Apparatus and method for inspecting defects in secondary batteries

Abstract

The present invention relates to a defect inspection device for a secondary battery including a jelly roll having first and second electrode tabs and an outermost uncoated electrode portion wound thereon, the device including a first contact unit contacting one of the first and second electrode tabs; a second contact unit contacting at least a portion of the uncoated electrode portion and moving toward the center of the jelly roll to contact the jelly roll; and an inspection unit electrically contacting the first and second electrode tabs and measuring one or more of a current, a voltage, and a resistance of the jelly roll to inspect the jelly roll for defects.

Description

[Technical field]

[0001] This application claims the benefit of the filing date of Korean Patent Application No. 10-2022-0052003, filed with the Korean Intellectual Property Office on April 27, 2022, the entire contents of which are incorporated herein by reference.

[0002] The present invention relates to an inspection device and a method for inspecting defects in a secondary battery, and more particularly to an inspection device and a method for inspecting defects in a secondary battery, which applies a voltage to a jelly roll to inspect whether or not there is a short circuit inside the jelly roll. [Background technology]

[0003] Unlike primary batteries, secondary batteries can be recharged, and they have the potential to be small and have large capacity, so they have been the subject of much research and development in recent years. As technological development and demand for mobile devices increases, the demand for secondary batteries as an energy source is rapidly increasing.

[0004] Secondary batteries are classified into coin type batteries, cylindrical type batteries, prismatic type batteries, and pouch type batteries according to the shape of the pouch. In secondary batteries, the electrode assembly attached inside the pouch is a chargeable and dischargeable power generating element having a laminated structure of electrodes and separators.

[0005] Electrode assemblies can be broadly classified into a jelly-roll type in which a separator is interposed between a sheet-like positive electrode and a negative electrode coated with an active material and the electrode is wound up; a stack type in which a plurality of positive electrodes and negative electrodes are sequentially stacked with a separator interposed therebetween; and a stack / folding type in which a stack type unit cell is wound up with a long separating film.

[0006] In such an electrode assembly, the separator serves to electrically insulate the positive electrode from the negative electrode and to prevent the occurrence of an internal short circuit.

[0007] However, during the manufacturing process of the electrode assembly or a secondary battery including the electrode assembly, the separator may be torn, damaged, or folded, causing local contact between the electrodes, which may result in problems such as low voltage failure, fire, and explosion due to the contact between the electrodes.

[0008] However, in the conventional electrode assembly defect inspection, it is difficult to precisely detect a local detection site between the electrodes. Summary of the Invention [Problem to be solved by the invention]

[0009] The present invention aims to solve the problems of the prior art by providing a defect inspection device and method for a secondary battery that reduces the defect rate of secondary batteries due to variables such as the thickness and position of the electrode tabs. [Means for solving the problem]

[0010] One embodiment of the present invention provides an apparatus for inspecting defects in a secondary battery including a jelly roll having first and second electrode tabs and an outermost uncoated electrode portion wound thereon, the apparatus including: a first contact unit contacting one of the first and second electrode tabs; a second contact unit contacting at least a portion of the uncoated electrode portion and moving toward the center of the jelly roll to contact the jelly roll; and an inspection unit electrically contacting the first and second electrode tabs and measuring one or more of a current, a voltage, and a resistance of the jelly roll to inspect the jelly roll for defects.

[0011] In one embodiment of the present invention, there is provided an apparatus for inspecting defects in a secondary battery, further including a first position adjustment unit that adjusts a position of the first contact unit such that the first contact unit contacts or separates from one of the first electrode tab and the second electrode tab, and a second position adjustment unit that adjusts a position of the second contact unit such that the second contact unit contacts or separates from the electrode uncoated portion.

[0012] In one embodiment of the present invention, there is provided an apparatus for inspecting defects in a secondary battery, wherein the first contact unit includes a forceps-like member for gripping the first electrode tab or the second electrode tab.

[0013] In one embodiment of the present invention, there is provided a defect inspection device for a secondary battery, wherein the second contact unit includes a main body and a second contact portion provided on one surface of the main body and in contact with the electrode uncoated portion.

[0014] In one embodiment of the present invention, there is provided a defect inspection device for a secondary battery, wherein the second contact portion includes a plate shape.

[0015] In one embodiment of the present invention, there is provided a defect inspection device for a secondary battery, wherein the second contact portion is provided in a form of a flat surface, a concave surface, or a combination thereof.

[0016] In one embodiment of the present invention, there is provided an apparatus for inspecting defects of a secondary battery, wherein the second contact unit presses the jelly roll to contact the jelly roll.

[0017] In one embodiment of the present invention, there is provided an apparatus for inspecting defects of a secondary battery, wherein the second contact unit contacts or presses the jelly roll at a pressure of 0.1 MPa or less.

[0018] In one embodiment of the present invention, there is provided a defect inspection device for a secondary battery, wherein the second contact unit contacts the jelly roll so as to reduce a length of the jelly roll by more than 0% to 10% based on the diameter of the jelly roll.

[0019] In one embodiment of the present invention, there is provided a defect inspection device for a secondary battery, wherein the second contact portion has a contact surface that comes into contact with the electrode uncoated portion and includes a material having electrical conductivity.

[0020] In one embodiment of the present invention, there is provided an apparatus for inspecting defects in a secondary battery, wherein the contact surface includes iron, nickel, stainless steel, or a mixture thereof.

[0021] In one embodiment of the present invention, there is provided a defect inspection device for a secondary battery, wherein the second contact portion is detachably attached to the main body.

[0022] In one embodiment of the present invention, there is provided an apparatus for inspecting defects in a secondary battery, further comprising a power supply unit that applies a test voltage to the first contact unit and the second contact unit.

[0023] In one embodiment of the present invention, there is provided an apparatus for inspecting defects in a secondary battery, further comprising a control unit that stores at least one reference value of a current, a voltage, and a resistance of the jelly roll, and compares data measured by the inspection unit with the reference value to determine whether the jelly roll is defective.

[0024] In one embodiment of the present invention, there is provided an apparatus for inspecting defects in a secondary battery, further comprising a mounting portion on which the jelly roll is mounted.

[0025] In one embodiment of the present invention, there is provided an apparatus for inspecting defects in a secondary battery, wherein the placement part includes a third contact part that contacts the jelly roll, and a placement part main body that supports the third contact part.

[0026] Another embodiment of the present invention provides a method for inspecting defects in a secondary battery including a jelly roll having first and second electrode tabs and an outermost uncoated electrode portion wound thereon, the method including a first contacting step of contacting a first contact unit with the first electrode tab or the second electrode tab; a second contacting step of contacting at least a portion of the second contact unit with the uncoated electrode portion; and an inspection step of electrically contacting the first electrode tab and the second electrode tab and measuring any one or more of a current, a voltage, and a resistance of the jelly roll to inspect for defects in the jelly roll.

[0027] In another embodiment of the present invention, there is provided a method for testing defects in a secondary battery, further comprising the step of applying a test voltage to the jelly roll.

[0028] In another embodiment of the present invention, there is provided a method for inspecting defects in a secondary battery, the inspecting step comprising comparing a measured value with a reference value to determine whether the jelly roll is defective. Effect of the Invention

[0029] According to the defect inspection device and defect inspection method for a secondary battery according to an embodiment of the present invention, the defect rate of secondary batteries due to variables such as the thickness and position of the electrode tabs can be reduced. [Brief description of the drawings]

[0030] [Figure 1] 1 is a front view showing an inspection device for detecting defects in a secondary battery according to an embodiment of the present invention; [Diagram 2] FIG. 4 is a cross-sectional view showing a second contact unit according to the present invention. [Diagram 3] FIG. 2 is a cross-sectional view showing a placement portion according to the present invention. [Explanation of symbols]

[0031] 100 Defect inspection device 10 First contact unit 10a...Support part 10b...1st contact part 11...1st position adjustment section 11a...Second moving part 11b...1st moving part 11c Cylinder 20 Second contact unit 21 Main unit 22...Second contact part 23...Second position adjustment section 30 ...Placement section 31 ...Placement unit main body 32...Third contact part DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0032] The detailed description of the present invention is intended to fully explain the present invention to those skilled in the art. Throughout the specification, when a part is described as "comprising" a certain element or as "featuring" a certain structure and shape, this does not mean that other elements are excluded or that other structures and shapes are excluded, but that other elements, structures, and shapes may be included, unless otherwise specified to the contrary.

[0033] The present invention may be modified in various ways and may have various embodiments, and specific embodiments will be presented and described in detail in the detailed description. However, this is not intended to limit the content of the invention to the embodiments, and it should be understood that the present invention includes all modifications, equivalents, or alternatives within the spirit and technical scope of the present invention.

[0034] The present invention will be described in detail below with reference to the drawings. However, the drawings are for illustrative purposes only and the scope of the present invention is not limited by the drawings.

[0035] FIG. 1 is a front view showing an inspection device 100 for inspecting secondary batteries for defects according to an embodiment of the present invention.

[0036] The secondary battery defect inspection device 100 inspects the jelly roll included in the secondary battery for defects, and includes a first contact unit 10, a second contact unit 20, and an inspection section (not shown).

[0037] The jelly roll applied to the defect inspection device 100 of the present invention may be provided with a first electrode tab and a second electrode tab, and may be provided in a form in which an uncoated electrode portion is wound on the outermost side. More specifically, the jelly roll may include a precursor in which a first electrode, a first separator, a second electrode, and a second separator are wound in this order, and an uncoated electrode portion wound around the outermost side of the precursor. Therefore, if the radius of the precursor is r, the periphery length of the precursor may be 2πr, and the length of the uncoated electrode portion may be 2πr or more.

[0038] At least a portion of the first contact unit 10 may be in contact with either the first electrode tab or the second electrode tab, where "in contact" means being electrically connected to the first electrode tab or the second electrode tab.

[0039] The first contact unit 10 may include a support portion 10a and a first contact portion 10b, and the first contact portion 10b is in contact with the first electrode tab or the second electrode tab and may be provided in a form capable of gripping the first electrode tab or the second electrode tab. For example, the first contact portion 10b may include a forceps shape or a finger shape. The support portion 10a may receive power from the outside and drive the first contact portion 10b. In other words, the support portion 10a may receive power from the outside or from a first position adjustment portion 11 described later and move the first contact portion 10b so that the first contact portion 10b can grip the first electrode tab or the second electrode tab.

[0040] The first contact unit 10 can grip a tab of an electrode different from that of the second contact unit 20. Preferably, the jelly roll according to the present invention is wound with the negative electrode uncoated portion at the outermost side, so that the first contact unit 10 can grip the positive electrode tab and come into contact with it, and the second contact unit 20 can come into contact with the negative electrode uncoated portion.

[0041] For example, if the first electrode tab is a positive electrode tab and the second electrode tab is a negative electrode tab, the first contact unit 10 can hold the first electrode tab, and if the first electrode tab is a negative electrode tab and the second electrode tab is a positive electrode tab, the first contact unit 10 can hold the second electrode tab.

[0042] The second contact unit 20 comes into contact with the negative electrode uncoated portion, thereby making it possible to detect defects in the electrode assembly without damaging the electrode assembly.

[0043] The secondary battery defect inspection device 100 according to the present invention may further include a first position adjustment unit 11. The first position adjustment unit 11 may adjust the position of the first contact unit 10 so that the first contact unit 10 can contact either the first electrode tab or the second electrode tab.

[0044] The first position adjustment unit 11 can move the first contact unit 10 in at least one or more directions. For example, the first position adjustment unit 11 can move the first contact unit 10 in a first direction and a second direction. In this case, the first direction may be a direction parallel to a direction in which the first electrode tab or the second electrode tab protrudes. And the second direction may be a direction perpendicular to the first direction.

[0045] The first position adjustment part 11 can include a first moving part 11b that moves the first contact unit 10 in a first direction, and a second moving part 11a that moves the first contact unit 10 in a second direction. The second moving part 11a is supplied with power from an external source and can move the first contact unit 10 in the second direction.

[0046] The first moving part 11b may include, for example, a rail, and one surface of the second moving part 11a may be provided with a driving part (not shown) that is coupled with the rail and moves along the rail.

[0047] Alternatively, the first moving part 11b may be coupled to a cylinder 11c, and the first contact unit 10 may be moved in a first direction by the movement of the cylinder. In this case, the second moving part 11a may be fixedly coupled to one surface of the first moving part 11b by screw coupling or the like.

[0048] The second contact unit 20 may be in contact with at least a portion of the electrode uncoated portion. In the jelly roll according to the present invention, the electrode uncoated portion is wound on the outermost side, so that the electrode uncoated portion and the inner wall of the case may be in direct contact with each other and electrically connected to each other.

[0049] Therefore, the second contact unit 20 according to the present invention can apply power to the jelly roll even if it contacts only a part of the electrode uncoated portion without contacting the first or second electrode tab. And, the secondary battery defect inspection device 100 according to the present invention can prevent errors due to poor contact with the negative electrode tab during secondary battery defect inspection by not gripping the negative electrode tab, and is not affected by the thickness or position of the electrode tab.

[0050] 2 is a cross-sectional view showing a second contact unit 20 according to the present invention. The second contact unit 20 may include a body 21 and a second contact portion 22. The second contact portion 22 may include a contact surface that contacts the electrode uncoated portion, and may include a certain height from the contact surface in the direction of the body 21.

[0051] The second contact portion 22 can be detachably coupled to the main body 21. That is, the second contact portion 22 can be detachably coupled to one side of the main body 21. Therefore, when the contact surface of the second contact unit 20 becomes contaminated or damaged and current cannot be transmitted to the jelly roll, only the second contact portion 22 can be separated and replaced.

[0052] The second contact portion 22 may be connected to the main body 21 of the second contact unit 20 in any suitable manner as long as the second contact portion 22 is separable from the main body 21 of the second contact unit 20. The main body 21 and the second contact portion 22 may be connected to each other by screw connection or snap connection.

[0053] The second contact portion 22 may have a plate shape. For example, the second contact portion 22 may have a flat surface, a curved surface, or a combination thereof.

[0054] In this case, the curved surface may be provided in a shape corresponding to the outer shape of the jelly roll, such as a concave curved surface. For example, when the jelly roll has a cylindrical shape, the cross section of the jelly roll that contacts the second contact unit 20 may have a convex shape, and the cross section of the contact surface of the second contact unit 20 may have a concave shape that fits with the convex cross section of the jelly roll.

[0055] The curvature of the second contacting unit 20 can be the same as the surface curvature of the jelly roll that contacts the second contacting unit 20, or the second contacting unit 20 can have a curvature that is greater than the surface of the jelly roll.

[0056] Alternatively, the radius of curvature of the second contacting unit 20 may be the same as or greater than the radius of curvature of the jelly roll.

[0057] In one embodiment, the jelly roll may be a 2170 model, which is a jelly roll having a diameter of 20 mm to 21 mm. In this case, the radius of curvature of the second contact unit 20 may be 0.02 mm to 0.1 mm larger than the radius of curvature of the jelly roll.

[0058] The second contact unit 20 can transmit a voltage applied from an external power source to the jelly roll through a contact surface with the jelly roll. Therefore, the contact surface of the second contact unit 20 can include a conductive material. For example, the conductive material can include a metal material, and the metal material can include iron, nickel, stainless steel, etc.

[0059] And, the body 21 may comprise a non-conductive material or a semiconductive material.

[0060] The secondary battery defect inspection device 100 according to the present invention may further include a second position adjusting unit 23. The second position adjusting unit 23 may adjust the position of the second contact unit 20 so that the second contact unit 20 and the electrode uncoated portion can be brought into contact with and separated from each other.

[0061] The second position adjustment part 23 can move the second contact unit 20 in at least one or more directions, and preferably the second position adjustment part 23 can move in only one direction. For example, the second contact unit 20 can contact a side of the jelly roll that is not provided with the first and second electrode tabs and move toward the center of the jelly roll and in the opposite direction.

[0062] The second position adjusting part 23 may include a second cylinder coupled to the body 21 of the second contact unit 20 and moving the second contact unit 20 in a direction perpendicular to the central axis of the jelly roll. In the second position adjusting part 23, a piston rod of the second cylinder is positioned in a direction perpendicular to the central axis of the jelly roll, and the second contact unit 20 is coupled to one surface of a screw that is positioned inside the piston rod and moves along the piston rod, so that the second contact unit 20 can be moved up and down by the screw.

[0063] The second contact unit 20 may descend toward the jelly roll to contact the jelly roll, and the second position adjustment unit 23 may include a pressure adjustment unit (not shown) capable of adjusting the pressure applied to the jelly roll when the second contact unit 20 contacts the jelly roll.

[0064] Therefore, the second contact unit 20 may be electrically connected to the jelly roll without contacting it, or may apply pressure to the jelly roll by a pressure adjusting unit with a force that does not damage the jelly roll.

[0065] For example, the pressure adjusting unit may adjust the pressure applied to the jelly roll by the second contact unit 20 to 0.1 MPa or less. Alternatively, the pressure adjusting unit may apply pressure to the jelly roll such that the diameter of the jelly roll is reduced by a length greater than 0% and less than 10% based on the diameter of the jelly roll.

[0066] The pressure adjusting unit controls the pressure of the second contact unit within the above range, thereby minimizing damage and destruction of the jelly roll.

[0067] The secondary battery defect inspection device 100 according to the present invention may further include a mounting unit 30 on which the jelly roll is mounted. The mounting unit 30 is provided at a position facing the second contact unit 20, and may include at least one mounting unit.

[0068] The contact surface of the mounting unit 30 that comes into contact with the jelly roll may have either a flat surface or a curved surface. When the contact surface of the mounting unit 30 is a curved surface, the curve may be formed in a shape that fits the jelly roll placed on the contact surface of the mounting unit 30.

[0069] The mounting portion 30 is movable toward and away from the second contact unit 20. Therefore, the secondary battery defect inspection device 100 can bring the jelly roll into contact with the second contact unit 20 by moving the mounting portion 30 up and down.

[0070] The contact surface of the support unit 30 may include one of a conductive material and a semiconductive material. For example, the conductive material may include a metal material, and the metal material may include iron, nickel, stainless steel, etc.

[0071] 3 is a cross-sectional view showing the mounting portion 30 according to the present invention. The mounting portion 30 may include a third contact portion 32 including a contact surface. That is, the mounting portion 30 includes a mounting portion body 31 and a third contact portion 32 coupled to one surface of the mounting portion body 31, and the third contact portion 32 may be separated from and coupled to the mounting portion body 31.

[0072] A pair of mounting parts 30 may be provided, or one mounting part may be provided extending along the length direction of the jelly roll, where the length direction of the jelly roll refers to the length of a straight line connecting both ends of the jelly roll from which the first and second electrode tabs protrude.

[0073] The inspection unit can inspect the jelly roll for defects by electrically contacting the first electrode tab and the second electrode tab, i.e., the inspection unit can inspect the jelly roll for defects by measuring at least one of a current, a voltage, and a resistance of the jelly roll.

[0074] The secondary battery defect inspection device 100 according to the present invention further includes a power supply unit (not shown) that applies a test power supply to the first contact unit 10 and the second contact unit 20, and the power supply unit supplies the first contact unit 10 and the second contact unit 20 with electricity required for charging and discharging the jelly roll.

[0075] In this case, the inspection unit can measure at least one of the current, voltage, and resistance of the jelly roll supplied with electricity.

[0076] For example, the secondary battery defect inspection device 100 can overcharge a jelly roll from an external power source and measure the current, voltage, and resistance when a short circuit occurs. If the separator shorts out inside the jelly roll, the positive and negative electrodes are not insulated, and an overcurrent occurs inside the jelly roll when overcharged. As the current value of the jelly roll increases, the capacity of the jelly roll may decrease. And, a jelly roll that includes an internal short circuit may experience a decrease in current and voltage when overcharged as the capacity of the jelly roll decreases.

[0077] Thus, if the secondary battery is defective, the test unit can measure a current and a voltage that are lower than the reference values ​​already stored in a control unit (not shown) described below.

[0078] In a jelly roll, the positive and negative electrodes should be insulated by a separator. If the separator shorts out, the positive and negative electrodes come into contact with each other, causing an overcurrent to flow, which can result in fire or explosion.

[0079] The inspection unit can further measure the temperature to detect fires and explosions of the jelly roll. For example, the inspection unit can include a data logger equipped with a thermocouple.

[0080] The secondary battery defect inspection device 100 according to the present invention may further include a control unit that stores or externally transmits reference values ​​for comparing with the current, voltage, and resistance of the jelly roll measured by the inspection unit, and compares the reference values ​​with the measured values ​​measured by the inspection unit to determine defects.

[0081] The reference value may include one or more values ​​of current, voltage, and resistance measured when power is supplied to a good jelly roll that is free of defects such as short circuits. In this case, the power supply applied to the good jelly roll may be the same as the power supply applied to the jelly roll when measuring defects in a secondary battery.

[0082] The method for inspecting a secondary battery for defects according to the present invention includes a first contacting step (S10), a second contacting step (S20), and an inspection step (S30).

[0083] The first contact step (S10) is a step of moving the first contact unit to bring the first contact unit into contact with the first electrode tab or the second electrode tab.

[0084] For example, the first contact step (S10) may include a step of receiving power from an external source and driving a pair of forceps or fingers provided on the first contact unit to increase the distance between the pair of forceps or fingers, a step of sensing the position of the first electrode tab or the second electrode tab to adjust the position of the first contact unit, and a step of decreasing the distance between the pair of forceps or fingers so that the forceps or fingers grasp the first electrode tab or the second electrode tab.

[0085] The second contact step (S20) is a step of contacting at least a portion of the second contact unit with the electrode uncoated portion.

[0086] For example, the second contact step (S20) may include a step of moving the second contact unit, and a step of stopping the movement of the second contact unit when the second contact unit comes into contact with the electrode non-coating portion.

[0087] The inspection step (S30) is a step of electrically contacting the first electrode tab and the second electrode tab and measuring at least one of the current, voltage, and resistance of the jelly roll to inspect the jelly roll for defects.

[0088] The method for testing defects in a secondary battery according to the present invention may further include applying a test voltage to the jelly roll.

[0089] The test step (S30) may measure any one of the current, voltage, and resistance of the jelly roll when the jelly roll is driven by a test voltage.

[0090] For example, the inspection step (S30) may include a step of an inspection unit contacting the first electrode tab and the second electrode tab, a step of measuring one or more of a current, a voltage, and a resistance of the jelly roll to which a test voltage is applied, and a step of comparing the measured values ​​with a reference value to determine whether the jelly roll is defective.

[0091] At this time, the reference value may be pre-stored or may be transmitted from an external device.

[0092] If the measured current and voltage are below the reference values ​​or the measured resistance is above the reference values, the secondary battery can be judged as defective, and if the measured current, voltage, and resistance are the same as the reference values, the secondary battery can be judged as good.

[0093] The description of the defect inspection method for secondary batteries can be made by citing the description of the overlapping configuration in the defect inspection device for secondary batteries.

[0094] Although the present invention has been described above with reference to preferred embodiments, those skilled in the art will understand that the present invention can be modified and changed in various ways without departing from the spirit and scope of the present invention as set forth in the claims below.

Claims

1. A defect inspection device for a secondary battery, comprising a jelly roll having a first electrode tab and a second electrode tab and an electrode non-coating portion wound on an outermost side thereof, a first contact unit contacting one of the first electrode tab and the second electrode tab; a second contact unit that is in electrical contact with at least a portion of the electrode non-coating portion and moves toward the center of the jelly roll to contact the jelly roll; and an inspection unit that electrically contacts the first contact unit and the second contact unit and measures at least one of a current, a voltage, and a resistance of the jelly roll to inspect whether the jelly roll is defective; A secondary battery defect inspection device comprising:

2. 2. The apparatus of claim 1, further comprising: a first position adjustment unit that adjusts a position of the first contact unit so that the first contact unit contacts or separates from one of the first electrode tab and the second electrode tab; and a second position adjustment unit that adjusts a position of the second contact unit so that the second contact unit contacts or separates from the electrode uncoated portion.

3. The secondary battery defect inspection device according to claim 1 , wherein the first contact unit includes a forceps-like structure that grips the first electrode tab or the second electrode tab.

4. The device for inspecting defects in a secondary battery according to claim 1 , wherein the second contact unit includes a body and a second contact portion provided on one surface of the body and in contact with the electrode uncoated portion.

5. The secondary battery defect inspection device according to claim 4 , wherein the second contact portion includes a plate-shaped structure.

6. The device for inspecting defects in a secondary battery according to claim 4 , wherein the second contact portion is provided in a form of a flat surface, a concave surface, or a combination thereof.

7. The apparatus for inspecting defects of a secondary battery according to claim 1 , wherein the second contact unit presses the jelly roll to contact the jelly roll.

8. The device for inspecting defects in a secondary battery according to claim 1 , wherein the second contact unit contacts or presses the jelly roll with a pressure of 0.1 MPa or less.

9. 2. The apparatus of claim 1, wherein the second contact unit contacts the jelly roll such that a length of the second contact unit is reduced by more than 0% to less than 10% of a diameter of the jelly roll based on the diameter of the jelly roll.

10. The device for inspecting defects in a secondary battery according to claim 4 , wherein the second contact portion has a contact surface that contacts the electrode uncoated portion and includes a material having electrical conductivity.

11. The device for inspecting defects in a secondary battery according to claim 10 , wherein the contact surface comprises iron, nickel, stainless steel, or a mixture thereof.

12. The secondary battery defect inspection device according to claim 4 , wherein the second contact portion is detachably attached to the main body.

13. The secondary battery defect inspection device according to claim 1 , further comprising a power supply unit applying a test voltage to the first contact unit and the second contact unit.

14. 2. The apparatus of claim 1, further comprising a control unit that stores at least one reference value of a current, a voltage, and a resistance of the jelly roll, and compares data measured by the inspection unit with the reference value to determine whether the jelly roll is defective.

15. The secondary battery defect inspection device according to claim 1 , further comprising a placement unit on which the jelly roll is placed.

16. The device for inspecting defects in a secondary battery according to claim 15 , wherein the mounting portion includes a third contact portion that contacts the jelly roll, and a mounting portion main body that supports the third contact portion.

17. A method for inspecting a secondary battery for defects, the method comprising: a jelly roll having a first electrode tab and a second electrode tab and an electrode non-coating portion wound on an outermost side of the jelly roll, the method comprising: a first contacting step of contacting a first contact unit with the first electrode tab or the second electrode tab; a second contacting step of electrically contacting at least a portion of the second contact unit to the electrode non-coating portion; and an inspection step of inspecting the jelly roll for defects by an inspection unit electrically contacting the first contact unit and the second contact unit and measuring at least one of a current, a voltage, and a resistance of the jelly roll; A method for inspecting a secondary battery for defects, comprising:

18. The method of claim 17 , further comprising the step of applying a test voltage to the jelly roll.

19. 20. The method of claim 17, wherein the inspecting step comprises comparing the measured value with a reference value to determine whether the jelly roll is defective.

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