Battery for testing, preparation method of battery and testing method

Abstract

The invention relates to the field of battery manufacturing, in particular to a battery for testing, a preparation method of the battery and a testing method. The test battery comprises a battery main body, a defect diaphragm and a cover film, the defective diaphragm is positioned between the positive plate and the negative plate of the battery main body, and is provided with a damaged hole; a detachable cover film is arranged between the defective diaphragm and the positive plate or between the defective diaphragm and the negative plate; the covering film covers the damaged hole, and the covering film extends out of the pole group of the battery main body to form a pick-up part. According to the battery for testing provided by the invention, the diaphragm is damaged to trigger the short-circuit failure of the battery on the premise of ensuring no short-circuit phenomenon in the manufacturing process of the battery and not damaging the structure of the battery during testing, so that different types of short-circuit failure modes of the battery can be reproduced; the safety performance condition of the battery under the conditions of different systems, different voltages, different test conditions, different service life states, different battery structures and the like can be researched.

Description

Technical Field

[0001] The present application relates to the field of battery manufacturing, and in particular to a test battery, a battery preparation method, and a test method. Background Art

[0002] Internal short circuit of the battery usually causes heat generation inside the battery. When the heat generation rate during the short circuit process is higher than the heat release rate, the battery temperature will rise. As the temperature rises, a series of side reactions inside the battery will release heat, aggravating the temperature rise of the battery, thus causing thermal runaway of the battery. Therefore, it is of great significance to study battery short circuit phenomena in different modes.

[0003] Common short circuit types inside batteries include four short circuit failure modes: positive electrode material-negative electrode material short circuit, positive electrode current collector-negative electrode material short circuit, negative electrode current collector-positive electrode material short circuit, and positive electrode current collector-negative electrode current collector short circuit. These failure modes are usually caused by diaphragm damage. For the risk assessment of the four common short circuit failure modes inside batteries, the current research is mainly carried out through simulation. By collecting battery design information to establish a corresponding three-dimensional or two-dimensional equivalent model, combined with the difference in short-circuit resistance under different short-circuit failure conditions, simulation is performed to conduct safety assessments of different short-circuit failure modes. However, the results output by the simulation method are only theoretical calculation results and can only be used for reference. Since the actual short-circuit failure mode cannot be reproduced, the credibility of the results cannot be verified.

[0004] At present, the method for battery short circuit is usually to disassemble the battery and confirm the failure under different short circuit modes by overlapping the positive and negative plates. However, this test method requires the battery to be completely disassembled, which destroys the internal structure of the battery. The test structure will inevitably be very different from the short circuit caused by diaphragm damage inside the actual battery, and can only be used for reference. If the diaphragm is damaged directly during the battery production process, the battery will not be able to perform the normal pre-charging and formation steps due to internal short circuit problems. Therefore, it is particularly important to find a method that can carry out the normal battery production process and achieve battery short circuit failure caused by diaphragm damage without destroying the battery structure. Summary of the invention

[0005] The purpose of the present application is to provide a test battery, a preparation method of the battery and a test method, which can achieve diaphragm damage to trigger battery short-circuit failure without destroying the battery structure during a short-circuit test.

[0006] The present application provides a test battery, comprising a battery body, a defective separator and a covering film;

[0007] The defective diaphragm is located between the positive electrode sheet and the negative electrode sheet of the battery body, and the defective diaphragm is provided with a damaged hole;

[0008] A detachable covering film is provided between the defective diaphragm and the positive electrode sheet or between the defective diaphragm and the negative electrode sheet; the covering film covers the damaged hole, and the covering film extends out of the electrode group of the battery body to form a pickup portion.

[0009] In the above technical solution, further, it also includes an air bag;

[0010] The air bag comprises a containing portion and an air collecting portion, the pole group is located in the containing portion, and the picking portion is located in the air collecting portion.

[0011] In the above technical solution, further, the test battery is one of a lithium iron ion battery, a ternary polymer lithium battery, a lithium cobalt oxide battery and a lithium manganese oxide battery.

[0012] The present application also provides a method for preparing a battery, which is used to manufacture the test battery described in the above scheme, and the method comprises the following steps:

[0013] Step S1, opening a damaged hole on the separator between the positive electrode sheet and the negative electrode sheet to form a defective separator;

[0014] Step S2, providing a covering film between the defective diaphragm and the positive electrode sheet or between the defective diaphragm and the negative electrode sheet; the covering film covers the damaged hole, and the covering film extends out of the electrode group formed by the positive electrode sheet, the negative electrode sheet and the defective diaphragm to form a pickup portion;

[0015] Step S3, performing subsequent battery processing steps; in the packaging step, the pickup portion is packaged in an air bag; the air bag is retained until the subsequent battery processing steps are completed to prepare the test battery.

[0016] In the above technical solution, further, in step S1, the cross-sectional area of ​​the damaged hole is less than or equal to the corresponding area of ​​the negative electrode sheet.

[0017] In the above technical solution, further, in step S2, the area of ​​the covering film is larger than the cross-sectional area of ​​the damaged hole; and the covering film extends out of the electrode group by at least 5 mm.

[0018] In the above technical solution, further, in step S2, the positive electrode sheet, the negative electrode sheet and the defective diaphragm are stacked to form the electrode group, or the positive electrode sheet, the negative electrode sheet and the defective diaphragm are wound to form the electrode group;

[0019] When the positive electrode sheet, the negative electrode sheet and the defective diaphragm stack form the electrode group, the pick-up portion is located in a first direction of the electrode group so as to face the air collecting portion of the air bag;

[0020] When the positive electrode sheet, the negative electrode sheet, and the defective separator are wound to form the electrode group, the pick-up portion is located in the second direction of the electrode group, and the pick-up portion is folded to face the air collecting portion of the air bag.

[0021] The present application also provides a battery testing method for performing short circuit detection on the test battery described in the above scheme, the method comprising the following steps:

[0022] Step S4, charging the test battery to the test required state, cutting the air bag and removing the covering film to form a short-circuited battery;

[0023] Step S5: testing the status information of the short-circuited battery.

[0024] In the above technical solution, further, in step S4, after charging the test battery and before removing the covering film, a heat insulation layer is covered on a large surface of the test battery;

[0025] And / or in step S4, before charging the test battery to the test required state, the test battery is charged and discharged for a preset number of cycles, and the preset number of cycles is greater than or equal to 1.

[0026] In the above technical solution, further, in step S5, before testing the short-circuited battery, the starting voltage of the short-circuited battery is between 1V and 6V;

[0027] And / or in step S5, before testing the short-circuited battery, a preset pressure is applied to the large surface of the short-circuited battery; the preset pressure is F, and 0≤F≤50000N;

[0028] And / or in step S5, the short-circuited battery is tested at a preset ambient temperature, wherein the preset ambient temperature is between -20°C and 60°C.

[0029] Compared with the prior art, the beneficial effects of this application are:

[0030] The test battery provided in the present application ensures that there is no short circuit in the battery during the manufacturing process, and during the test, the diaphragm can be damaged to trigger the short circuit failure of the battery without destroying the battery structure. Therefore, different types of short circuit failure modes of the battery can be reproduced to study the safety performance of the battery under different systems, different voltages, different test conditions, different life states, different battery structures and other conditions.

[0031] The present application also provides a battery preparation method and a test method for manufacturing the test battery described in the above scheme. The method can ensure that there is no short circuit in the battery during the manufacturing process, and during the test, the diaphragm can be damaged to trigger the battery short circuit failure without destroying the battery structure, thereby reproducing different types of short circuit failure modes of the battery to study the safety performance of the battery under different systems, different voltages, different test conditions, different life states, different battery structures and other conditions.

[0032] The present application also provides a battery testing method for short-circuit detection of the test battery described in the above scheme. The method can ensure that there is no short-circuit phenomenon in the battery during the manufacturing process, and during the test, the diaphragm can be damaged to trigger the battery short-circuit failure without destroying the battery structure, thereby reproducing different types of short-circuit failure modes of the battery to study the safety performance of the battery under different systems, different voltages, different test conditions, different life states, different battery structures and other conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the specific implementation methods of the present application or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0034] Figure 1 A schematic diagram of the internal structure of the test battery provided for this application;

[0035] Figure 2 A schematic diagram of the structure of a damaged hole provided in the defective diaphragm provided in the present application;

[0036] Figure 3 A schematic diagram of the structure of the covering film provided in this application covering the damaged hole;

[0037] Figure 4 This is a schematic diagram of the structure in which the electrode group provided in the present application is placed in an air bag.

[0038] In the figure: 101-electrode group; 102-defective diaphragm; 103-covering film; 104-positive electrode sheet; 105-negative electrode sheet; 106-damaged hole; 107-pickup part; 108-air bag; 109-accommodation part; 110-gas collecting part; 111-ear lead-out side. DETAILED DESCRIPTION

[0039] The technical solution of the present application will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present application.

[0040] In the description of the present application, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present application. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0041] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" 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 it can be indirectly connected 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 terms in this application can be understood according to specific circumstances.

[0042] Embodiment 1

[0043] See also Figures 1 to 4 As shown, the test battery provided in the present application includes a battery body, a defective separator 102 and a covering film 103 .

[0044] Among them, the defective diaphragm 102 is located between the positive electrode sheet 104 and the negative electrode sheet 105 of the battery body, and the defective diaphragm 102 is provided with a damaged hole 106; a removable covering film 103 is provided between the defective diaphragm 102 and the positive electrode sheet 104 or between the defective diaphragm 102 and the negative electrode sheet 105; the covering film 103 covers the damaged hole 106, and the covering film 103 extends out of the electrode group 101 of the battery body to form a picking portion 107.

[0045] Specifically, in the process of manufacturing the test battery, before the positive electrode sheet 104, the negative electrode sheet 105 and the diaphragm are processed to form the electrode group 101, the diaphragm material is first removed from a part of the diaphragm area to form a damaged hole 106 in the area, thereby simulating the damage defect of the short-circuited battery. Then, a layer of covering film 103 is covered at the damaged hole 106 to prevent the positive electrode sheet 104 and the negative electrode sheet 105 at the damaged hole 106 from short-circuiting during the processing. And a part of the covering film 103 needs to extend out of the unit to form a pickup portion 107. After the subsequent processing steps are completed, the pickup portion 107 is extracted to remove the covering film 103 from the unit, and the positive electrode sheet 104 and the negative electrode sheet 105 at the damaged hole 106 are short-circuited, thereby forming a short-circuited battery, and the short-circuited battery can be tested.

[0046] The test battery provided in the present application ensures that there is no short circuit in the battery during the manufacturing process, and during the test, the diaphragm can be damaged to trigger the short circuit failure of the battery without destroying the battery structure. Therefore, different types of short circuit failure modes of the battery can be reproduced to study the safety performance of the battery under different systems, different voltages, different test conditions, different life states, different battery structures and other conditions.

[0047] In an optional solution of this embodiment, the test battery further includes an air bag 108. The air bag 108 includes a receiving portion 109 and a gas collecting portion 110, the electrode group 101 is located in the receiving portion 109, and the picking portion 107 is located in the gas collecting portion 110. Figure 4 The dotted line shown in FIG. 1 is a marking line for cutting off the air bag 108 during the normal battery production process.

[0048] In this embodiment, in the production process of the battery, there is a process called the formation process, in which the electrolyte undergoes oxidation and reduction reactions on the electrode surface to form an SEI film and generate gas. Under normal circumstances, these gases can be temporarily stored in the air bag 108 and discharged in subsequent processes, and will not have an adverse effect on the battery. If an accident occurs in the formation process, such as gas is still generated after the air bag 108 is removed and packaged, the gas cannot be discharged normally, which may cause the battery to swell. Therefore, the presence and use of the air bag 108 are of great significance for preventing the occurrence of battery swell. The present application hides the pick-up portion 107 in the air bag 108, and the protruding pick-up portion 107 will not affect the processing of the battery, and the use of the air bag 108 to cover the pick-up portion 107 can achieve a protective effect on the covering film 103, avoiding the premature detachment of the covering film 103 during battery processing.

[0049] In an optional solution of this embodiment, the test battery is one of a lithium iron ion battery, a ternary polymer lithium battery, a lithium cobalt oxide battery and a lithium manganese oxide battery.

[0050] In this embodiment, when the test battery is a lithium iron phosphate battery, lithium iron phosphate (LiFePO4) is used as the positive electrode material and carbon is used as the negative electrode material. When the test battery is a ternary polymer lithium battery, the positive electrode material uses a ternary positive electrode material of lithium nickel cobalt manganese oxide (Li(NiCoMn)O2) or lithium nickel cobalt aluminum oxide. When the test battery is a lithium cobalt oxide battery, the positive electrode material is lithium cobalt oxide. When the test battery is a lithium manganese oxide battery, the positive electrode material is lithium manganese oxide.

[0051] Embodiment 2

[0052] See also Figures 2 to 4 As shown, the second embodiment of the present application provides a method for preparing a battery, which is used to manufacture the test battery of the first embodiment, and the method comprises the following steps:

[0053] Step S1: Open a damaged hole 106 on the separator between the positive electrode sheet 104 and the negative electrode sheet 105 to form a defective separator 102. Specifically, the damaged hole 106 can be a circular, square or other irregular shapes as shown in the figure.

[0054] Step S2: between the defective diaphragm 102 and the positive electrode sheet 104 or between the defective diaphragm 102 and the negative electrode sheet 105 ( Figure 1 A covering film 103 is arranged between the positive electrode sheet 104, the negative electrode sheet 105 and the defective diaphragm 102, and the covering film 103 can be made of the same material as the defective diaphragm 102. The covering film 103 covers the damaged hole 106, and can insulate the damaged hole 106 during the battery processing to avoid short circuit there. The covering film 103 extends out of the electrode group 101 formed by the positive electrode sheet 104, the negative electrode sheet 105 and the defective diaphragm 102 to form a pick-up portion 107. When testing the test battery, the pick-up portion 107 can be held to take out the covering film 103, and the positive electrode sheet 104 and the negative electrode sheet 105 at the damaged hole 106 are short-circuited.

[0055] Step S3, perform subsequent battery processing steps. In the packaging step, the pick-up portion 107 is packaged in the air bag 108 so that the existence of the pick-up portion 107 does not affect the gas collection function of the air bag 108. In the battery manufacturing process, the air bag 108 is not removed, and the air bag 108 is retained until the subsequent battery processing steps are completed, and the product is off the production line to prepare a test battery.

[0056] In an optional solution of this embodiment, in step S1 , the cross-sectional area of ​​the damaged hole 106 is smaller than or equal to the area of ​​the corresponding negative electrode sheet 105 .

[0057] In this embodiment, in the lithium battery, the negative electrode sheet 105 is usually designed to be larger than the positive electrode sheet 104. This is mainly because when charging, lithium ions are deintercalated from the positive electrode and embedded in the negative electrode. If the negative electrode space is not enough and the lithium embedding space is insufficient, the resistance of lithium ions to embed into the negative electrode will increase, causing the lithium ions that cannot be embedded in the negative electrode to gain electrons on the surface of the negative electrode, forming a silvery white metallic lithium single substance, which is often called the lithium precipitation phenomenon, and ultimately causing the performance of the lithium battery to decline and the cycle life to be greatly shortened. Generally speaking, the area of ​​the diaphragm will be slightly larger than the negative electrode sheet 105 to prevent the positive and negative electrode sheets 105 from short-circuiting. The present application defines that the cross-sectional area of ​​the broken hole 106 is less than or equal to the area of ​​the corresponding negative electrode sheet 105, wherein the cross-sectional area of ​​the broken hole 106 is less than the area of ​​the corresponding negative electrode sheet 105, which can simulate the situation of diaphragm damage; the cross-sectional area of ​​the broken hole 106 is equal to the area of ​​the corresponding negative electrode sheet 105, that is, no diaphragm is set there, which can simulate the situation of diaphragm missing.

[0058] In an optional solution of this embodiment, in step S2, the area of ​​the covering film 103 is larger than the cross-sectional area of ​​the damaged hole 106 to ensure a better covering effect on the damaged hole 106 and avoid local short circuit.

[0059] Furthermore, the covering film 103 at least extends out of the electrode group 101 , so as to facilitate the picking up of the picking-up portion 107 and the extraction of the covering film 103 .

[0060] In an optional solution of this embodiment, in step S2 , the positive electrode sheet 104 , the negative electrode sheet 105 and the defective separator 102 are stacked to form the electrode group 101 , or the positive electrode sheet 104 , the negative electrode sheet 105 and the defective separator 102 are wound to form the electrode group 101 .

[0061] See also Figures 2 to 4 As shown, when the positive electrode sheet 104, the negative electrode sheet 105 and the defective separator 102 are stacked to form the electrode group 101, the pick-up portion 107 is located in the first direction of the electrode group 101, so as to face the gas collecting portion 110 of the air bag 108. When the electrode group 101 is processed by stacking, the circumference of the electrode group 101 has gaps that allow the covering film 103 to be drawn out. At this time, the pick-up portion 107 is led out in the direction of the gas collecting portion 110 of the air bag 108, so that the covering film 103 is not easily bent and wound, so as to facilitate the subsequent extraction of the covering film 103 from the electrode group 101.

[0062] When the positive electrode sheet 104, the negative electrode sheet 105 and the defective separator 102 are wound to form the electrode group 101, the pick-up portion 107 is located in the second direction of the electrode group 101, and the pick-up portion 107 is folded to face the gas collecting portion 110 of the air bag 108. When the electrode group 101 is wound, only the tab lead-out side 111 of the electrode group 101 and the opposite side of the tab lead-out side 111 have gaps that allow the covering film 103 to be led out, so the pick-up portion 107 can only be led out from the above two sides. Specifically, the side on which the pick-up portion 107 is led out can be selected according to the location of the damaged hole 106, but the led-out pick-up portion 107 needs to be bent and folded so that the pick-up portion 107 is placed in the gas collecting portion 110 of the air bag 108.

[0063] Embodiment 3

[0064] Embodiment 3 of the present application provides a battery testing method for performing short circuit detection on the test battery of embodiment 1 above, and the method comprises the following steps:

[0065] Step S4, charging the test battery to the test required state, cutting the air bag 108 and removing the covering film 103 to form a short-circuited battery;

[0066] Step S5, testing the status information of the short-circuited battery, specifically testing the temperature and voltage parameters of the short-circuited battery during the short-circuit process, and recording a video to record whether the short-circuited battery emits smoke, catches fire, explodes, etc. during the short-circuit test.

[0067] In an optional solution of this embodiment, in step S4, after charging the test battery and before removing the covering film 103, the large surface of the test battery is covered with a heat insulating layer. The large surface of the test battery is specifically a surface formed by the long side and the wide side, and the large surface is covered with a heat insulating layer such as aerogel and foam to keep the charged test battery warm, which can simulate the temperature condition of the actual battery after charging.

[0068] In an optional solution of this embodiment, in step S4, before charging the test battery to the test required state, the test battery is charged and discharged for a preset number of times, and the preset number of times is greater than or equal to 1. This solution can simulate the situation in which the battery fails to short-circuit after undergoing several charge and discharge cycles during actual use of the battery.

[0069] In an optional solution of this embodiment, in step S5, before testing the short-circuited battery, the starting voltage of the short-circuited battery is between 1V and 6V.

[0070] In this embodiment, since the voltages of batteries of different systems are different, a ternary system battery is taken as an example: the voltage of the ternary system battery is distributed between 2.8 and 4.2V. During the short circuit of the battery, the battery is discharged and the voltage of the battery decreases. For a battery with a voltage of 4.2V, the voltage is reduced to 3V after being short-circuited for 1h. During the test, the short circuit test can be performed under the condition that the starting voltage of the battery is 4.2V, or the short circuit test can be performed under the condition that the starting voltage of the battery is 3.5V.

[0071] In an optional solution of this embodiment, in step S5, before testing the short-circuited battery, a preset pressure is applied to the large surface of the short-circuited battery; the preset pressure is F, and 0≤F≤50000 N. This solution can simulate the situation in which the battery fails due to short circuit when the battery is subjected to mechanical pressure during actual use.

[0072] In an optional solution of this embodiment, in step S5, the short-circuited battery is tested at a preset ambient temperature, which is between -20°C and 60°C. This solution can simulate the situation in which the battery fails due to a short circuit when the battery is in different ambient temperatures during actual use.

[0073] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them; although the present application is described in detail with reference to the above embodiments, a person skilled in the art should understand that the technical solutions described in the above embodiments can still be modified, or some or all of the technical features can be replaced by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application. In addition, a person skilled in the art can understand that although some embodiments herein include certain features included in other embodiments but not other features, the combination of features of different embodiments means being within the scope of the present application and forming different embodiments.

Claims

1. A test battery, characterized in that: It includes a battery body, a defective separator and a covering film support; The defective diaphragm support portion is located between the positive electrode sheet support portion and the negative electrode sheet support portion of the battery body, and the defective diaphragm support portion is provided with a broken hole support portion; A detachable covering film support portion is provided between the defective diaphragm support portion and the positive electrode sheet support portion or between the defective diaphragm support portion and the negative electrode sheet support portion; The covering film support portion covers the damaged hole support portion, and the covering film support portion extends out of the electrode group support portion of the battery body to form a pick-up portion support portion.

2. The test battery according to claim 1, characterized in that: Also included is an air bag support portion; The air bag support portion includes a receiving portion support portion and a gas collecting portion support portion, the pole group support portion is located at the receiving portion support portion, and the picking portion support portion is located at the gas collecting portion support portion.

3. The test battery according to claim 2, characterized in that: The test battery is one of a lithium iron phosphate battery, a ternary polymer lithium battery, a lithium cobalt oxide battery and a lithium manganese oxide battery.

4. A method for preparing a battery, characterized in that: For manufacturing the test battery according to claim 2 or 3, the method comprises the following steps: Step S1, opening a damaged hole support portion on the diaphragm between the positive electrode sheet support portion and the negative electrode sheet support portion to form a defective diaphragm support portion; Step S2, providing a covering film support portion between the defective diaphragm support portion and the positive electrode sheet support portion or between the defective diaphragm support portion and the negative electrode sheet support portion; The covering film support portion covers the damaged hole support portion, and the covering film support portion extends out of the electrode group support portion formed by the positive electrode sheet support portion, the negative electrode sheet support portion and the defective separator support portion to form a pickup portion support portion; Step S3, performing subsequent battery processing steps; in the packaging step, the pick-up portion support portion is packaged in the airbag support portion; the airbag support portion is retained until the subsequent battery processing steps are completed to prepare the test battery.

5. The method for preparing a battery according to claim 4, characterized in that: In step S1, the cross-sectional area of ​​the damaged hole support portion is less than or equal to the corresponding area of ​​the negative electrode sheet support portion.

6. The method for preparing a battery according to claim 4, characterized in that: In step S2, the area of ​​the covering film support portion is larger than the cross-sectional area of ​​the damaged hole support portion; and the covering film support portion extends out of the electrode group support portion by at least 5 mm.

7. The method for preparing a battery according to claim 4, characterized in that: In step S2, the positive electrode sheet support portion, the negative electrode sheet support portion and the defective diaphragm support portion are stacked to form the electrode group support portion, or the positive electrode sheet support portion, the negative electrode sheet support portion and the defective diaphragm support portion are wound to form the electrode group support portion; When the positive electrode sheet support portion, the negative electrode sheet support portion and the defective diaphragm support portion are stacked to form the electrode group support portion, the pick-up portion support portion is located in a first direction of the electrode group support portion to face the gas collecting portion support portion of the air bag support portion; When the positive electrode sheet support portion, the negative electrode sheet support portion and the defective separator support portion are wound to form the electrode group support portion, the pick-up portion support portion is located in the second direction of the electrode group support portion, and the pick-up portion support portion is folded to face the gas collecting portion support portion of the air bag support portion.

8. A battery testing method, characterized in that: Used to perform short circuit detection on the test battery according to claim 2 or 3, the method comprises the following steps: Step S4, charging the test battery to a state required by the test, cutting the air bag support portion and removing the covering film support portion to form a short-circuited battery; Step S5: testing the status information of the short-circuited battery.

9. The battery testing method according to claim 8, characterized in that: In step S4, after charging the test battery and before removing the covering film support portion, a large surface of the test battery is covered with a heat insulation layer; And / or in step S4, before charging the test battery to the test required state, the test battery is charged and discharged for a preset number of cycles, and the preset number of cycles is greater than or equal to 1.

10. The battery testing method according to claim 8, characterized in that: In step S5, before testing the short-circuited battery, the starting voltage of the short-circuited battery is between 1V and 6V; And / or in step S5, before testing the short-circuited battery, a preset pressure is applied to the large surface of the short-circuited battery; the preset pressure is F, and 0≤F≤50000N; And / or in step S5, the short-circuited battery is tested at a preset ambient temperature, wherein the preset ambient temperature is between -20°C and 60°C.

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