Battery and electric equipment

Abstract

The invention discloses a battery and electric equipment. The battery comprises an electrode assembly, a packaging bag and a tab, the electrode assembly is accommodated in the packaging bag. The packaging bag comprises a first packaging edge, and the tab is connected to the electrode assembly and extends out of the first packaging edge. The battery further comprises tab glue arranged between the first packaging edge and the tab. The melting point T1 of the first adhesive layer, the melting point T2 of the second adhesive layer and the melting point T3 of the third adhesive layer meet the following relations: T1 < T2, T3 < T2, 110 DEG C < = T1 < = 130 DEG C, 140 DEG C < = T2 < = 170 DEG C, and 110 DEG C < = T3 < = 130 DEG C. The sum of the thickness of the first adhesive layer, the thickness of the second adhesive layer and the thickness of the third adhesive layer ranges from 70 micrometers to 100 micrometers, and the thickness ratio of the first adhesive layer to the thickness of the second adhesive layer is 1: 1.2-2. The tab glue comprises a top and a bottom, the top and the bottom are oppositely arranged in the extending direction of the tab, the top is located outside the first packaging edge, and the bottom is located in the packaging bag. The length of the top protruding out of the first packaging edge ranges from 0.2 mm to 2 mm, and the length of the bottom protruding out of the first packaging edge ranges from 1.2 mm to 2 mm. The safety performance of the battery can be improved.

Description

[0001] This application is a divisional application with application number 202310079198.6, application date January 18, 2023, and invention name “Battery and electrical equipment”. Technical Field

[0002] The present application relates to the field of energy storage technology, and in particular to a battery and an electrical device. Background Art

[0003] In the existing battery structure, in order to achieve a good seal between the tab and the packaging bag, it is usually necessary to set the tab glue on the tab. Ordinary tab glue cannot achieve the function of pressure relief, and the existing tab glue that can achieve pressure relief needs to be designed with a lower melting point. However, the tab glue with a lower melting point lacks a supporting structure during the heat sealing or pressure relief process, which easily leads to the tab being exposed, causing the tab to contact and short-circuit with the metal material in the packaging bag, thereby causing safety problems. Summary of the invention

[0004] In view of the above situation, it is necessary to provide a battery that can solve the above problems.

[0005] An embodiment of the present application provides a battery, comprising an electrode assembly, a packaging bag and a tab. The electrode assembly is contained in the packaging bag. The packaging bag comprises a first packaging edge, and the tab is connected to the electrode assembly and extends from the first packaging edge. The battery also comprises a tab glue disposed between the first packaging edge and the tab. The tab glue comprises a first glue layer, a second glue layer and a third glue layer sequentially connected from the tab to the first packaging edge, and the relationship between the melting point T1 of the first glue layer, the melting point T2 of the second glue layer and the melting point T3 of the third glue layer satisfies: T1<T2, T3<T2, wherein 110℃≤T1≤130℃, 140℃≤T2≤170℃, and 110℃≤T3≤130℃. In the arrangement direction of the first glue layer, the second glue layer and the third glue layer, the sum of the thickness of the first glue layer, the second glue layer and the third glue layer is 70um to 100um, and the ratio of the thickness of the first glue layer to the second glue layer satisfies: 1:1.2~2. Observing along the thickness direction of the tab, the tab glue includes a top and a bottom, which are arranged opposite to each other in the extension direction of the tab, the top is located outside the first packaging edge, and the bottom is located inside the packaging bag. The length of the top protruding from the first packaging edge is 0.2 mm to 2 mm, and the length of the bottom protruding from the first packaging edge is 1.2 mm to 2 mm.

[0006] In the above-mentioned battery, by limiting the melting point and thickness of the first glue layer, the second glue layer and the third glue layer in the ear glue, the ear glue maintains a stable structure during heat sealing or pressure relief. Specifically, the melting point of the second glue layer is greater than the melting point of the first glue layer and the third glue layer. When the temperature of the ear glue reaches the melting point of the first glue layer and the third glue layer, the second glue layer remains in an unmelted state, which facilitates the second glue layer to form a support structure between the ear and the first packaging edge during heat sealing or pressure relief. In addition, the thickness of the second glue layer is greater than the thickness of the first glue layer, so that the second glue layer has a higher structural strength than the first glue layer, so as to improve the stability of the second glue layer supporting between the ear and the first packaging edge, reduce the risk of the ear being exposed and short-circuited with the metal material in the packaging bag due to excessive deformation of the ear glue, and thus improve the safety performance of the battery. The length of the top protruding from the first packaging edge is 0.2mm to 2mm, and the length of the bottom protruding from the first packaging edge is 1.2mm to 2mm, so as to reduce the risk of the ear leaking out and short-circuiting with the metal material in the packaging bag, thereby improving the safety performance of the battery.

[0007] In some embodiments of the present application, T1 and T3 are substantially equal, which is beneficial for synchronous melting of the first adhesive layer and the third adhesive layer.

[0008] In some embodiments of the present application, the sum of the thicknesses of the first glue layer, the second glue layer and the third glue layer is 72 um to 80 um, so as to further limit the packaging volume occupied by the tab glue and improve the energy density of the battery.

[0009] In some embodiments of the present application, the thickness ratio of the first adhesive layer, the second adhesive layer and the third adhesive layer satisfies: 1:1.2~2:1, so that the second adhesive layer has higher structural strength than the first adhesive layer and the third adhesive layer, and the second adhesive layer is centrally arranged between the electrode ear and the first packaging edge, further improving the stability of the second adhesive layer supporting between the electrode ear and the first packaging edge.

[0010] In some embodiments of the present application, the thickness ratio of the first adhesive layer, the second adhesive layer and the third adhesive layer satisfies: 1:1.5~1.8:1, so as to further limit the structural strength of the first adhesive layer, the second adhesive layer and the third adhesive layer, improve the stability of the second adhesive layer supporting between the tab and the first packaging edge, and thereby improve the safety performance of the battery.

[0011] In some embodiments of the present application, 120℃≤T1≤125℃, 145℃≤T2≤165℃, and 120℃≤T3≤125℃ are used to further limit the melting points of the first glue layer, the second glue layer, and the third glue layer, so that the melting points of the first glue layer and the third glue layer are adapted to the pressure relief temperature of the battery, and the second glue layer forms a supporting structure between the tab and the first packaging edge during heat sealing or pressure relief.

[0012] In some embodiments of the present application, the packaging strength of the ear glue at a temperature of 100°C is 0.8N / mm to 1.5N / mm; the packaging strength of the ear glue at a temperature of 120°C is 0.6N / mm to 1.2N / mm; the packaging strength of the ear glue at a temperature of 130°C is 0.2N / mm to 0.5N / mm. When the temperature of the ear glue reaches the melting point of the first glue layer and the third glue layer, the corresponding packaging strength of the ear glue is reduced, which facilitates the separation of at least one of the first glue layer and the third glue layer from the second glue layer so that the ear glue forms a pressure relief channel.

[0013] In some embodiments of the present application, the packaging strength of the tab glue at room temperature is 2.3N / mm to 4.25N / mm. When the tab glue is at room temperature, the tab glue maintains a relatively high packaging strength, thereby improving the sealing stability between the tab and the first packaging edge.

[0014] In some embodiments of the present application, the tab glue includes a first side portion and a second side portion when viewed along the thickness direction of the tab. The first side portion and the second side portion are connected between the top and the bottom and are arranged on both sides of the tab along the width direction of the tab.

[0015] In some embodiments of the present application, along the extension direction of the pole ear, the width of the first packaging edge is 1.2mm to 2.0mm, and along the width direction of the pole ear, the spacing between the first side portion and the second side portion is 8mm to 9mm. The wider the width of the first packaging edge, the longer the path required for pressure relief, the more difficult the pressure relief, and the narrower the path, the easier it is to form pressure relief. The longer the spacing between the first side portion and the second side portion, the longer the connection length between the pole ear glue and the outside, and the setting of the low melting point position is increased. Therefore, the longer the first side portion and the second side portion, the easier it is to form pressure relief. By balancing the spacing between the first side portion and the second side portion and the width of the first packaging edge, the pressure relief channel is formed neither too early nor too late.

[0016] In some embodiments of the present application, along the extension direction of the tab, the distance between the top and the bottom is 2.5 mm to 5 mm, so that the tab glue can extend from the inside of the packaging bag through the first packaging edge to the outside of the packaging bag, thereby improving the sealing effect of the tab glue.

[0017] In some embodiments of the present application, along the width direction of the pole ear, the spacing between the side of the pole ear facing the first side portion and the first side portion is 0.5mm to 2.5mm, and the spacing between the side of the pole ear facing the second side portion and the second side portion is 0.5mm to 2.5mm, so that the pole ear glue protrudes out of both sides of the pole ear in the width direction of the pole ear, thereby improving the sealing effect of the pole ear glue.

[0018] In some embodiments of the present application, the pole ear includes a first surface and a second surface arranged opposite to each other in the thickness direction, and the pole ear glue includes a first part and a second part, the first part is connected between the first surface and the first packaging edge, and the second part is connected between the second surface and the first packaging edge. Along the width direction of the pole ear, the two ends of the first part protruding from the first surface are connected to the two ends of the second part protruding from the second surface, so that the pole ear glue is coated on the peripheral side of the pole ear.

[0019] An embodiment of the present application further provides an electrical device, comprising the battery in any of the above embodiments.

[0020] In the battery and electrical equipment of the present application, by limiting the melting point and thickness of the first glue layer, the second glue layer and the third glue layer in the ear glue, the ear glue maintains a stable structure during heat sealing or pressure relief. Specifically, the melting point of the second glue layer is greater than the melting points of the first glue layer and the third glue layer. When the temperature of the ear glue reaches the melting points of the first glue layer and the third glue layer, the second glue layer remains unmelted, which facilitates the second glue layer to form a support structure between the ear and the first packaging edge during heat sealing or pressure relief. In addition, the thickness of the second glue layer is greater than the thickness of the first glue layer, so that the second glue layer has a higher structural strength than the first glue layer, so as to improve the stability of the second glue layer supporting between the ear and the first packaging edge, reduce the risk of excessive deformation of the ear glue causing the ear to leak out and short-circuit with the metal material in the packaging bag, and thus improve the safety performance of the battery. The length of the top protruding from the first packaging edge is 0.2mm to 2mm, and the length of the bottom protruding from the first packaging edge is 1.2mm to 2mm, so as to reduce the risk of short circuit caused by leakage of the tab and contact with the metal material in the packaging bag, thereby improving the safety performance of the battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of the structure of a battery in one embodiment of the present application.

[0022] Figure 2 It is a schematic diagram of the structure of the battery ear glue from a first perspective in one embodiment of the present application.

[0023] Figure 3 It is a schematic diagram of the structure of the battery ear glue from a second perspective in one embodiment of the present application.

[0024] Figure 4 It is a structural schematic diagram of a battery tab glue in a pressure relief state in an embodiment of the present application.

[0025] Figure 5 It is a structural schematic diagram of the cut part in the packaging strength test of this application.

[0026] Figure 6 It is a schematic diagram of the structure of the sample in the packaging strength test of this application.

[0027] Figure 7 It is a schematic diagram of the structure of an electrical device in an embodiment of the present application.

[0028] Main component symbols

[0029] Battery 100

[0030] Electrical equipment 200

[0031] Electrode assembly 10

[0032] Packaging bag 20

[0033] First packaging edge 21

[0034] The first melting layer 211

[0035] Second melting layer 212

[0036] Tab 30

[0037] First side 31

[0038] Second side 32

[0039] 1st paragraph 33

[0040] 34

[0041] Ear glue 40

[0042] The first adhesive layer 41

[0043] Second adhesive layer 42

[0044] The third adhesive layer 43

[0045] Part 140a

[0046] Part II 40b

[0047] Top 44

[0048] Bottom 45

[0049] The first side portion 46

[0050] Second side portion 47

[0051] Pressure relief channel 50

[0052] Cutting start 61

[0053] Cut end 62

[0054] Cutting part 63

[0055] Packaging section 631

[0056] Extension 632

[0057] First clamping end 64

[0058] Second clamping end 65

[0059] Thickness direction Z

[0060] Extension direction X

[0061] Width direction Y

[0062] The following specific implementation methods will further illustrate the present application in conjunction with the above-mentioned drawings. DETAILED DESCRIPTION

[0063] The technical solutions in the embodiments of the present application will be described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments.

[0064] It should be noted that when an element is considered to be "connected" to another element, it can be directly connected to the other element or there may be a centrally arranged element at the same time. When an element is considered to be "set" to another element, it can be directly set on the other element or there may be a centrally arranged element at the same time. When a value is considered to be "approximately equal" to another value, it means that the two are equal within the set deviation, and the set deviation range is within 5%. That is to say, when at least one of the two values ​​fluctuates within the set deviation range, even if their values ​​are not equal, they are still judged to be approximately equal. When a value is considered to be in a ratio of "1:1" to another value, it means that the two are equal within the set deviation, and the set deviation range is within 5%. That is to say, when at least one of the two values ​​fluctuates within the set deviation range, even if their values ​​are not equal, their ratio is still judged to be equal.

[0065] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those generally understood by those skilled in the art to which the present application belongs. The terms used herein in the specification of the present application are only for the purpose of describing specific embodiments and are not intended to limit the present application. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0066] An embodiment of the present application provides a battery, comprising an electrode assembly, a packaging bag and a tab. The electrode assembly is contained in the packaging bag. The packaging bag comprises a first packaging edge, and the tab is connected to the electrode assembly and extends from the first packaging edge. The battery also comprises a tab glue disposed between the first packaging edge and the tab. The tab glue comprises a first glue layer, a second glue layer and a third glue layer sequentially connected from the tab to the first packaging edge, and the relationship between the melting point T1 of the first glue layer, the melting point T2 of the second glue layer and the melting point T3 of the third glue layer satisfies: T1<T2, T3<T2, wherein 110℃≤T1≤130℃, 140℃≤T2≤170℃, and 110℃≤T3≤130℃. In the arrangement direction of the first glue layer, the second glue layer and the third glue layer, the sum of the thickness of the first glue layer, the second glue layer and the third glue layer is 70um to 100um, and the ratio of the thickness of the first glue layer to the second glue layer satisfies: 1:1.2~2.

[0067] In the above-mentioned battery, by limiting the melting point and thickness of the first glue layer, the second glue layer and the third glue layer in the ear glue, the ear glue maintains a stable structure during heat sealing or pressure relief. Specifically, the melting point of the second glue layer is greater than the melting points of the first glue layer and the third glue layer. When the temperature of the ear glue reaches the melting points of the first glue layer and the third glue layer, the second glue layer remains unmelted, which facilitates the second glue layer to form a support structure between the ear and the first packaging edge during heat sealing or pressure relief. In addition, the thickness of the second glue layer is greater than the thickness of the first glue layer, so that the second glue layer has a higher structural strength than the first glue layer, so as to improve the stability of the second glue layer supporting between the ear and the first packaging edge, reduce the risk of excessive deformation of the ear glue causing the ear to leak out and short-circuit with the metal material in the packaging bag, and thus improve the safety performance of the battery.

[0068] The embodiments of the present application are further described with reference to the accompanying drawings.

[0069] See also Figure 1 , an embodiment of the present application provides a battery 100, the battery 100 includes an electrode assembly 10, a packaging bag 20, a tab 30 and a tab glue 40. The electrode assembly 10 is stacked or wound by a positive electrode sheet, a separator and a negative electrode sheet. The electrode assembly 10 is contained in the packaging bag 20 for storing or releasing electrical energy. The packaging bag 20 includes a first packaging edge 21, the tab 30 is connected to the electrode assembly 10 and extends from the first packaging edge 21, and the portion of the tab 30 extending from the first packaging edge 21 is used to connect a circuit board assembly or an external electrical device.

[0070] Optionally, the battery 100 includes two tabs 30 , which are spaced apart and respectively connected to the positive electrode sheet and the negative electrode sheet in the electrode assembly 10 , so that the polarities of the two tabs 30 are opposite.

[0071] Please also read Figure 2The pole ear glue 40 is arranged between the pole ear 30 and the first packaging edge 21. Specifically, the first packaging edge 21 includes a first melting layer 211 and a second melting layer 212 which are sealed to each other in the thickness direction Z of the pole ear 30. An opening 213 for the pole ear 30 to extend out is formed between the first melting layer 211 and the second melting layer 212. The pole ear glue 40 is coated on the peripheral side of the pole ear 30. At least part of the pole ear glue 40 is located in the opening 213 and is sealed to the first melting layer 211 and the second melting layer 212.

[0072] In some embodiments, the tab 30 includes a first surface 31 and a second surface 32 that are arranged opposite to each other in the thickness direction Z of the tab 30. The tab glue 40 includes a first portion 40a and a second portion 40b, wherein the first portion 40a is connected between the first surface 31 and the first molten layer 211, and the second portion 40b is connected between the second surface 32 and the second molten layer 212. In the width direction Y of the tab 30, the two ends of the first portion 40a protruding from the first surface 31 are connected to the two ends of the second portion 40b protruding from the second surface 32, so that the tab glue 40 is wrapped around the tab 30.

[0073] It can be understood that, in some embodiments, the tab glue 40 can be disposed around the tab 30 so that the tab glue 40 is coated around the tab 30 .

[0074] Please also read Figure 3 The tab glue 40 includes a first glue layer 41, a second glue layer 42, and a third glue layer 43 sequentially connected from the tab 30 to the first packaging edge 21. Specifically, in the first part 40a, the first glue layer 41, the second glue layer 42, and the third glue layer 43 are sequentially arranged from the first surface 31 to the first melting layer 211; in the second part 40b, the first glue layer 41, the second glue layer 42, and the third glue layer 43 are sequentially arranged from the second surface 32 to the second melting layer 212.

[0075] Optionally, the first adhesive layer 41 and the third adhesive layer 43 are formed on both sides of the second adhesive layer 42 by copolymerization of propylene, ethylene or butene; or the first adhesive layer 41 and the third adhesive layer 43 are formed on both sides of the second adhesive layer 42 by blending polypropylene and polyethylene octene co-elastomers with different melting points; or the first adhesive layer 41 and the third adhesive layer 43 are formed on both sides of the second adhesive layer 42 by blending polypropylene and polyethylene.

[0076] Please also read Figure 4, the relationship between the melting point T1 of the first glue layer 41, the melting point T2 of the second glue layer 42 and the melting point T3 of the third glue layer 43 satisfies: T1<T2, T3<T2, wherein 110℃≤T1≤130℃, 140℃≤T2≤170℃, 110℃≤T3≤130℃. It can be understood that the melting points of the first glue layer 41 and the third glue layer 43 are adapted to the pressure relief temperature of the battery 100. When the temperature of the tab glue 40 reaches the melting point of the first glue layer 41 and the third glue layer 43, the second glue layer 42 remains in an unmelted state, so that the second glue layer 42 forms a support structure between the tab 30 and the first packaging edge 21 during heat sealing or pressure relief, reducing the risk of leakage of the tab 30 and short circuit contact with the metal material in the packaging bag 20, thereby improving the safety performance of the battery 100. Specifically, during the pressure relief process, the first adhesive layer 41 and the third adhesive layer 43 are melted respectively, and at least one of the first adhesive layer 41 and the third adhesive layer 43 is separated from the second adhesive layer 42 so that the tab adhesive 40 forms a pressure relief channel 50. In addition, the second adhesive layer 42 can also limit the amount of adhesive overflow during pressure relief.

[0077] Optionally, during the pressure relief process, the first adhesive layer 41 is separated from the second adhesive layer 42 so that the side of the pole ear adhesive 40 facing the pole ear 30 forms a pressure relief channel 50; or the third adhesive layer 43 is separated from the second adhesive layer 42 so that the side of the pole ear adhesive 40 facing the first packaging edge 21 forms a pressure relief channel 50; or the first adhesive layer 41 is separated from the second adhesive layer 42 so that pressure relief channels 50 are formed on both sides of the pole ear adhesive 40. The first adhesive layer 41 and the second adhesive layer 42 can increase the probability of the pole ear adhesive 40 forming a pressure relief channel 50, thereby improving the safety performance of the battery.

[0078] Optionally, T1 and T3 can be 110℃, 111℃, 112℃, 113℃, 114℃, 115℃, 116℃, 117℃, 118℃, 119℃, 120℃, 121℃, 122℃, 123℃, 124℃, 125℃, 126℃, 127℃, 128℃, 129℃, 130℃, and any other value in the range of 110℃≤T1≤130℃.

[0079] Optionally, T2 can be 140℃, 141℃, 142℃, 143℃, 144℃, 145℃, 148℃, 150℃, 153℃, 155℃, 158℃, 160℃, 161℃, 162℃, 163℃, 164℃, 165℃, 166℃, 167℃, 168℃, 169℃, 170℃, and any other value in the range of 140℃≤T2≤170℃.

[0080] In some implementation examples, T1 = T3, which is beneficial for the first adhesive layer 41 and the third adhesive layer 43 to melt synchronously.

[0081] It can be understood that, in some embodiments, T1>T3 or T1<T3, and the ear glue 40 may also melt synchronously when the temperature of the ear glue 40 reaches the higher melting point of the first glue layer 41 and the third glue layer 43 .

[0082] Furthermore, the relationship between the melting point T1 of the first glue layer 41, the melting point T2 of the second glue layer 42 and the melting point T3 of the third glue layer 43 satisfies: 120℃≤T1≤125℃, 145℃≤T2≤165℃, 120℃≤T3≤125℃, so as to further limit the melting points of the first glue layer 41, the second glue layer 42 and the third glue layer 43, so that the melting points of the first glue layer 41 and the third glue layer 43 are adapted to the pressure relief temperature of the battery 100, and the second glue layer 42 forms a supporting structure between the tab 30 and the first packaging edge 21 during the heat sealing or pressure relief process.

[0083] Furthermore, the relationship between the melting point T1 of the first glue layer 41, the melting point T2 of the second glue layer 42 and the melting point T3 of the third glue layer 43 satisfies: T1=T3=123°C; T2=165°C, so as to further limit the melting points of the first glue layer 41, the second glue layer 42 and the third glue layer 43, so that the melting points of the first glue layer 41 and the third glue layer 43 are adapted to the pressure relief temperature of the battery 100, and the second glue layer 42 forms a supporting structure between the tab 30 and the first packaging edge 21 during the heat sealing or pressure relief process.

[0084] Please refer again Figure 2 and Figure 3 In some embodiments, in the arrangement direction of the first glue layer 41, the second glue layer 42 and the third glue layer 43, the sum of the thicknesses of the first glue layer 41, the second glue layer 42 and the third glue layer 43 is 70 μm to 100 μm, so as to limit the packaging volume occupied by the ear glue 40 and improve the energy density of the battery 100.

[0085] Furthermore, the sum of the thicknesses of the first adhesive layer 41 , the second adhesive layer 42 and the third adhesive layer 43 is 72 μm to 80 μm, so as to further limit the packaging volume occupied by the tab adhesive 40 and improve the energy density of the battery 100 .

[0086] Optionally, the sum of the thicknesses of the first glue layer 41 , the second glue layer 42 and the third glue layer 43 may be 72 μm, 73 μm, 74 μm, 75 μm, 76 μm, 77 μm, 78 μm, 79 μm, 80 μm, or any other value within the range of 72 μm to 80 μm.

[0087] Please refer again Figure 4In some embodiments, the thickness ratio of the first adhesive layer 41 to the second adhesive layer 42 satisfies: 1:1.2~2, so that the second adhesive layer 42 has a higher structural strength than the first adhesive layer 41, improves the stability of the second adhesive layer 42 supporting between the tab 30 and the first packaging edge 21, and reduces the risk of excessive deformation of the tab adhesive 40 causing the tab 30 to leak out and short-circuit with the metal material in the packaging bag 20, thereby improving the safety performance of the battery.

[0088] It should be noted that, during the packaging process, the first adhesive layer 41 is in contact with the tab 30. Under the extrusion of the tab 30, the thickness of the first adhesive layer 41 at the position corresponding to the tab 30 will decrease. In the present application, the thickness of the first adhesive layer 41 is the initial thickness of the first adhesive layer 41 before being extruded by the tab 30, that is, Figure 2 The first adhesive layer 41 has a thickness exceeding that of the electrode tab 30 in the width direction Y of the electrode tab 30 .

[0089] It can be understood that, in some embodiments, the surface of the first adhesive layer 41 in contact with the pole tab 30 under the extrusion of the pole tab 30 will form a rough surface, and the rough surface includes a plurality of first concave surfaces and first convex surfaces continuously arranged in the width direction Y of the pole tab 30, and the rough surface abuts against the first surface 31 or the second surface 32 of the pole tab 30 to improve the connection strength between the first adhesive layer 41 and the pole tab 30.

[0090] Furthermore, the thickness of the first adhesive layer 41 is substantially equal to the thickness of the third adhesive layer 43, and the thickness ratio of the first adhesive layer 41, the second adhesive layer 42 and the third adhesive layer 43 satisfies: 1:1.2 to 2:1, so that the second adhesive layer 42 has a higher structural strength than the first adhesive layer 41 and the third adhesive layer 43, and the second adhesive layer 42 is centrally arranged between the tab 30 and the first packaging edge 21, further improving the stability of the second adhesive layer 42 supporting between the tab 30 and the first packaging edge 21.

[0091] Optionally, the thickness ratio of the first adhesive layer 41, the second adhesive layer 42 and the third adhesive layer 43 can be 1:1.2-2:1, 1:1.3:1, 1:1.4:1, 1:1.5:1, 1:1.6:1, 1:1.7:1, 1:1.8:1, 1:1.9:1, 1:2:1, and any other value in the range of 1:1.2-2:1.

[0092] In some embodiments, the sum of the thicknesses of the first adhesive layer 41 , the second adhesive layer 42 and the third adhesive layer 43 is 75.5 μm, the thickness of the first adhesive layer 41 is 20 μm, the thickness of the second adhesive layer 42 is 35.5 μm, and the thickness of the third adhesive layer 43 is 20 μm.

[0093] Furthermore, the thickness ratio of the first adhesive layer 41, the second adhesive layer 42 and the third adhesive layer 43 satisfies: 1:1.5~1.8:1, so as to further limit the structural strength of the first adhesive layer 41, the second adhesive layer 42 and the third adhesive layer 43, improve the stability of the second adhesive layer 42 supporting between the tab 30 and the first packaging edge 21, and thereby improve the safety performance of the battery 100.

[0094] In some embodiments, the sum of the thicknesses of the first adhesive layer 41 , the second adhesive layer 42 and the third adhesive layer 43 is 77 μm, the thickness of the first adhesive layer 41 is 22 μm, the thickness of the second adhesive layer 42 is 33 μm, and the thickness of the third adhesive layer 43 is 22 μm.

[0095] Furthermore, the thickness ratio of the first adhesive layer 41, the second adhesive layer 42 and the third adhesive layer 43 satisfies: 1:1.6:1, so as to further limit the structural strength of the first adhesive layer 41, the second adhesive layer 42 and the third adhesive layer 43, improve the stability of the second adhesive layer 42 supporting between the tab 30 and the first packaging edge 21, and thereby improve the safety performance of the battery 100.

[0096] In some embodiments, the sum of the thicknesses of the first adhesive layer 41 , the second adhesive layer 42 and the third adhesive layer 43 is 72 μm, the thickness of the first adhesive layer 41 is 20 μm, the thickness of the second adhesive layer 42 is 32 μm, and the thickness of the third adhesive layer 43 is 20 μm.

[0097] It can be understood that, in some embodiments, under the premise that the thickness of the second adhesive layer 42 is greater than the thickness of the third adhesive layer 43, the thickness of the first adhesive layer 41 of the third adhesive layer is greater than the thickness of the third adhesive layer 43, or the thickness of the first adhesive layer 41 is less than the thickness of the third adhesive layer 43, both of which can make the second adhesive layer 42 have a higher structural strength than the first adhesive layer 41 and the third adhesive layer 43, so that the second adhesive layer 42 has sufficient structural strength to play a supporting role on the tab 30 and the first packaging edge 21.

[0098] In the above-mentioned battery 100, by limiting the melting point and thickness of the first glue layer 41, the second glue layer 42 and the third glue layer 43 in the tab glue 40, the tab glue 40 maintains a stable structure during the pressure relief process. Specifically, the melting point of the second glue layer 42 is greater than the melting point of the first glue layer 41 and the third glue layer 43. When the temperature of the tab glue 40 reaches the melting point of the first glue layer 41 and the third glue layer 43, the second glue layer 42 remains in an unmelted state, which facilitates the second glue layer 42 to form a support structure between the tab 30 and the first packaging edge 21 during the heat sealing or pressure relief process. In addition, the thickness of the second glue layer 42 is greater than the thickness of the first glue layer 41, so that the second glue layer 42 has a higher structural strength than the first glue layer 41, so as to improve the stability of the second glue layer 42 supporting between the tab 30 and the first packaging edge 21, reduce the risk of excessive deformation of the tab glue 40 causing the tab 30 to leak out and contact the metal material in the packaging bag 20 to short-circuit, and thus improve the safety performance of the battery 100.

[0099] In some embodiments, the packaging strength of the ear glue 40 at room temperature is 2.3N / mm to 4.2N / mm; the packaging strength of the ear glue 40 at a temperature of 100°C is 0.8N / mm to 1.5N / mm; the packaging strength of the ear glue 40 at a temperature of 120°C is 0.6N / mm to 1.2N / mm; the packaging strength of the ear glue 40 at a temperature of 130°C is 0.2N / mm to 0.5N / mm. The ear glue 40 is partially located in the packaging bag 20, and the temperature in the packaging bag 20 is the temperature of the ear glue 40. Compared with the sealing strength of the traditional ear glue, the above setting makes the packaging strength of the ear glue 40 change more with the temperature. When the pole ear glue 40 is at room temperature of 25°C, the pole ear glue 40 maintains a relatively high packaging strength, thereby improving the sealing stability between the pole ear 30 and the first packaging edge 21. When the temperature of the pole ear glue 40 reaches the melting point of the first glue layer 41 and the third glue layer 43, the corresponding packaging strength of the pole ear glue 40 is reduced, thereby facilitating the separation of at least one of the first glue layer 41 and the third glue layer 43 from the second glue layer 42, so that the pole ear glue 40 forms a pressure relief channel.

[0100] Please also read Figure 5 and Figure 6 It should be noted that the packaging strength of this application is obtained by the following test method:

[0101] Step 1: Make samples;

[0102] Specifically, in the width direction Y of the pole tab 30, the positions where the first packaging edge 21 is located on both sides of the pole tab glue 40 are two cutting starting points 61. The pole tab 30 includes a first section 33 extending from the pole tab glue 40 into the packaging bag 20, and a second section 34 extending from the pole tab glue 40 into the outside of the packaging bag 20. The packaging bag 20 is cut from each cutting starting point 61 along the extension direction X of the pole tab 30 until the cutting end point 62 exceeds the end of the first section 33 away from the first section 33, and a cutting portion 63 is formed by cutting the two cutting end points 62. The cutting portion 63 includes the pole tab 30, the pole tab glue 40 coated on the pole tab 30, and a portion of the packaging bag 20 connected to both sides of the pole tab glue 40 in the thickness direction Z of the pole tab 30.

[0103] The packaging bag 20 in the cutting portion 63 includes a packaging portion 631 connected to the tab glue 40 and an extension portion 632 extending from the packaging portion 631 toward the first section 33, and the extension portion 632 is folded to cover the packaging portion 631 and the second section 34 to form a sample. The sample includes a first clamping end 64 and a second clamping end 65, the first clamping end 64 is a portion exceeding the second section 34 after the two extension portions 632 are folded, and the second clamping end 65 is the first section 33 exposed after the two extension portions 632 are folded.

[0104] Step 2: Tensile test.

[0105] Specifically, a tensile testing machine with an incubator is selected. The tensile testing machine is provided with two oppositely arranged chucks in the incubator. The sample is placed in the incubator, with one chuck clamping the first clamping end 64 and the other chuck clamping the second clamping end 65. After the incubator is heated to a specified temperature and maintained for 5 minutes, the two chucks are moved relative to each other at a speed of 175±5mm / min to perform a tensile test, and the maximum value when the tab glue 40 is separated from the tab 30 or the packaging bag 20 is recorded.

[0106] Optionally, the packaging strength of the ear glue 40 at room temperature can be 2.3N / mm, 2.5N / mm, 2.6N / mm, 2.9N / mm, 3.0N / mm, 3.3N / mm, 3.6N / mm, 3.8N / mm, 4.0N / mm, 4.2N / mm, and any other value in the range of 2.3N / mm to 4.2N / mm.

[0107] Optionally, the packaging strength of the ear glue 40 at 100° C. can be 0.8N / mm, 0.9N / mm, 1.0N / mm, 1.1N / mm, 1.2N / mm, 1.3N / mm, 1.4N / mm, 1.5N / mm, and any other value in the range of 0.8N / mm to 1.5N / mm.

[0108] Optionally, the packaging strength of the tab glue 40 at 120° C. can be 0.6 N / mm, 0.7 N / mm, 0.8 N / mm, 0.9 N / mm, 1.0 N / mm, 1.1 N / mm, 1.2 N / mm, and any other value within the range of 0.6 N / mm to 1.2 N / mm.

[0109] Optionally, the packaging strength of the tab glue 40 at 130° C. may be 0.2 N / mm, 0.3 N / mm, 0.4 N / mm, 0.5 N / mm, and any other value within the range of 0.2 N / mm to 0.5 N / mm.

[0110] In the above-mentioned battery 100, the relationship between the melting point of the first glue layer 41, the melting points of the second glue layer 42 and the third glue layer 43 in the tab glue 40, and the packaging strength of the tab glue 40 at various temperatures is limited to balance the relationship between the melting point of the tab glue 40 and the packaging strength. When the temperature of the tab glue 40 reaches the melting point of the first glue layer 41 and the third glue layer 43, the second glue layer 42 is not melted, so that the second glue layer 42 forms a support structure between the tab 30 and the first packaging edge 21 during heat sealing or pressure relief, and the corresponding packaging strength of the tab glue 40 is reduced, so that at least one of the first glue layer 41 and the third glue layer 43 is separated from the second glue layer 42 so that the tab glue 40 forms a pressure relief channel 50.

[0111] Please refer again Figure 1 , observed along the thickness direction Z of the tab 30, the tab glue 40 includes a top 44, a bottom 45, a first side portion 46, and a second side portion 47. The top 44 and the bottom 45 are arranged opposite to each other in the extension direction X of the tab 30, the top 44 is located outside the packaging bag 20, the bottom 45 is located inside the packaging bag 20, the first side portion 46 and the second side portion 47 are connected between the top 44 and the bottom 45, and are arranged opposite to each other on both sides of the tab 30 along the width direction Y of the tab 30.

[0112] Along the extension direction X of the pole ear 30, the width of the first packaging edge 21 is 1.2mm to 2.0mm, the length of the top 44 protruding from the first packaging edge 21 is 0.2 to 2mm, and the length of the bottom 45 protruding from the first packaging edge is greater than 1.2mm, so as to reduce the risk of leakage of the pole ear 30 and short circuit contact with the metal material in the packaging bag 20, thereby improving the safety performance of the battery 100.

[0113] Optionally, the width of the first packaging edge 21 may be 1.2 mm, 1.3 mm, 1.4 mm, 1.5 mm, 1.6 mm, 1.7 mm, 1.8 mm, 1.9 mm, 2.0 mm, or any other value within the range of 1.2 mm to 2.0 mm.

[0114] Optionally, the length of the top 44 protruding from the first packaging edge 21 can be 0.2mm, 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.8mm, 1mm, 1.2mm, 1.4mm, 1.6mm, 1.8mm, 2mm, and any other value in the range of 0.2 to 2mm.

[0115] Optionally, the length of the bottom 45 protruding from the first packaging edge can be 1.3 mm, 1.4 mm, 1.6 mm, 1.8 mm, 2 mm, or any other value greater than 1.2 mm.

[0116] Along the width direction Y of the pole ear 30, the spacing between the first side portion 46 and the second side portion 47 is 8 mm to 9 mm, so as to increase the extension length of the bottom 45 in the packaging bag 20, thereby increasing the low melting point position of the pole ear 30. When the temperature in the packaging bag 20 reaches the melting point of the first adhesive layer 41 and the third adhesive layer 43, it is convenient for the pole ear adhesive 40 to form a pressure relief channel 50.

[0117] Optionally, the spacing between the first side portion 46 and the second side portion 47 can be 8 mm, 8.1 mm, 8.2 mm, 8.3 mm, 8.4 mm, 8.5 mm, 8.6 mm, 8.7 mm, 8.8 mm, 8.9 mm, 9 mm, and any other value in the range of 8 mm to 9 mm.

[0118] Along the extension direction X of the tab 30 , the distance between the top 44 and the bottom 45 is 2.5 mm to 5 mm, so that the tab glue 40 extends from the inside of the packaging bag 20 through the first packaging edge 21 to the outside of the packaging bag 20 , thereby improving the sealing effect of the tab glue 40 .

[0119] Optionally, the distance between the top 44 and the bottom 45 may be 2.5 mm, 3 mm, 3.5 mm, 4 mm, 4.5 mm, 5 mm, or any other value within the range of 2.5 mm to 5 mm.

[0120] Along the width direction Y of the pole ear 30, the spacing between the side of the pole ear 30 facing the first side portion 46 and the first side portion 46 is 0.5mm to 2.5mm, and the spacing between the side of the pole ear 30 facing the second side portion 47 and the second side portion 47 is 0.5mm to 2.5mm, so that the pole ear glue 40 protrudes out of both sides of the pole ear 30 in the width direction Y of the pole ear 30, thereby improving the sealing effect of the pole ear glue 40.

[0121] Optionally, the spacing between the side of the tab 30 facing the first side portion 46 and the first side portion 46 can be 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm, 1.5 mm, 1.6 mm, 1.7 mm, 1.8 mm, 1.9 mm, 2 mm, 2.1 mm, 2.2 mm, 2.3 mm, 2.4 mm, 2.5 mm, and any other value in the range of 0.5 mm to 2.5 mm.

[0122] Optionally, the spacing between the side of the tab 30 facing the second side portion 47 and the second side portion 47 can be 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1mm, 1.1mm, 1.2mm, 1.3mm, 1.4mm, 1.5mm, 1.6mm, 1.7mm, 1.8mm, 1.9mm, 2mm, 2.1mm, 2.2mm, 2.3mm, 2.4mm, 2.5mm and any other value in the range of 0.5mm to 2.5mm.

[0123] In some embodiments, along the width direction Y of the pole lug 30, the pole lug 30 is centrally arranged between the first side portion 46 and the second side portion 47, that is, the distance between the side of the pole lug 30 facing the first side portion 46 and the first side portion 46 is equal to the distance between the side of the pole lug 30 facing the second side portion 47 and the second side portion 47, so that the force on both sides of the pole lug 30 is uniform.

[0124] See also Figure 7 The embodiment of the present application further provides an electric device 200, comprising the battery 100 in any of the above embodiments. The electric device 200 also includes a device body, and the battery 100 is electrically connected to the device body and supplies power to the device body. In some embodiments, the device body can be an electronic device such as a mobile phone, a tablet computer, or a transportation device such as an electric car.

[0125] The present application is described below by means of specific implementation methods:

[0126] The pressure relief test includes two methods: hot box test and 100℃ storage test.

[0127] Hot box testing consists of the following four steps:

[0128] Charge the battery until the remaining capacity of the battery reaches 100%;

[0129] Attach the temperature-sensitive wire to the center of the battery surface;

[0130] Place the battery flat in the box and heat it up to 130±2℃ at a rate of 5±2℃ and keep it there for 60 minutes;

[0131] Turn off the box heating, and remove the battery after it cools down to room temperature. The battery is considered to meet the safety standard if it does not catch fire or explode.

[0132] Hot box storage testing consists of the following three steps:

[0133] Charge the battery until the remaining capacity of the battery reaches 100%;

[0134] Store the battery in a box at 100±2℃ for 5 hours;

[0135] Open the box, take out the battery, and determine that the battery meets the safety standards: no packaging edges of the battery are broken, and the battery does not catch fire or explode.

[0136] The batteries of the comparative examples and the embodiments were placed in an incubator, and after the incubator was heated to a specified temperature, the pressure release of the batteries was observed.

[0137] The batteries in the comparative examples and the examples have most of the same parameters, and some chemical systems and cell structures commonly used in the art can be adopted. The parameters other than those involved in the examples and comparative examples in the following tables are the same.

[0138] Table 1 Other parameters and test results of each battery in Comparative Examples 1-2 and Examples 1-5

[0139]

[0140]

[0141] As can be seen from Table 1, the melting points of the first adhesive layer 41 and the third adhesive layer 43 in Comparative Example 1 are less than 110°C, which is not conducive to high-temperature storage of the battery 100. The melting points of the first adhesive layer 41 and the third adhesive layer 43 in Comparative Example 2 are greater than 130°C, which is not conducive to timely pressure relief of the battery 100. The melting points of the first adhesive layer 41 and the third adhesive layer 43 in Examples 1-5 are all between 110°C and 130°C, which can meet the requirements of high-temperature storage and timely pressure relief.

[0142] Table 2 Other parameters and test results of each battery in Comparative Examples 3-4 and Examples 6-10

[0143]

[0144]

[0145] As can be seen from Table 2, the melting point of the second adhesive layer 42 in Comparative Example 3 is less than 140°C, which is not conducive to high-temperature storage of the battery 100. The melting point of the second adhesive layer 42 in Comparative Example 4 is greater than 170°C. Although it can meet the requirements of the pressure relief test, the selection of the material of the ear glue 40 is relatively strict and the preparation is difficult. The melting point of the second adhesive layer 42 in Examples 6-10 is 140°C to 170°C, which can meet the requirements of high-temperature storage and can release pressure in time.

[0146] Table 3 Other parameters and test results of each battery in Comparative Examples 5-6 and Examples 11-14

[0147]

[0148] As can be seen from Table 3, the packaging strength of the ear glue 40 in Comparative Example 5 is relatively small. Although it can meet the requirements of the pressure relief test, the packaging strength at room temperature is relatively low, which is not conducive to the use of the battery 100. The packaging strength of the ear glue 40 in Comparative Example 6 is relatively high, which is not conducive to timely pressure relief of the battery 100. The packaging strength of the ear glue 40 in Examples 11-14 meets the above range, which can meet the requirements of high-temperature storage and timely pressure relief.

[0149] Table 4 Other parameters and test results of each battery in Comparative Examples 7-8 and Examples 15-18

[0150]

[0151] It can be seen from Table 4 that in Comparative Example 7, when the thickness ratio of the first adhesive layer 41 to the second adhesive layer 42 is large, the hot box pass rate and the high-temperature storage test pass rate are low. In Comparative Example 8, when the thickness ratio of the first adhesive layer 41 to the second adhesive layer 42 is small, the thicknesses of the first adhesive layer 41 and the third adhesive layer 43 are thinner, which will affect the hot box test pass rate.

[0152] In summary, in the above-mentioned battery 100 and the electrical device 200, the pole ear glue 40 maintains a stable structure during the pressure relief process by limiting the melting point and thickness of the first glue layer 41, the second glue layer 42 and the third glue layer 43 in the pole ear glue 40. Specifically, the melting point of the second glue layer 42 is greater than the melting points of the first glue layer 41 and the third glue layer 43. When the temperature of the pole ear glue 40 reaches the melting point of the first glue layer 41 and the third glue layer 43, the second glue layer 42 remains in an unmelted state, so that the second glue layer 42 forms a support structure between the pole ear 30 and the first packaging edge 21 during heat sealing or pressure relief. Furthermore, the thickness of the second adhesive layer 42 is greater than that of the first adhesive layer 41 , so that the second adhesive layer 42 has a higher structural strength than the first adhesive layer 41 , thereby improving the stability of the second adhesive layer 42 supporting the pole tab 30 and the first packaging edge 21 , and reducing the risk of excessive deformation of the pole tab adhesive 40 causing the pole tab 30 to leak out and short-circuit with the metal material in the packaging bag 20 , thereby improving the safety performance of the battery 100 .

[0153] In addition, those skilled in the art may also make other changes within the spirit of the present application. Of course, these changes made according to the spirit of the present application should be included in the scope disclosed in the present application.

Claims

1. A battery, comprising an electrode assembly, a packaging bag and a tab, wherein the electrode assembly is contained in the packaging bag, characterized in that: The packaging bag comprises a first packaging edge, the electrode tab is connected to the electrode assembly and extends from the first packaging edge, The battery further includes a tab glue disposed between the first packaging edge and the tab, the tab glue including a first glue layer, a second glue layer and a third glue layer sequentially connected from the tab to the first packaging edge, the relationship between the melting point T1 of the first glue layer, the melting point T2 of the second glue layer and the melting point T3 of the third glue layer satisfies: T1<T2, T3<T2, wherein 110℃≤T1≤130℃, 140℃≤T2≤170℃, 110℃≤T3≤130℃, In the arrangement direction of the first adhesive layer, the second adhesive layer and the third adhesive layer, the sum of the thicknesses of the first adhesive layer, the second adhesive layer and the third adhesive layer is 70 um to 100 um, and the thickness ratio of the first adhesive layer to the second adhesive layer satisfies: 1:1.2-2; Observing along the thickness direction of the tab, the tab glue comprises a top and a bottom, the top and the bottom are arranged opposite to each other in the extension direction of the tab, the top is located outside the first packaging edge, and the bottom is located inside the packaging bag; The length of the top protruding from the first packaging edge is 0.2 mm to 2 mm, and the length of the bottom protruding from the first packaging edge is 1.2 mm to 2 mm.

2. The battery according to claim 1, characterized in that The T1 is substantially equal to the T3.

3. The battery according to claim 1, characterized in that The sum of the thicknesses of the first adhesive layer, the second adhesive layer and the third adhesive layer is 72 um to 80 um.

4. The battery according to claim 3, characterized in that The thickness ratio of the first adhesive layer, the second adhesive layer and the third adhesive layer satisfies: 1:1.2 to 2:

1.

5. The battery according to claim 4, characterized in that The thickness ratio of the first adhesive layer, the second adhesive layer and the third adhesive layer satisfies: 1:1.5-1.8:

1.

6. The battery according to claim 1 or 2, characterized in that: 120℃≤T1≤125℃, 145℃≤T2≤165℃, 120℃≤T3≤125℃.

7. The battery according to claim 1, characterized in that The packaging strength of the ear glue at a temperature of 100°C is 0.8N / mm to 1.5N / mm; the packaging strength of the ear glue at a temperature of 120°C is 0.6N / mm to 1.2N / mm; the packaging strength of the ear glue at a temperature of 130°C is 0.2N / mm to 0.5N / mm.

8. The battery according to claim 7, characterized in that The packaging strength of the ear glue at room temperature is 2.3N / mm to 4.25N / mm.

9. The battery according to claim 1, characterized in that Observing along the thickness direction of the pole lug, the pole lug glue includes a first side portion and a second side portion, wherein the first side portion and the second side portion are connected between the top portion and the bottom portion, and are arranged on both sides of the pole lug along the width direction of the pole lug.

10. The battery according to claim 9, characterized in that Along the extending direction of the tab, the width of the first packaging edge is 1.2 mm to 2.0 mm, and along the width direction of the tab, the distance between the first side portion and the second side portion is 8 mm to 9 mm.

11. The battery according to claim 10, characterized in that Along the extending direction of the tab, the distance between the top and the bottom is 2.5 mm to 5 mm.

12. The battery according to claim 10, characterized in that Along the width direction of the tab, a distance between a side of the tab facing the first side portion and the first side portion is 0.5 mm to 2.5 mm, and a distance between a side of the tab facing the second side portion and the second side portion is 0.5 mm to 2.5 mm.

13. The battery according to claim 1, characterized in that The tab includes a first surface and a second surface that are oppositely arranged in the thickness direction, and the tab glue includes a first part and a second part, the first part is connected between the first surface and the first packaging edge, and the second part is connected between the second surface and the first packaging edge, and along the width direction of the tab, the two ends of the first part protruding from the first surface are connected to the two ends of the second part protruding from the second surface.

14. An electrical device, characterized in that: The electrical device comprises the battery according to any one of claims 1 to 13.

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