A wide-temperature adjustable cooling device suitable for an electrochemical mass spectrometry sampling system

Abstract

The application discloses a wide-temperature adjustable cooling device suitable for an electrochemical mass spectrum sampling system, and relates to the technical field of electrochemical mass spectrum sampling systems. The cooling device comprises a cold trap system, a cooling system and a vacuum system. The cooling system comprises a first digital display flow regulating valve. The vacuum system comprises a second digital display flow regulating valve. The cold trap system comprises a cold trap main body which has a cavity formed by being concave downward. The cold trap main body comprises a pipeline which is arranged at the outer periphery of the cavity. The pipeline is connected with the first digital display flow regulating valve and the second digital display flow regulating valve at two ends respectively. A heating rod is arranged in the pipeline. The prepared cooling device is used for the electrochemical mass spectrum sampling system, can effectively solve the problem that electrolyte of various electrochemical systems is volatilized into the mass spectrum, and is favorable for prolonging the service life of the electrochemical mass spectrum and increasing the accuracy of quantitative analysis.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of battery testing, and in particular to a wide-temperature adjustable cooling device suitable for an electrochemical mass spectrometry sampling system. BACKGROUND

[0002] With the rapid development of today's society, the demand for social energy is increasing, and electrochemical energy storage and conversion devices have attracted widespread attention due to their economic and environmental advantages. In order to realize high-performance electrochemical energy storage and conversion devices, it is essential to understand the principles of electrochemical interface reactions. In recent years, a large number of advanced in-situ or ex-situ characterization techniques (such as vibrational spectroscopy, X-ray technology, etc.) have been used to analyze the electrochemical reaction interface in depth, and important progress has been made. Among them, differential electrochemical mass spectrometry is a rare in-situ volatile species analysis technique, which can analyze the consumption of gaseous reactants and the release of volatile intermediates / products in the electrochemical interface reaction process online. Therefore, electrochemical mass spectrometry has become an indispensable powerful tool for studying electrochemical interface reactions related to volatile species.

[0003] Generally speaking, differential electrochemical mass spectrometry has membrane pumping filtration sampling and carrier gas purging capillary sampling. Membrane pumping filtration sampling directly connects the electrochemical cell and the mass spectrometry vacuum chamber together through a flange and is isolated by a PTFE membrane. The volatile species generated can quickly enter the mass spectrometry analysis and detection, and has a high time resolution. However, the electrochemical cell required for this sampling method needs to be specially designed, and is limited to the application of non-protic electrolyte systems (such as lithium-ion batteries, lithium-air batteries, etc.). The carrier gas purging capillary sampling method brings the volatile substances generated by the electrochemical reaction into the mass spectrometer for analysis through the carrier gas. The electrochemical system and the mass spectrometer are relatively independent, the design is simple, and it is closer to the actual electrochemical reaction conditions. In addition, it can be used for analysis of different electrochemical systems.

[0004] In fact, in addition to bringing the analyzed volatile substances into the mass spectrometer, the carrier gas may also bring electrolyte vapor into the mass spectrometer during the purging process. Therefore, the carrier gas purging capillary sampling method of differential electrochemical mass spectrometry requires a cooling device in series in the gas circuit to reduce the amount of electrolyte vapor entering the mass spectrometer. On the one hand, it can prolong the service life of the mass spectrometer, and on the other hand, it can avoid the interference of electrolyte vapor fragments on the analysis results. In addition, the cooling device needs to be wide-temperature adjustable for different volatile species and electrolyte vapors generated by different electrochemical systems.

[0005] Therefore, it is an urgent problem for those skilled in the art in the field to realize a wide-temperature adjustable cooling device in an electrochemical mass spectrometry sampling system. SUMMARY

[0006] The application aims at the problems in the prior art and discloses a wide-temperature adjustable cooling device suitable for an electrochemical mass spectrum sampling system.

[0007] The application is realized by the following technical scheme:

[0008] The application provides a wide-temperature adjustable cooling device suitable for an electrochemical mass spectrum sampling system.

[0009] The cooling system comprises a first digital flow regulating valve.

[0010] The vacuum system comprises a second digital flow regulating valve.

[0011] The cold trap system comprises a cold trap main body, and the cold trap main body has a cavity formed by being concave downward.

[0012] The pipeline is connected with the first digital flow regulating valve and the second digital flow regulating valve at two ends respectively.

[0013] The pipeline is provided with a heating rod.

[0014] The above design of the application passes liquid nitrogen into the pipeline, controls the flow of the liquid nitrogen in the pipeline through the first digital flow regulating valve and the second digital flow regulating valve, thereby reducing the temperature of the cavity, and the heating rod can adjust the temperature of the cavity by adjusting the power, so that the volatilized electrolyte is reduced to enter the mass spectrum sampling system, the service life of the electrochemical mass spectrum is prolonged, and the accuracy of quantitative analysis is increased.

[0015] As a further scheme, the vacuum system further comprises a vacuum pump, and the cooling system further comprises a compressor and a liquid nitrogen tank; the vacuum pump is connected with the second digital flow regulating valve, the liquid nitrogen tank is connected with the compressor and the first digital flow regulating valve respectively, the compressor controls the liquid nitrogen in the liquid nitrogen tank to enter the pipeline through the first digital flow regulating valve, and the vacuum pump is used to control the liquid nitrogen to flow through the second digital flow regulating valve from the pipeline, so that the liquid nitrogen is discharged.

[0016] As a further scheme, the vacuum system further comprises a pressure relief valve and a three-way valve, and the three-way valve is connected with the pressure relief valve, the second digital flow regulating valve and the pipeline respectively; the pressure relief valve is used to release the pressure in the pipeline.

[0017] As a further solution, the cold trap system further comprises a cold trap shell and a cold trap cover plate; the cold trap body is arranged in the cold trap shell; the cold trap cover plate is provided with a through hole; the surface of the cold trap body is provided with a threaded hole capable of corresponding matching with the through hole; a sealing gasket is arranged between the cold trap cover plate and the cold trap body; the through hole and the threaded hole of the cold trap cover plate are connected and fixed with the cold trap body, so that the cavity is sealed. After the cold trap cover plate and the cold trap body are fixed, the sealing property of the cold trap system is improved, and the sealing gasket makes the sealing property of the cold trap system better; the cold trap shell is used for supporting the cold trap body.

[0018] As a further solution, the cold trap cover plate is further provided with an air inlet pipeline hole, an air outlet pipeline hole and a thermocouple hole; the cavity is further provided with an air inlet pipeline, an air outlet pipeline and a thermocouple; the air inlet pipeline, the air outlet pipeline and the thermocouple respectively penetrate into the middle part of the cavity through the air inlet pipeline hole, the air outlet pipeline hole and the thermocouple hole arranged on the cold trap cover plate. On the basis of ensuring the sealing property of the cold trap system, the thermocouple is used for detecting the temperature in the cavity, and the air outlet pipeline is convenient for connecting with the mass spectrometry sampling system.

[0019] As a further solution, the cooling device further comprises a temperature controller and a power supply; the temperature controller is connected with the thermocouple, the power supply, a first digital display flow regulating valve and a second digital display flow regulating valve; the power supply is connected with the heating rod; the temperature controller receives the temperature signal of the thermocouple and indirectly controls the power of the heating rod through the power supply, and the temperature controller also receives the temperature signal of the thermocouple and controls the through flow of the first digital display flow regulating valve and the second digital display flow regulating valve. When the temperature detected by the thermocouple in the cavity is higher than the set value, the temperature controller controls the first digital display flow regulating valve and the second digital display flow regulating valve to increase the flow rate of liquid nitrogen; when the temperature detected by the thermocouple in the cavity is lower than the set value, the temperature controller controls the power supply, and the heating rod is heated; when the temperature detected by the thermocouple in the cavity is equal to the set value, the flow rate of liquid nitrogen and the power of the heating rod remain constant. The temperature control range of the temperature controller is-150℃-200℃, and the control accuracy is ±0.5℃.

[0020] As a further solution, the power supply is connected with the temperature controller, the first digital display flow regulating valve and the second digital display flow regulating valve, and is used for supplying power to the temperature controller, the first digital display flow regulating valve and the second digital display flow regulating valve.

[0021] As a further solution, the outermost layer of the cold trap shell is provided with heat insulation cotton. The heat loss rate of the cold trap system is slowed down, and condensate water is avoided on the outermost layer of the cold trap system.

[0022] As a further solution, the cold trap body, the cold trap cover plate and the cold trap shell are made of stainless steel.

[0023] As a further solution, the diameters of the air inlet pipeline and the air outlet pipeline are 1 / 8 inch or 1 / 16 inch.

[0024] The cooling device prepared by the application is used for an electrochemical mass spectrum sampling system, can effectively solve the problem of electrolyte volatilization into the mass spectrum of various electrochemical systems, is beneficial to prolong the service life of the electrochemical mass spectrum and increase the accuracy of quantitative analysis, and can regulate and control a very wide temperature range, the temperature range is specifically -150℃-200℃, and the control precision is ±0.5℃. BRIEF DESCRIPTION OF DRAWINGS

[0025] In order to more clearly illustrate the technical solutions in the embodiments of the application, the drawings needed to be used in the embodiments or prior art description will be briefly introduced as follows. Obviously, the drawings in the following description are only some embodiments of the application, and other drawings can also be obtained by those skilled in the art without any creative effort on the basis of these drawings.

[0026] Fig. 1 A cross-sectional view of the cooling device provided by the embodiments of the application is shown in the figure.

[0027] Fig. 2 A top view of the cooling device provided by the embodiments of the application is shown in the figure.

[0028] Among them, the above drawings include the following reference signs:

[0029] 1-power supply; 2-compressor; 3-liquid nitrogen tank; 4-first digital flow regulating valve; 5-temperature controller; 6-screw hole; 7-heating rod; 8-thermocouple; 9-inlet pipeline; 10-outlet pipeline; 11-cold trap cover plate; 12-sealing gasket; 13-vacuum pump; 14-second digital flow regulating valve; 15-cold trap shell; 16-pipeline; 17-through hole; 18-cold trap main body; 19-cooling system; 20-vacuum system; 21-cavity; 22-heat insulation cotton; 23-pressure relief valve; 24-three-way valve; 25-cold trap system; 26-thermocouple hole; 27-inlet pipeline hole; 28-outlet pipeline hole. DETAILED DESCRIPTION

[0030] In order to facilitate the understanding of the application, the application will be described more fully below, and the preferred embodiments of the application are given. It should be understood that these embodiments are only used for more detailed description, and should not be understood as limiting the application in any form, that is, it is not intended to limit the protection scope of the application; the relationship terms such as "first" and "second" are only used to distinguish one part from another part with the same name, and do not necessarily require or imply any such actual relationship or order between the parts.

[0031] We will further describe the cooling device of the application in more detail, such as Figs. 1-2The cooling device has three systems, namely, a vacuum system 20, a cold trap system 25 and a cooling system 19. The vacuum system 20 is provided with a vacuum pump 13, a second digital flow regulating valve 14, a pressure relief valve 23 and a three-way valve 24. The pressure relief valve 23 is beneficial to improve the safety of the cooling device. The second digital flow regulating valve 14 is connected with the vacuum pump 13 and the three-way valve 24, and the pressure relief valve 23 is connected with the three-way valve 24. The cold trap system 25 is composed of a cold trap main body 18, a cold trap shell 15 and a cold trap cover plate 11. The cold trap main body 18 is in the cold trap shell 15, and the cold trap shell 15 is used for supporting the cold trap main body 18. In the cold trap main body 18, the cold trap main body 18 is concave downward to form a cavity 21. A pipeline 16 is arranged outside the cavity 21. One end of the pipeline 16 is connected with the three-way valve 24 of the vacuum system 20, and the other end of the pipeline 16 is connected with a first digital flow regulating valve 4 of the cooling system 19. A heating rod 7 is further arranged in the pipeline 16, and the heating rod 7 is connected with a power supply 1. The temperature in the cavity 21 is controlled by controlling the flow of liquid nitrogen in the pipeline 16 and the heating rod 7 in the pipeline 16, so as to reduce the volatilized electrolyte entering the mass spectrometry sampling system, prolong the service life of the electrochemical mass spectrometer and increase the accuracy of quantitative analysis. Screw holes 6 and recesses for placing sealing gaskets are arranged on the surface of the cold trap main body 18. The cold trap cover plate 11 is provided with through holes 17, gas inlet pipeline holes 27, gas outlet pipeline holes 28 and thermocouple holes 26. The gas inlet pipeline 9 and the gas outlet pipeline 10 have a diameter of 1 / 8 inch or 1 / 16 inch, and are arranged in the cavity 21 through the gas inlet pipeline holes 27 and the gas outlet pipeline holes 28. A sealing gasket 12 is arranged between the cold trap main body 18 and the cold trap cover plate 11. Screws are connected and fixed through the through holes 17 of the cold trap cover plate 11 and the screw holes 6 of the cold trap main body 18, so as to form a sealed cavity 21. The sealing gasket 12 can further ensure the sealing property of the cavity 21. A thermocouple 8 is arranged in the cavity 21, and the thermocouple 8 is connected with a temperature controller 5 through the thermocouple holes 26 of the cold trap cover plate 11. The cold trap main body 18, the cold trap cover plate 11 and the cold trap shell 15 are all made of stainless steel. A layer of heat insulation cotton 22 is covered around the cold trap shell 15. The heat insulation cotton 22 slows down the temperature loss rate of the cavity 21 and avoids the appearance of condensed water on the outermost layer of the cold trap system 25.The cooling system 19 comprises the compressor 2, the liquid nitrogen tank 3 and the first digital flow regulating valve 4, wherein the liquid nitrogen tank 3 is connected with the compressor 2 and the first digital flow regulating valve 4 respectively, the compressor 2 discharges the liquid nitrogen from the liquid nitrogen tank 3 for instant ultra-low temperature refrigeration of the cold trap system 25; the temperature controller 5 is connected with the power supply 1, the first digital flow regulating valve 4 and the second digital flow regulating valve 14, when the temperature of the cavity 21 detected by the thermocouple 5 is higher than the set value, the temperature controller 5 controls the first digital flow regulating valve 4 and the second digital flow regulating valve 14 to increase the flow rate of the liquid nitrogen; when the temperature of the cavity 21 detected by the thermocouple 5 is lower than the set value, the temperature controller 5 controls the power supply 1 to heat the heating rod 7; when the temperature of the cavity 21 detected by the thermocouple 5 is equal to the set value, the flow rate of the liquid nitrogen and the power of the heating rod 7 remain constant. The temperature controller 5 can control the temperature in the range of-150℃ to 200℃, and the control accuracy is ±0.5℃.

[0032] In order to make the specific operation of the present application clearer, the following operation method is provided:

[0033] Before using the cooling device, the vacuum pump 13 is turned on, the second digital flow regulating valve 14 is adjusted to the maximum, the first digital flow regulating valve 4 is closed, and the air in the pipeline 16 in the cold trap main body 18 is completely pumped out to avoid condensation of moisture in the pipeline 16.

[0034] When using the cooling device, the second digital flow regulating valve 14 and the first digital flow regulating valve 4 are adjusted to appropriate openings, the compressor 2 discharges the liquid nitrogen in the liquid nitrogen tank 3, the liquid nitrogen enters the cold trap main body 18 through the first digital flow regulating valve 4, in the cold trap main body 18, the liquid nitrogen flows through the cavity 21 through the pipeline 16, and finally flows into the second digital flow regulating valve 14, the heating power of the heating rod 7 is controlled to adjust the temperature of the cavity 21 to the required experimental temperature. When the temperature is higher than the required experimental temperature, the thermocouple 8 transmits the temperature to the temperature controller 5, the temperature controller 5 is turned on to control the first digital flow regulating valve 4 and the second digital flow regulating valve 14 to increase the opening degree to accelerate the flow of the liquid nitrogen and accelerate the refrigeration to the required experimental temperature. When the temperature is lower than the required experimental temperature, the thermocouple 8 transmits the temperature to the temperature controller 5, the temperature controller 5 is turned on to control the heating rod 7 to heat to the required experimental temperature.

[0035] After using the cooling device, the cold trap cover plate 11 is disassembled, and the condensed electrolyte in the cavity 21 is wiped clean with alcohol cotton.

[0036] In order to further clarify the wide temperature adjustable cooling device suitable for the electrochemical mass spectrum sampling system of the present application, the present application also provides an embodiment, taking the non-aqueous solvent lithium-air battery system as an example.

[0037] Embodiment 1

[0038] The battery anode is porous carbon, the cathode is metal lithium, the solvent is ethylene glycol dimethyl ether (DME, boiling point is 84℃), the conductive lithium salt is lithium perchlorate, the electrolyte addition amount is 100 μL, the carrier gas is Ar / O2 mixed gas, and the flow rate is 1.5 mL / min. The battery and the cooling device are connected to the differential electrochemical mass spectrometry sampling system, and the cooling temperature is controlled to be -50℃. Continuous work is performed until the battery electrolyte is consumed, the cold trap cover plate is disassembled, the cooled electrolyte can be clearly seen in the cavity, and the test is about 80 μL. The cooling rate of the electrolyte vapor can be more than 80%. The cooling temperature is controlled to be -80℃. Continuous work is performed until the battery electrolyte is consumed, the cold trap cover plate is disassembled, the cooled electrolyte can be clearly seen in the cavity, and the test is about 85 μL. The cooling rate of the electrolyte vapor can be more than 85%.

[0039] In summary, in the continuous working period of the electrochemical system, the temperature control of the cooling device can effectively reduce the electrolyte vapor entering the mass spectrometry detection system; and the lower the cooling temperature in the cooling device, the less the electrolyte vapor enters the mass spectrometry. Therefore, the development of a wide-temperature controllable cooling device can obviously improve the service life of the mass spectrometry and increase the quantitative analysis accuracy of the electrochemical mass spectrometry.

[0040] It should be noted that the above only describes the preferred embodiments of the present application and is not intended to limit the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A wide temperature tunable cooling device for an electrochemical mass spectrometry sampling system, characterized in that, The cooling device comprises a cold trap system (25), a cooling system (19), and a vacuum system (20); The cooling system (19) comprises a first digital flow regulating valve (4); The vacuum system (20) comprises a second digital flow regulating valve (14); The cold trap system (25) comprises a cold trap body (18) and a thermocouple (8), the cold trap body (18) has a cavity (21) formed by downward concave, the cold trap body comprises a pipeline (16), the pipeline (16) is outside the cavity (21); the cavity (21) is provided with the thermocouple (8); The pipeline (16) is respectively connected with the first digital flow regulating valve (4) and the second digital flow regulating valve (14) at two ends; The pipeline (16) is provided with a heating rod (7), the heating rod (7) is connected with a power supply (1), The cooling device further comprises a temperature controller (5), the temperature controller (5) is respectively connected with the thermocouple (8), the power supply (1), the first digital flow regulating valve (4), and the second digital flow regulating valve (14); the temperature controller (5) can control the temperature in the range of-150℃~200℃, and the control precision is ±0.5℃.

2. The adjustable cooling device for use with an electrochemical mass spectrometry sampling system of claim 1, wherein, The vacuum system (20) further comprises a vacuum pump (13), and the cooling system (19) further comprises a compressor (2) and a liquid nitrogen tank (3); the vacuum pump (13) is connected with the second digital flow regulating valve (14), the liquid nitrogen tank (3) is respectively connected with the compressor (2) and the first digital flow regulating valve (4); the compressor (2) controls the liquid nitrogen in the liquid nitrogen tank (3) to enter the pipeline (16) through the first digital flow regulating valve (4), and the vacuum pump (13) is used for controlling the liquid nitrogen to flow through the second digital flow regulating valve (14) from the pipeline (16) so that the liquid nitrogen is discharged.

3. The adjustable cooling device for use with an electrochemical mass spectrometry sampling system of claim 1, wherein, The vacuum system (20) further comprises a pressure relief valve (23) and a three-way valve (24), the three-way valve (24) is respectively connected with the pressure relief valve (23), the second digital flow regulating valve (14) and the pipeline (16); the pressure relief valve (23) is used for releasing the pressure in the pipeline (16).

4. The adjustable cooling device for use with an electrochemical mass spectrometry sampling system of claim 1, wherein, The cold trap system (25) further comprises a cold trap shell (15) and a cold trap cover plate (11); the cold trap body (18) is arranged in the cold trap shell (15); the cold trap cover plate (11) is provided with a through hole (17); the surface of the cold trap body (18) is provided with a screw hole (6) capable of corresponding matching with the through hole (17); a sealing gasket (12) is arranged between the cold trap cover plate (11) and the cold trap body (18); the cold trap cover plate (11) can be connected and fixed with the cold trap body (18) through the through hole (17) and the screw hole (6), so that the cavity (21) is sealed.

5. The adjustable cooling device for use with an electrochemical mass spectrometry sampling system of claim 4, wherein, The cold trap cover plate (11) is further provided with an air inlet pipeline hole (27), an air outlet pipeline hole (28) and a thermocouple hole (26); the cavity (21) is further provided with an air inlet pipeline (9) and an air outlet pipeline (10); the air inlet pipeline (9), the air outlet pipeline (10) and the thermocouple (8) respectively penetrate into the middle part of the cavity (21) through the air inlet pipeline hole (27), the air outlet pipeline hole (28) and the thermocouple hole (26) arranged on the cold trap cover plate (11).

6. The adjustable cooling device for use with an electrochemical mass spectrometry sampling system of claim 1, wherein, The cooling device further comprises a power supply (1); the temperature controller (5) receives the temperature signal of the thermocouple (8) and indirectly controls the power of the heating rod (7) through the power supply (1), and the temperature controller (5) also receives the temperature signal of the thermocouple (8) and controls the through flow of the first digital display flow regulating valve (4) and the second digital display flow regulating valve (14).

7. The adjustable cooling device for use with an electrochemical mass spectrometry sampling system of claim 6, wherein, The power supply (1) is also connected with the temperature controller (5), the first digital display flow regulating valve (4) and the second digital display flow regulating valve (14) for supplying power for the temperature controller (5), the first digital display flow regulating valve (4) and the second digital display flow regulating valve (14).

8. The adjustable cooling device for use with an electrochemical mass spectrometry sampling system of claim 4, wherein, The outermost layer of the cold trap shell (15) is provided with heat insulation cotton (22).

9. The adjustable cooling device for use with an electrochemical mass spectrometry sampling system of claim 4, wherein, The cold trap main body (18), the cold trap cover plate (11) and the cold trap shell (15) are made of stainless steel.

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