Device for testing safety performance of battery

Abstract

The utility model relates to a device for testing the safety performance of a battery, and the device comprises a pair of clamping plates which are used for limiting the front surface of the battery. At least two groups of limiting fixing pieces are arranged, the two groups of limiting fixing pieces are arranged at intervals, and the distance between the two groups of limiting fixing pieces is approximately equal to the height of the battery; and the two groups of limiting fixing pieces respectively abut against the top surface and the bottom surface of the battery. According to the utility model, the pair of clamping plates is arranged to limit the front surface of the battery; secondly, limiting the top surface and the bottom surface of the battery through not less than two groups of limiting fixing pieces; in order to ensure that the top cover patch positioned on the top surface of the battery is not subjected to overheat expansion in a safety performance test and the opening pressure of the anti-explosion valve is normal, one group of limiting fixing pieces is arranged on the outer side of the anti-explosion valve and is positioned between the positive and negative poles.

Description

Technical Field

[0001] The utility model relates to the technical field of lithium ion battery safety, in particular to a device for testing battery safety performance. Background Art

[0002] Lithium-ion batteries have excellent characteristics such as light weight, high energy density, and long service life, so they are widely used. However, safety accidents of lithium-ion power batteries occasionally occur. The safety performance of lithium-ion power batteries is directly related to the safety of life and property of the people, and is also closely related to the large-scale industrialization of new energy vehicles. Lithium-ion batteries need to undergo safety tests required by national standards during the research and development stage to verify the safety performance of the battery. When the battery is exposed to external conditions such as heat, force, and electricity, gas is generated inside, causing the internal air pressure of the battery to gradually increase. Under the action of pressure, the battery top cover bulges and deforms, causing the opening pressure of the explosion-proof valve to be 20% to 30% higher than the conventional opening pressure. When the opening pressure of the explosion-proof valve increases, the energy of the air pressure energy converted into the air jet kinetic energy at the moment the explosion-proof valve is opened increases, the battery valve opening has a stronger impact on the outside, and the airflow disturbance caused by the internal pressure difference has greater damage to the pole piece. Therefore, it is necessary to use tooling to limit the deformation of the top cover to ensure the normal opening of the explosion-proof valve, thereby reducing the air pressure energy converted into the air jet kinetic energy, thereby improving the safety performance of the battery in the test.

[0003] Application number: 202123398837.0, application date: 2021.12.31, the name of the utility model is a battery safety testing device, including: an outer cover and a storage table, the storage table includes: a cover plate, a support plate and a bottom plate from top to bottom, the support plate is connected to the bottom plate, there are several height limit blocks between the cover plate and the support plate, and the shape of the opening on the lower side of the outer cover matches the shape of the bottom plate. The utility model adopts the outer cover and the storage table in combination, with low production cost and solves the problem of large space occupied by the previous oven; the outer cover of the utility model is first made of transparent material, which is convenient for observing the test piece during testing.

[0004] Although the above-mentioned prior art is provided with a cover plate, a support plate and a height limiting block, the function of the height limiting block is to connect the cover plate and the support plate, and can only limit the two sides of the battery. During testing, the cross section of the battery that is not limited will swell, and the explosion-proof valve will be deformed due to the expansion of the battery top cover patch, and the opening pressure will be higher than the set pressure; the stress at the battery weld position is too large, resulting in cracking and damage.

[0005] In addition, the above-mentioned prior art can only perform heating detection on the battery, and cannot perform other performance tests, such as overcharging, puncture, etc. Utility Model Content

[0006] In view of the defects in the prior art that only two surfaces of the battery are limited, the cross section of the battery that is not limited will swell, the explosion-proof valve will be deformed due to the expansion of the battery top cover patch, the opening pressure is higher than the set pressure, and only the battery can be heated and tested, and other performance tests cannot be performed, the purpose of the utility model is to provide a device for battery safety performance testing.

[0007] The technical solution provided by the utility model is:

[0008] A device for testing the safety performance of a battery comprises a pair of clamps for limiting the front surface of a battery; a limiting fixture, at least two groups of which are arranged at intervals and the intervals between the two groups are approximately equal to the height of the battery; and the two groups of the limiting fixtures are respectively against the top and bottom surfaces of the battery.

[0009] Preferably, the clamping plate is provided with two groups of through holes; the first group of through holes is adapted to the top surface of the battery, and the second group of through holes is adapted to the bottom surface of the battery; and the limiting fixing member is passed through the through holes.

[0010] Preferably, the through hole comprises:

[0011] A first through hole and a second through hole, wherein the first through hole and the second through hole are arranged at intervals and cooperate with a set of limiting fixing members to limit the top surface of the battery;

[0012] The third through hole and the fourth through hole are arranged at intervals and are used in conjunction with another set of limiting fixing members to limit the bottom surface of the battery.

[0013] Preferably, the first through hole and the second through hole are located in the same horizontal plane, and the third through hole and the fourth through hole are also located in the same horizontal plane; the spacing between the first through hole and the second through hole is smaller than the spacing between the third through hole and the fourth through hole; the height difference between the two sets of limiting fixings is adapted to the battery height value.

[0014] Preferably, the limiting fixture includes a first limiting fixture and a second limiting fixture; the first limiting fixture and the second limiting fixture are located outside the explosion-proof valve of the battery top cover patch and between the positive pole and the negative pole.

[0015] Preferably, the position-limiting fixing member further comprises the third position-limiting fixing member and the fourth position-limiting fixing member; and the distance between the third position-limiting fixing member and the fourth position-limiting fixing member is smaller than the length of the bottom surface of the battery.

[0016] Preferably, the position-limiting fixing member is a rod-shaped structure; the shape of the through hole is adapted to the rod-shaped structure to limit the position of the battery.

[0017] Preferably, the through hole is a screw hole; the limiting fixing piece is a screw matched with the screw hole; a screw head is provided at one end of the screw, and the cross-sectional area of ​​the screw head is larger than the cross-sectional area of ​​the through hole.

[0018] Preferably, the cross-section of the screw head is circular, and the diameter is not less than 2 cm.

[0019] Preferably, the clamping plate and the limiting fixing piece are both insulated, and the thickness of the clamping plate is not less than 8 mm.

[0020] Compared with the prior art, the technical solution provided by the utility model has the following beneficial effects:

[0021] The utility model firstly limits the front face of the battery by setting a pair of clamping plates; secondly limits the top face and bottom face of the battery by using a through hole in coordination with a limiting fixture; in order to ensure that the top cover patch located on the top face of the battery does not overheat and expand during the safety performance test and that the opening pressure of the explosion-proof valve is normal, the first limiting fixture and the second limiting fixture are arranged on the outside of the explosion-proof valve and between the positive and negative poles.

[0022] In addition, the battery can be connected to an external control system to conduct multiple safety performance tests such as overcharging, thermal runaway, puncture, and heating. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a schematic diagram of the overall structure of a device for battery safety performance testing in this application;

[0024] Figure 2 A front view of a device for battery safety performance testing in this application;

[0025] Figure 3 This is a right view of a device for battery safety performance testing in the present application;

[0026] Figure 4 It is a top view of a device for battery safety performance testing of the present application;

[0027] Figure 5 It is a schematic diagram of the overall structure of a battery that is limited in a device for battery safety performance testing of the present application;

[0028] Figure 6 It is a schematic diagram of the battery top cover patch structure in this application.

[0029] Explanation of the symbols in the schematic diagram:

[0030] Clamping plate 1, first through hole 11, second through hole 12, third through hole 13, fourth through hole 14;

[0031] Battery front 21, battery top 22, battery top cover patch 23, explosion-proof valve 231, positive pole 232, negative pole 233;

[0032] A first position-limiting fixing member 31 , a second position-limiting fixing member 32 , a third position-limiting fixing member 33 , and a fourth position-limiting fixing member 34 . DETAILED DESCRIPTION

[0033] In order to further understand the content of the utility model, the utility model is described in detail in conjunction with the drawings and embodiments.

[0034] The structures, proportions, sizes, etc. illustrated in the drawings of this specification are only used to match the contents disclosed in the specification for people familiar with this technology to understand and read, and are not used to limit the limiting conditions for the implementation of the present invention, so they have no substantial technical significance. Any modification of the structure, change of the proportion relationship or adjustment of the size, without affecting the effects and purposes that can be achieved by the present invention, should still fall within the scope of the technical content disclosed by the present utility model. At the same time, the terms such as "upper", "lower", "left", "right", "middle" and so on quoted in this specification are only for the convenience of description, and are not used to limit the scope of implementation. The change or adjustment of their relative relationship should also be regarded as the scope of implementation of the present invention without substantially changing the technical content.

[0035] In the prior art, when testing the safety performance of batteries, only the two front sides of the batteries are generally restricted. When the internal air pressure of the battery increases, the battery top cover swells and deforms, causing the explosion-proof valve opening pressure to be 20% to 30% higher than the conventional opening pressure. When the explosion-proof valve opening pressure increases, the energy of the air pressure energy converted into air jet kinetic energy at the moment the explosion-proof valve opens increases, the battery valve opening has a stronger impact on the outside, and the airflow disturbance caused by the internal pressure difference has a greater damage to the pole piece.

[0036] The present application discloses a device for testing the safety performance of a battery, which limits deformation of the battery top cover and ensures normal opening of the explosion-proof valve, thereby reducing the amount of air pressure that can be converted into air jet kinetic energy, thereby improving the safety performance of the battery during testing.

[0037] The present application discloses a device for testing the safety performance of a battery, comprising a pair of splints 1 and a limiting fixture. The splints 1 include at least two groups of limiting fixtures, the two groups of limiting fixtures are arranged at intervals, and the interval between the two groups of limiting fixtures is approximately equal to the height of the battery. The two groups of limiting fixtures are respectively against the top surface 22 and the bottom surface of the battery.

[0038] Preferably, the clamping plate 1 is provided with through holes used in conjunction with the limiting fixings, and there are at least two groups of through holes, the first group of through holes is adapted to the battery top surface 22, and the second group of through holes is adapted to the battery bottom surface, and the limiting fixings are penetrated through the through holes. By assembling the clamping plate 1, the through holes, and the limiting fixings, the front surface 21, the top surface 22, and the bottom surface of the battery can be limited or fixed.

[0039] Specifically, the first group of through holes includes a first through hole 11 and a second through hole 12, and the corresponding first group of limiting fixings are a first limiting fixing 31 and a second limiting fixing 32. The first group of through holes and the first group of limiting fixings limit or fix the battery top surface 22. The second group of through holes includes a third through hole 13 and a fourth through hole 14, and the corresponding second group of limiting fixings are a third limiting fixing 33 and a fourth limiting fixing 34. The second group of through holes and the second group of limiting fixings limit or fix the battery bottom surface.

[0040] The first group of through holes are located in the same horizontal plane, and the second group of through holes are located in another horizontal plane. The horizontal plane introduced here is a mathematical concept, that is, the horizontal plane is a plane composed entirely of horizontal parallel straight lines. The first group of through holes and the second group of through holes are arranged at intervals and parallel to each other, and the spacing between the first group of through holes is smaller than the spacing between the second group of through holes, and the spacing between the second group of through holes is smaller than the length of the bottom surface of the battery, that is, the spacing between the third limiting fixture 33 and the fourth limiting fixture 34 is smaller than the length of the bottom surface of the battery.

[0041] In order to ensure the normal opening of the explosion-proof valve 231 and reduce the damage to the battery pole piece, the first set of limiting fixing parts is installed outside the explosion-proof valve 231 on the battery top cover patch 23 and between the positive pole 232 and the negative pole 233.

[0042] More specifically, the through hole and the limiting fixture can be set into different structures according to the needs of the safety performance test. If it is only necessary to limit the battery without causing a large displacement, the limiting fixture can be set into a smooth round rod-shaped structure, and a seal may or may not be set in the through hole. The shape of the through hole is adapted to the rod-shaped structure to complete the battery limiting. The cross-section of the rod-shaped structure of the limiting fixture can be circular, square or hexagonal. There is no restriction on the specific cross-sectional shape as long as it can meet the limiting function.

[0043] If the battery needs to be fixed and not allowed to move, the limit fixing part can be set as a screw, and the through hole is a screw hole. A screw head is provided at one end of the screw, and the cross-sectional area of ​​the screw head is larger than the cross-sectional area of ​​the through hole. The cross-sectional area of ​​the screw head is preferably circular, and the diameter is not less than 2cm; when the screw is tightened in the screw hole, the battery is fixed. Screws and screw holes are only a fixing method, and can also be set as other compatible parts to meet the fixing function.

[0044] The clamping plate 1 and the limiting fixing parts are both insulated, and the clamping plate is preferably a steel plate with a thickness of not less than 8 mm.

[0045] When starting safety tests such as overcharging, thermal runaway, puncture, and heating, because the battery front 21, battery top 22, and bottom are all limited or fixed, the top cover will not be deformed after the battery swells, the explosion-proof valve will open normally, and the energy of air pressure converted into air jet kinetic energy at the moment the explosion-proof valve opens is small, and the loss of internal battery electrodes is small; the battery front 21 will not swell and deform, causing excessive stress at the weld position, thereby preventing abnormal cracking of the weld.

[0046] The above schematically describes the present invention and its implementation methods, which are not restrictive. The drawings show only one implementation method of the present invention, and the actual structure is not limited thereto. Therefore, if ordinary technicians in this field are inspired by it and design structural methods and embodiments similar to the technical solution without creativity without departing from the purpose of the present invention, they should all fall within the protection scope of the present invention.

Claims

1. A device for testing battery safety performance, It is characterized in that include: A pair of clamping plates (1) for limiting the position of the front side of the battery (21); The position-limiting fixing members include at least two groups, the two groups of position-limiting fixing members are arranged at intervals, and the intervals between the two groups are substantially equal to the height of the battery; the two groups of position-limiting fixing members are respectively against the top surface (22) and the bottom surface of the battery.

2. The device for battery safety performance testing according to claim 1, characterized in that: The clamping plate (1) is provided with two groups of through holes; the first group of through holes is matched with the top surface (22) of the battery, and the second group of through holes is matched with the bottom surface of the battery; the limiting fixing parts are passed through the through holes.

3. A device for battery safety performance testing according to claim 2, characterized in that: The through hole comprises: A first through hole (11) and a second through hole (12), wherein the first through hole (11) and the second through hole (12) are arranged at intervals and are used in conjunction with a set of limiting fixing members to limit the top surface (22) of the battery; The third through hole (13) and the fourth through hole (14) are arranged at intervals and are used in conjunction with another set of limiting fixing members to limit the bottom surface of the battery.

4. The device for battery safety performance testing according to claim 3, characterized in that: The first through hole (11) and the second through hole (12) are located on the same horizontal plane, and the third through hole (13) and the fourth through hole (14) are also located on the same horizontal plane; the spacing between the first through hole (11) and the second through hole (12) is smaller than the spacing between the third through hole (13) and the fourth through hole (14); and the height difference between the two groups of limiting fixings is adapted to the height value of the battery.

5. The device for battery safety performance testing according to claim 1, characterized in that: The position-limiting fixing member comprises a first position-limiting fixing member (31) and a second position-limiting fixing member (32); the first position-limiting fixing member (31) and the second position-limiting fixing member (32) are located outside the explosion-proof valve (231) of the battery top cover patch (23), and between the positive pole (232) and the negative pole (233).

6. The device for battery safety performance testing according to claim 5, characterized in that: The position-limiting fixing member further comprises a third position-limiting fixing member (33) and a fourth position-limiting fixing member (34); the distance between the third position-limiting fixing member (33) and the fourth position-limiting fixing member (34) is smaller than the length of the bottom surface of the battery.

7. The device for battery safety performance testing according to claim 1, characterized in that: The position-limiting fixing piece is a rod-shaped structure; the shape of the through hole is adapted to the rod-shaped structure to limit the position of the battery.

8. The device for battery safety performance testing according to claim 2, characterized in that: The through hole is a screw hole; the limiting fixing piece is a screw matched with the screw hole; a screw head is provided at one end of the screw, and the cross-sectional area of ​​the screw head is larger than the cross-sectional area of ​​the through hole.

9. The device for battery safety performance testing according to claim 8, characterized in that: The cross section of the screw head is circular, and the diameter is not less than 2 cm.

10. The device for battery safety performance testing according to claim 1, characterized in that: The clamping plate (1) and the limiting fixing piece are both subjected to insulation treatment, and the thickness of the clamping plate (1) is not less than 8 mm.

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