KR102151175B1 - Electrode damage inspection electrode damage method of pouch type secondary battery - Google Patents

Abstract

An embodiment of the present invention provides a method for inspecting an electrode damage location of a pouch-type secondary battery having a short damage inspection time and high accuracy for an electrode tab. Here, the method for inspecting the location of damage to the electrode of the pouch-type secondary battery includes a plurality of electrode assemblies sealed in a pouch-type seat case, and electrically connected to electrode tabs of the plurality of electrode assemblies and extending to the outside of the seat case. As a method for inspecting electrode damage of a pouch-type secondary battery including an electrode lead, a first sensor is placed on an upper side of an electrode tab, a second sensor is placed on a lower side of the electrode tab, and the first sensor and the second sensor are connected to the electrode tab. An induced electromotive force generation step of generating induced electromotive force to the second sensor by electromagnetic induction by applying electricity to the first sensor while moving from the first side to the second side along the width direction of and obtaining an amplitude signal by the induced electromotive force. And a determination step of determining the damage position of the electrode tab based on the amplitude signal and the signal acquisition step.

Description

Electrode damage location inspection method of pouch type secondary battery {ELECTRODE DAMAGE INSPECTION ELECTRODE DAMAGE METHOD OF POUCH TYPE SECONDARY BATTERY}

The present invention relates to a method for inspecting an electrode damage location of a pouch-type secondary battery, and more particularly, to a method for inspecting an electrode damage location of a pouch-type secondary battery with high accuracy and a short time to inspect electrode tabs.

Recently, secondary batteries capable of charging and discharging have been widely used as an energy source for wireless mobile devices. In addition, the secondary battery is an electric vehicle (EV), hybrid electric vehicle (HEV), and plug-in hybrid electric vehicle that is proposed as a solution to air pollution such as existing gasoline vehicles and diesel vehicles that use fossil fuels. It is attracting attention as a power source such as (Plug-In HEV), and in addition, power tools that require high output, electric bicycles, E-scooters, electric golf carts, Or, it is also used in power storage systems.

In general, secondary batteries are largely classified into cylindrical batteries, prismatic batteries, pouch-type batteries, etc. according to their appearance, and may be classified into lithium-ion batteries, lithium-ion polymer batteries, and lithium polymer batteries, depending on the shape of the electrolyte. Due to the recent trend toward miniaturization of mobile devices, the demand for prismatic batteries and pouch-type batteries having a thin thickness is increasing, and in particular, there is a high interest in pouch-type batteries that are easily deformable and have a small weight. .

Meanwhile, the secondary battery is based on a structure in which the battery case is sealed in a state in which an electrode assembly composed of a plurality of electrodes and a separator is embedded in the battery case together with a non-aqueous electrolyte, and electrode tabs formed on the electrode assembly for electrical connection are provided. It is coupled to the electrode lead, and the electrode lead has a structure that protrudes from the inside of the battery case to the outside.

In general, the electrode lead and the electrode tab are made of an electrically conductive metal material such as nickel, aluminum, copper, and lead, and based on these material characteristics, the electrode lead and the electrode lead are joined by welding or soldering based on metal fusion. The electrode tabs can be combined.

The electrode assembly is formed by stacking a plurality of positive electrodes and a plurality of negative electrodes. In addition, electrode tabs for connection with electrode leads are formed on each electrode, and these electrode tabs are composed of several to tens. However, when such a plurality of electrode tabs are welded to the electrode leads, tension is applied to the electrode tabs, and tension is generated by this tension, resulting in cracks and tears on the electrode tabs that are very thin, about 15 μm. Damage can occur.

As described above, since damage may occur to the electrode tabs due to various factors that may occur during the manufacturing process, inspections are performed on the electrode tabs of the secondary battery that has been manufactured.

In general, these tests are performed by X-ray (x-ray) or computed tomography (CT). Since the test time takes about 15 minutes per pouch-type secondary battery, it is used as a mass production line tester. There is a problem that is difficult to commercialize.

Republic of Korea Patent Publication No. 2013-0014223 (published on February 7, 2013)

In order to solve the above problems, an object of the present invention is to provide a method for inspecting an electrode damage location of a pouch-type secondary battery with high accuracy and a short inspection time for an electrode tab.

The technical problem to be achieved by the present invention is not limited to the technical problems mentioned above, and other technical problems that are not mentioned can be clearly understood by those of ordinary skill in the technical field to which the present invention belongs from the following description. There will be.

In order to achieve the above technical problem, an embodiment of the present invention provides a plurality of electrode assemblies sealed in a pouch-type seat case, and electrically connected to the electrode tabs of the plurality of electrode assemblies, and outside the seat case. A method for inspecting the electrode damage location of a pouch-type secondary battery that inspects the location of electrode damage that occurs when welding between electrode leads extending to, wherein a first sensor is positioned above the electrode tab and a second sensor is positioned below the electrode tab. And, while moving the first sensor and the second sensor from the first side to the second side along the width direction of the electrode tab, electricity is applied to the first sensor to be applied to the second sensor by electromagnetic induction. An induced electromotive force generating step of generating an induced electromotive force; A signal acquisition step of acquiring an amplitude signal by the induced electromotive force; And it provides a method for inspecting the damage position of an electrode of a pouch-type secondary battery including a determination step of determining whether the electrode tab is damaged based on the amplitude signal.

In an embodiment of the present invention, the determining step includes a measurement distribution curve acquisition step of acquiring a measurement distribution curve from the amplitude signal, a measurement distribution area of the measurement distribution curve is calculated, and the measurement distribution area is set in advance. If the positive or negative determination reference area of the positive reference curve is or more, it is determined as good product, and if the measurement distribution area is less than the good or bad determination reference area, a positive or negative determination step may be performed.

In an embodiment of the present invention, the determination step may further include an electrode damage occurrence location determination step of determining a location where the electrode damage occurs in the electrode tab of the pouch-type secondary battery determined as the electrode damage.

In an embodiment of the present invention, the preset good product average reference curve is bisected by a vertical center axis passing through the lowest amplitude point, and the first good product average reference area including the first side and the second good product including the second side The measurement distribution curve of the pouch-type secondary battery, which has an average reference area and is determined to be damaged by an electrode, is bisected by the vertical center axis and has a first measurement distribution area including the first side and the second side. 2 has a measurement distribution area, and in the step of determining the location of the electrode damage, the first difference value obtained by subtracting the first measurement distribution area from the first average reference area is 0 or more, and the second average reference area is equal to or greater than 0. If the second difference value obtained by subtracting the 2 measurement distribution area is less than 0, it can be determined that there is damage to the electrode on the second side of the electrode tab.

In an embodiment of the present invention, the preset good product average reference curve is bisected by a vertical center axis passing through the lowest amplitude point, and the first good product average reference area including the first side and the second good product including the second side The measurement distribution curve of the pouch-type secondary battery, which has an average reference area and is determined to be damaged by an electrode, is bisected by the vertical center axis and has a first measurement distribution area including the first side and the second side. 2 has a measurement distribution area, and in the step of determining the location of electrode damage, the first difference value obtained by subtracting the first measurement distribution area from the first average reference area is less than 0, and the second difference is less than 0. 2 If the second difference value obtained by subtracting the measurement distribution area is 0 or more, it can be determined that there is damage to the electrode on the first side of the electrode tab.

In an embodiment of the present invention, the preset good product average reference curve is bisected by a vertical center axis passing through the lowest amplitude point, and the first good product average reference area including the first side and the second good product including the second side The measurement distribution curve of the pouch-type secondary battery, which has an average reference area and is determined to be damaged by an electrode, is bisected by the vertical center axis and has a first measurement distribution area including the first side and the second side. 2 has a measurement distribution area, and in the step of determining the location of the electrode damage, a first difference value obtained by subtracting the first measurement distribution area from the first average reference area of the first product, and the second measurement distribution from the second average reference area of the second product. If the second difference values minus the area are all less than 0, it may be determined that there is damage to the electrode in the center of the electrode tab.

On the other hand, in order to achieve the above technical problem, an embodiment of the present invention is a plurality of electrode assemblies embedded in a sealed state in a pouch-type seat case, and electrically connected to the electrode tabs of the plurality of electrode assemblies, and the seat case As an electrode damage inspection device of a pouch-type secondary battery for inspecting damage to an electrode of a pouch-type secondary battery including an electrode lead extending to the outside of, it is located above the electrode tab, in the width direction of the electrode tab. A first sensor that generates a magnetic field when electricity is applied while moving, and a first sensor that is located under the electrode tab, and generates an induced electromotive force by electromagnetic induction while moving in the width direction of the electrode tab together with the first sensor. Inspection sensor unit having two sensors; And it provides an electrode damage inspection apparatus of a pouch-type secondary battery including a determination unit that obtains the amplitude signal by the induced electromotive force and determines whether the electrode tab is damaged based on the amplitude signal.

In an embodiment of the present invention, at least one of the distance between the first sensor and the second sensor and the angle between the first sensor and the second sensor around the electrode tab may be adjusted so that the sensing sensitivity is adjusted. have.

According to an embodiment of the present invention, it is possible to quickly and accurately determine whether or not the electrode tab is damaged by comparing the measurement distribution area of the measurement distribution curve with the reference area of the positive or negative determination reference curve.

In addition, according to an embodiment of the present invention, the first average reference area and the second average reference area of the product are bisected by the vertical center axis passing through the lowest amplitude of the average reference curve of the product, the first measurement distribution area, and the second measurement. By comparing the distributed area, it is possible to quickly and accurately determine the location of the damage in the electrode tab.

The effects of the present invention are not limited to the above effects, and should be understood to include all effects that can be deduced from the configuration of the invention described in the detailed description or claims of the present invention.

1 is an exemplary view showing an electrode damage inspection apparatus of a pouch-type secondary battery according to an embodiment of the present invention.
2 is an exemplary view showing the configuration of an electrode damage inspection apparatus and a pouch-type secondary battery of a pouch-type secondary battery according to an embodiment of the present invention.
3 is a flowchart illustrating a method of inspecting electrode damage of a pouch-type secondary battery according to an embodiment of the present invention.
4 is an exemplary view illustrating a relationship between a measurement distribution curve and an electrode tab obtained through a method for inspecting electrode damage of a pouch-type secondary battery according to an embodiment of the present invention.
5 is an exemplary view for explaining a step of determining whether or not an electrode is damaged in a pouch-type secondary battery according to an embodiment of the present invention.
6 is an exemplary view for explaining an average reference curve for good products used in a step of determining an electrode damage location in a method for inspecting electrode damage of a pouch-type secondary battery according to an embodiment of the present invention.
7 to 9 are exemplary views showing measurement distribution curves and electrode damage types obtained through a method for inspecting electrode damage of a pouch-type secondary battery according to an embodiment of the present invention.

Hereinafter, the present invention will be described with reference to the accompanying drawings. However, the present invention may be implemented in various different forms, and therefore is not limited to the embodiments described herein. In the drawings, parts irrelevant to the description are omitted in order to clearly describe the present invention, and similar reference numerals are assigned to similar parts throughout the specification.

Throughout the specification, when a part is said to be “connected (connected, contacted, bonded)” to another part, it is not only “directly connected”, but also “indirectly connected” with another member in the middle. This includes cases where there is "". In addition, when a part "includes" a certain component, it means that other components may be further provided, rather than excluding other components unless specifically stated to the contrary.

The terms used in the present specification are only used to describe specific embodiments, and are not intended to limit the present invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In the present specification, terms such as “comprise” or “have” are intended to designate the presence of features, numbers, steps, actions, components, parts, or a combination thereof described in the specification, but one or more other features It is to be understood that the presence or addition of elements or numbers, steps, actions, components, parts, or combinations thereof, does not preclude in advance.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is an exemplary view showing an electrode damage inspection apparatus of a pouch-type secondary battery according to an embodiment of the present invention, and FIG. 2 is an electrode damage inspection apparatus and a pouch of a pouch-type secondary battery according to an embodiment of the present invention. It is an exemplary diagram showing the configuration of a type secondary battery.

As shown in FIGS. 1 and 2, the pouch-type secondary battery subject to the inspection according to the present invention may have an electrode assembly 20, a seat case 30, and electrode leads 40a and 40b.

The electrode assembly 20 may have a plurality of positive plates 21, a plurality of negative plates 22, and a separator 23 provided between each of the positive plates 21 and the negative plates 22. The positive electrode plate 21 may each have an electrode tab 25 protruding from one side, and the negative electrode plate 22 may each have another electrode tab protruding from the other side. That is, the electrode tab is integrally formed with the electrode plate, and may mean a portion protruding from one end of the electrode plate.

The seat case 30 is formed in a pouch shape, and the plurality of electrode assemblies 20 may be embedded in a sealed state by the seat case 30. The seat case 30 may be formed of an aluminum thin film, but is not limited thereto.

The electrode leads 40a and 40b may be provided at both ends of the electrode assembly 20, respectively.

The electrode lead 40a may be electrically connected by welding (WD) with the electrode tab 25 of the positive electrode plate 21, and may extend to the outside of one end of the seat case 30. Likewise, the other electrode lead 40b may be electrically connected by welding with the electrode tab of the negative electrode plate 22, and may extend to the outside of the other end of the seat case 30.

In addition, the apparatus for inspecting electrode damage of a pouch-type secondary battery according to the present invention is an apparatus for inspecting damage to an electrode of the pouch-type secondary battery described above, and more specifically, it is possible to inspect the damage of the electrode tab 25. .

Hereinafter, for convenience of description, the electrode tabs 25 of the positive electrode plate 21 will be described as a reference, but it goes without saying that the same method may be applied to the electrode tabs of the negative electrode plate 22.

The apparatus for inspecting electrode damage of a pouch-type secondary battery may include an inspection sensor unit 100 and a determination unit 200.

The pouch type secondary battery 10 may be located above the table 60, and the inspection sensor unit 100 may be provided on one side of the pouch type secondary battery 10.

The inspection sensor unit 100 may have a first sensor 110 and a second sensor 120.

The first sensor 110 may be provided on the upper portion of the case 101 and may be provided on the protrusion 102a protruding downward.

The first sensor 110 may have a first core 111 and a first coil 112. The first core 111 may be a ferrite core.

The first coil 112 may be wound around the first core 111.

Meanwhile, the first coil 112 may not be wound directly on the first core 111. For example, the first sensor 110 may further include a first bobbin (not shown). In this case, the first coil 112 is wound around the first bobbin, and the first core 111 is Can be inserted into the bobbin.

The second sensor 120 may be formed to have the same configuration as the first sensor 110.

That is, the second sensor 120 may be provided in the lower portion of the case 101 and provided in the protrusion 102b protruding downward.

The second sensor 120 may have a second core 121 and a second coil 122. The second core 121 may be a ferrite core.

The second coil 122 may be wound around the second core 121.

Similarly, the second sensor 120 may further include a second bobbin (not shown). In this case, the second coil 122 is wound around the second bobbin, and the second core 121 is wound around the second bobbin. It is configured to be inserted, so that the second coil 122 may not be wound directly on the second core 121.

The first sensor 110 may be positioned above the electrode tab 25, and the second sensor 120 may be positioned below the electrode tab 25. The second sensor 120 may be positioned vertically below the first sensor 110, and the second sensor 120 may be simultaneously moved together with the first sensor 110.

The inspection sensor unit 100 may be moved in the width direction of the electrode tab 25. As the inspection sensor unit 100 is moved in the width direction of the electrode tab 25, the first sensor 110 is also moved in the width direction of the electrode tab 25, and when electricity is applied, a magnetic field may be generated. Then, induced electromotive force may be generated in the second sensor 120 by an electromagnetic induction phenomenon caused by a magnetic field generated by the first sensor 110.

The determination unit 200 may obtain an amplitude signal due to the induced electromotive force, and may determine whether the electrode tab 25 is damaged based on the obtained amplitude signal. The determination process performed by the determination unit 200 will be described later.

At least one of the distance H between the first sensor 110 and the second sensor 120 and the angle θ between the first sensor 110 and the second sensor 120 centered on the electrode tab 25 is It can be adjusted, through which the sensing sensitivity can be adjusted.

Also, the sensing sensitivity may be adjusted by the voltage frequency and magnitude applied to the primary sensor 110.

Hereinafter, a method for inspecting electrode damage of a pouch-type secondary battery will be described.

3 is a flowchart showing a method for inspecting electrode damage of a pouch-type secondary battery according to an embodiment of the present invention, and FIG. 4 is a flowchart obtained through a method for inspecting electrode damage of a pouch-type secondary battery according to an embodiment of the present invention. It is an exemplary diagram for explaining the relationship between the measured distribution curve and the electrode tap.

As shown in FIGS. 2 and 3, the method for inspecting electrode damage of the pouch-type secondary battery may include an induced electromotive force generation step (S310), a signal acquisition step (S320), and a determination step (S330).

In the induced electromotive force generation step (S310), the first sensor 110 is positioned above the electrode tab 25 and the second sensor 120 is positioned below the electrode tab 25, and the first sensor 110 and While moving the second sensor 120 from the first side 51 to the second side 52 along the width direction of the electrode tab 25, electricity is applied to the first sensor 110 to prevent electromagnetic induction. 2 It may be a step of generating an induced electromotive force in the sensor 120.

The signal acquisition step S320 may be a step of acquiring an amplitude signal by induced electromotive force.

4, for the electrode tab 25 of the pouch-type secondary battery 10, the inspection sensor unit 100 (refer to FIG. 2) is moved from the first side 51 to the second side 52 in the inspection direction ( When moving along SD), an amplitude signal due to induced electromotive force generated by the second sensor 120 (refer to FIG. 2) may be obtained. The amplitude signal may be in the form of a sinusoidal wave.

In addition, the measurement distribution curve MS can be obtained from the amplitude signal. The measurement distribution curve MS may have the largest amplitude at both ends of the electrode tab 25 in the width direction, and may have the smallest amplitude at the center of the electrode tab 25.

That is, the first side 51, which is the beginning of the inspection direction SD, has a large starting point B1, and the central portion of the electrode tab 25 has the lowest point B2, and The second side 52, which is the end, may have an end point B3 having a large amplitude again.

The reason that the amplitude is the smallest at the center of the electrode tab 25 is that the eddy current is most strongly generated at the center of the electrode tab 25, which most severely interferes with the electromagnetic induction phenomenon. This is because the induced electromotive force generated by is the smallest.

The measurement distribution curve (MS) can be bisected around the lowest point (B2), and the measurement distribution area (MA) of the measurement distribution curve (MS) is the first measurement distribution area (MA1) and the second measurement distribution area (MA1) around the lowest point (B2). It can be divided into 2 measurement distribution area (MA2).

The determining step S330 may be a step of determining whether the electrode tab is damaged based on the amplitude signal. The determination step S330 may include a measurement distribution curve acquisition step S331 and a good or bad determination step S332.

The measurement distribution curve acquisition step S331 may be a step of acquiring a measurement distribution curve from an amplitude signal.

In the determination of good or bad, the measurement distribution area of the measurement distribution curve is calculated. It may be a step of determining electrode damage.

The measurement distribution area can be calculated by using the normal distribution equation operation on the measurement distribution curve.

5 is an exemplary view for explaining a step of determining whether or not an electrode is damaged in a pouch-type secondary battery according to an embodiment of the present invention.

First, as shown in (a) of FIG. 5, the standard curve for determination of good or bad (SS) may be set in advance using data obtained by inspecting a plurality of good products, and the reference area for determining the good or bad (SA) is It can be obtained from the curve SS and set in advance. The reference area for determination of good or bad can be calculated by using the normal distribution equation calculation on the pre-divided reference curve. The positive and negative judgment reference curve is a form of inversion of the normal distribution curve, and the left and right sides can be symmetric.

The standard area for determination of good and bad (SA) may be equal to the sum of the first standard area for determining good or bad (SA1) and the area for determining the second good or bad (SA2).

The positive or negative determination reference curve SS may be measured in the electrode tab 25 in a state where there is no damage to the electrode tab 25 or can be regarded as having no damage.

And, as shown in (b) of FIG. 5, the measurement distribution curve (MS) can be obtained by inspecting the product to be measured, and the measurement distribution area (MA) is the first measurement distribution area (MA1) and the second measurement. It can be equal to the sum of the distributed areas (MA2).

When the electrode tab 25 is damaged, the measurement distribution area MA obtained from the electrode tab 25 may be relatively small as compared to the positive or negative determination reference area SA.

Therefore, as shown in (c) of FIG. 5, if the measurement distribution area (MA) of the measurement distribution curve (MS) is equal to or greater than the positive or negative judgment reference area (SA) of the positive or negative judgment reference curve (SS), the pouch-type secondary battery is It can be judged as good.

However, as shown in (d) of FIG. 5, if the measurement distribution area (MA) of the measurement distribution curve (MS) is less than the good or bad judgment reference area (SA) of the positive or negative judgment reference curve (SS), the pouch-type secondary battery is It can be determined as electrode damage.

The determination step S330 may further include an electrode damage occurrence location determination step S333 of determining a location where the electrode damage occurs in the electrode tab of the pouch-type secondary battery determined as the electrode damage.

6 is an exemplary view for explaining an average reference curve of a good product used in a step of determining an electrode damage location in a method for inspecting electrode damage of a pouch-type secondary battery according to an embodiment of the present invention.

As shown in FIG. 6, the average quality reference curve (SSS) is bisected by the vertical central axis (VA) passing through the lowest amplitude point to include the first quality average reference area (SSA1) including the first side (51, see FIG. 4). ) And a second side (52 (refer to FIG. 4)) and a second average standard area (SSA2).

The good product average reference curve SSS may be preset using data obtained by inspecting a plurality of good products. Whereas the good and bad judgment reference curve SS is an inverted form of the normal distribution curve in which the left and right sides are symmetrical, the good product average reference curve SSS does not form a normal distribution curve, and thus, the left and right sides may not be symmetric.

7 to 9 are exemplary diagrams showing measurement distribution curves and electrode damage types obtained through a method for inspecting electrode damage of a pouch-type secondary battery according to an embodiment of the present invention.

In the electrode damage occurrence location determination step (S333), a good product average reference curve (SSS) may be utilized.

In addition, the measurement distribution curve MS of the pouch-type secondary battery determined as electrode damage is bisected by the vertical central axis VA, so that the first measurement distribution area including the first side 51 and the second side ( 52) can have a second measurement distribution area.

In the electrode damage occurrence location determination step (S333), both the good product average reference curve (SSS) and the measurement distribution curve (MS) may be bisected by the vertical central axis (VA).

As shown in (a) of FIG. 7, the measurement distribution curve (MS) is in a form skewed to the left than the good product average reference curve (SSS), and the good product average reference curve (SSS) and the measurement distribution curve (MS) are the vertical center axis. When bisected by (VA), as shown in (b) of FIG. 7, the first difference value (DV1) minus the first measurement distribution area from the first good product average reference area exceeds 0, and the second good product average The second difference value DV2 obtained by subtracting the second measurement distribution area from the reference area is less than 0.

In this way, if the first difference value obtained by subtracting the first measurement distribution area from the first quality product average reference area is 0 or more, and the second difference value obtained by subtracting the second measurement distribution area from the second quality product average reference area is less than 0, electrode damage occurs. In the position determining step S333, it may be determined that there is an electrode damage D2 on the second side 52 of the electrode tab 25 as shown in FIG. 7C.

And, as shown in (a) of FIG. 8, the measurement distribution curve (MS) is in a form skewed to the right than the good product average reference curve (SSS), and the good product average reference curve (SSS) and the measurement distribution curve (MS) are vertical. When bisected by the central axis (VA), as shown in Fig. 8(b), the first difference value (DV1) obtained by subtracting the first measurement distribution area from the average reference area of the first good product becomes less than 0, and the second good product The second difference value (DV2) obtained by subtracting the second measurement distribution area from the average reference area exceeds 0.

In this way, if the first difference value obtained by subtracting the first measurement distribution area from the first good product average reference area is less than 0, and the second difference value obtained by subtracting the second measurement distribution area from the second product average reference area is 0 or more, electrode damage occurs. In the position determination step S333, it may be determined that there is an electrode damage D1 on the first side 51 of the electrode tab 25 as shown in FIG. 8C.

And, as shown in (a) of FIG. 9, the measurement distribution curve (MS) is located between the good product average reference curve (SSS), and the good product average reference curve (SSS) and the measurement distribution curve (MS) are When bisected by the vertical central axis (VA), as shown in (b) of FIG. 9, the first difference value (DV1) obtained by subtracting the first measurement distribution area from the average reference area of the first good product becomes less than 0 and the second The second difference value (DV2) obtained by subtracting the second measurement distribution area from the average reference area of good products is also less than zero.

In this way, the first difference value (DV1) obtained by subtracting the first measurement distribution area from the first quality product average reference area and the second difference value (DV2) obtained by subtracting the second measurement distribution area from the second quality product average reference area are all less than zero. In the step of determining the location of the damage to the back electrode (S333), it may be determined that the electrode damage D4 exists in the center of the electrode tab 25 as shown in (c) of FIG. 9.

According to the present invention, it is possible to obtain an inspection result with high accuracy while having a short inspection time for the electrode tab 25 through the above-described electrode damage inspection method.

The above description of the present invention is for illustrative purposes only, and those of ordinary skill in the art to which the present invention pertains can understand that it is possible to easily transform it into other specific forms without changing the technical spirit or essential features of the present invention. will be. Therefore, it should be understood that the embodiments described above are illustrative in all respects and not limiting. For example, each component described as a single type may be implemented in a distributed manner, and similarly, components described as being distributed may also be implemented in a combined form.

The scope of the present invention is indicated by the claims to be described later, and all changes or modified forms derived from the meaning and scope of the claims and the concept of equivalents thereof should be interpreted as being included in the scope of the present invention.

10: pouch type secondary battery 25: electrode tab
51: first side 52: second side
100: inspection sensor unit 110: first sensor
120: second sensor 200: determination unit
DV1: first difference value DV2: second difference value
MA: measurement distribution area MA1: first measurement distribution area
MA2: second measurement distribution area MS: measurement distribution curve
SA: Standard area for determination of good or bad SA1: Standard area for determination of good or bad
SA2: Second reference area for determination of good and bad SS: Standard curve for determination of good and bad
SSS: Average reference curve for good products SSA1: Average reference area for first good products
SSA2: Average standard area for second quality products

Claims (8)

delete delete delete Inspect the location of electrode damage that occurs during welding between a plurality of electrode assemblies sealed in a pouch-type seat case and electrode leads that are electrically connected to the electrode tabs of the plurality of electrode assemblies and extend to the outside of the seat case As a method for inspecting the damage location of the pouch-type secondary battery,
A first sensor is positioned above the electrode tab and a second sensor is positioned below the electrode tab, and the first sensor and the second sensor are moved from the first side to the second side along the width direction of the electrode tab. An induced electromotive force generating step of applying electricity to the first sensor while moving to generate an induced electromotive force to the second sensor by an electromagnetic induction phenomenon;
A signal acquisition step of acquiring an amplitude signal by the induced electromotive force;
Including a determination step of determining whether the electrode tab is damaged based on the amplitude signal,
The determination step is
A measurement distribution curve obtaining step of obtaining a measurement distribution curve from the amplitude signal; and
Calculate the measurement distribution area of the measurement distribution curve, and if the measurement distribution area is greater than or equal to the reference area for determination of good or bad, if the measurement distribution area is less than the standard area for determination of good or bad, it is judged as good. A judgment step of determining whether or not the decision is made;
The step of determining the good or bad is
Further comprising an electrode damage occurrence location determination step of determining a location where the electrode damage occurs in the electrode tab of the pouch-type secondary battery determined as electrode damage,
The preset average quality reference curve is bisected by a vertical center axis passing through the lowest amplitude and has a first average reference area including the first side and a second average reference area including the second side, and damages the electrode. The measurement distribution curve of the pouch-type secondary battery determined as has a first measurement distribution area including the first side and a second measurement distribution area having the second side by being bisected by the vertical center axis,
In the step of determining the location of the electrode damage, the first difference value obtained by subtracting the first measurement distribution area from the first good product average reference area is equal to or greater than 0, and the second measurement distribution area is subtracted from the second good product average reference area. If the second difference value is less than 0, it is determined that there is damage to the electrode on the second side of the electrode tab,
In the step of determining the location of the electrode damage, the first difference value obtained by subtracting the first measurement distribution area from the first good product average reference area is less than 0, and the second measurement distribution area is subtracted from the second good product average reference area. If the second difference value is 0 or more, it is determined that there is damage to the electrode on the first side of the electrode tab,
The electrode damage location determination step includes a first difference value obtained by subtracting the first measurement distribution area from the first average reference area of the first good product, and a second difference value obtained by subtracting the second measurement distribution area from the second average reference area of the second good product. If all of them are less than 0, it is determined that there is damage to the electrode in the center of the electrode tab. delete delete delete delete

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