Aluminum plastic film and battery

Abstract

The utility model relates to the technical field of batteries, and discloses an aluminum-plastic film and a battery, the aluminum-plastic film comprises an aluminum-plastic film body, a folding line is arranged on the aluminum-plastic film body, a first point coating area and a second point coating area are symmetrically arranged on two sides of the folding line, a pit punching area is arranged on the first point coating area, and a pit punching area is arranged on the second point coating area. The flushing pit area is used for forming a flushing pit for accommodating a battery cell, the surface of the first dispensing area and the surface of the second dispensing area are both provided with liquid retaining structures, and the liquid retaining structures have adhesion to the battery cell. In the subsequent use process of the battery, the thickness of the battery can be normally expanded along with the increase of the cycle number of the battery core, and the electrolyte stored in the electrolyte retaining structure flows back into the battery again under the influence of pressure and concentration difference, so that the electrolyte in the battery is supplemented, purple spots of a battery pole piece are relieved, the lithium precipitation time is shortened, and the service life of the battery is prolonged. And the cycle life and the safety characteristic of the battery are improved. In addition, the softening phenomenon of the packaged battery can be reduced, and the hardness of the battery is improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to battery technology field especially relates to an aluminum plastic film and battery. BACKGROUND

[0002] Lithium ion battery is mainly composed of electrode, diaphragm, electrolyte and shell four parts. With the wide application of lithium ion battery in various trades, people's long-term cycle performance and safety performance requirement is higher and higher. Electrolyte is the "blood" of lithium ion battery, as the carrier of ion transmission, ensures the normal operation of lithium ion battery.

[0003] However, the electrolyte in lithium ion battery is not invariable, and a large part of the capacity attenuation of the battery after the cycle is due to the consumption of electrolyte. If the electrolyte is forcibly supplemented, the battery is easy to swell after secondary packaging, which also leads to the softness and poor hardness of the battery, thereby affecting the safety performance and assembly of the battery.

[0004] Most of the current research direction puts the liquid preservation on the electrode and diaphragm, which may affect the performance of the battery while preserving the liquid. UTILITY MODEL CONTENT

[0005] To solve the above technical problems, the utility model provides an aluminum plastic film and battery, which realizes liquid preservation for the battery through the aluminum plastic film, avoids affecting the performance of the battery, improves the hardness of the battery, and increases the cycle life and safety characteristics of the battery.

[0006] The technical scheme adopted by the utility model to solve its technical problems is:

[0007] An aluminum plastic film, comprising an aluminum plastic film body, a folding line is arranged on the aluminum plastic film body, first point coating areas and second point coating areas are symmetrically arranged on both sides of the folding line, a pit area is arranged on the first point coating area, the pit area is used for forming a pit for accommodating a battery cell, a liquid preservation structure is arranged on the surfaces of the first point coating area and the second point coating area, and the liquid preservation structure has adhesion to the battery cell.

[0008] Preferably, the liquid preservation structure comprises a plurality of liquid preservation protrusions arranged in a rectangular array, and a containing cavity for containing electrolyte is formed in the liquid preservation protrusion.

[0009] Preferably, the liquid preservation protrusion comprises a connecting portion and an annular enclosing portion, the connecting portion and the inner wall of the enclosing portion define the containing cavity, and the outer wall of the connecting portion is connected to the aluminum plastic film body.

[0010] Preferably, the liquid preservation protrusion is formed by accumulation of liquid preservation particles, the particle size of the liquid preservation particles is 200-600 nm, and the material of the liquid preservation particles is PVDF or PVDF-HFP or PMMA.

[0011] Preferably, the projection of the enclosing part on the aluminum plastic film body is annular, the width W of the annular is 25-200 mu m, and the inner diameter D of the annular is 100-1000 mu m.

[0012] Preferably, the total area of the annular of all the liquid storage protrusions is S1, the sum of the areas of the first point coating area and the second point coating area is S2, and S1=(0.05-0.5)S2.

[0013] Preferably, the spacing L between the centers of two adjacent liquid storage protrusions is 100-1000 mu m.

[0014] Preferably, one end of the first point coating area away from the second point coating area is provided with a top sealing area, and the two sides of the first point coating area are respectively provided with a side sealing area and a second sealing area, and the aluminum plastic film body is further provided with a first sealing area and a gas bag area, and the gas bag area is located between the first sealing area and the second sealing area.

[0015] Preferably, the first point coating area and the top sealing area, the first point coating area and the side sealing area, and the first point coating area and the second sealing area all have a gap, and the spacing a is greater than or equal to 5 mm.

[0016] A battery comprising the aluminum plastic film.

[0017] Compared with the prior art, the aluminum plastic film and the battery of the embodiment of the application have the beneficial effects that: by arranging the liquid storage structure on the surfaces of the first point coating area and the second point coating area, when the battery cell is placed in the impact pit and the aluminum plastic film body is folded along the folding line, the liquid storage structures of the first point coating area and the second point coating area are attached to the battery cell, so that the amount of liquid storage of the battery is increased by the aluminum plastic film, and the performance of the battery is avoided. In the subsequent battery use process, as the cycle number of the battery cell increases, the thickness of the battery will normally expand, and the electrolyte stored in the liquid storage structure will flow back to the inside of the battery due to the influence of pressure and concentration difference, thereby supplementing the electrolyte in the battery, relieving the time of purple spots and lithium precipitation of the battery pole piece, and increasing the cycle life and safety characteristics of the battery.

[0018] In addition, the liquid storage structure has adhesion to the battery cell, and in the battery pressurization formation stage, the aluminum plastic film and the bare battery cell can be better attached, thereby reducing the softening phenomenon of the battery after packaging, and improving the hardness and safety performance of the battery. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 It is a structural schematic view of the aluminum plastic film of the utility model.

[0020] Figure 2 It is a side view of the aluminum plastic film of the utility model.

[0021] Figure 3 The liquid-keeping protrusion is a longitudinal section view of the utility model.

[0022] Figure 4 The projection view of the enclosing part is a projection view of the utility model.

[0023] Figure 5 The scanning view of the aluminum plastic film is a scanning view of the utility model.

[0024] Wherein: 1-aluminum plastic film body, 11-folding line, 12-first point coating area, 13-second point coating area, 14-pit area, 15-top sealing area, 16-side sealing area, 17-two sealing area, 18-one sealing area, 19-gas bag area, 2-liquid-keeping protrusion, 21-connection part, 22-enclosing part, 23-liquid-keeping particles, 24-holding cavity, 10-protection layer, 20-aluminum foil layer, 30-heat sealing layer, 100-aluminum plastic film. DETAILED DESCRIPTION

[0025] In the description of the utility model, it needs to explain, unless there is explicit stipulation and limitation, the term "installation", "connection", "connection" should be broad sense understanding, for example, can be fixed connection, also can be detachable connection, or integrally connected, can be mechanical connection, also can be electrical connection, can be directly connected, also can be indirectly connected through intermediate medium, can be the intercommunication of two elements. For ordinary skilled in the art, the specific meaning of the above-mentioned terms in the utility model can be understood according to specific circumstances.

[0026] The specific embodiments of the utility model are further described in detail below in combination with the drawings and examples. The following examples are used to illustrate the utility model, but not to limit the scope of the utility model.

[0027] As Figures 1-2 The utility model discloses a battery, it includes aluminum plastic film 100 and the electric core of cladding in the aluminum plastic film 100 inside. The aluminum plastic film 100 includes aluminum plastic film body 1, the aluminum plastic film body 1 is provided with folding line 11, the both sides symmetry of folding line 11 are equipped with first point coating area 12 and second point coating area 13, the first point coating area 12 is equipped with pit area 14, the pit area 14 is formed after single pit type cold pressure pit, the pit that holds the electric core, namely the first point coating area 12 covers pit area. The surface of first point coating area 12 and second point coating area 13 is equipped with liquid-keeping structure, and the liquid-keeping structure has adhesion to electric core. Specifically, the aluminum plastic film body 1 includes sequentially bonded protection layer 10, aluminum foil layer 20 and heat sealing layer 30, the liquid-keeping structure is arranged on the surface of heat sealing layer 30, and the layers are compounded by using glue hot method. Wherein, the material of protection layer 10 is PET (polyethylene terephthalate) or nylon, and the material of heat sealing layer 30 is CPP (chlorinated polypropylene resin).

[0028] Meanwhile, one end of the first spot coating area 12 away from the second spot coating area 13 is provided with a top sealing area 15, and both sides of the first spot coating area 12 are respectively provided with a side sealing area 16 and a second sealing area 17. The aluminum plastic film body 1 is further provided with a first sealing area 18 and a gas bag area 19, and the gas bag area 19 is located between the first sealing area 18 and the second sealing area 17. When the aluminum plastic film body 1 is folded along the folding line 11 after the electric core is placed in the punch, the first spot coating area 12 is attached to the second spot coating area 13 to package the electric core placed in the punch, and the gas bag area 19 is folded to form a gas bag. After the electric core is top sealed and side sealed, the aluminum plastic film body 1 only has an opening at the gas bag. After liquid injection is completed, the first sealing area 18 seals the opening of the gas bag. At this time, the electric core is completely isolated from the external environment. After the formation process, the gas generated by the electric core is introduced into the gas bag. Through packaging at the second sealing area 17, the battery packaging is completed after the gas bag is cut off, and a shaped soft-pack lithium ion battery is obtained.

[0029] Based on the above technical features, the battery is provided with a liquid storage structure on the surface of the first spot coating area 12 and the second spot coating area 13. When the electric core is placed in the punch, the liquid storage structure of the first spot coating area 12 and the second spot coating area 13 is attached to the electric core when the aluminum plastic film body 1 is folded along the folding line 11. Thus, the liquid storage capacity of the battery is increased by the aluminum plastic film 100, and the performance of the battery is avoided. During the subsequent use of the battery, as the number of cycles of the electric core increases, the thickness of the battery will normally expand. Affected by pressure and concentration difference, the electrolyte stored in the liquid storage structure flows back into the battery, replenishing the electrolyte in the battery, relieving the time of battery electrode purple and lithium precipitation, and increasing the cycle life and safety characteristics of the battery.

[0030] In addition, the liquid storage structure has adhesion to the electric core. During the pressurized formation of the battery, the aluminum plastic film 100 and the bare electric core can be better attached, thereby reducing the softening phenomenon of the packaged battery and improving the hardness and safety performance of the battery.

[0031] Please refer to the accompanying Figure 3 , 4In the embodiment, the liquid retaining structure comprises a plurality of liquid retaining protrusions 2 arranged in a rectangular array, and a containing cavity 24 for containing electrolyte is formed on the liquid retaining protrusion 2 to achieve the liquid retaining function. Specifically, the liquid retaining protrusion 2 comprises a connecting portion 21 and an annular enclosing portion 22, the connecting portion 21 and the inner wall of the enclosing portion 22 define the containing cavity 24, and the outer wall of the connecting portion 21 is connected to the aluminum plastic film body 1. The height of the liquid retaining protrusion 2 is 0.5-1.5 μm, such as 0.6 μm, 0.7 μm, 0.8 μm, 0.9 μm, 1 μm, 1.1 μm, 1.2 μm, 1.3 μm, 1.4 μm, etc., and is formed by stacking of liquid retaining particles 23. Preferably, the connecting portion is stacked by one layer of the liquid retaining particles 23.

[0032] The particle size of the liquid retaining particles 23 is 200-600 nm, such as 210 nm, 250 nm, 280 nm, 300 nm, 310 nm, 350 nm, 380 nm, 400 nm, 410 nm, 450 nm, 480 nm, 510 nm, 550 nm, 580 nm, etc. The liquid retaining particles 23 are organic particles, and the material is PVDF (polyvinylidene fluoride) or PVDF-HFP (polyvinylidene fluoride-hexafluoropropylene) or PMMA (polymethyl methacrylate).

[0033] In the embodiment, the enclosing portion 22 is annular in projection on the aluminum plastic film body 1, and the width W of the annular shape is 25-200 μm, such as 50 μm, 80 μm, 100 μm, 120 μm, 130 μm, 140 μm, 150 μm, 160 μm, 170 μm, 180 μm, 190 μm, etc. Meanwhile, the inner diameter D of the annular shape is 100-1000 μm, such as 150 μm, 200 μm, 250 μm, 300 μm, 350 μm, 400 μm, 450 μm, 500 μm, 550 μm, 600 μm, 650 μm, 700 μm, 750 μm, 800 μm, 850 μm, 900 μm, 950 μm, etc. The spacing L between the centers of two adjacent liquid retaining protrusions 2 is 100-1000 μm, such as 150 μm, 200 μm, 250 μm, 300 μm, 350 μm, 400 μm, 450 μm, 500 μm, 550 μm, 600 μm, 650 μm, 700 μm, 750 μm, 800 μm, 850 μm, 900 μm, 950 μm, etc.

[0034] By adjusting the width of the annular, the inner diameter of the annular and the spacing between adjacent liquid retaining protrusions 2, the coverage of the liquid retaining structure can be changed, and the required amount of liquid can be adjusted according to different systems in the later stage. Specifically, if the total area of the annular of all the liquid retaining protrusions 2 is S1, and the sum of the areas of the first point coating area 12 and the second point coating area 13 is S2, then they satisfy S1=(0.05-0.5)S2, such as S1=0.1S2, S1=0.15S2, S1=0.2S2, S1=0.25S2, S1=0.3S2, S1=0.35S2, S1=0.4S2, S1=0.45S2, etc.

[0035] In this application, in order not to affect the packaging effect, the first point coating area 12 and the top sealing area 15, the first point coating area 12 and the side sealing area 16, the first point coating area 12 and the second sealing area 17 all have gaps, and the gap size is preferably the same, and if the gap is a, then a≥5mm, such as 6mm, 6.5mm, 7mm, 7.5mm, 8mm, 8.5mm, 9mm, etc.

[0036] The following lists a specific embodiment to illustrate the technical effect of the present application:

[0037] The aluminum-plastic film body 1 is a conventional aluminum-plastic film, which is a multi-layer co-extrusion casting or multi-layer compression process aluminum-plastic film, from bottom to top in turn PET / nylon layer, aluminum foil layer, CPP layer; the CPP layer is provided with a liquid retaining mechanism, and the layers are compounded by glue hot method; the liquid retaining structure is dot matrix coated by a dot coater.

[0038] The material of the liquid retaining protrusion is an organic material, which can be PVDF, PVDF-HFP, PMMA, preferably PMMA; in the dot coating area, the outer circle width W is 50μm, the inner circle diameter D is 150μm, the dot spacing L is 600μm, the area density is 0.07g / ㎡, and the coverage is 9%;

[0039] The coated aluminum-plastic film is punched by cold pressure punching and single punching pit method;

[0040] The gap between the first point coating area 12 and the top sealing area 15, the first point coating area 12 and the side sealing area 16, and the first point coating area 12 and the second sealing area 17 is 5mm;

[0041] The SEM morphology after dot coating is shown in Figure 5

[0042] The above is only the preferred embodiment of the present application, it should be pointed out that for ordinary skilled in the art, without departing from the technical principle of the present application, a number of improvements and substitutions can be made, these improvements and substitutions should also be regarded as the protection scope of the present application.​

Claims

1. An aluminum laminate film characterized by: The aluminum-plastic film body is provided with a folding line, and first and second dot coating areas are symmetrically arranged on both sides of the folding line. The first dot coating area is provided with a pit area for forming a pit for accommodating an electric core. The first and second dot coating areas are both provided with liquid retaining structures, and the liquid retaining structures are adhesive to the electric core.

2. The aluminum laminate of claim 1, wherein: The liquid retaining structure comprises a plurality of liquid retaining protrusions arranged in a rectangular array, and the liquid retaining protrusions are provided with accommodating cavities for accommodating electrolyte.

3. The aluminum laminate of claim 2, wherein: The liquid retaining protrusion comprises a connecting portion and an annular enclosing portion, and the connecting portion and the inner wall of the enclosing portion define the accommodating cavity, and the outer wall of the connecting portion is connected to the aluminum-plastic film body.

4. The aluminum laminate of claim 3, wherein: The liquid retaining protrusion is formed by stacking liquid retaining particles, the particle size of the liquid retaining particles is 200-600 nm, and the material of the liquid retaining particles is PVDF or PVDF-HFP or PMMA.

5. The aluminum laminate of claim 3 wherein: The projection of the enclosing portion on the aluminum-plastic film body is an annular shape, the width W of the annular shape is 25-200 μm, and the inner diameter D of the annular shape is 100-1000 μm.

6. The aluminum laminate of claim 5 wherein: The total area of the annular shape of all the liquid retaining protrusions is S1, and the sum of the areas of the first and second dot coating areas is S2, S1=(0.05-0.5)S2.

7. The aluminum laminate of claim 2 wherein: The distance L between the centers of two adjacent liquid retaining protrusions is 100-1000 μm.

8. The aluminum laminate of any one of claims 1 to 7, wherein: The first dot coating area is provided with a top sealing area away from the second dot coating area, and the first dot coating area is provided with a side sealing area and a second sealing area on both sides, respectively. The aluminum-plastic film body is also provided with a first sealing area and a gas bag area, and the gas bag area is located between the first and second sealing areas.

9. The aluminum laminate of claim 8, wherein: The first dot coating area and the top sealing area, the first dot coating area and the side sealing area, and the first dot coating area and the second sealing area all have a gap, and the distance a is greater than or equal to 5 mm.

10. A battery, characterized by: The aluminum-plastic film comprises the aluminum-plastic film according to any one of claims 1-9.

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