WO2024060145A1 - 二次电池及包含其的电子装置 - Google Patents

二次电池及包含其的电子装置 Download PDF

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Publication number
WO2024060145A1
WO2024060145A1 PCT/CN2022/120612 CN2022120612W WO2024060145A1 WO 2024060145 A1 WO2024060145 A1 WO 2024060145A1 CN 2022120612 W CN2022120612 W CN 2022120612W WO 2024060145 A1 WO2024060145 A1 WO 2024060145A1
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WO
WIPO (PCT)
Prior art keywords
insulating glue
layer
insulating
thickness
glue layer
Prior art date
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PCT/CN2022/120612
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English (en)
French (fr)
Inventor
宋正菊
李琳
郭培培
李锐
Original Assignee
宁德新能源科技有限公司
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
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Application filed by 宁德新能源科技有限公司 filed Critical 宁德新能源科技有限公司
Priority to CN202280017424.1A priority Critical patent/CN117083755A/zh
Priority to PCT/CN2022/120612 priority patent/WO2024060145A1/zh
Publication of WO2024060145A1 publication Critical patent/WO2024060145A1/zh

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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/10—Primary casings; Jackets or wrappings
    • H01M50/102—Primary casings; Jackets or wrappings characterised by their shape or physical structure
    • H01M50/105—Pouches or flexible bags
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/10—Primary casings; Jackets or wrappings
    • H01M50/183—Sealing members
    • H01M50/186—Sealing members characterised by the disposition of the sealing members

Definitions

  • the present application relates to the field of energy storage devices, and in particular, to a secondary battery and an electronic device including the battery.
  • Lithium-ion secondary batteries have the characteristics of high energy density, long cycle life, high nominal voltage, low self-discharge rate, small size, and light weight. They are widely used in various fields such as electrical energy storage, portable electronic devices, and electric vehicles.
  • lithium-ion secondary batteries need to pass a series of tests before leaving the factory, including internal short circuit tests, drop tests, puncture tests, etc.
  • the drop test is a more stringent safety test for lithium-ion secondary batteries. After a lithium-ion secondary battery is dropped, problems such as the top seal being broken open and liquid leakage may occur at the tabs.
  • the sealing effect is usually improved by installing insulating glue at the tab packaging position. However, the sealing effect between the existing insulating glue and the housing still needs to be improved.
  • An object of the present application is to provide a secondary battery that can improve the packaging strength at the tab position and an electronic device including the secondary battery.
  • a first aspect of this application provides a secondary battery, including an electrode assembly, a tab assembly and a packaging bag.
  • the electrode assembly is contained in the packaging bag.
  • the packaging bag includes a sealing portion, and the tab assembly includes tabs and insulating glue respectively provided on both sides of the tabs.
  • the tabs are connected to the electrode assembly and extend out of the packaging bag through the sealing portion.
  • Insulating glue connects the tabs and packaging bag.
  • the insulating glue includes a first insulating glue layer, a second insulating glue layer and a third insulating glue layer that are stacked sequentially along the first direction.
  • the first insulating glue layer is connected to the tab, and the third insulating glue layer is connected to the packaging bag.
  • the insulating glue includes a first part, and the first part is a region of the insulating glue that coincides with the tab in the first direction and is spaced apart from the sealing part.
  • the thickness of the insulating glue is h1
  • the thickness of the first insulating glue layer is A1
  • the thickness of the second insulating glue layer is B1
  • the thickness of the third insulating glue layer is C1, 10.5 %h1 ⁇ B1 ⁇ 35%h1, 90%B1 ⁇ C1 ⁇ 500%B1, C1>A1, 60%B1 ⁇ A1 ⁇ 400%B1.
  • the secondary battery provided by this application has 10.5%h1 ⁇ B1 ⁇ 35%h1, which ensures that the second insulating adhesive layer will not be over-melted or insufficiently fused when the package is heated, causing the second insulating adhesive layer and the first insulating adhesive layer to The interface and delamination of the three insulating adhesive layers will lead to a reduction in packaging strength; 90% B1 ⁇ C1 ⁇ 500% B1, 60% B1 ⁇ A1 ⁇ 400% B1, C1 > A1, ensuring that the third insulating adhesive layer and the packaging bag can be fully integrated. And the first insulating glue layer is fused and bonded to the tab.
  • the insulating glue layer is asymmetric in thickness.
  • the three-layer structure with asymmetric thickness enables the insulating glue and the packaging bag to be completely integrated without an obvious interface during packaging, thus improving the packaging strength between the insulating glue and the packaging bag. , improve the sealing effect and reduce the risk of leakage.
  • the packaging pulling force ⁇ 5.75N, as the thickness of the third insulating adhesive layer increases, the packaging pulling force increases after packaging, and it becomes more difficult to obtain the secondary battery 100 If leakage occurs, 8.18A1 ⁇ C1, during packaging, the third insulating adhesive layer, the encapsulating layer, and the second insulating adhesive layer will have insufficient melting and the interface will cause the packaging tension to decrease, increasing the risk of leakage of the secondary battery 100.
  • the packaging pulling force is ⁇ 6.2N, and the secondary battery 100 obtained after packaging is less likely to leak.
  • the thickness of the tab in the first direction is t, and 3t ⁇ 2h1 ⁇ 0.9t.
  • the insulating glue further includes a second part, and the second part is an area where the insulating glue coincides with the sealing part in the first direction.
  • the insulating glue includes a second part of a first insulating glue layer, a second part of a second insulating glue layer and a second part of a third insulating glue layer that are stacked sequentially along the first direction. direction, the thicknesses of the second part of the first insulating glue layer, the second part of the second insulating glue layer, and the second part of the third part of the insulating glue layer are A2, B2, and C2 respectively.
  • a thickness of the third insulating adhesive layer of the second portion in the first direction is C2, and 92% C1 ⁇ C2 ⁇ 98% C1.
  • the packaging bag includes an encapsulation layer connected to a third insulating adhesive layer, and the thickness of the encapsulation layer in the first direction is P; in the second part, the total thickness of the third insulating adhesive layer and the encapsulation layer in the first direction is H, 0.25(C2+P) ⁇ H ⁇ 0.75(C2+P).
  • the thickness of the first insulating adhesive layer of the second part in the first direction is A2, and A1 and A2 satisfy the following formula: 5 ⁇ m ⁇ A1-A2 ⁇ 0.5 ⁇ m.
  • the thickness of the second insulating glue layer of the second part in the first direction is B2, and B1 and B2 satisfy the following formula: 3 ⁇ m ⁇ B1-B2 ⁇ 0.1 ⁇ m.
  • the packaging bag includes an packaging layer connected to the third insulating glue layer.
  • the thickness of the packaging bag is T and the thickness of the packaging layer is P; along the first direction, the tab assembly and The thickness of the part corresponding to the second part is G, and the thickness of the part of the secondary battery corresponding to the second part and the tab is K, where, 2T+G-(2P+2t) ⁇ 75% ⁇ K ⁇ 2T+ G-(2P+2t) ⁇ 15%.
  • the insulating glue also includes a third part.
  • the third part is the area where the insulating glue does not coincide with the sealing part and the tab in the first direction.
  • the insulating glue includes a third part of a first insulating glue layer, a third part of a second insulating glue layer and a third part of a third insulating glue layer that are stacked sequentially along the first direction. .
  • the thickness of the insulating glue is h3, the thickness of the first insulating glue layer is A3, the thickness of the second insulating glue layer is B3, the thickness of the third insulating glue layer is C3, 10.5%h3 ⁇ B3 ⁇ 35%h3, C3>A3 ,90%B3 ⁇ C3 ⁇ 500%B3, 60%B3 ⁇ A3 ⁇ 400B3%.
  • the tab assembly includes a bonding area.
  • the bonding area is a portion of the insulating glue on both sides of the tab in the first direction that adheres to each other.
  • the bonding area includes an adhesive area.
  • the thickness of the bonding area is Q, and the thickness of the first insulating adhesive layer in the bonding area is D.
  • the thickness of the second insulating glue layer in the bonding area is B4, and the thickness of the third insulating glue layer in the bonding area is C4, 10.5% (Q ⁇ 0.5) ⁇ B4 ⁇ 35% (Q ⁇ 0.5), C4>0.5D, 90 %B4 ⁇ C4 ⁇ 500%B4, 120%B4 ⁇ D ⁇ 800B4%.
  • the melting points of the first insulating glue layer and the third insulating glue layer are 100-140°C, and the melting points of the second insulating glue layer are 140-200°C.
  • the first insulating glue layer, the second insulating glue layer and the third insulating glue layer all include polypropylene, polyethylene, polyvinylidene fluoride, vinylidene fluoride-hexafluoropropylene copolymer, One or more of polymethyl methacrylate or polyethylene glycol.
  • the first insulating glue layer and/or the third insulating glue layer further includes a toughening modifier.
  • the toughening modifier includes ethylene-propylene diene rubber, ethylene-propylene diene rubber, styrene-butadiene rubber, low-density polyethylene, ethylene-vinyl acetate copolymer, linear low-density polyethylene, nylon , one or more of polyethylene terephthalate, polycarbonate, and ultra-high molecular weight polyethylene.
  • the content of the toughening modifier is 3%-10% based on the total mass of the first insulating glue layer; and/or the content of the toughening modifier is based on the total mass of the third insulating glue layer. is 3%-10%.
  • h1 is 30-160 ⁇ m.
  • a second aspect of the present application also provides an electronic device, including the above-mentioned secondary battery.
  • FIG1 is a schematic diagram of a secondary battery provided in one embodiment of the present application.
  • Figure 2 is a schematic cross-sectional view of the battery shown in Figure 1 along II-II;
  • FIG3 is a cross-sectional schematic diagram of a packaging film provided in one embodiment of the present application.
  • Figure 4 is a schematic cross-sectional view of an insulating glue provided by an embodiment of the present application.
  • FIG. 5 is a schematic diagram of an electronic device provided by an embodiment of the present application.
  • the first packaging film 41 is the first packaging film 41
  • spatially relative terms such as “on,” etc., may be used herein for convenience to describe the relationship of one element or feature to another element(s) or feature(s) as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device or device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the diagram is turned over, features described as “above” or “on” other features or features would then be oriented “below” or “beneath” the other features or features. Thus, the exemplary term “upper” may include both upper and lower directions. It will be understood that, although the terms first, second, third, etc.
  • an embodiment of the present application provides a secondary battery 100 , including an electrode assembly 10 , a tab assembly, and a packaging bag 40 .
  • the pole assembly includes a pole 20 and two insulating glues 30 respectively provided on both sides of the pole.
  • the tab 20 is connected to the electrode assembly 10 .
  • the packaging bag 40 wraps the electrode assembly 10 and covers a part of the pole tabs 20 .
  • the insulating glue 30 is disposed between the packaging bag 40 and the pole tabs 20 and connects the packaging bag 40 and the pole tabs 20 .
  • the number of pole tabs 20 is two, namely the positive pole tab and the negative pole tab.
  • the two pole tabs 20 are located on the same side of the secondary battery 100 and extend out of the packaging bag 40; the number of insulating glue 30 is Four, of which two insulating glues 30 are disposed on the two opposite surfaces of one tab 20, and the other two insulating glues 30 are disposed on the two opposite surfaces of the other tab 20, and are located between the two tabs 20.
  • the two insulating glues on the same side are placed 30 degrees apart.
  • the material of the positive electrode tab may include at least one of Ni, Ti, Al, Ag, Au, Pt, Fe and combinations thereof.
  • the material of the negative electrode tab may include at least one of Ni, Ti, Cu, Ag, Au, Pt, Fe and combinations thereof.
  • the two insulating glues 30 located on the same side of the two tabs 20 can be connected to each other to form a whole, and the two tabs 20 can also be located on different sides of the secondary battery 100.
  • the electrode assembly 10 includes a positive electrode sheet, a negative electrode sheet, and a separator disposed between the positive electrode sheet and the negative electrode sheet.
  • the electrode assembly 10 is formed by stacking or winding the positive electrode sheet, the separator, and the negative electrode sheet.
  • the positive electrode sheet and the negative electrode sheet are electrically connected to two tabs 20, respectively.
  • the packaging bag 40 includes a first packaging film 41 and a second packaging film 42 arranged oppositely.
  • the shapes of the first packaging film 41 and the second packaging film 42 match each other.
  • the first encapsulating film 41 and the second encapsulating film 42 are connected to each other and enclose to form an accommodating cavity 410 .
  • the accommodating cavity 410 is used to accommodate at least part of the electrolyte, the electrode assembly 10 , the tab 20 and the insulating glue 30 .
  • the edges of the first encapsulation film 41 and the second encapsulation film 42 are connected to form a sealing portion 420 .
  • the sealing portion 420 extends from the outer surface of the accommodating cavity 410 toward a side away from the accommodating cavity 410 .
  • the sealing portion 420 is a portion of the packaging bag 40 that is sealed through a hot pressing process after containing the electrode assembly 10 and the electrolyte.
  • the pole tab 20 is partially received in the accommodation cavity 410 and extends out of the packaging bag 40 through the sealing portion 420 .
  • Both the first encapsulation film 41 and the second encapsulation film 42 include an encapsulation layer 401 , a metal layer 402 and a protective layer 403 that are stacked sequentially along the first direction Z.
  • the encapsulation layer 401 is disposed close to the electrode assembly 10
  • the protective layer 403 is disposed away from the electrode assembly 10 .
  • the material of the packaging layer 401 is a polymer, such as polypropylene, polyamide, etc.
  • the packaging layer 401 of the first packaging film 41 and the second packaging film 42 are connected to seal the packaging bag 40 to prevent the packaging bag 40 from being contaminated by the electrolyte.
  • the organic solvent in the electrolyte is dissolved or swollen, and the encapsulation layer 401 is also used to prevent the electrolyte in the electrolyte from contacting the metal layer 402, causing the metal layer 402 to be corroded.
  • the protective layer 403 is made of polymer resin and is used to protect the metal layer 402 to prevent the metal layer 402 from being damaged by external forces. It can also prevent the air from the external environment from infiltrating and maintain a water-free and oxygen-free environment inside the secondary battery 100 .
  • the metal layer 402 is made of metal, such as aluminum, steel, etc., and is used to prevent moisture penetration from the external environment and prevent external forces from causing damage to the secondary battery 100 .
  • the packaging film can be folded in half, and then a heat sealing head is used to apply a certain temperature (180-215°C) and pressure (0.3-0.6MPa) to the surface of the folded packaging film at a certain level. Heat sealing is performed within a period of time (1.5-3S) to melt and connect the encapsulating layer 401 of the encapsulating film. At this time, the innermost layer of the packaging bag 40 is the packaging layer 401 .
  • the insulating adhesive 30 includes a first portion 303, a third portion 301, and a second portion 302 that are connected to each other.
  • the first portion 303 is a region where the insulating adhesive 30 overlaps with the tab 20 in the first direction Z and is spaced apart from the sealing portion 420.
  • the third portion 301 is a region where the insulating adhesive 30 does not overlap with the tab 20 and the sealing portion 420 in the first direction Z.
  • the second portion 302 is a region where the insulating adhesive 30 overlaps with the sealing portion 420 in the first direction Z.
  • the second direction X is perpendicular to the first direction Z.
  • the first direction Z is the thickness direction of the tab 20
  • the second direction X is the length direction of the tab 20.
  • the first part 303 includes a first end 303a located in the packaging bag 40 and a second end 303b located outside the packaging bag 40.
  • the insulating glue 30 includes four third parts 301 distributed at four corners, wherein two third parts 301 are located in the packaging bag 40 and are located on both sides of the first end 303a in the third direction Y, and the other two third parts 301 are located outside the packaging bag 40 and are located on both sides of the second end 303b in the third direction Y.
  • the third direction Y is perpendicular to the first direction Z and the second direction X. In this embodiment, the third direction Y is the width direction of the tab 20.
  • the insulating glue 30 is extended inwardly from the sealing part 420 to the accommodating cavity 410 to avoid the risk of the effective sealing width being narrowed due to the insulating glue 30 not extending from the sealing part 420 to the inside of the packaging bag 40; and the insulating glue 30 is extended outwardly from the sealing part 420 to the outside of the packaging bag 40 to avoid the risk of the edge of the packaging bag 40 being compressed during packaging, which is conducive to sealing.
  • the insulating glue 30 includes a first insulating glue layer 31 , a second insulating glue layer 32 and a third insulating glue layer 33 which are stacked in sequence.
  • the first insulating glue layer 31 and The tabs 20 are connected, and the third insulating glue layer 33 is connected to the packaging layer 401 of the packaging bag 40 .
  • the first insulating glue layer 31 and the third insulating glue layer 33 play a sealing role, and the second insulating glue layer 32 plays a supporting role to prevent the insulating glue 30 from over-melting and causing a short circuit.
  • the first part 303, the third part 301 and the second part 302 all include a first insulating glue layer 31, a second insulating glue layer 32 and a third insulating glue layer 33.
  • the thickness of the second insulating glue layer 32 and the third insulating glue layer 33 are approximately equal.
  • the insulating glue is located in different areas and has different names.
  • the insulating glue includes the first insulating glue layer 31 and the second insulating glue layer 32.
  • the third insulating glue layer 33 in the second part 302, the insulating glue includes a second part of a first insulating glue layer 31, a second part of a second insulating glue layer 32, and a second part of a third insulating glue layer 33; in the third part Part 301, the insulating glue includes a third part of a first insulating glue layer 31, a third part of a second insulating glue layer 32, and a third part of a third part of the insulating glue layer 33.
  • the thickness of the first insulating glue layer 31, the second insulating glue layer 32 and the third insulating glue layer 33 of the first end 303a is different from that of the insulating glue. 30
  • the thicknesses of the first insulating glue layer 31 , the second insulating glue layer 32 and the third insulating glue layer 33 before encapsulation are approximately equal.
  • the tab assembly also includes a bonding area 201, which is a portion where the insulating glue 30 on both sides of the tab 20 along the first direction Z adheres to each other.
  • the bonding area 201 is composed of a second portion 302 and a third portion 301 of the insulating glue 30 located on the same side of the tab 20 in the third direction Y.
  • the first insulating glue layers 31 of the two insulating glues 30 are bonded to form a first insulating glue bonding layer.
  • the melting point of the first insulating glue layer 31 and the third insulating glue layer 33 is 100-140°C, and the melting point of the second insulating glue layer 32 is 140-200°C.
  • the first insulating glue layer 31 , the second insulating glue layer 32 and the third insulating glue layer 33 may each include polypropylene (PP), polyethylene, polyvinylidene fluoride, vinylidene fluoride-hexafluoropropylene copolymer, polyethylene One or more of methyl methacrylate or polyethylene glycol.
  • the first insulating glue layer 31 and/or the third insulating glue layer 33 also includes a toughening modifier for improving flexibility and impact performance to improve the packaging strength of the insulating glue 30 and the packaging bag 40 .
  • Toughening modifiers can include rubber particles such as ethylene-propylene rubber (EPR), ethylene-propylene diene rubber (EPDM), styrene-butadiene rubber, etc., to prevent cracks from spreading.
  • the toughening modifier may also include one or more of flexible polymers, rigid polymers or ultra-high molecular weight polyethylene (UHMWPE), used to strengthen the connection between crystals and blur the interface between crystals.
  • UHMWPE ultra-high molecular weight polyethylene
  • Flexible polymers can be low-density polyethylene (LDPE), ethylene-vinyl acetate copolymer (EVA), linear low-density polyethylene (LLDPE), etc.
  • Rigid polymers can be nylon (PA6), polyethylene terephthalate (PET), polycarbonate (PC), etc.
  • the toughening modifier is ultra-high molecular weight polyethylene, and the amount of the toughening modifier added to the first insulating glue layer 31 and/or the third insulating glue layer 33 is 3%-10%.
  • the added amount of the toughening modifier is 3% to 10%, the packaging strength of the insulating glue 30 and the packaging bag 40 is relatively high.
  • the amount of toughening modifier added is excessive (more than 10%), the crystals will become integrated and delamination will occur.
  • the thickness of the insulating glue 30 is h1
  • the thickness of the first insulating glue layer 31 is A1
  • the thickness of the second insulating glue layer 32 is B1.
  • the secondary battery provided by this application has 10.5% h1 ⁇ B1 ⁇ 35% h1, which ensures that the second insulating adhesive layer will not be over-melted or insufficiently fused when the package is heated, causing the second insulating adhesive layer and the first insulating adhesive layer 31, Interfaces and delaminations occur in the third insulating adhesive layer 33, resulting in reduced packaging strength; 90% B1 ⁇ C1 ⁇ 500% B1, 60% B1 ⁇ A1 ⁇ 400% B1, C1 > A1, ensuring that the third insulating adhesive layer 33 is in contact with the packaging bag 40 can be completely fused and the first insulating glue layer 31 can be fused and bonded to the tab 20.
  • the third insulating glue layer 33 is heated first compared to the first insulating glue layer during packaging, this design can avoid the third insulating glue layer.
  • 33 Over-melting causes the packaging bag 40 and the second insulating glue layer 32 to fuse, resulting in a poor fusion interface problem. It can also avoid insufficient fusion or over-melting of the first insulating glue layer 31 to cause poor adhesion to the tab 20, and the first insulating glue layer 31
  • the insulating glue layer 31, the second insulating glue layer 32 and the third insulating glue layer 33 are asymmetric in thickness, and adopt the three-layer structure with asymmetric thickness, so that the insulating glue 30 and the packaging bag 40 can be completely integrated during packaging. , there is no obvious interface, thereby improving the sealing strength between the insulating glue 30 and the packaging bag 40, improving the sealing effect, and reducing the risk of leakage.
  • the secondary battery 100 can have high packaging strength while taking into account high insulation and Corrosion resistance.
  • the packaging tension of the secondary battery 100 increases after packaging, making it less likely to leak.
  • the third insulation The adhesive layer 33 , the encapsulating layer 401 and the second insulating adhesive layer 32 may have insufficient melting and interfaces, resulting in reduced packaging tension, increasing the risk of leakage of the secondary battery 100 .
  • the secondary battery 100 can have high packaging strength while taking into account high insulation and corrosion resistance.
  • the packaging pulling force is ⁇ 6.2N, and the secondary battery 100 obtained after packaging is less likely to leak.
  • the thickness of the pole tab 20 in the first direction Z is t.
  • t and h1 satisfy the following formula: 3t ⁇ 2h1 ⁇ 0.9t. With this arrangement, the secondary battery 100 can have high packaging strength and high insulation and corrosion resistance properties.
  • the thickness of the first insulating glue layer 31 of the second part is A2
  • the thickness of the second insulating glue layer 32 of the second part is B2
  • the thickness of the third insulating glue layer 33 is C2.
  • Such an arrangement makes the thickness of the second part of the third insulating adhesive layer 33 change less before and after heat sealing, which is beneficial to improving the packaging strength.
  • the thickness of the encapsulation layer 401 in the first direction Z is P.
  • the encapsulating layer 401 of the packaging bag 40 and the second part and the third insulating glue layer 33 of the insulating glue 30 are melted due to heat sealing, and the encapsulating layer 401 and the second part of the third insulating glue layer 33 are in the first
  • the total thickness in direction Z is H.
  • 0.25(C1+P) ⁇ H ⁇ 0.75(C1+P) such setting can completely fuse the packaging layer 401 of the packaging bag 40 with the second part and third insulating glue layer 33 of the insulating glue 30, Improve packaging strength.
  • the thickness of the portion of the tab assembly corresponding to the second portion 302 of the insulating glue 30 is G.
  • the thickness of the packaging bag 40 in the first direction Z is T.
  • the thickness of the first packaging film 41 and the second packaging film 42 in the first direction Z are both T.
  • the thickness of the portion of the secondary battery 100 corresponding to the tab 20 and the second portion 302 is K, wherein 2T+G-(2P+2t) ⁇ 75% ⁇ K ⁇ 2T+G-(2P+2t) ⁇ 15%.
  • the thickness of the insulating glue 30 is h3
  • the thickness of the first insulating glue layer 31 is A3
  • the thickness of the second insulating glue layer 32 of the third part is B3
  • the thickness of the third part 30 is h3.
  • C3>A3 ensures that the third part of the third insulating glue layer 33 and the packaging layer 401 of the packaging bag 40 can be completely integrated, because the third part of the third part of the third insulating glue layer 33 is relatively different from the third part of An insulating glue layer 31 is heated and melted first.
  • This design can prevent the third part of the third insulating glue layer 33 from over-melting, causing the encapsulation layer 401 and the third part of the second insulating glue layer 32 to fuse, resulting in poor fusion interface problems; Moreover, the thickness of the third part of the first insulating glue layer 31, the third part of the second insulating glue layer 32 and the third part of the third part of the insulating glue layer 33 are asymmetrical, and the three-layer structure with asymmetrical thickness is adopted, so that in packaging At this time, the insulating glue 30 and the packaging layer 401 of the packaging bag 40 can be completely integrated without an obvious interface, thereby improving the packaging strength between the insulating glue 30 and the packaging bag 40 and improving the sealing effect.
  • the thickness of the bonding area 201 is Q
  • the thickness of the first insulating adhesive layer in the bonding area is D
  • the thickness of the second insulating adhesive layer 32 in the bonding area is B4.
  • the thickness of the third insulating glue layer 33 in the bonding area is C4, where 10.5% (Q ⁇ 0.5) ⁇ B4 ⁇ 35% (Q ⁇ 0.5), C4>0.5D, 90%B4 ⁇ C4 ⁇ 500%B4, 120%B4 ⁇ D ⁇ 800B4%.
  • the secondary battery provided in the present application has 10.5% (Q ⁇ 0.5) ⁇ B4 ⁇ 35% (Q ⁇ 0.5), which ensures that the second insulating adhesive layer of the second part will not be over-melted or not fused enough when the package is heated, so that the second insulating adhesive layer of the second part and the first insulating adhesive layer 31 of the second part and the third insulating adhesive layer 33 of the second part will have an interface and delamination, resulting in reduced packaging strength; C4>0.5D, 90%B4 ⁇ C4 ⁇ 500%B4, 120%B4 ⁇ D ⁇ 800B4%, which ensures that the third insulating adhesive layer 33 of the second part can be completely fused with the packaging bag 40 and the second part
  • the first insulating rubber layer 31 is fused and bonded to the pole ear 20.
  • the third insulating rubber layer 33 of the second part is heated and melted first relative to the first insulating rubber layer of the second part during packaging, this design can avoid the problem of poor fusion interface caused by overmelting of the third insulating rubber layer 33 of the second part, which causes fusion between the packaging bag 40 and the second insulating rubber layer 32 of the second part. It can also avoid the problem that the first insulating rubber layer 31 of the second part is insufficiently fused or overmelted, resulting in poor adhesion to the pole ear 20.
  • the first insulating rubber layer 31 of the second part, the second insulating rubber layer 32 of the second part and the third insulating rubber layer 33 of the second part are asymmetric in thickness.
  • the three-layer structure with asymmetric thickness is adopted, so that during packaging, the insulating rubber 30 and the packaging bag 40 can be completely fused without obvious interface, thereby improving the packaging strength between the insulating rubber 30 and the packaging bag 40, improving the sealing effect, and reducing the risk of leakage.
  • an embodiment of the present application also provides an electronic device 200 .
  • the electronic device 200 includes a main body 220 and a secondary battery 100 .
  • the secondary battery 100 is housed in the main body 220 .
  • the electronic device 200 may be one of a mobile phone, a tablet, and an e-reader.
  • the electronic device 200 is a mobile phone as an example.
  • the secondary battery 100 is installed in the mobile phone to provide power to the mobile phone for use by the mobile phone.
  • the main body 220 is a mobile phone structure. It can be understood that in other embodiments, the electronic device 200 can also have other structures, and is not limited to the above-mentioned mobile phones, tablets, and e-readers.
  • Insulating glue 30 with a thickness h1 of 80 ⁇ m and 5 ⁇ 0.1mm aluminum strips and nickel strips are hot-melted and flat pressed to form the tab assembly as shown in Figure 1.
  • the shoulder width of the insulating glue 30 is 2.2mm and is located at the tab 20 The distance between two insulating glues 30 on the same side is 20mm.
  • the shoulder width of the insulating glue 30 is the distance along the third direction Y (the width direction of the tab 20 ), and one edge of the insulating glue 30 exceeds the edge on the same side of the tab.
  • the above-mentioned tab assembly is put into a packaging bag 40 with a thickness T of 91 ⁇ m, and then a 1.5 mm wide heat sealing head is used for heat sealing to obtain a secondary battery as shown in Figure 1.
  • the heat sealing temperature is 205°C.
  • the pressure is 0.4MPa and the heat sealing time is 1.5S.
  • samples are cut along the width or length direction of the tab 20, and the cross-section of the sample is tested using a Keyence VHX-5000 microscope (test magnification of 200X).
  • the thickness of 5 to 10 points evenly distributed in each area of the sample (first insulating adhesive layer 31, second insulating adhesive layer 32, third insulating adhesive layer 33, first insulating adhesive bonding layer, tab assembly, packaging layer 401, packaging bag 40) is tested and recorded, and the average value is taken as the thickness of each layer; along the first direction, the boundaries between some components are blurred due to heat sealing, and the color difference of each component can be used as an auxiliary line to help measure the thickness of each component;
  • the first adhesive insulating adhesive layer is composed of two first insulating adhesive layers bonded to each other, and half of the thickness of the first adhesive insulating adhesive layer can be regarded as the thickness of the first insulating adhesive layer.
  • the thickness A1 of the first insulating glue layer 31 is 14.8 ⁇ m
  • the thickness B1 of the second insulating glue layer 32 is 15.6 ⁇ m
  • the thickness t of the tab 20 is 100 ⁇ m.
  • the thickness C2 of the second part of the third insulating glue layer 33 is 48.6 ⁇ m
  • the total thickness H of the second part of the third part of the insulating glue layer 33 and the encapsulation layer 401 is 38.7 ⁇ m
  • the second part of the first insulating glue layer 33 has a thickness C2 of 48.6 ⁇ m.
  • the thickness A2 of the adhesive layer 31 is 14.9 ⁇ m
  • the thickness B2 of the second part of the second insulating adhesive layer 32 is 14.8 ⁇ m.
  • the thickness G of the portion of the tab assembly corresponding to the second part 302 of the insulating glue 30 is 260 ⁇ m
  • the thickness P of the packaging layer 401 is 35 ⁇ m
  • the portion of the secondary battery 100 corresponding to the tab 20 and the second part 302 The thickness K is 360 ⁇ m.
  • the thickness h3 of the insulating glue 30 is 80 ⁇ m
  • the thickness A3 of the first insulating glue layer 31 of the third part is 14.8 ⁇ m
  • the thickness B3 of the second insulating glue layer 32 of the third part is 15.6.
  • the thickness C3 of the third insulating glue layer 33 is 49.6 ⁇ m.
  • the thickness Q of the tab assembly is 160 ⁇ m
  • the thickness D of the first insulating adhesive layer in the bonding area is 29.6 ⁇ m
  • the thickness B4 of the second insulating adhesive layer 32 in the bonding area is 15.6 ⁇ m
  • the thickness C4 of the third insulating adhesive layer 33 in the bonding area is 49.6 ⁇ m.
  • the first insulating adhesive layer 31 is made of PP and has a melting point of 145°C.
  • the second insulating glue layer 32 is made of PP and has a melting point of 145°C.
  • the third insulating glue layer 33 includes PP with a mass fraction of 95% and UHMWPE with a mass fraction of 5%, and has a melting point of 120°C.
  • the battery prepared in Example 1 was subjected to a packaging tensile test, and the battery was visually inspected for leakage.
  • the specific package tensile test is as follows: cut the part of the battery corresponding to the second part of the tab and the insulating glue along the width direction of the tab to obtain a sample with a width of 5mm and a length of 5cm; clamp the sample on a high-speed rail tensile machine. The pole lug is fixed on the upper clamp and the packaging bag is fixed on the lower clamp. Set the stretching speed to 175 ⁇ 5mm/min. Pull the sample upward in the 180-degree direction for peeling and read the peeling force. Divide the read peeling force value (unit N) by the width of the sample to calculate the packaging tensile force F (N/mm) of the sample.
  • Embodiment 2-12 and Comparative Example 1-9 and Embodiment 1 lies in the thickness A1 of the first insulating glue layer 31, the thickness B1 of the second insulating glue layer 32 and the thickness A1 of the first insulating glue layer 32 in the first part 303 of the insulating glue 30.
  • the thickness C1 of the three insulating adhesive layers 33 is different, and the specific parameters and test results are shown in Table 1.
  • X/320 means that the number of leaking batteries among the 320 samples tested is X.
  • the packaging tensile force is ⁇ 5.75N.
  • the thickness C1 of the third insulating adhesive layer 33 is within the above range, the secondary battery 100 can have High packaging strength takes into account high insulation and corrosion resistance. As the thickness of the third insulating glue layer 33 increases, the packaging tension of the secondary battery 100 increases after packaging, making it less likely to leak. When the thickness of the third insulating glue layer 33 exceeds a certain range, the third insulation The adhesive layer 33 , the encapsulating layer 401 and the second insulating adhesive layer 32 may have insufficient melting and interfaces, resulting in reduced packaging tension, increasing the risk of leakage of the secondary battery 100 .
  • the secondary battery 100 can have high packaging strength while taking into account high insulation and corrosion resistance.
  • the packaging pulling force is ⁇ 6.1N, and the secondary battery 100 obtained after packaging is less likely to leak.
  • Example 20-23 The difference between Examples 20-23 and Comparative Examples 10-11 and Example 1 is that the thickness t of the tab 20 is different.
  • the specific parameters and test results are shown in Table 2.
  • the packaging tension F increases with the increase of the 2h1/t ratio.
  • 3 ⁇ 2h1/t ⁇ 0.9 the number of leaking batteries is 0, completely avoiding the problem of battery leakage; when 2h1/t ⁇ 0.9
  • t ⁇ 0.9 or 2h1/t ⁇ 3 the thicker the tab thickness or the thickness of the insulating glue will be unfavorable for packaging.
  • Embodiments 24-25 and Comparative Examples 12-14 and Embodiment 1 lies in the thickness C2 of the second third insulating glue layer 33 in the second part 302 of the insulating glue 30 and the first part of the second part of the insulating glue 30 At least one of the thickness C1 of the second part of the third insulating glue layer 33 in 301 is different.
  • the specific parameters and test results are shown in Table 3.
  • Embodiments 26-30 and Comparative Examples 15-16 and Embodiment 1 lies in the thickness A1 of the first insulating glue layer 31, the thickness B1 of the second insulating glue layer 32, and the thickness of the third insulating glue layer 303 in the first part 303 of the insulating glue layer 30.
  • the thickness C1 of the insulating glue layer 33, the thickness C2 of the second part of the third insulating glue layer 33 in the second part 302 of the insulating glue layer 30, and the thickness C2 of the second part of the third insulating glue layer 33 in the second part 302 and the encapsulation layer 401 At least one of the total thickness H is different.
  • the specific parameters and test results are shown in Table 4.
  • Example 1 The difference between Examples 31, 32 and Comparative Examples 17-18 and Example 1 is that the thickness A2 of the first insulating glue layer 31 in the second part 302 is different.
  • the specific parameters and test results are shown in Table 5.
  • Example 33-34 The difference between Examples 33-34 and Comparative Examples 19-20 and Example 1 is that the thickness B2 of the second insulating glue layer 32 in the second part 302 is different.
  • the specific parameters and test results are shown in Table 6.
  • Embodiments 35-36 and Comparative Examples 21-22 and Embodiment 1 lies in the thickness A1 of the first insulating glue layer 31, the thickness B1 of the second insulating glue layer 32, the thickness A1 of the third insulating glue layer 303 in the first part 303 of the insulating glue 30. At least one of the thickness C1 of the glue layer 33, the thickness G of the portion of the tab assembly corresponding to the second portion 302 of the insulating glue 30, and the thickness K of the portion of the secondary battery 100 corresponding to the second portion 302 and the tab 20.
  • Table 7 The specific parameters and test results are shown in Table 7.
  • Embodiments 37-49 and Comparative Examples 23-31 and Embodiment 1 lies in the thickness h3 of the third part 301 of the insulating glue 30, and the thickness A3 of the third part of the first insulating glue layer 31 in the third part 301.
  • at least one of the thickness B3 of the third part of the second insulating glue layer 32 and the thickness C3 of the third part of the third insulating glue layer 33 is different.
  • Table 8 The specific parameters and test results are shown in Table 8.
  • Example 50-62 and Comparative Examples 32-40 and Example 1 lies in the thickness Q of the bonding area 201 of the tab assembly, the thickness D of the first insulating glue bonding layer in the bonding area, At least one of the thickness B4 of the second insulating glue layer 32 and the thickness C4 of the third insulating glue layer 33 in the bonding area is different.
  • the specific parameters and test results are shown in Table 9.
  • Examples 63-68 and Comparative Examples 41-42 and Example 1 The difference between Examples 63-68 and Comparative Examples 41-42 and Example 1 is that the materials of the first insulating glue layer 31, the second insulating glue layer 32 and the third insulating glue layer 33 are different.
  • the specific parameters and test results are as shown in the table. Shown in 10.

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Abstract

二次电池包括电极组件（10）、极耳组件和包装袋（40）。电极组件（10）容纳于包装袋（40）。包装袋（40）包括密封部（420），极耳组件包括极耳（20）和绝缘胶（30），极耳（20）与电极组件（10）连接并穿过密封部（420）伸出包装袋（40）外。绝缘胶（30）设在极耳（20）上并连接极耳（20）和包装袋（40）。绝缘胶（30）包括沿第一方向依次堆叠设置的第一绝缘胶层（31）、第二绝缘胶层（32）以及第三绝缘胶层（33），第一绝缘胶层（31）与极耳（20）连接，第三绝缘胶层（33）与包装袋（40）连接。沿与第一方向垂直的第二方向，绝缘胶（30）包括第一部分（303），第一部分（303）为绝缘胶（30）在第一方向上与极耳（20）重合且与密封部（420）间隔设置的区域。第一部分（303）包括第一端部（303a），第一端部（303a）位于包装袋内，在第一端部（303a）中，沿第一方向，绝缘胶（30）的厚度为h1，第一绝缘胶层（31）的厚度为A1，第二绝缘胶层（32）的厚度为B1，第三绝缘胶层（33）的厚度为C1，10.5%h1≤B1≤35%h1，90%B1≤C1≤500%B1，C1＞A1，60%B1≤2A1≤400%B1。

Description

二次电池及包含其的电子装置 技术领域
本申请涉及储能装置领域，尤其是涉及一种二次电池及包括电池的电子装置。
背景技术
锂离子二次电池具有能量密度大、循环寿命长、标称电压高、自放电率低、体积小、重量轻等特点，广泛应用于电能储存、便携式电子设备和电动汽车等各个领域。为了保证二次电池的安全性能，在锂离子二次电池出厂前需要通过一系列的测试，包括内部短路测试、跌落测试、穿刺实验等。其中，跌落测试是锂离子二次电池的一项较为严苛的安全测试。锂离子二次电池跌落后极耳处容易出现顶封被冲开、漏液等问题。现通常通过在极耳封装位置处设置绝缘胶来提高密封效果。然而，现有绝缘胶与壳体的密封效果仍待提高。
发明内容
本申请的一个目的在于提供可提高极耳位置处的封装强度的二次电池以及包含该二次电池的电子装置。
本申请第一方面提供一种二次电池，包括电极组件、极耳组件和包装袋。电极组件容纳于包装袋中。包装袋包括密封部，极耳组件包括极耳和分别设置在所述极耳两侧的绝缘胶，极耳与电极组件连接并穿过密封部伸出包装袋外。绝缘胶连接极耳和包装袋。绝缘胶包括沿第一方向依次堆叠设置的第一绝缘胶层、第二绝缘胶层以及第三绝缘胶层，第一绝缘胶层与极耳连接，第三绝缘胶层与包装袋连接。沿与第一方向垂直的第二方向，绝缘胶包括第一部分，第一部分为绝缘胶在第一方向上与 极耳重合且与密封部间隔设置的区域。在第一端部中，沿第一方向，绝缘胶的厚度为h1，第一绝缘胶层的厚度为A1，第二绝缘胶层的厚度为B1，第三绝缘胶层的厚度为C1，10.5％h1≤B1≤35％h1，90％B1≤C1≤500％B1，C1＞A1，60％B1≤A1≤400％B1。
本申请提供的二次电池，10.5％h1≤B1≤35％h1，保证第二绝缘胶层在封装受热时不至于被过熔或者融合不够使第二绝缘胶层和第一绝缘胶层、第三绝缘胶层出现界面、分层导致封装强度降低；90％B1≤C1≤500％B1，60％B1≤A1≤400％B1，C1＞A1，保证第三绝缘胶层与包装袋能够完全融合以及第一绝缘胶层融合粘接在极耳上，由于第三绝缘胶层封装时相对第一绝缘胶层是先受热热熔，该设计可避免第三绝缘胶层过熔使包装袋与第二绝缘胶层之间融合导致产生融合界面不良问题，也可以避免第一绝缘胶层融合不足或者过熔而与极耳粘合不良，且第一绝缘胶层、第二绝缘胶层以及第三绝缘胶层在厚度上不对称，采用厚度上不对称的该三层结构，使得在封装时，绝缘胶与包装袋能够完全融合、无明显界面，从而提高绝缘胶与包装袋之间的封装强度，提高密封效果，减少漏液风险。
根据本申请的一些实施例，8.18A1≥C1≥1.05A1，封装拉力≥5.75N，随着第三绝缘胶层的厚度的增大，封装后封装拉力增加，获得的二次电池100越不容易产生漏液，8.18A1＜C1，封装时第三绝缘胶层与封装层和第二绝缘胶层会产生熔融不足以及界面导致封装拉力减小，增加二次电池100漏液风险。优选的，7A1≥C1≥1.3A1，在该范围内，封装拉力≥6.2N,封装后获得的二次电池100越不容易产生漏液。
根据本申请的一些实施例，极耳在第一方向上的厚度为t，3t≥2h1≥0.9t。
根据本申请的一些实施例，沿第二方向，绝缘胶还包括第二部分，第二部分为绝缘胶在第一方向上与密封部重合的区域。在 所述第二部分，所述绝缘胶包括沿第一方向依次堆叠设置的第二部分第一绝缘胶层、第二部分第二绝缘胶层以及第二部分第三绝缘胶层，沿第一方向，所述第二部分第一绝缘胶层、第二部分第二绝缘胶层以及第二部分第三绝缘胶层的厚度分别为A2、B2、C2。
根据本申请的一些实施例，在第二部分中，第二部分第三绝缘胶层在第一方向上的厚度为C2，92％C1≤C2≤98％C1。
根据本申请的一些实施例，7μm≥C1-C2≥1μm。
根据本申请的一些实施例，包装袋包括与第三绝缘胶层连接的封装层，封装层在第一方向上的厚度为P；在第二部分中，第三绝缘胶层和封装层在第一方向上的总厚度为H，0.25(C2+P)≤H≤0.75(C2+P)。
根据本申请的一些实施例，0.4(C2+P)≤H≤0.7(C2+P)。
根据本申请的一些实施例，在第二部分中，第二部分第一绝缘胶层在第一方向上的厚度为A2，A1和A2满足以下公式：5μm≥A1-A2≥0.5μm。
根据本申请的一些实施例，在第二部分中，第二部分第二绝缘胶层在第一方向上的厚度为B2，B1和B2满足以下公式：3μm≥B1-B2≥0.1μm。
根据本申请的一些实施例，包装袋包括与第三绝缘胶层连接的封装层，沿第一方向，包装袋的厚度为T，封装层的厚度为P；沿第一方向，极耳组件与第二部分相对应的部分的厚度为G，二次电池与第二部分和极耳相对应的部分的厚度为K，其中，2T+G-(2P+2t)×75％＜K＜2T+G-(2P+2t)×15％。
根据本申请的一些实施例，沿第二方向，绝缘胶还包括第三部分，第三部分为绝缘胶在第一方向上与密封部和极耳不重合的区域，在第三部分中，沿第一方向，在所述第三部分，所述绝缘胶包括沿第一方向依次堆叠设置的第三部分第一绝缘胶层、第三部分第二绝缘胶层以及第三部分第三绝缘胶层。绝缘 胶的厚度为h3，第一绝缘胶层的厚度为A3，第二绝缘胶层的厚度为B3，第三绝缘胶层的厚度为C3，10.5％h3≤B3≤35％h3，C3＞A3，90％B3≤C3≤500％B3，60％B3≤A3≤400B3％。
根据本申请的一些实施例，极耳组件包括粘合区域，粘合区域为沿所述第一方向极耳两侧的绝缘胶相互贴合的部分；沿第一方向，粘合区域包括粘合区第一绝缘胶粘合层、粘合区第二绝缘胶层、粘合区第三绝缘胶层，粘合区域的厚度为Q，粘合区第一绝缘胶粘合层的厚度为D，粘合区第二绝缘胶层的厚度为B4，粘合区第三绝缘胶层的厚度为C4，10.5％(Q×0.5)≤B4≤35％(Q×0.5)，C4＞0.5D，90％B4≤C4≤500％B4，120％B4≤D≤800B4％。
根据本申请的一些实施例，第一绝缘胶层和第三绝缘胶层的熔点为100～140℃，第二绝缘胶层的熔点为140～200℃。
根据本申请的一些实施例，第一绝缘胶层、第二绝缘胶层以及第三绝缘胶层均包括聚丙烯、聚乙烯、聚偏二氟乙烯、偏二氟乙烯-六氟丙烯共聚物、聚甲基丙烯酸甲酯或聚乙二醇中的一种或多种。
根据本申请的一些实施例，第一绝缘胶层及或第三绝缘胶层还包括增韧改性剂。
根据本申请的一些实施例，增韧改性剂包括二元乙丙橡胶、三元乙丙橡胶、丁苯橡胶、低密度聚乙烯、乙烯-乙酸乙烯酯共聚物、线性低密度聚乙烯、尼龙、聚对苯二甲酸乙二醇酯、聚碳酸酯、超高分子量聚乙烯中的一种或多种。
根据本申请的一些实施例，基于第一绝缘胶层的总质量，增韧改性剂含量为3％-10％；和/或基于第三绝缘胶层的总质量，增韧改性剂含量为3％-10％。
根据本申请的一些实施例，h1为30～160μm。
本申请第二方面还提供一种电子装置，包括上述二次电池。
附图说明
本申请的上述和/或附加的方面和优点从结合下面附图对实施例的描述中将变得明显和容易理解，其中：
图1为本申请一实施例提供的二次电池的示意图；
图2为图1所示电池沿II-II的截面示意图；
图3为本申请一实施例提供的封装膜的截面示意图；
图4为本申请一实施例提供的绝缘胶的截面示意图；
图5为本申请一实施例提供的电子装置的示意图。
主要元件符号说明
二次电池                      100
电极组件                      10
包装袋                        40
极耳                          20
绝缘胶                        30
第一封装膜                    41
第二封装膜                    42
容纳腔                        410
密封部                        420
第三部分                      301
第二部分                      302
第一部分                      303
封装层                        401
金属层                        402
保护层                        403
第一端部                      303a
第二端部                      303b
第一绝缘胶层                  31
第二绝缘胶层                  32
第三绝缘胶层                   33
粘合区域                       201
电子装置                       200
主体                           210
具体实施方式
下面对本申请实施例中的技术方案进行清楚、详细地描述，显然，所描述的实施例是本申请一部分实施例，而不是全部的实施例。除非另有定义，本文所使用的所有的技术和科学术语与属于本申请的技术领域的技术人员通常理解的含义相同。在本申请的说明书中所使用的术语只是为了描述具体的实施例的目的，不是旨在于限制本申请。
下文，将详细地描述本申请的实施方式。但是，本申请可体现为许多不同的形式，并且不应解释为限于本文阐释的示例性实施方式。而是，提供这些示例性实施方式，从而使本申请透彻的和详细的向本领域技术人员传达。
另外，为了简洁和清楚，在附图中，各种组件、层的尺寸或厚度可被放大。遍及全文，相同的数值指相同的要素。如本文所使用，术语“及/或”、“以及/或者”包括一个或多个相关列举项目的任何和所有组合。另外，应当理解，当要素A被称为“连接”要素B时，要素A可直接连接至要素B，或可能存在中间要素C并且要素A和要素B可彼此间接连接。
进一步，当描述本申请的实施方式时使用“可”指“本申请的一个或多个实施方式”。
本文使用的专业术语是为了描述具体实施方式的目的并且不旨在限制本申请。如本文所使用，单数形式旨在也包括复数形式，除非上下文另外明确指出。应进一步理解，术语“包括”，当在本说明书中使用时，指存在叙述的特征、数值、步骤、操作、要素和/或组分，但是不排除存在或增加一个或多个其他特征、 数值、步骤、操作、要素、组分和/或其组合。
空间相关术语，比如“上”等可在本文用于方便描述，以描述如图中阐释的一个要素或特征与另一要素(多个要素)或特征(多个特征)的关系。应理解，除了图中描述的方向之外，空间相关术语旨在包括设备或装置在使用或操作中的不同方向。例如，如果将图中的设备翻转，则描述为在其他要素或特征“上方”或“上”的要素将定向在其他要素或特征的“下方”或“下面”。因此，示例性术语“上”可包括上面和下面的方向。应理解，尽管术语第一、第二、第三等可在本文用于描述各种要素、组分、区域、层和/或部分，但是这些要素、组分、区域、层和/或部分不应受这些术语的限制。这些术语用于区分一个要素、组分、区域、层或部分与另一要素、组分、区域、层或部分。因此，下面讨论的第一要素、组分、区域、层或部分可称为第二要素、组分、区域、层或部分，而不背离示例性实施方式的教导。
请参阅1和图2，本申请一实施例提供一种二次电池100，包括电极组件10、极耳组件和包装袋40。极耳组件包括极耳20和分别设置在极耳两侧的两个绝缘胶30。极耳20与电极组件10连接。包装袋40包覆电极组件10并覆盖极耳20的一部分，绝缘胶30设置在包装袋40和极耳20之间并连接包装袋40和极耳20。本实施例中，极耳20的数量为两个，即为正极耳和负极耳，该两个极耳20位于二次电池100的同一侧并伸出包装袋40外；绝缘胶30的数量为四个，其中两个绝缘胶30设置于一个极耳20相对的两个表面上，另外两个绝缘胶30设置于另一个极耳20相对的两个表面上，且位于两个极耳20的同一侧的两个绝缘胶30间隔设置。正极耳的材质可包括Ni、Ti、Al、Ag、Au、Pt、Fe及其组合物中的至少一种。负极耳的材质可包括Ni、Ti、Cu、Ag、Au、Pt、Fe及其组合物中的至少一种。在其他实施例中，位于两个极耳20的同一侧的两个绝缘胶30可相互连接形成一个整体，两个极耳20还可位于二次 电池100的不同侧。
电极组件10包括正极片、负极片和配置于正极片和负极片之间的隔离膜。电极组件10由正极片、隔离膜以及负极片叠片或者卷绕形成。正极片和负极片分别与两个极耳20电连接。
包装袋40包括相对设置的第一封装膜41和第二封装膜42，第一封装膜41的形状和第二封装膜42的形状相互配合。第一封装膜41和第二封装膜42相互连接并合围形成容纳腔410，容纳腔410用于容纳电解液、电极组件10、极耳20和绝缘胶30的至少一部分。第一封装膜41和第二封装膜42的边缘连接形成密封部420，密封部420自容纳腔410的外侧面朝向背离容纳腔410的一侧延伸。密封部420是包装袋40收容电极组件10以及电解液后，通过热压工艺进行密封的部位。极耳20部分容纳于容纳腔410中并穿过密封部420伸出包装袋40外。
请参阅图2和图3，第一封装膜41和第二封装膜42均包括沿第一方向Z依次叠设的封装层401、金属层402和保护层403，封装层401靠近电极组件10设置，而保护层403远离电极组件10设置。封装层401的材质为聚合物，例如为聚丙烯、聚酰胺等，第一封装膜41和第二封装膜42的封装层401相连接以对包装袋40进行封装，防止包装袋40被电解液中的有机溶剂溶解或溶胀，封装层401还用于阻止电解液中的电解质与金属层402接触而导致金属层402被腐蚀。保护层403的材质为高分子树脂，用于保护金属层402，避免金属层402因外力作用破损，同时能够阻止外部环境的空气渗透，维持二次电池100内部处于无水无氧的环境。金属层402的材质为金属，例如为铝、钢等，用于阻止外部环境的水分渗透，并防止外力对二次电池100造成损伤。使用包装袋40封装二次电池100时，可将封装膜对折，然后利用热封封头在对折后的封装膜表面施加一定的温度(180-215℃)和压力(0.3-0.6MPa)在一定时间 (1.5-3S)内进行热封，使封装膜的封装层401熔融相连接。此时，包装袋40的最内层为封装层401。
请参阅图1，沿第二方向X，绝缘胶30包括相互连接的第一部分303、第三部分301和第二部分302，第一部分303为绝缘胶30在第一方向Z上与极耳20重合且与密封部420间隔设置的区域，第三部分301为绝缘胶30在第一方向Z上与极耳20和密封部420均不重合的区域，第二部分302为绝缘胶30在第一方向Z上与密封部420重合的区域。第二方向X与第一方向Z相垂直。本实施例中，第一方向Z为极耳20的厚度方向，第二方向X为极耳20的长度方向。
本实施例中，第一部分303包括位于包装袋40内的第一端部303a和位于包装袋40外的第二端部303b。绝缘胶30包括分布于四个角落位置的四个第三部分301，其中两个第三部分301位于包装袋40内并在第三方向Y上位于第一端部303a的两侧，另外两个第三部分301位于包装袋40外并在第三方向Y上位于第二端部303b的两侧。第三方向Y与第一方向Z和第二方向X相垂直，本实施例中，第三方向Y为极耳20的宽度方向。通过设置第三部分301和第一部分303，使绝缘胶30从密封部420向内延伸至容纳腔410中，以避免因绝缘胶30未从密封部420向包装袋40内部延伸而导致的有效封印宽度变窄的风险；且使绝缘胶30从密封部420向外延伸至包装袋40外，以避免包装袋40的边缘在封装时压空的风险，利于密封。
请参阅图2和图4，沿第一方向Z，绝缘胶30包括依次堆叠设置的第一绝缘胶层31、第二绝缘胶层32和第三绝缘胶层33，第一绝缘胶层31与极耳20连接，第三绝缘胶层33与包装袋40的封装层401连接。第一绝缘胶层31和第三绝缘胶层33起密封作用，第二绝缘胶层32起支撑作用以防止绝缘胶30过熔而导致短路。
在本发明中，第一部分303、第三部分301和第二部分302 均包括第一绝缘胶层31、第二绝缘胶层32、第三绝缘胶层33，在封装前的第一绝缘胶层31、第二绝缘胶层32和第三绝缘胶层33的厚度大致相等，绝缘胶所在区域不同，命名不同，在第一部分301，绝缘胶包括第一绝缘胶层31、第二绝缘胶层32、第三绝缘胶层33；在第二部分302，绝缘胶包括第二部分第一绝缘胶层31、第二部分第二绝缘胶层32、第二部分第三绝缘胶层33；在第三部分301，绝缘胶包括第三部分第一绝缘胶层31、第三部分第二绝缘胶层32、第三部分第三绝缘胶层33。而第一部分303包含的第一端部303a由于在封装时未受热熔，第一端部303a的第一绝缘胶层31、第二绝缘胶层32和第三绝缘胶层33的厚度与绝缘胶30封装前的第一绝缘胶层31、第二绝缘胶层32和第三绝缘胶层33的厚度大致相等。
极耳组件还包括粘合区域201，粘合区域201为沿第一方向Z位于极耳20两侧的绝缘胶30相互贴合的部分。粘合区域201由位于极耳20在第三方向Y的同侧的绝缘胶30的第二部分302和第三部分301构成。在粘合区域201中，两个绝缘胶30的第一绝缘胶层31相粘合构成第一绝缘胶粘合层。
在一些实施例中，第一绝缘胶层31和第三绝缘胶层33的熔点为100～140℃，第二绝缘胶层32的熔点为140～200℃。第一绝缘胶层31、第二绝缘胶层32和第三绝缘胶层33可均包括聚丙烯(PP)、聚乙烯、聚偏二氟乙烯、偏二氟乙烯-六氟丙烯共聚物、聚甲基丙烯酸甲酯或聚乙二醇中的一种或多种。
在一些实施例中，第一绝缘胶层31及/或第三绝缘胶层33还包括增韧改性剂，用于提高柔性和冲击性能，以提高绝缘胶30与包装袋40的封装强度。增韧改性剂可包括二元乙丙橡胶(EPR)、三元乙丙橡胶(EPDM)、丁苯橡胶等橡胶颗粒，用于阻止裂纹蔓延。增韧改性剂还可包括柔性聚合物、刚性聚合物物或超高分子量聚乙烯(UHMWPE)中的一种或多种，用于增强晶体间的连接，使晶间界面变得模糊。柔性聚合物可以为低密度 聚乙烯(LDPE)、乙烯-乙酸乙烯酯共聚物(EVA)、线性低密度聚乙烯(LLDPE)等。刚性聚合物物可以为尼龙(PA6)、聚对苯二甲酸乙二醇酯(PET)、聚碳酸酯(PC)等。
在一些实施例中，增韧改性剂为超高分子量聚乙烯，增韧改性剂在第一绝缘胶层31及/或第三绝缘胶层33中的添加量为3％-10％。当增韧改性剂的添加量为3％-10％时，绝缘胶30与包装袋40的封装强度较高。当增韧改性剂的添加量过量时(大于10％)，会造成晶体间各成一体、出现分层现象。
在第一端部303a和第二端部303b中，沿第一方向Z，绝缘胶30的厚度为h1，第一绝缘胶层31的厚度为A1，第二绝缘胶层32的厚度为B1，第三绝缘胶层33的厚度为C1，其中，h1＝A1+B1+C1，10.5％h1≤B1≤35％h1，90％B1≤C1≤500％B1，C1＞A1，60％B1≤A1≤400％B1。
本申请提供的二次电池，10.5％h1≤B1≤35％h1，保证第二绝缘胶层在封装受热时不至于被过熔或者融合不够使第二绝缘胶层和第一绝缘胶层31、第三绝缘胶层33出现界面、分层导致封装强度降低；90％B1≤C1≤500％B1，60％B1≤A1≤400％B1，C1＞A1，保证第三绝缘胶层33与包装袋40能够完全融合以及第一绝缘胶层31融合粘接在极耳20上，由于第三绝缘胶层33封装时相对第一绝缘胶层是先受热热熔，该设计可避免第三绝缘胶层33过熔使包装袋40与第二绝缘胶层32之间融合导致产生融合界面不良问题，也可以避免第一绝缘胶层31融合不足或者过熔而与极耳20粘合不良，且第一绝缘胶层31、第二绝缘胶层32以及第三绝缘胶层33在厚度上不对称，采用厚度上不对称的该三层结构，使得在封装时，绝缘胶30与包装袋40能够完全融合、无明显界面，从而提高绝缘胶30与包装袋40之间的封装强度，提高密封效果，减少漏液风险。
根据本申请的一些实施例，8.18A1≥C1≥1.05A1，第三绝缘胶层33的厚度C1为上述范围时，可使二次电池100具有高的 封装强度同时兼顾具有较高的绝缘性及抗腐蚀性能。随着第三绝缘胶层33的厚度的增大，封装后二次电池100封装拉力增加，越不容易产生漏液，而第三绝缘胶层33的厚度超过一定范围后，封装时第三绝缘胶层33与封装层401和第二绝缘胶层32会产生熔融不足以及界面导致封装拉力减小，增加二次电池100漏液风险。第三绝缘胶层33的厚度C1为上述范围时，可使二次电池100具有高的封装强度同时兼顾具有较高的绝缘性及抗腐蚀性能。优选的，7A1≥C1≥1.3A1，在该范围内，封装拉力≥6.2N,封装后获得的二次电池100越不容易产生漏液。
极耳20在第一方向Z上的厚度为t。在一些实施例中，t和h1满足以下公式：3t≥2h1≥0.9t。如此设置，可使二次电池100具有高的封装强度同时兼顾具有较高的绝缘性及抗腐蚀性能。
在第二部分302中，沿第一方向Z，第二部分第一绝缘胶层31的厚度为A2，第二部分第二绝缘胶层32的厚度为B2，第三绝缘胶层33的厚度为C2。在一些实施例中，92％C1≤C2≤98％C1，如此设置使第二部分第三绝缘胶层33热封前后厚度变化较小，利于提高封装强度。在一些实施例中，7μm≥C1-C2≥1μm，5μm≥A1-A2≥0.5μm，3μm≥B1-B2≥0.1μm。
封装层401在第一方向Z上的厚度为P。在第二部分302中，包装袋40的封装层401与绝缘胶30的第二部分第三绝缘胶层33因热封相熔融，封装层401和第二部分第三绝缘胶层33在第一方向Z上的总厚度为H。在一些实施例中，0.25(C1+P)≤H≤0.75(C1+P),如此设置可使包装袋40的封装层401与绝缘胶30的第二部分第三绝缘胶层33完全融合，提高封装强度。优选的，0.29(C1+P)≤H≤0.5(C1+P)。
在一些实施例中，沿第一方向Z，该极耳组件与绝缘胶30的第二部分302相对应部分的厚度为G。包装袋40在第一方向Z上的厚度为T。本申请中，第一封装膜41和第二封装膜42 在第一方向Z上的厚度均为T。沿第一方向Z，二次电池100与极耳20和第二部分302相对应的部分的厚度为K，其中，2T+G-(2P+2t)×75％＜K＜2T+G-(2P+2t)×15％。
在第三部分301中，沿第一方向Z，绝缘胶30的厚度为h3，第一绝缘胶层31的厚度为A3，第三部分第二绝缘胶层32的厚度为B3，第三部分第三绝缘胶层33的厚度为C3，其中，h3＝A3+B3+C3，10.5％h3≤B3≤35％h3，90％B3≤C3≤500％B3，C3＞A3，60％B3≤A3≤400％B3。在第三部分301中，C3＞A3，保证第三部分第三绝缘胶层33与包装袋40的封装层401能够完全融合，由于第三部分第三绝缘胶层33封装时相对第三部分第一绝缘胶层31是先受热热熔，该设计可避免第三部分第三绝缘胶层33过熔使封装层401与第三部分第二绝缘胶层32之间融合导致产生融合界面不良问题；且第三部分第一绝缘胶层31、第三部分第二绝缘胶层32以及第三部分第三绝缘胶层33在厚度上不对称，采用厚度上不对称的该三层结构，使得在封装时，绝缘胶30与包装袋40的封装层401能够完全融合、无明显界面，从而提高绝缘胶30与包装袋40之间的封装强度，提高密封效果。
在粘合区域201中，沿第一方向Z，粘合区域201的厚度为Q，粘合区第一绝缘胶粘合层的厚度为D，粘合区第二绝缘胶层32的厚度为B4，粘合区第三绝缘胶层33的厚度为C4，其中，10.5％(Q×0.5)≤B4≤35％(Q×0.5)，C4＞0.5D，90％B4≤C4≤500％B4，120％B4≤D≤800B4％。
本申请提供的二次电池，10.5％(Q×0.5)≤B4≤35％(Q×0.5)，保证第二部分第二绝缘胶层在封装受热时不至于被过熔或者融合不够使第二部分第二绝缘胶层和第二部分第一绝缘胶层31、第二部分第三绝缘胶层33出现界面、分层导致封装强度降低；C4＞0.5D，90％B4≤C4≤500％B4，120％B4≤D≤800B4％，保证第二部分第三绝缘胶层33与包装袋40能够完全融合以及第二部 分第一绝缘胶层31融合粘接在极耳20上，由于第二部分第三绝缘胶层33封装时相对第二部分第一绝缘胶层是先受热热熔，该设计可避免第二部分第三绝缘胶层33过熔使包装袋40与第二部分第二绝缘胶层32之间融合导致产生融合界面不良问题，也可以避免第二部分第一绝缘胶层31融合不足或者过熔而与极耳20粘合不良，且第二部分第一绝缘胶层31、第二部分第二绝缘胶层32以及第二部分第三绝缘胶层33在厚度上不对称，采用厚度上不对称的该三层结构，使得在封装时，绝缘胶30与包装袋40能够完全融合、无明显界面，从而提高绝缘胶30与包装袋40之间的封装强度，提高密封效果，减少漏液风险。
请参阅图5，本申请的实施例还提供一种电子装置200，电子装置200包括主体220和二次电池100。二次电池100收容于主体220内。电子装置200可为手机、平板、电子阅读器中的一种。
本申请中电子装置200以手机为例，二次电池100设置于手机内，以向手机提供电量供手机使用，主体220为手机结构。可以理解的是，在其他实施例中，电子装置200还可为其他结构，不限于上述的为手机、平板、电子阅读器。
以下通过具体实施例和对比例对本申请提供的电池的性能进行说明。
采用厚度h1为80μm的绝缘胶30与5×0.1mm的铝条和镍条通过热熔平压形成如图1所示的极耳组件，绝缘胶30的肩宽为2.2mm，位于极耳20同侧的两个绝缘胶30之间的间距为20mm。绝缘胶30的肩宽为沿第三方向Y(极耳20的宽度方向)，绝缘胶30的一侧边缘超出极耳同侧边缘的距离。
将上述极耳组件装入厚度T为91μm的包装袋40中，然后采用1.5mm宽的热封封头进行热封得到如图1所示的二次电池，热封温度为205℃，热封压力为0.4MPa，热封时间为1.5S。
对二次电池，沿极耳20的宽度方向或者长度方向进行裁切 得到样品，使用“基恩士”VHX-5000型号的显微镜(测试倍数为200X)，对样品截面进行测试，测试样品各区域(第一绝缘胶层31、第二绝缘胶层32、第三绝缘胶层33、第一绝缘胶粘合层、极耳组件、封装层401、包装袋40)中分布均匀的5～10个点的厚度并记录，取平均值作为各层厚度；沿第一方向，部分元件之间由于热封导致界限较模糊，可通过各元件色差做辅助线帮助测量各元件厚度；第一粘合绝缘胶粘合层由两个相贴合的第一绝缘胶层组成，可将第一粘合绝缘胶粘合层厚度的一半视为第一绝缘胶层的厚度。
其中，在第一部分303中，第一绝缘胶层31的厚度A1为14.8μm，第二绝缘胶层32的厚度B1为15.6μm，第三绝缘胶层33的厚度C1为49.6μm，其中B1＝19.5％h1，A1＝94.87％B，C1＝317.95％B。极耳20的厚度t为100μm。在第二部分302中，第二部分第三绝缘胶层33的厚度C2为48.6μm，第二部分第三绝缘胶层33和封装层401的总厚度H为38.7μm，第二部分第一绝缘胶层31的厚度A2为14.9μm，第二部分第二绝缘胶层32的厚度B2为14.8μm。极耳组件与绝缘胶30的第二部分第二部分302相对应部分的厚度G为260μm，封装层401的厚度P为35μm，二次电池100与极耳20和第二部分302相对应的部分的厚度K为360μm。在第三部分301中，绝缘胶30的厚度h3为80μm，第三部分第一绝缘胶层31的厚度A3为14.8μm，第三部分第二绝缘胶层32的厚度B3为15.6，第三部分第三绝缘胶层33的厚度C3为49.6μm。在极耳组件的粘合区域201中，极耳组件的厚度Q为160μm，粘合区第一绝缘胶粘合层的厚度D为29.6μm，粘合区第二绝缘胶层32的厚度B4为15.6μm，粘合区第三绝缘胶层33的厚度C4为49.6μm。
第一绝缘胶层31的材质为PP，熔点为145℃。第二绝缘胶层32的材质为PP，熔点为145℃。第三绝缘胶层33包括质量分数为95％的PP和质量分数为5％的UHMWPE，熔点为120℃。
对实施例1制得的电池进行封装拉力测试，并目检电池是否漏液。封装拉力测试具体为：沿极耳的宽度方向裁切电池与极耳和绝缘胶的第二部分相对应的部分，得到宽度为5mm、长度为5cm的样品；将样品夹持于高铁拉力机上，其中极耳固定在上夹具上、包装袋固定在下夹具上，设置拉伸速度为175±5mm/min，将样品沿180度方向向上提拉以进行剥离，读取剥离力。将读取的剥离力数值(单位N)除以样品宽度，计算得到样品的封装拉力F(N/mm)。
实施例2-12以及对比例1-9与实施例1的不同之处在于，绝缘胶30的第一部分303中第一绝缘胶层31的厚度A1、第二绝缘胶层32的厚度B1和第三绝缘胶层33的厚度C1不同，具体参数及测试结果如表1所示。
表1
Figure PCTCN2022120612-appb-000001
Figure PCTCN2022120612-appb-000002
注：X/320表示测试320个样品中出现漏液的电池的个数为X个。
比较实施例1-14和对比例1-9可知，当绝缘胶同时满足10.5％h1≤B1≤35％h1、90％B1≤C1≤500％B1、C1＞A1、60％B1≤A1≤400％B1时，封装拉力F≥5.5N/mm，且电池漏液情况减少。
比较实施例12，15-19可知，8.18A1≥C1≥1.05A1，在该范围内，封装拉力≥5.75N，第三绝缘胶层33的厚度C1为上述范围时，可使二次电池100具有高的封装强度同时兼顾具有较高的绝缘性及抗腐蚀性能。随着第三绝缘胶层33的厚度的增大，二次电池100封装后封装拉力增加，越不容易产生漏液，而第三绝缘胶层33的厚度超过一定范围后，封装时第三绝缘胶层33与封装层401和第二绝缘胶层32会产生熔融不足以及界面导致封装拉力减小，增加二次电池100漏液风险。第三绝缘胶 层33的厚度C1为上述范围时，可使二次电池100具有高的封装强度同时兼顾具有较高的绝缘性及抗腐蚀性能。优选的，7A1≥C1≥1.3A1，在该范围内，封装拉力≥6.1N,封装后获得的二次电池100越不容易产生漏液。
实施例20-23和对比例10-11与实施例1的区别在于，极耳20的厚度t不同，具体参数以及测试结果如表2所示。
表2
Figure PCTCN2022120612-appb-000003
由表2可知，封装拉力F随着2h1/t比值的增大而增大，当3≥2h1/t≥0.9时，漏液电池数量为0，完全避免了电池漏液的问题；当2h1/t＜0.9时或2h1/t≥3时，极耳厚度或者绝缘胶厚度越厚将不利于封装，在绝缘胶30的第三部分303中容易产生漏液通道，也容易使密封部非极耳处密封时压空，密封不足而漏液。
实施例24-25和对比例12-14与实施例1的区别在于，绝缘胶30的第二部分302中第二部分第三绝缘胶层33的厚度C2和绝缘胶30的第二部分第一部分301中第二部分第三绝缘胶层33的厚度C1中至少一者不同，具体参数以及测试结果如表3所示。
表3
Figure PCTCN2022120612-appb-000004
由表3可知，当满足92％C1≤C2≤98％C1且7μm≥C1-C2≥1μm时，漏液电池数量为0，完全避免了电池漏液的问题，进一步提高了密封效果。当C2＞98％C1或者1μm＞C1-C2时，第三绝缘胶层33由于压缩率太低而不能与封装层401融合，封装拉力下降，导致漏液；当C2＜92％C1或者7μm＜C1-C2时，造成绝缘胶30过熔，且厚度太小导致密封效果降低，漏液频次增加。
实施例26-30和对比例15-16与实施例1的区别在于，绝缘胶层30的第一部分303中第一绝缘胶层31的厚度A1、第二绝缘胶层32的厚度B1、第三绝缘胶层33的厚度C1、绝缘胶层30的第二部分302中第二部分第三绝缘胶层33的厚度C2以及第二部分302中第二部分第三绝缘胶层33和封装层401的总厚度H中至少一者不同，具体参数以及测试结果如表4所示。
表4
Figure PCTCN2022120612-appb-000005
由表4可知，当满足0.25(C2+P)≤H≤0.75(C2+P)时，封装拉力F更大，漏液电池数量减少，改善了电池漏液的问题。当H/(C2+P)＜0.25时，第三绝缘胶层33和封装层401由于压缩率太低导致界面间融合不良，封装拉力下降，导致漏液；H/(C2+P)＞0.75时，第三绝缘胶层33和封装层401由于过 熔且热熔后厚度太小导致密封效果降低，漏液频次增加。
实施例31、32和对比例17-18与实施例1的区别在于，第二部分302中第二部分第一绝缘胶层31的厚度A2不同，具体参数以及测试结果如表5所示。
表5
  A1(um) A2(um) A1-A2 F(N/mm) 漏液情况
实施例1 14.8 12 2.8 6.76 0/320
实施例31 14.8 14.3 0.5 6.26 2/320
实施例32 14.8 9.8 5 6.65 0/320
对比例17 14.8 14.6 0.2 4.85 12/320
对比例18 14.8 5.5 10.2 5.15 9/320
由表5可知，当满足5μm≥A1-A2≥0.5μm时，封装拉力F更大，漏液电池数量减少，改善了电池漏液的问题。
实施例33-34和对比例19-20与实施例1的区别在于，第二部分302中第二部分第二绝缘胶层32的厚度B2不同，具体参数以及测试结果如表6所示。
表6
  B1(um) B2(um) B1-B2 F(N/mm) 漏液情况
实施例1 15.6 14.8 0.8 6.76 0/320
实施例33 15.6 15.5 0.1 5.95 2/320
实施例34 15.6 12.7 2.9 6.63 0/320
对比例19 15.6 8.4 7.2 5.32 8/320
对比例20 15.6 6.4 9.2 4.93 10/320
由表6可知，当满足3μm≥B1-B2≥0.1μm时，封装拉力F更大，漏液电池数量减少，改善了电池漏液的问题。
实施例35-36和对比例21-22与实施例1的区别在于，绝缘胶30的第一部分303中第一绝缘胶层31的厚度A1、第二绝缘胶层32的厚度B1、第三绝缘胶层33的厚度C1、极耳组件与绝缘胶30的第二部分302相对应部分的厚度G、以及二次电池100与第二部分302和极耳20相对应的部分的厚度K中至少一者不同，具体参数以及测试结果如表7所示。
表7
Figure PCTCN2022120612-appb-000006
Figure PCTCN2022120612-appb-000007
由表8可知，当满足2T+G-(2P+2t)×75％＜K＜2T+G-(2P+2t)×15％时，封装拉力F更大，漏液电池数量减少，改善了电池漏液的问题。
实施例37-49以及对比例23-31与实施例1的不同之处在于，绝缘胶30的第三部分301的厚度h3，第三部分301中第三部分第一绝缘胶层31的厚度A3、第三部分第二绝缘胶层32的厚度B 3和第三部分第三绝缘胶层33的厚度C3中至少一者不同，具体参数及测试结果如表8所示。
表8
Figure PCTCN2022120612-appb-000008
Figure PCTCN2022120612-appb-000009
比较实施例30-43和对比例22-30可知，当绝缘胶30同时满足10.5％h3≤B3≤35％h3、90％B3≤C3≤500％B3、C3＞A3、60％B3≤A3≤400％B3时，封装拉力F≥5.5N/mm，且电池漏液情况减少。
实施例50-62以及对比例32-40与实施例1的不同之处在于，极耳组件的粘合区域201的厚度Q、粘合区第一绝缘胶粘合层的厚度D、粘合区第二绝缘胶层32的厚度B4以及粘合区第三绝缘胶层33的厚度C4中至少一者不同，具体参数及测试结果如表9所示。
表9
Figure PCTCN2022120612-appb-000010
Figure PCTCN2022120612-appb-000011
由表9可知，当同时满足10.5％(Q×0.5)≤B4≤35％(Q×0.5)，C4＞0.5D，90％B4≤C4≤500％B4，120％B4≤D≤800B4％时，封装拉力F≥5.5N/mm，且电池漏液情况减少。
实施例63-68和对比例41-42与实施例1的区别在于，第一绝缘胶层31、第二绝缘胶层32和第三绝缘胶层33的材质不同，具体参数以及测试结果如表10所示。
表10
Figure PCTCN2022120612-appb-000012
Figure PCTCN2022120612-appb-000013
由表10可知，当第三胶层33中的增韧改性剂的添加量为3％-10％时，封装拉力F达到6.22N/mm，漏液电池数量减少，改善了电池漏液的问题。当第一绝缘胶层31中的增韧改性剂添加量为3％～10％时，漏液电池数量减少，改善了电池漏液的问题；当增韧改性剂添加量不在范围3％～10％中时，会使漏液电池数量增加，使电池漏液的可能增大。
以上所揭露的仅为本申请较佳实施方式而已，当然不能以此来限定本申请，因此依本申请所作的等同变化，仍属本申请所涵盖的范围。

Claims (21)

  1. 一种二次电池，包括电极组件、极耳组件和包装袋，所述电极组件容纳于所述包装袋中，所述包装袋包括密封部，所述极耳组件包括极耳和分别设置在所述极耳两侧的绝缘胶，所述极耳与所述电极组件连接并穿过所述密封部伸出所述包装袋外，所述绝缘胶连接所述极耳和所述包装袋，其特征在于，所述绝缘胶包括沿第一方向依次堆叠设置的第一绝缘胶层、第二绝缘胶层以及第三绝缘胶层，所述第一绝缘胶层与所述极耳连接，所述第三绝缘胶层与所述包装袋连接；沿与所述第一方向垂直的第二方向，所述绝缘胶包括第一部分，第一部分为所述绝缘胶在所述第一方向上与所述极耳重合且与所述密封部间隔设置的区域，所述第一部分包括第一端部，所述第一端部位于所述包装袋内，在所述第一端部中，沿所述第一方向，所述绝缘胶的厚度为h1，所述第一绝缘胶层的厚度为A1，所述第二绝缘胶层的厚度为B1，所述第三绝缘胶层的厚度为C1，10.5％h1≤B1≤35％h1，C1＞A1，90％B1≤C1≤500％B1，60％B1≤A1≤400％B1。
  2. 如权利要求1所述的二次电池，其中，8.18A1≥C1≥1.05A1。
  3. 如权利要求1所述的二次电池，其中，7A1≥C1≥1.3A1。
  4. 如权利要求1所述的二次电池，其中，所述极耳在所述第一方向上的厚度为t，3t≥2h1≥0.9t。
  5. 如权利要求1所述的二次电池，其中，沿所述第二方向，所述绝缘胶还包括第二部分，所述第二部分为所述绝缘胶在所述第一方向上与所述密封部重合的区域，在所述第二部分，所述绝缘胶包括沿第一方向依次堆叠设置的第二部分第一绝缘胶层、第二部分第二绝缘胶层以及第二部分第三绝缘胶层，沿第一方向，所述第二部分第一绝缘胶层、第二部分第二绝缘胶层以及第二部分第三绝缘胶层的厚度分别为A2、B2、C2。
  6. 如权利要求5所述的二次电池，其中，92％C1≤C2≤98％C1。
  7. 如权利要求5所述的二次电池，其中，7μm≥C1-C2≥1μm。
  8. 如权利要求5所述的二次电池，其中，所述包装袋包括与所述第三绝缘胶层连接的封装层，所述封装层在所述第一方向上的厚度为P；在所述第二部分中，所述第二部分第三绝缘胶层和所述封装层在所述第一方向上的总厚度为H，0.25(C2+P)≤H≤0.75(C2+P)。
  9. 如权利要求8所述的二次电池，其中，0.4(C2+P)≤H≤0.7(C2+P)。
  10. 如权利要求5所述的二次电池，其中，A1和A2满足以下公式：5μm≥A1-A2≥0.5μm。
  11. 如权利要求5所述的二次电池，其中，3μm≥B1-B2≥0.1μm。
  12. 如权利要求5所述的二次电池，其中，所述包装袋包括与所述第三绝缘胶层连接的封装层，沿所述第一方向，所述包装袋的厚度为T，所述封装层的厚度为P；沿所述第一方向，所述极耳组件与所述第二部分相对应的部分的厚度为G，所述二次电池与所述第二部分和所述极耳相对应的部分的厚度为K，其中，2T+G-(2P+2t)×75％＜K＜2T+G-(2P+2t)×15％。
  13. 如权利要求1所述的二次电池，其中，沿所述第二方向，所述绝缘胶还包括第三部分，所述第三部分为所述绝缘胶在所述第一方向上与所述密封部和所述极耳不重合的区域，在所述第三部分中，沿所述第一方向，所述绝缘胶包括沿第一方向依次堆叠设置的第三部分第一绝缘胶层、第三部分第二绝缘胶层以及第三部分第三绝缘胶层，所述绝缘胶的厚度为h3，所述第一绝缘胶层的厚度为A3，所述第二绝缘胶层的厚度为B3，所述第三绝缘胶层的厚度为C3，10.5％h3≤B3≤35％h3，C3＞A3，90％B3≤C3≤500％B3，60％B3≤A3≤400B3％。
  14. 如权利要求1所述的二次电池，其中，所述极耳组件包括粘合区域，所述粘合区域为沿所述第一方向所述极耳两侧的绝缘胶相互贴合的部分；沿所述第一方向，所述粘合区域包括第一 绝缘胶粘合层、粘合区第二绝缘胶层及粘合区第三绝缘胶层，所述粘合区域的厚度为Q，所述第一绝缘胶粘合层的厚度为D，所述粘合区第二绝缘胶层的厚度为B4，所述粘合区第三绝缘胶层的厚度为C4，10.5％(Q×0.5)≤B4≤35％(Q×0.5)，C4＞0.5D，90％B4≤C4≤500％B4，120％B4≤D≤800B4％。
  15. 如权利要求1所述的二次电池，其中，所述第一绝缘胶层和所述第三绝缘胶层的熔点为100～140℃，所述第二绝缘胶层的熔点为140～200℃。
  16. 如权利要求1所述的二次电池，其中，所述第一绝缘胶层、所述第二绝缘胶层以及所述第三绝缘胶层均包括聚丙烯、聚乙烯、聚偏二氟乙烯、偏二氟乙烯-六氟丙烯共聚物、聚甲基丙烯酸甲酯或聚乙二醇中的一种或多种。
  17. 如权利要求16所述的二次电池，其中，所述第一绝缘胶层和/或所述第三绝缘胶层还包括增韧改性剂。
  18. 如权利要求17所述的二次电池，其中，所述增韧改性剂包括二元乙丙橡胶、三元乙丙橡胶、丁苯橡胶、低密度聚乙烯、乙烯-乙酸乙烯酯共聚物、线性低密度聚乙烯、尼龙、聚对苯二甲酸乙二醇酯、聚碳酸酯、超高分子量聚乙烯中的一种或多种。
  19. 如权利要求17所述的二次电池，其中，基于所述第一绝缘胶层的总质量，所述增韧改性剂含量为3％-10％；和/或基于所述第三绝缘胶层的总质量，所述增韧改性剂含量为3％-10％。
  20. 如权利要求1所述的二次电池，其中，h1为30～160μm。
  21. 一种电子装置，其中，包括如权利要求1-20中任一项所述的二次电池。
PCT/CN2022/120612 2022-09-22 2022-09-22 二次电池及包含其的电子装置 WO2024060145A1 (zh)

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CN203528010U (zh) * 2013-10-14 2014-04-09 东莞新能源科技有限公司 一种软包装锂离子电池用极耳胶和极耳
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CN113097617A (zh) * 2021-03-30 2021-07-09 宁德新能源科技有限公司 电化学装置和电子装置
CN114824642A (zh) * 2021-03-30 2022-07-29 宁德新能源科技有限公司 电化学装置和电子装置

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