Method and device for combining in-situ electrochemical nuclear magnetic resonance and online differential mass spectrometry

Abstract

The invention provides an in-situ electrochemical nuclear magnetic resonance and online differential mass spectrometry combined method and device, and relates to the field of electrochemical detection. The method comprises the following steps: establishing a gas inlet passage and a gas outlet passage on an electrochemical nuclear magnetic resonance in-situ pool; an electrochemical reaction process in the electrochemical nuclear magnetic resonance in-situ pool is controlled through the electrochemical workstation, and electrochemical signals are collected; inert gas is introduced into an occurrence place of the electrochemical reaction process through the gas inlet channel, gas generated in the electrochemical reaction process is introduced into the mass spectrometer from the gas outlet channel along with the inert gas, and a mass spectrum signal is collected; nuclear magnetic resonance signals are collected through a nuclear magnetic resonance spectrometer. In the device, an electrochemical nuclear magnetic resonance in-situ pool assembly comprises a counter electrode binding post, a shell, a micrometer head and a working electrode binding post; an air inlet channel and an air outlet channel are formed in the micrometer head. According to the invention, an electrochemical signal, a nuclear magnetic resonance signal and a mass spectrum signal can be monitored at the same time, and real-time synchronous detection of solid, liquid and gas phases is realized.

Description

Technical Field

[0001] The present invention relates to the field of electrochemical testing technology, and in particular to an in-situ electrochemical nuclear magnetic resonance and online differential mass spectrometry coupling method and device. Background Art

[0002] In response to energy and environmental challenges, electrochemical energy technologies such as lithium-ion batteries, fuel cells, and electrocatalytic hydrogen production are booming. However, their scientific understanding urgently needs to be deepened. Spectroscopic electrochemistry faces unprecedented challenges and development opportunities in addressing these complex electrode reaction mechanisms and electrode-electrolyte interfaces.

[0003] In situ electrochemical nuclear magnetic resonance (EC-NMR) technology is an important characterization tool for monitoring the dynamic processes of microscopic electrochemical reactions occurring in electrochemical systems at the atomic level, and for quantitatively analyzing the composition and structural evolution of electrodes, electrolytes, and interfaces. However, EC-NMR capabilities are not yet sufficient for the research needs of some key electrochemical systems. Currently, rapidly developing electrochemical systems such as carbon dioxide electroreduction, electrocatalytic hydrogen production, and lithium-ion batteries involve the generation of small and trace amounts of gaseous products. The simultaneous analysis of solid, liquid, and, in the future, gaseous products is key to effectively revealing the electrochemical reaction processes in these systems. Therefore, the development of a combined EC-NMR and mass spectrometry characterization platform, combined with gas characterization methods such as online differential electrochemical mass spectrometry, is an inevitable trend. Summary of the Invention

[0004] In order to achieve effective quantitative and qualitative characterization of solid, liquid and trace / trace gas products of electrochemical systems under working conditions through in situ electrochemical nuclear magnetic resonance and online mass spectrometry, the present invention provides a method and device for the combination of in situ electrochemical nuclear magnetic resonance and online differential mass spectrometry, which can simultaneously monitor electrochemical signals, nuclear magnetic resonance signals and mass spectrometry signals, and realize real-time synchronous detection of solid, liquid and gas phases, providing an effective innovative in situ characterization technology for the research and development and industrial application of low-carbon new energy technologies such as high-energy lithium-ion batteries, electrocatalytic hydrogen production, and carbon dioxide electroreduction.

[0005] The technical means adopted in the present invention are as follows: An in-situ electrochemical nuclear magnetic resonance and online differential mass spectrometry method, specifically comprising: An air inlet passage and an air outlet passage are established on the electrochemical nuclear magnetic resonance in-situ cell, so that both the air inlet passage and the air outlet passage are connected to a location where an electrochemical reaction process occurs in the electrochemical nuclear magnetic resonance in-situ cell; an electrochemical workstation is connected to the electrochemical nuclear magnetic resonance in-situ cell, the air outlet passage is connected to a mass spectrometer, and the electrochemical nuclear magnetic resonance in-situ cell is placed inside a coil of an in-situ electrochemical nuclear magnetic resonance probe and placed in the nuclear magnetic resonance spectrometer; The electrochemical workstation, nuclear magnetic resonance spectrometer, and mass spectrometer were started simultaneously to collect electrochemical signals, nuclear magnetic resonance signals, and mass spectrometry signals. The specific process was as follows: According to the requirements of the electrochemical test, the electrochemical reaction process in the electrochemical nuclear magnetic resonance in-situ cell is controlled by the electrochemical workstation and the electrochemical signals are collected; during the electrochemical reaction process, an inert gas is introduced into the place where the electrochemical reaction process occurs through the air inlet passage, and the gas generated during the electrochemical reaction is introduced into the mass spectrometer through the air outlet passage along with the inert gas to collect the mass spectrometry signal; at the same time, by setting the working parameters of the nuclear magnetic resonance spectrometer, the nuclear magnetic resonance signal during the electrochemical reaction process is collected.

[0006] The present invention also provides an in-situ electrochemical nuclear magnetic resonance and online differential mass spectrometry coupling device, comprising an electrochemical nuclear magnetic resonance in-situ cell assembly and an online differential mass spectrometry air inlet interface assembly; The electrochemical nuclear magnetic resonance in-situ cell assembly comprises a counter electrode terminal, a shell, a differential head and a working electrode terminal; The electrochemical reaction occurs in the cavity inside the housing. A counter electrode, a diaphragm, and a working electrode are sequentially arranged in the cavity from bottom to top. The counter electrode is attached to the bottom of the cavity, and the diaphragm is used to separate the working electrode from the counter electrode. The upper end of the counter electrode terminal extends into the cavity of the housing, is flush with the bottom surface of the cavity, and is electrically connected to the counter electrode; The differential head is inserted into the cavity of the shell from the top of the shell, and the bottom is tightly fitted with the working electrode; an air inlet passage and an air outlet passage are opened inside the differential head, and one end of the air inlet passage and the air outlet passage are opened at the bottom of the differential head, and the other end is opened at the side of the differential head; The working electrode terminal passes through the differential head, with the lower end flush with the bottom surface of the differential head and electrically connected to the working electrode; The online differential mass spectrometry air inlet interface assembly includes a pair of air path connectors; the air inlet passage is connected to the air source through the corresponding air path connectors, and the air outlet passage is connected to the mass spectrometer through the corresponding air path connectors. The air source and the mass spectrometer are respectively connected to the place where the electrochemical reaction process occurs in the electrochemical nuclear magnetic resonance in-situ cell through the air inlet passage and the air outlet passage.

[0007] Furthermore, an electrode terminal mounting hole extending from the bottom of the cavity to the bottom surface of the shell is opened in the shell, the upper end of the electrode terminal passes through the electrode terminal mounting hole to be electrically connected to the electrode, and the lower end extends out of the shell.

[0008] Furthermore, a through hole is opened from top to bottom in the center of the differential head for installing the working electrode terminal; the lower end of the working electrode terminal is flush with the bottom surface of the differential head and is electrically connected to the working electrode, and the upper end extends out of the differential head.

[0009] Furthermore, the micrometer head is connected to the internal thread of the housing through the external thread.

[0010] Furthermore, the electrochemical nuclear magnetic resonance in-situ cell component is made of non-metallic materials such as polyetheretherketone, polytetrafluoroethylene or polymer ceramics.

[0011] Furthermore, the gas path connector has an external thread, and the air inlet passage and the air outlet passage are provided with internal threads at the openings on the side of the micrometer head.

[0012] Furthermore, the air inlet passage is an air inlet passage threaded hole at the opening on the side of the differential head, and the air path connector is threadedly installed on the air inlet passage threaded hole; the air outlet passage is an air outlet passage threaded hole at the opening on the side of the differential head, and the air path connector is threadedly installed on the air outlet passage threaded hole.

[0013] Furthermore, the material of the gas pipeline connected to the gas line connector is non-metallic material such as polyetheretherketone, polytetrafluoroethylene or polymer ceramics.

[0014] The working principle of the present invention is: The nuclear magnetic resonance signal generated by the transition of atomic nuclei is used to detect the dynamic process of microscopic electrochemical reactions in the electrochemical system, and quantitatively analyze the composition and structural evolution of electrodes, electrolytes and interfaces. At the same time, inert gas is introduced into the nuclear magnetic resonance in-situ cell to bring the gas generated during the electrochemical reaction to the online differential mass spectrometer for testing, which can realize real-time synchronous detection of the solid, liquid and gas phases during the charging and discharging process.

[0015] Compared with the prior art, the present invention has the following advantages: The in-situ electrochemical nuclear magnetic resonance and online differential mass spectrometry combined method and device provided by the present invention can perform online detection of electrochemical reaction processes that produce gas, such as carbon dioxide electroreduction, electrocatalytic hydrogen production, and lithium-ion batteries, and perform real-time synchronous analysis of solid, liquid, and gas products, thereby revealing the key reaction behaviors of the electrochemical reaction process.

[0016] Based on the above reasons, the present invention can be widely promoted in the field of electrochemical testing. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0018] Figure 1 Schematic diagram of the structure of the combined device of the present invention.

[0019] Figure 2 It is a schematic diagram of the cross-sectional structure of the combined device of the present invention.

[0020] Figure 3 Schematic diagram of the analysis principle of the electrochemical reaction process using the combined device of the present invention.

[0021] Figure 4 This is a charging curve diagram of the copper / lithium peroxide battery (Cu / Li2O2) in Example 1 obtained using the combined device of the present invention.

[0022] Figure 5 The gas production data are obtained by using the combined device of the present invention for the copper / lithium peroxide battery (Cu / Li2O2) in Example 1.

[0023] Figure 6 These are the in-situ nuclear magnetic resonance data obtained for the copper / lithium peroxide battery (Cu / Li2O2) in Example 1 using the combined apparatus of the present invention.

[0024] Figure 7 This is a charge and discharge curve diagram of the copper / lithium cobalt oxide battery (Cu / LiCoO2) in Example 2 obtained using the combined device of the present invention.

[0025] Figure 8 The gas production data are obtained by using the combined device of the present invention for the copper / lithium cobalt oxide battery (Cu / LiCoO2) in Example 2.

[0026] Figure 9 These are the in-situ nuclear magnetic resonance data obtained for the copper / lithium cobalt oxide battery (Cu / LiCoO2) in Example 2 using the combined apparatus of the present invention.

[0027] In the figure: 1. Counter electrode terminal; 2. Shell; 3. Differential head; 4. Air inlet passage; 5. Air outlet passage; 6. Working electrode terminal; 7. Electrochemical reaction process; 8. Counter electrode; 9. Diaphragm; 10. Working electrode; 11. Air path connector; 401. Air inlet threaded hole; 501. Air outlet threaded hole; 101. Mass spectrometer; 102. Cold trap; 103. Argon; 104. Filter; 105. Flow meter; 106. Electrochemical nuclear magnetic resonance in-situ cell assembly; 107. Nuclear magnetic resonance spectrometer; 108. Electrochemical workstation. DETAILED DESCRIPTION

[0028] It should be noted that, in the absence of conflict, the embodiments and features of the embodiments of the present invention can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0029] In order to make the purpose, 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 in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is in no way intended to limit the present invention and its application or use. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0030] 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 form is intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, they indicate the presence of features, steps, operations, devices, components and / or combinations thereof.

[0031] Unless otherwise specified, the relative arrangement of the parts 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 ease of description, the sizes of the various parts shown in the accompanying drawings are not drawn according to actual proportional relationships. The technology, methods and equipment known to those of ordinary skill in the relevant art may not be discussed in detail, but in appropriate cases, the technology, methods and equipment should be considered as a part of the specification. In all examples shown and discussed here, any specific value should be interpreted as being merely exemplary, rather than as a limitation. Therefore, other examples of the exemplary embodiments can have different values. It should be noted that similar numbers and letters represent similar items in the following drawings, and therefore, once an item is defined in an accompanying drawing, it does not need to be further discussed in subsequent drawings.

[0032] In the description of the present invention, it should be understood that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", "horizontal, vertical, vertical, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description. Unless otherwise specified, these directional words do not indicate or imply that the device or element referred to must have a specific direction or be constructed and operated in a specific direction. Therefore, they cannot be understood as limiting the scope of protection of the present invention: the directional words "inside and outside" refer to the inside and outside relative to the outline of each component itself.

[0033] For ease of description, spatially relative terms such as "above," "above," "on the upper surface of," and "above" may be used herein to describe the spatial positional relationship of a device or feature to other devices or features as shown in the figures. It should be understood that spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is inverted, a device described as "above" or "on top of" another device or structure would then be positioned as "below" or "below" the other device or structure. Thus, the exemplary term "above" may include both the orientations of "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used herein should be interpreted accordingly.

[0034] In addition, it should be noted that the use of terms such as "first" and "second" to limit components is only for the convenience of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore cannot be understood as limiting the scope of protection of the present invention.

[0035] The present invention provides an in-situ electrochemical nuclear magnetic resonance and online differential mass spectrometry coupling method for testing an electrochemical reaction process. The method can perform online real-time detection of gas production in a series of electrochemical reaction processes, and simultaneously test the change of nuclear magnetic resonance signals over time while the electrochemical reaction process occurs. The coupling method specifically comprises: establishing an air inlet passage and an air outlet passage on an electrochemical nuclear magnetic resonance in-situ cell, so that both the air inlet passage and the air outlet passage are connected to the place where the electrochemical reaction process occurs in the electrochemical nuclear magnetic resonance in-situ cell; connecting an electrochemical workstation to the electrochemical nuclear magnetic resonance in-situ cell, connecting the air outlet passage to a mass spectrometer, placing the electrochemical nuclear magnetic resonance in-situ cell inside a coil of an in-situ electrochemical nuclear magnetic resonance probe and placing it in the nuclear magnetic resonance spectrometer; and simultaneously starting the electrochemical workstation. The chemical workstation, nuclear magnetic resonance spectrometer and mass spectrometer are used to simultaneously collect electrochemical signals, nuclear magnetic resonance signals and mass spectrometry signals to realize real-time synchronous detection of solid, liquid and gas phases. The specific process is as follows: according to the requirements of the electrochemical test, the electrochemical reaction process in the electrochemical nuclear magnetic resonance in-situ cell is controlled by the electrochemical workstation and the electrochemical signals are collected; during the electrochemical reaction process, an inert gas is introduced into the place where the electrochemical reaction process occurs through the air inlet passage, and the gas generated in the electrochemical reaction process is introduced into the mass spectrometer from the air outlet passage along with the inert gas to collect the mass spectrometry signal; at the same time, by setting the working parameters of the nuclear magnetic resonance spectrometer, such as spectrum width, scanning time of each spectrum and sampling time, the nuclear magnetic resonance signal during the electrochemical reaction process is collected.

[0036] like Figure 1-2As shown, the present invention also provides an in-situ electrochemical nuclear magnetic resonance and online differential mass spectrometry combined device including an electrochemical nuclear magnetic resonance in-situ cell assembly and an online differential mass spectrometry air inlet interface assembly; the electrochemical nuclear magnetic resonance in-situ cell assembly includes a counter electrode terminal 1, a shell 2, a differential head 3 and a working electrode terminal 6; the place where the electrochemical reaction process 7 occurs is located in the internal cavity of the shell 2, and a counter electrode 8, a diaphragm 9 and a working electrode 10 are arranged in the cavity from bottom to top, the counter electrode 8 is attached to the bottom surface of the cavity, and the diaphragm 9 is used to separate the working electrode 10 from the counter electrode 8; the upper end of the counter electrode terminal 1 extends into the cavity of the shell 2, is flush with the bottom surface of the cavity, and is electrically connected to the counter electrode 8; the differential head 3 is inserted into the cavity of the shell 2 from the top of the shell 2, and the bottom It fits tightly with the working electrode 10; an air inlet passage 4 and an air outlet passage 5 are opened inside the differential head 3, and one end of the air inlet passage 4 and the air outlet passage 5 are opened at the bottom of the differential head 3, and the other end is opened at the side of the differential head 3; the working electrode terminal 6 passes through the differential head 3, and the lower end is flush with the bottom surface of the differential head 3, and is electrically connected to the working electrode 10; the online differential mass spectrometry air inlet interface assembly includes a pair of air path connectors 11; the air inlet passage 4 is connected to the air source through the corresponding air path connectors 11, and the air outlet passage 5 is connected to the mass spectrometer through the corresponding air path connectors 11, and the air source and the mass spectrometer are respectively connected to the place where the electrochemical reaction process 7 in the electrochemical nuclear magnetic resonance in-situ cell occurs through the air inlet passage 4 and the air outlet passage 5.

[0037] Furthermore, an electrode terminal mounting hole extending from the bottom of the cavity to the bottom surface of the shell 2 is opened in the shell 2 , the upper end of the electrode terminal 1 passes through the electrode terminal mounting hole to be electrically connected to the electrode 8 , and the lower end extends out of the shell 2 .

[0038] Furthermore, a through hole is opened from top to bottom in the center of the differential head 3 for installing the working electrode terminal 6; the lower end of the working electrode terminal 6 is flush with the bottom surface of the differential head 3 and is electrically connected to the working electrode 10, and the upper end extends out of the differential head 3.

[0039] Furthermore, in order to ensure the sealing performance of the combined device, the differential head 3 is thread-sealed with the internal thread of the housing 2 through the external thread.

[0040] Furthermore, the electrochemical nuclear magnetic resonance in-situ cell component is made of non-metallic materials such as polyetheretherketone (PEEK), polytetrafluoroethylene (PTFE) or polymer ceramics.

[0041] Furthermore, the gas path connector 11 has external threads, and the air inlet passage 4 and the air outlet passage 5 are provided with internal threads at the openings on the side of the differential head 3 .

[0042] Furthermore, the air inlet passage 4 is an air inlet passage threaded hole 401 at the opening on the side of the differential head 3, and the air path connector 11 is threadedly installed on the air inlet passage threaded hole 401; the air outlet passage 5 is an air outlet passage threaded hole 501 at the opening on the side of the differential head 3, and the air path connector 11 is threadedly installed on the air outlet passage threaded hole 501.

[0043] Furthermore, the gas pipeline connected to the gas line connector 11 is made of non-metallic materials such as polyetheretherketone, polytetrafluoroethylene or polymer ceramics.

[0044] Furthermore, the gas source is an inert gas commonly used in mass spectrometry testing and contained in equipment such as gas cylinders and gas generators.

[0045] Furthermore, when the in-situ electrochemical nuclear magnetic resonance and online differential mass spectrometry combined device provided in the present application is used for testing, the electrochemical reaction process 7 occurs in the cavity of the shell 2, and the working electrode 10, the diaphragm 9 and the counter electrode 8 are immersed in the electrolyte in the cavity, wherein the working electrode 10 is tightly fitted to the bottom of the differential head 3, and the diaphragm 9 and the counter electrode 8 are arranged closely below the working electrode 10 in sequence; the electrochemical nuclear magnetic resonance in-situ cell assembly can be tested using a customized in-situ electrochemical nuclear magnetic resonance probe. When in use, the electrochemical nuclear magnetic resonance in-situ cell assembly is placed as a whole inside the coil of the in-situ electrochemical nuclear magnetic resonance probe, and then placed in the cavity of the nuclear magnetic resonance spectrometer, and the nuclear magnetic resonance signal is detected by emitting pulse excitation.

[0046] At the same time, the lower end of the counter electrode terminal 1 is arranged outside the shell 2, and it is electrically connected to the counter electrode 8. When performing electrochemical testing, it is only necessary to connect the connecting wire of the electrochemical workstation to the counter electrode terminal 1, which is equivalent to connecting the counter electrode 8; specifically, the counter electrode 8 is tightly attached to the bottom surface of the cavity of the shell 2, and directly abuts against the counter electrode terminal 1, thereby realizing the conduction between the counter electrode 8 and the counter electrode terminal 1; the working electrode 10 is similar to the counter electrode 8, and the working electrode terminal 6 is arranged on the differential head 3, and it is electrically connected to the working electrode 10. When performing electrochemical testing, it is only necessary to connect the connecting wire of the electrochemical workstation to the working electrode terminal 6, which is equivalent to connecting the working electrode 10; specifically, the working electrode 10 is tightly attached to the bottom of the differential head 3, and directly abuts against the working electrode terminal 6, thereby realizing the conduction between the working electrode 10 and the working electrode terminal 6.

[0047] The working principle of the combined device described in the present invention is: the nuclear magnetic resonance signal generated by the transition of atomic nuclei is used to detect the dynamic process of microscopic electrochemical reactions occurring in the electrochemical system, and quantitatively analyze the composition and structural evolution of electrodes, electrolytes and interfaces; at the same time, an inert gas, such as argon, is introduced into the nuclear magnetic resonance in-situ cell to carry the gas generated during the electrochemical reaction to an online differential mass spectrometer for testing, which can realize real-time synchronous detection of the solid, liquid and gas phases during the charging and discharging process.

[0048] Examples 1-2 are examples of using the in-situ electrochemical nuclear magnetic resonance and online differential mass spectrometry combined method and device provided by the present invention to perform synchronous detection of solid, liquid and gas three-phases during charging and discharging.

[0049] Example 1 like Figure 3 As shown, in a glove box filled with high-purity argon, an electrochemical nuclear magnetic resonance (NMR) in-situ cell assembly was assembled. The working electrode was Li2O2, the counter electrode was Cu, and the diaphragm was a glass fiber membrane. After the cell was assembled, it was allowed to rest for 1 hour. Argon gas 103 passed through filter 104 to flow meter 105 and then into the inlet passage 4 of the electrochemical nuclear magnetic resonance (NMR) in-situ cell assembly. The flow meter flow rate was set according to the experimental requirements. The gas then passed through the electrochemical nuclear magnetic resonance (NMR) in-situ cell assembly 106 and the cold trap 102 in sequence before entering the mass spectrometer 101. The response signal of the mass spectrometer 101 was observed. After the nitrogen in the gas path decreased to the ideal value and reached stability, the electrochemical workstation 108 and the NMR spectrometer 107 were activated to observe the real-time gas generated during the charging process and the changes in the NMR signal. Figure 4-6 They are respectively the charging curve diagram, gas production data and in-situ nuclear magnetic resonance data of the copper / lithium peroxide battery (Cu / Li2O2) in the embodiment of the present invention.

[0050] Example 2 like Figure 3 As shown, in a glove box filled with high-purity argon, an electrochemical nuclear magnetic resonance (ENR) in-situ cell assembly was assembled. The working electrode was LiCoO2, the counter electrode was Cu, and the diaphragm was a glass fiber membrane. After the cell was assembled, it was allowed to rest for 1 hour. Argon gas 103 passed through filter 104 to flow meter 105 and then into the inlet passage 4 of the ENR in-situ cell assembly. The flow meter flow rate was set according to the experimental requirements. The gas then passed through the ENR in-situ cell assembly 106 and the cold trap 102 in sequence before entering the mass spectrometer 101. The response signal of the mass spectrometer 101 was observed. After the nitrogen in the gas path decreased to the ideal value and reached stability, the electrochemical workstation 108 and the NMR spectrometer 107 were started to observe the real-time gas generated during the charging process and the changes in the NMR signal. Figure 7-9 They are respectively the charge and discharge curves, gas production data and in-situ nuclear magnetic resonance data of the copper / lithium cobalt oxide battery (Cu / LiCoO2) in the embodiment of the present invention.

[0051] 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 above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above 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 method for combining in situ electrochemical nuclear magnetic resonance and online differential mass spectrometry, characterized in that: Specifically include: An air inlet passage and an air outlet passage are established on the electrochemical nuclear magnetic resonance in-situ cell, so that both the air inlet passage and the air outlet passage are connected to a location where an electrochemical reaction process occurs in the electrochemical nuclear magnetic resonance in-situ cell; an electrochemical workstation is connected to the electrochemical nuclear magnetic resonance in-situ cell, the air outlet passage is connected to a mass spectrometer, and the electrochemical nuclear magnetic resonance in-situ cell is placed inside a coil of an in-situ electrochemical nuclear magnetic resonance probe and placed in the nuclear magnetic resonance spectrometer; The electrochemical workstation, nuclear magnetic resonance spectrometer, and mass spectrometer were started simultaneously to collect electrochemical signals, nuclear magnetic resonance signals, and mass spectrometry signals. The specific process was as follows: According to the requirements of the electrochemical test, the electrochemical reaction process in the electrochemical nuclear magnetic resonance in-situ cell is controlled by the electrochemical workstation and the electrochemical signals are collected; during the electrochemical reaction process, an inert gas is introduced into the place where the electrochemical reaction process occurs through the air inlet passage, and the gas generated during the electrochemical reaction is introduced into the mass spectrometer through the air outlet passage along with the inert gas to collect the mass spectrometry signal; at the same time, by setting the working parameters of the nuclear magnetic resonance spectrometer, the nuclear magnetic resonance signal during the electrochemical reaction process is collected.

2. An in-situ electrochemical nuclear magnetic resonance and online differential mass spectrometry device, characterized in that: It includes an electrochemical nuclear magnetic resonance in-situ cell assembly and an online differential mass spectrometry gas inlet interface assembly; The electrochemical nuclear magnetic resonance in-situ cell assembly comprises a counter electrode terminal (1), a shell (2), a differential head (3) and a working electrode terminal (6); The electrochemical reaction process (7) occurs in the cavity inside the housing (2), and a counter electrode (8), a diaphragm (9), and a working electrode (10) are sequentially arranged in the cavity from bottom to top. The counter electrode (8) is attached to the bottom surface of the cavity, and the diaphragm (9) is used to separate the working electrode (10) from the counter electrode (8). The upper end of the counter electrode terminal (1) extends into the cavity of the housing (2), is flush with the bottom surface of the cavity, and is electrically connected to the counter electrode (8); The differential head (3) is inserted into the cavity of the shell (2) from the top of the shell (2), and the bottom is tightly fitted with the working electrode (10); an air inlet passage (4) and an air outlet passage (5) are provided inside the differential head (3), and one end of the air inlet passage (4) and the air outlet passage (5) are opened at the bottom of the differential head (3), and the other end is opened at the side of the differential head (3); The working electrode terminal (6) passes through the differential head (3), the lower end of which is flush with the bottom surface of the differential head (3) and is electrically connected to the working electrode (10); The online differential mass spectrometry air inlet interface assembly includes a pair of air path connectors (11); the air inlet passage (4) is connected to the air source via the corresponding air path connectors (11), and the air outlet passage (5) is connected to the mass spectrometer via the corresponding air path connectors (11); the air source and the mass spectrometer are respectively connected to the place where the electrochemical reaction process (7) occurs in the electrochemical nuclear magnetic resonance in-situ cell via the air inlet passage (4) and the air outlet passage (5).

3. The in-situ electrochemical nuclear magnetic resonance and online differential mass spectrometry device according to claim 2, characterized in that: The shell (2) is provided with an electrode terminal mounting hole extending from the bottom of the cavity to the bottom surface of the shell (2); the upper end of the electrode terminal (1) passes through the electrode terminal mounting hole to be electrically connected to the electrode (8), and the lower end extends out of the shell (2).

4. The in-situ electrochemical nuclear magnetic resonance and online differential mass spectrometry device according to claim 2, characterized in that: A through hole extending from top to bottom is provided in the center of the differential head (3) for mounting the working electrode terminal (6); the lower end of the working electrode terminal (6) is flush with the bottom surface of the differential head (3) and is electrically connected to the working electrode (10), and the upper end extends out of the differential head (3).

5. The in-situ electrochemical nuclear magnetic resonance and online differential mass spectrometry device according to claim 2, characterized in that: The differential head (3) is connected to the internal thread of the housing (2) through an external thread.

6. The in-situ electrochemical nuclear magnetic resonance and online differential mass spectrometry device according to claim 2, characterized in that: The material of the electrochemical nuclear magnetic resonance in-situ cell component is non-metallic material.

7. The in-situ electrochemical nuclear magnetic resonance and online differential mass spectrometry device according to claim 2, characterized in that: The air path connector (11) has an external thread, and the air inlet passage (4) and the air outlet passage (5) are provided with internal threads at the openings on the side of the differential head (3).

8. The in-situ electrochemical nuclear magnetic resonance and online differential mass spectrometry device according to claim 7, characterized in that: The air inlet passage (4) is an air inlet passage threaded hole (401) at the opening on the side of the differential head (3), and the air path connector (11) is threadedly mounted on the air inlet passage threaded hole (401); the air outlet passage (5) is an air outlet passage threaded hole (501) at the opening on the side of the differential head (3), and the air path connector (11) is threadedly mounted on the air outlet passage threaded hole (501).

9. The in-situ electrochemical nuclear magnetic resonance and online differential mass spectrometry device according to claim 7, characterized in that: The material of the gas pipeline connected to the gas line connector (11) is non-metallic material.

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