Preparation method of aluminum-plastic film and soft package battery, and soft package battery

Abstract

The application belongs to the technical field of batteries, and particularly relates to a preparation method of an aluminum-plastic film and a soft package battery and the soft package battery. The aluminum-plastic film comprises an aluminum-plastic film body, the aluminum-plastic film body comprises a groove area for placing an electric core and a gas pocket area; wherein the aluminum-plastic film body has a top sealing edge, a first bottom sealing edge and a first side sealing edge, the first side sealing edge is located on a side of the gas pocket area away from the groove area, a pre-sealing edge is arranged between the first bottom sealing edge and the groove area, a first channel is formed between the pre-sealing edge and the groove area, and the first channel is in communication with the gas pocket area. Compared with the traditional aluminum-plastic film, the previous bottom-up casing mode is changed into a left-to-right casing mode, and sufficient space is reserved between the first bottom sealing edge and the groove pit. When the soft package battery is processed, the generated gas and free liquid can enter the gas pocket area through the first channel, the impact of the gas and the free liquid on the top sealing seal is reduced, and the top sealing seal is prevented from being broken to cause liquid leakage.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of batteries, and particularly relates to a preparation method of an aluminum-plastic film and a soft package battery and the soft package battery. BACKGROUND

[0002] Lithium ion batteries are highly concerned due to their high energy density and good safety performance, and gradually transition to the field of new energy vehicles as their application in 3C electronic products becomes more and more mature.

[0003] Among them, the soft package battery is an important component part of the lithium ion battery, which is composed of an aluminum-plastic film and a battery cell. The conventional aluminum-plastic film includes a side sealing edge and a top sealing edge. During packaging, the side edge and the top edge are respectively fused by a sealing head to form the side sealing edge and the top sealing edge. As the energy density demand of the battery cell is higher and higher, the length direction and the width direction of the battery cell have less margin. In order to improve the energy density of the soft package battery, the top sealing seal is usually narrowed, and the electrode sheet compaction density is increased. However, the use of these methods can easily lead to the difficulty of battery cell immersion, the increase of internal free electrolyte, the production of gas during the main pressure of the battery cell during formation, and the increase of the impact of the gas-liquid on the top sealing seal. The narrower the top sealing seal, the smaller the gas-liquid channel to the gas belt, and the more intense the impact of the battery cell internal gas-liquid on the top sealing seal. The phenomenon of the top sealing / side sealing seal being broken often occurs. SUMMARY

[0004] The purpose of the present application is to provide an aluminum-plastic film to solve the problem of the soft package battery that the top sealing / side sealing seal is easily broken.

[0005] In order to achieve the above purpose, the following technical scheme is adopted: an aluminum-plastic film, comprising an aluminum-plastic film body, the aluminum-plastic film body comprising a groove area for placing a battery cell and a gas pocket area, the groove area and the gas pocket area being arranged side by side; wherein the aluminum-plastic film body has a top sealing edge, a first bottom sealing edge arranged opposite to the top sealing edge, and a first side sealing edge, the first side sealing edge being located on a side of the gas pocket area away from the groove area, a pre-sealing edge being arranged between the first bottom sealing edge and the groove area, a first channel being formed between the pre-sealing edge and the groove area, and the first channel being in communication with the gas pocket area.

[0006] Further, the seal thickness of the pre-sealing edge is 10um-30um greater than the seal thickness of the top sealing edge.

[0007] Further, the width of the first channel is 2.0mm-5.0mm.

[0008] Further, a second channel is formed between the top sealing edge and the groove area, and the width of the second channel is 0.5mm-2mm.

[0009] Further, the length of the pre-seal edge is less than the width of the groove area.

[0010] The application further provides a preparation method of the soft package battery.

[0011] S1, a punching machine is used to punch the aluminum plastic film to form a groove area and a gas pocket area;

[0012] S2, the electric core is placed in the groove area, the aluminum plastic film is folded along a first direction, and the first direction is the length direction of the top seal edge;

[0013] S3, the aluminum plastic film is respectively sealed along the top seal edge, the pre-seal edge and the first bottom seal edge, and then is baked;

[0014] S4, electrolyte is injected into the groove area, and the first side seal edge is sealed;

[0015] S5, the battery prepared in step S4 is placed and subjected to formation treatment;

[0016] S6, the gas pocket area is cut out, then the second side seal edge is formed by sealing along the cutting direction, and the second bottom seal edge is formed by precision sealing the bottom of the battery.

[0017] Further, a gap is formed between the second bottom seal edge and the electric core, and the width of the gap is 0.5mm-2.0mm.

[0018] Further, the second side seal edge and the second bottom seal edge are formed by one-time forming of an L-shaped seal head.

[0019] The application further provides a soft package battery prepared by the preparation method of the soft package battery.

[0020] The application has the following beneficial effects:

[0021] (1) The aluminum plastic film provided by the application comprises an aluminum plastic film body, the aluminum plastic film body comprises a groove area for placing an electric core and a gas bag area, and the groove area and the gas bag area are arranged side by side; wherein the aluminum plastic film body has a top sealing edge, a first bottom sealing edge arranged opposite to the top sealing edge, and a first side sealing edge, the first side sealing edge is located on a side of the gas bag area away from the groove area, a pre-sealing edge is arranged between the first bottom sealing edge and the groove area, a first channel is formed between the pre-sealing edge and the groove area, and the first channel is in communication with the gas bag area. Compared with the traditional aluminum plastic film, the aluminum plastic film provided by the application changes from the previous bottom-up cladding mode to the left-right cladding mode, and sufficient space is reserved between the first bottom sealing edge and the groove pit. When the soft-pack battery is processed, the gas generated due to the chemical reaction inside the electric core and the free liquid in the groove pit can enter the gas bag area through the first channel, reducing the impact of the gas and the free liquid on the top seal, thereby avoiding the top seal being broken and causing liquid leakage.

[0022] (2) The aluminum plastic film provided by the application comprises a pre-sealing edge arranged between the first bottom sealing edge and the groove area, and the distance between the pre-sealing edge and the groove area is less than the distance between the first bottom sealing edge and the groove area, so that when packaging, the electric core placed in the groove area can be fixed.

[0023] (3) The length of the pre-sealing edge of the aluminum plastic film provided by the application is less than the width of the groove area, after the gas and the free liquid flow out to the rightmost end of the first channel through the first channel, they enter the gap between the first bottom sealing edge and the groove area, and the gap is greater than the width of the first channel, so that the gas and the free liquid can smoothly enter the gas bag area, reducing the impact on the first bottom sealing edge. BRIEF DESCRIPTION OF DRAWINGS

[0024] The features, advantages, and technical effects of the exemplary embodiments of the application will be described below with reference to the accompanying drawings.

[0025] Figure 1 It is a packaging diagram of the existing soft-pack battery;

[0026] Figure 2 It is a packaging diagram of the existing soft-pack battery after cutting the gas bag;

[0027] Figure 3 It is a packaging diagram of the soft-pack battery in the embodiment of the application;

[0028] Figure 4 It is a packaging diagram of the soft-pack battery in the embodiment of the application after cutting the gas bag.

[0029] Among them, the reference signs are explained as follows:

[0030] 1, aluminum plastic film body; 11, top sealing edge; 12, first bottom sealing edge; 13, first side sealing edge; 14, pre-sealing edge; 15, second side sealing edge; 16, second bottom sealing edge; 2, groove area; 3, air bag area; 4, first channel; 5, second channel; W1, width of the first channel; L, length of the pre-sealing edge; W2, width of the groove area; W3, width of the gap; X, first direction. DETAILED DESCRIPTION

[0031] In the description and claims of the application, each of the words "comprise" "comprises" "comprising" "include" "includes" "including" and the like are to be understood in their non-limiting sense to mean that the stated item, step, or the like, but not other non-stated items, steps, or the like, are present. Recitation of "first", "second", "third", etc. does not imply an order or ranking of importance, but rather is used to distinguish one component from another. The term "plurality" shall mean two or more. The term "connected" shall mean directly or indirectly connected, unless otherwise indicated. The term "coupled" shall mean directly or indirectly connected, unless otherwise indicated.

[0032] In the description of the application, it should be understood that the orientation or positional relationship indicated by the terms "upper", "lower", "front", "back", "left", "right", "horizontal", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0033] In the description of the application, unless otherwise expressly specified and limited, the terms "first", "second", "third" are only for the purpose of description, and cannot be understood as indicating or implying relative importance; the term "plurality" means two or more; unless otherwise specified or explained, the terms "connected", "fixed" and the like should be understood in a broad sense, for example, "connected" can be fixed connection, or detachable connection, or integrally connected, or electrically connected; "connected" can be directly connected, or indirectly connected through an intermediate medium. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0034] The following will be described in detail in conjunction with the accompanying drawings Figures 1-4 The present application will be further described in detail, but not as a limitation of the present application.

[0035] The existing soft package battery generally includes the following steps in its preparation process:

[0036] Punching shell-top sealing-side sealing-vacuum baking-liquid injection-resting-formation treatment-degassing packaging, the soft package battery after liquid injection packaging is shown as Figure 1 ​

[0037] Specifically, a small pit and an inner pit are punched on the cut aluminum plastic film by a punch shell machine; the bare battery cell is placed in the inner pit, and the side with the inner pit is used as the main body, the air bag is located on the right side of the battery cell, the aluminum plastic film is folded from bottom to top to form a shell, and then top sealing and side sealing are completed respectively, electrolyte is injected into the battery cell through the air bag side after the battery cell is baked, and then one sealing is completed, and the battery cell is charged after standing. During the chemical reaction process of the battery cell, the gas generated in the battery cell and the liquid in the groove pit can enter the air bag area through the first channel 4, reducing the impact of the gas and the liquid on the top seal, thereby avoiding the top seal from being broken and causing liquid leakage.

[0038] Based on this, the present application provides an aluminum plastic film, which comprises an aluminum plastic film body 1, the aluminum plastic film body 1 comprises a groove area 2 for placing a battery cell and an air bag area 3, and the groove area 2 and the air bag area 3 are arranged side by side; wherein the aluminum plastic film body 1 has a top sealing edge 11, a first bottom sealing edge 12 arranged opposite to the top sealing edge 11, and a first side sealing edge 13, the first side sealing edge 13 is located on the side of the air bag area 3 away from the groove area 2, a pre-sealing edge 14 is arranged between the first bottom sealing edge 12 and the groove area 2, a first channel 4 is formed between the pre-sealing edge 14 and the groove area 2, and the first channel 4 is in communication with the air bag area 3. The aluminum plastic film provided by the present application is changed from the previous bottom-up sealing method to the left-right sealing method compared with the traditional aluminum plastic film, and sufficient space is reserved between the first bottom sealing edge 12 and the groove pit. When the soft package battery is processed, the gas generated due to the chemical reaction inside the battery cell and the liquid in the groove pit can enter the air bag area 3 through the first channel 4, reducing the impact of the gas and the liquid on the top seal, thereby avoiding the top seal from being broken and causing liquid leakage.

[0039] In the embodiment, the sealing thickness of the pre-sealing edge 14 is 10-30 um larger than that of the top sealing edge 11, the width W1 of the first channel is 2.0-5.0 mm, preferably, the width W1 of the first channel is preferably 2.0 mm, 2.2 mm, 2.5 mm, 2.6 mm, 3.0 mm, 3.5 mm, 3.8 mm, 4.0 mm, 4.5 mm or 4.8 mm, which is designed to ensure that the first channel 4 has sufficient width, so that the gas generated inside the battery and the liquid in the free state can quickly enter the air bag through the first channel 4, and to ensure that the distance between the pre-sealing edge 14 and the groove area 2 is appropriate, so that the battery does not shake in the groove area 2.

[0040] Preferably, the second channel 5 is formed between the top sealing edge 11 and the groove area 2, and the width of the second channel 5 is 0.5-2 mm. When the battery generates gas, the generated gas and the liquid in the free state can also enter the air bag through the second channel 5, and when the gas and liquid passing through the second channel 5 are close to saturation, the gas and liquid in the groove area 2 can also flow into the air bag through the first channel 4. That is, the present application opens up multiple channels for gas and liquid to flow into the air bag area 3, which can ensure that the energy density of the soft-pack battery is not lost, and the top sealing seal is not broken, so that the gas and liquid generated during the formation stage can quickly enter the air bag, avoiding the continuous rise of the gas pressure inside the battery.

[0041] More specifically, the length L of the pre-sealing edge is smaller than the width W2 of the groove area, which is designed to allow the gas and liquid to smoothly enter the channel formed by the first bottom sealing edge 12 and the groove area 2 when the gas and liquid flow to the outlet of the first channel 4, and the width of the channel is greater than the width W1 of the first channel, which can slow down the flow rate of the gas and liquid.

[0042] The present application also provides a preparation method of a soft-pack battery, comprising the following steps:

[0043] S1, using a shell punching machine to punch an aluminum plastic film to form a groove area 2 and an air bag area 3;

[0044] S2, placing the battery into the groove area 2, and folding the aluminum plastic film along the first direction X, which is the length direction of the top sealing edge 11;

[0045] S3, packaging the aluminum plastic film along the top sealing edge 11, the pre-sealing edge 14 and the first bottom sealing edge 12, and then baking;

[0046] S4, injecting electrolyte into the groove area 2 and sealing along the first side sealing edge 13;

[0047] S5, placing the battery prepared in step S4 for standing and formation treatment;

[0048] S6, the gas bag area 3 is cut out, then the edge is sealed along the cutting direction to form the second side seal 15, and the bottom of the battery is fine sealed to form the second bottom seal 16.

[0049] Preferably, the second bottom seal 16 is formed with a gap between the battery cell, and the width W3 of the gap is 0.5mm-2.0mm.

[0050] Preferably, the second side seal 15 and the second bottom seal 16 are formed by L-shaped seal once.

[0051] It is worth mentioning that the width W1 of the first channel in the application is 2.0mm-5.0mm, so that the aluminum plastic film bottom has a larger space, and the electrolyte can quickly diffuse and infiltrate to the battery cell through the first channel 4. The infiltration effect is faster than that of the traditional process, the battery cell infiltration effect is more obvious, and after standing, the battery cell is formed. The gas generated in the formation stage can be discharged into the gas bag through the first channel 4 and the second channel 5, respectively. The width of the first channel 4 is larger than that of the second channel 5, so that the gas generated by the battery cell is discharged into the gas bag at a faster speed, and the impact of the liquid and gas in the groove area 2 on the top seal is smaller, thereby ensuring the effectiveness of the top seal. After the battery cell is formed, the degassing packaging is completed. Specifically, the bayonet pierces the gas bag, then the excess gas and liquid in the battery cell are pumped out by vacuum pumping, then the gas bag is cut off, and the degassing packaging and bottom fine sealing are completed by L-shaped seal. The degassing packaging and bottom fine sealing can be completed at one time, thereby improving the production efficiency.

[0052] In addition, it should be understood that although the present specification is described in terms of embodiments, not every embodiment contains only one independent technical solution. The description of the specification is only for the sake of clarity, and those skilled in the art should understand the specification as a whole. The technical solutions in each embodiment can also be combined appropriately to form other embodiments that can be understood by those skilled in the art.

[0053] According to the disclosure and teaching of the above description, those skilled in the art of the present application can also make changes and modifications to the above embodiments. Therefore, the present application is not limited to the above specific embodiments, and any obvious improvements, replacements or modifications made by those skilled in the art on the basis of the present application shall fall within the scope of the present application. In addition, although some specific terms are used in the present specification, these terms are only for convenience of description and do not constitute any limitation on the present application.

Claims

1. An aluminum laminate film characterized by: Comprising An aluminum plastic film body (1) comprising a groove area (2) for placing an electric core and a gas bag area (3), the groove area (2) and the gas bag area (3) being arranged side by side; Wherein, the aluminum plastic film body (1) has a top sealing edge (11), a first bottom sealing edge (12) arranged opposite to the top sealing edge (11), and a first side sealing edge (13) located on the side of the gas bag area (3) away from the groove area (2), a pre-sealing edge (14) is arranged between the first bottom sealing edge (12) and the groove area (2), a first channel (4) is formed between the pre-sealing edge (14) and the groove area (2), and the first channel (4) is in communication with the gas bag area (3); The width of the first channel (4) is 2.0mm-5.0mm; The length of the pre-sealing edge (14) is less than the width of the groove area (2).

2. The aluminum laminate as claimed in claim 1, wherein: The sealing thickness of the pre-sealing edge (14) is 10um-30um larger than that of the top sealing edge (11).

3. The aluminum laminate of claim 1 wherein: A second channel (5) is formed between the top sealing edge (11) and the groove area (2), and the width of the second channel (5) is 0.5mm-2mm.

4. A method for producing a pouch-shaped battery using the aluminum laminate film according to any one of claims 1 to 3, characterized by, Comprising the following steps: S1, using a shell punching machine to punch the aluminum plastic film to form a groove area (2) and a gas bag area (3); S2, placing an electric core into the groove area (2), and folding the aluminum plastic film along a first direction, the first direction being the length direction of the top sealing edge (11); S3, packaging the aluminum plastic film along the top sealing edge (11), the pre-sealing edge (14) and the first bottom sealing edge (12) respectively, and then baking; S4, injecting electrolyte into the groove area (2) and sealing along the first side sealing edge (13); S5, placing the battery prepared in step S4 for standing and formation treatment. 5.The method of claim 4, wherein: Further comprising the following steps: S6, cutting out the gas bag area (3), then sealing along the cutting direction to form a second side sealing edge (15), and precision sealing the bottom of the battery to form a second bottom sealing edge (16). 6.The method of claim 5, wherein: the first electrode layer is formed by coating a first electrode material on the first surface of the first substrate; and the second electrode layer is formed by coating a second electrode material on the second surface of the second substrate. A gap is formed between the second bottom sealing edge (16) and the electric core, and the width of the gap is 0.5mm-2.0mm. 7.The method of claim 5, wherein: the first electrode layer is formed by coating a first electrode material on the first surface of the first substrate; and the second electrode layer is formed by coating a second electrode material on the second surface of the second substrate. The second side sealing edge (15) and the second bottom sealing edge (16) are formed by L-shaped sealing heads in one step.

8. A pouch battery, characterized by, Made by the preparation method of the soft package battery according to any one of claims 4-7.

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