Battery parameter detection method and device

Abstract

The application discloses a battery parameter detection method and device, and relates to the field of battery detection. The battery parameter detection method comprises the following steps: detecting the current and voltage of a battery at a first time point, wherein the first time point is a time point when the battery is being charged; stopping charging the battery; detecting the voltage of the battery at 2n time points after the first time point, wherein the interval between any two adjacent time points among the first time point and the 2n time points is a first time length, n is an integer greater than or equal to 1; and determining the battery parameter of the battery according to the current and voltage of the battery at the first time point, the voltage of the battery at the 2n time points and the first time length. Through the method, the detection condition of the battery parameter can be reduced, the battery parameter can be detected during the charging process of the battery, the battery parameter of the battery can be acquired in real time, and the abnormality of the battery can be detected in time.

Description

TECHNICAL FIELD

[0001] Embodiments of the present application relate to the field of battery detection, and in particular to a battery parameter detection method and device. BACKGROUND

[0002] With the rapid development of fast charging technology, battery safety is particularly important. In order to accurately judge the battery health status, real-time detection of battery parameters is needed. According to the detected battery parameters, abnormal conditions of the battery can be found in time to prevent safety accidents. For example, common battery parameters include: alternative current resistance (ACR), direct current resistance (DCR), electrochemical impedance spectroscopy (EIS), and polarization time constant. Among them, ACR can reflect whether there is an internal short circuit anomaly in the battery; DCR can reflect the aging degree of the battery; EIS can reflect the fast charging performance of the battery. The polarization time constant can reflect the fast charging characteristics, aging degree of the battery, and the power supply capacity of the battery under certain conditions (such as low temperature conditions).

[0003] Currently, when detecting the above-mentioned battery parameters such as ACR, DCR, EIS, and polarization time constant, the system (i.e., the circuit system where the battery is located, hereinafter referred to as the system) needs to periodically load square wave or sinusoidal wave current or constant current on the battery. Taking the detection of ACR as an example, the system needs to load 1 kilohertz (kHz) square wave or sinusoidal wave current I(n) on the battery through a current source, while sampling the voltage change value V(n) of the battery, and then taking the base frequency information of the voltage change value V(n) and the current I(n) respectively Fourier transform and dividing, the impedance information of the battery at 1k can be obtained, and the real part of the impedance information is the ACR value of the battery.

[0004] However, during the use of the battery, the current loaded on the battery by the system (such as the circuit system where the battery is located) has no regularity, and it is difficult to achieve periodic square wave or sinusoidal wave current, constant current, etc. Therefore, the current detection of ACR, DCR, EIS, and polarization time constant generally needs to be carried out under the condition that the charger of the battery is in place but not charging (i.e., the battery is in a full charge state at this time), and the detection of the battery parameters cannot be realized during the charging process of the battery. SUMMARY

[0005] Embodiments of the present application provide a battery parameter detection method and device, which can realize the detection of battery parameters during the charging process of the battery.

[0006] In a first aspect, an embodiment of the present application provides a battery parameter detection method, comprising: detecting a current and a voltage of a battery at a first time, the first time being a time when the battery is being charged; stopping charging the battery; detecting the voltage of the battery at 2n times after the first time, respectively; wherein any two adjacent times among the first time and the 2n times are separated by a first time length, n is an integer greater than or equal to 1; and determining a battery parameter of the battery according to the current and the voltage of the battery at the first time, the voltage of the battery at the 2n times, and the first time length.

[0007] Optionally, the battery parameter of the battery comprises at least one of: an alternating current resistance ACR, a direct current resistance DCR, an electrochemical impedance spectrum EIS, and a polarization time constant.

[0008] The method can reduce the detection conditions of the battery parameter, and the battery parameter can be detected during the charging process of the battery, so that the battery parameter of the battery can be obtained in real time, and the abnormality of the battery can be detected in time, thereby reducing the life attenuation and even the safety accident caused by improper use of the battery, and providing a better use experience for the user.

[0009] In a possible design, the determining of the battery parameter of the battery according to the current and the voltage of the battery at the first time, the voltage of the battery at the 2n times, and the first time length comprises: determining parameters of an n-order impedance equivalent circuit model of the battery according to the current and the voltage of the battery at the first time, the voltage of the battery at the 2n times, and the first time length; and determining the battery parameter of the battery according to the parameters of the n-order impedance equivalent circuit model of the battery.

[0010] In a possible design, the determining of the parameters of the n-order impedance equivalent circuit model of the battery according to the current and the voltage of the battery at the first time, the voltage of the battery at the 2n times, and the first time length comprises: determining a parameter R0 of the n-order impedance equivalent circuit model of the battery according to the current and the voltage of the battery at the first time, and the voltage of the battery at a first time among the 2n times.

[0011] The parameters R1 to Rn and the parameters τ1 to τn of the n-order impedance equivalent circuit model of the battery are determined according to the following equation group.

[0012]

[0013] Wherein, Vbat(0) represents the voltage of the battery at the first time; Vbat(1) to Vbat(2n) represent the voltage of the battery at the 2n times, respectively; I represents the current of the battery at the first time; t represents the first time length; e is a natural constant.

[0014] For example, the n-order impedance equivalent circuit model of the battery can be a second-order impedance equivalent circuit model, a first-order impedance equivalent circuit model, etc. The parameters of the second-order impedance equivalent circuit model include: a parameter R0, parameters (Re, τe), (Rp, τp). The parameters of the first-order impedance equivalent circuit model include: a parameter R0, a parameter (Re, τe).

[0015] In the battery parameter detection method, the parameters of the n-order impedance equivalent circuit model of the battery are calculated according to the detected voltage and current data of the battery, and ACR, DCR, EIS, polarization time constant, etc. are calculated simultaneously according to the detected voltage and current data of the battery and the parameters of the n-order impedance equivalent circuit model, which can effectively reduce the development cost.

[0016] In a possible design, the battery parameters of the battery are determined according to the parameters of the n-order impedance equivalent circuit model of the battery, including: determining the ACR of the battery according to the following equation.

[0017]

[0018] In a possible design, the battery parameters of the battery are determined according to the parameters of the n-order impedance equivalent circuit model of the battery, including: determining the DCR of the battery according to the following equation.

[0019]

[0020] Where ΔT represents a fixed discharge time, which is a constant. For example, ΔT is 1 second, 3 seconds, etc.

[0021] In the current DCR detection, the constant current is loaded for a period of time (for example, ΔT), which increases the power consumption. However, the embodiment of the present application does not need to load the constant current, and the power consumption is relatively reduced.

[0022] In a possible design, the battery parameters of the battery are determined according to the parameters of the n-order impedance equivalent circuit model of the battery, including: determining the EIS of the battery according to the following equation.

[0023]

[0024]

[0025] Where f represents a frequency; EIS Re represents the real part of the EIS of the battery corresponding to f; EIS Im represents the imaginary part of the EIS of the battery corresponding to f.

[0026] The current EIS needs to be measured once per frequency, and the overall test time is long (for example, about 2 minutes is needed for measuring from 1000 Hz to 1 Hz), and the user experience is poor, while the EIS of the battery can be obtained by calculating according to the detected voltage and current data of the battery and combining the algorithm, so that the user experience can be effectively improved.

[0027] In a possible design, the determining, according to the parameters of the n-order impedance equivalent circuit model of the battery, of the battery parameter of the battery includes: determining the parameters τ1 to τn of the n-order impedance equivalent circuit model of the battery as the polarization time constant of the battery.

[0028] The current calculation of the polarization time constant of the battery uses the least square method, which needs to be iterated repeatedly, and the operation amount, error and power consumption loss are relatively large, while the way of calculating the polarization time constant of the battery in the embodiment of the application is relatively simple, the error is smaller, and the power consumption is smaller.

[0029] In a possible design, the method further includes: detecting the current of the battery at 2n time instants after the first time instant respectively; and determining whether the battery stops charging according to the currents of the battery at the 2n time instants.

[0030] When the voltage of the battery is detected at 2n time instants after the first time instant, the current flowing through the battery is detected, which can be used to determine whether the detected current of the battery at the 2n time instants is 0, so as to determine whether the charging stopping is normal. If the current of the battery at the 2n time instants is all 0, it indicates that the charging current disappears instantaneously, and the charging stopping is normal. Otherwise, as long as the current at one time instant among the 2n time instants is not 0, it indicates that the charging current does not disappear instantaneously, and the charging stopping is abnormal.

[0031] In a possible design, the method further includes: detecting the current of the battery at 2n time instants after the first time instant respectively; and determining whether the battery stops charging according to the currents of the battery at the 2n time instants.

[0032] In a possible design, the processing module is specifically configured to determine parameters of an n-order impedance equivalent circuit model of the battery according to the current and the voltage of the battery at the first moment, the voltages of the battery at the 2n moments, and the first time length; and determine the battery parameters of the battery according to the parameters of the n-order impedance equivalent circuit model of the battery.

[0033] In a possible design, the processing module is specifically configured to determine a parameter R0 of an n-order impedance equivalent circuit model of the battery according to the current and the voltage of the battery at the first moment, and the voltage of the battery at a first moment of the 2n moments.

[0034] The parameters R1 to Rn and the parameters τ1 to τn of the n-order impedance equivalent circuit model of the battery are determined according to the following equation group:

[0035]

[0036] wherein Vbat(0) represents the voltage of the battery at the first moment; Vbat(1) to Vbat(2n) respectively represent the voltages of the battery at the 2n moments; I represents the current of the battery at the first moment; t represents the first time length; e is a natural constant.

[0037] In a possible design, the processing module is specifically configured to determine the ACR of the battery according to the following equation:

[0038]

[0039] In a possible design, the processing module is specifically configured to determine the DCR of the battery according to the following equation:

[0040]

[0041] wherein ΔT represents a fixed discharge time, which is a constant.

[0042] In a possible design, the processing module is specifically configured to determine the EIS of the battery according to the following equation:

[0043]

[0044]

[0045] wherein f represents a frequency; EIS Re represents a real part of the EIS of the battery corresponding to f; EIS Im represents an imaginary part of the EIS of the battery corresponding to f.

[0046] In a possible design, the processing module is specifically configured to determine the parameters τ1 to τn of the n-order impedance equivalent circuit model of the battery as polarization time constants of the battery.

[0047] In a possible design, the processing module is further configured to control the sampling circuit to detect the current of the battery at 2n time instants after the first time instant respectively, and determine whether the battery stops charging according to the current of the battery at the 2n time instants.

[0048] In a third aspect, an electronic device is provided, which can be a terminal device such as a mobile phone or a tablet computer. The electronic device includes a processor, a memory storing processor-executable instructions, and the processor is configured to execute the instructions so that the electronic device implements the method in the first aspect. The electronic device is provided with a battery and a sampling circuit.

[0049] In a fourth aspect, a computer-readable storage medium is provided, which stores computer program instructions. When the computer program instructions are executed by an electronic device, the electronic device implements the method in the first aspect. The electronic device is provided with a battery and a sampling circuit.

[0050] In a fifth aspect, a computer program product is provided, which includes computer-readable code. When the computer-readable code is executed in an electronic device, the electronic device implements the method in the first aspect. The electronic device is provided with a battery and a sampling circuit.

[0051] The advantages of the second aspect to the fifth aspect are the same as those of the first aspect, which will not be repeated here.

[0052] It should be understood that the description of technical features, technical solutions, advantages or similar language in this application does not imply that all features and advantages can be achieved in any single embodiment. On the contrary, it can be understood that the description of a feature or advantage means that the specific technical feature, technical solution or advantage is included in at least one embodiment. Therefore, the description of technical features, technical solutions or advantages in this specification does not necessarily refer to the same embodiment. Furthermore, the technical features, technical solutions and advantages described in this embodiment can be combined in any appropriate manner. Those skilled in the art will understand that the embodiments can be implemented without one or more specific technical features, technical solutions or advantages of a particular embodiment. In other embodiments, additional technical features and advantages can be identified in specific embodiments that do not embody all embodiments. BRIEF DESCRIPTION OF DRAWINGS

[0053] Figure 1 A flowchart of a battery parameter detection method provided by an embodiment of the application is shown;

[0054] Figure 2 A detection result diagram of the voltage and current of a battery provided by an embodiment of the application is shown.

[0055] Figure 3 A structure schematic diagram of an n-order impedance equivalent circuit model provided by an embodiment of the present application is shown;

[0056] Figure 4 A structure schematic diagram of a second-order impedance equivalent circuit model provided by an embodiment of the present application is shown;

[0057] Figure 5 A detection result schematic diagram of voltage and current of another battery provided by an embodiment of the present application is shown;

[0058] Figure 6 A structure schematic diagram of a first-order impedance equivalent circuit model provided by an embodiment of the present application is shown;

[0059] Figure 7 A detection result schematic diagram of voltage and current of another battery provided by an embodiment of the present application is shown;

[0060] Figure 8 A structure schematic diagram of a battery parameter detection circuit is shown;

[0061] Figure 9 A structure schematic diagram of a battery parameter detection device is shown. DETAILED DESCRIPTION

[0062] With the rapid development of fast charging technology, battery safety is particularly important. In order to accurately judge the battery health status, real-time detection of battery parameters is needed. According to the detected battery parameters, abnormal conditions of the battery can be found in time to prevent safety accidents. For example, common battery parameters include: alternative current resistance (ACR), direct current resistance (DCR), electrochemical impedance spectroscopy (EIS), and polarization time constant. Among them, ACR can reflect whether there is an internal short circuit abnormality in the battery; DCR can reflect the aging degree of the battery; EIS can reflect the fast charging performance of the battery. The polarization time constant can reflect the fast charging characteristics, aging degree of the battery, and the power supply capability of the battery under certain conditions (such as low temperature conditions).

[0063] In the prior art, when detecting battery parameters such as ACR, DCR, EIS, and polarization time constant, the system (i.e., the circuit system in which the battery is located, hereinafter referred to as the system) needs to periodically load a square wave or sinusoidal wave current or a constant current on the battery. However, during the use of the battery, the current loaded by the system on the battery is irregular, and it is difficult to achieve periodic square wave or sinusoidal wave current, constant current, etc. Therefore, the prior art solution needs to be performed under the condition that the charger of the battery is in place but not charging, and cannot be implemented during the charging of the battery. Under this background technology, the embodiments of the present application provide a battery parameter detection method, which can be applied to a terminal device (or electronic device) configured with a battery. For example, the terminal device can be a mobile phone, a tablet computer, a handheld computer, a PC, a cellular phone, a personal digital assistant (PDA), a wearable device (such as a smart watch, a smart bracelet), a smart home device (such as a television), a car machine (such as a car computer), a smart screen, a game console, a headset, an artificial intelligence (AI) sound box, and an augmented reality (AR) / virtual reality (VR) device, etc. The embodiments of the present application do not specially limit the specific device form of the terminal device.

[0064] The battery parameter detection method comprises: detecting the current and voltage of the battery at a first time, the first time being a time when the battery is being charged; stopping charging the battery; detecting the voltage of the battery at 2n times after the first time, wherein any two adjacent times in the first time and the 2n times are separated by a first time length, n is an integer greater than or equal to 1; and determining the battery parameter of the battery according to the current and voltage of the battery at the first time, the voltage of the battery at the 2n times, and the first time length. For example, the battery parameter of the battery can include at least one of ACR, DCR, EIS, and polarization time constant.

[0065] By this method, the detection conditions of the battery parameter can be reduced, and the detection of the battery parameter can be realized during the charging of the battery, so that the battery parameter of the battery can be obtained in real time, and the abnormality of the battery can be detected in time, thereby reducing the life attenuation and even safety accidents caused by improper use of the battery, and providing better use experience for the user.

[0066] The battery parameter detection method provided by the embodiments of the present application is exemplarily described below. It should be noted that in the description of the present application, "at least one" means one or more, and "multiple" means two or more than two. The terms "first", "second", and the like are merely used for distinguishing description and do not serve as a special limitation on a certain feature, that is, the first or the second can include more contents, rather than being limited to a certain specific concept. The term "and / or" is used to describe the association relationship of the associated objects, which means that there can be three kinds of relationships. For example, A and / or B can mean that A exists alone, A and B exist together, and B exists alone. The character " / " generally represents an "or" relationship between the front and rear associated objects. Unless otherwise defined, all technical and scientific terms used in the present application have the same meanings as those commonly understood by a person skilled in the art to which the present application belongs. The terms used in the specification of the present application are only for the purpose of describing the specific embodiments and are not intended to limit the present application.

[0067] Figure 1 A flowchart of the battery parameter detection method provided by the embodiments of the present application is shown. As shown in the figure, the battery parameter detection method includes S101-S105. S101, detecting the current and the voltage of the battery at a first time, the first time being a time when the battery is charged. Figure 1

[0068] The first time refers to the time when the battery parameter detection is initiated. For example, the current and the voltage of the battery can be detected at the moment when the detection is started. Taking the case that the method is applied to a mobile phone as an example, the battery parameter detection can be initiated by the mobile phone in response to the operation of a user, or the battery parameter detection can be automatically initiated by the mobile phone according to a certain preset period (for example, one day, one week, one month, etc.). The embodiments of the present application do not limit the conditions for initiating the battery parameter detection.

[0069] Optionally, at the first time, the charge of the battery can be a certain value between 0-100%, such as 8%, 40%, 51%, etc., or can be 100%, which is not limited herein.

[0070] S102, stopping charging the battery. S103, detecting the voltage of the battery at 2n times after the first time; wherein the interval between any two adjacent times of the first time and the 2n times is a first time length, and n is an integer greater than or equal to 1. Optionally, the first time length can be 0.05 milliseconds (ms), 0.1 ms, 0.5 ms, 1 ms, etc., and the present application does not limit the size of the first time length.

[0071] ​Taking the application of the method to a mobile phone as an example, the mobile phone can be provided with a sampling circuit. The specific process of S101-S103 can be: at a certain first time when the mobile phone charges the battery, the mobile phone can detect the current and voltage of the battery through the sampling circuit. After detecting the current and voltage of the battery at the first time, the mobile phone can control the charging circuit of the battery to stop charging the battery. After stopping charging the battery, the mobile phone can detect the voltage of the battery at 2n times after the first time through the sampling circuit respectively.

[0072] For example, the first time is t0, and the first time length is m, the first time t1 of the 2n times is t0+m, the second time t2 of the 2n times is t0+2m, the third time t3 of the 2n times is t0+3m, and so on. The 2n time t2n of the 2n times is t0+2nm.

[0073] If the voltage of the battery at t0 is represented as Vbat(0), the voltage of the battery at t1 is represented as Vbat(1), the voltage of the battery at t2 is represented as Vbat(2), and so on, the voltage of the battery at t2n is represented as Vbat(2n), and the current of the battery at the first time is represented as I, the detection results of the current and voltage of the battery at the first time and the voltage of the battery at the 2n times can be as shown in Figure 2 .

[0074] After detecting the current and voltage of the battery at the first time and the voltage of the battery at the 2n times through S101-S103, the battery parameters of the battery can be determined according to the current and voltage of the battery at the first time, the voltage of the battery at the 2n times, and the first time length. For example, S104 and S105 can be performed.

[0075] S104, according to the current and voltage of the battery at the first time, the voltage of the battery at the 2n times, and the first time length, determine the parameters of the n-order impedance equivalent circuit model of the battery. Wherein, n in the n-order impedance equivalent circuit model of the battery, that is, n in the above 2n times. For example, if the impedance equivalent circuit model of the battery is selected as a second-order impedance equivalent circuit model, the above S103 is to detect the voltage of the battery at 2*2=4 times after the first time, and the first time and any two adjacent times of the four times interval the first time length. If the impedance equivalent circuit model of the battery is selected as a first-order impedance equivalent circuit model, the above S103 is to detect the voltage of the battery at 2*1=2 times after the first time, and the first time and any two adjacent times of the two times interval the first time length.

[0076] Figure 3 The structure diagram of the n-order impedance equivalent circuit model provided by the embodiment of the application is shown. As Figure 3As shown, the n-order impedance equivalent circuit model of the battery can be equivalent to a series connection of a resistance R0 and n-order parallel RC networks, i.e., a first RC network composed of a resistance R1 and a capacitance C1 in parallel, a second RC network composed of a resistance R2 and a capacitance C2 in parallel, and so on, and an n-th RC network composed of a resistance Rn and a capacitance Cn in parallel; the resistance R0 can be connected in series with the n RC networks in turn to form the n-order impedance equivalent circuit model.

[0077] For Figure 3 As shown in the n-order impedance equivalent circuit model, the parameters R0, R1 to Rn, and τ1 to τn of the n-order impedance equivalent circuit model can be determined according to the current and voltage of the battery at the first time, the voltages of the battery at the 2n times, and the first time interval between any two adjacent times among the first time and the 2n times, which are detected in S101-S103. For the parameter R0 of the n-order impedance equivalent circuit model, it can be calculated and obtained by substituting the current and voltage of the battery at the first time into the following formula (6).

[0078] R0 = (Vbat(1)-Vbat(0)) / I (6)

[0079] In formula (6), Vbat(1) represents the voltage of the battery at the first time among the 2n times; Vbat(0) represents the voltage of the battery at the first time; and I represents the current of the battery at the first time.

[0080] After the parameter R0 is calculated, R0, the current and voltage of the battery at the first time, the voltages of the battery at the 2n times, and the first time interval can be substituted into the following formula (7) to calculate and obtain the parameters R1 to Rn and τ1 to τn of the n-order impedance equivalent circuit model.

[0081]

[0082] In formula (7), Vbat(0) represents the voltage of the battery at the first time; Vbat(1) to Vbat(2n) respectively represent the voltages of the battery at the 2n times (from the first time to the 2n time among the 2n times); I represents the current of the battery at the first time; t represents the first time interval; and e is a natural constant.

[0083] S105, determine the battery parameters of the battery according to the parameters of the n-order impedance equivalent circuit model of the battery. As described in S104, the parameters R0, the parameters R1 to Rn, and the parameters τ1 to τn of the n-order impedance equivalent circuit model of the battery can be determined according to the current and voltage of the battery at the first time, the voltage of the battery at the 2n time, and the first time length. In this application, after obtaining the parameters R0, the parameters R1 to Rn, and the parameters τ1 to τn of the n-order impedance equivalent circuit model of the battery, the ACR, DCR, EIS, polarization time constant and other battery parameters of the battery can be determined according to the parameters R0, the parameters R1 to Rn, and the parameters τ1 to τn, respectively. The specific process of determining the ACR, DCR, EIS, and polarization time constant of the battery according to the parameters R0, the parameters R1 to Rn, and the parameters τ1 to τn is described below.

[0084] 1) For ACR, the parameters R0, the parameters R1 to Rn, and the parameters τ1 to τn can be substituted into the following formula (8), and then the equation result obtained after substituting formula (8) is calculated to obtain the ACR of the battery.

[0085]

[0086] 2) For DCR, the parameters R0, the parameters R1 to Rn, and the parameters τ1 to τn can be substituted into the following formula (9), and then the equation result obtained after substituting formula (9) is calculated to obtain the DCR of the battery.

[0087]

[0088] In formula (9), ΔT represents a fixed discharge time, which is a constant. For example, ΔT can be 1 second, 3 seconds, etc. When ΔT is 1 second, the DCR of the battery corresponding to the discharge time of 1 second can be calculated. When ΔT is 3 seconds, the DCR of the battery corresponding to the discharge time of 3 seconds can be calculated. In the embodiment of the application, ΔT can be determined according to the discharge time corresponding to the DCR of the battery as needed, and different ΔT can be input to obtain the DCR of the battery corresponding to different discharge times.

[0089] 3) For EIS, the parameters R0, the parameters R1 to Rn, and the parameters τ1 to τn can be substituted into the following formula (10) and formula (11), and then the equation result obtained after substituting formula (10) and formula (11) is calculated to obtain the EIS of the battery.

[0090]

[0091]

[0092] In the formula (10) and the formula (11), f represents frequency; EIS Re represents the real part of the EIS of the battery corresponding to f; EIS Im represents the imaginary part of the EIS of the battery corresponding to f.

[0093] It should be noted that, in the above formula (10) and formula (11), f can be different values, for example, can be 1 Hz, 1 / 2 Hz, 10 Hz. When f is different, the EIS (the real part is EIS Re , and the imaginary part is EIS Im ) value of the battery at different frequencies can be calculated.

[0094] 4) For the polarization time constant, the parameters τ1 to τn of the n-order impedance equivalent circuit model of the battery calculated above are directly determined as the polarization time constant of the battery.

[0095] That is, the polarization time constant of the battery is the above parameters τ1 to τn, and τ1 to τn respectively represent the polarization time constant of the battery in different polarization processes, such as the polarization time constant of the solid electrolyte interface (SEI) film of the battery, the polarization time constant of the electrochemical reaction, etc.

[0096] Next, taking a typical model of a lithium ion battery of a mobile phone as an example, a second-order impedance equivalent circuit model (that is, n is 2 in the above n-order impedance equivalent circuit model of the battery), the specific implementation process of the battery parameter detection method is illustrated.

[0097] Figure 4 The structure of the second-order impedance equivalent circuit model provided by the embodiment of the application is shown. As Figure 4 shown, the second-order impedance equivalent circuit model of the battery can be equivalent to the series connection of the resistance R0 and the second-order parallel RC network, such as: the first RC network composed of the resistance Re and the capacitance Ce in parallel, and the second RC network composed of the resistance Rp and the capacitance Cp in parallel; the resistance R0 can be connected in series with the above two RC networks in turn to form the second-order impedance equivalent circuit model.

[0098] When the impedance equivalent circuit model of the battery is the second-order impedance equivalent circuit model shown in Figure 4 , the specific implementation process of the battery parameter detection method is: at a certain first time (denoted as 0 time) when charging the battery, detecting the current and voltage of the battery; then, stopping charging the battery; after stopping charging the battery, taking 0 time as the starting time, every first time interval (denoted as t), that is, taking t as the period, the voltage of the battery is detected at four time points (denoted as t time, 2t time, 3t time, and 4t time) after 0 time in turn.

[0099] If the voltage of the battery at time 0 is denoted as Vbat(0), the voltage of the battery at time t is denoted as Vbat(1), the voltage of the battery at time 2t is denoted as Vbat(2), the voltage of the battery at time 3t is denoted as Vbat(3), the voltage of the battery at time 4t is denoted as Vbat(4), and the current of the battery at time 0 is denoted as I, the detection results of the current and the voltage of the battery at time 0, and the voltage of the battery at times t, 2t, 3t, and 4t can be as shown in FIG. 6. Figure 5

[0100] After obtaining the voltages Vbat(0), Vbat(1), Vbat(2), Vbat(3), and Vbat(4) of the battery at times 0, t, 2t, 3t, and 4t, respectively, and the current I of the battery at time 0, the parameters R0 of the second-order impedance equivalent circuit model can be calculated by substituting Vbat(0), Vbat(1), and I into formula (6) first.

[0101] After substituting Vbat(0), Vbat(1), and I, formula (6) can be expressed as the following equation:

[0102] R0 = (Vbat(1) - Vbat(0)) / I.

[0103] In this equation, Vbat(0), Vbat(1), and I are known quantities, and the result R0 can be easily obtained by solving.

[0104] Then, the parameters (Re, te), (Rp, tp) of the second-order impedance equivalent circuit model can be calculated by substituting R0, Vbat(0), Vbat(1), Vbat(2), Vbat(3), Vbat(4), and I into formula (7). Here, (Re, te) is (R1, t1) when n = 2 in the n-order impedance equivalent circuit model, and (Rp, tp) is (R2, t2) when n = 2.

[0105] After substituting R0, Vbat(0), Vbat(1), Vbat(2), Vbat(3), Vbat(4), and I, formula (7) can be expressed as the following equation set:

[0106]

[0107] By calculating the equation set, the parameters (Re, te), (Rp, tp) of the second-order impedance equivalent circuit model can be obtained.

[0108] ​As can be seen, in the equation set, R0, Vbat(0), Vbat(l), Vbat(2), Vbat(3), Vbat(4), and I are all known quantities. Then, the solution process for the equation set can be as follows.

[0109] First, each term of the equation set can be divided by I, and it can be transformed as follows:

[0110]

[0111] For the transformed equation set, (Vbat(0)-Vbat(l)) / I-R0 in the 1st equation can be denoted as K1. (Vbat(0)-Vbat(2)) / I-R0 in the 2nd equation can be denoted as K2. (Vbat(0)-Vbat(3)) / I-R0 in the 3rd equation can be denoted as K3. (Vbat(0)-Vbat(4)) / I-R0 in the 4th equation can be denoted as K4.

[0112] At this time, the equation set can be further transformed as follows:

[0113]

[0114] In the further transformed equation set, since R0, Vbat(0), Vbat(l), Vbat(2), Vbat(3), Vbat(4), and I are all known quantities, the values of K1, K2, K3, and K4 can be easily calculated.

[0115] Assuming that K1, K2, K3, and K4 in the above further transformed equation set are denoted as y, then according to the above further transformed equation set, the following equation can be obtained.

[0116] a*y 2 +b*y+c=0.

[0117] In the equation, a=K1*K2+K1*K3-K1 2 -K2 2 ; b=K1*K2+K2*K3-K2 2 -K1*K4; c=K1*K3+K2*K3+K2*K4-K2 2 -K3 2 -K1*K4.

[0118] Solving the equation, we have:

[0119]

[0120] Substituting y into the above equation set, we have:

[0121]

[0122] Further, according to x and y, we can get:

[0123]

[0124]

[0125]

[0126]

[0127] After obtaining the parameters R0, (Re, te), (Rp, tp) of the second-order impedance equivalent circuit model, the parameters R0, (Re, te), (Rp, tp) can be substituted into formula (8) to calculate the ACR of the battery.

[0128] After substituting R0, (Re, te), (Rp, tp), formula (8) can be expressed as the following equation:

[0129]

[0130] By calculating this equation, the ACR of the battery can be obtained.

[0131] Similarly, the parameters R0, (Re, te), (Rp, tp) can also be substituted into formula (9) to calculate the DCR of the battery.

[0132] After substituting R0, (Re, te), (Rp, tp), formula (9) can be expressed as the following equation:

[0133]

[0134] Where ΔT represents a fixed discharge time, which is a constant (see the aforementioned embodiments for details). By calculating this equation, the DCR of the battery can be obtained.

[0135] Similarly, the parameters R0, (Re, te), (Rp, tp) can also be substituted into formula (10) and formula (11) to calculate the EIS of the battery.

[0136] After substituting R0, (Re, te), (Rp, tp), formula (10) and formula (11) can be expressed as the following two equations:

[0137]

[0138] By substituting f in the above two equations with different values, such as 1 Hz, 1 / 2 Hz, etc., the EIS at different frequencies can be obtained Re and EISIm Re Re Re Im Re Re Re Im Re

[0139] For the typical model of lithium-ion battery for mobile phone, i.e., the second-order impedance equivalent circuit model, the parameters τe and τp obtained in the process of determining the parameters of the second-order impedance equivalent circuit model are the polarization time constants of the battery.

[0140] Among the two polarization time constants τe and τp of the battery, the smaller one is the polarization time constant of the SEI film of the battery (referred to as SEI polarization time constant), and the larger one is the polarization time constant of the electrochemical reaction (referred to as electrochemical polarization time constant).

[0141] For example, the SEI polarization time constant and the electrochemical polarization time constant can be determined among τe and τp in the following manner.

[0142] SEI polarization time constant = min{τe, τp}, min{} represents the minimum value of the number in {}; electrochemical polarization time constant = max{τe, τp}, max{} represents the maximum value of the number in {}.

[0143] In some possible examples, the above-mentioned second-order impedance equivalent circuit model can be replaced by a simplified model of lithium-ion battery, i.e., a first-order impedance equivalent circuit model, that is, n in the above-mentioned n-order impedance equivalent circuit model of the battery is 1. The specific implementation process of the battery parameter detection method will be exemplarily described below taking the first-order impedance equivalent circuit model as an example.

[0144] Figure 6 A structure schematic diagram of the first-order impedance equivalent circuit model provided by the embodiment of the application is shown. As shown in Figure 6 The first-order impedance equivalent circuit model of the battery can be equivalent to the series connection of a resistor R0 and a first-order parallel RC network, i.e., the resistor Re and the capacitor Ce are connected in parallel to form an RC network, and the resistor R0 can be connected in series with the RC network to form the first-order impedance equivalent circuit model.

[0145] When the impedance equivalent circuit model of the battery is Figure 6The specific implementation process of the battery parameter detection method is as follows: at a first time (also recorded as 0 time) when the battery is being charged, the current and the voltage of the battery are detected; then, the charging of the battery is stopped; after the charging of the battery is stopped, the voltage of the battery is detected at 2 time points (recorded as t time and 2t time respectively) after 0 time, with 0 time as the starting time and t as the period.

[0146] If the voltage of the battery at 0 time is denoted as Vbat(0), the voltage of the battery at t time is denoted as Vbat(1), the voltage of the battery at 2t time is denoted as Vbat(2), and the current of the battery at 0 time is denoted as I, the detection results of the current and the voltage of the battery at 0 time, and the voltages of the battery at t time and 2t time can be as shown in Figure 7

[0147] After obtaining the voltages Vbat(0), Vbat(1), and Vbat(2) of the battery at 0 time, t time, and 2t time respectively, and the current I of the battery at 0 time, Vbat(0), Vbat(1), and I can be substituted into formula (6) to calculate the parameter R0 of the first-order impedance equivalent circuit model.

[0148] After substituting Vbat(0), Vbat(1), and I, formula (6) can be expressed as the following equation:

[0149] R0 = (Vbat(1) - Vbat(0)) / I.

[0150] In the equation, Vbat(0), Vbat(1), and I are known quantities, and the result R0 is easily obtained by solving.

[0151] Then, R0, Vbat(0), Vbat(1), Vbat(2), and I can be substituted into formula (7) to calculate the parameter (Re, τe) of the first-order impedance equivalent circuit model. Wherein, (Re, τe) is (R1, τ1) when n = 1 in the n-order impedance equivalent circuit model.

[0152] After substituting R0, Vbat(0), Vbat(1), Vbat(2), and I, formula (7) can be expressed as the following equation group:

[0153]

[0154] By calculating the equation group, the parameter (Re, τe) of the second-order impedance equivalent circuit model can be obtained.

[0155] ​As can be seen, in the equation set, R0, Vbat(0), Vbat(l), Vbat(2), and I are all known quantities. Then, the solution process for the equation set can be as follows.

[0156] First, each term of the equation set can be divided by I, and it is transformed as follows:

[0157]

[0158] For the transformed equation set, (Vbat(0)-Vbat(l)) / I-R0 in the 1st equation is denoted as K1, and (Vbat(0)-Vbat(2)) / I-R0 in the 2nd equation is denoted as K2.

[0159] At this time, the equation set can be further transformed as follows:

[0160]

[0161] In the further transformed equation set, since R0, Vbat(0), Vbat(l), Vbat(2), and I are all known quantities, the values of K1, K2, K3, and K4 can be easily calculated.

[0162] Suppose that y is denoted as in the above further transformed equation set, then y can be solved according to the above further transformed equation set.

[0163]

[0164] Substituting y into the above equation set, the following equation can be obtained:

[0165]

[0166]

[0167] After obtaining the parameters R0, (Re, te) of the first-order impedance equivalent circuit model, the parameters R0, (Re, te) can be substituted into Equation (8) to calculate the ACR of the battery.

[0168] After substituting R0, (Re, te), Equation (8) can be expressed as the following equation:

[0169]

[0170] By calculating the equation, the ACR of the battery can be obtained.

[0171] Similarly, the parameters R0, (Re, te) can also be substituted into Equation (9) to calculate the DCR of the battery.

[0172] Substitute R0, (Re, τe) into formula (9), formula (9) can be expressed as the following equation:

[0173]

[0174] Wherein, ΔT represents fixed discharge time, is a constant (see the foregoing embodiment for details). By calculating the equation, the DCR of the battery can be obtained.

[0175] Similarly, the parameters R0, (Re, τe) can also be substituted into formula (10) and formula (11) to calculate the EIS of the battery.

[0176] Substitute R0, (Re, τe) into formula (10) and formula (11), formula (10) and formula (11) can be expressed as the following two equations:

[0177]

[0178] By substituting f in the above two equations as different values, such as 1Hz, 1 / 2Hz, etc., the EIS at different frequencies can be obtained Re and EIS Im . EIS Re represents the real part of the EIS of the battery corresponding to f; EIS Im represents the imaginary part of the EIS of the battery corresponding to f. EIS Re and EIS Im together constitute the EIS of the battery at the corresponding frequency.

[0179] For the typical model of the lithium ion battery of the mobile phone, the first-order impedance equivalent circuit model, in the determination process of the parameters of the above-mentioned first-order impedance equivalent circuit model, the obtained parameter τe is the polarization time constant of the battery, and the polarization time constant τe refers to the electrochemical polarization time constant of the battery.

[0180] It can be understood that in the embodiment of the application, τ1 to τn time constants in the parameters of the n-order impedance equivalent circuit model of the battery are approximately the polarization time constant of the battery.

[0181] In summary, the battery parameter detection method provided in the embodiment of the application can reduce the detection conditions of the battery parameters, realize detection of the battery parameters during the battery charging process, thereby realizing real-time acquisition of the battery parameters of the battery, timely detection of possible abnormalities of the battery, reduction of life attenuation and even safety accidents caused by improper use of the battery, and better use experience for users.

[0182] The possible hardware structures for implementing the battery parameter detection method will be exemplarily described below. Figure 8 Figure 8 ​A structural diagram of a battery parameter detection circuit is shown. As shown in Figure 8 the battery parameter detection circuit can include: a battery 10, a charging circuit 20, a control module 30, a sampling circuit 40, and a calculation module 50. The charging circuit 20 is connected with the battery 10; the control module 30 is connected with the charging circuit 20, and is configured to control the charging circuit 20 to charge or stop charging the battery 10; the control module 30 is also connected with the sampling circuit 40, and is configured to control the sampling circuit 40 to collect the voltage across the battery 10 and / or the current flowing through the battery 10. The calculation module 50 is connected with the sampling circuit 40, and is configured to receive or obtain the voltage and current data collected by the sampling circuit 40, and calculate the battery parameters according to a preset algorithm.

[0183] For example, at a first time during the charging process of the battery 10 by the charging circuit 20, the control module 30 can send a trigger signal to the sampling circuit 40 to control the sampling circuit 40 to detect the voltage and current of the battery at the first time, thereby achieving the S101 shown in Figure 1 Then, the control module 30 can send a stop charging signal to the charging circuit 20, and the charging circuit 20 will stop charging the battery 10 after receiving the stop charging signal, thereby achieving the S102 shown in Figure 1 Then, at 2n times after the first time (for details, refer to the foregoing embodiments), the control module 30 can send a trigger signal to the sampling circuit 40 at each of the 2n times, to control the sampling circuit 40 to detect the voltage of the battery at the 2n times, thereby achieving the S103 shown in Figure 1 The calculation module 50 can receive or read the current and voltage of the battery at the first time, the voltage of the battery at the 2n times, and the first time length collected by the sampling circuit 40, and calculate the parameters of the n-order impedance equivalent circuit model of the battery according to a preset algorithm, and calculate the battery parameters of the battery according to the calculated parameters of the n-order impedance equivalent circuit model of the battery, thereby achieving the S104 and S105 shown in Figure 1 The preset algorithm refers to the process of determining the parameters of the n-order impedance equivalent circuit model of the battery according to the current and voltage at the first time, the voltage of the battery at the 2n times, and the first time length, and the process of calculating the battery parameters of the battery according to the parameters of the n-order impedance equivalent circuit model of the battery, as described in the foregoing embodiments.

[0184] It can be understood that Figure 8The shown structure does not constitute a specific limitation on the hardware structure for implementing the battery parameter detection method. For example, in some embodiments, the control module 30 and the calculation module 50 can also be an integrated module, such as a CPU. The sampling circuit 40 can also include an amplification circuit for amplifying the detected signal. Alternatively, the control module 30 and / or the calculation module 50 can also be split into more sub-modules, etc. In some other embodiments, the charging circuit 20, the control module 30, the sampling circuit 40, the calculation module 50, etc. can also be integrated in a power management chip. In other words, Figure 8 The shown structure can also include more or fewer components than Figure 8 shown, or combine some components, or split some components, or different component arrangements, etc. Alternatively, Figure 8 Some components shown can be implemented in hardware, software, or a combination of software and hardware. The present application does not limit this.

[0185] Alternatively, the battery parameter detection method provided by the embodiments of the present application can further include: detecting the current of the battery at the 2n time instants after the first time instant, and determining whether the battery stops charging according to the current of the battery at the 2n time instants.

[0186] That is, the above Figure 1 In S103, when the voltage of the battery is detected at the 2n time instants after the first time instant, the current flowing through the battery can also be detected. Normally, since the charging of the battery is stopped after the voltage and current of the battery are detected at the first time instant, the current of the battery at the 2n time instants after the first time instant should be 0. Therefore, in the embodiments of the present application, the current of the battery is detected at the 2n time instants after the first time instant, which can be used to determine whether the detected current of the battery at the 2n time instants is 0, so as to determine whether the charging stop is normal (the charging stop means stopping charging). If the current of the battery at the 2n time instants is all 0, it indicates that the charging current disappears instantaneously (i.e. stops charging), and the charging stop is normal. Otherwise, as long as the current at one of the 2n time instants is not 0, it indicates that the charging current does not disappear instantaneously (i.e. does not stop charging), and the charging stop is abnormal.

[0187] Optionally, for a terminal device (such as a mobile phone), when the charging stop appears to be abnormal, it may indicate that the battery or the power management chip has a problem, and the terminal device can send a relevant prompt information to the user, such as prompting the user to restart the terminal device, or to restart the battery parameter detection, or to prompt the user to restart the terminal device, or to only prompt that the battery is abnormal, etc. The content of the prompt information is not limited in the present application. Of course, the terminal device may also take more different measures when the charging stop appears to be abnormal, which can be configured by the user or the developer, and will not be repeated here.

[0188] As can be seen from the foregoing embodiments, the embodiments of the present application not only meet the terminal battery safety requirements and realize the detection of battery parameters during battery charging, but also can detect multiple battery parameters based on a set of hardware, with simple control and high precision.

[0189] In addition, in the current DCR detection, pulling a constant current for a period of time increases power consumption, while the embodiments of the present application do not need to pull a constant current, which relatively reduces power consumption. The current EIS needs to be measured once for each frequency, and the overall test time is relatively long (such as about 2 minutes from 1000 Hz to 1 Hz), and the user experience is poor, while the embodiments of the present application only need to calculate the EIS of the battery according to the detected voltage and current data of the battery, which can effectively improve the user experience. The current battery polarization time constant calculation uses the least square method, which needs to be iterated repeatedly, and the operation amount, error and power loss are relatively large, while the way of calculating the battery polarization time constant in the embodiments of the present application is relatively simple, with smaller error and less power consumption.

[0190] From the cost aspect, in the current detection methods of battery parameters such as ACR, DCR, EIS and polarization time constant, if ACR, DCR and EIS are tested at the same time, each corresponding module needs to be opened, the excitation current requirements of each module are different, and the voltage / current sampling rate and sampling accuracy requirements are also different. For example, ACR detection needs to pull a sine wave or a square wave, and DCR detection needs to pull a constant current. The development of each corresponding module will increase the area, wiring and other costs. However, in the battery parameter detection method provided by the embodiments of the present application, ACR, DCR, EIS and polarization time constant can be calculated at the same time by detecting the voltage and current data of the battery, so the development cost can be effectively reduced.

[0191] Corresponding to the method described in the foregoing embodiments, the embodiments of the present application also provide a battery parameter detection device that can be applied to a terminal device. For example, Figure 9 A structural schematic diagram of a battery parameter detection device is shown, such as Figure 9As shown in the figure, the apparatus includes a processing module 901 and a sampling circuit 902. The processing module 901 is connected with the sampling circuit 902, configured to control the sampling circuit 902 to detect the current and the voltage of the battery at a first time, the first time being a time when the battery is charged; the processing module 901 is further configured to control a charging circuit of the battery to stop charging the battery; the processing module 901 is further configured to control the sampling circuit to detect the voltage of the battery at 2n times after the first time; wherein any two adjacent times in the first time and the 2n times are separated by a first time length, n is an integer greater than or equal to 1; the processing module 901 is further configured to determine the battery parameter of the battery according to the current and the voltage of the battery at the first time, the voltage of the battery at the 2n times, and the first time length; the battery parameter of the battery includes at least one of the following: alternating current resistance ACR, direct current resistance DCR, electrochemical impedance spectrum EIS, and polarization time constant.

[0192] In a possible design, the processing module 901 is specifically configured to determine the parameter of an n-order impedance equivalent circuit model of the battery according to the current and the voltage of the battery at the first time, the voltage of the battery at the 2n times, and the first time length; and determine the battery parameter of the battery according to the parameter of the n-order impedance equivalent circuit model of the battery.

[0193] In a possible design, the processing module 901 is specifically configured to:

[0194] determine the parameter R0 of the n-order impedance equivalent circuit model of the battery according to the current and the voltage of the battery at the first time, and the voltage of the battery at the first time of the 2n times;

[0195] determine the parameters R1 to Rn and the parameters τ1 to τn of the n-order impedance equivalent circuit model of the battery according to the following equation group:

[0196]

[0197] wherein Vbat(0) represents the voltage of the battery at the first time; Vbat(1) to Vbat(2n) respectively represent the voltage of the battery at the 2n times; I represents the current of the battery at the first time; t represents the first time length; e is a natural constant.

[0198] In a possible design, the processing module 901 is specifically configured to determine the ACR of the battery according to the following equation:

[0199]

[0200] In a possible design, the processing module 901 is specifically configured to determine the DCR of the battery according to the following equation:

[0201]

[0202] wherein ΔT represents a fixed discharging time, which is a constant.

[0203] In a possible design, the processing module 901 is specifically configured to determine the EIS of the battery according to the following equation.

[0204]

[0205]

[0206] wherein f represents a frequency; EIS Re represents a real part of the EIS of the battery corresponding to f; EIS Im represents an imaginary part of the EIS of the battery corresponding to f.

[0207] In a possible design, the processing module 901 is specifically configured to determine the parameters τ1 to τn of the n-order impedance equivalent circuit model of the battery as polarization time constants of the battery.

[0208] In a possible design, the processing module 901 is further configured to control the sampling circuit to detect the current of the battery at 2n time instants after the first time instant respectively, and determine whether the battery stops charging according to the currents of the battery at the 2n time instants.

[0209] It should be understood that the division of the processing module 901 in the above apparatus is merely a logical functional division, for example, the processing module 901 can include a control module and a calculation module. In actual implementation, the processing module 901 can be integrated wholly or partially on one physical entity, or can be physically separate. The processing module 901 in the apparatus can be implemented in the form of being called by a processing element in software wholly; can be implemented in the form of hardware wholly; or can be implemented in the form of being called by a processing element in software partially and in the form of hardware partially.

[0210] For example, the processing module 901 can be a separately established processing element, or can be integrated in a chip of the apparatus, and in addition, can be stored in the form of a program in the memory and called and executed by a processing element of the apparatus to implement the functions of the unit. In addition, all or part of these units can be integrated together, or can be independently implemented. The processing element described herein can also be referred to as a processor, and can be an integrated circuit with a signal processing capability. In the implementation process, each step of the above method or each unit can be implemented by an integrated logic circuit of hardware in the processing element, or in the form of being called by a processing element in software.

[0211] In one example, the processing module 901 in the above apparatus can be one or more integrated circuits configured to implement the above method, for example: one or more ASICs, or, one or more DSPs, or, one or more FPGAs, or a combination of at least two of these integrated circuit forms.

[0212] For another example, when the processing module 901 in the apparatus can be implemented in the form of a processing element scheduler, the processing element can be a general-purpose processor, such as a CPU or other processor that can invoke programs. For another example, these units can be integrated together to implement in the form of a system-on-a-chip (SOC).

[0213] In one implementation, the processing module 901 in the above apparatus can be implemented in the form of a processing element scheduler. For example, the processing module 901 can include a processing element and a storage element, and the processing element invokes the program stored in the storage element to implement the functions of the processing module 901. The storage element can be a storage element on the same chip as the processing element, i.e., an on-chip storage element.

[0214] In another implementation, the program for implementing the functions of the processing module 901 in the above apparatus can be in a storage element on a different chip from the processing element, i.e., an off-chip storage element. At this time, the processing element invokes or loads the program from the off-chip storage element to the on-chip storage element to invoke and execute the method described in the above method embodiments.

[0215] For example, the embodiments of the present application can also provide an apparatus, such as an electronic device, which can include a processor and a memory storing instructions executable by the processor. The processor is configured to execute the above instructions, so that the electronic device implements the method as described in the foregoing embodiments. The memory can be located inside the electronic device, or outside the electronic device. The processor includes one or more. Among them, the electronic device is provided with a battery and a sampling circuit.

[0216] In yet another implementation, the units of the apparatus implementing the steps in the above method can be configured as one or more processing elements, which can be provided on the terminal corresponding to the above terminal with a battery. The processing element here can be an integrated circuit, such as one or more ASICs, or one or more DSPs, or one or more FPGAs, or a combination of these integrated circuits. These integrated circuits can be integrated together to form a chip.

[0217] For example, the embodiments of the present application further provide a chip which can be applied to the terminal device. The chip comprises one or more interface circuits and one or more processors; the interface circuits and the processors are interconnected through lines; the processor receives and executes computer instructions from the memory of the electronic device through the interface circuit, so as to realize the method described in the above method embodiments.

[0218] Through the description of the above embodiments, those skilled in the art can clearly understand that, for the convenience and brevity of description, only the division of the above functional modules is taken as an example for illustration, and in actual application, the above functions can be completed by different functional modules according to needs, that is, the internal structure of the device is divided into different functional modules to complete all or part of the functions described above.

[0219] In several embodiments provided in the present application, it should be understood that the disclosed apparatus and method can be implemented by other ways. For example, the above-described device embodiments are only illustrative, for example, the division of the modules or units is only a logical function division, and actual implementation can have another division manner, for example, a plurality of units or components can be combined or integrated into another device, or some features can be ignored or not executed. In addition, the coupling or direct coupling or communication connection between the displayed or discussed units can be indirect coupling or communication connection through some interfaces, devices or units, which can be electrical, mechanical or other forms.

[0220] The units described as separate components can or can not be physically separated, and the components displayed as units can be one physical unit or multiple physical units, that is, can be located in one place, or can be distributed to multiple different places. Part or all of the units can be selected according to actual needs to achieve the purpose of the present embodiment scheme.

[0221] In addition, each functional unit in each embodiment of the present application can be integrated in one processing unit, or each unit can exist physically, or two or more units can be integrated in one unit. The above integrated unit can be realized in the form of hardware or in the form of software functional unit.

[0222] The integrated unit, if implemented in the form of a software function unit and sold or used as an independent product, can be stored in a readable storage medium. Based on such understanding, the technical solutions of the embodiments of the present application essentially or say the part that contributes to the prior art or the whole or part of the technical solutions can be embodied in the form of a software product, such as a program. The software product is stored in a program product, such as a computer readable storage medium, and includes a plurality of instructions for causing an apparatus (which can be a single-chip microcomputer, a chip, etc.) or a processor to execute all or part of the steps of the method described in the embodiments of the present application. The foregoing storage medium includes various media that can store program codes, such as a U disk, a mobile hard disk, a ROM, a RAM, a magnetic disk or an optical disk.

[0223] For example, the embodiments of the present application can also provide a computer readable storage medium having computer program instructions stored thereon. When the computer program instructions are executed by an electronic device, the electronic device implements the method described in the foregoing method embodiments. Among them, the electronic device is provided with a battery and a sampling circuit.

[0224] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto, any change or replacement within the technical scope disclosed in the present application should be covered in the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A method of detecting a battery parameter, the method comprising: The method comprises: detecting a current and a voltage of the battery at a first time point, the first time point being a time point when the battery is being charged; stopping charging the battery; detecting voltages of the battery at 2n time points after the first time point, respectively, wherein any two adjacent time points among the first time point and the 2n time points are separated by a first time length, n is an integer greater than or equal to 1, and the n is an order of an impedance equivalent circuit model of the battery; determining a battery parameter of the battery according to the current and the voltage of the battery at the first time point, the voltages of the battery at the 2n time points, and the first time length; the battery parameter of the battery comprises at least one of an alternating current resistance (ACR), a direct current resistance (DCR), an electrochemical impedance spectrum (EIS), and a polarization time constant.

2. The method of claim 1, wherein, The determining of the battery parameter of the battery according to the current and the voltage of the battery at the first time point, the voltages of the battery at the 2n time points, and the first time length comprises: determining parameters of an n-order impedance equivalent circuit model of the battery according to the current and the voltage of the battery at the first time point, the voltages of the battery at the 2n time points, and the first time length; determining the battery parameter of the battery according to the parameters of the n-order impedance equivalent circuit model of the battery.

3. The method of claim 2, wherein, The determining of the parameters of the n-order impedance equivalent circuit model of the battery according to the current and the voltage of the battery at the first time point, the voltages of the battery at the 2n time points, and the first time length comprises: determining a parameter R0 of the n-order impedance equivalent circuit model of the battery according to the current and the voltage of the battery at the first time point, and a voltage of the battery at a first time point among the 2n time points; determining parameters R1 to Rn and parameters τ1 to τn of the n-order impedance equivalent circuit model of the battery according to the following equation group: wherein Vbat(0) represents the voltage of the battery at the first time point, Vbat(1) to Vbat(2n) represent the voltages of the battery at the 2n time points, respectively, I represents the current of the battery at the first time point, t represents the first time length, and e is a natural constant.

4. The method of claim 3, wherein, The determining of the battery parameter of the battery according to the parameters of the n-order impedance equivalent circuit model of the battery comprises: determining the ACR of the battery according to the following equation:

5. The method according to claim 3 or 4, characterized in that, The determining of the battery parameter of the battery according to the parameters of the n-order impedance equivalent circuit model of the battery comprises: determining the DCR of the battery according to the following equation: wherein ΔT represents a fixed discharge time, which is a constant.

6. The method according to claim 3 or 4, characterized in that, The determining of the battery parameter of the battery according to the parameters of the n-order impedance equivalent circuit model of the battery comprises: determining the EIS of the battery according to the following equation: where f represents frequency; EIS Re represents the real part of the EIS of the battery corresponding to f; EIS Im represents the imaginary part of the EIS of the battery corresponding to f.

7. The method according to claim 3 or 4, characterized in that, The determining of the battery parameter of the battery according to the parameters of the n-order impedance equivalent circuit model of the battery comprises: determining the parameters τ1 to τn of the n-order impedance equivalent circuit model of the battery as the polarization time constant of the battery.

8. The method according to any one of claims 1 to 4, characterized in that, The method further comprises: detecting a current of the battery at 2n time points after the first time point, respectively; Determine whether the battery stops charging according to the current of the battery at the 2n time points.

9. A battery parameter detection device, characterized by, Comprise: A processing module and a sampling circuit; The processing module is connected with the sampling circuit, and is used for controlling the sampling circuit to detect the current and voltage of the battery at a first time point, the first time point being a time point when the battery is charged; The processing module is further used for controlling a charging circuit of the battery to stop charging the battery; The processing module is further used for controlling the sampling circuit to detect the voltage of the battery at 2n time points after the first time point respectively; wherein, any two adjacent time points among the first time point and the 2n time points are separated by a first time length, n is an integer greater than or equal to 1, and the n is the order of an impedance equivalent circuit model of the battery; The processing module is further used for determining the battery parameters of the battery according to the current and voltage of the battery at the first time point, the voltage of the battery at the 2n time points, and the first time length. The battery parameters of the battery comprise at least one of the following: alternating current resistance (ACR), direct current resistance (DCR), electrochemical impedance spectroscopy (EIS), and polarization time constant.

10. The apparatus of claim 9, wherein, The processing module is specifically used for determining the parameters of the n-order impedance equivalent circuit model of the battery according to the current and voltage of the battery at the first time point, the voltage of the battery at the 2n time points, and the first time length; and determining the battery parameters of the battery according to the parameters of the n-order impedance equivalent circuit model of the battery.

11. The apparatus of claim 10, wherein, The processing module is specifically used for: Determining the parameter R0 of the n-order impedance equivalent circuit model of the battery according to the current and voltage of the battery at the first time point, and the voltage of the battery at the first time point among the 2n time points; Determining the parameters R1 to Rn and parameters τ1 to τn of the n-order impedance equivalent circuit model of the battery according to the following equation group; Wherein, Vbat(0) represents the voltage of the battery at the first time point; Vbat(1) to Vbat(2n) respectively represent the voltage of the battery at the 2n time points; I represents the current of the battery at the first time point; t represents the first time length; e is a natural constant.

12. The apparatus of claim 11, wherein, The processing module is specifically used for determining the ACR of the battery according to the following equation; 13. The apparatus of claim 11 or 12, wherein, The processing module is specifically used for determining the DCR of the battery according to the following equation; Wherein, ΔT represents a fixed discharge time, which is a constant.

14. The apparatus of claim 11 or 12, wherein, The processing module is specifically used for determining the EIS of the battery according to the following equation; where f represents frequency; EIS Re represents the real part of the EIS of the battery corresponding to f; EIS Im represents the imaginary part of the EIS of the battery corresponding to f.

15. The apparatus of claim 11 or 12, wherein, The processing module is specifically used for determining the parameters τ1 to τn of the n-order impedance equivalent circuit model of the battery as the polarization time constant of the battery.

16. The apparatus of any one of claims 9-12, wherein, The processing module is further used for controlling the sampling circuit to detect the current of the battery at 2n time points after the first time point respectively, and determining whether the battery stops charging according to the current of the battery at the 2n time points.

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