Quality inspection device and method for soft package type secondary battery unit

Abstract

The present invention relates to an apparatus and a method for inspecting quality of a pouch-type secondary battery cell in which an AC signal generating unit generates an AC signal, a magnetic field generating mechanism generates a magnetic field on the basis of the generated AC signal, and the magnetic field generating mechanism generates a magnetic field on the basis of the magnetic field generated by the AC signal generating unit. The one or more induction current detection sensors detect signals of the induction current flowing through the pouch-type secondary battery cells, and the control / determination unit compares the detected signals of the induction current with values of a pre-stored determination range, and determines whether the detected signals of the induction current flow through the pouch-type secondary battery cells or not, and determines whether the detected signals of the induction current flow through the pouch-type secondary battery cells flow through the pouch-type secondary battery cells. And the quality of the soft package type secondary battery unit is judged.

Description

Technical Field

[0001] The present invention relates to a quality inspection device and method for a soft-pack type secondary battery unit, which are used to inspect the quality of a pole plate, a bent portion or a welded portion in the soft-pack type secondary battery unit. Background Art

[0002] As fossil fuels, which are widely used energy sources, are gradually becoming depleted, their prices continue to rise. In addition, fossil fuels emit a variety of pollutants such as soot, thereby polluting the environment. In particular, vehicles using fossil fuels emit a large amount of pollutants, which is one of the main factors that seriously pollute the environment. Therefore, there is an urgent need for countermeasures that can reduce the use of fossil fuels in vehicles.

[0003] Accordingly, the demand for environmentally friendly alternative energy that does not emit pollutants and can be widely used throughout the industry has become an indispensable factor.

[0004] A variety of environmentally friendly alternative energy sources are known that do not emit pollutants. As one of these environmentally friendly alternative energy sources, a secondary battery that can drive a power device by repeatedly charging and discharging is used.

[0005] The secondary battery can not only significantly reduce the use of fossil fuels, but also does not produce byproducts such as pollutants caused by the use of electricity. Therefore, it has attracted much attention as an environmentally friendly and energy-efficient new energy source.

[0006] Recently, secondary batteries are widely used in the entire industry, including portable devices such as smartphones, electric vehicles (EV), hybrid vehicles (HV), or drive devices that require large-capacity electric power, etc. In addition, the charging capacity of secondary batteries is also showing a trend of continuous increase.

[0007] As one of the above-mentioned secondary batteries, a pouch-type secondary battery is known, which is formed by combining a plurality of pouch-type secondary battery cells.

[0008] The soft-pack type secondary battery cell is formed by repeatedly stacking the anode plate and the cathode plate with a separation membrane interposed between them. In addition, the electrodes of the stacked anode plate and the electrodes of the cathode plate are respectively crimped, and the anode terminal and the cathode terminal are respectively welded to the crimped electrodes of the anode plate and the cathode plate. In addition, the stacked anode plate, the separation membrane, and the cathode plate are wrapped together with the electrolyte in a soft pack made of, for example, an aluminum film.

[0009] Such a pouch-type secondary battery cell is configured such that only an anode terminal and a cathode terminal are exposed outside the pouch.

[0010] The soft-pack type secondary battery cell can be manufactured with little internal deformation and no empty space. In addition, the soft-pack type secondary battery cell can be manufactured in a variety of shapes, so the design freedom is high, the weight is light, and the energy density is very high.

[0011] When manufacturing such a pouch type secondary battery cell, various defect factors may occur.

[0012] For example, during the process of laminating the anode plate and the cathode plate with a separator interposed therebetween, defects such as fine cracks or disconnections may occur on the anode plate and the cathode plate.

[0013] In addition, when the electrodes of the anode plates and the cathode plates are crimped, a bent portion is formed between the ends of the anode plates and the cathode plates and the electrodes, and defects such as fine cracks or disconnection may occur when the bent portion is bent.

[0014] Furthermore, in the process of welding the anode terminal and the cathode terminal to the crimped electrodes, a welding defect in which the electrodes are not welded to the anode terminal and the cathode terminal may occur.

[0015] These defects hinder the flow of current for charging and discharging the pouch-type secondary battery cell, thereby reducing the current flowing in the defective portion and relatively concentrating the current flow in the non-defective portion.

[0016] Therefore, a large amount of current may flow in the non-defective part, causing overheating. In addition, due to the higher resistance value, the defective part may overheat. Such overheating may cause safety accidents such as fire in the secondary battery.

[0017] Therefore, a highly reliable inspection device is required that can accurately inspect the entire part of the soft-pack type secondary battery cell, namely the anode plate and cathode plate, or the bent part of the electrode for defects such as cracks or broken wires after manufacturing the soft-pack type secondary battery cell, and whether the electrode has welding defects.

[0018] As a related art for inspecting the quality of a pouch-type secondary battery cell, Korean Patent No. 10-2023739 (granted on September 16, 2019) is known.

[0019] According to the above-mentioned prior art, it includes: a first sensor, which senses eddy current to a secondary battery cell; and a second sensor, which senses the eddy current signal sensed by the first sensor, and includes: an inspection unit, which performs inspection using eddy current during the operation of the secondary battery cell; a transfer unit, which sequentially transfers a plurality of secondary battery cells from an input point of the secondary battery cell to a removal point; and a control unit, which is electrically connected to the inspection unit, and receives, evaluates and controls the eddy current signal sensed by the inspection unit. The inspection unit is designed to be able to move the first sensor and the second sensor to a position to be inspected, and to perform inspection using eddy current when the first sensor and the second sensor are fixed, thereby being constructed to detect cracks inside a soft-pack type secondary battery cell using eddy current.

[0020] Such prior art can detect whether fine cracks or disconnections occur in the anode and cathode plates and electrodes of a soft-pack type secondary battery cell and their locations by using eddy current in a non-destructive method, and can detect whether there are defects in the welding of the welded parts.

[0021] Generally, when manufacturing soft-pack type secondary battery cells, the height, bending angle, width, etc. of the bending part are not constant, but appear in various forms. In addition, the position, direction, width, shape, etc. of the part where cracks or broken wires occur are not constant, but appear in various forms. In addition, due to the influence of electrolytes and welding parts, the manufactured soft-pack type secondary battery cells are not uniform, and there will be some differences between them.

[0022] The eddy current method is very sensitive to the measurement distance between the soft-pack type secondary battery cell and the sensor. That is, the characteristics of inspecting defects at the plate and the bent part of the soft-pack type secondary battery cell, welding defects at the welding part of the electrode, etc. will be different depending on the measurement distance.

[0023] Therefore, the above-mentioned prior art has limitations in precisely inspecting whether the pouch-type secondary battery cell has defects.

[0024] Furthermore, since eddy current is generated only at a local portion to inspect whether the pouch-type secondary battery cell has a defect, there is a limitation in inspecting the entire electrode, electrode, and weld portion of the pouch-type secondary battery cell.

[0025] Furthermore, when the pouch type secondary battery cell is deformed or there is a position error between the pouch type secondary battery cell and a sensor, it may be very difficult to detect whether the pouch type secondary battery cell is defective.

[0026] Therefore, the above-mentioned prior art has hardly been put into practical use.

[0027] [Prior art literature]

[0028] [Patent Document]

[0029] Korean Patent No. 10-2023739 (granted on September 16, 2019) Summary of the invention

[0030] 1. Technical issues to be resolved

[0031] One problem that the present invention aims to solve is to provide a quality inspection device and method for a soft-pack type secondary battery cell. By allowing an induced current to flow in the entire soft-pack type secondary battery cell and detecting the induced current at the plate or bent portion of the soft-pack type secondary battery cell, it is possible to accurately inspect whether the plate or bent portion has fine cracks or broken wires.

[0032] In addition, a problem that the present invention aims to solve is to provide a quality inspection device and method for a soft-pack type secondary battery cell. By allowing an induced current to flow in the entire soft-pack type secondary battery cell and detecting the induced current at the welding position of the electrode, it is possible to accurately inspect whether there are welding defects in the welding portion.

[0033] In addition, the problem that the present invention aims to solve is to provide a quality inspection device and method for a soft-pack type secondary battery cell, which can accurately detect the location of defects when defects such as fine cracks or broken wires appear in the plates or bent parts of the soft-pack type secondary battery cell.

[0034] Another object of the present invention is to provide a quality inspection device and method for a pouch-type secondary battery cell, which can accurately detect a position where a welding defect occurs in a welded portion of the pouch-type secondary battery cell.

[0035] Another object of the present invention is to provide a quality inspection device and method for a soft-pack type secondary battery cell, which can inspect the quality of the soft-pack type secondary battery cell without being affected by external factors such as dust or moisture or noise signals.

[0036] In addition, the problems that the present invention aims to solve are not limited to the problems described above, and a person skilled in the art to which the present invention belongs will be able to clearly understand other problems not described from the following description.

[0037] (II) Technical solution

[0038] According to the quality inspection device of the soft-pack type secondary battery cell of the present invention, it may include: an AC signal generating unit, which generates an AC signal; a magnetic field generating mechanism, which generates a magnetic field according to the AC signal to make an induced current flow in the soft-pack type secondary battery cell; one or more induced current detection sensors, which detect the signal of the induced current flowing in the soft-pack type secondary battery cell; and a control / judgment unit, which compares the signal of the induced current detected by the induced current detection sensor with the value of a pre-stored judgment range, and judges the quality of the soft-pack type secondary battery cell based on the comparison result.

[0039] In addition, the quality inspection device for the soft-pack type secondary battery cell of the present invention may further include: a power loss detection unit, which is used to detect the power loss of the AC signal generated by the AC signal generating unit, and the control / judgment unit uses the detection signal of the power loss detection unit to determine whether the one or more induced current detection sensors are located at the starting position for detecting the induced current from the soft-pack type secondary battery cell.

[0040] The magnetic field generating mechanism may include: a transformer, which transmits the AC current generated by the AC signal generating unit; a series resonance unit, which resonates in series with the low frequency of the AC current to cause the coil to generate a magnetic field; and a parallel resonance unit, which resonates in parallel with the high frequency of the AC current to cause the coil to generate a magnetic field.

[0041] In addition, the quality inspection device of the soft-pack type secondary battery cell of the present invention may also include: one or more signal processing units, which output the signal of the induced current detected by the induced current detection sensor to the control / judgment unit, the AC signal generating unit generates an AC signal with a low frequency and a high frequency, and the signal processing unit may include: a low-frequency detection filter, which detects the low-frequency AC current signal and outputs it to the control / judgment unit; and a high-frequency detection filter, which detects the high-frequency AC current signal and outputs it to the control / judgment unit.

[0042] Furthermore, in the quality inspection device for a soft-pack type secondary battery cell of the present invention, when the soft-pack type secondary battery cell is located at a starting position, the one or more induction current detection sensors move and scan the soft-pack type secondary battery cell to detect an induction current signal.

[0043] In addition, in the quality inspection device of the soft-pack secondary battery cell of the present invention, the soft-pack secondary battery cell and the one or more inductive current detection sensors can be fixed, and the soft-pack secondary battery cell moves so that it is scanned by the one or more inductive current detection sensors to detect the signal of the inductive current.

[0044] A shielding mechanism may be further included between the magnetic field generating mechanism and the induced current detection sensor, and is used to shield the magnetic field of the magnetic field generating mechanism.

[0045] In addition, the quality inspection method of the soft-pack type secondary battery cell of the present invention may include: a step in which an AC signal generating unit generates an AC signal, and a magnetic field generating mechanism generates a magnetic field based on the generated AC signal to cause an induced current to flow in the soft-pack type secondary battery cell; a step in which an induced current detection sensor detects a signal of the induced current flowing in the soft-pack type secondary battery cell; and a step in which a control / judgment unit compares the signal of the induced current detected by the induced current detection sensor with a value within a judgment reference range to judge the quality of the soft-pack type secondary battery cell.

[0046] (III) Beneficial effects

[0047] According to the quality inspection device and method of the soft-pack type secondary battery cell of the present invention, the induced current is made to flow in the soft-pack type secondary battery cell. In addition, in addition to detecting the induced current flowing in the soft-pack type secondary battery cell at the plate and the bending part to determine whether cracks or disconnections occur, the induced current flowing in the soft-pack type secondary battery cell is also detected at the welding part of the electrode to determine whether there are welding defects in the electrode.

[0048] Therefore, the present invention can accurately detect whether cracks, disconnections, welding defects, etc. occur in the pouch-type secondary battery cell by using the induced current detected from the pouch-type secondary battery cell.

[0049] In addition, in the present invention, when defects such as cracks or broken wires occur in the soft-pack type secondary battery cell, or welding defects occur in the electrode, the induced current detected from the soft-pack type secondary battery cell can be used to accurately determine the location of the cracks, broken wires or welding defects.

[0050] Furthermore, in the present invention, an induced current is allowed to flow in a soft-pack type secondary battery cell manufactured into a variety of shapes rather than a uniform shape, and the induced current is detected at the electrode plate or the bent portion and the welding portion to determine cracks or broken wires and welding defects, etc. Therefore, even if there is a positional error between the soft-pack type secondary battery cell and the sensor, it is possible to accurately check whether the soft-pack type secondary battery cell has defects. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] The present invention will be described in more detail below by way of non-limiting embodiments with reference to the accompanying drawings, in which the same elements are given the same reference numerals in some figures.

[0052] Figure 1 This is a diagram schematically showing the structure of a general pouch-type secondary battery cell.

[0053] Figure 2 It is a diagram for explaining the operation of an induction current flowing in a pouch-type secondary battery cell according to the present invention.

[0054] Figures 3a to 3d It is a diagram showing an example of the installation position of the magnetic field generating mechanism according to the present invention.

[0055] Figure 4a and Figure 4b It is a diagram for explaining the operation of inspecting a pouch-type secondary battery cell according to the present invention.

[0056] Figure 5a to Figure 5c This is a diagram for explaining the induced current detected by the induced current detection sensor when there are defects such as fine cracks or disconnection in the bent portion.

[0057] Figures 6a to 6c This is a diagram for explaining the induced current detected by the induced current detection sensor when there are defects such as fine cracks or disconnection in the electrode plate.

[0058] Figure 7 It is a block diagram showing the structure of the quality inspection device of the present invention.

[0059] Figure 8 yes Figure 7 Detailed circuit diagram of the magnetic field generating mechanism.

[0060] Fig. 9 It is shown Figure 7 A block diagram of the configuration of each of the multiple signal processing units.

[0061] Fig.10 is a signal flow chart showing the quality inspection method of the present invention. DETAILED DESCRIPTION

[0062] The following detailed description is merely exemplary and merely illustrates embodiments of the present invention. In addition, the principles and concepts of the present invention are provided for the purpose of being most useful and easily explained.

[0063] Therefore, it is not intended to provide a detailed structure beyond what is necessary for a basic understanding of the present invention, and the accompanying drawings are used to illustrate various forms that can be implemented by entities of the present invention by those skilled in the art.

[0064] Figure 1 1 is a diagram schematically showing the structure of a general soft pack type secondary battery cell. Figure 1 The pouch-type secondary battery cell 100 may include a plurality of anode plates 110 , a plurality of cathode plates 120 , and a plurality of separation membranes 130 .

[0065] Separation membranes 130 are respectively interposed between the plurality of anode plates 110 and the plurality of cathode plates 120 and are repeatedly stacked in sequence.

[0066] One side of the anode plates 110 is formed to slightly protrude from one side of the separation membranes 130 , and the other side of the cathode plates 120 is also stacked on the other side of the separation membranes 130 in a slightly protruding manner.

[0067] Here, the lengths of the protruding anode plates 110 and cathode plates 120 may be determined differently depending on the total number of anode plates 110 , cathode plates 120 , and separation membranes 130 , the total stacking height, and the like.

[0068] In addition, an electrode 150 for welding the anode terminal 140 is integrally formed at each end of one side of the plurality of anode plates 110. In addition, an electrode 160 for welding the cathode terminal 142 is integrally formed at each end of the other side of the plurality of cathode plates 120.

[0069] Here, an example is shown and described in which the electrode 150 is formed at the end of one side of the plurality of anode plates 110, and the electrode 160 is formed at the end of the other side of the plurality of cathode plates 120. When implementing the present invention, it is not limited to this, and the electrodes 150 and 160 can also be formed at various positions that will not short-circuit each other, including the side surfaces of the plurality of anode plates 110 and the plurality of cathode plates 120.

[0070] When the anode terminal 140 and the cathode terminal 142 are welded and joined to the electrodes 150 and 160 , respectively, the plurality of electrodes 150 and 160 are crimped from the upper and lower parts with a predetermined pressure, and the anode terminal 140 and the cathode terminal 142 are welded and joined to the crimped electrodes 150 and 160 , respectively.

[0071] Then, the plurality of anode plates 110 , the plurality of cathode plates 120 , the plurality of separation membranes 130 , and the electrodes 150 and 160 are all sealed in a soft pack 170 together with a predetermined electrolyte.

[0072] Here, the soft pack 170 may be made of a film of aluminum material, for example.

[0073] Therefore, the pouch-type secondary battery cell 100 may be configured such that only the terminals 140 , 142 are exposed to the outside of the pouch 170 .

[0074] In such a pouch-type secondary battery cell 100 , when a plurality of anode plates 110 and a plurality of cathode plates 120 are stacked with the separator 130 interposed therebetween, defects such as fine cracks or disconnections may occur in the anode plates 110 and the cathode plates 120 .

[0075] In addition, during the process of crimping the electrodes 150 , 160 , one end of the anode plate 110 and the other end of the cathode plate 120 bend to form bent portions 112 , 122 , and defects such as fine cracks or disconnection may occur in the bent portions 112 , 122 .

[0076] Here, the anode plate 110 and the cathode plate 120 may be configured not to protrude from the separation membrane 130 , but to be formed so that the electrodes 150 , 160 protrude from the separation membrane 130 , so that the bent portions 112 , 122 are formed on the electrodes 150 , 160 .

[0077] In the process of crimping and welding the anode terminal 140 and the cathode terminal 142 to the electrodes 150 and 160 , welding defects may occur such as inaccurate welding between the electrode 150 and the anode terminal 140 or inaccurate welding between the electrode 160 and the cathode terminal 142 .

[0078] Such fine cracks, broken wires, or welding defects may cause high-temperature heating during the charging and discharging of the pouch-type secondary battery cell, thereby possibly causing safety accidents such as fire.

[0079] Therefore, in the present invention, induced electricity is allowed to flow in the soft-pack type secondary battery cell 100, and the induced current flowing in the soft-pack type secondary battery cell 100 is detected at the electrode plates 110, 120 and the curved portions 112, 122, so that it is possible to accurately detect whether defects such as fine cracks or broken wires occur in the electrode plates 110, 120 or the curved portions 112, 122.

[0080] In the present invention, an induced current is made to flow in the pouch-type secondary battery cell 100 and the induced current flowing in the pouch-type secondary battery cell 100 is detected at the electrodes 150 and 160 , so that it is possible to accurately detect whether welding defects occur in the electrodes 150 and 160 .

[0081] Figure 2 2 is a diagram for explaining the flow of induced current in a soft-pack type secondary battery cell according to the present invention. Here, reference numeral 200 is a magnetic field generating mechanism. The magnetic field generating mechanism 200 is formed by, for example, winding a coil 204 around an iron core 202 multiple times. Such a magnetic field generating mechanism 200 applies a magnetic field generating signal of a predetermined frequency for generating a magnetic field to the coil 204.

[0082] Then, the magnetic field generating mechanism 200 generates a magnetic field according to the magnetic field generating signal, and the generated magnetic field is induced to the soft-pack type secondary battery cell 100 , so that the induced current 102 corresponding to the magnetic field signal flows in the soft-pack type secondary battery cell 100 .

[0083] For example, due to the magnetic field generated by the magnetic field generating mechanism 200 , the induced current 102 flows in the pouch-type secondary battery cell 100 along the length direction.

[0084] In the present invention, the magnetic field generating mechanism 200 can be as follows: Figure 3a As shown, it is located at the upper portion of the other side of the pouch-type secondary battery cell 100 , so that the induction current 102 flows in the pouch-type secondary battery cell 100 .

[0085] In addition, if Figure 3b As shown, the magnetic field generating mechanism 200 may be located at the upper portion and the lower portion of the other side of the pouch-type secondary battery cell 100 , respectively, so that the induced current 102 flows in the pouch-type secondary battery cell 100 .

[0086] In addition, if Figure 3c As shown, the magnetic field generating mechanism 200 may be located at the upper middle portion of the pouch-type secondary battery cell 100 so that the induced current 102 flows in the pouch-type secondary battery cell 100 .

[0087] In addition, if Figure 3d As shown, the magnetic field generating mechanisms 200 may be located at the upper and lower parts of the middle portion of the pouch-type secondary battery cell 100 , respectively, so that the induced current 102 flows in the pouch-type secondary battery cell 100 .

[0088] In the above Figures 3a to 3d In the embodiment, the position of the magnetic field generating mechanism 200 that causes the induction current 102 to flow in the pouch-type secondary battery cell 100 is illustrated and described as an example.

[0089] When implementing the present invention, the magnetic field generating mechanism 200 is not limited thereto, and may be located at various positions for causing the induced current 102 to flow in the pouch-type secondary battery cell 100 , including a side portion of the pouch-type secondary battery cell 100 .

[0090] In addition, the magnetic field generating signal applied to the magnetic field generating mechanism 200 to generate the magnetic field may use an AC signal of various shapes, such as a sine wave or a rectangular wave with a frequency of 60 Hz to 1 MHz.

[0091] With respect to the induced current 102 flowing in the soft-pack type secondary battery cell 100, due to the frequency characteristics, when the frequency is high, the induced current 102 flowing in the surface layer of the soft-pack type secondary battery cell 100 is large, and the induced current 102 flowing in the middle layer is relatively small compared to the surface layer. In addition, when the frequency becomes low, the induced current 102 flowing in the middle layer gradually increases.

[0092] Therefore, when implementing the present invention, it is preferred to use a dual-frequency AC signal of a lower frequency and a higher frequency synthesized and selected within the frequency range of 60 Hz to 1 MHz to check whether there are defects in the entire layer of the pouch type secondary battery cell 100 .

[0093] Here, the magnetic field generating mechanism 200 is illustrated as an example in which a coil 204 having a quadrilateral cross section is wound multiple times around an iron core 202. When implementing the present invention, it is not limited to this, and it can also be configured in various ways, such as winding a copper wire coated with enameled wire as the coil 204 multiple times around the iron core 202 to form the magnetic field generating mechanism 200.

[0094] Figure 4a and Figure 4b 1 is a diagram for explaining the operation of inspecting the quality of the soft pack type secondary battery cell 100 according to the present invention. Figure 4a As shown, when the pouch-type secondary battery cell 100 is transferred by a transfer mechanism (not shown) such as a conveyor belt to reach the inspection position, the magnetic field generating mechanism 200 is located above the pouch-type secondary battery cell 100 .

[0095] Here, the position of the magnetic field generating mechanism 200 shown in the figure is an exemplary illustration, and when implementing the present invention, as described above, the magnetic field generating mechanism 200 can be located at various positions to make the induced current flow in the pouch type secondary battery cell 100.

[0096] In addition, four induced current detection sensors 300 ( 300 a to 300 d ) to scan the pouch-type secondary battery cell 100 to detect the induced current may be provided at adjacent positions of the pouch-type secondary battery cell 100 .

[0097] For example, an induced current detection sensor 300a may be provided to scan the upper portion of the curved portion 112, 122 of the soft-pack type secondary battery cell 100 to detect the induced current. In addition, an induced current detection sensor 300b may be provided to scan the lower portion of the curved portion 112, 122 of the soft-pack type secondary battery cell 100 to detect the induced current. In addition, an induced current detection sensor 300c may be provided to scan the upper portion of the electrode plate 110 of the soft-pack type secondary battery cell 100 to detect the induced current. In addition, an induced current detection sensor 300d may be provided to scan the lower portion of the electrode plate 110 of the soft-pack type secondary battery cell 100 to detect the induced current.

[0098] Here, the four induced current detection sensors 300 ( 300 a - 300 d ) are shown as an exemplary diagram. When implementing the present invention, the number of the induced current detection sensors 300 may be increased or decreased or the installation positions may be changed as needed.

[0099] In this state, when an AC signal is applied to coil 204 of magnetic field generating mechanism 200, magnetic field generating mechanism 200 generates a magnetic field. The magnetic field generated by magnetic field generating mechanism 200 is induced to pouch type secondary battery cell 100, so that an induced current flows in pouch type secondary battery cell 100.

[0100] In addition, the plurality of induced current detection sensors 300 ( 300 a - 300 d ) scan the pouch-type secondary battery cell 100 in the width direction to detect induced currents respectively.

[0101] Here, when there are defects such as fine cracks or disconnections in the electrode plates 110 , 120 or the bent portions 112 , 122 , the defects may affect the induced currents detected by the plurality of induced current detection sensors 300 ( 300 a - 300 d ).

[0102] Therefore, in the present invention, the induced currents detected by the plurality of induced current detection sensors 300 ( 300 a - 300 d ) are compared with a preset reference range to determine whether a defect exists.

[0103] For example, Figure 5a As shown, it is assumed that fine cracks 302 appear in the upper electrode 140 .

[0104] Then, when the induced current detection sensors 300a, 300b scan the portion of the electrode 140 where the crack 302 appears, for example, Figure 5b and Figure 5c The induced current is detected as shown.

[0105] Right now, Figure 5b is a graph showing the induced current detected by the upper induced current detection sensor 300a, Figure 5c 1 is a graph showing the induced current detected by the induced current detection sensor 300b at the bottom. When scanning the portion where the electrodes 140 of the induced current detection sensors 300a and 300b are not present, a higher induced current is detected; when scanning the portion where the electrodes 140 are cracked, a lower induced current is detected.

[0106] This phenomenon occurs because the induced current flowing through the portion where the cracks 302 are formed decreases, and the induced current flowing through the portion where the cracks 302 are not formed increases in accordance with the decrease in the induced current.

[0107] In addition, the fluctuation range of the induced current detected by the upper induced current detection sensor 300a is large and exceeds the judgment reference range, while the fluctuation range of the induced current detected by the lower induced current detection sensor 300b is smaller than the fluctuation range of the induced current detected by the induced current detection sensor 300a. It can be seen that the crack 302 appears in the layer of the electrode 112 adjacent to the upper surface layer of the soft-pack type secondary battery cell 100.

[0108] Therefore, when defects such as cracks 302 appear on the electrodes 140 and 142, the induced current detected by the induced current detection sensors 300a and 300b can be used to determine the location and approximate depth of the defects such as cracks 302.

[0109] For example, Figure 6a As shown, it is assumed that fine cracks 304 appear in the upper electrode plates 110 and 120.

[0110] Then, when the inductive current detection sensors 300c and 300d scan the parts of the plates 110 and 120 where the cracks 304 have appeared, for example, Figure 6b and Figure 6c As shown, the induced current is detected.

[0111] Right now, Figure 6b is a graph showing the induced current detected by the upper induced current detection sensor 300c, Figure 6c 3 is a graph showing the induced current detected by the lower induced current detection sensor 300d. When the induced current detection sensors 300c and 300d scan the cracked portion of the electrode plates 110 and 120, a relatively low induced current is detected; when the induced current detection sensors 300c and 300d scan the cracked portion of the electrode plates 110 and 120, a relatively high induced current is detected.

[0112] This phenomenon occurs because the induced current flowing through the portion where the cracks 304 are formed decreases, and the induced current flowing through the portion where the cracks 304 are not formed increases in accordance with the decrease in the induced current.

[0113] In addition, the fluctuation range of the induced current detected by the upper induced current detection sensor 300c is large and exceeds the judgment reference range, while the fluctuation range of the induced current detected by the lower induced current detection sensor 300d is smaller than the fluctuation range of the induced current detected by the induced current detection sensor 300c. It can be seen that the crack 304 appears in the layer of the electrode 112, 122 adjacent to the surface layer of the soft-pack type secondary battery unit 100.

[0114] Thus, in the present invention, when a magnetic field signal is applied to the magnetic field generating mechanism 200 so that an induced current flows in the soft-pack type secondary battery cell 100 , multiple induced current detection sensors 300 detect the induced current respectively when scanning multiple parts of the soft-pack type secondary battery cell 100 .

[0115] Then, the induced currents detected by the plurality of induced current detection sensors 300 are compared with a determination reference range, and it is determined whether the soft pack type secondary battery cell 100 has defects such as cracks according to the comparison result.

[0116] In the above description, an example is given in which a plurality of induced current detection sensors 300 are provided based on the pouch-type secondary battery cell 100 located at a fixed position, and the plurality of induced current detection sensors 300 scan the pouch-type secondary battery cell 100 in the width direction to detect the induced current.

[0117] When implementing the present invention, it is not limited to this. Multiple induced current detection sensors 300 can be provided in the length direction and width direction of the soft-pack type secondary battery cell 100, so that the induced current can be detected in the entire part of the soft-pack type secondary battery cell 100 without the need for multiple induced current detection sensors 300 to perform scanning operations.

[0118] The above example illustrates and explains that when the magnetic field generating mechanism 200 is fixed, the soft-pack type secondary battery cell 100 is moved and reaches a position where the magnetic field generated by the magnetic field generating mechanism 200 causes an induced current of sufficient strength to flow, multiple induced current detection sensors 300 move and scan the soft-pack type secondary battery cell 100 to detect the induced current.

[0119] When implementing the present invention, it is not limited to this, and various deformations can be performed to implement the present invention. For example, the magnetic field generating mechanism 200 and the multiple induced current detection sensors 300 can be constructed to be fixed separately, and when the soft-pack type secondary battery cell 100 is transferred, the induced current flows through the magnetic field generating mechanism 200, and the multiple induced current detection sensors 300 scan the soft-pack type secondary battery cell 100 in a fixed state to detect the induced current, etc.

[0120] In addition, the induced current detected by the plurality of induced current detection sensors 300 described above may be affected by the magnetic field generated by the magnetic field generating mechanism 200 .

[0121] Therefore, when implementing the present invention, in order to prevent the magnetic field generated by the magnetic field generating mechanism 200 from affecting the induced currents detected by the plurality of induced current detection sensors 300, a shielding mechanism for shielding the magnetic field may be provided.

[0122] For the shielding mechanism, for example, Figure 4a and Figure 4bAs shown, the magnetic field of the magnetic field generating mechanism 200 can be shielded by providing a shielding mechanism 400 in such a manner that the entire portion of the magnetic field generating mechanism 200 is covered with a magnetic substance.

[0123] Alternatively, although not shown in the drawings, a shielding mechanism may be provided on each of the plurality of induced current detection sensors 300 to prevent the magnetic field of the magnetic field generating mechanism 200 from affecting the induced current detection sensor 300 .

[0124] In addition, in addition to the above-mentioned configuration, various shielding mechanisms that can prevent the magnetic field of the magnetic field generating mechanism 200 from affecting the induced current detection sensor 300 may be used.

[0125] Figure 7 1 is a block diagram showing the structure of the quality inspection device of the present invention. Figure 7 The quality inspection device of the present invention may include a magnetic field generating mechanism 200, a plurality of induction current detection sensors 300, an AC signal generating unit 600, a power loss detecting unit 610, a plurality of signal processing units 620, a memory 630, and a judgment / control unit 640.

[0126] In the quality inspection device of the present invention, the determination / control unit 640 controls the AC signal generation unit 600 to generate an AC signal.

[0127] Here, the AC signal generating unit 600 can generate AC signals of various shapes, including sine waves or rectangular waves.

[0128] In addition, it is preferred that the frequency of the AC signal has a dual frequency synthesized from a lower frequency and a higher frequency within a range of 60 Hz to 1 MHz.

[0129] That is, as described in detail above, for the induced current 102 flowing in the soft-pack type secondary battery cell 100, due to the frequency characteristics, when the frequency is high, the induced current 102 flowing in the surface layer of the soft-pack type secondary battery cell 100 is large, and the induced current 102 flowing in the middle layer is relatively small compared to the surface layer. In addition, when the frequency becomes lower, the induced current 102 flowing in the middle layer gradually increases.

[0130] Therefore, in the present invention, the AC signal generating unit 600 generates an AC signal having two frequencies, a lower frequency and a higher frequency, which are synthesized and selected within the frequency range of 60 Hz to 1 MHz.

[0131] The dual-frequency AC signal generated by the AC signal generating unit 600 is output to the magnetic field generating mechanism 200 .

[0132] like Figure 8As shown, the magnetic field generating mechanism 200 may include: a transformer 210 for transmitting the dual-frequency AC signal generated by the AC signal generating unit 600 to the coil 204; a low-frequency resonance unit 220, wherein a capacitor 222 is connected in series between the transformer 210 and the coil 204 and resonates in series with the low frequency; and a high-frequency resonance unit 230, wherein a capacitor 232 is connected in parallel between the transformer 210 and the coil 204 and resonates in parallel with the high frequency.

[0133] The dual-frequency AC signal generated by the AC signal generating unit 600 passes through the transformer 210 of the magnetic field generating mechanism 200 .

[0134] In the dual-frequency AC signal passing through the transformer 210, the coil 204 and the capacitor 222 of the low-frequency resonance part 220 form a series resonance due to the lower frequency AC signal, i.e., the low-frequency signal. In addition, in the dual-frequency AC signal passing through the transformer 210, the coil 204 and the capacitor 232 of the high-frequency resonance part 230 form a parallel resonance due to the higher frequency AC signal, i.e., the high-frequency signal.

[0135] Then, the coil 204 generates a dual-frequency magnetic field using a dual-frequency AC signal.

[0136] In addition, the power loss detection unit 610 receives the AC signal generated by the AC signal generation unit 600 to detect whether power is lost, and outputs a detection signal to the control / determination unit 640 .

[0137] When the soft-pack type secondary battery cell 100 is not in a position where the quality can be checked, the magnetic field generated by the magnetic field generating mechanism 200 will not be lost, and the power loss detection unit 610 will not be able to detect the power loss. Then, the control / judgment unit 640 can use the detection signal of the power loss detection unit 610 to determine that the soft-pack type secondary battery cell 100 is not in a position where the quality can be checked.

[0138] When the soft pack type secondary battery cell 100 is in a position where the quality can be inspected, the dual-frequency magnetic field generated by the magnetic field generating mechanism 200 is induced to the soft pack type secondary battery cell 100, so that the dual-frequency induced current flows in the soft pack type secondary battery cell 100. In addition, the power loss detecting unit 610 detects power loss caused by the magnetic field being induced to the soft pack type secondary battery cell 100.

[0139] Then, the control / determination part 640 may determine that the pouch type secondary battery cell 100 is in a position where the quality can be inspected using the detection signal of the power loss detection part 610 .

[0140] In this state, multiple induced current detection sensors 300 respectively detect the dual-frequency induced current flowing in the soft-pack type secondary battery cell 100 at multiple positions of the soft-pack type secondary battery cell 100, and output the detected dual-frequency induced current signals to multiple signal processing units 620 respectively.

[0141] like Fig. 9 As shown, each of the plurality of signal detection units 620 may include a low frequency detection filter 622 and a high frequency detection filter 624 .

[0142] The low-frequency induced current signal among the dual-frequency induced current signals detected by each of the plurality of induced current detection sensors 300 is detected by the low-frequency detection filter 622 of each of the plurality of signal processing units 620 and input to the control / determination unit 640. In addition, the high-frequency induced current signal among the dual-frequency induced current signals detected by each of the plurality of induced current detection sensors 300 is detected by the high-frequency detection filter 624 of each of the plurality of signal processing units 620 and input to the control / determination unit 640.

[0143] Then, the control / judgment unit 640 compares the low-frequency induced current signal and the high-frequency induced current signal input from each of the multiple signal processing units 620 with the values ​​of the judgment reference range pre-stored in the memory 630, and judges whether the soft-pack type secondary battery cell 100 has a defect based on the comparison result to generate a judgment signal.

[0144] Fig.10 1 is a signal flow chart showing the quality inspection method of the present invention. Fig.10 Under the control of the control / determination unit 640 , the AC signal generation unit 600 generates a dual-frequency AC signal and outputs the generated dual-frequency AC signal to the magnetic field generation mechanism 200 ( S1000 ).

[0145] Then, the magnetic field generating mechanism 200 generates a dual-frequency magnetic field according to the dual-frequency AC signal, and the generated dual-frequency magnetic field is induced to the soft-pack type secondary battery cell 100 , so that a dual-frequency induced current flows in the soft-pack type secondary battery cell 100 .

[0146] In this state, the power loss detector 610 detects power loss by inputting the dual-frequency AC signal from the AC signal generator 600 , and a power loss detection signal is input from the control / determination unit 640 ( S1010 ).

[0147] In addition, the control / determination unit 640 determines whether a sufficient induction current flows in the pouch-type secondary battery cell 100 , which is the starting position where the quality of the pouch-type secondary battery cell 100 can be inspected, using the power loss detection signal ( S1020 ).

[0148] When the control / determination part 640 determines that the pouch type secondary battery cell 100 is located at the starting position where the quality can be checked, the dual-frequency induced current signals are input from the plurality of signal processing parts 620 ( S1030 ).

[0149] Then, the control / determination unit 640 compares the dual-frequency induced current signal with a value within a determination reference range ( S1040 ), and determines whether the pouch-type secondary battery cell 100 is a good product or a defective product based on the comparison result ( S1050 ).

[0150] Although the present invention has been described in detail above through representative embodiments, those skilled in the art to which the present invention belongs may selectively combine and configure all or part of the embodiments so as to be able to make various modifications to the above embodiments without departing from the scope of the present invention.

[0151] Therefore, the scope of the present invention should not be limited to the described embodiments, but should be defined by not only the following claims but also the equivalents of the claims.

Claims

1. A quality inspection device for a soft-pack type secondary battery cell, characterized in that: include: an AC signal generating unit, which generates an AC signal; a magnetic field generating mechanism that generates a magnetic field according to the AC signal so as to cause an induced current to flow in the soft-pack type secondary battery cell; one or more induced current detection sensors that detect signals of induced current flowing in the pouch-type secondary battery cell; as well as A control / judgment unit compares the signal of the induced current detected by the induced current detection sensor with a value of a pre-stored judgment range, and judges the quality of the soft pack type secondary battery cell according to the comparison result.

2. The quality inspection device for a soft-pack type secondary battery cell according to claim 1, characterized in that: Also includes: a power loss detection unit for detecting power loss of the AC signal generated by the AC signal generation unit, The control / determination unit determines whether the one or more induced current detection sensors are located at a start position for detecting an induced current from a pouch-type secondary battery cell, using a detection signal from the power loss detection unit.

3. The quality inspection device for a soft-pack type secondary battery cell according to claim 1, characterized in that: The magnetic field generating mechanism comprises: a transformer for transmitting the AC current generated by the AC signal generating unit; a series resonance part, which resonates in series with the low frequency of the alternating current to cause the coil to generate a magnetic field; and The parallel resonant part resonates in parallel with the high frequency of the alternating current to cause the coil to generate a magnetic field.

4. The quality inspection device for a soft-pack type secondary battery cell according to claim 1, characterized in that: Also includes: one or more signal processing units, which output the signal of the induced current detected by the induced current detection sensor to the control / determination unit, The AC signal generating unit generates an AC signal having a low frequency and a high frequency. The signal processing unit comprises: A low-frequency detection filter, which detects the low-frequency AC current signal and outputs it to the control / determination unit; as well as A high frequency detection filter detects the high frequency AC current signal and outputs the high frequency AC current signal to the control / determination unit.

5. The quality inspection device for a soft-pack type secondary battery cell according to claim 1, characterized in that: When the soft-pack type secondary battery cell is located at a starting position, the one or more induced current detection sensors move and scan the soft-pack type secondary battery cell to detect an induced current signal.

6. The quality inspection device for a soft-pack type secondary battery cell according to claim 1, characterized in that: The pouch-type secondary battery cell and the one or more induction current detection sensors are fixed, and the pouch-type secondary battery cell moves so as to be scanned by the one or more induction current detection sensors to detect a signal of an induction current.

7. The quality inspection device for a soft-pack type secondary battery cell according to claim 1, characterized in that: Between the magnetic field generating mechanism and the induced current detection sensor, it also includes: The shielding mechanism is used for shielding the magnetic field of the magnetic field generating mechanism.

8. A quality inspection method for a soft-pack type secondary battery cell, characterized in that: include: The AC signal generating unit generates an AC signal, and the magnetic field generating mechanism generates a magnetic field according to the generated AC signal, so that an induced current flows in the soft pack type secondary battery cell; The step of detecting a signal of an induced current flowing in the pouch type secondary battery cell by an induced current detection sensor; as well as The control / determination unit compares the signal of the induced current detected by the induced current detection sensor with a value within a determination reference range to determine the quality of the pouch-type secondary battery cell.

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