Structure for improving weight impact safety of lithium ion battery

Abstract

The utility model discloses a structure for improving the weight impact safety of a lithium ion battery, which belongs to the technical field of lithium ion batteries and comprises a roll core, the roll core consists of a diaphragm, a positive plate and a negative plate, a positive lug is welded on the positive plate, a negative lug is welded on the negative plate, and the diaphragm is arranged in the roll core. The positive tab and the negative tab are respectively welded on 5 * 5mm welding positions at the upper ends of the positive plate and the negative plate, and a steel shell is fixedly connected to the outer side of the roll core. According to the structure for improving the weight impact safety of the lithium ion battery, the positive tab and the negative tab are welded on the welding positions at the upper ends of the positive plate and the negative plate, so that short circuit caused by non-uniform stress of an impact point at the tabs when the lithium ion battery is impacted by a weight and sudden stress change caused by asymmetric structure can be effectively avoided; and a buffer interlayer is arranged, so that a buffer effect can be achieved when the battery falls off, and the situation that the interior of the battery is damaged due to the fact that the battery is impacted is prevented.

Description

Technical Field

[0001] The utility model relates to the technical field of lithium ion batteries, in particular to a structure for improving the safety of lithium ion batteries against heavy object impact. Background Art

[0002] Compared to other secondary batteries, lithium-ion batteries offer advantages such as high voltage, compact size, light weight, high specific capacity, no memory effect, no pollution, low self-discharge, and long cycle life. They are widely used in digital products, electric vehicles, hybrid vehicles, and many other fields. With the widespread use of lithium-ion batteries, their safety performance is also receiving increasing attention.

[0003] When existing lithium-ion batteries are impacted by heavy objects, uneven force will be applied at the tabs, causing a short circuit. The asymmetric structure leads to a sudden change in stress, tearing the diaphragm and tabs, causing an internal short circuit and thus a safety accident. Summary of the Invention

[0004] The purpose of the utility model is to provide a structure that improves the safety of lithium-ion batteries against heavy object impact. By welding the positive and negative tabs to the 5*5mm welding position on the upper ends of the positive and negative plates, it can effectively avoid the problem that the uneven force at the tabs at the impact point causes a short circuit when the battery is impacted by a heavy object, and the structural asymmetry causes a sudden change in stress, tearing the diaphragm and the tabs, causing an internal short circuit and thus causing a safety accident. By setting a buffer interlayer, it can play a buffering role when the battery falls, preventing the battery from being damaged by impact and causing damage to the inside of the battery.

[0005] To achieve the above-mentioned purpose, the utility model provides a structure for improving the safety of lithium-ion batteries against heavy object impact, including a winding core, which is composed of a diaphragm, a positive electrode sheet and a negative electrode sheet. A positive electrode ear is welded on the positive electrode sheet, and a negative electrode ear is welded on the negative electrode sheet. The positive electrode ear and the negative electrode ear are respectively welded to the 5*5mm welding position on the upper end of the positive electrode sheet and the negative electrode sheet, and a steel shell is fixedly connected to the outside of the winding core.

[0006] Preferably, the steel shell includes an inner shell and an outer shell, a buffer interlayer is provided between the inner shell and the outer shell, a buffer member is provided in the buffer interlayer, and the buffer member is wavy.

[0007] Preferably, the gaps in the buffer interlayer are filled with elastic material, and the elastic material is silica gel.

[0008] Preferably, the separator is provided between the positive electrode sheet and the negative electrode sheet, the positive electrode sheet, the separator and the negative electrode sheet are alternately arranged, and one end of the positive electrode sheet, the negative electrode sheet and the separator are all fixedly connected to the central tube.

[0009] Preferably, double-layer sealing rings are fixed to both ends of the steel shell.

[0010] Preferably, the separator is provided on both sides of the positive electrode sheet, the separator on one side is arranged horizontally, and the separator on the other side is arranged vertically.

[0011] Therefore, the utility model adopts the above-mentioned structure to improve the safety of lithium-ion batteries against heavy object impact. By welding the positive and negative ears to the 5*5mm welding positions on the upper ends of the positive and negative electrodes, it can effectively avoid the problem of uneven force at the ears causing short circuits when impacted by heavy objects, and structural asymmetry leading to sudden stress changes, tearing of the diaphragm and the ears, causing internal short circuits and thus causing safety accidents. By setting a buffer interlayer, it can play a buffering role when the battery falls, preventing the battery from being damaged by impact and causing damage to the inside of the battery.

[0012] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 This is a schematic structural diagram of a structural embodiment of the utility model for improving the safety of lithium-ion batteries against heavy object impact;

[0014] Figure 2 This is a cross-sectional view of a steel shell of a structural embodiment of the utility model for improving the safety of lithium-ion batteries against heavy object impact;

[0015] Figure 3 This is a schematic diagram of the winding core structure of a structural embodiment of the utility model for improving the safety of lithium-ion batteries against heavy object impact.

[0016] Reference numerals

[0017] 1. Winding core; 2. Positive electrode sheet; 3. Negative electrode sheet; 4. Diaphragm; 5. Positive electrode ear; 6. Negative electrode ear; 7. Steel shell; 8. Inner shell; 9. Outer shell; 10. Buffer; 11. Sealing ring. DETAILED DESCRIPTION

[0018] The technical solution of the present utility model is further described below through the accompanying drawings and embodiments.

[0019] Unless otherwise defined, the technical or scientific terms used in this utility model shall have the usual meanings understood by persons of ordinary skill in the field to which this utility model belongs. The words "first", "second" and similar terms used in this utility model do not indicate any order, quantity or importance, but are only used to distinguish different components. Words such as "include" or "comprise" mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. Words such as "connect" or "connected" are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the object being described changes, the relative positional relationship may also change accordingly.

[0020] Example 1

[0021] like Figures 1 to 3 As shown, the utility model provides a structure for improving the safety of lithium-ion batteries against heavy object impact, including a winding core 1. The winding core 1 structure provides the necessary mechanical stability for the battery, especially when the battery undergoes volume changes during charging and discharging. A good winding core 1 design can maintain the integrity of the battery structure and prevent internal short circuits or other failures.

[0022] The core 1 consists of a separator 4, a positive electrode sheet 2 and a negative electrode sheet 3. The positive electrode sheet 2 and the negative electrode sheet 3 are coated with active materials that can embed and de-embed lithium ions. They are the basis for the electrochemical reaction of the battery and are responsible for storing and releasing electrical energy.

[0023] A positive electrode tab 5 is welded on the positive electrode sheet 2, and a negative electrode tab 6 is welded on the negative electrode sheet 3. The positive electrode tab 5 and the negative electrode tab 6 are respectively welded to the 5*5mm welding position on the upper end of the positive electrode sheet 2 and the negative electrode sheet 3. The positive electrode tab 5 is connected to the positive electrode sheet 2 of the battery, and transfers the electrons of the lithium ions generated during the electrochemical reaction on the positive electrode to the external circuit to realize the output of electrical energy, and provides an interface for connecting to the external lead or battery cover (usually the positive terminal of the battery) during battery assembly to ensure the continuity and stability of electrical energy transmission.

[0024] The negative electrode tab 6 is connected to the negative electrode sheet 3 of the battery, forming the other end of the current path, so that the electrons flowing out of the positive electrode can return to the negative electrode through the external circuit, completing the charge cycle. As part of the battery assembly, the negative electrode tab 6 ensures that the negative electrode of the battery is reliably connected to the external circuit or the battery casing (usually the negative terminal of the battery), maintaining the basic electrical path for the battery to operate.

[0025] A diaphragm 4 is provided between the positive electrode sheet 2 and the negative electrode sheet 3. The diaphragm 4 is located between the positive and negative electrode sheets 3 and not only plays a physical isolation role to prevent the positive and negative electrodes from directly contacting each other and causing a short circuit, but also allows lithium ions to pass through, forming a conduction path for ions during the charging and discharging process.

[0026] The positive electrode sheets 2, separators 4, and negative electrode sheets 3 are arranged alternately. One end of each of the positive, negative, and separators 4 is fixedly connected to a central tube. The central tube serves as a support structure, preventing the positive and negative electrode sheets 2, 3, and separators 4 from shifting or wrinkling, ensuring the uniform cylindrical shape of the winding core 1. Separators 4 are positioned on both sides of the positive electrode sheet 2, with one side arranged horizontally and the other longitudinally. The opposite orientation of the separators 4 on either side of the positive electrode sheet 2 enhances the strength of the winding core 1. The alternating arrangement of separators 4 can withstand significant stress without breaking.

[0027] The outer side of the core 1 is fixedly connected to a steel shell 7, which is used to provide protection for the internal structure. Double-layer sealing rings 11 are fixed to both ends of the steel shell 7. The sealing rings 11 are used to optimize the sealing design to ensure that even if the outer shell 9 is slightly deformed, it will not cause electrolyte leakage. The steel shell 7 includes an inner shell 8 and an outer shell 9. A buffer interlayer is provided between the inner shell 8 and the outer shell 9. The buffer interlayer is a buffer space that can effectively prevent the core 1 from expanding during use and causing deformation of the outer wall, resulting in safety failure. It can also effectively reduce the direct force on the battery core 1 during the impact of heavy objects, thereby improving the safety performance of the battery.

[0028] A wavy buffer member 10 is provided within the buffer interlayer. The gaps within the buffer interlayer are filled with an elastic material, such as silicone. This material improves sealing and provides shock absorption. When the battery temperature rises, the elastic material also acts as a thermal buffer, helping to regulate the battery's temperature. The elastic material isolates the inner shell 8 from the outer shell 9, reducing the possibility of internal positive and negative short circuits caused by breakage of the outer shell 9.

[0029] When using a structure provided by the present invention to improve the safety of lithium-ion batteries against heavy object impact, the positive electrode ear 5 is first welded to the positive electrode sheet 2, the negative electrode ear 6 is welded to the negative electrode sheet 3, and the diaphragm 4, the positive electrode sheet 2, the diaphragm 4, and the negative electrode sheet 3 are rolled up on the central tube in order, and then the steel shell 7 is put on the winding core 1, and finally the sealing ring 11 is put on the sealing parts at both ends of the battery to achieve sealing.

[0030] Therefore, the utility model adopts the above-mentioned structure to improve the safety of lithium-ion batteries against heavy object impact. By welding the positive and negative ears to the 5*5mm welding positions on the upper ends of the positive and negative electrodes, it can effectively avoid the problem of uneven force at the ears causing short circuits when impacted by heavy objects, and structural asymmetry leading to sudden stress changes, tearing of the diaphragm and the ears, causing internal short circuits and thus causing safety accidents. By setting a buffer interlayer, it can play a buffering role when the battery falls, preventing the battery from being damaged by impact and causing damage to the inside of the battery.

[0031] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that they can still modify or replace the technical solution of the present invention with equivalents, and these modifications or equivalent replacements cannot cause the modified technical solution to deviate from the spirit and scope of the technical solution of the present invention.

Claims

1. A structure for improving the safety of lithium-ion batteries against heavy object impact, characterized by: It includes a winding core, which is composed of a diaphragm, a positive electrode sheet and a negative electrode sheet. A positive electrode ear is welded on the positive electrode sheet, and a negative electrode ear is welded on the negative electrode sheet. The positive electrode ear and the negative electrode ear are respectively welded to the 5*5mm welding position on the upper end of the positive electrode sheet and the negative electrode sheet. A steel shell is fixedly connected to the outside of the winding core.

2. The structure for improving the safety of lithium-ion batteries against heavy object impact according to claim 1, characterized in that: The steel shell comprises an inner shell and an outer shell, a buffer interlayer is provided between the inner shell and the outer shell, a buffer member is provided in the buffer interlayer, and the buffer member is wavy.

3. The structure for improving the safety of lithium-ion batteries against heavy object impact according to claim 2, characterized in that: The gaps in the buffer interlayer are filled with elastic material, which is silica gel.

4. The structure for improving the safety of lithium-ion batteries against heavy object impact according to claim 1, characterized in that: The separator is provided between the positive electrode sheet and the negative electrode sheet. The positive electrode sheet, the separator and the negative electrode sheet are alternately arranged. One end of the positive electrode sheet, the negative electrode sheet and the separator are all fixedly connected to the central tube.

5. The structure for improving the safety of lithium-ion batteries against heavy object impact according to claim 1, characterized in that: Double-layer sealing rings are fixed on both ends of the steel shell.

6. The structure for improving the safety of lithium-ion batteries against heavy object impact according to claim 1, characterized in that: The separator is provided on both sides of the positive electrode sheet, the separator on one side is arranged horizontally, and the separator on the other side is arranged vertically.

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