CN220692287U - An electrode terminal, battery cell, battery and electrical device - Google Patents

Abstract

An electrode terminal, a battery cell, a battery and an electrical device, belonging to the field of battery technology; the electrode terminal comprises a first metal layer, a safety protection layer and a second metal layer which are stacked in sequence, the first metal layer, the safety protection layer and the second metal layer are integrally formed, and the safety protection layer comprises a conductive fuse layer and/or a thermistor material layer; by arranging the safety protection layer in the electrode terminal, the safety performance of the battery is improved. In addition, the first metal layer, the safety protection layer and the second metal layer are integrally formed, which is conducive to the rapid assembly of the battery.

Description

An electrode terminal, battery cell, battery and electrical device

Technical Field

The present application relates to the field of battery technology, specifically, to an electrode terminal, a battery cell, a battery and an electrical device.

Background technique

Lithium-ion batteries are widely used due to their high energy density and long cycle life. The large number of applications of lithium-ion batteries has attracted more and more attention to their safety, especially in large-scale applications, such as electric bicycles, electric vehicles, energy storage power stations and other fields. At present, the most important obstacle restricting the application of lithium-ion batteries is battery safety, that is, batteries are prone to explosion or combustion and other unsafe events under abuse conditions such as overcharging, short circuit, puncture, extrusion, and high temperature thermal shock. Therefore, lithium-ion batteries The safety performance of ion batteries still needs to be improved.

Utility model content

In view of the above problems, this application provides an electrode terminal, a battery cell, a battery and an electrical device, which can improve the safety performance of the battery.

In a first aspect, the present application provides an electrode terminal, which includes a first metal layer, a safety protection layer, and a second metal layer stacked in sequence, wherein the first metal layer, the safety protection layer, and the second metal layer are fixedly connected, and the safety protection layer includes a conductive fuse layer and/or a thermistor material layer, wherein the melting temperature of the conductive fuse layer material is lower than the melting temperature of the first metal layer material and the second metal layer material; and the material of the thermistor material layer includes a positive temperature coefficient thermistor material.

In the above implementation process, a safety protection layer is provided in the electrode terminal, and the safety protection layer includes a conductive fuse layer and/or a thermistor material layer. The conductive fuse layer can be caused by melting when the battery heats up to a certain level. The melted conductive fuse layer shrinks in size due to phase changes, which in turn causes the electrode terminals to open circuits, thereby improving battery safety performance. At the same time, since the sides of the electrode terminals are wrapped with plastic parts, no parts will fall into the battery after melting and disconnection, reducing the possibility of the separator melting and causing a short circuit in the battery. Moreover, due to the obstruction of the wrapped plastic part, the molten liquid will not flow out. After the battery temperature decreases, the conductive fuse layer returns to its original state, making the battery reversible. The resistance value of the thermistor material layer increases as the temperature increases. The increase in resistance value will lead to an increase in voltage. When the battery heats up to a certain level, the voltage value can trigger system protection, thereby improving the safety performance of the battery. In addition, the first metal layer, the safety protection layer and the second metal layer are fixedly connected, which is beneficial to the rapid assembly of the battery.

In some embodiments, the first metal layer, the security protection layer and the second metal layer are integrally formed.

In the above implementation process, the integrated first metal layer, safety protection layer and second metal layer can further reduce the assembly process of the electrode terminals, thereby facilitating the rapid assembly of the battery.

In some embodiments, the thickness of the safety protection layer is 10% to 60% of the thickness of the electrode terminal.

In the above implementation process, the thicker the safety protection layer, the more beneficial it is to the safety performance of the battery, and the thinner the safety protection layer is, the more beneficial it is to maintaining a small internal resistance of the battery, which in turn is beneficial to the electrical performance of the battery. Controlling the thickness of the safety protection layer to 10% to 60% of the electrode terminal can take into account both the safety and electrical performance of the battery.

In some embodiments, the thickness of the security protection layer is 0.2~3mm.

In some embodiments, the melting temperature of the material of the conductive fuse layer is 85~300°C; and/or

The conductivity of the material of the conductive fuse layer is 10 ^-7 ~10 ^-2 S/M.

During the above implementation process, the melting temperature of the material of the conductive fuse layer is equal to the maximum operating temperature of the battery to a certain extent. Controlling the melting temperature of the material of the conductive fuse layer between 80 and 300°C can effectively reduce the occurrence of thermal runaway of the battery. probability, which is conducive to improving the safety performance of the battery. The conductivity of the conductive fuse layer is usually smaller than the conductivity of the first metal layer and the second metal layer, so the conductivity of the conductive fuse layer usually has a greater impact on the entire electrode terminal. The conductivity of the material that controls the conductive fuse layer is 10 ^{- 7} ~10 ^-2 S/M, which is beneficial to the electrode terminals to maintain good conductivity, which is beneficial to the electrical performance of the battery.

In some embodiments, the melting temperature of the material of the conductive fuse layer is 85°C to 150°C.

During the above implementation process, controlling the melting temperature of the material of the conductive fuse layer between 85 and 150°C can effectively reduce the probability of thermal runaway of the battery and help improve the safety performance of the battery.

In some embodiments, the material of the conductive fuse layer includes a conductive polymer.

In some embodiments, the conductive polymer includes one of polypyrrole, polyphenylene vinylene, polyphenylene sulfide, polythiophene, polyfuran, polyaniline, polycarboxylic acid, a derivative of polypyrrole, a derivative of polyphenylene vinylene, a derivative of polyphenylene sulfide, a derivative of polythiophene, a derivative of polyfuran, a derivative of polyaniline, and a derivative of polycarboxylic acid.

In some embodiments, the thickness of the conductive fuse layer is 0.1~3mm.

In the above implementation process, the thicker the thickness of the conductive fuse layer, the more conducive to the safety performance of the battery, and the thinner the thickness of the conductive fuse layer, the more conducive to maintaining a smaller internal resistance of the battery, which in turn is conducive to the electrical performance of the battery. Controlling the thickness of the conductive fuse layer to 0.1~3mm can take into account the safety and electrical performance of the battery.

In some embodiments, the temperature coefficient of resistance of the material of the thermistor material layer is 10 ^-7 ~10 ^-5 PPM/°C; and/or

The nominal resistance value of the material of the thermistor material layer is 10 ^-3 ~10 ^-1 mΩ.

In some embodiments, the material of the thermistor material layer includes one of a semiconductor thermistor material, a metal thermistor material, an alloy thermistor material, and a composite thermistor material.

In some embodiments, the thickness of the thermistor material layer is 0.1-3 mm.

In the above implementation process, the thicker the thickness of the thermistor material layer, the more conducive to the safety performance of the battery, and the thinner the thickness of the thermistor material layer, the more conducive to maintaining a smaller internal resistance of the battery, which in turn is conducive to the battery. electrical properties. Controlling the thickness of the thermistor material layer to 0.1~3mm can take into account the safety performance and electrical performance of the battery.

In some embodiments, the first metal layer includes a copper layer; and/or

The second metal layer includes an aluminum layer.

In a second aspect, the present application provides a battery cell, which includes the electrode terminal provided in the first aspect.

In some embodiments, the melting temperature of the conductive fuse layer is lower than the maximum safe operating temperature of the battery cell.

In a third aspect, the present application provides a battery, which includes the battery cell provided in the second aspect.

In a fourth aspect, the present application provides an electrical device. The electrical device includes the battery cell provided in the second aspect or the battery provided in the third aspect.

Description of drawings

Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present application. Moreover, the same reference numerals are used throughout the drawings to represent the same components. In the drawings:

Figure 1 is a schematic structural diagram of a vehicle provided by some embodiments of the present application;

Figure 2 is a schematic diagram of the exploded structure of a battery provided by some embodiments of the present application;

Figure 3 is a schematic structural diagram of a battery cell provided by some embodiments of the present application;

Figure 4 is an exploded view of a battery cell provided by some embodiments of the present application;

Figure 5 is a first structural schematic diagram of an electrode terminal provided by some embodiments of the present application;

Figure 6 is a second structural schematic diagram of an electrode terminal provided by some embodiments of the present application.

The reference numbers in the specific implementation are as follows:

1000-vehicle; 100-battery; 200-motor; 300-controller; 10-box; 11-accommodation space; 12-first part; 13-second part; 20-battery cell; 21-casing; 211- Opening; 22-end cover assembly; 221-end cover; 222-electrode terminal; 2221-first metal layer; 2222-safety protection layer; 2222a-conductive fuse layer; 2222b-thermistor material layer; 2223-second metal layer; 2224-plastic part; 23-electrode assembly; 24-current collecting component; 25-insulation protection piece.

Detailed ways

The embodiments of the technical solution of the present application will be described in detail below with reference to the accompanying drawings. The following examples are only used to illustrate the technical solution of the present application more clearly, and are therefore only used as examples and cannot be used to limit the protection scope of the present application.

Unless otherwise defined, all technical and scientific terms used herein have the same meanings as commonly understood by those skilled in the technical field belonging to this application; the terms used herein are for the purpose of describing specific embodiments only and are not intended to be used in Limitation of this application; the terms "including" and "having" and any variations thereof in the description and claims of this application and the above description of the drawings are intended to cover non-exclusive inclusion.

In the description of the embodiments of this application, the technical terms "first", "second", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying the relative importance or implicitly indicating the quantity or specificity of the indicated technical features. Sequence or priority relationship. In the description of the embodiments of this application, "plurality" means two or more, unless otherwise explicitly and specifically limited.

Reference herein 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 present application. The appearances of this 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. Those skilled in the art understand, both explicitly and implicitly, that the embodiments described herein may be combined with other embodiments.

In the description of the embodiments of the present application, the term "and/or" is only a description of the association relationship of associated objects, indicating that three relationships may exist. For example, A and/or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character "/" in this article generally indicates that the associated objects before and after are in an "or" relationship.

In the description of the embodiments of this application, the term "multiple" refers to more than two (including two). Similarly, "multiple groups" refers to two or more groups (including two groups), and "multiple pieces" refers to It is more than two pieces (including two pieces).

In the description of the embodiments of this application, the technical terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "back", "left", "right" and "vertical" The orientation or positional relationships indicated by "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. are based on those shown in the accompanying drawings. The orientation or positional relationship is only for the convenience of describing the embodiments of the present application and simplifying the description. It does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the implementation of the present application. Example limitations.

In the description of the embodiments of this application, unless otherwise clearly stated and limited, technical terms such as "installation", "connection", "connection" and "fixing" should be understood in a broad sense. For example, it can be a fixed connection or a removable connection. It can be disassembled and connected, or integrated; it can also be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be an internal connection between two elements or an interaction between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of this application can be understood according to specific circumstances.

At present, from the perspective of market development, the application of power batteries is becoming more and more extensive. Power batteries are not only used in energy storage power systems such as hydropower, thermal power, wind power and solar power stations, but also widely used in electric vehicles such as electric bicycles, electric motorcycles, electric cars, as well as military equipment and aerospace and other fields. With the continuous expansion of the application field of power batteries, the market demand is also constantly expanding.

The power battery can be a lithium-ion battery, a sodium-ion battery or a magnesium-ion battery, but is not limited thereto. Taking lithium-ion batteries as an example, lithium-ion batteries are widely used in portable electronic devices, electric vehicles and other fields. At present, the main obstacle restricting the application of lithium-ion batteries is the safety of the battery. That is, the battery is very prone to explosion or combustion and other unsafe events under abuse conditions such as overcharging, short circuit, puncture, extrusion, high temperature thermal shock, etc. Therefore, the safety performance of lithium-ion batteries still needs to be improved.

However, installing safety protection components between each electrical connection component will add additional steps, thereby increasing the difficulty of battery assembly. At the same time, there is also the risk that some components will fall into the battery after the protection takes effect, causing the separator to melt, resulting in a short circuit of the battery. In addition, There is also a problem that after the protection takes effect, the battery is damaged and cannot be used anymore.

Based on the above considerations, the safety performance of the battery can be improved without increasing the difficulty of battery assembly. This application proposes an electrode terminal. The electrode terminal includes a first metal layer, a safety protection layer and a second metal layer that are stacked in sequence. The first metal layer, the safety protection layer and the second metal layer are fixedly connected. The safety protection layer It includes a conductive fuse layer and/or a thermistor material layer, the melting temperature of the conductive fuse layer material is lower than the melting temperature of the first metal layer material and the second metal layer material; the material of the thermistor material layer includes a positive temperature coefficient thermosensitive Resistive materials.

In such an electrode terminal, by providing a safety protection layer in the electrode terminal, the safety protection layer includes a conductive fuse layer and/or a thermistor material layer. The conductive fuse layer can be caused by melting when the battery heats up to a certain level. The melted conductive fuse layer shrinks in size due to phase changes, which in turn causes the electrode terminals to open circuits, thereby improving battery safety performance. At the same time, since the side of the electrode terminal is wrapped with a plastic part (the plastic part is at least partially connected to the first metal layer, safety protection layer and second metal layer), no parts will fall into the battery after melting and disconnection. Reduce the possibility of the separator melting and causing a short circuit in the battery. Moreover, due to the obstruction of the wrapped plastic part, the molten liquid will not flow out. After the battery temperature decreases, the conductive fuse layer returns to its original state, making the battery reversible. The resistance value of the thermistor material layer increases as the temperature increases. The increase in resistance value will cause the voltage to rise. When the battery heats up to a certain level, the voltage value can trigger system protection, thereby improving the safety performance of the battery. . In addition, the first metal layer, the safety protection layer and the second metal layer are fixedly connected, which is beneficial to the rapid assembly of the battery.

The electrode terminal can be used to prepare a battery cell, and the battery cell can be, but is not limited to, used in electrical devices such as vehicles, ships, or aircrafts. A power supply system including the battery cells, batteries, etc. disclosed in this application can be used to form the electrical device.

Embodiments of the present application provide an electrical device that uses a battery as a power source. The electrical device may be, but is not limited to, a mobile phone, a tablet, a laptop, an electric toy, an electric tool, a battery car, an electric vehicle, a ship, a spacecraft, etc. Among them, electric toys can include fixed or mobile electric toys, such as game consoles, electric car toys, electric ship toys, electric airplane toys, etc., and spacecraft can include airplanes, rockets, space shuttles, spaceships, etc.

For the convenience of explanation in the following embodiments, an electric device 1000 according to an embodiment of the present application is used as an example.

Please refer to FIG. 1 , which is a schematic structural diagram of a vehicle 1000 provided by some embodiments of the present application. The vehicle 1000 may be a fuel vehicle, a gas vehicle or a new energy vehicle, and the new energy vehicle may be a pure electric vehicle, a hybrid vehicle or an extended-range vehicle, etc. The battery 100 is disposed inside the vehicle 1000 , and the battery 100 may be disposed at the bottom, head, or tail of the vehicle 1000 . The battery 100 may be used to power the vehicle 1000 , for example, the battery 100 may serve as an operating power source for the vehicle 1000 . The vehicle 1000 may also include a controller 300 and a motor 200 . The controller 300 is used to control the battery 100 to provide power to the motor 200 , for example, to meet the power requirements for starting, navigation, and driving of the vehicle 1000 .

In some embodiments of the present application, the battery 100 can not only be used as an operating power source for the vehicle 1000 , but also can be used as a driving power source for the vehicle 1000 , replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000 .

In this application, the battery 100 may refer to a single battery cell 20, or it may refer to a single physical module including multiple battery cells 20 to provide higher voltage and capacity, which may be a battery pack, a battery module, etc. form. The battery 100 may include a case 10 for packaging a plurality of battery cells 20 . The case 10 may prevent liquid or other foreign matter from affecting charging or discharging of the battery cells 20 .

FIG. 2 is a schematic diagram of the exploded structure of the battery 100 provided by some embodiments of the present application. Please refer to FIG. 2 . The battery 100 includes a case 10 and a battery cell 20 . The battery cell 20 is contained in the case 10 .

The box body 10 is used to provide a storage space 11 for the battery cell 20. In some embodiments, the box body 10 may include a first portion 12 and a second portion 13, and the first portion 12 and the second portion 13 cover each other to define the storage space 11 for accommodating the battery cell 20. Of course, the connection between the first portion 12 and the second portion 13 can be sealed by a sealing member (not shown in the figure), and the sealing member can be a sealing ring, a sealant, etc.

The first part 12 and the second part 13 can be in various shapes, such as cuboid, cylinder, etc. The first part 12 may be a hollow structure with one side open to form a receiving cavity for accommodating the battery cells 20 , and the second part 13 may also be a hollow structure with one side open to form a receiving cavity for accommodating the battery cells 20 . The open side of the part 13 is covered with the open side of the first part 12 to form a box 10 having a receiving space 11 . Of course, as shown in Figure 2, the first part 12 can also be a hollow structure with one side open, the second part 13 can be a plate-like structure, and the second part 13 covers the open side of the first part 12 to form a receiving space. 11 in box 10.

In the battery 100, there are a plurality of battery cells 20, and the plurality of battery cells 20 can be connected in series, in parallel, or in mixed connection. Mixed connection means that the plurality of battery cells 20 are connected in series and in parallel. The plurality of battery cells 20 can be directly connected in series or in parallel or mixed together, and then the whole composed of the plurality of battery cells 20 can be accommodated in the box 10 ; of course, the plurality of battery cells 20 can also be connected in series first. They may be connected in parallel or mixed to form a battery module, and multiple battery modules may be connected in series, parallel or mixed to form a whole, and be accommodated in the box 10 . The battery cell 20 may be in the shape of a cylinder, a flat body, a rectangular parallelepiped or other shapes. FIG. 2 exemplarily shows the case where the battery cell 20 is in a square shape.

In some embodiments, the battery 100 may also include a bus component (not shown), through which the multiple battery cells 20 may be electrically connected to achieve series, parallel, or mixed connection of the multiple battery cells 20 . Union.

FIG3 is a schematic diagram of the structure of a battery cell 20 provided in some embodiments of the present application, and FIG4 is an exploded view of a battery cell 20 provided in some embodiments of the present application. Referring to FIG3 and FIG4, the battery cell 20 may include a housing 21, an end cap assembly 22, and an electrode assembly 23. The housing 21 has an opening 211, the electrode assembly 23 is accommodated in the housing 21, and the end cap assembly 22 is used to cover the opening 211.

The shape of the housing 21 can be determined according to the specific shape of the electrode assembly 23. For example, if the electrode assembly 23 is a rectangular parallelepiped structure, the housing 21 can be a rectangular parallelepiped structure. FIG. 3 and FIG. 4 exemplarily show the case where the housing 21 and the electrode assembly 23 are square.

The outer casing 21 can also be made of a variety of materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, etc., which are not particularly limited in the embodiment of the present application.

The end cap assembly 22 includes an end cap 221 and an electrode terminal 222. The end cap assembly 22 is used to cover the opening 211 of the housing 21 to form a sealed installation space (not shown), and the installation space is used to accommodate the electrode assembly 23 . The installation space is also used to accommodate electrolytes, such as electrolytes. The end cap assembly 22 serves as a component for outputting electrical energy from the electrode assembly 23. The electrode terminals 222 in the end cap assembly 22 are used to be electrically connected to the electrode assembly 23, that is, the electrode terminals 222 are electrically connected to the tabs of the electrode assembly 23. For example, the electrode terminals 222 and the tab are connected through the current collecting member 24 to realize the electrical connection between the electrode terminal 222 and the tab.

It should be noted that the opening 211 of the housing 21 may be one or two. If the shell 21 has one opening 211 , the end cover assembly 22 can also have one. The end cover assembly 22 can be provided with two electrode terminals 222 , and the two electrode terminals 222 are respectively used to connect the positive electrode tab and the negative electrode of the electrode assembly 23 . Ear electrical connection. If there are two openings 211 of the housing 21, for example, the two openings 211 are provided on opposite sides of the housing 21, the number of end cover assemblies 22 can also be two, and the two end cover assemblies 22 cover two openings 211 of the housing 21 respectively. Opening 211. In this case, the electrode terminal 222 in one end cap assembly 22 may be a positive electrode terminal for electrical connection with the positive tab of the electrode assembly 23; the electrode terminal 222 in the other end cap assembly 22 may be a negative electrode. The terminal is used for electrical connection with the negative electrode piece of the electrode assembly 23 .

In some embodiments, as shown in FIG. 4 , the battery cell 20 may further include an insulating protective member 25 fixed on the periphery of the electrode assembly 23 . The insulating protective member 25 is used to insulate and isolate the electrode assembly 23 and the outer shell 21 . For example, the insulating protective member 25 is an adhesive tape adhered to the outer periphery of the electrode assembly 23 . In some embodiments, the number of electrode assemblies 23 is multiple, and the insulating protection member 25 is arranged around the periphery of the multiple electrode assemblies 23 to form an integral structure to maintain the structural stability of the electrode assembly 23 .

The electrode assembly 23 includes a positive electrode sheet, a negative electrode sheet and a separator. The cathode sheet includes a cathode current collector and a cathode active material layer. The cathode active material layer is coated on the surface of the cathode current collector. The cathode current collector that is not coated with the cathode active material layer protrudes from the cathode current collector that is coated with the cathode active material layer. , the cathode current collector without coating the cathode active material layer serves as the cathode tab.

The negative electrode sheet includes a negative electrode current collector and a negative electrode active material layer. The negative electrode active material layer is coated on the surface of the negative electrode current collector. The negative electrode current collector that is not coated with the negative electrode active material layer protrudes from the negative electrode current collector that is coated with the negative electrode active material layer. , the negative electrode current collector that is not coated with the negative electrode active material layer is used as the negative electrode tab. The material of the negative electrode current collector can be copper, and the negative electrode active material can be carbon or silicon. In order to ensure that large currents can pass through without melting, the number of positive electrode tabs is multiple and stacked together, and the number of negative electrode tabs is multiple and stacked together. The material of the isolation film can be PP (polypropylene, polypropylene) or PE (polyethylene, polyethylene), etc. In addition, the electrode assembly 23 may be a rolled electrode assembly or a laminated electrode assembly, and the embodiments of the present application are not limited thereto.

5 and 6 are schematic diagrams of the structure of the electrode terminal 222 provided in some embodiments of the present application; please refer to Figures 5 and 6, an embodiment of the present application provides an electrode terminal 222, the electrode terminal 222 includes a first metal layer 2221, a safety protection layer 2222 and a second metal layer 2223 stacked in sequence, the first metal layer 2221, the safety protection layer 2222 and the second metal layer 2223 are fixedly connected, the safety protection layer 2222 includes a conductive fuse layer 2222a and/or a thermistor material layer 2222b, the melting temperature of the conductive fuse layer material is lower than the melting temperature of the first metal layer material and the second metal layer material; the material of the thermistor material layer includes a positive temperature coefficient thermistor material.

The first metal layer 2221, the security protection layer 2222 and the second metal layer 2223 are stacked in sequence, which means that in a vector direction, the security protection layer 2222 is provided on one side of the first metal layer 2221, and the second metal layer 2223 is provided on the security layer. The protective layer 2222 is away from a side of the first metal layer 2221. Normally, the first metal layer 2221, the security protection layer 2222 and the second metal layer 2223 have the same shape. And the first metal layer 2221 or the second metal layer 2223 is in contact with the pole substrate.

The safety protection layer 2222 includes the conductive fuse layer 2222a and/or the thermistor material layer 2222b. This means that the safety protection layer 2222 may be only the conductive fuse layer 2222a, may be only the thermistor material layer 2222b, or may also be composed of the conductive fuse layer 2222a. 2222a and the thermistor material layer 2222b are jointly formed, and the relative positional relationship between the conductive fuse layer 2222a and the thermistor material layer 2222b is not limited, that is, the conductive fuse layer 2222a can be closer to the first metal layer 2221, or it can be thermally The sensitive resistor material layer 2222b is closer to the first metal layer 2221. The conductive fuse layer 2222a refers to a functional layer that can melt when the temperature rises to cause the electrode terminal 222 to break. The thermistor material layer 2222b refers to a functional layer that can trigger system protection of the battery 100 by changing the resistance value after the temperature rises.

The electrode terminal 222 is formed by disposing a safety protection layer 2222 in the electrode terminal 222. The safety protection layer 2222 includes a conductive fuse layer 2222a and/or a thermistor material layer 2222b. The conductive fuse layer 2222a can melt when the battery 100 heats up to a certain level (for example, when an internal short circuit or an external short circuit occurs in the circuit of the battery 100, a huge current is generated, resulting in a rapid generation of heat), resulting in the melted conductive fuse layer 2222a. Due to the phase change, the volume is reduced, thereby causing the electrode terminal 222 to form an open circuit, thereby improving the safety performance of the battery 100 . At the same time, since the side of the electrode terminal 222 is wrapped with the plastic part 2224 (the plastic part 2224 is at least partially connected to the first metal layer 2221, the safety protection layer 2222 and the second metal layer 2223), there will be no The parts fall inside the battery 100, reducing the possibility of the separator melting and causing the battery 100 to short-circuit. Moreover, due to the blocking of the wrapped plastic part 2224, the molten liquid will not flow out. After the temperature of the battery 100 is lowered, the conductive fuse layer 2222a returns to its original state, making the battery 100 reversible. The resistance value of the thermistor material layer 2222b increases as the temperature increases, and the increase in resistance value will lead to an increase in voltage. When the temperature of the battery 100 rises to a certain extent (for example, when an internal short circuit or an external short circuit occurs in the circuit of the battery 100, Generating a huge current, causing rapid generation of heat), this voltage value can trigger system protection, thereby improving the safety performance of the battery 100. In addition, the first metal layer 2221, the safety protection layer 2222 and the second metal layer 2223 are fixedly connected, which is beneficial to the rapid assembly of the battery 100.

In the technical solution of some embodiments of the present application, the first metal layer 2221, the security protection layer 2222 and the second metal layer 2223 are integrally formed.

The first metal layer 2221, the safety protection layer 2222 and the second metal layer 2223 are integrally formed, which means that the first metal layer 2221, the safety protection layer 2222 and the second metal layer 2223 are manufactured in the same process, and the first metal layer 2221. The security protection layer 2222 and the second metal layer 2223 are integrated. For example, the first metal layer 2221, the safety protection layer 2222, and the second metal layer 2223 are formed into a composite plate by precision rolling, and then are stamped to form the electrode terminal 222.

The integrated first metal layer, safety protection layer and second metal layer can further reduce the assembly process of the electrode terminal, thereby facilitating the rapid assembly of the battery.

In the technical solutions of some embodiments of the present application, the thickness of the safety protection layer 2222 is 10% to 60% of the thickness of the electrode terminal 222 . The thicker the safety protection layer 2222 is, the better it is for the safety performance of the battery 100 . The thinner the safety protection layer 2222 is, the better it is for maintaining a smaller internal resistance of the battery 100 , which in turn is better for the electrical performance of the battery 100 . The thickness of the safety protection layer 2222 is controlled to be 10% to 60% of the electrode terminal 222, which can take into account the safety performance and electrical performance of the battery 100.

For example, the thickness of the safety protection layer 2222 may be 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55% or 60% of the electrode terminal 222, etc., It can also be any value within the range of 10% to 60%.

In the technical solutions of some embodiments of the present application, the safety protection layer 2222 has a thickness of 0.2~3 mm, and the safety protection layer 2222 with a thickness of 0.2~3 mm can be applied to the electrode terminals 222 of most batteries 100 .

For example, the thickness of the security protection layer 2222 may be 0.2mm, 0.4mm, 0.6mm, 0.8mm, 1mm, 1.2mm, 1.4mm, 1.6mm, 1.8mm, 2mm, 2.2mm, 2.4mm, 2.6mm, 2.8 mm or 3mm.

In the technical solutions of some embodiments of the present application, the melting temperature of the material of the conductive fuse layer is 85~300°C. Further, the melting temperature of the material of the conductive fuse layer 2222a is 80~150°C. Melting temperature refers to the temperature at which a material melts completely and can usually be measured using a differential scanning calorimeter (DSC). The melting temperature of the material of the conductive fuse layer 2222a is equal to the maximum working temperature of the battery 100 to a certain extent. Controlling the maximum working temperature of the battery 100 at 85~150°C can effectively reduce the probability of thermal runaway of the battery 100 and help improve Battery 100 safety performance.

Exemplarily, the melting temperature of the material of the conductive fuse layer 2222a can be 85°C, 90°C, 95°C, 100°C, 105°C, 110°C, 115°C, 120°C, 125°C, 130°C, 135°C, 140°C, 145°C, 150°C, 155°C, 160°C, 165°C, 170°C, 175°C, 180°C, 185°C, 190°C, 195°C, 200°C, 205°C, 210°C, 215°C, 220°C, 225°C, 230°C, 235°C, 240°C, 245°C, 250°C, 255°C, 260°C, 265°C, 270°C, 275°C, 280°C, 285°C, 290°C, 295°C or 300°C, etc., and it can also be any value in the range of 85~300°C.

It should be noted that in other embodiments, the melting temperature of the material of the conductive fuse layer can be determined according to the maximum safe operating temperature of the battery cell to which it is applied. The melting temperature of the material of the conductive fuse layer only needs to be lower than the maximum safe operating temperature of the battery cell.

In the technical solutions of some embodiments of the present application, the conductivity of the material of the conductive fuse layer 2222a is 10 ^-7 ~10 ^{- 2} S/M. Electrical conductivity, also known as conductivity, is a measurement value that indicates the strength of a substance's ability to transmit current. When voltage is applied to both ends of a substance, its charge carriers will behave in a certain direction, thereby generating current. Conductivity is defined by Ohm's law as the ratio of current density to electric field strength, and conductivity is the reciprocal of resistivity. The unit in the International System of Units is Siemens/meter (S·m ^-1 ). The conductivity of the conductive fuse layer 2222a is usually less than the conductivity of the first metal layer 2221 and the second metal layer 2223, so the conductivity of the conductive fuse layer 2222a usually has a greater impact on the entire electrode terminal 222. Controlling the conductivity of the material of the conductive fuse layer 2222a to be 10 ^-7 ~10 ^-2 S/M is beneficial to maintaining a good conductivity of the electrode terminal 222, and thus beneficial to the electrical performance of the battery 100.

For example, the conductivity of the material of the conductive fuse layer 2222a may be 10 ^-7 S/M, 10 ^-6 S/M, 10 ^-5 S/M, 10 ^{-4 S} /M, 10 ^-3 S/M or 10 ^-2 S/M, etc., which can also be any value within the range of 10 ^-7 ~10 ^-2 S/M.

In technical solutions of some embodiments of the present application, the material of the conductive fuse layer 2222a includes conductive polymer. Conductive polymers refer to polymer materials that have electrical conductivity.

Exemplarily, the conductive polymer may be selected from polypyrrole, polyphenylene vinylene, polyphenylene sulfide, polythiophene, polyfuran, polyaniline, polycarboxylic acid, polypyrrole derivatives, polyphenylene vinylene derivatives, polyphenylene oxide One of thioether derivatives, polythiophene derivatives, polyfuran derivatives, polyaniline derivatives and polycarboxylic acid derivatives.

In the technical solutions of some embodiments of the present application, the thickness of the conductive fuse layer 2222a is 0.1~3 mm. The thicker the conductive fuse layer 2222a is, the better it is for the safety performance of the battery 100. The thinner the conductive fuse layer 2222a is, the better it is for maintaining a smaller internal resistance of the battery 100, which in turn is better for the electrical performance of the battery 100. Controlling the thickness of the conductive fuse layer 2222a to 0.1~3 mm can take into account the safety performance and electrical performance of the battery 100.

For example, the thickness of the conductive fuse layer 2222a may be 0.1mm, 0.3mm, 0.5mm, 0.7mm, 0.9mm, 1.1mm, 1.3mm, 1.5mm, 1.7mm, 1.9mm, 2.1mm, 2.3mm, 2.5mm , 2.7mm, 2.9mm or 3mm, etc., it can also be any value within the range of 0.1~3mm.

In the technical solution of some embodiments of the present application, the resistance temperature coefficient of the material of the thermistor material layer 2222b is 10 ^-7 ~10 ^-5 PPM/℃. The nominal resistance value of the material of the thermistor material layer 2222b is 10 ^-3 ~10 ^-1 mΩ.

For example, the resistance temperature coefficient of the material of the thermistor material layer 2222b may be 10 ^-7 PPM/℃, 10 ^{- 6} PPM/℃ or 10 ^-5 PPM/℃, etc., or it may be 10 ^-7 ~10 ^- Any value within the range of ⁵ PPM/℃. The nominal resistance value of the material of the thermistor material layer 2222b may be 10 ^-3 mΩ, 10 ^-2 mΩ or 10 ^-1 mΩ, etc., and may also be 10 ^-3 ~ 10 ^-1 mΩ.

In the technical solutions of some embodiments of the present application, the material of the thermistor material layer 2222b includes one of a semiconductor thermistor material, a metal thermistor material, an alloy thermistor material and a composite thermistor material.

Semiconductor thermistor materials can be selected from single crystal semiconductors, polycrystalline semiconductors, glass semiconductors, organic semiconductors and metal oxides; metal thermistor materials are widely used as thermal resistance temperature measurement, current limiters and automatic constant temperature heating elements. Applications. Alloy thermistor material is also called thermistor alloy. This alloy has high resistivity and is sensitive to changes in resistance value with temperature. It is a good material for manufacturing temperature-sensitive sensors. The composite thermistor material is mixed with raw materials including fullerene materials, PTC materials and additives and then pre-sintered at 1000~1250℃ to obtain a solid solution; then the solid solution material is ball milled, granulated and heated at 1000~1500℃ obtained by sintering. Among them, the PTC material is barium titanate; or a mixture of iron powder, copper powder and titanium dioxide; the auxiliary agent is a mixture of coupling agent, flame retardant, antioxidant, anti-aging agent, accelerator, cross-linking agent and dispersant; The fullerene material is C60 fullerene.

In the technical solutions of some embodiments of the present application, the thickness of the thermistor material layer 2222b is 0.1~3mm. The thicker the thermistor material layer 2222b is, the more conducive it is to the safety performance of the battery 100. The thinner the thermistor material layer 2222b is, the more conducive it is to maintaining a smaller internal resistance of the battery 100, which in turn is conducive to the safety of the battery 100. electrical properties. Controlling the thickness of the thermistor material layer 2222b to 0.1~3 mm can take into account the safety performance and electrical performance of the battery 100.

For example, the thickness of the thermistor material layer 2222b may be 0.1 mm, 0.3 mm, 0.5 mm, 0.7 mm, 0.9 mm, 1.1 mm, 1.3 mm, 1.5 mm, 1.7 mm, 1.9 mm, 2.1 mm, 2.3 mm, 2.5 mm, 2.7 mm, 2.9 mm or 3 mm, etc. It can also be any value within the range of 0.1~3mm.

In the technical solution of some embodiments of the present application, the first metal layer 2221 includes a copper layer; the second metal layer 2223 includes an aluminum layer.

After the structure of the electrode terminal 222 is introduced above, the preparation method of the electrode terminal 222 will be introduced in detail below.

The preparation method of the electrode terminal 222 includes the following steps: the first metal layer 2221, the safety protection layer 2222 and the second metal layer 2223 are often stacked, and together formed by precision rolling to form an integrated composite plate, and then the composite plate is stamped to form the electrode terminal 222. Electrode terminal 222.

The method is to form an electrode terminal 222 by forming a composite plate integrally formed with a first metal layer 2221, a safety protection layer 2222 and a second metal layer 2223, wherein the electrode terminal 222 is formed by setting a safety protection layer 2222 in the electrode terminal 222, and the safety protection layer 2222 includes a conductive fusing layer 2222a and/or a thermistor material layer 2222b. The conductive fusing layer 2222a can melt when the battery 100 is heated to a certain degree (for example, when an internal short circuit or an external short circuit occurs in the circuit of the battery 100, a huge current is generated, causing a sharp generation of heat). The conductive fusing layer 2222a after melting is reduced in volume due to phase change, thereby causing the electrode terminal 222 to be disconnected, thereby improving the safety performance of the battery 100. At the same time, after the melting is disconnected, no parts will fall into the battery 100, reducing the possibility of the diaphragm melting and causing the battery 100 to short-circuit. Moreover, when the temperature of the battery 100 is low, the conductive fuse layer 2222a returns to its initial state, making the battery 100 reversible. The resistance value of the thermistor material layer 2222b changes with the increase of temperature, and the change of resistance value will cause the change of voltage. When the battery 100 is heated to a certain degree (for example, when the circuit of the battery 100 has an internal short circuit or an external short circuit, a huge current is generated, causing a sharp generation of heat), the voltage value can trigger system protection, thereby improving the safety performance of the battery 100. In addition, the first metal layer 2221, the safety protection layer 2222 and the second metal layer 2223 are integrally formed, which is conducive to the rapid assembly of the battery 100.

The above are only specific embodiments of the present application and are not intended to limit the present application. For those skilled in the art, the present application may have various modifications and changes. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of this application shall be included in the protection scope of this application.

Claims (17)

1. The electrode terminal is characterized by comprising a first metal layer, a safety protection layer and a second metal layer which are sequentially stacked, wherein the first metal layer, the safety protection layer and the second metal layer are fixedly connected, the safety protection layer comprises a conductive fusion layer and/or a thermistor material layer, and the fusion temperature of the conductive fusion layer material is lower than that of the first metal layer material and the second metal layer material; the material of the thermistor material layer comprises a positive temperature coefficient thermistor material.

2. The electrode terminal of claim 1, wherein the first metal layer, the safety protection layer, and the second metal layer are integrally formed.

3. The electrode terminal according to claim 1, wherein the thickness of the safety protection layer is 10% -60% of the thickness of the electrode terminal.

4. The electrode terminal according to claim 3, wherein the thickness of the safety protection layer is 0.2 to 3mm.

5. The electrode terminal according to any one of claims 1 to 4, wherein a melting temperature of a material of the conductive fusion layer is 85 to 300 ℃; and/or

The conductivity of the material of the conductive fusion layer is 10 ^-7 ~10 ^-2 S/M。

6. The electrode terminal according to claim 5, wherein the melting temperature of the material of the conductive fusion layer is 85-150 ℃.

7. The electrode terminal according to any one of claims 1 to 4, wherein the material of the conductive fusion layer comprises a conductive polymer.

8. The electrode terminal according to claim 7, wherein the conductive polymer comprises one of polypyrrole, polyphenylacetylene, polyphenylenesulfide, polythiophene, polyfuran, polyaniline, polycarboxylic acid, a derivative of polypyrrole, a derivative of polyphenylacetylene, a derivative of polyphenylenesulfide, a derivative of polythiophene, a derivative of polyfuran, a derivative of polyaniline, and a derivative of polycarboxylic acid.

9. The electrode terminal according to any one of claims 1 to 4, wherein the thickness of the conductive fusion layer is 0.1 to 3mm.

10. The electrode terminal according to any one of claims 1 to 4, wherein a temperature coefficient of resistance of a material of the thermistor material layer is 10 ^-7 ~10 ^-5 PPM/. Degree.C; and/or

The nominal resistance of the material of the thermistor material layer is 10 ^-3 ~10 ^-1 mΩ。

11. The electrode terminal according to any one of claims 1 to 4, wherein a material of the thermistor material layer includes one of a semiconductor thermistor material, a metal thermistor material, an alloy thermistor material, and a composite thermistor material.

12. The electrode terminal according to any one of claims 1 to 4, wherein the thickness of the thermistor material layer is 0.1 to 3mm.

13. The electrode terminal according to any one of claims 1 to 4, wherein the first metal layer comprises a copper layer; and/or

The second metal layer includes an aluminum layer.

14. A battery cell characterized in that the battery cell comprises the electrode terminal of any one of claims 1 to 13.

15. The battery cell of claim 14, wherein the conductive melt layer has a melting temperature that is less than a safe maximum operating temperature of the battery cell.

16. A battery, characterized in that the battery comprises the battery cell of any one of claims 14 to 15.

17. An electrical device comprising the battery cell of any one of claims 14 to 15 or the battery of claim 16.