Lithium battery
By setting capsules of strongly conductive liquid in the central tube of the lithium battery, the problem of thermal runaway caused by the lithium battery caused by heat disconnection during extrusion or needle puncture test is solved, and the safety performance and pass rate of the lithium battery test are improved.
Patent Information
- Application Number
- CN202421716270.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-07-18
- Publication Date
- 2025-06-03
- Estimated Expiration
- 2034-07-18
AI Technical Summary
Lithium batteries are prone to thermal runaway and cause fires when subjected to extrusion or needle puncture tests, which reduces the safety performance and pass rate of lithium battery tests.
A lithium battery was designed, with the center tube placed in the through hole in the center of the battery cell winding, and a capsule was installed inside the center tube, and a strongly conductive liquid was loaded in the capsule. When the battery is squeezed or needle-punched, the capsule softens, melts or breaks, releasing a strong conductive liquid, making the positive and negative poles turn on first, forming a current loop, quickly releasing the battery energy and avoiding thermal runaway.
By quickly releasing battery energy, the lithium battery is avoided from thermal runaway and fire, and the safety performance and pass rate of lithium battery tests are improved.
Smart Images
Figure CN222939972U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of lithium batteries, and particularly relates to a lithium battery. Background Art
[0002] Lithium batteries are widely used as reliable energy sources for the power supply of portable electronic products due to their advantages such as high specific energy, high voltage, no memory effect, environmental protection, and long service life.
[0003] When producing lithium batteries, safety tests need to be carried out on the lithium batteries. The main safety test methods for lithium batteries include extrusion and needle punching, etc. When the lithium battery is subjected to extrusion or needle punching tests, the lithium battery is short-circuited and a large amount of heat is generated locally, which is prone to thermal runaway and cause fire, thereby reducing the safety performance of the lithium battery test and the passing rate of the lithium battery test. Summary of the Utility Model
[0004] The main purpose of the utility model is to propose a lithium battery, aiming to solve the problem that when the current lithium battery is subjected to extrusion or needle punching tests, thermal runaway is prone to occur and cause fire, thereby reducing the safety performance of the lithium battery test and the passing rate of the lithium battery test.
[0005] To achieve the above object, the utility model proposes a lithium battery, which includes:
[0006] A housing;
[0007] A battery cell, the battery cell includes a positive electrode sheet, a negative electrode sheet, and a separator disposed between the positive electrode sheet and the negative electrode sheet. After the positive electrode sheet, the negative electrode sheet, and the separator are wound, they are accommodated in the housing and a through hole is formed at the winding center;
[0008] A central tube, the central tube is disposed in the housing and located in the through hole, and slits are formed on the side wall of the central tube;
[0009] A capsule, the capsule is disposed in the housing and located in the central tube, and a strong conductive liquid is loaded in the capsule.
[0010] In some embodiments, the strong conductive liquid is a polypyrrole organic solution or a polybenzodifuranone organic solution.
[0011] In some embodiments, a low-pressure gas is also loaded in the capsule.
[0012] In some embodiments, both opposite ends of the central tube are open.
[0013] In some embodiments, the capsule is cylindrical; and / or, there is one capsule, and the height of the capsule is less than the height of the central tube.
[0014] In some embodiments, the height of the central tube is less than or equal to 64 mm; and / or, the height of the capsule is less than or equal to 63 mm.
[0015] In some embodiments, a plurality of gaps are provided, and the plurality of gaps are arranged along the circumferential direction of the central tube.
[0016] In some embodiments, the shape of the gap is oval, circular or polygonal.
[0017] In some embodiments, the melting temperature of the capsule is 55°C to 150°C.
[0018] In some embodiments, the central tube is a circular tube, and the central tube is supported by the battery cell.
[0019] The lithium battery provided by the present utility model places a central tube in the through hole at the center of the battery cell winding, and a capsule is arranged inside the central tube. The capsule is filled with a highly conductive liquid. When the battery is squeezed or punctured during a safety test, the capsule softens and melts or is squeezed and broken, releasing the highly conductive liquid inside. The highly conductive liquid can enable the positive and negative electrodes to conduct preferentially, form a current loop, quickly release the battery energy, avoid battery thermal runaway and cause fire, and improve the safety performance of lithium battery testing and the passing rate of lithium battery testing. Description of the Drawings
[0020] Figure 1 is a schematic internal structure diagram of a lithium battery in an embodiment of the present utility model;
[0021] Figure 2 is Figure 1 a schematic structural diagram of the central tube and the capsule of the lithium battery in the embodiment;
[0022] Figure 3 is Figure 1 a schematic structural diagram of the central tube of the lithium battery in the embodiment;
[0023] Explanation of the Reference Numerals in the Drawings:
[0024] Reference numeral Name Reference numeral Name 110 Housing 120 Electric cell 130 Central tube 140 Capsule 121 Positive electrode plate 122 Negative electrode plate 123 Separator 124 Through hole 131 Gap
[0025] The realization, functional features and advantages of the object of the present utility model will be further described in conjunction with the embodiments and with reference to the drawings. Detailed Embodiments
[0026] Next, the solutions in the embodiments of the present utility model will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all the embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present utility model.
[0027] It should be noted that all directional indications (such as up, down, left, right, front, back...) in the embodiments of the present utility model are only used to explain the relative positional relationship and movement conditions between components in a specific posture (as shown in the accompanying drawings). If this specific posture changes, then the directional indications will also change accordingly.
[0028] It should also be noted that when an element is referred to as "fixed to" or "disposed on" another element, it can be directly on the other element or there may be an intermediate element at the same time. When an element is referred to as "connected to" another element, it can be directly connected to the other element or there may be an intermediate element at the same time.
[0029] In addition, the descriptions involving "first", "second", etc. in the present utility model are only for descriptive purposes, and cannot be understood as indicating or implying their relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one of such features. In addition, the technical solutions between various embodiments can be combined with each other, but it must be based on the fact that those of ordinary skill in the art can implement it. When the combination of technical solutions results in contradictions or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the protection scope required by the present utility model.
[0030] An embodiment of the present utility model provides a lithium battery. Referring to Figures 1 to 3 , the lithium battery includes:
[0031] A housing 110;
[0032] A battery cell 120, the battery cell 120 includes a positive electrode plate 121, a negative electrode plate 122, and a separator 123 disposed between the positive electrode plate 121 and the negative electrode plate 122. After the positive electrode plate 121, the negative electrode plate 122, and the separator 123 are wound, they are accommodated in the housing 110 and a through hole 124 is formed at the winding center;
[0033] A central tube 130, the central tube 130 is disposed in the housing 110 and located in the through hole 124, and a slit 131 is formed on the side wall of the central tube 130;
[0034] A capsule 140, the capsule 140 is disposed in the housing 110 and located in the central tube 130, and a highly conductive liquid is loaded in the capsule 140.
[0035] In the present utility model, the housing 110 is made of a steel shell or an aluminum shell and is arranged in a cylindrical shape. Among them, the steel shell housing 110 has high compressive strength, which can not only ensure the structural strength of the housing 110, but also reduce the corrosion of the electrolyte on the housing 110; the aluminum shell housing 110 has the advantages of light weight and high energy density. Whether the steel shell housing 110 or the aluminum shell housing 110 is adopted, the safety performance of the housing 110 can be improved.
[0036] The battery cell 120 is accommodated in the housing 110. Among them, the battery cell 120 includes a positive electrode sheet 121, a negative electrode sheet 122, and a separator 123 disposed between the positive electrode sheet 121 and the negative electrode sheet 122. Specifically, the positive electrode sheet 121, the separator 123, and the negative electrode sheet 122 are stacked in sequence and then wound to form the battery cell 120, and a through hole 124 is formed at the center of the battery cell 120. The battery cell 120 is accommodated in the housing 110, and the housing 110 can be used to protect the battery cell 120.
[0037] The central tube 130 is disposed in the housing 110 and located in the through hole 124, and a slit 131 is formed on the side wall of the central tube 130. As can be seen from the battery cell 120 described above, the battery cell 120 is formed by stacking the positive electrode sheet 121, the separator 123, and the negative electrode sheet 122 in sequence and then winding. When winding the battery cell 120, the battery cell 120 can be wound around the central tube 130. After the battery cell 120 is wound, the central tube 130 is separated from the battery cell 120, and the through hole 124 can be formed.
[0038] The capsule 140 is disposed in the housing 110 and located in the central tube 130, and a highly conductive liquid is loaded in the capsule 140. Among them, the capsule 140 is made of a thermoplastic resin, and the thermoplastic resin has the properties of softening when heated and hardening when cooled, and can be, but is not limited to, polyethylene, polyvinyl chloride, or polyamide polymers;
[0039] In the lithium battery provided by the present utility model, the central tube 130 is placed in the through hole 124 at the center of the winding of the battery cell 120, and the capsule 140 is disposed inside the central tube 130. A highly conductive liquid is loaded in the capsule 140. When the battery is squeezed or punctured during a safety test, the capsule 140 softens and melts or is squeezed and broken, releasing the internal highly conductive liquid. The highly conductive liquid can make the positive and negative electrodes conduct preferentially, form a current loop, quickly release the battery energy, avoid the battery thermal runaway and cause fire, and improve the safety performance of the lithium battery test and the passing rate of the lithium battery test.
[0040] In some embodiments, the highly conductive liquid is a polypyrrole organic solution or a polybenzodifuranone organic solution. Among them, both the polypyrrole organic solution and the polybenzodifuranone organic solution have good electrical conductivity, which helps the transfer and distribution of charges in the battery. In addition, the polypyrrole organic solution and the polybenzodifuranone organic solution have strong chemical stability, can maintain the stability of the lithium battery, and reduce the loss and lifespan decline of the lithium battery in a high-temperature environment.
[0041] In some embodiments, the capsule 140 is also filled with a low-pressure gas. Among them, the low-pressure gas can be nitrogen. After filling the highly conductive liquid in the capsule 140, nitrogen is filled. After the capsule 140 is filled with nitrogen, the internal pressure becomes larger, so that the capsule 140 becomes more inflated. During safety tests such as extrusion or puncture, the capsule 140 can quickly rupture and release the highly conductive liquid and nitrogen.
[0042] In some embodiments, both opposite ends of the central tube 130 are open. Among them, after the central tube 130 is placed in the through hole 124, the capsule 140 is placed into the central tube 130 from the upper open end of the central tube 130. During safety tests such as extrusion or puncture, the capsule 140 softens and melts or is squeezed and ruptured. The released highly conductive liquid can not only flow out from the gap 131, but also flow out from the lower open end, reducing the time for the highly conductive liquid to flow into the battery cell 120, accelerating the conduction speed between the positive and negative electrodes, and further improving the safety performance of the lithium battery.
[0043] In some embodiments, referring to Figure 1 and Figure 2 , the capsule 140 is cylindrical and adapted to the internal space of the central tube 130. In addition, the capsule 140 can also be ellipsoidal or spherical. And / or, in some embodiments, there is one capsule 140, and the height of the capsule 140 is less than the height of the central tube 130. Among them, the tube wall of the central tube 130 can provide a supporting force for the capsule 140. During the puncture safety test, the capsule 140 will not shake randomly, and the needle can pierce the capsule 140 faster. In addition, multiple capsules 140 can also be provided, and the multiple capsules 140 are arranged in sequence along the height direction of the central tube 130.
[0044] In some embodiments, the height of the central tube 130 is less than or equal to 64 mm. Among them, the height of the central tube 130 can be set with reference to the height of the battery cell 120. For example, when the height specification of the battery cell 120 is relatively high, the height of the central tube 130 can be set to 64 mm; when the height specification of the battery cell 120 is relatively low, the height of the central tube 130 can be set to less than 64 mm; and / or, the height of the capsule 140 is less than or equal to 63 mm. Among them, the height of the capsule 140 can be set with reference to the height of the central tube 130. For example, when the height of the central tube 130 is relatively high, the height of the capsule 140 can be set to 63 mm, and when the height of the central tube 130 is relatively low, the height of the capsule 140 can be set to less than 63 mm. The above data are only exemplary and not restrictive.
[0045] In some embodiments, a plurality of gaps 131 are provided, and the plurality of gaps 131 are arranged circumferentially along the central tube 130. As can be seen from the previously described gaps 131, the gaps 131 are used to discharge strongly conductive liquid and low-pressure gas. Among them, the circumferential arrangement of the gaps 131 enables the strongly conductive liquid and the low-pressure gas to be evenly discharged into the surroundings of the battery cell 120. In addition, since a plurality of gaps 131 are provided, the strongly conductive liquid and the low-pressure gas are discharged from the plurality of gaps 131 at the same time, which speeds up the discharge speed of the strongly conductive liquid and the low-pressure gas from the central tube 130, and thus speeds up the conduction speed of the positive and negative electrodes of the battery cell 120.
[0046] In some embodiments, the shape of the gap 131 is oval, circular or polygonal. When manufacturing the central tube 130, the shape of the gap 131 on the central tube 130 can be set to any one of oval, circular and polygonal. Among them, when the gap 131 is polygonal, it can be triangular, square or rectangular, etc.
[0047] In some embodiments, the melting temperature of the capsule 140 is 55°C to 150°C. Among them, the capsule 140 is made of thermoplastic resin, and the capsule 140 can be softened and melted by heat when the temperature inside the lithium battery reaches a certain level. Specifically, when the temperature inside the lithium battery reaches 55°C to 150°C, the capsule 140 is softened and melted by heat and ruptures, thereby releasing the strongly conductive liquid and low-pressure gas inside.
[0048] In some embodiments, the central tube 130 is a circular tube, and the central tube 130 supports the battery cell 120. As can be seen from the previously described battery cell 120, the battery cell 120 is formed by stacking and winding the positive electrode sheet 121, the separator 123 and the negative electrode sheet 122 in sequence. When the central tube 130 is used as the winding center, the central tube 130 has a supporting effect on each layer of electrode material, which can effectively prevent the battery cell 120 from being deformed unevenly during the winding process, and the ellipticity of the wound battery cell 120 is smaller.
[0049] The above are only partial or preferred embodiments of the present utility model. Neither the text nor the drawings can limit the scope of protection of the present utility model. Any equivalent structural transformation made by using the content of the specification and drawings of the present utility model under the overall concept of the present utility model, or any direct / indirect application in other related technical fields is included in the scope of protection of the present utility model.
Claims
1. A lithium battery, characterized in that: include: case; A battery cell, the battery cell comprising a positive electrode sheet, a negative electrode sheet and a separator disposed between the positive electrode sheet and the negative electrode sheet, the positive electrode sheet, the negative electrode sheet and the separator are wound and accommodated in the housing and a through hole is formed at the center of the winding; A central tube, the central tube is disposed in the shell and located in the through hole, and a slit is formed on a side wall of the central tube; The capsule is arranged in the shell and located in the central tube, and is loaded with a strong conductive liquid.
2. The lithium battery according to claim 1, characterized in that: The highly conductive liquid is a polypyrrole organic solution or a polybenzodifuranone organic solution.
3. The lithium battery according to claim 1, characterized in that The capsule is also loaded with low-pressure gas.
4. The lithium battery according to claim 1, characterized in that The opposite ends of the central tube are both open.
5. The lithium battery according to claim 1, characterized in that: The capsule is cylindrical; and / or, The capsule is provided with one, and the height of the capsule is smaller than the height of the central tube.
6. The lithium battery according to claim 1, characterized in that: The height of the central tube is less than or equal to 64 mm; and / or, The height of the capsule is less than or equal to 63 mm.
7. The lithium battery according to claim 1, characterized in that: There are a plurality of slits, and the plurality of slits are arranged along the circumference of the central tube.
8. The lithium battery according to claim 1 or 7, characterized in that: The shape of the gap is oval, circular or polygonal.
9. The lithium battery according to claim 1, characterized in that: The melting temperature of the capsule is 55°C to 150°C.
10. The lithium battery according to claim 1, characterized in that: The central tube is a round tube, and the central tube is supported by the battery core.