KR20230078052A - Defect inspection equipment for secondary battery and method for same - Google Patents

Abstract

The present invention relates to a secondary battery defect inspection device (1) and a method (S1) thereof, and more particularly, after generating a heat (temperature) deviation for each part of the secondary battery cell (9), the secondary battery cell ( 9) to detect a heat wave (or thermal energy) from a secondary battery defect inspection device (1) and a method (S1) for determining a defective part in a non-contact manner.

Description

Secondary battery defect inspection device and method thereof {DEFECT INSPECTION EQUIPMENT FOR SECONDARY BATTERY AND METHOD FOR SAME}

The present invention relates to a secondary battery defect inspection device (1) and a method (S1) thereof, and more particularly, after generating a heat (temperature) deviation for each part of the secondary battery cell (9), the secondary battery cell ( 9) to detect a heat wave (or thermal energy) from a secondary battery defect inspection device (1) and a method (S1) for determining a defective part in a non-contact manner.

In general, a battery includes a cathode or a negative electrode and an anode or negative electrode separated from each other by a separator, and an electrolyte that enables ion transfer between the two electrodes to supply electrical energy.

The battery is divided into a primary battery (general battery) that is discarded after one use and a secondary battery that can be reused through charging. In line with this, the performance of secondary batteries is gradually improved and mass-produced. On the other hand, conventional batteries, including lithium ion (Li-ion) batteries, use a liquid electrolyte as an electrolyte that enables ion movement within the battery. That is, the battery is manufactured by inserting a positive electrode plate, a negative electrode plate, and a separator that blocks between the positive electrode plate and the negative electrode plate into the battery case, injecting electrolyte into the battery case, and sealing the battery case.

Briefly describing the secondary battery manufacturing process, two electrode tabs are formed extending from the electrode plate of the electrode assembly, and these electrode tabs are electrically connected to each other by welding with the electrode leads, and the electrode leads are outside the pouch case. partially exposed as After the electrode lead is formed, a sealing process is performed on the edge of the pouch on the side where the lead is formed by heat and pressure. Then, a process of injecting the electrolyte solution into the inner space of the pouch case is performed through the open edge of the side where the sealing process is not performed. When the electrolyte injection process is finished, a process of sealing the open edge side in a vacuum state is additionally performed.

Such a secondary battery cell may have defects due to various factors, such as cracks at the edge when forming a specific shape such as an electrode assembly accommodating groove or a gas chamber during the manufacturing process, and cracks on a welded part during lead welding. It can be a major cause of safety accidents such as fire and explosion.

In order to prevent such possible safety accidents in advance, the inventor of the present invention proposes a secondary battery defect inspection device and method for minimizing the occurrence of defects in the manufacturing process, and details thereof will be described later.

Registered Patent No. 10-2236815 'A device for detecting missing and folded defects in secondary battery electrode tabs'

It was devised to solve the problems of the prior art,

The present invention is a defect inspection device for a secondary battery that detects a defective area in a non-contact manner by measuring heat waves (or thermal energy) from the secondary battery cell after generating a heat (temperature) deviation for each part of the secondary battery cell to be charged, and the same Its purpose is to provide a method.

In addition, the present invention can be configured to supply heat to a secondary battery cell into which a thermal deviation generating unit for generating thermal deviation is inserted or to take heat away, so that defect inspection of secondary batteries that can be flexibly applied under various environments Its purpose is to provide an apparatus and its method.

In addition, an object of the present invention is to provide a defect inspection apparatus and method for a secondary battery in which a scale bar for a temperature numerical range is provided in a thermal image generated by a thermal imaging camera unit to enable intuitive recognition by a user. there is.

In addition, an object of the present invention is to provide a defect inspection device and method for a secondary battery that can easily detect not only defects generated on the surface of a secondary battery cell by excitation of a laser beam through a thermal deviation generating unit, but also defects generated inside the cell. .

The present invention can be implemented by an embodiment having the following configuration in order to achieve the above-described object.

According to one embodiment of the present invention, a defect inspection apparatus for a secondary battery according to the present invention includes a thermal deviation generating unit for radiating heat waves from an inserted secondary battery cell; a thermal measurement unit generating a thermal image by measuring the heat wave emitted from the secondary battery cell by the thermal deviation generating unit along a scanning direction; and a controller that controls operations of the thermal deviation generating unit and the thermal measurement unit, and determines whether a defect occurs in the secondary battery cell based on a thermal image transmitted from the thermal measurement unit.

According to another embodiment of the present invention, the thermal deviation generating unit in the secondary battery defect inspection apparatus according to the present invention is characterized in that the inserted secondary battery cells absorb heat or generate heat.

According to another embodiment of the present invention, the heat measuring unit in the secondary battery defect inspection apparatus according to the present invention includes a thermal imaging camera unit that generates a thermal image of a thermal wave shape of a secondary battery cell; and a focusing lens disposed between the thermal imaging camera unit and the secondary battery cell to control a focus so that the thermal imaging camera unit receives a heat wave shape from the secondary battery cell.

According to another embodiment of the present invention, the thermal imaging camera unit in the secondary battery defect inspection device according to the present invention automatically generates a scale bar for the temperature numerical range of the secondary battery cell measured by heat in the generated thermal image. Let it be.

According to another embodiment of the present invention, the thermal imaging camera unit in the secondary battery defect inspection device according to the present invention has frames formed by extracting only a corresponding line after a predetermined time from the laser beam excitation of the thermal deviation generating unit characterized by

According to another embodiment of the present invention, the frames in the secondary battery defect inspection apparatus according to the present invention are arranged row by row to generate an entire thermal image.

According to another embodiment of the present invention, the control unit in the secondary battery defect inspection apparatus according to the present invention includes an image storage unit for storing a thermal image of a normal test piece of a secondary battery cell having no defects; and a defect identification module that determines whether a defect occurs by comparing the thermal image of the secondary battery cell stored in the image storage unit with the thermal image of the inserted secondary battery cell.

According to another embodiment of the present invention, the thermal deviation generating unit in the secondary battery defect inspection apparatus according to the present invention includes a laser output device that excites an output laser beam toward a secondary battery cell; and a laser focus control lens for controlling the focus of the laser beam output from the laser output device.

According to another embodiment of the present invention, the secondary battery defect inspection apparatus according to the present invention is disposed between the laser output device and the laser focus control lens, the laser shape control lens for modulating the laser shape output from the laser output device; It is characterized in that it further comprises.

According to another embodiment of the present invention, the laser shape control lens in the secondary battery defect inspection device according to the present invention is characterized in that the continuous wave point laser beam output from the laser output device is modulated into a linear laser beam.

According to one embodiment of the present invention, a defect inspection method of a secondary battery according to the present invention includes the steps of generating thermal deviation for each part of a charged secondary battery cell; generating a thermal image by measuring heat waves radiated from the secondary battery cell; and comparing the thermal image with the thermal image of the normal test piece to determine whether or not a defect has occurred in the loaded secondary battery cell.

The present invention has the following effects by the above configuration.

The present invention has an effect of detecting a defective part in a non-contact manner by measuring a heat wave (or thermal energy) from the secondary battery cell after generating a heat (temperature) deviation for each part of the secondary battery cell to be injected.

In addition, the present invention can be configured to supply heat to a secondary battery cell into which a thermal deviation generating unit for generating thermal deviation is inserted or to take heat away, so it has an effect that can be flexibly applied under various environments.

In addition, according to the present invention, a scale bar for a temperature numerical range is provided to a thermal image generated by a thermal imaging camera unit, so that an intuitive recognition of the user is possible.

In addition, the present invention has an effect of enabling easy detection of not only defects generated on the surface of the secondary battery cell by laser beam excitation through the thermal deviation generating unit, but also defects generated inside.

On the other hand, even if the effects are not explicitly mentioned here, it is added that the effects described in the following specification expected by the technical features of the present invention and their provisional effects are treated as described in the specification of the present invention.

1 is a schematic reference diagram of a pouch type secondary battery cell;
2 is a conceptual diagram of a secondary battery defect inspection device according to an embodiment of the present invention;
3 is a block diagram of a defect inspection device for a secondary battery according to FIG. 2;
4 is a reference diagram of a thermal image generated by the thermal imaging camera unit according to FIG. 2;
Fig. 5 is a block diagram of a control unit according to Fig. 2;
6 is a flowchart of a method for inspecting defects in a secondary battery according to an embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in more detail with reference to the accompanying drawings. Embodiments of the present invention may be modified in various forms, and the scope of the present invention should not be construed as being limited to the following examples, but should be interpreted based on the matters described in the claims. In addition, this embodiment is only provided as a reference in order to more completely explain the present invention to those skilled in the art.

As used herein, the singular form may include the plural form unless the context clearly indicates otherwise. Also, when used herein, "comprise" and/or "comprising" specifies the presence of the recited shapes, numbers, steps, operations, elements, elements, and/or groups thereof. and does not exclude the presence or addition of one or more other shapes, numbers, operations, elements, elements and/or groups.

Hereinafter, when one component (or layer) is described as being disposed on another component (or layer), one component may be directly disposed on the other component, or another component may be disposed on another component (or layer). It should be noted that component(s) or layer(s) may be interposed. In addition, when an element is expressed as being directly disposed on or above another element, the other element(s) is not positioned between the corresponding elements. Also, being located on the 'upper', 'upper', 'lower', 'upper', 'lower' or 'one side' or 'side' of one component means a relative positional relationship.

In addition, the secondary battery defect inspection device 1 according to an embodiment of the present invention can be applied to any type of secondary battery, such as a pouch-type secondary battery, a prismatic secondary battery, and a cylindrical secondary battery, and there are separate restrictions on this It is not. Hereinafter, for convenience, a pouch type secondary battery will be described.

1 is a schematic reference view of a pouch type secondary battery cell.

Prior to describing the present invention, the structure of the pouch-type secondary battery cell 9 will be briefly described below with reference to the accompanying drawings.

Referring to FIG. 1 , in general, a pouch-type secondary battery cell 9 includes an electrode assembly 91 having an electrode tab 911, a lead 93 electrically connected to an end side of the electrode tab 911, and a receiving A pouch case 95 accommodating the electrode assembly 91 in the groove 951 is included. In addition, the end 951 of the pouch case 95 on the side where the lid 93 is formed maintains a sealed state by the sealing process, and the open side 955 adjacent to the gas chamber 953 maintains an open state. Thus, a process of injecting the electrolyte solution into the pouch case 95 through the side portion 955 is performed. After that, a process of sealing the side portion 955 in a vacuum state is performed.

Such a secondary battery cell 9 is formed in a predetermined shape in the pouch case 95, such as the accommodation groove 951 and the gas chamber 953 during the manufacturing process, cracks occur at the edge, and when the lead 93 is welded Defects can occur due to various factors such as cracks on the welded joint, which can be a major cause of safety accidents such as fire and explosion. In order to prevent such possible safety accidents in advance, the present invention proposes a secondary battery defect inspection device 1 for minimizing the occurrence of defects in the manufacturing process, and details thereof will be described later.

2 is a conceptual diagram of a secondary battery defect inspection device according to an embodiment of the present invention; FIG. 3 is a block diagram of a defect inspection device for a secondary battery according to FIG. 2 .

Hereinafter, a defect inspection apparatus 1 for a secondary battery according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

2 and 3, the present invention relates to a secondary battery defect inspection device 1, and more particularly, after generating a heat (temperature) deviation for each part of a secondary battery cell 9, the secondary battery cell 9 It relates to a secondary battery defect inspection device (1) that detects heat waves (or thermal energy) from a battery cell (9) and specifies a defect site in a non-contact manner.

To this end, the secondary battery defect inspection device 1 may include a thermal deviation generating unit 10, a heat measurement unit 30, and a control unit 50.

The thermal deviation generator 10 is a device configuration that radiates heat waves (EH: thermal energy) to the secondary battery cells 9 introduced for defect inspection. The thermal deviation generating unit 10 may be a heat generating unit that radiates high-temperature heat to the secondary battery cell 9 or, conversely, may be a configuration for lowering the heat of the secondary battery cell 9, and is limited thereto. It is not that there is

For example, the thermal deviation generating unit 10 may include a laser beam irradiation device, a fluorescent lamp, etc. as a high-temperature heat radiation configuration, or may include a refrigerant configuration using water, air, carbon dioxide, etc. Examples of the invention are not limited thereto. That is, the thermal deviation generating unit 10 may generate a thermal deviation in each part of the secondary battery cell 9 through a method of excitation of a laser beam to the secondary battery cell 9 or by supplying a predetermined gas, for example. there is. That is, the thermal deviation generating unit 10 can utilize any of methods capable of inducing a predetermined temperature (for example, 5°C) deviation for each part of the secondary battery cell 9 .

Hereinafter, excitation of a laser beam to the secondary battery cell 9 by the thermal deviation generating unit 10 according to an embodiment of the present invention, including a laser output device, will be described as an example. To this end, the thermal deviation generator 10 may include a laser excitation device 110 , a laser shape control lens 130 and a laser focus control lens 150 . Heat waves may be radiated from the secondary battery cell 9 through the thermal deviation generator 10 that excites the laser beam to the secondary battery cell 9 .

The laser output device 110 is configured to excite the outputted laser beam to the injected secondary battery cell 9 side. The laser beam excited by the laser output device 110 may be a continuous wave laser.

The laser shape control lens 130 modulates the shape of a point-shaped laser beam output from the laser output device 110 . The laser shape control lens 130 may modulate a point laser beam into various shapes such as a linear laser or a polygonal laser, but is not limited thereto. The laser shape control lens 130 may be disposed between the laser output device 110 and the secondary battery cell 9 .

The laser focus control lens 150 is a lens component that controls the focus of the linear laser beam output from the laser output device 110 . The laser focus control lens 150 is preferably formed between the laser shape control lens 130 and the secondary battery cell 9, but is not particularly limited thereto. The laser focus control lens 150 may perform a focus control operation under the control of the control unit 50 .

FIG. 4 is a reference diagram of a thermal image generated by the thermal imaging camera unit according to FIG. 2 .

The heat measurement unit 30 is a component that measures the heat wave generated from the secondary battery cell 9 by the thermal deviation generating unit 10 along the scanning direction. The thermal measurement unit 30 generates thermal images for each part by copying the shape of the heat wave measured from the secondary battery cell 9 , and the generated thermal image may be delivered or transmitted to the control unit 50 .

To this end, the thermal measurement unit 30 may include a thermal imaging camera unit 310 and a focus lens 330 .

The thermal imaging camera unit 310 is a component that generates a thermal image of the heat wave shape generated from the secondary battery cell 9 . For example, the thermal imaging camera unit 310 may be an infrared camera, but is not limited thereto. Also, as described above, the thermal image may be transmitted to the controller 50 side. Referring to FIG. 4 , a scale bar for the temperature numerical range of the secondary battery cell 9 where heat is measured is automatically formed in the thermal image, so that intuitive recognition is possible. For example, when a specific part of the secondary battery cell 9 whose heat is measured is within the range of 24˚C to 32˚C, a scale bar for the corresponding temperature range may be automatically generated.

Illustratively describing the method of generating the thermal image, each frame constituting the thermal image may be specified by extracting only a corresponding line after a predetermined time from excitation of a laser beam of the thermal deviation generating unit 10. there is. More specifically, a thermal image integrating the entire frame may be configured by extracting corresponding lines (for example, lines orthogonal to the scanning direction) after 1 second of laser exposure for each frame. At this time, the location line 1 second after the laser beam is excitation according to the start of operation of the thermal deviation generating unit 10 may constitute the first frame of the thermal image. Each frame can be arranged row by row to create an entire thermal image.

Referring to FIGS. 2 and 3 , the focus lens 330 is disposed between the thermal imaging camera unit 310 and the secondary battery cell 9 to capture the heat wave shape from the secondary battery cell 9 to the thermal imaging camera unit ( 310) is a lens configuration that controls the focus to receive. The focus lens 330 may perform a focus control operation under the control of the control unit 50 .

Fig. 5 is a block diagram of a control unit according to Fig. 2;

2, 3 and 5, the controller 50 controls the operation of the thermal deviation generator 10 and the thermal measurement unit 30, based on the thermal image transmitted from the thermal measurement unit 30. This is a configuration for specifying whether or not a defect occurs in the secondary battery cell 9 and the location where the defect occurs. For example, the control unit 50 compares the thermal image of the secondary battery cell 9 currently being measured and the thermal image of the normal test piece transmitted from the heat measuring unit 30 to detect a side outside a preset temperature difference range. It can be specified by the location of the defect.

For example, when the predetermined temperature difference range is set to 3˚C, a position corresponding to a normal test piece at an arbitrary position of the secondary battery cell 9 and a side exceeding the corresponding temperature difference range can be determined as a defect occurrence part. In addition, the size of the defect may be determined by the ratio of the area or size of the defective part in the thermal image to the size of the inserted secondary battery cell 9 .

The thermal conductivity of the defective part of the secondary battery cell 9 is relatively low, and when a temperature deviation is generated in the secondary battery cell 9 by the heat deviation generating unit 10, the temperature value of the corresponding defective part is higher than that of the non-defective part. measured very high or very low. That is, it exceeds the preset temperature difference range. Therefore, it is possible to specify the defect occurrence site of the secondary battery cell 9 in a non-contact manner.

To this end, the controller 50 may include an image storage unit 510 and a defect specification module 530 .

The image storage unit 510 is a component that stores a thermal image of a normal test piece of the secondary battery cell 9 with no defects. The thermal image stored in the image storage unit 510 generates a temperature deviation with respect to the secondary battery cell 9 with no defects (normal test piece) by the thermal deviation generator 10, and then is sent to the thermal measurement unit 30. It may refer to a thermal image generated by The thermal image of the secondary battery cell 9 stored in the image storage unit 510 may be a single image for each part of the secondary battery cell 9 or may include multiple images, but is not limited thereto.

The defect specification module 530 compares the thermal image of the secondary battery cell 9 currently measured by the thermal measuring unit 30 with the thermal image of the secondary battery cell 9 for each part stored in the image storage unit 510. This is a configuration for specifying whether or not a defect occurs in the secondary battery cell 9 by doing so. For example, the defect specification module 530 may determine that a defect has occurred in the corresponding portion when the temperature value of the same portion between the normal test piece and the secondary battery cell 9 currently being measured is out of a preset range.

6 is a flowchart of a method for inspecting defects in a secondary battery according to an embodiment of the present invention.

Hereinafter, a defect inspection method (S1) of a secondary battery according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

Referring to FIG. 6 , first, thermal deviation is generated in the secondary battery cell 9 input by the thermal deviation generator 10 (S10). As described above, the thermal deviation generating unit 10 may cause the secondary battery cell 9 to absorb or generate heat by utilizing, for example, a laser beam or a refrigerant. For example, a laser beam may be irradiated to the secondary battery cell 9 or a temperature deviation may be generated for each part of the cell 9 by supplying gas. When using the laser beam excitation method in step S10, for example, a continuous linear laser beam may be excited to the secondary battery cell 9.

Then, a thermal image is generated by measuring the heat wave emitted from the secondary battery cell 9 through the thermal measuring unit 30 (S30). Step S30 may be performed through the thermal imaging camera unit 310, and each frame constituting the thermal image may be identified by extracting only the corresponding line after a predetermined time from the laser beam excitation of the thermal deviation generating unit 10. can More specifically, an entire thermal image may be constructed by extracting corresponding lines (for example, lines orthogonal to the scanning direction) after 1 second of having a laser beam for each frame. At this time, the position line 1 second after the start of the operation of the thermal deviation generating unit 10 may constitute the first frame of the thermal image. Each frame can be arranged row by row to create an entire thermal image.

After that, whether or not the secondary battery cell 9 is defective and the location of the defect are specified through the generated thermal image (S50). Step S50 may be performed through the control unit 50, and whether or not there is a defect and the part may be specified by determining whether the temperature difference between the normal test piece and the part of the secondary battery 9 currently under inspection exceeds a preset value.

The above detailed description is illustrative of the present invention. In addition, the foregoing is intended to illustrate and describe preferred embodiments of the present invention, and the present invention can be used in various other combinations, modifications and environments. That is, changes or modifications are possible within the scope of the concept of the invention disclosed in this specification, within the scope equivalent to the written disclosure and / or within the scope of skill or knowledge in the art. The foregoing embodiment describes the best state for implementing the technical idea of the present invention, and various changes required in specific application fields and uses of the present invention are also possible. Therefore, the above detailed description of the invention is not intended to limit the invention to the disclosed embodiments.

1: Secondary battery defect inspection device
10: thermal deviation generating unit
110: laser output machine 130: laser shape control lens
150: laser focus control lens
30: heat measuring unit
310: thermal imaging camera unit 330: focus lens
50: control unit
510: image storage unit 530: defect specific module
9: secondary battery cell
91: electrode assembly 911: electrode tab
93: lead
95: pouch case
951: accommodation home 953: gas room
955: side

Claims (11)

a thermal deviation generating unit for radiating heat waves from the inserted secondary battery cells;
a thermal measurement unit generating a thermal image by measuring the heat wave emitted from the secondary battery cell by the thermal deviation generating unit along a scanning direction; and
and a controller that controls the operation of the thermal deviation generating unit and the thermal measurement unit and determines whether or not a defect occurs in the secondary battery cell based on the thermal image transmitted from the thermal measurement unit. Device.
The method of claim 1, wherein the thermal deviation generating unit
A defect inspection device for a secondary battery, characterized in that the charged secondary battery cell absorbs heat or generates heat.
The method of claim 1, wherein the heat measuring unit
a thermal imaging camera unit generating a thermal image of a thermal wave shape of a secondary battery cell; and
and a focus lens disposed between the thermal imaging camera unit and the secondary battery cell to control a focus so that the thermal imaging camera unit receives a heat wave shape from the secondary battery cell.
The method of claim 3, wherein the thermal imaging camera unit
A defect inspection device for a secondary battery that automatically creates a scale bar for the numerical range of the temperature of a cell of a secondary battery where heat is measured in a generated thermal image.
The method of claim 3, wherein the thermal imaging camera unit
A defect inspection apparatus for a secondary battery, characterized in that it has frames formed by extracting only the corresponding line after a predetermined time from the laser beam excitation of the thermal deviation generating unit.
6. The method of claim 5, wherein the frames are
A defect inspection apparatus for a secondary battery, characterized in that it is arranged in rows to generate an entire thermal image.
The method of claim 3, wherein the control unit
an image storage unit for storing a thermal image of a normal test piece of a secondary battery cell having no defects; and
and a defect identification module that determines whether a defect occurs by comparing the thermal image of the secondary battery cell stored in the image storage unit with the thermal image of the inserted secondary battery cell.
The method of claim 3, wherein the thermal deviation generating unit
a laser output device that excites an output laser beam toward a secondary battery cell; and
A defect inspection apparatus for a secondary battery comprising a; laser focus control lens for controlling the focus of the laser beam output from the laser output device.
According to claim 8,
The secondary battery defect inspection apparatus further comprising a; laser shape control lens disposed between the laser output unit and the laser focus control lens to modulate the laser shape output from the laser output unit.
10. The method of claim 9, wherein the laser shape control lens
A defect inspection device for a secondary battery, characterized in that for modulating a continuous wave point laser beam output from the laser output device into a linear laser beam.
generating a thermal deviation for each part of the charged secondary battery cell;
generating a thermal image by measuring heat waves radiated from the secondary battery cell; and
Determining whether a defect occurs in the charged secondary battery cell by comparing the thermal image with the thermal image of the normal test piece;

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