Raman spectrometer for synchronous micro-area electrochemical detection and method for synchronously collecting electrochemical and Raman spectral signals in battery micro-area

Abstract

The present invention relates to a Raman spectrometer capable of synchronously performing micro-area electrochemical detection, which effectively combines the functions of the Raman spectrometer and the scanning electrochemical microscope, and can detect the electrochemical current given by the oxidation or reduction of substances in the micro-area inside the battery; it can also synchronously detect the Raman spectrum of substances in the micro-area inside the battery, and then identify and analyze the structure of the substances in the micro-area. Therefore, the Raman spectrometer capable of synchronously performing micro-area electrochemical detection according to the present invention can effectively construct the relationship between the performance and structural changes of the battery.

Description

Technical Field

[0001] The invention belongs to the field of electrochemical detection, and in particular relates to a Raman spectrometer for synchronous micro-area electrochemical detection and a method for synchronously collecting electrochemical and Raman spectral signals in a battery micro-area. Background Art

[0002] With the development of the world economy, energy issues have become increasingly prominent, and the research and development of electrochemical energy storage technology has become a hot topic. The working process of the battery involves the occurrence of various chemical and physical processes, such as volume change, phase change, side reactions, etc. The study of the reaction mechanism, kinetic behavior and attenuation mechanism of the electrochemical charge and discharge process of the battery interface can provide a theoretical basis for further improving the battery performance. Scanning electrochemical microscopy can measure the electrochemical current given by the oxidation or reduction of substances in the micro-area. By driving a very small electrode (probe) to scan near the sample, the corresponding micro-area electrochemistry and related information can be obtained. Scanning electrochemical microscopy can be used to study heterogeneous charge transfer reactions, homogeneous chemical reaction kinetics, liquid / liquid interface research, etc., but scanning electrochemical microscopy cannot identify and analyze the structure of the material, cannot obtain the changes in the material structure at the interface between the electrode and the electrolyte during the electrochemical reaction, and cannot study the relationship between electrochemical performance and changes in the material structure of the battery.

[0003] Raman spectroscopy is an analytical method used to study the structure of inorganic, organic, polymer, functional materials, biomolecules, etc. However, the existing Raman spectrometers can only collect spectra of working batteries, but cannot achieve synchronous electrochemical signal collection.

[0004] In summary, there is an urgent need in this field to develop a Raman spectrometer that can simultaneously perform micro-area electrochemical detection. Summary of the invention

[0005] In view of the problems existing in the prior art, the present invention provides a Raman spectrometer that can be used for synchronous micro-area electrochemical detection, including a laser focusing system for focusing laser and irradiating the laser to the internal area of ​​the battery, a spectrum acquisition system for collecting Raman signals generated from the battery structure irradiated by the laser after being focused by the laser focusing system, and a control platform for controlling the movement of the laser on the battery structure; an electrochemical signal acquisition system for collecting electrochemical signals of the battery to be tested; and an electrochemical signal processing system for processing the electrochemical signals from the electrochemical signal acquisition system to obtain electrochemical information of the battery; the spectrum acquisition system and the electrochemical signal acquisition system collect signals from the same position of the battery to be tested. It also includes a Raman spectrum processing system for processing the Raman spectrum signals from the spectrum acquisition system to obtain the Raman spectrum signals of the battery structure; a microscopic imaging system for microscopic imaging of the battery structure to be tested; an acquisition planning control system for controlling the control platform to move according to a set route, so that the spectrum acquisition system collects Raman spectra of points, lines, and surfaces of the battery to be tested; and a stage.

[0006] On the basis of the above scheme, the electrochemical signal acquisition system includes a microelectrode fixed on a microelectrode positioning platform; the microelectrode positioning platform is arranged on the control platform and is used to adjust the height and angle of the microelectrode.

[0007] On the basis of the above scheme, it also includes a light path expansion arm for changing the direction of the light path; one end of the light path expansion arm is connected to the objective lens installation port, and the other end is connected to the microscope objective lens;

[0008] The control platform is used to drive the microelectrode positioning platform and the optical path expansion arm to move synchronously, so that the spectrum collection system and the microelectrode collect Raman signals and electrochemical signals at the same position of the battery to be tested.

[0009] Based on the above solution, the adjustment range of the angle between the microelectrode and the vertical direction is 0-90 degrees.

[0010] Based on the above solution, the adjustable range of the angle between the microscope objective lens connected to the optical path expansion arm and the vertical direction is 0-90 degrees.

[0011] On the basis of the above scheme, it also includes a linkage rod fixed on the control platform, and the optical path expansion arm and the microelectrode positioning platform are respectively connected to the control platform through the linkage rod.

[0012] The present invention also provides a method for synchronously collecting electrochemical and Raman spectral signals in a battery micro-area. Specifically, the direction of the microelectrode is adjusted by a microelectrode positioning platform, and the angle of the microscope objective lens is adjusted at the same time, so that the focused laser spot is located outside the end of the microelectrode, thereby synchronously collecting the Raman spectral signal and the electrochemical signal at the same position.

[0013] On the basis of the above scheme, the control platform moves according to the parameters set by the acquisition planning control system, and drives the microscope objective and the microelectrode to move synchronously through the linkage rod, so that the laser spot and the microelectrode move synchronously inside the battery, and at the same time collect the Raman spectral signals and electrochemical signals of the points, lines and surfaces of the battery to be tested, and finally obtains the experimental results through the Raman spectral processing system and the electrochemical signal processing system.

[0014] The present invention relates to a Raman spectrometer capable of synchronously performing micro-area electrochemical detection, which effectively combines the functions of the Raman spectrometer and the scanning electrochemical microscope, and can detect the electrochemical current given by the oxidation or reduction of substances in the micro-area inside the battery; it can also synchronously detect the Raman spectrum of substances in the micro-area inside the battery, and then identify and analyze the structure of the substances in the micro-area. Therefore, the Raman spectrometer capable of synchronously performing micro-area electrochemical detection according to the present invention can effectively construct the relationship between the performance and structural changes of the battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The advantages and benefits of the present invention will become apparent to those skilled in the art by reading the detailed description of the specific embodiments below. The accompanying drawings are illustrative and are not to be considered as limiting the present invention. In the accompanying drawings:

[0016] Figure 1 It is a schematic diagram of the system structure of the Raman spectrometer that can be used for micro-area electrochemical detection of the present invention;

[0017] Figure 2 The linear scanning voltammetry curve of electrolyte (sodium trifluoroacetate aqueous solution) in three electrodes, the horizontal axis is: Ewe / Vvs.SCE, the vertical axis is: / mA;

[0018] Figure 3 This is the Raman spectrum of the electrolyte (sodium trifluoroacetate aqueous solution). DETAILED DESCRIPTION

[0019] To facilitate understanding of the present application, a more comprehensive description of the present application is provided below.

[0020] Example 1

[0021] like Figure 1 As shown, a Raman spectrometer that can be used for micro-area electrochemical detection is based on an upright microscope and includes a laser focusing system 2 for focusing laser and irradiating the laser to the internal area of ​​the battery, a spectrum acquisition system 3 for collecting Raman signals generated by the battery structure irradiated by the laser after being focused by the laser focusing system 2, a control platform 9 for controlling the movement of the laser on the battery structure, a Raman spectrum processing system 4 for processing the Raman spectrum signal from the spectrum acquisition system 3 to obtain the Raman spectrum signal of the battery structure, a microscopic imaging system 1 for microscopic imaging of the component structure of the battery to be tested, an acquisition planning control system 10 for controlling the control platform 9 to move according to a set route, so that the spectrum acquisition system 3 collects the Raman spectrum of points, lines and surfaces of the battery to be tested, and a stage 13 for placing the battery to be tested.

[0022] It also includes an electrochemical signal acquisition system for acquiring electrochemical signals of the battery to be tested; and an electrochemical signal processing system 12 for processing the electrochemical signals from the electrochemical signal acquisition system to obtain electrochemical information of the battery;

[0023] The spectrum acquisition system 3 and the electrochemical signal acquisition system acquire signals at the same position of the battery to be tested.

[0024] Specifically, the system for electrochemical signal collection and signal processing can directly use an existing scanning electrochemical microscope.

[0025] As a specific solution, the electrochemical signal acquisition system includes a microelectrode 11 fixed on a microelectrode positioning platform 8; the microelectrode positioning platform 8 is arranged on the control platform 9 and is used to adjust the height and angle of the microelectrode 11. As a preferred solution, the adjustment range of the angle between the microelectrode 11 and the vertical direction is 0-90 degrees.

[0026] As a specific implementation scheme for synchronously collecting electrochemical signals and Raman spectral signals at the same position of a battery, the Raman spectrometer of this patent also includes an optical path expansion arm 7 for changing the direction of the optical path (Renishaw's flexible three-dimensional scanning arm, model: Flexible 3D) can be directly selected; in order to expand the application of the technical solution of this patent, the optical path expansion arm 7 can be directly installed on the existing Raman spectrometer. The specific installation method is to remove the objective lens of the existing Raman spectrometer, install the optical path expansion arm 7 at the original objective lens installation position, and then install the microscope objective lens 5 at the other end of the optical path expansion arm 7; after installing the optical path expansion arm 7, the originally fixed microscope objective lens 5 can be adjusted within a range of 0-90 degrees with the vertical direction, in order to cooperate with the microelectrode 11 to realize the collection of signals at the same position of the battery to be tested.

[0027] During the signal collection process, the signal of not only one position is collected, but the collection position needs to be constantly changed. Therefore, each time a position is changed, the angle of the microscope objective 5 and the angle of the microelectrode 11 need to be adjusted, which is very difficult for the user. In order to solve this problem, the control platform 9 needs to drive the microelectrode positioning stage 8 and the optical path expansion arm 7 to move synchronously, so that when the collection position changes, the spectral collection system 3 and the microelectrode 11 can also collect the Raman signal and electrochemical signal of the same position of the battery to be tested.

[0028] As a specific implementation scheme, in order to realize the above functions, the present patent fixes a linkage rod 6 on the control platform 9, so that the optical path expansion arm 7 and the microelectrode positioning platform 8 are respectively connected to the control platform 9 through the linkage rod 6. This setting can make the focused laser spot and the microelectrode 11 move synchronously when the detection position is changed, and the focused laser spot is always located outside the end of the microelectrode 11, ensuring that the spectrum collection system 3 and the microelectrode 11 collect Raman signals and electrochemical signals at the same position of the battery to be tested.

[0029] Example 2

[0030] Based on Example 1, this patent provides a method for synchronously collecting electrochemical signals and Raman spectral signals in a battery micro-area. The method uses the Raman spectrometer in Example 1 to synchronously collect Raman spectral signals and electrochemical signals at the same position of the battery.

[0031] Specifically, when in use, the direction of the microelectrode 11 is adjusted by the microelectrode positioning stage 8, and the angle of the microscope objective lens 5 is adjusted at the same time, so that the focused laser spot is located outside the end of the microelectrode 11, and then the Raman spectrum signal and electrochemical signal of the same position of the battery are synchronously collected. The control platform 9 moves according to the parameters set by the acquisition planning control system 10, and drives the microscope objective lens 5 and the microelectrode 11 to move synchronously through the linkage rod 6, so that the laser spot and the microelectrode 11 move synchronously inside the battery, and the Raman spectrum signals and electrochemical signals of the points, lines and surfaces of the battery to be tested are collected at the same time, and finally the experimental results are obtained through the Raman spectrum processing system 4 and the electrochemical signal processing system 12.

[0032] Example 3

[0033] An electrolytic cell was assembled using a Ag / AgCl standard electrode (0.199 V vs. SHE) as a reference electrode, a Pt microelectrode as a working electrode, a stainless steel wire as a counter electrode, and a sodium trifluoroacetate aqueous solution as an electrolyte.

[0034] Using the Raman spectrometer for micro-area electrochemical detection in Example 1, the electrolytic cell is placed on the stage 13 and connected to the electrochemical signal processing system 12 .

[0035] Turn on the main switch of the spectrometer, and the microscopic imaging system 1, the laser focusing system 2, the spectrum acquisition system 3, and the Raman spectrum processing system 4 start to operate and preheat for 15 minutes.

[0036] Install the microelectrode 11 onto the microelectrode positioning stage 8, adjust the position of the microelectrode 11 and the angle of the 50L microscope objective lens 5, so that the end of the microelectrode 11 is in the focal plane of the microscope objective lens 5, and the end of the microelectrode 11 can be clearly seen through the 50L microscope objective lens 5.

[0037] The acquisition parameters were set on the control software (original Raman spectrometer RENISHAW inVia Raman Microscope-QONTOR), the control platform 9 moved according to the set parameters, and the 50L microscope objective 5 and the microelectrode 11 were driven to move synchronously through the linkage rod 6, so that the laser spot and the microelectrode 11 moved synchronously inside the battery, and Raman spectrum signals and electrochemical signals were collected at the same time, and finally the experimental results were obtained through the Raman spectrum processing system 4 and the electrochemical signal processing system 12 (see the results). Figure 2 , 3 ).

[0038] The above is only a preferred embodiment of the present invention, and does not limit the present invention in other forms. Any technician familiar with the profession may use the above disclosed technical content to change or modify it into an equivalent embodiment with equivalent changes. However, any simple modification, equivalent change and modification made to the above embodiment according to the technical essence of the present invention without departing from the technical solution of the present invention still belongs to the protection scope of the technical solution of the present invention.

Claims

1. A Raman spectrometer for synchronous micro-area electrochemical detection, comprising a laser focusing system (2) for focusing laser light and irradiating the laser light to the internal area of ​​a battery, a spectrum collection system (3) for collecting Raman signals generated by the battery structure irradiated by the laser light focused by the laser focusing system (2), and a control platform for controlling the movement of the laser light on the battery structure; characterized in that: Also includes An electrochemical signal acquisition system for acquiring electrochemical signals of a battery to be tested; and An electrochemical signal processing system (12) for processing the electrochemical signal from the electrochemical signal acquisition system to obtain electrochemical information of the battery; The spectrum acquisition system (3) and the electrochemical signal acquisition system acquire signals at the same position of the battery to be tested; The electrochemical signal acquisition system comprises a microelectrode (11) fixed on a microelectrode positioning platform (8); the microelectrode positioning platform (8) is arranged on the control platform (9) and is used to adjust the height and angle of the microelectrode (11); It comprises a light path expansion arm (7) for changing the direction of the light path; one end of the light path expansion arm (7) is connected to the objective lens mounting port, and the other end is connected to the microscope objective lens (5); The control platform (9) is used to drive the microelectrode positioning platform (8) and the optical path expansion arm (7) to move synchronously, so that the spectrum collection system (3) and the microelectrode (11) collect Raman signals and electrochemical signals at the same position of the battery to be tested; It comprises a linkage rod (6) fixed on a control platform (9), and the optical path expansion arm (7) and the microelectrode positioning platform (8) are respectively connected to the control platform (9) via the linkage rod (6); Also included is a stage (13).

2. The Raman spectrometer according to claim 1, characterized in that: The adjustment range of the angle between the microelectrode (11) and the vertical direction is 0-90 degrees.

3. The Raman spectrometer according to claim 1, characterized in that: The adjustable range of the angle between the microscope objective lens (5) connected to the optical path expansion arm (7) and the vertical direction is 0-90 degrees.

4. The Raman spectrometer according to claim 3, characterized in that: Also includes: A Raman spectrum processing system (4) for processing the Raman spectrum signal from the spectrum acquisition system (3) to obtain the Raman spectrum signal of the battery structure; A microscopic imaging system (1) for microscopically imaging the battery structure to be tested; A collection planning control system (10) is used to control the control platform (9) to move according to a set route, so that the spectrum collection system (3) collects Raman spectra of points, lines and surfaces of the battery to be tested.

5. A method for synchronously collecting electrochemical signals and Raman spectroscopy signals in a battery micro-area, characterized in that: Use the Raman spectrometer described in any one of claims 1 to 4.

6. The method according to claim 5, characterized in that The direction of the microelectrode (11) is adjusted by a microelectrode positioning stage (8), and the angle of the microscope objective lens (5) is adjusted simultaneously, so that the focused laser spot is located outside the end of the microelectrode (11), thereby synchronously collecting the Raman spectrum signal and the electrochemical signal at the same position.

7. The method according to claim 6, characterized in that The control platform (9) moves according to the parameters set by the acquisition planning control system (10), and drives the microscope objective lens (5) and the microelectrode (11) to move synchronously through the linkage rod (6), so that the laser spot and the microelectrode (11) move synchronously inside the battery, and simultaneously collects Raman spectrum signals and electrochemical signals of points, lines and surfaces of the battery to be tested, and finally obtains the experimental results through the Raman spectrum processing system (4) and the electrochemical signal processing system (12).

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