Soft package battery and manufacturing method thereof

Abstract

The invention belongs to the technical field of soft package batteries, and discloses a soft package battery and a manufacturing method of the soft package battery. The soft package battery comprises an electrolyte, a packaging film and a naked battery cell, an accommodating cavity is defined by the packaging film, and the naked battery cell and the electrolyte are arranged in the accommodating cavity. According to the soft package battery, the part, located on one side of the naked battery cell, of the packaging film is provided with the first outwards-protruding structure in the preset first direction, the first containing space is formed in the inner side of the first outwards-protruding structure and used for increasing the electrolyte containing capacity of the soft package battery, and therefore the long-term performance is improved. Meanwhile, the effect of increasing the liquid retention capacity can be achieved only by improving the packaging film, so that the structure of the soft package battery is prevented from being excessively improved, and the production efficiency and the production cost are ensured.

Description

Technical Field

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

[0002] Soft-pack batteries use a lighter aluminum-plastic film as their outer shell. Under the same other conditions, soft-pack batteries have the advantages of being lighter and having higher energy density than square-shell batteries or cylindrical batteries, and therefore have been widely used.

[0003] Unlike the good mechanical structural strength of square or cylindrical battery shells, the mechanical properties of aluminum-plastic film are relatively poor, resulting in a relatively small amount of liquid retained in the soft-pack battery after vacuuming, which is not conducive to its long-term performance. The Chinese utility model patent with application number 202023023966.7 discloses a liquid-rich soft-pack battery cell, which adopts the method of setting large and small batteries to form a storage cavity for electrolyte in the soft-pack battery cell, thereby increasing the liquid retention. However, the implementation of this solution requires the use of batteries of different sizes or special-shaped batteries, which complicates the production process and significantly increases the application cost and production cost.

[0004] Therefore, there is an urgent need for a soft-pack battery and a soft-pack battery manufacturing method to solve the above technical problems. Summary of the Invention

[0005] An object of the present invention is to provide a soft-pack battery that can achieve a high liquid retention capacity at a low cost.

[0006] To achieve this object, the present invention adopts the following technical solutions:

[0007] A soft-pack battery includes an electrolyte, a packaging film, and a bare cell. The packaging film defines a receiving cavity, and the bare cell and the electrolyte are arranged in the receiving cavity.

[0008] Along a preset first direction, a portion of the packaging film located on one side of the bare battery cell is provided with a first convex structure, and a first accommodating space is formed inside the first convex structure. The first accommodating space is used to increase the electrolyte holding capacity of the soft-pack battery, and along a preset second direction, the first convex structure is provided on one side of the bare battery cell. The preset first direction is parallel to the thickness direction of the soft-pack battery, and the preset second direction is perpendicular to the preset first direction.

[0009] Preferably, the packaging film is provided with a plurality of the first convex structures.

[0010] Along the preset first direction, a portion of the packaging film located on one side of the bare cell is provided with at least two first protruding structures; and / or,

[0011] Along the preset first direction, a portion of the packaging film located on the other side of the bare cell is provided with at least one first convex structure.

[0012] Preferably, along the preset first direction, a second convex structure is further provided on the side of the packaging film where the first convex structure is provided, and a second accommodating space is formed inside the second convex structure, and the second accommodating space is used to limit and accommodate the bare battery cell, and

[0013] The depth L of the first accommodating space is not greater than the depth h of the second accommodating space.

[0014] Preferably, the first convex structure is arranged on the tab side of the soft-pack battery.

[0015] Preferably, along the preset first direction, the outer contour of the first convex structure includes at least one of a square and a circle.

[0016] Preferably, the end of the first convex structure away from the bare battery cell is an arched end; or,

[0017] The end of the first convex structure away from the bare battery cell is a flat end.

[0018] Preferably, the soft-pack battery further includes a support member, at least a portion of which is disposed in the first accommodating space, and the support member is used to support the first convex structure.

[0019] The present invention has the following beneficial effects: The packaging film is provided with a first convex structure, and a first accommodation space is formed inside the first convex structure. The first accommodation space is used to increase the electrolyte capacity of the soft-pack battery, thereby improving long-term performance. Furthermore, since the increase in electrolyte retention can be achieved by simply modifying the packaging film, excessive modifications to the soft-pack battery structure are avoided, ensuring production efficiency and costs.

[0020] Another object of the present invention is to provide a method for manufacturing a soft-pack battery, which can manufacture batteries with a high liquid retention capacity at a low cost.

[0021] To achieve this object, the present invention adopts the following technical solutions:

[0022] A method for manufacturing a soft-pack battery, used to manufacture the above-mentioned soft-pack battery, comprising:

[0023] Forming a first convex structure on a packaging film; surrounding the bare cell with the packaging film so that the first convex structure is located on one side of the bare cell along the length direction or the width direction of the soft-pack battery;

[0024] An electrolyte is injected into the packaging film and formed, and the first accommodation space of the first convex structure is kept filled with the electrolyte.

[0025] Preferably, before the electrolyte is injected, a support member is provided in the packaging film, and at least a portion of the support member is provided in the first accommodating space.

[0026] Preferably, after formation, liquid replenishment is performed to keep the first containing space filled with electrolyte; and / or,

[0027] The first convex structure is shaped from the outside of the soft-pack battery during formation.

[0028] The present invention has the following beneficial effects: This method can form a first convex structure on the packaging film and produce a soft-pack battery. A first storage space is formed inside the first convex structure. The first storage space is used to increase the electrolyte capacity of the soft-pack battery, thereby improving long-term performance. Furthermore, since the increase in electrolyte retention can be achieved by simply modifying the packaging film, excessive modifications to the soft-pack battery structure are avoided, ensuring production efficiency and costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 1 is a front view of the structure of a soft-pack battery in one embodiment of the present invention;

[0030] Figure 2 It is along Figure 1 Side view of the soft pack battery structure in the AA direction;

[0031] Figure 3 is a front view of a packaging film in an unfolded state according to an embodiment of the present invention;

[0032] Figure 4 is a side view of a packaging film in an unfolded state according to an embodiment of the present invention;

[0033] Figure 5 It is along Figure 4 Schematic diagram of the shape of the first convex structure in the middle BB direction;

[0034] Figure 6 is a side view of a support member according to one embodiment of the present invention;

[0035] Figure 7 is a front view of a support member according to one embodiment of the present invention;

[0036] Figure 8 1 is a front view of a packaging film in an unfolded state according to another embodiment of the present invention.

[0037] In the picture:

[0038] 1. Packaging film; 11. First convex structure; 12. Second convex structure; 13. Sealing portion;

[0039] 2. Support member; 21. Protrusion; 22. Connecting portion. DETAILED DESCRIPTION

[0040] The present invention will be further described in detail below with reference to the accompanying drawings and examples. It will be understood that the specific embodiments described herein are intended only to illustrate the present invention and are not intended to limit the present invention. It should also be noted that, for ease of description, the accompanying drawings only illustrate portions relevant to the present invention, not all structures.

[0041] In the description of the present invention, unless otherwise expressly specified or limited, the terms "connected," "connected," "fixed," and "abutted" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integration; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and may refer to internal communication between two elements or interaction between two elements. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0042] In the present invention, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may include the first and second features being in direct contact, or may include the first and second features being in contact not directly but through another feature between them. Furthermore, a first feature being "above," "above," and "above" a second feature may include the first feature being directly above or obliquely above the second feature, or may simply mean that the first feature is higher in level than the second feature. A first feature being "below," "below," and "below" a second feature may include the first feature being directly below or obliquely below the second feature, or may simply mean that the first feature is lower in level than the second feature.

[0043] In the description of this embodiment, terms such as "upper," "lower," "right," and "left" are used to refer to positions or locations based on those shown in the accompanying drawings. These terms are intended solely to facilitate description and simplify operation, and are not intended to indicate or imply that the devices or components referred to must have, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on the present invention. Furthermore, the terms "first" and "second" are used solely for descriptive purposes and have no special meaning.

[0044] The following is based on the attached Figure 1 To the attached Figure 8 The present invention introduces a soft-pack battery and a method for manufacturing the soft-pack battery.

[0045] like Figures 1 to 2As shown, in one embodiment provided by the present invention, the soft-pack battery includes an electrolyte, a packaging film 1 and a bare cell. The packaging film 1 is formed with a receiving cavity, and the bare cell and the electrolyte are arranged in the receiving cavity. Along the preset first direction, a portion of the packaging film 1 located on one side of the bare cell is provided with a first convex structure 11, and a first receiving space is formed on the inner side of the first convex structure 11. The first receiving space can accommodate the electrolyte, thereby increasing the electrolyte capacity of the soft-pack battery. Moreover, along the preset second direction, the first convex structure 11 is provided on one side of the bare cell. Specifically, in the present invention, the preset first direction is parallel to the thickness direction of the soft-pack battery (as shown by the Z axis), and the preset second direction is perpendicular to the preset first direction, for example, the length direction (as shown by the Y axis) or the width direction (as shown by the X axis) of the soft-pack battery.

[0046] For example, Figure 3 、 Figure 4 As shown, in this embodiment, the packaging film 1 is provided with the above-mentioned first convex structure 11, and is provided with a second convex structure 12, and a second accommodating space is formed inside the second convex structure 12, and the second accommodating space can accommodate the bare battery cell in a limited position. Specifically, with the folding line of the packaging film 1 as the axis of symmetry (the folding line can be selected as the central axis), a second convex structure 12 and a plurality of first convex structures 11 are provided on both sides of the folding line by stamping. When forming the accommodating cavity, the packaging film 1 is folded along the folding line so that the first convex structures 11 on both sides of the folding line can be closed accordingly, the second convex structures 12 on both sides of the folding line can be closed accordingly, and the edges of the packaging film 1 can be sealed and connected, thereby forming a sealing portion 13. After the edges of the packaging film 1 are sealed and connected, the above-mentioned accommodating cavity can be formed.

[0047] Continue to refer to Figures 1 to 4 As shown, after the second convex structure 12 is closed, along the preset first direction, one end of the bare cell is limited and accommodated in the second accommodation space of a second convex structure 12, and the other end of the bare cell is limited and accommodated in the second accommodation space of another second convex structure 12. When the bare cell tends to move independently relative to the packaging film 1, the inner wall surface of the second accommodation space can abut against the bare cell, thereby limiting the bare cell along the thickness direction, length direction and width direction of the soft-pack battery, and preventing the bare cell from being damaged due to large movement due to vibration, inertia, etc. In this embodiment, since only the edge of the packaging film 1 is sealed and connected, after the first convex structure 11 is closed, a first accommodation space can be formed on both sides of the thickness direction of the soft-pack battery, and the first accommodation space and the second accommodation space are connected, thereby increasing the amount of electrolyte that the accommodation cavity can accommodate, thereby increasing the liquid retention capacity of the soft-pack battery.

[0048] It should be emphasized that in this embodiment, first protruding structures 11 are provided on both sides of the soft-pack battery in the thickness direction, with at least one first protruding structure 11 provided on each side, thereby significantly increasing the liquid retention capacity. Furthermore, since this increase in liquid retention can be achieved by simply modifying the packaging film 1, excessive modifications to the soft-pack battery structure are avoided, ensuring production efficiency and costs.

[0049] Of course, in some other embodiments, depending on the desired liquid retention, the first protruding structure 11 may be provided only on one side in the thickness direction, that is, only on one side of the fold line of the packaging film 1. It should also be noted that the second protruding structure 12 is provided solely to position the bare cell. Therefore, in some embodiments where positioning the bare cell is not required, the first protruding structure 11 may be provided only on the packaging film 1, which can still achieve the effect of increasing liquid retention.

[0050] Continue to refer to Figures 1 to 4 As shown, along the predetermined second direction, the first protruding structure 11 is disposed to the side of the bare cell, thereby preventing the bare cell from encroaching on the first accommodation space. This effectively and fully utilizes the unused portion of the soft-pack battery installation space, increases the soft-pack battery's liquid retention capacity, and thus enhances the soft-pack battery's long-term performance. Therefore, preferably, the depth L of the first accommodation space is no greater than the depth h of the second accommodation space, so that the first protruding structure 11 does not protrude beyond the second protruding structure 12. This achieves the effect of increasing the soft-pack battery's liquid retention capacity without increasing the size of the soft-pack battery installation space.

[0051] Preferably, in this embodiment, the first protruding structure 11 is disposed on the tab side of the soft-pack battery, thereby further avoiding an increase in the length or width of the soft-pack battery. Because the aluminum-plastic film encapsulation of the soft-pack battery is subject to greater mechanical stress on the tab side, the wider tab side can enhance the tensile strength of the sealing portion 13, preventing the aluminum-plastic film from rupturing due to excessive tension during heat sealing. Therefore, compared to the non-tab side, the tab side is wider, providing space for the first protruding structure 11. Placing the first protruding structure 11 on the tab side avoids the need to provide corresponding space on the non-tab side to accommodate the first protruding structure 11, while also fully utilizing the wide tab side, thereby avoiding the negative impact of increasing the length or width of existing soft-pack batteries.

[0052] It should be noted that, in some embodiments, the plurality of first accommodation spaces may be set to different depths, and the plurality of second accommodation spaces may be set to different depths. Figure 3 、 Figure 4As shown, in one embodiment of the present invention, the packaging film 1 is provided with two first accommodating spaces of different depths and two second accommodating spaces of different depths. Specifically, 10 first convex structures 11 are provided on one side of the fold line, and the 10 first convex structures 11 are arranged at a spacing of 1.8 mm. The depth L1 of the first accommodating space is 1.6 mm, and the depth h1 of the second accommodating space on this side is 3.8 mm. 8 first convex structures 11 are provided on the other side of the fold line, and the 8 first convex structures 11 are arranged at a spacing of 2.1 mm. The depth L2 of the first accommodating space is 2.0 mm, and the depth h2 of the second accommodating space on this side is 4.0 mm.

[0053] Continue to refer to Figure 3 、 Figure 4 As shown, in this embodiment, the distance between two adjacent first convex structures 11 is not less than half of the depth L and not more than twice the depth L. Such a setting can avoid reducing the strength of the entire packaging film 1 due to the provision of the first convex structure 11, thereby ensuring the safety of the soft-pack battery. Figure 3 As shown, the outer contour of the first convex structure 11 is a square, which has excellent and uniform force-bearing strength in all directions. This not only facilitates the formation of the first convex structure 11 by stamping, but also further ensures the strength of the entire packaging film 1. Of course, in some embodiments, the outer contour of the first convex structure 11 can also be set to be circular along the predetermined first direction, which can also achieve similar technical effects.

[0054] Of course, the present invention does not limit the number or size of the first external convex structures 11 on either side of the fold line. The first external convex structures 11 on either side of the fold line can be of different or identical numbers or sizes, or can be positioned in opposite or opposite positions. Alternatively, multiple first external convex structures 11 of varying numbers and sizes can be positioned on one side of the fold line. All of these are within the scope of protection of the present invention. For example, in some other embodiments, twelve first external convex structures 11 are positioned on one side of the fold line, spaced 2.0 mm apart. The depth L1 of the first accommodating space is 1.8 mm, and the depth h1 of the second accommodating space on that side is 4.0 mm. Twelve first external convex structures 11 are positioned on the other side of the fold line, spaced 2.0 mm apart. The depth L2 of the first accommodating space is 1.8 mm, and the depth h2 of the second accommodating space on that side is 4.0 mm.

[0055] Reference Figure 4 As shown, in this embodiment, the end of the first convex structure 11 away from the bare cell is a flat end, that is, it has a flat bottom wall. In some embodiments, such as Figure 5Therefore, the combination of a square outer profile and a flat end, a circular outer profile and a flat end, a circular outer profile and a circular arched end, and a square outer profile and a circular arched end all fall within the scope of protection of the present invention.

[0056] like Figure 6 、 Figure 7 As shown, the soft-pack battery also includes a support member 2, at least part of which is arranged in the first accommodating space, and the support member 2 is used to support the first convex structure 11. In one embodiment, along the preset first direction, protrusions 21 are formed on both sides of the support member 2, and the protrusions 21 can extend into the first accommodating space, thereby supporting the inner wall of the first convex structure 11, preventing the first convex structure 11 from collapsing in processes such as formation that require vacuuming, and ensuring that the first convex structure 11 can achieve the technical effect of increasing the liquid retention capacity. It should be noted that in some embodiments, the protrusion 21 can also be provided on only one side of the support member 2, that is, only the first convex structure 11 located on one side of the thickness direction of the soft-pack battery is supported.

[0057] Of course, when both sides of the support member 2 are provided with protrusions 21, and the protrusions 21 can be embedded in the corresponding first accommodation spaces, the support member 2 can be fixed in place. Preferably, the multiple support members 2 can also be connected along the arrangement direction of the first convex structure 11 by the connecting portion 22, so that the multiple support members 2 can be stably arranged in the accommodation cavity, preventing the support members 2 from moving and scratching the bare battery cells.

[0058] Alternatively, as Figure 8 As shown, in some other embodiments, the first convex structure 11 can also be set on the non-ear side, which can also achieve the effect of increasing the liquid retention capacity of the soft-pack battery and is also within the scope of protection of the present invention.

[0059] Furthermore, a container storing electrolyte or other components may be provided within the first accommodation space, so that after the battery is packaged, the stored electrolyte or other components can be released into the battery as needed. For example, the electrolyte can be released slowly based on the battery's service life, or a fire extinguishing agent can be released quickly based on the battery's temperature.

[0060] The present invention also provides a method for manufacturing a soft-pack battery, which is used to manufacture the soft-pack battery mentioned above. The method specifically comprises:

[0061] A first convex structure 11 is formed on the packaging film 1; the packaging film 1 is arranged to surround the bare cell, and the first convex structure 11 is located on one side of the bare cell along the length direction or width direction of the soft-pack battery;

[0062] An electrolyte is injected into the packaging film 1 and formed, and the first accommodation space of the first convex structure 11 is kept filled with the electrolyte.

[0063] Specifically, in this method, the packaging film 1 can be made of aluminum-plastic film, steel-plastic film, or a film structure made of other materials, as long as it can serve as the outer shell of the soft-pack battery. This is not specifically limited in the present invention. The first convex structure 11 is preferably formed by stamping, which is convenient and quick. Negative pressure, i.e., vacuum molding, can also be used to form the first convex structure 11 (and the second convex structure 12).

[0064] After forming, the bare cell can be enclosed by folding one packaging film 1 in half. By controlling the relative position of the bare cell and the first protruding structure 11, the first protruding structure 11 can be positioned on one side of the bare cell along the length or width of the soft-pack battery. Alternatively, in some embodiments, two packaging films 1 can be connected in opposite directions to enclose the bare cell, which also falls within the scope of protection of the present invention.

[0065] Then, electrolyte is injected into the packaging film 1 and formed, while maintaining the electrolyte in the first receiving space of the first convex structure 11. After the above steps are completed, the conventional battery production procedures are further carried out to finally obtain a soft-pack battery with a large liquid retention capacity, thereby improving the long-term performance of the battery.

[0066] Optionally, in some embodiments, before the electrolyte is injected, a support member 2 is arranged in the packaging film 1, and at least a portion of the support member 2 is arranged in the first accommodating space, which can support the inner wall of the first convex structure 11, thereby resisting the vacuum during formation and ensuring that the first convex structure 11 will not collapse.

[0067] Of course, in some embodiments, liquid can be replenished after formation to restore the shape of the collapsed first convex structure 11 and restore its ability to accommodate additional electrolyte. Therefore, the soft-pack battery manufactured according to this method can be provided with the above-mentioned support member 2 or not, or the support member 2 can be provided in part of the first accommodating space and not in part of the first accommodating space, all of which fall within the scope of protection of the present invention.

[0068] Optionally, in some other embodiments, the first convex structure 11 can be shaped from the outside of the soft-pack battery during formation to prevent the first convex structure 11 from collapsing. For example, negative pressure adsorption on the outside of the first convex structure 11 can counteract the vacuum during formation and prevent the first convex structure 11 from collapsing.

[0069] Throughout this specification, references to "some embodiments," "other embodiments," and the like indicate that the specific features, structures, materials, or characteristics described in connection with that embodiment or example are included in at least one embodiment or example of the present invention. In this specification, schematic representations of these terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0070] Obviously, the above embodiments of the present invention are merely examples for the purpose of clearly illustrating the present invention and are not intended to limit the embodiments of the present invention. A person skilled in the art would be able to make various obvious changes, readjustments, and substitutions without departing from the scope of protection of the present invention. It is not necessary and impossible to enumerate all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the claims of the present invention.

Claims

1. A soft pack battery, characterized in that: The invention comprises an electrolyte, a packaging film (1) and a bare battery cell, wherein the packaging film (1) defines a receiving cavity, and the bare battery cell and the electrolyte are arranged in the receiving cavity. Along a preset first direction, a portion of the packaging film (1) located on one side of the bare battery cell is provided with a first convex structure (11), a first accommodation space is formed inside the first convex structure (11), and the first accommodation space is used to increase the electrolyte accommodation capacity of the soft-pack battery. In addition, along a preset second direction, the first convex structure (11) is provided on one side of the bare battery cell, the preset first direction is parallel to the thickness direction of the soft-pack battery, and the preset second direction is perpendicular to the preset first direction.

2. The soft pack battery according to claim 1, characterized in that: The packaging film (1) is provided with a plurality of the first convex structures (11), Along the preset first direction, a portion of the packaging film (1) located on one side of the bare cell is provided with at least two first convex structures (11); and / or, Along the preset first direction, a portion of the packaging film (1) located on the other side of the bare battery cell is provided with at least one first convex structure (11).

3. The soft pack battery according to claim 2, characterized in that: Along the preset first direction, the packaging film (1) is provided with a second convex structure (12) on one side of the packaging film (1) provided with the first convex structure (11), a second accommodating space is formed inside the second convex structure (12), and the second accommodating space is used to limit and accommodate the bare battery cell, and, The depth L of the first accommodating space is not greater than the depth h of the second accommodating space.

4. The soft pack battery according to claim 1, characterized in that The first convex structure (11) is arranged on the tab side of the soft-pack battery.

5. The soft pack battery according to claim 1, characterized in that: Along the preset first direction, the outer contour shape of the first convex structure (11) includes at least one of a square and a circle.

6. The soft pack battery according to claim 1, characterized in that The end of the first convex structure (11) away from the bare battery cell is an arched end; or, The end of the first convex structure (11) away from the bare battery core is a flat end.

7. The soft pack battery according to any one of claims 1 to 6, characterized in that: The soft-pack battery further comprises a support member (2), at least a portion of the support member (2) is disposed in the first accommodating space, and the support member (2) is used to support the first convex structure (11).

8. A method for manufacturing a soft pack battery, for manufacturing the soft pack battery according to any one of claims 1 to 7, characterized in that: include: A first convex structure (11) is formed on a packaging film (1); the packaging film (1) is arranged to surround the bare battery cell, and the first convex structure (11) is located on one side of the bare battery cell along the length direction or the width direction of the soft-pack battery; Electrolyte is injected into the packaging film (1) and formed, and the first accommodating space of the first convex structure (11) is kept filled with electrolyte.

9. The method for manufacturing a soft pack battery according to claim 8, wherein: Before the electrolyte is injected, a support member (2) is arranged in the packaging film (1), and at least a portion of the support member (2) is arranged in the first accommodating space.

10. The method for manufacturing a soft pack battery according to claim 8, wherein: After formation, the electrolyte is replenished to keep the first containing space filled with electrolyte; and / or, The first convex structure (11) is shaped from the outside of the soft-pack battery during formation.

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