Pouch cell analysis apparatus and pouch cell analysis method using same

Abstract

The present invention relates to a pouch battery cell analysis apparatus and a pouch battery cell analysis method using same, and, specifically, to a pouch battery cell analysis apparatus and a pouch battery cell analysis method using same, the apparatus comprising: a measurement unit for measuring the voltage of a pouch battery cell; a control unit for determining, on the basis of the voltage value measured by the measurement unit, whether there is a defect; a cutting member capable of cutting a pouch case of the pouch battery cell; a gripping member capable of griping the pouch case while being in close contact therewith; and an analysis unit positioned above the pouch battery cell.

Description

Pouch battery cell analysis device and pouch battery cell analysis method using the same

[0001] This application claims the benefit of priority based on Korean Patent Application No. 2024-0178214 filed December 4, 2024, and all contents disclosed in the document of said Korean patent application are incorporated herein as part of this specification.

[0002] The present invention relates to a pouch battery cell analysis device and a pouch battery cell analysis method using the same. Specifically, it relates to a pouch battery cell analysis device capable of safely disassembling and analyzing a pouch battery cell determined to be defective, and a pouch battery cell analysis method using the same.

[0003] Recently, due to air pollution caused by the use of fossil fuels and the development of alternative energy sources resulting from energy depletion, the demand for secondary batteries capable of storing generated electrical energy is increasing.

[0004] Rechargeable batteries, which serve as an indispensable energy source for various electronic devices in modern society, are seeing increased capacity requirements due to the growing usage and complexity of mobile devices and the development of electric vehicles. While multiple battery cells are arranged in small devices to meet user demand, vehicles utilize battery modules that electrically connect multiple battery cells, or battery packs equipped with multiple such modules.

[0005] Meanwhile, the battery cell can be charged and discharged multiple times, and the voltage value is measured to determine whether defects such as short circuits or low voltage have occurred in the battery cell.

[0006] In addition, battery cells determined to have defects such as short circuits or low voltage are disassembled by a worker using a cutting knife or similar tool, and analyzed to identify the cause of the defect.

[0007] FIG. 1 is a perspective view showing an automatic inspection device according to the prior art. As shown in FIG. 1, the automatic inspection device according to the prior art is configured to include a machine (10) made of a robot device and a test tool (12) that contacts a battery cell (14) to measure voltage.

[0008] In this conventional automatic inspection device, the machine (10) contacts the test tool (12) to the electrode lead of the battery cell (14) to measure the voltage value of the battery cell (14) and determine whether it is defective.

[0009] For battery cells (14) that are determined to be defective, a worker cuts the pouch case with a cutting knife or similar tool to analyze the condition of the internal electrode assembly and the condition of the electrode tabs to identify the cause of the defect.

[0010] However, there is a problem in that safety accidents, such as overheating and ignition, may occur during disassembly and analysis to determine whether a battery cell is defective according to conventional technology.

[0011] In addition, there is a problem in that workers may experience fatigue from performing repetitive tasks such as disassembly and analysis, which can make accurate disassembly and analysis difficult.

[0012] (Prior Art Literature)

[0013] (Patent Document 1) Korean Registered Patent Publication No. 1939966

[0014] To solve the above-mentioned problems, the present invention aims to provide a pouch battery cell analysis device and a pouch battery cell analysis method using the same, which can prevent worker safety accidents by disassembling and analyzing pouch battery cells determined to be defective through the device.

[0015] In addition, the present invention aims to provide a pouch battery cell analysis device capable of accurately and rapidly performing the process of disassembly and analysis by conducting disassembly and analysis through the device, and a pouch battery cell analysis method using the same.

[0016] A pouch battery cell analysis device according to the present invention for achieving the above-mentioned purpose is characterized by comprising: a control unit (200) that determines whether there is a defect based on a voltage value measured by a measuring unit (100); a cutting member (300) capable of cutting the pouch case of the pouch battery cell (C); a gripping member (400) capable of gripping in close contact with the pouch case; and an analysis unit (500) located on the upper part of the pouch battery cell (C) to analyze the defect state.

[0017] In addition, in the pouch battery cell analysis device according to the present invention, the cutting member (300) is characterized as being a robot arm equipped with a blade head (310).

[0018] In addition, in the pouch battery cell analysis device according to the present invention, the gripping member (400) is characterized as being a robot arm equipped with an adsorption head (410).

[0019] In addition, in the pouch battery cell analysis device according to the present invention, the gripping member (400) is characterized by being connected to an air pump (600) that supplies and sucks in air.

[0020] In addition, in the pouch battery cell analysis device according to the present invention, the analysis unit (500) is characterized as being a vision camera capable of photographing the pouch battery cell (C).

[0021] In addition, in the pouch battery cell analysis device according to the present invention, the blade head (310) is characterized by having a detachable structure.

[0022] In addition, the pouch battery cell analysis method according to the present invention is characterized by comprising: a first step of measuring the voltage of the pouch battery cell; a second step of determining whether the pouch battery cell is defective based on the measured voltage value; a third step of disassembling the pouch battery cell when it is determined to be defective; and a fourth step of photographing and analyzing the disassembled pouch battery cell.

[0023] In addition, in the method for analyzing a pouch battery cell according to the present invention, the second step of determining whether the pouch battery cell is defective based on the measured voltage value is characterized by determining whether it is defective by comparing the voltage value of a normal state according to existing data with the measured voltage value.

[0024] In addition, the pouch battery cell analysis method according to the present invention is characterized by determining that the measured voltage value is lower than the normal state voltage value and higher than 0 as a low voltage defect.

[0025] In addition, the pouch battery cell analysis method according to the present invention is characterized by first cutting the pouch case portion corresponding to the location where the electrode assembly is housed in the pouch battery cell when a low voltage defect is determined.

[0026] In addition, in the pouch battery cell analysis method according to the present invention, the electrode assembly is formed by stacking one or more unit cells and a bicell on the uppermost side of the unit cells, and the gripping member is separated from the electrode assembly and disassembled sequentially starting from the uppermost component among the components forming the electrode assembly, and simultaneously performs analysis through an analysis unit.

[0027] In addition, in the pouch battery cell analysis method according to the present invention, the above configuration is characterized as being any one of the separator, positive electrode, and negative electrode constituting the unit cell and the bicell.

[0028] In addition, the pouch battery cell analysis method according to the present invention is characterized by determining that there is a short circuit defect when the measured voltage value is 0.

[0029] In addition, the pouch battery cell analysis method according to the present invention is characterized by prioritizing the cutting of the pouch case terrace portion adjacent to the portion where the electrode tab and the electrode lead are connected in the pouch battery cell when a short circuit defect is determined.

[0030] As explained above, the pouch battery cell analysis device and the pouch battery cell analysis method using the same according to the present invention have the advantage of preventing worker safety accidents by disassembling through a cutting member and a gripping member made of a robot arm and analyzing through an analysis unit made of a vision camera.

[0031] In addition, the pouch battery cell analysis device and the pouch battery cell analysis method using the same according to the present invention have the advantage of being able to quickly and accurately disassemble and analyze pouch battery cells determined to be defective by automating the disassembly and analysis.

[0032] FIG. 1 is a perspective view showing an automatic inspection device according to the prior art.

[0033] FIG. 2 is a perspective view showing a pouch battery cell analysis device according to a preferred embodiment of the present invention.

[0034] FIG. 3 is a flowchart illustrating a pouch battery cell analysis method according to a preferred embodiment of the present invention.

[0035] Embodiments that enable a person skilled in the art to easily implement the present invention are described in detail below with reference to the attached drawings. However, in describing the operating principles of preferred embodiments of the present invention in detail, if it is determined that a specific description of related known functions or configurations may unnecessarily obscure the essence of the present invention, such detailed description will be omitted.

[0036] In addition, the same reference numerals are used for parts having similar functions and operations throughout the drawings. Throughout the specification, when a part is described as being connected to another part, this includes not only cases where they are directly connected, but also cases where they are indirectly connected with other elements in between. Furthermore, unless specifically stated otherwise, the inclusion of a certain component does not exclude other components but implies that additional components may be included.

[0037] Hereinafter, a pouch battery cell analysis device and a pouch battery cell analysis method using the same according to the present invention will be described with reference to the attached drawings.

[0038] FIG. 2 is a perspective view showing a pouch battery cell analysis device according to a preferred embodiment of the present invention.

[0039] Referring to FIG. 2, a pouch battery cell analysis device according to a preferred embodiment of the present invention comprises a measuring unit (100), a control unit (200), a cutting member (300), a gripping member (400), an analysis unit (500), and an air pump (600).

[0040] First, the measuring unit (100) is for measuring the voltage value of the pouch battery cell (C) and is connected to the electrode lead, which consists of the negative lead and the positive lead of the pouch battery cell (C).

[0041] In addition, the measuring unit (200) transmits the measured voltage value of the pouch battery cell (C) to the control unit (200).

[0042] Here, the pouch battery cell (C) comprises an electrode assembly, a pouch case housing the electrode assembly, and an electrode lead protruding outward from the pouch case.

[0043] The electrode assembly has a structure in which positive and negative electrodes are stacked alternately multiple times with a separator in between, and a pair of electrode leads, consisting of a positive lead and a negative lead, are electrically connected to the positive tab and the negative tab and then exposed to the outside of the pouch case.

[0044] The positive electrode is manufactured by applying a positive electrode composite containing a positive electrode active material onto a positive electrode current collector and then drying it, and the positive electrode composite may optionally further include a binder, a conductive agent, a filler, etc., as needed.

[0045] The positive current collector can generally have a thickness of 3 to 500 μm. Such a positive current collector is not particularly limited as long as it has high conductivity without causing chemical changes in the battery, and for example, stainless steel, aluminum, nickel, titanium, calcined carbon, or aluminum or stainless steel surface-treated with carbon, nickel, titanium, silver, etc. may be used. In addition, the positive current collector may form fine irregularities on its surface to increase the adhesion of the positive active material, and various forms such as films, sheets, foils, nets, porous bodies, foams, and nonwoven fabrics are possible.

[0046] As the positive electrode active material, layered compounds such as lithium cobalt oxide (LiCoO2) or lithium nickel oxide (LiNiO2), or compounds substituted with one or more transition metals; chemical formula Li 1+x Mn 2-x Lithium manganese oxides such as O4 (where x is 0 to 0.33), LiMnO3, LiMn2O3, LiMnO2, etc.; lithium copper oxide (Li2CuO2); vanadium oxides such as LiV3O8, V2O5, Cu2V2O7, etc.; chemical formula LiNi 1-x M x Ni-site type lithium nickel oxide represented by O2 (where M = Co, Mn, Al, Cu, Fe, Mg, B, or Ga, and x = 0.01 ~ 0.3); chemical formula LiMn2-x M x Examples include lithium manganese complex oxides represented by O2 (where M = Co, Ni, Fe, Cr, Zn or Ta and x = 0.01 to 0.1) or Li2Mn3MO8 (where M = Fe, Co, Ni, Cu or Zn); LiMn2O4 in which part of the Li in the chemical formula is substituted with alkaline earth metal ions; disulfide compounds; Fe2(MoO4)3, but are not limited to these.

[0047] The cathode is manufactured by applying a cathode composite containing a cathode active material onto a cathode current collector and then drying it, and the cathode composite may include components such as a conductive agent, a binder, and a filler, as needed.

[0048] The negative electrode current collector is generally made with a thickness of 3 to 500 μm. Such a negative electrode current collector is not particularly limited as long as it has high conductivity without causing chemical changes in the battery, and for example, copper, stainless steel, aluminum, nickel, titanium, calcined carbon, copper or stainless steel surface treated with carbon, nickel, titanium, silver, etc., and aluminum-cadmium alloy may be used. In addition, similar to the positive electrode current collector, fine irregularities may be formed on the surface to strengthen the bonding strength of the negative electrode active material, and it may be used in various forms such as film, sheet, foil, net, porous body, foam, nonwoven fabric, etc.

[0049] The separator prevents a short circuit between the aforementioned cathode and anode and enables only the movement of lithium ions; an insulating thin film having high ion permeability and mechanical strength is used. The pore diameter of the separator is generally 0.01 to 10 μm, and the thickness is generally 5 to 300 μm. The material of such a separator is preferably selected from polyethylene, polypropylene, polyethylene / polypropylene double layer, polyethylene / polypropylene / polyethylene triple layer, polypropylene / polyethylene / polypropylene triple layer, and organic fiber filter paper, but is not limited thereto.

[0050] Meanwhile, the cathode current collector and the anode current collector are composed of a portion coated with a slurry mixed with an active material and a non-coated portion not coated with the slurry. Electrode tabs are formed by cutting the non-coated portion or by connecting a separate conductive member to the non-coated portion using ultrasonic welding, and these electrode tabs are assembled to form a tab bundle.

[0051] The pouch case may be formed using a laminate sheet composed of an inner coating layer, a metal layer, and an outer coating layer, with a pocket portion capable of accommodating an electrode assembly and an edge portion extending to a certain length on the outer side of one side of the pocket portion.

[0052] Since the inner coating layer comes into direct contact with the electrode assembly, it must possess insulation and electrostatic resistance. Additionally, to ensure sealing from the outside, the sealing area where the inner layers are heat-bonded must have excellent thermal bonding strength.

[0053] The material for this inner coating layer may be selected from, but is not limited to, polyolefin resins such as polypropylene, polyethylene, polyethylene acrylic acid, and polybutylene, polyurethane resins, and polyimide resins, which have excellent chemical resistance and good sealing properties; however, polypropylene is most preferable as it has excellent mechanical properties such as tensile strength, stiffness, surface hardness, and impact strength, as well as excellent chemical resistance.

[0054] The metal layer in contact with the inner coating layer serves as a barrier layer that prevents moisture or various gases from penetrating into the battery from the outside, and a lightweight aluminum film with excellent formability can be used as a preferred material for this metal layer.

[0055] In addition, an outer coating layer is provided on the other side of the metal layer, and this outer coating layer may use a heat-resistant polymer with excellent tensile strength, moisture barrier properties, and air barrier properties to ensure heat resistance and chemical resistance while protecting the electrode assembly, and may use, for example, nylon or polyethylene terephthalate, but is not limited thereto.

[0056] In addition, a pair of electrode leads, consisting of a positive lead and a negative lead, are generally connected to the aforementioned electrode tab bundle, more specifically the positive tab bundle and the negative tab bundle by means such as welding, and then protrude to the outside of the pouch case.

[0057] Next, the control unit (200) determines whether the pouch battery cell (C) is defective based on the voltage value received from the measurement unit (100), and is located on one side of the measurement unit (100).

[0058] Although the control unit (200) is individually provided on one side of the measuring unit (100) in the drawing, it is also possible for the control unit (200) to be built into the measuring unit (100) and formed as an integral unit.

[0059] The cutting member (300) is for cutting and disassembling the pouch case of a pouch battery cell (C) that is determined to be defective, and is equipped with a blade head (310) at the end.

[0060] The cutting member (300) can be formed as a robot arm and can move freely to cut the pouch case of the pouch battery cell (C) with a blade head (310).

[0061] At this time, the blade head (310) is formed in a structure that is detachable from the cutting member (300), so that if the cutting function deteriorates due to wear of the blade head (310) from repeated use, it can be replaced.

[0062] Meanwhile, the gripping member (400) grips a part of the pouch case when the pouch case is cut through the cutting member (300), and has an adsorption head (410) at the end.

[0063] The gripping member (400) can be formed as a robot arm and is free to move, so that it can grip a portion of the entire surface of the pouch case with the suction head (410).

[0064] At this time, the suction head (410) is formed in a structure that allows it to be detachably attached from the gripping member (400).

[0065] The suction head (410) is provided with a suction head (410) of different sizes depending on the suction force and gripping area required for gripping, and can be attached to and detached from the gripping member (400).

[0066] Additionally, the gripping member (400) can grip the configuration located on the upper part of the electrode assembly embedded inside when the cutting member (300) cuts the pouch case, thereby separating the gripped configuration from the electrode assembly and disassembling it.

[0067] The analysis unit (500) analyzes the electrode assembly, electrode tab, or electrode lead of the pouch battery cell (C) that has been disassembled by the cutting member (300) and the gripping member (400), and may be equipped with a vision camera capable of taking images.

[0068] The analysis unit (500) can be positioned spaced apart from the upper part of the pouch battery cell (C) and is provided to be movable, so that its position is adjusted according to the movement radius of the cutting member (300) and the gripping member (400).

[0069] Meanwhile, the air pump (600) is connected to the suction head (410) of the gripping member (400) and can suck in and supply air so that the suction head (410) can grip and release the gripping state.

[0070] The air pump (600) may be equipped with an air hose for sucking in and supplying air.

[0071] One end of the air hose is connected to an air pump (600), and the other end can be connected to a suction head (410) by passing through a gripping member (400).

[0072] FIG. 3 is a flowchart illustrating a pouch battery cell analysis method according to a preferred embodiment of the present invention.

[0073] Referring to FIG. 3, a pouch battery cell analysis method according to a preferred embodiment of the present invention comprises a first step of measuring the voltage of a pouch battery cell, a second step of determining whether the pouch battery cell is defective based on the measured voltage value, a third step of disassembling the pouch battery cell when it is determined to be defective, and a fourth step of photographing and analyzing the disassembled pouch battery cell.

[0074] The first step of measuring the voltage of a pouch battery cell is to connect a measuring unit to the electrode lead of the pouch battery cell and measure the voltage value of the pouch battery cell.

[0075] At this time, the measuring unit transmits the measured voltage value of the pouch battery cell to the control unit for determining whether it is defective.

[0076] The second step, which determines whether the pouch battery cell is defective based on the measured voltage value, is a step of determining whether the pouch battery cell is defective based on the voltage value received from the measuring unit.

[0077] To explain in more detail, the control unit determines whether there is a defect by comparing the measured voltage value with the voltage value of a pouch battery cell in a normal state that was previously stored.

[0078] If the measured voltage value is the same as the normal state voltage value, the measured pouch battery cell is determined to be normal.

[0079] If the measured voltage value is lower than the normal voltage value and greater than 0, the measured pouch battery cell is determined to be a low voltage defect.

[0080] Also, if the measured voltage value is 0, the measured pouch battery cell is determined to have a short circuit defect.

[0081] The third step, which involves disassembling the pouch battery cell when it is determined to be defective, is a step of disassembling the pouch battery cell using a cutting member and a gripping member according to the defect determined in the second step.

[0082] More specifically, if the measured voltage value is determined to be a low voltage defect, the pouch case corresponding to the part equipped with the electrode assembly in the pouch battery cell is cut using a cutting member.

[0083] At this time, cutting can be performed while the gripping member is gripping the part to be cut.

[0084] Here, the gripping member is raised a certain distance while in a gripped state so that cutting is performed when the pouch case and the electrode assembly are separated; this is to prevent the electrode assembly from being damaged by the blade head during cutting.

[0085] Once the cutting is complete, the gripping member moves the cut portion of the pouch case so that the embedded electrode assembly is exposed.

[0086] At this time, the electrode assembly consists of one or more unit cells and a bicell located at the uppermost side of the unit cells.

[0087] After releasing the gripping of the cut portion of the pouch case, the gripping member is disassembled by separating it from the electrode assembly sequentially, starting from the uppermost component among the components forming the electrode assembly.

[0088] Here, the component located at the top may be any one of the separator, anode, and cathode constituting the unit cell and the bicell, and as an example, the bicell located at the top is disassembled by grasping and separating it in the order of separator, cathode, and separator starting from the top.

[0089] Additionally, after the bicell is separated and disassembled, the unit cell is disassembled by grasping and separating it in the order of anode, separator, cathode, and separator starting from the top.

[0090] That is, the separator, cathode, and anode are separated from each other and disassembled so that the state between the components forming the electrode assembly can be checked.

[0091] Meanwhile, if the measured voltage value is 0 and it is determined to be a short circuit defect, the part to be cut is held by suction using a gripping member, and the terrace part of the pouch case adjacent to the part where the electrode tab and electrode lead are connected is cut first using a cutting member.

[0092] At this time, the gripping member may be cut after rising a certain distance while gripping the pouch case.

[0093] This is to increase the distance between the pouch case and the electrode tab to prevent damage to the electrode tab and electrode lead by the blade head when cutting the pouch case.

[0094] The fourth step of photographing and analyzing the disassembled pouch battery cell is to photograph and analyze the internal state of the pouch case through an analysis unit positioned spaced apart from the upper part of the pouch battery cell.

[0095] More specifically, when a low voltage defect is detected, the electrode assembly is separated using a gripping member, and upon disassembly, the state of the separator, anode, and cathode is captured by an analysis unit consisting of a vision camera.

[0096] Based on the images and photos captured by the analysis unit, the occurrence of lithium precipitation, the location of lithium precipitation, and damage to the anode, cathode, and separator are analyzed to derive the cause of the low-voltage failure.

[0097] In addition, the analysis unit can photograph the electrode tab and electrode lead to analyze whether the electrode tab and electrode lead are damaged.

[0098] Meanwhile, if a short circuit is determined, the cut pouch case portion is separated using a gripping member so that the parts where the electrode tab and electrode lead are formed can be checked from the outside, and then the electrode tab and electrode lead portions are photographed using an analysis unit to analyze whether there is a short circuit in the electrode tab or electrode lead.

[0099] A person skilled in the art to which this invention pertains will be able to perform various applications and modifications within the scope of this invention based on the above content.

[0100] (Explanation of symbols)

[0101] 100: Measurement section

[0102] 200: Control unit

[0103] 300: Cutting member

[0104] 310: Blade Head

[0105] 400: Grasp member

[0106] 410: Suction head

[0107] 500: Analysis Department

[0108] 600: Air pump

[0109] C: Pouch battery cell

Claims

1. Measures the voltage of a pouch battery cell and a measuring unit; A control unit that determines whether there is a defect based on the voltage value measured by the above-mentioned measuring unit; A cutting member capable of cutting the pouch case of the above pouch battery cell; A gripping member capable of gripping in close contact with the above pouch case; and A pouch battery cell analysis device characterized by including an analysis unit located on the upper part of the pouch battery cell to analyze a defective state.

2. In Paragraph 1, A pouch battery cell analysis device characterized in that the above-mentioned cutting member is a robot arm equipped with a blade head.

3. In Paragraph 2, A pouch battery cell analysis device characterized in that the above-mentioned gripping member is a robot arm equipped with an adsorption head.

4. In Paragraph 3, A pouch battery cell analysis device characterized in that the above-mentioned gripping member is connected to an air pump that supplies and sucks in air.

5. In Paragraph 2, A pouch battery cell analysis device characterized in that the above analysis unit is a vision camera capable of photographing the above pouch battery cell.

6. In Paragraph 2, A pouch battery cell analysis device characterized by the above blade head having a detachable structure.

7. A method for analyzing a pouch battery cell using a pouch battery cell analysis device described in any one of paragraphs 1 to 6, First step of measuring the voltage of a pouch battery cell; A second step of determining whether the pouch battery cell is defective based on the measured voltage value; A third step of disassembling the above pouch battery cell when it is determined to be defective; and A method for analyzing a pouch battery cell characterized by including a fourth step of photographing and analyzing the disassembled pouch battery cell.

8. In Paragraph 7, A method for analyzing a pouch battery cell, characterized in that the second step of determining whether the pouch battery cell is defective based on the measured voltage value is to determine whether it is defective by comparing the normal state voltage value according to existing data with the measured voltage value.

9. In Paragraph 8, A pouch battery cell analysis method characterized by determining a low voltage defect when the measured voltage value is lower than the normal state voltage value and higher than 0.

10. In Paragraph 9, A pouch battery cell analysis method characterized by prioritizing the cutting of the pouch case portion corresponding to the location where the electrode assembly is housed in the pouch battery cell when the above low voltage defect is determined.

11. In Paragraph 10, The above electrode assembly is formed by stacking one or more unit cells and a bicell on the uppermost side of the unit cells, and A pouch battery cell analysis method characterized by sequentially separating and disassembling a gripping member from the electrode assembly starting from the uppermost component among the components forming the electrode assembly, and simultaneously performing analysis through an analysis unit.

12. In Paragraph 11, A pouch battery cell analysis method characterized in that the above configuration is any one of a separator, a positive electrode, and a negative electrode constituting the unit cell and the bicell.

13. In Paragraph 8, A pouch battery cell analysis method characterized by determining a short circuit defect when the measured voltage value is 0.

14. In Paragraph 13, A pouch battery cell analysis method characterized by prioritizing the cutting of the pouch case terrace portion adjacent to the portion where the electrode tab and electrode lead are connected in the pouch battery cell when the above short circuit is determined to be defective.

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