Insulating member, tab assembly, battery cell, battery, and electrical device

Abstract

The present application discloses an insulating member, a tab assembly, a battery cell, a battery, and an electrical device. The insulating member comprises a first insulating member and a second insulating member; the first insulating member and the second insulating member are configured to be connected to the two sides of a tab in the thickness direction; the first insulating member comprises a first substrate layer, and the melting point of the first substrate layer is higher than the melting point of the second insulating member. The first insulating member and the second insulating member are arranged on the two sides of the tab, and the melting point of the first substrate layer is higher than the melting point of the second insulating member, so that when the temperature rise of the tab intensifies, the risk of a short circuit caused by the melting of the first substrate layer leading to exposure of the tab on the side where the first substrate layer is located, thermal damage to a separator of the battery cell and contact of the tab with an adjacent electrode sheet, can be reduced; additionally, the risk of a short circuit occurring between adjacent first and second electrode sheets can also be reduced.

Description

Insulation parts, tab components, battery cells, batteries and electrical equipment Technical Field

[0001] The present application relates to the field of energy storage technology, and in particular to an insulating member, a tab assembly, a battery cell, a battery, and an electrical device. Background Art

[0002] With the continuous updating and development of lithium-ion battery technology, the application fields of lithium-ion batteries are also expanding. The resulting battery cell safety issues are receiving more and more public attention. Lithium-ion battery safety accidents characterized by battery thermal runaway caused by external short circuits occur frequently, which brings certain resistance to the development of lithium-ion batteries. How to solve the battery cell safety issue is a difficult problem that the current lithium-ion battery industry cannot avoid. Summary of the Invention

[0003] In view of this, it is necessary to provide an insulating part, a tab assembly, a battery cell, a battery and an electrical device to reduce the risk of short circuit.

[0004] An embodiment of the present application provides an insulating member, comprising a first insulating member and a second insulating member, the first insulating member and the second insulating member being configured to connect both sides of a tab in a thickness direction, the first insulating member comprising a first base layer, the melting point of the first base layer being higher than the melting point of the second insulating member. By arranging the first insulating member and the second insulating member on both sides of the tab, the melting point of the first base layer being higher than the melting point of the second insulating member, so that when the tab temperature rises, the risk of the first base layer melting, which would expose the tab on the side where the first base layer is located and burn the isolation membrane of the battery cell, and contact with the adjacent pole piece and cause a short circuit, can be reduced. At the same time, the risk of a short circuit between adjacent first and second pole pieces can also be reduced. The second insulating member may have at least one melting point. The melting point of the first base layer being higher than the melting point of the second insulating member means that the melting point of the first base layer is higher than all melting points of the second insulating member during the melting point test.

[0005] In one or more of the above optional embodiments, the melting point A of the first substrate layer satisfies A greater than 160°C. The high melting point can reduce the exposure of the tabs due to melting of the insulating parts, which is beneficial to reducing the risk of the tabs contacting the battery cell and causing burns to the isolation membrane, and the risk of short circuiting due to contact with the pole piece, as well as reducing the risk of short circuiting between the adjacent first pole piece and the second pole piece.

[0006] In one or more optional embodiments above, 180℃≤A≤500℃ is further beneficial to reducing the risk of exposure of the tab, which may cause the isolation membrane to contact the pole piece and cause a short circuit, and reducing the risk of a short circuit between the adjacent first pole piece and the second pole piece.

[0007] In one or more of the above optional embodiments, the thickness of the first base layer is 6% to 25% of the thickness of the first insulating member, which is beneficial to reducing the appearance of pore channels in the sealing portion of the battery cell and reducing the risk of leakage and short circuit. If the thickness of the first base layer is too thick, pore channels may easily appear in the packaging triangle area of ​​the sealing portion (the edge area of ​​the insulating member). If the thickness of the first base layer is too thin, it may easily melt, resulting in the exposure of the tab, and thus a short circuit.

[0008] In one or more of the above optional embodiments, the melting point D of the second substrate layer satisfies D less than or equal to 160°C, which facilitates the insulating adhesive to form a pressure relief channel when the battery cell is at high temperature, thereby relieving pressure inside the battery cell housing and improving safety. The melting point of the second substrate layer is the maximum melting point of the second insulating member.

[0009] In one or more optional embodiments above, 105° C. ≤ D ≤ 145° C. is conducive to forming a pressure relief channel and improving the connection strength between the second base layer and the third packaging layer and the connection strength between the second base layer and the fourth packaging layer.

[0010] In one or more optional embodiments above, the material of the first substrate layer includes one or more of polyimide, polyamideimide, polyethyleneimine, polyethylene naphthalate, polyethylene terephthalate or modified polypropylene.

[0011] In one or more optional embodiments above, the thickness of the second base layer is 30% to 40% of the thickness of the second insulating member, which is beneficial to improving the connection strength between the second base layer and the third packaging layer and the fourth packaging layer and reducing the occupied space.

[0012] In one or more optional embodiments above, the first insulating member includes a first packaging layer and a second packaging layer, the first packaging layer and the second packaging layer are located on both sides of the first base layer, the first packaging layer is used to connect the sealing part of the battery cell, and the second packaging layer is used to connect the electrode ear.

[0013] In one or more optional embodiments above, the melting point of the first packaging layer is lower than that of the first substrate layer. When the internal temperature of the battery cell rises, the first packaging layer may melt first and form a pressure relief channel, which is conducive to pressure relief.

[0014] In one or more optional embodiments above, the melting point of the second packaging layer is lower than that of the first base layer. When the internal temperature of the battery cell rises, the second packaging layer may melt first and form a pressure relief channel, which is conducive to pressure relief and thereby reduces the risk of battery cell fire.

[0015] In one or more optional embodiments above, the melting point B of the first packaging layer satisfies 120°C ≤ B < 160°C. When the temperature inside the battery cell rises, a thermochemical reaction occurs, causing inflation and deformation. The low-melting-point first packaging layer melts to form a pressure relief channel, which is beneficial for relieving pressure inside the battery cell shell, improving safety, and reducing the occurrence of premature failure of the battery cell.

[0016] In one or more optional embodiments above, the melting point C of the second packaging layer satisfies 120°C≤C<160°C. When the temperature inside the battery cell rises, a thermochemical reaction occurs, causing inflation and deformation, and the low-melting-point packaging layer melts to form a pressure relief channel, which is beneficial for relieving pressure inside the battery cell shell, improving safety, and reducing the occurrence of premature failure of the battery cell.

[0017] In one or more of the above optional embodiments, the thickness of the first packaging layer is 30% to 44% of the thickness of the first insulating member, which is beneficial to improving the connection strength between the first packaging layer and the adhesive layer, facilitating pressure relief and reducing occupied space.

[0018] In one or more optional embodiments above, the thickness of the second packaging layer is 30% to 44% of the thickness of the first insulating member, which is beneficial to improving the connection strength between the second packaging layer and the tab, facilitating pressure relief and reducing occupied space.

[0019] In one or more optional embodiments above, the first insulating member includes a first connection layer and a second connection layer, the first encapsulation layer is connected to the first base layer through the first connection layer, and the second encapsulation layer is connected to the first base layer through the second connection layer.

[0020] In one or more of the above optional embodiments, the thickness of the first connection layer is 3% to 8% of the thickness of the first insulating member, which can improve the connection strength between the first base layer and the first packaging layer and reduce the occupied space.

[0021] In one or more optional embodiments above, the thickness of the second connection layer is 3% to 8% of the thickness of the first insulating member, which can improve the connection strength between the first base layer and the second packaging layer and reduce the occupied space.

[0022] In one or more optional embodiments above, the second insulating member includes a third packaging layer and a fourth packaging layer. Along the thickness direction of the second base layer, the third packaging layer and the fourth packaging layer connect the two sides of the second base layer. The fourth packaging layer is used to connect the tabs, and the third packaging layer is used to connect the sealing part of the battery cell.

[0023] In one or more optional embodiments above, the melting point E of the third packaging layer satisfies 120°C ≤ E < 145°C. When the temperature inside the battery cell rises, a thermochemical reaction occurs, causing inflation and deformation, and the low-melting-point packaging layer melts to form a pressure relief channel, which is beneficial for relieving pressure inside the battery cell shell and improving safety.

[0024] In one or more of the above optional embodiments, the thickness of the third packaging layer is 30% to 40% of the thickness of the second insulating member, which is beneficial to improving the fusion effect of the third packaging layer and the adhesive layer. A sufficient fusion packaging layer can improve the connection strength and ensure the packaging reliability of the battery during long-term use.

[0025] In one or more optional embodiments above, the melting point F of the fourth packaging layer satisfies 120°C ≤ F < 145°C. When the temperature inside the battery cell rises, a thermochemical reaction occurs, causing inflation and deformation, and the low-melting-point packaging layer melts to form a pressure relief channel, which is beneficial for relieving pressure inside the battery cell shell, reducing the risk of fire, and improving safety.

[0026] In one or more optional embodiments above, the thickness of the fourth packaging layer is 30% to 40% of the thickness of the second insulating member, which is beneficial to improving the connection strength between the fourth packaging layer and the tab. When the temperature inside the battery cell rises, a thermochemical reaction occurs, causing inflation and deformation, and the fourth packaging layer with a low melting point melts and opens, which is beneficial to pressure relief and reduces occupied space.

[0027] In one or more optional embodiments above, the difference α between the melting point of the first base layer 41 and the maximum melting point of the second insulating member 50 is greater than or equal to 41° C., thereby reducing the risk of short circuit.

[0028] In one or more optional embodiments above, α≥117° C., further reducing the risk of short circuit.

[0029] In one or more optional embodiments above, α≥147° C., further reducing the risk of short circuit.

[0030] In one or more optional embodiments above, α≥227°C, further reducing the short circuit risk. On the basis that the melting point of the first substrate layer is greater than 160°C, the greater the difference in α, the higher the external short circuit test pass rate of the battery cell.

[0031] An embodiment of the present application provides a tab assembly, comprising a first insulating member and a second insulating member, wherein the first insulating member and the second insulating member are configured to connect two sides of the tab, and the first insulating member comprises a first base layer, and the melting point of the first base layer is higher than the melting point of the second insulating member.

[0032] An embodiment of the present application provides a battery cell, comprising a battery cell housing, an electrode assembly, a tab, a first insulating member, and a second insulating member. The battery cell housing comprises a main body and a sealing member. The electrode assembly is disposed within the main body. The tab is connected to the electrode assembly and extends from the sealing member. Along the thickness direction of the tab, the first insulating member and the second insulating member are connected to both sides of the tab. Inside the battery cell housing, the first insulating member faces the electrode assembly. The first insulating member is connected to the sealing member, and the second insulating member faces the battery cell housing. The second insulating member is connected to the sealing member. The first insulating member comprises a first base layer, the melting point of the first base layer being higher than the melting point of the second insulating member. By arranging the first insulating member and the second insulating member on both sides of the tab, the melting point of the first base layer is higher than the melting point of the second insulating member, so that when the tab temperature rises more sharply, the risk of the first base layer melting, which causes the tab on the side where the first base layer is located to be exposed and burn the isolation membrane, and to contact with the adjacent pole piece and cause a short circuit, can be reduced. At the same time, the risk of a short circuit between the adjacent first pole piece and the second pole piece can also be reduced. The second insulating member may have at least one melting point, and the melting point of the first substrate layer being higher than the melting point of the second insulating member means that the melting point of the first substrate layer is higher than all melting points of the second insulating member appearing during a melting point test.

[0033] In one or more of the above optional embodiments, the sealing portion includes two adhesive layers along the thickness direction of the battery cell housing. Along the thickness direction of the battery cell housing, the sealing portion includes a first region that does not overlap with the first insulating member and the second insulating member. The two adhesive layers in the first region are bonded together, and the thickness of the first base layer is less than the sum of the thicknesses of the two adhesive layers after hot pressing. This reduces or avoids the formation of pores and channels in the sealing portion, thereby reducing the risk of leakage and short circuits.

[0034] In one or more of the above optional embodiments, the electrode assembly includes a first electrode piece, a second electrode piece, and a separator, wherein the separator is disposed between the first electrode piece and the second electrode piece. The electrode tab includes a first segment, a second segment, and a third segment. At least a portion of the first segment is connected to the first electrode piece or the second electrode piece. The second segment is bent and connected to the first segment, and a first insulating member is provided on a side of the second segment facing the electrode assembly. The third segment is bent and connected to the second segment, and a portion of the third segment extends beyond the sealing portion.

[0035] In one or more of the above optional embodiments, the battery cell includes at least three tabs, wherein the polarity of two tabs is opposite to the polarity of another tab. When the battery cell includes multiple tabs, the tabs do not overlap in the thickness direction of the battery cell, and some tabs are bent and then extend from the sealing portion.

[0036] An embodiment of the present application provides a battery, comprising the battery cell in any one of the above embodiments.

[0037] An embodiment of the present application provides an electrical device, comprising the battery in any one of the above embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] FIG1 is a schematic structural diagram of a battery cell in some embodiments.

[0039] FIG2 shows an exploded schematic diagram of a battery cell in some embodiments.

[0040] FIG3 shows a schematic cross-sectional view of a battery cell in some embodiments.

[0041] FIG4 is a schematic cross-sectional view of a battery cell casing in some embodiments.

[0042] FIG5 is a schematic structural diagram of a tab, a first insulating member, and a second insulating member in some embodiments.

[0043] FIG6 shows a schematic structural diagram of batteries and electrical devices in other embodiments.

[0044] Description of the main component symbols: Battery cell 100 First region 101 Second region 102 Battery cell housing 10 Adhesive layer 10a Metal layer 10b Outer layer 10c Main body 11 First housing 111 First recess 111a Second housing 112 Second recess 112a First extended edge 113 Second extended edge 114 Sealing portion 12 First sealing portion 12a Second sealing portion 12b Electrode assembly 20 First pole piece 21 Second pole piece 22 Separator 23 Tab 30 First segment 31 Second segment32 Third section 33 First protective layer 100a First insulating member 40 First base layer 41 First encapsulation layer 42 First connection layer 43 Second encapsulation layer 44 Second connection layer 45 Second insulating member 50 Second base layer 51 Third encapsulation layer 52 Fourth encapsulation layer 53 Insulating member 110 Tab assembly 120 Battery 200 Electrical device 300

[0045] The following specific embodiments will further illustrate the present application in conjunction with the above-mentioned drawings. DETAILED DESCRIPTION

[0046] The following detailed description is illustrative and non-limiting. It is intended to provide a basic understanding of the present application and is not intended to identify the key or decisive elements of the present application or to limit the scope of protection. As long as there is no structural conflict, the various technical features mentioned in the various embodiments can be combined in any manner.

[0047] When a component is referred to as being “disposed on” another component, it can be directly disposed on the other component or there may be a component intervening therebetween. When a component is referred to as being “connected to” another component, it can be directly connected to the other component or there may be a component intervening therebetween.

[0048] Unless otherwise defined, the term "plurality" herein, when used to describe the number of components, specifically means that the components are two or more.

[0049] An embodiment of the present application provides a battery cell, comprising a battery cell housing, an electrode assembly, a tab, a first insulating member, and a second insulating member. The battery cell housing comprises a main body and a sealing member. The electrode assembly is disposed within the main body. The tab is connected to the electrode assembly and extends from the sealing member. Along the thickness direction of the tab, the first insulating member and the second insulating member are connected to both sides of the tab. Within the battery cell housing, the first insulating member faces the electrode assembly. The first insulating member is connected to the sealing member, and the second insulating member faces the battery cell housing. The second insulating member is connected to the sealing member. The first insulating member comprises a first base layer, the melting point of the first base layer being higher than the melting point of the second insulating member. By arranging the first insulating member and the second insulating member on both sides of the tab, the melting point of the first base layer is higher than the melting point of the second insulating member, so that when the tab temperature rises, the risk of the first base layer melting, which causes the tab on the side where the first base layer is located to be exposed and burn the isolation membrane, and to contact the pole piece and cause a short circuit, can be reduced. At the same time, the risk of a short circuit between adjacent first and second pole pieces can also be reduced.

[0050] The following will describe some embodiments of the present application in conjunction with the accompanying drawings. In the absence of conflict, the following embodiments and features in the embodiments may be combined with each other.

[0051] 1 to 4 , an embodiment of the present application provides a battery cell 100 including a battery cell housing 10 , an electrode assembly 20 , and a tab 30 . The electrode assembly 20 is disposed within the battery cell housing 10 , and the tab 30 is connected to the electrode assembly 20 and extends from the battery cell housing 10 .

[0052] In some embodiments, the battery cell shell 10 may be a packaging bag encapsulated by a packaging film (such as an aluminum-plastic film), that is, the battery cell 100 is a soft-pack battery cell.

[0053] In some embodiments, the cell casing 10 includes a stacked adhesive layer 10a, a metal layer 10b, and an outer layer 10c. The metal layer 10b is disposed between the adhesive layer 10a and the outer layer 10c, and the outer layer 10c is located at the outermost layer of the cell casing 10. The outer layer 10c can be a nylon layer or a composite layer of polyester resin (PET) and nylon, and provides protection against pollution, corrosion, and damage from external forces. The metal layer 10b can include one of aluminum and steel, and provides waterproofing, a barrier function, and helps shape the cell casing 10. The adhesive layer 10a is a heat-sealing layer and can include a polymer, including one of polypropylene and polyethylene. The adhesive layer 10a is used to seal the cell casing 10 by hot pressing and to separate the metal layer 10b from the electrode assembly 20, thereby reducing the risk of electrolyte leakage from the cell casing 10 and corrosion of the metal layer 10b.

[0054] In some embodiments, the cell housing 10 includes a main body 11 and a sealing portion 12 , wherein the main body 11 is connected to the sealing portion 12 . The electrode assembly 20 is disposed on the main body 11 , and the tab 30 extends from the sealing portion 12 out of the cell housing 10 .

[0055] In some embodiments, the main body 11 includes a first shell 111 and a second shell 112. The first shell 111 is provided with a first recess 111a, and the second shell 112 is provided with a second recess 112a. The first shell 111 is connected to the second shell 112 to form a storage space. Part of the electrode assembly 20 is provided in the first recess 111a, and part is provided in the second recess 112a. The circumferential side of the first shell 111 extends outward to form a first extended edge 113, and the circumferential side of the second shell 112 extends outward to form a second extended edge 114. After the first shell 111 is connected to the second shell 112, the first extended edge 113 and the second extended edge 114 overlap and are sealed and connected to form a sealing portion 12.

[0056] In some embodiments, the first shell 111 and the second shell 112 may be an integral structure or a separate structure.

[0057] In some embodiments, the sealing portion 12 includes a first sealing portion 12 a , and the tab 30 extends out of the cell casing 10 from the first sealing portion 12 a .

[0058] In some embodiments, the sealing portion 12 includes a second sealing portion 12b connected to the first sealing portion 12a.

[0059] In some embodiments, the electrode assembly 20 includes a first electrode piece 21, a second electrode piece 22, and a separator 23, wherein the separator 23 is disposed between the first electrode piece 21 and the second electrode piece 22. The separator 23 is used to prevent the first electrode piece 21 and the second electrode piece 22 from directly contacting each other, thereby reducing the risk of a short circuit between the first electrode piece 21 and the second electrode piece 22.

[0060] In some embodiments, the electrode assembly 20 is a wound structure, that is, the first electrode piece 21, the separator 23, and the second electrode piece 22 are stacked in sequence and then wound to form the electrode assembly 20. In other embodiments, the electrode assembly 20 can also be a laminated structure, that is, the first electrode piece 21, the separator 23, and the second electrode piece 22 are stacked in sequence to form an electrode assembly unit, and multiple electrode assembly units are stacked to form the electrode assembly 20. In some embodiments, the first electrode piece 21 is a negative electrode piece or a positive electrode piece, and the second electrode piece 22 is a electrode piece with opposite polarity to the first electrode piece 21. This application is described as an example of the first electrode piece 21 being a positive electrode piece and the second electrode piece 22 being a negative electrode piece.

[0061] In some embodiments, the tab 30 includes a first section 31, a second section 32, and a third section 33. At least a portion of the first section 31 is connected to the first electrode piece 21 or the second electrode piece 22. The second section 32 is bent and connected to the first section 31. A first insulating member 40 is provided on the side of the second section 32 facing the electrode assembly 20. The third section 33 is bent and connected to the second section 32. A portion of the third section 33 extends beyond the sealing portion 12. A portion of the third section 33 extends beyond the first insulating member 40 and the second insulating member 50 for connection to other components for energy transmission.

[0062] In some embodiments, the first section 31 is welded to the first pole piece 21 or the second pole piece 22. Welding methods include laser welding, ultrasonic welding, and the like.

[0063] In some embodiments, along the thickness direction of the battery cell 100, the length of the second segment 32 is 5%-70% of the thickness of the battery cell 100, which helps to reduce the head space of the battery cell 100 occupied by the tab 30. Optionally, the length of the second segment 32 is any one of 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, and 70% of the thickness of the battery cell 100.

[0064] In some embodiments, the battery cell 100 includes a first protective layer 100 a , which covers the overlapping portion of the first section 31 and the first electrode 21 , thereby reducing the risk of burrs piercing the isolation membrane 23 and causing a short circuit between the first electrode 21 and the second electrode 22 .

[0065] In some embodiments, along the thickness direction of the first segment 31 , the first insulating member 40 connects one side of the first segment 31 , and the second insulating member 50 connects the other side of the first segment 31 .

[0066] In some embodiments, the battery cell 100 includes at least three tabs 30. When there are three tabs 30, the polarity of two of the tabs 30 is opposite to the polarity of the other tab 30. When there are four tabs 30, the polarity of three of the tabs 30 is opposite to the polarity of the other tab 30, or the polarity of two of the tabs 30 is opposite to the polarity of the other two tabs 30. When there are three tabs 30, at least one tab 30 needs to be bent before extending out of the battery cell casing 10.

[0067] Referring to Figures 3, 4, and 5, in some embodiments, the battery cell 100 includes a first insulating member 40 and a second insulating member 50. The first insulating member 40 and the second insulating member 50 connect the two sides of the tab 30 along the thickness direction of the tab 30. Within the battery cell housing 10, the first insulating member 40 faces the electrode assembly 20 and is connected to the sealing portion 12. The second insulating member 50 faces the battery cell housing 10 and is connected to the sealing portion 12. The first insulating member 40 includes a first base layer 41, the melting point of which is higher than that of the second insulating member 50.

[0068] In the present application, a first insulating member 40 and a second insulating member 50 are provided on both sides of the tab 30. The melting point of the first base layer 41 is higher than that of the second insulating member 50. This reduces the risk of melting of the first base layer 41 when the temperature of the tab 30 increases, thereby exposing the tab 30 on the side where the first base layer 41 is located, scalding the isolation membrane 23, and causing a short circuit by contact with the pole piece. At the same time, the risk of a short circuit between the adjacent first pole piece 21 and the second pole piece 22 can also be reduced.

[0069] In some embodiments, the melting point A of the first substrate layer satisfies A greater than 160°C, which helps reduce the risk of exposure of the tab 30, resulting in burns and contact between the isolation membrane 23 and the pole piece, and reduces the risk of short circuit between the adjacent first pole piece 21 and the second pole piece 22.

[0070] In some embodiments, 180°C≤A≤500°C further helps reduce the risk of exposure of the tab 30, which may cause the isolation membrane 23 to contact the pole piece and cause a short circuit, and reduces the risk of a short circuit between the adjacent first pole piece 21 and the second pole piece 22.

[0071] Optionally, the melting point A of the first substrate layer 41 can be any one of 180℃, 190℃, 200℃, 210℃, 220℃, 230℃, 240℃, 250℃, 260℃, 270℃, 280℃, 290℃, 300℃, 310℃, 320℃, 330℃, 340℃, 350℃, 360℃, 370℃, 380℃, 390℃, 400℃, 410℃, 420℃, 430℃, 440℃, 450℃, 460℃, 470℃, 480℃, 490℃, and 500℃.

[0072] In some embodiments, the material of the first base layer 41 includes one or more of polyimide (PI), polyamideimide (PAI), polyethyleneimine (PEI), polyethylene naphthalate (PEN), polyethylene terephthalate (PET), or modified polypropylene (PP).

[0073] Referring to FIG. 5 , in some embodiments, the first insulating member 40 includes a first packaging layer 42 , and the first packaging layer 42 is connected to the sealing portion 12 .

[0074] In some embodiments, the first encapsulation layer 42 is connected to the adhesive layer 10 a . Optionally, the first encapsulation layer 42 is adhesively connected to the adhesive layer 10 a by heat pressing.

[0075] In some embodiments, the melting point of the first packaging layer 42 is lower than that of the first base layer 41 . When the internal temperature of the battery cell 100 rises, the first packaging layer 42 may melt first and form a pressure relief channel, which is conducive to pressure relief and reduces the risk of fire.

[0076] In some embodiments, the melting point B of the first packaging layer 42 satisfies 120°C ≤ B < 160°C. When the temperature of the melting point B is relatively low (lower than 120°C), the battery cell 100 may fail prematurely, thereby reducing the service life of the battery cell 100. When the temperature of the melting point B is relatively high (higher than 160°C), the pressure relief may not be timely, which is detrimental to the safety of the battery cell 100. By limiting 120°C ≤ B < 160°C, when the temperature inside the battery cell rises, a thermochemical reaction occurs, causing inflation and deformation, and the low-melting-point first packaging layer 42 melts to form a pressure relief channel, which is further beneficial to relieving the pressure inside the battery cell shell 10, improving safety, and reducing the occurrence of premature failure of the battery cell 100, thereby improving the service life of the battery cell 100.

[0077] Optionally, the melting point B of the first encapsulation layer 42 can be any one of 120℃, 121℃, 122℃, 123℃, 124℃, 125℃, 126℃, 127℃, 128℃, 129℃, 130℃, 131℃, 132℃, 133℃, 134℃, 135℃, 136℃, 137℃, 138℃, 139℃, 140℃, 141℃, 142℃, 143℃, 144℃, 145℃, 146℃, 147℃, 148℃, 149℃, 150℃, 151℃, 152℃, 153℃, 154℃, 155℃, 156℃, 157℃, 158℃, and 159℃.

[0078] In some embodiments, satisfying 120°C≤B<145°C can further facilitate pressure relief.

[0079] In some embodiments, the material of the first encapsulation layer 42 includes polypropylene.

[0080] In some embodiments, the first insulating member 40 includes a first connecting layer 43, and the first encapsulation layer 42 is connected to the first base layer 41 via the first connecting layer 43. Because the first base layer 41 and the first encapsulation layer 42 are made of different materials and have different melting points, they cannot be composited using a high-temperature tape casting process. The first connecting layer 43 facilitates bonding between the first base layer 41 and the first encapsulation layer 42.

[0081] In some embodiments, the material of the first connection layer 43 includes one or more of hot melt adhesive, aminosilane adhesive, polyurethane adhesive, epoxy resin, and acrylic adhesive.

[0082] In some embodiments, the material of the first connecting layer 43 includes a first type of glue and a second type of glue, the first type of glue includes one or more of silica gel, thickener, and phenolic resin, and the second type of glue includes one or more of silane coupling agent, curing agent, and amino resin.

[0083] In some embodiments, the melting point W of the first connection layer 43 is 100° C. ≤ W ≤ 200° C.

[0084] Optionally, the melting point W of the first connecting layer 43 can be any one of 100℃, 105℃, 110℃, 115℃, 120℃, 125℃, 130℃, 135℃, 140℃, 145℃, 150℃, 155℃, 160℃, 165℃, 170℃, 175℃, 180℃, 185℃, 190℃, 195℃, and 200℃.

[0085] In some embodiments, the first insulating member 40 includes a second encapsulation layer 44. Along the thickness direction of the first insulating member 40, the second encapsulation layer 44 and the second encapsulation layer 44 are located on both sides of the first base layer 41. The second encapsulation layer 44 is connected to the side of the tab 30 facing away from the second insulating member 50. Optionally, the second encapsulation layer 44 is bonded to the tab 30 by hot pressing.

[0086] In some embodiments, the melting point of the second packaging layer 44 is lower than that of the first base layer 41 . When the internal temperature of the battery cell 100 increases, the second packaging layer 44 may melt first and form a pressure relief channel, which is beneficial for pressure relief.

[0087] In some embodiments, the melting point C of the second packaging layer 44 satisfies 120°C≤C<160°C. When the temperature of the melting point C is relatively low (lower than 120°C), the battery cell 100 may fail prematurely, thereby reducing the service life of the battery cell 100. When the temperature of the melting point B is relatively high (higher than 160°C), the pressure relief may not be timely, which is detrimental to the safety of the battery cell 100. By limiting 120°C≤C<160°C, when the temperature inside the battery cell rises, a thermochemical reaction occurs, causing inflation and deformation, and the low-melting-point second packaging layer 44 melts to form a pressure relief channel, which is further beneficial for relieving pressure inside the battery cell shell 10, improving safety, and reducing the occurrence of premature failure of the battery cell 100, thereby improving the service life of the battery cell 100.

[0088] Optionally, the melting point C of the second encapsulation layer 44 can be any one of 120℃, 121℃, 122℃, 123℃, 124℃, 125℃, 126℃, 127℃, 128℃, 129℃, 130℃, 131℃, 132℃, 133℃, 134℃, 135℃, 136℃, 137℃, 138℃, 139℃, 140℃, 141℃, 142℃, 143℃, 144℃, 145℃, 146℃, 147℃, 148℃, 149℃, 150℃, 151℃, 152℃, 153℃, 154℃, 155℃, 156℃, 157℃, 158℃, and 159℃.

[0089] In some embodiments, satisfying 120°C≤C<145°C can further facilitate pressure relief.

[0090] In some embodiments, the material of the second encapsulation layer 44 includes polypropylene.

[0091] In some embodiments, the first insulating member 40 includes a second connecting layer 45, and the second encapsulation layer 44 is connected to the first base layer 41 via the second connecting layer 45. Because the first base layer 41 and the second encapsulation layer 44 are made of different materials and have different melting points, they cannot be composited using a high-temperature tape casting process. The second connecting layer 45 facilitates bonding between the first base layer 41 and the second encapsulation layer 44.

[0092] In some embodiments, the material of the second connecting layer 45 includes one or more of hot melt adhesive, aminosilane adhesive, polyurethane adhesive, epoxy resin, and acrylic adhesive.

[0093] In some embodiments, the material of the second connecting layer 45 includes a first type of glue and a second type of glue, the first type of glue contains one or more of silica gel, thickener, and phenolic resin, and the second type of glue contains one or more of silane coupling agent, curing agent, and amino resin.

[0094] In some embodiments, the melting point S of the second connection layer 45 is 100° C. ≤ S ≤ 200° C.

[0095] Optionally, the melting point S of the second connecting layer 45 can be any one of 100℃, 105℃, 110℃, 115℃, 120℃, 125℃, 130℃, 135℃, 140℃, 145℃, 150℃, 155℃, 160℃, 165℃, 170℃, 175℃, 180℃, 185℃, 190℃, 195℃, and 200℃.

[0096] In some embodiments, after the first shell 111 and the second shell 112 are connected, the sealing portion 12 includes two adhesive layers 10a along the thickness direction of the battery cell shell 10. Along the thickness direction of the battery cell shell 10, the sealing portion 12 includes a first region 101 that does not overlap with the first insulating member 40 and the second insulating member 50. The two adhesive layers 10a located in the first region 101 are adhesively connected, and the thickness of the first base layer 41 is less than the sum of the thicknesses of the two adhesive layers 10a. Because the first base layer 41 has a high melting point and cannot melt during the packaging process, if the first base layer 41 is too thick and does not melt after packaging, it is easy to form pore channels, resulting in leakage. External moisture can easily enter the interior of the battery cell shell 10, which is prone to short circuits. By making the thickness of the first base layer 41 less than the sum of the thicknesses of the two adhesive layers 10a after hot pressing, the formation of pore channels in the battery cell shell 10 is reduced, reducing the risk of leakage and short circuits.

[0097] In some embodiments, the thickness of the first base layer 41 is 6% to 25% of the thickness of the first insulating member 40. If the thickness of the first base layer 41 is too small (less than 6%), the tab 30 is easily exposed. If the thickness of the first base layer 41 is too large (greater than 25%), leakage and short circuit may occur. If the thickness of the first base layer 41 is too thick, pore channels may easily appear in the packaging triangle area (edge ​​area of ​​the insulating member) of the sealing portion 12. If the thickness of the first base layer 41 is too thin, it may easily melt and cause the tab to be exposed, thereby short circuiting. By limiting the thickness of the first base layer 41 to 6% to 25% of the thickness of the first insulating member 40, it is helpful to reduce the formation of pore channels in the sealing portion 12, thereby reducing the risk of leakage and short circuit.

[0098] Optionally, the thickness of the first base layer 41 can be any one of 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, 21%, 22%, 23%, 24%, and 25% of the thickness of the first insulating member 40.

[0099] In some embodiments, the thickness of the first encapsulation layer 42 is 30% to 44% of the thickness of the first insulating member 40. If the thickness of the first encapsulation layer 42 is too small (less than 30%), the connection strength between the first encapsulation layer 42 and the adhesive layer 10a will be affected, and the pressure relief channel formed by the melting of the first encapsulation layer 42 will be reduced, which is not conducive to pressure relief. If the thickness of the first encapsulation layer 42 is too large (greater than 44%), the occupied space will be increased, affecting the head space of the battery cell 100. By limiting the thickness of the first encapsulation layer 42 to 30% to 44% of the thickness of the first insulating member 40, it is beneficial to improve the connection strength between the first encapsulation layer 42 and the adhesive layer 10a, which is beneficial to pressure relief and reduces the occupied space.

[0100] Optionally, the thickness of the first encapsulation layer 42 is any one of 30%, 31%, 32%, 33%, 34%, 35%, 36%, 37%, 38%, 39%, 40%, 41%, 42%, 43%, and 44% of the thickness of the first insulating member 40.

[0101] In some embodiments, the thickness of the second packaging layer 44 is 30% to 44% of the thickness of the first insulating member 40. If the thickness of the second packaging layer 44 is too small (less than 30%), the connection strength between the second packaging layer 44 and the tab 30 will be affected, and the pressure relief channel formed by the melting of the second packaging layer 44 will be reduced, which is not conducive to pressure relief. If the thickness of the second packaging layer 44 is too large (greater than 44%), the occupied space will be increased, affecting the head space of the battery cell 100. By limiting the thickness of the second packaging layer 44 to 30% to 44% of the thickness of the first insulating member 40, it is beneficial to improve the connection strength between the second packaging layer 44 and the tab 30, which is beneficial to pressure relief and reduces the occupied space.

[0102] Optionally, the thickness of the second encapsulation layer 44 is any one of 30%, 31%, 32%, 33%, 34%, 35%, 36%, 37%, 38%, 39%, 40%, 41%, 42%, 43%, and 44% of the thickness of the first insulating member 40.

[0103] In some embodiments, the thickness of the first connection layer 43 is 3% to 8% of the thickness of the first insulating member 40 .

[0104] In some embodiments, the thickness h1 of the first connection layer 43 ranges from 3 μm ≤ h1 ≤ 5 μm. When the thickness h1 is less than 3 μm, the connection strength between the first base layer 41 and the first encapsulation layer 42 is easily affected. When the thickness h1 is greater than 5 μm, the occupied space increases, affecting the headroom of the battery cell 100. By limiting the range from 3 μm ≤ h1 ≤ 5 μm, the connection strength between the first base layer 41 and the first encapsulation layer 42 can be improved while reducing the occupied space.

[0105] Optionally, the thickness h1 may be any one of 3 μm, 3.1 μm, 3.2 μm, 3.3 μm, 3.4 μm, 3.5 μm, 3.6 μm, 3.7 μm, 3.8 μm, 3.9 μm, 4.0 μm, 4.1 μm, 4.2 μm, 4.3 μm, 4.4 μm, 4.5 μm, 4.6 μm, 4.7 μm, 4.8 μm, 4.9 μm, and 5.0 μm.

[0106] In some embodiments, the thickness of the second connection layer 45 is 3% to 8% of the thickness of the first insulating member 40 .

[0107] In some embodiments, the thickness h2 of the second connection layer 45 ranges from 3 μm ≤ h2 ≤ 5 μm. When the thickness h2 is less than 3 μm, the connection strength between the first base layer 41 and the second encapsulation layer 44 is easily affected. When the thickness h2 is greater than 5 μm, the occupied space increases, affecting the head space of the battery cell 100. By limiting the range from 3 μm ≤ h2 ≤ 5 μm, the connection strength between the first base layer 41 and the second encapsulation layer 44 can be improved while reducing the occupied space.

[0108] Optionally, the thickness h2 may be any one of 3 μm, 3.1 μm, 3.2 μm, 3.3 μm, 3.4 μm, 3.5 μm, 3.6 μm, 3.7 μm, 3.8 μm, 3.9 μm, 4.0 μm, 4.1 μm, 4.2 μm, 4.3 μm, 4.4 μm, 4.5 μm, 4.6 μm, 4.7 μm, 4.8 μm, 4.9 μm, and 5.0 μm.

[0109] In some embodiments, the second insulating member 50 includes a second base layer 51 .

[0110] In some embodiments, the second insulating member 50 includes a third encapsulation layer 52 , and the third encapsulation layer 52 is connected to the sealing portion 12 .

[0111] In some embodiments, the third encapsulation layer 52 is connected to the adhesive layer 10 a . Optionally, the third encapsulation layer 52 is adhesively connected to the adhesive layer 10 a by heat pressing.

[0112] In some embodiments, the melting point of the third packaging layer 52 is lower than that of the second base layer 51 . When the internal temperature of the battery cell 100 increases, the third packaging layer 52 may melt first and form a pressure relief channel, which is beneficial for pressure relief.

[0113] In some embodiments, the second insulating member 50 includes a fourth encapsulation layer 53. Along the thickness direction of the second insulating member 50, the third encapsulation layer 52 and the fourth encapsulation layer 53 are located on both sides of the second base layer 51, and the second base layer 51 connects the third encapsulation layer 52 and the fourth encapsulation layer 53. Optionally, the fourth encapsulation layer 53 is bonded to the tab 30 by hot pressing.

[0114] In some embodiments, the melting point of the fourth packaging layer 53 is lower than that of the second base layer 51 . When the internal temperature of the battery cell 100 increases, the fourth packaging layer 53 may melt first and form a pressure relief channel, which is beneficial for pressure relief.

[0115] In some embodiments, the melting point D of the second base layer 51 satisfies D less than or equal to 160° C., which is conducive to forming a pressure relief channel to relieve pressure inside the battery cell housing 10 and improve safety.

[0116] In some embodiments, 105℃≤D≤145℃. When the temperature of the melting point D is relatively low (lower than 105℃), it is not conducive to forming a pressure relief channel between the second substrate layer 51 and the third packaging layer 52 and between the second substrate layer 51 and the fourth packaging layer 53. When the temperature of the melting point D is relatively high (higher than 145℃), it cannot melt during the packaging process, affecting the connection strength between the second substrate layer 51 and the third packaging layer 52 and the connection strength between the second substrate layer 51 and the fourth packaging layer 53. By limiting 105℃≤D≤145℃, it is conducive to forming a pressure relief channel and improving the connection strength between the second substrate layer 51 and the third packaging layer 52 and the connection strength between the second substrate layer 51 and the fourth packaging layer 53.

[0117] Optionally, the melting point D of the second substrate layer can be any one of 105°C, 106°C, 107°C, 108°C, 109°C, 110°C, 111°C, 112°C, 113°C, 114°C, 115°C, 116°C, 117°C, 118°C, 119°C, 120°C, 121°C, 122°C, 123°C, 124°C, 125°C, 126°C, 127°C, 128°C, 129°C, 130°C, 131°C, 132°C, 133°C, 134°C, 135°C, 136°C, 137°C, 138°C, 139°C, 140°C, 141°C, 142°C, 143°C, 144°C, and 145°C.

[0118] In some embodiments, the melting point E of the third packaging layer 52 satisfies 120°C ≤ E < 145°C. When the melting point E is relatively low (lower than 120°C), the battery cell 100 may fail prematurely, thereby reducing the service life of the battery cell 100. When the melting point E is relatively high (higher than 145°C), the pressure relief may not be timely, which is detrimental to the safety of the battery cell 100. By limiting 120°C ≤ E < 145°C, when the internal temperature of the battery cell rises, a thermochemical reaction occurs, causing inflation and deformation, and the low-melting-point third packaging layer 52 melts to form a pressure relief channel, which is further beneficial for relieving pressure inside the battery cell shell 10, improving safety, and reducing the occurrence of premature failure of the battery cell 100, thereby improving the service life of the battery cell 100.

[0119] Optionally, the melting point E of the third encapsulation layer 52 can be any one of 120℃, 121℃, 122℃, 123℃, 124℃, 125℃, 126℃, 127℃, 128℃, 129℃, 130℃, 131℃, 132℃, 133℃, 134℃, 135℃, 136℃, 137℃, 138℃, 139℃, 140℃, 141℃, 142℃, 143℃, and 144℃.

[0120] In some embodiments, satisfying 120°C≤E≤130°C may further facilitate pressure relief.

[0121] In some embodiments, the material of the third encapsulation layer 52 includes polypropylene.

[0122] In some embodiments, the melting point F of the fourth packaging layer 53 satisfies 120°C ≤ F < 145°C. When the melting point F is relatively low (lower than 120°C), the battery cell 100 may fail prematurely, thereby reducing the service life of the battery cell 100. When the melting point F is relatively high (higher than 145°C), the pressure relief may not be timely, which is detrimental to the safety of the battery cell 100. By limiting 120°C ≤ F < 145°C, when the internal temperature of the battery cell rises, a thermochemical reaction occurs, causing inflation and deformation, and the low-melting-point fourth packaging layer 53 melts to form a pressure relief channel, which is further beneficial for relieving pressure inside the battery cell shell 10, improving safety, and reducing the occurrence of premature failure of the battery cell 100, thereby improving the service life of the battery cell 100.

[0123] Optionally, the melting point F of the fourth encapsulation layer 53 can be any one of 120℃, 121℃, 122℃, 123℃, 124℃, 125℃, 126℃, 127℃, 128℃, 129℃, 130℃, 131℃, 132℃, 133℃, 134℃, 135℃, 136℃, 137℃, 138℃, 139℃, 140℃, 141℃, 142℃, 143℃, and 144℃.

[0124] In some embodiments, satisfying 120°C≤F<145°C can further facilitate pressure relief.

[0125] In some embodiments, the material of the fourth encapsulation layer 53 includes polypropylene.

[0126] In some embodiments, the thickness of the second base layer 51 is 30% to 40% of the thickness of the second insulating member 50. If the thickness of the second base layer 51 is too small (less than 30%), the connection strength between the second base layer 51 and the third and fourth encapsulation layers 52, 53 will be affected. If the thickness of the second base layer 51 is too large (greater than 40%), the space occupied will increase, affecting the headroom of the battery cell 100. By limiting the thickness of the second base layer 51 to 30% to 40% of the thickness of the second insulating member 50, the connection strength between the second base layer 51 and the third and fourth encapsulation layers 52, 53 will be improved, and the space occupied will be reduced.

[0127] Optionally, the thickness of the second base layer 51 is any one of 30%, 31%, 32%, 33%, 34%, 35%, 36%, 37%, 38%, 39%, and 40% of the thickness of the second insulating member 50 .

[0128] In some embodiments, the thickness of the third encapsulation layer 52 is 30% to 40% of the thickness of the second insulating member. If the thickness of the third encapsulation layer 52 is too small (less than 30%), the connection strength between the third encapsulation layer 52 and the adhesive layer 10a will be affected, and the pressure relief channel formed by the melting of the third encapsulation layer 52 will be reduced, which is not conducive to pressure relief. If the thickness of the third encapsulation layer 52 is too large (greater than 40%), it will increase the occupied space and affect the head space of the battery cell 100. By limiting the thickness of the third encapsulation layer 52 to 30% to 40% of the thickness of the second insulating member 50, the fusion effect of the third encapsulation layer and the adhesive layer is improved, which is conducive to improving the connection strength between the third encapsulation layer 52 and the adhesive layer 10a, ensuring the packaging reliability of the battery during long-term use.

[0129] Optionally, the thickness of the third encapsulation layer 52 is any one of 30%, 31%, 32%, 33%, 34%, 35%, 36%, 37%, 38%, 39%, and 40% of the thickness of the second insulating member 50 .

[0130] In some embodiments, the thickness of the fourth packaging layer 53 is 30% to 40% of the thickness of the second insulating member. If the thickness of the fourth packaging layer 53 is too small (less than 30%), the connection strength between the fourth packaging layer 53 and the tab 30 will be affected, and the pressure relief channel formed by the melting of the fourth packaging layer 53 will be reduced, which is not conducive to pressure relief. If the thickness of the fourth packaging layer 53 is too large (greater than 40%), the occupied space will be increased, affecting the head space of the battery cell 100. By limiting the thickness of the fourth packaging layer 53 to 30% to 40% of the thickness of the second insulating member 50, it is beneficial to improve the connection strength between the fourth packaging layer 53 and the tab 30, facilitate pressure relief and reduce the occupied space.

[0131] Optionally, the thickness of the fourth encapsulation layer 53 is any one of 30%, 31%, 32%, 33%, 34%, 35%, 36%, 37%, 38%, 39%, and 40% of the thickness of the second insulating member 50 .

[0132] In some embodiments, the difference α between the melting point of the first base layer 41 and the maximum melting point of the second insulating member 50 is greater than or equal to 41° C., thereby reducing the risk of short circuit.

[0133] In some embodiments, α≥117° C., further reducing the short circuit risk.

[0134] In some embodiments, α≥147° C., further reducing the short circuit risk.

[0135] In some embodiments, α≥227° C., further reducing the short circuit risk.

[0136] On the basis that the melting point of the first base layer 41 is greater than 160° C., the greater the difference in α is, the higher the passing rate of the external short-circuit test of the battery cell is.

[0137] The present application will be further described below through specific examples.

[0138] The external short circuit test and 130℃ hot box test were carried out in groups of 100 battery cells.

[0139] In some embodiments, the external short circuit test method includes: 1. Pre-processing - 1CAP process 1) test temperature is 20°C (±5°C); 2) rest 5min; 3) 0.5CCC to 4.5V, CV to 0.025C 4) rest 5min;

[0140] Testing process:

[0141] Check the appearance and take photos before and after the test;

[0142] Attach the temperature-sensing wire to the center of the cell surface. Place the sample in a test environment at 55±2°C. After the cell surface temperature reaches the test temperature, let it stand for 40±1 minutes. Use an 80±20mΩ load resistor to short-circuit the positive and negative electrodes of the sample and test until the voltage is lower than 0.1V.

[0143] Measurement frequency: Voltage and internal resistance measurements use 1KHz specifications, and are measured after pre-processing and testing.

[0144] Judgment criteria: The surface temperature of the sample does not exceed 150℃, and it does not catch fire or explode.

[0145] The test ends when one of the following conditions is met:

[0146] 1) Stop when the sample voltage is lower than 0.1V and the surface temperature drops to the test environment temperature ±10℃.

[0147] 2) If the voltage cannot be reduced to 0.1V, the surface temperature is allowed to drop to the test environment temperature.

[0148] In some embodiments, the 130°C hot box test method includes: pre-treatment-1CAP process: 1) test temperature is 20°C (±5°C); 2) Rest 5 min; 3) 0.5CCC to 4.5V, CV to 0.025C; 4) Rest 5 min.

[0149] Testing process:

[0150] Check the appearance and take photos before and after the test;

[0151] Temperature sensing line location;

[0152] Place the sample vertically in the box and heat it to 130±2℃ at a rate of 5±2℃ and maintain for 60 minutes;

[0153] Measurement frequency: Voltage and internal resistance measurements use 1KHz specifications, measured after pre-processing and testing;

[0154] Judgment criteria: no fire, no explosion.

[0155] As can be seen from Table 1, Examples 1 to 11 and Comparative Example 1 show that when the melting point A of the first base layer 41 is greater than 160°C, the external short-circuit test pass rate can be improved, reducing the short-circuit risk. Given that the melting point A of the first base layer 41 is greater than 160°C and the melting point of the second insulating member is between 105°C and 160°C, the higher the melting point of A, the lower the melting point of B, and the greater the difference α between the melting point A of the first base layer 41 and the melting point B of the first encapsulation layer 42, the higher the external short-circuit test pass rate, reducing the short-circuit risk. Furthermore, the higher the 130°C hot box test pass rate, reducing the fire risk.

[0156] Please refer to FIG. 5 . An embodiment of the present application provides an insulating member 110 , which includes the first insulating member 40 and the second insulating member 50 in any one of the above embodiments.

[0157] Please refer to FIG. 5 . An embodiment of the present application provides a tab assembly 120 , including a tab 30 and an insulating member 110 according to any of the above embodiments.

[0158] In some embodiments, along the width direction of the tab 30, the width of the first insulating member 40 is greater than the width of the tab 30, and the width of the second insulating member 50 is greater than the width of the tab 30. The insulating member 110 includes a second region 102 that does not overlap with the tab 30. In the second region 102, the second encapsulation layer 44 is bonded to the fourth encapsulation layer 53.

[0159] Please refer to FIG. 6 . The present application further provides a battery 200 using the above-mentioned battery cell 100 . The battery 200 includes at least one battery cell 100 .

[0160] 6 , the present application also provides an electrical device 300 using the battery 200. In one embodiment, the electrical device 300 of the present application may be, but is not limited to, electronic equipment, drones, backup power supplies, electric vehicles, electric motorcycles, electric power-assisted bicycles, power tools, large household batteries, and the like.

[0161] Those skilled in the art should recognize that the above embodiments are merely intended to illustrate the present application and are not intended to limit the present application. As long as they are within the spirit of the present application, appropriate changes and modifications to the above embodiments fall within the scope disclosed in the present application.

Claims

1. An insulating part, characterized in that, It includes a first insulating member and a second insulating member. The first insulating member and the second insulating member are configured to connect both sides in the thickness direction of the tab. The first insulating member includes a first base layer, and the melting point of the first base layer is higher than that of the second insulating member.

2. The insulating member according to claim 1, wherein The melting point of the first base layer is A, and A is greater than 160 °C.

3. The insulating member according to claim 1 or 2, characterized in that 180℃≤A≤500℃。 4. The insulating part according to any one of claims 1 to 3, characterized in that, The thickness of the first base layer is 6% to 25% of the thickness of the first insulating member.

5. The insulating member according to any one of claims 1 to 4, characterized in that, The second insulating member includes a second base layer, and the melting point of the second base layer is D, and D is less than or equal to 160 °C.

6. The insulating member according to claim 5, characterized in that, 105℃≤D≤145℃。 7. The insulating member according to any one of claims 1 to 6, characterized in that, The difference α between the melting point of the first base layer and the melting point of the second insulating member is greater than or equal to 41 °C.

8. The insulating member according to any one of claims 1 to 7, characterized in that, The difference α between the melting point of the first base layer and the melting point of the second insulating member is greater than or equal to 117 °C.

9. The insulating member according to any one of claims 1 to 8, characterized in that, The difference α between the melting point of the first base layer and the melting point of the second insulating member is greater than or equal to 147 °C.

10. The insulating member according to any one of claims 1 to 9, characterized in that, The difference α between the melting point of the first base layer and the melting point of the second insulating member is greater than or equal to 227 °C.

11. The insulating member according to any one of claims 1 to 10, characterized in that, The material of the first base layer includes one or more of polyimide, polyamideimide, polyethyleneimine, polyethylene naphthalate, polyethylene terephthalate, or modified polypropylene.

12. The insulating member according to any one of claims 1 to 11, characterized in that, The second insulating member includes a second base layer, and the thickness of the second base layer is 30% to 40% of the thickness of the second insulating member.

13. The insulating member according to any one of claims 1 to 12, characterized in that, The first insulating member includes a first encapsulation layer and a second encapsulation layer, and the first encapsulation layer and the second encapsulation layer are located on both sides of the first base layer.

14. The insulating member according to claim 13, characterized in that, The melting point of the first encapsulation layer is lower than that of the first base layer, and the melting point of the second encapsulation layer is lower than that of the first base layer.

15. The insulating member according to any one of claims 13 to 14, characterized in that, The melting point of the first encapsulation layer is B, and 120 °C ≤ B < 160 °C, and / or the melting point of the second encapsulation layer is C, and 120 °C ≤ C < 160 °C.

16. The insulating member according to any one of claims 13 to 15, characterized in that The thickness of the first encapsulation layer is 30% to 44% of the thickness of the first insulating member, and / or the thickness of the second encapsulation layer is 30% to 44% of the thickness of the first insulating member.

17. The insulating member according to any one of claims 13 to 16, characterized in that, The first insulating member includes a first connection layer and a second connection layer. The first encapsulation layer connects the first base layer through the first connection layer, and the second encapsulation layer connects the first base layer through the second connection layer.

18. The insulating member according to claim 17, wherein The thickness of the first connection layer is 3% to 8% of the thickness of the first insulating member, and / or the thickness of the second connection layer is 3% to 8% of the thickness of the first insulating member.

19. The insulating member according to claim 12, wherein The second insulating member includes a third encapsulation layer and a fourth encapsulation layer. Along the thickness direction of the second base layer, the third encapsulation layer and the fourth encapsulation layer connect both sides of the second base layer.

20. The insulating member according to claim 19, wherein, The melting point E of the third encapsulation layer satisfies 120 °C ≤ E < 145 °C, and / or the melting point F of the fourth encapsulation layer satisfies 120 °C ≤ F < 145 °C.

21. The insulating member according to any one of claims 19 to 20, characterized in that, The thickness of the third encapsulation layer is 30% to 40% of the thickness of the second insulating member, and / or the thickness of the fourth encapsulation layer is 30% to 40% of the thickness of the second insulating member.

22. An electrode tab assembly, characterized in that, Comprising a tab and the insulating member according to any one of claims 1 to 21, the insulating member comprising a first insulating member and a second insulating member, the first insulating member and the second insulating member being configured to connect two sides of the tab, the first insulating member comprising a first base layer, the melting point of the first base layer being higher than the melting point of the second insulating member.

23. A battery cell, characterized in that, Comprising: a battery cell housing, comprising a main body portion and a sealing portion; an electrode assembly, disposed within the main body portion; a tab, connecting the electrode assembly and protruding from the sealing portion; comprising the insulating member according to any one of claims 1 to 21, the insulating member comprising a first insulating member and a second insulating member, along the thickness direction of the tab, the first insulating member and the second insulating member connecting two sides of the tab; inside the battery cell housing, the first insulating member faces the electrode assembly, the first insulating member connects to the sealing portion, the second insulating member faces the battery cell housing, and the second insulating member connects to the sealing portion; the first insulating member comprises a first base layer, the melting point of the first base layer being higher than the melting point of the second insulating member.

24. The battery cell according to claim 23, characterized in that, The electrode assembly comprises a first electrode tab, a second electrode tab and a separator, the separator being disposed between the first electrode tab and the second electrode tab; the tab comprises a first section, a second section and a third section; at least a part of the first section connects to the first electrode tab or the second electrode tab; the second section is bent to connect to the first section, and the first insulating member is disposed on a side of the second section facing the electrode assembly; the third section is bent to connect to the second section, and a part of the third section protrudes from the sealing portion.

25. The battery cell according to any one of claims 23 to 24, characterized in that, Along the thickness direction of the battery cell housing, the sealing portion comprises two adhesive layers; Along the thickness direction of the battery cell housing, the sealing portion comprises a first region, the first region being a region where the sealing portion does not overlap with the first insulating member and the second insulating member, and the two adhesive layers located in the first region are adhesively connected, and the thickness of the first base layer is less than the sum of the thicknesses of the two adhesive layers.

26. The battery cell according to any one of claims 23 to 25, characterized in that, The battery cell comprises at least three tabs, wherein, the polarities of two of the tabs are opposite to the polarity of the other tab.

27. A battery, characterized in that, Comprising a battery cell according to any one of claims 23 to 26.

28. An electrical device, characterized in that, Comprising a battery according to claim 27.

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