CN215989140U - Battery cell, battery and power consumption device - Google Patents

Abstract

The application discloses battery monomer, battery and power consumption device. The battery cell of the embodiment of the application includes: packaging bags; an electrode assembly accommodated in the package bag; a first electrode lead at least partially disposed within the pouch and electrically connected to the electrode assembly; the second electrode lead at least partially extends out of the packaging bag; and a connection member for connecting the first electrode lead and the second electrode lead to electrically connect the first electrode lead and the second electrode lead, the connection member being for disconnecting the electrical connection between the first electrode lead and the second electrode lead and discharging the internal pressure when the internal pressure of the battery cell reaches a threshold value. This application can be when electrode subassembly thermal runaway, and the electric connection of disconnection electrode subassembly and external equipment in time releases the gas that produces, improves the security performance.

Description

Battery cell, battery and power consumption device

Technical Field

The present disclosure relates to a battery, and more particularly to a battery cell, a battery and an electric device.

Background

The battery cell is widely used in electronic devices such as a mobile phone, a notebook computer, a battery car, an electric airplane, an electric ship, an electric toy car, an electric toy ship, an electric toy airplane, an electric tool, and the like. The battery monomer can comprise a cadmium-nickel battery monomer, a hydrogen-nickel battery monomer, a lithium ion battery monomer, a secondary alkaline zinc-manganese battery monomer and the like.

In addition to improving the performance of the battery cell, safety issues are a considerable problem in the development of battery technology. If the safety problem of the battery cell cannot be guaranteed, the battery cell cannot be used. Therefore, how to enhance the safety of the battery cell is a technical problem to be solved urgently in the battery technology.

SUMMERY OF THE UTILITY MODEL

The application provides a battery monomer, battery and power consumption device, it can improve the free security of battery.

In a first aspect, the present application provides a battery cell comprising:

packaging bags;

an electrode assembly accommodated in the package bag;

a first electrode lead at least partially disposed within the packaging bag and electrically connected to the electrode assembly;

the second electrode lead at least partially extends out of the packaging bag; and

and a connection member for connecting the first electrode lead and the second electrode lead to electrically connect the first electrode lead and the second electrode lead, the connection member being used to disconnect the electrical connection between the first electrode lead and the second electrode lead and to discharge the internal pressure when the internal pressure of the battery cell reaches a threshold value.

In the above scheme, when short circuit, overcharge and other phenomena occur, the electrode assembly is thermally runaway and releases a large amount of high-temperature and high-pressure gas, the gas acts on the connecting piece and pushes away the connecting piece to disconnect the electrical connection of the first electrode lead and the second electrode lead, so that the electrical connection of the electrode assembly and external equipment is disconnected, a circuit is cut off, the charging or discharging of the electrode assembly is stopped, and the thermal runaway of the electrode assembly is slowed down. The passageway that can form the inside and outside intercommunication of wrapping bag behind the connecting piece is broken away to gaseous dashing to make gaseous and gaseous high temperature high pressure material release the free outside of battery fast, thereby pressure of in time releasing reduces the free explosion of battery, the risk of catching a fire, improves the free security of battery.

In some embodiments, the connection member is positioned between and connected to the first and second electrode leads in a thickness direction of the second electrode lead. The inner end of the connector is disposed opposite to the electrode assembly, and the outer end of the connector is exposed to the outside of the package bag.

In the above-described aspect, when the electrode assembly thermally runaway, the generated gas impinges on the inner end of the connection member to blow the connection member apart. After the gas rushes off the connecting piece, a channel for discharging the gas is formed between the first electrode lead and the second electrode lead. The outer end of the coupling member is exposed to the outside of the bag, so that the passage may extend to the outer end of the coupling member and communicate with the outer space of the bag.

In some embodiments, the packaging bag surrounds a portion of the first electrode lead and a portion of the second electrode lead to connect to the first electrode lead and the second electrode lead. The bonding strength of the first electrode lead and the connecting piece is smaller than that of the first electrode lead and the packaging bag, and the bonding strength of the second electrode lead and the connecting piece is smaller than that of the second electrode lead and the packaging bag.

In the above scheme, the bonding strength of the first electrode lead and the connecting piece and the bonding strength of the second electrode lead and the connecting piece are small, so that the connecting piece can be easily opened by gas, the packaging bag is prevented from being opened by gas, and the safety is improved. When the electrode assembly generates gas, the packaging bag is expanded, and at the same time, the packaging bag can pull the first electrode lead and the second electrode lead in opposite directions so as to accelerate the separation of the first electrode lead from the connecting piece and the separation of the second electrode lead from the connecting piece.

In some embodiments, the package comprises: a pouch body for accommodating the electrode assembly; and an insulator surrounding a portion of the first electrode lead and a portion of the second electrode lead and connected to the pouch body to bond the first electrode lead and the second electrode lead to the pouch body. The bonding strength between the first electrode lead and the connecting piece is smaller than that between the first electrode lead and the insulator and between the bag body and the insulator, and the bonding strength between the second electrode lead and the connecting piece is smaller than that between the second electrode lead and the insulator and between the bag body and the insulator.

In the above scheme, the bonding strength of the first electrode lead and the connecting piece and the bonding strength of the second electrode lead and the connecting piece are small, so that the connecting piece can be easily opened by gas, the bag body and the insulator are prevented from being opened by gas, and the safety is improved.

In some embodiments, the outer end of the second electrode lead, facing away from the electrode assembly, extends outside the pouch and beyond the outer end of the first electrode lead, facing away from the electrode assembly, and the outer end of the first electrode lead extends outside the pouch and beyond the outer end of the connector. The outer end of the first electrode lead exceeds the outer end of the connector by a dimension less than the thickness of the connector.

In the above scheme, the outer end of the second electrode lead exceeds the outer end of the first electrode lead, so that the second electrode lead is connected with external equipment, and the risk that the first electrode lead interferes with the external equipment is reduced. The outer end of the first electrode lead and the outer end of the second electrode lead both exceed the outer end of the connecting piece, so that the risk that the outer end of the connecting piece exceeds the first electrode lead and the second electrode lead due to assembly errors can be reduced, and the bonding strength of the connecting piece and the first electrode lead and the bonding strength of the connecting piece and the second electrode lead are ensured. The size that this scheme made the outer end of first electrode lead wire surpassed the outer end of connecting piece is less than the thickness of connecting piece, can reduce the risk of first electrode lead wire overlap joint on the second electrode lead wire like this.

In some embodiments, the inner end of the first electrode lead facing the electrode assembly exceeds the inner end of the second electrode lead facing the electrode assembly and is connected to the electrode assembly, and the inner end of the second electrode lead exceeds the inner end of the connection member. The dimension of the inner end of the second electrode lead beyond the inner end of the connector is less than the thickness of the connector.

In the above scheme, the inner end of the first electrode lead exceeds the inner end of the second electrode lead, so that the first electrode lead is connected with the electrode assembly, and the risk of conducting the second electrode lead with the electrode assembly is reduced. The inner end of the first electrode lead and the inner end of the second electrode lead both exceed the inner end of the connecting piece, so that the risk that the inner end of the connecting piece exceeds the first electrode lead and the second electrode lead due to assembly errors can be reduced, and the bonding strength of the connecting piece and the first electrode lead and the bonding strength of the connecting piece and the second electrode lead are ensured. The size that this scheme made the inner of second electrode lead wire surpass the inner of connecting piece is less than the thickness of connecting piece, can reduce the risk of second electrode lead wire overlap joint on first electrode lead wire like this.

In some embodiments, the connecting member is attached to the bag at both ends in a first direction perpendicular to the direction from the inner end of the connecting member to the outer end of the connecting member.

In the above scheme, the connecting piece is connected to the packaging bag to seal the space between the first electrode lead and the second electrode lead, and the sealing performance of the battery cell is ensured.

In some embodiments, the connector is a conductive polymer and is bonded to the first electrode lead and the second electrode lead.

In a second aspect, the present application provides a battery comprising a plurality of battery cells according to any of the embodiments of the first aspect.

In a third aspect, the present application provides an electrical device comprising the battery of the second aspect, the battery being configured to provide electrical energy.

Drawings

Features, advantages and technical effects of exemplary embodiments of the present application will be described below with reference to the accompanying drawings.

FIG. 1 is a schematic illustration of a vehicle according to some embodiments of the present application;

fig. 2 is an exploded schematic view of a battery provided in accordance with some embodiments of the present application;

fig. 3 is an exploded schematic view of the battery module shown in fig. 2;

fig. 4 is a schematic structural diagram of a battery cell provided in some embodiments of the present application;

fig. 5 is a schematic cross-sectional view of the battery cell shown in fig. 4;

fig. 6 is an enlarged schematic view of the battery cell shown in fig. 5 at block a;

fig. 7 is a schematic partial cross-sectional view of the battery cell shown in fig. 4;

fig. 8 is an enlarged schematic view of fig. 7 at circle B.

In the drawings, the drawings are not necessarily to scale.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are some embodiments of the present application, but not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

Unless defined otherwise, 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 in the description of the application herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application; the terms "including" and "having," and any variations thereof, in the description and claims of this application and the description of the above figures are intended to cover non-exclusive inclusions. The terms "first," "second," and the like in the description and claims of this application or in the above-described drawings are used for distinguishing between different elements and not for describing a particular sequential or chronological order.

Reference in the specification to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the specification. The appearances of the phrase in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments.

In the description of the present application, it is to be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "attached" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present application can be understood by those of ordinary skill in the art as the case may be.

The term "and/or" in this application is only one kind of association relationship describing the associated object, and means that there may be three kinds of relationships, for example, a and/or B, which may mean: a exists alone, A and B exist simultaneously, and B exists alone. In addition, the character "/" in this application generally indicates that the former and latter related objects are in an "or" relationship.

In the embodiments of the present application, like reference numerals denote like parts, and a detailed description of the same parts is omitted in different embodiments for the sake of brevity. It should be understood that the thickness, length, width and other dimensions of the various components in the embodiments of the present application and the overall thickness, length, width and other dimensions of the integrated device shown in the drawings are only exemplary and should not constitute any limitation to the present application.

The appearances of "a plurality" in this application are intended to mean more than two (including two).

In this application, the battery cell may include a lithium ion secondary battery cell, a lithium ion primary battery cell, a lithium sulfur battery cell, a sodium lithium ion battery cell, a sodium ion battery cell, or a magnesium ion battery cell, and the embodiment of the present application is not limited thereto. The battery cell may be a cylinder, a flat body, a rectangular parallelepiped, or other shapes, which is not limited in the embodiments of the present application.

Reference to a battery in embodiments of the present application refers to a single physical module that includes one or more battery cells to provide higher voltage and capacity. For example, the battery referred to in the present application may include a battery module or a battery pack, etc. Batteries generally include a case for enclosing one or more battery cells. The box can avoid liquid or other foreign matters to influence the charging or discharging of battery monomer.

The battery cell includes an electrode assembly and an electrolyte, the electrode assembly including a positive electrode tab, a negative electrode tab, and a separator. The battery cell mainly depends on metal ions to move between the positive pole piece and the negative pole piece to work. The positive pole piece comprises a positive current collector and a positive active substance layer, and the positive active substance layer is coated on the surface of the positive current collector; the positive current collector comprises a positive current collecting part and a positive electrode lug connected to the positive current collecting part, wherein the positive current collecting part is coated with a positive active substance layer, and the positive electrode lug is not coated with the positive active substance layer. Taking a lithium ion battery as an example, the material of the positive electrode current collector may be aluminum, the positive electrode active material layer includes a positive electrode active material, and the positive electrode active material may be lithium cobaltate, lithium iron phosphate, ternary lithium, lithium manganate, or the like. The negative pole piece comprises a negative pole current collector and a negative pole active substance layer, and the negative pole active substance layer is coated on the surface of the negative pole current collector; the negative current collector comprises a negative current collecting part and a negative electrode lug connected to the negative current collecting part, wherein the negative current collecting part is coated with a negative active material layer, and the negative electrode lug is not coated with the negative active material layer. The material of the negative electrode current collector may be copper, the negative electrode active material layer includes a negative electrode active material, and the negative electrode active material may be carbon, silicon, or the like. In order to ensure that the high current can be passed through without fusing, a plurality of positive electrode tabs are stacked together, and a plurality of negative electrode tabs are stacked together. The material of the spacer may be PP (polypropylene) or PE (polyethylene). In addition, the electrode assembly may have a winding structure or a lamination structure, and the embodiment of the present application is not limited thereto.

The safety of the battery cell is deteriorated due to various problems, such as an internal short circuit due to external impact, heat generation due to overcharge and overdischarge, decomposition of an electrolyte due to the generated heat, and a thermal runaway phenomenon. Particularly, when the battery cell rapidly generates gas due to thermal runaway or the like, the generated gas rapidly increases the internal pressure of the battery cell, thereby causing safety problems such as explosion and the like.

In view of this, the embodiment of the present application provides a technical solution, in which a connecting member having a protection function is provided to disconnect an electrical connection between an electrode assembly and an external device when an internal pressure of a battery cell reaches a threshold value, and to discharge the internal pressure of the battery cell, so that a safety risk is reduced, and a safety performance of the battery cell is improved.

The technical scheme described in the embodiment of the application is suitable for the battery and the electric device using the battery.

The electric device can be a vehicle, a mobile phone, a portable device, a notebook computer, a ship, a spacecraft, an electric toy, an electric tool and the like. The vehicle can be a fuel oil vehicle, a gas vehicle or a new energy vehicle, and the new energy vehicle can be a pure electric vehicle, a hybrid electric vehicle or a range-extended vehicle and the like; spacecraft include aircraft, rockets, space shuttles, and spacecraft, among others; the electric toys include stationary or mobile electric toys, such as game machines, electric car toys, electric ship toys, electric airplane toys, and the like; the electric power tools include metal cutting electric power tools, grinding electric power tools, assembly electric power tools, and electric power tools for railways, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, electric impact drills, concrete vibrators, and electric planers. The embodiment of the present application does not particularly limit the above power utilization apparatus.

For convenience of explanation, the following embodiments will be described with an electric device as an example of a vehicle.

Fig. 1 is a schematic structural diagram of a vehicle according to some embodiments of the present disclosure.

As shown in fig. 1, a battery 2 is provided inside a vehicle 1, and the battery 2 may be provided at the bottom or the head or the tail of the vehicle 1. The battery 2 may be used for power supply of the vehicle 1, and for example, the battery 2 may serve as an operation power source of the vehicle 1.

The vehicle 1 may further comprise a controller 3 and a motor 4, the controller 3 being adapted to control the battery 2 to power the motor 4, e.g. for start-up, navigation and operational power demands while driving of the vehicle 1.

In some embodiments of the present application, the battery 2 may be used not only as an operating power source of the vehicle 1, but also as a driving power source of the vehicle 1, instead of or in part of fuel or natural gas, to provide driving power for the vehicle 1.

Fig. 2 is an exploded view of a battery provided in some embodiments of the present application.

As shown in fig. 2, the battery 2 includes a case 5 and a battery cell (not shown) accommodated in the case 5.

The case 5 is used for accommodating the battery cells, and the case 5 may have various structures. In some embodiments, the case 5 may include a first case portion 5a and a second case portion 5b, the first case portion 5a and the second case portion 5b cover each other, and the first case portion 5a and the second case portion 5b together define a receiving space 5c for receiving the battery cell. The second casing part 5b may be a hollow structure with one open end, the first casing part 5a is a plate-shaped structure, and the first casing part 5a covers the open side of the second casing part 5b to form a casing 5 with a containing space 5 c; the first casing portion 5a and the second casing portion 5b may each be a hollow structure having one side opened, and the opened side of the first casing portion 5a may be covered with the opened side of the second casing portion 5b to form the casing 5 having the accommodation space 5c. Of course, the first casing portion 5a and the second casing portion 5b may be various shapes, such as a cylinder, a rectangular parallelepiped, or the like.

In order to improve the sealing property after the first casing portion 5a and the second casing portion 5b are connected, a sealing member, such as a sealant or a gasket, may be provided between the first casing portion 5a and the second casing portion 5 b.

Assuming that the first box portion 5a covers the top of the second box portion 5b, the first box portion 5a may also be referred to as an upper box cover, and the second box portion 5b may also be referred to as a lower box cover.

In the battery 2, one or more battery cells may be provided. If the number of the battery monomers is multiple, the multiple battery monomers can be connected in series or in parallel or in series-parallel, and the series-parallel refers to that the multiple battery monomers are connected in series or in parallel. The plurality of battery monomers can be directly connected in series or in parallel or in series-parallel, and the whole formed by the plurality of battery monomers is accommodated in the box body 5; of course, a plurality of battery cells may be connected in series or in parallel or in series-parallel to form the battery module 6, and a plurality of battery modules 6 may be connected in series or in parallel or in series-parallel to form a whole and accommodated in the box 5.

Fig. 3 is an exploded view of the battery module shown in fig. 2.

In some embodiments, as shown in fig. 3, the battery cell 7 is multiple, and the multiple battery cells 7 are connected in series or in parallel or in series-parallel to form the battery module 6. The plurality of battery modules 6 are connected in series or in parallel or in series-parallel to form a whole and are accommodated in the case.

The plurality of battery cells 7 in the battery module 6 may be electrically connected to each other by a bus member, so as to realize parallel connection, series connection, or parallel-series connection of the plurality of battery cells 7 in the battery module 6.

Fig. 4 is a schematic structural diagram of a battery cell provided in some embodiments of the present application; fig. 5 is a schematic cross-sectional view of the battery cell shown in fig. 4; fig. 6 is an enlarged schematic view of the battery cell shown in fig. 5 at block a.

As shown in fig. 4 to 6, the battery cell 7 of the embodiment of the present application includes: a packaging bag 20; an electrode assembly 10 accommodated in the package bag 20; a first electrode lead 30 at least partially positioned within the pouch 20 and electrically connected to the electrode assembly 10; a second electrode lead 40 at least partially protruding out of the package bag 20; and a connection member 50 for connecting the first and second electrode leads 30 and 40 to electrically connect the first and second electrode leads 30 and 40, the connection member 50 for disconnecting the electrical connection between the first and second electrode leads 30 and 40 and discharging the internal pressure when the internal pressure of the battery cell 7 reaches a threshold value.

The packing bag 20 is formed at the inside thereof with a receiving cavity to receive the electrode assembly 10 and the electrolyte. The shape of the pouch 20 may be determined according to the specific shape of the electrode assembly 10.

The packaging bag 20 includes a bag body 21, the bag body 21 includes a first packaging film 211 and a second packaging film 212, the first packaging film 211 and the second packaging film 212 are arranged one above the other, and the electrode assembly 10 is disposed between the first packaging film 211 and the second packaging film 212.

The first wrapping film 211 and the second wrapping film 212 may be provided separately or integrally. For example, the first wrapping film 211 and the second wrapping film 212 are formed by folding a sheet of wrapping film (e.g., aluminum-plastic film, steel-plastic film, etc.) in half.

The first wrapping film 211 and the second wrapping film 212 are each a multilayer structure. For example, each of the first and second packaging films 211 and 212 includes a protective layer, a metal layer, and a heat-seal layer, which are respectively disposed on both sides of the metal layer. Specifically, the heat-seal layer may be disposed on a surface of the metal layer facing the electrode assembly 10 by an adhesive, and the protective layer may be disposed on a surface of the metal layer facing away from the electrode assembly 10 by an adhesive.

Alternatively, the protective layer may be made of nylon or polyethylene terephthalate, the metal layer may be made of aluminum foil or steel foil, and the heat-sealing layer may be made of polypropylene.

The first and second packaging films 211 and 212 are connected at the outside of the electrode assembly 10 and form a sealing region 213. For example, by heat pressing, the heat seal layer of the first packaging film 211 is fused to the heat seal layer of the second packaging film 212 and forms the seal region 213.

The electrode assembly 10 includes a first pole piece 11, a second pole piece 12, and a separator 13, and the separator 13 serves to separate the first pole piece 11 and the second pole piece 12. The polarities of the first pole piece 11 and the second pole piece 12 are opposite, in other words, one of the first pole piece 11 and the second pole piece 12 is a positive pole piece, and the other of the first pole piece 11 and the second pole piece 12 is a negative pole piece.

A first tab is arranged at the end part of the first pole piece 11, and the first tab is a part of the first pole piece 11 which is not coated with an active substance layer; the end of the second pole piece 12 is provided with a second tab, and the second tab is a part of the second pole piece 12 that is not coated with the active material layer.

One end of the first electrode lead 30 is positioned in the pouch 20 to be connected to the electrode assembly 10 in the pouch 20. The other end of the first electrode lead 30 may or may not extend out of the envelope 20.

Optionally, the first electrode lead 30 is electrically connected to the first pole piece 11, for example, the first electrode lead 30 may be welded to a first tab of the first pole piece 11 to be electrically connected to the first pole piece 11.

The second electrode lead 40 is protruded to the outside of the envelope 20 and is used to electrically connect with an external device. The first electrode lead 30, the connector 50, and the second electrode lead 40 conduct the electrode assembly 10 with an external device to accomplish the charge and discharge of the electrode assembly 10.

The connection member 50 includes a conductive material to electrically connect the first electrode lead 30 and the second electrode lead 40. The connection member 50 may be directly connected to the first and second electrode leads 30 and 40, or may be indirectly connected to the first and second electrode leads 30 and 40.

When a short circuit, overcharge, or the like occurs, the electrode assembly 10 thermally runaway and releases a large amount of high temperature and high pressure substances, such as high temperature and high pressure gas, which acts on the connector 50 and pushes open the connector 50 to electrically disconnect the first electrode lead 30 and the second electrode lead 40, thereby electrically disconnecting the electrode assembly 10 from an external device, breaking a circuit, stopping the charge or discharge of the electrode assembly 10, and slowing down the thermal runaway of the electrode assembly 10. The channel for communicating the inside and the outside of the packaging bag 20 can be formed after the gas rushes out the connecting piece 50, so that the gas and high-temperature and high-pressure substances are quickly discharged to the outside of the single battery 7, the internal pressure is timely discharged, the risks of explosion and fire of the single battery 7 are reduced, and the safety of the single battery 7 is improved.

In some embodiments, the connection member 50 is positioned between the first and second electrode leads 30 and 40 and connected to the first and second electrode leads 30 and 40 in the thickness direction Z of the second electrode lead 40. The inner end 52 of the connector is disposed opposite the electrode assembly 10 and the outer end 51 of the connector is exposed to the outside of the pouch 20.

The first electrode lead 30 and the second electrode lead 40 at least partially overlap in the thickness direction Z. Alternatively, the first and second electrode leads 30 and 40 are each a flat plate structure perpendicular to the thickness direction Z.

Upon thermal runaway of the electrode assembly 10, the generated gas impinges on the inner end 52 of the connector to blow the connector 50 apart.

The gas break-away connection 50 comprises: punching the connection member 50 at the contact surface of the connection member 50 and the first electrode lead 30 to disconnect the connection member 50 from the first electrode lead 30; and/or, punching the connection member 50 at the contact surface of the connection member 50 and the second electrode lead 40 to disconnect the connection member 50 and the second electrode lead 40; and/or, the connection member 50 is punched out of the middle into two parts to disconnect the second electrode lead 40 from the first electrode lead 30.

After the gas blows off the connection member 50, a passage through which the gas is discharged is formed between the first electrode lead 30 and the second electrode lead 40. The outer end 51 of the connector is exposed to the outside of the packing bag 20 so that the passage can extend to the outer end 51 of the connector and communicate with the outside space of the packing bag 20.

In some embodiments, the packing bag 20 surrounds a portion of the first electrode lead 30 and a portion of the second electrode lead 40 to be connected to the first electrode lead 30 and the second electrode lead 40. The bonding strength of the first electrode lead 30 to the connector 50 is less than the bonding strength of the first electrode lead 30 to the packaging bag 20, and the bonding strength of the second electrode lead 40 to the connector 50 is less than the bonding strength of the second electrode lead 40 to the packaging bag 20.

The sealing region 213 of the package bag 20 surrounds a portion of the first electrode lead 30 and a portion of the second electrode lead 40.

The packing bag 20 is connected to the first electrode lead 30 and the second electrode lead 40 to play a role in fixing the first electrode lead 30 and the second electrode lead 40, so that the shaking amplitude of the first electrode lead 30 and the second electrode lead 40 when the battery cell 7 shakes is reduced, and the risk of short circuit is reduced.

The bond strength referred to herein can be characterized by peel strength. In other words, the bond strength between the parts can be compared by a 90 ° peel test.

The position with smaller bonding strength is easier to separate under the action of gas, in the embodiment, the bonding strength of the first electrode lead 30 and the connecting piece 50 and the bonding strength of the second electrode lead 40 and the connecting piece 50 are both smaller, so that the gas can more easily break the connecting piece 50, the gas is prevented from breaking the packaging bag 20 (if the packaging bag 20 is broken, the electric connection between the first electrode lead 30 and the second electrode lead 40 cannot be broken), and the safety is improved.

When the gas is generated from the electrode assembly 10, the packing bag 20 is expanded, and at this time, the packing bag 20 may pull the first electrode lead 30 and the second electrode lead 40 in opposite directions to accelerate the separation of the first electrode lead 30 from the connection member 50 and the separation of the second electrode lead 40 from the connection member 50.

In some embodiments, the package 20 includes: a pouch body 21 for accommodating the electrode assembly 10; and an insulator 22 surrounding a portion of the first electrode lead 30 and a portion of the second electrode lead 40 and connected to the pouch body 21 to bond the first electrode lead 30 and the second electrode lead 40 to the pouch body 21.

The heat-seal layer in the pouch body 21 is thin, and the first electrode lead 30 and the second electrode lead 40 are likely to come into contact with the metal layer in the pouch body 21, causing a risk of short circuit. Therefore, the present embodiment reduces the risk of a short circuit by providing the insulator 22 to separate the first and second electrode leads 30 and 40 from the package bag 20.

At least a portion of the insulator 22 is sandwiched between the first and second wrapping films 211 and 212 and welded to the first and second wrapping films 211 and 212, and the first and second electrode leads 30 and 40 pass through the middle of the insulator 22.

Optionally, the material of the insulator 22 is polypropylene.

The bonding strength of the first electrode lead 30 to the connector 50 is less than the bonding strength of the first electrode lead 30 to the insulator 22 and the bonding strength of the pouch 21 to the insulator 22, and the bonding strength of the second electrode lead 40 to the connector 50 is less than the bonding strength of the second electrode lead 40 to the insulator 22 and the bonding strength of the pouch 21 to the insulator 22.

The position with smaller bonding strength is easier to separate under the action of gas, in the embodiment, the bonding strength of the first electrode lead 30 and the connecting piece 50 and the bonding strength of the second electrode lead 40 and the connecting piece 50 are both smaller, so that gas can more easily break through the connecting piece 50, the gas is prevented from breaking through the bag body 21 and the insulator 22, and the safety is improved.

In some embodiments, the outer end of the second electrode lead 40, facing away from the electrode assembly 10, extends outside the package bag 20 and beyond the outer end of the first electrode lead 30, facing away from the electrode assembly 10, and the outer end 31 of the first electrode lead extends outside the package bag 20 and beyond the outer end 51 of the connector. The dimension of the outer end 31 of the first electrode lead beyond the outer end 51 of the connector is less than the thickness of the connector 50.

The outer end 41 of the second electrode lead exceeds the outer end 31 of the first electrode lead to facilitate connection of the second electrode lead 40 to an external device and to reduce the risk of interference of the first electrode lead 30 with the external device. The outer ends 31 and 41 of the first and second electrode leads each exceed the outer end 51 of the connector, which can reduce the risk of the outer end 51 of the connector exceeding the first and second electrode leads 30 and 40 due to assembly errors, and ensure the bonding strength of the connector 50 to the first electrode lead 30 and the bonding strength of the connector 50 to the second electrode lead 40.

The outer end 31 of the first electrode lead is a free end which may be bent towards the second electrode lead 40, which may result in overlapping of the outer end 31 of the first electrode lead on the second electrode lead 40 and a functional failure of the connection member 50 if the portion of the first electrode lead 30 beyond the outer end 51 of the connection member is too long.

This embodiment makes the dimension of the outer end 31 of the first electrode lead beyond the outer end 51 of the connector smaller than the thickness of the connector 50, which can reduce the risk of the first electrode lead 30 overlapping the second electrode lead 40.

In some embodiments, the inner end of the first electrode lead 30 facing the electrode assembly 10 exceeds the inner end of the second electrode lead 40 facing the electrode assembly 10 and is connected to the electrode assembly 10, and the inner end 42 of the second electrode lead exceeds the inner end 52 of the connector. The dimension of the inner end 42 of the second electrode lead beyond the inner end 52 of the connector is less than the thickness of the connector 50.

The inner end 32 of the first electrode lead exceeds the inner end 42 of the second electrode lead to facilitate the connection of the first electrode lead 30 with the electrode assembly 10 and reduce the risk of the second electrode lead 40 being electrically connected with the electrode assembly 10. Both the inner end 32 of the first electrode lead and the inner end 42 of the second electrode lead exceed the inner end 52 of the connector, which can reduce the risk that the inner end 52 of the connector exceeds the first electrode lead 30 and the second electrode lead 40 due to assembly errors, and ensure the bonding strength of the connector 50 to the first electrode lead 30 and the bonding strength of the connector 50 to the second electrode lead 40.

This embodiment makes the inner end 42 of the second electrode lead beyond the inner end 52 of the connector smaller than the thickness of the connector 50, which can reduce the risk of the second electrode lead 40 overlapping the first electrode lead 30.

In some embodiments, the connection member 50 is a conductive polymer and is adhered to the first and second electrode leads 30 and 40.

In some embodiments, the melting point of the connecting member 50 is lower than the melting point of the insulator 22 and the melting point of the bag body 21, so that the connecting member 50 is more easily softened and first pushed open by the high-temperature and high-pressure gas.

Fig. 7 is a schematic partial cross-sectional view of the battery cell shown in fig. 4; fig. 8 is an enlarged schematic view of fig. 7 at circle B. Fig. 7 is a schematic cross-sectional view of the battery cell of fig. 4 at the sealing part.

As shown in fig. 7 and 8, in some embodiments, the connector 50 is attached to the bag 20 at both ends in a first direction X that is perpendicular to the direction from the inner end of the connector to the outer end of the connector.

In the present embodiment, the connection member 50 is coupled to the packing bag 20 to seal the space between the first electrode lead 30 and the second electrode lead 40, ensuring the sealability of the battery cell 7.

In some embodiments, the connector 50 is adhesively attached to the insulator 22.

It should be noted that the embodiments and features of the embodiments in the present application may be combined with each other without conflict.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, and not to limit the same; although the present application has been described in detail with reference to the foregoing embodiments, it should be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may be modified or some technical features may be equivalently replaced, but the modifications or the replacements do not cause the essence of the corresponding technical solutions to depart from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims (10)

1. A battery cell, comprising:

packaging bags;

an electrode assembly accommodated in the package bag;

a first electrode lead at least partially disposed within the pouch and electrically connected to the electrode assembly;

a second electrode lead at least partially extending out of the packaging bag; and

a connection member for connecting the first electrode lead and the second electrode lead to electrically connect the first electrode lead and the second electrode lead, the connection member being for disconnecting the electrical connection between the first electrode lead and the second electrode lead and discharging the internal pressure when the internal pressure of the battery cell reaches a threshold value.

2. The battery cell according to claim 1, wherein the connector is located between and connected to the first electrode lead and the second electrode lead in a thickness direction of the second electrode lead;

the inner end of the connector is disposed opposite to the electrode assembly, and the outer end of the connector is exposed to the outside of the package bag.

3. The battery cell according to claim 2, wherein the packing bag surrounds a portion of the first electrode lead and a portion of the second electrode lead to be connected to the first electrode lead and the second electrode lead;

the bonding strength of the first electrode lead and the connecting piece is smaller than that of the first electrode lead and the packaging bag, and the bonding strength of the second electrode lead and the connecting piece is smaller than that of the second electrode lead and the packaging bag.

4. The battery cell of claim 3, wherein the packaging bag comprises:

a pouch body for accommodating the electrode assembly; and

an insulator surrounding a portion of the first electrode lead and a portion of the second electrode lead and connected to the pouch body to bond the first electrode lead and the second electrode lead to the pouch body;

wherein a bonding strength of the first electrode lead to the connector is less than a bonding strength of the first electrode lead to the insulator and a bonding strength of the bag to the insulator, and a bonding strength of the second electrode lead to the connector is less than a bonding strength of the second electrode lead to the insulator and a bonding strength of the bag to the insulator.

5. The battery cell as recited in claim 2, wherein the outer end of the second electrode lead facing away from the electrode assembly projects outside the pouch and beyond the outer end of the first electrode lead facing away from the electrode assembly, and the outer end of the first electrode lead projects outside the pouch and beyond the outer end of the connector;

the size of the outer end of the first electrode lead beyond the outer end of the connector is smaller than the thickness of the connector.

6. The battery cell according to claim 2, wherein an inner end of the first electrode lead facing the electrode assembly exceeds an inner end of the second electrode lead facing the electrode assembly and is connected to the electrode assembly, and an inner end of the second electrode lead exceeds an inner end of the connector;

the size of the inner end of the second electrode lead exceeding the inner end of the connector is smaller than the thickness of the connector.

7. The battery cell as claimed in claim 2, wherein both ends of the connecting member are connected to the pouch in a first direction perpendicular to a direction from the inner end of the connecting member to the outer end of the connecting member.

8. The battery cell of claim 1, wherein the connector is a conductive polymer and is bonded to the first and second electrode leads.

9. A battery comprising a plurality of battery cells according to any one of claims 1-8.

10. An electrical device comprising a battery according to claim 9 for providing electrical energy.

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