Initiating device for short circuit test in battery cell

Abstract

The invention discloses a battery cell internal short circuit test triggering device which comprises a positioning piece made of a first magnetic material, and the positioning piece is pre-embedded in one side of a to-be-penetrated area in a battery cell; the penetrating piece is made of a second magnetic material with the Curie temperature higher than that of the first magnetic material, and the penetrating piece is adsorbed in the positioning piece and faces the to-be-penetrated area; the adsorption part is made of a third magnetic material of which the Curie temperature is higher than that of the first magnetic material, is pre-buried on the other side of the to-be-penetrated area in the battery cell and is aligned with the penetration part; and the heating piece is installed outside the battery cell shell to heat the positioning piece, and when the positioning piece is heated to the Curie temperature of the first magnetic material, the penetrating piece penetrates through the to-be-penetrated area under the magnetic attraction of the adsorption piece to trigger the short circuit in the battery cell. The penetration piece can be triggered to penetrate through the to-be-penetrated area to trigger the internal short circuit only by controlling the heating piece to heat, the operation safety is high, and thermal runaway caused by the internal short circuit can be simulated more truly.

Description

Technical Field

[0001] The present application relates to a battery cell testing device, and in particular to a battery cell internal short circuit test initiating device. Background Art

[0002] In the design and development of battery cells, it is often necessary to trigger thermal runaway caused by internal short circuits to test whether the safety protection measures in the design are effective. The commonly used methods currently include built-in heating plate triggering and acupuncture triggering. The built-in heating plate triggering method cannot pre-design the short circuit position in the battery cell, which has certain limitations. In addition, the failure mode of thermal shrinkage of the diaphragm by heating is quite different from the internal short circuit mode caused by impurities in the battery cell in terms of temperature, voltage and other warning signals, and cannot accurately simulate the thermal runaway caused by internal short circuits. The acupuncture triggering method can pre-design the short circuit position, and the thermal runaway caused by this is more similar to the thermal runaway caused by internal short circuits. However, this method is greatly affected by the outer shell, and it is necessary to pre-open holes in the outer shell. In addition, the acupuncture operation is difficult and the risk factor is also high. Summary of the invention

[0003] The purpose of the present application is to overcome the deficiency in the prior art that it is not possible to simultaneously ensure the simulation effect of the internal short circuit and the operational safety, and to provide a battery cell internal short circuit test initiation device.

[0004] The technical solution of the present application provides a battery cell internal short circuit test initiation device, comprising:

[0005] A positioning piece, made of a first magnetic material, and pre-buried at one side of the area to be penetrated in the battery core;

[0006] A penetrating member, made of a second magnetic material, wherein the Curie temperature of the second magnetic material is greater than the Curie temperature of the first magnetic material, the penetrating member is adsorbed in the positioning member and faces the area to be penetrated;

[0007] An adsorbing member is made of a third magnetic material, and the Curie temperature of the third magnetic material is greater than the Curie temperature of the first magnetic material. The adsorbing member is pre-buried on the other side of the area to be penetrated in the battery core and aligned with the penetrating member;

[0008] A heating element is installed outside the battery cell shell to heat the positioning element. When the positioning element is heated to the Curie temperature of the first magnetic material, the penetrating element penetrates the area to be penetrated under the magnetic attraction of the adsorption element to trigger a short circuit in the battery cell.

[0009] Furthermore, the Curie temperature of the third magnetic material is greater than the Curie temperature of the second magnetic material.

[0010] Furthermore, the Curie temperature of the first magnetic material is 80-150°C, the Curie temperature of the second magnetic material is 200-300°C, and the Curie temperature of the third magnetic material is above 400°C.

[0011] Furthermore, the first magnetic material is at least one of chromium dioxide and rubber magnet, the second magnetic material is at least one of neodymium magnet and manganese oxide-iron oxide, and the third magnetic material is at least one of magnesium oxide-iron oxide, copper oxide-iron oxide, nickel oxide-iron oxide, and ferrosoferric oxide.

[0012] Furthermore, the mass of the positioning member is greater than the mass of the adsorption member.

[0013] Furthermore, a receiving cavity is provided in the positioning member, the opening of the receiving cavity faces the area to be penetrated, and the penetrating member is adsorbed in the receiving cavity.

[0014] Furthermore, one end of the penetrating member is provided with an adsorption plane, and the other end is provided with a conical tip, the adsorption plane is adsorbed on the cavity wall of the accommodating cavity, and the conical tip faces the area to be penetrated.

[0015] Furthermore, a through cavity is provided in the adsorption member, and the center of the conical tip is in the same straight line as the axis of the through cavity.

[0016] Furthermore, the battery cell is provided with a positive electrode sheet and a negative electrode sheet arranged at intervals, and a separator is provided between adjacent positive electrode sheets and negative electrode sheets;

[0017] The area to be penetrated includes at least one layer of the diaphragm.

[0018] Furthermore, the positioning member is glued to the diaphragm or the positive electrode sheet or the negative electrode sheet on one side of the area to be penetrated, and the adsorption member is glued to the diaphragm or the positive electrode sheet or the negative electrode sheet on the other side of the area to be penetrated.

[0019] After adopting the above technical solution, the following beneficial effects are achieved:

[0020] The present application pre-buries a positioning member and an adsorption member on both sides of an area to be penetrated in the battery cell, wherein the positioning member is magnetically adsorbed with the penetrating member, the adsorption member is arranged on the other side of the area to be penetrated and aligned with the penetrating member, and when internal short circuit thermal runaway is caused, the heating member is controlled to heat the positioning member to the Curie temperature of the first magnetic material, at which time the positioning member loses its magnetism, and since the Curie temperature of the third magnetic material making the adsorption member is greater than the Curie temperature of the first magnetic material, the adsorption member is still magnetic at this time, so the penetrating member penetrates the area to be penetrated under the magnetic attraction of the adsorption member, causing internal short circuit thermal runaway, that is, the present device can cause an internal short circuit only by heating, has high operational safety, and can more realistically simulate thermal runaway caused by an internal short circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The disclosure of the present application will become easier to understand with reference to the accompanying drawings. It should be understood that these drawings are only for illustrative purposes and are not intended to limit the scope of protection of the present application. In the drawings:

[0022] Figure 1 It is a structural schematic diagram of a short-circuit test triggering device in a battery cell in one embodiment of the present application;

[0023] Figure 2 It is an exploded view of the positioning member, the penetrating member and the adsorption member in one embodiment of the present application.

[0024] Reference table of reference numerals:

[0025] Positioning member 01: accommodating cavity 11;

[0026] Penetrating member 02: adsorption plane 21, conical tip 22;

[0027] Adsorption member 03: through cavity 31;

[0028] Heating element 04; battery cell shell 05: pole piece 51, negative pole piece 52, diaphragm 53. DETAILED DESCRIPTION

[0029] The specific implementation of the present application is further described below with reference to the accompanying drawings.

[0030] It is easy to understand that according to the technical solution of the present application, without changing the essential spirit of the present application, a variety of structural modes and implementation modes that can be replaced by those skilled in the art can be replaced with each other. Therefore, the following specific implementation modes and drawings are only exemplary descriptions of the technical solution of the present application, and should not be regarded as the entirety of the present application or as a limitation or restriction on the technical solution of the application.

[0031] The directional terms such as up, down, left, right, front, back, front, back, top, bottom, etc. mentioned or may be mentioned in this specification are defined relative to the structures shown in the drawings. They are relative concepts and may change accordingly according to their different positions and different usage conditions. Therefore, these or other directional terms should not be interpreted as restrictive terms. In addition, the terms "first", "second", and "third" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0032] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installation", "connection" and "connection" 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, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above-mentioned in this application can be understood according to the specific circumstances.

[0033] The battery cell internal short circuit test triggering device in the embodiment of the present application is as follows: Figure 1 Shown, including

[0034] The positioning member 01 is made of a first magnetic material and is pre-buried on one side of the area to be penetrated in the battery core;

[0035] The penetrating member 02 is made of a second magnetic material, and the Curie temperature of the second magnetic material is greater than the Curie temperature of the first magnetic material. The penetrating member 02 is adsorbed in the positioning member and faces the area to be penetrated;

[0036] The adsorption member 03 is made of a third magnetic material, and the Curie temperature of the third magnetic material is greater than the Curie temperature of the first magnetic material. The adsorption member 03 is pre-buried on the other side of the area to be penetrated in the battery core and aligned with the penetration member 02;

[0037] The heating element 04 is installed outside the battery cell shell 05 to heat the positioning element 01. When the positioning element 01 is heated to the Curie temperature of the first magnetic material, the penetrating element 02 penetrates the area to be penetrated under the magnetic attraction of the adsorption element 03 to trigger a short circuit in the battery cell.

[0038] In the embodiment of the present application, the positioning member 01, the penetrating member 02 and the adsorbing member 03 are all made of magnetic materials and have magnetism. The Curie temperature of the first magnetic material used to make the positioning member 01 is lower than the Curie temperature of the second magnetic material used to make the penetrating member 02 and the third magnetic material used to support the adsorbing member 03. When the temperature of the battery core rises to the Curie temperature of the first magnetic material, the positioning member 01 loses its magnetism, while the penetrating member 02 and the adsorbing member 03 still have magnetism.

[0039] When making the battery cell, the positioning member 01, the penetrating member 02 and the adsorption member 03 are pre-buried in the battery cell. Among them, the positioning member 01 is fixedly installed on one side of the area to be penetrated, and the adsorption member 03 is fixedly installed on the other side of the area to be penetrated. The penetrating member 02 is magnetically adsorbed in the positioning member 01. At room temperature, the attraction of the adsorption member 03 to the penetrating member 02 is smaller than the attraction of the positioning member 01 to the penetrating member 02, so that the penetrating member 02 can be stably adsorbed in the positioning member 01. The line connecting the positioning member 01 and the adsorption member 03 is perpendicular to the area to be penetrated, and the penetrating member 02 is adsorbed on the side of the positioning member 01 facing the area to be penetrated.

[0040] The heating element 04 is installed outside the battery cell housing 05. Figure 1 As shown, the heating element 04 can be a smaller heating element, installed on the outer surface of the battery cell housing 05 at the position with the smallest straight-line distance from the positioning element 01, to locally heat the battery cell to heat the positioning element 01. The heating element 04 can also be a larger heating element to heat the entire battery cell.

[0041] The battery cell internal short circuit test triggering device in the embodiment of the present application, when triggering an internal short circuit, controls the heating element 04 to heat the positioning element 01 to the Curie temperature of the first magnetic material, at which time the positioning element 01 loses its magnetism, and the penetrating element 02 breaks free from the positioning element 01 under the magnetic attraction of the adsorbing element 03 and moves toward the adsorbing element 03. In this process, the penetrating element 02 passes through the area to be penetrated and triggers thermal runaway of the internal short circuit. This device pre-buries the positioning element 01, the penetrating element 02 and the adsorbing element 03, and only needs to control the heating element 04 to trigger an internal short circuit. It has high operational safety and can more realistically simulate thermal runaway caused by an internal short circuit. This triggering device can be recycled after returning to normal temperature.

[0042] In one of the embodiments, in order to prevent the third magnetic material and the second magnetic material from losing their magnetism simultaneously due to excessive temperature rise during the test, the Curie temperature of the third magnetic material is set to be greater than the Curie temperature of the second magnetic material. In this way, even if the penetrating member 02 loses its magnetism, the adsorption member 03 still has magnetism, thereby triggering the penetration action of the penetrating member 02 before the adsorption member 03 fails.

[0043] As an example, the Curie temperature of the first magnetic material is 80-150° C., the Curie temperature of the second magnetic material is 200-300° C., and the Curie temperature of the third magnetic material is above 400° C.

[0044] Specifically, the first magnetic material can be at least one of chromium dioxide and rubber magnet, the second magnetic material can be at least one of neodymium magnet and manganese oxide-iron oxide, and the third magnetic material can be at least one of magnesium oxide-iron oxide, copper oxide-iron oxide, nickel oxide-iron oxide, and ferroferric oxide. The formulas of the above three magnetic materials can be adjusted according to the requirements of magnetism and Curie temperature.

[0045] In one embodiment, the mass of the positioning member 01 is greater than the mass of the adsorption member 03 . The greater the mass of the magnetic material, the stronger the magnetism. Such a setting can ensure that the adsorption force of the positioning member 01 on the penetrating member 02 is greater than the adsorption force of the adsorption member 03 on the penetrating member 02 .

[0046] In one embodiment, if Figure 2 As shown, a receiving cavity 11 is provided in the positioning member 01 , the opening of the receiving cavity 11 faces the area to be penetrated, and the penetrating member 02 is adsorbed in the receiving cavity 11 .

[0047] The positioning member 01 is cylindrical, and the accommodating cavity 11 is set as a cylindrical cavity. The opening of the accommodating cavity 11 is axially toward the area to be penetrated. The penetrating member 02 is at least partially installed in the accommodating cavity 11. When the positioning member 01 loses its magnetism, the penetrating member 02 passes through the opening.

[0048] The penetrating member 02 is conical, with an adsorption plane 21 at one end and a conical tip 22 at the other end. The adsorption plane 21 is adsorbed on the cavity wall of the accommodating cavity 11 and fits closely with the end plane of the accommodating cavity 11 to improve the adsorption stability; the conical tip 22 faces the area to be penetrated, so that the conical tip 22 can pierce the area to be penetrated when the penetrating member 02 is separated from the positioning member 01.

[0049] A through cavity 31 is provided in the adsorbent 03, and the center of the conical tip 22 is in the same straight line with the axis of the through cavity 31. The adsorbent 03 is a circular column, and the through cavity 31 is an axially through cylindrical cavity. The center of the conical tip 22 is aligned with the axis of the through cavity 31, which can reduce the direct attraction of the adsorbent 03 to the penetrating member 02 at room temperature, and prevent the penetrating member 02 from being triggered by the magnetic force of the adsorbent 03 before the test begins, thereby improving the safety of the device.

[0050] The axes of the positioning member 01, the penetrating member 02 and the adsorption member 03 are all arranged on the same straight line to ensure that the penetrating member 02 can accurately penetrate the area to be penetrated.

[0051] In one embodiment, if Figure 1 As shown, a positive electrode sheet 51 and a negative electrode sheet 52 are arranged at intervals in the battery cell, and a separator 53 is provided between adjacent positive electrode sheets 51 and negative electrode sheets 52 to separate the positive electrode sheets 51 and negative electrode sheets 52 to avoid short circuit.

[0052] The area to be penetrated is set according to the test requirements, and includes at least one layer of diaphragm 53, and at most may include all the positive electrode sheets 51, negative electrode sheets 52 and diaphragms 53 in the battery cell.

[0053] Figure 2 A schematic diagram shows that the area to be penetrated is a layer of diaphragm 53. When the area to be penetrated is penetrated, the positive electrode sheet 51 and the negative electrode sheet 52 come into contact to cause a short circuit, which is very similar to the thermal runaway caused by lithium deposition and foreign matter inside the battery cell. It can be used as an equivalent test for testing the thermal runaway protection measures of the battery cell.

[0054] Specifically, the positioning member 01 and the adsorption member 03 can be fixed in the battery cell by gluing, wherein the positioning member 01 is glued to the diaphragm 53 or the positive electrode sheet 51 or the negative electrode sheet 52 on one side of the area to be penetrated, and the adsorption member 03 is glued to the diaphragm 53 or the positive electrode sheet 51 or the negative electrode sheet 52 on the other side of the area to be penetrated.

[0055] like Figure 1 As shown, the area to be penetrated is a diaphragm 53, and the positioning member 01 is glued to the negative electrode sheet 52 on one side of the area to be penetrated, and the adsorption member 03 is glued to the positive electrode sheet 51 on the other side of the area to be penetrated.

[0056] As required, the above embodiments can be combined to obtain the best implementation method.

[0057] The above description is only the principle and preferred embodiment of the present application. It should be pointed out that for ordinary technicians in this field, the implementation methods obtained by appropriately combining the technical solutions disclosed in different embodiments are also included in the technical scope of the present invention. On the basis of the principle of the present application, several other variations can be made, which should also be regarded as the protection scope of the present application.

Claims

1. A short circuit test triggering device for a battery cell, characterized in that: include A positioning piece, made of a first magnetic material, and pre-buried at one side of the area to be penetrated in the battery core; A penetrating member, made of a second magnetic material, wherein the Curie temperature of the second magnetic material is greater than the Curie temperature of the first magnetic material, the penetrating member is adsorbed in the positioning member and faces the area to be penetrated; An adsorbing member is made of a third magnetic material, and the Curie temperature of the third magnetic material is greater than the Curie temperature of the first magnetic material. The adsorbing member is pre-buried on the other side of the area to be penetrated in the battery core and aligned with the penetrating member; A heating element is installed outside the battery cell shell to heat the positioning element. When the positioning element is heated to the Curie temperature of the first magnetic material, the penetrating element penetrates the area to be penetrated under the magnetic attraction of the adsorption element to trigger a short circuit in the battery cell.

2. The battery cell internal short circuit test initiation device according to claim 1, characterized in that: The Curie temperature of the third magnetic material is greater than the Curie temperature of the second magnetic material.

3. The battery cell internal short circuit test initiation device according to claim 2, characterized in that: The Curie temperature of the first magnetic material is 80-150°C, the Curie temperature of the second magnetic material is 200-300°C, and the Curie temperature of the third magnetic material is above 400°C.

4. The battery cell internal short circuit test initiation device according to claim 2, characterized in that: The first magnetic material is at least one of chromium dioxide and rubber magnet, the second magnetic material is at least one of neodymium magnet and manganese oxide-iron oxide, and the third magnetic material is at least one of magnesium oxide-iron oxide, copper oxide-iron oxide, nickel oxide-iron oxide, and ferrosoferric oxide.

5. The battery cell internal short circuit test initiation device according to claim 1, characterized in that: The mass of the positioning member is greater than the mass of the adsorption member.

6. The battery cell internal short circuit test initiation device according to claim 1, characterized in that: The positioning member is provided with a receiving cavity, the opening of the receiving cavity faces the area to be penetrated, and the penetrating member is adsorbed in the receiving cavity.

7. The battery cell internal short circuit test initiation device according to claim 6, characterized in that: One end of the penetrating member is provided with an adsorption plane, and the other end is provided with a conical tip, the adsorption plane is adsorbed on the cavity wall of the accommodating cavity, and the conical tip faces the area to be penetrated.

8. The battery cell internal short circuit test initiation device according to claim 7, characterized in that: A through cavity is provided in the adsorption member, and the center of the conical tip is in the same straight line as the axis of the through cavity.

9. The battery cell internal short circuit test initiation device according to any one of claims 1 to 8, characterized in that: The battery cell is provided with a positive electrode sheet and a negative electrode sheet arranged at intervals, and a separator is provided between adjacent positive electrode sheets and negative electrode sheets; The area to be penetrated includes at least one layer of the diaphragm.

10. The battery cell internal short circuit test initiation device according to claim 9, characterized in that: The positioning member is glued to the diaphragm or the positive electrode sheet or the negative electrode sheet on one side of the area to be penetrated, and the adsorption member is glued to the diaphragm or the positive electrode sheet or the negative electrode sheet on the other side of the area to be penetrated.

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