Cylindrical steel shell lithium battery side face extrusion test tool and test method

Abstract

The invention provides a cylindrical steel shell lithium battery side surface extrusion test tool and test method, and the tool comprises a battery body, the outer side of the battery body is provided with a tool body in a nested manner; the strong magnetic block is arranged in the tool body; the tool body comprises an upper pressing plate and a lower pressing plate, the upper pressing plate and the lower pressing plate are consistent in structure, the battery body is located between the upper pressing plate and the lower pressing plate, and grooves are formed in the inner sides of the upper pressing plate and the lower pressing plate. When the cylindrical steel shell lithium battery side face extrusion test tool and the test method are used, the tool wraps the battery and then places the battery on an extrusion platform, extrusion test is carried out at the speed of 0.1 mm / s, the surface contact stress state of the battery in a PACK structure can be accurately simulated, the problem that a traditional line contact / point contact test result is inaccurate is solved, and the test efficiency is improved. And the reliability of battery anti-extrusion performance evaluation is improved.

Description

Technical Field

[0001] This invention relates to the field of lithium battery testing equipment technology, and more specifically, to a tooling and method for testing the side extrusion of a cylindrical steel-cased lithium battery. Background Technology

[0002] In the safety performance testing of cylindrical steel-cased lithium batteries (such as 18650 and 21700 models), the side compression test is a key item for evaluating the battery's resistance to external force damage. In traditional compression tests, the tooling and the battery are mostly in line or point contact, which deviates significantly from the actual surface contact force form of the battery in the PACK structure. This leads to inaccurate test results, which cannot truly reflect the battery's compression resistance performance in real-world application scenarios, thus limiting battery safety assessment and structural optimization.

[0003] This invention can improve the reliability of battery crush resistance performance evaluation. Summary of the Invention

[0004] The present invention aims to solve the technical problems mentioned in the background art and provide a tooling and method for testing the side extrusion of cylindrical steel-cased lithium batteries.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a cylindrical steel-shell lithium battery side extrusion test fixture and test method, comprising: a battery body, wherein a fixture body is nested on the outside of the battery body; A strong magnetic block is disposed inside the tooling body; The tooling body includes an upper pressure plate and a lower pressure plate. The upper pressure plate and the lower pressure plate have the same structure, and the battery body is located between the upper pressure plate and the lower pressure plate. Grooves are provided on the inner sides of both the upper pressure plate and the lower pressure plate.

[0006] A further preferred embodiment: the outer ends of both the upper and lower pressure plates are flat.

[0007] A further preferred embodiment: the groove is completely fitted to the outer arc surface of the battery body, and the arc degree is 60°.

[0008] A further preferred embodiment: the strong magnetic block is a neodymium iron boron strong magnet.

[0009] A further preferred embodiment: the strong magnetic blocks are respectively embedded inside the upper pressure plate and the lower pressure plate, and the number of strong magnetic blocks inside the upper pressure plate and the lower pressure plate is the same.

[0010] The test method for the side extrusion test fixture of a cylindrical steel-cased lithium battery includes the following steps: S1. Wrap the cylindrical battery to be tested with the upper and lower pressure plates, and use the magnetic attraction of the strong magnetic block to make the fixture fit tightly against the side of the battery. S2. Place the battery with tooling on the flat extrusion platform; S3. Set the extrusion platform descent speed to 0.1 mm / s; S4. Record the maximum pressure the battery can withstand to complete the crush performance test. Beneficial effects

[0011] 1. By setting up an upper pressure plate and a lower pressure plate, the outer ends of both the upper and lower pressure plates are flat, which is used to make parallel contact with the extrusion equipment; the groove set on the inner side is completely fitted with the curved surface of the cylindrical battery, with a curvature of 60°, which makes the battery more accurate in positioning. Through the design of the flat surface and the curved groove, the battery and the tooling are in surface contact, which perfectly matches the actual stress scenario of the battery in the PACK structure, and the test results are more accurate. 2. By incorporating a strong magnetic block, the fixture is ensured to adhere firmly to the battery without slipping, thus avoiding errors caused by relative displacement during testing. This effectively improves testing accuracy. Furthermore, the fixture has a simple structure, is easy to assemble and disassemble, and allows for quick completion of test preparation. 3. In summary, this cylindrical steel-cased lithium battery side extrusion test fixture and method, through the setting of structures such as upper pressure plates, achieves precise positioning by the grooves in which the inner sides of the upper and lower pressure plates and the outer arc surface of the battery are completely fitted. The upper and lower pressure plates are tightly attracted by neodymium iron boron strong magnets to reliably fix the battery. Its consistent structure and flat outer end design facilitate processing and manufacturing and equipment compatibility. At the same time, the highly adaptable arc surface design can simulate the actual side extrusion condition, effectively detect the battery's safety performance and structural stability, and also has good structural adaptability and high test effectiveness. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of the overall structure of the present invention.

[0013] Figure 2 This is a schematic diagram of the tooling body structure of the present invention.

[0014] Figure 3 This is a schematic diagram of the position structure of the strong magnetic block in this invention.

[0015] Figure 4 This is a schematic diagram of the arc-surface contact extrusion test curve of the 18650 battery of the present invention.

[0016] Figure 1-4 In the middle: 1. Upper pressure plate; 2. Lower pressure plate; 3. Battery body; 4. Groove; 5. Strong magnetic block. Detailed Implementation

[0017] The following will refer to the appendices in the embodiments of the present invention. Figures 1-4 The technical solutions in the embodiments of the present invention will be clearly and completely described.

[0018] Please see Figure 1-4 In this embodiment of the invention, a cylindrical steel-shell lithium battery side extrusion test fixture and test method are provided, including: a battery body 3, with a fixture body nested on the outside of the battery body 3; a strong magnetic block 5, which is disposed inside the fixture body; the fixture body includes an upper pressure plate 1 and a lower pressure plate 2, the upper pressure plate 1 and the lower pressure plate 2 have the same structure, and the battery body 3 is located between the upper pressure plate 1 and the lower pressure plate 2, and grooves 4 are provided on the inner sides of both the upper pressure plate 1 and the lower pressure plate 2; the outer ends of the upper pressure plate 1 and the lower pressure plate 2 are both flat; the grooves 4 are completely fitted with the outer arc surface of the battery body 3, and the arc degree is 60°; the strong magnetic block 5 is a neodymium iron boron strong magnet; the strong magnetic blocks 5 are respectively embedded inside the upper pressure plate 1 and the lower pressure plate 2, and the number of strong magnetic blocks 5 disposed inside the upper pressure plate 1 and the lower pressure plate 2 is the same; A cylindrical steel-cased lithium battery is placed between the upper pressure plate 1 and the lower pressure plate 2 of the fixture body. The battery is positioned using grooves 4 on the inner sides of the upper and lower pressure plates 1 and 2 that are fully fitted to the outer arc surface of the battery body 3. Simultaneously, the magnetic force of neodymium iron boron magnets 5 embedded inside the upper and lower pressure plates 1 and 2 causes them to adhere tightly, thus applying a stable compressive force to the side of the battery. This achieves the side compression test of the cylindrical steel-cased lithium battery. The grooves 4 on the upper and lower pressure plates 1 and 2 are fully fitted to the outer arc surface of the battery body 3, positioning the battery and ensuring stable force position and direction during the compression test. The strong magnetic force of the iron-boron strong magnet 5 tightly attracts the upper pressure plate 1 and the lower pressure plate 2, stabilizing the battery and preventing displacement during testing, thus ensuring the accuracy of the test results. The upper pressure plate 1 and lower pressure plate 2 have identical structures and flat outer ends, facilitating tooling manufacturing and compatibility with testing equipment. Furthermore, the curved surface design of the groove 4 is highly compatible with the shape of the cylindrical steel-cased battery. Through a stable side-extrusion fixture, the side-extrusion conditions that the battery may experience in actual applications can be simulated, effectively testing the battery's safety performance and structural stability under these conditions. This device improves the accuracy of the extrusion test results by setting a pre-pressure and then resetting to zero.

[0019] Working principle: The outer ends of the upper pressure plate 1 and the lower pressure plate 2 are both flat, used for parallel contact with the extrusion equipment; the groove 4 on the inner side is completely fitted with the curved surface of the cylindrical battery, with a curvature of 60°; the strong magnetic block 5 is embedded inside, used to magnetically attract the battery side to prevent the tooling from sliding; when the upper pressure plate 1 and the lower pressure plate 2 are used together, the gap is more than 5mm to allow the battery to be deformed by extrusion; the upper pressure plate 1 and the lower pressure plate 2 are made of insulating materials with a certain strength; the strong magnetic block 5 is a neodymium iron boron strong magnet to ensure that the tooling is in close contact with the side of the battery without slippage; the cylindrical battery to be tested is wrapped with the upper pressure plate 1 and the lower pressure plate 2 from top to bottom, and the magnetic attraction of the strong magnetic block 5 makes the tooling fit tightly against the side of the battery; the battery with the tooling is placed on the flat extrusion platform; the extrusion platform is set to descend at a speed of 0.1mm / s; the maximum pressure that the battery can withstand is recorded to complete the extrusion performance test.

[0020] Example: Test method using an 18650 cylindrical steel-cased lithium battery; Includes the following steps: S1. Wrap the cylindrical battery to be tested with the upper pressure plate 1 and the lower pressure plate 2 from top to bottom, and use the magnetic attraction of the strong magnetic block 5 to make the fixture fit tightly against the side of the battery. S2. Place the battery with tooling on the flat extrusion platform; S3. Set the extrusion platform descent speed to 0.1 mm / s; S4. Record the maximum pressure the battery can withstand to complete the crush performance test.

[0021] Tooling preparation: Using insulating and high-strength engineering plastics such as POM, symmetrical upper and lower pressure plates 1 and 2 are fabricated. Each plate has one flat side and a 60° arc groove 4 on the other side to completely fit the arc surface of the 18650 battery. A neodymium iron boron magnet 5 is embedded inside. The clearance between the upper and lower tooling components is designed to be 6mm. During testing, the upper and lower pressure plates 1 and 2 wrap around the 18650 battery, with the magnet 5 adsorbing onto the side of the battery, ensuring a secure fit without slippage. The battery with the tooling is placed on a flat extrusion platform. The extrusion platform is set to descend at a speed of 0.1mm / s, and the extrusion test is initiated. The equipment records the maximum pressure the battery can withstand, as shown in the attached figure. Figure 4 The test curve shown indicates that the maximum pressure that the Haisida 18650 battery can withstand when its arc surface is compressed is approximately 24 kg; this allows for the evaluation of the battery's compression resistance. As can be seen from this example, this fixture can effectively simulate the surface contact force of the battery in the PACK structure, and the test results are accurate and highly stable. It can be widely used in the field of safety performance testing of cylindrical steel-cased lithium batteries.

Claims

1. A tooling for testing the side extrusion of a cylindrical steel-cased lithium battery, comprising: The battery body (3) is characterized in that: a tooling body is nested on the outside of the battery body (3); A strong magnetic block (5) is disposed inside the tooling body; The tooling body includes an upper pressure plate (1) and a lower pressure plate (2). The upper pressure plate (1) and the lower pressure plate (2) have the same structure, and the battery body (3) is located between the upper pressure plate (1) and the lower pressure plate (2). The upper pressure plate (1) and the lower pressure plate (2) are both provided with grooves (4).

2. The cylindrical steel-cased lithium battery side extrusion test fixture according to claim 1, characterized in that: The outer ends of the upper pressure plate (1) and the lower pressure plate (2) are both flat.

3. The cylindrical steel-cased lithium battery side extrusion test fixture according to claim 1, characterized in that: The groove (4) is fully fitted to the outer arc surface of the battery body (3), and the arc degree is 60°.

4. The cylindrical steel-cased lithium battery side extrusion test fixture according to claim 1, characterized in that: The strong magnetic block (5) is a neodymium iron boron strong magnet.

5. The cylindrical steel-cased lithium battery side extrusion test fixture according to claim 1, characterized in that: The strong magnetic blocks (5) are embedded in the upper pressure plate (1) and the lower pressure plate (2) respectively, and the number of strong magnetic blocks (5) inside the upper pressure plate (1) and the lower pressure plate (2) is the same.

6. A test method based on the cylindrical steel-cased lithium battery side extrusion test fixture according to any one of claims 1-5, characterized in that: Includes the following steps: S1. Wrap the cylindrical battery to be tested with the upper and lower pressure plates, and use the magnetic attraction of the strong magnetic block to make the fixture fit tightly against the side of the battery. S2. Place the battery with tooling on the flat extrusion platform; S3. Set the extrusion platform descent speed to 0.1 mm / s; S4. Record the maximum pressure the battery can withstand to complete the crush performance test.

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