Nail penetration test device

Abstract

A nail penetration test device, which can improve the performance of nail penetration tests. The device comprises: a voltage acquisition module, which comprises a first connection port and a second connection port, the first connection port being connected to a nail, and the second connection port being connected to a first electrode terminal of a battery cell; and a nail mechanism, which is used for controlling the nail to move towards the battery cell. The voltage acquisition module is used for measuring the voltage between the nail and the first electrode terminal during the process of the nail moving towards the battery cell, the voltage being used for determining an initial penetration position of the nail on the battery cell.

Description

Acupuncture test device

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to Chinese patent application 202322955983.1, filed on November 2, 2023, entitled “Device for acupuncture test,” the entire contents of which are incorporated by reference into this application. Technical Field

[0003] The present application relates to the field of batteries, and in particular to a device for a needle penetration test. Background Art

[0004] Battery penetration testing, also known as internal short-circuit testing, is used to assess the safety risks of battery cells when an internal short circuit occurs. Typically, a probe is inserted into the battery cell to assess the safety risk caused by a short circuit between the electrode and the probe. Improving the performance of the penetration test has become a pressing issue.

[0005] Summary of the Invention

[0006] The embodiments of the present application provide a device for a needle penetration test, which can improve the performance of the needle penetration test.

[0007] In a first aspect, a device for a needle penetration test is provided, the device comprising: a voltage acquisition module, the voltage acquisition module comprising a first connection port and a second connection port, the first connection port being connected to a needle, and the second connection port being connected to a first electrode terminal of a battery cell; a needle mechanism for controlling the movement of the needle toward the battery cell, wherein the voltage acquisition module is configured to detect a voltage between the needle and the first electrode terminal during movement of the needle toward the battery cell, the voltage being used to determine a starting insertion position of the needle on the battery cell.

[0008] Optionally, the battery cell includes a first pole piece and a second pole piece that are overlapped, and the pole piece located on the outermost layer is the second pole piece, the polarity of the first pole piece and the second pole piece are opposite, the first electrode terminal is the electrode terminal connected to the first pole piece, and the voltage is used to determine the starting insertion position of the needle on the battery cell.

[0009] The needle mechanism in the needle penetration test device can fix and control the needle's movement toward the battery cell. During the needle's movement, the voltage acquisition module detects the voltage between the needle and the first electrode terminal connected to the first electrode piece. When the needle touches or punctures the outermost second electrode piece, the voltage acquisition module can detect a significant change in the voltage between the needle and the first electrode terminal. Therefore, the needle's starting point on the battery cell can be determined based on the change in voltage between the needle and the first electrode terminal. Using this starting point as a starting point, the needle is controlled to continue moving to a predetermined depth within the battery cell. In this way, using this device, the needle's starting point on the battery cell can be accurately determined by utilizing the relationship between the battery cell's physical structure and voltage, thus completing the needle penetration test. This improves test accuracy while also meeting testing requirements for different penetration depths.

[0010] In some possible implementations, the device further includes a supporting mechanism for supporting a battery cell to be tested and adjusting the position of the battery cell in a first direction; wherein the puncture needle mechanism is specifically configured to control the movement of the puncture needle toward the battery cell in a second direction, the second direction being perpendicular to the first direction. The cooperation between the supporting mechanism and the puncture needle mechanism can effectively locate the insertion position of the puncture needle on the surface of the battery cell.

[0011] In some possible implementations, the puncture needle mechanism includes a connecting member, a clamping member and a first pushing member, the clamping member and the first pushing member are respectively arranged on both sides of the connecting member along the second direction, the clamping member is used to clamp the puncture needle, and the first pushing member is configured to move along the second direction to push the connecting member, the clamping member and the puncture needle to move along the second direction.

[0012] In this embodiment, the puncture needle mechanism includes a clamping member for clamping the puncture needle, a first pushing member for pushing the puncture needle to move, and a connecting member for connecting and setting the clamping member and the first pushing member, so that when the first pushing member is driven, it can push the connecting member, the clamping member and the puncture needle toward the battery cell.

[0013] In some possible implementations, the needle mechanism further includes a first guide member, disposed on the connector on the side of the first pusher, configured to restrain the first pusher from moving in the second direction. The provision of the first guide member provides the first pusher with a certain degree of anti-tilting capability, improving its reliability and enabling the needle to penetrate the battery cell vertically or approximately vertically along the second direction, rather than at an angle.

[0014] In some possible implementations, the puncture needle mechanism further includes a force sensor, which is disposed between the clamping member and the connecting member and is configured to detect the force generated when the puncture needle penetrates the battery cell.

[0015] The force sensor can detect the force generated when the needle penetrates the battery cell, so as to assist in analyzing the changes in the force exerted by the electrode on the needle during the needle penetration test, thereby expanding the parameter range in the needle penetration test based on the force change, making the analysis of the test data more complete.

[0016] The force sensor may have any shape. For example, the force sensor includes a first bending portion and a second bending portion arranged along the second direction, the first bending portion is connected to the connecting member, and the second bending portion is connected to the clamping member.

[0017] In some possible implementations, the device further includes a housing, and the puncture mechanism further includes a first fixing member, the first fixing member being configured to fix the first guide member to a first wall of the housing, the first wall being perpendicular to the second direction. The first fixing member fixes the first guide member to the first wall of the housing so that the first guide member can accurately restrain the first pusher from moving in the second direction.

[0018] In some possible implementations, the carrying mechanism includes a carrying platform and a second pushing member, and the second pushing member is configured to move along the first direction to push the carrying platform and the battery cell to move along the first direction.

[0019] In this embodiment, the carrying mechanism includes a carrying platform for carrying the battery cell and a second pushing member for pushing the battery cell to move. In this way, when the second pushing member is driven, it can push the carrying platform and the battery cell to move along the first direction.

[0020] In some possible implementations, the supporting mechanism further includes a second guide member, which is disposed on a side of the supporting platform where the second pushing member is located, and is used to restrain the second pushing member from moving along the first direction.

[0021] By providing a second guide member, the second pusher can have a certain anti-tilting ability, improve its reliability, and prevent the battery cell from deviating along the first direction, so that the needle can penetrate the battery cell vertically or approximately vertically instead of obliquely.

[0022] In some possible implementations, the support platform is provided with holes for mounting stoppers, which are used to limit the position of the battery cells. By providing holes for mounting stoppers, the battery cells can be fixed to the support platform, thereby improving the stability of the needle penetration test process.

[0023] In some possible implementations, the device further includes a housing, and the supporting mechanism further includes a second fixing member, the second fixing member being configured to fix the second guide member to a second wall of the housing, the second wall being perpendicular to the first direction. The second fixing member fixes the second guide member to the second wall of the housing so that the second guide member can accurately restrain the second pusher from moving in the first direction.

[0024] In some possible implementations, the device further includes a housing and a protective panel disposed between the battery cell and a third wall of the housing. The protective panel can protect the third wall of the housing adjacent to the battery cell, thereby preventing, to a certain extent, residue, smoke, and other emissions generated by the battery cell during testing from adhering to the third wall and reducing damage to the third wall.

[0025] In some possible implementations, the protective panel is detachably connected to the third wall to facilitate replacement of the protective panel.

[0026] In some possible implementations, the protective panel is provided with a countersunk hole for receiving a fixing member, which is used to fix the protective panel to the third wall, wherein the third wall is perpendicular to the second direction. The design of the countersunk hole helps reduce the probability of interference between the protective panel and the battery cell.

[0027] In some possible implementations, the protective panel is provided with notches for locating the battery cells. The visual notches on the protective panel facilitate locating the battery cells, helping testers determine the positional relationship between the battery cells and the protective panel, for example, determining whether the battery cells are approximately located in the center of the protective panel.

[0028] In some possible implementations, the battery cell further includes a housing for accommodating the first and second pole pieces, and a clearance hole is provided on the housing at a position for the needle to penetrate. The clearance hole can effectively avoid the needle, thereby facilitating the needle's penetration into the pole pieces.

[0029] In some possible implementations, the device further includes: a control module, connected to the voltage acquisition module and the puncture needle mechanism, for determining the starting puncture position according to the voltage, and based on the starting puncture position, driving the puncture needle mechanism to move along the second direction so that the puncture needle punctures to a predetermined depth of the battery cell.

[0030] The control module can obtain voltage information during the test from the voltage acquisition module, and can also drive the puncture needle mechanism and the supporting mechanism to move the puncture needle mechanism and the supporting mechanism in corresponding directions, so that the puncture needle can accurately penetrate the battery cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments of the present application. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the drawings without creative work.

[0032] Figure 1 is a schematic diagram of the needle penetration test.

[0033] FIG2 is a schematic diagram of the initial insertion position of the needle stick test.

[0034] FIG3 is a schematic structural diagram of a device for acupuncture test according to an embodiment of the present application.

[0035] FIG4 is a schematic diagram of a possible electrode stack of a battery cell according to an embodiment of the present application.

[0036] FIG5 is a schematic diagram of a possible process of a needle prick test according to an embodiment of the present application.

[0037] FIG6 is a schematic diagram of a possible structure of the needle mechanism of an embodiment of the present application.

[0038] FIG. 7 is a schematic diagram of a possible structure of a supporting mechanism according to an embodiment of the present application.

[0039] FIG8 is a schematic diagram of a possible structure of a protection panel according to an embodiment of the present application. DETAILED DESCRIPTION

[0040] The following detailed description of the embodiments of the present application is provided in conjunction with the accompanying drawings and examples. The following detailed description of the embodiments and the accompanying drawings are used to illustrate the principles of the present application, but are not intended to limit the scope of the present application, that is, the present application is not limited to the described embodiments.

[0041] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by technicians in the technical field to which this application belongs; the terms used in this application and in the specification of the application are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" in the specification and claims of this application and the above-mentioned figure descriptions and any variations thereof are intended to cover non-exclusive inclusions. The terms "first", "second", etc. in the specification and claims of this application or the above-mentioned figures are used to distinguish different objects, rather than to describe a specific order or a primary and secondary relationship. "Vertical" is not strictly perpendicular, but is within the allowable error range. "Parallel" is not strictly parallel, but is within the allowable error range.

[0042] References to "embodiments" in this application mean that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described in this application may be combined with other embodiments.

[0043] In the description of this application, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," "connected," and "attached" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; they may refer to direct connections, indirect connections through an intermediate medium, or internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on specific circumstances.

[0044] The term "and / or" in this application simply describes an association between related objects, indicating that three possible relationships exist. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this application generally indicates that the related objects are in an "or" relationship.

[0045] In the embodiments of this application, the same reference numerals represent the same components, and for the sake of brevity, detailed descriptions of the same components in different embodiments are omitted. It should be understood that the thickness, length, width, and other dimensions of the various components in the embodiments of this application, as well as the overall thickness, length, width, and other dimensions of the integrated device shown in the drawings are for illustrative purposes only and do not constitute any limitation on this application.

[0046] A battery generally refers to a single physical module that includes one or more battery cells to provide a higher voltage and capacity. For example, a battery can include a battery module or a battery pack. Batteries typically also include a casing that encloses the battery cells. This casing prevents liquids and other foreign matter from affecting the charging or discharging of the battery cells.

[0047] A battery cell includes an electrode assembly and an electrolyte. The electrode assembly consists of a positive electrode sheet, a negative electrode sheet, and a separator located between the positive and negative electrode sheets. A battery cell primarily operates by the movement of metal ions between the positive and negative electrode sheets. The positive electrode sheet includes a positive current collector and a positive active material layer. The positive active material layer is coated on the main surface of the positive current collector. The portion of the positive current collector not coated with the positive active material layer protrudes from the main body of the positive current collector as the positive electrode tab. For lithium-ion batteries, for example, the positive current collector can be made of aluminum, and the positive active material can be lithium cobalt oxide, lithium iron phosphate, ternary lithium, or lithium manganese oxide. The negative electrode sheet includes a negative current collector and a negative active material layer. The negative active material layer is coated on the main surface of the negative current collector. The portion of the negative current collector not coated with the negative active material layer protrudes from the main body of the negative current collector as the negative electrode tab. The negative current collector can be made of copper, and the negative active material can be carbon or silicon, among others. In order to reduce the probability of melting due to large current, the number of positive electrode tabs can be multiple and stacked together, and the number of negative electrode tabs can be multiple and stacked together.

[0048] To simulate an internal short circuit scenario caused by contamination of the battery by conductive particles, a fine needle with a diameter of about 1 mm can be used to penetrate the electrode in the battery cell to induce an internal short circuit in the battery cell, thereby assessing the safety risk of the battery cell when an internal short circuit occurs. This process is usually called a needle penetration test, a shallow penetration test, or a battery internal short circuit test. It is understood that the penetration position of the needle on the electrode corresponds to the main part of the current collector coated with the positive electrode active material layer on the electrode.

[0049] For example, as shown in FIG1 , the needle 10 is connected to the first electrode terminal 21 of the battery cell 20. The first electrode terminal 21 and the second electrode terminal 22 have opposite polarities. For example, the first electrode terminal 21 is a negative electrode terminal and the second electrode terminal 22 is a positive electrode terminal, or the first electrode terminal 21 is a positive electrode terminal and the second electrode terminal 22 is a negative electrode terminal. The battery cell 20 includes a positive electrode sheet and a negative electrode sheet arranged in an overlapping manner. If the positive electrode sheet is the outermost layer, the first electrode terminal 21 connected to the needle 10 is the negative electrode terminal; if the negative electrode sheet is the outermost layer, the first electrode terminal 21 connected to the needle 10 is the positive electrode terminal.

[0050] Taking the example of a battery cell 20 where the negative electrode sheet is on the outermost layer and the first electrode terminal 21 is the positive electrode terminal, the needle 10 is connected to the first electrode terminal 21. As the needle 10 moves toward the battery cell 20, before it touches or punctures the outermost negative electrode sheet, no circuit is formed between the outermost negative electrode sheet, the needle 10, the detection module 30, and the first electrode terminal 21. When the needle 10 touches or punctures the outermost negative electrode sheet, a circuit is formed between the outermost negative electrode sheet, the needle 10, the detection module 30, and the first electrode terminal 21, allowing the detection module 30 to detect the voltage between the positive and negative electrode sheets. As the needle 10 continues to penetrate the interior of the battery cell 20, an internal short circuit is formed between the positive and negative electrode sheets through the needle 10, and the detection module 30 can detect a voltage drop between the needle 10 and the first electrode terminal 21. At this time, the needle 10 stops moving. At this time, it is considered that the needle 10 has pierced the negative electrode sheet and the positive electrode sheet of the first layer of the battery cell 20.

[0051] Typically, a needle penetration test requires that the needle 10 penetrate one layer of the positive and negative electrode sheets within the battery cell 20. The processing module 40 can determine whether the needle 10 has penetrated one layer of the positive and negative electrode sheets of the battery cell 20 based on the change in voltage between the needle 10 and the first electrode terminal 21 detected by the detection module 30.

[0052] However, in other scenarios, it is also desirable to penetrate the test needle 10 into multiple layers of positive and negative electrode sheets within the battery cell 20. Because the positive and negative electrode sheets are stacked and have a certain degree of looseness, as shown in FIG2 , when the needle 10 penetrates the interior of the battery cell 20, it compresses the electrode sheets 23 in the area near the penetration position. Therefore, there is a deviation between the theoretical starting position A of the needle on the battery cell 20 and the actual starting position B of the needle 10 on the battery cell 20. Since the starting penetration position of the needle 10 cannot be accurately determined, it is impossible to identify the voltage drop generated when the multiple layers of positive and negative electrode sheets are short-circuited by the needle 10, and thus it cannot adapt to more testing requirements.

[0053] To this end, this application proposes a needle penetration test scheme, which aims to utilize the relationship between the physical structure and voltage of the battery cell to accurately determine the starting penetration position of the needle on the battery cell, and thus control the penetration depth or number of layers of the needle in the battery cell based on the starting penetration position, so as to meet different testing requirements.

[0054] As an example, FIG3 shows a schematic structural diagram of a device for a puncture test according to an embodiment of the present application. Optionally, the battery cell 20 to be tested may include, for example, a secondary battery such as a sodium ion battery or a lithium ion battery, and its structure includes a first pole piece and a second pole piece arranged in an overlapping manner, and the pole piece located on the outermost layer is the second pole piece, and the polarity of the first pole piece is opposite to that of the second pole piece. The device 100 can be applied to the puncture test of battery cells 20 of various structural types. The battery cell 20 may be a wound structure, a laminated structure, a cylindrical battery cell, or a soft-pack battery cell. All of these battery cells can be tested using the device 100 for a puncture test provided in an embodiment of the present application.

[0055] As shown in Figure 3, the device 100 includes a needle mechanism 120 and a voltage acquisition module 130. The voltage acquisition module 130 is connected between the needle 10 and the first electrode terminal of the battery cell 20. For example, the voltage acquisition module 130 includes a first connection port and a second connection port. The first connection port is used to connect to the needle 10, and the second connection port is used to connect to the first electrode terminal of the battery cell 20. The first electrode terminal is the electrode terminal on the battery cell 20 that is connected to the first electrode plate. The needle mechanism 120 is used to control the movement of the needle 10 toward the battery cell 20. The voltage acquisition module 130 is used to detect the voltage between the needle 10 and the first electrode terminal during the movement of the needle 10 toward the battery cell 20.

[0056] Optionally, the voltage is used to determine the penetration depth of the needle in the battery cell 20 , so that the penetration depth of the needle 10 in the battery cell 20 reaches a predetermined depth. For example, the voltage can be used to determine the starting penetration position of the needle 10 on the battery cell 20 .

[0057] The initial insertion position refers to the position of the needle 10 when it begins to penetrate the battery cell 20. At this time, the needle 10 may touch or slightly pierce the outermost second electrode sheet. In other words, the initial insertion position can be regarded as the position of the needle 10 when it touches or pierces the outermost second electrode sheet. For example, it can be the position of the needle tip of the needle 10, the position of the needle tail of the needle 10, or the position of other parts of the needle 10. Then, the initial insertion position can be used as the starting point, and the needle mechanism 120 can be used to control the needle 10 to continue moving until it penetrates the battery cell 20 to a predetermined depth.

[0058] Specifically, one end of the voltage acquisition module 130 is connected to the needle 10 through a voltage acquisition line, and the other end is connected to the electrode terminal corresponding to the first electrode through a voltage acquisition line. At this time, the needle 10, the voltage acquisition module 130 and the electrode terminal will form a path. When the needle 10 pierces the electrode of the battery cell 20, the path will form a loop, so that the voltage can be measured.

[0059] In some embodiments, the device 100 further includes a supporting mechanism 110, which is used to support the battery cell 20 and adjust the position of the battery cell 20 in the first direction X; wherein the needle mechanism 120 is specifically used to control the needle 10 to move along the second direction Y toward the battery cell.

[0060] The second direction Y is perpendicular to the first direction X. The needle 10 moves toward the battery cell 20 along the second direction Y. Usually, the second direction Y is perpendicular or approximately perpendicular to the electrode surface of the battery cell 20 , that is, the needle 10 penetrates the electrode of the battery cell 20 perpendicularly or approximately perpendicularly.

[0061] Through the cooperation between the supporting mechanism 110 and the puncture needle mechanism 120 , the puncture position of the puncture needle 10 on the surface of the battery cell 20 can be effectively positioned.

[0062] Since the positive electrode sheet of the battery cell 20 is connected to the positive electrode terminal, and the negative electrode sheet is connected to the negative electrode terminal, if the outermost electrode sheet of the battery cell 20 is configured as the negative electrode sheet, the voltage acquisition module 130 can be connected between the needle 10 and the positive electrode terminal of the battery cell 20 to detect the voltage between the needle 10 and the positive electrode terminal during the process of the needle 10 moving toward the battery cell 20. The voltage between the needle 10 and the positive electrode terminal is the voltage between the needle 10 and the total positive voltage of the battery cell 20; if the outermost electrode sheet of the battery cell 20 is configured as the positive electrode sheet, the voltage acquisition module 130 can be connected between the needle 10 and the negative electrode terminal of the battery cell 20 to detect the voltage between the needle 10 and the negative electrode terminal during the process of the needle 10 moving toward the battery cell 20. The voltage between the needle 10 and the negative electrode terminal is the voltage between the needle 10 and the total negative voltage of the battery cell 20.

[0063] The needle mechanism 120 in the needle penetration test device 100 can secure and control the movement of the needle 10 toward the battery cell 20. The securing method may be, for example, clamping, welding, or gluing. During the movement of the needle 10, the voltage acquisition module 130 detects the voltage between the needle 10 and the first electrode terminal. When the needle 10 touches or punctures the outermost second electrode sheet, a circuit is formed between the outermost second electrode sheet, the needle 10, the detection module 30, and the first electrode terminal 21. The voltage acquisition module 130 can detect changes in the voltage between the needle 10 and the first electrode terminal 21. Therefore, based on the change in voltage between the needle 10 and the first electrode terminal, the starting point of the needle 10's penetration into the battery cell 20 can be determined. Using this starting point as a starting point, the needle 10 can be controlled to continue moving within the battery cell 20 to a predetermined depth. In this way, by using the device 100, there is no need to perform complex modifications on the battery cell 20. By utilizing the relationship between the physical structure and voltage of the battery cell 20, the starting penetration position of the needle into the battery cell 20 can be determined, so as to achieve needle penetration testing of a predetermined number of layers or a predetermined depth within the battery cell 20, meeting the testing requirements for different penetration layers and depths.

[0064] For example, in the process of the needle mechanism 120 controlling the needle 10 to move toward the battery cell 20, when the voltage acquisition module 130 detects that the voltage between the needle 10 and the first electrode terminal suddenly changes and exceeds the preset voltage, the position to which the needle 10 moves when the voltage between the needle 10 and the first electrode terminal exceeds the preset voltage can be used as the starting insertion position of the needle 10 on the battery cell 20, and with this starting insertion position as the starting point, the clamping structure 120 is used to control the needle 10 to continue moving to a predetermined depth inside the battery cell 20.

[0065] In some embodiments, the device 100 further includes a housing 140 , which is used to accommodate the supporting mechanism 110 , the puncture needle mechanism 120 , the voltage acquisition module 130 , and the like.

[0066] In some embodiments, the device 100 further includes a control module, which is connected to the voltage acquisition module 130 and the puncture needle mechanism 120, and is used to determine the starting insertion position according to the voltage detected by the voltage acquisition module 130, and based on the starting insertion position, drive the puncture needle mechanism 120 to move along the second direction Y so that the puncture needle 10 penetrates to a predetermined depth of the battery cell 20.

[0067] The control module may also be connected to the carrying mechanism 110 to drive the carrying mechanism 110 to move along the first direction X, so as to move the battery cells 20 on the carrying mechanism 110 to a suitable position.

[0068] It can be seen that the control module can obtain voltage information during the test from the voltage acquisition module 130, and can also drive the needle mechanism 120 and the supporting mechanism 110 to move the needle mechanism 120 and the supporting mechanism 110 in corresponding directions, so that the needle 10 can accurately penetrate the battery cell 20.

[0069] In theory, the preset voltage can be any voltage value between 0V and the open circuit voltage of the battery cell 20. That is, as long as a change in voltage is detected starting from 0, the starting insertion position can be confirmed. When the sensitivity of the voltage detection device is sufficient, the smaller the preset voltage, the better. However, in actual applications, the preset voltage can be set to be greater than or equal to 0.5V and less than or equal to 1.5V, greater than or equal to 0.6V and less than or equal to 1.4V, greater than or equal to 0.7V and less than or equal to 1.3V, greater than or equal to 0.8V and less than or equal to 1.2V, or greater than or equal to 0.9V and less than or equal to 1.1V.

[0070] In the embodiment of the present application, the preset voltage is 1V. During the process of the needle 10 moving toward the battery cell 20, if the voltage between the needle 10 and the first electrode terminal suddenly exceeds the preset voltage, it is considered that the needle 10 touches or punctures the outermost second electrode sheet. The position of the needle 10 at this time can be used as the starting insertion position. Based on the starting insertion position, the needle 10 is controlled to continue moving a certain distance and then stop. The distance that the needle 10 continues to move from the starting insertion position is equal to the above-mentioned predetermined depth.

[0071] If the preset voltage is large, the test accuracy will be relatively poor, and it will not be possible to locate the starting insertion position in time when the needle 10 touches or punctures the outermost second electrode; if the preset voltage is small, it places higher demands on the sensitivity of the test device, and the test results are easily affected by interference from other factors in the test. To this end, after repeated experimental demonstrations, it was found that when the preset voltage is within the above-mentioned voltage range, the deviation of the starting insertion position is within 1 layer, which can meet the test requirements of most battery cells. Preferably, the preset voltage can be set to 1V. Of course, if the sensitivity of the test device is high enough, the preset voltage can also be set to a smaller value, such as 0.5V, 0.6V, 0.7V or 0.8V, etc.

[0072] The need for a needle penetration test can be characterized by the number of layers. The need for a needle penetration test may be to expect the needle 10 to penetrate multiple layers of positive and negative electrode sheets within the battery cell 20. Optionally, the predetermined depth is associated with the number of electrode sheets that need to be penetrated during the needle penetration test. For example, different depths correspond to different numbers of layers. When the number of electrode sheets to be penetrated is N1, the predetermined depth is M1; when the number of electrode sheets to be penetrated is N2, the predetermined depth is M2; when the number of electrode sheets to be penetrated is N3, the predetermined depth is M3; and so on.

[0073] To this end, it is necessary to convert the number of electrode layers to be penetrated into the penetration depth, and then control the movement distance of the needle 10 based on the starting penetration position so that it penetrates to a predetermined depth within the battery cell 20. In this way, the desired test requirements can be achieved through the above-mentioned needle penetration test method.

[0074] Of course, if the needle penetration test requirement is characterized by depth, for example, the needle penetration test requirement may be to expect the needle 10 to penetrate a predetermined depth within the battery cell 20. Then, after determining the starting penetration position, the needle 10 can be controlled to move a corresponding distance based on the starting penetration position. For example, if the predetermined depth is 1.5 mm, the needle 10 can be controlled to move 1.5 mm starting from the starting penetration position. For another example, if the predetermined depth is 2 mm, the needle 10 can be controlled to move 2 mm starting from the starting penetration position.

[0075] Therefore, the number of electrode layers to be penetrated and the thickness of the electrode sheets to be penetrated can be used to convert between the number of penetration layers and the penetration depth. For example, the predetermined penetration depth can be determined based on the number of electrode layers to be penetrated, the thickness of the first electrode sheet, and the thickness of the second electrode sheet. For another example, the predetermined depth can be determined based on the number of electrode layers, the thickness of the first electrode sheet, the thickness of the second electrode sheet, and the thickness of the isolation film between the first electrode sheet and the second electrode sheet and / or a preset gap value.

[0076] It is understood that the number of electrode layers described in the embodiments of the present application refers to the number of electrode layers formed by a first electrode and a second electrode, that is, each electrode layer includes one first electrode and one second electrode. In the case of considering the isolation film, each electrode layer may include one first electrode, one second electrode, and one or two isolation films.

[0077] The “penetration” described in the embodiments of the present application can be understood in a broad sense, and the penetration of the needle 10 into a certain electrode includes the needle 10 touching and / or piercing the electrode.

[0078] Figure 4 shows a schematic diagram of a possible electrode stack for a battery cell 20. As shown in Figure 4, a first electrode 231 and a second electrode 232 are arranged in an overlapping manner, with the outermost electrode being the second electrode 232. A separator 233 is disposed between the first and second electrode 231 and 232, and an insulating layer 234 is also disposed on the outermost layer. As the needle 10 moves toward the battery cell 20, it first penetrates the outermost insulating layer 234 and the two separators 233, compressing the electrode sheets to a certain extent. It then touches or penetrates the outermost second electrode 232, detecting a voltage change between the battery cell's first electrode terminal and the needle 10 during this process. The starting insertion position is determined based on this voltage change.

[0079] Based on this initial insertion position, the needle 10 continues to move and sequentially penetrates the first electrode layer, the second electrode layer, the third electrode layer, and so on. As an example, Figure 4 only shows three electrode layers, where the first electrode layer includes a first electrode layer 231, a second electrode layer 232, and an isolation film 233 between the two. Starting from the second electrode layer, each electrode layer includes a first electrode layer 231, a second electrode layer 232, and two isolation films 233, such as the second and third electrode layers shown in Figure 4.

[0080] It should be noted that the definition of the number of electrode layers in the embodiments of the present application is only an example and can be appropriately adjusted in actual applications. For example, the first electrode 231 is used as a single electrode layer, and the second electrode 232 is used as a single electrode layer. In this case, as shown in FIG4 , the first electrode layer includes a second electrode 232, the second electrode layer includes a first electrode 231 and an isolation film 233, the third electrode layer includes a second electrode 232 and an isolation film, and so on.

[0081] Optionally, the predetermined depth is associated with the thickness of the first pole piece and the thickness of the second pole piece of the battery cell. Further, the predetermined depth may also be associated with the thickness of the first pole piece and the thickness of the second pole piece of the battery cell, as well as the thickness of the separator between the first pole piece and the second pole piece and / or a preset gap value.

[0082] In some embodiments, the predetermined depth may be determined based on the number of electrode layers that need to be penetrated in the needle penetration test, the thickness of the first electrode 231 , and the thickness of the second electrode 232 .

[0083] Furthermore, in other embodiments, the predetermined depth can be determined based on the number of electrode layers that need to be penetrated in the needle penetration test, the thickness of the first electrode 231, the thickness of the second electrode 232, and the thickness of the isolation membrane 233 between the first electrode 231 and the second electrode 232 and / or the preset gap value D.

[0084] That is to say, according to the desired number of penetration layers and the thickness of the electrode, the number of penetration layers and the penetration depth are converted. For example, according to the desired number of penetration layers of the electrode, the thickness of the first electrode 231 and the thickness of the second electrode 232, and the thickness of the isolation membrane 233 between the first electrode 231 and the second electrode 232 and / or the preset gap value D, the desired predetermined penetration depth is determined.

[0085] Alternatively, when the number of electrode layers to be penetrated is one, that is, it is desired to penetrate one first electrode 231 and one second electrode 232, the predetermined depth is L1, C+S+D≤L1≤A+C+S+D. Where A is the thickness of the first electrode, C is the thickness of the second electrode, S is the thickness of the isolation film, and D is the gap value.

[0086] For example, the above-mentioned depth range can be mapped based on data such as the first electrode 231, the second electrode 232, the isolation membrane 233 or the number of layers to be penetrated of the battery cell 20, and any value within the depth range can be selected as the predetermined depth, for example, the middle value within the depth range can be selected.

[0087] Alternatively, when the number of electrode layers to be penetrated is N, that is, it is desired to penetrate N layers of first electrode pieces 231 and N layers of second electrode pieces 232, the predetermined depth is L N , (A+C+S+D)+(A+C+2S)*(N-2)+(C+2S)≤L N ≤(A+C+S+D)+(A+C+2S)*(N-1), where N is a positive integer greater than 1.

[0088] Because the first electrode piece 231 and the second electrode piece 232 of the battery cell 20 are compacted to different degrees after overlapping, a certain gap exists between the electrode pieces. The size of the gap D can be determined, for example, based on the manufacturing process. When the needle 10 penetrates the battery cell 20, it compresses the electrode pieces in the penetration area. This gap D can compensate for this, thereby improving test accuracy.

[0089] For example, if one electrode layer needs to be penetrated, the penetration depth L1 of the needle 10 in the battery cell 20 can be in the range of C+S+D to A+C+S+D; if two electrode layers need to be penetrated, the penetration depth L2 of the needle 10 in the battery cell 20 can be in the range of (A+C+S+D)+(C+2S) to (A+C+S+D)+(A+C+2S); ...; if N ...1 of the needle 10 in the battery cell 20 can be in the range of (A+C+S+D)+(C+2S) to (A+C+S+D)+(A+C+2S). NIt can be in the range of (A+C+S+D)+(A+C+2S)*(N-2)+(C+2S) to (A+C+S+D)+(A+C+2S)*(N-1). In this way, the first electrode piece 231 and the second electrode piece 232 in each layer of electrode pieces can be short-circuited, thereby achieving an internal short circuit at the corresponding position in the battery cell 20.

[0090] Taking the case where one electrode layer, i.e., the first electrode layer, needs to be penetrated as an example, as shown in FIG4 , the first electrode layer includes, from top to bottom, the second electrode 232, the isolation membrane 233, and the first electrode 231. When the penetration depth L1 of the needle 10 in the battery cell 20 is equal to C+S+D, the needle 10 penetrates the outermost second electrode 232 and the isolation membrane 233 on its lower surface in the process of movement, and then the needle tip contacts the upper surface of the first electrode 231; when the penetration depth L1 of the needle 10 in the battery cell 20 is equal to A+C+S+D, the needle 10 penetrates the outermost second electrode 232 and the isolation membrane 233 on its lower surface in the process of movement, and then continues to penetrate the first electrode 231, and then the needle tip reaches the lower surface of the first electrode 231. Therefore, when C+S+D≤L1≤A+C+S+D, the needle tip can be located at any position inside the first electrode piece 231. At this time, the second electrode piece 232 and the first electrode piece 231 will be short-circuited by the needle 10, causing an internal short circuit in the battery cell 20, thereby achieving the purpose of the needle penetration test.

[0091] It is understandable that in actual applications, due to the sensitivity of the voltage detection device or the movement speed of the needle 10, the starting insertion position determined based on the above method may have deviations. For example, when the starting insertion position is determined based on the voltage between the positive electrode terminal and the needle 10, the needle 10 may have penetrated a certain depth into the outermost second electrode sheet 232. In this way, after the needle 10 continues to penetrate the predetermined depth, the actual penetration depth of the needle in the battery cell 10 is slightly greater than the predetermined depth. For example, if it is necessary to penetrate one electrode sheet, the maximum penetration depth L of the needle 10 in the battery cell 20 is 1max It may be slightly larger than A+C+S+D; if it is necessary to penetrate two layers of electrode sheets, the maximum penetration depth of the needle 10 in the battery cell 20 is L 2max It may be slightly greater than (A+C+S+D)+(A+C+2S); ...; If it is necessary to penetrate N layers of electrode sheets, the maximum penetration depth of the needle 10 in the battery cell 20 is L Nmax It may be slightly larger than (A+C+S+D)+(A+C+2S)*(N-1).

[0092] Of course, as long as the deviation of the predetermined depth is within an acceptable range, such deviation can be accepted. Usually, the deviation of the predetermined depth will not exceed the preset value P. For example, when the number of layers of the electrode to be penetrated is 1, the maximum value L of the predetermined depth is1max Satisfy A+C+S+D≤L 1max ≤A+C+S+D+P; when the number of layers of the electrode to be penetrated is N, the maximum value of the predetermined depth L 2max Satisfies (A+C+S+D)+(A+C+2S)*(N-1)≤L nmax ≤(A+C+S+D)+(A+C+2S)*(N-1)+P, where P is a preset value. For example, P may be equal to the thickness of the second pole piece 232 or the sum of the thickness of the second pole piece 232 and the thickness of the isolation film 233 .

[0093] As an example, generally, for a battery cell 10 of the NCM chemical system, the thicknesses of the positive electrode sheet, the negative electrode sheet and the separator (including CCS+PCS) are 0.116 mm, 0.173 mm and 0.011 mm respectively; for a battery cell 20 of the LFP chemical system, the thicknesses of the positive electrode sheet, the negative electrode sheet and the separator (including CCS+PCS) are 0.144 mm, 0.172 mm and 0.0118 mm respectively; for a sodium-ion battery cell 20, the thicknesses of the positive electrode sheet, the negative electrode sheet and the separator (including CCS+PCS) are 0.204 mm, 0.205 mm and 0.0120 mm respectively.

[0094] The thickness of the positive or negative electrode sheet of the battery cell 20 can be, for example, between 0.1 mm and 0.5 mm, or further, between 0.1 mm and 0.25 mm. The thickness of the negative electrode sheet can be greater than that of the positive electrode sheet. The thickness of the separator is typically much smaller than that of the positive and negative electrode sheets. Therefore, in the embodiments of the present application, the separator can be ignored when converting the number of layers and depth.

[0095] FIG5 illustrates a possible needle penetration test process, which may be executed by a control module, such as a host computer or a processor. FIG5 uses the outermost electrode as an example, where the negative electrode is used as the outermost electrode. In this example, voltage acquisition module 130 is connected between the positive electrode terminal of battery cell 20 and needle 10.

[0096] As shown in FIG5 , in step 101 , the parameters of the acupuncture test are set, for example, the above-mentioned preset voltage, predetermined depth and other parameters are set.

[0097] In step 102 , it is determined that a needle stick test is started.

[0098] It is understandable that before the needle penetration test, for example, before step 101 , the battery cell 20 to be tested may be pre-treated, the SOC may be adjusted, the shell may be peeled, and other operations may be performed.

[0099] Pre-processing includes taking photos of the battery cell to be tested, testing its voltage, internal resistance, and weight, and recording the state of the battery cell 20 before testing. Adjusting the SOC involves charging the battery cell to a predetermined SOC according to the charging method specified in the relevant standard. To make the test conditions more stringent, the battery cell 20 may typically be charged to 100% SOC, for example, by charging the battery cell 20 to its cutoff voltage at a current of not less than 1 / 3C and then allowing the battery cell 20 to stabilize for one to two hours. Shelling involves providing a clearance hole with a certain diameter, such as at least 20 mm or at least 10 mm, on the outer shell of the battery cell 20 at the location where the needle is inserted. The clearance hole effectively avoids the needle 10, facilitating its insertion into the electrode. The clearance hole may be slightly larger than the diameter of the needle 10, for example, approximately 10 mm in diameter, or greater than or equal to 10 mm. After completing these operations, the positive electrode terminal of the battery cell 20 is connected to the needle 10 via a voltage line, and parameters are set. FIG4 takes the outermost second electrode piece as the negative electrode piece as an example.

[0100] In step 103 , the needle mechanism 120 is driven to move the needle 10 along the second direction Y, and during the movement, the voltage between the needle 10 and the positive electrode terminal of the battery cell 20 is acquired from the voltage acquisition module 130 .

[0101] In step 104 , it is determined whether the voltage between the needle 10 and the positive electrode terminal exceeds a predetermined voltage during the movement of the needle 10 .

[0102] A high-temperature-resistant steel needle with an insulating stopper 52 can be selected as the needle 10. The diameter of the needle 10 can be, for example, 1 mm, and the cone angle of the needle tip can be, for example, 20° to 30°. The surface of the needle 10 should be smooth and free of rust, oxide layers, and oil stains. The movement speed of the needle 10 can be, for example, less than or equal to 0.1 mm / s. The values ​​of parameters such as the diameter and movement speed of the needle 10 can be selected based on actual conditions and are not limited thereto.

[0103] If the voltage between the needle 10 and the positive electrode terminal exceeds the predetermined voltage, step 105 is executed.

[0104] In step 105, the initial insertion position is determined, and the position is used as the starting point to control the needle to continue moving.

[0105] For example, the position of the needle 10 when the voltage between the needle 10 and the positive electrode terminal exceeds the predetermined voltage is determined as the starting insertion position of the needle 10, and the needle mechanism 120 is driven to drive the needle 10 to continue moving with the starting insertion position as the starting point.

[0106] In step 106, it is determined whether the needle 10 has moved to a predetermined depth from the initial insertion position.

[0107] If the predetermined depth is reached, step 108 is executed. The predetermined depth is, for example, a penetration depth converted from a desired number of penetration layers, or a desired penetration depth such as 2 mm ± 0.5 mm.

[0108] In step 107 , the needle driving mechanism 120 is stopped.

[0109] Afterwards, the state of the battery cell 20 can be observed. For example, the battery cell 20 can be observed for a certain period of time, such as one hour, at the test ambient temperature to see if fire, explosion, or the like occurs in the battery cell 20.

[0110] In step 108 , it is determined that the needle prick test is complete.

[0111] The needle 10 is removed, and the battery cell 20 is discharged to a specified discharge termination voltage. The battery cell 20 is disassembled and the number of short-circuit layers is recorded.

[0112] As can be seen, the device 100 of the embodiment of the present application, based on the aforementioned needle penetration test process, can accurately determine the starting penetration position of the needle 10 when the needle 10 touches or penetrates the outermost second electrode sheet, and control the needle 10 to continue moving based on the starting penetration position until it penetrates the battery cell 20 to a predetermined depth. In this way, without the need for complex modifications to the battery cell 20, the needle penetration test can be completed accurately and conveniently by utilizing the relationship between the physical structure and voltage of the battery cell 20, improving test accuracy while also meeting testing requirements for different penetration depths.

[0113] FIG6 illustrates a possible structure of a needle mechanism 120 in an embodiment of the present application. As shown in FIG6 , the needle mechanism 120 includes a connecting member 121, a clamping member 122, and a first pushing member 123. The clamping member 122 and the first pushing member 123 are respectively disposed on either side of the connecting member 121 along the second direction Y. The clamping member 122 is used to clamp the needle 10, and the first pushing member 123 is configured to move along the second direction Y to push the connecting member 121, the clamping member 122, and the needle 10 along the second direction Y. The first pushing member 123 may be, for example, a push rod disposed parallel to the second direction Y.

[0114] The control module can drive the first pushing member 123 to move along the second direction Y, thereby pushing the connecting member 121 , the clamping member 122 and the needle 10 to move along the second direction Y toward the battery cell 20 .

[0115] The clamping member 122 can be, for example, a drill chuck. The front end of the clamping member 122, i.e., the end close to the needle 10, is provided with an opening structure for securing the needle 10. The size of the opening structure is adjustable to accommodate needles 10 of different diameters, lengths, and materials.

[0116] The connecting member 121 can be, for example, in the shape of a plate, such as a flat plate structure made of steel, and is provided with corresponding holes for setting fixing members for connecting the clamping member 122, the first pushing member 123, the first guide member 124 and other components.

[0117] In some embodiments, as shown in FIG6 , the puncture mechanism 120 further includes a first guide member 124 , which is disposed on a side of the connecting member 121 where the first pusher 123 is located. The first guide member 124 is configured to restrain the first pusher 123 from moving along the second direction Y. The first guide member 124 may be, for example, a guide rod disposed parallel to the second direction Y.

[0118] By providing the first guide member 124 for guidance, the first pusher 123 can have a certain anti-tilting ability, thereby improving its reliability, so that the needle 10 can penetrate the battery cell 20 vertically or approximately vertically along the second direction Y, rather than piercing the battery cell 20 at an angle.

[0119] The number of the first pushing members 123 can be one or more. For example, Figure 6 takes one first pushing member 123 as an example. The connecting member 121 and the clamping member 122 are relatively arranged on both sides of the connecting member 121 along the second direction Y, and the first pushing member 123 and the clamping member 122 are located in the middle area of ​​the connecting member 121.

[0120] The number of the first guide members 124 can be one or more. For example, Figure 6 takes two first guide members 124 as an example. As shown in Figure 6, the two first guide members 124 are arranged on the side of the connecting member 121 where the first pushing member 123 is located, and the two first guide members 124 are respectively located on both sides of the first pushing member 123 to improve the uniformity of the restraining force exerted on the first pushing member 123.

[0121] In some embodiments, as shown in FIG6 , the puncture needle mechanism 120 may further include a force sensor 125 , also known as a force sensor or pressure sensor. The force sensor 125 may be disposed between the clamping member 122 and the connecting member 121 to detect the force generated when the puncture needle 10 punctures the battery cell 20 .

[0122] A force sensor 125 is provided in the puncture needle mechanism 120, which can detect the force generated when the puncture needle 10 penetrates the battery cell 20, so as to assist in analyzing the change in the force generated by the electrode on the puncture needle 10 during the puncture test, thereby expanding the parameter range in the puncture test based on the change in force value, making the analysis of the test data more complete.

[0123] The force sensor 125 can be a sensor of any shape with force detection capability. For example, Figure 6 takes an "S"-shaped force sensor 125 as an example. The force sensor 125 includes a first bending portion 1251 and a second bending portion 1252 arranged along the second direction Y. The first bending portion 1251 is connected to the connecting member 121 and can play a supporting role; the second bending portion 1252 is connected to the clamping member 122 for receiving the force on the front end.

[0124] The force sensor 125 is in slight contact with the clamp 122. When the needle 10 penetrates the battery cell 20, the force exerted by the battery cell 20 on the needle 10 is transmitted back through the needle 10 and to the force sensor 125. The force sensor 125 detects the corresponding force changes and transmits the parameters back to the control module or data acquisition card for recording. This force data can then be used to analyze test results and optimize test parameters.

[0125] In some embodiments, the puncture mechanism 120 further includes a first fixing member 126, which is used to fix the first guide member 124 to the first wall 141 of the housing 140. The first fixing member 126 is used to fix the first guide member 124 to the first wall 141 of the housing 140, so that the first guide member 124 can accurately restrain the first pusher 123 from moving in the second direction Y.

[0126] For example, as shown in FIG. 3 and FIG. 6 , the first wall 141 of the housing 140 is perpendicular to the movement direction of the first pusher 123 of the lancet mechanism 120 , ie, the second direction Y. As shown in FIG.

[0127] Figure 7 illustrates a possible structure of a support mechanism 110 in an embodiment of the present application. As shown in Figure 7 , the support mechanism 110 includes a support platform 111 and a second pusher 112 . The second pusher 112 is configured to move along a first direction X to push the support platform 111 and the battery cell 20 along the first direction X. The second pusher 112 may be, for example, a push rod disposed parallel to the first direction X.

[0128] The control module can drive the second pusher 112 to move along the first direction X, thereby pushing the carrying platform 111 and the battery cell 20 to move along the first direction X.

[0129] In order to adapt to battery cells of different sizes, the carrying platform 111 can be, for example, a lifting platform, which moves in the first direction X so that battery cells 20 of different sizes can be in appropriate positions, so that the needle 10 can penetrate the puncture point position on the battery cell 20.

[0130] Optionally, the battery cell 20 further comprises a housing for accommodating the first and second pole pieces, wherein a clearance hole is provided on the housing for the insertion of the needle 10. The clearance hole can effectively avoid the needle 10, thereby facilitating the needle 10 to penetrate the pole pieces.

[0131] Before the needle penetration test begins, the battery cell 20 is placed on the carrying platform 111. The control module can drive the carrying platform 111 to move along the first direction X so that the needle 10 is aligned with the avoidance hole. When the needle 10 moves toward the battery cell 20 along the second direction Y, it can pass through the avoidance hole and penetrate the interior of the battery cell 20. For example, as shown in Figure 7, the control module can be connected to the motor 115 and control the motor 115 to drive the carrying platform 111 to move along the first direction X.

[0132] In some embodiments, as shown in FIG7 , the carrying mechanism 110 further includes a second guide member 113 . The second guide member 113 is disposed on the carrying platform 111 on a side where the second pusher 112 is located. The second guide member 113 is configured to restrain the second pusher 112 from moving along the first direction X. The second guide member 113 may be, for example, a guide rod disposed parallel to the first direction X.

[0133] By providing the second guide member 113 for guidance, the second pusher 112 can have a certain anti-tilting ability, thereby improving its reliability, so that the battery cell 20 will not deviate along the first direction X, so that the needle 10 can penetrate the battery cell 20 vertically or approximately vertically, rather than obliquely.

[0134] The number of the second pushing member 112 can be one or more. For example, FIG. 7 takes one second pushing member 112 as an example. The second pushing member 112 is disposed in the middle area of ​​the carrying platform 111 .

[0135] The number of the second guide members 113 can be one or more. For example, FIG. 7 shows four second guide members 113 as an example. The four second guide members 113 are respectively arranged at the four corners of the supporting platform 111 to improve the uniformity of the restraining force exerted on the second pusher 112 .

[0136] In some embodiments, the supporting mechanism 110 further includes a second fixing member 114, which is used to fix the second guide member 113 to the second wall 142 of the housing 140. The second fixing member 114 is used to fix the second guide member 113 to the second wall 142 of the housing 140, so that the second guide member 113 can accurately restrain the second pusher 112 from moving in the first direction X.

[0137] For example, as shown in FIG. 3 and FIG. 7 , the second wall 142 of the housing 140 is perpendicular to the movement direction of the second pushing member 112 of the supporting mechanism 110 , ie, the first direction X.

[0138] In some embodiments, the carrying platform 111 is provided with holes 1111 for mounting a stopper (not shown) that is used to limit the position of the battery cell 20. By providing holes 1111 for mounting the stopper, the battery cell 20 can be secured to the carrying platform 111, thereby improving stability during the needle penetration test.

[0139] Due to the huge capacity of the battery cell 20, the failure of the battery cell 20 during the needle penetration test may cause risks such as smoke, fire, or even explosion. The high temperature generated during this process may cause the sheet metal of the housing 140 of the device 100 to deform.

[0140] In addition, when the battery cell 20 fails during the needle penetration test, a large amount of smoke and residue will be generated. These residues will adhere to the outer shell 140 and are difficult to clean, resulting in an uneven surface of the outer shell 140. In this way, the battery cell 20 may slip during the test, affecting the test results.

[0141] Therefore, in some embodiments, as shown in Figures 3 and 8, the device 100 may further include a protective panel 150, which is disposed between the battery cell 20 and the third wall 143 of the housing 140. In this way, the protective panel 150 can be used as a "scapegoat" to reduce the impact of the needle penetration test on the housing 140 and extend the service life of the device 100.

[0142] As shown in Figures 3 and 8 , the protective panel 150 is disposed between the battery cell 20 and the third wall 143 of the outer shell 140. The third wall 143 can, for example, be perpendicular to the second direction Y. The protective panel 150 protects the third wall 143 of the outer shell 140 adjacent to the battery cell 20, to a certain extent preventing emissions such as residue and smoke generated by the battery cell 20 during testing from adhering to the third wall 143, thereby reducing damage to the third wall 143.

[0143] The protection panel 150 may be located at a side of the carrying platform 111 but may not be in contact with the carrying platform 111 .

[0144] The protection panel 150 and the third wall 143 may be provided with a detachable connection, for example, to facilitate replacement of the protection panel 150 .

[0145] In some embodiments, as shown in FIG8 , the protective panel 150 is provided with a countersunk hole 151 for receiving a fixing member (not shown) for fixing the protective panel 150 to the third wall 143. The design of the countersunk hole 151 helps reduce the probability of interference between the protective panel 150 and the battery cell 20, thereby enabling testing of larger battery cells 20.

[0146] The fixing members may be screws, for example. As shown in FIG8 , the protective panel 150 may be fastened to the third wall 143 using four screws. The thickness of the protective panel 150 may be, for example, between 15 mm and 25 mm, such as 20 mm. The length and width of the protective panel 150 may be between 300 mm and 400 mm, such as 400 mm by 300 mm.

[0147] In some embodiments, the protective panel 150 is provided with a notch 152, such as the "X" notch shown in FIG8, which is used to locate the battery cell 20. The visible notch 152 on the protective panel 150 facilitates the positioning of the battery cell 20 and helps testers determine the positional relationship between the battery cell 20 and the protective panel 150, for example, to determine whether the battery cell 20 is approximately located in the center area of ​​the protective panel 150.

[0148] Based on the above description, it can be seen that the needle penetration test device 100 of the embodiment of the present application includes a supporting mechanism 110, a needle mechanism 120, and a voltage acquisition module 130. The supporting mechanism 110 can support the battery cell 20 to be tested and drive the battery cell 20 to move in a first direction X. The needle mechanism 120 can control the needle 10 to move along a second direction Y toward the battery cell 20. During the movement of the needle 10, the voltage acquisition module 130 detects the voltage between the needle 10 and the electrode terminal connected to the first electrode sheet. When the needle 10 touches or punctures the outermost second electrode sheet, the voltage acquisition module 130 can detect a significant change in the voltage between the needle 10 and the electrode terminal. Therefore, based on the change in the voltage between the needle 10 and the electrode terminal, the starting point of the needle 10's penetration into the battery cell 20 can be determined. Using this starting point as a starting point, the needle 10 can be controlled to continue moving to a predetermined depth within the battery cell 20. In this way, by using the device 100, there is no need to perform complex modifications on the battery cell 20. By utilizing the relationship between the physical structure and voltage of the battery cell 20, the starting insertion position of the needle 10 on the battery cell 20 can be accurately determined, thereby completing the needle penetration test. While improving the test accuracy, it can also meet the test requirements of different penetration depths.

[0149] It should be noted that, under the premise of no conflict, the various embodiments and / or technical features in each embodiment described in this application can be arbitrarily combined with each other, and the technical solution obtained after the combination should also fall within the scope of protection of this application.

[0150] Those skilled in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0151] In the several embodiments provided in this application, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. For example, the device embodiments described above are merely schematic. For example, the division of the units is merely a logical function division. In actual implementation, there may be other division methods, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0152] The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solutions of the embodiments of the present application.

Claims

1. A device for acupuncture testing, characterized in that: The device comprises: A voltage collection module, the voltage collection module comprising a first connection port and a second connection port, the first connection port being connected to the puncture needle, and the second connection port being connected to the first electrode terminal of the battery cell; The pricking needle mechanism is used to control the movement of the pricking needle toward the battery cell, wherein the voltage acquisition module is used to detect the voltage between the pricking needle and the first electrode terminal during the movement of the pricking needle toward the battery cell, and the voltage is used to determine the starting insertion position of the pricking needle on the battery cell.

2. The device according to claim 1, characterized in that The battery cell includes a first pole piece and a second pole piece that are overlapped, and the pole piece located at the outermost layer is the second pole piece. The polarity of the first pole piece is opposite to that of the second pole piece. The first electrode terminal is an electrode terminal connected to the first pole piece. The voltage is used to determine the starting insertion position of the needle on the battery cell.

3. The device according to claim 1 or 2, characterized in that: The device also includes: A carrying mechanism, used for carrying a battery cell to be tested and adjusting a position of the battery cell in a first direction; The pricking needle mechanism is specifically used to control the pricking needle to move toward the battery cell along a second direction, and the second direction is perpendicular to the first direction.

4. The device according to claim 3, characterized in that The pricking needle mechanism includes a connecting member, a clamping member and a first pushing member, wherein the clamping member and the first pushing member are respectively arranged on both sides of the connecting member along the second direction, the clamping member is used to clamp the pricking needle, and the first pushing member is arranged to move along the second direction to push the connecting member, the clamping member and the pricking needle to move along the second direction.

5. The device according to claim 4, characterized in that The puncture mechanism further comprises a first guide member, which is arranged on a side of the connecting member where the first pushing member is located, and is used to restrain the first pushing member from moving along the second direction.

6. The device according to claim 5, characterized in that The device further comprises a housing, and the lancet mechanism further comprises a first fixing member, wherein the first fixing member is used to fix the first guide member to a first wall of the housing, and the first wall is perpendicular to the second direction.

7. The device according to claim 4, characterized in that The puncture needle mechanism further comprises a force sensor, which is arranged between the clamping member and the connecting member and is used to detect the force generated when the puncture needle punctures the battery cell.

8. The device according to claim 7, characterized in that The force sensor includes a first bending portion and a second bending portion arranged along the second direction, the first bending portion is connected to the connecting member, and the second bending portion is connected to the clamping member.

9. The device according to claim 3, characterized in that The carrying mechanism includes a carrying platform and a second pushing member, and the second pushing member is configured to move along the first direction to push the carrying platform and the battery cell to move along the first direction.

10. The device according to claim 9, characterized in that The bearing mechanism further includes a second guide member, which is disposed on the bearing platform at a side where the second pushing member is located, and is used to restrain the second pushing member from moving along the first direction.

11. The device according to claim 10, characterized in that The device further includes a housing, and the supporting mechanism further includes a second fixing member, wherein the second fixing member is used to fix the second guide member to a second wall of the housing, and the second wall is perpendicular to the first direction.

12. The device according to claim 9, characterized in that The carrying platform is provided with holes for installing limiting members, and the limiting members are used to limit the position of the battery cells.

13. The device according to claim 1 or 2, characterized in that The device further includes a housing, and the device further includes a protection panel, wherein the protection panel is disposed between the battery cell and a third wall of the housing, and the third wall is perpendicular to the second direction.

14. The device according to claim 13, characterized in that The protection panel is detachably connected to the third wall.

15. The device according to claim 14, characterized in that The protection panel is provided with a countersunk hole, the countersunk hole is used to set a fixing piece, and the fixing piece is used to fix the protection panel and the third wall.

16. The device according to claim 15, characterized in that The protection panel is provided with notches, and the notches are used to position the battery cells.

17. The device according to claim 1 or 2, characterized in that The battery cell further comprises a shell, wherein the shell is used to accommodate the first pole piece and the second pole piece of the battery cell, and an avoidance hole is arranged at a position for the puncture needle to pierce.

18. The device according to claim 1 or 2, characterized in that The device also includes: A control module is connected to the voltage acquisition module and the puncture needle mechanism, and is used to The starting puncture position is determined by pressure, and based on the starting puncture position, the puncture needle mechanism is driven to control the puncture needle to move toward the battery cell, so that the puncture needle punctures the battery cell to a predetermined depth.

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