Gas collection device

Abstract

The present invention provides a gas collection device that can sample gases generated inside a secondary battery at a concentration level appropriate for analysis.

Description

Technical Field

[0001] This application claims the benefit of priority based on Korean Patent Application No. 10-2023-0183114 filed on December 15, 2023, and all the contents disclosed in the document of the Korean Patent Application are incorporated herein by reference in their entirety.

[0002] The present invention relates to a gas collection device, and more particularly, to a gas collection device capable of adjusting and sampling the gas generated inside a secondary battery to an appropriate level of concentration for analyzing the gas.

Background Art

[0003] A secondary battery is a battery that can be repeatedly used through a discharge process of converting chemical energy into electrical energy and a charging process of converting electrical energy into chemical energy. Examples of such secondary batteries include nickel-cadmium (Ni-Cd) batteries, nickel-metal hydride (Ni-MH) batteries, lithium metal batteries, lithium-ion batteries, and lithium-ion polymer batteries (Li-ion Polymer Battery), which are generally known. Among these secondary batteries, lithium secondary batteries having high energy density, voltage, long cycle life, and low self-discharge rate have been commercialized and widely used.

[0004] Inside a lithium secondary battery, various gases such as hydrogen, oxygen, nitrogen, carbon monoxide, carbon dioxide, hydrocarbons represented by C H 2n-2 (n = 2 to 5), C n H 2n (n = 2 to 5), C​​​​​​​Furthermore, lithium-ion secondary batteries generate a large amount of gas during the degradation process as the electrolyte decomposes due to repeated charging and discharging. This process manifests itself in various ways depending on the battery's design and usage. Therefore, in the battery development process, it is essential to analyze the gases generated inside the battery and infer the battery's degradation mechanism.

[0006] Therefore, it is extremely important to collect and accurately analyze the gases generated within secondary batteries. Information on the composition and content of the various gases generated during the charging and discharging of lithium secondary batteries is useful in the development of battery materials, optimization of battery manufacturing processes, and identification of the causes of battery failures. For this reason, the development of technologies for collecting gases generated inside secondary batteries is crucial.

[0007] One method for analyzing the gases generated inside a secondary battery involves the following process.

[0008] To collect the target gas generated from inside the secondary battery, holes are drilled into the battery case, and the target gas is extracted through these holes.

[0009] The extracted analyte gas is diffused into a sealed gas diffusion space.

[0010] The analyte gas diffused in the gas diffusion space is sampled into a sampling container.

[0011] The analyte gas sampled in a sampling container is injected into a gas analyzer such as GC-MS (Gas Chromatography-Mass Spectrometry) to perform gas analysis.

[0012] In the process described above, the sensitivity of a gas analyzer is affected by the concentration of the gas to be analyzed. However, if the concentration of the gas to be analyzed is excessively low, accurate analysis becomes difficult. The concentration of the gas to be analyzed is determined by the volume of the gas flow path, including the gas diffusion space and sampling container. For accurate quantitative analysis, it is necessary to know the precise volume values ​​of the gas diffusion space and gas flow path within the entire gas analysis system, but this is not easy. Therefore, gas collection technology is needed for such gas analysis systems. [Overview of the project] [Problems that the invention aims to solve]

[0013] The present invention relates to a gas collection device, and aims to provide a gas collection device that can sample a target gas generated inside a secondary battery at a concentration level appropriate for analysis.

[0014] The technical problems that this invention aims to solve are not limited to those described above, and any other technical problems not mentioned will be clearly understood by those skilled in the art from the following description. [Means for solving the problem]

[0015] The gas collection device includes a gas extraction unit for extracting gas from the battery to be analyzed, a gas diffusion unit having a gas diffusion space to which the gas extracted from the gas extraction unit is transmitted and diffused, a sampling unit having a gas sampling space to which the gas diffused from the gas diffusion unit is transmitted and sampled, and a control unit for controlling the gas diffusion unit. The volume of the gas diffusion space is variable, and the volume of the gas sampling space is fixed.

[0016] According to one embodiment, the gas extraction unit includes a gas extraction chamber section having a battery housing space in which the battery to be analyzed is housed, and a punching section for punching gas extraction holes in the battery to be analyzed housed in the battery housing space.

[0017] According to one embodiment, the gas diffusion unit includes a base plate portion consisting of a plane perpendicular to the vertical direction, a cylindrical side wall portion whose lower end is fixed to the base plate portion and which expands and contracts in the vertical direction, a vertical moving portion coupled and fixed to the upper end of the cylindrical side wall portion and which moves in the vertical direction, a guide support portion that guides the vertical movement of the vertical moving portion, and a vertical drive portion that provides a driving force for the vertical movement of the vertical moving portion, and the gas diffusion space is formed as a space surrounded by the base plate portion, the cylindrical side wall portion, and the vertical moving portion.

[0018] According to one embodiment, a gas inlet and outlet are formed in the base plate portion, and gas is injected into or discharged into the gas diffusion space through the gas inlet and outlet.

[0019] According to one embodiment, the cylindrical side wall may have a bellows structure.

[0020] According to one embodiment, the vertically moving portion includes a cylindrical body member extending in the vertical direction and an upper plate member having a plane perpendicular to the vertical direction, to which the upper end of the body member is joined and fixed at the bottom surface. The upper end of the cylindrical side wall is joined and fixed to the bottom surface of the upper plate member, the body member is located inside the cylindrical side wall, and the space surrounded by the lower end of the body member, the upper surface of the base plate, and the inner circumferential surface of the cylindrical side wall is formed as a gas diffusion space.

[0021] According to one embodiment, when the vertically moving part is descending to its lowest point, the lower end of the fuselage member is in contact with the upper surface of the base plate, and all inner surfaces of the cylindrical side wall face the outer surface of the fuselage member.

[0022] According to one embodiment, the upper plate member is disc-shaped, the guide support portion is cylindrical and extends in the vertical direction, the inner diameter of the guide support portion is the same as the diameter of the upper plate member, and the upper plate member is guided while sliding against the inner circumferential surface of the guide support portion.

[0023] According to one embodiment, the lower end of the guide support portion is fixed to the upper surface of the base plate portion, a guide hole extending in the vertical direction is formed on the side surface of the guide support portion, the vertical drive portion is a power transmission member, and has one end portion inserted into the guide support portion through the guide hole and the other end portion located outside the guide support portion, a power transmission member coupled to the upper surface of the upper plate member, a vertical movement shaft extending in the vertical direction and coupled to the other end portion of the power transmission member, and a drive actuator supported by the base plate portion and moving the vertical movement shaft in the vertical direction.

Effects of the Invention

[0024] The gas collection device of the present invention can adjust the concentration of the analysis target gas generated inside the secondary battery to an appropriate level and sample it.

[0025] When sampling the gas generated inside the analysis target battery such as a cylindrical or rectangular secondary battery, the gas collection device of the present invention can control the gas diffusion speed by adjusting the volume of the gas diffusion space with the driving force acting on the gas diffusion chamber unit.

[0026] When sampling the analysis target gas diffused into the gas diffusion space of the gas diffusion chamber unit to the sampling unit, the gas collection device of the present invention can sample the analysis target gas at an optimized concentration for analysis by the gas analysis unit because the volume of the gas diffusion space is variable.

Brief Description of the Drawings

[0027] [Figure 1] It is a conceptual diagram showing a gas collection device according to one embodiment. [Figure 2] It is a side view of a gas diffusion unit according to one embodiment. [Figure 3] It is a cross-sectional view showing a longitudinal section of a gas diffusion unit according to one embodiment. [Figure 4]This is a cross-sectional view showing a longitudinal section of a gas diffusion unit according to one embodiment. [Figure 5] This is a perspective view showing a guide support portion according to one embodiment. [Modes for carrying out the invention]

[0028] Embodiments of the present invention will be described in detail below with reference to the attached drawings. In this process, the size and shape of the components shown in the drawings may be exaggerated for clarity and convenience of explanation. Furthermore, terms specifically defined in consideration of the configuration and operation of the present invention may change depending on the intent or convention of the user or operator. Definitions of such terms should be based on the overall content of this specification.

[0029] In describing the present invention, it should be noted that the orientations or positional relationships indicated by terms such as "center," "up," "down," "left," "right," "vertical," "horizontal," "inside," "outside," "one side," and "other side" are based on the orientations or positional relationships shown in the drawings, or the orientations or positional relationships in which the product of the present invention is typically placed during use. These terms are merely for the purpose of describing and briefly explaining the present invention, and do not mean or suggest that the displayed device or element must necessarily be configured or operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0030] Figure 1 is a conceptual diagram showing a gas collection device according to one embodiment. Figure 2 is a plan view showing a side view of a gas diffusion unit 100 according to one embodiment. Figures 3 and 4 are cross-sectional views showing a longitudinal section of the gas diffusion unit 100 according to one embodiment. Figure 5 is a perspective view showing a guide support portion 140 according to one embodiment.

[0031] The gas collection device of the present invention will be described in detail below with reference to Figures 1 to 5.

[0032] The gas collection device can use a secondary battery having a rigid case, such as a cylindrical secondary battery or a prismatic secondary battery, as the battery to be analyzed 11, but is not limited to these.

[0033] The gas collection device collects gases generated inside the secondary battery, specifically those produced by the active material, binder, additives, and electrolyte.

[0034] The gas collection device may include three sealed spaces. Specifically, it may consist of a battery housing space 211, a gas diffusion space 121, and a gas sampling space.

[0035] In the gas collection device, the battery housing space 211 is the space in which the battery to be analyzed 11 is housed. For example, in the battery housing space 211, holes may be formed in the case of the battery to be analyzed 11. Furthermore, in the battery housing space 211, the gas to be analyzed generated from inside the battery to be analyzed 11 is discharged from the battery to be analyzed 11 for the first time, and in the battery housing space 211, the gas to be analyzed and the electrolyte are mixed together depending on the situation.

[0036] The gas diffusion space 121 is a space that adjusts the concentration and pressure of the analyte gas. The volume of the gas diffusion space 121 may be variable. Specifically, the volume of the gas diffusion space 121 is controlled by a control unit, and the concentration and pressure of the analyte gas are adjusted to a state optimized for analysis.

[0037] The gas sampling space is a space for storing the analyte gas in an optimized state. The gas sampling space is connected to GC-MS, GC-PDD (Gas Chromatography-Pulsed Discharge Detector), GC-TCD (Gas Chromatography-Thermal Conductivity Detector), GC-FID (Gas Chromatography-Flame Ionization Detector), FT-IR (Fourier Transform Infrared Spectroscopy), and Raman spectrometers.

[0038] As shown in Figures 1 and 2, the gas collection device of the present invention includes a gas extraction unit 200 for extracting the analyte gas from inside the analyte battery 11; a gas diffusion unit 100 having a gas diffusion space 121 to which the analyte gas is transmitted and diffused from the gas extraction unit 200; a sampling unit 300 having a gas sampling space to which the gas diffused in the gas diffusion space 121 is transmitted and sampled; and a control unit (not shown) for controlling the gas diffusion unit 100.

[0039] The control unit is a computing device that combines hardware and software to control the gas extraction unit 200, the gas diffusion unit 100, and the gas sampling unit 300.

[0040] In the gas collection device, the volume of the gas diffusion space 121 is variable, while the volumes of the battery housing space 211 and the gas sampling space are fixed.

[0041] The gas collection device is provided with a gas diffusion space 121 and a battery housing space 211 as separate spaces, which prevents the gas from dissolving again in the electrolyte and improves the accuracy of quantitative analysis.

[0042] The gas collection device can control the gas diffusion rate by varying the volume of the gas diffusion space 121 through a control unit, thereby adjusting the concentration of the analyte gas sampled in the gas sampling space.

[0043] As shown in Figure 1, the gas extraction unit 200 includes a gas extraction chamber section 210 in which a battery housing space 211 for housing the battery to be analyzed is formed, and a punching section 220 for punching gas extraction holes in the case of the battery to be analyzed housed in the battery housing space 211. Inside the gas extraction chamber section 210, a jig (not shown) for fixing the battery to be analyzed in place may be provided. Furthermore, the gas extraction chamber section 210 may be equipped with a heater for heating the battery to be analyzed 11, a chiller for cooling the battery to be analyzed 11, impact means or vibration means for applying physical force to the battery to be analyzed 11, a charge / discharge module for charging or discharging the battery to be analyzed 11, and the like.

[0044] The punching section 220 may include a punching needle that penetrates the case of the battery 11 to be analyzed. The punching needle is located in the battery housing space 211, and the punching section 220 may further include a drive means for providing driving force to the punching needle outside the gas extraction chamber section 210.

[0045] As shown in Figures 2 and 3, the gas diffusion unit 100 includes a base plate portion 110 consisting of a plane perpendicular to the vertical direction; a cylindrical side wall portion 120 whose lower end is fixed to the base plate portion 110 and which expands and contracts in the vertical direction; a vertical moving portion 130 which is coupled and fixed to the upper end of the cylindrical side wall portion 120 and moves in the vertical direction; a guide support portion 140 which guides the vertical movement of the vertical moving portion 130; and a vertical drive portion 150 which provides driving force for the vertical movement of the vertical moving portion 130.

[0046] The space surrounded by the base plate portion 110, the cylindrical side wall portion 120, and the vertical movement portion 130 forms a gas diffusion space 121.

[0047] The base plate portion 110 is a planar plate perpendicular to the vertical direction and is made of a rigid material. For example, the material of the base plate portion 110 is SUS (Steel Use Stainless).

[0048] A gas inlet / outlet 111 is formed in the base plate portion 110, and the gas to be analyzed is injected into or discharged into the gas diffusion space 121 through the gas inlet / outlet 111. The center of the gas inlet / outlet 111 may be located at the center of a circular region of the base plate portion 110 that faces the cylindrical side wall portion 120. A flow path connected to the gas inlet / outlet 111 is connected to the sampling unit 300 and the gas extraction unit 200. The flow path connected to the gas inlet / outlet 111 includes hoses, tubes, pipes, etc. As shown in Figure 1, the flow path connected to the gas inlet / outlet 111 branches off from a specific point and branches off to the sampling unit 300 and the gas extraction unit 200, respectively.

[0049] A valve is provided in the flow path connecting the gas inlet / outlet 111 to a specific point, and the valve is controlled by a control unit. Furthermore, a valve is also provided in the flow path connecting the specific point to the gas extraction unit 200, and this valve is also controlled by the control unit. As shown in Figure 1, the sampling unit 300 may include a sampling container 320 in which a gas sampling space is formed, which is a space in which the gas to be analyzed is sampled and stored at an optimal pressure and concentration, and an on-off valve 310 for opening and closing the sampling container 320. The on-off valve 310 is connected to a flow path branched from the specific point. The on-off valve 310 is also controlled by the control unit.

[0050] As shown in Figures 3 and 4, the cylindrical sidewall portion 120 is cylindrical with a vertical central axis. The cylindrical sidewall portion 120 can be stretched or contracted in the vertical direction. When the cylindrical sidewall portion 120 is stretched or contracted in the vertical direction, the inner diameter value is fixed. For example, the cylindrical sidewall portion 120 may have a bellows structure.

[0051] The vertical movement section 130 includes a cylindrical body member 131 extending in the vertical direction, and an upper plate member 133 which is a plane perpendicular to the vertical direction, with the upper end of the body member 131 being joined and fixed to its bottom surface.

[0052] The upper end of the cylindrical side wall portion 120 is joined and fixed to the bottom surface of the upper plate member 133, and the body member 131 is located inside the cylindrical side wall portion 120. The space surrounded by the lower end of the body member 131, the upper surface of the base plate portion 110, and the inner circumferential surface of the cylindrical side wall portion 120 forms the gas diffusion space 121. In this ideal structure, the inner diameter of the cylindrical side wall portion 120 and the outer diameter of the body member 131 are the same, and the coefficient of friction between the outer circumferential surface of the body member 131 and the inner circumferential surface of the cylindrical side wall portion 120 is also 0.

[0053] When the vertical movement section 130 is lowered to its lowest point, the lower end of the fuselage member 131 contacts the upper surface of the base plate section 110, and all inner surfaces of the cylindrical side wall section 120 face the outer surface of the fuselage member 131. In other words, in an ideal structure, as shown in Figure 4, the volume of the gas diffusion space 121 is "0" when the vertical movement section 130 is in the lowest lowered state.

[0054] The upper plate member 133 is disc-shaped, and the guide support portion 140 is cylindrical and extends vertically. The inner diameter of the guide support portion 140 is the same as the diameter of the upper plate member 133, and the upper plate member 133 slides against and is guided by the inner circumferential surface of the guide support portion 140. For example, in an ideal state, the coefficient of friction between the side surface of the upper plate member 133 and the inner circumferential surface of the guide support portion 140 is 0. The upper plate member 133 has a predetermined thickness and can prevent twisting of its position when moving vertically.

[0055] As shown in Figure 5, the lower end of the guide support portion 140 is fixed to the upper surface of the base plate portion 110, and a guide hole 141 extending in the vertical direction may be formed on the side surface of the guide support portion 140.

[0056] The vertical drive unit 150 includes a power transmission member 151 having one end inserted into the guide support unit 140 through a guide hole 141 and the other end of a power transmission member 151 located outside the guide support unit 140; a vertical movement shaft 152 extending in the vertical direction and coupled to the other end of the power transmission member 151; and a drive actuator 153 supported by the base plate unit 110 and moving the vertical movement shaft 152 in the vertical direction.

[0057] The power transmission member 151 is a support made of a rigid material and is rod-shaped, extending in a direction perpendicular to the vertical direction.

[0058] The power transmission member 151 is coupled to the upper surface of the upper plate member 133. More specifically, the bottom surface of one end of the power transmission member 151, which is inserted into the guide support portion 140 through the guide hole 141, is attached to the upper surface of the upper plate member 133.

[0059] Although embodiments of the present invention have been described above, these are merely illustrative, and those skilled in the art should understand that a wide variety of modifications and equivalent embodiments are possible. Therefore, the true scope of technical protection of the present invention is determined by the claims. [Explanation of Symbols]

[0060] 11: Battery to be analyzed 100: Gas diffusion unit 110: Base plate section 111: Gas Inlet / Outlet 120: Cylindrical side wall 121: Gas diffusion space 130: Vertical moving part 131: Fuselage component 133: Upper plate member 140: Guide support section 141: Guide Hall 150: Vertical drive unit 151: Power transmission member 152: Vertical movement shaft 153: Drive Actuator 200: Gas extraction unit 210: Gas extraction chamber section 211: Battery housing space 220: Punching section 300: Sampling Unit 310: Shut-off valve 320: Sampling container

Claims

1. A gas extraction unit that extracts gas from the battery, A gas diffusion unit having a gas diffusion space to which the gas extracted from the gas extraction unit is transmitted and to which the gas extracted from the gas extraction unit is diffused, A sampling unit having a gas sampling space to which the gas diffused from the gas diffusion unit is transmitted and to which the diffused gas is sampled, Includes a control unit for controlling the gas diffusion unit, The volume of the gas diffusion space is variable. A gas collection device in which the volume of the gas sampling space is fixed.

2. The aforementioned gas extraction unit is A gas extraction chamber section having a battery housing space in which the aforementioned battery is housed, The gas collection device according to claim 1, further comprising a punching section for creating gas extraction holes in the battery housed in the battery housing space.

3. The aforementioned gas diffusion unit is A base plate section consisting of a plane perpendicular to the vertical direction, The lower end is fixed to the base plate portion, and the cylindrical side wall portion expands and contracts in the vertical direction, A vertically moving part is connected and fixed to the upper end of the cylindrical side wall portion, and moves in the vertical direction. A guide support portion that guides the vertical movement of the aforementioned vertical moving portion, The vertical drive unit includes a vertical drive unit that provides a driving force for the vertical moving unit to move in the vertical direction, The gas collection device according to claim 2, wherein the space surrounded by the base plate portion, the cylindrical side wall portion, and the vertically moving portion is formed as the gas diffusion space.

4. The base plate portion has gas inlets and outlets formed therein. The gas collection device according to claim 3, wherein gas is injected into or discharged into the gas diffusion space through the gas inlet or outlet.

5. The gas collection device according to claim 3, wherein the cylindrical side wall portion has a bellows structure.

6. The vertical movement section is A cylindrical body member extending in the vertical direction, It includes an upper plate member which is a plane perpendicular to the vertical direction and to which the upper end of the body member is joined and fixed at the bottom surface, The upper end of the cylindrical side wall portion is joined and fixed to the bottom surface of the upper plate member. The body member is located inside the cylindrical side wall portion, The gas collection device according to any one of claims 3 to 5, wherein the gas diffusion space is formed as a space surrounded by the lower end of the body member, the upper surface of the base plate portion, and the inner circumferential surface of the cylindrical side wall portion.

7. When the vertical movement section is descending to its lowest point, The lower end of the fuselage member is in contact with the upper surface of the base plate portion. The gas collection device according to claim 6, wherein all inner surfaces of the cylindrical side wall portion face the outer surface of the body member.

8. The aforementioned upper plate member is disc-shaped, The aforementioned guide support portion is cylindrical in shape and extends in the vertical direction. The inner diameter of the guide support portion is the same as the diameter of the upper plate member. The gas collection device according to claim 6, wherein the upper plate member is guided while sliding with the inner circumferential surface of the guide support portion.

9. The lower end of the guide support portion is fixed to the upper surface of the base plate portion. A guide hole extending in the vertical direction is formed on the side surface of the guide support portion. The aforementioned vertical drive unit is A power transmission member having one end inserted into the guide support portion through the guide hole and the other end located outside the guide support portion, and a power transmission member coupled to the upper surface of the upper plate member, A vertical moving shaft extending in the vertical direction and connected to the other end of the power transmission member, The gas collection device according to claim 8, further comprising a drive actuator supported on the base plate portion for moving the vertical movement shaft in the vertical direction.

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