Battery and power consuming device

Abstract

A battery and an electrical device are disclosed. The battery includes an electrode assembly, a packaging bag, and tabs. The packaging bag includes a first sealing edge, from which the tabs extend. The battery also includes tab adhesive, which includes a first adhesive layer, a second adhesive layer, and a third adhesive layer sequentially connected from the tabs towards the first sealing edge. The melting points T1 of the first adhesive layer, T2 of the second adhesive layer, and T3 of the third adhesive layer are T1 < T2, T3 < T2, 110℃ ≤ T1 ≤ 130℃, 140℃ ≤ T2 ≤ 170℃, and 110℃ ≤ T3 ≤ 130℃. The sum of the thicknesses of the first, second, and third adhesive layers is 70µm to 100µm, and the thickness ratio of the first and second adhesive layers is 1:1.2 to 2. The tab adhesive includes a top, a bottom, a first side, and a second side. Along the extension direction of the tab, the width of the first encapsulation edge is 1.2 mm to 2.0 mm. The distance between the side of the tab facing the first side and the first side is 0.5 mm to 2.5 mm. The distance between the side of the tab facing the second side and the second side is 0.5 mm to 2.5 mm. This type of battery improves safety performance.

Description

[0001] This application is a divisional application of application number 202310079198.6, filed on January 18, 2023, entitled "Battery and Electrical Equipment". Technical Field

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

[0003] In existing battery structures, tab adhesive is typically used to achieve a good seal between the tabs and the packaging bag. Ordinary tab adhesive cannot provide pressure relief, and existing tab adhesives that can provide pressure relief require a lower melting point. However, lower melting point tab adhesives lack support structures during heat sealing or pressure relief, which can easily lead to tab exposure and short circuits between the tabs and the metal materials in the packaging bag, causing safety issues. 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] Embodiments of this application provide a battery, including an electrode assembly, a packaging bag, and tabs. The electrode assembly is housed in the packaging bag. The packaging bag includes a first sealing edge, and the tabs are connected to the electrode assembly and extend from the first sealing edge. The battery also includes tab adhesive disposed between the first sealing edge and the tabs. The tab adhesive includes a first adhesive layer, a second adhesive layer, and a third adhesive layer sequentially connected from the tabs to the first sealing edge. 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 satisfy the following relationship: T1 < T2, T3 < T2, where 110℃ ≤ T1 ≤ 130℃, 140℃ ≤ T2 ≤ 170℃, and 110℃ ≤ T3 ≤ 130℃. In the arrangement direction of the first, second, and third adhesive layers, the sum of the thicknesses of the first, second, and third adhesive layers is 70µm to 100µm, and the thickness ratio of the first and second adhesive layers satisfies 1:1.2 to 2. Viewed along the thickness direction of the tab, the tab adhesive includes a top, a bottom, a first side, and a second side. The top and bottom are positioned opposite each other in the tab's extension direction. The top is located outside the first encapsulation edge, and the bottom is located inside the packaging bag. The first and second sides connect the top and bottom and are located on both sides of the tab along its width direction. Along the tab's extension direction, the width of the first encapsulation edge is 1.2 mm to 2.0 mm. The distance between the side of the tab facing the first side and the first side is 0.5 mm to 2.5 mm, and the distance between the side of the tab facing the second side and the second side is 0.5 mm to 2.5 mm.

[0006] In the aforementioned battery, by limiting the melting points and thicknesses of the first, second, and third adhesive layers in the tab adhesive, a stable structure is maintained in the tab adhesive during heat sealing or pressure relief. Specifically, the melting point of the second adhesive layer is higher than that of the first and third adhesive layers. When the temperature of the tab adhesive reaches the melting points of the first and third adhesive layers, the second adhesive layer remains unmelted, facilitating the formation of a support structure between the tab and the first encapsulation edge during heat sealing or pressure relief. Furthermore, the thickness of the second adhesive layer is greater than that of the first adhesive layer, giving it higher structural strength. This improves the stability of the second adhesive layer's support between the tab and the first encapsulation edge, reducing the risk of short circuits caused by excessive deformation of the tab adhesive leading to exposure of the tab and contact with metal materials in the packaging bag, thereby improving battery safety performance. The wider the width of the first encapsulation edge, the longer the path required for pressure relief, making pressure relief more difficult; conversely, a narrower edge makes pressure relief easier. The longer the distance between the first and second sides, the longer the connection length between the tab adhesive and the outside, increasing the placement of low-melting-point positions. Therefore, the longer the first and second sides, the easier it is to form pressure relief. By balancing the distance between the first and second sides and the width of the first encapsulation edge, the pressure relief channel is formed neither too early nor too late.

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

[0008] In some embodiments of this application, the sum of the thicknesses of the first adhesive layer, the second adhesive layer, and the third adhesive layer is 72µm to 80µm, in order to further limit the encapsulation volume occupied by the tab adhesive and improve the energy density of the battery.

[0009] In some embodiments of this application, the thickness ratio of the first adhesive layer, the second adhesive layer, and the third adhesive layer satisfies 1:1.2 to 2:1, which makes the second adhesive layer have higher structural strength than the first adhesive layer and the third adhesive layer, and makes the second adhesive layer centrally disposed between the tab and the first encapsulation edge, further improving the stability of the second adhesive layer in supporting the tab and the first encapsulation edge.

[0010] In some embodiments of this application, the thickness ratio of the first adhesive layer, the second adhesive layer, and the third adhesive layer satisfies 1:1.5 to 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 in supporting the tab and the first encapsulation edge, and thus improve the safety performance of the battery.

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

[0012] In some embodiments of this application, the encapsulation strength of the tab adhesive at 100°C is 0.8 N / mm to 1.5 N / mm; the encapsulation strength of the tab adhesive at 120°C is 0.6 N / mm to 1.2 N / mm; and the encapsulation strength of the tab adhesive at 130°C is 0.2 N / mm to 0.5 N / mm. When the temperature of the tab adhesive reaches the melting point of the first and third adhesive layers, the encapsulation strength of the tab adhesive decreases, facilitating the separation of at least one of the first and third adhesive layers from the second adhesive layer, thus forming a pressure relief channel in the tab adhesive.

[0013] In some embodiments of this application, the encapsulation strength of the tab adhesive at room temperature is between 2.3 N / mm and 4.25 N / mm. When the tab adhesive is at room temperature, it maintains high encapsulation strength, improving the stability of the seal between the tab and the first encapsulation edge.

[0014] In some embodiments of this application, the distance between the first side and the second side is 8mm to 9mm along the extension direction of the tab and along the width direction of the tab. The longer the distance between the first side and the second side, the longer the connection length between the tab adhesive and the outside, which increases the setting of the low melting point position. Therefore, the longer the first side and the second side, the easier it is to form pressure relief. By limiting the distance between the first side and the second side, the pressure relief channel is formed neither too early nor too late.

[0015] In some embodiments of this application, the length of the top protrusion extending beyond the first encapsulation edge is 0.2 mm to 2 mm, and the length of the bottom protrusion extending beyond the first encapsulation edge is greater than 1.2 mm, so as to reduce the risk of short circuit when the exposed tab comes into contact with the metal material in the packaging bag, thereby improving the safety performance of the battery.

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

[0017] In some embodiments of this application, the tab includes a first surface and a second surface disposed opposite to each other in the thickness direction, and the tab adhesive includes a first part and a second part. The first part is connected between the first surface and the first encapsulation edge, and the second part is connected between the second surface and the first encapsulation edge. 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, so that the tab adhesive covers the periphery of the tab.

[0018] Embodiments of this application also provide an electrical device, including the battery in any of the above embodiments.

[0019] In the battery and electrical device of this application, by limiting the melting points and thicknesses of the first, second, and third adhesive layers in the tab adhesive, a stable structure is maintained in the tab adhesive during heat sealing or pressure relief. Specifically, the melting point of the second adhesive layer is higher than that of the first and third adhesive layers. When the temperature of the tab adhesive reaches the melting points of the first and third adhesive layers, the second adhesive layer remains unmelted, facilitating the formation of a support structure between the tab and the first encapsulation edge during heat sealing or pressure relief. Furthermore, the thickness of the second adhesive layer is greater than that of the first adhesive layer, giving it higher structural strength. This improves the stability of the second adhesive layer's support between the tab and the first encapsulation edge, reducing the risk of excessive deformation of the tab adhesive leading to leakage and short circuits due to contact with metal materials in the packaging bag, thereby improving battery safety performance. The wider the width of the first encapsulation edge, the longer the path required for pressure relief, making pressure relief more difficult; the narrower the edge, the easier it is to cause pressure relief. The longer the distance between the first and second sides, the longer the connection length between the tab adhesive and the outside, increasing the placement of low-melting-point positions. Therefore, the longer the first and second sides, the easier it is to form pressure relief. By balancing the distance between the first and second sides and the width of the first encapsulation edge, the pressure relief channel is formed neither too early nor too late. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the battery structure in one embodiment of this application.

[0021] Figure 2 This is a first-view structural schematic diagram of the battery tab adhesive in one embodiment of this application.

[0022] Figure 3 This is a second-view structural schematic diagram of the battery tab adhesive in one embodiment of this application.

[0023] Figure 4 This is a schematic diagram of the battery tab adhesive in a depressurized state in one embodiment of this application.

[0024] Figure 5 This is a schematic diagram of the cut-out portion used in the packaging strength test of this application.

[0025] Figure 6 This is a schematic diagram of the sample structure used in the packaging strength test of this application.

[0026] Figure 7 This is a schematic diagram of the structure of an electrical device in one embodiment of this application.

[0027] Explanation of main component symbols

[0028] Battery 100

[0029] 200 electrical appliances

[0030] Electrode assembly 10

[0031] Packaging bag 20

[0032] First encapsulation edge 21

[0033] First melting layer 211

[0034] Second melting layer 212

[0035] Earl 30

[0036] Page 1, page 31

[0037] Page 2, 32

[0038] Paragraph 1, 33

[0039] Paragraph 2, 34

[0040] Ear gel 40

[0041] First adhesive layer 41

[0042] Second adhesive layer 42

[0043] Third adhesive layer 43

[0044] Part 1, 40a

[0045] Part 2, 40b

[0046] Top 44

[0047] Bottom 45

[0048] First side section 46

[0049] Second side 47

[0050] Pressure relief channel 50

[0051] Cutting start point 61

[0052] Cutting endpoint 62

[0053] Cutting section 63

[0054] Packaging section 631

[0055] Extension 632

[0056] First clamping end 64

[0057] Second clamping end 65

[0058] Z-direction of thickness

[0059] Extend in the direction X

[0060] Width direction Y

[0061] The following detailed description, in conjunction with the accompanying drawings, will further illustrate this application. Detailed Implementation

[0062] The technical solutions of the embodiments of this application will be described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments.

[0063] It should be noted that when a component is considered to be "connected" to another component, it can be directly connected to the other component or may also have a component that is centrally positioned. When a component is considered to be "set" on another component, it can be directly set on the other component or may also have a component that is centrally positioned. When a value is considered to be "approximately equal" to another value, it means that the two are equal within a set deviation range, which is within 5%. In other words, when at least one of the two values ​​fluctuates within the set deviation range, even if their values ​​are not equal, they are still considered to be approximately equal. When a value is considered to be in a "1:1" ratio with another value, it means that the two are equal within a set deviation range, which is within 5%. In other words, when at least one of the two values ​​fluctuates within the set deviation range, even if their values ​​are not equal, they are still considered to be in a 1:1 ratio.

[0064] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0065] This application provides a battery including an electrode assembly, a packaging bag, and tabs. The electrode assembly is housed in the packaging bag. The packaging bag includes a first sealing edge, and the tabs are connected to the electrode assembly and extend from the first sealing edge. The battery also includes tab adhesive disposed between the first sealing edge and the tabs. The tab adhesive includes a first adhesive layer, a second adhesive layer, and a third adhesive layer sequentially connected from the tabs to the first sealing edge. 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 satisfy the following relationship: T1 < T2, T3 < T2, where 110℃ ≤ T1 ≤ 130℃, 140℃ ≤ T2 ≤ 170℃, and 110℃ ≤ T3 ≤ 130℃. In the arrangement direction of the first, second, and third adhesive layers, the sum of the thicknesses of the first, second, and third adhesive layers is 70 μm to 100 μm, and the thickness ratio of the first and second adhesive layers satisfies 1:1.2 to 2.

[0066] In the aforementioned battery, by limiting the melting points and thicknesses of the first, second, and third adhesive layers in the tab adhesive, a stable structure is maintained in the tab adhesive during heat sealing or pressure relief. Specifically, the melting point of the second adhesive layer is higher than that of the first and third adhesive layers. When the temperature of the tab adhesive reaches the melting points of the first and third adhesive layers, the second adhesive layer remains unmelted, facilitating the formation of a support structure between the tab and the first encapsulation edge during heat sealing or pressure relief. Furthermore, the thickness of the second adhesive layer is greater than that of the first adhesive layer, giving it higher structural strength. This improves the stability of the second adhesive layer's support between the tab and the first encapsulation edge, reducing the risk of excessive deformation of the tab adhesive leading to leakage and short circuits between the tab and the metal materials in the packaging bag, thereby improving the battery's safety performance.

[0067] The embodiments of this application will be further described with reference to the accompanying drawings.

[0068] Please see Figure 1 This application provides a battery 100, which includes an electrode assembly 10, a packaging bag 20, tabs 30, and tab adhesive 40. The electrode assembly 10 is formed by stacking or winding a positive electrode sheet, a separator, and a negative electrode sheet. The electrode assembly 10 is housed in the packaging bag 20 for storing or releasing electrical energy. The packaging bag 20 includes a first encapsulation edge 21, and the tabs 30 are connected to the electrode assembly 10 and extend from the first encapsulation edge 21. The portion of the tabs 30 extending beyond the first encapsulation edge 21 is used to connect a circuit board assembly or an external electrical device.

[0069] Optionally, the battery 100 includes two tabs 30, which are spaced apart and respectively connected to the positive electrode and the negative electrode in the electrode assembly 10, so that the polarities of the two tabs 30 are opposite.

[0070] Please refer to the following: Figure 2The tab adhesive 40 is disposed between the tab 30 and the first encapsulation edge 21. Specifically, the first encapsulation edge 21 includes a first molten layer 211 and a second molten layer 212 that are sealed to each other in the thickness direction Z of the tab 30. An opening 213 for the tab 30 to extend is formed between the first molten layer 211 and the second molten layer 212. The tab adhesive 40 covers the periphery of the tab 30, and at least a portion of the tab adhesive 40 is located in the opening 213 and is sealed to the first molten layer 211 and the second molten layer 212.

[0071] In some embodiments, the tab 30 includes a first surface 31 and a second surface 32 disposed opposite to each other in the thickness direction Z of the tab 30. The tab adhesive 40 includes a first portion 40a and a second portion 40b. 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 adhesive 40 covers the periphery of the tab 30.

[0072] It is understood that in some embodiments, the tab adhesive 40 may be disposed around the tab 30 so that the tab adhesive 40 covers the periphery of the tab 30.

[0073] Please refer to the following: Figure 3 The tab adhesive 40 includes a first adhesive layer 41, a second adhesive layer 42, and a third adhesive layer 43 sequentially connected from the tab 30 to the first encapsulation edge 21. Specifically, in the first part 40a, the first adhesive layer 41, the second adhesive layer 42, and the third adhesive layer 43 are sequentially disposed from the first surface 31 to the first molten layer 211; in the second part 40b, the first adhesive layer 41, the second adhesive layer 42, and the third adhesive layer 43 are sequentially disposed from the second surface 32 to the second molten layer 212.

[0074] 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.

[0075] Please refer to the following: Figure 4The melting point T1 of the first adhesive layer 41, the melting point T2 of the second adhesive layer 42, and the melting point T3 of the third adhesive layer 43 satisfy the following relationship: T1 < T2, T3 < T2, where 110℃ ≤ T1 ≤ 130℃, 140℃ ≤ T2 ≤ 170℃, and 110℃ ≤ T3 ≤ 130℃. It can be understood that the melting points of the first adhesive layer 41 and the third adhesive layer 43 are adapted to the pressure relief temperature of the battery 100. When the temperature of the tab adhesive 40 reaches the melting points of the first adhesive layer 41 and the third adhesive layer 43, the second adhesive layer 42 remains unmelted. This facilitates the formation of a support structure between the tab 30 and the first encapsulation edge 21 during heat sealing or pressure relief, reducing the risk of short circuits caused by contact between the tab 30 and the metal materials 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 melt respectively, and at least one of the first adhesive layer 41 and the third adhesive layer 43 separates from the second adhesive layer 42, thereby forming a pressure relief channel 50 in the tab adhesive 40. Furthermore, the second adhesive layer 42 can also limit the amount of adhesive overflow during pressure relief.

[0076] Optionally, during the pressure relief process, the first adhesive layer 41 separates from the second adhesive layer 42, forming a pressure relief channel 50 on the side of the tab adhesive 40 facing the tab 30; or the third adhesive layer 43 separates from the second adhesive layer 42, forming a pressure relief channel 50 on the side of the tab adhesive 40 facing the first encapsulation edge 21; or the first adhesive layer 41 separates from the second adhesive layer 42, forming pressure relief channels 50 on both sides of the tab adhesive 40. The first adhesive layer 41 and the second adhesive layer 42 can increase the probability of the tab adhesive 40 forming a pressure relief channel 50, thereby improving the safety performance of the battery.

[0077] Optionally, T1 and T3 can be any one of the following values ​​within the range of 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 within the range of 110℃≤T1≤130℃.

[0078] Optionally, T2 can be any value within the range of 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 within the range of 140℃≤T2≤170℃.

[0079] In some implementation examples, T1 = T3, which is beneficial for the simultaneous melting of the first adhesive layer 41 and the third adhesive layer 43.

[0080] It is understood that in some embodiments, T1 > T3 or T1 < T3, and simultaneous melting can also occur when the temperature of the tab adhesive 40 reaches the higher melting point of the first adhesive layer 41 and the third adhesive layer 43.

[0081] Furthermore, the relationship between the melting point T1 of the first adhesive layer 41, the melting point T2 of the second adhesive layer 42, and the melting point T3 of the third adhesive layer 43 satisfies: 120℃≤T1≤125℃, 145℃≤T2≤165℃, and 120℃≤T3≤125℃, in order to further limit the melting points of the first adhesive layer 41, the second adhesive layer 42, and the third adhesive layer 43, so that the melting points of the first adhesive layer 41 and the third adhesive layer 43 are adapted to the pressure relief temperature of the battery 100, and so that the second adhesive layer 42 forms a support structure between the tab 30 and the first encapsulation edge 21 during the heat sealing or pressure relief process.

[0082] Furthermore, the relationship between the melting point T1 of the first adhesive layer 41, the melting point T2 of the second adhesive layer 42, and the melting point T3 of the third adhesive layer 43 satisfies: T1 = T3 = 123℃; T2 = 165℃, in order to further limit the melting points of the first adhesive layer 41, the second adhesive layer 42, and the third adhesive layer 43, so that the melting points of the first adhesive layer 41 and the third adhesive layer 43 are adapted to the pressure relief temperature of the battery 100, and so that the second adhesive layer 42 forms a support structure between the tab 30 and the first encapsulation edge 21 during the heat sealing or pressure relief process.

[0083] Please refer to it again. Figure 2 and Figure 3 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 in the arrangement direction of the first adhesive layer 41, the second adhesive layer 42, and the third adhesive layer 43 is 70 μm to 100 μm, so as to limit the encapsulation volume occupied by the tab adhesive 40 and improve the energy density of the battery 100.

[0084] Furthermore, the combined thickness of the first adhesive layer 41, the second adhesive layer 42, and the third adhesive layer 43 is 72 μm to 80 μm, in order to further limit the encapsulation volume occupied by the tab adhesive 40 and improve the energy density of the battery 100.

[0085] Optionally, the sum of the thicknesses of the first adhesive layer 41, the second adhesive layer 42, and the third adhesive layer 43 can be any one of 72μm, 73μm, 74μm, 75μm, 76μm, 77μm, 78μm, 79μm, 80μm, or any other value within the range of 72μm to 80μm.

[0086] Please refer to it again. Figure 4In some embodiments, the thickness ratio of the first adhesive layer 41 and the second adhesive layer 42 is 1:1.2 to 2, so that the second adhesive layer 42 has higher structural strength than the first adhesive layer 41, improves the stability of the second adhesive layer 42 in supporting the tab 30 and the first encapsulation edge 21, reduces the risk of the tab 30 leaking out due to excessive deformation of the tab adhesive 40 and short-circuiting with the metal material in the packaging bag 20, and thus improves the safety performance of the battery.

[0087] It should be noted that during the encapsulation process, the first adhesive layer 41 comes into contact with the tab 30. Under the compression of the tab 30, the thickness of the first adhesive layer 41 at the position corresponding to the tab 30 will decrease. In this application, the thickness of the first adhesive layer 41 is the initial thickness of the first adhesive layer 41 before it is subjected to the compression of the tab 30, i.e. Figure 2 The thickness of the first adhesive layer 41 in the width direction Y of the tab 30 exceeds that of the portion of the tab 30.

[0088] It is understood that in some embodiments, the surface of the first adhesive layer 41 that contacts the electrode 30 under the compression of the electrode 30 will form a rough surface. The rough surface includes a plurality of first concave surfaces and first convex surfaces continuously arranged in the width direction Y of the electrode 30. The rough surface abuts against the first surface 31 or the second surface 32 of the electrode 30 to improve the connection strength between the first adhesive layer 41 and the electrode 30.

[0089] Furthermore, the thickness of the first adhesive layer 41 and the thickness of the third adhesive layer 43 are approximately equal, 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, which makes the second adhesive layer 42 have higher structural strength than the first adhesive layer 41 and the third adhesive layer 43, and makes the second adhesive layer 42 centrally located between the tab 30 and the first encapsulation edge 21, further improving the stability of the second adhesive layer 42 in supporting the tab 30 and the first encapsulation edge 21.

[0090] Optionally, the thickness ratio of the first adhesive layer 41, the second adhesive layer 42, and the third adhesive layer 43 can be one of the following: 1:1.2 to 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, or any other value within the range of 1:1.2 to 2:1.

[0091] 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.

[0092] 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 to 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 in supporting between the tab 30 and the first encapsulation edge 21, and thus improve the safety performance of the battery 100.

[0093] 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.

[0094] 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, in order 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 in supporting between the tab 30 and the first encapsulation edge 21, and thereby improve the safety performance of the battery 100.

[0095] 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.

[0096] It is understood that, in some embodiments, provided 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, can enable the second adhesive layer 42 to have 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 in the tab 30 and the first encapsulation edge 21.

[0097] In the aforementioned battery 100, by limiting the melting points and thicknesses of the first adhesive layer 41, the second adhesive layer 42, and the third adhesive layer 43 in the tab adhesive 40, the tab adhesive 40 maintains a stable structure during pressure relief. Specifically, the melting point of the second adhesive layer 42 is greater than that of the first adhesive layer 41 and the third adhesive layer 43. When the temperature of the tab adhesive 40 reaches the melting points of the first adhesive layer 41 and the third adhesive layer 43, the second adhesive layer 42 remains unmelted, facilitating the formation of a support structure between the tab 30 and the first encapsulation 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, giving the second adhesive layer 42 higher structural strength than the first adhesive layer 41. This improves the stability of the second adhesive layer 42 in supporting the tab 30 and the first encapsulation edge 21, reducing the risk of excessive deformation of the tab adhesive 40 leading to leakage of the tab 30 and short circuit due to contact with metal materials in the packaging bag 20, thereby improving the safety performance of the battery 100.

[0098] In some embodiments, the encapsulation strength of the tab adhesive 40 at room temperature is 2.3 N / mm to 4.2 N / mm; the encapsulation strength of the tab adhesive 40 at 100°C is 0.8 N / mm to 1.5 N / mm; the encapsulation strength of the tab adhesive 40 at 120°C is 0.6 N / mm to 1.2 N / mm; and the encapsulation strength of the tab adhesive 40 at 130°C is 0.2 N / mm to 0.5 N / mm. The tab adhesive 40 is partially located inside the packaging bag 20, and the temperature inside the packaging bag 20 is the temperature at which the tab adhesive 40 is located. Compared to the sealing strength of conventional tab adhesives, the above configuration allows the encapsulation strength of the tab adhesive 40 to vary more significantly with temperature. When the tab adhesive 40 is at room temperature (25°C), the tab adhesive 40 maintains high encapsulation strength, improving the sealing stability between the tab 30 and the first encapsulation edge 21. When the temperature of the tab adhesive 40 reaches the melting point of the first adhesive layer 41 and the third adhesive layer 43, the encapsulation strength of the tab adhesive 40 decreases, making it easier for at least one of the first adhesive layer 41 and the third adhesive layer 43 to separate from the second adhesive layer 42, thus forming a pressure relief channel in the tab adhesive 40.

[0099] Please refer to the following: Figure 5 and Figure 6 It should be noted that the encapsulation strength of this application was obtained through the following test method:

[0100] Step 1: Make a sample;

[0101] Specifically, in the width direction Y of the tab 30, two cutting starting points 61 are defined at the portions of the first encapsulation edge 21 located on both sides of the tab adhesive 40. The tab 30 includes a first segment 33 extending into the packaging bag 20 from the tab adhesive 40, and a second segment 34 extending out of the packaging bag 20 from the tab adhesive 40. The packaging bag 20 is cut from each cutting starting point 61 along the extension direction X of the tab 30 until the cutting endpoint 62 extends beyond the end of the first segment 33 away from the first segment 33, forming a cut portion 63 by cutting the two cutting endpoints 62. The cut portion 63 includes the tab 30, the tab adhesive 40 covering the tab 30, and a portion of the packaging bag 20 connected to both sides of the tab adhesive 40 in the thickness direction Z of the tab 30.

[0102] The packaging bag 20 in the cut section 63 includes a sealing portion 631 that connects to the tab adhesive 40 and an extension portion 632 extending from the sealing portion 631 toward the first segment 33. The extension portion 632 is folded over to cover the sealing portion 631 and the second segment 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 the portion of the two extension portions 632 that extends beyond the second segment 34 after being folded over, and the second clamping end 65 is the first segment 33 exposed after the two extension portions 632 are folded over.

[0103] Step two, tensile test.

[0104] Specifically, a tensile testing machine with a temperature chamber is selected. The tensile testing machine has two opposing clamps inside the temperature chamber. The sample is placed in the temperature chamber, with one clamp holding the first clamping end 64 and the other clamp holding the second clamping end 65. After the temperature chamber is heated to the specified temperature and held for 5 minutes, the two clamps are moved relative to each other at a speed of 175±5mm / min to perform a tensile test. The maximum value when the tab adhesive 40 is separated from the tab 30 or the packaging bag 20 is recorded.

[0105] Optionally, the encapsulation strength of the tab adhesive 40 at room temperature can be any one of the following values: 2.3 N / mm, 2.5 N / mm, 2.6 N / mm, 2.9 N / mm, 3.0 N / mm, 3.3 N / mm, 3.6 N / mm, 3.8 N / mm, 4.0 N / mm, 4.2 N / mm, and any other value within the range of 2.3 N / mm to 4.2 N / mm.

[0106] Optionally, the encapsulation strength of the tab adhesive 40 at 100°C can be one of 0.8 N / mm, 0.9 N / mm, 1.0 N / mm, 1.1 N / mm, 1.2 N / mm, 1.3 N / mm, 1.4 N / mm, 1.5 N / mm, and any other value in the range of 0.8 N / mm to 1.5 N / mm.

[0107] Optionally, the encapsulation strength of the tab adhesive 40 at 120°C can be one of 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 in the range of 0.6 N / mm to 1.2 N / mm.

[0108] Optionally, the encapsulation strength of the tab adhesive 40 at 130°C can be one of 0.2 N / mm, 0.3 N / mm, 0.4 N / mm, 0.5 N / mm, or any other value in the range of 0.2 N / mm to 0.5 N / mm.

[0109] In the aforementioned battery 100, the relationship between the melting point and the encapsulation strength of the tab adhesive 40 is balanced by limiting the melting point of the first adhesive layer 41, the melting points of the second adhesive layer 42 and the third adhesive layer 43, and the encapsulation strength of the tab adhesive 40 at various temperatures. When the temperature of the tab adhesive 40 reaches the melting point of the first adhesive layer 41 and the third adhesive layer 43, the second adhesive layer 42 does not melt, which facilitates the formation of a support structure between the tab 30 and the first encapsulation edge 21 during heat sealing or pressure relief. Furthermore, the encapsulation strength of the tab adhesive 40 decreases, which facilitates the separation of at least one of the first adhesive layer 41 and the third adhesive layer 43 from the second adhesive layer 42, thereby forming a pressure relief channel 50 in the tab adhesive 40.

[0110] Please refer to it again. Figure 1 Viewed along the thickness direction Z of the tab 30, the tab adhesive 40 includes a top 44, a bottom 45, a first side 46, and a second side 47. The top 44 and the bottom 45 are positioned opposite each other in the extension direction X of the tab 30. The top 44 is located outside the packaging bag 20, and the bottom 45 is located inside the packaging bag 20. The first side 46 and the second side 47 connect the top 44 and the bottom 45 and are positioned opposite each other on both sides of the tab 30 along the width direction Y of the tab 30.

[0111] Along the extension direction X of the tab 30, the width of the first encapsulation edge 21 is 1.2mm to 2.0mm, the top 44 protrudes from the first encapsulation edge 21 by 0.2mm to 2mm, and the bottom 45 protrudes from the first encapsulation edge by more than 1.2mm, so as to reduce the risk of short circuit between the exposed tab 30 and the metal material in the packaging bag 20, thereby improving the safety performance of the battery 100.

[0112] Optionally, the width of the first encapsulation edge 21 can be one of 1.2mm, 1.3mm, 1.4mm, 1.5mm, 1.6mm, 1.7mm, 1.8mm, 1.9mm, 2.0mm, or any other value within the range of 1.2mm to 2.0mm.

[0113] Optionally, the length of the top 44 protruding from the first encapsulation edge 21 can be one of 0.2mm, 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.8mm, 1mm, 1.2mm, 1.4mm, 1.6mm, 1.8mm, 2mm, or any other value within the range of 0.2 to 2mm.

[0114] Optionally, the length of the bottom 45 protruding from the first package edge can be one of 1.3mm, 1.4mm, 1.6mm, 1.8mm, 2mm, or any other value within the range greater than 1.2mm.

[0115] Along the width direction Y of the tab 30, the distance between the first side portion 46 and the second side portion 47 is 8mm to 9mm to increase the extension length of the bottom 45 within the packaging bag 20, thereby increasing the low melting point position of the tab 30. When the temperature inside 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 tab adhesive 40 to form a pressure relief channel 50.

[0116] Optionally, the distance between the first side portion 46 and the second side portion 47 can be one of 8mm, 8.1mm, 8.2mm, 8.3mm, 8.4mm, 8.5mm, 8.6mm, 8.7mm, 8.8mm, 8.9mm, 9mm, or any other value within the range of 8mm to 9mm.

[0117] Along the extension direction X of the tab 30, the distance between the top 44 and the bottom 45 is 2.5mm to 5mm, so that the tab adhesive 40 can extend from inside the packaging bag 20 through the first sealing edge 21 to the outside of the packaging bag 20, thereby improving the sealing effect of the tab adhesive 40.

[0118] Optionally, the spacing between the top 44 and the bottom 45 can be one of 2.5mm, 3mm, 3.5mm, 4mm, 4.5mm, 5mm, or any other value within the range of 2.5mm to 5mm.

[0119] Along the width direction Y of the tab 30, the distance between the side of the tab 30 facing the first side 46 and the first side 46 is 0.5mm to 2.5mm, and the distance between the side of the tab 30 facing the second side 47 and the second side 47 is 0.5mm to 2.5mm, so that the tab adhesive 40 protrudes from both sides of the tab 30 in the width direction Y of the tab 30, thereby improving the sealing effect of the tab adhesive 40.

[0120] Optionally, the distance between the side of the tab 30 facing the first side portion 46 and the first side portion 46 can be any one of the following values: 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 within the range of 0.5mm to 2.5mm.

[0121] Optionally, the distance between the side of the tab 30 facing the second side 47 and the second side 47 can be any one of 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 within the range of 0.5mm to 2.5mm.

[0122] In some embodiments, along the width direction Y of the tab 30, the tab 30 is centrally disposed between the first side portion 46 and the second side portion 47, that is, the distance between the side of the tab 30 facing the first side portion 46 and the first side portion 46 is equal to the distance between the side of the tab 30 facing the second side portion 47 and the second side portion 47, so that the force on both sides of the tab 30 is uniform.

[0123] Please see Figure 7 Embodiments of this application also provide an electrical device 200, including the battery 100 in any of the above embodiments. The electrical device 200 further includes a device body, to which the battery 100 is electrically connected and supplies power. In some embodiments, the device body may be an electronic device such as a mobile phone or tablet computer, or a transportation device such as an electric vehicle.

[0124] This application will be described below through specific implementation methods:

[0125] Pressure relief testing includes two methods: hot chamber testing and 100°C storage testing.

[0126] The hot box test includes the following four steps:

[0127] Charge the battery until it reaches 100% of its remaining capacity;

[0128] Attach the temperature sensing wire to the center of the battery surface;

[0129] Place the battery flat in the box and heat it to 130±2℃ at a rate of 5±2℃ and maintain the temperature for 60 minutes.

[0130] Turn off the cabinet heating and wait for the battery to cool to room temperature before removing it. The standard for determining that the battery meets safety requirements is that the battery does not catch fire or explode.

[0131] Hot box storage testing includes the following three steps:

[0132] Charge the battery until it reaches 100% of its remaining capacity;

[0133] Store the battery in a box at 100±2℃ for 5 hours;

[0134] Open the box, remove the battery, and determine if the battery meets the safety standard by ensuring that the battery does not break any seal edges and does not catch fire or explode.

[0135] The batteries of each comparative example and each embodiment were placed in a temperature chamber. After the temperature chamber was heated to the specified temperature, the pressure relief of the batteries was observed.

[0136] The batteries in each comparative example and embodiment have most of the same parameters and can use some chemical systems and cell structures commonly used in the art. The parameters in each embodiment and comparative example in the following tables are the same except for the parameters involved.

[0137] Table 1 shows the remaining parameters and test results of each battery in Comparative Examples 1-2 and Examples 1-5.

[0138]

[0139]

[0140] As shown in Table 1, in Comparative Example 1, the melting points of the first adhesive layer 41 and the third adhesive layer 43 are less than 110°C, which is not conducive to the high-temperature storage of battery 100. In Comparative Example 2, the melting points of the first adhesive layer 41 and the third adhesive layer 43 are greater than 130°C, which is not conducive to the timely pressure relief of battery 100. In Examples 1-5, the melting points of the first adhesive layer 41 and the third adhesive layer 43 are all between 110°C and 130°C, which can meet the requirements of high-temperature storage and timely pressure relief.

[0141] Table 2 shows the remaining parameters and test results for each battery in Comparative Examples 3-4 and Examples 6-10.

[0142]

[0143]

[0144] As shown in 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 the high-temperature storage of battery 100. In Comparative Example 4, the melting point of the second adhesive layer 42 is greater than 170°C, which meets the requirements for pressure relief testing, but the selection of the tab adhesive 40 material is more stringent, and the preparation is more difficult. In Examples 6-10, the melting point of the second adhesive layer 42 is between 140°C and 170°C, which meets both the requirements for high-temperature storage and allows for timely pressure relief.

[0145] Table 3 shows the remaining parameters and test results for each battery in Comparative Examples 5-6 and Examples 11-14.

[0146]

[0147] As shown in Table 3, the encapsulation strength of the tab adhesive 40 in Comparative Example 5 is relatively low. Although it meets the requirements of the pressure relief test, its encapsulation strength at room temperature is low, which is not conducive to the use of battery 100. The encapsulation strength of the tab adhesive 40 in Comparative Example 6 is relatively high, which is not conducive to the timely pressure relief of battery 100. The encapsulation strength of the tab adhesive 40 in Examples 11-14 meets the above range, which can meet both the requirements of high-temperature storage and timely pressure relief.

[0148] Table 4 shows the remaining parameters and test results of each battery in Comparative Examples 7-8 and Examples 15-18.

[0149]

[0150] As shown in Table 4, 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 thickness of the first adhesive layer 41 and the third adhesive layer 43 is thin, which will affect the hot box test pass rate.

[0151] In summary, in the battery 100 and the electrical device 200 described above, by limiting the melting points and thicknesses of the first adhesive layer 41, the second adhesive layer 42, and the third adhesive layer 43 in the tab adhesive 40, the tab adhesive 40 maintains a stable structure during pressure relief. Specifically, the melting point of the second adhesive layer 42 is greater than that of the first adhesive layer 41 and the third adhesive layer 43. When the temperature of the tab adhesive 40 reaches the melting points of the first adhesive layer 41 and the third adhesive layer 43, the second adhesive layer 42 remains unmelted, which facilitates the formation of a support structure between the tab 30 and the first encapsulation edge 21 by the second adhesive layer 42 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, giving the second adhesive layer 42 higher structural strength than the first adhesive layer 41. This improves the stability of the second adhesive layer 42 in supporting the tab 30 and the first encapsulation edge 21, reduces the risk of the tab 30 leaking out due to excessive deformation and short circuit with the metal material in the packaging bag 20, and thus improves the safety performance of the battery 100.

[0152] In addition, those skilled in the art may make other changes within the spirit of this application. Of course, all such changes made in accordance with the spirit of this application should be included within the scope disclosed in this application.

Claims

1. A battery comprising an electrode assembly, a packaging bag, and tabs, wherein the electrode assembly is housed in the packaging bag, characterized in that, The packaging bag includes a first sealing edge, and the electrode tab is connected to the electrode assembly and extends from the first sealing edge. The battery further includes tab adhesive disposed between the first encapsulation edge and the tab. The tab adhesive includes a first adhesive layer, a second adhesive layer, and a third adhesive layer sequentially connected from the tab towards the first encapsulation edge. 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 are related by the following conditions: T1 < T2, T3 < T2, where 110℃ ≤ T1 ≤ 130℃, 140℃ ≤ T2 ≤ 170℃, and 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 70um to 100um, and the thickness ratio of the first adhesive layer and the second adhesive layer satisfies: 1:1.2 to 2; Viewed along the thickness direction of the tab, the tab adhesive includes a top, a bottom, a first side and a second side. 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 first side and the second side are connected between the top and the bottom and are arranged on both sides of the tab along the width direction of the tab. Along the extension direction of the tab, the width of the first encapsulation edge is 1.2 mm to 2.0 mm, the distance between the side of the tab facing the first side and the first side is 0.5 mm to 2.5 mm, and the distance between the side of the tab facing the second side and the second side is 0.5 mm to 2.5 mm.

2. The battery as described in claim 1, characterized in that, The T1 and T3 are approximately equal.

3. The battery as described in 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 μm to 80 μm.

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

1.

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

1.

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

7. The battery as claimed in claim 1, characterized in that, The encapsulation strength of the tab adhesive at 100°C is 0.8 N / mm to 1.5 N / mm; the encapsulation strength of the tab adhesive at 120°C is 0.6 N / mm to 1.2 N / mm; and the encapsulation strength of the tab adhesive at 130°C is 0.2 N / mm to 0.5 N / mm.

8. The battery as claimed in claim 7, characterized in that, The encapsulation strength of the tab adhesive at room temperature is 2.3 N / mm to 4.25 N / mm.

9. The battery as claimed in claim 1, characterized in that, Along the width direction of the tab, the distance between the first side and the second side is 8mm to 9mm.

10. The battery as claimed in claim 1, characterized in that, 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 greater than 1.2mm.

11. The battery as claimed in claim 1, characterized in that, Along the extension direction of the tab, the distance between the top and the bottom is 2.5 mm to 5 mm.

12. The battery as claimed in claim 1, characterized in that, The tab includes a first surface and a second surface disposed opposite to each other in the thickness direction. The tab adhesive includes a first part and a second part. The first part is connected between the first surface and the first encapsulation edge, and the second part is connected between the second surface and the first encapsulation edge. 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.

13. An electrical appliance, characterized in that, The electrical device includes a battery as described in any one of claims 1 to 12.

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