In-situ Raman-ultraviolet visible spectrum reaction tank

Abstract

The utility model discloses an in-situ Raman-ultraviolet visible spectrum reaction tank, which comprises a reaction tank main body used for placing electrolyte in charging and discharging processes, a material inlet / outlet arranged above the reaction tank main body and used for filling or pouring out the electrolyte, and a material outlet arranged above the reaction tank main body and used for filling or pouring out the electrolyte, the electrode comprises a positive electrode current collector and a negative electrode and is used for being connected with an electrochemical workstation to carry out charging and discharging tests; a window is arranged on the side surface of the reaction tank main body, the window comprises a front window and two opposite side windows, the front window is used for measuring an in-situ Raman spectrum, and the side windows are used for measuring an in-situ ultraviolet-visible absorption spectrum. According to the utility model, the Raman spectrum and ultraviolet visible spectrum detection of the polyiodide can be synchronously carried out in real time in the charging and discharging process of the zinc-iodine battery, the conversion / dissipation process and state of the polyiodide on the surface of the electrode and in the electrolyte are fed back, real-time linked dynamic reaction information is provided, and the accuracy and real-time performance of the detection result are improved.

Description

Technical Field

[0001] This invention belongs to the technical field of battery testing devices, and particularly relates to an in-situ Raman-UV-Vis spectroscopy reaction cell. Background Technology

[0002] Zinc-iodine batteries possess advantages such as low cost, high safety, and high theoretical capacity, showing potential applications in large-scale energy storage, such as energy storage in smart grids and distributed energy systems. Zinc-iodine batteries primarily achieve electrochemical energy storage through a conversion reaction mechanism: during charging, zinc ions lose electrons from the zinc negative electrode and enter the electrolyte, while iodide ions gain electrons at the positive electrode and are reduced to elemental iodine, reacting with the electrode material to form iodine-containing compounds. During discharging, the iodine-containing compounds undergo oxidation, releasing electrons and iodide ions. Zinc ions gain electrons from the electrolyte and are reduced to elemental zinc at the negative electrode, thus completing the entire charge-discharge process. During charging and discharging, the polyiodides formed by the reduction of iodide ions at the positive electrode easily dissolve in the electrolyte and shuttle to the negative electrode, reacting with zinc, leading to capacity decay, reduced coulombic efficiency, and shortened cycle life. In research related to the charge-discharge of zinc-iodine batteries, Raman spectroscopy is generally used to detect the conversion process and state of polyiodides on the electrode surface (110 / 160 cm⁻¹). -1 Corresponding to I3 - / I5 - The process and state of polyiodide efflux into the electrolyte were detected using ultraviolet-visible spectroscopy (223 nm corresponds to I). - 288nm and 351nm correspond to I3 - (445nm corresponds to I2). In order to better detect the conversion / escape process and state of polyiodides on the electrode surface and in the electrolyte during the charging and discharging of zinc-iodine batteries, so as to study the improvement of the capacity and cycle life of zinc-iodine batteries, it is urgent to develop an electrochemical reaction cell that can be detected by both Raman spectroscopy and ultraviolet-visible spectroscopy. Utility Model Content

[0003] To address the above problems, this invention proposes an in-situ Raman-UV-Vis spectroscopy reaction cell.

[0004] An in-situ Raman-UV-Vis spectroscopy reaction cell includes:

[0005] The reaction tank body is used to hold the electrolyte during the charge-discharge process. An inlet and outlet are provided at the top of the reaction tank body for loading or unloading the electrolyte. Electrodes, including a positive current collector and a negative electrode, are used to connect to an electrochemical workstation for charge-discharge testing.

[0006] The reaction cell body has a window on its side, which includes a front window and two opposite side windows. The front window is used to measure in-situ Raman spectra, and the side windows are used to measure in-situ ultraviolet-visible absorption spectra.

[0007] Preferably, the main body of the reaction tank is integrally formed or assembled from parts.

[0008] Preferably, the window has a window pane that allows stable light transmission and does not react with the electrolyte.

[0009] Preferably, the window is a quartz window or a sapphire window.

[0010] Preferably, the electrode is located inside the reaction tank body and in contact with the electrolyte; a portion of the positive current collector is disposed on the window slat of the front window; and the negative electrode is disposed on the rear plate opposite to the front window.

[0011] This utility model has the following beneficial effects:

[0012] This invention provides an in-situ Raman-UV-Vis spectroscopy reaction cell that can simultaneously and in real-time detect the Raman and UV-Vis spectra of polyiodides during the charging and discharging process of zinc-iodine batteries. It provides feedback on the conversion / escape process and state of polyiodides on the electrode surface and in the electrolyte, offering real-time and dynamic reaction information, thus improving the accuracy and real-time performance of the detection results. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the structure of an in-situ Raman-UV-Vis spectroscopy reaction cell according to a preferred embodiment of the present invention.

[0014] Figure 2 This is a top view of an in-situ Raman-UV-Vis spectroscopy reaction cell according to a preferred embodiment of the present invention.

[0015] Figure 3 This is a top view of an in-situ Raman-UV-Vis spectroscopy reaction cell using visible space light to measure UV-Vis spectra, according to a preferred embodiment of this utility model.

[0016] Figure 4 This is a top view of an in-situ Raman-UV-Vis spectroscopy reaction cell using a coupler and optical fiber to measure UV-Vis spectra, which is a preferred embodiment of this utility model. Detailed Implementation

[0017] The embodiments of this utility model will be described below with reference to the accompanying drawings. It should be noted that the embodiments described in this specification are not exhaustive and do not represent the only embodiments of this utility model. The following corresponding embodiments are only for clearly illustrating the utility model content of this patent and are not intended to limit its implementation. For those skilled in the art, different variations and modifications can be made based on these embodiments. Any obvious variations or modifications that fall within the technical concept and utility model content of this utility model are also within the protection scope of this utility model.

[0018] like Figure 1 , 2 As shown, the reaction tank includes a reaction tank body 1, a positive electrode current collector 2, and a negative electrode 3. The reaction tank body 1 has windows on its sides, including a front window 4, a left side window 5, and a right side window 6 arranged opposite each other. The reaction tank body 1 holds electrolyte 7, and an inlet / outlet 8 is provided at the top of the reaction tank body 1 for loading or unloading electrolyte. Preferably, the reaction tank body 1 is formed integrally or by splicing. The reaction tank body 1 is made of polytetrafluoroethylene or quartz material, but can also be made of acrylic, polymethyl methacrylate, polyethylene terephthalate, polycarbonate resin, polyoxymethylene resin, or other polymer insulating materials.

[0019] In each preferred embodiment, both the positive current collector 2 and the negative electrode 3 are located within the reaction cell body 1 and are in contact with the electrolyte 7. The positive current collector 2 is disposed on the side of the front window 4. Preferably, the positive current collector 2 is attached to a portion of the front window 4, for example, to a window pane of the front window 4 so that light passes through the front window 4 and is focused onto the positive current collector 2. The negative electrode 3 is located at the rear plate 27 opposite to the front window 4 and is attached to the rear plate 27. Preferably, the positive current collector 2 is carbon paper or titanium mesh, and the negative electrode 3 is zinc foil. The positive current collector 2 and the negative electrode 3 are used to connect to an electrochemical workstation (not shown) for charge-discharge testing.

[0020] In each preferred embodiment, the left window 5 and the right window 6 are positioned opposite each other, located on either side of the front window 4. The front window 4 is used for in-situ Raman spectroscopy measurements to detect the polyiodide conversion process and state on the positive electrode surface during the charging and discharging of the zinc-iodine battery. The left window 5 and the right window 6 are used for in-situ ultraviolet-visible absorption spectroscopy measurements to detect the process and state of polyiodides dissolving and escaping from the positive electrode surface into the electrolyte during the charging and discharging of the zinc-iodine battery. The front window 4, left window 5, and right window 6 are all stable light-transmitting windows that do not react with the electrolyte 7. Preferably, the windows are quartz windows or sapphire windows. In the in-situ ultraviolet-visible absorption spectroscopy measurements, light is focused onto the positive electrode current collector 2 through the front window 4, and light passes through the electrolyte 7 in the reaction cell body 1 through the left window 5 and the right window 6. The light can be spatial light, or it can be incident and emitted through a coupler and optical fiber.

[0021] Preferably, the reaction cell body 1 can be equipped with an optical precision displacement stage (not shown) to allow for precise adjustment in space.

[0022] The following description, in conjunction with preferred embodiments of the present invention, further illustrates different measurement methods for in-situ ultraviolet-visible absorption spectroscopy.

[0023] 1. Under spatial light conditions

[0024] Figure 3 This is a schematic diagram of a preferred embodiment of the present invention using spatial light measurement in an in-situ Raman-UV-Vis spectroscopy reaction cell. Figure 3 As shown, in-situ Raman measurements utilize a microscope objective 9 and a dichroic mirror 10. After the positive current collector 2 and the negative electrode 3 are connected to an electrochemical workstation (not shown) and charging / discharging begins, the excitation light 11 is transmitted through the dichroic mirror 10, refracted by the microscope objective 9, and then enters the front window 4, where it is focused onto the positive current collector 2, generating a Raman signal 12. The Raman signal 12 is refracted into a parallel beam by the microscope objective 9, reflected by the dichroic mirror 10, separated from the excitation light 11, and identified.

[0025] Preferably, the dichroic mirror 10 reflects long wavelengths and transmits short wavelengths. In other embodiments, a dichroic mirror that transmits long wavelengths and reflects short wavelengths is also applicable. During measurement, the excitation light 11 is reflected into the microscope objective 9, and the Raman signal 12 is transmitted out of the dichroic mirror 10. This can be freely selected as needed.

[0026] In in-situ UV-Vis measurements, incident light 13 enters the reaction cell body 1 perpendicularly through the left window 5 and exits through the right window 6. The intensity of the emitted light 14 is I0 when the reaction cell 1 is without electrolyte 7. When electrolyte is added and charging / discharging begins, the intensity of the emitted light 14 is I(t). Therefore, the UV-Vis absorption value is A = -log0 10 [I(t) / I0].

[0027] 2. Under the condition of using couplers and optical fibers

[0028] Some measurements require coupling with a commercial UV-Vis absorption spectrometer. In such cases, the light needs to be exported, passed through the sample, and then imported. In this situation, a combination of coupler, collimator, and optical fiber becomes a good option. Figure 4This is a schematic diagram of an in-situ Raman-UV-Vis spectroscopy reaction cell using a coupler and optical fiber to measure UV-Vis spectra according to a preferred embodiment of this utility model. The incident section includes a first coupler 21, a first collimator 23, and an incident optical fiber 22; the exiting section includes a second coupler 24, a second collimator 26, and an exiting optical fiber 25. The first coupler 21 and the second coupler 24 are used to converge parallel light rays into the optical fiber; the first collimator 23 and the second collimator 26 are used to re-refract the light rays transmitted in the optical fiber into parallel light rays; the incident optical fiber 22 is used to transmit the incident light 13, and the exiting optical fiber 25 is used to transmit the exiting light 14.

[0029] The in-situ Raman measurement is the same as the measurement under spatial light conditions described above. In the in-situ UV-Vis absorption spectroscopy measurement section, the incident light 13, after passing through the first coupler 21, is focused onto the incident fiber 22. After passing through the first collimator 23, it is refracted into parallel light and enters the reaction cell 1. It then passes sequentially through the left window 5, the electrolyte 7, and the right window 6 before exiting as light 14. This light enters the second coupler 24 and is focused into the exit fiber 25. After exiting the exit fiber 25, it is focused into parallel light by the second collimator 26 and transmitted to the UV-Vis absorption spectrometer for detection. The UV-Vis absorption value is also A = -log 10 [I(t) / I0]. In the usage described above, the incident light 13 enters from the left window 5 and exits from the right window 6. In other usages, it is also feasible for the incident light 13 to enter from the right window 6 and exit from the left window 5, and the effect is the same.

[0030] Obviously, those skilled in the art should recognize that the above embodiments are only used to illustrate the present utility model and are not intended to limit the present utility model. Any changes or modifications to the above embodiments within the essential spirit of the present utility model will fall within the scope of the claims of the present utility model.

Claims

1. An in-situ Raman-UV-Vis spectroscopy reaction cell, comprising: The main body of the reaction tank is used to hold the electrolyte during the charging and discharging process. The main body of the reaction tank is provided with an inlet and outlet for loading or unloading the electrolyte. The device includes electrodes, including a positive current collector and a negative electrode, for connecting to an electrochemical workstation for charge-discharge testing. The device is characterized by having a window on the side of the reaction cell body, comprising a front window and two opposing side windows. The front window is used to measure in-situ Raman spectra, and the side windows are used to measure in-situ UV-Vis absorption spectra.

2. The in-situ Raman-UV-Vis spectroscopy reaction cell according to claim 1, characterized in that, The main body of the reaction tank is either integrally formed or assembled from parts.

3. An in-situ Raman-UV-Vis spectroscopy reaction cell according to claim 1, characterized in that, The window has a stable light transmission structure that does not react with the electrolyte.

4. The in-situ Raman-UV-Vis spectroscopy reaction cell according to claim 3, characterized in that, The window is a quartz window or a sapphire window.

5. An in-situ Raman-UV-Vis spectroscopy reaction cell according to claim 1, characterized in that, The electrode is located inside the main body of the reaction tank and is in contact with the electrolyte. A portion of the positive current collector is disposed on the window of the front window. The negative electrode is disposed on the rear plate opposite to the front window.

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