Cylindrical battery and electronic equipment
By reducing the assembly ratio of the diameter of the cylindrical battery core to the inner wall diameter of the shell, and installing expansion tape inside the shell, the problem of explosiveness of existing batteries in heavy objects is solved, and the safety and testing of the battery are improved Pass rate.
Patent Information
- Application Number
- CN202421222720.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-05-30
- Publication Date
- 2025-02-25
- Estimated Expiration
- 2034-05-30
AI Technical Summary
In the heavy impact test, existing cylindrical batteries are prone to rupture of positive and negative electrode foils and internal gas leakage, resulting in explosion.
By reducing the assembly ratio between the diameter of the cylindrical battery core and the diameter of the inner wall of the housing, the core is easier to break, and an expansion tape is provided inside the housing to increase the gas pressure inside the battery.
Improves the pass rate of cylindrical batteries in heavy object impact tests, reduces the risk of explosion, and enhances the safety of the batteries.
Smart Images
Figure CN222530573U_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the technical field of battery structure, and in particular to a cylindrical battery and an electronic device. Background Art
[0002] Conventional cylindrical batteries are composed of three parts, namely, a steel shell, a winding core, and a cap. In addition, the assembly of conventional cylindrical batteries is relatively high, so when the battery is subjected to a heavy object impact test, a heavy object falls from a high place and hits the cylindrical battery. The steel shell is deformed first, and then the winding core is deformed, causing the positive or negative electrode foil to rupture and puncture the diaphragm, forming a positive and negative short circuit. In particular, a large amount of heat and exhaust gas will be released in a short period of time after the short circuit, but the gas pressure inside the deformed battery is not enough, so that the CID result on the cap is not flipped in time, and the pressure cannot be released, causing the battery to explode.
[0003] In order to pursue high-safety cylindrical batteries, it is urgent to design a new cylindrical battery to improve the test pass rate of heavy object impact of cylindrical batteries. Utility Model Content
[0004] In view of this, the purpose of the present application is to overcome the deficiencies in the prior art and provide a cylindrical battery and an electronic device.
[0005] This application provides the following technical solutions:
[0006] The present application provides a cylindrical battery, including a shell, a cap and a winding core;
[0007] The shell is a hollow cylindrical structure with one end open, the cap is correspondingly arranged at the open end of the shell, and the winding core is arranged inside the cylindrical structure of the shell;
[0008] The diameter D of the winding core 芯 The inner wall diameter D of the shell 壳 The ratio meets: 88% ≤ (D 芯 / D 壳 ) 2 ≤92%.
[0009] Preferably, the cylindrical battery further comprises an expansion tape disposed inside the shell, wherein the expansion tape is attached to two ends of the winding core around the radial direction of the winding core.
[0010] Further preferably, the axial length of the expansion tape at any end of the winding core does not exceed one third of the axial length of the winding core.
[0011] Further preferably, an electrolyte is further provided inside the shell, and the thickness of the expansion tape before expansion is less than 1 mm, and the expansion rate after expansion by absorbing the electrolyte is not higher than 1000%.
[0012] Further preferably, the material of the expansion tape includes any one of liquid-absorbing resin, polyvinyl chloride and carboxymethyl cellulose.
[0013] Preferably, the winding core comprises a separator, a positive electrode sheet and a negative electrode sheet;
[0014] The positive electrode sheet is provided with a positive electrode tab, the negative electrode sheet is provided with a negative electrode tab, the positive electrode tab is connected to the cap, and the negative electrode tab is connected to the inner wall of the shell.
[0015] Preferably, the cap includes a steel cap and a CID structure, and the CID structure is used for power-off protection.
[0016] Preferably, the shell is made of any one of stainless steel and aluminum alloy.
[0017] Preferably, an insulating sealing sheet is provided between the open end of the shell and the cover cap.
[0018] The present application also provides an electronic device, comprising the above-mentioned cylindrical battery.
[0019] Beneficial effects of this application:
[0020] The present application makes the battery core easier to break by reducing the assembly ratio of the core diameter in the cylindrical battery to the inner diameter of the shell. This is because the smaller the circular area at the bottom of the cylindrical object, the smaller the external force required for the same position to break. Reducing the assembly ratio of the cylindrical battery can be achieved by reducing the diameter of the battery core. Then, when the external force of the heavy object impact test remains unchanged, the smaller the diameter of the cylindrical battery core, the easier it is for the core to break. Reducing the diameter of the battery core will increase the gap between the core and the inner wall. The larger the gap, the more gas there is inside the battery. After the shell is deformed, the greater the pressure inside the battery, the easier it is to trigger the battery protection device, thereby improving the pass rate of the heavy object impact test.
[0021] In order to make the above-mentioned objects, features and advantages of the present application more obvious and understandable, preferred embodiments are given below and described in detail with reference to the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS
[0022] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.
[0023] Figure 1 The schematic diagram of the structure of the cylindrical battery of Example 1 is shown;
[0024] Figure 2 A schematic structural diagram of a cylindrical battery of Example 2 is shown.
[0025] Description of main component symbols:
[0026] 101-shell; 102-cap; 103-winding core; 104-expansion tape; 1021-CID structural part; 1031-positive electrode ear; 1032-negative electrode ear. DETAILED DESCRIPTION
[0027] The embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application, and cannot be understood as limiting the present application.
[0028] It should be noted that when an element is referred to as being "fixed to" another element, it may be directly on the other element or there may also be a centered element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a centered element at the same time. In contrast, when an element is referred to as being "directly on" another element, there is no intermediate element. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for illustrative purposes only.
[0029] In this application, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.
[0030] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.
[0031] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein in the specification of the template are only for the purpose of describing specific embodiments and are not intended to limit this application. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.
[0032] The present application provides a cylindrical battery, including a shell 101, a cap 102 and a winding core 103. The shell 101 is a hollow cylindrical structure with one end open, the cap 102 is correspondingly arranged at the open end of the shell 101, and the winding core 103 is arranged inside the cylindrical shell 101.
[0033] The diameter D of the winding core 103 is 芯 The inner wall diameter D of the housing 101 壳 The ratio meets: 88% ≤ (D 芯 / D 壳 ) 2 ≤92%.
[0034] The working principle of this application is: the reason why the battery explodes during the heavy object impact test is mainly due to the partial deformation of the battery core (incomplete deformation). Therefore, if you want to improve the pass rate of the heavy object impact test, there are two directions: one is to make the battery core not deformed at all, and the other is to make the battery core completely deformed (that is, the battery core breaks directly). However, it is impossible to completely prevent the battery core from deforming in the prior art, so this application uses the second direction to improve the pass rate of the heavy object impact test.
[0035] The present invention reduces the cylindrical battery assembly ratio X, and the formula is X = (D 芯 / D 壳 ) 2 , making the battery core more likely to break. The assembly ratio X of conventional cylindrical batteries is generally 93%-95%, while the present application reduces it to 88%-92%, which makes it easier for the battery core to break during a heavy object impact test to form two smaller cores.
[0036] Generally, reducing the assembly ratio of cylindrical batteries can be achieved by reducing the diameter of the battery core. This is because the smaller the circular area at the bottom of the cylindrical object, the smaller the external force required for the same position to break. When the external force of the heavy object impact test remains unchanged, the smaller the diameter of the cylindrical battery core, the easier it is for the core to break. In addition, reducing the diameter of the battery core will cause the gap between the core and the inner wall of the steel shell to increase. The larger the gap, the more gas inside the battery, the greater the pressure inside the battery when the steel shell is deformed, and the CID on the cylindrical battery is easier to break.
[0037] In a preferred embodiment of the present application, the cylindrical battery further includes an expansion tape 104 disposed inside the shell 101 , and the expansion tape 104 is attached to two ends of the winding core 103 along the radial direction of the winding core 103 .
[0038] It is understandable that the middle part of the core 103 is not surrounded by the expansion tape 104. After the expansion tape 104 is wrapped around the two ends of the core 103, a gourd-shaped structure is formed. In this way, when a heavy object impact test is performed, the battery core is more likely to break into two small cores.
[0039] In a preferred embodiment of the present application, the axial length of the expansion tape 104 at any end of the winding core 103 does not exceed one third of the axial length of the winding core 103 .
[0040] In a preferred embodiment of the present application, an electrolyte is further provided inside the housing 101, and the thickness of the expansion tape 104 before expansion is less than 1 mm, and the expansion rate after absorbing the electrolyte expansion is not higher than 1000%. For example, the thickness of the expansion tape 104 before expansion can be 0.05 mm, 0.1 mm, 0.2 mm, 0.35 mm, 0.48 mm, 0.6 mm or 0.8 mm. After absorbing the electrolyte expansion, the thickness can change from 0.01 mm to 1 mm, or from 0.05 mm to 0.5 mm, or from 0.1 mm to 0.8 mm, or from 0.8 mm to 1.5 mm.
[0041] In a preferred embodiment of the present application, the material of the expansion tape 104 includes any one of liquid-absorbing resin, polyvinyl chloride and carboxymethyl cellulose.
[0042] It should be noted that the thickness of the expansion tape 104 before expansion is less than 1 mm, which can prevent it from occupying too much space and reduce the impact of the expansion tape on the battery volume. Moreover, when the expansion tape itself is thin, after absorbing the electrolyte, the expansion tape will not expand too much, so that the expansion tape can apply appropriate force to the core 103, thereby avoiding damage to the core 103.
[0043] In a preferred embodiment of the present application, the winding core 103 further includes a separator, a positive electrode sheet and a negative electrode sheet. The positive electrode sheet is provided with a positive electrode tab 1031, and the negative electrode sheet is provided with a negative electrode tab 1032. The positive electrode tab 1031 is connected to the cap 102, and the negative electrode tab 1032 is connected to the inner wall of the shell 101.
[0044] In a preferred embodiment of the present application, the cap 102 includes a CID structure 1021, and the CID structure 1021 is used for power-off protection.
[0045] In a preferred embodiment of the present application, the material of the housing 101 includes any one of stainless steel and aluminum alloy.
[0046] In a preferred embodiment of the present application, an insulating sealing sheet is provided between the open end of the housing 101 and the cover cap 102 .
[0047] Example 1
[0048] This embodiment provides a cylindrical battery, including a housing 101, a cap 102 and a winding core 103. Figure 1 As shown. Among them, the diameter D of the winding core 103 芯 The inner wall diameter D of the housing 101 壳 The ratio satisfies:
[0049] (D 芯 / D 壳 ) 2 =90%.
[0050] The winding core 103 is also provided with a positive electrode tab 1031 and a negative electrode tab 1032 . The positive electrode tab 1031 is connected to the cap 102 , and the negative electrode tab 1032 is connected to the inner wall of the shell 101 . The cap 102 also includes a CID structural component 1021 .
[0051] Example 2
[0052] This embodiment provides a cylindrical battery, and its structure is the same as that of the embodiment 1. The diameter D of the winding core 103 is 芯 The inner wall diameter D of the housing 101 壳 The ratio satisfies:
[0053] (D 芯 / D 壳 ) 2 =92%.
[0054] In addition, this embodiment is also provided with an expansion tape 104, such as Figure 2 The expansion tape 104 is attached to the two ends of the winding core 103 along the radial direction of the winding core 103 , wherein the axial length of the expansion tape 104 at one end is 1 / 4 of the axial length of the entire winding core.
[0055] Example 3
[0056] This embodiment provides a cylindrical battery, and its structure is the same as that of Embodiment 2. The diameter D of the winding core 103 is 芯 The inner wall diameter D of the housing 101 壳 The ratio satisfies:
[0057] (D 芯 / D 壳 ) 2 =88%.
[0058] In addition, the axial length of the expansion tape 104 at one end of the winding core 103 is 1 / 3 of the axial length of the entire winding core.
[0059] Comparative Example 1
[0060] This comparative example provides a cylindrical battery, the structure of which is the same as that of Example 1. The diameter D of the winding core 103 is 芯 The inner wall diameter D of the housing 101 壳 The ratio satisfies:
[0061] (D 芯 / D 壳 ) 2 =94%.
[0062] A heavy object impact test was performed on the cylindrical batteries designed in the above embodiments and comparative examples, specifically: the cylindrical battery was placed on a platform surface, a metal rod with a diameter of 15.8 mm ± 0.2 mm was placed horizontally on the upper surface of the geometric center of the battery, the metal rod was perpendicular to the longitudinal axis of the battery, and a weight with a mass of 9.1 kg ± 0.1 kg was freely dropped from a height of 610 mm ± 25 mm to hit the battery surface where the metal rod was placed, and observed for 6 hours. The test results are shown in Table 1.
[0063] Table 1 Heavy object impact test results of each embodiment and comparative example
[0064]
[0065]
[0066] In all the examples shown and described above, any specific values should be interpreted as merely exemplary and not as limiting, and thus other examples of the exemplary embodiments may have different values.
[0067] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.
[0068] The above-mentioned embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present application. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application.
Claims
1. A cylindrical battery, characterized in that: It includes a shell, a cap and a winding core; The shell is a hollow cylindrical structure with one end open, the cap is correspondingly arranged at the open end of the shell, and the winding core is arranged inside the cylindrical structure of the shell; The diameter D of the winding core 芯 The inner wall diameter D of the shell 壳 The ratio meets: 88% ≤ (D 芯 / D 壳 ) 2 ≤92%.
2. The cylindrical battery according to claim 1, characterized in that: The cylindrical battery further includes an expansion tape disposed inside the shell, and the expansion tape is attached to two ends of the winding core in a radial direction of the winding core.
3. The cylindrical battery according to claim 2, characterized in that: The axial length of the expansion tape at any end of the winding core does not exceed one third of the axial length of the winding core.
4. The cylindrical battery according to claim 2, characterized in that: Electrolyte is also provided inside the shell. The thickness of the expansion tape before expansion is less than 1 mm, and the expansion rate after expansion by absorbing the electrolyte is not higher than 1000%.
5. The cylindrical battery according to claim 2, characterized in that: The material of the expansion tape includes any one of liquid-absorbing resin, polyvinyl chloride and carboxymethyl cellulose.
6. The cylindrical battery according to claim 1, characterized in that: The winding core comprises a separator, a positive electrode sheet and a negative electrode sheet; The positive electrode sheet is provided with a positive electrode tab, the negative electrode sheet is provided with a negative electrode tab, the positive electrode tab is connected to the cap, and the negative electrode tab is connected to the inner wall of the shell.
7. The cylindrical battery according to claim 1, characterized in that: The cap includes a CID structure, and the CID structure is used for power-off protection.
8. The cylindrical battery according to claim 1, characterized in that: The material of the shell includes any one of stainless steel and aluminum alloy.
9. The cylindrical battery according to any one of claims 1 to 8, characterized in that: An insulating sealing sheet is provided between the opening end of the shell and the cover cap.
10. An electronic device, characterized in that: A cylindrical battery comprising any one of claims 1 to 9.