CN220341474U

CN220341474U - Safety battery

Info

Publication number: CN220341474U
Application number: CN202321812007.4U
Authority: CN
Inventors: 臧世伟; 刘文卿
Original assignee: Shenzhen Jinmei New Material Technology Co ltd
Current assignee: Shenzhen Jinmei New Material Technology Co ltd
Priority date: 2023-07-11
Filing date: 2023-07-11
Publication date: 2024-01-12
Anticipated expiration: 2033-07-11

Abstract

The present utility model provides a safety battery including: the lithium ion battery comprises a shell, and a positive pole piece, a negative pole piece and a diaphragm which are arranged in the shell, wherein the diaphragm is positioned between the positive pole piece and the negative pole piece; the positive pole piece and the negative pole piece both comprise current collectors, and when the internal temperature of the safety battery reaches the thermal runaway temperature, the current collectors enable the current of the positive pole piece and the current of the negative pole piece to be cut off. In the embodiment of the utility model, when the internal temperature of the battery is about to reach the runaway temperature, the current collector can damage the structure of the battery, so that the current of the positive pole piece and the negative pole piece is cut off, the ignition and combustion caused by the high temperature of the battery are avoided, and the safety of the battery is greatly improved.

Description

Safety battery

Technical Field

The utility model relates to the technical field of ion batteries, in particular to a safety battery.

Background

The ion battery has higher energy density and cycle performance, is widely applied in the fields of consumer electronics, electric automobiles, energy storage and the like, and has great attention in the industry under the background of the times, and the development of the ion battery has great economic and social significance.

However, the safety problem of the use of the ion battery cannot be ignored, the ion battery is available according to the electric power formula w= UIt, and under the condition that the current flowing through the battery is the same in the same time, the higher the discharge voltage of the battery is, the greater the acting power is, namely the higher the internal resistance is, the acting power and the heating are, and the temperature of the battery is also gradually increased; the working temperature of the battery is too high, so that serious thermal hazard effect is caused, and safety accidents such as fire and explosion are finally caused.

Currently, there is a need for a battery that can solve the problem that the battery is easily burned due to the difficulty in digestion of heat accumulated in the battery due to the uncontrolled internal temperature of the battery, and that can cut off the current and thus prevent the battery from burning when the internal temperature of the battery is out of control.

Disclosure of Invention

Accordingly, an objective of the embodiments of the present utility model is to provide a safety battery, so as to solve the technical problem that the battery is easy to burn due to the fact that the internal temperature of the battery is out of control and the heat is difficult to digest in the battery.

In order to achieve the above object, an embodiment of the present utility model provides a safety battery including: the lithium ion battery comprises a shell, and a positive pole piece, a negative pole piece and a diaphragm which are arranged in the shell, wherein the diaphragm is positioned between the positive pole piece and the negative pole piece;

the positive pole piece and the negative pole piece both comprise current collectors, and when the internal temperature of the safety battery reaches the thermal runaway temperature, the current collectors enable the current of the positive pole piece and the current of the negative pole piece to be cut off.

In some possible embodiments, the current collector comprises: the conductive material comprises a base material layer, a conductive layer or a deformation material layer, wherein the deformation material layer is positioned between the base material layer and the conductive layer;

the deformation material layer is made of a first thermal deformation material.

In some possible embodiments, the current collector comprises: a substrate layer and a conductive layer arranged on the surface of the substrate layer;

the base material layer is made of a first thermal deformation material.

In some possible embodiments, the first thermal deformation material has a thermal deformation temperature below the thermal runaway temperature.

In some possible embodiments, the current collector comprises: the conductive material comprises a substrate layer, a conductive layer arranged on the surface of the substrate layer and a hot melt material layer arranged on the surface of the conductive layer;

the layer of hot melt material has a melting temperature that is lower than the thermal runaway temperature.

In some possible embodiments, the conductive layer is metallic aluminum, metallic copper, or a metallic alloy.

In some possible embodiments, the separator comprises:

the support layer and a plurality of holes arranged on the support layer;

the supporting layer is made of a second thermal deformation material.

In some possible embodiments, the separator comprises: the support layer, the deformation layer arranged on one surface or two surfaces of the support layer, and a plurality of holes penetrating through the support layer and the deformation layer;

in some possible embodiments, the second thermal deformation material has a thermal deformation temperature that is lower than the deformation temperature of the first thermal deformation material.

In some possible embodiments, the first thermal deformation material and the second thermal deformation material are both memory materials.

The beneficial technical effects of the technical scheme are as follows:

the embodiment of the utility model provides a safety battery, which comprises: the lithium ion battery comprises a shell, and a positive pole piece, a negative pole piece and a diaphragm which are arranged in the shell, wherein the diaphragm is positioned between the positive pole piece and the negative pole piece; the positive pole piece and the negative pole piece both comprise current collectors, and when the internal temperature of the safety battery reaches the thermal runaway temperature, the current collectors enable the current of the positive pole piece and the current of the negative pole piece to be cut off. In the embodiment of the utility model, when the internal temperature of the battery is about to reach the runaway temperature, the current collector can damage the structure of the battery, so that the current of the positive pole piece and the negative pole piece is cut off, the ignition and combustion caused by the high temperature of the battery are avoided, and the safety of the battery is greatly improved.

Drawings

In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings that are required in the embodiments or the description of the prior art will be briefly described, it being obvious that the drawings in the following description are only some embodiments of the utility model, and that other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

Fig. 1 is a schematic structural view of a safety battery according to an embodiment of the present utility model;

fig. 2 is a schematic structural view of a first current collector according to an embodiment of the present utility model;

fig. 3 is a schematic structural view of a second current collector according to an embodiment of the present utility model;

fig. 4 is a schematic structural view of a third current collector according to an embodiment of the present utility model;

FIG. 5 is a top view of a septum of an embodiment of the utility model;

fig. 6 is a cross-sectional view of a diaphragm of an embodiment of the utility model.

Reference numerals illustrate:

10. a housing; 11. a positive electrode sheet; 12. a negative electrode plate; 13. a diaphragm; 131. a support layer; 132. a hole; 133. a deformation layer;

2. a current collector; 21. a substrate layer; 22. a conductive layer; 23. a deformation material layer; 24. a layer of hot melt material.

Detailed Description

Features and exemplary embodiments of various aspects of the utility model are described in detail below. In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of the utility model. It will be apparent, however, to one skilled in the art that the present utility model may be practiced without some of these specific details. The following description of the embodiments is merely intended to provide a better understanding of the utility model by showing examples of the utility model. In the drawings and the following description, at least some well-known structures and techniques have not been shown in detail in order not to unnecessarily obscure the present utility model; also, the dimensions of some of the structures may be exaggerated for clarity. Furthermore, the described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.

Fig. 1 is a schematic structural view of a safety battery according to an embodiment of the present utility model, as shown in fig. 1, including: a case 10, a positive electrode tab 11, a negative electrode tab 12 and a separator 13 disposed inside the case 10, the separator 13 being located between the positive electrode tab 11 and the negative electrode tab 12; the positive electrode tab 11 and the negative electrode tab 12 each include a current collector 2, and when the internal temperature of the safety battery reaches a thermal runaway temperature, the current collector 2 cuts off the current of the positive electrode tab 11 and the negative electrode tab 12.

In the embodiment of the utility model, when the internal temperature of the battery is about to reach the runaway temperature, the current collector 2 can damage the structure of the battery, so that the current of the positive electrode plate 11 and the negative electrode plate 12 is cut off, the ignition and combustion caused by the high temperature of the battery are avoided, and the safety of the battery is greatly improved.

Fig. 2 is a schematic structural view of a first current collector according to an embodiment of the present utility model, and as shown in fig. 2, in some embodiments, the current collector 2 includes: a base material layer 21, a conductive layer 22, or a deformation material layer 23, the deformation material layer 23 being located between the base material layer 21 and the conductive layer 22; the material of the deformation material layer 23 is a first thermal deformation material.

In this embodiment, the deformation material layer 23 is disposed between the base material layer 21 and the conductive layer 22, when the internal temperature of the battery reaches the thermal runaway temperature, since the deformation material layer 23 is a first thermal deformation material, the deformation material layer 23 will deform after reaching the deformation temperature after being heated, the conductive layer 22 outside the deformation material layer 23 will be damaged, and then the positive pole piece 11 or the negative pole piece 12 can prevent the formation of current, cut off the current in the battery, and avoid the internal temperature rise of the battery, and the accumulation of heat difficult to digest, which results in the ignition and burning of the battery.

Fig. 3 is a schematic structural view of a second current collector according to an embodiment of the present utility model, and as shown in fig. 3, in some embodiments, the current collector 2 includes: a base material layer 21, and a conductive layer 22 provided on the surface of the base material layer 21; the material of the base material layer 21 is a first thermal deformation material. In this embodiment, since the base material layer 21 is made of the first thermal deformation material, when the base material layer 21 is heated and deformed after reaching the deformation temperature, the conductive layer 22 on the outer side of the base material layer 21 will be damaged, and then the positive electrode plate 11 or the negative electrode plate 12 can prevent the formation of current, cut off the current in the battery, and avoid the increase of the temperature in the battery, and the accumulation of heat difficult to digest, which results in the ignition and burning of the battery.

Fig. 4 is a schematic structural view of a third current collector according to an embodiment of the present utility model, and as shown in fig. 4, in some embodiments, the current collector 2 includes: a base material layer 21, a conductive layer 22 provided on the surface of the base material layer 21, and a hot melt material layer 24 provided on the surface of the conductive layer 22; the melting temperature of the layer of hot melt material 24 is below the thermal runaway temperature.

In this embodiment, since the melting temperature of the hot-melt material layer 24 is lower than the thermal runaway temperature, if the temperature inside the battery reaches or is about to reach the thermal runaway temperature, that is, the melting temperature of the hot-melt material is reached, the hot-melt material layer 24 disposed on the surface of the conductive layer 22 will melt, the active material coated on the surface of the current collector 2 will fall off along with the melting of the hot-melt material, after the active material falls off, the positive electrode tab 11 or the negative electrode tab 12 can prevent the formation of current, cut off the current inside the battery, and avoid the internal temperature rise of the battery, the accumulation of heat difficult to digest, and the ignition and burning of the battery. In this embodiment, the hot-melt material may be a modified bismaleimide polymer obtained by modifying a bismaleimide group-containing compound with barbituric acid, wherein the molar ratio of barbituric acid to the bismaleimide group-containing compound is 1:0.5-5, and of course, other materials may be used as long as the melting temperature of the hot-melt material layer 24 is lower than the runaway temperature of the battery.

In some embodiments, the conductive layer 22 is metallic aluminum, metallic copper, or a metallic alloy. In this embodiment, the metal alloy may be nickel-copper alloy or nickel-aluminum alloy, and in addition, the metal type of the conductive layer 22 may be determined according to the polarity of the electrode sheet or the specific application, for example, when the current collector 2 in this embodiment is used as the positive current collector of the positive electrode sheet 11, the metal material of the outermost conductive layer 22 is aluminum; of course, other metal or nonmetal layers may be disposed between the aluminum layer and the base material layer 21, and may be determined according to specific requirements, but as the positive electrode sheet 11, the outer layer of the current collector 2 must be aluminum, and then a positive electrode active material is disposed on the positive electrode current collector. When the current collector 2 in the present embodiment is used as the negative current collector of the negative electrode tab 12, the metal material of the outermost conductive layer 22 is copper; of course, other metal or nonmetal layers may be provided between the copper layer and the base material layer 21, depending on specific requirements, but the outermost must be copper, and then the anode active material is provided on the copper layer.

Fig. 5 is a top view of a diaphragm of an embodiment of the utility model, as shown in fig. 5, the diaphragm 13 includes: a supporting layer 131 and a plurality of holes 132 arranged on the supporting layer 131; the material of the supporting layer 131 is a second thermal deformation material. In this embodiment, when the battery temperature rises to the battery thermal runaway temperature, that is, when the battery internal temperature reaches the deformation temperature of the second thermal deformation material, the supporting layer 131 will deform, so that the hole 132 is closed to reduce or close the ion operation channel in the battery, thereby realizing the function of cutting off the internal current of the battery, avoiding the ignition and burning of the battery and further preventing the danger.

Fig. 6 is a cross-sectional view of a diaphragm of an embodiment of the utility model, as shown in fig. 6, the diaphragm 13 comprising: the support layer 131 and the deformation layer 133 disposed on one surface or both surfaces of the support layer 131, and a plurality of holes 132 penetrating the support layer 131 and the deformation layer 133, wherein the support layer 131 is made of a second thermal deformation material. The holes 132 in this embodiment penetrate through the supporting layer 131 and the deformation layer 133 at the same time, when the battery temperature rises to the battery thermal runaway temperature, that is, when the battery internal temperature reaches the deformation temperature of the second thermal deformation material, the deformation layer 133 will deform, so that the holes 132 above the supporting layer 131 and the holes 132 above the deformation layer 133 are partially or completely staggered, so as to reduce or close the function of the ion operation channel in the battery, further realize cutting off the internal current of the battery, avoid causing the ignition and burning of the battery, and further prevent the danger.

In some embodiments, the thermal deformation temperature of the second thermal deformation material is lower than the deformation temperature of the first thermal deformation material, i.e. the deformation temperature of the separator 13 is lower than the deformation temperature of the current collector, so that the safety factor of the battery will be greatly improved, because firstly the deformation of the separator 13 will absorb heat, then the holes above are closed, the movement of ions is prevented, the current is blocked, then if the temperature is still further increased, the deformation material of the current collector 2 will deform, at this time thoroughly cutting off the transmission of current, and at the same time, the temperature of the battery can also be reduced because the deformation material will absorb heat.

In addition, the thermal deformation temperature of the deformation layer 133 is lower than the thermal runaway temperature of the battery by 1 to 50 degrees. In this embodiment, the thermal deformation temperature of the deformation layer 133 is lower than the thermal runaway temperature by 1-50 ℃ for example, when the battery temperature reaches the thermal runaway temperature by 50 °, the deformation layer 133 starts to deform slightly, so that the holes 132 on the deformation layer 133 and the holes 132 on the supporting layer 131 can be partially staggered, and the partial ion transmission inside the battery can be reduced or isolated, thereby reducing the probability of thermal runaway. When the temperature reaches the thermal runaway temperature, the deformation layer 133 and the supporting layer 131 deform simultaneously, the holes 132 on the deformation layer 133 are staggered with the holes 132 on the supporting layer 131, and partial ion transmission in the battery is isolated, so that the probability of thermal runaway can be reduced; meanwhile, the thermal deformation of the deformation layer 133 and the support layer 131 may absorb a certain amount of heat, thereby further reducing the risk of combustion of the battery.

In some embodiments, the first and second thermally deformable materials are both memory materials. In some embodiments, the thermally deformable material is a memory material. In this embodiment, the thermal deformation material is preferably a deformation material having a memory effect, i.e., a memory material; the deformation material with memory effect means that the deformation material is deformed at a certain temperature, but when the temperature is reduced, the deformation material is restored to a state without deformation, particularly when the temperature of the battery is not restored from the thermal runaway temperature to a certain temperature space, and at this time, the risk of thermal runaway is reduced, but the efficiency of the battery is reduced when the temperature is reduced, however, if the deformation material with memory effect is used, after the deformation material deforms to close the part of the hole 132, the deformation material can be restored, and the use of the battery after the temperature rise and the temperature drop is not reduced. In this embodiment, the memory effect thermal deformation material may be a memory alloy material in the existing materials. That is, the deformation layer 133 in the present embodiment can be restored, and the performance of the battery is not affected after the restoration.

In some embodiments, the deformation material layer 23, the base material layer 21, the support layer 131, or the deformation layer 133 may be polypropylene, polystyrene, polychloroetene, polyethylene, or polyamide. Specifically, the thermal deformation temperature of polypropylene (PP) is 160 ℃, the thermal deformation temperature of Polystyrene (PS) is 200 ℃, the thermal deformation temperature of Polychloroethylene (PVC) is 220 ℃, the thermal deformation temperature of polypropylene (PP) is 160 ℃, the thermal deformation temperature of Polystyrene (PS) is 200 ℃, and the thermal deformation temperature of Polychloroethylene (PVC) is 220 ℃, the first thermal deformation material and the second thermal deformation material in this embodiment may be selected according to the thermal runaway temperature of the battery, as long as the thermal deformation temperature of the thermal deformation material is lower than the thermal runaway temperature of the battery.

In the description of the embodiments of the present utility model, it should be noted that the orientation or positional relationship indicated by "upper, lower, inner and outer", etc. in terms are based on the orientation or positional relationship shown in the drawings, and are merely for convenience of describing the present utility model and simplifying the description, rather than indicating or suggesting that the device or element in question must have a specific orientation, be configured and operated in a specific orientation, and thus should not be construed as limiting the present utility model. Furthermore, the terms "first, second, or third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

The terms "mounted, connected, and coupled" in embodiments of the utility model are to be construed broadly, unless otherwise specifically indicated and defined, for example: can be fixed connection, detachable connection or integral connection; it may also be a mechanical connection, an electrical connection, or a direct connection, or may be indirectly connected through an intermediate medium, or may be a communication between two elements. The specific meaning of the above terms in the present utility model will be understood in specific cases by those of ordinary skill in the art.

While the utility model has been described with reference to a preferred embodiment, various modifications may be made and equivalents may be substituted for elements thereof without departing from the scope of the utility model. In particular, the technical features mentioned in the respective embodiments may be combined in any manner as long as there is no structural conflict. The present utility model is not limited to the specific embodiments disclosed herein, but encompasses all technical solutions falling within the scope of the claims.

Claims

1. A safety battery, characterized in that the safety battery comprises: a housing (10), and a positive electrode sheet (11), a negative electrode sheet (12) and a diaphragm (13) which are arranged inside the housing (10), wherein the diaphragm (13) is positioned between the positive electrode sheet (11) and the negative electrode sheet (12);

the positive electrode piece (11) and the negative electrode piece (12) both comprise a current collector (2), and when the internal temperature of the safety battery reaches a thermal runaway temperature, the current collector (2) cuts off the current of the positive electrode piece (11) and the negative electrode piece (12).

2. A safety battery according to claim 1, characterized in that the current collector (2) comprises: -a substrate layer (21), a conductive layer (22) or a deformation material layer (23), the deformation material layer (23) being located between the substrate layer (21) and the conductive layer (22);

the deformation material layer (23) is made of a first thermal deformation material.

3. A safety battery according to claim 1, characterized in that the current collector (2) comprises: a base material layer (21) and a conductive layer (22) provided on the surface of the base material layer (21);

the material of the base material layer (21) is a first thermal deformation material.

4. A safety cell according to claim 3, wherein the first thermally deformable material has a thermal deformation temperature below the thermal runaway temperature.

5. A safety battery according to claim 1, characterized in that the current collector (2) comprises: a base material layer (21), a conductive layer (22) provided on the surface of the base material layer (21), and a hot melt material layer (24) provided on the surface of the conductive layer (22);

the layer of hot melt material (24) has a melting temperature below the thermal runaway temperature.

6. A safety battery according to any of claims 2-5, characterized in that the conductive layer (22) is metallic aluminium, metallic copper or a metallic alloy.

7. A safety battery according to claim 2, characterized in that the separator (13) comprises:

a support layer (131), and a plurality of holes (132) arranged on the support layer (131);

the supporting layer (131) is made of a second thermal deformation material.

8. A safety battery according to claim 2, characterized in that the separator (13) comprises: the support layer (131) and the deformation layer (133) arranged on one surface or two surfaces of the support layer (131), and a plurality of holes (132) penetrating through the support layer (131) and the deformation layer (133);

the supporting layer (131) is made of a second thermal deformation material.

9. A safety cell according to claim 7 or 8, wherein the second thermally deformable material has a lower thermal deformation temperature than the first thermally deformable material.

10. The safety battery of claim 9, wherein the first thermal deformation material and the second thermal deformation material are both memory materials.