Detection device and detection method

Abstract

The present application relates to a detection device and a detection method. The detection device comprises: a first detection part formed with an accommodating cavity for accommodating a working medium; a second detection part arranged opposite and spaced apart from the first detection part; two composite end plates, one of the composite end plates being fixed to the side of the first detection part facing the second detection part, the other composite end plate being fixed to the side of the second detection part facing the first detection part, and a region between the two composite end plates being formed as a detection zone for placing a battery cell to be detected; an ultrasonic probe movably accommodated in the accommodating cavity for performing acoustic detection on the battery cell to be detected; and a driving part for driving the second detection part to move towards or away from the first detection part. The detection device and the detection method according to the embodiments of the present application have the advantage of a high production efficiency.

Description

Detection device and detection method Related applications

[0001] This application incorporates Chinese Patent Application No. 2024118137943, filed on December 10, 2024, entitled “Detection Apparatus and Detection Method”, which is incorporated herein by reference in its entirety. Technical Field

[0002] This application relates to the field of battery technology, and in particular to a detection device and detection method. Background Technology

[0003] Currently, judging from market trends, battery applications are becoming increasingly widespread. Batteries are not only used in energy storage systems such as hydropower, thermal power, wind power, and solar power plants, but also extensively in electric vehicles such as electric bicycles, electric motorcycles, and electric cars, as well as in aerospace and other fields. With the continuous expansion of battery applications, market demand is also constantly increasing.

[0004] Currently, solid-state batteries are generally tested using ultrasound. However, during the testing process, solid-state batteries may come into contact with working media such as water or silicone oil, which can lead to contamination of the solid-state batteries, making surface cleaning difficult and affecting production efficiency. Summary of the Invention

[0005] Therefore, it is necessary to provide a detection device and detection method to address the problem of low production efficiency.

[0006] A first aspect of this application provides a detection device, comprising: a first detection section having a receiving cavity for containing a working medium; a second detection section disposed at a distance from the first detection section; two composite end plates, one of which is fixed to the side of the first detection section facing the second detection section, and the other composite end plate is fixed to the side of the second detection section facing the first detection section; a region between the two composite end plates is formed as a detection area for placing a battery cell to be tested; an ultrasonic probe movably housed in the receiving cavity for performing acoustic wave detection on the battery cell to be tested; and a driving section for driving the second detection section to move closer to or away from the first detection section.

[0007] In one embodiment, the composite end plate includes a strength layer and a flexible layer; the flexible layer of the entire composite end plate is located on the side closest to the detection area.

[0008] In one embodiment, the strength layer comprises at least one of polytetrafluoroethylene, polyetheretherketone, aluminum, copper, and iron; and / or, the hardness of the strength layer is 5 HRB to 500 HRB.

[0009] In one embodiment, the flexible layer comprises at least one of silicone, rubber, polyethylene, polypropylene, polyimide, and polyethylene terephthalate; and / or, the hardness of the flexible layer is 3HC to 300HC.

[0010] In one embodiment, the thickness of the central region of the flexible layer is greater than the thickness of the surrounding regions.

[0011] In one embodiment, the thickness of the strength layer is A, and the thickness of the flexible layer is B, satisfying: 1.5*B≤A≤100*B.

[0012] In one embodiment, the working medium includes at least one of water, silicone oil, and esters.

[0013] In one embodiment, the second detection unit and the first detection unit are arranged at a distance from each other in the vertical direction; the first detection unit is located above the second detection unit.

[0014] In one embodiment, the second detection unit includes a pressure transmitting plate, and a composite end plate is mounted on the pressure transmitting plate; the driving unit is connected to the pressure transmitting plate in a driving manner.

[0015] In one embodiment, the ultrasonic probe is a phased array ultrasonic probe; the ultrasonic probe is capable of exciting and receiving acoustic signals with a frequency of 3MHz to 100MHz.

[0016] In one embodiment, the ultrasonic probe includes a wedge, an array element, a probe, and signal lines; the array element is used to excite acoustic signals, and the probe is used to receive acoustic signals; the wedge covers the array element and the probe to isolate the working medium; the signal lines are respectively connected to the array element and the probe.

[0017] In one embodiment, the detection device includes a follower bracket and a power source; the ultrasonic probe is mounted on the follower bracket; the power source is used to drive the follower bracket to move the ultrasonic probe within the receiving cavity.

[0018] A second aspect of this application provides a detection method using the aforementioned detection apparatus. The detection method includes:

[0019] Place the battery cell to be tested in the testing area;

[0020] The control drive unit drives the second detection unit to approach the first detection unit so as to apply a pre-tightening force vertically to the large surface of the cell to be tested;

[0021] The ultrasonic probe is activated to generate a sound wave signal, and the ultrasonic probe is controlled to collect the reflected sound wave signal.

[0022] The beneficial effects are:

[0023] An embodiment of this application provides a testing device comprising a first testing unit, a second testing unit, two composite end plates, an ultrasonic probe, and a driving unit. The first testing unit forms a receiving cavity for accommodating a working medium, allowing the ultrasonic probe to be placed in the working medium within the receiving cavity, completely immersing the ultrasonic probe. The acoustic signal propagates through the working medium within the receiving cavity, reaches the composite end plates, and then reaches the battery cell under test, thereby completing the testing of the battery cell. This effectively avoids air interference with acoustic signal transmission at the contact interface, thus reducing the impact of air on acoustic wave propagation. This results in low acoustic signal attenuation, strong signal, and higher detection accuracy at normal transmission frequencies, eliminating the need to increase the ultrasonic transmission frequency and lowering costs. Furthermore, since the battery cell under test only contacts the composite end plates throughout the process, avoiding contact with the working medium, it effectively prevents contamination, eliminating the need for post-test cleaning and coating, simplifying the production process, and effectively improving production efficiency.

[0024] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, the following are specific embodiments of this application. Attached Figure Description

[0025] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the embodiments of this application will be briefly described below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on the drawings without creative effort. In the drawings:

[0026] Figure 1 is a schematic diagram of the structure of the detection device provided in some embodiments of this application.

[0027] Figure 2 is a schematic diagram showing the orientation of two composite end plates and the battery cell to be tested according to some embodiments of this application.

[0028] Figure 3 is a schematic diagram of the structure of an ultrasonic probe provided in some embodiments of this application.

[0029] Figure 4 is a flowchart of a detection method provided in some embodiments of this application.

[0030] Explanation of reference numerals in the attached figures:

[0031] First detection section-10, receiving cavity-11, second detection section-20, pressure transmission plate-21, composite end plate-30, strength layer-31, flexible layer-32, detection area-40, ultrasonic probe-50, wedge-51, array element-52, probe-53, signal line-54, drive section-60, follow-up bracket-70, battery cell under test-900. Detailed Implementation

[0032] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0033] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms “comprising” and “having”, and any variations thereof, in the specification, claims, and foregoing description of the drawings are intended to cover non-exclusive inclusion.

[0034] In the description of the embodiments of this application, if the technical terms such as "first" and "second" appear, these terms are used only for descriptive purposes to distinguish different objects, and should not be construed as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features.

[0035] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0036] In the description of the embodiments in this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.

[0037] In the description of the embodiments of this application, if the term "multiple" appears, "multiple" means at least two (including two), such as two, three, etc., unless otherwise explicitly specified. Similarly, if the term "multiple sets" appears, "multiple sets" refers to two or more sets (including two sets), and if the term "multiple pieces" appears, "multiple pieces" refers to two or more pieces (including two pieces).

[0038] In the description of the embodiments of this application, if the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. appear, these terms indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this application.

[0039] In the description of the embodiments of this application, unless otherwise explicitly specified and limited, the technical terms "installation," "connection," "joining," "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of this application according to the specific circumstances.

[0040] In this application, unless otherwise expressly specified and limited, the use of descriptions such as "above" or "below" the second feature indicates that the first and second features are in direct contact or indirect contact via an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. Similarly, "below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0041] It should be noted that if an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. If an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. If so, the terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used in this application are for illustrative purposes only and do not represent the only possible implementation.

[0042] Currently, judging from market trends, battery applications are becoming increasingly widespread. Batteries are not only used in energy storage systems such as hydropower, thermal power, wind power, and solar power plants, but also extensively in electric vehicles such as electric bicycles, electric motorcycles, and electric cars, as well as in aerospace and other fields. With the continuous expansion of battery applications, market demand is also constantly increasing.

[0043] Solid-state batteries, as one of the future development trends of power batteries, have advantages such as high density, high energy density, and good safety. With the technological advancement of solid-state batteries, higher demands are being placed on their production efficiency. In related technologies, ultrasonic testing is often used for solid-state batteries, with two methods: contact testing and non-contact testing. For non-contact testing, the sound waves attenuate quickly and the signal is not significant, resulting in low testing accuracy, easy misjudgment, and the flow of defective products into the next process, thus leading to unstable solid-state battery quality. For contact testing, the solid-state battery needs to come into contact with working media such as water or silicone oil, which can lead to contamination of the solid-state battery, making surface cleaning difficult and affecting production efficiency.

[0044] To alleviate the problem of low production efficiency, a cavity can be designed to hold the working medium, and the ultrasonic probe can be placed in the working medium. The sound wave signal propagates through the working medium, avoiding the influence of air on the sound wave signal transmission within the contact interface. This results in low sound wave signal attenuation, strong signal, and higher detection accuracy. At the same time, it avoids contact between the solid-state battery and the working medium, effectively improving production efficiency.

[0045] This application provides a detection device and method for detecting batteries that can provide electrical energy to or store electrical energy in electrical devices. Electrical devices can be, but are not limited to, mobile phones, tablets, laptops, electric toys, power tools, electric vehicles, electric cars, ships, spacecraft, energy storage products, etc. Electric toys can include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc. Spacecraft can include airplanes, rockets, space shuttles, and spacecraft, etc. Energy storage products can include energy storage stations, etc.

[0046] It should be understood that the batteries described in the embodiments of this application can be solid-state batteries using solid materials as electrolytes or liquid-state batteries using liquid materials as electrolytes; however, for the sake of brevity, unless otherwise specified, the batteries mentioned in the following embodiments are all solid-state batteries.

[0047] Figure 1 is a schematic diagram of the detection device provided in some embodiments of this application. Figure 2 is a schematic diagram of the orientation of the two composite end plates and the battery cell to be tested provided in some embodiments of this application. Figure 3 is a schematic diagram of the ultrasonic probe provided in some embodiments of this application.

[0048] Referring to Figures 1 to 3, a first aspect of this application provides a detection device, including: a first detection unit 10, a second detection unit 20, two composite end plates 30, an ultrasonic probe 50, and a drive unit 60.

[0049] The first detection unit 10 has a receiving cavity 11 for containing the working medium; the second detection unit 20 is disposed at a distance from the first detection unit 10; one composite end plate 30 is fixed to the side of the first detection unit 10 facing the second detection unit 20, and the other composite end plate 30 is fixed to the side of the second detection unit 20 facing the first detection unit 10; the area between the two composite end plates 30 is formed as a detection area 40 for placing the battery cell 900 to be tested; the ultrasonic probe 50 is movably housed in the receiving cavity 11 for performing acoustic wave detection on the battery cell 900 to be tested; and the driving unit 60 is used to drive the second detection unit 20 to move closer to or away from the first detection unit 10.

[0050] Specifically, the battery cell 900 to be tested is placed within the testing area 40 formed between the two composite end plates 30. The control drive unit 60 adjusts the position of the second testing unit 20, moving it toward the first testing unit 10 until the two composite end plates 30 clamp the battery cell 900 to be tested. At this time, the large surface of the battery cell 900 to be tested is in close contact with the composite end plates 30, which on the one hand avoids residual air from affecting the test results, and on the other hand ensures that the battery cell 900 to be tested remains stable during the test, thereby improving the test accuracy.

[0051] The ultrasonic probe 50 is activated to generate a sound wave signal. This sound wave signal passes through the working medium and the composite end plate 30 sequentially from the receiving cavity 11 and reaches the battery cell 900 to be tested. When the sound wave signal propagates inside the battery cell 900, it will produce reflection and scattering phenomena when it encounters different material interfaces or cracks. Thus, the ultrasonic probe 50 can collect the reflected sound wave signal and transmit it to an external processor for analysis and processing. This allows the processor to determine the degree of densification of the battery cell 900 to be tested, as well as to detect whether there are internal cracks, internal foreign objects, and the alignment of the stacked electrodes. This effectively prevents defective products in the battery cell 900 from flowing into subsequent processes.

[0052] In this embodiment, the first detection unit 10 forms a receiving cavity 11 for containing the working medium. The ultrasonic probe 50 can be placed in the working medium of the receiving cavity 11, and the working medium completely immerses the ultrasonic probe 50. The sound wave signal propagates through the working medium in the receiving cavity 11, reaches the battery cell 900 under test through the composite end plate 30, and thus completes the detection of the battery cell 900 under test. This effectively avoids the influence of air on the sound wave signal transmission within the contact interface, thereby reducing the influence of air on the sound wave propagation, resulting in low sound wave signal attenuation, strong signal, and higher detection accuracy at the normal transmission frequency. There is no need to increase the ultrasonic transmission frequency, resulting in lower cost. In addition, since the battery cell 900 under test only contacts the composite end plate 30 throughout the process, it avoids contact with the working medium, which can effectively prevent it from being contaminated. There is no need for cleaning after detection or coating, which simplifies the production process and can effectively improve production efficiency.

[0053] It is understood that the battery cell 900 to be tested in various embodiments of this application may be a semi-finished product in the battery manufacturing process. Specifically, in some embodiments, the battery cell 900 to be tested may include a semi-finished product formed by stacking a negative electrode, an electrolyte, and a positive electrode; in other embodiments, the battery cell 900 to be tested may only include a negative electrode; in other embodiments, the battery cell 900 to be tested may only include a positive electrode; in other embodiments, the battery cell 900 to be tested may include a composite formed by a negative electrode and an electrolyte; and in other embodiments, the battery cell 900 to be tested may include a composite formed by a positive electrode and an electrolyte.

[0054] In some embodiments of this application, the drive unit 60 includes a motor or cylinder for driving the second detection unit 20 to move toward or away from the first detection unit 10. During the detection process of the battery cell 900 to be tested, the drive unit 60 can continuously provide pressure to ensure that sufficient preload is applied to the battery cell 900 to be tested. The preload is typically 1 to 500t ± 0.5t; the specific value depends on the design.

[0055] In some embodiments of this application, the working medium includes at least one of water, silicone oil, and esters.

[0056] In some embodiments, the ultrasonic probe 50 is a phased array ultrasonic probe. The ultrasonic probe 50 can excite and receive acoustic signals with frequencies ranging from 3MHz to 100MHz. Specifically, when the acoustic signal propagates inside the battery cell 900 under test, it will produce reflection and scattering phenomena when it encounters different material interfaces or cracks. Depending on the material properties and the size of the crack, the reflection and scattering phenomena are better when the frequency of the acoustic signal is between 5MHz and 70MHz, which can effectively improve the detection accuracy. Therefore, the ultrasonic probe 50 of this application embodiment can excite and receive acoustic signals with frequencies ranging from 5MHz to 70MHz; for example, it can be 5MHz, 15MHz, 18MHz, 23MHz, 35MHz, 47.5MHz, 51MHz, 58MHz, 60MHz, 65MHz, or 70MHz, depending on the actual design, and this application does not limit it.

[0057] In some possible embodiments, as shown in Figures 1 to 3, the composite end plate 30 includes a strength layer 31 and a flexible layer 32; the flexible layer 32 of all composite end plates 30 is located on the side close to the detection area 40.

[0058] Thus, the strength layer 31 serves as a connecting structure. The strength layer 31 of one composite end plate 30 is fixed to the mounting surface of the first detection unit 10 facing the second detection unit 20, and the strength layer 31 of the other composite end plate 30 is fixed to the mounting surface of the second detection unit 20 facing the first detection unit 10. The flexible layer 32 of all composite end plates 30 is located on the side closest to the detection area 40, allowing the flexible layer 32 to make large-area contact with the battery cell 900 under test. This prevents excessive hardness from damaging the battery cell 900. Simultaneously, the flexible layer 32 can deform flexibly within a certain range, effectively expelling air between the flexible layer 32 and the battery cell 900 under test. This effectively prevents air from affecting the transmission of acoustic signals within the contact interface, thereby reducing the impact of air on acoustic wave propagation and resulting in higher detection accuracy.

[0059] It is understandable that the strength layer 31 and the flexible layer 32 are stacked in the same direction as their thickness.

[0060] As the structure that is in close contact with the battery cell 900 under test, the composite end plate 30 needs to be made of a material that can effectively transmit acoustic signals while reducing signal attenuation, thereby improving the accuracy and sensitivity of the detection. In addition, the surface treatment process of the composite end plate 30 also needs to ensure the cleanliness of the part in contact with the battery cell 900 under test, avoiding the contamination problems that may be introduced in traditional contact testing.

[0061] In some possible embodiments, referring to Figures 1 to 3, the strength layer 31 may include at least one of polytetrafluoroethylene, polyetheretherketone, aluminum, copper, and iron. The flexible layer 32 includes at least one of silicone, rubber, polyethylene, polypropylene, polyimide, and polyethylene terephthalate.

[0062] The hardness of the strength layer 31 is 5 HRB to 500 HRB. Specifically, the hardness of the strength layer 31 can be 10 HRB to 300 HRB. The Rockwell hardness test is used to measure the material hardness of the strength layer 31. The measurement method is a test load of 980.7 N 100 KG-F using a quenched steel ball with a diameter of 1.59 mm. The strength layer 31 can be made of other metallic or non-metallic materials, and this application does not limit this, but the hardness of the material should conform to the above hardness range. For example, the strength layer 31 can also be made of aluminum alloy, copper alloy, and stainless steel, and has sufficient strength and stable connection.

[0063] The hardness of the flexible layer 32 is 3HC to 300HC. Specifically, the hardness of the flexible layer 32 is 5HC to 200HC. The Shore hardness is used to measure the material hardness of the flexible layer 32. The static extrusion measurement method is used to determine the material hardness by measuring the depth of the indenter on the sample surface. Other non-metallic materials can also be used for the flexible layer 32, and this application does not limit this, but the hardness of the material should conform to the above hardness range; in this way, the flexible layer 32 has sufficient flexibility and deformation capability and can effectively expel air between the flexible layer 32 and the cell 900 under test, effectively avoiding the influence of air on the acoustic signal transmission within the contact interface.

[0064] In some possible embodiments, as shown in Figures 1 to 3, the thickness of the central region of the flexible layer 32 is greater than the thickness of the surrounding regions.

[0065] That is, the flexible layer 32 is not a plane, but a spherical surface that is raised in the middle and thinner around the edges.

[0066] In related technologies, when an ultrasonic probe is attached to the surface of the battery cell to be tested, there will always be a gap at the attachment point. The air in the gap will affect the sound wave signal emitted by the ultrasonic probe, resulting in an unsatisfactory imaging effect of the ultrasonic wave at normal frequencies.

[0067] In this embodiment, the thickness of the central region of the flexible layer 32 is set to be greater than the thickness of the surrounding region. When the driving unit 60 adjusts the position of the second detection unit 20 so that it moves toward the first detection unit 10, the two composite end plates 30 move closer to each other, and the highest point of the central region of the flexible layer 32 can first contact the middle of the cell 900 to be tested. This can effectively expel all the internal air at the interface between the flexible layer 32 and the cell 900 to be tested, avoiding residual air from affecting the test results and resulting in high test accuracy.

[0068] In some embodiments, the thickness of the central region of the flexible layer 32 is typically 8-10 mm, and the thickness of the surrounding region of the flexible layer 32 is typically 2-8 mm. Of course, the thickness of each region of the flexible layer 32 can also be specifically set as needed, and this application does not limit this.

[0069] In some possible embodiments, referring to Figures 1 to 3, the composite end plate 30 can be rectangular or square when projected along the thickness direction. The projected areas of the strength layer 31 and the flexible layer 32 should be the same, that is, the length and width should be the same.

[0070] Projecting along the thickness direction of the composite end plate 30, the composite end plate 30 can be circular or elliptical. The projected areas of the strength layer 31 and the flexible layer 32 should be the same, that is, the center and radius are the same.

[0071] In some possible embodiments, referring to Figures 1 to 3, the thickness of the strength layer 31 is A, and the thickness of the flexible layer 32 is B, satisfying: 1.5*B≤A≤100*B.

[0072] Specifically, the thickness A of the strength layer 31 and the thickness B of the flexible layer 32 can be 2*B≤A≤50*B in some embodiments; thus, by limiting the ratio of the thickness of the strength layer 31 to the thickness of the flexible layer 32, it can be ensured that the composite end plate 30 can effectively transmit acoustic signals while reducing signal attenuation, thereby effectively improving detection accuracy.

[0073] It is understood that, in the embodiments of this application, the thickness B of the flexible layer 32 refers to the thickness of the central region of the flexible layer 32.

[0074] In the actual structure, a 40mm thick aluminum plate can be used as the strength layer 31, and a 6mm thick sound-transmitting silicone can be used as the flexible layer 32. The strength layer 31 and the flexible layer 32 are connected as one piece by adhesive bonding and pressing.

[0075] In some possible embodiments, as shown in Figures 1 to 3, the second detection unit 20 and the first detection unit 10 are arranged at a distance from each other in the vertical direction; the first detection unit 10 is located above the second detection unit 20.

[0076] It should be understood that the second detection unit 20 and the first detection unit 10 are arranged vertically at intervals, and the working medium will be located at the bottom of the first detection unit 10 under its own weight. When the receiving cavity 11 is not filled with the working medium, air may easily exist at the top of the receiving cavity 11, affecting the propagation of the acoustic signal and thus affecting the acoustic imaging quality; therefore, the first detection unit 10 needs to be placed above the second detection unit 20 to ensure that the acoustic signal does not need to pass through the air area, effectively improving the acoustic imaging quality.

[0077] The battery cell 900 to be tested is placed in the testing area 40 formed between the two composite end plates 30. The control drive unit 60 adjusts the position of the second testing unit 20, moving it vertically upward toward the first testing unit 10 until the two composite end plates 30 clamp the battery cell 900 to be tested. The drive unit 60 can drive the composite end plates 30 to apply a pre-tightening force perpendicular to the large surface of the battery cell 900 to ensure that the large surface of the battery cell 900 to be tested is tightly attached to the composite end plates 30. This avoids residual air from affecting the test results and ensures that the battery cell 900 to be tested remains stable during the test, ultimately effectively improving the testing accuracy of the testing device.

[0078] In some possible embodiments, referring to Figures 1 to 3, the first detection unit 10 includes a hollow housing; specifically, the first detection unit 10 may be made of aluminum alloy, copper alloy, or stainless steel, possessing sufficient strength and stable connection. The composite end plate 30 may serve as one of the side plates of the hollow housing, and its strength layer 31 may be welded and fixed to the other side plates of the first detection unit 10.

[0079] In some possible embodiments, as shown in Figures 1 to 3, the second detection unit 20 includes a pressure transmitting plate 21, and a composite end plate 30 is mounted on the pressure transmitting plate 21; the driving unit 60 is connected to the pressure transmitting plate 21 in a driving manner.

[0080] The pressure plate 21 can be made of aluminum alloy, copper alloy, or stainless steel, and has sufficient strength and stable connection. The strength layer 31 of the composite end plate 30 can be fixed to the pressure plate 21 by bolts or welding.

[0081] In some possible embodiments, as shown in Figures 1 to 3, the ultrasonic probe 50 includes a wedge 51, an array element 52, a probe 53, and a signal line 54; the array element 52 is used to excite acoustic signals, and the probe 53 is used to receive acoustic signals; the wedge 51 covers the array element 52 and the probe 53 to isolate the working medium; the signal line 54 is connected to the array element 52 and the probe 53 respectively.

[0082] Once the battery cell 900 to be tested and the testing device are ready, the ultrasonic probe 50 is activated via signal line 54, and the array element 52 excites a sound wave signal. This sound wave signal passes through the working medium and the composite end plate 30 sequentially from the receiving cavity 11 and reaches the battery cell 900 to be tested. The sound wave signal is reflected and scattered in the battery cell 900 to be tested. The probe 53 collects the reflected sound wave signal and transmits it to an external processor via signal line 54 to analyze and process the reflected sound wave signal, thereby determining the degree of densification of the battery cell 900 to be tested, as well as detecting whether there are internal cracks, internal foreign objects, and the alignment of the stacked electrodes, etc. This can effectively prevent defective products in the battery cell 900 to be tested from flowing into subsequent processes and complete the testing.

[0083] The wedge 51 covers the array element 52 and the probe 53 to isolate the working medium, prevent damage to the ultrasonic probe 50, and extend the service life of the detection device.

[0084] In some possible embodiments, referring to Figures 1 to 3, the detection device includes a follower bracket 70 and a power source (not shown); the ultrasonic probe 50 is mounted on the follower bracket 70; the power source is used to drive the follower bracket 70 to move the ultrasonic probe 50 in the receiving cavity 11.

[0085] The power source drives the follower bracket 70 to move the ultrasonic probe 50 up, down, left, and right within the receiving cavity 11. This allows the distance between the first detection unit 10 and the second detection unit 20 to be flexibly adjusted as needed during testing, thus accommodating the testing requirements of battery cells 900 of different sizes. Simultaneously, the position of the ultrasonic probe 50 within the receiving cavity 11 can also be fine-tuned by driving the follower bracket 70 with the power source, ensuring that the acoustic signal is accurately focused on the key testing area of ​​the battery cell 900, further improving testing accuracy.

[0086] In some embodiments, the power source may be an electric motor.

[0087] A second aspect of this application provides a detection method applied to the detection apparatus described above. Referring to Figures 1 to 4, Figure 4 is a flowchart of a detection method provided in some embodiments of this application.

[0088] The detection methods include:

[0089] S10. Place the battery cell 900 to be tested in the testing area 40.

[0090] S20, the control drive unit 60 drives the second detection unit 20 to approach the first detection unit 10, so as to apply a pre-tightening force vertically to the large surface of the battery cell 900 to be tested. The pre-tightening force is typically 1t to 500t.

[0091] S30. Start the ultrasonic probe 50 to generate a sound wave signal and control the ultrasonic probe 50 to collect the reflected sound wave signal.

[0092] Specifically, the battery cell 900 to be tested is placed within the testing area 40 formed between the two composite end plates 30. The control drive unit 60 adjusts the position of the second testing unit 20, moving it toward the first testing unit 10 until the two composite end plates 30 clamp the battery cell 900 to be tested. At this time, the large surface of the battery cell 900 to be tested is in close contact with the composite end plates 30, which on the one hand avoids residual air from affecting the test results, and on the other hand ensures that the battery cell 900 to be tested remains stable during the test, thereby improving the test accuracy.

[0093] The ultrasonic probe 50 is activated to generate a sound wave signal. This sound wave signal passes through the working medium and the composite end plate 30 sequentially from the receiving cavity 11 and reaches the battery cell 900 to be tested. When the sound wave signal propagates inside the battery cell 900, it will produce reflection and scattering phenomena when it encounters different material interfaces or cracks. Thus, the ultrasonic probe 50 can collect the reflected sound wave signal and transmit it to an external processor for analysis and processing. This allows the processor to determine the degree of densification of the battery cell 900 to be tested, as well as to detect whether there are internal cracks, internal foreign objects, and the alignment of the stacked electrodes. This effectively prevents defective products in the battery cell 900 from flowing into subsequent processes.

[0094] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0095] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A detection device, comprising: The first detection section (10) has a receiving cavity (11) for containing the working medium; The second detection unit (20) is disposed at a distance from the first detection unit (10); Two composite end plates (30), one of which is fixed to the side of the first detection unit (10) facing the second detection unit (20), and the other is fixed to the side of the second detection unit (20) facing the first detection unit (10); the area between the two composite end plates (30) is formed as a detection area (40) for placing the battery cell (900) to be tested; An ultrasonic probe (50) is movably housed in the receiving cavity (11) for performing acoustic wave detection on the battery cell (900) to be tested; And a drive unit (60) for driving the second detection unit (20) to move closer to or further away from the first detection unit (10).

2. The detection device according to claim 1, wherein the composite end plate (30) includes a strength layer (31) and a flexible layer (32); the flexible layer (32) of all the composite end plates (30) is located on the side close to the detection area (40).

3. The detection device according to claim 2, wherein the strength layer (31) comprises at least one of polytetrafluoroethylene, polyetheretherketone, aluminum, copper, and iron; and / or, The hardness of the strength layer (31) is 5HRB to 500HRB.

4. The detection device according to claim 2, wherein the flexible layer (32) comprises at least one of silicone, rubber, polyethylene, polypropylene, polyimide, and polyethylene terephthalate; and / or, The hardness of the flexible layer (32) is 3HC to 300HC.

5. The detection device according to claim 2, wherein the thickness of the central region of the flexible layer (32) is greater than the thickness of the surrounding region.

6. The detection device according to claim 2, wherein the thickness of the strength layer (31) is A and the thickness of the flexible layer (32) is B, satisfying: 1.5*B≤A≤100*B.

7. The detection device according to any one of claims 1 to 6, wherein the working medium comprises at least one of water, silicone oil, and esters.

8. The detection device according to any one of claims 1 to 7, wherein the second detection unit (20) and the first detection unit (10) are arranged at a distance from each other in the vertical direction; the first detection unit (10) is located above the second detection unit (20).

9. The detection device according to any one of claims 1 to 8, wherein the second detection unit (20) includes a pressure transmission plate (21), the composite end plate (30) is mounted on the pressure transmission plate (21), and the driving unit (60) is connected to the pressure transmission plate (21) in a driving connection.

10. The detection device according to any one of claims 1 to 9, wherein the ultrasonic probe (50) is a phased array ultrasonic probe; the ultrasonic probe (50) is capable of exciting and receiving acoustic signals with a frequency of 3MHz to 100MHz.

11. The detection device according to claim 10, wherein the ultrasonic probe (50) comprises a wedge (51), an array element (52), a probe (53), and a signal line (54); the array element (52) is used to excite acoustic signals, and the probe (53) is used to receive acoustic signals; the wedge (51) covers the array element (52) and the probe (53) to isolate the working medium; and the signal line (54) is connected to the array element (52) and the probe (53) respectively.

12. The detection device according to any one of claims 1 to 11, wherein the detection device includes a follower bracket (70) and a power source; the ultrasonic probe (50) is disposed on the follower bracket (70); and the power source is used to drive the follower bracket (70) to move the ultrasonic probe (50) in the receiving cavity (11).

13. A detection method, applied to the detection apparatus as described in any one of claims 1 to 12, the detection method comprising: Place the battery cell (900) to be tested in the testing area (40); The control drive unit (60) drives the second detection unit (20) to approach the first detection unit (10) to apply a preload force vertically to the large surface of the cell (900) to be tested; The ultrasonic probe (50) is activated to generate a sound wave signal, and the ultrasonic probe (50) is controlled to collect the reflected sound wave signal.

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