Battery monomer, battery device, electric equipment and welding quality detection method

Abstract

The invention discloses a single battery, a battery device, electric equipment and a welding quality detection method, and relates to the technical field of battery production detection, the single battery comprises a body and an output electrode arranged on the body, one side, away from the body, of the output electrode is a welding surface, a groove is formed in the welding surface, and the welding surface is used for being welded with a conductive connecting piece to form a welding seam; the groove intersects with the weld joint, the ultrasonic waves are emitted towards the intersection of the weld joint and the groove, the reflected signal intensity of the ultrasonic waves at the target positions of different depths is detected, and the weld penetration depth is obtained according to the reflected signal intensity. By adopting the single battery, the welding part of the output electrode and the chip can be fully detected, the control strength on the welding quality is improved, welding seam cutting and metallographic phase grinding detection are not needed, automatic detection equipment is not needed, automatic detection can be realized, and the detection efficiency is high.

Description

Technical Field

[0001] The present application relates to the technical field of battery production detection, and in particular to a battery cell, a battery device, an electrical equipment and a welding quality detection method. Background Art

[0002] In the process of power battery manufacturing, laser is needed to weld the conductive connector and the pole together. The conductive connector generally refers to the bar. However, the failure of the welded joint may lead to insufficient local strength of the battery device, which may cause abnormal sampling signals and even the risk of overheating and fire. Therefore, it is necessary to control the welding quality between the conductive connector and the pole. However, due to the limitations of the detection method, the current detection method can only be done by random inspection, and the detection efficiency is low. Summary of the invention

[0003] The main purpose of the present application is to propose a battery cell, a battery device, an electrical equipment and a welding quality detection method, aiming to at least improve the technical problem that the welding quality detection of the pole and the conductive connector in the battery device can only be carried out by random inspection and the detection efficiency is low.

[0004] According to some embodiments of the present application, the present application provides a battery cell, including a main body and an output pole arranged on the main body, the side of the output pole away from the main body is a welding surface, a groove is arranged on the welding surface, the welding surface is used to weld with a conductive connector to form a weld, the groove intersects with the weld, so that ultrasonic waves are emitted toward the intersection of the weld and the groove, the reflected signal intensity of the ultrasonic waves at target positions at different depths is detected, and the penetration depth of the weld is obtained according to the reflected signal intensity.

[0005] By setting a groove on the welding surface of the output pole and the weld intersecting with the groove, ultrasonic waves can be emitted toward the intersection of the weld and the groove to detect the reflection signal intensity of the ultrasonic waves at target positions at different depths. The different reflection signal intensities of ultrasonic waves in media of different densities are utilized to obtain the penetration depth of the weld according to the reflection signal intensity, thereby realizing non-destructive detection of the weld. This is a non-destructive detection method, which can realize full inspection of the welding part of the output pole and the bar, improve the control over the welding quality, and does not require cutting of the weld and metallographic phase detection. With the assistance of automatic detection equipment, automatic detection can be realized, and the detection efficiency is high.

[0006] In some embodiments, the number of the groove is one, and both ends of the groove extend to the outer edge of the welding surface respectively.

[0007] By extending both ends of the groove to the outer edge of the welding surface, it is ensured that the weld and the groove can intersect, which is convenient for subsequent penetration detection.

[0008] In some embodiments, there are multiple grooves, each of which intersects with the weld, and both ends of each groove extend to the outer edge of the welding surface respectively.

[0009] By setting multiple grooves of different depths and adjusting the position of the ultrasonic transmitter, the ultrasonic wave can be emitted in sequence toward the intersections of the weld and the multiple grooves in a preset emission order. This can be used to quantitatively detect the penetration depth of the weld, and can detect welds with different penetration depths, thereby improving the scope of application of the welding quality detection method.

[0010] In some embodiments, the depth of each groove is set in a gradient.

[0011] By setting the groove depth of each groove in a gradient, the detection range of the weld penetration depth can be expanded.

[0012] In some embodiments, the welding surface is a circular surface, and the shape of the weld is a circular ring; or, The welding surface is a rectangular surface, and the shape of the weld is a rectangle.

[0013] By setting the welding surface and the weld to match each other, the weld and the groove can be easily intersected, and the detection of the penetration depth can be facilitated.

[0014] According to some embodiments of the present application, the present application provides a welding quality detection method, which is applied to detect the weld between the output electrode and the conductive connector of the above-mentioned battery cell, and the welding quality detection method includes: Adjust the position of the ultrasonic transmitter so that the ultrasonic wave is emitted toward the intersection of the weld and the groove.

[0015] Detecting the reflected signal intensity of the ultrasonic wave at target positions at different depths; The depth is: the distance from the upper surface of the conductive connecting member to the target position in the thickness direction of the conductive connecting member, and the upper surface is a side of the conductive connecting member away from the output pole.

[0016] The penetration depth of the weld is obtained according to the intensity of the reflected signal.

[0017] In the above-mentioned embodiment of the present application, by emitting ultrasonic waves toward the intersection of the weld and the groove, detecting the reflected signal intensity of the ultrasonic waves at the target position at different depths, utilizing the different reflected signal intensities of ultrasonic waves in different density media, and obtaining the penetration depth of the weld according to the reflected signal intensity, non-destructive testing of the weld can be achieved. This is a non-destructive testing method, which can achieve full inspection of the welding part of the output pole and the bar, improve the control over the welding quality, and does not require cutting the weld and grinding metallographic testing. With the assistance of automatic testing equipment, automatic testing can be achieved, and the detection efficiency is high.

[0018] In some embodiments, the number of the grooves is multiple, and the groove depths of the multiple grooves are set in a gradient; the step of adjusting the position of the ultrasonic transmitter head so that the ultrasonic wave is emitted toward the intersection of the weld and the groove comprises: Adjust the position of the ultrasonic transmitter so that the ultrasonic wave is transmitted in sequence toward the intersections of the weld and the plurality of grooves according to a preset transmission sequence; The preset emission sequence is: the sequence in which the groove depth values ​​of the plurality of grooves are arranged from small to large.

[0019] By setting multiple grooves of different depths and adjusting the position of the ultrasonic transmitter, the ultrasonic wave can be emitted in sequence toward the intersections of the weld and the multiple grooves in a preset emission order. This can be used to quantitatively detect the penetration depth of the weld, and can detect welds with different penetration depths, thereby improving the scope of application of the welding quality detection method.

[0020] In some embodiments, the step of detecting the reflected signal strength of the ultrasonic wave at target positions at different depths includes: The reflected signal strength of the ultrasonic wave at different depths is obtained in order from small to large depth values.

[0021] By setting the depth values ​​in ascending order to obtain the reflected signal strength of the ultrasonic wave at different depths, it is convenient to operate and also convenient to obtain the trend change graph of the reflected signal strength change.

[0022] In some embodiments, the step of detecting the reflected signal strength of the ultrasonic wave at target positions at different depths includes: If the reflected signal strength is greater than or equal to the preset threshold, it is defined as a strong reflected signal; If the reflected signal strength is less than the preset threshold, it is defined as a weak reflected signal; The step of obtaining the penetration depth of the weld according to the reflected signal strength comprises: When the intensity of the reflection signal changes from a weak reflection signal to a strong reflection signal, the depth value at this time is recorded, and the depth value is the penetration depth of the weld.

[0023] By defining the numerical range of strong reflection signals and weak reflection signals, the penetration depth of the weld can be directly read from the trend change diagram of reflection signal intensity-depth, which is very convenient to operate.

[0024] In some embodiments, the welding quality detection method further includes: Detecting the reflected signal intensity of the ultrasonic wave in each area at a preset depth position; wherein the preset depth position is the depth position where the lower surface of the conductive connecting member is located; Determine the outer contour of the weld at a preset depth according to the intensity of the reflected signal; The weld width of the weld is obtained according to the outer contour.

[0025] By detecting the intensity of ultrasonic reflection signals in various areas at a preset depth position, the outer contour of the weld at the preset depth position is determined according to the intensity of the reflection signal, and the weld width is obtained according to the outer contour. The weld width data can be obtained through non-destructive and automated testing.

[0026] According to some embodiments of the present application, the present application provides a battery device, including a box body, a plurality of battery cells, a conductive connector, a sampling piece and a battery management module, the box body is provided with a accommodating cavity, the battery cell is the battery cell described above, the conductive connector is welded to the welding surface of the battery cell to form a weld, and the sampling piece electrically connects the conductive connector and the battery management module.

[0027] The output pole and the sampling piece are electrically connected through a conductive connector, and the electrical signal is transmitted to the battery management module through the sampling piece to realize the monitoring of the battery cell signal. At the same time, the battery cell used can be subjected to ultrasonic non-destructive testing to efficiently detect the penetration depth and width of the weld.

[0028] In some embodiments, the weld is annular in shape, and the weld intersects the groove at multiple locations.

[0029] By setting the weld to be a circular weld and intersecting the groove at multiple locations, the convenience of detection can be improved.

[0030] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. 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 structures shown in these drawings without paying any creative work.

[0032] Figure 1 A schematic diagram of the structure of a vehicle according to some embodiments of the present application; Figure 2 A schematic diagram of the exploded structure of a battery according to some embodiments of the present application; Figure 3 A schematic diagram of a structure in which a plurality of battery cells of a battery device and a conductive connector are connected in some embodiments of the present application; Figure 4 A schematic diagram of the structure of a battery cell of a battery device according to some embodiments of the present application; Figure 5 for Figure 4 A schematic diagram of the structure of the output pole without the conductive connection welded on the left; Figure 6 for Figure 4 The right side shows a schematic diagram of the structure of the output pole with the conductive connector welded thereto, the conductive connector and the weld; Figure 7 A schematic diagram of a welding quality detection method according to some embodiments of the present application; Figure 8 A schematic diagram of a trend change of the reflected signal strength and depth in some embodiments of the present application; Fig. 9 A schematic diagram of a welding quality detection method according to some embodiments of the present application; Fig.10 A schematic diagram of the structure of a battery cell in some embodiments of the present application, provided with a first sub-seam and a second sub-seam with different melting depths; Fig.11 for Fig.10 Another schematic diagram of the trend of the reflected signal intensity and depth in the structure; Fig.12 Another schematic diagram of the change trend of the reflected signal intensity and depth of grooves with different groove depths is provided for some embodiments of the present application; Fig.13 A schematic diagram of a welding quality detection method according to some embodiments of the present application; Fig.14 A schematic diagram of a welding quality detection method according to some embodiments of the present application; Fig.15 A schematic diagram of a welding quality detection method according to some embodiments of the present application; Fig.16 This is a schematic diagram of the structure of the conductive connector and the battery cell in some embodiments of the present application; Fig.17 A schematic diagram of the distribution of reflected signal intensity at a preset depth position during ultrasonic detection in some embodiments of the present application.

[0033] Description of Figure Numbers: 1000. Vehicles; 100, battery device; 200, controller; 300, motor; 10. Box body; 11. Upper cover; 12. Box base; 20. Battery cells; 1. Main body; 2. Output pole; 21. Welding surface; 3. Groove; 4. Welding seam; 41. First sub-seam; 42. Second sub-seam; 5. Conductive connector; 6. Gap.

[0034] The realization of the purpose, functional features and advantages of this application will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0035] The following will be combined with the drawings in this embodiment to clearly and completely describe the technical solution in this embodiment. Obviously, the described embodiment is only a part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0036] It should be noted that all directional indications in this embodiment (such as up, down, left, right, front, back, etc.) are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0037] In addition, the descriptions of "first", "second", etc. in this application are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of this application, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0038] In this application, unless otherwise clearly specified and limited, the terms "connection", "fixation", etc. should be understood in a broad sense. For example, "fixation" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0039] In addition, the technical solutions between the various embodiments of the present application can be combined with each other, but it must be based on the fact that ordinary technicians in the field can implement it. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection required by this application. It should be understood that the specific embodiments described here are only used to explain this application and are not used to limit this application.

[0040] The descriptions of directions such as "up", "down", "front", "back", "left" and "right" in this application are based on the directions shown in the drawings and are only used to explain the relative positional relationship between the components in the postures shown in the drawings. If the specific posture changes, the directional indication will also change accordingly.

[0041] At present, from the perspective of market development, the application of power batteries is becoming more and more extensive. Power batteries are not only used in energy storage power systems such as hydropower, thermal power, wind power and solar power stations, but also widely used in electric vehicles such as electric bicycles, electric motorcycles, electric cars, as well as military equipment and aerospace and other fields. With the continuous expansion of the application field of power batteries, the market demand is also constantly expanding.

[0042] In the process of power battery manufacturing, laser is needed to weld the conductive connector and the pole together. The conductive connector generally refers to the tab, and welding forms a welded joint, that is, a weld. Failure of the welded joint may lead to insufficient local strength of the battery device, which may cause abnormal sampling signals and even the risk of overheating and fire. Therefore, it is necessary to control the welding quality between the conductive connector and the pole.

[0043] However, the industry's method of testing welding quality is random inspection, and the inspection efficiency is low. After careful research, the applicant found that for the quality inspection of laser welding joints, penetration detection is an extremely important indicator, and the relevant technology is carried out by metallographic testing of welding joints. Metallographic testing requires obtaining the inspection cross-section, and the bar and pole need to be cut off from the weld. It is a destructive inspection method, so it is impossible to conduct a full inspection, and the overall pass rate can only be estimated through random inspection. In addition, this method is time-consuming and labor-intensive, difficult to automate, and has low inspection efficiency.

[0044] To this end, the present application provides a battery cell, including a body and an output pole arranged on the body, the side of the output pole away from the body is a welding surface, a groove is arranged on the welding surface, the welding surface is used to weld with a conductive connector to form a weld, the groove intersects with the weld, and the groove is used to detect the penetration depth of the weld according to the difference in the intensity of the ultrasonic reflection signal after welding. The battery cell of the present application can realize a full inspection of the welding part of the output pole and the bar sheet, improve the control of the welding quality, and does not need to cut the weld and grind metallographic detection, and can also realize automatic detection with the assistance of automatic detection equipment, with high detection efficiency.

[0045] Please refer to Figure 1 , Figure 1A schematic diagram of the structure of a vehicle 1000 provided for some embodiments of the present application. The electrical equipment may be a vehicle 1000, and the vehicle 1000 may be a fuel vehicle, a gas vehicle or a new energy vehicle, and the new energy vehicle may be a pure electric vehicle, a hybrid vehicle or an extended-range vehicle, etc. A battery device 100 is provided inside the vehicle 1000, and the battery device 100 may be provided at the bottom, head or tail of the vehicle 1000. The battery device 100 may be used to power the vehicle 1000, for example, the battery device 100 may be used as an operating power source for the vehicle 1000. The vehicle 1000 may also include a controller 200 and a motor 300, and the controller 200 is used to control the battery device 100 to power the motor 300, for example, for the working power demand of the vehicle 1000 during starting, navigation and driving.

[0046] In some embodiments of the present application, the battery device 100 can not only serve as an operating power source for the vehicle 1000, but also serve as a driving power source for the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000.

[0047] Please refer to Figure 2 , Figure 2 Schematic diagram of the exploded structure of the battery device 100 provided in some embodiments of the present application. The battery device 100 includes a box body 10 and a battery cell 20, and the battery cell 20 is contained in the box body 10. Among them, the box body 10 is used to provide a storage space for the battery cell 20, and the box body 10 can adopt a variety of structures. In some embodiments, the box body 10 may include an upper cover 11 and a box base 12, and the upper cover 11 and the box base 12 cover each other, and the upper cover 11 and the box base 12 jointly define a storage space for accommodating the battery cell 20. The box base 12 can be a hollow structure with one end open, and the upper cover 11 can be a plate-like structure. The upper cover 11 covers the open side of the box base 12, so that the upper cover 11 and the box base 12 jointly define a storage space; the upper cover 11 and the box base 12 can also be hollow structures with one side open, and the open side of the upper cover 11 covers the open side of the box base 12. Of course, the box body 10 formed by the upper cover 11 and the box base 12 can be in various shapes, such as a cylinder, a cuboid, etc.

[0048] The battery device 100 mentioned in the embodiment of the present application may include one or more battery cell assemblies for providing voltage and capacity. The battery cell assembly may include a plurality of battery cells 20, and the plurality of battery cells 20 are connected in series, in parallel or in mixed connection through a busbar.

[0049] In some embodiments, a battery cell assembly is generally formed by arranging a plurality of battery cells 20 .

[0050] As an example, the battery cell assembly may be a battery module, which is formed by arranging and fixing a plurality of battery cells 20 to form an independent module. As an example, the battery module may be formed by bundling a plurality of battery cells 20 by a cable tie.

[0051] In some embodiments, the battery device 100 may be a battery pack, which includes a case 10 and one or more battery cell assemblies, wherein the battery cell assemblies are accommodated in the case 10 .

[0052] As an example, the battery cell assembly may be a battery module, and the battery cell assembly may be accommodated in the box body 10 by fixing the battery module in the box body 10 .

[0053] As an example, the battery cell assembly may also be accommodated in the case 10 by directly fixing the plurality of battery cells 20 to the case 10 .

[0054] In the battery device 100, there may be multiple battery cells 20, and the multiple battery cells 20 may be connected in series, in parallel, or in a mixed connection. A mixed connection means that the multiple battery cells 20 are both connected in series and in parallel. The multiple battery cells 20 may be directly connected in series, in parallel, or in a mixed connection, and then the whole formed by the multiple battery cells 20 is accommodated in the box 10; of course, the battery device 100 may also be a battery module formed by connecting multiple battery cells 20 in series, in parallel, or in a mixed connection, and then the multiple battery modules are connected in series, in parallel, or in a mixed connection to form a whole, and accommodated in the box 10. The battery device 100 may also include other structures, for example, the battery device 100 may also include a busbar component for realizing electrical connection between the multiple battery cells 20.

[0055] Each battery cell 20 may be a secondary battery or a primary battery, or a lithium-sulfur battery, a sodium-ion battery, or a magnesium-ion battery, but is not limited thereto. The battery cell 20 may be cylindrical, flat, rectangular, or in other shapes.

[0056] Reference Figure 3-Figure 6 According to some embodiments of the present application, the present application provides a battery cell 20, including a main body 1 and an output pole 2 arranged on the main body 1, the side of the output pole 2 away from the main body 1 is a welding surface 21, a groove 3 is arranged on the welding surface 21, the welding surface 21 is used to weld with a conductive connector 5 to form a weld 4, the groove 3 intersects with the weld 4, so that ultrasonic waves are emitted toward the intersection of the weld 4 and the groove 3, and the reflected signal strength of the ultrasonic waves at the target position at different depths is detected, and the penetration depth of the weld 4 is obtained according to the reflected signal strength.

[0057] It should be noted that the above-mentioned depth is: the distance from the upper surface of the conductive connector 5 to the target position in the thickness direction of the conductive connector 5, and the upper surface is the side of the conductive connector 5 away from the output pole. The battery cell 20 includes a shell, the shell is formed with a mounting cavity, the mounting cavity is used to accommodate the bare battery cell, the shell is formed with an opening connected to the mounting cavity, and the cover plate is arranged at the opening to close the mounting cavity. The body 1 here refers to the structure such as the shell, the cover plate and the bare battery cell. The output pole 2 of the battery cell 20 is set to extend out of the cover plate for a distance. The output pole 2 is also called a pole. Generally, a battery cell 20 has two output poles 2, which are the positive output pole and the negative output pole, which are what we often call the positive pole and the negative pole. The output pole 2 is used to connect with the conductive connector 5, and the conductive connector 5 can be a bar sheet. The battery device 100 also includes a sampling part, which can be a circuit board. The electrical signal of the output pole 2 is transmitted to the sampling part through the conductive connector 5, and finally transmitted to the battery management module to monitor the parameters of the battery cell 20, and the parameters include but are not limited to the temperature, current and voltage of the battery cell 20. At present, the connection between the output pole 2 and the conductive connector 5 is generally welded. Specifically, the top surface of the output pole 2 is welded to the conductive connector 5. The top surface refers to the side of the pole away from the body 1, that is, the welding surface 21 mentioned in this application. The actual welding is performed from the side of the conductive connector 5 away from the output pole 2. The output pole 2 and the conductive connector 5 will form a weld 4 through laser welding. The welding quality is generally reflected by the detection of the weld 4. Here, the welding quality index includes at least the penetration depth of the weld 4. Before welding, there will be a gap 6 between the conductive connector 5 and the output pole 2. In the related art, the penetration depth refers to the length of the weld 4 penetrating the conductive connector 5 and extending into the gap 6. In the above embodiment of the present application, a groove 3 is provided on the welding surface 21. The groove 3 is a concave groove provided on the welding surface 21. The intersection of the groove 3 and the weld 4 refers to the part where the groove 3 and the weld 4 are combined with each other. For example, it can be that the weld 4 extends into the groove body of the groove 3, and the two are combined with each other. Of course, when the penetration of the weld 4 is small, the projection of the weld 4 on the welding surface 21 may intersect the groove 3. The depth of the groove 3 is called the groove depth. When testing, the position of the ultrasonic transmitter can be adjusted to emit the ultrasonic wave toward the intersection of the weld 4 and the groove 3; then the reflected signal strength of the ultrasonic wave at the target position at different depths is detected, and the penetration of the weld 4 is obtained according to the reflected signal strength.

[0058] According to the principle of ultrasonic nondestructive testing, ultrasonic waves attenuate in media of different densities, and the reflected signal strength varies. Specifically, if the density difference is large, such as the detection location is at the solid-gas interface or the gas-solid interface, the reflected signal strength of the ultrasonic wave at such an interface is large, which is a strong reflected signal. If the density difference is small, such as the solid-solid interface, the density difference is small, and the reflected signal strength of the ultrasonic wave at this depth is weak, which is a weak reflected signal.

[0059] Specifically, in the technical solution of this application, refer to Figure 8 and Fig. 9 , the conductive connector 5 can be a bar sheet, and the ultrasonic detection position gradually penetrates downward from the upper surface of the bar sheet. The origin with a depth of 0 refers to the upper surface position of the bar sheet. When the depth is inside the bar sheet, the density is basically the same and there is no obvious change. Therefore, the reflection signal intensity is small, which is a weak reflection signal. If the detection position is the intersection of the weld 4 and the groove 3, when there is a weld 4 on the lower surface of the bar sheet, the reflection signal intensity of the ultrasonic wave is small at the depth of the intersection interface of the weld 4 and the bar sheet and the reflection signal intensity inside the weld 4, which is a weak reflection signal. When the weld 4 has a small penetration depth, the depth of the groove 3 is not filled by the welding molten pool, and there will be a solid-gas interface at the top position where the weld 4 extends into the groove 3. The reflection signal intensity here is large, which is a strong reflection signal. As for the groove depth and position of the groove 3, they can be known in advance, so the penetration depth of the weld 4 can be determined. If the penetration depth is defined as: starting from the upper surface of the conductive connector 5, the length of the top of the weld 4 in the vertical direction, the strong reflection signal appears at point C, and the reflection signal strength at this time is as follows: Figure 8 The vertical coordinate corresponding to point C is shown in the figure. The melting depth is as follows: Figure 8 As shown at point C1, C1 is the horizontal coordinate value corresponding to C, and C1 is the depth value corresponding to the strong reflection signal, that is, the penetration depth. The specific detection method can refer to the welding quality detection method described later.

[0060] In the above-mentioned embodiment of the present application, by setting a groove 3 on the welding surface 21 of the output pole 2, the weld 4 intersects with the groove 3, and the ultrasonic wave can be emitted toward the intersection of the weld 4 and the groove 3 to detect the reflection signal intensity of the ultrasonic wave at the target position at different depths. The different reflection signal intensities of the ultrasonic wave in media of different densities are utilized to obtain the penetration depth of the weld 4 according to the reflection signal intensity, thereby realizing non-destructive detection of the weld 4. This is a non-destructive detection method, which can realize a full inspection of the welding part of the output pole 2 and the bar sheet, improve the control over the welding quality, and does not require cutting of the weld 4 and metallographic phase detection. With the assistance of automatic detection equipment, automatic detection can also be realized, and the detection efficiency is high.

[0061] In some embodiments, the number of the groove 3 is one, and both ends of the groove 3 extend to the outer edge of the welding surface 21 respectively.

[0062] The number of grooves 3 can be one, and the two ends of the groove 3 extend to the outer edge of the welding surface 21 respectively, and the outer edge refers to the edge position of the outer side. The weld 4 formed after laser welding is generally annular. The groove 3 can be a straight groove, a curved groove or any other shape. The two ends of the groove 3 are extended to the edge of the welding surface 21 respectively to ensure that the groove 3 can intersect with the weld 4, which is convenient for the subsequent detection of the penetration depth of the weld 4 with the help of the groove 3.

[0063] By extending both ends of the groove 3 to the outer edge of the welding surface 21 respectively, it is ensured that the weld 4 and the groove 3 can intersect, which is convenient for subsequent penetration detection.

[0064] To show the structure of the groove 3, please refer to Figure 5 , Figure 5 for Figure 4 Schematic diagram of the structure without welding the conductive connector 5 on the middle output pole 2. In some embodiments, there are multiple grooves 3, each groove 3 intersects with the weld 4, and both ends of each groove 3 extend to the outer edge of the welding surface 21 respectively.

[0065] If the weld penetration is large, the depth of groove 3 is completely filled with the weld molten pool, and the ultrasonic wave will not strongly reflect the signal until the bottom of groove 3 is detected. Therefore, it can be determined that the weld penetration has at least reached the bottom of groove 3. Filling the bottom of groove 3 means at least filling the gap 6 between welding surface 21 and the bar. Therefore, it can also be determined that the welding quality is good. However, this can only perform a qualitative detection on the value of the penetration, but cannot quantitatively obtain the specific value of the penetration. For some scenarios where quantitative penetration data needs to be obtained, multiple grooves 3 can be set on the welding surface 21, and the groove depths of the multiple grooves 3 are different, which can also be said to be set in a gradient.

[0066] The depth of each groove 3 can be obtained in advance, either by recording it when the groove 3 is made, or by testing it before welding. The specific detection method is to adjust the position of the ultrasonic transmitter so that the ultrasonic wave is emitted toward the intersection of the weld 4 and the groove 3 with the smallest groove depth, and then detect the penetration depth of the target position at different depths. If a strong reflection signal appears after the depth reaches the output pole 2, the penetration depth of the weld 4 can be obtained by recording the depth corresponding to the strong reflection signal. If there is still no strong reflection signal when the depth reaches the bottom of the groove 3, it means that the welding molten pool has filled the groove 3. It can be confirmed that the penetration depth must be greater than or equal to the depth of the groove 3, but the specific value of the penetration depth cannot be quantitatively confirmed.

[0067] Therefore, the ultrasonic transmitter can be moved to the groove 3 with the second smallest groove depth, and the ultrasonic wave can be emitted at the intersection of the groove 3 and the weld 4. If a strong reflection signal appears after the depth exceeds the output pole 2, it means that the weld 4 has extended into the groove 3 and has not completely filled the groove 3. Therefore, the quantitative value of the penetration depth can be determined according to the depth of the strong reflection signal. Of course, if there is still no strong reflection signal, the next groove 3 with a larger groove depth can be selected for detection.

[0068] By setting a plurality of grooves 3 of different depths and adjusting the position of the ultrasonic transmitter, the ultrasonic wave is emitted in sequence toward the intersections of the weld 4 and the plurality of grooves 3 in a preset emission order. This can be used to quantitatively detect the penetration depth of the weld 4 and can detect welds 4 of different penetration depths, thereby improving the scope of application of the welding quality detection method.

[0069] In some embodiments, the depth of each groove 3 is set in a gradient.

[0070] Theoretically, as long as the groove depths of multiple grooves 3 are not completely the same, the effect of quantitative detection of the grooves 3 can be improved. However, in order to expand the detection range of the penetration depth of the weld 4, the depths of the grooves 3 are set to be different and in a gradient.

[0071] By setting the groove depth of each groove 3 to be gradient, the detection range of the penetration depth of the weld 4 can be expanded.

[0072] In some embodiments, the welding surface 21 is a circular surface, and the shape of the weld 4 is a circular ring; or, The welding surface 21 is a rectangular surface, and the shape of the weld 4 is a rectangle.

[0073] It should be noted that the shape of the welding surface 21 is not specifically limited in the present application, and can be a circular surface, a rectangular surface or other shapes, and can be a regular shape or an irregular shape. Correspondingly, the shape of the weld 4 is not specifically limited, as long as the weld 4 can intersect with the groove 3. In a specific embodiment, when the welding surface 21 is a circular surface or a rectangular surface, each groove 3 passes through the center point of the welding surface 21, and the weld 4 is correspondingly annular or rectangular, so that the groove 3 and the weld 4 can intersect conveniently.

[0074] By setting the welding surface 21 and the weld 4 to have matching shapes, the weld 4 and the groove 3 can be easily intersected, which facilitates the detection of the penetration depth.

[0075] In the above-mentioned embodiment of the present application, the battery cell 20 includes a main body 1 and an output pole 2 arranged on the main body 1, and the side of the output pole 2 away from the main body 1 is a welding surface 21, and a groove 3 is arranged on the welding surface 21. The welding surface 21 is used to weld with the conductive connector 5 to form a weld 4, wherein the number of the grooves 3 is one or more. When the number of the grooves 3 is multiple, the groove depth of each groove 3 is set in a gradient, and the two ends of the groove 3 extend to the outer edge of the welding surface 21 respectively, and the groove 3 intersects with the weld 4. The groove 3 is used to detect the penetration depth of the weld 4 according to the difference in the intensity of the reflected signal of the ultrasonic wave after welding. By setting a groove 3 on the welding surface 21 of the output pole 2, the weld 4 intersects with the groove 3. The ultrasonic wave can be emitted toward the intersection of the weld 4 and the groove 3 to detect the reflected signal intensity of the ultrasonic wave at the target position at different depths. The different reflected signal intensities of the ultrasonic wave in media of different densities are utilized to obtain the penetration depth of the weld 4 according to the reflected signal intensity, thereby realizing non-destructive detection of the weld 4. This is a non-destructive detection method, which can realize a full inspection of the welding part of the output pole 2 and the bar, improve the control over the welding quality, and does not require cutting of the weld 4 and metallographic phase detection. With the assistance of automatic detection equipment, automatic detection can also be realized with high detection efficiency.

[0076] Reference Figure 7According to some embodiments of the present application, the present application provides a welding quality detection method, which is applied to detect the weld 4 between the output pole 2 and the conductive connector 5 of the above-mentioned battery cell 20. Specifically, the output pole 2 is provided with a welding surface 21 on the side of the output pole 2 away from the body 1, and the welding surface 21 is provided with a groove 3. The welding surface 21 is used to weld with the conductive connector 5 to form a weld 4. The groove 3 intersects with the weld 4, so that the ultrasonic wave is emitted toward the intersection of the weld 4 and the groove 3, and the reflected signal intensity of the ultrasonic wave at the target position at different depths is detected, and the penetration depth of the weld 4 is obtained according to the reflected signal intensity. The output pole 2 is used to connect with the conductive connector 5, and the conductive connector 5 can be a bar sheet. The battery device 100 also includes a sampling component, which can be a circuit board. The electrical signal of the output pole 2 is transmitted to the sampling component through the bar sheet, and finally transmitted to the battery management module, and the parameters of the battery cell 20 are detected, and the parameters include but are not limited to the temperature, current and other information of the battery cell 20. At present, the connection between the output pole 2 and the conductive connector 5 is generally made by welding. Specifically, the top surface of the output pole 2 is welded to the conductive connector 5. The top surface refers to the side of the output pole 2 away from the body 1, that is, the welding surface 21 mentioned in the text. The actual welding is performed from the side of the conductive connector 5 away from the output pole 2. The output pole 2 and the conductive connector 5 will form a weld 4 through laser welding. The welding quality is generally reflected by the detection of the weld 4. Here, the welding quality index at least includes the penetration depth of the weld 4. Before welding, there will be a gap 6 between the conductive connector 5 and the output pole 2. In the related art, the penetration depth refers to the length of the weld 4 penetrating the conductive connector 5 and extending into the gap 6. In the above embodiment of the present application, a groove 3 is provided on the welding surface 21, and the groove 3 is a concave groove provided on the welding surface 21, and the weld 4 may extend into the groove 3. The penetration depth in the present application refers to the length of the weld 4 penetrating the conductive connector 5 and extending into the gap 6 or the groove 3. The intersection of the groove 3 and the weld 4 refers to the part where the groove 3 and the weld 4 are combined with each other, for example, the weld 4 may extend into the groove body of the groove 3, and the two may be combined with each other. Of course, when the penetration depth of the weld 4 is small, it may also be that the projection of the weld 4 on the welding surface 21 has an intersection with the groove 3.

[0077] Specifically, the welding quality detection method includes: S100, adjusting the position of the ultrasonic transmitter head so that the ultrasonic wave is emitted toward the intersection of the weld 4 and the groove 3.

[0078] The ultrasonic transmitter is used to emit ultrasonic waves to weld the conductive connector 5 and the welding surface 21 to form a weld 4. The groove 3 is pre-set on the output pole 2, that is, it is made when the battery cell 20 is made. Before welding the conductive connector 5 and the output pole 2, the position information of the groove 3 will be obtained first. After the welding is completed, the contour information of the weld 4 can be obtained. The position where the weld 4 and the groove 3 intersect can be determined by the position information of the groove 3 and the outer contour of the weld 4. The ultrasonic transmitter is aligned with the intersection of the weld 4 and the groove 3, so that the ultrasonic detection position is in the area where the weld 4 and the groove 3 intersect.

[0079] S200, detecting the reflected signal intensity of the ultrasonic wave at the target position at different depths; The depth is: the distance from the upper surface of the conductive connecting member 5 to the target position in the thickness direction of the conductive connecting member 5, and the upper surface is the side of the conductive connecting member 5 away from the output pole 2; Specifically, the ultrasonic reflection signal strength at different depths can be detected starting from the upper surface of the conductive connector 5 and gradually going downwards. The upper surface refers to the side facing the ultrasonic transmitter, and is also the side of the conductive connector 5 away from the output pole 2. Starting from the upper surface of the conductive connector 5 at a depth position, the depth is recorded as 0 at this time, and the ultrasonic reflection signal strength at different depths is gradually detected downwards along the vertical direction, thereby obtaining the reflection signal strength at each depth, and the reflection signal strength-depth trend change diagram can be automatically obtained by a computer.

[0080] S300, obtaining the penetration depth of the weld 4 according to the intensity of the reflected signal.

[0081] There are many definitions of penetration in the related art. It can be the length from the upper surface of the conductive connector 5 to the top of the weld 4 in the vertical direction, or it can be the length from the lower surface of the conductive connector 5 to the top of the weld 4 in the vertical direction. The top of the weld 4 here refers to the end of the weld 4 away from the upper surface of the conductive connector 5. The difference between these two definitions is the thickness value of a conductive connector 5, and there is no substantial difference. The definition of penetration used in this application is: the length from the upper surface of the conductive connector 5 to the top of the weld 4 in the vertical direction.

[0082] The principle of ultrasonic nondestructive testing is used here. Ultrasonic waves attenuate in media of different densities, and the reflected signal strength varies. Specifically, if the density difference is large, such as the detection location is at the solid-gas interface or the gas-solid interface, the reflected signal strength of the ultrasonic wave at such an interface is large, which is a strong reflected signal. If the density difference is small, such as the solid-solid interface, the density difference is small, and the reflected signal strength of the ultrasonic wave at this depth is weak, which is a weak reflected signal.

[0083] Specifically, in the technical solution of this application, refer to Figure 8 and Fig. 9 , the conductive connector 5 can be a bar sheet, and the ultrasonic detection position gradually penetrates downward from the upper surface of the bar sheet. When the depth is inside the bar sheet, the seal is basically the same without obvious changes, so the reflection signal intensity is small, which is a weak reflection signal. If the detection position is the intersection of the weld 4 and the groove 3, when there is a weld 4 on the lower surface of the bar sheet, the ultrasonic reflection signal intensity is small at the depth of the interface of the intersection of the weld 4 and the bar sheet and the reflection signal intensity inside the weld 4, which is a weak reflection signal. When the weld 4 has a small penetration depth, the groove 3 is not filled with the welding molten pool, and there will be a solid-gas interface at the top position where the weld 4 extends into the groove 3. The reflection signal intensity here is large, which is a strong reflection signal. As for the groove depth and position of the groove 3, they can be known in advance, and the penetration depth of the weld 4 can be determined. If the penetration depth is defined as: starting from the upper surface of the conductive connector 5, the length of the top of the weld 4 along the vertical direction, the area where the strong reflection signal appears is at point C, and the penetration depth is as follows Figure 8 As shown at point C1, C1 is the horizontal coordinate value corresponding to C, and C1 is the depth value corresponding to the strong reflection signal. The depth value can reflect the penetration depth of the weld 4.

[0084] Of course, if the welding penetration is large, the depth of groove 3 is completely filled with the welding molten pool, and the ultrasonic wave will not reflect a strong signal until the bottom of groove 3 is detected. Therefore, it can be judged that the welding penetration has at least reached the bottom of groove 3. Filling the bottom of groove 3 means at least filling the gap 6 between the welding surface 21 and the bar, which can also be judged that the welding quality is good.

[0085] In the above-mentioned embodiment of the present application, by emitting ultrasound toward the intersection of the weld 4 and the groove 3, detecting the reflected signal intensity of the ultrasound at the target position at different depths, utilizing the different reflected signal intensity of ultrasound in different density media, and obtaining the penetration depth of the weld 4 according to the reflected signal intensity, non-destructive testing of the weld 4 can be achieved. This is a non-destructive testing method, which can achieve full inspection of the welding part of the output pole 2 and the bar, improve the control over the welding quality, and does not require cutting of the weld 4 and grinding phase testing. With the assistance of automatic testing equipment, automatic testing can be achieved, and the detection efficiency is high.

[0086] Reference Fig. 9 In some embodiments, there are multiple grooves 3, and the groove depths of the multiple grooves 3 are set in a gradient manner; the step S100 includes: S101, adjusting the position of the ultrasonic transmitter so that the ultrasonic wave is sequentially emitted toward the intersections of the weld 4 and the plurality of grooves 3 in a preset emission sequence; the preset emission sequence is: the sequence in which the groove depth values ​​of the plurality of grooves 3 are arranged from small to large.

[0087] As mentioned above, when the welding depth is small, Fig.10 The second sub-slit 42 does not fill the groove 3 of the output pole 2, and the melting depth can be obtained by a single test, such as Fig.11 A strong reflection signal appears at point D, and the corresponding horizontal coordinate D1 is the penetration depth of the second sub-seam 42. However, when the penetration depth of the weld 4 is large, the depth of the groove 3 is completely filled with the weld pool, such as Fig.10 The first sub-slit 41 extends into the groove 3 of the output pole 2 to fill the weld pool. The ultrasonic wave will not reflect a strong signal until the bottom of the groove 3 is detected. It can also be determined that the welding penetration has at least reached the bottom of the groove 3, that is, it can be known that the penetration must be greater than a value, but the depth value of the penetration cannot be quantitatively obtained. Therefore, for some scenarios where quantitative penetration data needs to be obtained, multiple grooves 3 can be set on the welding surface 21, and the groove depths of the multiple grooves 3 are different, which can also be said to be set in a gradient.

[0088] The depth of each groove 3 can be obtained in advance, either by recording it when the groove 3 is made, or by testing it before welding. The specific detection method is to adjust the position of the ultrasonic transmitter so that the ultrasonic wave is emitted toward the intersection of the weld 4 and the groove 3 with the smallest groove depth, and then detect the penetration depth of the target position at different depths. If a strong reflection signal appears after the depth reaches the output pole 2, the penetration depth of the weld 4 can be obtained by recording the depth corresponding to the strong reflection signal. If no strong reflection signal appears when the depth reaches the bottom of the groove 3, it means that the welding molten pool has filled the groove 3. It can be confirmed that the penetration depth must be greater than the depth of the groove 3, but the specific value of the penetration depth cannot be confirmed. Fig.12 As shown at point F, it means that the groove 3 with a depth of F1 in the figure is filled, but there is no strong reflection signal, which means that the weld 4 has filled the molten pool. The molten depth of the weld 4 cannot be quantitatively detected by the groove 3 with a depth of F1 alone.

[0089] Therefore, the ultrasonic transmitter can be moved to the groove 3 with the second smallest groove depth, and the ultrasonic wave can be emitted at the intersection of the groove 3 and the weld 4. If a strong reflection signal appears after the depth exceeds the output pole 2, it means that the weld 4 has extended into the groove 3 and has not completely filled the groove 3. Therefore, the quantitative value of the penetration depth can be confirmed according to the depth of the strong reflection signal, such as Fig.12 As shown at point E, the coordinate value of point E1 indicates the melting depth, and E1 is the horizontal coordinate value of point E. Of course, if there is still no strong reflection signal, the next groove 3 with a larger groove depth is selected for detection.

[0090] It should also be noted that, although the embodiment defines the preset emission order as the order in which the groove depth values ​​of the multiple grooves 3 are arranged from small to large, in the actual detection process, the detection may not be performed in the order of the groove depth values ​​of the grooves 3. If the approximate range of the penetration depth of the weld 4 can be estimated, the groove 3 close to the penetration depth range can be started for detection, further improving the detection efficiency. In addition, the depths of some of the multiple grooves 3 can also be set to be the same, which is used to detect the penetration depths of the weld 4 at different cross-sectional positions at the same depth.

[0091] By setting a plurality of grooves 3 of different depths and adjusting the position of the ultrasonic transmitter, the ultrasonic wave can be emitted in sequence toward the intersections of the weld 4 and the plurality of grooves 3 in a preset emission order. This can be used to quantitatively detect the penetration depth of the weld 4 and can detect welds 4 of different penetration depths, thereby improving the scope of application of the weld 4 quality detection method.

[0092] Reference Fig.13 In some embodiments, the step of S200 further includes: S210, obtaining the reflected signal strength of the ultrasonic wave at different depths in order from small to large depth values.

[0093] The depth value here refers to the depth of the position where the ultrasonic reflection signal intensity is detected, that is, the vertical distance from the upper surface of the conductive connector 5 to the target position. The greater the depth, the farther the distance from the upper surface of the conductive connector 5. The ultrasonic reflection signal intensity is obtained in order from small to large depth values. This is convenient for operation and data recording, and a trend graph of the reflection signal intensity changing with depth is obtained.

[0094] By setting the depth values ​​in ascending order to obtain the reflected signal strength of the ultrasonic wave at different depths, it is convenient to operate and also convenient to obtain the trend change graph of the reflected signal strength change.

[0095] Reference Fig.14 In some embodiments, the step of S200 includes: S201, if the reflected signal strength is greater than or equal to a preset threshold, it is defined as a strong reflected signal; If the reflected signal strength is less than the preset threshold, it is defined as a weak reflected signal; The specific preset threshold here can be a certain value of ultrasonic reflection intensity, which can be obtained according to the initial ultrasonic intensity emitted by the transmitter, and can be set by technicians in this field according to actual needs. For example, it can be defined that a strong reflection signal is 5% or more of the initial ultrasonic intensity, and a weak reflection signal is less than 5% of the initial ultrasonic intensity. If the reflection signal is shown as a horizontal straight line in the reflection signal intensity-depth trend change diagram.

[0096] The steps of S300 include: S301, when the reflection signal strength changes from a weak reflection signal to a strong reflection signal, the depth value at this time is recorded, and the depth value is the penetration depth of the weld 4.

[0097] When the reflected signal intensity is less than 5% of the initial ultrasonic intensity, a horizontal line is shown in the reflected signal intensity-depth trend change diagram. When the transmitted signal intensity is a strong reflected signal, a leap will appear, forming a peak point. The vertical line corresponding to this peak point is the depth value corresponding to the solid-gas interface. The depth value can be used to obtain the weld depth. Fig.11 Point D and Fig.12 Point E in .

[0098] By defining the numerical ranges of strong reflection signals and weak reflection signals, the penetration depth of the weld 4 can be directly read from the reflection signal intensity-depth trend diagram, which is very convenient to operate.

[0099] Reference Fig.15 In some embodiments, the welding quality detection method further includes: S400, detecting the reflected signal strength of the ultrasonic wave in each area at a preset depth position; wherein the preset depth position is the depth position where the lower surface of the conductive connecting member 5 is located.

[0100] Combined with reference Fig.16 and Fig.17 , Fig.16 R indicates that there is a weak reflection signal in this area, indicating that there is a weld at this location, and Q indicates that there is a strong reflection signal in this area. Specifically for this solution, before welding, there is a certain gap 6 between the bar plate and the output pole 2. If the weld 4 can penetrate the bar plate and the pole, then the interface between the bar plate and the pole is a solid-solid interface, and the density difference is small. The reflection signal intensity of the ultrasonic wave at this depth is weak, which is a weak reflection signal, indicating that there is a weld 4 here. However, if the detection position is at the solid-gas interface or the gas-solid interface, the density difference is large, and the reflection signal intensity of the ultrasonic wave at such an interface is large, which is a strong reflection signal, proving that there is no weld 4 here.

[0101] S500, obtaining the outer contour of the weld 4 at a preset depth position according to the reflection signal strength.

[0102] By statistically combining the weak reflection signals and the strong reflection signals in each area, the outer contour of the weld 4 at a preset depth can be obtained based on the statistical information of the weak reflection signal area.

[0103] S600, obtaining the weld width of the weld 4 according to the outer contour.

[0104] By using the algorithm to count the outer contour, the welding area can be obtained, and the weld width data can be obtained based on the welding area. For example, the weld width of weld 4 can be obtained by dividing the welding area by the length of weld 4. If weld 4 is generally an annular weld, the length of weld 4 is the circumference of the annular weld, and specifically, the central circumference of the annular weld can be taken.

[0105] In addition, it should be noted that the weld width detection of the weld 4 can be performed before or after the weld depth detection. This application does not make any specific limitation to this, and those skilled in the art can set it according to actual needs.

[0106] By detecting the reflected signal intensity of the ultrasonic wave in each area at the preset depth position, the outer contour of the weld 4 at the preset depth position is obtained according to the reflected signal intensity, and the melt width of the weld 4 is obtained according to the outer contour. The melt width data of the weld 4 can be obtained through non-destructive testing.

[0107] According to some embodiments of the present application, the present application provides a welding quality detection method, which is applied to detect the weld 4 between the output pole 2 of the above-mentioned battery cell 20 and the conductive connector 5. The welding quality detection method includes: adjusting the position of the ultrasonic transmitter so that the ultrasonic wave is sequentially emitted toward each intersection of the weld 4 and the plurality of grooves 3 in a preset emission order; the preset emission order is: the order of the groove depth values ​​of the plurality of grooves 3 from small to large; sequentially obtaining the reflected signal strength of the ultrasonic wave at different depths in the order of the depth value from small to large, if the reflected signal strength is greater than or equal to the preset threshold, it is defined as a strong reflected signal; if the reflected signal strength is less than the preset threshold, it is defined as a weak reflected signal; when the reflected signal strength changes from a weak reflected signal to a strong reflected signal, the depth value at this time is recorded, and the depth value is the penetration depth of the weld 4. The welding quality detection method also includes: detecting the reflected signal strength of the ultrasonic wave in each area at the preset depth position; obtaining the outer contour of the weld 4 at the preset depth position according to the reflected signal strength; obtaining the molten width of the weld 4 according to the outer contour; wherein the preset depth position is the depth position where the lower surface of the conductive connector 5 is located. Through the above detection method, the penetration depth and width information of the weld 4 can be non-destructively detected, and full inspection can be achieved and the detection efficiency can be improved.

[0108] According to some embodiments of the present application, the present application provides a battery device 100, including a box body 10, multiple battery cells 20, a conductive connector 5, a sampling piece and a battery management module, the box body 10 is provided with a accommodating cavity, the battery cell 20 is the above-mentioned battery cell 20, the conductive connector 5 is welded to the welding surface 21 of the battery cell 20 to form a weld 4, and the sampling piece is electrically connected to the conductive connector 5 and the battery management module.

[0109] As mentioned above, the conductive connecting member 5 can be a bar sheet, the battery cell 20 is provided with an output pole 2, and the sampling member can be a circuit board. The bar sheet electrically connects the output pole 2 and the circuit board. The electrical signal of the battery cell 20 obtained from the output pole 2 is transmitted to the battery management module through the circuit board to realize the monitoring of the battery cell 20.

[0110] The output pole 2 and the sampling piece are electrically connected through the conductive connector 5, and the electrical signal is transmitted to the battery management module through the sampling piece to realize the monitoring of the battery cell 20 signal. At the same time, the battery cell 20 used can perform ultrasonic non-destructive testing to efficiently detect the penetration depth and width of the weld 4.

[0111] In some embodiments, the weld 4 is in the shape of a ring, and the weld 4 intersects with the groove 3 at multiple locations. The weld 4 is ring-shaped and may intersect with a groove 3 at multiple locations. For example, if the groove 3 is a straight line, there may be two intersections. When there are multiple grooves 3, there are more intersections, and the ultrasonic reflection signal strength is detected at the intersection, which can increase the number of detection positions and improve the convenience of detection.

[0112] By setting the weld 4 as an annular weld and intersecting the groove 3 at multiple locations, the convenience of detection can be improved.

[0113] According to some embodiments of the present application, the present application provides an electric device, which includes an equipment body and the above-mentioned battery device 100, and the battery device 100 is arranged in the equipment body. The above-mentioned electric device can be a vehicle 1000. Since the electric device includes any technical solution of all the above-mentioned embodiments, it has at least all the beneficial effects brought by any of the above-mentioned technical solutions, which will not be repeated here one by one.

[0114] The above description is only an optional embodiment of the present application, and does not limit the patent scope of the present application. All equivalent structural changes made by using the contents of the present application specification and drawings under the application concept of the present application, or directly / indirectly applied in other related technical fields are included in the patent protection scope of the present application.

Claims

1. A battery cell, characterized in that: The invention comprises a main body and an output electrode arranged on the main body, wherein a side of the output electrode away from the main body is a welding surface, a groove is arranged on the welding surface, the welding surface is used for welding with a conductive connecting member to form a weld, the groove intersects with the weld, so that ultrasonic waves are emitted toward the intersection of the weld and the groove, and the reflected signal intensity of the ultrasonic waves at target positions at different depths is detected, and the penetration depth of the weld is obtained according to the reflected signal intensity.

2. The battery cell according to claim 1, characterized in that: The number of the groove is one, and both ends of the groove extend to the outer edge of the welding surface respectively.

3. The battery cell according to claim 1, characterized in that: There are multiple grooves, each of which intersects with the weld, and both ends of each groove extend to the outer edge of the welding surface respectively.

4. The battery cell according to claim 3, characterized in that: The groove depth of each groove is set in a gradient manner.

5. The battery cell according to any one of claims 1 to 4, characterized in that: The welding surface is a circular surface, and the shape of the weld is a circular ring; or, The welding surface is a rectangular surface, and the shape of the weld is a rectangle.

6. A welding quality detection method, applied to detect the weld between the output electrode and the conductive connector of the battery cell according to any one of claims 1 to 5, characterized in that: The welding quality detection method comprises: Adjust the position of the ultrasonic transmitter so that the ultrasonic wave is emitted toward the intersection of the weld and the groove; Detecting the reflected signal intensity of the ultrasonic wave at target positions at different depths; The depth is: the distance from the upper surface of the conductive connecting member to the target position in the thickness direction of the conductive connecting member, and the upper surface is the side of the conductive connecting member away from the output electrode; The penetration depth of the weld is obtained according to the intensity of the reflected signal.

7. The welding quality detection method according to claim 6, characterized in that: There are multiple grooves, and the depths of the multiple grooves are set in a gradient; the step of adjusting the position of the ultrasonic transmitter so that the ultrasonic wave is emitted toward the intersection of the weld and the groove comprises: Adjust the position of the ultrasonic transmitter so that the ultrasonic wave is transmitted in sequence toward the intersections of the weld and the plurality of grooves according to a preset transmission sequence; The preset emission sequence is: the sequence in which the groove depth values ​​of the plurality of grooves are arranged from small to large.

8. The welding quality detection method according to claim 7, characterized in that: The step of detecting the reflected signal strength of the ultrasonic wave at target positions at different depths comprises: The reflected signal strength of the ultrasonic wave at different depths is obtained in order from small to large depth values.

9. The welding quality detection method according to any one of claims 6 to 8, characterized in that: The step of detecting the reflected signal strength of the ultrasonic wave at target positions at different depths also includes: If the reflected signal strength is greater than or equal to the preset threshold, it is defined as a strong reflected signal; If the reflected signal strength is less than the preset threshold, it is defined as a weak reflected signal; The step of obtaining the penetration depth of the weld according to the reflected signal strength comprises: When the intensity of the reflection signal changes from a weak reflection signal to a strong reflection signal, the depth value at this time is recorded, and the depth value is the penetration depth of the weld.

10. The welding quality detection method according to claim 6, characterized in that: The welding quality detection method also includes: Detecting the reflected signal intensity of the ultrasonic wave in each area at a preset depth position; wherein the preset depth position is the depth position where the lower surface of the conductive connecting member is located; Determine the outer contour of the weld at a preset depth according to the intensity of the reflected signal; The weld width of the weld is obtained according to the outer contour.

11. A battery device, characterized in that: include: A box body, wherein the box body is provided with a containing cavity; A plurality of battery cells, wherein the battery cells are the battery cells according to any one of claims 1 to 5; A conductive connector, wherein the conductive connector is welded to a welding surface of an output electrode of the battery cell to form a weld; Sampling pieces; The sampling member is electrically connected to the battery management module.

12. The battery device according to claim 11, characterized in that: The weld is annular in shape, and the weld intersects with the groove at multiple locations.

13. An electrical equipment, characterized in that: The electrical equipment comprises an equipment body and the battery device according to claim 11 or 12, wherein the battery device is arranged on the equipment body.

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