Sealing device and secondary battery

Abstract

The invention relates to a sealing device and a secondary battery. The sealing device comprises a sealing block, and the sealing block is used for sealing a lead film wrapping lead metal and a soft package surrounding the lead film. The sealing block includes a first sealing surface configured to seal a central portion of the lead film overlapping the lead metal. The first sealing surface comprises a central sealing surface; the side sealing faces are located on the two sides of the center sealing face in the length direction of the first sealing face, and step differences are formed between the side sealing faces and the center sealing face. The side sealing surface has a sealing protrusion protruding by a predetermined thickness in the pressing direction of the sealing block so as to prevent the lead film from moving in the width direction of the side sealing surface. According to the sealing device disclosed by the invention, more fused insulating parts of the inner resin layer and the lead film of the soft package can be extruded into the gap between the soft package and the lead film and filled in the gap in the process of sealing the soft package, so that the manufactured secondary battery is reliably sealed.

Description

Technical Field

[0001] The present invention relates to the field of secondary batteries. More specifically, the present invention relates to a sealing device for sealing a secondary battery during the manufacturing process of the secondary battery and a secondary battery manufactured using the sealing device. Background Art

[0002] The content of this section only provides background information related to the present invention, which may not constitute prior art.

[0003] With the active development of mobile devices such as portable electronic products (e.g., laptop computers, portable imaging devices, mobile phones, etc.), electric vehicles, and robots, as an alternative energy source to fossil fuels, the demand for rechargeable and dischargeable secondary batteries has increased rapidly. Secondary batteries are widely used as driving power sources in these mobile devices to provide power. A secondary battery includes a battery case and an electrode assembly accommodated in the battery case. According to the shape of the battery case for accommodating the electrode assembly, secondary batteries are classified into cylindrical batteries with a cylindrical metal can as the battery case, prismatic batteries with a prismatic metal can as the battery case, and pouch-shaped batteries with a pouch-shaped shell as the battery case. The pouch-shaped shell of the pouch-shaped battery is usually made of an aluminum laminate and has flexibility and can change its shape. Therefore, the pouch-shaped shell of the pouch-shaped battery is usually referred to as a soft pack, and the pouch-shaped battery is usually also referred to as a soft pack type battery. Soft pack type batteries are widely used due to advantages such as being easy to stack and arrange.

[0004] During the manufacturing process of a soft pack type battery, a laminate sheet for the soft pack wraps the electrode assembly and is heat-sealed to accommodate the electrode assembly in the soft pack, and a part of the lead metal connected to the electrode assembly is clamped and sealed between the upper and lower parts of the soft pack to prevent the electrolyte solution injected into the soft pack from leaking. During the process of heat-sealing the soft pack, due to the thickness of the lead metal, there is a thickness difference between the part of the sealing part of the soft pack where the lead metal is sealed and the part without the lead metal, thus forming a stepped portion. Correspondingly, a void is formed at the sealing part corresponding to the stepped portion. For example, voids are formed on both sides of the sealing part where the lead metal is sealed, and the void increases as the thickness of the lead metal increases. During the sealing process, when there are still unfilled voids in the sealing part, the sealing is not tight, and thus the phenomenon of electrolyte solution leakage is likely to occur.

[0005] Therefore, it is necessary to improve the sealing of the secondary battery to avoid forming voids in the sealing part of the soft pack and affecting the sealing performance of the secondary battery, thereby preventing the electrolyte solution from leaking. Summary of the Invention

[0006] An object of the present invention is to solve at least one of the above problems. An object of the present invention is to promote the flow of the molten insulating material towards the gap between the flexible package and the lead film during the sealing of the flexible package, so as to facilitate the achievement of reliable sealing.

[0007] One aspect of the present invention is to provide a sealing device, which includes a sealing block configured to seal a lead film wrapping a lead metal and a flexible package surrounding the lead film. The sealing block includes a first sealing surface configured to seal the central portion of the lead film overlapping with the lead metal. The first sealing surface includes: a central sealing surface; and side sealing surfaces located on both sides of the central sealing surface in the length direction of the first sealing surface, and forming a step difference with the central sealing surface. The side sealing surface has a sealing protrusion protruding a predetermined thickness in the pressing direction of the sealing block to prevent the lead film from moving in the width direction of the side sealing surface.

[0008] In one embodiment, the side sealing surface extends from the end of the central sealing surface and protrudes from the central sealing surface in the pressing direction to form a step difference.

[0009] In one embodiment, the sealing block further includes a second sealing surface located on both sides in the length direction of the first sealing surface and forming a step difference with the first sealing surface in a manner of sealing the side portion of the lead film and the flexible package, and the side portion of the lead film does not overlap with the lead metal in the thickness direction.

[0010] In one embodiment, the central sealing surface, the side sealing surface, and the second sealing surface sequentially form a step difference in the pressing direction.

[0011] In one embodiment, the side sealing surface overlaps with the end region in the width direction of the lead metal.

[0012] In one embodiment, between the side sealing surface and the second sealing surface, there is an inclined portion that extends obliquely between one end of the side sealing surface and one end of the second sealing surface.

[0013] In one embodiment, the sealing protrusion has a shape extending along the length direction perpendicular to the width direction of the side sealing surface.

[0014] In one embodiment, a plurality of sealing protrusions are spaced apart at a predetermined interval in the width direction of the side sealing surface.

[0015] In one embodiment, the sealing protrusion is formed at the edge in the width direction of the side sealing surface.

[0016] In one embodiment, the sealing protrusion includes: a first sealing protrusion formed at one edge in the width direction of the side sealing surface; and a second sealing protrusion formed at the other edge in the width direction of the side sealing surface.

[0017] In one embodiment, the sealing protrusion extends from the side sealing surface to the second sealing surface.

[0018] In one embodiment, the sealing device includes a pair of sealing blocks arranged facing each other in the pressurizing direction.

[0019] Another aspect of the present invention is to provide a secondary battery, which includes: a pouch that includes a storage part for accommodating an electrode assembly and a sealing part located around the storage part; a lead metal that is connected to the electrode assembly and protrudes outward from the sealing part; and a lead film that wraps the lead metal and is sealed with the sealing part. The sealing part includes a first region that is sealed with the central part of the lead film and overlaps with the lead metal. The first region includes: a central region; and side regions that are located on both sides of the central region in the length direction of the first region and form a step difference with the central region. The side regions are formed with pressing parts that extend along the length direction of the side regions.

[0020] In one embodiment, the pressing parts are configured as a pair of pressing parts that extend side by side at a predetermined interval in the width direction of the side regions.

[0021] In one embodiment, the pressing parts are formed on both side edges in the width direction of the side regions.

[0022] In one embodiment, the sealing part further includes a second region that is located on both sides in the length direction of the first region and forms a step difference with the first region, and the second region is sealed with the side part of the lead film, and the side part of the lead film does not overlap with the lead metal in the thickness direction of the sealing part.

[0023] In one embodiment, the central region, the side regions, and the second region form step differences in sequence in the thickness direction.

[0024] In one embodiment, the sealing part includes an inclined region that is formed between the side regions and the second region and extends obliquely between one end of the side region and one end of the second region.

[0025] In one embodiment, the pressing parts extend from the side regions to the second region.

[0026] In one embodiment, the central region, the side regions, and the pressing parts are formed on both sides in the thickness direction of the sealing part.

[0027] Another aspect of the present invention is to provide a sealing device. The sealing device includes a sealing block configured to seal a lead film wrapping a lead metal and a flexible package surrounding the lead film. The sealing block includes a first sealing surface configured to seal a central portion of the lead film overlapping with the lead metal. The first sealing surface includes: a central sealing surface; and side sealing surfaces located on both sides of the central sealing surface in the length direction of the first sealing surface and forming a step difference with the central sealing surface. The sealing block further includes a second sealing surface located on both sides in the length direction of the first sealing surface and protruding relative to the first sealing surface in the pressing direction of the sealing block to form a step difference. The second sealing surface seals a side portion of the lead film and the flexible package, and the side portion of the lead film does not overlap with the lead metal in the thickness direction. The central sealing surface, the side sealing surfaces, and the second sealing surface form a step difference in the pressing direction.

[0028] In one embodiment, the side sealing surfaces protrude relative to the central sealing surface in the pressing direction to form a step difference, and the side sealing surfaces have sealing protrusions protruding a specified thickness in the pressing direction of the sealing block to prevent the lead film from moving in the width direction of the side sealing surfaces.

[0029] Another aspect of the present invention is to provide a secondary battery. The secondary battery includes: a flexible package including a storage portion for accommodating an electrode assembly and a sealing portion located around the storage portion; a lead metal connected to the electrode assembly and protruding outward from the sealing portion; and a lead film wrapping the lead metal and sealed with the sealing portion. The sealing portion includes a first region sealed with a central portion of the lead film and overlapping with the lead metal. The first region includes: a central region; and side regions located on both sides of the central region in the length direction of the first region and forming a step difference with the central region. The sealing portion further includes a second region located on both sides in the length direction of the first region and forming a step difference with the first region. The second region seals a side portion of the lead film, and the side portion of the lead film does not overlap with the lead metal in the thickness direction of the sealing portion. The central region, the side regions, and the second region form a step difference in sequence in the thickness direction.

[0030] In one embodiment, the side regions are further pressed in the thickness direction relative to the central region, and the side regions are formed with pressing portions extending along the length direction of the side regions.

[0031] The present invention provides an improved sealing device and a secondary battery. According to the sealing device of the present invention, by providing a central sealing surface and a side sealing surface that form a step difference with each other on the first sealing surface, and preferably providing a sealing protrusion on the first sealing surface, more molten insulating portions of the inner resin layer of the flexible package and the lead film can be squeezed into the gap between the flexible package and the lead film and fill the gap. Thus, even when the thickness of the lead metal is relatively thick, the gap can be filled to reduce the gap in the sealing portion and even avoid leaving a gap in the sealing portion, thereby enabling a reliable seal to be formed. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Embodiments of the present invention will be described below by way of example only with reference to the drawings. In the drawings, the same features or components are denoted by the same reference numerals, and the drawings are not necessarily drawn to scale, and in the drawings:

[0033] Figure 1 is a perspective view of a flexible package type secondary battery.

[0034] Figure 2 is a perspective view of a sealing block of a sealing device according to a comparative example.

[0035] Figure 3 is Figure 2 an enlarged view of a portion B shown in

[0036] Figure 4 is a cross-sectional view taken along line I-I' in Figure 1 showing a flexible package type secondary battery manufactured by a sealing device according to a comparative example.

[0037] Figure 5 is a top view showing an enlarged portion around a lead film of a sealing portion of a flexible package formed using a sealing device according to a comparative example.

[0038] Figure 6 is a cross-sectional view taken at a position corresponding to line II-II' in Figure 5 when sealing a flexible package using a sealing device according to a comparative example.

[0039] Figure 7 is a view showing the phenomenon of the lead film protruding in the width direction of the sealing portion during the sealing process.

[0040] Figure 8 is a perspective view of a sealing block of a sealing device according to Embodiment 1 of the present invention.

[0041] Figure 9 is Figure 8 an enlarged view of a portion C shown in

[0042] Figure 10is a cross-sectional view taken at I-I' in a pouch-type secondary battery manufactured by the sealing device according to Embodiment 1 of the present invention. Figure 1 in

[0043] Figure 11 is a top view showing an enlarged view of a portion around a lead film of a sealing portion of a pouch formed using the sealing device according to Embodiment 1 of the present invention.

[0044] Figure 12 is a cross-sectional view taken at a position corresponding to the line III-III' when sealing a pouch using the sealing device according to Embodiment 1 of the present invention. Figure 11 in

[0045] Figure 13 is a partially enlarged perspective view of a sealing block of the sealing device according to Embodiment 2 of the present invention.

[0046] Figure 14 is a top view showing an enlarged view of a portion around a lead film of a sealing portion of a pouch formed using the sealing device according to Embodiment 2 of the present invention.

[0047]

Reference Signs

[0048] 10: Pouch 11: Accommodating Portion

[0049] 12: Sealing Portion 13: First Region

[0050] 13A: Central Region 13B: Side Region

[0051] 14: Second Region 15: Pressing Portion

[0052] 15A: First Pressing Portion 15B: Second Pressing Portion

[0053] 16: Inclined Region 17: Third Region

[0054] 20: Lead Metal 30: Lead Film

[0055] 30A: Central Portion 30B: Side Portion

[0056] 100, 200, 200A: Sealing Block 110, 210: First Sealing Surface

[0057] 211: Central Sealing Surface 212: Side Sealing Surface

[0058] 120, 220: Second Sealing Surface 230, 230A: Sealing Protrusion

[0059] 231, 231A: First Sealing Protrusion 232, 232A: Second Sealing Protrusion

[0060] 140, 240: Third sealing surface 150, 250: Inclined portion

[0061] S: Gap Detailed implementation mode

[0062] The following description is merely exemplary in nature and is not intended to limit the present invention, its applications, and uses. It should be understood that in all these drawings, like reference numerals indicate the same or similar parts and features. Each drawing only schematically shows the concept and principle of the implementation mode of the present invention, and does not necessarily show the specific dimensions and their ratios of each implementation mode of the present invention. Specific parts in a specific drawing may be exaggerated to illustrate relevant details or structures of the implementation mode of the present invention.

[0063] In the description of the implementation mode of the present invention, the orientation terms related to "upper", "lower", "left", and "right" are described based on the upper, lower, left, and right positions of the views shown in the drawings. In actual applications, the "upper", "lower", "left", and "right" position relationships used herein can be defined according to actual situations, and these relationships can be reversed with each other.

[0064] Figure 1 A perspective view of a pouch-type secondary battery is shown. As Figure 1 shown, the pouch-type secondary battery includes a pouch 10 and an electrode assembly (not shown in the figure). The pouch 10 includes an upper pouch 10A and a lower pouch 10B. Both the upper pouch 10A and the lower pouch 10B can be formed of a laminate, which may include an inner resin layer, a metal layer, and an outer resin layer, for example. The outer peripheral edges of the upper pouch 10A and the lower pouch 10B are heat-sealed together to form a sealing portion 12 and a receiving portion 11 enclosed within the sealing portion 12. The receiving portion 11 is used to accommodate the electrode assembly (not shown in the figure) between the upper pouch 10A and the lower pouch 10B. The peripheral portions of the upper pouch 10A and the lower pouch 10B are heat-sealed to each other around the receiving portion 11 to form the sealing portion 12, so as to seal the electrode assembly within the receiving portion 11 of the pouch 10. The pouch-type secondary battery further includes a lead metal 20. One end of the lead metal 20 is connected to the electrode assembly accommodated in the receiving portion 11, and the other end of the lead metal 20 extends out of the pouch 10. In the example shown in the figure, the two lead metals 20 of the pouch-type secondary battery are respectively led out from opposite sides of the pouch 10 in the Y-axis direction. However, the way of leading out the lead metal 20 is not limited to this. In other examples, the two lead metals 20 of the pouch-type secondary battery can be led out from the same side of the pouch 10.

[0065] At the sealing portion 12, the lead metal 20 is sandwiched and sealed between the upper pouch 10A and the lower pouch 10B. In order to enhance the sealing engagement between the upper pouch 10A and the lower pouch 10B and the lead metal 20 and to provide insulation between the lead metal 20 and the pouch 10, a lead film 30 can be wrapped around the lead metal 20 such that when the upper pouch 10A and the lower pouch 10B of the pouch 10 are heat-sealed, the lead film 30 is sandwiched between the upper pouch 10A and the lower pouch 10B and the lead metal 20 and forms a seal with the upper pouch 10A and the lower pouch 10B. The lead film 30 can be made of the same insulating material as the inner resin layer of the pouch 10.

[0066] Figure 2 FIG. shows a perspective view of a sealing block 100 of a sealing device for sealing a pouch 10 according to a comparative example. The sealing device includes a plurality of sealing blocks. When sealing the pouch 10, the plurality of sealing blocks sandwich the upper pouch 10A and the lower pouch 10B toward each other between opposing sealing blocks from the side where the upper pouch 10A is located and from the side where the lower pouch 10B is located, and heat-seal the upper pouch 10A and the lower pouch 10B together by applying heat to form a sealing portion 12. Figure 2 The sealing block 100 shown in is for sealing the portion of the pouch 10 from which the lead metal 20 extends ( Figure 1 the portion extending in the direction shown by the X-axis in ). For the portion of the pouch 10 where the lead metal 20 is not provided ( Figure 1 the portion extending in the direction shown by the Y-axis in ), the sealing block only needs to be able to heat-seal the corresponding portions of the upper pouch 10A and the lower pouch 10B together, and there are no particular restrictions. Therefore, any suitable sealing block can be used. For example, a sealing block of an existing design in the art can be used, and thus will not be described in detail herein.

[0067] Figure 3 FIG. shows Figure 2 an enlarged view of part B of the sealing block 100 shown in, and part B of the sealing block 100 is for sealing the area of the pouch 10 where the lead metal 20 and the lead film 30 are provided. As Figure 3 shown, the sealing block 100 includes a first sealing surface 110, a second sealing surface 120, and a third sealing surface 140. The first sealing surface 110 is for sealing the central portion of the pouch 10 and the lead film 30 overlapping the lead metal 20. That is, the first sealing surface 110 corresponds to the portion of the sealing portion 12 where both the lead metal 20 and the lead film 30 are sealed in the thickness direction between the upper pouch 10A and the lower pouch 10B. The second sealing surface 120 is located on both sides in the longitudinal direction of the first sealing surface 110 ( Figure 3 the direction shown by the X-axis in ) and the second sealing surface 120 faces the pressurizing direction of the sealing block 100 relative to the first sealing surface 110 ( Figure 3The first sealing surface 110 protrudes in the direction indicated by the Z axis in FIG. 1 , and an inclined portion 150 is formed between the first sealing surface 110 and the second sealing surface 120. The second sealing surface 120 is used to seal the side portion of the soft package 10 and the lead film 30. That is, the second sealing surface 120 corresponds to the portion of the sealing portion 12 where the lead film 30 is sealed in the thickness direction between the upper soft package 10A and the lower soft package 10B without sandwiching the lead metal 20. The third sealing surface 140 is located on the outside of the second sealing surface 120 in the length direction, and is used to seal the upper soft package 10A and the lower soft package 10B. That is, the third sealing surface 140 corresponds to the portion of the sealing portion 12 where the lead metal 20 or the lead film 30 is not sandwiched in the thickness direction between the upper soft package 10A and the lower soft package 10B.

[0068] Figure 4 Shown by Figure 2 and Figure 3 The soft pack type secondary battery manufactured by sealing the soft pack 10 according to the sealing device of the comparative example shown in FIG. Figure 1 A partial cross-sectional view taken at a position corresponding to I-I' in FIG. 1 , wherein the sealing block 100 is used to seal the peripheral portion of the soft package 10 provided with the lead metal 20 and the lead film 30 ( Figure 1 ). After the outer peripheries of the upper soft bag 10A and the lower soft bag 10B are sandwiched between a pair of sealing blocks 100 to seal the soft bag 10 to form a sealing portion 12, as shown in FIG. Figure 4 As shown, a first region 13, a second region 14, and an inclined region 16 are formed on the sealing portion 12 on the upper soft package 10A side. The inclined region 16 is formed between the first region 13 and the second region 14, and extends obliquely between one end of the first region 13 and one end of the second region 14 to connect the first region 13 and the second region 14. The first region 13 corresponds to the first sealing surface 110 of the sealing block 100, the second region 14 corresponds to the second sealing surface 120 of the sealing block 100, and the inclined region 16 corresponds to the inclined portion 150 of the sealing block 100. Accordingly, the sealing portion 12 on the lower soft package 10B side also forms similar first regions, second regions, and an inclined region connecting the first region and the second region.

[0069] like Figure 4 As shown, the lead film 30 is wrapped on the lead metal 20, and the lead film 30 includes a central portion 30A and side portions 30B ( Figure 4 Only one side portion 30B is shown in FIG. 3 ). The central portion 30A of the lead film 30 is thin in the thickness direction ( Figure 4 The side portion 30B of the lead film 30 overlaps the lead metal 20 in the thickness direction ( Figure 4does not overlap with the lead metal 20 in the direction indicated by the Z-axis in []. There is a thickness difference due to the thickness of the lead metal 20 between the central portion 30A and the side portion 30B of the lead film 30. Accordingly, after sealing, a gap S is formed between the upper pouch 10A and the lead film 30 at a position corresponding to the portion between the central portion 30A and the side portion 30B of the lead film 30, and a similar gap is also formed between the lower pouch 10B and the lead film 30.

[0070] Figure 5 shows a partial top view corresponding to the portion in the frame F in [] of a pouch-type secondary battery manufactured by sealing the pouch 10 using a sealing device according to a comparative example, shows the sealing portion 12 of the pouch 10 near the lead metal 20 and the lead film 30, and shows the portions of the lead metal 20 and the lead film 30 located outside the pouch 10 to show the correspondence between the regions of the sealing portion 12 and the lead metal 20 and the lead film 30. In Figure 1 [], the first region 13 and the second region 14 of the sealing portion 12 are shown, and the third region 17 is also shown. The third region 17 corresponds to the third sealing surface 140 of the sealing block 100. In Figure 5 [], the first region 13 of the sealing portion 12 of the pouch 10 overlaps both the lead metal 20 and the lead film 30 at the line II-II'. Figure 5 [], the first region 13 of the sealing portion 12 of the pouch 10 overlaps both the lead metal 20 and the lead film 30 at the line II-II'.

[0071] Figure 6 shows a cross-sectional view taken along the width direction ( Figure 5 the direction indicated by the Y-axis in []) at a position corresponding to the line II-II' in [] when sealing the pouch 10 using a sealing device according to a comparative example. As Figure 6 shown, in the thickness direction ( Figure 6 the direction indicated by the Z-axis in []) of the pouch-type secondary battery, the upper pouch 10A and the lower pouch 10B of the pouch 10 are sandwiched between a pair of sealing blocks 100, and the first sealing surface 110 of the sealing block 100 faces and presses the first region 13 of the pouch 10. As Figure 6 shown, at least the middle portion of the first sealing surface 110 of the sealing block 100 is substantially flat in the width direction. Figure 6 shown, at least the middle portion of the first sealing surface 110 of the sealing block 100 is substantially flat in the width direction.

[0072] During the process of heat-sealing the pouch 10 using the sealing block 100, when heat is applied to the peripheral portion of the pouch 10, the inner resin layers of the upper pouch 10A and the lower pouch 10B and the lead film 30 partially melt and flow. A part of the molten insulating portions of the inner resin layers of the upper pouch 10A and the lower pouch 10B and the lead film 30 flows into the gap S between the pouch 10 and the lead metal 20 (see Figure 4)。Moreover, since the first sealing surface 110 of the sealing block 100 is substantially flat in the width direction, during the process of squeezing and heat-sealing the flexible package 10 by the sealing block 100, another part of the inner resin layer of the upper flexible package 10A and the lower flexible package 10B and the molten insulating part of the lead film 30 will be extruded from both sides in the width direction ( Figure 6 the direction indicated by the Y-axis in Figure 7 ) of the sealing part 12, so as to be extruded towards the accommodating part 11 or towards the outside of the sealing part 12.

[0073] Fig. shows a view of a part P of the lead film 30 being extruded at the sealing part 12 and protruding from the width direction of the sealing part 12 during the sealing process. Figure 6 When the thickness of the lead metal 20 (the dimension in the Z-axis direction in

[0074] ) is small, the gap S formed between the flexible package 10 and the lead film 30 is also small. In this case, the molten insulating part of the inner resin layer of the upper flexible package 10A and the lower flexible package 10B and the lead film 30 flowing into the gap S can fully fill the gap S. Therefore, the gap in the sealing part 12 of the formed flexible package 10 is small or even has no gap, and a reliable seal can be formed between the flexible package 10 and the lead metal 20. However, when the thickness of the lead metal 20 is large, the gap S formed between the flexible package 10 and the lead film 30 will also be large. During the process of heat-sealing the flexible package 10 using the sealing block 100, the molten insulating part of the inner resin layer of the upper flexible package 10A and the lower flexible package 10B and the lead film 30 flowing into the gap S is not sufficient to fully fill the larger gap S. Therefore, in the sealing part 12 of the flexible package 10 of the manufactured flexible package secondary battery, there is still a large unfilled gap, making the seal unreliable and thus prone to electrolyte solution leakage.

[0075] Figure 8 Fig. shows a perspective view of a sealing block 200 of a sealing device according to Embodiment 1 of the present invention, and Figure 9 Fig. shows Figure 8 an enlarged view of a part C of the sealing block 200 shown in

[0076] Similar to the sealing block 100 according to the comparative example, the sealing block 200 is used to seal the part of the flexible package 10 sandwiching the lead metal 20 and the lead film 30. Figure 9As shown, the sealing block 200 includes a first sealing surface 210, a second sealing surface 220, and a third sealing surface 240. The first sealing surface 210 is used to seal the peripheral portion of the soft package 10 sandwiching the lead metal 20 and the lead film 30, corresponding to the portion where both the lead metal 20 and the lead film 30 are sealed in the thickness direction between the upper soft package 10A and the lower soft package 10B of the sealing portion 12. The first sealing surface 210 includes a central sealing surface 211 and a side sealing surface 212. The side sealing surface 212 is located on both sides of the central sealing surface 211 in the length direction of the first sealing surface 210 ( Figure 9 the direction shown by the X-axis in the figure), and forms a step difference with the central sealing surface 211. In the example shown in the figure, the side sealing surface 212 protrudes relative to the central sealing surface 211 in the pressing direction of the sealing block 200 ( Figure 9 the direction shown by the Z-axis in the figure), thereby forming a step difference therebetween.

[0077] Preferably, one or more sealing protrusions 230 protruding a predetermined thickness in the pressing direction are provided on the side sealing surface 212. The sealing protrusions 230 extend in the length direction of the side sealing surface 212 ( Figure 9 the direction shown by the X-axis in the figure). In the example shown in the figure, a first sealing protrusion 231 and a second sealing protrusion 232 spaced apart from each other in the width direction ( Figure 9 the direction shown by the Y-axis in the figure) are provided on each side sealing surface 212. The first sealing protrusion 231 and the second sealing protrusion 232 are respectively located at the edge portions in the width direction of the side sealing surface 212, and the lengths of the first sealing protrusion 231 and the second sealing protrusion 232 extending in the width direction ( Figure 9 the direction shown by the Y-axis in the figure) of the side sealing surface 212 correspond to the width of the side sealing surface 212. However, the present invention is not limited thereto. In other examples according to the present invention, the sealing protrusions 230 on the side sealing surface 212 may also adopt other suitable arrangements.

[0078] The second sealing surface 220 is located on both sides in the length direction of the first sealing surface 110, and more specifically, on the outer sides in the length direction of the side sealing surface 212 of the first sealing surface 210. The second sealing surface 220 protrudes relative to the first sealing surface 210 in the pressing direction of the sealing block 200 ( Figure 9 the direction shown by the Z-axis in the figure), and more specifically, the second sealing surface 220 protrudes relative to the side sealing surface 212 of the first sealing surface 210 in the pressing direction of the sealing block 200 to form a step difference. An inclined portion 250 is formed between the second sealing surface 220 and the side sealing surface 212 of the first sealing surface 210. The third sealing surface 240 is located on the outer side in the length direction of the second sealing surface 220.

[0079] Figure 10Shows a partial cross-sectional view taken at a position corresponding to I-I' in the soft-pack type secondary battery manufactured by sealing the soft pack 10 with the sealing device according to Embodiment 1 of the present invention. Among them, the sealing block 200 according to Embodiment 1 of the present invention is used to seal the peripheral portion of the soft pack 10 where the lead metal 20 and the lead film 30 are sandwiched ( Figure 1 the peripheral portion of the soft pack 10 in the X-axis direction shown in Figure 1 ).

[0080] After sandwiching the outer peripheral edges of the upper soft pack 10A and the lower soft pack 10B between a pair of sealing blocks 200 to seal the soft pack 10 to form the sealing portion 12, as Figure 10 shown, a first region 13, a second region 14, and an inclined region 16 are formed in the sealing portion 12 on the upper soft pack 10A side. The inclined region 16 extends between one end of the first region 13 and one end of the second region 14 to connect the first region 13 and the second region 14. The first region 13 corresponds to the first sealing surface 210 of the sealing block 200, the second region 14 corresponds to the second sealing surface 220 of the sealing block 200, and the inclined region 16 corresponds to the inclined portion 250 of the sealing block 200. Accordingly, a similar first region, second region, and an inclined region connecting the first region and the second region are also correspondingly formed in the sealing portion 12 on the lower soft pack 10B side.

[0081] As Figure 10 shown, the first region 13 includes a central region 13A and side regions 13B located on both sides in the length direction of the central region 13A, where Figure 10 only one side of the side region 13B is shown. The central region 13A corresponds to the central sealing surface 211 of the first sealing surface 210 of the sealing block 200, and the side region 13B corresponds to the side sealing surface 212 of the first sealing surface 210 of the sealing block 200. As described above, the side sealing surface 212 protrudes toward the pressing direction of the sealing block 200 relative to the central sealing surface 211. Accordingly, after using the sealing block 200 to seal the soft pack 10, the side region 13B of the first region 13 of the soft pack 10 is further squeezed in the thickness direction (i.e., Figure 10 the direction shown by the Z-axis in

[0082] which corresponds to the pressing direction of the sealing block 200), and a step difference is formed between the central region 13A and the side region 13B.Compared with the case where the pouch 10 is sealed by the sealing device of the comparative example above, when the sealing device according to Embodiment 1 of the present invention is used to seal the pouch 10, by providing a central region 13A and a side region 13B that form a step difference with each other in the first region 13, more molten insulating portions of the inner resin layers of the upper pouch 10A and the lower pouch 10B and the lead film 30 are extruded from the portion corresponding to the first region 13. Therefore, more molten insulating portions are extruded into the gap S between the pouch 10 and the lead metal 20 and the gap S is sufficiently filled. Therefore, even when the thickness of the lead metal 20 is large, when the sealing device according to Embodiment 1 of the present invention is used to seal the pouch 10, the gap S between the pouch 10 and the lead film 30 can still be sufficiently filled by the molten insulating portions of the inner resin layers of the upper pouch 10A and the lower pouch 10B and the lead film 30, so that the voids in the formed sealing portion 12 are small or even there are no voids, thereby forming a reliable seal in the pouch 10.

[0083] Figure 11 is similar to Figure 5 view, Figure 11 shows Figure 10 the portion corresponding to the portion in the frame F shown in Figure 1 of the pouch-type secondary battery shown in, a top view of the portion of the pouch 10 near the lead metal 20 and the lead film 30 is shown, and the portions of the lead metal 20 and the lead film 30 located outside the pouch 10 are shown to show the corresponding relationship between the regions of the sealing portion 12 and the lead metal 20 and the lead film 30. Figure 11 shows the first region 13, the second region 14, and the third region 17 of the sealing portion 12, and the third region 17 corresponds to the third sealing surface 240 of the sealing block 200. In Figure 11 the first region 13 of the sealing portion 12 is the side region 13B at line III-III', corresponding to the side sealing surface 212 of the first sealing surface 210 of the sealing block 200, and overlaps both the lead metal 20 and the lead film 30 in the thickness direction. As Figure 11 shown, in the side region 13B of the first region 13 of the sealing portion 12, a pressing portion 15 is formed, and the pressing portion 15 extends along the length direction of the side region 13B ( Figure 11 the direction shown by the X-axis in Figure 11 ). The pressing portion 15 corresponds to the sealing protrusion 230 on the side sealing surface 212 of the sealing block 200. In the example shown in the figure, the pressing portion 15 includes a first pressing portion 15A and a second pressing portion 15B, and the first pressing portion 15A and the second pressing portion 15B are spaced apart from each other in the width direction (

[0084] Figure 12 shows a cross-sectional view taken along the width direction (the direction indicated by the Y-axis in Figure 11 ) at a position corresponding to line III-III' in the process of sealing the pouch 10 using the sealing device according to Embodiment 1 of the present invention. As shown in Figure 12 and Figure 11 and Figure 12 , in the thickness direction of the pouch-type secondary battery (the direction indicated by the Z-axis in Figure 12 ), the upper pouch 10A and the lower pouch 10B are sandwiched between a pair of sealing blocks 200, and the first sealing surface 210 of the sealing block 200 faces and presses the first region 13 of the pouch 10. As shown in Figure 12 , in the width direction of the side region 13B of the first sealing surface 210 of the sealing block 200 (the direction indicated by the Y-axis in Figure 12 ), the first sealing protrusion 231 and the second sealing protrusion 232 protrude further in the pressing direction (the direction indicated by the Z-axis in Figure 12 ) with respect to the side sealing surface 212, so that the side sealing surface 212 is formed in a shape with both sides protruding and the middle concave in the width direction. On the one hand, the first sealing protrusion 231 and the second sealing protrusion 232 can further press the side region 13B of the pouch 10 to form a pressing portion 15 in the pouch 10, so that more molten insulating portions of the inner resin layer of the upper pouch 10A and the lower pouch 10B and the lead film 30 are extruded from the portion corresponding to the first region 13, thereby being able to more fully fill the gap S. On the other hand, the first sealing protrusion 231 and the second sealing protrusion 232 protrude further in the pressing direction with respect to the side sealing surface 212, which can limit the molten insulating portions of the inner resin layer of the upper pouch 10A and the lower pouch 10B and the lead film 30 from being extruded in the width direction (the Y direction in Figure 12 ), thereby guiding the molten insulating portions of the inner resin layer of the upper pouch 10A and the lower pouch 10B and the lead film 30 to be extruded along the length direction (the direction indicated by the X-axis) into the gap S (see Figure 10 ) located between the pouch and the lead film 30, so that more molten insulating portions can be further extruded into the gap S, thereby filling the gap S. Therefore, by providing the first sealing protrusion 231 and the second sealing protrusion 232 on the side sealing surface 212 of the first sealing surface 210 of the sealing block 200, it is possible to further facilitate the full filling of the gap S between the pouch 10 and the lead film 20, so that even if the thickness of the lead metal 20 is large, the gap in the formed sealing portion 12 can be made small or even no gap, thereby contributing to the formation of a reliable seal.

[0085] The sealing block 200 of the sealing device according to Embodiment 1 of the present invention and the pouch-type secondary battery formed by using the sealing device to seal a pouch have been introduced above. The sealing device according to Embodiment 1 of the present invention has a central sealing surface 211 and a side sealing surface 212 with a step difference formed therebetween on the first sealing surface 210 of the sealing block 200. When using the sealing device to seal the pouch 10, more molten insulating portions of the inner resin layers of the upper pouch 10A and the lower pouch 10B of the pouch 10 and the lead film 30 can be squeezed into the gap S between the pouch 10 and the lead film 30 and fill the gap S, so that even when the thickness of the lead metal 20 is large, the gap S can be sufficiently filled, making the gap in the formed sealing portion 12 small or even having no gap, thereby enabling a reliable seal to be formed. Preferably, by providing sealing protrusions 230 (for example, a first sealing protrusion 231 and a second sealing protrusion 232) on the side sealing surface 212, the molten insulating material portions of the inner resin layers of the upper pouch 10A and the lower pouch 10B and the lead film 30 can be prevented from flowing in the width direction (the direction shown by the Y axis in the drawing) of the sealing portion 12, so that the molten insulating portions of the inner resin layers of the upper pouch 10A and the lower pouch 10B and the lead film 30 are guided to the gap S between the pouch 10 and the lead film 30 and fill the gap S, which further facilitates the formation of a reliable seal.

[0086] Figure 13 In a manner similar to Figure 9 An enlarged view of a part of the sealing block 200A of the sealing device according to Embodiment 2 of the present invention is shown. The sealing block 200A according to Embodiment 2 of the present invention has a similar structure to the sealing block 200 according to Embodiment 1 of the present invention, and the difference lies only in the design of the sealing protrusions. In the drawing, the same or corresponding parts are denoted by the same reference numerals and will not be described repeatedly.

[0087] As Figure 13 shown, the sealing block 200A is provided with one or more sealing protrusions 230A protruding a predetermined thickness in the pressing direction. Different from the sealing protrusions 230 of the sealing block 200 according to Embodiment 1 of the present invention, which are only provided on the side sealing surface 212, the sealing protrusions 230A of the sealing block 200A according to Embodiment 2 of the present invention extend from the side sealing surface 212 of the first sealing surface 210 in the length direction ( Figure 13 the direction shown by the X axis in Figure 13 the drawing) to the second sealing surface 220. That is, the sealing protrusions 230A are provided on both the side sealing surface 212 and the second sealing surface 220 and protrude in the pressing direction ( Figure 13 the direction shown by the Z axis inFigure 13 a first sealing protrusion 231A and a second sealing protrusion 232A spaced apart from each other in a direction shown by the Y-axis in

[0088] Figure 14 is similar to Figure 11 a similar view, showing a portion of a pouch-type secondary battery formed by sealing a pouch using the sealing device according to Embodiment 2 of the present invention, corresponding to the portion within the frame F in Figure 1 After sandwiching the outer peripheral edges of the upper pouch 10A and the lower pouch 10B between a pair of sealing blocks 200A according to Embodiment 2 of the present invention to seal the pouch 10 to form a sealing portion 12, as shown in Figure 14 a pressing portion 151 is formed on the sealing portion 12. The pressing portion 151 includes a first pressing portion 15A1 and a second pressing portion 15B1, and the first pressing portion 15A1 and the second pressing portion 15B1 respectively correspond to the first sealing protrusion 231A and the second sealing protrusion 232A of the sealing block 200A according to Embodiment 2 of the present invention. As described above, the first sealing protrusion 231A and the second sealing protrusion 232A extend from the side sealing surface 212 to the second sealing surface 220 in the length direction. Accordingly, the first pressing portion 15A1 and the second pressing portion 15B1 are located between the central region 13A of the first region 13 and the third region 17 in the length direction of the sealing portion 12, and extend in the side region 13B and the second region 14 of the first region 13 of the sealing portion 12 in the direction shown by the X-axis in Figure 14 so that the first pressing portion 15A1 and the second pressing portion 15B1 can prevent the inner resin layer of the upper pouch 10A and the lower pouch 10B and the molten insulating portion of the lead film 30 from being extruded in the width direction of the sealing portion 12 ( Figure 14 the direction shown by the Y-axis in Figure 14 at the side region 13B), and can also prevent the inner resin layer of the upper pouch 10A and the lower pouch 10B and the molten insulating portion of the lead film 30 from being extruded in the width direction of the sealing portion 12 at the second region 14, as shown by the arrow C in

[0089] The sealing device according to Embodiment 2 of the present invention can achieve the above-mentioned beneficial technical effects similar to those of the sealing device according to Embodiment 1 of the present invention. And, as described above, by extending the first sealing protrusion 231A and the second sealing protrusion 232A from the side sealing surface 212 to the second sealing surface 220, the sealing device according to Embodiment 2 of the present invention can also prevent the inner resin layer of the upper soft package 10A and the lower soft package 10B and the molten insulating portion of the lead film 30 from being extruded in the width direction at the second sealing surface 220 during the process of sealing the soft package 10, thereby being more conducive to guiding the molten insulating portion into the gap S and being more conducive to achieving a reliable seal.

[0090] The sealing device and the secondary battery according to the preferred embodiments of the present invention have been introduced above. In the preferred embodiments shown above, a central sealing surface and a side sealing surface with a step difference are formed on the first sealing surface of the sealing block, and a sealing protrusion is preferably provided. Correspondingly, a central region and a side region with a step difference are formed on the sealing portion of the soft package, and a pressing portion is preferably further formed. However, the present invention is not limited thereto. In other modified examples according to the present invention, a central sealing surface and a side sealing surface with a step difference can be provided on the first sealing surface of the sealing block as needed without providing a sealing protrusion. The sealing device and the manufactured soft package type secondary battery according to these modified examples can still achieve beneficial technical effects similar to those described above.

[0091] Here, the exemplary embodiments of the sealing device and the secondary battery of the present invention have been described in detail, but it should be understood that the present invention is not limited to the specific embodiments described and shown above in detail. Without departing from the gist and scope of the present invention, those skilled in the art can make various modifications and variations to the present invention. All such modifications and variations fall within the scope of the present invention. Moreover, all the components described herein can be replaced by other technically equivalent components.

Claims

1. A sealing device, comprising a sealing block (200), wherein the sealing block (200) is configured to seal a lead film (30) wrapping a lead metal (20) and a soft package (10) surrounding the lead film (30), characterized in that: The sealing block (200) includes a first sealing surface (210), wherein the first sealing surface (210) is configured to seal a central portion (30A) of the lead film (30) overlapping the lead metal (20). The first sealing surface (210) comprises: a central sealing surface (211); and side sealing surfaces (212), the side sealing surfaces (212) being located on both sides of the central sealing surface (211) in the length direction of the first sealing surface (210) and forming a step difference with the central sealing surface (211), The side sealing surface (212) has a sealing protrusion (230) protruding with a predetermined thickness in the pressurizing direction of the sealing block (200) to prevent the lead film (30) from moving in the width direction of the side sealing surface (212).

2. The sealing device according to claim 1, characterized in that: The side sealing surface (212) extends from an end of the center sealing surface (211), and protrudes from the center sealing surface (211) toward the pressurizing direction to form a step difference.

3. The sealing device according to claim 1, characterized in that: The sealing block (200) further comprises a second sealing surface (220), wherein the second sealing surface (220) is located on both sides of the first sealing surface (210) in the length direction and forms a step difference with the first sealing surface (210) in a manner of sealing the side portion (30B) of the lead film (30) and the soft package (10), and the side portion (30B) of the lead film (30) does not overlap with the lead metal (20) in the thickness direction.

4. The sealing device according to claim 3, characterized in that: The central sealing surface (211), the side sealing surface (212), and the second sealing surface (220) sequentially form step differences in the pressurizing direction.

5. The sealing device according to claim 1, characterized in that: The side sealing surface (212) overlaps with an end region of the lead metal (30) in a width direction.

6. The sealing device according to claim 3, characterized in that: Between the side sealing surface (212) and the second sealing surface (220), there is an inclined portion (250) extending obliquely between one end of the side sealing surface (212) and one end of the second sealing surface (220).

7. The sealing device according to claim 3, characterized in that: The sealing protrusion (230) has a shape extending along a length direction perpendicular to the width direction of the side sealing surface (212).

8. The sealing device according to claim 3, characterized in that: The plurality of sealing protrusions (230) are spaced apart at predetermined intervals along the width direction of the side sealing surface (212).

9. The sealing device according to claim 3, characterized in that: The sealing protrusion (230) is formed on an edge of the side sealing surface (212) in the width direction.

10. The sealing device according to claim 8, characterized in that: The sealing protrusion (230) comprises: a first sealing protrusion (231) formed at one edge in the width direction of the side sealing surface (212); and A second sealing protrusion (232) is formed at the other edge of the side sealing surface (212) in the width direction.

11. The sealing device according to claim 7, characterized in that: The sealing protrusion (230) extends from the side sealing surface (212) to the second sealing surface (220).

12. The sealing device according to claim 1, characterized in that: The sealing device comprises a pair of sealing blocks (200) arranged facing each other along the pressurizing direction.

13. A secondary battery, comprising: A soft package (10), the soft package (10) comprising a receiving portion (11) for receiving the electrode assembly and a sealing portion (12) located around the receiving portion (11), a lead metal (20), the lead metal (20) being connected to the electrode assembly and protruding outward from the sealing portion (12); and a lead film (30), the lead film (30) wrapping the lead metal (20) and being sealed with the sealing portion (12), The sealing portion (12) includes a first region (13) that is sealed with a central portion (30A) of the lead film (30) and overlaps with the lead metal (20). The first region (13) comprises: Central area (13A); and side regions (13B), the side regions (13B) being located on both sides of the central region (13A) in the length direction of the first region (13) and forming a step difference with the central region (13A), The side region (13B) is formed with a pressing portion (15, 151) extending along the length direction of the side region (13B).

14. The secondary battery according to claim 13, characterized in that: The pressing portions (15, 151) are configured as a pair of pressing portions extending side by side with each other at a predetermined interval in the width direction of the side region (13B).

15. The secondary battery according to claim 13, characterized in that: The pressing portions (15, 151) are formed on both side edges of the side region (13B) in the width direction.

16. The secondary battery according to claim 13, characterized in that: The sealing portion (12) also includes a second region (14), which is located on both sides of the first region (13) in the length direction and forms a step difference with the first region (13), and the second region (14) is sealed with a side portion (30B) of the lead film (30), and the side portion (30B) of the lead film (30) does not overlap with the lead metal (20) in the thickness direction of the sealing portion (12).

17. The secondary battery according to claim 16, characterized in that: The central region (13A), the side region (13B) and the second region (14) sequentially form step differences in the thickness direction.

18. The secondary battery according to claim 16, characterized in that: The sealing portion (12) includes an inclined region (16) formed between the side region (13B) and the second region (14) and extending obliquely between one end of the side region (13B) and one end of the second region (14).

19. The secondary battery according to claim 16, characterized in that: The pressing portion (151) extends from the side region (13B) to the second region (14).

20. The secondary battery according to claim 13, characterized in that: The central region (13A), the side region (13B), and the pressing portion (15, 151) are formed on both sides of the sealing portion (12) in the thickness direction.

21. A sealing device, comprising a sealing block (200), wherein the sealing block (200) is configured to seal a lead film (30) wrapping a lead metal (20) and a soft package (10) surrounding the lead film (30), characterized in that: The sealing block (200) includes a first sealing surface (210), wherein the first sealing surface (210) is configured to seal a central portion (30A) of the lead film (30) overlapping the lead metal (20). The first sealing surface (210) comprises: a central sealing surface (211); and side sealing surfaces (212), the side sealing surfaces (212) being located on both sides of the central sealing surface (211) in the length direction of the first sealing surface (210), and protruding relative to the central sealing surface (211) in the pressurizing direction of the sealing block (200) to form a step difference with the central sealing surface (211), The sealing block (200) further comprises a second sealing surface (220), the second sealing surface (220) being located on both sides of the first sealing surface (210) in the length direction and protruding relative to the first sealing surface (210) in the pressurizing direction of the sealing block (200) to form a step difference, the second sealing surface (220) sealing the side portion (30B) of the lead film (30) and the soft package (10), the side portion (30B) of the lead film (30) not overlapping with the lead metal (20) in the thickness direction; and The central sealing surface (211), the side sealing surface (212), and the second sealing surface (220) sequentially form step differences in the pressurizing direction.

22. The sealing device according to claim 21, characterized in that The side sealing surface (212) has a sealing protrusion (230) protruding with a predetermined thickness in the pressurizing direction of the sealing block (200) to prevent the lead film (30) from moving in the width direction of the side sealing surface (212).

23. A secondary battery, comprising: A soft package (10), the soft package (10) comprising a receiving portion (11) for receiving the electrode assembly and a sealing portion (12) located around the receiving portion (11), a lead metal (20), the lead metal (20) being connected to the electrode assembly and protruding outward from the sealing portion (12); and a lead film (30), the lead film (30) wrapping the lead metal (20) and being sealed with the sealing portion (12), The sealing portion (12) includes a first region (13) that is sealed with a central portion (30A) of the lead film (30) and overlaps with the lead metal (20). The first region (13) comprises: Central area (13A); and side regions (13B), the side regions (13B) being located on both sides of the central region (13A) in the length direction of the first region (13) and forming a step difference with the central region (13A), The sealing portion (12) further comprises a second region (14), the second region (14) being located on both sides of the first region (13) in the length direction and forming a step difference with the first region (13), the second region (14) being sealed with a side portion (30B) of the lead film (30), and the side portion (30B) of the lead film (30) not overlapping with the lead metal (20) in the thickness direction of the sealing portion (12), The central region (13A), the side region (13B) and the second region (14) sequentially form step differences in the thickness direction.

24. The secondary battery according to claim 23, characterized in that: The side region (13B) is further pressed in the thickness direction relative to the central region (13A), and the side region (13B) is formed with a pressing portion (15, 151) extending along the length direction of the side region (13B).

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