Gas pressure measurement method for battery, apparatus, device and system

Abstract

Disclosed in the present application are a gas pressure measurement method for a battery, an apparatus, a device and a system. The gas pressure measurement method for a battery comprises: separately inputting excitation signals of different frequencies into a piezoelectric device arranged on a battery; acquiring impedances of the piezoelectric device under the excitation signals of different frequencies; and determining a target impedance from amongst the impedances corresponding to the excitation signals of different frequencies, and determining a value of the gas pressure in the battery matched with the target impedance. The solution can measure the gas pressure in batteries.

Description

Battery air pressure detection method, device, equipment and system

[0001]

Cross-reference

[0002] This application claims priority to the Chinese patent application filed with the China Patent Office on November 1, 2023, with application number 2023114439583 and application name “Battery Air Pressure Detection Method, Device, Equipment and System”, all contents of which are incorporated by reference into this application.

Technical field

[0003] The present application relates to the field of batteries, and in particular to a method, device, equipment and system for detecting air pressure of a battery. [Background Technology]

[0004] During the battery formation and circulation process, a series of chemical reactions may produce gas, which may cause high gas pressure inside the battery, thereby affecting the battery performance and safety.

[0005] Currently, there are few methods and equipment for testing battery pressure. The common water drainage and paraffin drainage methods are cumbersome and dangerous. The water drainage method requires puncturing the explosion-proof valve to release the internal gas, which is then collected in a container to measure the internal pressure. This method damages the integrity of the battery structure. If the external humidity is high, water can easily cause the lithium ions in the negative electrode to rapidly reduce, which can easily cause fires and other safety accidents. When measuring with the paraffin drainage method, paraffin can enter the battery, contaminating the internal structure and rendering the battery scrapped.

[0006] [Summary of the invention]

[0007] The present application at least provides a battery air pressure detection method, device, equipment and system.

[0008] The present application provides a method for detecting air pressure of a battery, comprising: inputting excitation signals of different frequencies to a piezoelectric device arranged on the battery; obtaining the impedance of the piezoelectric device under the excitation signals of different frequencies; determining a target impedance from the impedances corresponding to the excitation signals of different frequencies, and determining an air pressure value in the battery that matches the target impedance.

[0009] In the above scheme, an excitation signal is input to the piezoelectric device provided on the battery. The piezoelectric device causes the battery to vibrate after receiving the excitation signal. Since the air pressure inside the battery is different, the vibration form of the battery may be different, and the vibration of the battery affects the impedance of the piezoelectric device through the positive piezoelectric effect. Therefore, the air pressure value inside the battery can be determined based on the impedance of the piezoelectric device under excitation signals of different frequencies. Compared with the drainage method, this scheme does not need to destroy the structure of the battery, nor does it need to pull out the relevant pipelines to detect the air pressure inside the battery.

[0010] In some embodiments, determining the air pressure value in the battery that matches the target impedance includes: taking the frequency corresponding to the target impedance as the target frequency; determining the air pressure value that matches the target frequency in a preset correspondence relationship, where the preset correspondence relationship represents the correspondence between the frequency and the air pressure value.

[0011] In the above solution, by establishing a corresponding relationship between frequency and air pressure value, and then determining the target impedance from various impedances, it is possible to determine the air pressure in the battery according to the frequency corresponding to the target impedance.

[0012] In some embodiments, determining the target impedance from the impedances corresponding to the excitation signals of different frequencies includes: selecting at least one impedance that meets the conditions required by a preset correspondence from the impedances corresponding to the excitation signals of different frequencies as the target impedance.

[0013] In the above scheme, the preset correspondence relationship can be established based on the frequency corresponding to a specific impedance. Therefore, by selecting at least one impedance that meets the conditions required by the preset correspondence relationship from the impedances corresponding to excitation signals of different frequencies as the target impedance, compared with randomly selecting an impedance as the target impedance, the gas pressure in the battery determined by this scheme is more accurate.

[0014] In some embodiments, determining the target impedance from the impedances corresponding to the excitation signals of different frequencies includes: sorting the excitation signals of different frequencies according to magnitude; and selecting the impedance in a preset sequence as the target impedance.

[0015] In the above scheme, the air pressures corresponding to impedances of different positions in the preset correspondence may be different. Compared with randomly selecting impedances of a position sequence as the target impedance, the accuracy of the detected air pressure can be guaranteed by selecting impedances in the preset position sequence as the target impedance.

[0016] In some embodiments, the battery pressure detection method also includes: when the air pressure in the test battery is at different air pressure values, inputting multiple test frequency excitation signals to the piezoelectric device on the test battery respectively; obtaining the test impedance of the piezoelectric device at each test frequency under different air pressure values; for each air pressure value, selecting at least one test impedance as the target test impedance from the test impedances corresponding to the air pressure value; establishing a relationship between the frequency corresponding to each target test impedance and each air pressure value, and determining a preset corresponding relationship.

[0017] In the above scheme, by controlling the air pressure of the test battery to be at different air pressure values, multiple excitation signals of test frequencies are input to the piezoelectric device on the test battery, so that the differences between different frequencies corresponding to the target test impedance at different air pressure values ​​can be observed, such as the frequency difference corresponding to the minimum impedance or maximum impedance at each air pressure value, and thus the preset corresponding relationship is determined according to the relationship between the frequency corresponding to each target test impedance and each air pressure value, so as to facilitate the subsequent determination of the air pressure in the battery using the target frequency corresponding to the target impedance and the preset corresponding relationship.

[0018] In some embodiments, different frequencies are within a target frequency range, each test frequency is within a test frequency range, the test frequency range includes a target frequency range, and for each air pressure value, at least one test impedance is selected as a target test impedance from each test impedance corresponding to the air pressure value, including: determining the target frequency range from the test frequency range; determining the target test impedance from a test impedance region corresponding to the target frequency range, the test impedance region being the interval in which the test impedance for the air pressure value within the target frequency range is located.

[0019] In the above scheme, the test impedance corresponding to the same test frequency at different air pressure values ​​may be slightly different in the test frequency range, which makes it inconvenient to distinguish different air pressure values. If the entire test frequency range is used as the target frequency range, the preset correspondence relationship determined may be inaccurate. Therefore, the scheme can improve the accuracy of the preset correspondence determined subsequently by selecting the target frequency range from the test frequency range.

[0020] In some embodiments, different frequencies are within a target frequency range, each test frequency is within a test frequency range, the test frequency range includes the target frequency range, and the difference between the test impedances corresponding to different air pressure values ​​at the same test frequency in the target frequency range is greater than the difference between the test impedances corresponding to different air pressure values ​​at the same test frequency in other frequency ranges. The other frequency range is the frequency range in the test frequency range other than the target frequency range.

[0021] In the above scheme, by selecting a frequency range in which the test impedance difference at different air pressure values ​​is large from the test frequency range as the target frequency range, and determining the target test impedance based on the impedances within the range, thereby establishing a corresponding preset correspondence, the detection efficiency and the accuracy of the detected air pressure in the subsequent battery air pressure detection process can be reduced.

[0022] In some embodiments, the target impedance is the maximum impedance or the minimum impedance, and the target test impedance is the maximum test impedance or the minimum test impedance of the air pressure value in the test impedance area. Based on the frequency corresponding to each target test impedance and each air pressure value, a preset corresponding relationship is determined, including: fitting the frequency corresponding to each maximum test impedance or minimum test impedance and each air pressure value to obtain a fitting line of the frequency and the air pressure value; based on the fitting line, determining the preset corresponding relationship.

[0023] In the above scheme, within the target frequency range, the maximum impedance or the frequency corresponding to the impedance of different air pressure values ​​is quite different, so a preset corresponding relationship is established through the maximum test impedance or the minimum test impedance, so that the air pressure value determined subsequently is more accurate.

[0024] In some embodiments, when the air pressure in the test battery is at different pressure values, multiple excitation signals of test frequencies are input to the piezoelectric device on the test battery respectively, including: using an air pressure control component to control the air pressure in the test battery, and the air pressure control component is connected to the test battery through a through hole opened on the test battery.

[0025] In the above solution, the air pressure in the battery can be controlled to be at a specific air pressure value through the air pressure control component, and the impedance corresponding to the excitation signal of different frequencies is determined at different air pressure values, thereby establishing the preset corresponding relationship.

[0026] In some embodiments, after determining the target impedance from the impedances corresponding to excitation signals of different frequencies and determining the air pressure value in the battery that matches the target impedance, the battery air pressure detection method further includes: executing a preset alarm process in response to the air pressure value in the battery being greater than or equal to a preset air pressure value.

[0027] In the above solution, by executing the preset alarm process when the air pressure value in the battery is greater than or equal to the preset air pressure value, accidents caused by excessive air pressure value in the battery can be reduced.

[0028] The present application provides a battery air pressure detection device, comprising: a signal input module, an impedance acquisition module, and an air pressure determination module; the signal input module is used to input excitation signals of different frequencies to a piezoelectric device provided on the battery; the impedance acquisition module is used to obtain the impedance of the piezoelectric device under excitation signals of different frequencies; the air pressure determination module is used to determine a target impedance from the impedances corresponding to the excitation signals of different frequencies, and determine an air pressure value in the battery that matches the target impedance.

[0029] The present application provides a battery air pressure detection device, including an impedance acquisition component and a processor. The impedance acquisition component is used to connect to a piezoelectric device arranged on the battery, and is used to input excitation signals of different frequencies to the piezoelectric device arranged on the battery, and obtain the impedance of the piezoelectric device under the excitation signals of different frequencies; the processor is connected to the impedance acquisition component, and is used to determine the target impedance from the impedances corresponding to the excitation signals of different frequencies, and determine the air pressure value in the battery that matches the target impedance.

[0030] The present application provides a battery air pressure detection system, which includes an impedance acquisition device and an electronic device that establishes a communication connection with the impedance acquisition device. The impedance acquisition device is used to connect to a piezoelectric device provided on the battery, and is used to input excitation signals of different frequencies to the piezoelectric device provided on the battery, and obtain the impedance of the piezoelectric device under the excitation signals of different frequencies. The electronic device is used to determine the target impedance from the impedances corresponding to the excitation signals of different frequencies, and determine the air pressure value in the battery that matches the target impedance.

[0031] In the above scheme, an excitation signal is input to the piezoelectric device provided on the battery. The piezoelectric device causes the battery to vibrate after receiving the excitation signal. Since the air pressure inside the battery is different, the vibration form of the battery may be different, and the vibration of the battery affects the impedance of the piezoelectric device through the positive piezoelectric effect. Therefore, the air pressure value inside the battery can be determined based on the impedance of the piezoelectric device under excitation signals of different frequencies. Compared with the drainage method, this scheme does not need to destroy the structure of the battery, nor does it need to pull out the relevant pipelines to detect the air pressure inside the battery.

[0032] It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present application.

Brief Description of the Drawings

[0033] The drawings herein are incorporated into and constitute a part of the specification. These drawings illustrate embodiments consistent with the present application and, together with the specification, are used to illustrate the technical solutions of the present application.

[0034] FIG1 is a flow chart of an embodiment of a method for detecting battery pressure according to some embodiments;

[0035] FIG2 is a schematic diagram of various piezoelectric device placement locations provided by some embodiments;

[0036] FIG3 is a schematic diagram of a sub-flow diagram of step S13 provided in some embodiments;

[0037] FIG4 is another schematic flow chart of a method for detecting battery pressure according to some embodiments;

[0038] FIG5 is a schematic diagram of test impedance of a piezoelectric device at various test frequencies under different air pressure values ​​in a method for detecting air pressure of a battery provided in some embodiments;

[0039] FIG6 is a scatter plot of the relationship between air pressure and frequency in an air pressure detection method provided by some embodiments;

[0040] FIG7 is a schematic structural diagram of an embodiment of a battery air pressure detection device provided in some embodiments;

[0041] FIG8 is a schematic structural diagram of an embodiment of a battery air pressure detection device provided in some embodiments;

[0042] FIG9 is a schematic structural diagram of an embodiment of an air pressure detection system provided in some embodiments. [Specific implementation method]

[0043] The following describes the embodiments of the present application in detail with reference to the accompanying drawings.

[0044] In the following description, for the purpose of explanation rather than limitation, specific details such as specific subsystem structures, interfaces, and technologies are provided to facilitate a thorough understanding of the present application.

[0045] The term "and / or" in this article is simply a description of the association relationship of associated objects, indicating that three relationships can exist. For example, A and / or B can represent three situations: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects are in an "or" relationship. In addition, "many" in this article means two or more than two. In addition, the term "at least one" in this article means any combination of at least two of any one or more of a plurality of. For example, including at least one of A, B, and C can mean including any one or more elements selected from the set consisting of A, B, and C.

[0046] Considering that abnormal gas pressure inside batteries is likely to affect battery health, how to detect gas pressure inside batteries is a relatively important topic. Currently, the main methods for sampling gas pressure inside batteries include water drainage method and paraffin drainage method, but these two methods will damage the battery structure.

[0047] This solution proposes a method for detecting the air pressure of a battery. By inputting an excitation signal to a piezoelectric device arranged on the battery, the piezoelectric device causes the battery to vibrate after receiving the excitation signal. Because the air pressure in the battery is different, the vibration frequency and amplitude of the battery may be different, and the vibration of the battery affects the impedance of the piezoelectric device through the positive piezoelectric effect. That is, under different air pressures in the battery, if excitation signals of different frequencies are input to the piezoelectric device, the impedance reflected by the piezoelectric device will be different under the excitation of different excitation signals. Therefore, the air pressure value in the battery can be determined based on the impedance of the piezoelectric device under excitation signals of different frequencies, and the air pressure in the battery can be detected without destroying the structure of the battery.

[0048] Referring to FIG. 1 , the battery pressure detection method provided herein may include steps S11 to S13. Step S11: Inputting excitation signals of different frequencies to the piezoelectric device disposed on the battery. Step S12: Obtaining the impedance of the piezoelectric device under the excitation signals of different frequencies. Step S13: Determining a target impedance from the impedances corresponding to the excitation signals of different frequencies, and determining an air pressure value within the battery that matches the target impedance.

[0049] The air pressure detection method provided by this solution can be performed by an air pressure detection device. The voltage device can be a piezoelectric piece or any other device that can produce mechanical deformation with the change of voltage and frequency when voltage acts on the piezoelectric device. When the piezoelectric device is vibrated, an electric charge is generated. In this embodiment, the piezoelectric device is taken as an example of a piezoelectric piece. Among them, the material of the piezoelectric device is not limited, and can be an organic material or an inorganic material (such as ceramics, etc.). The position of the piezoelectric device on the battery can be at any position outside the battery. Please refer to Figure 2. The piezoelectric piece can be above, on the front or on the side of the battery shell. Figure 2 only illustrates the possible installation positions of the piezoelectric piece, and does not mean that three piezoelectric pieces are required to detect the air pressure in the battery. Inputting excitation signals of different frequencies to the piezoelectric device set on the battery can be understood as the frequencies of the excitation signals input at different times are different. The excitation signal can be a current signal or a voltage signal. After receiving the excitation signal, the piezoelectric device causes the battery to vibrate. Because the air pressure inside the battery is different, the vibration form of the battery may be different, and the vibration of the battery affects the impedance of the piezoelectric device through the positive piezoelectric effect. Therefore, the impedance of the piezoelectric device under the action of excitation signals of different frequencies can be collected. The impedance of the piezoelectric device can be obtained by using an impedance acquisition device or a circuit with an impedance acquisition function to collect the impedance of the piezoelectric device. There are many ways to collect the impedance of a device, and no specific restrictions are made here. The impedance at different frequencies may be different. The method of determining the target impedance from the impedance corresponding to the excitation signals of different frequencies can be to select an impedance in a specific size order among the impedances as the target impedance. The number of target impedances can be one or more. The method of determining the air pressure value in the battery that matches the target impedance based on the target impedance can be to determine the air pressure value based on the change law between each target impedance, or to determine the air pressure value based on the correspondence between the target impedance and a pre-set relationship. The air pressure value can also be first determined based on the correspondence between each target impedance and a pre-set relationship, and then the air pressure values ​​are weighted according to the weight corresponding to each target impedance to obtain the final air pressure value. It can be seen that there are many ways to determine the target impedance, which are not specifically limited here.

[0050] In the above scheme, an excitation signal is input to the piezoelectric device provided on the battery. The piezoelectric device causes the battery to vibrate after receiving the excitation signal. Since the air pressure inside the battery is different, the vibration form of the battery may be different, and the vibration of the battery affects the impedance of the piezoelectric device through the positive piezoelectric effect. Therefore, the air pressure value inside the battery can be determined based on the impedance of the piezoelectric device under excitation signals of different frequencies. Compared with the drainage method, this scheme does not need to destroy the structure of the battery, nor does it need to pull out the relevant pipelines to detect the air pressure inside the battery.

[0051] In some embodiments, referring to FIG. 3 , determining the pressure value within the battery that matches the target impedance may include steps S131 and S132 . Step S131 : Using the frequency corresponding to the target impedance as the target frequency. Step S132 : Determining the pressure value that matches the target frequency based on a preset correspondence relationship, where the preset correspondence relationship represents the correspondence between frequency and pressure.

[0052] Each frequency of the excitation signal corresponds to an impedance, and the frequency corresponding to the target impedance is the target frequency. A preset correspondence can be established based on the relationship between the frequency of the excitation signal and the air pressure value. The air pressure value in the battery can then be determined based on the preset correspondence and the target frequency.

[0053] For example, different air pressure values ​​have different target impedances at different frequencies. For example, the lowest impedance of air pressure value a under excitation signals of different frequencies is m, the lowest impedance of air pressure value b under excitation signals of different frequencies is n, and the lowest impedance of air pressure value c under excitation signals of different frequencies is k. m, n, and k are different. The frequency corresponding to m is x, the frequency corresponding to n is v, and the frequency corresponding to k is e. v, x, and e are different. In other words, this solution uses the lowest impedance among the impedances corresponding to excitation signals of different frequencies as the target impedance, and then determines the air pressure in the battery based on the frequency corresponding to the target impedance. For example, if the target impedance is m, and the frequency corresponding to the target impedance is exactly x, then based on the pre-established correspondence, the air pressure in the battery can be determined to be x. Assuming the target impedance is m, but the frequency corresponding to the target impedance is not x, then we can estimate the air pressure in the battery based on the pre-established correspondence to obtain the air pressure value in the battery.

[0054] In the above solution, by establishing a corresponding relationship between frequency and air pressure value, and then determining the target impedance from various impedances, it is possible to determine the air pressure in the battery according to the frequency corresponding to the target impedance.

[0055] In some embodiments, determining the target impedance from the impedances corresponding to the excitation signals of different frequencies includes: selecting at least one impedance that meets the conditions required by a preset correspondence from the impedances corresponding to the excitation signals of different frequencies as the target impedance.

[0056] At least one impedance can be one impedance or two or more impedances. The conditions required to meet the preset correspondence can be understood to be the same as the characteristics of the impedance used when establishing the preset correspondence. Optionally, the conditions required by the preset correspondence include being in a preset order in the impedances corresponding to the excitation signals of different frequencies sorted by size. Exemplarily, the frequency corresponding to the lowest impedance reflected by the different air pressure values ​​used when establishing the preset correspondence under the excitation signals of different frequencies, then the target impedance is the lowest impedance under the excitation signals of different frequencies, or the highest impedance is used to establish the preset relationship, then the target impedance is the highest impedance under the excitation signals of different frequencies. Or the lowest impedance and the highest impedance are used when establishing the preset correspondence, then the target impedance includes the lowest impedance and the highest impedance under the excitation signals of different frequencies.

[0057] In the above scheme, the preset correspondence relationship can be established based on the frequency corresponding to a specific impedance. Therefore, by selecting at least one impedance that meets the conditions required by the preset correspondence relationship from the impedances corresponding to excitation signals of different frequencies as the target impedance, compared with randomly selecting an impedance as the target impedance, the gas pressure in the battery determined by this scheme is more accurate.

[0058] In some embodiments, determining the target impedance from the impedances corresponding to the excitation signals of different frequencies includes: sorting the excitation signals of different frequencies according to magnitude; and selecting the impedance in a preset sequence as the target impedance.

[0059] In the above scheme, the air pressures corresponding to impedances of different positions in the preset correspondence may be different. Compared with randomly selecting impedances of a position sequence as the target impedance, the accuracy of the detected air pressure can be guaranteed by selecting impedances in the preset position sequence as the target impedance.

[0060] In some embodiments, referring to FIG. 4 , the battery pressure detection method further includes: Step S21: inputting excitation signals of multiple test frequencies to the piezoelectric device on the test battery when the air pressure in the test battery is at different pressure values. Step S22: obtaining the test impedance of the piezoelectric device at each test frequency under different air pressure values. Step S23: for each air pressure value, selecting at least one test impedance from the test impedances corresponding to the air pressure value as a target test impedance. Step S24: establishing a relationship between the frequencies corresponding to each target test impedance and each air pressure value to determine a preset corresponding relationship.

[0061] The test battery and the battery requiring air pressure testing are of the same type, that is, they have the same structure, etc., to ensure the accuracy of the air pressure test results. Optionally, the piezoelectric device is positioned on the test battery in the same location as the piezoelectric device on the battery requiring air pressure testing, thereby ensuring the accuracy of the air pressure test results. In other embodiments, the piezoelectric device may be positioned differently. Optionally, the piezoelectric device used in establishing the preset correspondence and the piezoelectric device used in subsequent air pressure testing should be of the same type, for example, with the same material and dimensions. When the air pressure within the test battery is processed at different pressure values, multiple excitation signals of test frequencies are input to the piezoelectric device on the test battery. Specifically, when the air pressure within the test battery is at pressure a, multiple excitation signals of test frequencies are input to the piezoelectric device on the test battery; when the air pressure within the test battery is at pressure b, multiple excitation signals of test frequencies are input to the piezoelectric device on the test battery; and when the air pressure within the test battery is at pressure c, multiple excitation signals of test frequencies are input to the piezoelectric device on the test battery.

[0062] The test impedance of the piezoelectric device at different test frequencies under different air pressure values ​​is shown in Figure 5. In Figure 5, the vertical axis represents the impedance, the horizontal axis represents the frequency of the excitation signal, and the different lines represent the air pressure values ​​in the battery. Obviously, the difference between the air pressure values ​​at different frequencies circled in Figure 5 is large, while the impedance difference corresponding to different air pressure values ​​at other frequencies is small. Different materials of the piezoelectric device or different positions of the piezoelectric device on the battery may cause the piezoelectric device to react to different impedances under different air pressure values ​​when inputting excitation signals of different frequencies. Therefore, Figure 5 is only an example. In step S23, for each air pressure value, at least one test impedance is selected from the test impedances corresponding to the air pressure value as the target test impedance. Specifically, for air pressure value a, one or more test impedances are selected from the test impedances corresponding to air pressure value a as the target test impedance, one or more test impedances are selected from the test impedances corresponding to air pressure value b as the target test impedance, one or more test impedances are selected from the test impedances corresponding to air pressure value c as the target test impedance, and so on. Please refer to Figure 6. The selected target test impedances can establish a scatter plot between air pressure and frequency. Figure 6 only shows some of the air pressure values ​​in Figure 5. Then, a preset corresponding relationship can be established based on the scatter plot between air pressure and frequency.

[0063] In the above scheme, by controlling the air pressure of the test battery to be at different air pressure values, multiple excitation signals of test frequencies are input to the piezoelectric device on the test battery, so that the differences between different frequencies corresponding to the target test impedance at different air pressure values ​​can be observed, such as the frequency difference corresponding to the minimum impedance or maximum impedance at each air pressure value, and thus the preset corresponding relationship is determined according to the relationship between the frequency corresponding to each target test impedance and each air pressure value, so as to facilitate the subsequent determination of the air pressure in the battery using the target frequency corresponding to the target impedance and the preset corresponding relationship.

[0064] In some embodiments, the different frequencies are within a target frequency range, the test frequencies are within the test frequency range, and the test frequency range includes the target frequency range. The step of selecting at least one test impedance from the test impedances corresponding to each air pressure value as the target test impedance may include determining the target frequency range from the test frequency range. Then, determining the target test impedance from a test impedance region corresponding to the target frequency range. The test impedance region is the interval within which the test impedance for air pressure values ​​within the target frequency range lies.

[0065] The test frequency range is wide, and the impedance of the piezoelectric device may not differ significantly at some air pressure values ​​under the same frequency excitation signal. For example, in Figure 5, under the excitation signal frequency range of 666,000 MHz to 978,000 MHz, the impedance corresponding to each air pressure value is almost the same. If the test frequency range is used as the target frequency range, the preset correspondence relationship may be inaccurate. Therefore, this solution selects a frequency range within the test frequency range as the target frequency range, and then determines the target test impedance within the target frequency range, making the preset correspondence relationship more accurate.

[0066] In the above scheme, the test impedance corresponding to the same test frequency at different air pressure values ​​may be slightly different in the test frequency range, which makes it inconvenient to distinguish different air pressure values. If the entire test frequency range is used as the target frequency range, the preset correspondence relationship determined may be inaccurate. Therefore, the scheme can improve the accuracy of the preset correspondence determined subsequently by selecting the target frequency range from the test frequency range.

[0067] In some embodiments, the different frequencies are within a target frequency range, each test frequency is within a test frequency range, and the test frequency range includes the target frequency range. A difference between test impedances corresponding to different air pressure values ​​at the same test frequency in the target frequency range is greater than a difference between test impedances corresponding to different air pressure values ​​at the same test frequency in other frequency ranges, where the other frequency range is a frequency range within the test frequency range excluding the target frequency range.

[0068] Alternatively, the difference between different test frequencies corresponding to the same impedance at different air pressure values ​​within the target frequency range is greater than the difference between different test frequencies corresponding to the same impedance at different air pressure values ​​within other frequencies. For example, the target frequency range may be the frequency range marked with a box in FIG5 .

[0069] In the above scheme, by selecting a frequency range in which the test impedance difference at different air pressure values ​​is large from the test frequency range as the target frequency range, and determining the target test impedance based on the impedances within the range, thereby establishing a corresponding preset correspondence, the detection efficiency and the accuracy of the detected air pressure in the subsequent battery air pressure detection process can be reduced.

[0070] In some embodiments, the target impedance is the maximum impedance or the minimum impedance, and the target test impedance is the maximum test impedance or the minimum test impedance of the air pressure value within the test impedance region. Determining the preset correspondence based on the frequencies and air pressure values ​​corresponding to the target test impedances can include fitting the frequencies and air pressure values ​​corresponding to the maximum test impedance or the minimum test impedance to obtain a fitted line between the frequencies and air pressure values. Determining the preset correspondence based on the fitted line.

[0071] The fitting line can be a straight line or a curve. This solution takes the fitting line as a straight line as an example. The specific fitting method can be to select a straight line so that the sum of the distances between this straight line and all the scattered points is minimized to obtain a fitting straight line. Of course, there are many ways to obtain a fitted straight line or a fitted curve by fitting specific scatter points, which are not specifically limited here. For example, the scatter plot in Figure 6 is fitted to obtain a fitting straight line y = -77.718x + 498676, and the fitting degree R2 = 0.9937. Among them, y represents the frequency, x represents the air pressure value, and the preset corresponding relationship can be specifically understood as the expression of the fitting line. The target frequency corresponding to the target impedance can be substituted into the expression of the fitting line to obtain the air pressure value in the battery.

[0072] In the above scheme, within the target frequency range, the maximum impedance or the frequency corresponding to the impedance of different air pressure values ​​is quite different, so a preset corresponding relationship is established through the maximum test impedance or the minimum test impedance, so that the air pressure value determined subsequently is more accurate.

[0073] In some embodiments, when the air pressure in the test cell is at different pressure values, inputting excitation signals of multiple test frequencies to the piezoelectric device on the test cell includes controlling the air pressure in the test cell using an air pressure control assembly, wherein the air pressure control assembly is connected to the test cell via a through hole defined in the test cell.

[0074] The air pressure control assembly can be any assembly capable of detecting and adjusting the air pressure within the test battery. Specifically, a through hole can be provided in the shell of the test battery, through which the gas transmission channel in the air pressure control assembly is connected to the battery, and the interface then controls the air pressure within the test battery.

[0075] In the above solution, the air pressure in the battery can be controlled to be at a specific air pressure value through the air pressure control component, and the impedance corresponding to the excitation signal of different frequencies is determined at different air pressure values, thereby establishing the preset corresponding relationship.

[0076] In some embodiments, after determining the target impedance from the impedances corresponding to excitation signals of different frequencies and determining the air pressure value in the battery that matches the target impedance, the battery air pressure detection method further includes: executing a preset alarm process in response to the air pressure value in the battery being greater than or equal to a preset air pressure value.

[0077] The preset pressure value can be set as needed and is not specified here. The preset alarm processing can be to display an alarm light, emit an alarm voice, or send an alarm message to a preset recipient. The specific form of the preset alarm processing is not specifically limited here.

[0078] In the above solution, by executing the preset alarm process when the air pressure value in the battery is greater than or equal to the preset air pressure value, accidents caused by excessive air pressure value in the battery can be reduced.

[0079] In some embodiments, the piezoelectric device can be a piezoelectric sheet. The battery can be a battery cell, and the piezoelectric sheet can be coupled to the shell of the battery cell. Specific coupling methods include, but are not limited to, bonding using epoxy resin glue or other adhesive glue. The two electrodes on the piezoelectric sheet are connected to the impedance acquisition component in the air pressure detection device or the impedance acquisition device in the air pressure detection system, and an excitation signal (electrical signal) is applied to the piezoelectric sheet through the two electrodes. The piezoelectric sheet can be set at any position on the battery shell. The piezoelectric sheet causes the coupled shell to vibrate, and the mechanical properties of the shell will be reflected in its vibration form. The vibration of the shell, in turn, causes the piezoelectric sheet to feedback a corresponding electrical signal through the positive piezoelectric effect. The feedback electrical signal carries the change in the mechanical properties of the shell (associated with the change in internal air pressure). The electrical signal collected by the impedance acquisition component or the impedance acquisition device determines its impedance and / or admittance value, and the mechanical properties of the battery shell (internal air pressure) are characterized by its impedance or admittance value.

[0080] In one embodiment, a battery of the same model is opened on the top cover of the shell and connected to the air pressure control component through a conduit. The air pressure control component is used to control the air pressure inside the battery to a fixed value. Then, the impedance acquisition module is used to collect the impedance amplitude of the piezoelectric piece as the frequency changes, and a frequency-impedance amplitude curve under different air pressures is obtained. For example, the frequency is swept from the 10KHz-1MHz range to obtain the impedance amplitude and frequency curve. According to the curve characteristics, the frequency value of the lowest amplitude (lowest impedance) in the characteristic frequency region and the air pressure value are selected to form a frequency-air pressure scatter plot. The scatter plot is fitted to obtain the corresponding fitting line and expression of frequency-air pressure. The battery under test must be a battery of the same system. The piezoelectric piece is coupled to the same position of the battery shell. The impedance acquisition module is used to collect the impedance amplitude of different frequencies. The frequency of the lowest amplitude in the corresponding characteristic frequency region is selected. Through the expression, combined with the frequency of the lowest amplitude, the real-time air pressure value of the battery can be obtained. For example, the expression can be: y = -77.718x + 498676, where y is the frequency and x is the air pressure value inside the battery. When the same type of battery is coupled with a piezoelectric piece at the same position on the top cover, and the resonant frequency measured above is y1, then its internal air pressure can be obtained by the above expression: (498676-y1) / 77.718kPa.

[0081] In one embodiment, a battery of the same model is opened at the bottom end of a side wall of the shell, connected to the air pressure control component through a conduit. The air pressure control component is used to control the internal air pressure of the battery to a fixed value. Then, the impedance acquisition module is used to collect the impedance amplitude of the piezoelectric plate as it changes with frequency, and a frequency-impedance amplitude curve under different air pressures is obtained. According to the characteristics of the curve, the frequency value of the lowest amplitude (lowest impedance) in the characteristic frequency region and the air pressure value are selected to form a frequency-air pressure scatter plot. The scatter plot is fitted to obtain the corresponding fitting line and expression of frequency-air pressure. The battery under test must be a battery of the same system. The piezoelectric plate is coupled to the same position of the battery shell. The impedance acquisition module is used to collect the impedance amplitude of different frequencies. The frequency of the lowest amplitude in the corresponding characteristic frequency region is selected. Through the expression, combined with the frequency of the lowest amplitude, the real-time air pressure value of the battery can be obtained. For example, the expression can be: y = 167.78x + 506710, where y is the frequency and x is the air pressure value inside the battery cell. When the same type of battery cell is coupled with a piezoelectric piece at the same position on the top cover, and the resonant frequency measured above is y2, then its internal air pressure can be obtained by the above expression: (y2-506710) / 167.78kPa.

[0082] This solution uses piezoelectric impedance technology to monitor the internal pressure of the battery in real time. Specifically, the linear correlation between the frequency change at the lowest impedance point and the pressure change is used to achieve real-time characterization of the internal pressure of the battery cell.

[0083] Please refer to Figure 7. The air pressure detection device 30 provided in this application includes a signal input module 31, an impedance acquisition module 32, and an air pressure determination module 33; the signal input module 31 is used to input excitation signals of different frequencies to the piezoelectric device set on the battery; the impedance acquisition module 32 is used to obtain the impedance of the piezoelectric device under excitation signals of different frequencies; the air pressure determination module 33 is used to determine the target impedance from the impedances corresponding to the excitation signals of different frequencies, and determine the air pressure value in the battery that matches the target impedance.

[0084] In the above scheme, an excitation signal is input to the piezoelectric device provided on the battery. The piezoelectric device causes the battery to vibrate after receiving the excitation signal. Since the air pressure inside the battery is different, the vibration form of the battery may be different, and the vibration of the battery affects the impedance of the piezoelectric device through the positive piezoelectric effect. Therefore, the air pressure value inside the battery can be determined based on the impedance of the piezoelectric device under excitation signals of different frequencies. Compared with the drainage method, this scheme does not need to destroy the structure of the battery, nor does it need to pull out the relevant pipelines to detect the air pressure inside the battery.

[0085] In some embodiments, the air pressure determination module 33 determines the air pressure value in the battery that matches the target impedance, including: taking the frequency corresponding to the target impedance as the target frequency; determining the air pressure value that matches the target frequency in a preset correspondence relationship, and the preset correspondence relationship represents the correspondence between the frequency and the air pressure value.

[0086] In the above solution, by establishing a corresponding relationship between frequency and air pressure value, and then determining the target impedance from various impedances, it is possible to determine the air pressure in the battery according to the frequency corresponding to the target impedance.

[0087] In some embodiments, the air pressure determination module 33 determines the target impedance from the impedances corresponding to the excitation signals of different frequencies, including: selecting at least one impedance that meets the conditions required by the preset correspondence from the impedances corresponding to the excitation signals of different frequencies as the target impedance.

[0088] In the above scheme, the preset correspondence relationship can be established based on the frequency corresponding to a specific impedance. Therefore, by selecting at least one impedance that meets the conditions required by the preset correspondence relationship from the impedances corresponding to excitation signals of different frequencies as the target impedance, compared with randomly selecting an impedance as the target impedance, the gas pressure in the battery determined by this scheme is more accurate.

[0089] In some embodiments, determining the target impedance from the impedances corresponding to the excitation signals of different frequencies includes: sorting the excitation signals of different frequencies according to magnitude; and selecting the impedance in a preset sequence as the target impedance.

[0090] In the above scheme, the air pressures corresponding to impedances of different positions in the preset correspondence may be different. Compared with randomly selecting impedances of a position sequence as the target impedance, the accuracy of the detected air pressure can be guaranteed by selecting impedances in the preset position sequence as the target impedance.

[0091] In some embodiments, the air pressure detection device 30 of the battery also includes a relationship determination module (not shown in the figure), which is used to: when the air pressure in the test battery is at different air pressure values, input multiple test frequency excitation signals to the piezoelectric device on the test battery respectively; obtain the test impedance of the piezoelectric device at each test frequency under different air pressure values; for each air pressure value, select at least one test impedance as the target test impedance from the test impedances corresponding to the air pressure value; establish the relationship between the frequency corresponding to each target test impedance and each air pressure value, and determine the preset corresponding relationship.

[0092] In the above scheme, by controlling the air pressure of the test battery to be at different air pressure values, multiple excitation signals of test frequencies are input to the piezoelectric device on the test battery, so that the differences between different frequencies corresponding to the target test impedance at different air pressure values ​​can be observed, such as the frequency difference corresponding to the minimum impedance or maximum impedance at each air pressure value, and thus the preset corresponding relationship is determined according to the relationship between the frequency corresponding to each target test impedance and each air pressure value, so as to facilitate the subsequent determination of the air pressure in the battery using the target frequency corresponding to the target impedance and the preset corresponding relationship.

[0093] In some embodiments, different frequencies are within a target frequency range, each test frequency is within a test frequency range, and the test frequency range includes a target frequency range. The relationship determination module selects at least one test impedance as a target test impedance from each test impedance corresponding to the air pressure value for each air pressure value, including: determining the target frequency range from the test frequency range; determining the target test impedance from a test impedance region corresponding to the target frequency range, and the test impedance region is an interval in which the test impedance of the air pressure value within the target frequency range is located.

[0094] In the above scheme, the test impedance corresponding to the same test frequency at different air pressure values ​​may be slightly different in the test frequency range, which makes it inconvenient to distinguish different air pressure values. If the entire test frequency range is used as the target frequency range, the preset correspondence relationship determined may be inaccurate. Therefore, the scheme can improve the accuracy of the preset correspondence determined subsequently by selecting the target frequency range from the test frequency range.

[0095] In some embodiments, different frequencies are within a target frequency range, each test frequency is within a test frequency range, the test frequency range includes the target frequency range, and the difference between the test impedances corresponding to different air pressure values ​​at the same test frequency in the target frequency range is greater than the difference between the test impedances corresponding to different air pressure values ​​at the same test frequency in other frequency ranges. The other frequency range is the frequency range in the test frequency range other than the target frequency range.

[0096] In the above scheme, by selecting a frequency range in which the test impedance difference at different air pressure values ​​is large from the test frequency range as the target frequency range, and determining the target test impedance based on the impedances within the range, thereby establishing a corresponding preset correspondence, the detection efficiency and the accuracy of the detected air pressure in the subsequent battery air pressure detection process can be reduced.

[0097] In some embodiments, the target impedance is the maximum impedance or the minimum impedance, and the target test impedance is the maximum test impedance or the minimum test impedance of the air pressure value in the test impedance area. The relationship determination module determines the preset corresponding relationship based on the frequency corresponding to each target test impedance and each air pressure value, including: fitting the frequency corresponding to each maximum test impedance or minimum test impedance and each air pressure value to obtain a fitting line of the frequency and the air pressure value; based on the fitting line, determining the preset corresponding relationship.

[0098] In the above scheme, within the target frequency range, the maximum impedance or the frequency corresponding to the impedance of different air pressure values ​​is quite different, so a preset corresponding relationship is established through the maximum test impedance or the minimum test impedance, so that the air pressure value determined subsequently is more accurate.

[0099] In some embodiments, the relationship determination module inputs multiple test frequency excitation signals to the piezoelectric device on the test battery when the air pressure in the test battery is at different pressure values, including: using an air pressure control component to control the air pressure in the test battery, and the air pressure control component is connected to the test battery through a through hole opened on the test battery.

[0100] In the above solution, the air pressure in the battery can be controlled to be at a specific air pressure value through the air pressure control component, and the impedance corresponding to the excitation signal of different frequencies is determined at different air pressure values, thereby establishing the preset corresponding relationship.

[0101] In some embodiments, after determining the target impedance from the impedances corresponding to excitation signals of different frequencies and determining the air pressure value in the battery that matches the target impedance, the battery air pressure detection device also includes an alarm module (not shown), which is used to: execute a preset alarm process in response to the air pressure value in the battery being greater than or equal to a preset air pressure value.

[0102] In the above solution, by executing the preset alarm process when the air pressure value in the battery is greater than or equal to the preset air pressure value, accidents caused by excessive air pressure value in the battery can be reduced.

[0103] Referring to FIG8 , a battery pressure detection device 40 provided in an embodiment of the present application includes an impedance acquisition component 41 and a processor 42. Impedance acquisition component 41 is connected to a piezoelectric device provided on the battery, inputting excitation signals of different frequencies to the piezoelectric device and obtaining the impedance of the piezoelectric device under the excitation signals of different frequencies. Processor 42 is connected to impedance acquisition component 41 and is configured to determine a target impedance from the impedances corresponding to the excitation signals of different frequencies, thereby determining an air pressure value within the battery that matches the target impedance. Processor 42 in air pressure detection device 40 cooperates with impedance acquisition component 41 to implement the air pressure detection method provided in the above-described air pressure detection method embodiment.

[0104] The processor 42 may also be referred to as a CPU (Central Processing Unit). The processor 42 may be an integrated circuit chip having signal processing capabilities. The processor 42 may also be a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components. A general-purpose processor may be a microprocessor or any conventional processor. In addition, the processor 42 may be implemented by an integrated circuit chip.

[0105] In the above scheme, an excitation signal is input to the piezoelectric device provided on the battery. The piezoelectric device causes the battery to vibrate after receiving the excitation signal. Since the air pressure inside the battery is different, the vibration form of the battery may be different, and the vibration of the battery affects the impedance of the piezoelectric device through the positive piezoelectric effect. Therefore, the air pressure value inside the battery can be determined based on the impedance of the piezoelectric device under excitation signals of different frequencies. Compared with the drainage method, this scheme does not need to destroy the structure of the battery, nor does it need to pull out the relevant pipelines to detect the air pressure inside the battery.

[0106] Referring to FIG9 , an embodiment of the present application provides a battery air pressure detection system 50. The air pressure detection system includes an impedance acquisition device 51 and an electronic device 52 that establishes a communication connection with the impedance acquisition device. The impedance acquisition device 51 is used to connect to a piezoelectric device provided on the battery, input excitation signals of different frequencies to the piezoelectric device provided on the battery, and obtain the impedance of the piezoelectric device under the excitation signals of different frequencies. The electronic device 52 is used to determine the target impedance from the impedances corresponding to the excitation signals of different frequencies, and determine the air pressure value within the battery that matches the target impedance. The air pressure detection system 50 can implement the air pressure detection method provided in the above-mentioned air pressure detection method embodiment.

[0107] In the above scheme, an excitation signal is input to the piezoelectric device provided on the battery. The piezoelectric device causes the battery to vibrate after receiving the excitation signal. Since the air pressure inside the battery is different, the vibration form of the battery may be different, and the vibration of the battery affects the impedance of the piezoelectric device through the positive piezoelectric effect. Therefore, the air pressure value inside the battery can be determined based on the impedance of the piezoelectric device under excitation signals of different frequencies. Compared with the drainage method, this scheme does not need to destroy the structure of the battery, nor does it need to pull out the relevant pipelines to detect the air pressure inside the battery.

[0108] In some embodiments, the functions or modules included in the device provided by the embodiments of the present disclosure can be used to execute the method described in the above method embodiments. The specific implementation can refer to the description of the above method embodiments. For the sake of brevity, it will not be repeated here.

[0109] The above description of the various embodiments tends to emphasize the differences between the various embodiments. The same or similar aspects can be referenced with each other and will not be repeated herein for the sake of brevity.

[0110] In the several embodiments provided in this application, it should be understood that the disclosed methods and devices can be implemented in other ways. For example, the device implementation methods described above are only schematic. For example, the division of modules or units is only a logical function division. There may be other division methods in actual implementation. For example, units or components can be combined or integrated into another system, or some features can be ignored or not executed. In another image position, the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, and the indirect coupling or communication connection of devices or units can be electrical, mechanical or other forms.

[0111] In addition, the functional units in the various embodiments of the present application can be integrated into a processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The above-mentioned integrated unit can be implemented in the form of hardware or in the form of a software functional unit. If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application is essentially or the part that contributes to the prior art or all or part of the technical solution can be embodied in the form of a software product, which is stored in a storage medium and includes several instructions for causing a computer device (which can be a personal computer, server, or network device, etc.) or a processor to execute all or part of the steps of the various embodiments of the present application. The aforementioned storage medium includes various media that can store program code, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk.

Claims

1. A method for detecting the air pressure of a battery, characterized in that: include: Inputting excitation signals of different frequencies to the piezoelectric devices arranged on the battery respectively; Obtaining the impedance of the piezoelectric device under the excitation signals of different frequencies; A target impedance is determined from the impedances corresponding to the excitation signals of different frequencies, and an air pressure value in the battery that matches the target impedance is determined.

2. The air pressure detection method according to claim 1, characterized in that: The determining of the air pressure value in the battery that matches the target impedance includes: Using the frequency corresponding to the target impedance as the target frequency; The air pressure value matching the target frequency is determined in a preset corresponding relationship, wherein the preset corresponding relationship represents a corresponding relationship between the frequency and the air pressure value.

3. The air pressure detection method according to claim 2, characterized in that: The determining the target impedance from the impedances corresponding to the excitation signals of different frequencies comprises: At least one impedance that meets the conditions required by the preset corresponding relationship is selected as the target impedance from the impedances corresponding to the excitation signals of different frequencies.

4. The air pressure detection method according to claim 2, characterized in that: The determining the target impedance from the impedances corresponding to the excitation signals of different frequencies comprises: sorting the excitation signals of different frequencies according to their magnitude; The impedance in the preset sequence is selected as the target impedance.

5. The air pressure detection method according to any one of claims 2 to 4, characterized in that: The air pressure detection method also includes: When the air pressure in the test battery is at different pressure values, inputting excitation signals of multiple test frequencies to the piezoelectric device on the test battery respectively; Obtaining the test impedance of the piezoelectric device at each test frequency under different air pressure values; For each of the air pressure values, selecting at least one test impedance from the test impedances corresponding to the air pressure value as a target test impedance; A relationship between the frequencies corresponding to the target test impedances and the air pressure values ​​is established to determine the preset corresponding relationship.

6. The air pressure detection method according to claim 5, characterized in that: The different frequencies are within a target frequency range, each of the test frequencies is within a test frequency range, the test frequency range includes the target frequency range, and for each of the air pressure values, selecting at least one test impedance from each of the test impedances corresponding to the air pressure value as a target test impedance, comprises: determining the target frequency range from the test frequency range; The target test impedance is determined from a test impedance region corresponding to the target frequency range, where the test impedance region is an interval where the test impedance of the air pressure value within the target frequency range is located.

7. The air pressure detection method according to claim 5 or 6, characterized in that: The different frequencies are within a target frequency range, each of the test frequencies is within a test frequency range, the test frequency range includes the target frequency range, the difference between the test impedances corresponding to different air pressure values ​​at the same test frequency in the target frequency range is greater than the difference between the test impedances corresponding to different air pressure values ​​at the same test frequency in other frequency ranges, and the other frequency range is a frequency range in the test frequency range excluding the target frequency range.

8. The air pressure detection method according to claim 5 or 6, characterized in that: The target impedance is the maximum impedance or the minimum impedance, the target test impedance is the maximum test impedance or the minimum test impedance of the air pressure value in the test impedance area, and the relationship between the frequencies corresponding to the target test impedances and the air pressure values ​​is established to determine the preset corresponding relationship, including: Fitting the frequencies corresponding to the maximum test impedance or the minimum test impedance and the air pressure values ​​to obtain fitting lines of the frequencies and the air pressure values; Based on the fitting line, the preset corresponding relationship is determined.

9. The air pressure detection method according to claim 5, characterized in that: When the air pressure in the test battery is at different pressure values, inputting a plurality of excitation signals of test frequencies to the piezoelectric device on the test battery respectively includes: The air pressure in the test battery is controlled by an air pressure control component, and the air pressure control component is connected to the test battery through a through hole opened on the test battery.

10. The air pressure detection method according to any one of claims 1 to 9, characterized in that: After determining the target impedance from the impedances corresponding to the excitation signals of different frequencies and determining the air pressure value in the battery that matches the target impedance, the air pressure detection method further includes: In response to the air pressure value in the battery being greater than or equal to a preset air pressure value, a preset alarm process is executed.

11. A battery air pressure detection device, characterized in that: include: A signal input module, used for inputting excitation signals of different frequencies to the piezoelectric devices arranged on the battery; The impedance acquisition module is used to obtain the impedance of the piezoelectric device under the excitation signals of different frequencies. anti; The air pressure determination module is used to determine a target impedance from the impedances corresponding to the excitation signals of different frequencies, and to determine an air pressure value in the battery that matches the target impedance.

12. A battery air pressure detection device, characterized in that: include: An impedance acquisition component, the impedance acquisition component is used to connect to the piezoelectric device arranged on the battery, and is used to input excitation signals of different frequencies to the piezoelectric device arranged on the battery, and obtain the impedance of the piezoelectric device under the excitation signals of different frequencies; A processor is connected to the impedance acquisition component and is used to determine a target impedance from the impedances corresponding to the excitation signals of different frequencies, and to determine an air pressure value in the battery that matches the target impedance.

13. An air pressure detection system, characterized in that: The air pressure detection system includes an impedance acquisition device and an electronic device that establishes a communication connection with the impedance acquisition device. The impedance acquisition device is used to connect to a piezoelectric device arranged on a battery, and is used to input excitation signals of different frequencies to the piezoelectric device arranged on the battery, and obtain the impedance of the piezoelectric device under the excitation signals of different frequencies. The electronic device is used to determine the target impedance from the impedances corresponding to the excitation signals of different frequencies, and determine the air pressure value in the battery that matches the target impedance.

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