Detection system and detection method

Abstract

The invention relates to the technical field of chemical analysis, in particular to a detection system and a detection method. The detection system comprises a carrier gas module which comprises a gas source and a first multi-way connecting valve, and the first multi-way connecting valve at least comprises a first connector, a second connector and a third connector; the first interface is connected with an air source; the gas sampling and sampling module is provided with a gas inlet pipeline and a gas outlet pipeline, and the gas inlet pipeline is connected with the second interface; each group of reaction module comprises a second multi-way connecting valve and a reaction container for reacting a sample to be detected to generate gas to be detected; the second multi-way connecting valve at least comprises a first interface, a second interface, a third interface and a fourth interface, the first interface is connected with the third interface, and the second interface is connected with a gas inlet pipeline of the gas sampling and sampling module; the detection module is provided with an air inlet pipeline; and a gas inlet pipeline of the detection module is connected with a gas outlet pipeline of the gas sampling and sampling module. The detection system has high detection efficiency.

Description

Technical Field

[0001] This application relates to the field of chemical analysis technology, and in particular to a detection system and detection method. Background Technology

[0002] In batteries, inactive lithium, formed by side reactions between active lithium ions and liquid electrolytes, is a significant cause of battery failure. Studying the formation mechanism and composition of inactive lithium can provide important theoretical support for inhibiting its formation and growth.

[0003] Currently, the main method for detecting inactive lithium in batteries involves titrating the inactive lithium with a titration solution, followed by analyzing the gas produced during the titration reaction using a mass spectrometer. This method has a long analysis cycle and low detection efficiency. Summary of the Invention

[0004] This application is made in view of the above-mentioned technical problems, and its purpose is to shorten the detection time and improve the detection efficiency of the system.

[0005] To achieve the above objectives, this application provides a detection system and a detection method.

[0006] The first aspect of this application provides a detection system, comprising:

[0007] The carrier gas module includes a gas source and a first multi-way connection valve, the first multi-way connection valve including at least a first interface, a second interface and a third interface; and the first interface is connected to the gas source.

[0008] The gas sampling module is equipped with an inlet pipe and an outlet pipe; the inlet pipe of the gas sampling module is connected to the second interface.

[0009] At least one set of reaction modules, each set of reaction modules including a second multi-port connecting valve and a reaction container for reacting the sample to generate the gas to be tested; the second multi-port connecting valve includes at least a first interface, a second interface, a third interface and a fourth interface, the first interface is connected to the third interface, and the second interface is connected to the gas inlet pipeline of the gas sampling module; the reaction container is provided with an inlet and an outlet, the inlet is connected to the third interface and the outlet is connected to the fourth interface;

[0010] The detection module is equipped with an air inlet pipe; the air inlet pipe of the detection module is connected to the air outlet pipe of the gas sampling module.

[0011] The detection system of this application embodiment can achieve the following beneficial effects:

[0012] 1) The detection system includes multiple reaction modules, so multiple test samples can be connected to the detection system in one experiment and multiple test samples can be detected, instead of being limited to a single test sample in one experiment. This increases the detection throughput of the detection system and improves the detection efficiency.

[0013] 2) A special piping structure is designed in the detection system using a second multi-way valve: the first port of the second multi-way valve is connected to the third port of the first multi-way valve, the second port is connected to the inlet pipe of the gas sampling module, and the third and fourth ports are connected to the inlet and outlet of the reaction vessel, respectively. By disconnecting the first port of the second multi-way valve from the third port of the first multi-way valve, and disconnecting the second port of the second multi-way valve from the inlet pipe of the gas sampling module, the reaction vessel and the second multi-way valve in the reaction module can be detached from the detection system as a whole. The sample to be tested, contained in the reaction vessel, can react offline. The gas generated by the reaction can be stored in the reaction vessel and the piping between it and the second multi-way valve. After the reaction is complete, the reaction vessel and the second multi-way valve are reconnected to the detection system. The state of the second multi-way valve is then controlled to extract the gas stored in the reaction vessel and the piping between it into the gas sampling module, which then enters the detection module for testing. This allows for offline reaction.

[0014] Because the reaction in the reaction vessel can be carried out offline, rather than online, the detection time can be flexibly adjusted according to the actual experimental situation. For example, when multiple samples need to be detected, they can be placed in an offline reaction vessel for reaction, and the generated analyte gas can be stored in the reaction vessel and the pipeline connecting it to the second multi-way valve. During the reaction of these samples, samples that have completed the reaction can be detected, or other experiments can be arranged; or, if it is inconvenient to detect the samples after the reaction is completed, the reaction vessel and the connected second multi-way valve can be set aside and detected when it is convenient. Compared with the online reaction mode, this detection mode reduces the time occupied by a single sample in the detection system, which can greatly shorten the detection time, improve the detection efficiency, and provide great convenience for experimental research.

[0015] In some embodiments, the first multi-way connection valve includes an n-way valve, where n ≥ 3 and n is an integer. The path of the carrier gas purging can be controlled by switching the state of the first multi-way connection valve. Optionally, n is an integer between 3 and 10. By increasing the number of interfaces of the first multi-way connection valve, the newly added interfaces can also be connected to the first interface of the second multi-way connection valve in the reaction module, thus increasing the number of reaction modules in the detection system, increasing the detection throughput, and thereby improving detection efficiency. Alternatively, the newly added interfaces can be connected to other structures in the reaction module besides the first interface of the second multi-way connection valve, thereby enriching the application scenarios of the detection system.

[0016] In some embodiments, the gas sampling module includes a sampler, the sampler includes a gas metering device, the gas metering device is provided with a gas storage chamber; the gas storage chamber is provided with an inlet pipe, the inlet pipe of the gas storage chamber is connected to a second interface and is also connected to a second interface.

[0017] In the detection system of this application, the gas inlet pipe of the gas storage chamber is connected to the second interface and the third interface. After the sample to be tested reacts in the reaction vessel to generate the gas to be tested, a portion of the gas to be tested can be extracted and stored in the gas storage chamber of the gas metering device. The composition of this portion of the gas to be tested is the same as that of all the gas to be tested generated in the reaction vessel. Therefore, the detection module can be used to detect this portion of the gas to be tested to obtain a detection signal. Then, the amount of the sample to be tested can be obtained by using the standard curve between the amount of the standard corresponding to the sample to be tested and the detection signal.

[0018] Since it is not necessary to detect all the test gases during the detection process, but only a portion of them, the carrier gas can be used to bring that portion of the test gases into the detection module for detection in a very short time. This significantly shortens the injection time compared to the method of using the carrier gas to bring all the test gases into the detection module. Moreover, the smaller the amount of gas, the shorter the analysis time of the gas in the detection module, which also shortens the analysis time of the test gases in the detection module. Therefore, it greatly saves the overall detection time and improves detection efficiency.

[0019] In some embodiments, the sampler includes an autosampler. This application incorporates an autosampler into the detection system, improving the system's automation level. Using an autosampler enables automated sampling and injection, which is faster than manual sampling and injection and reduces errors. When the autosampler includes a multi-channel autosampler, the test throughput of the detection system can be increased, time costs reduced, and the detection system can be applied on a large scale to the analysis of actual batteries.

[0020] In some embodiments, the second multi-way connection valve includes an m-way valve, where m ≥ 4 and m is an integer. Optionally, m is an integer between 4 and 10. Switching the state of the second multi-way connection valve can control whether the reaction module is connected to the carrier gas; and by controlling whether the interface of the second multi-way connection valve is connected or disconnected from the interface of the first multi-way connection valve, and by controlling whether the interface of the second multi-way connection valve is connected or disconnected from the gas inlet pipeline of the gas sampling module, it is possible to adjust whether the reaction module is separated from the detection system, which is beneficial for achieving offline reaction and detecting the gas to be tested generated after offline reaction. Increasing the number of interfaces of the second multi-way connection valve can enrich the application scenarios of the detection system.

[0021] In some embodiments, the number of reaction modules is 1 to 50. At least one set of reaction modules is used, and the number can be set as needed. By setting multiple sets of reaction modules in the detection system, multiple test samples can be connected to the detection system in a single experiment, rather than being limited to a single test sample in one experiment. This increases the detection throughput and improves the detection efficiency.

[0022] In some embodiments, the reaction module further includes a heating unit for heating the reaction vessel. This heating unit may include a thermostatic chamber, inside which the reaction vessel is disposed. By incorporating the heating unit, the test temperature of the reaction vessel can be adjusted according to varying test requirements, enabling the implementation of diverse test scenarios.

[0023] In some embodiments, the detection system further includes an exhaust gas treatment module, which has an intake pipe; the detection module has an exhaust pipe; and the intake pipe of the exhaust gas treatment module is connected to the exhaust pipe of the detection module.

[0024] A second aspect of this application provides a detection method, which utilizes the detection system described in the first aspect, and includes the following steps:

[0025] The sample to be tested is placed in a reaction vessel to allow it to react and generate the gas to be tested.

[0026] The gas to be tested is delivered to the gas sampling module, and the gas stored in the gas sampling module is delivered to the detection module for detection.

[0027] The detection method of this application embodiment is performed in the detection system of the first aspect. Since the detection system includes at least one set of reaction modules, that is, it can include multiple sets of reaction modules, multiple test samples can be placed in different reaction modules in one experiment, and then multiple test samples can be detected, instead of being limited to only loading a single test sample into the detection system in one experiment, thereby increasing the detection throughput of the detection system and improving the detection efficiency.

[0028] Furthermore, the reaction vessel and the second multi-way connecting valve in the detection system can be detached as a whole from the detection system. Therefore, the sample to be tested contained in the reaction vessel can react offline. The gas to be tested generated by the reaction can be stored in the reaction vessel and the pipeline between it and the second multi-way connecting valve. After the reaction is completed, the reaction vessel and the second multi-way connecting valve are connected back to the detection system. Then, the state of the second multi-way connecting valve is controlled to extract the gas stored in the reaction vessel and the pipeline between it and the second multi-way connecting valve into the gas sampling module, and then into the detection module for detection. In this way, offline reaction can be achieved.

[0029] Because the reaction in the reaction vessel can be carried out offline, rather than online, the detection time can be flexibly adjusted according to the actual experimental situation. For example, when multiple samples need to be detected, they can be placed in an offline reaction vessel for reaction, and the generated analyte gas can be stored in the reaction vessel and the pipeline connecting it to the second multi-way valve. During the reaction of these samples, samples that have completed the reaction can be detected, or other experiments can be arranged; or, if it is inconvenient to detect the samples after the reaction is completed, the reaction vessel and the connected second multi-way valve can be set aside and detected when it is convenient. Compared with the online reaction mode, this detection mode reduces the time occupied by a single sample in the detection system, greatly shortens the detection time, improves detection efficiency, and provides great convenience for experimental research.

[0030] In some embodiments, the sample to be tested includes any sample that can react to generate gas. Optionally, the sample to be tested contains one or more of an active metal, a metal hydride, an inorganic carbonate, an inorganic bicarbonate, an organometallic compound, and a metal carbide. Optionally, the sample to be tested contains one or more of inactive lithium and inactive sodium.

[0031] The detection method described in this application can detect any sample that can react to generate gas, making it widely applicable. In particular, the detection of samples containing inactive lithium, inactive sodium, etc., can provide important information for battery research.

[0032] In some embodiments, the step of reacting the sample to generate the gas to be tested includes:

[0033] A portion of the gas to be tested is delivered to the gas storage chamber, and the gas stored in the gas storage chamber is then delivered to the detection module for testing.

[0034] This application extracts and stores a portion of the gas to be tested into the gas storage chamber of a gas metering device. The composition of this portion of the gas to be tested is the same as that of all the gas to be tested generated in the reaction vessel. Therefore, a detection module can be used to detect this portion of the gas to be tested to obtain a detection signal. Then, the amount of the sample to be tested can be obtained by using the standard curve between the amount of the standard corresponding to the sample to be tested and the detection signal.

[0035] Since it is not necessary to detect all the test gases during the detection process, but only a portion of them, the carrier gas can be used to bring that portion of the test gases into the detection module for detection in a very short time. Compared with the injection method that uses the carrier gas to bring all the test gases into the detection module, the injection time is significantly shortened, as is the analysis time of the test gases in the detection module. Therefore, the overall detection time is greatly saved and the detection efficiency is improved.

[0036] In some embodiments, the detection method further includes a step of purging air from the piping of the detection system. Purging air improves the stability of the sample to be tested, thereby increasing the accuracy of the detection. Attached Figure Description

[0037] Figure 1 This is a schematic diagram of an embodiment of the detection system of this application;

[0038] Figure 2 A schematic diagram showing the states of the first multi-way connecting valve as a three-way valve, in states 1 and 2.

[0039] Figure 3 A schematic diagram showing the states of the second multi-way connection valve as a four-way valve, in states 1 and 2.

[0040] Figure 4 A schematic diagram of the connection structure of the interfaces other than the first, second, and third interfaces of the first multi-way connection valve;

[0041] Figure 5 This is the standard curve of Li mass versus H2 signal integral area in Example 2;

[0042] Figure 6 This is a schematic diagram of the detection system in Comparative Example 1;

[0043] Figure 7 This is the standard curve of Li mass versus H2 signal integral area in Comparative Example 1.

[0044] Explanation of reference numerals in the attached figures:

[0045] 100-Carrier gas module, 101-Gas source, 102-Flow meter, 103-First multi-way connection valve (three-way valve), 103a-First interface of the first multi-way connection valve, 103b-Second interface of the first multi-way connection valve, 103c-Third interface of the first multi-way connection valve;

[0046] 200 - Gas sampling and injection module; 201 - Multi-channel pulse injector;

[0047] 300 - Reaction module, 301 - First titration cell, 302 - First four-way valve, 302a - First port of the first four-way valve, 302b - Second port of the first four-way valve, 302c - Third port of the first four-way valve, 302d - Fourth port of the first four-way valve, 303 - Second titration cell, 304 - Second four-way valve, 304a - First port of the second four-way valve, 304b - Second port of the second four-way valve, 304c - Third port of the second four-way valve, 304d - Fourth port of the second four-way valve;

[0048] 400 - Detection module, 401 - Cold trap, 402 - Mass spectrometer;

[0049] 500 - Exhaust Gas Treatment Module. Detailed Implementation

[0050] The following detailed description of the implementation of the detection system and detection method of this application is provided with appropriate reference to the accompanying drawings. However, unnecessary detailed descriptions may be omitted. For example, detailed descriptions of well-known matters and repetitive descriptions of actually identical structures may be omitted. This is to avoid making the following description unnecessarily lengthy and to facilitate understanding by those skilled in the art. Furthermore, the accompanying drawings and the following description are provided to enable those skilled in the art to fully understand this application and are not intended to limit the subject matter of the claims.

[0051] The "range" disclosed in this application is defined by a lower limit and an upper limit. A given range is defined by selecting a lower limit and an upper limit, which define the boundaries of a particular range. Ranges defined in this way can include or exclude endpoints and can be arbitrarily combined; that is, any lower limit can be combined with any upper limit to form a range. For example, if ranges of 60–120 and 80–110 are listed for a specific parameter, it is understood that ranges of 60–110 and 80–120 are also expected. Furthermore, if minimum range values ​​of 1 and 2 are listed, and if maximum range values ​​of 3, 4, and 5 are listed, then the following ranges are all expected: 1–3, 1–4, 1–5, 2–3, 2–4, and 2–5. In this application, unless otherwise stated, the numerical range "a–b" represents a shortened representation of any combination of real numbers between a and b, where a and b are real numbers. For example, the numerical range "0~5" indicates that all real numbers between "0~5" have been listed in this article; "0~5" is simply a shortened representation of these numerical combinations. Furthermore, when a parameter is stated as an integer ≥2, it is equivalent to disclosing that the parameter is, for example, an integer such as 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0052] Unless otherwise specified, all embodiments and optional embodiments of this application can be combined to form new technical solutions.

[0053] Unless otherwise specified, all technical features and optional technical features of this application may be combined to form new technical solutions.

[0054] Unless otherwise specified, all steps in this application may be performed sequentially or randomly, preferably sequentially. For example, the method includes steps (a) and (b), indicating that the method may include steps (a) and (b) performed sequentially, or it may include steps (b) and (a) performed sequentially. For example, the mention that the method may also include step (c) indicates that step (c) may be added to the method in any order. For example, the method may include steps (a), (b), and (c), or it may include steps (a), (c), and (b), or it may include steps (c), (a), and (b), etc.

[0055] Unless otherwise specified, the terms "comprising" and "including" as used in this application can be open-ended or closed-ended. For example, "comprising" and "including" can mean that other components not listed may also be included, or that only the listed components may be included.

[0056] Unless otherwise specified, the term "or" is inclusive in this application. For example, the phrase "A or B" means "A, B, or both A and B". More specifically, the condition "A or B" is satisfied by any of the following conditions: A is true (or exists) and B is false (or does not exist); A is false (or does not exist) and B is true (or exists); or both A and B are true (or exist).

[0057] During battery charging and discharging, active ions, such as lithium ions, gradually deactivate due to various reasons (e.g., side reactions with the electrolyte), transforming into inactive lithium. The formation of inactive lithium severely affects battery performance; therefore, analyzing inactive lithium can provide a deeper understanding of the battery's microstructure, offering crucial theoretical support for battery research and optimization.

[0058] The main method for detecting inactive lithium in batteries involves titrating the inactive lithium with a titration solution, followed by analyzing the gas generated during the titration reaction using a mass spectrometer. A typical detection system for inactive lithium analysis includes a carrier gas unit, a titration reaction unit, and a mass spectrometer connected in sequence. The carrier gas unit provides the carrier gas and purges the air from the titration reaction unit. The sample to be tested is placed in the titration reaction unit, and the gas generated by the reaction between the titration solution and the sample is purged by the carrier gas and detected by the mass spectrometer. The inactive lithium components and their corresponding capacity loss are calculated based on the detected gas composition and content. However, this method only allows for the detection of a single sample per experiment, and each experiment requires online reaction, resulting in low detection efficiency due to the long processing time of a single sample.

[0059] Based on this, this application proposes a detection system. A first multi-port valve with at least three ports is installed in the carrier gas module, and a second multi-port valve with at least four ports is connected to the reaction vessel in the reaction module. The two multi-port valves form a special pipeline structure, allowing multiple reaction modules to be connected to the detection system, thus increasing the testing throughput and detection efficiency. Furthermore, the reaction modules can be detached from the detection system via the second multi-port valve for offline reaction. After the reaction is complete, the modules are reconnected to the detection system for testing. This detection mode significantly shortens the detection time and improves detection efficiency compared to online reaction, providing great convenience for experimental research.

[0060] Furthermore, embodiments of this application also provide a method for detecting a sample to be tested using the detection system, which has high detection efficiency.

[0061] Please refer to Figure 1 , Figure 1 This is a schematic diagram of the structure of a detection system according to the first aspect of the embodiments of this application. The detection system provided by the embodiments of this application includes:

[0062] The carrier gas module 100 includes a gas source 101 and a first multi-way connection valve 103. The first multi-way connection valve 103 includes at least a first interface 103a, a second interface 103b and a third interface 103c; and the first interface 103a is connected to the gas source 101.

[0063] The gas sampling module 200 is equipped with an inlet pipe and an outlet pipe; the inlet pipe of the gas sampling module 200 is connected to the second interface 103b.

[0064] At least one set of reaction modules 300, each set of reaction modules 300 includes a second multi-port connecting valve and a reaction container for reacting the sample to generate the gas to be tested; the second multi-port connecting valve includes at least a first interface, a second interface, a third interface and a fourth interface, the first interface is connected to the third interface 103c, and the second interface is connected to the gas inlet pipe of the gas sampling module 200; the reaction container is provided with an inlet and an outlet, the inlet is connected to the third interface and the outlet is connected to the fourth interface;

[0065] The detection module 400 is equipped with an air inlet pipe; the air inlet pipe of the detection module 400 is connected to the air outlet pipe of the gas sampling module 200.

[0066] The carrier gas module 100 is a module unit used to provide carrier gas. Specifically, the carrier gas is output from the gas source 101. The carrier gas can purge the pipeline of the detection system to reduce the interference of impurity gases on the sample to be tested and the gas to be tested generated by the reaction of the sample to be tested. At the same time, the carrier gas can be used to purge the gas to be tested into the detection module 400 for detection.

[0067] The term "first multi-way connection valve 103" in this application embodiment refers to a connection valve with multiple ports, which can adjust the connection or disconnection relationship between different ports to achieve different pathways. The first multi-way connection valve 103 includes at least a first port 103a, a second port 103b, and a third port 103c. It can adjust any two ports to be connected or to disconnect any two ports from each other. For example, it can adjust the first port 103a to be connected to the second port 103b, or it can adjust the first port 103a to be connected to the third port 103c; it can adjust the second port 103b to be connected to the first port 103a, or it can adjust the second port 103b to be connected to the third port 103c; it can adjust the third port 103c to be connected to the first port 103a, or it can adjust the third port 103c to be connected to the second port 103b. When any two ports are connected, neither of those two ports is connected to the third port. For example, when the first interface 103a and the second interface 103b are connected, the first interface 103a and the third interface 103c are disconnected and not connected, and the second interface 103b and the third interface 103c are also disconnected and not connected; when the first interface 103a and the third interface 103c are connected, the first interface 103a and the second interface 103b are disconnected and not connected, and the third interface 103c and the second interface 103b are also disconnected and not connected.

[0068] The first port 103a of the first multi-way connecting valve 103 is connected to the gas source 101, the second port 103b of the first multi-way connecting valve 103 is connected to the inlet pipe of the gas sampling module 200, and the third port 103c of the first multi-way connecting valve 103 is connected to the first port of the second multi-way connecting valve. When the first port 103a and the second port 103b are connected, the carrier gas provided by the gas source 101 can be purged along the path of first port 103a-second port 103b → gas sampling module 200 (since the outlet pipe of the gas sampling module 200 is connected to the inlet pipe of the detection module 400, the carrier gas can also enter the detection module 400). When the first port 103a and the third port 103c are connected, the carrier gas provided by the gas source 101 can be purged along the path of first port 103a-third port 103c → reaction module 300. When the second interface 103b and the third interface 103c are connected, there is no carrier gas purging in the pipeline after the first multi-way valve 103 in the detection system. Therefore, the carrier gas purging path can be controlled by switching the state of the first multi-way valve 103.

[0069] In this application's embodiments, the term "gas sampling module 200" is used to deliver the test gas generated from the reaction of the test sample in the reaction module 300 to the detection module 400 for detection and analysis. The reaction container in the reaction module 300 is used for the test sample to react and generate the test gas, which can ultimately be detected and analyzed by the detection module 400.

[0070] Similar to the first multi-way connection valve 103, the term "second multi-way connection valve" in this embodiment is also a connection valve with multiple ports, which can adjust the connection or disconnection relationship between different ports to achieve different passages. The second multi-way connection valve includes at least a first port, a second port, a third port, and a fourth port, and can adjust any two ports to be connected or to disconnect any two ports from each other. For example, it can adjust the first port to be connected to any one of the second, third, and fourth ports; it can also adjust the second port to be connected to any one of the first, third, and fourth ports; it can also adjust the third port to be connected to any one of the first, second, and fourth ports; and it can also adjust the fourth port to be connected to any one of the first, second, and third ports.

[0071] When any two interfaces are connected, neither of those interfaces is connected to the other two interfaces. For example, if interface 1 is connected to interface 2, interface 1 is not connected to interface 3 or interface 4; interface 2 is not connected to interface 3 or interface 4. Similarly, if interface 1 is connected to interface 3, interface 1 is not connected to interface 2 or interface 4; interface 3 is not connected to interface 2 or interface 4. It should be noted that when any two interfaces are connected, the connection of the other two interfaces can be adjusted. For example, if interface 1 is connected to interface 2, the connection between interface 3 and interface 4 can be adjusted; and if interface 1 is connected to interface 3, the connection between interface 2 and interface 4 can be adjusted.

[0072] The first port of the second multi-way connecting valve is connected to the third port 103c of the first multi-way connecting valve 103, the second port is connected to the inlet pipe of the gas sampling module 200, the third port is connected to the inlet of the reaction vessel, and the fourth port is connected to the outlet of the reaction vessel. When the first port 103a and the third port 103c of the first multi-way connecting valve 103 are connected, and the first port and the third port 103c of the second multi-way connecting valve are also connected, as are the first and third ports, and the second and fourth ports, the reaction vessel can be connected to carrier gas. The carrier gas provided by the gas source 101 can purge the reaction vessel and its inlet and outlet pipes. When the third and fourth ports are connected, the reaction vessel is in a connected state, and carrier gas cannot enter the reaction vessel. Therefore, switching the state of the second multi-way connecting valve can control whether the reaction vessel is connected to the carrier gas purging path.

[0073] The term "detection module 400" in the embodiments of this application is used to detect and analyze the gas generated by the reaction of the sample to be tested in the reaction module 300.

[0074] The term "connected" in the embodiments of this application can include both direct and indirect connections. For example, the connection between A and B can be a direct physical connection where A and B are in contact with each other; or it can be a connection between A and B that is not in direct physical contact, achieved through a pipeline or other structure. Furthermore, the "connection" relationship can be detachable as needed.

[0075] The detection system of this application embodiment can achieve the following beneficial effects:

[0076] 1) The detection system includes multiple reaction modules 300, so multiple test samples can be connected to the detection system in one experiment and multiple test samples can be detected, instead of being limited to a single test sample in one experiment. This increases the detection throughput of the detection system and improves the detection efficiency.

[0077] 2) A special piping structure is set in the detection system through the second multi-way connecting valve: the first port of the second multi-way connecting valve is connected to the third port 103c of the first multi-way connecting valve 103, the second port is connected to the gas inlet pipeline of the gas sampling module 200, and the third and fourth ports are connected to the gas inlet and outlet of the reaction vessel, respectively. Therefore, after disconnecting the first port of the second multi-way connecting valve from the third port 103c of the first multi-way connecting valve 103, and disconnecting the second port of the second multi-way connecting valve from the gas sampling module 200's gas inlet pipeline, the reaction vessel in the reaction module 300 and the second multi-way connecting valve can be detached from the detection system as a whole. The sample to be tested, contained in the reaction vessel, can undergo an offline reaction. The resulting gas can be stored in the reaction vessel and the pipeline connecting it to the second multi-way valve. After the reaction is complete, the reaction vessel and the second multi-way valve are connected to the detection system. The state of the second multi-way valve is then controlled to extract the gas stored in the reaction vessel and the pipeline between them into the gas sampling module 200, which then enters the detection module 400 for detection. This allows for offline reaction.

[0078] Because the reaction in the reaction vessel can be carried out offline, rather than online, the detection time can be flexibly adjusted according to the actual experimental situation. For example, when multiple samples need to be detected, they can be placed in an offline reaction vessel for reaction, and the generated analyte gas can be stored in the reaction vessel and the pipeline connecting it to the second multi-way valve. During the reaction of these samples, samples that have completed the reaction can be detected, or other experiments can be arranged; or, if it is inconvenient to detect the samples after the reaction is completed, the reaction vessel and the connected second multi-way valve can be set aside and detected when it is convenient. Compared with the online reaction mode, this detection mode reduces the time occupied by a single sample in the detection system, greatly shortens the detection time, improves detection efficiency, and provides great convenience for experimental research.

[0079] The following provides a detailed description of the different modules of the detection system.

[0080] (1) Carrier gas module 100

[0081] The carrier gas module 100 is used to provide carrier gas.

[0082] In some embodiments, the carrier gas module 100 includes a gas source 101, a flow meter 102, and a first multi-way connection valve 103. The first interface 103a of the gas source 101, the flow meter 102, and the first multi-way connection valve 103 are connected in sequence. That is, the carrier gas provided by the gas source 101 will pass through the flow meter 102 and the first interface 103a of the first multi-way connection valve 103 in sequence.

[0083] The gas source 101 may include one or more inert gases selected from argon, nitrogen, and helium. These inert gases can purge the pipelines of the detection system and provide power for the test gas generated by the reaction of the test sample in the reaction module 300 to enter the detection module 400, without reacting with the test sample or the test gas generated by the reaction.

[0084] The flow meter 102 includes one or more of a mass flow meter (MFC) and a volumetric flow meter, optionally including a mass flow meter. By installing the flow meter 102 in the carrier gas module 100, the flow rate of the carrier gas can be precisely controlled, facilitating subsequent quantitative analysis.

[0085] In some embodiments, the first multi-way connection valve 103 includes an n-way valve, where n ≥ 3 and n is an integer, and the path of the carrier gas purging can be controlled by switching its state. Optionally, n can be 3 to 10, for example, n is any one or any two of 3, 4, 5, 6, 7, 8, 9, 10. When n > 3, the n-way valve includes a first port 103a, a second port 103b, a third port 103c, ..., an nth port, wherein any port other than the first port 103a, the second port 103b, and the third port 103c may not be connected to any structure; or, please refer to Figure 4 Other interfaces can also be connected to the first interface of one or more sets of second multi-way connecting valves of the reaction modules 300. These interfaces, similar to the third interface 103c, can be connected to the first interface of the second multi-way connecting valve of the reaction module 300. Alternatively, other interfaces can be connected to structures other than the first interface of the second multi-way connecting valve. By increasing the number of interfaces of the first multi-way connecting valve 103, the newly added interfaces can also be connected to the first interface of the second multi-way connecting valve of the reaction module 300. This increases the number of reaction modules 300 in the detection system, increases the detection throughput, and thus improves detection efficiency. Alternatively, the newly added interfaces can be connected to structures other than the reaction module 300, thereby enriching the application scenarios of the detection system.

[0086] In some embodiments, n=3, that is, the first multi-way connection valve 103 includes a three-way valve. The three-way valve includes three ports: a first port 103a, a second port 103b, and a third port 103c. Common port connection methods include: adjusting the connection between the first port 103a and the second port 103b, or adjusting the connection between the first port 103a and the third port 103c.

[0087] (2) Gas sampling and injection module 200

[0088] The gas sampling module 200 of this application embodiment is used to deliver the gas to be tested generated by the reaction vessel to the detection module 400 for detection and analysis.

[0089] In some embodiments, the gas sampling module 200 includes a sampler, which includes a gas metering device. The gas metering device has a gas storage chamber. The gas storage chamber has an inlet pipe connected to a second interface 103b and a second interface. Optionally, the gas metering device includes a metering loop.

[0090] In this application, the term "sampler" refers to a device capable of quantitatively delivering an analytical sample into the detection module 400, and "gas metering device" refers to a structural unit with a certain volume used to control the injection volume. Understandably, the gas sampling module 200 is provided with an inlet pipe, and the gas sampling module 200 includes a sampler, which includes a gas metering device. The gas metering device is provided with a gas storage chamber, and the gas storage chamber is provided with an inlet pipe. The inlet pipe of the gas storage chamber is also the inlet pipe of the gas sampling module 200, and also the inlet pipe of the sampler.

[0091] In the detection system of this application embodiment, the gas inlet pipe of the gas storage chamber is connected to the second interface 103b and the second interface. After the sample to be tested in the reaction container reacts to generate the gas to be tested, a portion of the gas to be tested can be extracted and stored in the gas storage chamber of the gas metering device. The composition of this portion of the gas to be tested is the same as that of all the gas to be tested generated in the reaction container. Therefore, the detection module 400 can be used to detect this portion of the gas to be tested to obtain a detection signal. Then, the amount of the sample to be tested can be obtained by using the standard curve between the amount of the standard corresponding to the sample to be tested and the detection signal.

[0092] Since it is not necessary to detect all the test gases during the detection process, but only a portion of them, the carrier gas can be used to bring this portion of the test gases into the detection module 400 for detection in a very short time. Compared with the injection method of using the carrier gas to bring all the test gases into the detection module 400, the injection time is significantly shortened. Moreover, the smaller the amount of gas, the shorter the analysis time of the gas in the detection module 400. Therefore, this also shortens the analysis time of the test gases in the detection module 400, thus greatly saving the overall detection time and improving detection efficiency.

[0093] In some embodiments, the volume of the gas storage chamber is smaller than the total volume of the reaction vessel and the pipeline between it and the second multi-way connecting valve. Thus, even if the gas storage chamber is filled with the analyte gas, the amount of this analyte gas will be less than the total amount of gas generated by the reaction of the sample in the reaction vessel. During the detection process, only this small amount of analyte gas needs to be detected, which can shorten the sample introduction time and the analysis time of the analyte gas in the detection module 400, thereby improving detection efficiency.

[0094] In some embodiments, the injector includes an autosampler. The autosampler may include a multi-channel autosampler, and more specifically, a multi-channel pulse sampler. An autosampler is an intelligent, automated sample delivery device capable of automatically and quantitatively delivering samples into the detection module 400. A multi-channel pulse sampler is a multi-channel autosampler with a pulse injection mode, which, through a set pulse injection program, achieves automatic, timed, and alternating injection of samples from multiple channels.

[0095] This application embodiment incorporates an autosampler in the detection system, enhancing its automation level. The autosampler enables automated sampling and injection, offering faster speeds and reduced errors compared to manual sampling. Furthermore, when the autosampler includes a multi-channel version, the system's throughput is increased, time costs are reduced, and the system can be widely applied to the analysis of actual batteries.

[0096] (3) Reaction module 300

[0097] The detection system of this application embodiment includes at least one set of reaction modules 300, each set of reaction modules 300 including a second multi-way connection valve and a reaction container for reacting the sample to be tested to generate the gas to be tested.

[0098] In some embodiments, the number of reaction modules 300 is 1 to 50 groups, optionally 1 to 10 groups, for example, any one or a range between 1, 2, 5, 10, 15, 20, 25, 30, 35, 40, 45, and 50 groups. The number of reaction modules 300 is at least one group, which can be set as needed. By setting multiple groups of reaction modules 300 in the detection system, multiple test samples can be connected to the detection system in one experiment, instead of being limited to a single test sample in one experiment, thereby increasing the detection throughput and improving the detection efficiency of the detection system.

[0099] In some embodiments, the reaction vessel can be any device with a cavity, such as a titration cell. Each group of reaction modules 300 includes a reaction vessel. It is understood that the reaction vessels in each group of reaction modules may be the same or different; and each group of reaction modules 300 includes at least one reaction vessel, for example, each group of reaction modules 300 includes 1 to 10 reaction vessels, such as any one or a range between 1, 2, 4, 6, 8, and 10. When a group of reaction modules 300 includes multiple reaction vessels, these reaction vessels can be interconnected in parallel or in series as needed.

[0100] The titration cell, typically made of glass or polyethylene, is a sealed container with a certain volume, mainly used for preparing solutions, performing acid-base titrations, or other experiments requiring controlled addition of liquid. It is generally equipped with a burette or dropper to precisely control the rate and amount of liquid addition. In this embodiment, the titration cell has an inlet and an outlet; the inlet is connected to the third interface, and the outlet is connected to the fourth interface.

[0101] In some embodiments, the second multi-way connection valve includes an m-way valve, where m ≥ 4 and m is an integer. m can be 4 to 10, for example, m is any one or any two of 4, 5, 6, 7, 8, 9, and 10. Switching the state of the second multi-way connection valve can control whether the reaction module 300 is connected to the carrier gas; and by controlling whether the interface of the second multi-way connection valve is connected or disconnected from the interface of the first multi-way connection valve, and by controlling whether the interface of the second multi-way connection valve is connected or disconnected from the gas inlet pipe of the gas sampling module 200, it is possible to adjust whether the reaction module 300 is separated from the detection system, which is beneficial for achieving offline reaction and detecting the gas to be tested generated after the offline reaction. Moreover, when m > 4, other interfaces besides the first, second, third, and fourth interfaces can be connected in different ways as needed. For example, any of the other interfaces may not be connected to any structure. In this case, when needed, the interface can be connected to the fourth interface to discharge the analyte gas generated by the reaction of the sample in the reaction vessel. Alternatively, any of the other interfaces can be connected to another gas sampling module 200, and then that gas sampling module 200 can be connected to another detection module 400, or any of the other interfaces can be directly connected to another detection module 400. This allows different detection modules 400 to detect the analyte gas generated in the same reaction vessel. It should be noted that this is only an example of the connection methods for interfaces other than the first, second, third, and fourth interfaces. In reality, the connection methods for other interfaces can be flexibly changed according to different usage scenarios and different requirements. Therefore, by increasing the number of interfaces of the second multi-way connection valve, the application scenarios of the detection system can be enriched.

[0102] In some embodiments, m = 4, meaning the second multi-way valve includes a four-way valve. The four-way valve includes four ports: port 1, port 2, port 3, and port 4. Common port connection configurations include: adjusting the connection between port 1 and port 2, and simultaneously adjusting the connection between port 3 and port 4; or, adjusting the connection between port 1 and port 3, and simultaneously adjusting the connection between port 2 and port 4.

[0103] In some embodiments, the reaction module 300 further includes a heating unit for heating the reaction vessel. This heating unit may include a constant temperature chamber, inside which the reaction vessel is disposed. By incorporating the heating unit, the test temperature of the reaction vessel can be adjusted according to varying test requirements, enabling the implementation of diverse test scenarios.

[0104] (4) Detection module 400

[0105] The detection module 400 of this application embodiment is used to detect and analyze the test gas generated by the reaction of the test sample in the reaction vessel. The detection module 400 is provided with an inlet pipe and an outlet pipe.

[0106] In some embodiments, the detection module 400 includes analytical instruments, including one or more of a mass spectrometer and a gas chromatograph. These analytical instruments can perform qualitative and quantitative analysis on the analyte gas generated by the reaction of the analyte sample.

[0107] It should be noted that the main structure and working principle of analytical instruments such as mass spectrometers and gas chromatographs can be referred to the structure and working principle of conventional analytical instruments such as mass spectrometers and gas chromatographs in the existing technology, and will not be repeated in this article.

[0108] In some embodiments, the detection module 400 further includes a cooling device disposed between the gas sampling module 200 and the analytical instrument. Specifically, it may be disposed between the multi-channel autosampler and the analytical instrument (or between the quantitative loop and the analytical instrument). The cooling device includes a cold trap.

[0109] The gas generated by the reaction of the sample in the reaction vessel passes through a cooling device before reaching the analytical instrument. The cooling device can condense the vaporized solution carried out by the gas, reduce noise, and improve the signal-to-noise ratio of the system.

[0110] (5) Exhaust gas treatment module 500

[0111] The detection system in this embodiment further includes an exhaust gas treatment module 500, which has an intake pipe; the intake pipe of the exhaust gas treatment module 500 is connected to the exhaust pipe of the detection module 400. The exhaust gas treatment module 500 is used to treat the waste gas generated during the experiment.

[0112] Depending on the different gases generated in the reaction vessel, different exhaust gas treatment modules 500 can be used. For example, if the gases generated in the reaction vessel include H2 and D2, the exhaust gas treatment module 500 may include a combustion unit to burn H2 and D2 into pollution-free H2O and D2O. If the gases generated in the reaction vessel include CO2, the exhaust gas treatment module 500 may include an exhaust gas absorption tank containing an alkaline solution to react CO2 with the alkaline solution. If the gases generated in the reaction vessel include C2H2, the exhaust gas treatment module 500 may include a combustion unit and an exhaust gas absorption tank containing an alkaline solution, first burning the gas and then using the alkaline solution to absorb the CO2 produced by combustion.

[0113] Secondly, embodiments of this application provide a detection method, which utilizes the detection system described in the first aspect for detection, and includes the following steps:

[0114] S1: Place the sample to be tested in the reaction vessel to allow it to react and generate the gas to be tested;

[0115] S2: The gas to be tested is delivered to the gas sampling module 200, and the gas to be tested stored in the gas sampling module 200 is delivered to the detection module 400 for detection.

[0116] The detection method of this application embodiment is carried out in the detection system of the first aspect. Since the detection system includes at least one set of reaction modules 300, that is, it can include multiple sets of reaction modules 300, multiple test samples can be placed in different reaction modules 300 in one experiment, and then multiple test samples can be detected, instead of being limited to only loading a single test sample into the detection system in one experiment, thereby increasing the detection throughput of the detection system and improving the detection efficiency.

[0117] Furthermore, the reaction vessel and the second multi-way connecting valve in the detection system can be detached from the detection system as a whole. Therefore, the sample to be tested contained in the reaction vessel can react offline. The gas to be tested generated by the reaction can be stored in the reaction vessel and the pipeline between it and the second multi-way connecting valve. After the reaction is completed, the reaction vessel and the second multi-way connecting valve are connected back to the detection system. Then, the state of the second multi-way connecting valve is controlled so that the gas stored in the reaction vessel and the pipeline between it and the second multi-way connecting valve is extracted into the gas sampling module 200 and then enters the detection module 400 for detection. In this way, offline reaction can be achieved.

[0118] Because the reaction in the reaction vessel can be carried out offline, rather than online, the detection time can be flexibly adjusted according to the actual experimental situation. For example, when multiple samples need to be detected, they can be placed in an offline reaction vessel for reaction, and the generated analyte gas can be stored in the reaction vessel and the pipeline connecting it to the second multi-way valve. During the reaction of these samples, samples that have completed the reaction can be detected, or other experiments can be arranged; or, if it is inconvenient to detect the samples after the reaction is completed, the reaction vessel and the connected second multi-way valve can be set aside and detected when it is convenient. Compared with the online reaction mode, this detection mode reduces the time occupied by a single sample in the detection system, greatly shortens the detection time, improves detection efficiency, and provides great convenience for experimental research.

[0119] In some embodiments, in step S1, the sample to be tested is placed in a reaction vessel under a protective atmosphere. This protective atmosphere may include one or more of argon, nitrogen, and helium. In practice, this operation can be performed in a glove box. Placing the sample to be tested in a reaction vessel under a protective atmosphere maintains the chemical stability of the sample, preventing it from reacting with air, thereby improving the accuracy of the detection.

[0120] In some embodiments, in step S1, the sample to be tested includes any sample that can react to generate gas. For example, the sample to be tested contains one or more of the following: active metals, metal hydrides, inorganic carbonates, inorganic bicarbonates, organometallic compounds, and metal carbides. The detection method of this application embodiment can detect various samples that can react to generate gas, and has wide applicability.

[0121] Among them, "active metals" refers to metallic elements that precede hydrogen in the activity series of metals. Active metals react with acids to produce hydrogen gas, and some active metals can also react with ethanol and water to produce hydrogen gas. Therefore, they can be detected using the detection system of this application embodiment. Metal hydrides can react with ethanol, water, etc., to produce hydrogen gas; inorganic carbonates, inorganic bicarbonates, organometallic compounds, etc., can react with acids or other solutions to produce gases (e.g., carbon dioxide); metal carbides can react with acids to produce carbon-containing gases. Therefore, samples containing these substances can be detected using the detection system of this application embodiment.

[0122] For example, the active metals include one or more of Li, Na, K, Fe, and Zn; the metal hydrides include one or more of LiH and NaH. Inorganic carbonates include one or more of Li₂CO₃, Na₂CO₃, K₂CO₃, and CaCO₃. Inorganic bicarbonates include one or more of LiHCO₃, NaHCO₃, and KHCO₃. Organometallic compounds include one or more of organolithium compounds formed by the solvent in the electrolyte and lithium ions, and organosoil compounds formed by the solvent in the electrolyte and sodium ions, wherein the solvent in the electrolyte includes one or more of carbonate solvents, carboxylic acid ester solvents, and sulfite solvents; carbonate solvents include one or more of ethyl methyl carbonate (EMC), ethylene carbonate (EC), propylene carbonate (PC), dimethyl carbonate (DMC), and diethyl carbonate (DEC); carboxylic acid ester solvents include one or more of ethyl acetate, butyl butyrate, and methyl propionate; and sulfite solvents include one or more of dimethyl sulfite, diethyl sulfite, and ethylene sulfite. For example, organolithium compounds include HOCH2CH2OCO2Li (LiEMC) formed by EMC and lithium ions, and organosoil compounds include HOCH2CH2OCO2Na (NaEMC) formed by EMC and sodium ions. Metal carbides include Li2C2.

[0123] Among these exemplary active metals, metal hydrides, inorganic carbonates, organometallic compounds, and metal carbides, Li, LiH, Li2CO3, organolithium compounds, and Li2C2 are inactive lithium components in lithium-ion batteries or lithium metal batteries, while Na, NaH, Na2CO3, and organosodium compounds are inactive sodium components in sodium-ion batteries.

[0124] Inactive lithium, also known as "dead lithium," refers to lithium or lithium compounds that cannot participate in electrochemical reactions during battery charging and discharging. In lithium-ion batteries and lithium metal batteries, inactive lithium mainly includes one or more of Li, LiH, Li₂CO₃, organic lithium carbonate formed by the reaction of carbonate solvents with lithium ions, and Li₂C₂. Typically, test samples containing these inactive lithiums include one or more of the electrodes and cells of lithium-ion batteries and the electrodes and cells of lithium metal batteries. These inactive lithiums can be titrated with a titration solution to generate a gas, and therefore can be detected using the detection system of the embodiments of this application. For example, for Li and LiH, one or more of ethanol, deuterated ethanol, and heavy water can be used independently as titration solutions to react with Li or LiH to generate the test gas. For Li₂CO₃, organic lithium compounds (taking LiEMC as an example), and Li₂C₂, sulfuric acid can be used independently as titration solutions to react with Li₂CO₃, LiEMC, or Li₂C₂ to generate the test gas.

[0125] The reactions that occur when titrating different inactive lithium components with titration solutions are shown in the table below.

[0126] [Table 1]

[0127]

[0128] The purity and concentration of the reagents used in each titration solution can be selected according to actual conditions. For example, the purity of the reagents can include one or more of the following: analytical grade, chemically pure, and superior grade. The concentration of sulfuric acid can be set to 0.1–18.4 mol / L, for example, any one or any two of the following: 0.1 mol / L, 0.5 mol / L, 1 mol / L, 2 mol / L, 4 mol / L, 6 mol / L, 8 mol / L, 10 mol / L, 12 mol / L, 14 mol / L, 16 mol / L, 18 mol / L, and 18.4 mol / L.

[0129] Similarly, inactive sodium refers to sodium or sodium compounds that cannot participate in electrochemical reactions during battery charging and discharging. In sodium-ion batteries, inactive sodium mainly includes one or more of Na, NaH, Na2CO3, and organic sodium compounds. Typically, test samples containing these inactive sodiums include one or more of the electrodes and cells of sodium-ion batteries. These inactive sodiums can be titrated with a titration solution to generate gas, and therefore can be detected using the detection system of the embodiments of this application. For example, for Na and NaH, one or more of ethanol, deuterated ethanol, and heavy water can be used independently as titration solutions to react with Na or NaH to generate the test gas. For Na2CO3 and organic sodium compounds (taking NaEMC as an example), sulfuric acid can be used independently as titration solutions to react with Na2CO3 and NaEMC to generate the test gas.

[0130] The reactions that occur when titrating different inactive sodium components with titration solutions are shown in the table below.

[0131] [Table 2]

[0132]

[0133] Therefore, the sample to be tested may contain one or more of inactive lithium and inactive sodium. The detection system according to the embodiments of this application can detect inactive lithium, inactive sodium, etc., providing important information for battery research.

[0134] As mentioned earlier, inactive lithium, inactive sodium, etc. are usually present in electrodes. Therefore, the sample to be tested can include electrodes, such as one or more of the positive and negative electrodes of lithium-ion batteries, lithium metal batteries, and sodium-ion batteries.

[0135] Simultaneously, during the charging and discharging process, the electrodes of the battery react to generate gas. Therefore, the entire battery or cell can be placed in a reaction vessel as a test sample for detection. Typically, for ease of operation, the basic unit of the battery, the cell, can be used as the test sample and placed in the reaction vessel. Understandably, to facilitate cell charging and discharging, the reaction vessel needs to be equipped with terminals for contact with tabs. Equipment used for charging and discharging the cell can be connected to these terminals. Additionally, the reaction vessel can also include a pressurization structure to ensure tight contact between the interfaces within the cell during charging and discharging.

[0136] In some embodiments, the detection method further includes a step of purging air from the piping of the detection system. Purging air improves the stability of the sample to be tested, thereby increasing the accuracy of the detection.

[0137] Methods for removing air from the piping of the detection system include one or more of the following: 1) to 3)

[0138] 1) Connect the first port 103a of the first multi-port valve 103 to the second port 103b. In this way, the air in the passage from the first port 103a to the second port 103b → gas sampling module 200 → detection module 400 can be purged and cleared by the carrier gas provided by the gas source 101.

[0139] 2) Connect the first port 103a and the third port 103c of the first multi-port connecting valve 103, and connect the first port and the second port of the second multi-port connecting valve. In this way, the carrier gas provided by the gas source 101 can be used to purge and remove the air in the passage from the first port 103a to the third port 103c → the passage from the first port to the second port → the gas sampling module 200 → the detection module 400.

[0140] 3) Connect the first port 103a to the third port 103c of the first multi-port valve 103, connect the first port to the third port, and connect the second port to the fourth port. In this way, the carrier gas provided by the gas source 101 can be used to purge and remove the air in the passage from the first port 103a-third port 103c → the passage from the first port to the third port → the reaction vessel → the passage from the second port to the fourth port → the gas sampling module 200 → the detection module 400.

[0141] In some embodiments, the state of the first multi-way connection valve 103 includes state 1 and state 2. State 1 of the first multi-way connection valve 103 is: the first port 103a is connected to the third port 103c; State 2 is: the first port 103a is connected to the second port 103b.

[0142] The second multi-way connection valve has two states: state 1 and state 2. State 1 is when the first port is connected to the second port and the third port is connected to the fourth port; state 2 is when the first port is connected to the third port and the second port is connected to the fourth port.

[0143] Step S1 specifically includes:

[0144] S11: Connect the gas inlet of the reaction vessel to the third port of the second multi-way connection valve, connect the gas outlet of the reaction vessel to the fourth port of the second multi-way connection valve, and put the second multi-way connection valve in state 2.

[0145] The reaction vessel connected to the second multi-way valve is transferred into a protective atmosphere. Then, the sample to be tested is placed into the reaction vessel and the reaction vessel is sealed. The state of the second multi-way valve is then switched to state 1, and the second multi-way valve and the reaction vessel connected to it are transferred out of the protective atmosphere together.

[0146] S12: Set the first multi-way connection valve 103 to state 1, connect the first port of the second multi-way connection valve to the third port 103c of the first multi-way connection valve 103, and connect the second port of the second multi-way connection valve to the gas inlet pipe of the gas sampling module 200.

[0147] S13: Remove residual air from the pipeline;

[0148] S14: Switch the state of the first multi-way connection valve 103 to state 2, add reactants to the reaction vessel, and the reactants react with the sample to generate the gas to be tested. The reactants are usually a titration solution.

[0149] The sample to be tested is assembled in the reaction vessel using the method in step S11. The process of loading the sample to be tested into the reaction vessel is carried out in a protective atmosphere, which can isolate the sample to be tested from the air and maintain the chemical stability of the sample to be tested.

[0150] Meanwhile, during the process of connecting the reaction vessel containing the sample to be tested to the carrier gas purging gas path (step S12), the second multi-port connecting valve connected to the reaction vessel is in state 1, that is, the first port of the second multi-port connecting valve is connected to the second port, and the third port is connected to the fourth port, so that the reaction vessel is in a state of being connected end to end, which can keep the sample to be tested in the reaction vessel in a sealed environment and isolated from the air.

[0151] In addition, after connecting the reaction vessel and the second multi-way valve connected to it to the carrier gas purging gas path, the residual air in the pipeline is removed, so that even if the reaction vessel is subsequently connected to other pipelines, the sample to be tested will not come into contact with air and react.

[0152] Therefore, by using the above method to assemble the sample to be tested and allow it to react, the chemical stability of the sample can be maintained, preventing it from reacting with air and achieving air-free sample introduction, which is beneficial to improving the accuracy of detection.

[0153] In some embodiments, step S1 specifically includes:

[0154] S11': Connect the gas inlet of the reaction vessel to the third port of the second multi-way connection valve, connect the gas outlet of the reaction vessel to the fourth port of the second multi-way connection valve, and put the second multi-way connection valve in state 2.

[0155] The reaction vessel connected to the second multi-way valve is transferred into a protective atmosphere. Then, the sample to be tested is placed into the reaction vessel and the reaction vessel is sealed. The state of the second multi-way valve is switched to state 1, and then the second multi-way valve and the reaction vessel connected to it are transferred out of the protective atmosphere.

[0156] S12': Add reactants to the reaction vessel, and the reactants react with the sample to generate the gas to be tested;

[0157] S13': Set the first multi-way connection valve 103 to state 1, connect the first port of the second multi-way connection valve to the third port 103c of the first multi-way connection valve 103, and connect the second port of the second multi-way connection valve to the gas inlet pipe of the gas sampling module 200.

[0158] S14': Remove residual air from the pipeline.

[0159] After step S14', the process may include switching the state of the first multi-way connection valve 103 to state 2.

[0160] In addition to using steps S11 to S14 to assemble the test sample in the reaction vessel and allow it to react online, steps S11' to S14' can also be used. Steps S11' to S14' involve assembling the test sample into the reaction vessel, allowing it to react offline, and then connecting the reaction vessel and its connected second multi-way valve to the carrier gas purge path. The test gas generated from the offline reaction can be stored in the reaction vessel and the pipeline between it and the second multi-way valve. Because the reaction in the reaction vessel can be carried out offline, without requiring online reaction, the detection time can be flexibly adjusted according to the actual experimental situation. For example, when multiple test samples need to be detected, multiple test samples can be placed in an offline reaction vessel for reaction, and the test gas generated can be stored in the reaction vessel and the pipeline between it and the second multi-way valve. During the reaction of these test samples, samples that have completed the reaction can be detected, or other experiments can be arranged; or, if it is inconvenient to detect the test samples after the reaction is complete, the reaction vessel and its connected second multi-way valve can be set aside and detected when it is convenient. Compared to online reaction methods, this detection mode significantly reduces the time a single sample occupies the detection system, shortens the detection time, improves detection efficiency, and provides great convenience for experimental research.

[0161] In some embodiments, the detection method of this application further includes a step of stabilizing the baseline of the detection module 400. For example, when the detection module 400 includes a mass spectrometer, a step of stabilizing the mass spectrometry baseline is included. This step can be implemented by: setting the first multi-way connection valve to state 1 and setting the second multi-way connection valve to state 1 or state 2, causing the carrier gas provided by the gas source 101 to purge the pipeline and enter the detection module 400; and causing the detection module 400 to operate until the signals of each gas entering the detection module 400 are reduced to a sufficiently low level.

[0162] When the reaction in the reaction vessel is an online reaction (i.e., the reaction vessel is connected to the pipeline of the detection system before the reaction takes place), the second multi-way connection valve can be in state 1 or state 2 during the step of stabilizing the baseline of the detection module 400. When the reaction in the reaction vessel is an offline reaction (i.e., the reaction has already occurred in the reaction vessel without being connected to the pipeline of the detection system, and the reaction vessel is connected to the pipeline of the detection system during or after the reaction), the second multi-way connection valve is in state 1 during the step of stabilizing the baseline of the detection module 400.

[0163] When both the first and second multi-port valves are in state 1, the carrier gas purging path is: the first port 103a-third port 103c passage of the first multi-port valve 103 → the first port-second port passage of the second multi-port valve → the gas sampling module 200 → the detection module 400. When both the first and second multi-port valves are in state 2, the carrier gas purging path is: the first port 103a-third port 103c passage of the first multi-port valve 103 → the first port-third port passage of the second multi-port valve → the reaction vessel → the second port-fourth port passage of the second multi-port valve → the gas sampling module 200 → the detection module 400. A stable baseline facilitates the formation of accurate peak shape and area during subsequent detection of the analyte gas, reducing the signal-to-noise ratio and thus improving the accuracy and reliability of the detection.

[0164] The above steps can be performed before step S14, specifically after step S13 and before step S14; or they can be performed after step S14'.

[0165] In some embodiments, the step of reacting the sample to generate the gas to be tested includes:

[0166] A portion of the gas to be tested is delivered to the gas storage chamber, and the gas stored in the gas storage chamber is then delivered to the detection module 400 for testing.

[0167] In this embodiment, a portion of the gas to be tested is extracted and stored in a gas storage chamber. The composition of this portion of the gas to be tested is the same as that of all the gas to be tested generated in the reaction vessel. Therefore, the detection module 400 can be used to detect this portion of the gas to be tested to obtain a detection signal. Then, the amount of the sample to be tested can be obtained by using the standard curve between the amount of the standard corresponding to the sample to be tested and the detection signal.

[0168] Since it is not necessary to detect all the test gases during the detection process, but only a portion of them, the carrier gas can be used to bring that portion of the test gases into the detection module 400 for detection in a very short time. Compared with the injection method of using the carrier gas to bring all the test gases into the detection module 400, the injection time is significantly shortened, as is the analysis time of the test gases in the detection module 400. Therefore, the overall detection time is greatly saved and the detection efficiency is improved.

[0169] In some embodiments, step S2, the method of delivering the gas to be tested stored in the gas storage chamber to the detection module 400 for detection, includes: setting the first multi-way connection valve 103 to state 2, and using the carrier gas provided by the carrier gas module 100 to deliver the gas to be tested stored in the gas storage chamber into the detection module 400 for detection. The carrier gas provides power to the gas to be tested stored in the gas storage chamber, enabling it to enter the detection module 400.

[0170] It should be noted that in actual testing, a standard curve can be established using standard substances or standard gases of known mass or content, relating the amount of the standard substance or standard gas to the detection signal of the gas to be tested generated in the reaction. This allows for quantitative analysis of the sample to be tested based on the standard curve.

[0171] Example

[0172] The following describes embodiments of this application. The embodiments described below are exemplary and are only used to explain this application, and should not be construed as limiting this application. Where specific techniques or conditions are not specified in the embodiments, they are performed according to the techniques or conditions described in the literature in this field or according to the product instructions. Reagents or instruments used, unless otherwise specified, are all conventional products that can be obtained commercially.

[0173] Example 1

[0174] This embodiment provides an automated mass spectrometry titration detection system, such as... Figure 1 As shown, the detection system includes a carrier gas module 100, a gas sampling and injection module 200, two sets of reaction modules 300, a detection module 400, and a tail gas treatment module 500. The structure of these modules and their interconnections are as follows:

[0175] (1) The carrier gas module 100 includes a gas source (argon cylinder) 101, a flow meter (mass flow meter MFC) 102, and a first multi-way valve (specifically a three-way valve) 103 connected in sequence. The three-way valve 103 includes a first port 103a, a second port 103b, and a third port 103c, wherein the first port 103a is connected to the outlet pipeline of the flow meter 102. That is, the argon gas provided by the gas source 101 passes through the flow meter 102 and then enters the three-way valve 103 through the first port 103a.

[0176] (2) The gas sampling module 200 includes a multi-channel pulse injector 201. The multi-channel pulse injector 201 includes a metering loop with a gas storage chamber. Figure 1 (Not shown in the image), the intake pipe of the metering ring is connected to the second port 103b of the three-way valve 103.

[0177] (3) The two sets of reaction modules 300 are the first reaction module and the second reaction module, respectively.

[0178] The first reaction module includes a first titration cell 301 and a first constant temperature chamber. Figure 1 (Not shown in the diagram) A first four-way valve 302, a first titration cell 301 having an air inlet and an air outlet, the first titration cell 301 being disposed inside a first constant temperature chamber. The first four-way valve 302 includes a first interface 302a, a second interface 302b, a third interface 302c, and a fourth interface 302d, wherein the first interface 302a is connected to the third interface 303c, the second interface 302b is connected to the air inlet pipe of the metering loop, the third interface 302c is connected to the air inlet of the first titration cell 301, and the fourth interface 302d is connected to the air outlet of the first titration cell 301.

[0179] The second reaction module includes a second titration cell 303 and a second constant temperature chamber. Figure 1 (Not shown in the diagram) A second four-way valve 304 and a second titration cell 303 are provided with an air inlet and an air outlet, and the second titration cell 303 is located inside a second constant temperature chamber. The second four-way valve 304 includes a first interface 304a, a second interface 304b, a third interface 304c, and a fourth interface 304d, wherein the first interface 304a is connected to the third interface 304c, the second interface 304b is connected to the air inlet pipe of the metering loop, the third interface 304c is connected to the air inlet of the second titration cell 303, and the fourth interface 304d is connected to the air outlet of the second titration cell 303.

[0180] (4) The detection module 400 includes a cold trap 401 and a mass spectrometer 402. The gas inlet pipe of the cold trap 401 is connected to the gas outlet pipe of the multi-channel pulse sampler 201, and the gas inlet pipe of the mass spectrometer 402 is connected to the gas outlet pipe of the cold trap 401.

[0181] (5) The exhaust gas treatment module 500 includes a combustion unit, and the intake pipe of the combustion unit is connected to the exhaust pipe of the mass spectrometer 402.

[0182] Example 2

[0183] This embodiment uses the automated mass spectrometry titration detection system of Example 1 to quantitatively detect inactive lithium Li in the electrode.

[0184] It should be noted that during the testing process, the three-way valve 103 and the two four-way valves each have two states. Please refer to [the documentation / reference]. Figure 2 For the three-way valve 103, its state 1 is: the first port 103a is connected to the third port 103c; state 2 is: the first port 103a is connected to the second port 103b.

[0185] For a four-way valve, state 1 is: port 1 is connected to port 2, and port 3 is connected to port 4; state 2 is: port 1 is connected to port 3, and port 2 is connected to port 4. For more details, please refer to [reference needed]. Figure 3 For the first four-way valve 302, its state 1 is: the first port 302a is connected to the second port 302b, and the third port 302c is connected to the fourth port 302d; its state 2 is: the first port 302a is connected to the third port 302c, and the second port 302b is connected to the fourth port 302d. Similarly, for the second four-way valve 304, its state 1 is: the first port 304a is connected to the second port 304b, and the third port 304c is connected to the fourth port 304d; its state 2 is: the first port 304a is connected to the third port 304c, and the second port 304b is connected to the fourth port 304d.

[0186] In this embodiment, the volume of the first titration cell 301 and the second titration cell 303 is 25.12 mL, and the gas storage chamber volume of the quantitative loop in the multichannel pulse injector 201 is 0.5 mL.

[0187] I. Establishing a Standard Curve

[0188] Before detecting Li in the electrode, the entire detection system needs to be calibrated to establish a standard curve and obtain the direct relationship between the integral area of ​​the mass spectrum signal intensity of the analyte gas H2 generated after the Li titration reaction (the titration solution is ethanol) and the mass of Li.

[0189] A standard curve can be established using the external standard method, which may include the following steps:

[0190] (1) Sample assembly before testing

[0191] First, connect the air inlet pipe of the first titration cell 301 to the third port 302c of the first four-way valve 302 outside the glove box, connect the air outlet pipe of the first titration cell 301 to the fourth port 302d of the first four-way valve 302, and put the first four-way valve 302 in state 2.

[0192] Transfer the first four-way valve 302 and the first titration cell 301 connected to it into the glove box. Then, take the Li standard stored in the glove box out of the sealed bag (weighed to 0.54 mg using a balance) and place it into the first titration cell 301, ensuring that the first titration cell 301 is tightly sealed. Finally, switch the state of the first four-way valve 302 to state 1, and then transfer the first four-way valve 302 in state 1 and the first titration cell 301 connected to it out of the glove box.

[0193] Using the same method, the second titration cell 303 was connected to the second four-way valve 304, and 0.95 mg of Li standard was loaded into the second titration cell 303.

[0194] (2) Connect the titration cell to the carrier gas purging path.

[0195] After rotating the first titration cell 301 and the first four-way valve 302 (state 1) connected to it, as well as the second titration cell 303 and the second four-way valve 304 (state 1) connected to it out of the glove box, the three-way valve 103 is set to state 1. The first port 302a of the first four-way valve 302 and the first port 304a of the second four-way valve 304 are both connected to the third port 103c of the three-way valve 103. The second port 302b of the first four-way valve 302 and the second port 304b of the second four-way valve 304 are both connected to the air inlet pipe of the multi-channel pulse injector 201, thus completing the connection of the titration cell.

[0196] (3) Remove residual air from the pipeline.

[0197] A small amount of air will be introduced during the connection of the first four-way valve 302 and the second four-way valve 304 to the carrier gas path. After the first four-way valve 302 and the second four-way valve 304 are connected to the carrier gas path, the state of the three-way valve 103 should be kept in state 1, and the MFC should be turned on to keep the carrier gas (Ar) flow rate (20 mL / min) stable. At the same time, the multi-channel pulse injector 201 should be turned on to the sampling state. At this time, the carrier gas will be purged according to the following path: the first port 103a-third port 103c passage of the three-way valve 103 → the first port 302a-second port 302b passage of the first four-way valve 302 (the first port 304a-second port 304b passage of the second four-way valve 304) → multi-channel automatic pulse injector 201 → cold trap 401 → mass spectrometer 402. The purging should be continued for more than half an hour to remove the residual air in the pipeline.

[0198] (4) Mass spectral baseline of stable gases

[0199] After removing residual air from the pipeline, maintain a constant MFC flow rate (20 mL / min) and switch the first four-way valve 302 and the second four-way valve 304 to state 2. At this time, the carrier gas will pass through the first port 103a-third port 103c of the three-way valve 103 → the first port 302a-third port 302c of the first four-way valve 302 (the first port 304a-third port 304c of the second four-way valve 304) → the first titration cell 301 (the second titration cell 303) → the second port 302b-fourth port 302d of the first four-way valve 302 (the second port 304b-fourth port 304d of the second four-way valve 304) → the multi-channel automatic pulse injection 201 → the cold trap 401 and then reach the mass spectrometer 402. Turn on the online mass spectrometer and let the filament run for one hour until the ion current of m / z = 40 (representing Ar) is constant, and the signal of the ion current of each gas to be tested (for Li, titration is performed with ethanol, and the corresponding gas to be tested is H2, with an ion current of m / z = 2) drops to a sufficiently low value, so that a stable mass spectrometry baseline can be obtained for each gas.

[0200] (5) Start the titration experiment

[0201] After the mass spectrometry baseline stabilizes, switch the state of the multi-channel automatic pulse injection 201 to purge state and switch the state of the three-way valve 103 to state 2. At this time, the flow direction of the carrier gas becomes: the passage from the first port 103a to the second port 103b of the three-way valve 103 → multi-channel automatic pulse injection 201 → cold trap 401 → mass spectrometer 402. The carrier gas no longer flows through the first titration cell 301 (second titration cell 303). The first titration cell 301 (second titration cell 303) and the carrier gas, multi-channel automatic pulse injection 201... The connecting valves (first four-way valve 302 and second four-way valve 304) between 01 are both in the closed state. At this time, an excess of titration solution (ethanol) is injected into the first titration cell 301 (second titration cell 303), so that the titration solution reacts with the Li standard in the first titration cell 301 (second titration cell 303). The generated gas H2 will be stored in the first titration cell 301 (second titration cell 303) and the pipeline of the first four-way valve 302 (second four-way valve 304) connected to it.

[0202] (6) Measure the amount of each gas produced in the experiment.

[0203] After the reaction in the first titration cell 301 is completed, the carrier gas flow rate (20 mL / min) is kept constant, and the state of the multi-channel automatic pulse injection 201 is switched to the sampling state. At this time, the first titration cell 301 will be connected to the multi-channel automatic pulse injection 201 through the passage of the second port 302b-the fourth port 302d of the first four-way valve 302. The gas H2 to be tested stored in the first titration cell 301 and the pipeline of the first four-way valve 302 can be extracted by the multi-channel automatic pulse injection 201 and stored in its own quantitative loop. When the quantitative loop is full of gas, the gas in the quantitative loop will be sent to the online mass spectrometer 402 for detection by the carrier gas connected to the multi-channel automatic pulse injection 201. The online mass spectrometer 402 will record the signal of the ion current of the gas H2 to be tested and the change of its intensity over time during the entire experiment.

[0204] Similarly, after the reaction in the second titration cell 303 is completed, the same method as described above is used for detection.

[0205] (7) Complete the test

[0206] When the ion signal intensity of each gas completely decays and returns to the baseline, it means that all the analyte gas H2 extracted from the multi-channel automatic pulse injection 201 has been passed through the mass spectrometer 402 and detected. At this point, the mass spectrometer 402 can be stopped to complete the automatic titration detection of Li.

[0207] Based on the curve obtained by mass spectrometer 402, the signal area of ​​H2 is integrated (normalized with respect to Ar) to obtain the corresponding integrated area of ​​H2.

[0208] In addition, weigh 2.13 mg, 3.26 mg, 3.95 mg, and 5.23 mg of Li standard, and repeat steps (1) to (7) above to detect them, thereby obtaining a series of data points in which the H2 signal integral area corresponds one-to-one with the Li mass. Then, fit these data points to obtain the standard curve. The standard curve of Li mass versus H2 signal integral area is shown below. Figure 5 As shown.

[0209] II. Li mass in the detection electrode

[0210] The mass of Li in the negative electrode (specifically, copper foil) of a fully discharged lithium metal battery after 60 cycles was measured using the same method as described above for establishing the standard curve. The measurement method includes the following steps:

[0211] Step 1: Extract and clean the negative electrode

[0212] Disassemble the battery in a glove box, extract the negative electrode, and gently rinse it three times a minute in a small amount of dimethyl carbonate (DMC) to remove residual electrolyte and prevent residual ethylene carbonate from releasing CO2 during titration, which could affect the mass spectrometer's detection of CO2. After rinsing the negative electrode, seal and store it.

[0213] Step 2: Sample assembly before testing

[0214] Same as step (1) above.

[0215] Step 3: Connect the titration cell to the carrier gas purging line.

[0216] Same as step (2) above.

[0217] Step 4: Remove residual air from the pipeline

[0218] Same as step (3) above.

[0219] Step 5: Mass Spectrometry Baseline of the Stabilized Gas

[0220] Same as step (4) above.

[0221] Step Six: Begin the Titration Experiment

[0222] Same as step (5) above.

[0223] Step 7: Measure the amount of each gas produced in the experiment.

[0224] Same as step (6) above.

[0225] Step 8: Complete the test

[0226] Same as step (7) above.

[0227] Steps two to eight are similar to steps (1) to (7) above, except that the Li standard is replaced with the negative electrode. Since only one negative electrode sample is tested, only the first titration cell 301 and the first four-way valve 302 are used, and the second titration cell 303 and the second four-way valve 304 are not used.

[0228] Based on the obtained mass spectrum, the signal area of ​​H2 is integrated (normalized with respect to Ar) to obtain the corresponding integrated area of ​​H2. Substituting this integrated area into the standard curve equation and performing calculations, the Li mass in the negative electrode can be obtained.

[0229] Comparative Example 1

[0230] This comparative example uses a detection system based on existing technology to perform Li quality detection on the same negative electrode as in Example 2.

[0231] like Figure 6 As shown, the detection system includes an argon cylinder, a mass flow meter, a titration cell, a cold trap, and a mass spectrometer connected in sequence. The argon gas supplied by the argon cylinder can be purged along the path of the mass flow meter, titration cell, cold trap, and mass spectrometer. The argon cylinder, mass flow meter (MFC), titration cell, cold trap, and mass spectrometer are the same as those in Example 1 (same model or structure, same volume).

[0232] The method for detecting the Li mass in the negative electrode (specifically, copper foil) of a lithium metal battery that has been fully discharged after 60 cycles, similar to that in Example 2, using this detection system includes the following steps:

[0233] Step S01: Extract and clean the negative electrode

[0234] The same as step one in Example 2.

[0235] Step S02: Sample assembly before testing

[0236] Transfer the titration cell into the glove box, then remove the negative electrode from the sealed bag and place it into the titration cell, ensuring that the titration cell is tightly sealed. Finally, transfer the titration cell containing the negative electrode out of the glove box.

[0237] Step S03: Connect the titration cell to the carrier gas purging gas path.

[0238] Connect the inlet of the titration cell containing the negative electrode to the outlet pipe of the MFC, and connect the outlet of the titration cell to the inlet pipe of the cold trap to complete the connection of the titration cell.

[0239] Step S04: Remove residual air from the pipeline

[0240] Open the argon cylinder and purge the pipeline of the detection system continuously at a flow rate of 20 mL / min for more than half an hour to remove residual air from the pipeline.

[0241] Step S05: Mass Spectrometry Baseline of Stable Gas

[0242] After purging residual air from the tubing, maintain a constant MFC flow rate (20 mL / min). Turn on the online mass spectrometer and allow the filament to run for one hour until the ion current at m / z = 40 (representing Ar) becomes constant, and the ion current signals of each analyte gas (for Li, titration with ethanol is used, and the corresponding analyte gas is H2 with an ion current of m / z = 2) drop to sufficiently low values, thus obtaining stable mass spectrometry baselines for each gas.

[0243] Step S06: Begin the titration experiment

[0244] After the mass spectrometry baseline stabilizes, an excess of titration solution (ethanol) is injected into the titration cell to allow the titration solution to react with the Li contained in the negative electrode of the titration cell.

[0245] Step S07: Detect gas production during the reaction online until detection is complete.

[0246] After injecting the titration solution, maintain a constant carrier gas flow rate (20 mL / min). Use a mass spectrometer to detect the gas generated by the reaction between the titration solution and Li in the negative electrode. Record the signal of the ion current of the analyte gas H2 and its intensity change over time throughout the entire reaction process. When the ion signal intensity of each gas completely decays and returns to the baseline, it indicates that the reaction in the titration cell has been completed, and all the generated gases have been detected by the mass spectrometer. At this point, the mass spectrometer can be stopped, and the detection is complete.

[0247] Based on the mass spectrum obtained by the mass spectrometer, the signal area of ​​H2 is integrated (normalized with respect to Ar) to obtain the corresponding integrated area of ​​H2.

[0248] The negative electrode is replaced with a series of Li standards with gradient masses (0.5 mg, 1 mg, 2 mg, 3 mg, 4 mg, 5 mg; more specifically, 0.61 mg, 1.03 mg, 2.3 mg, 3.35 mg, 4.13 mg, 4.24 mg). Following steps S02-S07 above, a series of data points are obtained where the H2 signal integral area corresponds one-to-one with the Li mass. These data points are then fitted to obtain a standard curve. The standard curve of Li mass versus H2 signal integral area obtained using the detection system of this comparative example is shown below. Figure 7 As shown.

[0249] By substituting the H2 integral area obtained from the negative electrode detection into the standard curve equation, the mass of Li in the negative electrode can be obtained.

[0250] Test Result Analysis:

[0251] (1) Detection time

[0252] The time consumed in each stage of the Li quality detection process at the negative electrode in Example 2 and Comparative Example 1 is shown in the table below:

[0253] [Table 3]

[0254]

[0255] Note: The time for step six in Example 2 and step S06 in Comparative Example 1 both include the time from the start to the completion of the reaction.

[0256] Data shows that Comparative Example 1 required a total of 406 minutes to test a single negative electrode, which was a long testing time. In contrast, Example 2, using the detection system of Example 1, only required 132 minutes to test a single negative electrode, a reduction of approximately 67% in total time compared to Comparative Example 1, demonstrating a significant improvement in detection efficiency.

[0257] Analysis of the detection systems used in Example 2 and Comparative Example 1 reveals that the significant difference in detection time between the two is mainly due to the fact that in Comparative Example 1, the gas to be tested generated in the titration cell during the detection process needs to be completely purged into the mass spectrometer using a carrier gas. Since the total volume of the gas to be tested is large, it takes a long time for all of it to be purged into the mass spectrometer.

[0258] In contrast, Example 2 uses the detection system of Example 1. During the detection process, the analyte gas generated in the titration cell is partially extracted into the quantitative loop of the multi-channel pulse sampler. Therefore, the volume of analyte gas entering the mass spectrometer is significantly smaller than that in Comparative Example 1, thus reducing the injection time. Furthermore, it is understood that if the detection system of Example 1 is needed to detect multiple samples, multiple titration cells and the same number of four-way valves can be used. These titration cells and four-way valves are assembled, and the series of analyte samples are placed into different titration cells in a glove box. Then, the titration cells and four-way valves containing the analyte samples are removed from the glove box, and the titration solution is directly added to the titration cells for titration. After the titration reaction is complete, the titration cells and four-way valves are connected to the detection system, and then steps three, four, five, seven, and eight are performed sequentially. That is, for each analyte sample, steps one, two, and six can be performed offline without occupying the detection system, thereby improving the utilization rate of the detection system and increasing detection efficiency. Moreover, multiple titration cells containing different test samples can be connected to the detection system. After testing the first test sample, the other test sample can be tested by switching the pipeline, realizing continuous injection and detection of multiple test samples with high detection efficiency.

[0259] However, if the detection system of Comparative Example 1 is used to detect multiple samples, each sample needs to complete all steps from S01 to S07, which takes a long time and reduces the detection efficiency compared to the detection system of Example 1.

[0260] (2) Detection accuracy

[0261] The negative electrode detection results for Example 2 and Comparative Example 1 are as follows:

[0262] [Table 4]

[0263]

[0264] It can be seen that there are certain differences in the detection results of the same negative electrode Li mass in Example 2 and Comparative Example 1.

[0265] To verify the accuracy of the data, the same mass (weighed using a balance, 3.2000 mg, denoted as the theoretical mass) of Li standard was tested using the methods of Example 2 and Comparative Example 1, respectively. The two sets of experiments are designated as Experiment 1 (corresponding to the detection method of Example 2) and Experiment 2 (corresponding to the detection method of Comparative Example 1), respectively. The test results are as follows:

[0266] [Table 5]

[0267]

[0268] The experimental results show that Experiment 1, which tested the Li standard, had a smaller deviation from the theoretical mass than Experiment 2, and the test results were more accurate.

[0269] The main reason for this is that in Experiment 2, the sealed titration cell containing the sample to be tested (with its inlet and outlet connected) needs to be connected to the detection system first. Connecting the titration cell to the carrier gas system requires first disconnecting the inlet and outlet of the sealed titration cell, then connecting the inlet of the titration cell to the outlet of the carrier gas system, and finally connecting the outlet of the titration cell to the inlet of the mass spectrometer. If the inlet and outlet of the sealed titration cell are disconnected but the inlet is not yet connected to the outlet of the carrier gas system, air will enter the titration cell. The state of the sample in the titration cell will be affected by the incoming air, directly impacting the detection results. Experiment 1 used the detection system of Example 1. Before and immediately after connecting the sealed titration cell containing the sample to the detection system, the inlet of the titration cell was connected to the third port of the four-way valve, and the outlet of the titration cell was connected to the fourth port of the four-way valve (the four-way valve was in state 1). This ensured that the titration cell was in a closed state, preventing air from entering. Then, carrier gas was used to purge the system along the following path: the first port 103a-third port 103c of the three-way valve 103 → the first port 302a-second port 302b of the first four-way valve 302 → the multi-channel automatic pulse injection 201 → the cold trap 401 → the mass spectrometer 402. This process effectively removed residual air from all pipelines in the detection system. Even if the state of the four-way valve was subsequently changed to state 2, no air would enter the titration cell or any pipelines, achieving air-free sample injection and thus improving the accuracy of the detection.

[0270] It should be noted that this application is not limited to the above-described embodiments. The above embodiments are merely examples, and any embodiments with the same structure and effect as the technical concept within the scope of this application are included in the technical scope of this application. Furthermore, various modifications that can be conceived by those skilled in the art to the embodiments, and other ways of constructing by combining some of the constituent elements of the embodiments, without departing from the spirit of this application, are also included in the scope of this application.

Claims

1. A detection system, characterized in that, include: The carrier gas module (100) includes a gas source (101) and a first multi-way connection valve (103), wherein the first multi-way connection valve (103) includes at least a first interface (103a), a second interface (103b) and a third interface (103c); and the first interface (103a) is connected to the gas source (101); The gas sampling module (200) is provided with an inlet pipe and an outlet pipe; the inlet pipe of the gas sampling module (200) is connected to the second interface (103b); At least one set of reaction modules (300), each set of reaction modules (300) includes a second multi-port connecting valve and a reaction container for reacting the sample to generate the gas to be tested; the second multi-port connecting valve includes at least a first interface, a second interface, a third interface and a fourth interface, the first interface is connected to the third interface (103c), the second interface is connected to the gas inlet pipeline of the gas sampling module (200); the reaction container is provided with an inlet and an outlet, the inlet is connected to the third interface, and the outlet is connected to the fourth interface; The detection module (400) is provided with an air inlet pipe; the air inlet pipe of the detection module (400) is connected to the air outlet pipe of the gas sampling module (200).

2. The detection system according to claim 1, characterized in that, The first multi-way connection valve (103) includes an n-way valve, where n ≥ 3 and n is an integer.

3. The detection system according to claim 2, characterized in that, n is an integer between 3 and 10.

4. The detection system according to any one of claims 1 to 3, characterized in that, The gas sampling module (200) includes a sampler, which includes a gas metering device and a gas storage chamber. The gas storage chamber is provided with an inlet pipe, which is connected to the second interface (103b) and the second interface.

5. The detection system according to claim 4, characterized in that, The injector includes an autosampler.

6. The detection system according to any one of claims 1 to 5, characterized in that, The second multi-way connection valve includes an m-way valve, where m ≥ 4 and m is an integer.

7. The detection system according to claim 6, characterized in that, m is an integer between 4 and 10.

8. The detection system according to any one of claims 1 to 7, characterized in that, The number of reaction modules (300) is 1 to 50.

9. The detection system according to any one of claims 1 to 8, characterized in that, The reaction module (300) also includes a heating unit for heating the reaction vessel.

10. The detection system according to any one of claims 1 to 9, characterized in that, The detection system further includes an exhaust gas treatment module (500), which is provided with an intake pipe; the detection module (400) is provided with an exhaust pipe; the intake pipe of the exhaust gas treatment module (500) is connected to the exhaust pipe of the detection module (400).

11. A detection method, characterized in that, The detection using the detection system according to any one of claims 1 to 10 includes the following steps: The sample to be tested is placed in the reaction vessel, and the sample to be tested reacts to generate the gas to be tested. The gas to be tested is delivered to the gas sampling module (200), and the gas to be tested stored in the gas sampling module (200) is delivered to the detection module (400) for detection.

12. The detection method according to claim 11, characterized in that, The sample to be tested includes any sample that can react to generate gas.

13. The detection method according to claim 11 or 12, characterized in that, The sample to be tested contains one or more of the following: active metals, metal hydrides, inorganic carbonates, inorganic bicarbonates, organometallic compounds, and metal carbides.

14. The detection method according to claim 11 or 12, characterized in that, The sample to be tested contains one or more of inactive lithium and inactive sodium.

15. The detection method according to any one of claims 11 to 14, characterized in that, The detection system, as described in claim 4 or 5, further includes the following step after the step of causing the sample to react and generate the gas to be tested: A portion of the gas to be tested is delivered to the gas storage chamber, and the gas to be tested stored in the gas storage chamber is delivered to the detection module (400) for detection.

16. The detection method according to any one of claims 11 to 15, characterized in that, It also includes the step of removing air from the piping of the detection system.

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