Method and apparatus for improving sensitivity and signal-to-noise ratio of in-situ electrochemical nuclear magnetic resonance

Abstract

The application provides a method and device for improving the sensitivity and signal-to-noise ratio of in-situ electrochemical nuclear magnetic resonance, and relates to the field of in-situ electrochemical nuclear magnetic resonance. The method comprises the following steps: designing an electrochemical nuclear magnetic resonance in-situ cell according to the coil of an in-situ electrochemical nuclear magnetic resonance probe; the electrochemical nuclear magnetic resonance in-situ cell is externally attached with a micro coil and a micro capacitor; the sensitivity and spectral signal-to-noise ratio of the in-situ electrochemical nuclear magnetic resonance probe are improved through inductive coupling between the micro coil and the micro capacitor and the coil of the in-situ electrochemical nuclear magnetic resonance probe. The device comprises: an electrochemical nuclear magnetic resonance in-situ cell assembly, a micro coil and a micro capacitor; the micro coil and the micro capacitor are fixedly bonded to the outer wall of a shell, and the micro coil and the micro capacitor are connected through a welded copper wire. The in-situ spectral signal-to-noise ratio and the sensitivity of the probe are improved through the micro coil coupling nuclear magnetic resonance in-situ cell integration scheme.

Description

Technical Field

[0001] The present invention relates to the technical field of in-situ electrochemical nuclear magnetic resonance (EC-NMR), and in particular to a method and device for improving the sensitivity and signal-to-noise ratio of in-situ electrochemical nuclear magnetic resonance. Background Art

[0002] Electrochemical reaction systems often generate short-lived intermediates, undergo structural relaxation, and undergo dynamic bond evolution during operation, highlighting the need for the development and utilization of in situ / operono characterization techniques. The application of in situ spectroscopy to dynamically elucidate the microstructure and ion transfer dynamics of electrochemical systems is key to accurately understanding the microscopic electrochemical processes. Nuclear magnetic resonance (NMR) has proven to be a powerful tool for elucidating the changing chemical environment surrounding the nucleus, providing valuable insights into crystalline and amorphous phases, nonstoichiometric species, and local structure. Its unique advantages lie in its ability to quantitatively track phase and structural transitions during electrochemical reactions and its nondestructive nature, allowing for in situ detection while avoiding information loss due to material instabilities. Real-time data acquisition in in situ electrochemical NMR captures relatively comprehensive and quantitative analytical results, enabling a more nuanced understanding of electrochemical processes. Furthermore, NMR is a unique technique for characterizing ion dynamics, a critical issue related to charge transfer and polarization in high-performance batteries. The development of in situ electrochemical NMR spectroscopy will provide critical R&D support and characterization technology for the development of high-performance electrochemical new energy technologies. The design of in situ electrochemical nuclear magnetic resonance probe and electrochemical in situ cell is the core of this.

[0003] EC-NMR technology offers many unique advantages. However, compared to B1 coils, currently developed in situ cells have a significant inactivity burden, particularly for electrochemical energy storage systems. This impacts the fill factor and, consequently, the sensitivity and signal-to-noise ratio of in situ spectra. Furthermore, applying EC-NMR spectroscopy to investigate key electrochemical issues requires a deep understanding of the electrochemical system and its underlying theory.

[0004] EC-NMR technology has gained increasing attention with the development of lithium-ion batteries. In 2000, Rathke et al. first achieved EC-NMR analysis of batteries by integrating the battery's current collector and probe coil. However, this method was unable to simultaneously detect NMR signals and electrochemical tests. Subsequently, Letellier et al. advanced effective EC-NMR testing by equipping Bellcore-type plastic pouch batteries with a commercial static probe. However, compared with traditional button cells, this method still has some issues, including insufficient contact pressure between components, insufficient airtightness, and electrolyte leakage. Fu et al. significantly improved the signal-to-noise ratio (SNR) of EC-NMR spectra by designing a dedicated EC-NMR probe with an integrated shielded power cable, combined with the development of cylindrical cells, achieving near-operating-state performance for in-situ electrochemical NMR cells. However, EC-NMR technology requires further refinement and optimization. A good match between the electrochemical in-situ cell and the coil to improve the fill factor and quality factor is key to further improving the SNR of in-situ spectra and probe sensitivity. Summary of the Invention

[0005] In order to further improve the in-situ spectrum signal-to-noise ratio and probe sensitivity, the present invention provides a method and device for improving the sensitivity and signal-to-noise ratio of in-situ electrochemical nuclear magnetic resonance. By designing an inductive coupling circuit, a microcoil and a microcapacitor are attached to the electrochemical nuclear magnetic resonance in-situ cell, realizing an integrated design of the nuclear magnetic resonance in-situ cell and coil, improving the fill factor and quality factor, thereby improving the in-situ spectrum signal-to-noise ratio and probe sensitivity, and establishing a research paradigm for in-situ electrochemical nuclear magnetic resonance in electrochemical systems.

[0006] The technical means adopted in the present invention are as follows:

[0007] A method for improving the sensitivity and signal-to-noise ratio of in-situ electrochemical nuclear magnetic resonance, comprising:

[0008] Designing an electrochemical nuclear magnetic resonance in-situ cell according to the coil of the in-situ electrochemical nuclear magnetic resonance probe so that the electrochemical nuclear magnetic resonance in-situ cell can be placed in the coil of the in-situ electrochemical nuclear magnetic resonance probe;

[0009] A micro-coil and a micro-capacitor are attached to the outside of the electrochemical nuclear magnetic resonance in-situ cell. The position of the micro-coil corresponds to the location where the electrochemical reaction process occurs in the electrochemical nuclear magnetic resonance in-situ cell. The micro-coil and the micro-capacitor are connected by copper wire.

[0010] The electrochemical nuclear magnetic resonance in-situ cell is placed in the coil of the in-situ electrochemical nuclear magnetic resonance probe. When electrochemical testing and nuclear magnetic resonance signal detection are performed using an electrochemical workstation and a nuclear magnetic resonance spectrometer, inductive coupling occurs between the microcoil and the microcapacitor and the coil of the in-situ electrochemical nuclear magnetic resonance probe, thereby improving the sensitivity and spectrum signal-to-noise ratio of the in-situ electrochemical nuclear magnetic resonance probe.

[0011] Furthermore, after inductive coupling occurs between the microcoil and the microcapacitor and the coil of the in-situ electrochemical nuclear magnetic resonance probe, a characteristic tuning curve obtained has two peak signals.

[0012] Furthermore, the method is applicable to improving the sensitivity and spectral signal-to-noise ratio when the in-situ electrochemical nuclear magnetic resonance probe is used for electrochemical testing and nuclear magnetic resonance signal detection of the following atomic nuclei: 1 H. 7 Li, 11 B. 13 C. 17 O. 19 F. 23 Na, 27 Al, 29 4. 31 P. 64 Cu, 67 Zn.

[0013] The present invention also provides a device for improving the sensitivity and signal-to-noise ratio of in-situ electrochemical nuclear magnetic resonance, comprising an electrochemical nuclear magnetic resonance in-situ cell assembly, a micro coil and a micro capacitor;

[0014] The electrochemical nuclear magnetic resonance in-situ cell assembly comprises a counter electrode terminal, a shell, a differential head and a working electrode terminal;

[0015] 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.

[0016] 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;

[0017] 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; the working electrode terminal passes through the differential head, the lower end is flush with the bottom surface of the differential head, and is electrically connected to the working electrode;

[0018] The micro coil and the micro capacitor are bonded and fixed to the outer wall of the shell. The position of the micro coil corresponds to the place where the electrochemical reaction process occurs in the shell. The micro coil and the micro capacitor are connected by welding copper wire.

[0019] Furthermore, the height of the microcoil is equal to the sum of the heights of the counter electrode, the diaphragm and the working electrode.

[0020] Furthermore, the electrochemical nuclear magnetic resonance in-situ cell assembly is configured as but not limited to a tubular, bag-type or column-type in-situ cell, and its size and shape match the coil of the in-situ electrochemical nuclear magnetic resonance probe, so that the electrochemical nuclear magnetic resonance in-situ cell assembly can be placed in the coil of the in-situ electrochemical nuclear magnetic resonance probe.

[0021] Furthermore, a mounting hole for the electrode terminal is provided in the shell, extending from the bottom of the cavity to the bottom surface of the shell. The upper end of the electrode terminal passes through the mounting hole for the electrode terminal and is electrically connected to the electrode, and the lower end extends out of the shell. A through hole is provided 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. The micro capacitor is installed in the capacitor mounting hole provided on the outer wall of the shell.

[0022] Furthermore, the two ports of the micro coil are respectively connected to the micro capacitor through a copper wire, and the two copper wires do not contact each other.

[0023] Furthermore, the electrochemical nuclear magnetic resonance in-situ cell component is made of non-metallic material.

[0024] Furthermore, the shape of the microcoil is selected from, but not limited to, a saddle shape, a spiral shape, or a birdcage shape.

[0025] The working principle of the present invention is as follows: in situ electrochemical nuclear magnetic resonance technology detects the dynamic process of microscopic electrochemical reactions occurring in the electrochemical system through the nuclear magnetic resonance signals generated by the transition of atomic nuclei, and quantitatively analyzes the composition and structural evolution of electrodes, electrolytes and interfaces; the introduction of micro coils and micro capacitors can improve the filling factor and quality factor through inductive coupling, thereby improving the in situ spectrum signal-to-noise ratio and probe sensitivity.

[0026] Compared with the prior art, the present invention has the following advantages:

[0027] The method and device for improving the sensitivity and signal-to-noise ratio of in-situ electrochemical nuclear magnetic resonance provided by the present invention can improve the sensitivity and signal-to-noise ratio of existing in-situ electrochemical nuclear magnetic resonance technology through an integrated solution of micro-coil coupling nuclear magnetic resonance in-situ cell.

[0028] Based on the above reasons, the present invention can be widely promoted in the field of in-situ electrochemical-nuclear magnetic resonance. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] 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.

[0030] Figure 1 Schematic diagram of the structure of the nuclear magnetic resonance in-situ cell of the present invention.

[0031] Figure 2 This is a schematic cross-sectional view of the nuclear magnetic resonance in-situ cell structure of the present invention.

[0032] Figure 3 This is a schematic diagram of a partially enlarged cross-sectional structure of the in-situ nuclear magnetic resonance cell of the present invention.

[0033] Figure 4 Schematic diagram of the microcoil of the present invention.

[0034] Figure 5 Schematic diagram of the connection between the micro coil and the copper wire according to the present invention.

[0035] Figure 6 Schematic diagram of the micro capacitor of the present invention.

[0036] Figure 7 This is the tuning curve of the lithium / lithium cobalt oxide battery (Li / LiCoO2) in Example 1.

[0037] Figure 8 This is a comparison chart of the sensitivity enhancement effect of the lithium / lithium cobalt oxide battery (Li / LiCoO2) in Example 1.

[0038] In the figure: 1. Counter electrode terminal; 2. Shell; 3. Capacitor mounting hole; 4. Counter electrode; 5. Diaphragm; 6. Working electrode; 7. Differentiator head; 8. Working electrode terminal; 9. Micro coil; 10. Micro capacitor; 11. Electrochemical reaction process; 12. Copper wire I; 13. Copper wire II. DETAILED DESCRIPTION

[0039] 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.

[0040] In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the following will clearly and completely describe the technical solutions in the embodiments of the present application with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, but not all embodiments of the present application. The following description of at least one example embodiment is merely illustrative in nature and is in no way limiting on the application or its applications or uses. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the scope of protection of the present application.

[0041] It should be noted that the terminology used herein is for the purpose of describing specific embodiments only and is not intended to limit exemplary embodiments according to the present application. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and / or "comprising," when used in this specification, specify the presence of stated features, steps, operations, elements, components, and / or groups thereof, but do not preclude the presence or addition of one or more other features, steps, operations, elements, components, and / or groups thereof.

[0042] The relative arrangement of components and steps, numerical expressions, and numerical values set forth in the embodiments are not intended to limit the scope of the present application unless specifically stated otherwise. It should be clear that the sizes of the various portions shown in the drawings are not drawn to scale for ease of description. Techniques, methods, and devices known to those of ordinary skill in the relevant art can not be discussed in detail, but should be considered as part of the specification where appropriate. In all examples shown and discussed herein, any specific value should be interpreted as merely exemplary, and not as a limitation. Thus, other examples of the exemplary embodiments can have different values. It should be noted that like reference numerals and letters represent like items in the following drawings, and therefore, once an item is defined in one drawing, it need not be discussed further in subsequent drawings.

[0043] In the description of the present application, it should be understood that the orientation words such as "front, back, up, down, left, right", "horizontal, vertical, perpendicular, horizontal" and "top, bottom" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, which is only for the convenience of describing the present application and simplifying the description, and does not indicate and imply that the indicated device or element must have a particular orientation or be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the scope of protection of the present application: the orientation words "inner, outer" refer to the inner and outer relative to the contour of each component.

[0044] 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.

[0045] 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.

[0046] The present invention provides a method for improving the sensitivity and signal-to-noise ratio of in-situ electrochemical nuclear magnetic resonance. The method specifically comprises: designing an electrochemical nuclear magnetic resonance in-situ cell according to the coil of an in-situ electrochemical nuclear magnetic resonance probe so that the electrochemical nuclear magnetic resonance in-situ cell can be placed in the coil of the in-situ electrochemical nuclear magnetic resonance probe; a microcoil and a microcapacitor are attached to the outside of the electrochemical nuclear magnetic resonance in-situ cell, the position of the microcoil corresponds to the location where an electrochemical reaction process occurs in the electrochemical nuclear magnetic resonance in-situ cell, and the microcoil and the microcapacitor are connected by a copper wire; the electrochemical nuclear magnetic resonance in-situ cell is placed in the coil of the in-situ electrochemical nuclear magnetic resonance probe, and when an electrochemical workstation and a nuclear magnetic resonance spectrometer are used to perform electrochemical testing and nuclear magnetic resonance signal detection, the sensitivity and spectrum signal-to-noise ratio of the in-situ electrochemical nuclear magnetic resonance probe are improved by inductive coupling between the microcoil and the microcapacitor and the coil of the in-situ electrochemical nuclear magnetic resonance probe.

[0047] Specifically, when the in-situ electrochemical nuclear magnetic resonance probe is used to perform electrochemical testing and detect nuclear magnetic resonance signals, the electrochemical workstation is connected to the electrochemical nuclear magnetic resonance in-situ cell, and after the electrochemical nuclear magnetic resonance in-situ cell is placed in the coil of the in-situ electrochemical nuclear magnetic resonance probe, the in-situ electrochemical nuclear magnetic resonance probe is placed in a nuclear magnetic resonance spectrometer; after starting the electrochemical workstation and the nuclear magnetic resonance spectrometer, the electrochemical signals and changes in the nuclear magnetic resonance signals during the electrochemical reaction process in the electrochemical nuclear magnetic resonance in-situ cell can be observed; when the electrochemical reaction process occurs in the electrochemical nuclear magnetic resonance in-situ cell, inductive coupling occurs between the microcoil and the microcapacitor and the coil of the in-situ electrochemical nuclear magnetic resonance probe, thereby improving the in-situ spectrum signal-to-noise ratio and probe sensitivity.

[0048] The working principle of the method described in the present invention is: in situ electrochemical nuclear magnetic resonance technology detects the dynamic process of microscopic electrochemical reactions occurring in the electrochemical system through the nuclear magnetic resonance signals generated by the transition of atomic nuclei, and quantitatively analyzes the composition and structural evolution of electrodes, electrolytes and interfaces; the introduction of micro coils and micro capacitors in the present invention can improve the filling factor and quality factor through inductive coupling, thereby improving the in situ spectrum signal-to-noise ratio and probe sensitivity.

[0049] Furthermore, the electrochemical reaction processes that may occur in the electrochemical nuclear magnetic resonance in-situ cell include a series of electrochemical reactions such as electrocatalysis or battery charging and discharging.

[0050] Furthermore, after inductive coupling occurs between the microcoil and the microcapacitor and the coil of the in-situ electrochemical nuclear magnetic resonance probe, the characteristic tuning curve obtained has two peak signals, indicating that after inductive coupling occurs, the nuclear magnetic resonance signal intensity is enhanced, and the sensitivity and spectrum signal-to-noise ratio of the in-situ electrochemical nuclear magnetic resonance probe are both improved.

[0051] Furthermore, the method is applicable to improving the sensitivity and spectral signal-to-noise ratio when the in-situ electrochemical nuclear magnetic resonance probe is used for electrochemical testing and nuclear magnetic resonance signal detection of the following atomic nuclei: 1 H. 7 Li, 11 B. 13 C. 17 O. 19 F. 23 Na, 27 Al, 29 4. 31 P. 64 Cu, 67 Zn and other atomic nuclei.

[0052] Furthermore, the inductance of the microcoil can be measured by a digital bridge. L 1 and resistorR 1 and the inductance of the coil on the in situ electrochemical nuclear magnetic resonance probe L 2 and resistor R 2, and then the quality factor of the microcoil can be calculated Q 1 and the quality factor of the coil on the in situ electrochemical nuclear magnetic resonance probe Q 2. In order to ensure that the microcoil used can improve the sensitivity and spectrum signal-to-noise ratio of the in-situ electrochemical nuclear magnetic resonance probe, it is necessary to ensure that the microcoil can be inductively coupled with the coil on the in-situ electrochemical nuclear magnetic resonance probe; according to the inductive coupling principle, the coupling coefficient between the microcoil and the coil on the in-situ electrochemical nuclear magnetic resonance probe is calculated. k and critical coupling coefficient k c , the coupling state between the two coils can be determined, so as to ensure that inductive coupling can occur between the two coils; according to the frequency of the atomic nucleus tested as needed , the capacitance of the micro capacitor can be calculated.

[0053] Furthermore, the quality factor of the microcoil and the coil on the in-situ electrochemical nuclear magnetic resonance probe is The calculation formula is:

[0054] (1)

[0055] in, Indicates the operating frequency of the NMR spectrometer during testing;

[0056] Coupling coefficient k and critical coupling coefficient k c The calculation formula is:

[0057] (2)

[0058] (3)

[0059] Wherein, M represents the mutual inductance between the microcoil and the coil on the in-situ electrochemical nuclear magnetic resonance probe; whether the microcoil can be inductively coupled with the coil on the in-situ electrochemical nuclear magnetic resonance probe can also be determined by directly observing whether two peak signals appear on the characteristic tuning curve obtained; according to the frequency of the atomic nucleus tested as needed , the capacitance C1 of the micro capacitor is calculated using the following formula:

[0060] (5).

[0061] Furthermore, the effectiveness of the method of the present invention can be verified by comparing the theoretical value of the sensitivity enhancement factor of the in situ electrochemical nuclear magnetic resonance probe with the actual value of the sensitivity enhancement factor determined based on the actual spectrum obtained experimentally using the following formula:

[0062] (4)

[0063] in, V 1 represents the volume of the microcoil, V 2 represents the volume of the coil on the in-situ electrochemical nuclear magnetic resonance probe; is the theoretical value of the sensitivity enhancement factor of the in-situ electrochemical nuclear magnetic resonance probe; when the in-situ electrochemical nuclear magnetic resonance probe is used for electrochemical testing and nuclear magnetic resonance signal detection, represents the magnetic field strength after the micro-coil and the micro-capacitor are installed on the electrochemical nuclear magnetic resonance in-situ cell, represents the magnetic field strength when the micro-coil and the micro-capacitor are not set on the electrochemical nuclear magnetic resonance in-situ cell, and The ratio of is the actual value of the sensitivity enhancement factor of the in situ electrochemical nuclear magnetic resonance probe. Comparing the theoretical value and the actual value of the sensitivity enhancement factor can verify the effectiveness of the method of the present invention (the closer the actual value is to the theoretical value, the better the effect of the micro-coil and the micro-capacitor used in improving the sensitivity of the probe); assuming that the sensitivity enhancement factor of the in situ electrochemical nuclear magnetic resonance probe is A, the corresponding spectrum signal-to-noise ratio improvement factor is Therefore, it is verified that the method of the present invention can improve the sensitivity of the probe and also can be determined to improve the signal-to-noise ratio of the spectrum.

[0064] Furthermore, the sensitivity of the in-situ electrochemical nuclear magnetic resonance probe is further improved by optimizing the parameters of the microcoil, such as size, shape, material and the like.

[0065] The method described in the present invention addresses the key issue of the coil filling factor, sensitivity and signal-to-noise ratio being affected by the size differences of the electrochemical system and coil contained in the in-situ nuclear magnetic resonance cell. Based on the principle of inductive coupling, an integrated solution of micro-coils, micro-capacitors and in-situ nuclear magnetic resonance cells is proposed to improve the coil filling factor and quality factor, thereby improving the in-situ spectrum signal-to-noise ratio and probe sensitivity.

[0066] like Figure 1-6As shown, the present invention also provides a device for improving the sensitivity and signal-to-noise ratio of in-situ electrochemical nuclear magnetic resonance, comprising an electrochemical nuclear magnetic resonance in-situ cell assembly, a microcoil 9 and a microcapacitor 10; the electrochemical nuclear magnetic resonance in-situ cell assembly comprises a counter electrode terminal 1, a shell 2, a differential head 7 and a working electrode terminal 8; the place where the electrochemical reaction process 11 occurs is located in the internal cavity of the shell 2, and a counter electrode 4, a diaphragm 5 and a working electrode 6 are arranged in the cavity from bottom to top, the counter electrode 4 is attached to the bottom surface of the cavity, and the diaphragm 5 is used to separate the working electrode 6 from the counter electrode 4; the upper end of the counter electrode terminal 1 extends into the The micro-coil 9 and the micro-capacitor 10 are bonded and fixed to the outer wall of the shell 2. The position of the micro-coil 9 corresponds to the place where the electrochemical reaction process 11 occurs in the shell 2. The micro-coil 9 and the micro-capacitor 10 are connected by soldered copper wire.

[0067] The device of the present invention achieves enhancement of the sensitivity and signal-to-noise ratio of in-situ electrochemical nuclear magnetic resonance by constructing an integrated solution of a micro coil, a micro capacitor and an electrochemical nuclear magnetic resonance in-situ cell assembly.

[0068] Furthermore, the electrochemical nuclear magnetic resonance in-situ cell assembly is an in-situ cell in the form of a tube, bag or column, and its size and shape match the coil of the in-situ electrochemical nuclear magnetic resonance probe, so that the electrochemical nuclear magnetic resonance in-situ cell assembly can be placed in the coil of the in-situ electrochemical nuclear magnetic resonance probe.

[0069] Furthermore, 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 and is electrically connected to the electrode 4, and the lower end extends out of the shell 2; the center of the differential head 7 is provided with a through hole from top to bottom for installing the working electrode terminal 8; the lower end of the working electrode terminal 8 is flush with the bottom surface of the differential head 7 and is electrically connected to the working electrode 6, and the upper end extends out of the differential head 7; the micro capacitor 10 is installed in the capacitor mounting hole 3 opened on the outer wall of the shell 2.

[0070] Furthermore, the two ports of the micro coil 9 are connected to the micro capacitor 10 through a copper wire I 12 and a copper wire II 13 respectively, and the two copper wires do not contact each other.

[0071] Further, the height of the micro coil 9 is equal to the sum of the heights of the working electrode 6, the diaphragm 5 and the counter electrode 4, so that the micro coil 9 can affect the electrochemical reaction process 11.

[0072] Further, the material of the electrochemical NMR in-situ cell assembly is non-metallic material such as polyether ether ketone (PEEK), polytetrafluoroethylene (PTFE) or high polymer ceramic glass.

[0073] Further, the shape of the micro coil 9 is saddle-shaped, solenoid-shaped or birdcage-shaped.

[0074] Further, the micro differential head 7 is threadedly connected to the inner thread of the shell 2 through the outer thread arranged thereon.

[0075] Further, when the device provided in the present application is used for testing, the electrochemical NMR in-situ cell assembly with the micro coil 9 and the micro capacitor 10 arranged thereon is placed into the coil of the in-situ electrochemical NMR probe, the electrochemical workstation is connected to the electrochemical NMR in-situ cell assembly, and then the in-situ electrochemical NMR probe is placed into the NMR spectrometer; the electrochemical reaction process 11 occurs in the cavity of the shell 2, the working electrode 6, the diaphragm 5 and the counter electrode 4 are immersed in the electrolyte in the cavity, wherein the working electrode 6 is closely attached to the bottom of the micro differential head 7, and the diaphragm 5 and the counter electrode 4 are sequentially attached to the bottom of the working electrode 6; the lower end of the counter electrode terminal 1 is arranged outside the shell 2, and the counter electrode terminal 1 is electrically connected to the counter electrode 4, so that when the electrochemical test is performed, the connection wire of the electrochemical workstation is only needed to be connected to the counter electrode terminal 1, which is equivalent to connecting to the counter electrode 4; specifically, the counter electrode 4 is closely attached to the bottom surface of the cavity of the shell 2, and directly abuts against the counter electrode terminal 1, so as to realize the conduction between the counter electrode 4 and the counter electrode terminal 1; the working electrode 6 is similar to the counter electrode 4, the working electrode terminal 8 is arranged on the micro differential head 7, and the working electrode terminal 8 is electrically connected to the working electrode 6, so that when the electrochemical test is performed, the connection wire of the electrochemical workstation is only needed to be connected to the working electrode terminal 8, which is equivalent to connecting to the working electrode 6; specifically, the working electrode 6 is closely attached to the bottom of the micro differential head 7, and directly abuts against the working electrode terminal 8, so as to realize the conduction between the working electrode 6 and the working electrode terminal 8; during the test, after the electrochemical workstation and the NMR spectrometer are started, the change of the electrochemical signal and the NMR signal during the electrochemical reaction process in the electrochemical NMR in-situ cell can be observed.

[0076] Example 1

[0077] In this example, the method and device provided in the present application are used for testing the electrochemical NMR in-situ cell assembly. 7Li was subjected to electrochemical testing and nuclear magnetic resonance signal detection: in a glove box filled with high-purity argon, an electrochemical nuclear magnetic resonance in-situ cell assembly was assembled, with the working electrode being LiCoO2, the counter electrode being Li, and the diaphragm being a glass fiber membrane. After the battery was assembled, it was left to stand for 1 hour, and the electrochemical workstation and nuclear magnetic resonance spectrometer were started to observe the changes in electrochemical signals and nuclear magnetic resonance signals during the charging process. Figure 7 To fit the tuning curves of the microcoil and microcapacitor on the in-situ NMR cell, it was proved that the coil of the in-situ probe and the microcoil were inductively coupled; Figure 8 This is a comparison chart of the sensitivity enhancement of the lithium / lithium cobalt oxide battery (Li / LiCoO2) in this embodiment. Through the calculation of the inductive coupling formula, it can be concluded that the enhancement effect is 1.6 times, and the experimental test result is 1.57 times. The theoretical and experimental results are basically consistent, verifying that the method and device provided by the present invention can effectively enhance the sensitivity of the in situ electrochemical nuclear magnetic resonance probe and improve the spectrum signal-to-noise ratio.

[0078] 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 method for improving the sensitivity and signal-to-noise ratio of in-situ electrochemical nuclear magnetic resonance, characterized in that: Specifically include: Designing an electrochemical nuclear magnetic resonance in-situ cell according to the coil of the in-situ electrochemical nuclear magnetic resonance probe so that the electrochemical nuclear magnetic resonance in-situ cell can be placed in the coil of the in-situ electrochemical nuclear magnetic resonance probe; A micro-coil and a micro-capacitor are attached to the outside of the electrochemical nuclear magnetic resonance in-situ cell. The position of the micro-coil corresponds to the location where the electrochemical reaction process occurs in the electrochemical nuclear magnetic resonance in-situ cell. The micro-coil and the micro-capacitor are connected by copper wire. The electrochemical nuclear magnetic resonance in-situ cell is placed in the coil of the in-situ electrochemical nuclear magnetic resonance probe. When electrochemical testing and nuclear magnetic resonance signal detection are performed using an electrochemical workstation and a nuclear magnetic resonance spectrometer, inductive coupling occurs between the microcoil and the microcapacitor and the coil of the in-situ electrochemical nuclear magnetic resonance probe, thereby improving the sensitivity and spectrum signal-to-noise ratio of the in-situ electrochemical nuclear magnetic resonance probe.

2. The method for improving the sensitivity and signal-to-noise ratio of in-situ electrochemical nuclear magnetic resonance according to claim 1, wherein: After inductive coupling occurs between the microcoil and the microcapacitor and the coil of the in-situ electrochemical nuclear magnetic resonance probe, the obtained characteristic tuning curve has two peak signals.

3. The method for improving the sensitivity and signal-to-noise ratio of in-situ electrochemical nuclear magnetic resonance according to claim 1, wherein: The method is applicable to improving the sensitivity and spectral signal-to-noise ratio when the in-situ electrochemical nuclear magnetic resonance probe is used for electrochemical testing and nuclear magnetic resonance signal detection of the following atomic nuclei: 1 H. 7 Li, 11 B. 13 C. 17 O. 19 F. 23 Na, 27 Al, 29 4. 31 P. 64 Cu, 67 Zn.

4. A device for improving the sensitivity and signal-to-noise ratio of in-situ electrochemical nuclear magnetic resonance, characterized in that: It includes an electrochemical nuclear magnetic resonance in-situ cell assembly, a micro coil (9) and a micro capacitor (10); The electrochemical nuclear magnetic resonance in-situ cell assembly comprises a counter electrode terminal (1), a shell (2), a differential head (7) and a working electrode terminal (8); The electrochemical reaction process (11) occurs in the cavity inside the housing (2), wherein a counter electrode (4), a diaphragm (5) and a working electrode (6) are sequentially arranged in the cavity from bottom to top, wherein the counter electrode (4) is attached to the bottom surface of the cavity, and the diaphragm (5) is used to separate the working electrode (6) from the counter electrode (4); 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 (4); The differential head (7) 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 (6); the working electrode terminal (8) passes through the differential head (7), the lower end is flush with the bottom surface of the differential head (7), and is electrically connected to the working electrode (6); The micro coil (9) and the micro capacitor (10) are bonded and fixed to the outer wall of the shell (2); the position of the micro coil (9) corresponds to the place where the electrochemical reaction process (11) occurs in the shell (2); the micro coil (9) and the micro capacitor (10) are connected by a welded copper wire.

5. The device for improving the sensitivity and signal-to-noise ratio of in-situ electrochemical nuclear magnetic resonance according to claim 4, characterized in that: The height of the microcoil (9) is equal to the sum of the heights of the counter electrode (4), the diaphragm (5) and the working electrode (6).

6. The device for improving the sensitivity and signal-to-noise ratio of in-situ electrochemical nuclear magnetic resonance according to claim 4, characterized in that: The electrochemical nuclear magnetic resonance in-situ cell assembly is configured as, but not limited to, a tubular, bag-type or column-type in-situ cell, and its size and shape match the coil of the in-situ electrochemical nuclear magnetic resonance probe, so that the electrochemical nuclear magnetic resonance in-situ cell assembly can be placed in the coil of the in-situ electrochemical nuclear magnetic resonance probe.

7. The device for improving the sensitivity and signal-to-noise ratio of in-situ electrochemical nuclear magnetic resonance according to claim 4, 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 and is electrically connected to the electrode (4), and the lower end extends out of the shell (2); the center of the differential head (7) is provided with a through hole extending from top to bottom for mounting the working electrode terminal (8); the lower end of the working electrode terminal (8) is flush with the bottom surface of the differential head (7) and is electrically connected to the working electrode (6), and the upper end extends out of the differential head (7); the micro capacitor (10) is mounted in the capacitor mounting hole (3) provided on the outer wall of the shell (2).

8. The device for improving the sensitivity and signal-to-noise ratio of in-situ electrochemical nuclear magnetic resonance according to claim 4, characterized in that: The two ports of the micro coil (9) are respectively connected to the micro capacitor (10) via a copper wire, and the two copper wires do not contact each other.

9. The device for improving the sensitivity and signal-to-noise ratio of in-situ electrochemical nuclear magnetic resonance according to claim 4, characterized in that: The electrochemical nuclear magnetic resonance in-situ cell component is made of non-metallic material.

10. The device for improving the sensitivity and signal-to-noise ratio of in-situ electrochemical nuclear magnetic resonance according to claim 4, characterized in that: The shape of the microcoil (9) includes a saddle shape, a spiral shape or a birdcage shape.

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