A wide temperature range electrochemical in-situ infrared spectrum testing device based on attenuated total reflection mode

Abstract

The utility model provides a kind of wide temperature range electrochemical in-situ infrared spectrum testing device based on attenuated total reflection mode, including pool body, shell, ATR prism, sealing ring, temperature control component and temperature sensor, the pool body has a working surface, the working surface is recessed with reaction groove;The pool body is metal material, can be as counter electrode current collector;The ATR prism is connected in the working surface of pool body, the ATR prism has top surface oppositely arranged with the working surface, and the top surface is equipped with metal plating layer;The metal plating layer can be as working electrode current collector;The sealing ring is installed between the pool body and the ATR prism, overall structure is compact, cost is lower, thermal inertia is small, with good temperature control capacity, can realize the rapid response to temperature change, suitable for in-situ infrared testing demand under the temperature variation condition of wide temperature range.

Description

Technical Field

[0001] This invention relates to the field of electrochemical spectroscopy technology, and in particular to a wide-temperature-range electrochemical in-situ infrared spectroscopy testing device based on attenuated total reflection mode. Background Technology

[0002] The intermittency and uneven spatial distribution of renewable energy sources have become core bottlenecks restricting their large-scale application. For example, photovoltaic power generation is only effective during daylight hours and cannot match peak and off-peak electricity demand at night. Therefore, energy storage technology has become a core challenge in the energy transition. Among various energy storage technologies, electrochemical energy storage stands out due to its advantages such as fast response speed (milliseconds), environmental friendliness, and flexible modular deployment. Among these, lithium-ion batteries (LIBs) have become the mainstream choice due to their high energy density (250-300 Wh / kg), long lifespan (>2000 cycles), and mature commercial applications.

[0003] Despite their widespread use, lithium-ion batteries experience significant performance degradation and safety risks at extreme temperatures (such as below 0°C or above 50°C). As human activities expand into environments like polar regions, the deep sea, and outer space, the market urgently needs high-performance batteries capable of stable operation across a wide temperature range. Developing such batteries has become a strategic priority for energy storage technology innovation, but the technological bottleneck lies in understanding and solving the problem of performance degradation and even failure at extreme temperatures.

[0004] The performance of a battery over a wide temperature range largely depends on its internal electrode / electrolyte interface. Electrochemical in-situ infrared spectroscopy is a powerful tool for real-time monitoring of changes at this interface. By monitoring molecular vibrational information at the electrode / electrolyte interface in real time, it provides a key means to reveal the evolution of interfacial molecular structures, intermediate formation, and dynamic reaction pathways, helping us to analyze the impact of temperature on electrode / electrolyte interfacial processes. However, conventional electrochemical in-situ infrared spectroscopy equipment can usually only perform tests at room temperature and cannot characterize electrode / electrolyte interfacial processes under wide temperature conditions.

[0005] Most existing infrared spectrometers do not have built-in temperature control systems. To meet variable temperature requirements, modifications to the optical path accessories are needed, or the entire instrument needs to be placed in a variable temperature environmental chamber. However, this is costly, has poor compatibility with infrared spectrometers from different manufacturers, and is inconvenient for wide-temperature operation, posing a risk of instrument damage. In addition, some existing electrochemical in-situ spectroscopy testing devices that can achieve a certain temperature range still suffer from problems such as large device size.

[0006] Therefore, there is an urgent need to develop a low-cost, versatile, and precisely temperature-controlled electrochemical in-situ infrared testing cell. Utility Model Content

[0007] Therefore, in response to at least one of the above problems, this utility model provides a wide-temperature-range electrochemical in-situ infrared spectroscopy testing device based on attenuated total reflection mode.

[0008] This utility model is achieved using the following solution:

[0009] This invention proposes a wide-temperature-range electrochemical in-situ infrared spectroscopy testing device based on attenuated total reflection mode, comprising:

[0010] The pool body has a working surface, and the working surface is recessed with a reaction groove; the pool body is made of metal and can be used as a current collector for the counter electrode;

[0011] An ATR prism is connected to the working surface of the pool body. The ATR prism has a top surface that is opposite to the working surface and is provided with a metal coating. The metal coating can serve as a working electrode current collector.

[0012] A sealing ring is installed between the pool body and the ATR prism. The sealing ring is arranged around the periphery of the reaction tank. The sealing ring can seal the gap between the pool body and the ATR prism, thereby providing a reaction chamber.

[0013] A temperature control component, wherein the temperature control component is attached to the pool body;

[0014] A housing, wherein the housing is a cavity structure, for mounting the pool body and the temperature control assembly therein; and

[0015] A temperature sensor is used to monitor the temperature of the pool.

[0016] In one embodiment, the ATR prism is a three-dimensional structure with an inverted trapezoidal cross-section, and the ATR prism further includes a bottom surface, an incident surface, an exit surface, and two side surfaces.

[0017] In one embodiment, the ATR prism is mounted on the working surface of the pool body via a prism bracket. The prism bracket includes a flange, one side of which is connected to a first side plate and a second side plate. The lower ends of the first side plate and the second side plate are connected via a base plate, thereby forming a prism mounting cavity within the prism bracket. The prism mounting cavity has a first opening and a second opening, which correspond to the light-incident surface and the light-exit surface of the ATR prism, respectively.

[0018] In one embodiment, the prism support is made of metal; the flange has screw holes for inserting screws to install the prism support onto the working surface of the pool body; insulating material is provided inside and around the screw holes.

[0019] In one embodiment, the insulating material is PEEK material.

[0020] In one embodiment, the material of the ATR prism is ZnSe.

[0021] In one embodiment, the temperature control component includes a TEC heating and cooling element that is disposed against the pool body; the temperature control component also includes a heat dissipation copper busbar that has a cooling fluid channel.

[0022] In one embodiment, the temperature sensor is a PT100 thermistor, and a sensor mounting hole is provided on one side of the pool body, through which the temperature sensor is embedded in the pool body.

[0023] In one embodiment, the housing includes a first half-shell and a second half-shell connected to each other. The first half-shell is provided with a mounting groove for mounting the pool body, and the bottom of the mounting groove is provided with an opening. The pool body is provided with a boss that protrudes and fits into the opening, and the working surface of the pool body is flush with the lower surface of the first half-shell.

[0024] In one embodiment, the metal plating is a gold plating; and / or, the pool body is made of 316L stainless steel.

[0025] The technical solution provided by this utility model has the following technical effects:

[0026] 1. This utility model proposes a wide-temperature-range electrochemical in-situ infrared spectroscopy testing device based on attenuated total internal reflection mode, including a cell body, a shell, an ATR prism, a sealing ring, a temperature control component, and a temperature sensor. The cell body has a working surface with a reaction groove recessed therein. The cell body is made of metal and can serve as a current collector for the counter electrode. The ATR prism is connected to the working surface of the cell body and has a top surface opposite to the working surface, with a metal coating on the top surface. The metal coating can serve as a current collector for the working electrode. The sealing ring is installed between the cell body and the ATR prism. The overall structure is compact, low in cost, has low thermal inertia, and good temperature control capability, enabling rapid response to temperature changes. It is suitable for in-situ infrared testing under wide-temperature-range variable-temperature conditions.

[0027] 2. The ATR prism is made of zinc selenide (ZnSe). ZnSe prisms have good temperature stability and high transparency over a wide infrared range. They also have a relatively high refractive index and a low absorption coefficient, which can ensure the effective transmission of infrared light and improve the analytical accuracy of the device. Their good mechanical strength and thermal shock resistance make them more suitable for electrochemical in-situ infrared spectroscopy testing devices with a wide temperature range.

[0028] 3. The temperature control component includes a TEC heating and cooling element and a heat dissipation copper busbar. The heat dissipation copper busbar is provided with a cooling fluid channel to promote heat exchange and through which cooling water flows, thereby achieving high-power rapid temperature change, thus forming a semiconductor temperature-controlled variable temperature electrochemical in-situ infrared cell with an integrated water-cooling system.

[0029] 4. The ATR prism is mounted on the working surface of the pool body via a prism bracket. The prism bracket includes a flange with screw holes for screws to be inserted to mount the prism bracket on the working surface of the pool body. Insulating material is provided inside and around the screw holes to prevent short circuits between electrodes, thus enhancing the safety of the device. Attached Figure Description

[0030] Figure 1 This is a perspective view of the infrared spectroscopy testing device according to an embodiment of the present invention;

[0031] Figure 2 This is an exploded view of the infrared spectroscopy testing device of this embodiment;

[0032] Figure 3 This is a partial cross-sectional perspective view of the infrared spectroscopy testing device of this embodiment;

[0033] Figure 4 This is a perspective view of the pool body in this embodiment;

[0034] Figure 5 This is a perspective view of the first half-shell of this embodiment;

[0035] Figure 6 This is a perspective view of the ATR prism in this embodiment;

[0036] Figure 7 This is a full sectional view of the ATR prism in this embodiment;

[0037] Figure 8 This is a perspective view of the prism support in this embodiment;

[0038] Figure 9 This is a perspective view of the prism bracket in this embodiment from another direction;

[0039] Figure 10Using a blank prism at 20 ℃ as a background, the infrared spectra of blank samples collected by Si and ZnSe prisms at -20 ℃ are compared with the infrared spectra of electrolytes collected at 20 ℃.

[0040] Figure 11 The results of the pool temperature control test are shown in Figure (a), which represents the test conducted at 30–70 ℃; and Figure (b), which represents the test conducted at -20–17 ℃.

[0041] Figure 12 This is the infrared spectrum of the 1 M LiFSI DME electrolyte tested by the infrared spectroscopy testing device of this embodiment in the range of -20 to 70°C. Detailed Implementation

[0042] To further illustrate the various embodiments, the present invention provides accompanying drawings. These drawings are part of the disclosure of the present invention and are mainly used to illustrate the embodiments, and can be used in conjunction with the relevant descriptions in the specification to explain the operating principles of the embodiments. With reference to these drawings, those skilled in the art should be able to understand other possible implementations and the advantages of the present invention. Components in the drawings are not drawn to scale, and similar component symbols are generally used to represent similar components.

[0043] The present invention will now be further described in conjunction with the accompanying drawings and specific embodiments.

[0044] like Figures 1-12 As shown, this embodiment provides a wide-temperature-range electrochemical in-situ infrared spectroscopy testing device 1 based on attenuated total reflection mode, including a cell body 10, a shell 20, an ATR prism 30, a sealing ring 40, a temperature control component 50, a prism support 60, and a temperature sensor 70.

[0045] The housing 20 includes a first half-shell 21 and a second half-shell 22, which are connected to each other to form the housing 20, for example, by screws. The housing 20 is a cavity structure used to install the pool body 10 and the temperature control component 50 therein. The temperature control component 50 is attached to the pool body 10 and is used to regulate the temperature of the pool body 10.

[0046] The temperature control component 50 includes a TEC heating and cooling element 51, which is attached to the cell body 10. The TEC heating and cooling element 51 is a semiconductor temperature controller. Semiconductor temperature control is based on the Peltier effect, that is, when a direct current passes through a semiconductor thermocouple pair, electrons move from the N-type semiconductor to the P-type semiconductor, while holes move in the opposite direction, resulting in heat absorption (cold end) and heat release (hot end) processes at the junction. This method is suitable for in-situ testing scenarios with a temperature range of -20 to 60 ℃ and requiring rapid temperature changes. However, its cooling efficiency decreases significantly with increasing temperature difference, and a water-cooling or air-cooling system is required to maintain stable performance during high-power operation. Based on the above considerations, the temperature control component 50 in this embodiment further includes a heat dissipation copper busbar 52, which is provided with cooling fluid channels 521 and 522 for promoting heat exchange, such as channels for cooling water flow, thereby achieving rapid temperature changes at high power, and thus forming a semiconductor temperature-controlled variable-temperature electrochemical in-situ infrared cell body with an integrated water-cooling system. In this embodiment, a TEC heating and cooling element is used for temperature control. Compared with traditional fluid circulation temperature control, the temperature change speed of this embodiment is faster, and the system is simple and occupies a small volume.

[0047] The pool body 10 is also equipped with a temperature sensor 70, which is embedded in the pool body 10 through a sensor mounting hole 13 on one side of the pool body 10. The temperature sensor 70 is, for example, a PT100 thermistor, used to monitor the temperature of the pool body in real time. The first half-shell 21 has a through hole 213 for the temperature sensor 70 and its leads to pass through. The PT100 thermistor is covered with a polytetrafluoroethylene sleeve to prevent charged objects from affecting the resistance temperature measurement.

[0048] The first half-shell 21 is provided with a mounting groove 212 for mounting the pool body 10. The bottom of the mounting groove 212 has an opening 211, and the pool body 10 at least partially protrudes into the opening 211. Preferably, the pool body 10 has a boss 11 that protrudes and fits into the opening 211, and the working surface 12 of the pool body 10 is flush with the lower surface of the first half-shell 21. Figure 3 As shown. The working surface 12 of the pool body 10 is recessed with a reaction tank 15, which can serve as a cavity for at least partially containing electrochemical reaction materials. The ATR prism 30 is mounted and connected to the working surface 12 of the pool body 10 via a prism bracket 60. A sealing ring 40 is installed between the pool body 10 and the ATR prism 30. The sealing ring 40 is arranged around the periphery of the reaction tank 15 and can seal the gap between the pool body 10 and the ATR prism 30, thereby providing a sealed reaction cavity 80.

[0049] The reaction chamber 80 includes a reaction tank 15 and is used to house the battery assembly; more specifically, the reaction chamber 80 houses the counter electrode, separator, working electrode, and electrolyte. The cell body 10 is made of metal, thus contacting and electrically connecting with the counter electrode. The cell body 10 also serves as a current collector for the counter electrode, conducting current to the counter electrode. A counter electrode wire 101 is connected to the cell body 10, serving as the lead-out wire for the counter electrode. The top surface 31 of the ATR prism 30 is provided with a metal plating layer 301, which is positioned opposite to the working surface 12. The metal plating layer 301 is attached to and electrically connected to the working electrode; the metal plating layer 301 can also serve as a current collector for the working electrode, conducting current to the external circuit.

[0050] In this embodiment, the metal plating layer 301 is specifically a gold plating layer, which provides good conductivity. The gold plating process is mature and reliable, and the gold plating layer can enhance infrared radiation, increasing the observed infrared spectral intensity. The pool body 10 is specifically made of 316L stainless steel, which is resistant to reaction with other chemicals and has stable performance.

[0051] Conventional in-situ Fourier transform infrared spectroscopy (FTIR) testing modes include external reflection (thin-layer mode) and internal reflection (attenuated total internal reflection mode). The thin-layer mode relies on a thin electrolyte layer between the electrode surface and the infrared window to reduce interference from excessive infrared absorption by the bulk electrolyte on the interface infrared signal acquisition. Typically, the thin-layer solution is 1–10 μm thick. The presence of this thin electrolyte layer increases solution resistance and mass transfer resistance, resulting in a slow potential response (approximately tens of milliseconds). Furthermore, species are easily depleted, and there are issues such as uneven current density distribution on the electrode surface. In this embodiment, however, the internal reflection (attenuated total internal reflection) mode is used, causing total internal reflection of infrared light at the prism test surface. Testing is then performed using a hidden vector wave, thus eliminating the need for a thin layer and overcoming the aforementioned problems associated with the thin-layer mode.

[0052] The ATR prism 30 is an attenuated total reflection (ATR) prism. It is a three-dimensional structure with an inverted trapezoidal cross-section, including a top surface 31, a bottom surface 34, an incident surface 32, an exiting surface 33, and two side surfaces 35. The area of ​​the top surface 31 of the ATR prism 30 is larger than that of the bottom surface 34. Because the top surface 31 of the ATR prism 30 has a metal coating 301, infrared light enters the ATR prism 30 through the incident surface 32 and illuminates the reaction chamber 80. At an appropriate incident angle, the infrared light undergoes attenuated total reflection within the ATR prism 30 and exits through the exiting surface 33. When the sample in the reaction chamber 80 is irradiated with infrared light of continuously varying frequencies, the molecules absorb radiation at some frequencies. Their vibrations or rotations cause changes in the molecular dipole moments, and the vibrational and rotational energy levels transition from the ground state to the excited state, forming a molecular absorption spectrum. By analyzing the infrared absorption spectrum of emitted infrared light, it is possible to perform group structure analysis, qualitative and quantitative analysis of materials.

[0053] The ATR prism 30 is used to ensure the effective transmission of infrared light. In this embodiment, the material of the ATR prism 30 is zinc selenide (ZnSe). However, it is not limited to this; in some other embodiments, the ATR prism 30 can also be made of Si prism material.

[0054] To evaluate the stability of different ATR prism materials under varying temperature conditions and the reliability of sample testing, ATR prisms made of Si and ZnSe were tested respectively. The test wavelength range for Si prisms was 4000-1000 cm⁻¹. -1 ZnSe prisms have a diameter of 4000-650 cm. -1 The spectral resolution is 4 cm⁻¹. -1 .

[0055] First, single-beam spectra of blank prisms were acquired at 20℃ and -20℃, respectively. Using the spectrum at 20℃ as a reference, the transmission spectra of Si and ZnSe prisms at a temperature difference of 40℃ were obtained by differential spectroscopy. The intensity changes in the obtained spectra can be used to assess the response of the prism material to temperature changes, thereby determining its impact on the stability of infrared spectral acquisition.

[0056] Furthermore, single-beam spectra of electrolyte samples were acquired at 20 °C using Si and ZnSe prisms, respectively. Differential spectroscopy was performed using the spectrum of a blank prism under the same conditions as a reference to obtain the electrolyte transmission spectra of Si and ZnSe prisms at room temperature. The electrolyte used was a 1 M LiFSI-DME electrolyte, which is a 1 mol / L electrolyte prepared by dissolving bis(fluorosulfonyl)imide in lithium salt (LIFSI) in ethylene glycol dimethyl ether (DME). The influence of prism temperature variation on the reliability of sample testing was analyzed by comparing the spectral results obtained under different temperature conditions using the same prism. Experimental results are as follows: Figure 10 As shown.

[0057] from Figure 10 As can be seen from this, the Si prism is in the range of 1500-1000 cm. -1 The wavelength range is highly sensitive to temperature changes, corresponding to its inherent absorption peak. At a temperature difference of 40°C, the maximum intensity change of the Si prism is approximately twice the sample signal intensity, severely interfering with normal sample detection. In contrast, the ZnSe prism exhibits excellent temperature stability within the 760-650 cm⁻¹ range. -1 The maximum intensity variation in the band is only 0.1 (relative intensity), and this variation does not affect the accurate identification of the sample signal. Therefore, in this embodiment, after precise experimental analysis, zinc selenide (ZnSe), which has good temperature stability, was selected as the material for the ATR prism 30. Furthermore, the ZnSe prism exhibits high transparency over a wide infrared range, with a relatively high refractive index and a low absorption coefficient, ensuring effective transmission of infrared light and improving the analytical accuracy of the device. Its good mechanical strength and thermal shock resistance make it more suitable for wide-temperature-range electrochemical in-situ infrared spectroscopy testing devices.

[0058] As previously described, the ATR prism 30 is mounted and connected to the working surface 12 of the pool body 10 via the prism bracket 60. (Refer to...) Figures 8-9 The prism support 60 includes a flange 61, with a first side plate 62 and a second side plate 63 connected to one side of the flange 61. The lower ends of the first side plate 62 and the second side plate 63 are connected by a base plate 64, thereby forming a prism mounting cavity 65 within the prism support 60. The prism mounting cavity 65 has a first opening 651 and a second opening 652, which correspond to the light-incident surface 32 and the light-exit surface 33 of the ATR prism 30, respectively.

[0059] Flange 61 has screw holes 67 for screws to be inserted to mount the prism support 60 to the working surface 12 of the tank body 10. The working surface 12 of the tank body 10 has threaded holes 14 for screw connection. The prism support 60 is usually made of metal. However, since the metal plating 301 on the ATR prism 30 can act as a current collector for the working electrode, conducting current to the external circuit, if it is connected to the tank body 10, which acts as a current collector for the counter electrode, by screws made of metal, a short circuit between the electrodes can easily occur, making testing impossible. In this embodiment, insulating material is provided inside and around the screw holes 67 to achieve insulation between the electrodes, facilitating subsequent testing. In this embodiment, the insulating material inside and around the screw holes 67 is PEEK material. PEEK material is an ideal electrical insulator, maintaining good electrical insulation performance even under harsh working conditions such as high temperature, high pressure, and high humidity, thus enhancing the safety of the device.

[0060] Preferably, the housing 20 is made of heat-insulating material, such as PEEK material, so that the device exchanges less heat with the outside world, and the temperature control is more precise and stable.

[0061] In addition, to reduce the interference of water vapor condensation on infrared spectrum acquisition under low temperature conditions, an air compressor is introduced into the system for dehumidification, which effectively improves signal quality and test stability.

[0062] The wide-temperature-range electrochemical in-situ infrared spectroscopy testing device 1 based on attenuated total reflectance mode provided in this embodiment has a compact overall structure, low cost, and low thermal inertia. The temperature regulation stability of the device was tested using a PID control algorithm, and the experimental results are as follows: Figure 11 As shown. From Figure 11 As can be seen, the device can stably reach 70℃ under high-temperature conditions with a relatively fast heating rate; at low temperatures, it can reach as low as -20℃ with good temperature control accuracy. In summary, the system has good temperature control capabilities, can achieve rapid response to temperature changes, and is suitable for in-situ infrared testing under variable temperature conditions over a wide temperature range.

[0063] The infrared spectrum of 1 M LiFSI DME electrolyte in the range of -20 to 70 °C was tested using the wide-temperature-range electrochemical in-situ infrared spectroscopy testing device 1 provided in this embodiment. The test results are as follows: Figure 12 As shown, the test curves are generally smooth with low noise levels, indicating that the platform can effectively meet the infrared testing requirements under different temperature conditions.

[0064] Although the present invention has been specifically shown and described in conjunction with preferred embodiments, those skilled in the art should understand that various changes in form and detail may be made to the present invention without departing from the spirit and scope of the present invention as defined in the appended claims, and all such changes shall be within the scope of protection of the present invention.

Claims

1. A wide temperature range electrochemical in-situ infrared spectroscopy testing device based on attenuated total reflection mode, characterized in that, include: The pool body has a working surface, and the working surface is recessed with a reaction groove; the pool body is made of metal and can be used as a current collector for the counter electrode; An ATR prism is connected to the working surface of the pool body. The ATR prism has a top surface that is opposite to the working surface and is provided with a metal coating. The metal coating can serve as a working electrode current collector. A sealing ring is installed between the pool body and the ATR prism. The sealing ring is arranged around the periphery of the reaction tank. The sealing ring can seal the gap between the pool body and the ATR prism, thereby providing a reaction chamber. A temperature control component, wherein the temperature control component is attached to the pool body; The housing is a hollow structure used to install the pool body and the temperature control component therein; as well as A temperature sensor is used to monitor the temperature of the pool.

2. The test device of claim 1, wherein: The ATR prism is a three-dimensional structure with an inverted trapezoidal cross-section. The ATR prism also includes a bottom surface, an incident surface, an exit surface, and two side surfaces.

3. The test device of claim 2, wherein: The ATR prism is mounted on the working surface of the pool body via a prism bracket. The prism bracket includes a flange, and a first side plate and a second side plate are connected to one side of the flange. The lower ends of the first side plate and the second side plate are connected via a base plate, thereby forming a prism mounting cavity within the prism bracket. The prism mounting cavity has a first opening and a second opening, which correspond to the light-incident surface and the light-exit surface of the ATR prism, respectively. The material of the ATR prism is ZnSe.

4. The test device of claim 3, wherein: The prism support is made of metal; the flange has screw holes for screws to be inserted to install the prism support onto the working surface of the pool body; insulating material is provided inside and around the screw holes; the insulating material is PEEK material.

5. The test device of claim 1, wherein: The temperature control component includes a TEC heating and cooling element, which is disposed in contact with the pool body; the temperature control component also includes a heat dissipation copper busbar, which is provided with a cooling fluid channel.

6. The test device of claim 1, wherein: The temperature sensor is a PT100 thermistor. A sensor mounting hole is provided on one side of the pool body, and the temperature sensor is embedded in the pool body through the sensor mounting hole.

7. The test device of claim 1, wherein: The housing includes a first half-shell and a second half-shell connected to each other. The first half-shell is provided with a mounting groove for mounting the pool body. The bottom of the mounting groove is provided with an opening. The pool body is provided with a boss that protrudes and fits into the opening. The working surface of the pool body is flush with the lower surface of the first half-shell. The metal plating is a gold plating layer, and the pool body is made of 316L stainless steel.

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