Diaphragm testing method and electronic equipment
By conducting AC impedance test and simulation experiments on the battery separator and calculating its performance parameters, the problems of complex and low accuracy of diaphragm testing in the existing technology are solved, and efficient and accurate diaphragm testing is achieved, reducing costs and risks.
Patent Information
- Application Number
- CN202510164309.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-02-13
- Publication Date
- 2025-05-06
AI Technical Summary
In the prior art, the diaphragm testing method is complex, with low accuracy, and requires a large amount of electrolyte, resulting in high cost and low safety.
By obtaining the separator data and electrolyte liquid conductivity of each battery in the test battery pack, performing AC impedance tests, obtaining the liquid phase impedance of a single-layer separator, and calculating the performance parameters of the separator based on this data, and conducting simulation and experimental tests to determine the simulation accuracy.
The diaphragm testing method is simplified, the testing accuracy is improved, the testing cost and safety risks are reduced, and the battery design is enhanced.
Smart Images
Figure CN119936535A_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the field of battery technology, and in particular to a diaphragm testing method and electronic equipment. Background Art
[0002] In the battery, the diaphragm is used to separate the battery pole pieces to prevent short circuits. The performance of the diaphragm determines the interface structure and internal resistance of the battery, which can directly affect the battery's capacity, cycle and safety performance. However, diaphragms with different numbers of layers have different pore structures, so the ion conduction paths are also different. In the related art, diaphragms with different numbers of layers are often immersed in electrolyte, and AC impedance tests are performed on them by externally connecting aluminum foil. The impedance is linearly fitted, and the membrane resistance of the single-layer diaphragm is obtained to calculate the various design parameters. The process of connecting aluminum foil to the diaphragm is relatively complicated, and the accuracy of the test results is low. At the same time, the diaphragm immersed in the electrolyte for testing requires the consumption of more electrolyte, which increases the cost and reduces the safety factor. Summary of the invention
[0003] In order to solve the deficiencies of the prior art, the present application provides a diaphragm testing method and electronic equipment, which can improve the efficiency of diaphragm selection.
[0004] The technical solution of this application is as follows: The first aspect of the present application provides a diaphragm testing method, the method comprising: obtaining diaphragm data and electrolyte liquid phase conductivity of each battery in the test battery group, wherein each battery in the test battery group includes a different number of diaphragm layers. Performing an AC impedance test on each battery to obtain an AC impedance spectrum of each battery. Obtaining a single-layer diaphragm liquid phase impedance based on all AC impedance spectra. Determining the performance data of the diaphragm based on the single-layer diaphragm liquid phase impedance, diaphragm data, and electrolyte liquid phase conductivity. Performing simulation tests and experimental tests on the diaphragm based on the performance data to obtain simulation data and real data, comparing the simulation data with the real data, and determining that the simulation accuracy meets the simulation standard when the difference between the simulation data and the real data is within the error range.
[0005] In one embodiment, obtaining the single-layer membrane liquid phase impedance according to all AC impedance spectra includes: obtaining the corresponding high-frequency impedance of the battery according to the intercept of the coordinate axis corresponding to the real part of the battery impedance in each AC impedance spectrum, and determining the single-layer membrane liquid phase impedance according to each high-frequency impedance.
[0006] In one embodiment, determining the liquid phase impedance of the single-layer diaphragm according to each high-frequency impedance includes: obtaining a preset fitting model and performing fitting according to each high-frequency impedance and the preset fitting model to obtain the liquid phase impedance of the single-layer diaphragm.
[0007] In one embodiment, the membrane data includes the area and thickness of the membrane, and the performance data includes the effective liquid phase conductivity of the membrane; the performance data of the membrane is determined based on the liquid phase impedance of the single-layer membrane, the membrane data and the liquid phase conductivity of the electrolyte, including: determining the effective liquid phase conductivity of the membrane based on the liquid phase impedance, area and thickness of the single-layer membrane.
[0008] In one embodiment, the membrane data also includes the membrane porosity; the performance data includes the membrane liquid phase conductivity / diffusion coefficient correction factor, McMullin number, tortuosity and Bruggmann coefficient; the performance data of the membrane is determined according to the single-layer membrane liquid phase impedance, the membrane data and the electrolyte liquid phase conductivity, and further includes: determining the liquid phase conductivity / diffusion coefficient correction factor according to the effective liquid phase conductivity and the electrolyte liquid phase conductivity. The McMullin number, tortuosity and Bruggmann coefficient are determined according to the liquid phase conductivity / diffusion coefficient correction factor and the porosity.
[0009] In one embodiment, the performance data also includes an effective liquid phase diffusion coefficient, and the performance data of the diaphragm is determined according to the liquid phase impedance of the single-layer diaphragm, the diaphragm data and the liquid phase conductivity of the electrolyte, and further includes: obtaining the liquid phase diffusion coefficient of the electrolyte of the battery. The effective liquid phase diffusion coefficient is determined according to the liquid phase conductivity / diffusion coefficient correction coefficient and the liquid phase diffusion coefficient of the electrolyte.
[0010] In one embodiment, simulation test and experimental test are performed on the diaphragm according to the performance data to obtain simulation data and real data, including: establishing a corresponding battery model according to the performance data; simulating the working condition of the battery DC internal resistance according to the battery model to obtain simulation data; and experimentally testing the working condition of the battery DC internal resistance to obtain real data.
[0011] In one embodiment, the battery includes a symmetrical battery or a symmetrical cell.
[0012] In one embodiment, before performing an AC impedance test on the battery, the method further includes: when the static time of the battery reaches a preset time and the ambient temperature of the battery reaches a preset temperature, executing a step of performing an AC impedance test on the battery.
[0013] The second aspect of the present application provides an electronic device, comprising: at least one processor. And a memory connected to the at least one processor in communication. The memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor so that the at least one processor can execute the diaphragm testing method of any of the above embodiments.
[0014] The technical solution of this application has at least the following technical effects or advantages: The present application provides a diaphragm testing method, which obtains the diaphragm data and electrolyte liquid phase conductivity of each battery in the test battery group, obtains the AC impedance spectrum of each battery by performing an AC impedance test on each battery, obtains the liquid phase impedance of the single-layer diaphragm based on all the AC impedance spectra, and calculates the performance data of the diaphragm, and performs simulation tests and experimental tests on the diaphragm based on the performance data, obtains simulation data and real data and compares them to determine whether the simulation accuracy of the diaphragm meets the simulation standard. In this way, the diaphragm testing method provided by the present application can simplify the diaphragm testing method, improve the accuracy of diaphragm testing, and improve the efficiency of diaphragm selection on the one hand; on the other hand, the diaphragm testing method provided by the present application can directly test the diaphragm without connecting other equipment to the diaphragm, thereby improving the safety of the test, reducing the cost of diaphragm testing, and enhancing the robustness of battery design. BRIEF DESCRIPTION OF THE DRAWINGS
[0015] Figure 1 It is a step flow chart of the diaphragm testing method provided in an embodiment of the present application.
[0016] Figure 2 It is a schematic diagram of the assembly structure of a battery provided in one embodiment of the present application.
[0017] Figure 3 It is a schematic diagram of an AC impedance spectrum provided in an embodiment of the present application.
[0018] Figure 4 It is a linear fitting diagram of high-frequency impedance provided by an embodiment of the present application.
[0019] Figure 5 It is a schematic diagram of a simulation verification result provided in an embodiment of the present application.
[0020] Figure 6 This is another schematic diagram of simulation verification results provided by an embodiment of the present application.
[0021] Figure 7 This is a schematic diagram of an electronic device provided by an embodiment of the present application. DETAILED DESCRIPTION
[0022] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution 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 part of the embodiments of the present application, rather than all the embodiments. The components of the embodiments of the present application described and shown in the drawings here can be arranged and designed in various different configurations.
[0023] Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the present application for which protection is sought, but merely represents selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present application.
[0024] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.
[0025] In conjunction with the accompanying drawings, some embodiments of the present application are described in detail below. In the absence of conflict, the following embodiments and features in the embodiments can be combined with each other.
[0026] In the battery, the diaphragm is used to separate the battery pole pieces to prevent short circuits. The performance of the diaphragm determines the interface structure and internal resistance of the battery, which can directly affect the battery's capacity, cycle and safety performance. However, diaphragms with different numbers of layers have different pore structures, so the ion conduction paths are also different. In the related art, diaphragms with different numbers of layers are often immersed in electrolyte, and AC impedance tests are performed on them by externally connecting aluminum foil. The impedance is linearly fitted, and the membrane resistance of the single-layer diaphragm is obtained to calculate the various design parameters. The process of connecting aluminum foil to the diaphragm is relatively complicated, and the accuracy of the test results is low. At the same time, the diaphragm immersed in the electrolyte for testing requires the consumption of more electrolyte, which increases the cost and reduces the safety factor.
[0027] Based on this, the present application provides a diaphragm testing method and electronic equipment, which can improve the efficiency of diaphragm selection.
[0028] Next, the diaphragm testing method and electronic device provided in the embodiments of the present application are further introduced. In the following embodiments, the battery is taken as an example of a symmetrical battery. It is understandable that the symmetrical battery can be a button-type symmetrical battery including at least one layer of diaphragm, or a single-layer soft-pack symmetrical battery cell or other batteries with similar structures.
[0029] See also Figure 1 , shows a flow chart of the steps of the diaphragm testing method provided by the embodiment of the present application. It can be understood that the diaphragm testing method provided by the present application can be executed by a processor of a testing device or a simulation device. Figure 1 As shown, the method comprises the following steps: Step S1, obtaining the separator data and the electrolyte liquid phase conductivity of each battery in the test battery group.
[0030] Wherein, each battery in the test battery group includes a different number of diaphragm layers. The diaphragm data includes but is not limited to the diaphragm size data, material data or other physical property data, chemical property data, etc.
[0031] The liquid phase conductivity of the electrolyte is the amount of charge contained per unit length or volume in the electrolyte solution, and reflects the ability of the electrolyte to conduct current. The liquid phase conductivity of the electrolyte can be measured by a conductivity meter or other methods, and this application does not limit the specific method for obtaining the liquid phase conductivity of the electrolyte.
[0032] Step S2: Perform an AC impedance test on each battery to obtain an AC impedance spectrum of each battery.
[0033] Among them, the electrochemical impedance spectroscopy (EIS) test applies a small-amplitude sinusoidal potential or current disturbance signal to the electrochemical system, causing the electrochemical system to generate a corresponding current or potential response, thereby obtaining an electrochemical impedance spectrum. The spectrum reflects the relationship between the impedance of the electrochemical system and the frequency.
[0034] In one embodiment of the present application, the AC impedance test can adopt the voltage amplitude method. For example, a disturbance signal with a frequency range of 0.05Hz to 100kHz and a voltage amplitude of 5mV can be applied to the battery, and the voltage and current of the battery at different frequencies are recorded, and then a phase-locked amplifier or a spectrum analyzer is used to convert the recorded voltage / current signal into impedance and phase angle, thereby obtaining the AC impedance spectrum corresponding to the battery. In other embodiments, the AC impedance test can also apply other types of disturbance signals, and the present application does not limit the specific implementation method of the AC impedance test.
[0035] Step S3: obtaining the liquid phase impedance of the single-layer diaphragm according to all AC impedance spectra.
[0036] In one embodiment of the present application, Figure 3 As shown, the abscissa of the AC impedance spectrum represents the real part of the impedance, and the ordinate represents the imaginary part of the impedance. Several test points form a continuous curve. According to the intercept of the coordinate axis corresponding to the real part of the battery impedance in each AC impedance spectrum, the corresponding high-frequency impedance of the battery is obtained, that is, when the imaginary part of the impedance is 0, the value corresponding to the real part of the impedance is the high-frequency impedance.
[0037] In one embodiment of the present application, a preset fitting model is obtained, and a fitting is performed based on each high-frequency impedance and the preset fitting model to obtain the single-layer diaphragm liquid phase impedance. Figure 4As shown, in one embodiment, the fitting equation of the preset fitting model is y=a+bx, and no additional weight is added in the process of calculating the liquid phase impedance of the single-layer diaphragm according to the fitting equation, that is, each high-frequency impedance is regarded as equally important in the fitting process, and no higher weight or priority is given to certain high-frequency impedances. The impact of each high-frequency impedance on the final fitting result is the same, and the fitting process will not be biased towards certain high-frequency impedances due to their particularity, which can effectively ensure the fairness and consistency of the fitting results. In this way, it can be obtained Figure 4 The linear fitting graph is shown. The horizontal axis of the linear fitting graph represents the number of diaphragm layers, and the vertical axis represents the high-frequency impedance. The slope of the fitting line is the liquid phase impedance of the single-layer diaphragm, for example, the liquid phase impedance of the single-layer diaphragm R HER It is 0.04329Ω. In the linear fitting diagram, the intercept represents the sum of the interference impedances other than the liquid phase impedance of the single-layer diaphragm, for example, the interference impedance includes the structural impedance, etc. The present application does not limit the specific form of the interference impedance. Furthermore, the fitting effect of the curve can be determined by setting an evaluation index. The evaluation index may include the residual square, the Pearson correlation coefficient, the determination coefficient (R-squared) or the determination coefficient of the corrected degrees of freedom (Adjusted R-Squared). In one embodiment of the present application, the Pearson correlation coefficient (i.e. Figure 4 Pearson's) is used to measure the degree of linear correlation between two variables. The Pearson correlation coefficient is preset to have a range of [-1,1]. The closer the Pearson correlation coefficient is to 1, the more positively linearly correlated the two variables are, and the better the fitting effect. Understandably, the closer the Pearson correlation coefficient is to 1, the closer the point corresponding to the high-frequency impedance is to the fitting curve. When the Pearson correlation coefficient is equal to 1, the point corresponding to the high-frequency impedance is completely on the fitting curve. The determination coefficient (i.e. Figure 4 The R-squared (COD) in the formula is used to measure the contribution of the independent variable to the change of the dependent variable. The range of the determination coefficient is set to [0,1]. The closer the determination coefficient is to 1, the better the fitting effect. Figure 4 The adjusted R-squared in the model is improved on the basis of the coefficient of determination, and the range of the coefficient of determination is preset to [0,1]. The closer the coefficient of determination of the corrected degree of freedom is to 1, the better the fitting effect is. In addition, since the influence of the number of independent variables in the model is taken into account, the fitting situation can be reflected more accurately. It can be understood that in other embodiments of the present application, the evaluation index may include more or fewer parameters, and the present application does not limit the specific content and specific range of values of the evaluation index. In this way, by obtaining the corresponding single-layer diaphragm liquid phase impedance through a preset fitting model, the error in measuring and controlling the single-layer diaphragm liquid phase impedance can be effectively reduced, and the accuracy of the single-layer diaphragm liquid phase impedance can be improved.
[0038] The present application does not limit the specific fitting equation of the preset fitting model, and those skilled in the art may also set other fitting equations.
[0039] Step S4, determining the performance data of the diaphragm according to the single-layer diaphragm liquid phase impedance, diaphragm data and the liquid phase conductivity of the electrolyte.
[0040] The performance data include but are not limited to the effective liquid phase conductivity of the diaphragm, the correction factor of the liquid phase conductivity / diffusion coefficient, the McMullin number, the tortuosity, the Brugmann coefficient and the effective liquid phase diffusion coefficient, etc., which are used to measure the performance of the diaphragm.
[0041] In some embodiments, step S4 includes the following steps: S41. Determine the effective liquid phase conductivity of the membrane based on the liquid phase impedance, area and thickness of the single-layer membrane.
[0042] The membrane data includes the area and thickness of the membrane, and the performance data includes the effective liquid phase conductivity of the membrane. In step S41, the effective liquid phase conductivity σ of the membrane can be calculated by formula (1): eff Perform the calculation: (1); Where, d represents the thickness of the diaphragm, R s It is expressed as the liquid phase impedance of a single-layer diaphragm, and S is the area of the diaphragm. Effective liquid phase conductivity σ eff It indicates the conductivity of the electrolyte when it acts in the diaphragm.
[0043] S42. Determine a liquid phase conductivity / diffusion coefficient correction factor according to the effective liquid phase conductivity and the liquid phase conductivity of the electrolyte.
[0044] For example, the liquid phase conductivity / diffusion coefficient correction factor f is calculated by formula (2): I Perform the calculation: σ eff =σf I (2); Among them, σ represents the liquid phase conductivity of the electrolyte, that is, the conductivity of the electrolyte when it acts in the battery. It can be understood that the effective liquid phase conductivity σ eff is the electrolyte liquid phase conductivity σ after the liquid phase conductivity / diffusion coefficient correction factor f I The corrected value is the effective liquid conductivity σ obtained in step S41. eff The obtained electrolyte liquid phase conductivity σ is substituted into the formula to reversely obtain the liquid phase conductivity / diffusion coefficient correction factor f I .
[0045] S43. Determine the McMullin number, tortuosity and Brugmann coefficient based on the liquid phase conductivity / diffusion coefficient correction factor and porosity.
[0046] The diaphragm data also include the porosity of the diaphragm, and the performance data include the MacMulin number, tortuosity and Bruggeman coefficient of the diaphragm.
[0047] The McMullin number of the diaphragm is calculated by formula (3): N m =1 / f I (3); Among them, N m is the liquid phase conductivity / diffusion coefficient correction factor f I The reciprocal of. Through the McMullin number N m It can effectively characterize the migration rate of ions in the electrode, thereby reflecting the performance of the battery.
[0048] The tortuosity τ and Bruggman coefficient Brugg are calculated by formula (4): (4); Wherein, ε represents the porosity of the diaphragm. The porosity of the diaphragm is the proportion of pores in the diaphragm material, and the size of the pores directly affects the air permeability and ion conductivity of the diaphragm. The electrolyte is conducted in the pores, and the larger the porosity, the more complete the electrolyte infiltration. The porosity can be directly obtained based on the factory parameters of the diaphragm, or it can be tested and verified by methods such as mercury injection method or gas method. This application does not limit the specific method of obtaining the porosity.
[0049] S44. Determine the effective liquid phase diffusion coefficient based on the liquid phase conductivity / diffusion coefficient correction coefficient and the liquid phase diffusion coefficient of the electrolyte.
[0050] In step S44, the electrolyte liquid phase diffusion coefficient of the battery can be obtained to calculate the effective liquid phase diffusion coefficient. The electrolyte liquid phase diffusion coefficient represents the diffusion coefficient of ions in the electrolyte in the liquid. In some embodiments, the effective liquid phase diffusion coefficient D can be calculated by formula (5) eff Perform the calculation: D eff =D×f I (5); Where D is the electrolyte liquid phase diffusion coefficient. The effective liquid phase diffusion coefficient D eff It indicates the diffusion coefficient of the electrolyte in the diaphragm. The effective liquid phase diffusion coefficient D eff is the electrolyte liquid phase diffusion coefficient D and the liquid phase conductivity / diffusion coefficient correction factor f I The product of the liquid conductivity / diffusion coefficient correction factor f ICorrecting the electrolyte liquid phase diffusion coefficient D and reducing the deviation of the electrolyte liquid phase diffusion coefficient D, such as the deviation caused by factors such as ion concentration or battery structure, can effectively improve the prediction ability of battery performance and improve accuracy.
[0051] It is understandable that in other embodiments, in addition to calculating the corresponding performance data based on the above formulas (1)-(5), a table lookup operation can also be performed in step S4 to determine the performance data of the diaphragm based on the single-layer diaphragm liquid phase impedance, diaphragm data and electrolyte liquid phase conductivity.
[0052] Step S5, performing simulation test and experimental test on the diaphragm according to the performance data to obtain simulation data and real data, comparing the simulation data with the real data, and when the difference between the simulation data and the real data is within the error range, determining that the simulation accuracy meets the simulation standard.
[0053] It can be understood that when the difference between the simulation data obtained by the simulation test and the real data is within the error range, it means that the simulation accuracy of the current battery diaphragm meets the preset simulation standard, and further shows that the current diaphragm testing method meets the design standard. When the difference between the simulation data obtained by the simulation test and the real data is outside the error range, it means that the current battery diaphragm does not meet the design standard.
[0054] In some embodiments, a corresponding battery model is established based on the performance data. Based on the battery model, the working conditions of the DC internal resistance of the battery are simulated to obtain simulation data. The working conditions of the DC internal resistance of the battery are experimentally tested to obtain real data. The real data is compared with the simulation data. When the difference in the preset output indicators between the real data and the simulation data is within a preset range, it is determined that the diaphragm meets the simulation design standards. Among them, the diaphragm is qualified means that the current diaphragm further meets the manufacturing requirements of the battery in addition to meeting the design standards. Among them, the preset output indicators may include test relative errors or other values that can reflect the difference between simulation data and real data. This application does not limit the specific content of the preset output indicators. In one embodiment of the present application, the DC internal resistance (DCR) of the battery is monitored at different states of charge (SOC), i.e., different amounts of power remaining in the battery, to determine the battery's performance. The battery includes a tested diaphragm. When the battery has 20% power remaining, the DC internal resistance of the battery is monitored, and the following is obtained: Figure 5 The simulation verification result diagram is shown in FIG. 1 ; when the battery has 50% of its power remaining, the working condition of the battery DC internal resistance is monitored, and the following is obtained: Figure 6The schematic diagram of the simulation verification results is shown in the figure. Among them, Sim represents simulation data, Exp represents experimental data, and RD represents the relative error (Relative Deviation, RD) of the test result. The deviation between the simulation data and the experimental data is judged by the relative error of the test result. When the battery has 20% of power remaining, the relative error of the test result is 0.07%, and when the battery has 50% of power remaining, the relative error of the test result is 1.41%. At the same time, according to Figure 5 and Figure 6 It can be seen that the curve corresponding to the simulation data and the curve corresponding to the experimental data basically overlap, so the deviation between the simulation data and the actual data is small, which can effectively show that the diaphragm meets the design standards of the battery. At the same time, based on the accurate prediction of the simulation model, the DC internal resistance of the battery using the diaphragm performs well on different time scales, which can effectively reflect the accuracy of the diaphragm test, facilitate the rapid determination of whether the diaphragm meets the standards during the battery design process, improve the test efficiency of the diaphragm, and enhance the robustness of the battery design.
[0055] In some embodiments, before executing step S2, the diaphragm testing method further includes: when the static time of the battery reaches a preset time, and the ambient temperature of the battery reaches a preset temperature, executing step S2.
[0056] That is to say, in one embodiment, before executing step S2, the battery may be left to stand to allow the separator and the electrode to be fully wetted.
[0057] When the static time of the battery reaches the preset time, place the battery in a thermostat and adjust the temperature of the thermostat to the preset temperature. The preset time can be 12 hours or other time. This application does not limit the specific static time of the battery. The temperature of the thermostat can be selected according to the actual test situation. For example, the temperature of the thermostat is set to 25°C. This application does not limit the specific temperature of the thermostat. When the ambient temperature of the battery reaches the preset temperature, execute step S2.
[0058] In this way, by leaving the battery still, the electrolyte can better penetrate into the pores of the diaphragm, which is conducive to the ion concentration inside the diaphragm reaching a stable state and improving the stability of the diaphragm performance. Placing the battery in a constant temperature box can provide a stable and accurate temperature environment, ensuring that the battery is less affected by temperature fluctuations in subsequent tests, which helps the chemical reaction inside the battery to proceed more smoothly. By simulating the ambient temperature through the constant temperature box, the authenticity and accuracy of the test can be improved, ensuring the safety of the test.
[0059] In one embodiment of the present application, the battery is a symmetrical battery and includes at least two conductive parts, a separator and an electrolyte. Figure 2As shown, the battery may include: a negative battery shell 101a, a spring 102, a gasket 103, a first conductive member 104a, a diaphragm 105, a second conductive member 104b and a positive battery shell 101b. Among them, the diaphragm 105 may have different numbers of layers, and the different layers of diaphragms remain flat. It is understandable that the battery may include a layer of diaphragm, or may include multiple layers of diaphragms, such as two, four, six or eight layers, and the present application does not limit the specific number of layers of the diaphragm. The first conductive member 104a and the second conductive member 104b are symmetrically arranged between the negative battery shell 101a and the positive battery shell 101b with respect to the diaphragm 105 to form a symmetrical structure. The first conductive member 104a and the second conductive member 104b may be fresh negative electrode sheets. Among them, a fresh negative electrode sheet refers to a negative electrode sheet whose charge and discharge times are less than a preset number. The negative electrode sheet may be made of graphite or other materials. The first conductive member 104a and the second conductive member 104b can also be lithium foils. The present application does not limit the specific materials used for the first conductive member 104a and the second conductive member 104b. The first conductive member 104a and the second conductive member 104b are used to ensure that the active material can effectively participate in the electrochemical reaction, realize the transmission and collection of current, and ensure the stable performance of the overall performance of the battery. The spring 102 is arranged between the first conductive member 104a and the negative electrode battery shell 101a. The spring 102 is used to connect the battery to power on. The spring 102 can be made of stainless steel, or iron or beryllium copper. The present application does not limit the specific material of the spring 102. The gasket 103 is arranged between the spring 102 and the first conductive member 104a. The gasket 103 is used to prevent the internal material of the battery from deforming, keep the internal part of the battery in close contact, and prevent loosening. The gasket 103 can be a stainless steel gasket or a rubber gasket, etc. The present application does not limit the specific material of the gasket 103.
[0060] It is understood that the structure illustrated in the embodiment of the present application does not constitute a specific limitation on the battery. In other embodiments of the present application, the battery may include more or fewer components than shown, or combine certain components, or separate certain components, or arrange the components differently.
[0061] See also Figure 7 ,like Figure 7 As shown, the present application also provides an electronic device 10, comprising: at least one processor 20; and a memory 30 communicatively connected to the at least one processor 20; wherein the memory 30 stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor 20 so that the at least one processor 20 can execute the above-mentioned diaphragm testing method.
[0062] Among them, the memory 30 and the processor 20 are connected in a bus manner, and the bus may include any number of interconnected buses and bridges, and the bus connects various circuits of one or more processors 20 and the memory 30 together. The bus can also connect various other circuits such as peripheral devices, voltage regulators, and power management circuits, which are well known in the art, so they are not further described in this article. The bus interface provides an interface between the bus and the transceiver. The transceiver can be one element or multiple elements, such as multiple receivers and transmitters, providing a unit for communicating with various other devices on a transmission medium. The data processed by the processor 20 is transmitted on the wireless medium through the antenna, and further, the antenna also receives the data and transmits the data to the memory 30. The processor 20 is responsible for managing the bus and general processing, and can also provide various functions, including timing, peripheral interfaces, voltage regulation, power management and other control functions. The memory 30 can be used to store data used by the processor 20 when performing operations.
[0063] It should be noted that, for the aforementioned method embodiments, for the sake of simplicity of description, they are all expressed as a series of action combinations, but those skilled in the art should know that the present application is not limited by the described order of actions, because according to the present application, certain steps can be performed in other orders or simultaneously.
[0064] The above embodiments are described in the form of preferred embodiments of the present application, and are not intended to limit the scope of the present application. Without departing from the design spirit of the present application, various modifications and improvements made to the technical solutions of the present application by ordinary technicians in this field should fall within the scope of protection determined by the claims of the present application.
Claims
1. A diaphragm testing method, characterized in that: The method comprises: Acquiring separator data and electrolyte liquid phase conductivity of each battery in the test battery group, wherein each battery in the test battery group includes a different number of separator layers; Performing an AC impedance test on each of the batteries to obtain an AC impedance spectrum of each of the batteries; Obtaining the liquid phase impedance of the single-layer diaphragm according to all the AC impedance spectra; Determining performance data of the diaphragm according to the liquid phase impedance of the single-layer diaphragm, the diaphragm data and the liquid phase conductivity of the electrolyte; The diaphragm is subjected to simulation test and experimental test according to the performance data to obtain simulation data and real data, and the simulation data is compared with the real data. When the difference between the simulation data and the real data is within the error range, it is determined that the simulation accuracy meets the simulation standard.
2. The diaphragm testing method according to claim 1, characterized in that: The step of obtaining the liquid phase impedance of the single-layer diaphragm according to all the AC impedance spectra includes: Obtaining the corresponding high-frequency impedance of the battery according to the intercept of the coordinate axis corresponding to the real part of the battery impedance in each of the AC impedance spectra; The single-layer diaphragm liquid phase impedance is determined according to each of the high-frequency impedances.
3. The diaphragm testing method according to claim 2, characterized in that: The determining of the single-layer diaphragm liquid phase impedance according to each high-frequency impedance comprises: Get the preset fitting model; Fitting is performed according to each of the high-frequency impedances and the preset fitting model to obtain the liquid phase impedance of the single-layer diaphragm.
4. The diaphragm testing method according to claim 2, characterized in that: The membrane data includes the area and thickness of the membrane, and the performance data includes the effective liquid phase conductivity of the membrane; Determining the performance data of the diaphragm according to the liquid phase impedance of the single-layer diaphragm, the diaphragm data and the liquid phase conductivity of the electrolyte includes: The effective liquid phase conductivity of the membrane is determined according to the liquid phase impedance of the single-layer membrane, the area and the thickness.
5. The diaphragm testing method according to claim 4, characterized in that: The membrane data also includes the porosity of the membrane; the performance data includes the liquid phase conductivity / diffusion coefficient correction factor, McMullin number, tortuosity and Bruggmann coefficient of the membrane, and the performance data of the membrane is determined according to the liquid phase impedance of the single-layer membrane, the membrane data and the liquid phase conductivity of the electrolyte, and further includes: Determining the liquid phase conductivity / diffusion coefficient correction coefficient according to the effective liquid phase conductivity and the liquid phase conductivity of the electrolyte; The McMullin number, the tortuosity and the Brugmann coefficient are determined according to the liquid phase conductivity / diffusion coefficient correction coefficient and the porosity.
6. The diaphragm testing method according to claim 5, characterized in that: The performance data also includes an effective liquid phase diffusion coefficient, and the performance data of the diaphragm is determined according to the liquid phase impedance of the single-layer diaphragm, the diaphragm data and the liquid phase conductivity of the electrolyte, and further includes: Obtaining a liquid phase diffusion coefficient of an electrolyte of the battery; The effective liquid phase diffusion coefficient is determined according to the liquid phase conductivity / diffusion coefficient correction coefficient and the electrolyte liquid phase diffusion coefficient.
7. The diaphragm testing method according to claim 1, characterized in that: The diaphragm is subjected to simulation test and experimental test according to the performance data to obtain simulation data and real data, including: Establishing a corresponding battery model according to the performance data; According to the battery model, simulating the working condition of the DC internal resistance of the battery to obtain the simulation data; The operating conditions of the DC internal resistance of the battery are experimentally tested to obtain the real data.
8. The diaphragm testing method according to claim 1, characterized in that: Before performing an AC impedance test on the battery, the method further includes: When the static time of the battery reaches a preset time and the ambient temperature of the battery reaches a preset temperature, the step of performing an AC impedance test on the battery is performed.
9. The diaphragm testing method according to claim 1, characterized in that: The battery comprises a symmetrical battery or a symmetrical battery cell.
10. An electronic device, characterized in that: include: at least one processor; and, a memory communicatively coupled to the at least one processor; The memory stores instructions that can be executed by the at least one processor, and the instructions are executed by the at least one processor so that the at least one processor can perform the diaphragm testing method according to any one of claims 1 to 9.