An electrochemical mass spectrometry device suitable for solid-state battery gas generation research

Abstract

This invention provides an electrochemical mass spectrometry device, including a sealed battery placement chamber for housing a solid-state battery. The sealed battery placement chamber is connected to a calibration system for quantitative gas calibration, a battery testing system, a mass spectrometer, and a differential pressure system. The calibration system includes a standard gas connected to the sealed battery placement chamber and a pressure gauge A capable of directly reflecting the real-time pressure within the sealed battery placement chamber. A standard leak is provided on the inlet pipe of the standard gas, and the standard gas enters the sealed battery placement chamber after its flow rate is controlled through the standard leak. A pressure gauge B is also connected to the standard gas. This invention is suitable for direct solid-state battery gas generation testing, exhibiting good time resolution and testing sensitivity.

Description

Technical Field

[0001] This invention relates to the field of battery testing technology, and more specifically, to an electrochemical mass spectrometry device suitable for gas generation studies in laboratory and commercial / industrial solid-state batteries. Background Technology

[0002] With the ever-increasing energy demands of modern society, the transformation and upgrading of the energy structure is urgently needed. New energy storage and conversion technologies, with lithium batteries as a typical example, represent an advanced solution. Currently, organic electrolytes with high ionic conductivity and a wide operating temperature range are the mainstream electrolytes for lithium batteries. However, the operation of lithium batteries involves the release of a large amount of heat, such as from numerous side reactions and heat generation caused by varying degrees of abuse (thermal, electrical, and mechanical). Organic electrolytes are flammable and can easily lead to safety accidents. Therefore, developing safe solid-electrolyte-based lithium batteries has become a cutting-edge research area in academia and industry. However, the interface between solid electrolytes (including inorganic and organic polymers) and electrodes is not completely stable, and some side reactions still exist, seriously affecting the performance improvement of solid-state batteries. Therefore, the development and optimization of solid electrolytes requires the establishment of a sensitive, high-time-resolution detection method to determine their feasibility and reaction mechanisms in order to further optimize and design high-performance solid-state lithium batteries.

[0003] Differential electrochemical mass spectrometry (DEMS) is an in-situ gas analysis technique that enables in-situ qualitative and quantitative studies of gas consumption and release at battery interfaces. Generally, DEMS employs two sample introduction modes: carrier gas purge and membrane injection. Membrane injection, due to the use of PTFE membranes, is only suitable for aqueous electrocatalytic / aqueous batteries, requires specialized mold design, and is challenging for quantification. Carrier gas purge, on the other hand, involves a carrier gas carrying the electrochemical reaction products into the mass spectrometer for analysis, overcoming the limitations of membrane injection. However, carrier gas purge suffers from poor time resolution due to its long injection system tubing, and the carrier gas volume required for purging is typically much larger than the battery's gas production, resulting in low detection sensitivity. Furthermore, it is currently only suitable for studying gas production in laboratory model batteries; commercial / industrial solid-state batteries cannot be directly coupled into the injection system, as direct coupling would lead to very poor time resolution, sensitivity, and detection accuracy. Therefore, expanding the application of DEMS to commercial / industrial solid-state batteries, providing an efficient, sensitive, and accurate battery testing method, is of great significance to enterprise users. Summary of the Invention

[0004] The purpose of this invention is to provide an electrochemical mass spectrometry device suitable for direct gas generation testing of solid-state batteries (including laboratory and commercial / industrial applications), and to improve time resolution and testing sensitivity.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] An electrochemical mass spectrometry device includes: a battery placement sealed cavity for placing a solid-state battery; the battery placement sealed cavity is connected to a calibration system for quantitative gas calibration, the calibration system includes a standard gas connected to the battery placement sealed cavity and a pressure gauge A capable of directly reflecting the real-time pressure inside the battery placement sealed cavity, the standard gas inlet pipe is provided with a standard leak hole, the standard gas enters the battery placement sealed cavity after the flow rate is controlled through the standard leak hole, and a pressure gauge B is also connected to the standard gas.

[0007] As an optimized alternative, the sealed battery placement cavity is also connected to: a battery testing system for providing the parameters required for the solid-state battery's operation; a mass spectrometer for analyzing the gas production of the solid-state battery; and a differential pressure system for generating a pressure difference within the sealed battery placement cavity. The differential pressure system, in conjunction with the calibration system, completes the calibration of the mass spectrometer before detection. The battery testing system can control and adjust the solid-state battery under target detection conditions, and, in conjunction with the calibrated device state, completes high-sensitivity detection.

[0008] As an optimized alternative, the battery testing system, mass spectrometer, and differential pressure system are connected directly or via one or more solenoid valves in the valve group to the sealed cavity where the battery is placed. This reduces the complexity of the design and the length of the piping.

[0009] As an optimized alternative, the differential pressure system includes a pumping device, which is preferably a vacuum pump.

[0010] As an optimized alternative, the battery placement sealed cavity is provided with interfaces for connecting to other components. Specifically, the battery placement sealed cavity is provided with interfaces a and e for connecting to a battery testing system, interface c for connecting to a mass spectrometer, interface d for connecting to a differential pressure system, and interface b for connecting to a calibration system. Each interface can be located on the sealing cover of the battery placement sealed cavity. The interface configuration facilitates the connection between components and ensures sealing stability.

[0011] As an optimized alternative, the differential pressure system, mass spectrometer, and calibration system are each equipped with a solenoid valve to control the opening and closing of the connection between each pipeline and the sealed cavity where the battery is placed.

[0012] The present invention also provides a battery placement sealed cavity structure, having a sealed cavity that can be opened and closed to place a solid-state battery. The wall for enclosing the sealed cavity is provided with interfaces, including interfaces a and e for connecting to a battery testing system that provides the parameters required for the operation of the solid-state battery, interface c for connecting to a mass spectrometer for analyzing the gas production of the reaction cell, interface d for connecting to a differential pressure system that generates a pressure difference for the battery placement sealed cavity, and interface b for connecting to a calibration system for quantitative calibration of the gas.

[0013] As an optimized alternative, the sealing cavity is formed by a hollow cavity and a cover, with the aforementioned interfaces respectively opened on the cavity and / or the cover.

[0014] As an optimized alternative, a sealing gasket is also provided at the sealing part between the cavity and the cover, and the sealing gasket is provided with fixing holes that correspond to the upper positioning hole on the cover and the lower positioning hole on the cavity.

[0015] The present invention also provides a method for testing gas generation in solid-state batteries using the above-described electrochemical mass spectrometry apparatus, comprising the following steps:

[0016] S1: Place the solid-state battery in the battery placement sealed cavity, connect it to the battery testing system, and close the battery placement sealed cavity to complete the sealing;

[0017] S2: A differential pressure system is used to remove air or impurities from the sealed cavity where the battery is placed and the pipelines, including the calibration system, and to create a differential pressure.

[0018] S3: Open the pipelines containing the calibration system, pressure gauge A, and mass spectrometer, close other pipelines, determine the leakage rate of the standard leak in the calibration system through pressure gauge A and pressure gauge B in the calibration system, and establish a standard curve between the flow rate of the standard gas components and the mass spectrometer ion current.

[0019] S4: Turn on the pipelines containing the battery testing system and mass spectrometer, and close other pipelines to allow the solid-state battery to start operating under the target operating parameters. Perform electrochemical mass spectrometry analysis on the gas generated during operation.

[0020] As an optimized alternative, in step S1, the solid-state battery is placed in front of the sealed battery placement cavity, leaving an outlet for easy gas collection.

[0021] As an optimized alternative, in step S2, solenoid valve B is closed, solenoid valves C and A are opened, the vacuum pump is turned on to evacuate the gas, and it is observed whether pressure gauge A drops to a vacuum state. Subsequently, solenoid valve A and the vacuum pump are closed, solenoid valve B is opened, and the corresponding response signal of the mass spectrometer is observed to determine whether the content of air or impure gas in the entire system has decreased to the ideal value and reached a stable state.

[0022] As an optimized alternative, in step S2, solenoid valves A and B are closed, and solenoid valve C is opened. The standard gas flows through the standard leak, solenoid valve C, and reaches the battery placement sealed cavity. Then, under the pressure difference in the battery placement sealed cavity, it quickly diffuses through solenoid valve B into the mass spectrometer, allowing the mass spectrometer to obtain the corresponding mass spectrometric ion current of the standard gas component at the standard gas flow rate. The standard gas pressure is changed to change the leakage rate of the standard leak, i.e., the standard gas flow rate is changed. The above steps are repeated to establish a standard curve between the standard gas component flow rate and the mass spectrometric ion current.

[0023] The electrochemical mass spectrometry device provided by this invention, suitable for solid-state battery gas generation research / testing, meets the requirements for direct gas generation testing of various types of solid-state batteries (laboratory and commercial / industrial). It employs a standard leak with two pressure gauges for quantitative gas calibration, significantly improving detection accuracy. A vacuum pump removes impurities from the battery's sealed chamber, allowing the battery-generated gas to diffuse directly and rapidly into the mass spectrometer via pressure difference. The mass spectrometer and the battery's sealed chamber are directly connected, reducing the use of complex piping and effectively improving time resolution. This ensures that almost 100% of the gas generated by batteries with relatively small overall gas volumes enters the mass spectrometer, overcoming the impact of some solid-state battery carrier gas blowing and injection methods on detection sensitivity and reliability, thus guaranteeing both time resolution and testing sensitivity. Attached Figure Description

[0024] Figure 1 A schematic diagram of an electrochemical mass spectrometry device for studying gas generation in solid-state batteries, provided in an embodiment of the present invention.

[0025] Figure 2 The battery placement sealed cavity structure is provided in the electrochemical mass spectrometry device according to the embodiments of the present invention. Detailed Implementation

[0026] To facilitate understanding of the present invention, a more comprehensive description of the invention will be provided below, along with preferred embodiments. However, it should be understood that these embodiments are merely for more detailed explanation and should not be construed as limiting the invention in any way, i.e., not intended to limit the scope of protection of the invention.

[0027] An exemplary connection structure of the electrochemical mass spectrometry device of the present invention is as follows: Figure 1 As shown, it includes:

[0028] Battery placement sealed cavity 9 for placing solid-state battery 8;

[0029] Battery testing system 10 is used to provide the parameters required for the operation of solid-state battery 8;

[0030] Calibration system for quantitative gas calibration;

[0031] Mass spectrometer 12 is used to analyze the gas produced by solid-state battery 8; mass spectrometer 12 can perform in-situ qualitative and quantitative analysis of the gas produced by solid-state battery 8.

[0032] The differential pressure system is used to create a pressure drop in the sealed cavity 9 where the battery is placed, so as to carry the gas generated by the solid-state battery 8 to the mass spectrometer 12 through the pressure difference.

[0033] Valve assemblies that control the on / off state of various pipelines;

[0034] The battery testing system 10, mass spectrometer 12, and differential pressure system are directly or through one or more solenoid valves in the valve group connected to the sealed cavity 9 where the battery is placed.

[0035] The battery placement sealed cavity 9 can be equipped with several interfaces for connecting to other components as needed; such as... Figure 2 As shown, an exemplary battery placement sealed cavity structure is illustrated, comprising a hollow cavity j and a cover g. The cavity j and the cover g are sealed together to form a sealed cavity for placing a solid-state battery 8. The cover g has interfaces a, b, c, d, and e for connection. A sealing gasket h is also provided at the sealing portion between the cavity j and the cover g to improve the sealing effect. The sealing gasket h can be provided with fixing holes that correspond to the upper positioning hole f on the cover g and the lower positioning hole i on the cavity j, respectively, for installing and positioning the sealing gasket h.

[0036] The battery testing system 10 can be connected to the battery placement sealed cavity 9 through interface a and interface e respectively, thereby connecting the pipeline to the positive and negative terminals of the solid-state battery 8, and realizing the control and adjustment of the working parameters and state of the solid-state battery 8.

[0037] The calibration system is a crucial component for achieving high-sensitivity detection in this invention. It includes a standard gas 2 connected to the battery placement sealed cavity 9 and a pressure gauge A7 that directly reflects the real-time pressure within the cavity 9. The standard gas 2 has a standard leak hole 3 on its inlet pipe. The standard gas 2 enters the battery placement sealed cavity 9 after its flow rate is controlled through the standard leak hole 3. A pressure gauge B1 is also connected to the standard gas 2. By comparing the pressure gauges A7 and B1, the leak rate of the standard leak hole 3 can be determined, thus enabling quantitative gas calibration. This invention innovatively employs a standard leak hole 3 in conjunction with two pressure gauges for quantitative gas calibration. Because the leak rate of the standard leak hole 3 is stable and it can provide a gas flow rate comparable to the gas production of a solid-state battery, the detection sensitivity is greatly improved, avoiding dilution of the produced gas by a large amount of carrier gas. Furthermore, since the leak rate of the standard leak hole 3 can stably change with the inlet pressure, the leak rate can be easily adjusted by changing the pressure of the standard gas 2, thereby meeting the needs of detecting different gas production volumes. In addition, the standard gas 2 can be detachably connected to the inlet pipe in the form of a gas cylinder or the like, and different standard gas 2 can be replaced to meet the needs of different standard gas types.

[0038] The pressure gauge A7 can be installed in various ways. For example, it can be connected to the battery placement sealed cavity 9 through a separate interface, or it can be installed inside the sealed cavity of the battery placement sealed cavity 9 and the pressure result can be displayed through an integrated display device installed on the battery placement sealed cavity 9.

[0039] The differential pressure system includes a gas extraction device, which can be a vacuum pump. The gas extraction device is connected to the battery placement sealed cavity 9 via interface d, thereby creating a negative pressure (differential pressure) by extracting gas from the battery placement sealed cavity 9. When the pipelines of other components such as the calibration system are in the open state connected to the battery placement sealed cavity 9, the gas in the pipelines connecting other components can also be extracted simultaneously to fully remove impurities. The operating pressure of the mass spectrometer 12 is generally also in a vacuum state. When the battery placement sealed cavity 9 generates a negative pressure through the differential pressure system, the standard gas entering the battery placement sealed cavity 9 through the standard leak 3 and / or the reaction gas generated by the solid-state battery 8 can rapidly diffuse into the mass spectrometer 12 through the pressure difference. Since the amount of standard gas and reaction gas is controlled at a low level, almost 100% of the gas enters the mass spectrometer, ensuring detection accuracy and improving time resolution.

[0040] The valve assembly includes solenoid valves respectively installed on the pipelines of the differential pressure system, mass spectrometer 12, and calibration system. Specifically, these can be solenoid valve A5 connected to interface d on the differential pressure system (vacuum pump 6) pipeline, solenoid valve B11 connected to interface c on the mass spectrometer 12 pipeline, and solenoid valve C4 connected to interface b on the calibration system pipeline. Each pipeline is directly connected to the battery placement sealed cavity 9 via a solenoid valve, reducing the use of complex and branched pipelines, shortening the gas diffusion path length, and helping to further improve time resolution and detection sensitivity. Each solenoid valve can be a manual valve, and there is no specific limitation on this. The port size of the valves can also be adapted, for example, preferably 1 / 8 inch or 1 / 16 inch, but it is not limited to these.

[0041] The size of the sealed cavity 9 for placing the battery can be adapted to the structure and size of the solid-state battery 8 being tested.

[0042] It should be noted that the main structure and working principle of the mass spectrometer 12 and the battery testing system 10 can be referred to conventional battery testing systems and mass spectrometers in the prior art, and will not be repeated in this article.

[0043] To illustrate the working process of this embodiment more specifically, the following is based on... Figure 1 The electrochemical mass spectrometry system shown below is used to describe the test operation procedures in detail as follows:

[0044] Before testing, the solid-state battery 8 should generally have a vent to allow the gas generated by the solid-state battery to escape into the battery placement sealed cavity 9 for easy gas collection. Then, the solid-state battery 8 is placed in the battery placement sealed cavity 9 and connected to the battery testing system 10. The battery placement sealed cavity 9 is then closed to complete the sealing connection.

[0045] Before testing, the solid-state battery 8, the battery placed in the sealed chamber 9, and all residual air or impurities in the pipelines of the calibration system and differential pressure system were thoroughly removed. Specifically, solenoid valve B11 was closed, solenoid valves C4 and A5 were opened, and vacuum pump 6 was turned on to evacuate the system. The pressure gauge A7 was observed to drop to a vacuum state, indicating that impurities or air had been expelled from the entire apparatus. Subsequently, solenoid valve A5 and vacuum pump 6 were closed, solenoid valve B11 was opened, and the corresponding response signal of mass spectrometer 12 was observed to further determine whether the content of air or impurities in the entire system had decreased to the ideal value and reached a stable state.

[0046] After the above steps are completed, the battery placement sealed cavity 9 is in a vacuum state, and the gas calibration step can be initiated to obtain the calibration factor of the tested gas. The standard gas 2 is determined according to the gas being tested in the experiment. The standard leak rate of the standard leak hole 3 can be determined when the pressures on both sides (pressure gauge B1 and pressure gauge A7) are known. Specifically, solenoid valves A5 and B11 are closed, and solenoid valve C4 is opened. The standard gas 2 flows through the standard leak hole 3, solenoid valve C4, and reaches the battery placement sealed cavity 9. Then, under the pressure difference of the battery placement sealed cavity 9, it quickly diffuses through solenoid valve B11 into the mass spectrometer 12. At this time, the mass spectrometer can obtain the corresponding mass spectrometric ion current of the standard gas component at a certain standard gas flow rate. By changing the standard gas pressure to change the leak rate of the standard leak hole 3, i.e., changing the standard gas flow rate, and repeating the above steps, a standard curve between the standard gas component flow rate (e.g., μL / min) and the mass spectrometric ion current can be established. Based on this, the generation rate (mol / s, converted according to the standard gas molar volume) of the solid-state battery 8 can be obtained in situ according to the magnitude of the ion current, and the total production of the gas components (mol) can be obtained after integration.

[0047] After completing the above steps, close the solenoid valve C4. Start the battery testing system 10 and connect the solid-state battery 8 to allow the solid-state battery 8 to start operating under the target operating parameters. The generated gas during operation will escape into the battery placement sealed cavity 9 and then quickly diffuse into the mass spectrometer 12, allowing for electrochemical mass spectrometry analysis of the solid-state battery gas.

[0048] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for testing gas generation in solid-state batteries using an electrochemical mass spectrometer. The electrochemical mass spectrometry device includes: A battery placement sealed cavity (9) for placing solid-state batteries (8); the battery placement sealed cavity (9) is connected to a calibration system for quantitative gas calibration, the calibration system includes a standard gas (2) connected to the battery placement sealed cavity (9) and a pressure gauge A (7) that can directly reflect the real-time pressure inside the battery placement sealed cavity (9), the standard gas (2) is provided with a standard leak hole (3) on the gas inlet pipe, the standard gas (2) enters the battery placement sealed cavity (9) after the flow rate is controlled by the standard leak hole (3), and a pressure gauge B (1) is also connected to the standard gas (2) pipe; The battery placement sealed cavity (9) is also connected to: a battery testing system (10) for providing the parameters required for the operation of the solid-state battery (8); a mass spectrometer (12) for analyzing the gas production of the solid-state battery (8); and a differential pressure system for generating a differential pressure in the battery placement sealed cavity (9). The battery testing system (10), the mass spectrometer (12), and the differential pressure system are indirectly connected to the battery placement sealed cavity (9) through a solenoid valve in a valve group. The pipelines of the differential pressure system, the mass spectrometer (12), and the calibration system are respectively equipped with solenoid valves for controlling the opening and closing of the connection between each pipeline and the battery placement sealed cavity (9). The sealed cavity (9) for placing the battery is provided with interfaces a and e for connecting to the battery testing system (10), interface c for connecting to the mass spectrometer (12), interface d for connecting to the differential pressure system, and interface b for connecting to the calibration system. The valve group includes solenoid valves respectively installed on the pipelines of the differential pressure system, the mass spectrometer (12) and the calibration system, specifically solenoid valve A (5) connected to interface d on the pipeline of the differential pressure system, solenoid valve B (11) connected to interface c on the pipeline of the mass spectrometer (12) and solenoid valve C (4) connected to interface b on the pipeline of the calibration system. The method includes the following steps: S1: Place the solid-state battery (8) in the battery placement sealed cavity (9) and connect it to the battery testing system (10). Close the battery placement sealed cavity (9) to complete the sealing. S2: A differential pressure system is used to remove impurities from the sealed cavity (9) where the battery is placed and the pipeline, including the calibration system, and to create a differential pressure. S3: Open the pipelines containing the calibration system, pressure gauge A (7) and mass spectrometer (12), close other pipelines, determine the leakage rate of the standard leak hole (3) in the calibration system through pressure gauge A (7) and pressure gauge B (1) in the calibration system, and establish a standard curve between the flow rate of standard gas components and the mass spectrometer ion current; S4: Turn on the pipelines of the battery testing system (10) and the mass spectrometer (12), and close other pipelines to enable the solid-state battery (8) to start operating under the target operating parameters and perform electrochemical mass spectrometry analysis on the gas generated during operation. In step S2, solenoid valve B (11) is closed, solenoid valve C (4) and solenoid valve A (5) are opened, vacuum pump (6) is turned on to pump gas, and pressure gauge A (7) is observed to drop to vacuum state. Then, solenoid valve A (5) and vacuum pump (6) are closed, solenoid valve B (11) is opened, and the corresponding response signal of mass spectrometer (12) is observed to determine whether the content of impure gas in the whole system has dropped to the ideal value and reached a stable state. In step S3, solenoid valve A (5) is closed, and solenoid valves B (11) and C (4) are opened. The standard gas (2) flows through the standard leak (3), solenoid valve C (4), and reaches the battery placement sealing chamber (9). Then, under the pressure difference of the battery placement sealing chamber (9), it quickly diffuses through solenoid valve B (11) into the mass spectrometer (12), so that the mass spectrometer can obtain the corresponding mass spectrometric ion current of the standard gas component at the standard gas flow rate. The leakage rate of the standard leak (3) is changed by changing the standard gas pressure, that is, the standard gas flow rate is changed. The above steps are repeated to establish a standard curve between the standard gas component flow rate and the mass spectrometric ion current.

2. The method according to claim 1, characterized in that, The differential pressure system includes an air extraction device.

3. The method according to claim 2, characterized in that, The air extraction device is a vacuum pump (6).

4. The method according to claim 1, characterized in that, The sealed cavity (9) where the battery is placed is provided with an interface for connecting with other components.

5. The method according to claim 1, characterized in that, In step S1, the solid-state battery (8) is placed in front of the battery placement sealed cavity (9), with an outlet for easy gas collection.

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