JP7482160B2 - Pole assemblies, battery cells and electrical equipment - Google Patents

Description

Embodiments of the present invention relate to the field of battery technology, and in particular to pole assemblies, battery cells, and electrical equipment.

A battery cell is a device that converts external energy into electrical energy, stores it internally, and supplies power to external devices such as portable electronic devices when needed. Currently, batteries are widely used in electronic products such as mobile phones, tablets, and laptops.

Battery cells constantly generate heat under high temperature conditions or when a short circuit occurs, and heat inside the battery cell constantly accumulates, which can lead to thermal runaway and the generation of high-temperature, high-pressure gas inside. If this gas is not immediately released, it may swell and cause a safety accident such as an explosion. Therefore, at present, there is a need to provide a battery cell that can release the gas when the temperature of the battery cell rises above a specified temperature, thereby completing the safety performance of the battery cell.

Embodiments of the present invention aim to provide a pole assembly, a battery cell, and electrical equipment to improve on the current situation where current battery cells are unable to quickly vent internal gases at temperatures above a certain temperature.

In order to solve the above technical problems, the embodiment of the present application takes the following measures.

A pole assembly for use in a battery cell, comprising a pole, a thermal deformation member, and a fixing device. The thermal deformation member is provided to surround the pole and is fixed to the pole. The fixing device has a through hole, is provided to surround the thermal deformation member via the through hole, and is fixed to the thermal deformation member. When the temperature is higher than a predetermined threshold, the thermal deformation member deforms so that pressure relief passages are formed in the through hole that communicate with both ends of the through hole.

As a further improvement to the above embodiment, the thermal deformation member is an insulating material, and the fixing device is located between both ends of the thermal deformation member along the axial direction of the through hole.

As a further improvement to the above embodiment, the fixing device has a non-circular cross section perpendicular to the axial direction of the through hole.

As a further improvement to the above embodiment, the first end of the pole extends beyond the thermal deformation member and the fixing device along the axial direction of the pole.

As a further improvement to the above embodiment, a conductive terminal is further provided that is fixed to the first end, and the end face of the conductive terminal that faces the pole is larger than the end face of the pole and completely covers the pole.

As a further improvement to the above embodiment, the end face is rectangular or rounded, and the difference between the width of the end face and the maximum linear dimension of the end face of the fixture is less than 4 mm.

Further improvements to the above embodiment include that the pole includes a metal, and/or that the thermally deformable member includes polyethylene, polypropylene, or polypropylene ethylene, and/or that the fastener includes a metal.

As a further improvement to the above embodiment, the thermal deformation member melts or shrinks when the temperature is higher than a predetermined threshold so that the pressure relief passage is formed within the through hole.

Another embodiment of the present application further provides a battery cell including a case and an electrode assembly, the case having a housing cavity for housing the electrode assembly and an opening communicating with the housing cavity and the external environment of the battery cell, respectively. The battery cell further includes any one of the pole assemblies described above. The fixture is attached to the opening, a first end of the pole is exposed to the external environment, and a second end of the pole is electrically connected to the electrode assembly.

As a further improvement to the above embodiment, the shape of the opening is configured to match the shape of the fastener.

A battery cell according to yet another embodiment of the present application includes a case and an electrode assembly, and the case has a housing cavity for housing the electrode assembly and an opening communicating with the housing cavity and the external environment of the battery cell, respectively. The battery cell further includes a pole assembly. The pole assembly is attached to the opening and includes a pole and a thermal deformation member. A first end of the pole is exposed to the external environment, and a second end of the pole is electrically connected to the electrode assembly. The thermal deformation member is provided to surround the pole and is located between the pole and the inner wall of the opening.

Another embodiment of the present application further provides an electrical device including any of the pole assemblies described above or any of the battery cells described above.

The beneficial effects of the present application are as follows: The pole assembly provided by the present embodiment is applied to a battery cell including a pole, a thermal deformation member, and a fixing device. Here, the thermal deformation member is provided so as to surround the pole, and is fixed to the pole. A through hole is provided in the fixing device, and the fixing device is placed over the thermal deformation member by the through hole and is fixed to the thermal deformation member. The thermal deformation member is configured to deform so as to form a pressure relief passage in the through hole that is connected to both ends of the through hole when the temperature is higher than a predetermined threshold value.

Compared to battery cells currently available on the market, when the pole assembly according to the embodiment of the present application is applied to a battery cell, the internal thermal deformation member deforms when the temperature of the battery cell exceeds a certain threshold, and further, a pressure relief passage is formed in the through hole of the fastener, allowing the gas in the battery cell to be discharged to the outside, thereby reducing the safety risk of the battery cell exploding. In other words, the pole assembly provided by the embodiment of the present application can improve the current situation in which current battery cells are unable to quickly discharge internal gas when the temperature is higher than a certain temperature.

One or more embodiments are illustrated by way of example only and not by way of limitation in the accompanying drawings. Elements in the drawings that are labeled with the same reference numerals refer to similar elements. Unless otherwise specified, the drawings in the drawings are not to scale.

1 is a schematic cross-sectional view of a battery cell according to an embodiment of the present application taken in one direction; FIG. 2 is a schematic cross-sectional view of the pole assembly in FIG. 1 . FIG. 2 is a view showing the projection of the pole assembly in FIG. 1 in another direction. FIG. 1 is a schematic diagram of an electrical installation according to an embodiment of the present application.

In the following, in order to facilitate understanding of the present application, the present application will be described in more detail in combination with the attached drawings and specific embodiments. Note that when a part is described as being "fixed"/"attached"/"mounted" to another part, they may be directly connected to the other part, or there may be one or more intermediate media between them. When a part is described as being "connected" to another part, it may be directly connected to the other part, or there may be one or more intermediate media between them. The terms "vertical", "horizontal", "left", "right", "inside", "outside" and similar expressions used in this specification are used for explanatory purposes only.

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

Furthermore, the technical features of different embodiments of the present application described below may be combined with each other as long as they do not conflict with each other.

In this specification, "attaching" includes fixing or restricting a part or device to a specific position or location by means of welding, screwing, fastening, adhesion, etc. The part or device may remain stationary at the specific position or location or may move within a limited range. The part or device may be removable or non-removable after being fixed or restricted to the specific position or location, and is not limited in the present embodiment.

1 to 3 show a schematic cross-sectional view of a battery cell 1 according to one embodiment of the present invention, a schematic cross-sectional view along one direction of a pole assembly, and a schematic projection view of the pole assembly from bottom to top. The battery cell 1 includes a case 100, an electrode assembly 200, and a pole assembly 300. Here, an accommodating cavity 101 is provided inside the case 100, and an opening 102 is provided that communicates with the accommodating cavity 101 and the external environment of the battery cell 1, respectively. The electrode assembly 200 is accommodated in the accommodating cavity 101. The pole assembly 300 is attached to the opening 102, and one end is electrically connected to the electrode assembly 200 and the other end is exposed to the external environment, forming an external terminal of the battery cell 1.

As shown in FIG. 1, the case 100 has a generally flat rectangular parallelepiped shape, and has an accommodation cavity 101 for accommodating the electrode assembly 200 and the electrolyte therein. The case 100 further has an opening 102 that connects the accommodation cavity 101 to the external environment of the battery cell 1. The opening 102 is used to attach the pole assembly 300. In this embodiment, the battery cell 1 is a steel shell battery cell, i.e., the case 100 is a steel shell, but in other embodiments of the present application, the battery cell 1 may be a battery cell with another type of hard case. For example, the case 100 may be another metal case, such as an aluminum case.

As shown in FIG. 1, the electrode assembly 200 includes a first electrode sheet (not shown), a second electrode sheet (not shown), and a separation film (not shown) that are accommodated in the accommodation cavity 101 and stacked. Here, the first electrode sheet and the second electrode sheet have opposite polarities and are spaced apart. One of the two electrode sheets is a positive electrode sheet, and the other is a negative electrode sheet. The separation film is disposed between the two electrode sheets and is used to separate the two. The first electrode sheet, the second electrode sheet, and the separation film are arranged in a stacked manner and wound into a columnar structure having an oval cross section so as to be accommodated in the accommodation cavity 101. Note that, although the electrode assembly 200 in this embodiment is a wound electrode assembly, the present application is not limited thereto. In other embodiments of the present application, the electrode assembly 200 may be a stacked electrode assembly. The case 100 is further filled with an electrolyte, and the electrode assembly 200 is soaked in the electrolyte. The electrolyte provides an environment in which lithium ions can be conducted, allowing the first electrode sheet or the second electrode sheet to absorb lithium ions at the appropriate time, thereby realizing the charging and discharging process of the battery cell 1.

Regarding the above-mentioned pole assembly 300, referring specifically to FIG. 1 with reference to FIG. 2 and FIG. 3, the pole assembly 300 is attached to the above-mentioned opening 102 and includes a pole 310, a thermal deformation member 320, and a fixing device 330. Here, the thermal deformation member 320 is provided so as to surround the pole 310 and is fixed to the pole 310. The fixing device 330 is provided with a through hole 301. The fixing device 330 is provided so as to surround the thermal deformation member 320 through the through hole 301 and is fixed to the thermal deformation member 320. The thermal deformation member 320 is configured to deform so that a pressure relief passage communicating with both ends of the through hole 301 is formed in the through hole 301 when the temperature is higher than a predetermined threshold value. As a result, when the temperature of the battery cell 1 becomes higher than the predetermined threshold, the high-pressure gas generated inside the battery cell 1 can be discharged to the external environment of the battery cell 1 through the pressure relief passage, and the swelling of the battery cell 1 can be avoided, thereby reducing or eliminating the risk of explosion of the battery cell 1. Note that the "predetermined threshold" in this application means that the temperature of the battery cell 1 rises to a temperature value at which the thermal deformation member 320 is deformed to fit so as to form a pressure relief passage in the through hole 301 of the fixing device 330. When the temperature of the battery cell is higher than the predetermined threshold, the pressure relief passage is already formed. The predetermined threshold is a temperature value that is higher than the normal operating temperature of the battery cell 1 and lower than the thermal runaway temperature of the battery cell 1. That is, when the battery cell 1 is in a normal operating state, the battery cell 1 is at a temperature lower than the predetermined threshold so that the pressure relief passage is not formed during normal operation. When the battery cell 1 is in a thermal runaway state, the battery cell 1 is at a temperature higher than the predetermined threshold to prevent the internal gas from being unable to be quickly discharged from the battery cell 1 during thermal runaway. In this application, "deformation" specifically includes thermal melting and shrinkage.

The pole 310 is generally in the shape of a pole made of a conductive material. In this embodiment, the pole 310 includes a metal, but of course, in other embodiments of the present application, the pole 310 may include a conductive nonmetal or may include both a metal and a nonmetal. Along the axial direction of the pole 310, the first end 311 thereof exceeds the thermal deformation member 320 and the fixing member 330 and is exposed to the outside of the battery cell 1 to facilitate electrical connection with an external electrical load. The second end 312 enters the above-mentioned housing cavity 101 and is electrically connected to one electrode sheet of the electrode assembly 200 so that the pole 310 constitutes one external terminal of the battery cell 1. In addition, the other electrode sheet in the electrode assembly 200 is electrically connected to the case 100 so that the case 100 as a whole constitutes the other external terminal of the battery cell 1. Here, the first end 311 and the second end 312 are opposite ends along the axial direction of the pole 310.

The thermal deformation member 320 is a core part of the pole assembly 300 having the pressure relief function of the present application, has a cylindrical structure as a whole, is provided so as to surround the pole 310, and is fixed to the pole 310. The above-mentioned cylindrical structure is not limited to a cylindrical shape, and may be a rectangular tube or a cylindrical structure having a polygonal cross section. The thermal deformation member 320 is formed of a material with a relatively low melting point, so that deformation such as melting or shrinking is likely to occur before the thermal runaway of the battery cell 1, and further forms a pressure relief passage for releasing gas into the through hole 301. In some embodiments, the normal operating temperature of the battery cell 1 is less than 100°C and the thermal runaway temperature is 150°C, but considering the possibility of pressure leakage due to thermal shrinkage, it is preferable that the thermal deformation member 320 is made of a material with a melting point between 110°C and 170°C. The thermal deformation member 320 is made of any one of polyethylene, polypropylene, and polypropylene ethylene, or a mixture of these materials.

The fixture 330 is a mounting and fixing part of the pole assembly 300, and is cylindrical as a whole, and has the above-mentioned through hole 301. The fixture 330 is fitted to the outer surface of the thermal deformation member 320 through the inner wall of the through hole 301, and is attached to the opening 102 through the outer wall. The thermal deformation member 320, the pole 310, and the fixture 330 are fixed by hot melt connection. Of course, in other embodiments of the present application, the above-mentioned pole 310, the thermal deformation member 320, and the fixture 330 may be integrally molded by injection molding. Specifically, the pole 310 and the fixture 330 are placed as inserts in an injection molding die. The injection molding die molds the pole assembly 300 by injecting the above-mentioned polyethylene (or polypropylene/polypropylene ethylene). In this embodiment, the fixture 330 is made of metal, and is fixed to the case 100 by welding, and is attached to the case 100 while sealing the opening 102. Preferably, the thermal deformation member 320 is an insulating material to prevent short-circuiting of the positive and negative electrodes of the battery cell 1 caused by the fixing device 330 coming into contact with the pole 310. At the same time, both ends of the fixing device 330 are located between both ends of the thermal deformation member 320 along the longitudinal direction of the through hole 301.

Preferably, in order to prevent the fixing device 330 from rotating relative to the case 100 and to prevent the fixing effect between the fixing device 330 and the case 100 from being destroyed, the fixing device 330 has a non-circular outer shape, for example, a rectangle, a square, a rhombus, a pentagon, etc., in a cross section perpendicular to the axial direction of the through hole 301. Correspondingly, the opening 102 matches the shape of the fixing device 330. That is, the cross section is formed in a non-circular shape that matches the fixing device 330. In this way, after the fixing device 330 is attached to the opening 102, the inner wall of the opening 102 suitably prevents the fixing device 330 from rotating, thereby achieving the above-mentioned purpose. More preferably, in order to prevent the thermal deformation member 320 from rotating relative to the fixing device 330 and further to prevent the fixing effect between the thermal deformation member 320 and the fixing device 330 from being damaged, the outer shape of the cross section perpendicular to the axial direction of the through hole 301 of the thermal deformation member 320 is made non-circular. Correspondingly, the shape of the through hole 301 matches the thermal deformation member 320. More preferably, in order to prevent the pole 310 from rotating relative to the thermal deformation member 320 and to prevent the fixing effect between the pole 310 and the thermal deformation member 320 from being destroyed, the outer contour of the cross section perpendicular to the axial direction of the through hole 301 of the pole 310 is made non-circular. Correspondingly, the shape of the inner hole of the thermal deformation member 320 matches the pole 310.

Furthermore, in order to increase the area where the pole assembly 300 can contact the external load, the pole assembly 300 further includes a conductive terminal 340. Specifically, as shown in FIG. 2, the conductive terminal 340 has a flat plate-like structure and is fixed to the first end of the pole 310. The conductive terminal 340 has two end faces 341 that are provided opposite to each other along the axial direction of the pole 310. One end face 341 of the conductive terminal 340 facing the pole 310 is larger than the end face of the pole 310 and completely covers the pole 310. That is, the entire cross-sectional area of the conductive terminal 340 is set to be larger than the cross-sectional area of the pole 310, thereby effectively expanding the area for electrically connecting to the load in the pole assembly 300. In addition, the first end 311 of the pole 310 is provided beyond the thermal deformation member 320 and the fixing device 330 so that there is a certain gap between the conductive terminal 340 and the through hole 301, so that the gas in the battery cell 1 can be smoothly discharged to the outside when it is exhausted. The conductive terminal 340 may be integrally formed with the pole 310 by a process such as crimping or cutting. In other embodiments of the present application, the conductive terminal 340 and the pole 310 may be formed separately and fixed by welding or the like. In addition, the end face 341 of the conductive terminal 340 is rectangular or rectangular with rounded corners. If the end face 341 of the conductive terminal 340 is too large, the head of the welding device will enter the edge of the opening 102, making it difficult to perform the welding process. Therefore, in this embodiment, the difference between the width dimension of the end face 341 and the maximum linear dimension of the fixing device 330 is less than 4 mm. That is, the dimension by which one side of the conductive terminal 340 exceeds the fixing device 330 along the width direction of the end face 341 is less than 2 mm.

The battery cell 1 according to the embodiment of the present application includes a case 100, an electrode assembly 200, and a pole assembly 300. The pole assembly 300 includes a pole 310, a thermal deformation member 320, and a fixing device 330. The thermal deformation member 320 and the fixing device 330 are annularly arranged in this order from the inside to the outside on the outer periphery of the pole 310. The thermal deformation member 320 is configured to deform when the temperature becomes higher than a preset threshold value, and to form a pressure relief passage in the through hole 301 that is connected to both ends of the through hole 301.

Compared to battery cells currently available on the market, the thermal deformation member 320 inside the battery cell 1 according to the embodiment of the present application deforms when the temperature of the battery cell exceeds a certain threshold, and forms a pressure relief passage in the through hole 301 of the fixing device 330, thereby allowing the gas inside the battery cell 1 to be discharged to the outside, thereby reducing the safety risk of the battery cell exploding. In other words, the battery cell provided by the embodiment of the present application can improve the current situation in which current battery cells cannot quickly discharge internal gas when the temperature is higher than a certain temperature.

In the above embodiment, the pole assembly 300 of the battery cell 1 simultaneously includes the pole 310, the thermal deformation member 320, and the fixing device 330, but the present application is not limited to this, and the fixing device 330 may be omitted. For example, in some other embodiments of the present application, the pole assembly in the battery cell 1 may include only the pole and the thermal deformation member described above. In this case, the first end of the pole is exposed to the outside of the case, the second end of the pole enters the case, and the thermal deformation member is provided to surround the pole and is located between the pole and the inner wall of the opening. In this way, the battery cell including the pole assembly can improve the current situation in which internal gas cannot be discharged in a timely manner when the temperature of a conventional battery cell becomes higher than a certain temperature.

Based on the same inventive concept, the present application further provides a pole assembly. As shown in Figs. 1 to 3, the pole assembly has a similar configuration to the pole assembly of the battery cell 1 in any of the above-mentioned embodiments. When this pole assembly is applied to a battery cell, when the temperature of the battery cell exceeds a predetermined threshold, the thermal deformation member inside the battery cell deforms, forming a pressure relief passage in the through hole of the fixing device, and the gas inside the battery cell is released to the outside, thereby reducing the safety risk of the battery cell exploding. In other words, the pole assembly provided by the present embodiment can improve the current situation in which the internal gas cannot be released in a timely manner when the temperature of a conventional battery cell becomes higher than a certain temperature.

Based on the same inventive concept, the present application further provides an electrical device 2 having a battery cell described in any of the above-mentioned embodiments. FIG. 4 shows the electrical device 2 according to one embodiment of the present application. In this embodiment, the electrical device 2 is a mobile phone, but in other embodiments, the electrical device 2 may be a tablet, a personal computer, a drone, or another power-using device that needs to be powered by electricity.

Finally, the above embodiments are used only to explain the technical proposal of the present application, and are not limited thereto. Under the technical idea of the present application, the technical features in the above embodiments or different embodiments can be combined with each other, and the steps can be realized in any order, and there are many variations of the above different aspects, which are not provided in detail for the sake of clarity. Although the present application has been described in detail with reference to the above embodiments, those skilled in the art should understand that the technical proposals described in each of the above embodiments can be modified or some of the technical features can be replaced with equivalents. However, the essence of the invention corresponding to these amendments or replacements does not deviate from the scope of the present invention.

REFERENCE SIGNS LIST 1 battery cell 100 case 101 receiving cavity 102 opening 200 electrode assembly 300 pole assembly 310 pole 311 first end 312 second end 320 thermal deformation member 330 fastener 340 conductive terminal 341 end surface 301 through hole

Claims (10)

A pole assembly for application to a battery cell, comprising:
a pole, a thermal deformation member, and a fixing member, the thermal deformation member being provided so as to surround the pole and being fixed to the pole;
the fixing device has a through hole, is provided so as to surround the thermal deformation member via the through hole, and is fixed to the thermal deformation member;
When the temperature of the thermal deformation member is higher than a predetermined threshold value, the thermal deformation member deforms so that a pressure relief passage is formed in the through hole, the pressure relief passage communicating with both ends of the through hole,
The thermal deformation member is made of an insulating material, and the fixing device is located between both ends of the thermal deformation member along the axial direction of the through hole. The pole assembly according to claim 1, characterized in that a first end of the pole protrudes from the thermal deformation member and the fixing device along the axial direction of the pole. 3. The pole assembly according to claim 2, further comprising a conductive terminal fixed to the first end, the end surface of the conductive terminal facing the pole being larger than the end surface of the pole and completely covering the pole. 4. The pole assembly according to claim 3 , wherein the end face is rectangular or rectangular with rounded corners, and the difference between the width of the end face and the maximum linear dimension of the end face of the fastener is less than 4 mm. The pole assembly of claim 1, characterized in that the pole includes a metal, and/or the thermal deformation member includes polyethylene, polypropylene, or polypropylene ethylene, and/or the fastener includes a metal. The pole assembly of claim 1, characterized in that the thermal deformation member melts or shrinks when the temperature is higher than a predetermined threshold so that the pressure relief passage is formed within the through hole. The battery cell includes a case and an electrode assembly, the case having a receiving cavity for receiving the electrode assembly, and an opening communicating with the receiving cavity and an external environment of the battery cell, respectively;
The battery cell further comprises the electrode post assembly according to any one of claims 1 to 6 , wherein the fixing device is attached to the opening, a first end of the electrode post is exposed to the external environment, and a second end of the electrode post is electrically connected to the electrode assembly. The battery cell according to claim 7 , wherein the shape of the opening is configured to match the shape of the fastener. A battery cell,
The battery cell includes a case and an electrode assembly, the case having a receiving cavity for receiving the electrode assembly, and an opening communicating with the receiving cavity and an external environment of the battery cell, respectively;
The battery cell further comprises a pole assembly;
the pole assembly is mounted in the opening and includes a pole, a thermal deformation member, and a fastener fixed to the thermal deformation member, a first end of the pole being exposed to the external environment, and a second end of the pole being electrically connected to the electrode assembly;
the fixing tool has a through hole and is provided so as to surround the thermal deformation member via the through hole,
the thermal deformation member is provided so as to surround the electrode post and is located between the electrode post and an inner wall of the opening ,
the thermal deformation member is an insulating material, and the fixing device has a non-circular cross section perpendicular to an axial direction of the through hole;
The battery cell, wherein the thermal deformation member melts or shrinks when the temperature is higher than a predetermined threshold value so that a pressure relief passage is formed within the through hole. An electrical device comprising the pole assembly according to any one of claims 1 to 6 or the battery cell according to any one of claims 7 to 9 .