High-coverage ionization mass spectrum device for battery gas production analysis

Abstract

The invention relates to the technical field of mass spectrum analyzers, in particular to a high-coverage ionization mass spectrum device for battery gas production analysis. Comprising a battery placing box, a photo ionization system and an electron ionization system, wherein the battery placing box is used for placing a battery; the photoionization system is connected with the battery placement box through a sample introduction capillary tube and is used for ionizing volatile organic compound gas in gas produced by the battery in the battery placement box to obtain an ionization spectrogram of the volatile organic compound gas; and the electron ionization system is communicated with the photo ionization system and is used for ionizing inorganic components in the gas produced by the battery to obtain an inorganic component mass spectrum. A photo ionization source and an electron impact ionization source are ingeniously combined, efficient ionization of high-ionization-energy inorganic compounds and soft ionization of volatile organic compounds in the gas produced by the battery can be achieved at the same time, and therefore the real-time concentration change trend of components of the gas produced by the battery is obtained at the same time.

Description

Technical Field

[0001] The present invention relates to the technical field of mass spectrometers, and particularly to a high-coverage ionization mass spectrometry device for battery gas production analysis. Background Art

[0002] Battery gas production analysis is a method for detecting chemical reactions occurring inside a battery. By monitoring the gases generated during battery use, important information about the battery's state and performance can be provided. Battery gas production analysis can help monitor whether there are abnormal conditions inside the battery, such as overcharging, over-discharging, or short-circuiting. These problems may cause the battery to overheat or even catch fire or explode. Therefore, it is very important to detect and take measures early to ensure the safety of battery use. The type and quantity of the generated gases can provide clues about the chemical reactions inside the battery and help evaluate the battery's performance. For example, different gas generations may imply chemical changes inside the battery, thus providing information about the battery's life and health status. Abnormal gas generation is often an indicator of battery failure. Analyzing these gases can help determine the problems with the battery, which may be electrolyte leakage, electrode corrosion, or other internal problems. By continuously analyzing the gases generated by the battery, the battery design can be improved to enhance its performance and safety. Therefore, battery gas production analysis is an important technology that helps ensure the safety, performance, and durability of batteries and provides key information for future improvements in battery technology.

[0003] However, almost all existing battery gas production mass spectrometry technologies use electron impact ionization mass spectrometry (EI-MS). Although this type of mass spectrometry has a high ionization efficiency, it has the problem of severe fragmentation and can only analyze some simple inorganic gases. There is a problem of spectral peak overlap for volatile organic compounds (VOCs) in complex gas production components, making it difficult to perform qualitative and quantitative analysis.

[0004] Through the retrieval of patents and papers, the patents related to batteries, gas generation, and mass spectrometry are as follows: 1. The China Electric Power Research Institute published a lithium-ion battery swelling gas detection device and its detection method on May 3, 2017. The device includes a box for accommodating the lithium-ion battery with a liquid medium inside, a box cover, a gas component and content detection device, a battery swelling gas volume detection device, and a battery charge and discharge instrument. The main technical solution provided by this invention lies in the invention of the battery wrapping device, lacking a high-coverage detection method for the generated gas. 2. Shanghai Zero Dew Instrument Equipment Co., Ltd. applied for and published an electrochemical mass spectrometer on July 27, 2018, including a carrier gas injection system, an electrochemical cell, an electrochemical workstation, and a mass spectrometer; the mass spectrometer has a multi-channel injection port, an electron impact ionization source, and a detector, which can record and display the composition, content, and their changes over time of the products in each channel in real time, providing mass spectrometry analysis data of the reaction products in the electrochemical cell. However, the EI source has serious fragmentation and cannot meet the detection requirements of volatile organic compounds during the electrochemical reaction process. Therefore, there is still a need to develop an electrochemical mass spectrometry method that can simultaneously analyze inorganic gases and volatile organic compounds in complex components. Summary of the Invention

[0005] In view of the above problems, the purpose of the present invention is to provide a high-coverage ionization mass spectrometry device for battery gas generation analysis to achieve simultaneous analysis of inorganic and organic gases during the battery gas generation process.

[0006] To achieve the above purpose, the present invention adopts the following technical solutions:

[0007] The present invention provides a high-coverage ionization mass spectrometry device for battery gas generation analysis, including:

[0008] A battery placement box for placing the battery;

[0009] A photoionization system connected to the battery placement box through an injection capillary, for ionizing the volatile organic compound gas in the gas generated by the battery in the battery placement box to obtain an ionization spectrum of the volatile organic compound gas;

[0010] An electron ionization system communicated with the photoionization system, for ionizing the inorganic components in the gas generated by the battery to obtain a mass spectrum of the inorganic components.

[0011] The photoionization system includes a photoionization cavity, a vacuum ultraviolet light source, a photoionization repulsion electrode, a photoionization ion introduction electrode, and a first mass spectrometer. The first mass spectrometer is arranged at one end of the photoionization cavity along the x direction, and the vacuum ultraviolet light source, the photoionization repulsion electrode, and the photoionization ion introduction electrode are sequentially arranged in the photoionization cavity along the x direction. The sampling capillary is inserted into the photoionization cavity along the y direction. The vacuum ultraviolet light generated by the vacuum ultraviolet light source ionizes the volatile organic compound gas with a relatively low ionization energy in the sampling capillary. The ions generated after ionization enter the first mass spectrometer along the x direction under the action of the photoionization repulsion electrode and the photoionization ion introduction electrode for analysis, and a soft ionization spectrum of the volatile organic compound gas is obtained.

[0012] Both the photoionization repulsion electrode and the photoionization ion introduction electrode are flat plate structures with a cylindrical through hole in the middle, and the vacuum ultraviolet light source, the photoionization repulsion electrode, and the photoionization ion introduction electrode are coaxially placed. The vacuum ultraviolet light source is a gas discharge light source, a laser light source, or a synchrotron radiation light source.

[0013] The electron ionization system includes an electron ionization cavity, an electron ionization repulsion electrode, an electron bombardment ionization source, an electron ionization ion introduction electrode, and a second mass spectrometer. The two sides of the electron ionization cavity along the y direction are respectively connected to the photoionization cavity and the second mass spectrometer. The electron ionization repulsion electrode, the electron bombardment ionization source, and the electron ionization ion introduction electrode are sequentially arranged in the electron ionization cavity along the y direction. The gas generated in the battery placement box enters the electron ionization cavity along the Y direction under the action of the vacuum pressure difference, and the inorganic components with high ionization energy are ionized under the action of the electron bombardment ionization source. The generated ions enter the second mass spectrometer for analysis under the action of the electron ionization repulsion electrode and the electron ionization ion introduction electrode, and a mass spectrum of the inorganic components is obtained.

[0014] Both the electron ionization repulsion electrode and the electron ionization ion introduction electrode are flat plate structures with a cylindrical through hole in the middle, and the central holes of the sampling capillary, the electron ionization repulsion electrode, and the electron ionization ion introduction electrode are coaxially placed.

[0015] The air pressure in the photoionization cavity is 0.1 - 100 Pa; the air pressure in the electron ionization cavity is 0.001 - 0.0001 Pa.

[0016] The first mass spectrometer and the second mass spectrometer are any two of a quadrupole mass spectrometer, a time-of-flight mass spectrometer, a magnetic mass spectrometer, an ion trap mass spectrometer, and an orbitrap mass spectrometer.

[0017] Both the photoionization cavity and the electron ionization cavity are hollow metal cavities.

[0018] The inner diameter of the sampling capillary is 0.1 - 0.5 mm, the length is 0.5 - 5 m, and the material is stainless steel, PEEK, or quartz.

[0019] The battery placement box is provided with two pipeline interfaces, one of which is connected to the sampling capillary, and the other is connected to the air supplement capillary. The air supplement capillary is used to balance the pressure at the front end of the mass spectrometer.

[0020] The advantages and beneficial effects of the present invention are as follows: The present invention provides a high-coverage ionization mass spectrometry device for battery gas production analysis. Through reasonable design, the photoionization source and the electron impact ionization source are cleverly combined, which can simultaneously achieve the efficient ionization of high-ionization-energy inorganic compounds and the soft ionization of volatile organic compounds in battery gas production, so as to simultaneously obtain the real-time concentration change trend of battery gas production components. The present invention can realize high-coverage ionization and mass spectrometry analysis of gas components during the charging and discharging process of the battery, and is expected to become a powerful tool for the research of the technical mechanism of new energy batteries. Description of the Drawings

[0021] The drawings further illustrate the present invention, but the content in the drawings does not constitute any limitation to the present invention.

[0022] Figure 1 It is a schematic structural diagram of a high-coverage ionization mass spectrometry device for battery gas production analysis according to the present invention.

[0023] In the figure: 1 - air supplement capillary, 2 - sampling capillary, 3 - photoionization cavity, 4 - vacuum ultraviolet light source, 5 - photoionization repulsion electrode, 6 - electron ionization cavity, 7 - electron ionization ion introduction electrode, 8 - second mass spectrometer, 9 - electron impact ionization source, 10 - electron ionization repulsion electrode, 11 - first mass spectrometer, 12 - photoionization ion introduction electrode, 13 - battery placement box. Detailed Embodiments

[0024] It should be noted that, without conflict, the embodiments in the present invention and the features in the embodiments can be combined with each other. The present invention will be described in detail below with reference to the drawings and in combination with the embodiments.

[0025] To make the objectives, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. The description of at least one exemplary embodiment below is actually only illustrative and in no way restrictive of the present invention and its application or use. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0026] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular forms are also intended to include the plural forms. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, they specify the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0027] Unless otherwise specifically stated, the relative arrangements of components and steps, numerical expressions, and numerical values set forth in these embodiments do not limit the scope of the present invention. At the same time, it should be clear that, for the sake of convenience of description, the dimensions of the various parts shown in the drawings are not drawn in actual proportional relationships. Technologies, methods, and devices known to those of ordinary skill in the relevant art may not be discussed in detail, but where appropriate, the said technologies, methods, and devices should be regarded as part of the authorized specification. In all the examples shown and discussed here, any specific values should be interpreted as merely exemplary and not as a limitation. Therefore, other examples of the exemplary embodiments may have different values. It should be noted that like reference numerals and letters denote like items in the following drawings, and thus, once an item is defined in one drawing, it does not need to be further discussed in subsequent drawings.

[0028] In the description of the present invention, it should be understood that the orientation or positional relationships indicated by orientation words such as "front, rear, upper, lower, left, right", "lateral, vertical, perpendicular, horizontal", and "top, bottom", etc. are usually based on the orientation or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description. Without contrary instructions, these orientation words do not indicate and imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and thus should not be construed as limiting the protection scope of the present invention. The orientation words "inside, outside" refer to the inside and outside relative to the contour of each component itself.

[0029] As Figure 1 shown, an embodiment of the present invention provides a high-coverage ionization mass spectrometry device for battery gas production analysis, including a battery placement box 13, a photoionization system, and an electron ionization system. The battery placement box 13 is used to place a battery. The photoionization system is connected to the battery placement box 13 through an injection capillary 2 and is used to ionize volatile organic compound gases in the gas produced by the battery in the battery placement box 13 to obtain an ionization spectrum of the volatile organic compound gases. The electron ionization system is communicated with the photoionization system and is used to ionize inorganic components in the battery gas production to obtain an inorganic component mass spectrum.

[0030] In an embodiment of the present invention, the battery placement box 13 is provided with two pipeline interfaces. One pipeline interface is connected to the sampling capillary 2, and the other pipeline interface is connected to the air supplement capillary 1. The air supplement capillary 1 is used to balance the pressure at the front end of the mass spectrometer. Specifically, the inner diameter of the sampling capillary 2 is 0.1 - 0.5 mm, the length is 0.5 - 5 m, and the material is stainless steel, PEEK or quartz.

[0031] As Figure 1 shown, in an embodiment of the present invention, the left direction is defined as the x direction and the downward direction is defined as the y direction. The photoionization system includes a photoionization cavity 3, a vacuum ultraviolet light source 4, a photoionization repulsion electrode 5, a photoionization ion introduction electrode 12, and a first mass spectrometer 11. The first mass spectrometer 11 is arranged at one end of the photoionization cavity 3 along the x direction. The vacuum ultraviolet light source 4, the photoionization repulsion electrode 5, and the photoionization ion introduction electrode 12 are sequentially arranged in the photoionization cavity 3 along the x direction. The sampling capillary 2 is inserted into the photoionization cavity 3 along the y direction. The vacuum ultraviolet light generated by the vacuum ultraviolet light source 4 ionizes the volatile organic compound gas with relatively low ionization energy in the sampling capillary 2. The ions generated after ionization enter the first mass spectrometer 11 along the x direction under the action of the photoionization repulsion electrode 5 and the photoionization ion introduction electrode 12 for analysis, and a soft ionization spectrum of the volatile organic compound gas is obtained.

[0032] Furthermore, both the photoionization repulsion electrode 5 and the photoionization ion introduction electrode 12 are flat structures with cylindrical through holes in the middle, and the vacuum ultraviolet light source 4, the photoionization repulsion electrode 5, and the photoionization ion introduction electrode 12 are coaxially placed. The photoionization repulsion electrode 5 and the photoionization ion introduction electrode 12 are respectively located at both ends of the axis of the photoionization cavity 3. The vacuum ultraviolet light source 4 is a gas discharge light source, a laser light source, or a synchrotron radiation light source.

[0033] As Figure 1 shown, in an embodiment of the present invention, the electron ionization system includes an electron ionization cavity 6, an electron ionization repulsion electrode 10, an electron bombardment ionization source 9, an electron ionization ion introduction electrode 7, and a second mass spectrometer 8. The two sides of the electron ionization cavity 6 along the y direction are respectively connected to the photoionization cavity 3 and the second mass spectrometer 8. The electron ionization repulsion electrode 10, the electron bombardment ionization source 9, and the electron ionization ion introduction electrode 7 are sequentially arranged in the electron ionization cavity 6 along the y direction. The gas generated in the battery placement box 13 enters the electron ionization cavity 6 along the y direction under the action of the vacuum pressure difference, and the inorganic components with high ionization energy are ionized under the action of the electron bombardment ionization source 9. The ions generated enter the second mass spectrometer 8 under the action of the electron ionization repulsion electrode 10 and the electron ionization ion introduction electrode 7 for analysis, and a mass spectrum of the inorganic components is obtained.

[0034] Further, both the electron ionization repulsion electrode 10 and the electron ionization ion introduction electrode 7 are flat plate structures with cylindrical through holes in the middle, and the central holes of the sampling capillary 2, the electron ionization repulsion electrode 10, and the electron ionization ion introduction electrode 7 are coaxially arranged. The sampling capillary 2 can introduce the gas generated in the battery placement box 13 into the photoionization cavity 3 and the electron ionization cavity 6 in sequence under the action of vacuum.

[0035] Specifically, both the photoionization cavity 3 and the electron ionization cavity 6 are hollow metal cavities. The air pressure in the photoionization cavity 3 is 0.1 - 100 Pa; the air pressure in the electron ionization cavity 6 is 0.001 - 0.0001 Pa. The first mass spectrometer 11 and the second mass spectrometer 8 are any two of a quadrupole mass spectrometer, a time-of-flight mass spectrometer, a magnetic mass spectrometer, an ion trap mass spectrometer, and an orbitrap mass spectrometer.

[0036] Preferably, the air pressure in the photoionization cavity 3 is 10 Pa, which not only has sufficient fractional density but also can avoid complex molecular ion reactions; the air pressure in the electron ionization cavity 6 is 0.001 Pa. Under the premise of meeting the operating pressure of the EI source, the molecular number density is increased as much as possible to improve the sensitivity.

[0037] Preferably, the vacuum ultraviolet light source is a Kr discharge lamp source, which has the advantages of small volume, low power consumption, and high cost performance. The 10.6 eV energy photons generated by it can meet the measurement of most volatile organic compounds; the sampling capillary 2 is selected with an inner diameter of 0.13 mm, a length of 1 m, and a PEEK material, which can resist electrolyte corrosion and has little impact on the mass spectrometry vacuum load pressure.

[0038] Preferably, the first mass spectrometer 11 is selected as a time-of-flight mass spectrometer, which has a high analysis speed and resolution; the second mass spectrometer 8 is selected as a quadrupole mass spectrometer for the measurement of inorganic small molecules without the need for high resolution.

[0039] An embodiment of the present invention provides a high-coverage ionization mass spectrometry device for battery gas production analysis, and its working principle is:

[0040] During operation, the gas generated in the battery placement box 13 enters the photoionization cavity 3 through the sampling capillary 2 under the action of vacuum; the vacuum ultraviolet light generated by the vacuum ultraviolet light source 4 ionizes the volatile organic compound (VOCs) gas with low ionization energy generated in the sampling capillary 2, and the ions generated after ionization enter the first mass spectrometer 11 along the x direction for analysis under the action of the photoionization repeller electrode 5 and the photoionization ion introduction electrode 12 to obtain a clean VOCs soft ionization spectrum; at the same time, the gas generated in the battery placement box 13 enters the electron ionization cavity 6 along the y direction under the action of the vacuum pressure difference, and ionizes the inorganic components with high ionization energy under the action of the electron bombardment ionization source 9, and the generated ions enter the second mass spectrometer 8 under the action of the electron ionization repeller electrode 10 and the electron ionization ion introduction electrode 7 for analysis to obtain an inorganic component mass spectrum, thereby realizing simultaneous in-situ detection of volatile organic components and inorganic components during the electrochemical reaction process.

[0041] The present invention, through reasonable design, skillfully combines the photoionization source and the electron bombardment ionization source, and can simultaneously realize the efficient ionization of high ionization energy inorganic compounds and the soft ionization of volatile organic compounds in the battery gas production, thereby simultaneously obtaining the real-time concentration change trend of the battery gas production components. The present invention can realize high coverage ionization and mass spectrometry analysis of gas components in the battery charging and discharging process, and is expected to become a powerful tool for the research of the mechanism of new energy battery technology.

[0042] The technical principle of the present invention is described above in conjunction with specific embodiments. These descriptions are only for explaining the principle of the present invention and cannot be interpreted as limiting the scope of protection of the present invention in any way. Based on the explanations herein, those skilled in the art can associate other specific embodiments of the present invention without creative work, and these equivalent variations or substitutions are all included in the scope defined by the claims of this application.

[0043] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A high-coverage ionization mass spectrometry device for battery gas production analysis, characterized in that, it includes: A battery placement box (13) for placing batteries; A photoionization system, connected to the battery placement box (13) through a sampling capillary (2), for ionizing volatile organic compounds in the gas produced by the battery in the battery placement box (13) to obtain an ionization spectrum of the volatile organic compounds; An electron ionization system, communicating with the photoionization system, for ionizing inorganic components in the battery gas production to obtain an inorganic component mass spectrum.

2. The high-coverage ionization mass spectrometry device for battery gas production analysis according to claim 1, characterized in that, The photoionization system includes a photoionization cavity (3), a vacuum ultraviolet light source (4), a photoionization repulsion electrode (5), a photoionization ion introduction electrode (12) and a first mass spectrometer (11), wherein the first mass spectrometer (11) is arranged at one end of the photoionization cavity (3) along the x direction, and the vacuum ultraviolet light source (4), the photoionization repulsion electrode (5) and the photoionization ion introduction electrode (12) are sequentially arranged in the photoionization cavity (3) along the x direction; the sampling capillary (2) is inserted into the photoionization cavity (3) along the y direction, and the vacuum ultraviolet light generated by the vacuum ultraviolet light source (4) ionizes the volatile organic compounds with relatively low ionization energy in the sampling capillary (2), and the ions generated after ionization enter the first mass spectrometer (11) along the x direction under the action of the photoionization repulsion electrode (5) and the photoionization ion introduction electrode (12) for analysis to obtain a soft ionization spectrum of the volatile organic compounds.

3. The high-coverage ionization mass spectrometry device for battery gas production analysis according to claim 2, characterized in that, Both the photoionization repulsion electrode (5) and the photoionization ion introduction electrode (12) are flat structures with cylindrical through holes in the middle, and the vacuum ultraviolet light source (4), the photoionization repulsion electrode (5) and the photoionization ion introduction electrode (12) are coaxially placed; the vacuum ultraviolet light source (4) is a gas discharge light source, a laser light source or a synchrotron radiation light source.

4. The high-coverage ionization mass spectrometry device for battery gas production analysis according to claim 2, characterized in that, The electron ionization system includes an electron ionization cavity (6), an electron ionization repulsion electrode (10), an electron bombardment ionization source (9), an electron ionization ion introduction electrode (7) and a second mass spectrometer (8), wherein both sides of the electron ionization cavity (6) along the y direction are respectively connected to the photoionization cavity (3) and the second mass spectrometer (8), and the electron ionization repulsion electrode (10), the electron bombardment ionization source (9) and the electron ionization ion introduction electrode (7) are sequentially arranged in the electron ionization cavity (6) along the y direction; the gas generated in the battery placement box (13) enters the electron ionization cavity (6) along the Y direction under the action of a vacuum pressure difference, and the inorganic components with high ionization energy are ionized under the action of the electron bombardment ionization source (9), and the generated ions enter the second mass spectrometer (8) under the action of the electron ionization repulsion electrode (10) and the electron ionization ion introduction electrode (7) for analysis to obtain an inorganic component mass spectrum.

5. The high-coverage ionization mass spectrometry device for battery gas production analysis according to claim 4, characterized in that, both the electron ionization repulsion electrode (10) and the electron ionization ion introduction electrode (7) are flat plate structures with cylindrical through holes in the middle, and the central holes of the sampling capillary (2), the electron ionization repulsion electrode (10), and the electron ionization ion introduction electrode (7) are coaxially arranged.

6. The high-coverage ionization mass spectrometry device for battery gas production analysis according to claim 4, characterized in that, the air pressure in the photoionization cavity (3) is 0.1 - 100 Pa; the air pressure in the electron ionization cavity (6) is 0.001 - 0.0001 Pa.

7. The high-coverage ionization mass spectrometry device for battery gas production analysis according to claim 4, characterized in that, the first mass spectrometer (11) and the second mass spectrometer (8) are any two of quadrupole mass spectrometer, time-of-flight mass spectrometer, magnetic mass spectrometer, ion trap mass spectrometer, and orbitrap mass spectrometer.

8. The high-coverage ionization mass spectrometry device for battery gas production analysis according to claim 4, characterized in that, both the photoionization cavity (3) and the electron ionization cavity (6) are hollow metal cavities.

9. The high-coverage ionization mass spectrometry device for battery gas production analysis according to claim 1, characterized in that, the inner diameter of the sampling capillary (2) is 0.1 - 0.5 mm, the length is 0.5 - 5 m, and the material is stainless steel, PEEK, or quartz.

10. The high-coverage ionization mass spectrometry device for battery gas production analysis according to claim 1, characterized in that, the battery placement box (13) is provided with two pipeline interfaces, one pipeline interface is connected to the sampling capillary (2), and the other pipeline interface is connected to the gas supplement capillary (1), and the gas supplement capillary (1) is used to balance the pressure at the front end of the mass spectrometer.

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