A multi-point expansion force testing device for lithium batteries

Abstract

The utility model discloses a kind of lithium battery multipoint expansion force testing device, it includes cover plate one, cover plate two, several locking bolts, ultrasonic probe and data acquisition instrument;Cover plate one, cover plate two are oppositely arranged and are provided with battery to be measured between the two, several locking bolts are all through cover plate one, cover plate two to connect the two;Several ultrasonic probes are respectively corresponding with several locking bolts one to one;Data acquisition instrument is connected with several ultrasonic probes.The utility model innovatively combines ultrasonic force measurement technology and traditional expansion force test, solve the difficulty that battery multipoint position expansion force cannot be measured simultaneously, and using ultrasonic testing, without additional pressure sensor to measure the expansion of multipoint position, will not affect battery life, can simultaneously obtain the stress condition of the whole and local of battery to be measured.

Description

Technical Field

[0001] This utility model relates to the field of lithium battery technology, and in particular to a multi-point expansion force testing device for lithium batteries. Background Technology

[0002] Driven by the new energy vehicle market, the power battery industry has experienced rapid growth in recent years, with significant increases in market production and sales volume and product performance. Flat-shaped batteries, with their advantages of high energy density, high safety, flexible design, flexible battery pack assembly, and low cost, have seen increasing application in recent years. The expansion force of the battery cell affects its lifespan and safety. Limited by tooling and fixtures, most existing tests use the overall expansion force of the cell as the research object, which is one-sided. Other methods use multiple sensors for multi-point expansion force testing, requiring the plate in contact with the cell to be cut into multiple pieces. This results in uneven stress on the cell, affecting cycle life, and also fails to collect overall stress data. Utility Model Content

[0003] Therefore, the purpose of this utility model is to provide a multi-point expansion force testing device for lithium batteries, so as to solve the difficulty of simultaneously measuring the expansion force of multiple points of the battery.

[0004] To achieve the above objectives, the present invention adopts the following technical solution: This utility model provides a lithium battery multi-point expansion force testing device, which includes a cover plate one, a cover plate two, a plurality of locking bolts, ultrasonic probes and a data acquisition instrument; the cover plate one and the cover plate two are arranged opposite to each other and the battery to be tested is placed between them; the plurality of locking bolts all pass through the cover plate one and the cover plate two to connect them; the plurality of ultrasonic probes correspond one-to-one with the plurality of locking bolts; the data acquisition instrument is connected to the plurality of ultrasonic probes.

[0005] As a further improvement to the above-mentioned solution of this utility model, both ends of the locking bolt are mirror polished.

[0006] As a further improvement to the above-mentioned solution of this utility model, the lithium battery multi-point expansion force testing device also includes a support plate and an adjusting component. The support plate is set on the side of the cover plate two away from the cover plate one, and a pressure sensor connected to a data acquisition instrument is set between the cover plate two and the support plate. The adjusting component is used to adjust the distance between the cover plate two and the support plate.

[0007] As a further improvement to the above-mentioned solution of this utility model, the lithium battery multi-point expansion force testing device also includes a substrate, and a cover plate is fixed to the substrate by a number of fixing bolts.

[0008] As a further improvement to the above-mentioned solution of this utility model, the adjusting component includes a fixing plate and a screw. The fixing plate is fixed on the base plate, the screw penetrates the fixing plate vertically and is threadedly engaged with the fixing plate, and one end of the screw is rotatably connected to the support plate.

[0009] As a further improvement to the above-mentioned solution of this utility model, a handle is provided at the other end of the screw.

[0010] As a further improvement to the above-mentioned solution of this utility model, both cover plate one and cover plate two are made of metal.

[0011] As a further improvement to the above-mentioned solution of this utility model, the tray, the base plate, and the adjusting component are all made of metal.

[0012] As a further improvement to the above-mentioned solution of this utility model, the battery to be tested is a flat soft-pack battery or a square-shell battery.

[0013] Compared with the prior art, the present invention has the following beneficial effects: This invention innovatively combines ultrasonic force measurement technology with traditional expansion force testing, solving the difficulty of simultaneously measuring the expansion force at multiple points on a battery. Furthermore, by using ultrasonic testing, it eliminates the need for additional pressure sensors to measure expansion at multiple points, thus not affecting battery life. It can simultaneously acquire information on the overall and localized stress conditions of the battery under test. This invention has a compact structure, allowing for flexible arrangement of ultrasonic force measurement potentials according to requirements, resulting in high testing flexibility. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the structure of a multi-point expansion force testing device for lithium batteries according to an embodiment of the present invention; Figure 2 This is a graph showing the relationship between the deformation of the locking bolt and the force value.

[0015] Reference numerals in the attached diagram: 1. Cover plate one; 2. Cover plate two; 3. Locking bolt; 4. Ultrasonic probe; 5. Data acquisition instrument; 6. Battery under test; 7. Support plate; 8. Pressure sensor; 9. Fixing plate; 10. Screw; 11. Handle; 12. Base plate. Detailed Implementation

[0016] To facilitate understanding of this invention, a more comprehensive description of the invention will be provided below with reference to specific embodiments. However, this invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to enable a more thorough and complete understanding of the disclosure of this invention.

[0017] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

[0018] Reference Figure 1 This embodiment proposes a multi-point expansion force testing device for lithium batteries, which includes a cover plate 1, a cover plate 2, several locking bolts 3, an ultrasonic probe 4, and a data acquisition instrument 5. It may also include a support plate 7, an adjustment component, and a base plate 12.

[0019] The substrate 12 is arranged vertically and provides a mounting base for other components of the device. In this embodiment, the substrate 12 is made of metal, such as stainless steel. The metal substrate 12 has sufficient strength and rigidity to ensure that it does not deform during testing.

[0020] The cover plate 1 is horizontally arranged on one side of the substrate 12 and fixed to the substrate 12 by at least two fixing bolts. The cover plate 1 is made of metal, such as stainless steel, and the metal cover plate 1 has sufficient strength and rigidity to ensure that it will not deform during testing. Multiple screw holes are pre-drilled through the cover plate 1, and the positions of the screw holes are reasonably arranged according to the size of the battery 6 under test to meet the requirements of multi-point testing.

[0021] Cover plate 2 is horizontally positioned below cover plate 1, with a gap between them for placing the battery 6 to be tested. Cover plate 2 is made of metal, such as stainless steel, which provides sufficient strength and rigidity to prevent deformation during testing. Similarly, multiple screw holes are pre-drilled into cover plate 2, corresponding one-to-one with those in cover plate 1, to meet multi-point testing requirements.

[0022] Several locking bolts 3 are used to connect cover plate 1 and cover plate 2 to apply a preload to the battery 6 under test. The type, quantity, and position of the locking bolts 3 are selected according to the test requirements. In this embodiment, both ends of the locking bolts 3 are mirror polished.

[0023] A support plate 7 is horizontally arranged below a cover plate 2, and a pressure sensor 8 is positioned between the support plate 7 and the cover plate 2. An adjusting component is used to adjust the distance between the support plate 7 and the cover plate 2 to ensure that the pressure sensor 8 can accurately detect the overall expansion force of the battery 6 under test. The adjusting component includes a fixing plate 9 and a screw 10. The fixing plate 9 is fixed to the base plate 12, and the screw 10 vertically penetrates the fixing plate 9 and is threaded into it. One end of the screw 10 is rotatably connected to the support plate 7, and the other end is provided with a handle 11. In this embodiment, both the support plate 7 and the adjusting component are made of metal, such as stainless steel. The metal support plate 7 and the adjusting component have sufficient strength and rigidity to ensure that they do not deform during testing.

[0024] Several ultrasonic probes 4 correspond one-to-one with several locking bolts 3. The ultrasonic probes 4 can emit and receive ultrasonic waves of a fixed wavelength. The data acquisition unit 5 is connected to the ultrasonic probes 4 and the pressure sensor 8.

[0025] The length of the locking bolt 3 under different conditions can be detected by the ultrasonic probe 4. The principle of ultrasonic bolt length measurement is based on the speed of acoustic propagation. The ultrasonic probe 4 emits ultrasonic waves, which are reflected after passing through the locking bolt 3. The length of the locking bolt 3 can be measured by measuring the time from the emission of the ultrasonic wave to its reflection and re-reception, and then adding the ultrasonic wave propagation speed: L=V*t / 2; where L is the length of the locking bolt 3, V is the speed of ultrasonic wave propagation in the bolt, and t is the time from the emission of the ultrasonic wave to its re-reception (acquired by the data acquisition instrument 5).

[0026] The working principle of the multi-point expansion force testing device in this embodiment will be explained below, taking a square-shell battery as an example.

[0027] First, select four appropriate locking bolts 3 according to the size of the square battery to be tested. Then, use a universal testing machine to test the four locking bolts 3 respectively, and obtain the relationship curves between the deformation and force of the four locking bolts 3. Figure 2 The curve showing the relationship between the deformation and force of one of the locking bolts 3; Fix cover plate 1 to substrate 12, place the square battery to be tested between cover plate 1 and cover plate 2, rotate handle 11 to make pressure sensor 8 on support plate 7 contact cover plate 2, apply initial pre-tightening force; use four locking bolts 3 to fix cover plate 1 and cover plate 2, the four locking bolts 3 are distributed in a rectangle and are close to the four corners of the square battery to be tested respectively. Four ultrasonic probes 4 are placed on top of four locking bolts 3 respectively, and the initial length of the corresponding locking bolts 3 is measured using the ultrasonic probes 4. The test prismatic battery is connected to a charging and discharging device for charging and discharging cycles. If the test prismatic battery expands, the overall expansion force of the prismatic battery can be measured by the pressure sensor 8. The expansion of different positions of the prismatic battery will cause the corresponding locking bolts 3 to undergo slight deformation. The length of each locking bolt 3 after deformation is obtained by the ultrasonic probe 4, and the deformation amount of the locking bolt 3 is obtained. Then, the expansion force at that position is obtained according to the relationship curve between the deformation amount of the locking bolt 3 and the force value.

[0028] It should be noted that when a component is said to be "installed on" another component, it can be directly on the other component or it may be in a component that is centered on it. When a component is said to be "set on" another component, it can be directly set on the other component or it may also be in a component that is centered on it. When a component is said to be "fixed to" another component, it can be directly fixed to the other component or it may also be in a component that is centered on it.

[0029] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "or / and" as used herein includes any and all combinations of one or more of the associated listed items.

[0030] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0031] The embodiments described above are merely illustrative of several implementations of this utility model, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the utility model patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this utility model, and these all fall within the protection scope of this utility model. Therefore, the protection scope of this utility model patent should be determined by the appended claims.

Claims

1. A multi-point expansion force testing device for lithium batteries, characterized in that, It includes a cover plate one (1), a cover plate two (2), several locking bolts (3), an ultrasonic probe (4), and a data acquisition instrument (5); the cover plate one (1) and the cover plate two (2) are arranged opposite to each other and a battery to be tested (6) is placed between them; the several locking bolts (3) all pass through the cover plate one (1) and the cover plate two (2) to connect them; the several ultrasonic probes (4) correspond one-to-one with the several locking bolts (3); the data acquisition instrument (5) is connected to the several ultrasonic probes (4).

2. The lithium battery multi-point expansion force testing device according to claim 1, characterized in that, Both ends of the locking bolt (3) are mirror polished.

3. The lithium battery multi-point expansion force testing device according to claim 1, characterized in that, The lithium battery multi-point expansion force testing device also includes a support plate (7) and an adjusting component. The support plate (7) is located on the side of the cover plate two (2) away from the cover plate one (1), and a pressure sensor (8) connected to the data acquisition instrument (5) is provided between the cover plate two (2) and the support plate (7). The adjusting component is used to adjust the distance between the cover plate two (2) and the support plate (7).

4. The lithium battery multi-point expansion force testing device according to claim 3, characterized in that, The lithium battery multi-point expansion force testing device also includes a substrate (12), and a cover plate (1) is fixed to the substrate (12) by several fixing bolts.

5. The lithium battery multi-point expansion force testing device according to claim 4, characterized in that, The adjusting component includes a fixing plate (9) and a screw (10). The fixing plate (9) is fixed on the base plate (12). The screw (10) passes vertically through the fixing plate (9) and is threadedly engaged with the fixing plate (9). One end of the screw (10) is rotatably connected to the support plate (7).

6. The lithium battery multi-point expansion force testing device according to claim 5, characterized in that, A handle (11) is provided at the other end of the screw (10).

7. The lithium battery multi-point expansion force testing device according to claim 1, characterized in that, Both cover plate one (1) and cover plate two (2) are made of metal.

8. The lithium battery multi-point expansion force testing device according to claim 5, characterized in that, The tray (7), base plate (12) and adjustment components are all made of metal.

9. The lithium battery multi-point expansion force testing device according to claim 1, characterized in that, The battery under test (6) is a flat pouch battery or a square battery.

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