Battery lithium precipitation judgment method and device, electronic equipment and readable storage medium

Abstract

The invention discloses a battery lithium precipitation judgment method, which comprises the following steps: determining a first characteristic frequency and a second characteristic frequency of a battery to be detected, the first characteristic frequency being a frequency corresponding to a junction point of an arc part and a straight line part in a Nyquist diagram of the battery to be detected, and the second characteristic frequency being a frequency corresponding to a junction point of an arc part and a straight line part in a Nyquist diagram of the battery to be detected; the second characteristic frequency is the frequency corresponding to a point of which the imaginary part of the arc part is zero in the Nyquist diagram; obtaining first real part data of the impedance at the first characteristic frequency and second real part data of the impedance at the second characteristic frequency of the to-be-tested battery in different preset charge states; according to the first real part data and the second real part data, acquiring electrochemical transfer internal resistance in different preset charge states; judging whether the electrochemical transfer internal resistance tends to increase and then decrease along with the increase of the preset charge state, and if so, determining that the to-be-detected battery generates lithium precipitation; if not, lithium precipitation does not occur. And whether lithium precipitation occurs in the battery can be quickly and accurately judged. The invention further discloses a lithium precipitation judgment device, electronic equipment and a readable storage medium.

Description

Technical Field

[0001] The present invention belongs to the field of battery detection, and relates to a battery lithium deposition judgment method, a battery lithium deposition judgment device, an electronic device and a readable storage medium. Background Art

[0002] With the popularity of electric vehicles and the rapid development of energy storage systems, lithium-ion batteries are developing towards high energy density and high power density to meet the needs of electric vehicles and energy storage equipment for high efficiency and long battery life. However, although fast charging technology has improved the efficiency of use, it has also brought great challenges to the safety and service life of battery packs. Under high-rate charging, the diffusion rate of lithium ions in the negative electrode is slow, resulting in a large amount of lithium ions accumulating on the surface of the negative electrode, and the negative electrode potential decreases accordingly. When the negative electrode potential is lower than the Li / Li+ equilibrium potential, lithium ions may be deposited on the surface of the negative electrode to form metallic lithium. The precipitated metallic lithium will react with the electrolyte, causing active lithium loss and available capacity decay, ultimately affecting the battery life; more serious lithium precipitation may even pierce the diaphragm, causing short circuit and thermal runaway. How to accurately determine whether lithium precipitation occurs in the battery cell and ensure that the battery cell works in a safe environment is crucial to improving the safety of the battery cell and extending the life of the battery. Existing technologies mainly use three-electrode method, voltage relaxation method, ultrasonic method, and impedance spectroscopy to determine whether lithium precipitation occurs.

[0003] The three-electrode method directly determines whether lithium deposition occurs by introducing a reference electrode into the battery and measuring the change in the negative electrode potential in real time. However, the three-electrode method requires special electrode settings and a complex testing environment, and cannot be applied to the actual battery management system (BMS). Therefore, it is only suitable for experimental research and is difficult to achieve online monitoring.

[0004] The voltage relaxation curve differentiation method measures the curve change of the battery voltage relaxation process after charging and differentiates it to determine whether lithium deposition occurs. The inflection point of the voltage is considered to be an indicator of lithium deposition. However, this method is time-consuming, requires a large amount of data, and has high requirements on battery stability. Due to the long monitoring cycle, the voltage relaxation curve differentiation method is not suitable for practical application scenarios that require fast response.

[0005] The ultrasonic detection method uses the changes in the negative electrode structure caused by the lithium deposition process to determine lithium deposition by detecting changes in ultrasonic reflection, attenuation and propagation speed. However, the detection sensitivity and application range of the ultrasonic method are limited, and it is greatly affected by the internal structure of the battery. The signal is easily interfered, making it difficult to achieve stable and efficient lithium deposition detection in a complex environment, and the detection accuracy is poor.

[0006] Although impedance spectroscopy has high testing accuracy, its operation is cumbersome and complicated, time-consuming, and data processing is complex. Full spectrum scanning of impedance spectrum requires impedance measurement at each frequency point, and it takes a long time to cover the entire frequency band, which makes it difficult to meet rapid response requirements.

[0007] For example, patent document CN110161417A discloses a quantitative analysis method for lithium deposition in lithium-ion batteries based on a three-electrode system. The patent uses a three-electrode method to compare the potential changes of the negative electrode and the reference electrode to determine whether lithium deposition occurs inside the battery. Since the three-electrode method requires a specific test environment and requires the addition of an additional reference electrode, it is not suitable for use in an actual battery management system environment. The three-electrode method has some limitations in determining lithium deposition.

[0008] For example, patent document CN116265934A discloses a lithium ion battery lithium deposition detection method based on ultrasonic detection. The patent uses impedance spectrum testing and ultrasonic scanning, compares with the existing database, and has obvious color difference on the image, so as to judge whether the battery has lithium deposition. The operation and judgment steps are cumbersome and complicated, and the accuracy of the judgment needs to be improved.

[0009] The existing technology is relatively complicated to judge whether the battery cell has lithium deposition. How to quickly and accurately judge whether the battery has lithium deposition, improve the accuracy of lithium deposition judgment, shorten the test time, and avoid tedious and complicated test steps has not been effectively solved. Summary of the invention

[0010] The purpose of the present invention is to solve the problem of how to quickly and accurately determine whether lithium deposition occurs in a battery, improve the accuracy of lithium deposition determination, shorten the test time, and avoid cumbersome and complicated test steps.

[0011] In a first aspect, the present invention provides a method for judging lithium plating in a battery, comprising: determining a first characteristic frequency and a second characteristic frequency of a battery to be tested, the first characteristic frequency being the frequency corresponding to the intersection point of the arc portion and the straight line portion in the Nyquist diagram of the battery to be tested, and the second characteristic frequency being the frequency corresponding to the point where the imaginary part of the arc portion in the Nyquist diagram is zero; respectively testing the impedance of the battery to be tested at the first characteristic frequency and the second characteristic frequency under different preset charge states, obtaining first real part data of the impedance of the battery to be tested at the first characteristic frequency and second real part data of the impedance of the battery to be tested at different preset charge states; obtaining electrochemical transfer internal resistance under different preset charge states according to the first real part data and the second real part data; judging whether the electrochemical transfer internal resistance shows a trend of first increasing and then decreasing with the increase of the preset charge state, and if so, lithium plating occurs in the battery to be tested; if not, lithium plating does not occur in the battery to be tested.

[0012] By adopting the above technical scheme, the first real part data and the second real part data are obtained according to the impedance at the first characteristic frequency and the second characteristic frequency, and the electrochemical transfer internal resistance of the battery to be tested under different charge states is obtained. It is possible to quickly and accurately judge whether lithium deposition occurs in the battery according to the change trend of the electrochemical transfer internal resistance, thereby improving the accuracy of lithium deposition judgment, shortening the test time, avoiding cumbersome and complicated test steps, and being simple, convenient and fast.

[0013] According to another specific embodiment of the present invention, obtaining the electrochemical transfer internal resistance under different preset charge states based on the first real data and the second real data includes: calculating the difference between the first real data and the second real data, the difference is the electrochemical transfer internal resistance of the battery to be tested, the first real data represents the sum of the ohmic internal resistance and the electrochemical transfer internal resistance of the battery to be tested, and the second real data represents the ohmic internal resistance of the battery to be tested.

[0014] According to another specific embodiment of the present invention, respectively testing the impedance of the battery to be tested at the first characteristic frequency and the second characteristic frequency under different preset charge states includes: charging the battery to be tested to different preset charge states in a first charging method, and detecting the impedance of the battery to be tested at the first characteristic frequency and the second characteristic frequency under each preset charge state, wherein the charging rate of the first charging method is 0.1C-6C.

[0015] According to another specific embodiment of the present invention, after the battery to be tested is charged in a first charging mode, the battery to be tested is left to stand at a first preset temperature for a first preset time, and then the impedance of the battery to be tested at a first characteristic frequency and a second characteristic frequency is detected, wherein the first preset temperature is 23-27°C, and the first preset time is 2-3h.

[0016] According to another specific embodiment of the present invention, it also includes: obtaining the electrochemical transfer internal resistance under different preset states of charge according to the first real part data and the second real part data, until lithium deposition occurs in the battery to be tested or until the preset state of charge reaches a preset state of charge cutoff value, and the preset state of charge cutoff value is 100%.

[0017] According to another specific embodiment of the present invention, different preset states of charge satisfy: (a) different preset states of charge are selected from 40%-100%, and the charge state interval between adjacent different preset states of charge is 10%; and / or (b) the starting point of the preset state of charge is 40%-50%.

[0018] According to another specific embodiment of the present invention, determining the first characteristic frequency and the second characteristic frequency of the battery to be tested includes: applying a preset AC voltage to both ends of the sample battery for testing, testing the impedance spectrum of the sample battery, and obtaining a Nyquist diagram, wherein the sample battery is the battery to be tested or a battery of the same type as the battery to be tested; wherein the voltage value of the AC voltage is 10mV, and the frequency range of the AC voltage is 100kHz-0.1Hz.

[0019] In a second aspect, the present invention further provides a battery lithium plating judgment device, comprising: a characteristic frequency determination module, used to determine a first characteristic frequency and a second characteristic frequency of a battery to be tested, the first characteristic frequency being the frequency corresponding to the intersection point of the arc part and the straight line part in the Nyquist diagram of the battery to be tested, and the second characteristic frequency being the frequency corresponding to the point where the imaginary part of the arc part in the Nyquist diagram is zero; a real data acquisition module, used to respectively test the impedance of the battery to be tested at the first characteristic frequency and the second characteristic frequency under different preset charge states, and obtain the first real part data of the impedance of the battery to be tested at the first characteristic frequency and the second real part data of the impedance of the battery to be tested at the second characteristic frequency under different preset charge states; an electrochemical transfer internal resistance determination module, used to obtain the electrochemical transfer internal resistance under different preset charge states according to the first real part data and the second real part data; a lithium plating judgment module, used to judge whether the electrochemical transfer internal resistance shows a trend of first increasing and then decreasing with the increase of the preset charge state, if so, lithium plating occurs in the battery to be tested; if not, lithium plating does not occur in the battery to be tested.

[0020] By adopting the above technical scheme, the battery lithium deposition judgment device obtains the first real part data and the second real part data according to the impedance at the first characteristic frequency and the second characteristic frequency, and obtains the electrochemical transfer internal resistance of the battery to be tested under different charge states. It can quickly and accurately judge whether lithium deposition occurs in the battery according to the change trend of the electrochemical transfer internal resistance, thereby improving the accuracy of lithium deposition judgment, shortening the test time, avoiding tedious and complicated test steps, and being simple, convenient and fast.

[0021] In a third aspect, the present invention further provides an electronic device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the above-mentioned battery lithium deposition judgment method when executing the computer program.

[0022] By adopting the above technical scheme, the electronic device obtains the first real part data and the second real part data according to the impedance at the first characteristic frequency and the second characteristic frequency, and obtains the electrochemical transfer internal resistance of the battery to be tested under different charge states. It can quickly and accurately judge whether lithium deposition occurs in the battery according to the change trend of the electrochemical transfer internal resistance, thereby improving the accuracy of lithium deposition judgment, shortening the test time, avoiding tedious and complicated test steps, and being simple, convenient and fast.

[0023] In a fourth aspect, the present invention further provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the above-mentioned battery lithium deposition judgment method is implemented.

[0024] By adopting the above technical scheme, the first real part data and the second real part data can be obtained according to the impedance at the first characteristic frequency and the second characteristic frequency, and the electrochemical transfer internal resistance of the battery to be tested under different charge states can be obtained. It is possible to quickly and accurately judge whether lithium deposition occurs in the battery according to the change trend of the electrochemical transfer internal resistance, thereby improving the accuracy of lithium deposition judgment, shortening the test time, avoiding tedious and complicated test steps, and being simple, convenient and fast. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 The process of the method for judging the lithium deposition of a battery in the embodiment of the present invention is shown as follows Figure 1 ;

[0026] Figure 2 The process of the method for judging the lithium deposition of a battery in the embodiment of the present invention is shown as follows Figure 2 ;

[0027] Figure 3 The process of the method for judging the lithium deposition of a battery in the embodiment of the present invention is shown as follows Figure 3 ;

[0028] Figure 4 The process of the method for judging the lithium deposition of a battery in the embodiment of the present invention is shown as follows Figure 4 ;

[0029] Figure 5 The process of the method for judging the lithium deposition of a battery in the embodiment of the present invention is shown as follows Figure 5 ;

[0030] Figure 6 A schematic diagram showing the structure of a battery lithium deposition judgment device according to an embodiment of the present invention Figure 1 ;

[0031] Figure 7 A schematic diagram showing the structure of a battery lithium deposition judgment device according to an embodiment of the present invention Figure 2 ;

[0032] Figure 8 A schematic diagram showing the structure of a battery lithium deposition judgment device according to an embodiment of the present invention Figure 3 ;

[0033] Fig. 9 A schematic diagram showing the structure of a battery lithium deposition judgment device according to an embodiment of the present invention Figure 4 ;

[0034] Fig.10 A schematic diagram showing the structure of a battery lithium deposition judgment device according to an embodiment of the present invention Figure 5 ;

[0035] Fig.11 A schematic diagram showing the structure of an electronic device in an embodiment of the present invention is shown;

[0036] Fig.12 The Nyquist diagram of the battery to be tested in the embodiment of the present invention is shown;

[0037] Fig.13 A graph showing the relationship between the modulus of the imaginary part of the impedance and the modulus of the real part of the impedance of the battery to be tested and the frequency in an embodiment of the present invention. DETAILED DESCRIPTION

[0038] The following specific embodiments illustrate the implementation of the present invention, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. Although the description of the present invention will be introduced in conjunction with the preferred embodiment, this does not mean that the features of this invention are limited to this implementation. On the contrary, the purpose of introducing the invention in conjunction with the implementation is to cover other options or modifications that may extend based on the claims of the present invention. In order to provide a deep understanding of the present invention, the following description will include many specific details. The present invention can also be implemented without using these details. In addition, in order to avoid confusion or blurring the focus of the present invention, some specific details will be omitted in the description. It should be noted that the embodiments of the present invention and the features in the embodiments can be combined with each other without conflict.

[0039] It should be noted that in this specification, similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not need to be further defined and explained in the subsequent drawings.

[0040] To make the objectives, technical solutions and advantages of the present invention more clear, the embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

[0041] Lithium deposition refers to the phenomenon that during the charging process of lithium-ion batteries, during the embedding and de-embedding process of lithium ions in electrode materials, due to some reasons, lithium ions fail to successfully embed into the lattice of electrode materials, but precipitate on the electrode surface to form metallic lithium. This phenomenon usually occurs on the negative electrode of the battery (usually graphite material). For a normal battery without lithium deposition, the reaction on the negative electrode surface is:

[0042] x + +xe - +6C→Li x C6 (Formula 1)

[0043] When lithium deposition occurs in the battery, the equation for the lithium deposition reaction is:

[0044] Li + +e- →Li (Formula 2)

[0045] Lithium will precipitate on the surface of the negative electrode, which will puncture the battery separator and cause a short circuit. Lithium precipitation will reduce the available capacity of the battery, affecting the battery's cycle performance and energy efficiency. Lithium precipitation is a negative phenomenon that may occur in lithium-ion batteries during the charging and discharging process, which will lead to a decline in battery performance and even safety hazards.

[0046] The existing technology uses impedance spectroscopy to determine whether lithium is deposited. It is necessary to perform a full spectrum scan of the impedance spectrum of the battery to be tested to determine the shape of the semicircle in the impedance spectrum data. The method is time-consuming, the steps are cumbersome, and the data processing is complex. The full spectrum scan of the impedance spectrum requires impedance measurement at each frequency point. It takes a long time to cover the entire frequency band, which makes it difficult to meet the needs of rapid response.

[0047] In order to solve the problems of time-consuming, cumbersome steps and complex data processing in the prior art, firstly, Figure 1 and Fig.12 As shown, the present invention provides a method for judging lithium deposition in a battery, comprising: S01: determining a first characteristic frequency and a second characteristic frequency of a battery to be tested, wherein the first characteristic frequency is a frequency corresponding to a junction point of an arc portion and a straight line portion in a Nyquist diagram of the battery to be tested, and the second characteristic frequency is a frequency corresponding to a point where the imaginary part of the arc portion in the Nyquist diagram is zero.

[0048] Specifically, in Fig.12 Find the intersection point of the arc part and the straight line part in the Nyquist diagram, get the real part and imaginary part corresponding to the point, get the corresponding first characteristic frequency according to the original data of the point, or calculate the modulus of the real part of the impedance and the modulus of the imaginary part of the impedance according to the real part and imaginary part corresponding to the point, and Fig.13 Find the first characteristic frequency corresponding to the modulus of the real part of the impedance and the modulus of the imaginary part of the impedance in the relationship diagram of the modulus of the imaginary part of the impedance and the modulus of the real part of the impedance with frequency. Fig.12 Find the point where the imaginary part of the arc is zero, get the real part and imaginary part corresponding to the point, get the corresponding second characteristic frequency according to the original data of the point, or calculate the modulus of the real part of the impedance and the modulus of the imaginary part of the impedance according to the real part and imaginary part corresponding to the point, and Fig.13 The second characteristic frequency in the high frequency region corresponding to the modulus of the real part of the impedance and the modulus of the imaginary part of the impedance is found in the relationship diagram of the modulus of the imaginary part of the impedance and the modulus of the real part of the impedance as a function of frequency.

[0049] Among them, the modulus of the real part of the impedance and the modulus of the imaginary part of the impedance are calculated as follows:

[0050] Z=R+jX (Formula 3)

[0051]

[0052] In the formula, Z represents impedance, R represents the real part of impedance, X represents the imaginary part of impedance, |Z R | represents the magnitude of the real part of the impedance, |Z X | represents the modulus of the imaginary part of impedance, j represents the unit of the imaginary part, j 2 =-1.

[0053] S02: Test the impedance of the battery to be tested at the first characteristic frequency and the second characteristic frequency under different preset charge states respectively, and obtain the first real part data of the impedance of the battery to be tested at the first characteristic frequency and the second real part data of the impedance of the battery to be tested at the second characteristic frequency under different preset charge states. Among them, testing the impedance of the battery to be tested at the first characteristic frequency and the second characteristic frequency under different preset charge states respectively means that the test condition is to test the impedance at the first characteristic frequency and the second characteristic frequency, and only the impedance of the first characteristic frequency and the second characteristic frequency are tested, rather than performing a full spectrum impedance spectrum test on the battery to be tested. Only the impedance data of two single points at the first characteristic frequency and the second characteristic frequency are tested.

[0054] S03: Obtain electrochemical transfer internal resistance under different preset charge states according to the first real part data and the second real part data. Specifically, the first real part data represents the sum of the ohmic internal resistance and the electrochemical transfer internal resistance, and the second real part data represents the ohmic internal resistance. The electrochemical transfer internal resistance is obtained according to the difference between the first real part data and the second real part data.

[0055] S04: Determine whether the electrochemical transfer internal resistance shows a trend of first increasing and then decreasing with the increase of the preset state of charge. If so, execute S05-1: lithium deposition occurs in the battery to be tested; if not, execute S05-2: lithium deposition does not occur in the battery to be tested. When lithium deposition does not occur in the battery, the electrochemical transfer internal resistance increases with the increase of the state of charge. When lithium deposition occurs, the electrochemical transfer internal resistance will drop sharply. With the increase of the state of charge, the electrochemical transfer internal resistance shows a trend of first increasing and then decreasing. When the electrochemical transfer internal resistance shows a trend of first increasing and then decreasing with the state of charge, it is considered that lithium deposition occurs. This is because when lithium is deposited, the lithium deposition behavior will transfer part of the negative electrode charging current. Part of the current is the current of lithium ions embedded in the negative electrode, and part of the current is the current of lithium ions deposited on the surface of the negative electrode (that is, the lithium deposition current). The current of lithium ions deposited on the surface of the negative electrode proceeds simultaneously with the normal lithium insertion reaction of the negative electrode, which is equivalent to connecting a resistance caused by lithium deposition in parallel on the basis of the original electrochemical transfer internal resistance, thereby reducing the total charge transfer impedance during the charging process, and thereby reducing the electrochemical transfer internal resistance. The lithium deposition battery cell shows that the electrochemical transfer internal resistance first increases and then decreases with the increase of the state of charge.

[0056] The Nyquist plot shows the changes in the real and imaginary parts of the impedance obtained by performing an impedance test under currents of different frequencies. The frequency refers to the frequency of the AC signal (voltage or current) applied to the battery under test in the impedance spectrum test. Since the time interval for applying the AC signal for impedance testing and the frequency of the impedance test are reciprocal to each other, the lower the frequency of the impedance test, the longer the time interval for applying the AC signal. Fig.12 : is the Nyquist diagram of the battery to be tested in the embodiment of the present invention, the horizontal axis is the real part of the impedance of the battery to be tested, the unit is ohm (Ω), and the vertical axis is the imaginary part of the impedance of the battery to be tested, the unit is ohm (Ω). In this embodiment, the AC signal is an AC current. The impedance test is performed under currents of different frequencies, and the horizontal axis of the Nyquist diagram obtained is from left to right, and the frequency of the current of the impedance test gradually decreases, and the graph is in the form of arcs and straight lines.

[0057] refer to Fig.12 , the arc part with the ordinate greater than or equal to zero in the Nyquist plot represents the high-frequency region of the impedance test of the battery to be tested. In the high-frequency region, due to the small time interval of applying the AC current, the impedance of the battery to be tested only represents the ohmic internal resistance, and the electrochemical transfer phenomenon and diffusion phenomenon have not yet occurred. The impedance of the impedance spectrum test in the high-frequency region can represent the ohmic internal resistance. Since impedance is a complex number consisting of a real part and an imaginary part, when the imaginary part is equal to zero, the value of the real part of the impedance is equal to the actual value of the impedance, then the real part of the impedance with the imaginary part of zero in the arc region of the Nyquist plot is equal to the ohmic internal resistance.

[0058] The arc portion of the Nyquist plot with a vertical coordinate less than zero represents the intermediate frequency region of the impedance test of the battery to be tested. In the intermediate frequency region, electrochemical transfer and diffusion phenomena will occur. The diffusion phenomenon has a very small effect on the impedance in the intermediate frequency test stage and can be ignored in this stage. Therefore, the impedance measured in the intermediate frequency test stage is equivalent to the sum of the ohmic internal resistance and the electrochemical transfer internal resistance. In the intermediate frequency region, the ohmic internal resistance remains unchanged. As the frequency of the impedance test gradually decreases, the time interval for applying the alternating current gradually increases, and the time for the electrochemical transfer phenomenon to occur gradually becomes longer, which is correspondingly manifested as a gradual increase in the electrochemical transfer internal resistance until, for example, Fig.12 Point A in the Nyquist diagram is the intersection of the arc and the straight line. At this time, the electrochemical transfer phenomenon is complete and the electrochemical transfer internal resistance reaches the maximum, which represents the final electrochemical transfer internal resistance of the battery. After that, the frequency continues to decrease and reaches the low-frequency region, that is, Fig.12In the straight line area, the electrochemical transfer internal resistance no longer increases and remains unchanged. However, the influence of diffusion phenomenon on impedance in the low-frequency area begins to increase, and the impedance measured in the low-frequency area is the sum of ohmic internal resistance, electrochemical transfer internal resistance and diffusion internal resistance. Therefore, the impedance corresponding to point A can be selected to reflect the sum of ohmic internal resistance and electrochemical transfer internal resistance of the battery to be tested. Since the imaginary part of the impedance at the intersection of the arc and the straight line in the Nyquist diagram is close to zero, the real part of the impedance here can represent the sum of ohmic internal resistance and electrochemical transfer internal resistance.

[0059] like Fig.13 As shown, Fig.13 A diagram showing the relationship between the modulus of the imaginary part of the impedance and the modulus of the real part of the impedance of two batteries to be tested and the frequency changes in the embodiment of the present invention is shown, which are a first battery to be tested and a second battery to be tested, and the two batteries to be tested are of the same type. Fig.13 The horizontal axis is the impedance test frequency (frequency), and the vertical axis is the impedance modulus. Specifically, the first type of curve in the figure is a trend curve of the modulus of the real part of the impedance and the frequency corresponding to the test of the real part of the impedance, and the second type of curve is a trend curve of the modulus of the imaginary part of the impedance and the frequency corresponding to the test of the imaginary part of the impedance. According to the relationship diagram of the modulus of the imaginary part of the impedance and the modulus of the real part of the impedance changing with the frequency, the frequency of the impedance test corresponding to the real and imaginary parts of different impedances of the battery can be obtained, and then the frequency corresponding to point A and point B in the above Nyquist diagram can be obtained.

[0060] because Fig.12 The real part of the impedance at point A represents the sum of the ohmic internal resistance and the electrochemical transfer internal resistance, and the real part of the impedance at point B represents the ohmic internal resistance. Therefore, it is only necessary to determine the frequency conditions corresponding to the impedance at point A and the impedance at point B of the battery to be tested, that is, the first characteristic frequency and the second characteristic frequency mentioned above, and then only apply the first characteristic frequency and the second characteristic frequency to the battery to be tested for impedance testing, so that the impedance at these two frequencies can be obtained, and the real part data corresponding to these two impedances, that is, the first real part data and the second real part data, can be further obtained, so that the sum of the ohmic internal resistance and the electrochemical transfer internal resistance and the ohmic internal resistance can be obtained, thereby further obtaining the final electrochemical transfer internal resistance of the battery to be tested without the need for full spectrum scanning.

[0061] Specifically, regarding the method of determining the first characteristic frequency and the second characteristic frequency, one method can be obtained through Nyquist plot data, and software can be used to find the frequency information applied behind the above-mentioned point A impedance and point B impedance in the data, thereby determining the above-mentioned first characteristic frequency and the second characteristic frequency.

[0062] As another specific implementation of the present invention, the frequency corresponding to the impedance of point A and point B in the Nyquist diagram can also be obtained directly according to the relationship diagram of the modulus of the imaginary part of the impedance and the modulus of the real part of the impedance with frequency. In the relationship diagram of the modulus of the imaginary part of the impedance and the modulus of the real part of the impedance with frequency, find the point where the real and imaginary parts of the impedance are the same as the real and imaginary parts of point A in the Nyquist diagram, and obtain the frequency corresponding to the point from the relationship diagram of the modulus of the imaginary part of the impedance and the modulus of the real part of the impedance with frequency, which is the above-mentioned first characteristic frequency. Similarly, in the relationship diagram of the modulus of the imaginary part of the impedance and the modulus of the real part of the impedance with frequency, find the point where the real and imaginary parts of the impedance are the same as the real and imaginary parts of point B in the Nyquist diagram, and obtain the frequency corresponding to the point from the relationship diagram of the modulus of the imaginary part of the impedance and the modulus of the real part of the impedance with frequency, which is the above-mentioned second characteristic frequency. In addition, two characteristic frequencies can also be obtained by finding two minimum values ​​of the second type of curve in the relationship diagram of the modulus of the imaginary part of the impedance and the modulus of the real part of the impedance with frequency. The minimum of the two minimum values ​​corresponds to point B in the Nyquist diagram, that is, the point where the imaginary part of the arc portion is zero, and the frequency corresponding to the minimum value is the second characteristic frequency. The other minimum value corresponds to point A in the Nyquist diagram, that is, the intersection of the arc portion and the straight line portion, and the frequency corresponding to the minimum value is the first characteristic frequency. Therefore, a specific embodiment of the present application determines the first characteristic frequency and the second characteristic frequency based on two minimum values ​​on a graph of the relationship between the modulus of the imaginary part of the impedance and the modulus of the real part of the impedance and the frequency.

[0063] Further, for the battery to be tested, the final electrochemical transfer internal resistance of the battery to be tested will change with the change of the state of charge of the battery to be tested. When lithium deposition does not occur in the battery to be tested, the electrochemical transfer internal resistance increases with the increase of the state of charge. When lithium deposition occurs, the electrochemical transfer internal resistance will drop sharply. With the increase of the state of charge, the electrochemical transfer internal resistance shows a trend of first increasing and then decreasing. When the electrochemical transfer internal resistance shows a trend of first increasing and then decreasing with the state of charge, it is considered that lithium deposition occurs. Therefore, the electrochemical transfer internal resistance of the battery to be tested under different states of charge is detected, so as to obtain the change trend of the electrochemical transfer internal resistance of the battery to be tested under different states of charge, and determine whether lithium deposition occurs in the battery to be tested.

[0064] By adopting the above technical scheme, the electrochemical transfer internal resistance of the battery to be tested under different charge states is obtained according to the first real part data and the second real part data. When the electrochemical transfer internal resistance shows a trend of first increasing and then decreasing, it is considered that lithium deposition has occurred. It is possible to quickly and accurately judge whether lithium deposition has occurred in the battery according to the change trend of the electrochemical transfer internal resistance, thereby improving the accuracy of lithium deposition judgment, shortening the test time, avoiding cumbersome and complicated test steps, and improving the convenience of operation. By monitoring the changes in the electrochemical transfer internal resistance of the battery under different charge states, the method can more accurately judge whether lithium deposition has occurred in the battery. There is no need to perform destructive testing on the battery, only the impedance of the battery needs to be tested at a specific frequency, so it will not affect the normal use of the battery. The above embodiment only tests the impedance data at two specific frequencies, rather than performing a full spectrum test, which reduces the time required for the test and simplifies the operation steps.

[0065] According to another specific embodiment of the present invention, Figure 2 As shown, S03: according to the first real data and the second real data, obtaining the electrochemical transfer internal resistance under different preset charge states includes: S031: calculating the difference between the first real data and the second real data, the difference is the electrochemical transfer internal resistance of the battery to be tested, the first real data represents the sum of the ohmic internal resistance and the electrochemical transfer internal resistance of the battery to be tested, and the second real data represents the ohmic internal resistance of the battery to be tested.

[0066] By adopting the above technical solution, the electrochemical transfer internal resistance can be accurately measured, and the occurrence of lithium deposition can be detected more accurately. By calculating the difference between the first real part data (representing the sum of the ohmic internal resistance and the electrochemical transfer internal resistance) and the second real part data (representing the ohmic internal resistance), the value of the electrochemical transfer internal resistance can be directly obtained. The occurrence of lithium deposition can be accurately judged, and the degree of lithium deposition can be quantified according to the size of the electrochemical transfer internal resistance.

[0067] According to another specific embodiment of the present invention, Figure 3 As shown, S02: testing the impedance of the battery to be tested at the first characteristic frequency and the second characteristic frequency under different preset charge states respectively includes: S021: charging the battery to be tested to different preset charge states respectively in a first charging method, and detecting the impedance of the battery to be tested at the first characteristic frequency and the second characteristic frequency under each preset charge state, wherein the charging rate of the first charging method is 0.1C-6C.

[0068] By adopting the above technical solution, the battery can be accurately controlled to reach different preset charge states by using a specific first charging method, which helps to ensure the consistency and repeatability of the test. Using the same charging rate for each test helps to reduce the fluctuation of test data caused by different charging rates, and improve the reliability of data and the accuracy of test results.

[0069] In some embodiments, the charging rate of the first charging method is selected from 0.1C-6C, and the lithium deposition phenomenon under different charging rates can be tested to determine whether lithium deposition occurs at different rates and explore the law of lithium deposition. Allowing different charging rates to be used can adapt to different charging scenarios and needs, such as fast charging or slow charging, making the method more flexible and practical.

[0070] According to another specific embodiment of the present invention, after the battery to be tested is charged in a first charging mode, the battery to be tested is left to stand at a first preset temperature for a first preset time, and then the impedance of the battery to be tested at a first characteristic frequency and a second characteristic frequency is detected, wherein the first preset temperature is 23-27°C, and the first preset time is 2-3h.

[0071] By adopting the above technical solution, it is possible to ensure that the battery to be tested is stably standing for a period of time after charging before performing impedance testing. After charging, the battery to be tested is standing for a period of time to ensure that the internal chemical reaction of the battery to be tested reaches a stable state, so that more accurate and consistent data can be obtained during impedance testing, and the accuracy of lithium precipitation judgment can be ensured. By standing the battery to be tested at a specific first preset temperature and a first preset time, the test error caused by temperature fluctuations or incomplete chemical reactions of the battery to be tested is reduced. The fixed first preset standing time and first preset temperature conditions help to improve the repeatability of the test results, so that the impedance data tested under different charge states can be compared with each other, thereby improving the accuracy of the test. Setting the standing temperature within the range of 23-27°C, close to room temperature, helps to provide a standardized test environment close to room temperature. Performing impedance testing after standing at a stable first preset temperature and a sufficient first preset time helps to more accurately detect lithium precipitation, because the change in electrochemical transfer internal resistance caused by lithium precipitation is more obvious in a stable state.

[0072] According to another specific embodiment of the present invention, Figure 4 As shown, it also includes: S06: according to the first real part data and the second real part data, obtaining the electrochemical transfer internal resistance under different preset charge states, until lithium deposition occurs in the battery to be tested or until the preset charge state reaches a preset charge state cutoff value, and the preset charge state cutoff value is 100%.

[0073] Specifically, when lithium deposition is detected in the battery to be tested, a lithium deposition signal is issued, and the battery to be tested is no longer charged or tested. When the preset state of charge reaches the preset state of charge cutoff value, that is, when the preset state of charge reaches 100%, the battery to be tested is no longer charged or tested.

[0074] The above technical solution can prevent the failure of the battery under test caused by continued charging after lithium plating occurs, and can also prevent damage to the battery caused by continued charging after the state of charge reaches 100%. Avoiding lithium plating can reduce battery damage and extend the battery life. Preventing battery overcharging can improve the safety of battery use.

[0075] According to another specific embodiment of the present invention, different preset states of charge satisfy: (a) different preset states of charge are selected from 40%-100%, and the interval between adjacent different preset states of charge is 10%; and / or (b) the starting point of the preset state of charge is 40%-50%. For example, the preset states of charge are 40%, 50%, 60%, 70%, 80%, 90% and 100%. For another example, the preset states of charge are 45%, 55%, 65%, 75%, 85%, 95% and 100%.

[0076] By adopting the above technical solution, since lithium plating generally occurs when the state of charge is relatively high, and generally does not occur when the preset state of charge is relatively low, setting the starting point of the preset state of charge to 40%-50%, or the preset state of charge is selected from 40%-100%, can reduce the workload and data volume, and improve the efficiency of lithium plating detection of the battery to be tested.

[0077] According to another specific embodiment of the present invention, Figure 5 , S01 determines the first characteristic frequency and the second characteristic frequency of the battery to be tested, including: S011: applying a preset AC voltage to both ends of the sample battery for testing, testing the impedance spectrum of the sample battery, and obtaining the Nyquist plot, the sample battery is the battery to be tested or a battery of the same type as the battery to be tested; wherein the voltage value of the AC voltage is 10mV, and the frequency range of the AC voltage is 100kHz-0.1Hz.

[0078] For the method of obtaining the above-mentioned Nyquist diagram and / or the modulus of the imaginary part of the impedance and the modulus of the real part of the impedance versus frequency relationship data of the battery to be tested, it is possible to obtain the data of the Nyquist diagram and / or the modulus of the imaginary part of the impedance and the modulus of the real part of the impedance versus frequency relationship data of a battery of the same type as the battery to be tested, and determine the first characteristic frequency and the second characteristic frequency that need to be applied to the battery to be tested by finding the frequency of the battery of the same type as the battery to be tested. Fig.13 The first battery to be tested and the second battery to be tested are the same type of batteries. It can be seen that the same type of batteries have the same first characteristic frequency and second characteristic frequency. Therefore, the first characteristic frequency and the second characteristic frequency of the battery to be tested can be determined by referring to the Nyquist diagram of the same type of batteries and / or the modulus of the imaginary part of the impedance and the modulus of the real part of the impedance versus frequency.

[0079] In addition, for the battery to be tested that does not have the Nyquist diagram or the modulus of the imaginary part of the impedance and the modulus of the real part of the impedance versus frequency, a full spectrum scanning impedance spectrum test can be performed on the battery to be tested to obtain the Nyquist diagram and / or the modulus of the imaginary part of the impedance and the modulus of the real part of the impedance versus frequency, and then determine the first characteristic frequency and the second characteristic frequency. After that, the impedance test of the battery to be tested is performed at different charge states using the first characteristic frequency and the second characteristic frequency determined by the above test, so as to determine the electrochemical transfer internal resistance of the battery to be tested at different charge states, without the need for a full spectrum scanning impedance test in subsequent tests.

[0080] The above technical solution uses a fixed AC voltage value (10mV) and frequency range (100kHz-0.1Hz) for testing, ensuring the standardization of test conditions and making different tests comparable. The frequency range from 100kHz to 0.1Hz covers the high-frequency, medium-frequency and low-frequency regions in the battery impedance spectrum, which can comprehensively evaluate the electrochemical behavior of the battery and determine whether lithium deposition has occurred. Fixed test parameters help improve the repeatability of the test, so that the results obtained at different times or on different test equipment are consistent, thereby improving the accuracy of lithium deposition judgment.

[0081] Specifically, the state of charge of the sample battery is preferably 10%-90%. The first characteristic frequency and the second characteristic frequency measured under this state of charge are more accurate and can better represent the sum of the ohmic internal resistance and the electrochemical transfer internal resistance and the ohmic internal resistance of the battery to be tested.

[0082] In some embodiments, the sample battery is, for example, a battery that has been charged and discharged 1-3 times. After 1-3 charge and discharge cycles, the internal chemical reaction of the battery tends to be stable, and the active material is activated to a certain extent, which helps to obtain stable and consistent impedance data in the test.

[0083] Second, as Figure 6As shown, the present invention also provides a battery lithium plating judgment device 100, including: a characteristic frequency determination module 101, used to determine the first characteristic frequency and the second characteristic frequency of the battery to be tested, the first characteristic frequency is the frequency corresponding to the intersection point of the arc part and the straight line part in the Nyquist diagram of the battery to be tested, and the second characteristic frequency is the frequency corresponding to the point where the imaginary part of the arc part in the Nyquist diagram is zero; a real data acquisition module 102, used to test the impedance of the battery to be tested at the first characteristic frequency and the second characteristic frequency under different preset charge states, respectively, to obtain the first real part data of the impedance of the battery to be tested at the first characteristic frequency and the second real part data of the impedance of the battery to be tested at different preset charge states; an electrochemical transfer internal resistance determination module 103, used to obtain the electrochemical transfer internal resistance under different preset charge states according to the first real part data and the second real part data; a lithium plating judgment module 104, used to judge whether the electrochemical transfer internal resistance shows a trend of first increasing and then decreasing with the increase of the preset charge state, if so, lithium plating occurs in the battery to be tested; if not, lithium plating does not occur in the battery to be tested.

[0084] By adopting the above technical scheme, the battery lithium deposition judgment device 100 obtains the first real part data and the second real part data according to the impedance at the first characteristic frequency and the second characteristic frequency, and obtains the electrochemical transfer internal resistance of the battery to be tested under different charge states. It can quickly and accurately judge whether lithium deposition occurs in the battery according to the change trend of the electrochemical transfer internal resistance, thereby improving the accuracy of lithium deposition judgment, shortening the test time, avoiding tedious and complicated test steps, and being simple, convenient and fast.

[0085] In some embodiments, reference Figure 7 The battery lithium deposition judgment device 100 also includes: an electrochemical transfer internal resistance calculation module 105, which is used to calculate the difference between the first real part data and the second real part data, the difference is the electrochemical transfer internal resistance of the battery to be tested, the first real part data represents the sum of the ohmic internal resistance and the electrochemical transfer internal resistance of the battery to be tested, and the second real part data represents the ohmic internal resistance of the battery to be tested.

[0086] In some embodiments, reference Figure 8 The battery lithium deposition judgment device 100 also includes: a charging module 106, which is used to charge the battery to be tested to different preset charge states in a first charging method, and detect the impedance of the battery to be tested at a first characteristic frequency and a second characteristic frequency in each preset charge state, wherein the charging rate of the first charging method is 0.1C-6C.

[0087] In some embodiments, reference Fig. 9The battery lithium deposition judgment device 100 also includes: a detection cutoff module 107, which is used to obtain the electrochemical transfer internal resistance under different preset charge states according to the first real part data and the second real part data, until lithium deposition occurs in the battery to be tested or until the preset charge state reaches a preset charge state cutoff value, and the preset charge state cutoff value is 100%.

[0088] In some embodiments, reference Fig.10 The battery lithium plating judgment device 100 also includes: an impedance spectrum testing module 108, which is used to apply a preset AC voltage to both ends of the sample battery for testing, test the impedance spectrum of the sample battery, and obtain a Nyquist diagram. The sample battery is the battery to be tested or a battery of the same type as the battery to be tested; wherein the voltage value of the AC voltage is 10mV, and the frequency range of the AC voltage is 100kHz-0.1Hz.

[0089] Thirdly, Fig.11 As shown, the present invention also provides an electronic device 200, including a memory 201, a processor 202, and a computer program stored in the memory 201 and executable on the processor 202, and the processor 202 implements the above-mentioned battery lithium deposition judgment method when executing the computer program.

[0090] By adopting the above technical scheme, the electronic device obtains the first real part data and the second real part data according to the impedance at the first characteristic frequency and the second characteristic frequency, and obtains the electrochemical transfer internal resistance of the battery to be tested under different charge states. It can quickly and accurately judge whether lithium deposition occurs in the battery according to the change trend of the electrochemical transfer internal resistance, thereby improving the accuracy of lithium deposition judgment, shortening the test time, avoiding tedious and complicated test steps, and being simple, convenient and fast.

[0091] In a fourth aspect, the present invention further provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the above-mentioned battery lithium deposition judgment method is implemented.

[0092] By adopting the above technical scheme, the first real part data and the second real part data are obtained according to the impedance at the first characteristic frequency and the second characteristic frequency, and the electrochemical transfer internal resistance under different charge states of the battery to be tested is obtained. According to the change trend of the electrochemical transfer internal resistance, it is possible to quickly and accurately judge whether lithium deposition occurs in the battery, thereby improving the accuracy of lithium deposition judgment, shortening the test time, avoiding cumbersome and complicated test steps, and being simple, convenient and fast.

[0093] Those skilled in the art will appreciate that embodiments of the present invention may be provided as methods, systems, or computer program products. Therefore, the present invention may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present invention may take the form of a computer program product implemented on one or more computer-usable non-transient storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0094] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0095] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0096] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0097] Although the present invention has been illustrated and described with reference to certain preferred embodiments of the present invention, it should be understood by those skilled in the art that the above is a further detailed description of the present invention in conjunction with specific embodiments, and it cannot be determined that the specific implementation of the present invention is limited to these descriptions. Those skilled in the art may make various changes in form and details, including making several simple deductions or substitutions, without departing from the spirit and scope of the present invention.

Claims

1. A method for judging battery lithium deposition, characterized in that: include: Determine a first characteristic frequency and a second characteristic frequency of the battery to be tested, wherein the first characteristic frequency is a frequency corresponding to a junction point of a circular arc portion and a straight line portion in a Nyquist diagram of the battery to be tested, and the second characteristic frequency is a frequency corresponding to a point in the Nyquist diagram where an imaginary part of the circular arc portion is zero; Respectively testing the impedance of the battery to be tested at the first characteristic frequency and the second characteristic frequency under different preset charge states, and obtaining first real part data of the impedance of the battery to be tested at the first characteristic frequency and second real part data of the impedance of the battery to be tested at the second characteristic frequency under different preset charge states; Obtaining electrochemical transfer internal resistance under different preset charge states according to the first real part data and the second real part data; It is determined whether the electrochemical transfer internal resistance increases first and then decreases with the increase of the preset state of charge. If so, lithium deposition occurs in the battery to be tested; if not, lithium deposition does not occur in the battery to be tested.

2. The method for determining battery lithium deposition as claimed in claim 1, characterized in that: The obtaining of the electrochemical transfer internal resistance under different preset charge states according to the first real part data and the second real part data comprises: The difference between the first real part data and the second real part data is calculated, the difference being the electrochemical transfer internal resistance of the battery to be tested, the first real part data representing the sum of the ohmic internal resistance and the electrochemical transfer internal resistance of the battery to be tested, and the second real part data representing the ohmic internal resistance of the battery to be tested.

3. The method for determining battery lithium deposition as claimed in claim 1, characterized in that: The method of respectively testing the impedance of the battery to be tested at the first characteristic frequency and the second characteristic frequency under different preset states of charge includes: charging the battery to be tested to different preset states of charge in a first charging method, and detecting the impedance of the battery to be tested at the first characteristic frequency and the second characteristic frequency under each preset state of charge, wherein the charging rate of the first charging method is 0.1C-6C.

4. The method for determining battery lithium deposition as claimed in claim 3, characterized in that: After charging the battery to be tested in the first charging mode, the battery to be tested is left to stand at a first preset temperature for a first preset time, and then the impedance of the battery to be tested at the first characteristic frequency and the second characteristic frequency is detected, wherein the first preset temperature is 23-27°C, and the first preset time is 2-3h.

5. The method for determining battery lithium deposition as claimed in claim 1, characterized in that: Also includes: According to the first real part data and the second real part data, the electrochemical transfer internal resistance under different preset states of charge is obtained until lithium deposition occurs in the battery to be tested or until the preset state of charge reaches a preset state of charge cutoff value, and the preset state of charge cutoff value is 100%.

6. The method for determining battery lithium deposition as claimed in claim 1, characterized in that: The different preset states of charge satisfy: (a) the different preset states of charge are selected from 40% to 100%, and the interval between adjacent different preset states of charge is 10%; And / or (b) the starting point of the preset state of charge is 40%-50%.

7. The method for determining battery lithium deposition as claimed in claim 1, characterized in that: Determining the first characteristic frequency and the second characteristic frequency of the battery to be tested includes: A preset AC voltage is applied to both ends of the sample battery for testing, and the impedance spectrum of the sample battery is tested to obtain the Nyquist plot. The sample battery is the battery to be tested or a battery of the same type as the battery to be tested; The voltage value of the AC voltage is 10 mV, and the frequency range of the AC voltage is 100 kHz-0.1 Hz.

8. A battery lithium deposition judgment device, characterized in that: include: A characteristic frequency determination module, used to determine a first characteristic frequency and a second characteristic frequency of the battery to be tested, wherein the first characteristic frequency is a frequency corresponding to a junction point of a circular arc portion and a straight line portion in a Nyquist diagram of the battery to be tested, and the second characteristic frequency is a frequency corresponding to a point in the Nyquist diagram where an imaginary part of the circular arc portion is zero; a real part data acquisition module, used to respectively test the impedance of the battery under test at the first characteristic frequency and the second characteristic frequency under different preset charge states, and obtain first real part data of the impedance of the battery under test at the first characteristic frequency and second real part data of the impedance at the second characteristic frequency under different preset charge states; an electrochemical transfer internal resistance determination module, configured to obtain the electrochemical transfer internal resistance under different preset charge states according to the first real part data and the second real part data; The lithium deposition judgment module is used to judge whether the electrochemical transfer internal resistance shows a trend of first increasing and then decreasing with the increase of the preset state of charge. If so, lithium deposition occurs in the battery to be tested; if not, lithium deposition does not occur in the battery to be tested.

9. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, the battery lithium deposition judgment method according to any one of claims 1 to 7 is implemented.

10. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the battery lithium deposition determination method according to any one of claims 1 to 7 is implemented.

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