Soft package battery and battery pack

Abstract

The utility model relates to the field of batteries, and discloses a soft package battery and a battery pack, the soft package battery comprises a shell and a battery cell, an accommodating cavity is formed in the shell, the battery cell is arranged in the accommodating cavity, the inner wall surface, facing the accommodating cavity, of the shell is provided with a first blocking layer, and the first blocking layer comprises a plurality of first blocking pieces which are arranged at intervals; a first storage gap for storing electrolyte is formed between any two first barriers; according to the utility model, the first barrier layer is arranged on the inner wall of the accommodating cavity, so that the battery cell is wrapped by the first barrier layer, and after electrolyte is injected into the battery cell, the first storage gaps among the plurality of first barrier pieces can store the electrolyte, so that the electrolyte is prevented from excessively dissociating to a secondary sealing area in a standing process; the formation gel state causes virtual sealing of the secondary sealing area, so that the sealing stability and safety of the secondary sealing area of the battery cell are improved.

Description

Technical Field

[0001] This utility model relates to the field of batteries, and in particular to a soft-pack battery and battery pack. Background Technology

[0002] The current safety issues of pouch batteries mainly focus on the heat sealing problem of the aluminum-plastic film. Pouch batteries achieve their sealing effect by using the polypropylene polymer of the inner layer of the aluminum-plastic film to be heat-fused together during the encapsulation process.

[0003] During the cell heat sealing process, after the top and side sealing is completed, electrolyte needs to be injected into the cell at the sealing point. The cell is then sealed and left to stand to allow the electrolyte to fully wet the electrodes before formation and capacity testing. Gas generated during formation enters the gas bag. After capacity testing, pressure is applied at the core winding point, simultaneously sealing the secondary sealing area. However, in actual operation, the free electrolyte inside the cell is randomly distributed. After capacity testing, some electrolyte becomes gel-like, and this gel-like electrolyte easily remains in the secondary sealing area, leading to a risk of incomplete sealing in the aluminum-plastic film secondary sealing area. This risk increases significantly with the size of pouch batteries. Incomplete sealing can cause gas and electrolyte leakage in pouch batteries. Moisture and oxygen from the air can also easily enter the battery through the incomplete sealing area, corroding and damaging the internal structure, posing a safety hazard. Utility Model Content

[0004] The technical problem to be solved by this utility model is: how to make the heat sealing of aluminum-plastic film more stable and reliable. In order to solve the above technical problem, this utility model provides a soft-pack battery, including a shell and a cell. A receiving cavity is formed inside the shell, and the cell is disposed in the receiving cavity. A first barrier layer is provided on the inner wall surface of the shell facing the receiving cavity. The first barrier layer includes a plurality of first barrier members arranged at intervals. A first storage gap for storing electrolyte is formed between any two first barrier members.

[0005] In some embodiments, the first barrier is an adhesive layer.

[0006] In some embodiments, the first barrier is a reinforcing rib disposed on the inner wall surface of the housing facing the accommodating cavity, the reinforcing rib protruding toward the battery cell and integrally formed with the housing.

[0007] In some embodiments, the housing includes two shell sections, with the accommodating cavity formed between the two shell sections. A connecting flange is formed on the outer peripheral edge of each shell section, and the two shell sections are connected by the connecting flange. A second barrier layer is provided on one side of the connecting flange of one shell section facing the other shell section. The second barrier layer includes a plurality of spaced second barrier members, and a second storage gap for storing electrolyte is formed between any two second barrier members.

[0008] In some embodiments, the width of the second storage gap is smaller than the width of the first storage gap.

[0009] In some embodiments, the thickness of the second barrier layer is less than the thickness of the first barrier layer.

[0010] In some embodiments, the edge of the second barrier layer is flush with the end of the connecting flange on the side away from the battery cell.

[0011] In some embodiments, one of the shell portions has a covering surface, and the other shell portion is formed with a first receiving pit, wherein the covering surface and the inner wall surface of the first receiving pit enclose the receiving cavity.

[0012] Alternatively, each of the two shell sections may be formed with a second receiving pit, and the inner walls of the two second receiving pits may be joined to form the receiving cavity.

[0013] In some embodiments, according to the above-described pouch battery, the first barrier is characterized in that its shape is dot-shaped, polygonal, or linear.

[0014] This utility model also provides a battery pack, including the aforementioned pouch battery, wherein at least one pouch battery is provided in the battery pack.

[0015] Compared with the prior art, the soft-pack battery provided in this embodiment of the present invention has the following advantages:

[0016] In this invention, a barrier layer is provided on the inner wall of the accommodating cavity. The barrier layer includes several first barrier members arranged at intervals. When the electrolyte is injected into the battery cell, the first storage gap between any two adjacent first barrier members can store the electrolyte, thereby preventing the electrolyte from excessively floating to the secondary sealing area during the standing process and turning into a gel state, causing the secondary sealing area to be poorly sealed, thus improving the stability and safety of the sealing of the secondary sealing area of ​​the battery cell. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of a single-pit shell structure in the traditional scheme;

[0018] Figure 2This is a schematic diagram of the double-pit shell structure in the traditional scheme;

[0019] Figure 3 This is a schematic diagram of the result of the shell wrapping the core in the traditional solution;

[0020] Figure 4 This is a side view of the traditional scheme where a single-pit shell encloses the core.

[0021] Figure 5 This is a side view of the traditional scheme where the double-pit shell encloses the core.

[0022] Figure 6 This is a side view of the single-corrugated shell enclosing the core in this utility model.

[0023] Figure 7 This is a side view of the double-pit shell enclosing the core in this utility model;

[0024] Figure 8 This is a schematic diagram of the double-pit shell structure after unfolding in this utility model;

[0025] Figure 9 This is a partial enlarged schematic diagram of the structure of the first barrier in this utility model.

[0026] In the diagram: 1. Shell; 11. Shell section; 12. Connecting flange; 13. Covering surface; 14. First receiving pit; 15. Second receiving pit; 16. Air bag; 2. Receiving cavity; 3. Battery cell; 4. First barrier layer; 41. First barrier component; 5. Second barrier layer; 51. Second barrier component; 6. Second sealing line; 7. First sealing line. Detailed Implementation

[0027] The specific embodiments of this utility model will be described in further detail below with reference to the accompanying drawings and examples. The following examples are used to illustrate this utility model, but are not intended to limit its scope.

[0028] like Figures 6 to 8 As shown, a preferred embodiment of the present invention provides a soft-pack battery, which includes a housing 1 and a battery cell 3. A receiving cavity 2 is formed inside the housing 1, and the battery cell 3 is disposed inside the receiving cavity 2. A first barrier layer 4 is provided on the inner wall surface of the housing 1 facing the receiving cavity 2. The first barrier layer 4 includes a plurality of first barrier members 41 arranged at intervals, and a first storage gap for storing electrolyte is formed between any two first barrier members 41.

[0029] In the prior art, see Figures 1 to 3When the battery is placed into the cavity 2, the unfolded shell 1 is folded to seal the cavity 2. Then, the top and sides of the folded shell 1 are sealed. Electrolyte is then injected into the shell 1 through the sealing line 7, so that the cell 3 is fully immersed in the electrolyte. During the formation process, the gas is discharged into the gas bag 16. After capacity separation, the core is pressurized and sealed at the second sealing line 6 to separate the cavity 2 part from the expected part. The gas bag 16 is then cut off to form a complete soft-pack battery. During the formation process, the electrolyte can easily migrate to the second sealing line 6 and become gel-like. This makes it difficult to completely seal the second sealing line 6 during the subsequent pressurization process, which can easily lead to a false seal and cause problems such as gas leakage and liquid leakage in the soft-pack battery. In this embodiment, a first barrier layer 4 is provided on the housing 1. The first barrier layer 4 is disposed on the inner wall of the accommodating cavity 2, thereby completely and comprehensively enclosing the battery cell 3 located in the accommodating cavity 2. The first barrier layer 4 includes a plurality of spaced first barrier members 41. After the electrolyte is injected into the accommodating cavity 2, the first barrier members 41 in the first barrier layer 4 can extend the movement path of the electrolyte, slow down the speed at which the electrolyte flows away towards the second sealing line 6, and prevent the electrolyte from moving further towards the second sealing line 6. In addition, the first storage gap between the first barrier members 41 can also accommodate and store a large amount of free electrolyte, further preventing a large amount of electrolyte from flowing away to the area of ​​the second sealing line 6 and affecting the sealing effect of the subsequent second sealing.

[0030] The first barrier 41 can be an adhesive layer disposed on the inner wall surface of the housing 1 facing the accommodating cavity 2. The composition of the first barrier 41 can be PVDF (polyvinylidene fluoride), and multiple adhesive layers can be coated on the inner wall surface of the accommodating cavity 2 by dispensing.

[0031] In some embodiments, the first barrier 41 may be a reinforcing rib disposed on the inner wall surface of the housing 1 facing the accommodating cavity 2, the reinforcing rib protruding toward the battery cell 3, and multiple reinforcing ribs being spaced apart and integrally formed with the housing.

[0032] In some embodiments, the thickness A of the first barrier layer 4 is 3 μm to 5 μm. Specifically, the choice of the thickness of the first barrier layer 4 is related to the height and volume of the first storage gap. When the thickness of the first barrier layer 4 is insufficient, excessive electrolyte can easily overflow the first storage gap and migrate towards the second sealing line 6, thus affecting the second sealing effect. Conversely, if the thickness of the first barrier layer 4 is sufficient, the first storage gap can hold more free electrolyte, thereby better preventing electrolyte from migrating to the second sealing line 6. In a preferred embodiment, the thickness of the first barrier layer 4 is preferably 3 μm to 5 μm, depending on actual needs, which can effectively avoid the above problems and ensure that the thickness of the first barrier layer 4 is neither too large nor too small. The thickness of the first barrier layer 4 can be measured by using a CCD vision inspection device to detect it from the side of the housing 1, or by using a slicer to detect the thickness of the first barrier layer 4. The specific working principles of the CCD vision inspection device and the slicer will not be elaborated here.

[0033] In some embodiments, the width C of the first storage gap is 100 μm to 200 μm. Specifically, the width of the first storage gap can control the ionization rate of the electrolyte and the storage effect of the electrolyte. If the first storage gap is too large, the electrolyte can naturally pass through the first storage gap more quickly to ionize to the second sealing line 6; while if the width of the first storage gap is too small, the overall storage space of the first barrier layer 4 will be insufficient, making it difficult to store a large amount of electrolyte. Too much electrolyte will overflow the first barrier layer 4 and ionize quickly to the second sealing line 6, which will also affect the subsequent second sealing effect. Preferably, the width of the first storage gap is 100 μm to 200 μm.

[0034] When monitoring and sampling the width of the first storage gap, measurements can be taken manually using microscopic measuring equipment or using CCD visual inspection equipment. In actual production, the size of the first storage gap between the first barrier elements 41 in the entire first barrier layer 4 can be controlled by controlling the areal density of the first barrier element 41 in combination with the control of the thickness of the first barrier element 41. Monitoring the areal density of the first barrier element 41 and testing the actual electrolyte storage capacity of the first barrier layer 4 can be done by weighing the first barrier layer 4 with an electronic balance and then weighing it after storing electrolyte. This allows for assessment of the effectiveness of the first barrier layer 4 in storing electrolyte at that areal density. Finally, by combining this with the testing of the second-sealing quality at the second seal, the first storage gap can be adjusted to a suitable range.

[0035] In some embodiments, the housing 1 includes two shell portions 11, a receiving cavity 2 is formed between the two shell portions 11, a connecting flange 12 is formed on the outer peripheral edge of the shell portion 11, the two shell portions 11 are connected by the connecting flange 12, a second barrier layer 5 is provided on one side of the connecting flange 12 of one shell portion 11 facing the other shell portion 11, the second barrier layer 5 includes a plurality of second barrier members 51 arranged at intervals, and a second storage gap for storing electrolyte is formed between any two second barrier members 51.

[0036] Specifically, in the actual secondary sealing process, after the two shell parts 11 are positioned relative to each other, the outer edge of the shell 1 extends into a connecting flange 12, which facilitates the docking of the two shell parts 11 and the subsequent sealing process. In this embodiment, the second barrier element 51 in the second barrier layer 5 on the connecting flange 12 can effectively prevent the free spread of electrolyte, and the second storage gap between the second barrier elements 51 can also store electrolyte, thereby preventing the electrolyte from continuing to flow towards the secondary sealing line 6, thus ensuring the quality of the subsequent secondary sealing.

[0037] It should be noted that the second barrier can be formed in the same way as the first barrier. That is, the second barrier can be an adhesive layer or a reinforcing rib on the connecting flange.

[0038] In some embodiments, the width of the second storage gap is smaller than the width of the first storage gap. In this embodiment, since the second storage gap is mainly used to store electrolyte that may overflow from the accommodating cavity 2, the amount of electrolyte that needs to be stored is not too large. Therefore, the main function of the second barrier layer 5 is to prevent electrolyte from flowing to the second sealing line 6. By reducing the width of the second storage gap and increasing the areal density of the second barrier member 51 in the second barrier layer 5, the complexity of the internal structure of the second barrier layer 5 can be increased, and the length of the electrolyte flow path can be extended, thereby preventing the electrolyte from flowing to the second sealing line 6 more efficiently. This allows more electrolyte to be blocked in the second storage gap of the second barrier layer 5, ensuring the quality of the second sealing.

[0039] In some embodiments, the thickness of the second barrier layer 5 is smaller than that of the first barrier layer 4. This is because the second barrier layer 5 needs to store a smaller amount of electrolyte, which improves the aesthetics of the pouch battery and enhances the quality of the subsequent pressing of the two separate casings 11. The thickness of the second barrier layer 5 and the setting of the second storage gap can also be detected by a CCD vision inspection device.

[0040] In some embodiments, the edge of the second barrier layer 5 is flush with the end of the connecting flange 12 away from the battery cell 3. It should be noted that this flushing refers to a near-flushing; specifically, a distance E between the edge of the second barrier layer 5 and the end of the connecting flange 12 away from the battery cell 3 can be considered near-flushing if it is between 0 μm and 0.1 μm. In this embodiment, the end of the connecting flange 12 away from the battery cell 3 is the location of the second sealing line 6, which will be used for subsequent secondary sealing. Because the second barrier layer 5 has a second storage gap, it contains a channel. Therefore, the second barrier layer 5 cannot be completely positioned at the second sealing line 6 to avoid affecting the quality of the subsequent secondary sealing.

[0041] In some embodiments, one shell portion 11 has a covering surface 13, and another shell portion 11 is formed with a first receiving pit 14, the covering surface 13 and the inner wall surface of the first receiving pit 14 enclose to form a receiving cavity 2.

[0042] Alternatively, the two shell sections 11 are each formed with a second receiving pit 15, and the inner walls of the two second receiving pits 15 enclose each other to form a receiving cavity 2.

[0043] Specifically, depending on the size of the cell 3 in the pouch battery, the casing 1 is also divided into two types. When the cell 3 is thin, it is only necessary to punch out the first receiving pit 14 on the casing 1 to completely accommodate the cell 3. At this time, the covering surface 13 on the other casing part 11 covers the first receiving pit 14 to form the receiving cavity 2. When the cell 3 is large, a single receiving pit cannot completely accommodate the cell 3. Therefore, it is necessary to form a second receiving pit 15 on each of the two casing parts 11. Through the corresponding fastening of the two casing parts 11, the two second receiving pits 15 can form a complete receiving cavity 2 to accommodate the cell 3.

[0044] In some embodiments, the first barrier 41 is in the shape of a dot, a polygon, or a line. Depending on the actual needs, the shape of the first barrier 41 is also different. The first barrier 41 can be in the shape of a dot, which can store more electrolyte and make the distribution of electrolyte in the receiving pit more uniform. The first barrier 41 can also be in the shape of a line, which can better restrict the flow and ionization of electrolyte.

[0045] In some embodiments, the second barrier 51 is in the shape of a dot, a polygon, or a line. Depending on the actual needs, the shape of the second barrier 51 can also be different. The second barrier 51 can be in the shape of a dot, which allows for the storage of more electrolyte and a more uniform distribution of electrolyte within the receiving pit. Alternatively, the second barrier 51 can be in the shape of a line, which can better restrict the flow and ionization of the electrolyte.

[0046] This utility model also provides a battery pack, which includes the aforementioned pouch battery, with at least one pouch battery disposed within the battery pack.

[0047] In summary, this utility model embodiment provides a soft-pack battery and battery pack. Both have a first barrier layer 4 and a second barrier layer 5 respectively disposed within the accommodating cavity 2 of the housing 1 and at the outer edge of the accommodating cavity 2. This prevents the electrolyte from flowing to the second sealing line 6, ensuring the quality of the subsequent second sealing and avoiding problems such as incomplete sealing. By limiting the thickness of the first barrier layer 4 and the second barrier layer 5, as well as the width between the first storage gap and the second storage gap, the first barrier layer 4 and the second barrier layer 5 can effectively block and restrict the free flow of the electrolyte while maintaining a large electrolyte retention capacity, further ensuring the quality of the second sealing.

[0048] The above are merely preferred embodiments of this utility model. It should be noted that, for those skilled in the art, several improvements and substitutions can be made without departing from the technical principles of this utility model, and these improvements and substitutions should also be considered within the protection scope of this utility model.

Claims

1. A soft-pack battery, characterized in that, The device includes a housing (1) and a battery cell (3). A cavity (2) is formed inside the housing (1). The battery cell (3) is disposed inside the cavity (2). A first barrier layer (4) is provided on the inner wall surface of the housing (1) facing the cavity (2). The first barrier layer (4) includes a plurality of first barrier members (41) arranged at intervals. A first storage gap for storing electrolyte is formed between any two first barrier members (41).

2. The soft-pack battery according to claim 1, characterized in that, The first barrier (41) is an adhesive layer.

3. The soft-pack battery according to claim 1, characterized in that, The first barrier (41) is a reinforcing rib disposed on the inner wall surface of the housing (1) facing the accommodating cavity (2), the reinforcing rib protruding towards the battery cell (3) and integrally formed with the housing (1).

4. The soft-pack battery according to claim 1, characterized in that, The housing (1) includes two shell sections (11), and the accommodating cavity (2) is formed between the two shell sections (11). A connecting flange (12) is formed on the outer peripheral edge of the shell section (11). The two shell sections (11) are connected by the connecting flange (12). A second barrier layer (5) is provided on one side of the connecting flange (12) of one shell section (11) facing the other shell section (11). The second barrier layer (5) includes a plurality of second barrier members (51) arranged at intervals. A second storage gap for storing electrolyte is formed between any two second barrier members (51).

5. The soft-pack battery according to claim 4, characterized in that, The width of the second storage gap is smaller than the width of the first storage gap.

6. The soft-pack battery according to claim 4, characterized in that, The thickness of the second barrier layer (5) is less than that of the first barrier layer (4).

7. The soft-pack battery according to claim 4, characterized in that, The edge of the second barrier layer (5) is flush with the end of the connecting flange (12) away from the cell (3).

8. The soft-pack battery according to claim 4, characterized in that, One of the shell portions (11) has a covering surface (13), and the other shell portion (11) is formed with a first receiving pit (14). The covering surface (13) and the inner wall surface of the first receiving pit (14) enclose the receiving cavity (2). Alternatively, each of the two shell portions (11) may be formed with a second receiving pit (15), and the inner wall surfaces of the two second receiving pits (15) may be enclosed to form the receiving cavity (2).

9. The soft-pack battery according to claim 1, characterized in that, The first barrier is in the shape of a dot, a polygon, or a line.

10. A battery pack, characterized in that, Includes a pouch cell as described in any one of claims 1 to 9, wherein at least one pouch cell is provided.

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