressing surface 20 of the lower head can form a butt joint during the hot-pressing sealing process, thereby realizing the hot-pressing sealing of the aluminum-plastic film bag.

[0073] In some embodiments, the method of top-sealing the aluminum-plastic film bag by the top-sealing mechanism is as follows:

[0074] S100, hot pressing the aluminum-plastic film for the test by using the upper head and the lower head.

[0075] S200, inspecting the sealing area formed on the test aluminum-plastic film by using an ultrasonic scanning microscope.

[0076] S300: In response to the detection result that the upper sealing head and the lower sealing head are aligned with each other and are horizontally positioned, the aluminum-plastic film bag to be packaged is placed between the upper sealing head and the lower sealing head.

[0077] S400, top-sealing the aluminum-plastic film bag using an upper sealing head and a lower sealing head according to hot pressing parameters corresponding to the model of the aluminum-plastic film bag.

[0078] It is understandable that before the aluminum-plastic film bag to be packaged is sealed, the parallelism of the upper and lower heads is first determined by testing to prevent poor sealing of the aluminum-plastic film bag. After confirming that the upper and lower heads are aligned with each other and in a horizontal position, the aluminum-plastic film bag to be packaged is sealed to ensure the sealing quality.

[0079] Among them, by using an ultrasonic scanning microscope to detect the sealing area formed on the test aluminum-plastic film, the parallelism of the upper and lower heads can be judged according to the amplitude in the image, and the parallelism of the upper and lower heads can be adjusted based on the amplitude. Specifically, when the ultrasonic scanning microscope detects the sealing area, the more uniform the color displayed in the test result, the better the consistency of the sealing area, and the better the parallelism of the upper and lower heads.

[0080] If the detection result shows that the upper head and the lower head are not aligned or the position is not level, adjust the position and angle of the upper head and / or the lower head, and repeat steps S100 to S200 until the upper head and the lower head are aligned with each other and the position is level.

[0081] The aluminum-plastic film bag to be packaged contains a roll core, and the sealing portion to be top-sealed needs to be folded in half. The folded portion of the aluminum-plastic film bag is hot-pressed by the upper sealing head and the lower sealing head, thereby achieving the top sealing of the aluminum-plastic film bag.

[0082] It should be noted that the hot pressing parameters, including but not limited to the hot pressing temperature and hot pressing time, can be adjusted based on the aluminum-plastic film bag model to ensure the reliability of the hot pressing sealing of the aluminum-plastic film bag by the upper and lower heads.

[0083] After the aluminum-plastic film bag is top-sealed by the aforementioned top-sealing mechanism, side-sealing, corner-sealing and other processes may be continued.

[0084] On the other hand, an embodiment of the present application further provides a sealing device, comprising the aforementioned top sealing mechanism.

[0085] In this embodiment, by setting at least part of the hot pressing surface 20 as an arc segment 30, the arc segment 30 includes at least two arc surfaces 40 connected in sequence, and a sealing area with a continuous arc surface 40 can be formed during the hot pressing process. Compared with the planar sealing area formed by the flat head, the sealing area of ​​the continuous arc surface 40 can achieve the same sealing effect as the planar sealing area with a smaller width. In this way, the width of the head 10 can be reduced, the width of the sealing area can be reduced, and the width of the core can be increased, thereby improving the energy density of the battery cell.

[0086] Among them, when the sealing device is used to perform hot-pressing sealing on the aluminum-plastic film bag, the hot-pressing surface 20 of the upper head and the hot-pressing surface 20 of the lower head are arranged opposite to each other. When the arc segment 30 of the hot-pressing surface 20 in the upper head is an inwardly concave arc surface 40, the arc segment 30 of the hot-pressing surface 20 in the lower head is an outwardly convex arc surface 40, and the inwardly concave arc surface 40 is matched with the outwardly convex arc surface 40. When the arc segment 30 of the hot-pressing surface 20 in the upper head is an outwardly convex arc surface 40, the arc segment 30 of the hot-pressing surface 20 in the lower head is an inwardly concave arc surface 40, and the inwardly concave arc surface 40 is matched with the outwardly convex arc surface 40. As a result, the hot-pressing surface 20 of the upper head and the hot-pressing surface 20 of the lower head can form a butt joint during the hot-pressing sealing process, thereby realizing the hot-pressing sealing of the aluminum-plastic film bag.

[0087] In some embodiments, the sealing device is used to seal the aluminum-plastic film bag as follows:

[0088] S100, hot pressing the aluminum-plastic film for the test by using the upper head and the lower head.

[0089] S200, inspecting the sealing area formed on the test aluminum-plastic film by using an ultrasonic scanning microscope.

[0090] S300: In response to the detection result that the upper sealing head and the lower sealing head are aligned with each other and are horizontally positioned, the aluminum-plastic film bag to be packaged is placed between the upper sealing head and the lower sealing head.

[0091] S400, top-sealing the aluminum-plastic film bag using an upper sealing head and a lower sealing head according to hot pressing parameters corresponding to the model of the aluminum-plastic film bag.

[0092] It is understandable that before the aluminum-plastic film bag to be packaged is sealed, the parallelism of the upper and lower heads is first determined by testing to prevent poor sealing of the aluminum-plastic film bag. After confirming that the upper and lower heads are aligned with each other and in a horizontal position, the aluminum-plastic film bag to be packaged is sealed to ensure the sealing quality.

[0093] Among them, by using an ultrasonic scanning microscope to detect the sealing area formed on the test aluminum-plastic film, the parallelism of the upper and lower heads can be judged according to the amplitude in the image, and the parallelism of the upper and lower heads can be adjusted based on the amplitude. Specifically, when the ultrasonic scanning microscope detects the sealing area, the more uniform the color displayed in the test result, the better the consistency of the sealing area, and the better the parallelism of the upper and lower heads.

[0094] If the detection result shows that the upper head and the lower head are not aligned or the position is not level, adjust the position and angle of the upper head and / or the lower head, and repeat steps S100 to S200 until the upper head and the lower head are aligned with each other and the position is level.

[0095] The aluminum-plastic film bag to be packaged contains a roll core, and the sealing portion to be top-sealed needs to be folded in half. The folded portion of the aluminum-plastic film bag is hot-pressed by the upper sealing head and the lower sealing head, thereby achieving the top sealing of the aluminum-plastic film bag.

[0096] It should be noted that the hot pressing parameters, including but not limited to the hot pressing temperature and hot pressing time, can be adjusted based on the aluminum-plastic film bag model to ensure the reliability of the hot pressing sealing of the aluminum-plastic film bag by the upper and lower heads.

[0097] After the aluminum-plastic film bag is top-sealed using the aforementioned sealing device, side sealing, corner sealing and other processes may be continued.

[0098] The above is a detailed introduction to the embodiments of the present invention. Specific examples are used in this article to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method and core idea of ​​the present invention. At the same time, for technicians in this field, according to the idea of ​​the present invention, there will be changes in the specific implementation method and application scope. In summary, the content of this specification should not be understood as a limitation on the present invention.

Claims

1. A head structure for hot pressing aluminum-plastic film bags, characterized in that: include: A head, one side of which has a hot pressing surface extending along its length direction, and along the width direction of the hot pressing surface, at least a portion of the hot pressing surface is an arc segment, and the arc segment includes at least two arc surfaces connected in sequence, wherein each of the arc surfaces is concave inwardly of the hot pressing surface, or each of the arc surfaces is convex inwardly of the hot pressing surface.

2. The head structure according to claim 1, characterized in that: The width of the head is D, which satisfies: 0.5 mm ≤ D ≤ 1.0 mm.

3. The head structure according to claim 1, characterized in that: Along the width direction of the hot pressing surface, the entire area of ​​the hot pressing surface is an arc segment.

4. The head structure according to any one of claims 1 to 3, characterized in that: The arc length and the corresponding central angle of each arc surface are the same.

5. The head structure according to claim 1, characterized in that: Along the width direction of the hot pressing surface, the hot pressing surface includes at least two arc segments arranged at intervals, and each two adjacent arc segments are connected by a straight segment.

6. The end cap structure according to claim 5, characterized in that: For the arc surfaces in the same arc segment, the arc lengths and corresponding center angles of the arc surfaces are the same; for the arc surfaces in different arc segments, at least one of the arc lengths and corresponding center angles of the arc surfaces is different.

7. The end cap structure according to any one of claims 1 to 3, characterized in that: Each of the arc surfaces is concave inwardly of the hot pressing surface, the concave depth of the arc surface is H1, the thickness of the roll core in the aluminum-plastic film bag is H2, and the relationship H1≤H2 is satisfied.

8. The end cap structure according to any one of claims 1 to 3, characterized in that: Each of the arc surfaces is convex to the hot pressing surface, the convex height of the arc surface is H3, the thickness of the roll core in the aluminum-plastic film bag is H2, and the following is satisfied: H3≤H2.

9. A top sealing mechanism, comprising an upper sealing head and a lower sealing head, characterized in that: At least one of the upper head and the lower head adopts the head structure as described in any one of claims 1-8.

10. A sealing device, characterized in that: It comprises the top sealing mechanism as claimed in claim 9.

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