Solid electrolyte detection method and system

Abstract

The invention discloses a solid electrolyte detection method and system. The method comprises the following steps: controlling gas to pass through a solid electrolyte, and determining parameters of the gas passing through the solid electrolyte; and determining a pore detection result of the solid electrolyte based on the gas parameters. According to the invention, the technical problem that the detection efficiency of pore detection is not ideal in the prior art is solved.

Description

Technical Field

[0001] The present application relates to the field of solid-state battery technology, and in particular to a solid-state electrolyte detection method and system. Background Art

[0002] Solid electrolytes are key materials for solid-state batteries, and the performance of solid electrolytes directly affects the performance of solid-state batteries. The permeability and tortuosity of solid electrolytes are important factors affecting their performance, both of which are related to the pore structure inside the solid electrolyte. Solid electrolytes with low permeability have fewer internal pores, higher density, and higher ionic conductivity. Tortuosity refers to the degree of curvature of the pores inside the solid electrolyte. Electrolytes with higher tortuosity will cause the ion transport path to become longer, thereby reducing the ion transport efficiency. Therefore, qualitatively and quantitatively characterizing the permeability and tortuosity of solid electrolytes is of great significance for studying the ion conduction of solid electrolytes and the performance of solid-state batteries.

[0003] In the related technologies, the pore structure inside the solid electrolyte is usually characterized by using a focused ion beam scanning electron microscope (FIB-SEM) or X-ray CT (Computed Tomography) equipment, so as to further evaluate its permeability and tortuosity. However, the above-mentioned related technologies have the problems of high cost, complex operation, long time consumption, high hardware requirements, etc., which limit the detection efficiency of pore detection of solid electrolytes.

[0004] To address the above-mentioned problems, no effective solution has been proposed yet. Summary of the invention

[0005] The embodiments of the present application provide a solid electrolyte detection method and system to at least solve the technical problem of unsatisfactory detection efficiency of pore detection in the related art.

[0006] According to one aspect of the embodiments of the present application, a solid electrolyte detection method is provided, including: controlling gas to pass through the solid electrolyte, determining gas parameters passing through the solid electrolyte; and determining the pore detection result of the solid electrolyte based on the gas parameters. Through a simple gas permeation test, combined with the gas parameters, the pore detection result is obtained, and an effective evaluation of the permeability and tortuosity of the solid electrolyte is achieved, which has the advantages of simple operation, low cost, and high efficiency.

[0007] Optionally, the pore detection result includes pore permeability and pore tortuosity, and the pore detection result is determined based on the gas parameter, including: determining the pore permeability based on the gas parameter, wherein the pore permeability is used to indicate the number of pores in the solid electrolyte; performing processing based on the pore permeability to obtain the pore tortuosity of the solid electrolyte, wherein the pore tortuosity is used to indicate the degree of curvature of the pores in the solid electrolyte. By measuring and analyzing the pore permeability and pore tortuosity, the performance of the solid electrolyte can be evaluated and optimized.

[0008] Optionally, the gas parameters include multiple pressure differences and pressure flows corresponding to the multiple pressure differences. Based on the gas parameters, the pore permeability is determined, including: performing linear fitting processing according to the multiple pressure differences and the pressure flows corresponding to the multiple pressure differences to obtain a fitting line representing the corresponding relationship between the pressure differences and the pressure flows; and determining the pore permeability based on the slope of the fitting line. The method of determining the pore permeability by linear fitting the pressure difference and pressure flow data provides an efficient permeability evaluation method for detecting the pore characteristics of solid electrolytes.

[0009] Optionally, performing linear fitting processing according to multiple air pressure differences and the air pressure flows corresponding to the multiple air pressure differences to obtain a fitting line representing the corresponding relationship between the air pressure differences and the air pressure flows includes: performing linear fitting processing according to multiple air pressure differences and the air pressure flows corresponding to the multiple air pressure differences to obtain a fitting line in the following manner:

[0010]

[0011] Among them, ΔP represents one of the multiple pressure differences, Q represents the pressure flow corresponding to one pressure difference, S is the cross-sectional area of ​​the solid electrolyte, δ is the thickness of the solid electrolyte, μ is the dynamic viscosity coefficient of the gas passing through the solid electrolyte, and k is the pore permeability. In the above manner, ΔP is changed to obtain multiple groups of ΔP and Q values ​​and data fitting is performed to obtain the slope of the graph, and then the permeability k of the solid electrolyte is obtained to improve the accuracy of the pore permeability test.

[0012] Optionally, the pore tortuosity of the solid electrolyte is obtained by processing according to the pore permeability, including: obtaining the density of the solid electrolyte and the average pore diameter on the surface of the solid electrolyte; and determining the pore tortuosity based on the density, the average pore diameter, and the pore permeability. Through the above processing, the pore tortuosity of the solid electrolyte is calculated in combination with the density, the average pore diameter, and the pore permeability of the solid electrolyte, so as to better understand the characteristics of its pore structure and the impact on the electrolyte performance.

[0013] Optionally, determining the pore tortuosity based on the density, the average pore diameter, and the pore permeability includes: determining the pore tortuosity based on the density, the average pore diameter, and the pore permeability by:

[0014]

[0015] Among them, k is the pore permeability, d is the average pore diameter, ρ is the density, and τ is the pore tortuosity. Through the above method, the pore tortuosity inside the solid electrolyte can be further calculated by the permeability of the solid electrolyte, which is conducive to obtaining accurate pore detection results.

[0016] Optionally, before controlling the gas to pass through the solid electrolyte and determining the gas parameters passing through the solid electrolyte, the method further includes: using a predetermined mold to press the solid electrolyte to obtain the solid electrolyte after pressing; before obtaining the density of the solid electrolyte and the average value of the pore diameter on the surface of the solid electrolyte, the method further includes: demolding the solid electrolyte from the predetermined mold. By demolding, the potential influence of the mold on the surface or internal structure of the solid electrolyte can be avoided, and the accuracy of the measurement results can be ensured.

[0017] Optionally, controlling the gas to pass through the solid electrolyte and determining the gas parameters passing through the solid electrolyte includes: controlling the gas to pass through the solid electrolyte, determining the pressure difference between the two ends of the solid electrolyte, and the pressure flow rate of the gas flowing out of the solid electrolyte; and determining the gas parameters based on the pressure difference and the pressure flow rate. Obtaining the gas parameters through the above processing is conducive to providing a data basis for the subsequent determination of the pore detection results.

[0018] According to another aspect of an embodiment of the present application, a solid electrolyte detection system is provided, comprising: a gas transmission device, a gas detection device, and a controller, wherein the gas transmission device is used to control the passage of gas through the solid electrolyte, the gas detection device is used to determine the gas parameters passing through the solid electrolyte, and the controller is used to determine the pore detection results of the solid electrolyte based on the gas parameters.

[0019] Optionally, the gas detection equipment includes an inlet pressure gauge, an outlet pressure gauge, and a flow meter, and a solid electrolyte is arranged in the test chamber, wherein one end of the inlet pressure gauge is connected to the gas transmission equipment, and the other end of the inlet pressure gauge is connected to the test chamber for detecting the pressure of the gas input into the test chamber, one end of the outlet pressure gauge is connected to the test chamber, and the other end of the outlet pressure gauge is connected to the flow meter for detecting the pressure of the gas flowing out of the test chamber, and the flow meter is used to detect the flow rate of the gas flowing out of the test chamber.

[0020] In the embodiment of the present application, a ventilation detection method is adopted to control the gas passing through the solid electrolyte to determine the gas parameters passing through the solid electrolyte; based on the gas parameters, the pore detection results of the solid electrolyte are determined. The purpose of quantitatively evaluating the pore characteristics of the solid electrolyte by ventilation means is achieved, and the technical effect of simplifying the pore structure characterization process and improving the test efficiency is achieved, thereby solving the technical problem of unsatisfactory detection efficiency of pore detection in related technologies. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0022] Figure 1 is a flow chart of an optional solid electrolyte detection method provided according to an embodiment of the present application;

[0023] Figure 2 is a fitting schematic diagram of an optional solid electrolyte detection method provided according to an embodiment of the present application;

[0024] Figure 3 is a structural block diagram of an optional solid electrolyte detection system provided according to an embodiment of the present application;

[0025] Figure 4 It is a schematic diagram of an optional solid electrolyte detection system provided according to an embodiment of the present application. DETAILED DESCRIPTION

[0026] In order to enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of this application.

[0027] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device comprising a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0028] For the convenience of description, some nouns or terms involved in the embodiments of the present application are explained below:

[0029] Solid-state batteries use solid electrolytes to replace the electrolytes and separators of traditional lithium batteries and are equipped with high-energy-density electrode materials. They can achieve higher energy density, wider electrochemical window, wider operating temperature range, better safety and cycle stability. They are the key development direction of safe, high-energy-density lithium-ion batteries in the future.

[0030] Pores. Pores in solid electrolytes refer to the spaces or gaps inside the electrolyte material. The presence of pores has an important influence on the performance of solid electrolytes, especially in terms of ion conduction and electrochemical window. The presence of pores affects the transmission path and efficiency of ions in the electrolyte. Pores can serve as channels for ion transmission, but they may also increase the transmission resistance of ions and reduce the transmission efficiency. The tortuosity of the pores (i.e., the degree of curvature of the pore channel) is also an important factor affecting the efficiency of ion transmission.

[0031] Electron microscopes (such as focused ion beam scanning electron microscopes) and X-ray CT technologies commonly used in related technologies can provide detailed internal morphology information when evaluating the pore structure of solid electrolytes, but they have obvious defects such as high cost, complex equipment, and cumbersome and time-consuming operation process. Although electron microscope technology can perform high-precision three-dimensional reconstruction, it requires strict experimental conditions and professional skills and is not suitable for large-scale or rapid testing. X-ray CT technology also requires high-resolution image acquisition and subsequent complex image analysis, which further increases the cost and testing difficulty. Especially when conducting batch testing, more efficient, low-cost and easy-to-operate evaluation methods are required, and the detection limitations of related technologies are particularly prominent.

[0032] In response to the above problems, an embodiment of the present application provides an embodiment of a method for solid electrolyte detection. It should be noted that the steps shown in the flowchart of the accompanying drawings can be executed in a computer system such as a set of computer executable instructions, and although a logical order is shown in the flowchart, in some cases, the steps shown or described can be executed in an order different from that shown here.

[0033] Figure 1 is a flow chart of an optional solid electrolyte detection method provided in an embodiment of the present application, such as Figure 1 As shown, the method comprises the following steps:

[0034] Step S102, controlling the gas to pass through the solid electrolyte and determining the gas parameters passing through the solid electrolyte;

[0035] It can be understood that by controlling the gas passing through the solid electrolyte and measuring the gas parameters (such as flow rate and pressure difference) when the gas passes through the solid electrolyte, basic data is provided for the calculation of subsequent pore measurement results (such as permeability and tortuosity). Complex imaging techniques such as electron microscopy or X-ray CT are avoided, thereby simplifying the test process and reducing the test cost.

[0036] Optionally, the solid electrolyte may include common inorganic solid electrolytes such as sulfides, oxides, and halides.

[0037] Optionally, the compressed gas used in the above-mentioned gas permeability treatment is an inert gas, including argon, nitrogen and other gases that do not react with the solid electrolyte sample to be tested, so as to ensure the accuracy of the test results.

[0038] In an optional embodiment, controlling the gas to pass through a solid electrolyte and determining the gas parameters passing through the solid electrolyte includes: controlling the gas to pass through the solid electrolyte and determining the gas pressure difference across the solid electrolyte and the gas pressure flow rate flowing out of the solid electrolyte; determining the gas parameters based on the gas pressure difference and the gas pressure flow rate.

[0039] It can be understood that the gas is directed to one side of the solid electrolyte and allowed to pass through the solid electrolyte. The solid electrolyte plays a permeable role, allowing gas molecules to pass through. In the process of gas passing through the solid electrolyte, the air pressure on both sides of the solid electrolyte will change due to the flow of gas. The air pressure difference on both sides of the solid electrolyte can be measured and recorded by air pressure detection equipment (such as a barometer). The air pressure difference at both ends reflects the resistance and flow rate of the gas when passing through the solid electrolyte. The permeation rate of gas in the solid electrolyte is used to evaluate the connectivity and size distribution of the pores. Larger pores and higher connectivity generally lead to faster permeation rates. Through the above processing, the gas parameters obtained are conducive to providing a data basis for the subsequent determination of the pore detection results.

[0040] Optionally, different gases and test conditions will have different effects on the pore characteristics of the solid electrolyte. Therefore, it is necessary to select appropriate test methods and conditions according to specific needs, conduct repeated tests on gas parameters, and use fitting methods to obtain pore permeability with higher accuracy.

[0041] Optionally, the solid electrolyte is pressed into a block in a mold, compressed gas is introduced into the mold, and the gas pressure flowing into the electrolyte block (denoted as P1) and the gas pressure flowing out (denoted as P2) are measured by a gas pressure gauge. The gas pressure difference (P1-P2) across the electrolyte is ΔP, and a flow meter is used to measure the outflowing gas flow rate Q.

[0042] Optionally, there is a Klinkenberg effect, also called slippage effect or Klinkenberg diffusion, in compressed gas passing through a solid electrolyte. It describes a phenomenon in which, in a porous medium (such as a solid electrolyte), when the gas pressure drops to a certain level, the interaction between the gas molecules and the pore walls weakens, causing the flow velocity of the gas molecules in the pores to no longer completely follow Darcy's Law.

[0043] Step S104, determining the pore detection result of the solid electrolyte based on the gas parameters.

[0044] It can be understood that through a simple gas permeability test combined with gas parameters, the pore detection results are obtained, which realizes the effective evaluation of the permeability and tortuosity of the solid electrolyte, and has the advantages of simple operation, low cost and high efficiency.

[0045] In an optional embodiment, the pore detection results include pore permeability and pore tortuosity. The pore detection results are determined based on gas parameters, including: determining the pore permeability based on the gas parameters, wherein the pore permeability is used to indicate the number of pores in the solid electrolyte; and processing according to the pore permeability to obtain the pore tortuosity of the solid electrolyte, wherein the pore tortuosity is used to indicate the degree of curvature of the pores in the solid electrolyte.

[0046] It can be understood that by controlling the gas to pass through the solid electrolyte and measuring relevant gas parameters, such as gas pressure difference, gas pressure flow rate, etc. Using these gas parameters, the pore permeability of the solid electrolyte can be calculated by combining Darcy's Law or its modified form, as well as possible empirical formulas or theoretical models. Pore permeability reflects the difficulty of gas passing through the pores in the solid electrolyte, and indirectly indicates the number and connectivity of the pores. The higher the pore permeability, the easier it is for the gas to pass through the solid electrolyte, which usually means that there are more pores in the solid electrolyte or the pore connectivity is better. On the basis of obtaining the pore permeability, the path and efficiency of gas transmission in the solid electrolyte are further analyzed. By comparing the actual gas transmission rate with the theoretical transmission rate when the pore is assumed to be a straight channel, the tortuosity of the pore can be estimated. The tortuosity represents the ratio of the actual pore path length to the straight path length, reflecting the degree of curvature of the pore. The greater the pore tortuosity, the more curved the pore path is, and the gas needs to bypass more obstacles during the transmission process, which will increase the resistance and time of the transmission.

[0047] Pore ​​permeability and pore tortuosity are two important parameters that describe the pore characteristics of solid electrolytes, and together reflect the number, connectivity, and tortuosity of pores in solid electrolytes. The performance of solid electrolytes can be evaluated and optimized by measuring and analyzing pore permeability and pore tortuosity. For example, in the fields of batteries, gas separation membranes, etc., increasing pore permeability and reducing pore tortuosity can help improve the transmission efficiency and performance of materials.

[0048] In an optional embodiment, the gas parameters include multiple air pressure differences and air pressure flow rates corresponding to the multiple air pressure differences. Based on the gas parameters, the pore permeability is determined, including: performing linear fitting processing according to the multiple air pressure differences and the air pressure flow rates corresponding to the multiple air pressure differences to obtain a fitting line representing the corresponding relationship between the air pressure differences and the air pressure flow rates; and determining the pore permeability based on the slope of the fitting line.

[0049] It can be understood that in order to determine the pore permeability of the material, a series of air pressure flow rates under different air pressure differences are collected, and then these data are used to fit the permeability characteristics of the pores. Linear fitting is a mathematical method for finding the straight line (i.e., "fitting line") that best fits the data points. This straight line can roughly represent the relationship between the air pressure difference and the air pressure flow rate. In the flow of gas through a porous medium, permeability is a physical quantity that measures the difficulty of the medium to allow fluid to pass through. Under the framework of Darcy's law, the air pressure flow rate is proportional to the air pressure gradient (i.e., the air pressure difference divided by the distance), and the proportionality coefficient is related to the permeability. Therefore, in this embodiment, the slope of the fitting line obtained by linear fitting (denoted as k) can be regarded as a parameter related to permeability, which is used to indirectly reflect the level of pore permeability: the larger the slope, the greater the gas flow rate under a given air pressure difference, thereby characterizing the higher the permeability of the pore. Based on the slope k of the fitting line, the pore permeability is determined. The method of determining the pore permeability by linear fitting of the air pressure difference and the air pressure flow data provides an efficient permeability evaluation method for detecting the pore characteristics of solid electrolytes.

[0050] Optionally, a straight line equation is calculated during the fitting process, which describes the linear relationship between the pressure difference (ΔP, corresponding to the x-axis) and the pressure flow (Q, corresponding to the y-axis), usually in the form of Q=kΔP+b, where k is the slope of the straight line and b is the intercept on the y-axis.

[0051] In an optional embodiment, a linear fitting process is performed according to a plurality of air pressure differences and the air pressure flows corresponding to the plurality of air pressure differences to obtain a fitting line representing the corresponding relationship between the air pressure differences and the air pressure flows, including: a linear fitting process is performed according to a plurality of air pressure differences and the air pressure flows corresponding to the plurality of air pressure differences to obtain a fitting line in the following manner:

[0052]

[0053] Among them, ΔP represents a pressure difference among multiple pressure differences, Q represents the pressure flow corresponding to one pressure difference, S is the cross-sectional area of ​​the solid electrolyte, δ is the thickness of the solid electrolyte, μ is the dynamic viscosity coefficient of the gas passing through the solid electrolyte, and k is the pore permeability.

[0054] It can be understood that in order to take into account the Klinkenberg effect, Darcy's law needs to be modified. To reflect the effect of the interaction between gas molecules and the pore wall on the gas flow rate. The above mathematical expression takes into account the Klinkenberg effect of compressed gas passing through the solid electrolyte, and uses the modified Darcy's law to describe the relationship between the gas flow rate Q and the pressure difference ΔP across the electrolyte. In order to fit the accuracy, the above thickness δ uses the demolding measurement of the solid electrolyte to calculate its cross-sectional area S. Change ΔP to obtain multiple sets of ΔP and Q values ​​and perform data fitting to verify their linear relationship. According to the slope of the fitted graph, the permeability k of the solid electrolyte is calculated by the above formula to improve the accuracy of the pore permeability test.

[0055] Optionally, before fitting, the data is preprocessed to eliminate noise and outliers. This can be achieved by filtering, smoothing, or removing data points that do not meet expectations. Select a suitable fitting model based on the data characteristics and specific testing requirements. For example, for the relationship between performance parameters such as pore permeability and test conditions, linear regression, polynomial regression, nonlinear regression and other models can be used for fitting.

[0056] In an optional embodiment, the pore tortuosity of the solid electrolyte is obtained by processing based on the pore permeability, including: obtaining the density of the solid electrolyte and the average pore diameter on the surface of the solid electrolyte; and determining the pore tortuosity based on the density, the average pore diameter, and the pore permeability.

[0057] It can be understood that in order to obtain the pore tortuosity of the solid electrolyte, it is necessary to combine the pore permeability, the density of the solid electrolyte and the average pore diameter on the surface of the solid electrolyte for calculation. Pore tortuosity is a parameter that describes the complexity of the fluid channel in the pore structure, which affects the flow efficiency of the fluid in the pore and the tortuosity of the path. According to the density of the solid electrolyte, the average pore diameter on the surface of the solid electrolyte, and the pore permeability, the pore tortuosity can be finally obtained. Through the above processing, the pore tortuosity of the solid electrolyte is calculated in combination with the density of the solid electrolyte, the average pore diameter and the pore permeability, so as to better understand the characteristics of its pore structure and its impact on the electrolyte performance.

[0058] In an optional embodiment, the pore tortuosity is determined based on the density, the average pore diameter, and the pore permeability in the following manner:

[0059]

[0060] Among them, k is the pore permeability, d is the average pore diameter, ρ is the density, and τ is the pore tortuosity.

[0061] It can be understood that the permeability of the solid electrolyte is further used to calculate the internal pore tortuosity τ, the density of the solid electrolyte is calculated, and the average pore size (i.e., the average pore diameter) of the solid electrolyte after demolding is measured and calculated. The relationship between the pore permeability of the solid electrolyte and its pore tortuosity τ satisfies the Kozeny-Carman equation. In the field of porous media, the Kozeny-Kalman equation assumes that the pore structure is uniform and isotropic, which can be used to estimate its permeability and further analyze its impact on ion conductivity. The mathematical relationship between the average pore size d of the pores and the density ρ of the solid electrolyte, as well as the pore tortuosity τ can be expressed in the above way. Among them, 72 is an empirical constant, also called the Kozeny-Carman constant, and the specific value may vary depending on the experimental conditions.

[0062] Optionally, the solid electrolyte density ρ is calculated from the mass and volume of the electrolyte, the mass of the solid electrolyte is M, the inner diameter of the mold for pressing the solid electrolyte is D, the thickness of the electrolyte is δ, and the density ρ is calculated based on the following formula:

[0063]

[0064] After demoulding, a scanning electron microscope photograph is taken of the solid electrolyte. The surface pores are observed in the electron microscope image, and the diameter of each pore is measured and the average value d is calculated. d can be approximately regarded as the average pore size of the pores inside the solid electrolyte.

[0065] Optionally, the thickness of the solid electrolyte may be detected in a variety of ways, for example, by a screw micrometer or a thickness gauge.

[0066] In an optional embodiment, before controlling the passage of gas through the solid electrolyte and determining the gas parameters passing through the solid electrolyte, the method further includes: using a predetermined mold to press the solid electrolyte to obtain a pressed solid electrolyte; before obtaining the density of the solid electrolyte and the average value of the pore diameter on the surface of the solid electrolyte, the method further includes: demolding the solid electrolyte from the predetermined mold.

[0067] It can be understood that before the compressed gas is introduced, the solid electrolyte is pressed using a predetermined mold in order to change the morphology and internal structure of the solid electrolyte through external pressure, which may help to improve its density, reduce the irregularity of the pores, or adjust its thickness and shape to meet the detection requirements. Before measuring the thickness, cross-sectional area, and average pore diameter of the solid electrolyte, demolding is required. By demolding, the potential influence of the mold on the surface or internal structure of the solid electrolyte can be avoided, ensuring the accuracy of the measurement results.

[0068] Optionally, the preparation pressure range of the above-mentioned solid electrolyte is 50-1000 MPa (megapascals). The greater the pressing pressure, the higher the density of the solid electrolyte block, and the smaller the number and diameter of the internal pores.

[0069] Through the above step S102, the gas is controlled to pass through the solid electrolyte to determine the gas parameters passing through the solid electrolyte; step S104, based on the gas parameters, the pore detection results of the solid electrolyte are determined. The purpose of quantitatively evaluating the pore characteristics of the solid electrolyte by ventilation means is achieved, and the technical effect of simplifying the pore structure characterization process and improving the test efficiency is achieved, thereby solving the technical problem of unsatisfactory detection efficiency of pore detection in related technologies.

[0070] Based on the above embodiments and optional embodiments, the present application proposes an optional implementation method for performing pore detection on LPSC (chemical formula Li6PS5Cl) solid electrolyte, which is a sulfide solid electrolyte. First, a certain amount of Li6PS5Cl solid electrolyte is weighed and placed in a mold with an inner diameter of D=10 mm (millimeter), and pressed into a block at a pressure of 500 MPa for 10 minutes (minutes).

[0071] Transfer the mold to the test cavity, conduct a gas permeability test, connect the argon bottle, open the valve to let in argon, adjust the pressure of the pressure reducing valve to the inlet standard pressure indication of 5psi (pounds per square inch), and pre-ventilate for 30 minutes to remove the residual gas in the sample. Then adjust the inlet pressure indication to 10psi, maintain for 10 minutes, record the outlet pressure indication, calculate the difference between the inlet pressure gauge and the outlet pressure gauge as ΔP1, and record the gas flow meter indication as Q1. Similarly, make multiple adjustments, control the inlet pressure indication to 20psi, calculate and record the pressure difference ΔP2 and flow Q2, then adjust the inlet pressure indication to 30psi, 40psi and 50psi in turn, calculate and record the values ​​of ΔP3, ΔP4, ΔP5 and Q3, Q4, Q5.

[0072] Figure 2 is a fitting schematic diagram of an optional solid electrolyte detection method provided in an embodiment of the present application. The above series of gas pressure differences ΔP and outlet flow Q values ​​are fitted to obtain the following: Figure 2 The corresponding relationship is shown, the slope of the graph is calculated, and the permeability k of the solid electrolyte is calculated by Darcy's law formula:

[0073]

[0074] Among them, S is the cross-sectional area of ​​the mold, and the cross-sectional area of ​​a 10mm inner diameter mold is 78.5mm 2 , μ is the dynamic viscosity coefficient of argon, which is 2.23x10 -5Pa·s (Pascal seconds). δ is the thickness of the solid electrolyte, which is measured by demolding the electrolyte block after testing with a screw micrometer.

[0075] Weigh the mass of the solid electrolyte after demoulding as M, and calculate the density of the solid electrolyte ρ:

[0076]

[0077] The surface of the solid electrolyte after demolding is subjected to SEM testing to measure the diameter of the surface pores, and the average pore diameter (which can be referred to as pore diameter) is calculated as d. Substituting the values ​​of density ρ and pore diameter d into the following Kozeny-Kalman equation, it can be expressed in the following way:

[0078]

[0079] Through the above-mentioned treatment, the pore tortuosity τ of the solid electrolyte can be obtained.

[0080] It should be noted that the above optional implementation can be similarly applied to the oxide solid electrolyte LLZO (compound Li7La3Zr2O 12 ), is a garnet-type solid electrolyte.

[0081] The above optional implementation method achieves at least the following effects: the permeability and tortuosity of the solid electrolyte are detected by gas permeability. Compared with the commonly used FIB-SEM method, X-ray CT imaging combined with three-dimensional structure reconstruction and other methods, the method provided by the embodiment of the present application is simple to operate, low cost, short time consumption, low hardware requirements, simple data processing, high test efficiency, and can quantitatively describe the permeability and tortuosity of the solid electrolyte. It is suitable for quantitative testing of solid electrolyte samples with low requirements on the internal pore morphology structure. It can provide guidance for the development and design of solid electrolyte materials, such as evaluating the corresponding relationship between the preparation pressure of inorganic solid electrolytes and their permeability and electrolyte conductivity, and adjusting the structure-activity relationship of the material to determine the structural design and preparation process parameters of the solid electrolyte that meet the performance requirements.

[0082] It should be noted that the steps shown in the flowcharts of the accompanying drawings can be executed in a computer system such as a set of computer executable instructions, and that, although a logical order is shown in the flowcharts, in some cases, the steps shown or described can be executed in an order different from that shown here.

[0083] A solid electrolyte detection system is also provided in an embodiment of the present application. The solid electrolyte detection system provided in the embodiment of the present application is introduced below.

[0084] Figure 3 is a structural block diagram of a solid electrolyte detection system provided in an embodiment of the present application, such as Figure 3 As shown, the system includes: a gas transmission device 302, a gas detection device 304, and a controller 306, wherein the gas transmission device 302 is used to control the gas passing through the solid electrolyte, the gas detection device 304 is used to determine the gas parameters passing through the solid electrolyte, and the controller 306 is used to determine the pore detection results of the solid electrolyte based on the gas parameters.

[0085] It can be understood that the main function of the gas transmission device 302 is to control the gas passing through the solid electrolyte. In this process, it is responsible for introducing the gas from the source end and ensuring that the gas can flow through the solid electrolyte stably and efficiently through appropriate pressure and flow control. As a medium for gas transmission, the characteristics and state of the solid electrolyte have an important influence on the transmission efficiency and effect of the gas. The gas detection device 304 is used to determine the gas parameters passing through the solid electrolyte. The above-mentioned gas parameters may include gas pressure (pressure difference), as well as gas, etc., and the above-mentioned gas parameters are transmitted to the controller 306 for further processing. The controller 306 determines the pore detection results of the solid electrolyte based on the gas parameters provided by the gas detection device 304, thereby evaluating the pore structure, permeability and other related properties of the solid electrolyte. Through the above-mentioned processing, the gas transmission device 302, the gas detection device 304 and the controller 306 constitute a solid electrolyte detection system, and through collaborative work, an efficient and accurate evaluation of the pore performance of the solid electrolyte is achieved.

[0086] In a solid electrolyte detection system provided in an embodiment of the present application, a gas transmission device 302, a gas detection device 304, and a controller 306 are used, wherein the gas transmission device 302 is used to control the gas passing through the solid electrolyte, the gas detection device 304 is used to determine the gas parameters passing through the solid electrolyte, and the controller 306 is used to determine the pore detection results of the solid electrolyte based on the gas parameters. The purpose of quantitatively evaluating the pore characteristics of the solid electrolyte by ventilation means is achieved, and the technical effect of simplifying the pore structure characterization process and improving the test efficiency is achieved, thereby solving the technical problem of unsatisfactory detection efficiency of pore detection in related technologies.

[0087] As an optional embodiment, the gas detection equipment includes an inlet pressure gauge, an outlet pressure gauge, and a flow meter, and the solid electrolyte is arranged in the test chamber, wherein one end of the inlet pressure gauge is connected to the gas transmission equipment, and the other end of the inlet pressure gauge is connected to the test chamber for detecting the pressure of the gas input into the test chamber, one end of the outlet pressure gauge is connected to the test chamber, and the other end of the outlet pressure gauge is connected to the flow meter for detecting the pressure of the gas flowing out of the test chamber, and the flow meter is used to detect the flow rate of the gas flowing out of the test chamber.

[0088] It can be understood that by integrating the inlet pressure gauge, the outlet pressure gauge and the flow meter, the flow state of the gas in the test chamber and its related parameters can be accurately measured and detected. One end of the inlet pressure gauge is connected to the gas transmission equipment, and the other end is connected to the test chamber, which is used to measure and display the initial air pressure of the gas input into the test chamber, and determine the air pressure of the gas before entering the test chamber. The test chamber is a place where the gas interacts with the solid electrolyte, and the solid electrolyte is arranged in the test chamber. The test chamber needs to have good sealing and stability to ensure the accuracy of the test results. At the same time, the above-mentioned test chamber can be designed to facilitate the installation and maintenance of the solid electrolyte. One end of the outlet pressure gauge is connected to the test chamber, and the other end is connected to the flow meter to measure and display the air pressure of the gas flowing out of the test chamber. By comparing the inlet and outlet pressures, the change of air pressure during the passage of the gas through the test chamber can be evaluated, and then the effect of the solid electrolyte on the gas can be analyzed. The flow meter is connected downstream of the outlet pressure gauge to measure and display the flow rate of the gas flowing out of the test chamber, and provide detection data on the gas flow rate (i.e., the volume of gas passing per unit time).

[0089] Optionally, the above-mentioned solid electrolyte detection system can be applied to batch detection of solid electrolytes. By setting up multiple test chambers, the controller can handle the parallel operation of multiple test chambers. The controller should be integrated into one or more gas cylinder control valves, which can automatically open or close the gas cylinders as needed to provide the required gas to each test chamber. Support preset gas flow and pressure to ensure that each test chamber obtains stable and consistent gas input conditions during the detection process. The controller also has multi-channel gas pressure detection capabilities and can simultaneously connect and read data from multiple inlet and outlet pressure gauges. The inlet and outlet gas pressure data of each test chamber should be recorded and processed independently for subsequent analysis and comparison. The controller can also automatically read flow data from the flow meter of each test chamber to ensure real-time and accurate acquisition of gas flow information. During the batch detection process, the controller should be able to automatically switch test chambers to ensure that each solid electrolyte can be fully detected and evaluated. The controller should have a built-in data processing and analysis module that can process data from each test chamber in real time and generate a preliminary analysis report. Support data filtering, sorting, comparison and visual display functions to help users quickly understand the performance differences and changing trends of solid electrolytes.

[0090] Based on the above embodiments and optional embodiments, the present application proposes an optional implementation manner. Figure 4 is a schematic diagram of an optional solid electrolyte detection system provided according to an embodiment of the present application, such as Figure 4As shown, it is composed of a gas cylinder, a gas transmission device, a test chamber, an inlet pressure gauge, an outlet pressure gauge and a flow meter. The gas transmission device includes a gas cylinder and a pressure reducing valve. The gas cylinder stores gas, which is usually an inert gas such as argon to avoid chemical effects on the solid electrolyte. The gas transmission device controls the gas to flow from the gas cylinder to the test chamber via the pressure reducing valve, wherein the gas passes through the solid electrolyte sample arranged in the test chamber.

[0091] The inlet pressure gauge and the outlet pressure gauge are located at both ends of the solid electrolyte, respectively, and are used to measure the pressure of the gas before and after passing through the solid electrolyte. The reading P1 of the inlet pressure gauge indicates the initial pressure of the gas flowing into the solid electrolyte, while the reading P2 of the outlet pressure gauge reflects the pressure of the gas after it flows out of the solid electrolyte. By comparing P1 and P2, the pressure difference ΔP can be calculated, which is an important parameter for evaluating the pore permeability of the solid electrolyte. The gas flowmeter is located after the outlet pressure gauge and is used to measure the gas flow rate Q flowing out of the solid electrolyte. After obtaining multiple sets of ΔP and Q values, the relationship between ΔP and Q can be analyzed through data fitting, which can help determine the pore permeability k of the solid electrolyte, and then determine the pore tortuosity τ.

[0092] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the present application may adopt the form of a computer program product implemented in one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) that include computer-usable program code.

[0093] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0094] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0095] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0096] In a typical configuration, a computing device includes one or more processors (CPU), input / output interfaces, network interfaces, and memory.

[0097] The memory may include non-permanent memory in a computer-readable medium, random access memory (RAM) and / or non-volatile memory in the form of read-only memory (ROM) or flash RAM. The memory is an example of a computer-readable medium.

[0098] Computer readable media include permanent and non-permanent, removable and non-removable media that can be implemented by any method or technology to store information. Information can be computer readable instructions, data structures, program modules or other data. Examples of computer storage media include, but are not limited to, phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technology, compact disk read-only memory (CD-ROM), digital versatile disk (DVD) or other optical storage, magnetic cassettes, magnetic tape disk storage or other magnetic storage devices or any other non-transmission media that can be used to store information that can be accessed by a computing device. As defined herein, computer readable media does not include temporary computer readable media (transitory media), such as modulated data signals and carrier waves.

[0099] It should also be noted that the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, commodity or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, commodity or device. In the absence of more restrictions, the elements defined by the sentence "comprises a ..." do not exclude the existence of other identical elements in the process, method, commodity or device including the elements.

[0100] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment or an embodiment in combination with software and hardware. Moreover, the present application may adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) that contain computer-usable program code.

[0101] The above are only embodiments of the present application and are not intended to limit the present application. For those skilled in the art, the present application may have various changes and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included within the scope of the claims of the present application.

Claims

1. A solid electrolyte detection method, characterized in that: include: Controlling the passage of gas through the solid electrolyte and determining gas parameters passing through the solid electrolyte; Based on the gas parameters, a pore detection result of the solid electrolyte is determined.

2. The method according to claim 1, characterized in that The pore detection result includes pore permeability and pore tortuosity, and the pore detection result is determined based on the gas parameter, including: Determining the pore permeability based on the gas parameter, wherein the pore permeability is used to represent the amount of pores in the solid electrolyte; The pore permeability is processed to obtain the pore tortuosity of the solid electrolyte, wherein the pore tortuosity is used to indicate the degree of curvature of the pores in the solid electrolyte.

3. The method according to claim 2, characterized in that The gas parameters include a plurality of pressure differences and pressure flow rates corresponding to the plurality of pressure differences. The pore permeability is determined based on the gas parameters, including: According to the plurality of air pressure differences and the air pressure flows corresponding to the plurality of air pressure differences, a linear fitting process is performed to obtain a fitting line representing a corresponding relationship between the air pressure differences and the air pressure flows; Based on the slope of the fitted line, the pore permeability is determined.

4. The method according to claim 3, characterized in that The method of performing linear fitting processing according to the plurality of air pressure differences and the air pressure flows corresponding to the plurality of air pressure differences to obtain a fitting line representing the corresponding relationship between the air pressure differences and the air pressure flows comprises: According to the multiple air pressure difference values ​​and the air pressure flow rates corresponding to the multiple air pressure difference values, a linear fitting process is performed to obtain the fitting line in the following manner: Among them, ΔP represents one of the multiple pressure differences, Q represents the pressure flow corresponding to the one pressure difference, S is the cross-sectional area of ​​the solid electrolyte, δ is the thickness of the solid electrolyte, μ is the dynamic viscosity coefficient of the gas passing through the solid electrolyte, and k is the pore permeability.

5. The method according to claim 2, characterized in that: The processing according to the pore permeability to obtain the pore tortuosity of the solid electrolyte includes: Obtaining the density of the solid electrolyte and the average value of the pore diameter on the surface of the solid electrolyte; The pore tortuosity is determined based on the density, the average pore diameter, and the pore permeability.

6. The method according to claim 5, characterized in that The determining of the pore tortuosity based on the density, the average pore diameter, and the pore permeability comprises: Based on the density, the average pore diameter, and the pore permeability, the pore tortuosity is determined in the following manner: Wherein, k is the pore permeability, d is the average pore diameter, ρ is the density, and τ is the pore tortuosity.

7. The method according to claim 5, characterized in that Before controlling the gas to pass through the solid electrolyte and determining the gas parameters passing through the solid electrolyte, the method further includes: using a predetermined mold to press the solid electrolyte to obtain a solid electrolyte after pressing; Before obtaining the density of the solid electrolyte and the average value of the pore diameter on the surface of the solid electrolyte, the method further includes: demolding the solid electrolyte from the predetermined mold.

8. The method according to any one of claims 1 to 7, characterized in that The controlling gas to pass through the solid electrolyte and determining the gas parameters passing through the solid electrolyte include: Controlling gas to pass through the solid electrolyte, determining the gas pressure difference across the solid electrolyte, and the gas pressure flow rate out of the solid electrolyte; The gas parameter is determined based on the gas pressure difference and the gas pressure flow.

9. A solid electrolyte detection system, characterized in that: include: A gas transmission device, a gas detection device, and a controller, wherein the gas transmission device is used to control the gas passing through a solid electrolyte, the gas detection device is used to determine the gas parameters passing through the solid electrolyte, and the controller is used to determine the pore detection results of the solid electrolyte based on the gas parameters.

10. The system according to claim 9, characterized in that The gas detection equipment includes an inlet pressure gauge, an outlet pressure gauge, and a flow meter. The solid electrolyte is arranged in a test chamber, wherein one end of the inlet pressure gauge is connected to the gas transmission equipment, and the other end of the inlet pressure gauge is connected to the test chamber for detecting the pressure of the gas input into the test chamber, one end of the outlet pressure gauge is connected to the test chamber, and the other end of the outlet pressure gauge is connected to the flow meter for detecting the pressure of the gas flowing out of the test chamber, and the flow meter is used to detect the flow rate of the gas flowing out of the test chamber.

Images