KR20230046594A - Apparatus for analyzing gas - Google Patents

Abstract

The present invention relates to an apparatus for analyzing gas, and is to provide an apparatus for analyzing gas, which can analyze secondary battery generation gas by accurately determining whether secondary battery generation gas is generated. The apparatus for analyzing gas comprises: a diffusion chamber unit which is provided with a gas diffusion space in which a secondary battery is accommodated; a gas sensor unit which is provided in the gas diffusion space to detect secondary battery generation gas generated in the secondary battery; a gas discharge pipe which is a flow path for delivering the secondary battery generation gas diffused in the gas diffusion space to a gas analysis unit or a gas collection unit located outside the diffusion chamber unit; and a control unit which controls opening and closing of the gas discharge pipe based on a gas sensing output value output from the gas sensor unit.

Description

Gas analysis device {APPARATUS FOR ANALYZING GAS}

The present invention relates to a gas analyzer, and more particularly, to a gas analyzer capable of accurately determining whether secondary battery generated gas is generated and analyzing the secondary battery generated gas.

In general, a secondary battery is a battery that can be used repeatedly through a process of discharging and charging in the reverse direction of converting chemical energy into electrical energy, and its types include a nickel-cadmium (Ni-Cd) battery and a nickel-hydrogen (Ni-MH) battery. ) battery, lithium-metal battery, lithium-ion (Li-ion) battery, and lithium-ion polymer battery (Li-ion Polymer Battery). Among these secondary batteries, lithium secondary batteries having high energy density and voltage, long cycle life, and low self-discharge rate have been commercialized and widely used.

Depending on the reaction inside the lithium secondary battery, hydrogen, oxygen, nitrogen, carbon monoxide, carbon dioxide, C _n H _{2n -2} (n=2~5), C _n H _2n (n=2~5), C _n H _{2n +2} Various types of gases such as hydrocarbons and other organic gases (n = 1 to 5) may be generated as secondary battery generated gases.

In addition, the lithium secondary battery degrades while generating a large amount of gas generated by the secondary battery due to electrolyte decomposition as repeated charging and discharging progresses, and this aspect appears differently depending on the design and use form of the battery. Therefore, it is essential to infer the deterioration mechanism of the battery by analyzing the generated gas of the secondary battery during the battery development process.

Therefore, it is very important to accurately analyze the gas generated by the secondary battery. Specifically, information on the composition and content of secondary battery generated gas is useful for developing battery materials, optimizing battery manufacturing processes, and identifying causes of battery defects. To this end, it is important to develop a technology that analyzes secondary battery generated gas.

The analysis of the secondary battery generated gas is performed by diffusing the secondary battery generated gas in the gas diffusion space in a state where the secondary battery is accommodated in the gas diffusion space, which is an airtight space, and then the secondary battery generated gas diffused in the gas diffusion space is stored in a separate gas collection container. After being stored in a gas analyzer such as a GC-MS (gas chromatography-mass spectrometer), the secondary battery generated gas diffused in the gas diffusion space may be directly transferred to the gas analyzer for analysis.

Specifically, a temperature sensor or a pressure gauge is provided in a diffusion chamber having a gas diffusion space therein, and gas collection or transmission is performed by determining whether or not secondary battery generated gas is generated based on a temperature measurement value or a pressure measurement value. It can be.

At this time, if the amount of gas generated by the secondary battery is small compared to the volume of the gas diffusion space, it is difficult to accurately determine the timing at which the generated gas from the secondary battery is vented from the secondary battery using a measured temperature value or a measured pressure value.

1 is a graph showing temperature measurement values and pressure measurement values when secondary battery-generated gas is diffused in a gas diffusion space of a diffusion chamber. The dashed-dotted line shown in FIG. 1 is the point at which the secondary battery-generated gas starts to diffuse (generate). Referring to the graph of FIG. 1 , at the time of diffusion, there is no change in the measured pressure value and the change in the measured temperature value, but the width is small and can be determined as noise. Therefore, it is difficult to accurately determine the diffusion time of the gas generated by the secondary battery using only the temperature measurement value or the pressure measurement value.

In addition, in a system for analyzing secondary battery generated gas, various structures such as a charging and discharging module, a heating module, a fixing jig, and a punching module may be provided in the gas diffusion space in order to provide experimental conditions to the secondary battery. In this case, Since the volume of the gas diffusion space becomes larger, it becomes more difficult to determine the generation time of the secondary battery generated gas using a temperature sensor or a pressure gauge.

There is a need for a device or system that solves the above problems, accurately determines the diffusion time of secondary battery-generated gas, collects the gas in a gas collection container, or transfers the gas to a gas analyzer.

The present invention relates to a gas analyzer, and is to provide a gas analyzer capable of accurately determining whether secondary battery generated gas is generated and analyzing the secondary battery generated gas.

The technical problems to be achieved by the present invention are not limited to the above-mentioned technical problems, and other technical problems not mentioned will be clearly understood by those skilled in the art from the description below. You will be able to.

The gas analysis device of the present invention,

a diffusion chamber unit having a gas diffusion space in which a secondary battery is accommodated;

a gas sensor unit provided in the gas diffusion space to detect secondary battery-generated gas generated in the secondary battery;

a gas discharge pipe connected to the diffusion chamber unit and serving as a flow path for transferring the secondary battery-generated gas diffused in the gas diffusion space to a gas analysis unit or a gas collection unit located outside the diffusion chamber unit; and

It may include a control unit that controls opening and closing of the gas discharge pipe based on a gas sensing output value output from the gas sensor unit.

In the gas analyzer of the present invention, the gas sensor unit may sense gas using a metal-oxide (MOx) method or a non-dispersive infrared (NDIR) method.

In the gas analyzer of the present invention, the gas sensor unit may sense one or more of CO, CO ₂ , H ₂ , CH ₄ , and TVOC (total volatile organic compounds).

In the gas analysis device of the present invention, the diffusion chamber unit includes a body chamber in which the gas diffusion space is formed and one side is open, and the gas diffusion space is converted into an airtight space by covering the open side surface of the body chamber. It may include a door part to be formed.

The gas diffusion space of the gas analyzer of the present invention may include a gas stirring unit for stirring the gas in the gas diffusion space, and the stirring unit may be located on an inner surface of the body chamber.

In the gas analysis device of the present invention, a mounting plate on which the secondary battery is mounted may be fixed to an inner surface of the door unit facing the open side surface of the body chamber.

In the gas analysis device of the present invention, the gas sensor unit is mounted on the mounting plate, and a feedthrough for electrically connecting the gas sensor unit and the control unit located outside the diffusion chamber is provided in the door part. may be provided.

The gas sensing output value output from the gas sensor unit of the gas analyzer of the present invention is output as a value proportional to the amount of the secondary battery generated gas, and when the gas sensing output value is greater than or equal to a set value, the control unit controls the gas It may be to open the discharge pipe.

An opening/closing valve may be provided in the gas discharge pipe of the gas analyzer of the present invention, and the control unit may control opening or closing of the opening/closing valve.

In the gas analysis device of the present invention, a gas sensor unit is provided in a gas diffusion space of a diffusion chamber unit in which secondary battery-generated gas is diffused, so that an accurate diffusion time point of secondary battery-generated gas can be confirmed.

The gas analyzer according to the present invention can determine in real time the point at which the gas generated by the secondary battery is diffused inside the diffusion chamber unit.

1 is a graph showing temperature measurement values and pressure measurement values when secondary battery-generated gas is diffused in a gas diffusion space of a diffusion chamber.
2 is a block diagram showing the gas analysis device of the present invention.
3 is a graph showing a temperature measurement value, a pressure measurement value, a gas sensing output value, and a gas generation amount measured in a diffusion chamber unit in the gas analyzer according to the present invention.
4 is a cross-sectional view showing a closed state of the diffusion chamber unit.
5 is a cross-sectional view showing an open state of the diffusion chamber unit.

Hereinafter, embodiments according to the present invention will be described in detail with reference to the accompanying drawings. In this process, the size or shape of the components shown in the drawings may be exaggerated for clarity and convenience of description. In addition, terms specifically defined in consideration of the configuration and operation of the present invention may vary according to the intentions or customs of users and operators. Definitions of these terms should be made based on the content throughout this specification.

In the description of the present invention, it should be noted that the terms "center", "top", "bottom", "left", "right", "vertical", "horizontal", "inside", "outside", "one side" The orientation or positional relationship indicated by "," "the other side", etc. is based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship normally placed when using the product of the present invention, and for explanation and brief description of the present invention However, it should not be understood as limiting the present invention because it does not suggest or imply that the displayed device or element must be configured or operated in a specific orientation with a specific orientation.

2 is a block diagram showing the gas analysis device of the present invention. 3 is a graph showing a temperature measurement value, a pressure measurement value, a gas sensing output value, and a generation amount of each type of gas measured in the diffusion chamber unit 200 in the gas analyzer according to the present invention. 4 is a cross-sectional view showing a closed state of the diffusion chamber unit 200. 5 is a cross-sectional view showing an open state of the diffusion chamber unit 200.

Hereinafter, the gas analyzer of the present invention will be described in detail with reference to FIGS. 2 to 5 .

As shown in FIG. 2, the gas analysis device of the present invention,

a diffusion chamber unit 200 having a gas diffusion space 211 in which the secondary battery 10 is accommodated;

a gas sensor unit 100 provided in the gas diffusion space 211 to detect secondary battery generated gas generated in the secondary battery 10;

The secondary battery-generated gas connected to the diffusion chamber unit 200 and diffused in the gas diffusion space 211 is transferred to a gas analysis unit 500 or a gas collection unit located outside the diffusion chamber unit 200. a gas discharge pipe 400, which is a flow path; and

It may include a control unit 300 that controls opening and closing of the gas discharge pipe 400 based on a gas sensing output value output from the gas sensor unit 100 .

In the secondary battery 10 accommodated in the diffusion chamber unit 200, an electrode assembly including a negative electrode, a positive electrode, and a separator may be packaged in a battery housing together with an electrolyte solution.

The gas analysis device of the present invention diffuses the secondary battery-generated gas generated from the secondary battery 10 into the gas diffusion space 211 in the gas diffusion space 211 of the gas diffusion chamber, and then analyzes the gas located outside the gas diffusion chamber. It may be delivered to the unit 500 or the gas collection unit. To this end, a carrier gas supply unit (not shown), a negative pressure pump (not shown), and the like may be additionally connected to the gas diffusion chamber. Specifically, the carrier gas supply unit may supply an inert gas or the like to the gas diffusion chamber to push the secondary battery-generated gas through the gas discharge pipe 400 . A vacuum pump may be used for pressure regulation or purging of the gas diffusion space 211 before or after the analysis begins.

The secondary battery generated gas is a gas generated by the secondary battery 10 and may be generated by evaporation of an electrolyte solution or the like. The gas analyzer of the present invention provides the gas sensor unit 100 in the gas diffusion space 211 to accurately detect the generation time (diffusion time) of the secondary battery-generated gas, and the secondary battery diffused in the gas diffusion space 211. The battery-generated gas may be transferred to the gas analysis unit 500 or the gas collection unit through the gas discharge pipe 400 .

The gas analysis unit 500 may include a gas detector such as GC-MS (Gas Chromatography-Mass Spectrometry), GC-TCD (Gas Chromatography-Thermal Conductivity Detector), GC-FID (Gas Chromatography-Flame Ionization Detector), etc. there is. A sampling loop capable of quantifying the amount of secondary battery generated gas is provided in the gas analysis unit 500, and the quantified secondary battery generated gas can be injected into a gas detector.

The gas collecting unit may receive and store the gas generated by the secondary battery from the diffusion chamber unit 200 . For example, the gas collection unit may include a gas collection pipe that is a gas storage container made of SUS or glass. A gas storage space is provided inside the gas collection pipe to store gas generated by the secondary battery. The gas collecting unit may include a plurality of gas collecting pipes, and may be stored in each of the plurality of gas collecting pipes for each section divided based on state of charge (SOC), temperature, time, mechanical impact, and the like. The gas collection unit provides a multi-position valve in a flow path connecting the gas discharge pipe 400 and a plurality of gas collection pipes to select one of the plurality of gas collection pipes to store the secondary battery generated gas. can

The gas discharge pipe 400 may be a pipe made of a chemical resistant material such as SUS. The secondary battery-generated gas diffused in the diffusion chamber unit 200 may be transferred to the gas analysis unit 500 or the gas collection unit outside the diffusion chamber through the gas discharge pipe 400 .

An opening/closing valve 410 for opening and closing the gas discharge pipe 400 may be provided in the gas discharge pipe 400 . The control unit 300 may control the open/close valve 410 based on the gas sensing output value. The opening/closing valve 410 may be a ball valve, a solenoid valve, or a pneumatically actuated valve.

The gas sensor unit 100 may sense gas using a metal-oxide (MOx) method or a non-dispersive infrared (NDIR) method. The gas sensor unit 100 may output a gas sensing output value as a signal whose intensity varies according to the concentration of the gas generated by the secondary battery. The gas sensor unit 100 may be provided in the gas diffusion space 211 .

As shown in FIG. 3 , the gas sensor unit 100 may sense one or more of CO, CO ₂ , H ₂ , CH ₄ , and total volatile organic compounds (TVOC). A graph indicated as a gas sensor in FIG. 3 may be a gas sensing output value output to the gas sensor unit 100 . The gas sensor unit 100 may sense one or more of vaporized electrolyte components such as CO, CO ₂ , H ₂ , CH ₄ , and total volatile organic compounds (TVOC). As shown in FIG. 3 , the gas sensor unit 100 shows a significant variation value at a point at which the secondary battery-generated gas diffuses (a point indicated by a dashed-dotted line).

Table 1 is for the bar graph shown in FIG. 3 . The time 109 min is the point indicated by the dashed-dotted line in FIG. 3, and from the dot-dash line point, the gas generated by the secondary battery in the gas diffusion space 211 was delivered to the gas analysis unit 500 every 5 minutes and analyzed. .

As shown in Table 1, it can be seen that the ppm values of CO, CO ₂ , H ₂ , CH ₄ , and TVOC (total volatile organic compounds) increase as the gas sensing output value increases.

The gas sensing output value output from the gas sensor unit 100 is output as a value proportional to the amount of the secondary battery generated gas, and when the gas sensing output value is greater than or equal to a set value, the control unit 300 controls the gas discharge pipe 400 may be opened. The amount of gas generated by the secondary battery may be a unit such as mass or volume.

The control unit 300 is an arithmetic device and may receive a gas sensing output value from the gas sensor unit 100 . The control unit 300 may output a control signal to the open/close valve 410 provided in the gas discharge pipe 400 based on the gas sensing output value. For example, when the gas sensing output value is greater than or equal to a set value or the change amount of the gas sensing output value is greater than or equal to a set change amount, a control signal for valve opening may be output to the on/off valve 410 .

The control unit 300 may be connected to the gas analysis unit 500 or the gas collection unit to output a control signal for the gas analysis unit 500 or the gas collection unit.

The control unit 300 may include a timer, and may output a control signal for opening the valve after waiting for a set time when the gas sensing output value is greater than or equal to a set value or the change amount of the gas sensing output value is greater than or equal to a set change value.

4 and 5, the diffusion chamber unit 200 includes a body chamber 210 in which the gas diffusion space 211 is formed and one side is open, and the body chamber 210. It may include a door part 220 covering the open side surface of the gas diffusion space 211 to form a closed space. The diffusion chamber unit 200 may be provided in a cylindrical shape, and one end may be opened as a door unit 220 .

The gas diffusion space 211 is provided with a gas stirring unit 212 for stirring the gas in the gas diffusion space 211, and the stirring unit 212 is located on the inner surface of the body chamber 210. can The stirring unit 212 may be a magnetic stirrer, an impeller, a blade fan, or the like. Specifically, the agitation unit 212 includes an agitation body that performs a mechanical movement such as rotation to agitate gas, and an agitation power unit that provides power to the agitation body, and the agitation body is an inner surface of the body chamber 210. Located in, the agitation power unit may be located inside and outside the torso chamber 210 without limitation. However, since the stirring power unit may be an electric device such as an electric motor, and the gas diffusion space may be an environment in which high or low temperatures are applied depending on circumstances, it is preferable that the stirring power unit be located outside the body chamber 210. can

A mounting plate 230 on which the secondary battery 10 is mounted may be fixed to an inner surface of the door part 220 facing the open side surface of the body chamber 210 . The mounting plate 230 may be a flat plate perpendicular to the vertical direction. One end of the mounting plate 230 is fixed to the inner surface of the door unit 220, and as shown in FIG. 5, the mounting plate 230 and the door unit 220 may move together. When the door unit 220 is opened, the mounting plate 230 is exposed to an external space, and when the door unit 220 is closed, the mounting plate 230 may be accommodated in the gas diffusion space 211 .

The gas sensor unit 100 is mounted on the mounting plate 230, and the gas sensor unit 100 and the control unit 300 located outside the diffusion chamber are electrically connected to the door part 220. A feedthrough 221 may be provided to do so. Since the gas sensor unit 100 moves together with the mounting plate 230, the feed-through 221 is used to prevent the wire connected to the gas sensor unit 100 from being deformed or stretched when the door unit 220 is opened or closed. may be provided on the door unit 220. Charge/discharge terminals 231 connected to the secondary battery 10 may be provided in the gas diffusion space 211 , and feedthroughs 221 for the charge/discharge terminals 231 may also be provided in the door unit 220 . there is.

A temperature sensor or a pressure sensor is provided in the gas diffusion chamber, and when the control unit 300 generates a control signal based on the gas sensing output value, it may act as a correction value.

Embodiments according to the present invention have been described above, but these are merely examples, and those skilled in the art will understand that various modifications and embodiments of equivalent range are possible therefrom. Therefore, the true technical protection scope of the present invention should be defined by the following claims.

10 ... secondary battery 100 ... gas sensor unit
200 ... diffusion chamber unit 210 ... body chamber
211 ... gas diffusion space 212 ... stirring section
220 ... door part 221 ... feed through
230 ... mount plate 231 ... charge/discharge terminal
300 ... control unit 400 ... gas discharge pipe
410 ... on-off valve 500 ... gas analysis unit

Claims (9)

a diffusion chamber unit having a gas diffusion space in which a secondary battery is accommodated;
a gas sensor unit provided in the gas diffusion space to detect secondary battery-generated gas generated in the secondary battery;
a gas discharge pipe connected to the diffusion chamber unit and serving as a flow path for transferring the secondary battery-generated gas diffused in the gas diffusion space to a gas analysis unit or a gas collection unit located outside the diffusion chamber unit; and
and a control unit controlling opening and closing of the gas discharge pipe based on a gas sensing output value output from the gas sensor unit. According to claim 1,
The gas sensor unit,
A gas analysis device that detects gas in a metal-oxide (MOx) method or a non-dispersive infrared (NDIR) method. According to claim 2,
Wherein the gas sensor unit detects one or more of CO, CO ₂ , H ₂ , CH ₄ , TVOC (total volatile organic compounds). According to claim 1,
The diffusion chamber unit,
A body chamber in which the gas diffusion space is formed and one side is open;
and a door unit covering the open side surface of the body chamber to form the gas diffusion space as a closed space. According to claim 4,
A gas stirring unit for stirring the gas in the gas diffusion space is provided in the gas diffusion space,
Wherein the stirring unit is located on the inner surface of the torso chamber. According to claim 4,
A gas analyzer, wherein a mounting plate on which the secondary battery is mounted is fixed to an inner surface of the door unit facing the open side surface of the body chamber. According to claim 6,
The gas sensor unit is mounted on the mounting plate,
Wherein the door unit is provided with a feedthrough for electrically connecting the gas sensor unit and the control unit located outside the diffusion chamber. According to claim 1,
The gas sensing output value output from the gas sensor unit is output as a value proportional to the amount of gas generated by the secondary battery,
When the gas sensing output value is greater than or equal to the set value, the control unit opens the gas discharge pipe. According to claim 8,
An on-off valve is provided in the gas discharge pipe,
Wherein the control unit controls the opening or closing of the on-off valve.

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