Lithium battery cap assembly and lithium battery

Abstract

The utility model relates to the technical field of lithium batteries, in particular to a lithium battery cap assembly and a lithium battery. The lithium battery cap assembly comprises an anti-explosion sheet. Wherein the anti-explosion piece comprises a first shell and a second shell which are connected with each other, a hollow cavity is formed between the first shell and the second shell, the hollow cavity is filled with a heat absorption part, and the heat absorption part is configured to absorb heat generated by the lithium battery. In the temperature rise process of the lithium battery, the heat absorption piece can absorb heat generated by the lithium battery, so that the internal temperature of the lithium battery is reduced, the risk of thermal runaway of the lithium battery is reduced, and the thermal stability and the safety performance of the lithium battery are improved. And meanwhile, the heat absorption piece has relatively high hardness and wear resistance after being compacted, so that the mechanical strength of the explosion-proof piece can be improved, the lithium battery cap assembly is not easy to deform under external pressure, the risk of failure of the lithium battery caused by mechanical damage is reduced, and the service life is prolonged.

Description

TECHNICAL FIELD

[0001] The utility model relates to lithium battery technical field especially relates to a lithium battery cap assembly and lithium battery. BACKGROUND

[0002] Lithium battery cap assembly is one of important components of lithium battery, it has the role of positive electrode conductive terminal and the role of safety valve in lithium battery, simultaneously, lithium battery cap assembly can also close to electric core to prevent the phenomenon of electrolyte leakage.

[0003] At present, lithium battery is easy to produce a large amount of heat in the process of high-power charge and discharge, thereby leading to the temperature rise of lithium battery, even the phenomenon of thermal runaway occurs. Meanwhile, the strength of the existing lithium battery cap assembly is low, the extrusion resistance is weak, the lithium battery cap assembly is easy to deform when being subjected to external pressure, thereby increasing the failure risk caused by extrusion, affecting the service life of lithium battery.

[0004] Therefore, it is urgent to design a lithium battery cap assembly and lithium battery to solve the above technical problems. UTILITY MODEL CONTENT

[0005] The first purpose of the utility model is to provide a lithium battery cap assembly, which can effectively absorb the heat generated in the working process of lithium battery, improve safety, improve extrusion resistance, reduce failure risk caused by mechanical damage and prolong service life.

[0006] To achieve this purpose, the utility model adopts the following technical scheme:

[0007] The utility model provides a lithium battery cap assembly, which comprises:

[0008] The explosion-proof sheet comprises a first shell and a second shell connected to each other, a hollow chamber is formed between the first shell and the second shell, a heat-absorbing piece is filled in the hollow chamber, and the heat-absorbing piece is configured to absorb the heat generated by the lithium battery.

[0009] As an optional technical scheme of the lithium battery cap assembly, the heat-absorbing piece fills the hollow chamber.

[0010] As an optional technical scheme of the lithium battery cap assembly, the heat-absorbing piece is in a granular structure or a powder structure.

[0011] As an optional technical scheme of the lithium battery cap assembly, the heat-absorbing piece is a ceramic piece and / or a carbonate.

[0012] As an optional technical scheme of the lithium battery cap assembly, the ceramic piece comprises a silicon carbide piece, and the carbonate comprises one of calcium bicarbonate, sodium carbonate or sodium bicarbonate.

[0013] As an optional technical solution of the lithium battery cap assembly, the ratio of the thickness of the explosion-proof sheet to the thickness of the first shell is set to 3:1-5:1.

[0014] As an optional technical solution of the lithium battery cap assembly, the first shell and / or the second shell is provided with a notch.

[0015] As an optional technical solution of the lithium battery cap assembly, the lithium battery cap assembly further comprises a top cover located above the explosion-proof sheet, and the top cover is welded to the first shell.

[0016] As an optional technical solution of the lithium battery cap assembly, the lithium battery cap assembly further comprises a hole plate located below the explosion-proof sheet, and the hole plate is welded to the second shell.

[0017] The second purpose of the utility model is to provide a lithium battery which has high safety and thermal stability, can improve the extrusion resistance of the lithium battery, reduce the failure risk caused by mechanical damage, and prolong the service life.

[0018] To achieve this purpose, the utility model adopts the following technical solutions:

[0019] The utility model provides a lithium battery, the lithium battery includes shell, the electric core of containing in the shell and the lithium battery cap assembly in any one of the above technical solutions, one end of the shell is provided with opening, the lithium battery cap assembly is sealed in the opening.

[0020] The utility model has at least the following beneficial effects:

[0021] The utility model provides a lithium battery cap assembly, and the lithium battery cap assembly comprises an explosion-proof sheet.

[0022] In the utility model, the explosion-proof sheet adopts a double-layer structure, that is, the explosion-proof sheet is connected by the first shell and the second shell to form a hollow chamber, and the heat-absorbing piece is filled in the hollow chamber. In the process of lithium battery heating, the heat-absorbing piece can absorb the heat generated by the lithium battery, thereby reducing the internal temperature of the lithium battery, reducing the risk of thermal runaway of the lithium battery, improving the thermal stability of the lithium battery, and improving the safety performance. At the same time, the heat-absorbing piece has high hardness and wear resistance after compaction, so that the mechanical strength of the explosion-proof sheet can be improved, so that the lithium battery cap assembly is not easy to deform under external pressure, thereby reducing the failure risk of the lithium battery caused by mechanical damage and prolonging the service life.

[0023] The lithium battery has high safety and thermal stability, can improve the extrusion resistance of the lithium battery, reduces the failure risk caused by mechanical damage, and prolongs the service life. BRIEF DESCRIPTION OF DRAWINGS

[0024] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the description of the embodiments of the present application will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and for those skilled in the art, other drawings can be obtained according to the contents of the embodiments of the present application and the drawings without creative labor.

[0025] Figure 1 is a sectional view of the lithium battery cap assembly provided by the embodiments of the present application;

[0026] Figure 2 is a sectional view of the explosion-proof sheet provided by the embodiments of the present application.

[0027] REFERENCE NUMERALS

[0028] 100, explosion-proof sheet; 110, first shell; 120, second shell; 130, hollow chamber; 140, heat absorbing piece;

[0029] 200, top cover; 300, hole plate; 400, insulating gasket; 500, sealing ring. DETAILED DESCRIPTION

[0030] In order to make the purpose, technical solutions and advantages of the embodiments of the present application more clear, the technical solutions in the embodiments of the present application will be clearly and completely described below in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are only some embodiments of the present application, not all the embodiments. The components of the embodiments of the present application described and shown in the drawings here can be arranged and designed in various different configurations.

[0031] Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the claimed present application, but only represents selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0032] It should be noted that: similar numerals and letters represent similar items in the following drawings, therefore, once an item is defined in one drawing, it does not need to be further defined and explained in the subsequent drawings.

[0033] In the description of the utility model, it needs to be explained that, the terms "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship commonly placed when the utility model product is used, and are only for the convenience of describing the utility model and simplifying the description, and therefore cannot be understood as indicating or implying that the indicated device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the utility model. In addition, the terms "first", "second", "third" and the like are only used for differentiation in description and cannot be understood as indicating or implying relative importance. In the description of the utility model, unless otherwise specified, the meaning of "a plurality of" is two or more.

[0034] In the description of the utility model, it also needs to be explained that, unless otherwise explicitly specified and limited, the terms "arrangement", "connection" should be understood broadly, for example, can be fixedly connected, or can be detachably connected, or integrally connected, can be mechanically connected, or can be electrically connected. For ordinary skilled persons in the art, the specific meaning of the above terms in the utility model can be understood according to the specific circumstances.

[0035] In the utility model, unless otherwise explicitly specified and limited, the "upper" or "lower" of the first feature to the second feature can include that the first and second features are in direct contact, or can include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, the "upper", "upper" and "upper" of the first feature to the second feature include that the first feature is directly above and obliquely above the second feature, or only indicates that the horizontal height of the first feature is higher than that of the second feature. The "below", "below" and "below" of the first feature to the second feature include that the first feature is directly below and obliquely below the second feature, or only indicates that the horizontal height of the first feature is less than that of the second feature.

[0036] The embodiments of the utility model are described in detail below, and examples of the embodiments are shown in the drawings, wherein the same or similar reference numerals represent the same or similar elements or elements with the same or similar functions throughout. The embodiments described below by referring to the drawings are exemplary and are only used to explain the utility model, and cannot be understood as limiting the utility model.

[0037] The embodiment provides a lithium battery cap assembly, which can effectively absorb the heat generated in the working process of the lithium battery, improve the safety, improve the extrusion resistance, reduce the failure risk caused by mechanical damage, and prolong the service life.

[0038] As Figures 1-2As shown, the lithium battery cover cap assembly mainly comprises an explosion-proof sheet 100. The explosion-proof sheet 100 comprises a first shell 110 and a second shell 120 connected to each other, a hollow chamber 130 is formed between the first shell 110 and the second shell 120, and a heat-absorbing piece 140 is filled in the hollow chamber 130. The heat-absorbing piece 140 is configured to absorb heat generated by the lithium battery.

[0039] Based on the above design, the explosion-proof sheet 100 in the embodiment adopts a double-layer structure, that is, the explosion-proof sheet 100 is connected by the first shell 110 and the second shell 120 to form a hollow chamber 130, and the heat-absorbing piece 140 is filled in the hollow chamber 130. During the heating process of the lithium battery, the heat-absorbing piece 140 can absorb the heat generated by the lithium battery, thereby reducing the internal temperature of the lithium battery, reducing the risk of thermal runaway of the lithium battery, improving the thermal stability of the lithium battery, and improving the safety performance. At the same time, the heat-absorbing piece 140 has high hardness and wear resistance after compaction, thereby improving the mechanical strength of the explosion-proof sheet 100. In this way, the lithium battery cover cap assembly is not easy to deform when subjected to external pressure, thereby reducing the risk of lithium battery failure caused by mechanical damage and prolonging the service life.

[0040] Optionally, the heat-absorbing piece 140 in the embodiment fills the hollow chamber 130, which not only improves the heat-absorbing effect, but also improves the mechanical strength of the explosion-proof sheet 100 and reduces the risk of deformation of the explosion-proof sheet 100 after being subjected to external force.

[0041] Optionally, the heat-absorbing piece 140 in the embodiment has a granular structure or a powder structure, which is conducive to filling the hollow chamber 130, reducing the gap in the hollow chamber 130, and improving the mechanical strength of the explosion-proof sheet 100.

[0042] Optionally, the first shell 110 and / or the second shell 120 in the embodiment is provided with a notch, and the notch is provided with a through hole, which is conducive to timely discharge of high-temperature gas by the explosion-proof sheet 100 and improves the thermal stability of the lithium battery. At the same time, the notch can ensure that the explosion-proof sheet 100 can be effectively broken when the pressure in the lithium battery reaches a preset pressure value, thereby ensuring the normal opening of the explosion-proof sheet 100 and improving the safety performance.

[0043] Optionally, the first shell 110 and the second shell 120 in the embodiment can be welded and connected by laser welding.

[0044] Optionally, the heat-absorbing piece 140 in the embodiment can be a ceramic piece and / or a carbonate; the ceramic piece and the carbonate are configured to absorb heat generated by the lithium battery.

[0045] Exemplarily, the ceramic piece in the embodiment includes a silicon carbide piece, and the carbonate includes one of calcium bicarbonate, sodium carbonate or sodium bicarbonate. In other words, the hollow chamber 130 can be filled with silicon carbide or calcium bicarbonate, sodium carbonate or sodium bicarbonate. Considering that the hardness and wear resistance of silicon carbide are better than those of compacted carbonate, the embodiment preferably fills the hollow chamber 130 with silicon carbide.

[0046] Optionally, the ratio of the thickness of the explosion-proof sheet 100 to the thickness of the first shell 110 in the embodiment is set to 3:1-5:1. For example, it can be set to 3:1, 4:1, 5:1, etc. When the ratio is less than 3:1, at this time, the thicknesses of the first shell 110 and the second shell 120 are relatively thick, which means that the volume of the hollow chamber 130 is reduced under the condition of the same thickness of the explosion-proof sheet 100, thereby reducing the filling amount of the ceramic piece and the carbonate, and further affecting the heat absorption effect and increasing the risk of thermal runaway. When the ratio is greater than 5:1, under the condition of the same thickness of the explosion-proof sheet 100, although the volume of the hollow chamber 130 is increased, the thicknesses of the first shell 110 and the second shell 120 are correspondingly reduced, thereby reducing the mechanical strength of the explosion-proof sheet 100 and reducing the extrusion resistance of the lithium battery cap assembly. Therefore, the ratio of the thickness of the explosion-proof sheet 100 to the thickness of the first shell 110 in the embodiment is preferably set to 3:1-5:1, which not only can ensure good heat absorption effect and reduce the risk of thermal runaway of the lithium battery, but also can improve the mechanical strength and reduce the risk of failure caused by mechanical damage.

[0047] Optionally, the thickness of the explosion-proof sheet 100 in the embodiment can be set to 50-500 microns. Exemplarily, the thickness of the explosion-proof sheet 100 is set to 50 microns, 100 microns, 300 microns, 500 microns, etc.

[0048] As shown in Figure 1 In the embodiment, the lithium battery cap assembly further includes a top cover 200, a hole plate 300, an insulating gasket 400 and a sealing ring 500. The top cover 200 is located above the explosion-proof sheet 100, and the top cover 200 is welded to the first shell 110. Exemplarily, the top cover 200 is connected to the first shell 110 by laser welding, which ensures the sealing performance of the lithium battery and improves the safety of the lithium battery.

[0049] The hole plate 300 is located below the explosion-proof sheet 100, and the hole plate 300 is welded to the second shell 120. Specifically, the hole plate 300 can be welded to the second shell 120 by ultrasonic welding, and the hole plate 300 is laser welded to the tab of the battery cell to realize the positive electrode lead-out of the lithium battery.

[0050] The insulating gasket 400 is arranged between the hole plate 300 and the explosion-proof sheet 100. One side of the insulating gasket 400 is in abutment with the hole plate 300, and the other side is in abutment with the explosion-proof sheet 100. The arrangement of the insulating gasket 400 can prevent the hole plate 300 and the explosion-proof sheet 100 from being reconnected after the CID of the battery cell is disconnected, so as to cause the battery cell to continue to react chemically and cause the danger of short circuit.

[0051] Optionally, the insulating gasket 400 can be made of plastic or other insulating materials.

[0052] The sealing ring 500 covers part of the explosion-proof sheet 100, part of the top cover 200 and part of the hole plate 300, so as to ensure the sealing performance of the lithium battery and prolong the service life.

[0053] Optionally, the sealing ring 500 can be made of silica gel.

[0054] The embodiment further provides a lithium battery, which comprises a shell (not shown in the figure), a battery cell accommodated in the shell and the lithium battery cap assembly described above. One end of the shell is provided with an opening, and the lithium battery cap assembly is sealed in the opening.

[0055] Since the lithium battery has the lithium battery cap assembly described above, the lithium battery has high safety and thermal stability, can improve the extrusion resistance of the lithium battery, reduce the failure risk caused by mechanical damage and prolong the service life.

[0056] Optionally, the shell in the embodiment can be made of stainless steel.

[0057] Obviously, the above only describes the preferred embodiments of the present application and the technical principles applied. Those skilled in the art will understand that the present application is not limited to the specific embodiments described herein, and those skilled in the art can make various obvious changes, re-adjustments and substitutions without departing from the protection scope of the present application. Therefore, although the present application has been described in more detail through the above embodiments, the present application is not limited to the above embodiments, and can include more other equivalent embodiments without departing from the concept of the present application, and the scope of the present application is determined by the scope of the appended claims.

[0058] Note that in the description of the present application, the description of the terms "some embodiments", "other embodiments", and the like means that the specific features, structures, materials or characteristics described in connection with the embodiments or examples are included in at least one embodiment or example of the present application. In the present application, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

Claims

1. A lithium battery cap assembly, characterized by, The application relates to a lithium battery cap assembly. The explosion-proof sheet (100) comprises a first shell (110) and a second shell (120) connected to each other, a hollow chamber (130) is formed between the first shell (110) and the second shell (120), and a heat-absorbing piece (140) is filled in the hollow chamber (130), wherein the heat-absorbing piece (140) is configured to absorb heat generated by a lithium battery.

2. The lithium battery cap assembly of claim 1, wherein, The heat-absorbing piece (140) is filled in the hollow chamber (130).

3. The lithium battery cap assembly of claim 1, wherein, The heat-absorbing piece (140) is in a granular structure or a powder structure.

4. The lithium battery cap assembly of claim 1, wherein, The heat-absorbing piece (140) is a ceramic piece and / or a carbonate.

5. The lithium battery cap assembly of claim 4, wherein, The ceramic piece comprises a silicon carbide piece, and the carbonate comprises one of calcium bicarbonate, sodium carbonate or sodium bicarbonate.

6. The lithium battery cap assembly of claim 1, wherein, The ratio of the thickness of the explosion-proof sheet (100) to the thickness of the first shell (110) is 3:1-5:

1.

7. The lithium battery cap assembly of claim 1, wherein, The first shell (110) and / or the second shell (120) is provided with an indentation.

8. The lithium battery cap assembly of claim 1, wherein, The lithium battery cap assembly further comprises a top cover (200) located above the explosion-proof sheet (100), wherein the top cover (200) is welded to the first shell (110).

9. The lithium battery cap assembly of claim 8, wherein, The lithium battery cap assembly further comprises a hole plate (300) located below the explosion-proof sheet (100), wherein the hole plate (300) is welded to the second shell (120).

10. A lithium battery characterized by, The lithium battery comprises a shell, a battery cell accommodated in the shell and the lithium battery cap assembly according to any one of claims 1-9, one end of the shell is provided with an opening, and the lithium battery cap assembly is sealed to the opening.

Images