Charging control method and device, electronic equipment and storage medium

Abstract

The invention discloses a charging control method and device, electronic equipment and a storage medium. The method comprises the steps of obtaining a current impedance value and a current health degree of a rechargeable battery under the condition that the rechargeable battery is charged through a charging signal; determining a target minimum impedance value corresponding to the current health degree according to a preset corresponding relationship between the health degree and the minimum impedance value; and controlling the charging signal according to the size relationship between the current impedance value and the target minimum impedance value. The impedance value and the health degree of the battery can be rapidly obtained in the battery charging process, charging control is carried out according to the impedance value and the health degree, and the effect of accurately controlling battery charging under the condition that the battery is not damaged is achieved.

Description

Technical Field

[0001] The embodiments of the present application relate to the field of charging technology, and are related to but not limited to a charging control method and device, an electronic device, and a storage medium. Background Art

[0002] Fast charging requires increasing the battery charging rate, which often triggers side reactions in the battery. Taking lithium-ion batteries such as graphite negative electrode systems as an example, when the negative electrode overpotential is lower than 0V vs. Li / Li+, lithium deposition occurs on the negative electrode surface, seriously affecting charging safety and battery life. Whether lithium deposition occurs on the negative electrode can be determined by whether the negative electrode overpotential is lower than the critical potential for lithium deposition. Monitoring and controlling the negative electrode overpotential during charging can effectively avoid the occurrence of side reactions such as lithium deposition and achieve safe and fast charging of the battery.

[0003] The existing technology can obtain the terminal voltage of commercial lithium-ion batteries by measuring the difference between the positive and negative electrode potentials, but cannot obtain the negative electrode potential inside the battery; implanting a reference electrode into the battery to form a three-electrode system, and measuring the potential between the electrode and the reference electrode can directly obtain the internal potential, but the existing reference electrode has a short life and is only used at the laboratory level and cannot be commercialized in lithium-ion batteries; the commonly used lithium-ion battery electrochemical model can predict the internal potential, but the model is complex and the calculation is large, making it difficult to apply to the battery management system (BMS); the commonly used equivalent circuit model parameters are simple and the calculation is small, but it can only describe the external characteristics of the battery and cannot provide the negative electrode potential. So far, there is no method that can monitor the change of the negative electrode potential of the battery and control the charging for safe and fast charging of lithium-ion batteries. Summary of the invention

[0004] In view of this, the charging control method and device, electronic device, and storage medium provided in the embodiments of the present application can quickly obtain the impedance value and health of the battery during the battery charging process, and perform charging control based on the impedance value and health, thereby achieving the effect of accurately controlling the battery charging without damaging the battery.

[0005] In a first aspect, the charging control method provided by the embodiment of the present application includes:

[0006] When the rechargeable battery is charged by the charging signal, a current impedance value and a current health of the rechargeable battery are obtained, wherein the current health is used to indicate a loss of a current capacity of the rechargeable battery relative to an initial capacity;

[0007] Determine a target minimum impedance value corresponding to the current health level according to a preset correspondence relationship between the health level and the minimum impedance value, wherein the minimum impedance value is used to indicate a minimum impedance value at which the rechargeable battery does not undergo lithium deposition;

[0008] The charging signal is controlled according to a magnitude relationship between the current impedance value and the target minimum impedance value.

[0009] In a second aspect, the charging control device provided by the embodiment of the present application includes:

[0010] A charging information acquisition module, used to acquire a current impedance value and a current health of the rechargeable battery when the rechargeable battery is charged by a charging signal, wherein the current health is used to indicate a loss of the current capacity of the rechargeable battery relative to the initial capacity;

[0011] An impedance value determination module, used to determine a target minimum impedance value corresponding to the current health state according to a preset correspondence relationship between the health state and the minimum impedance value, wherein the minimum impedance value is used to indicate a minimum impedance value at which the rechargeable battery does not undergo lithium deposition;

[0012] A charging signal control module is used to control the charging signal according to the magnitude relationship between the current impedance value and the target minimum impedance value.

[0013] In a third aspect, an electronic device provided in an embodiment of the present application includes a memory and a processor, wherein the memory stores a computer program that can be run on the processor, and when the processor executes the program, the steps of the charging control method provided in the first aspect of the embodiment of the present application are implemented.

[0014] In a fourth aspect, a computer-readable storage medium provided in an embodiment of the present application stores a computer program thereon, and when the computer program is executed by a processor, the steps of the charging control method provided in the first aspect of the embodiment of the present application are implemented.

[0015] The charging control method, device, electronic device and computer-readable storage medium provided in the embodiments of the present application can quickly obtain the impedance value and health of the battery during the battery charging process, and perform charging control based on the impedance value and health, thereby achieving the effect of accurately controlling the battery charging without damaging the battery, thereby solving the technical problems raised in the background technology. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The drawings herein are incorporated into the specification and constitute a part of the specification. These drawings illustrate embodiments consistent with the present application and are used together with the specification to illustrate the technical solution of the present application.

[0017] Figure 1 A schematic diagram of an implementation flow of a charging control method provided in an embodiment of the present application;

[0018] Figure 2 A flow chart of another charging control method provided in an embodiment of the present application;

[0019] Figure 3 A flow chart of another charging control method provided in an embodiment of the present application;

[0020] Figure 4 A flowchart of a method for controlling a charging signal provided in an embodiment of the present application;

[0021] Figure 5 The overall process of a non-lithium deposition charging control method provided in an embodiment of the present application;

[0022] Figure 6 A schematic diagram of the structure of a charging control device provided in an embodiment of the present application;

[0023] Figure 7 A schematic diagram of the structure of an electronic device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0024] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the specific technical solution of the present application will be further described in detail below in conjunction with the drawings in the embodiments of the present application. The following embodiments are used to illustrate the present application, but are not used to limit the scope of the present application.

[0025] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein are only for the purpose of describing the embodiments of this application and are not intended to limit this application.

[0026] In the following description, reference is made to “some embodiments”, which describe a subset of all possible embodiments, but it will be understood that “some embodiments” may be the same subset or different subsets of all possible embodiments and may be combined with each other without conflict.

[0027] It should be pointed out that the terms "first\second\third" involved in the embodiments of the present application are used to distinguish similar or different objects, and do not represent a specific ordering of the objects. It can be understood that "first\second\third" can be interchanged in a specific order or sequence where permitted, so that the embodiments of the present application described here can be implemented in an order other than that illustrated or described here.

[0028] Fast charging requires increasing the battery charging rate, which often triggers side reactions in the battery. Taking lithium-ion batteries such as graphite negative electrode systems as an example, when the negative electrode overpotential is lower than 0V vs. Li / Li+, lithium deposition occurs on the negative electrode surface, seriously affecting charging safety and battery life. Whether lithium deposition occurs on the negative electrode can be determined by whether the negative electrode overpotential is lower than the critical potential for lithium deposition. Monitoring and controlling the negative electrode overpotential during charging can effectively avoid the occurrence of side reactions such as lithium deposition and achieve safe and fast charging of the battery.

[0029] The existing technology can obtain the terminal voltage of commercial lithium-ion batteries by measuring the difference between the positive and negative electrode potentials, but cannot obtain the negative electrode potential inside the battery; implanting a reference electrode into the battery to form a three-electrode system, and measuring the potential between the electrode and the reference electrode can directly obtain the internal potential, but the existing reference electrode has a short life and is only used at the laboratory level and cannot be commercialized in lithium-ion batteries; the commonly used lithium-ion battery electrochemical model can predict the internal potential, but the model is complex and the calculation is large, making it difficult to apply to the battery management system (BMS); the commonly used equivalent circuit model parameters are simple and the calculation is small, but it can only describe the external characteristics of the battery and cannot provide the negative electrode potential. So far, there is no method that can monitor the change of the negative electrode potential of the battery and control the charging for safe and fast charging of lithium-ion batteries.

[0030] In view of this, an embodiment of the present application provides a charging control method, which obtains the current impedance value and current health of the rechargeable battery when the rechargeable battery is charged by a charging signal; determines the target minimum impedance value corresponding to the current health according to the corresponding relationship between the preset health and the minimum impedance value; and controls the charging signal according to the magnitude relationship between the current impedance value and the target minimum impedance value. This method can quickly obtain the impedance value and health of the battery during the battery charging process, and perform charging control according to the impedance value and health, achieving the effect of accurately controlling the battery charging without damaging the battery, and preventing the battery from rapidly aging or even causing serious safety risks while maintaining the battery charging speed.

[0031] Figure 1 The present invention provides a schematic diagram of the implementation process of a charging control method. The method can be applied to electronic devices, which can be various types of devices with information processing capabilities during implementation. For example, the electronic device can include a personal computer, a laptop computer, a PDA or a server, etc.; the electronic device can also be a mobile terminal, for example, the mobile terminal can include a mobile phone, a car computer, a tablet computer or a projector, etc. Figure 1 As shown, the method may include the following steps 101 to 103:

[0032] Step 101: When charging a rechargeable battery through a charging signal, obtain a current impedance value and a current health of the rechargeable battery, wherein the current health is used to indicate a loss of the current capacity of the rechargeable battery relative to an initial capacity.

[0033] Among them, when charging a rechargeable battery, there are many ways to obtain the current impedance value of the rechargeable battery, such as controlling voltage, controlling current, and a hybrid mode that can automatically adjust the disturbance amplitude, etc. These methods can scan within a preset frequency range or monitor impedance at a fixed frequency, which is applicable to various energy products such as lithium batteries, supercapacitors, and fuel cells. The embodiment of the present application does not limit the method for obtaining the current impedance value.

[0034] In addition, there are many ways to obtain the health of a rechargeable battery. The health here can be determined based on the current capacity and initial capacity of the rechargeable battery. The initial capacity is the capacity of the rechargeable battery when it is new. The health can be calculated by calculating a ratio, adding a factor, etc. The embodiment of the present application does not limit the method for calculating the current health.

[0035] In some embodiments, the current impedance value can be obtained by superimposing a preset AC signal on the charging signal. The reason for superimposing the preset AC signal is to obtain the fluctuation of the battery voltage, so that the frequency domain signal can be obtained through time-frequency conversion, that is, disturbance is required for conversion. The preset AC signal is superimposed on the charging signal, and the current impedance value of the rechargeable battery is obtained by measuring the AC impedance.

[0036] Furthermore, the preset AC signal may be a square wave signal or a sinusoidal signal. The sinusoidal signal may be generated by superposition of sinusoidal waves of multiple frequencies, and its mean value may be a preset value, which may be 0. The current step size △I of the square wave signal ≥ the preset current value, which may be 500mA. For example, 1000mA is used to charge for t / 2, and then 500mA is used to charge for t / 2, where t is the charging time. Exemplarily, the preset AC signal may be a 1s sinusoidal current with a frequency of 10Hz and an amplitude of 1A.

[0037] Step 102: Determine a target minimum impedance value corresponding to the current health level according to a preset correspondence relationship between the health level and the minimum impedance value.

[0038] It should be noted that the electronic device can pre-store a correspondence between health and minimum impedance value. The preset correspondence between health and minimum impedance value can be obtained by obtaining the measured impedance value of the sample battery at different health states, and then determining the minimum impedance value from the measured impedance value according to the preset screening rules, thereby obtaining the correspondence between health and minimum impedance value. It can also be other methods. The embodiment of the present application does not limit the method for obtaining the preset correspondence between health and minimum impedance value.

[0039] According to the corresponding relationship between the current health level and the preset health level and the minimum impedance value, the target minimum impedance value corresponding to the current health level can be determined.

[0040] Step 103: Control the charging signal according to the magnitude relationship between the current impedance value and the target minimum impedance value.

[0041] It should be noted that there are many ways to control the charging signal according to the relationship between the current impedance value and the target minimum impedance value, for example, the charging voltage, charging current, etc. The embodiment of the present application does not limit the method of controlling the charging signal according to the relationship between the current impedance value and the target minimum impedance value.

[0042] Given that the calculation of the negative electrode potential is very complex, and it is difficult to calculate online in real time, and the reference electrode has a short life, it is very difficult to control charging based on the negative electrode potential. Therefore, the embodiment of the present application provides a method for controlling charging based on battery impedance and health calculation, which achieves the effect of accurately controlling battery charging without damaging the battery, and prevents rapid aging of the battery and even causing serious safety risks while maintaining the battery charging speed.

[0043] In some embodiments, the current health of the rechargeable battery can be calculated based on the current impedance value of the rechargeable battery, thereby facilitating obtaining the current health.

[0044] In the embodiment of the present application, obtaining the current health of the rechargeable battery may include: determining the current health according to the current impedance value and a corresponding relationship between a preset health and a measured impedance value.

[0045] In some embodiments, the preset correspondence between the health level and the measured impedance value is a correspondence between the health level and the measured impedance value at a specific frequency.

[0046] It is understandable that, since the correspondence between the health degree and the measured impedance value at a specific frequency can reflect the correspondence between the health degree and the measured impedance value at other frequencies, the correspondence between the health degree and the measured impedance value calculated at a specific frequency can be used to obtain the preset correspondence between the health degree and the measured impedance value. The specific frequency here can be a medium or low frequency, preferably 0.01-10Hz. A method for obtaining the correspondence between the health degree and the measured impedance value is described in detail below.

[0047] Figure 2 A flow chart of another charging control method provided in an embodiment of the present application. Figure 2 As shown, in Figure 1 On the basis of the illustrated embodiment, when the rechargeable battery is charged by the charging signal in step 101, before obtaining the current impedance value and the current health of the rechargeable battery, the method further includes:

[0048] Step 201: Collect multiple voltages and multiple currents of multiple sample batteries under different charging conditions, wherein the different charging conditions are charging conditions in which a preset AC signal is superimposed on different charging signals, and the different charging signals include at least one of different charging voltages, different battery capacities, and different charging times. The multiple sample batteries are batteries with different initial capacities obtained by aging new batteries according to a set battery aging path.

[0049] It should be noted that several new lithium-ion batteries can be selected as sample batteries. The multiple sample batteries are aged according to the set aging path, and the initial capacity values ​​Qmax of the sample batteries are recorded. When the sample batteries are at different initial capacity values, the sample batteries are charged.

[0050] During the charging process of the sample battery, at the set temperature value, under different characteristic electrical signals, i.e. different charging signals, a specific current disturbance signal, i.e. a preset AC signal, is superimposed for a duration of t, and the voltage and current values ​​of the sample battery are recorded at the same time.

[0051] Among them, Qmax is the maximum usable capacity of the battery in the current state. For example, the battery is 5000mAh when it is first used, and 4500mAh after a period of use, then the health is 90%. This capacity will continue to age as the battery is used, but it will continue to decrease. Voltage and current are the signals of the detected battery. The duration is generally the duration of the disturbance signal, which is generally 1s to 2min. The charging signal can be a node, such as the current state of the sample battery. The voltage of the sample battery is constantly rising during the charging process, and the power and capacity are constantly rising. Here we just need to find a node, generally selecting voltage or power. For example, a battery is charged from 3V to 4.5V, and the power is full from 0% to 100%. We choose to make a disturbance at 4.2V, or when the power is 50%.

[0052] Step 202: Obtain a corresponding relationship between the preset health status and the measured impedance value according to the multiple voltages, the multiple currents and the current capacity of the sample battery.

[0053] It should be noted that, based on the obtained multiple voltages and currents and the current capacity of the sample battery, a corresponding relationship between the preset health status and the measured impedance value can be obtained, wherein the battery aging path can be used to determine the current capacity of the sample battery.

[0054] Furthermore, obtaining the correspondence between the preset health status and the measured impedance value based on the multiple voltages, the multiple currents and the current capacity may include: performing time-frequency analysis on the multiple voltages and the multiple currents to obtain the measured impedance values ​​at different initial capacities and different frequencies; obtaining the correspondence between different initial capacities and the measured impedance values ​​at a first frequency, wherein the first frequency is determined according to a preset first frequency screening rule; obtaining the correspondence between the preset health status and the measured impedance value according to the current capacity of each of the sample batteries and the correspondence between different initial capacities and the measured impedance values.

[0055] It should be noted that the wavelet transform method or the windowed Fourier transform method can be used for time-frequency analysis. The collected current and voltage signals are subjected to time-frequency conversion analysis, and the corresponding measured impedance value Z = [Z1, Z2, Z3, ... Zn] under the characteristic frequency f = [f1, f2, f3, ... fn] is obtained. The recorded initial capacity value Qmax of the sample battery is fitted with the impedance value Zn obtained under the specific frequency to obtain the fitting function Qmax = f'(Zn), so that the corresponding relationship between the Qmax value and the impedance of the sample battery under different aging conditions is obtained, and the health of the battery y = Qmax' / Qmax, where Qmax' is the current capacity value of the battery after the nth aging cycle, and Qmax is the initial capacity of the battery, that is, the corresponding relationship between the health and the measured impedance value can be obtained. Among them, the method for calculating the corresponding measured impedance value under the characteristic frequency can adopt the existing method, which is not limited here.

[0056] Exemplarily, the preset first frequency screening rule may be to screen medium and low frequencies, preferably 0.01-10 Hz. When the battery is 90%, the measured impedance value at the characteristic frequency is calculated, and the impedance value at a frequency of 0.025 Hz is selected, that is, the corresponding relationship of 90%-38.8 mΩ is obtained.

[0057] In the above embodiment, by superimposing a special disturbed current and voltage signal when the sample battery is working, the impedance of the battery at the characteristic frequency is obtained by using a time-frequency conversion method, which corresponds to the capacity of the battery, and the corresponding relationship between the health status and the measured impedance value is obtained. The health status of the rechargeable battery can be quickly determined by measuring the impedance value during the charging process, which facilitates the control of the charging signal.

[0058] Figure 3 A flow chart of another charging control method provided in an embodiment of the present application. Figure 3 As shown, in Figure 1 On the basis of the illustrated embodiment, when the rechargeable battery is charged by the charging signal in step 101, before obtaining the current impedance value and the current health of the rechargeable battery, the method further includes:

[0059] Step 301: Collect multiple voltages and multiple currents of multiple sample batteries under different charging conditions, wherein the different charging conditions are charging conditions in which a preset AC signal is superimposed on different charging signals, and the different charging signals include at least one of different charging voltages, different battery capacities, and different charging times. The multiple sample batteries are batteries with different initial capacities obtained by aging new batteries according to a set battery aging path.

[0060] Step 302: Perform time-frequency analysis on the multiple voltages and the multiple currents to obtain measured impedance values ​​at different initial capacities and different frequencies.

[0061] Step 303: Obtain the correspondence between different initial capacities and minimum impedance values ​​at the second frequency, where the minimum impedance value is a measured impedance value screened out according to a preset impedance screening condition, and the second frequency is determined according to a preset second frequency screening rule.

[0062] Step 304: According to the current capacity of each of the sample batteries and the corresponding relationship between different initial capacities and minimum impedance values, the corresponding relationship between the preset health level and the minimum impedance value is obtained.

[0063] It should be noted that in the process of charging sample batteries with different initial capacities, the change trend of the impedance value Zm at a specific frequency along with the characteristic electrical signal can be analyzed to obtain the minimum impedance value Zm of the sample battery when the sample battery is in a healthy state. Here, it can be the minimum impedance value or a smaller impedance value, and the screening conditions can be set according to needs.

[0064] Exemplarily, the preset second frequency screening rule can be to screen medium and low frequencies, preferably 0.01-10Hz. After obtaining the corresponding measured impedance values ​​Z = [Z1, Z2, Z3, ... Zn] under multiple characteristic frequencies f = [f1, f2, f3, ... fn], you can select the impedance value at a specific frequency, such as 0.25Hz, and then calculate the measured impedance value at this frequency from the health level 0%-100%, and select the minimum value according to the screening conditions.

[0065] In the above method, the impedance value under a specific electrical signal is calculated at multiple capacity retention rates of the sample battery to obtain the capacity retention rate, that is, the relationship between the health and the minimum impedance value, which can be used to control charging. It can be understood that the specific frequency selected when obtaining the correspondence between the health and the measured impedance value and the specific frequency selected when obtaining the correspondence between the health and the minimum impedance value may be the same or different, that is, the preset second frequency screening rule and the preset first frequency screening rule may be the same or different, and this embodiment does not limit this. It can be selected according to actual conditions. For example, 0.1Hz is used when calculating the correspondence between the health and the measured impedance value, and the frequency for calculating the correspondence between the health and the minimum impedance value is 0.62Hz, but it is recommended to prefer low frequencies.

[0066] In the above embodiment, a special disturbance current and voltage signal is superimposed when the battery is working, and the impedance of the battery at the characteristic frequency is obtained by using a time-frequency conversion method, so as to correspond to the capacity of the battery. Then, the impedance value under a specific electrical signal is calculated at the capacity retention rate, and the relationship between the capacity retention rate and the characteristic impedance value is obtained, so as to control charging.

[0067] In some embodiments, the method of controlling the charging signal may include controlling the charging voltage, the charging current, or other charging parameters, which will be described below using the charging current as an example.

[0068] Figure 4 The present invention provides a flow chart of a method for controlling a charging signal according to an embodiment of the present invention. The target minimum impedance value is a minimum impedance value, and the charging signal includes a charging current, such as Figure 4 As shown, the step 103 controls the charging signal according to the magnitude relationship between the current impedance value and the target minimum impedance value, which may include:

[0069] Step 401: Determine whether the current impedance value is less than the target minimum impedance value;

[0070] Step 402: If the current impedance value is less than the target minimum impedance value, reducing the charging current;

[0071] Step 403: If the current impedance value is greater than or equal to the target minimum impedance value, then the charging current is not adjusted or is increased.

[0072] It should be noted that after determining the target minimum impedance value corresponding to the current health, the current impedance value Zm can be maintained not lower than the minimum impedance value by controlling the magnitude of the charging current. If the current impedance value is less than the target minimum impedance value, the charging current is reduced; if the current impedance value is greater than or equal to the target minimum impedance value, the charging current is not adjusted or is increased.

[0073] Furthermore, before reducing the charging current, the method may also include: determining that the impedance difference between the current impedance value and the target minimum impedance value is greater than a preset threshold; or determining that the duration of the state in which the current impedance value is lower than the target minimum impedance value is greater than a preset duration.

[0074] It should be noted that since some mild lithium deposition can be reversed within a certain period of time, when controlling the charging current, the current can be reduced after the current impedance value Zm is lower than the minimum impedance value by a certain range, or the current can be reduced after the current impedance value Zm is lower than the minimum impedance value for a certain period of time.

[0075] The above method can adjust the charging current infrequently, that is, the number of times the charging current is adjusted is reduced, and the power consumption of the charging device can be reduced.

[0076] The following describes an exemplary application of the embodiments of the present application in a practical application scenario.

[0077] Figure 5 The overall process of a non-lithium deposition charging control method provided in the embodiment of the present application is as follows. Figure 5 As shown, the method includes the following steps 501 to 507:

[0078] Step 501: Select a number of newly manufactured lithium-ion batteries, perform aging according to a set aging path, and record the initial capacity value Qmax of the battery.

[0079] The number of sample batteries is ≥ 2, preferably 3. The specific aging path can be conventional battery aging or accelerated aging path, such as high temperature aging. The battery aging path in this solution is not limited. The sample battery capacity calculation method is preferably the rated capacity measurement method of the battery, or it can be the capacity measurement at other rates, such as 1C, 0.5C, 2C, etc.

[0080] Step 502: During the charging process, at a set temperature value and under different characteristic electrical signals, a specific current disturbance signal is superimposed for a duration of t, and the voltage and current values ​​of the battery are simultaneously recorded.

[0081] Among them, the set temperature value is preferably the measurement temperature range of Qmax, generally 20-40°C; the specific charging state SOC range is 10%-90%, preferably 30%-70%; the superimposed specific current disturbance signal includes a square wave signal and a sinusoidal signal. If it is a sinusoidal signal, the preferred feature is that it is generated by the superposition of sinusoidal waves of multiple frequencies, and its mean is 0; it can also be a square wave signal, and the current step size △I≥500mA, that is, for example, using 1000mA to charge t / 2, and then using 500mA to charge t / 2; the characteristic signal occurrence interval is determined according to the characteristic electrical signal, for example, it occurs once every 1% SOC, once every 10mv voltage, etc.; the characteristic electrical signal is not limited to voltage, open circuit voltage, positive electrode potential, negative electrode potential, charge, capacity, etc.

[0082] In addition, the charging duration t can be greater than or equal to twice the inverse of the frequency in the selected specific frequency impedance, that is, t≥2 / fn, preferably t≥10 / fn; the collected battery current frequency fs under the disturbance signal must be greater than or equal to twice the frequency in the selected specific frequency impedance, that is, fs≥2fn, preferably fs≥10fn.

[0083] Step 503: Perform time-frequency conversion analysis on the current and voltage signals collected in step 502, and obtain the impedance Z = [Z1, Z2, Z3, ... Zn] corresponding to the characteristic frequency f = [f1, f2, f3, ... fn].

[0084] Step 504: Fit the capacity value Qmax recorded in step 501 and the impedance value Zn at the specific frequency in step 503 to obtain a fitting function Qmax=f'(Zn), so as to obtain the corresponding relationship between the Qmax value and the impedance of the battery under different aging conditions, and the battery health y=Qmax' / Qmax, where Qmax' is the capacity value of the battery after the nth aging cycle, and Qmax is the initial capacity of the battery.

[0085] Exemplarily, first establish the relationship preset of Qmax=f'(Zn), such as y=ax+b, where y is Qmax or health, x is Zn, and then obtain the real-time Qmax' of the battery during use. Since the initial Qmax is known, obtaining Qmax' is an inherent way, so the health can be obtained.

[0086] The characteristic frequency is preferably 0.01 Hz-60 Hz, and particularly preferably 0.1-5 Hz.

[0087] Step 505: During the charging process, the variation trend of the impedance value Zm at a specific frequency along with the characteristic electrical signal is analyzed, and the minimum value of Zm under the battery health condition is obtained.

[0088] Among them, after calculating the Zn values ​​at many frequencies, you can select the impedance value at 0.025Hz, and then calculate the impedance at this frequency from 0% to 100% health, and take the minimum value.

[0089] Step 506: Repeat steps 501-505 to obtain the relationship between the battery health and Zn y=f(Zn), and the relationship between the battery health and the minimum value of Zm y=f[(zm)min].

[0090] Step 507: During the actual charging process, the current health of the battery is first calculated, and then the built-in relationship is checked to find the current minimum value of Zm, and the current is controlled to maintain Zm not lower than the minimum value.

[0091] Exemplary, the way to control the current, for example, when the Zm value is less than the minimum value of the battery health, the charging current is reduced, and when the Zm value is greater than this value, you can choose not to adjust the charging current, or increase the charging current; in particular, since some minor lithium plating can be reversed within a certain period of time, when controlling the charging current in 507, you can choose to reduce the current after Zm is lower than the minimum value for a certain range, or reduce the current after Zm has been lower than the minimum value for a certain period of time.

[0092] The method provided in the embodiment of the present application does not rely on complex calculations of the negative electrode potential to determine whether the battery has lithium deposition and to perform charging control. By quantifying the relationship between the battery health and the impedance value at a specific frequency, the impedance value can be quickly obtained during the charging process through Fourier transform and other methods, and then a judgment is made as to whether charging needs to be controlled, thereby achieving the effect of lossless and rapid calculation of the battery, protecting the battery charging speed, and preventing the battery from rapidly aging and even causing serious safety risks.

[0093] It should be understood that, although the steps in the above-mentioned flowcharts are displayed in sequence according to the indication of the arrows, these steps are not necessarily executed in sequence according to the order indicated by the arrows. Unless there is a clear explanation in this article, the execution of these steps is not strictly limited in order, and these steps can be executed in other orders. Moreover, at least a part of the steps in the above-mentioned flowcharts may include multiple sub-steps or multiple stages, and these sub-steps or stages are not necessarily executed at the same time, but can be executed at different times, and the execution order of these sub-steps or stages is not necessarily to be carried out in sequence, but can be executed in turn or alternately with other steps or at least a part of the sub-steps or stages of other steps.

[0094] Based on the foregoing embodiments, an embodiment of the present application provides a charging control device, and each module included in the device and each unit included in each module can be implemented by a processor; of course, it can also be implemented by a specific logic circuit; in the implementation process, the processor can be a central processing unit (CPU), a microprocessor (MPU), a digital signal processor (DSP) or a field programmable gate array (FPGA), etc.

[0095] Figure 6 A schematic diagram of the structure of a charging control device provided in an embodiment of the present application is shown in FIG. Figure 6 As shown, the device 600 includes a charging information acquisition module 601, an impedance value determination module 602 and a charging signal control module 603, wherein:

[0096] The charging information acquisition module 601 is used to acquire the current impedance value and the current health of the rechargeable battery when the rechargeable battery is charged by the charging signal, wherein the current health is used to indicate the loss of the current capacity of the rechargeable battery relative to the initial capacity;

[0097] The impedance value determination module 602 is used to determine the target minimum impedance value corresponding to the current health state according to the preset correspondence relationship between the health state and the minimum impedance value, wherein the minimum impedance value is used to indicate the minimum impedance value that prevents the rechargeable battery from lithium deposition;

[0098] The charging signal control module 603 is used to control the charging signal according to the magnitude relationship between the current impedance value and the target minimum impedance value.

[0099] In some embodiments, the charging information acquisition module 601 is specifically used to determine the current health level according to the current impedance value and a preset corresponding relationship between the health level and the measured impedance value.

[0100] In some embodiments, the device further includes: a first relationship acquisition module, which is used to acquire the corresponding relationship between the health level and the measured impedance value, and the first relationship acquisition module includes: a collection unit and a generation unit, wherein:

[0101] The collecting unit is used to collect multiple voltages and multiple currents of multiple sample batteries under different charging conditions, wherein the different charging conditions are charging conditions in which a preset AC signal is superimposed on different charging signals, and the different charging signals include at least one of different charging voltages, different battery capacities, and different charging times, and the multiple sample batteries are batteries with different initial capacities obtained by aging new batteries according to a set battery aging path;

[0102] The generating unit is used to obtain the corresponding relationship between the preset health status and the measured impedance value according to the multiple voltages, the multiple currents and the current capacity of the sample battery, and the health status is determined according to the current capacity and the initial capacity.

[0103] In some embodiments, the generating unit is specifically used to: perform time-frequency analysis on the multiple voltages and the multiple currents to obtain measured impedance values ​​at different initial capacities and different frequencies; obtain the correspondence between different initial capacities and measured impedance values ​​at a first frequency, wherein the first frequency is determined according to a preset first frequency screening rule; obtain the preset correspondence between the health degree and the measured impedance value according to the current capacity of each of the sample batteries and the correspondence between different initial capacities and the measured impedance values.

[0104] In some embodiments, the device further includes a second relationship acquisition module, which is used to obtain a correspondence between health and minimum impedance value, and the second relationship acquisition module is specifically used to: collect multiple voltages and multiple currents of multiple sample batteries under different charging conditions, wherein the different charging conditions are charging conditions in which a preset AC signal is superimposed on different charging signals, and the different charging signals include at least one of different charging voltages, different battery capacities, and different charging times, and the multiple sample batteries are batteries with different initial capacities obtained by aging new batteries according to a set battery aging path; perform time-frequency analysis on the multiple voltages and the multiple currents to obtain measured impedance values ​​at different initial capacities and different frequencies; obtain the correspondence between different initial capacities and minimum impedance values ​​at the second frequency, the minimum impedance value is the measured impedance value screened according to the preset impedance screening condition, and the second frequency is determined according to the preset second frequency screening rule; obtain the preset correspondence between health and minimum impedance value according to the current capacity of each of the sample batteries and the correspondence between different initial capacities and minimum impedance values.

[0105] In some embodiments, the target minimum impedance value is a minimum impedance value, the charging signal includes a charging current, and the charging signal control module 603 includes a determination unit, a first execution unit, and a second execution unit, wherein:

[0106] The impedance determination unit is used to determine whether the current impedance value is less than the target minimum impedance value;

[0107] The first execution unit is configured to reduce the charging current if the current impedance value is less than the target minimum impedance value;

[0108] The second execution unit is configured to not adjust the charging current or to increase the charging current if the current impedance value is greater than or equal to the target minimum impedance value.

[0109] In some embodiments, the first execution unit is specifically used to determine, before reducing the charging current, that the impedance difference between the current impedance value and the target minimum impedance value is greater than a preset threshold; or, to determine that the duration of the state in which the current impedance value is lower than the target minimum impedance value is greater than a preset duration.

[0110] In the embodiments of the present application, the impedance value and health of the battery can be quickly obtained during the battery charging process, and the charging can be controlled based on the impedance value and health, thereby achieving the effect of accurately controlling the battery charging without damaging the battery, and preventing the battery from aging rapidly or even causing serious safety risks while maintaining the battery charging speed.

[0111] The description of the above device embodiment is similar to the description of the above method embodiment, and has similar beneficial effects as the method embodiment. For technical details not disclosed in the device embodiment of the present application, please refer to the description of the method embodiment of the present application for understanding.

[0112] It should be noted that in the embodiments of this application Figure 6 The division of modules in the charging control device shown is schematic and is only a logical function division. There may be other division methods in actual implementation. In addition, each functional unit in each embodiment of the present application may be integrated into a processing unit, or may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of a software functional unit. It may also be implemented in the form of a combination of software and hardware.

[0113] It should be noted that in the embodiment of the present application, if the above method is implemented in the form of a software function module and sold or used as an independent product, it can also be stored in a computer-readable storage medium. Based on such an understanding, the technical solution of the embodiment of the present application can be essentially or partly embodied in the form of a software product that contributes to the relevant technology. The computer software product is stored in a storage medium, including several instructions to enable an electronic device to execute all or part of the methods described in each embodiment of the present application. The aforementioned storage medium includes: various media that can store program codes, such as a U disk, a mobile hard disk, a read-only memory (ROM), a magnetic disk or an optical disk. In this way, the embodiment of the present application is not limited to any specific combination of hardware and software.

[0114] Figure 7This is a schematic diagram of the structure of an electronic device provided in an embodiment of the present application. Figure 7 As shown, the electronic device 100 may include a processor 110, a memory 120, a wireless communication module 130, an audio module 140, a camera 150, a USB interface 160, a display screen 170, and the like.

[0115] The processor 110 may include one or more processing units. For example, the processor 110 is a central processing unit (CPU), or an application specific integrated circuit (ASIC), or one or more integrated circuits configured to implement the embodiments of the present application, such as one or more microprocessors (digital signal processors, DSPs), or one or more field programmable gate arrays (FPGAs). Different processing units may be independent devices or integrated into one or more processors.

[0116] The memory 120 can be used to store computer executable program codes, which include instructions. The internal memory 120 may include a program storage area and a data storage area. Among them, the program storage area may store an operating system, an application required for at least one function (such as a sound playback function, an image playback function, etc.), etc. The data storage area may store data created during the use of the electronic device 100 (such as audio data, video data, etc.), etc. In addition, the memory 120 may include a high-speed random access memory, and may also include a non-volatile memory, such as at least one disk storage device, a flash memory device, a universal flash storage (UFS), etc. The processor 110 executes various functional applications and data processing of the electronic device 100 by running instructions stored in the memory 120, and / or instructions stored in a memory provided in the processor.

[0117] The wireless communication module 130 can provide solutions for wireless communication including WLAN, such as Wi-Fi network, Bluetooth, NFC, IR, etc., applied to the electronic device 100. The wireless communication module 130 can be one or more devices integrating at least one communication processing module. In some embodiments of the present application, the electronic device 100 can establish a wireless communication connection with other electronic devices through the wireless communication module 130.

[0118] The electronic device 100 can implement audio functions such as music playing and recording through the audio module 140 , the speaker 140A, the receiver 140B, the microphone 140C, the headphone jack 140D, and the application processor.

[0119] The audio module 140 is used to convert digital audio information into analog audio signal output, and is also used to convert analog audio input into digital audio signals. The audio module 140 can also be used to encode and decode audio signals. In some embodiments, the audio module 140 can be arranged in the processor 110, or some functional modules of the audio module 140 can be arranged in the processor 110.

[0120] The camera 150 is used to capture still images or videos. The object generates an optical image through the lens and projects it onto the photosensitive element. The photosensitive element can be a charge coupled device (CCD) or a complementary metal-oxide-semiconductor (CMOS) phototransistor. The photosensitive element converts the optical signal into an electrical signal, and then passes the electrical signal to the ISP to be converted into a digital image signal. The ISP outputs the digital image signal to the DSP for processing. The DSP converts the digital image signal into an image signal in a standard RGB, YUV or other format. In some embodiments, the electronic device 100 may include 1 or N cameras 150, where N is a positive integer greater than 1.

[0121] The USB interface 160 is an interface that complies with the USB standard specification, and can be a Mini USB interface, a Micro USB interface, a USB Type C interface, etc. The USB interface 160 can be used to connect other electronic devices. In some other embodiments, the electronic device 100 can also be connected to an external camera through the USB interface 160 to capture images.

[0122] The display screen 170 is used to display images, videos, etc. The display screen 170 includes a display panel. The display panel can be a liquid crystal display (LCD), an organic light-emitting diode (OLED), an active-matrix organic light-emitting diode or an active-matrix organic light-emitting diode (AMOLED), a flexible light-emitting diode (FLED), Miniled, MicroLed, Micro-oLed, a quantum dot light-emitting diode (QLED), etc. In some embodiments, the electronic device 100 may include 1 or N display screens 170, where N is a positive integer greater than 1.

[0123] It is to be understood that the structure illustrated in the embodiment of the present invention does not constitute a specific limitation on the electronic device 100. In other embodiments of the present application, the electronic device 100 may include more or fewer components than shown in the figure, or combine some components, or separate some components, or arrange the components differently. The components shown in the figure may be implemented in hardware, software, or a combination of software and hardware.

[0124] An embodiment of the present application provides a computer-readable storage medium on which a computer program is stored. When the computer program is executed by a processor, the steps in the charging control method provided in the above embodiment are implemented.

[0125] The above-mentioned computer-readable storage medium can adopt any combination of one or more computer-readable media. The computer-readable medium can be a computer-readable signal medium or a computer-readable storage medium. The computer-readable storage medium can be, for example, - but not limited to - an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, device or device, or any combination of the above. More specific examples (non-exhaustive list) of computer-readable storage media include: an electrical connection with one or more wires, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM) or flash memory, an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above. In this document, a computer-readable storage medium can be any tangible medium containing or storing a program, which can be used by an instruction execution system, device or device or used in combination with it.

[0126] Computer-readable signal media may include a data signal propagated in baseband or as part of a carrier wave, which carries a computer-readable program code. Such propagated data signals may take a variety of forms, including, but not limited to, electromagnetic signals, optical signals, or any suitable combination of the above. Computer-readable signal media may also be any computer-readable medium other than a computer-readable storage medium, which may send, propagate, or transmit a program for use by or in conjunction with an instruction execution system, apparatus, or device.

[0127] The program code embodied on the computer-readable medium may be transmitted using any appropriate medium, including but not limited to wireless, wire, optical cable, radio frequency (RF), etc., or any suitable combination of the foregoing.

[0128] Computer program code for performing the operations of the present specification may be written in one or more programming languages ​​or a combination thereof, including object-oriented programming languages ​​such as Java, Smalltalk, C++, and conventional procedural programming languages ​​such as "C" or similar programming languages. The program code may be executed entirely on the user's computer, partially on the user's computer, as a separate software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In cases involving a remote computer, the remote computer may be connected to the user's computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or may be connected to an external computer (e.g., via the Internet using an Internet service provider).

[0129] An embodiment of the present application provides a computer program product including instructions, which, when executed on a computer, enables the computer to execute the steps of the charging control method provided in the above method embodiment.

[0130] The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, the process or function described in the embodiment of the present invention is generated in whole or in part. The computer may be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions may be stored in a computer-readable storage medium, or transmitted from one computer-readable storage medium to another computer-readable storage medium. For example, the computer instructions may be transmitted from a website site, a computer, a server, or a data center to another website site, a computer, a server, or a data center by wired (e.g., coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) means. The computer-readable storage medium may be any available medium that a computer can store or a data storage device such as a server or a data center that includes one or more available media integrated. The available medium may be a magnetic medium (e.g., a floppy disk, a hard disk, a tape), an optical medium (e.g., a DVD), or a semiconductor medium (e.g., a solid-state drive Solid State Disk (SSD)), etc.

[0131] It should be noted here that the description of the above storage medium, program product and device embodiments is similar to the description of the above method embodiment, and has similar beneficial effects as the method embodiment. For technical details not disclosed in the storage medium and device embodiments of this application, please refer to the description of the method embodiment of this application for understanding.

[0132] It should be understood that "one embodiment" or "an embodiment" or "some embodiments" mentioned throughout the specification means that specific features, structures or characteristics related to the embodiment are included in at least one embodiment of the present application. Therefore, "in one embodiment" or "in one embodiment" or "in some embodiments" appearing throughout the specification may not necessarily refer to the same embodiment. In addition, these specific features, structures or characteristics can be combined in one or more embodiments in any suitable manner. It should be understood that in various embodiments of the present application, the size of the sequence number of the above-mentioned processes does not mean the order of execution, and the execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiment of the present application. The above-mentioned sequence numbers of the embodiments of the present application are only for description and do not represent the advantages and disadvantages of the embodiments. The above description of each embodiment tends to emphasize the differences between the various embodiments, and the same or similar aspects can be referenced to each other. For the sake of brevity, this article will not repeat them.

[0133] The term "and / or" in this article is only a description of the association relationship of associated objects, indicating that there may be three relationships. For example, object A and / or object B can represent three situations: object A exists alone, object A and object B exist at the same time, and object B exists alone.

[0134] It should be noted that, in this article, the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "comprises a ..." does not exclude the existence of other identical elements in the process, method, article or device including the element.

[0135] In the several embodiments provided in the present application, it should be understood that the disclosed devices and methods can be implemented in other ways. The embodiments described above are only schematic. For example, the division of the modules is only a logical function division. There may be other division methods in actual implementation, such as: multiple modules or components can be combined, or can be integrated into another system, or some features can be ignored, or not executed. In addition, the coupling, direct coupling, or communication connection between the components shown or discussed can be through some interfaces, and the indirect coupling or communication connection of devices or modules can be electrical, mechanical or other forms.

[0136] The modules described above as separate components may or may not be physically separated, and the components displayed as modules may or may not be physical modules; they may be located in one place or distributed on multiple network units; some or all of the modules may be selected according to actual needs to achieve the purpose of the present embodiment.

[0137] In addition, all functional modules in the embodiments of the present application may be integrated into one processing unit, or each module may be a separate unit, or two or more modules may be integrated into one unit; the above-mentioned integrated modules may be implemented in the form of hardware or in the form of hardware plus software functional units.

[0138] A person skilled in the art can understand that all or part of the steps of implementing the above method embodiment can be completed by hardware related to program instructions, and the aforementioned program can be stored in a computer-readable storage medium. When the program is executed, it executes the steps of the above method embodiment; and the aforementioned storage medium includes: mobile storage devices, read-only memories (ROM), magnetic disks or optical disks, etc., various media that can store program codes.

[0139] Alternatively, if the above-mentioned integrated unit of the present application is implemented in the form of a software function module and sold or used as an independent product, it can also be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the embodiment of the present application can essentially or in other words, the part that contributes to the relevant technology can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including a number of instructions for enabling an electronic device to execute all or part of the methods described in each embodiment of the present application. The aforementioned storage medium includes: various media that can store program codes, such as mobile storage devices, ROMs, magnetic disks, or optical disks.

[0140] The methods disclosed in several method embodiments provided in this application can be arbitrarily combined without conflict to obtain new method embodiments.

[0141] The features disclosed in several product embodiments provided in this application can be arbitrarily combined without conflict to obtain new product embodiments.

[0142] The features disclosed in several method or device embodiments provided in this application can be arbitrarily combined without conflict to obtain new method embodiments or device embodiments.

[0143] The above is only an implementation method of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art who is familiar with the present technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A charging control method, characterized in that: include: When the rechargeable battery is charged by the charging signal, obtaining a current impedance value and a current health of the rechargeable battery, wherein the current health is used to indicate a loss of a current capacity of the rechargeable battery relative to an initial capacity; Determine a target minimum impedance value corresponding to the current health level according to a preset correspondence relationship between the health level and the minimum impedance value, wherein the minimum impedance value is used to indicate a minimum impedance value at which the rechargeable battery does not undergo lithium deposition; The charging signal is controlled according to a magnitude relationship between the current impedance value and the target minimum impedance value.

2. The method according to claim 1, characterized in that The current impedance value is obtained when a preset AC signal is superimposed on the charging signal.

3. The method according to claim 1 or 2, characterized in that: The obtaining the current health of the rechargeable battery includes: The current health degree is determined according to the current impedance value and a preset corresponding relationship between the health degree and the measured impedance value.

4. The method according to claim 3, characterized in that In the case of charging the rechargeable battery by the charging signal, before obtaining the current impedance value and the current health of the rechargeable battery, the method further includes: Collecting multiple voltages and multiple currents of multiple sample batteries under different charging conditions, wherein the different charging conditions are charging conditions in which a preset AC signal is superimposed on different charging signals, and the different charging signals include at least one of different charging voltages, different battery capacities, and different charging times, and the multiple sample batteries are batteries with different initial capacities obtained by aging new batteries according to a set battery aging path; A corresponding relationship between the preset health status and the measured impedance value is obtained according to the multiple voltages, the multiple currents and the current capacity of the sample battery, wherein the health status is determined according to the current capacity and the initial capacity.

5. The method according to claim 4, characterized in that The obtaining, according to the multiple voltages, the multiple currents and the current capacity of the sample battery, a corresponding relationship between the preset health status and the measured impedance value comprises: Performing time-frequency analysis on the multiple voltages and the multiple currents to obtain measured impedance values ​​at different initial capacities and different frequencies; Obtaining a correspondence between different initial capacities and measured impedance values ​​at a first frequency, wherein the first frequency is determined according to a preset first frequency screening rule; The preset corresponding relationship between the health degree and the measured impedance value is obtained according to the current capacity of each sample battery and the corresponding relationship between different initial capacities and the measured impedance value.

6. The method according to claim 1, characterized in that In the case of charging the rechargeable battery by the charging signal, before obtaining the current impedance value and the current health of the rechargeable battery, the method further includes: Collecting multiple voltages and multiple currents of multiple sample batteries under different charging conditions, wherein the different charging conditions are charging conditions in which a preset AC signal is superimposed on different charging signals, and the different charging signals include at least one of different charging voltages, different battery capacities, and different charging times, and the multiple sample batteries are batteries with different initial capacities obtained by aging new batteries according to a set battery aging path; Performing time-frequency analysis on the multiple voltages and the multiple currents to obtain measured impedance values ​​at different initial capacities and different frequencies; Obtaining a correspondence between different initial capacities and minimum impedance values ​​at a second frequency, wherein the minimum impedance value is a measured impedance value screened according to a preset impedance screening condition, and the second frequency is determined according to a preset second frequency screening rule; According to the current capacity of each of the sample batteries and the corresponding relationship between different initial capacities and minimum impedance values, the corresponding relationship between the preset health status and the minimum impedance value is obtained.

7. The method according to claim 1, characterized in that The charging signal includes a charging current, and controlling the charging signal according to a magnitude relationship between the current impedance value and the target minimum impedance value includes: determining whether the current impedance value is less than the target minimum impedance value; If the current impedance value is less than the target minimum impedance value, reducing the charging current; If the current impedance value is greater than or equal to the target minimum impedance value, the charging current is not adjusted or is increased.

8. The method according to claim 7, characterized in that Before reducing the charging current, the method further includes: Determine that the impedance difference between the current impedance value and the target minimum impedance value is greater than a preset threshold; or determine that the duration of the state in which the current impedance value is lower than the target minimum impedance value is greater than a preset duration.

9. The method according to claim 2, characterized in that: The preset AC signal is a square wave signal or a sinusoidal signal. The sinusoidal signal is generated by superimposing sinusoidal waves of multiple frequencies, and its average value is a preset value. The current step size ΔI of the square wave signal is ≥ the preset current value.

10. A charging control device, characterized in that: include: A charging information acquisition module, used to acquire a current impedance value and a current health of the rechargeable battery when the rechargeable battery is charged by a charging signal, wherein the current health is used to indicate a loss of the current capacity of the rechargeable battery relative to the initial capacity; An impedance value determination module, used to determine a target minimum impedance value corresponding to the current health state according to a preset correspondence relationship between the health state and the minimum impedance value, wherein the minimum impedance value is used to indicate a minimum impedance value at which the rechargeable battery does not undergo lithium deposition; A charging signal control module is used to control the charging signal according to the magnitude relationship between the current impedance value and the target minimum impedance value.

11. An electronic device comprising a memory and a processor, wherein the memory stores a computer program that can be run on the processor, characterized in that: When the processor executes the program, the steps of the charging control method according to any one of claims 1 to 9 are implemented.

12. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the charging control method according to any one of claims 1 to 9 are implemented.

Images